final report
TRANSCRIPT
Eelectrical Steering System in Automobile
A
Project Report
On
“ELECTRICAL STEERING SYSTEM IN AUTOMOBILE”
Submitted to in Partial Fulfillment of the award of
BACHELOR OF MECHANICAL ENGINEERING
To SHIVAJI UNIVERSITY, KOLHAPUR
Submitted by
MR. RAVALUCHE VINEET B. MR. WAGH SAMEER T.
MR. SALUNKHE VIKRANT S. MR. SALAVE KRISHNATH R.
Under the Guidance of
Professor P.D.KULKARNI
DEPARTMENT OF MECHANICAL ENGINEERING
TATYASAHEB KORE INSTITUTE OF ENGINEERING & TECHNOLOGY,Warananagar, Dist. Kolhapur 416 113 (M.S.)
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Eelectrical Steering System in Automobile
2011- 2012.
TATYASAHEB KORE INSTITUTE OF ENGINEERING &TECHNOLOGY
WARANANAGAR
DEPARTMENT OF MECHANICAL ENGINEERING
This is to certify that,
MR. RAVALUCHE VINEET B. MR. WAGH SAMEER T.
MR. SALUNKHE VIKRANT S. MR. SALAVE KRISHNATH R.
The students of final year Mechanical Engineering have successfully completed the
project work on “ELECTRICAL STEERING SYSTEM IN AUTOMOBILE” in partial
fulfillment for the award of Degree of Mechanical Engineering as laid down by Shivaji
University, Kolhapur during academic year 2011-2012.
Date:
Place: Warananagar
Prof. P.D.KULKARNI Prof. V. R. GAMBHIRE.
(Guide) (Head of Mechanical Dept.)
External Examiner Dr. A. M. Potdar
(Principal)
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ACKNOWLEDGEMENT
This whole work is outcome of all types of all those concerned
with it through their hearted cooperation and effective guidance. It is great
pleasure to express our most sincere gratitude and profound regards to Mr.
P.D.KULKARNI, project guide and Head of Mechanical Engineering
Department Prof. V. R. Gambhire for their constant encouragement,
guidance during the completion of this project. Words are inadequate to
acknowledge their great care and keen interest taken by him in all aspects
of this project.
We are also grateful to Dr. Avinash M. Potdar, the Principal of
TKIET, Warananagar for their help and invaluable guidance.
We are thankful to Mr. M. R. Jadhav, project coordinator for
coordinating us in all respet for completion our project.We cannot forget
the kind support of lecturers and staff members and people directly or
indirectly in success of our project.
All the knowledge will not lost forever and surely help us in our future.
Mr. Vineet B. Ravaluche Mr. Sameer T. Wagh.
Mr. Vikrant S. Salunkhe.
Mr. Krishnath R. Salave.
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PHOTOGRAPH OF PROJECT BATCH WITH GUIDE
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ABSTRACT
Additional future requirements for automobiles such as improved vehicle
dynamics control; enhanced comfort, increased safety and compact packaging are met by
modern electrical steering systems. Based on these requirements the new functionality is
realized by various additional electrical components for measuring, signal processing and
actuator control.
However, the reliability of these new systems has to meet the standard of
today's automotive steering products. To achieve the demands of the respective
components (e.g. sensors, bus systems, electronic control units, power units, actuators)
the systems have to be fault-tolerant
And/or fail-silent. The realization of the derived safety structures requires
both expertise and experience in design and mass production of safety relevant electrical
systems. Beside system safety and system availability the redundant electrical systems
also have to meet economic and market requirements. Within this scope the paper
discusses three different realizations of electrical steering systems
Electrical power steering system (mechanical system with electrical boosting)
Steer-by-wire system with hydraulic back-up and
Full steer-by-wire system
The paper presents solutions for these systems and discusses the various
advantages and disadvantages, respectively. Furthermore strategies for failure detection,
failure localization and failure treatment are presented. Finally the various specifications
for the components used are discussed.
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INDEX
1. INTRODUCTION 01
1.1 Aim of the project
1.2 Need of the project
1.3 Working principal
2. LITERATURE RVIEW 11
2.1 Steering system designs: Rack and Pinion
2.2 Steering system
2.3 Turning of car
2.4 Mechanical steering
2.5 Power steering
3. CONCEPT AND ITS DEVELOPM ENT
3.1 Electrical power steering system
3.2 Safety features
3.3 BMW Active steering
3.4 Advantages of steer-by-wire system
4. DESIGN 36
4.1 System design
4.2 Mechanical design
4.3 Motor selection
4.4 Design of main spindle
4.5 Selection of bearing
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5. COMPONENT USED IN SYSTEM AND ITS PROPERTIES
5.1 Used material and their properties
5.2 Non-metallic material
6. FABRICATION DETAILS 45
6.1 Part name: SHAFT
6.2 Part name: BEARING MOUNTER 1
6.3 Part name: BEARING MOUNTER 2
6.4 Part name: LOWER FRAME
7. COST ESTIMATION 47
7.1 Cost of material
7.2 Cost of standards parts
7.3 Other cost
7.4 Total project cost
8. APPLICATIONS
8.1 Advantages
8.2 Disadvantages
9. CONCLUSION
10. REFERENCE
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LIST OF FIGURES
1. Basic components of steering system.2. Wheel path while turning.3. Off-centerline angle.4. Steering geometry parallelogram.5. Rack and Pinion steering.6. Under steer.7. Over steer.8. Counter steer.9. Turning the car.10. Rack and Pinion steering.11. Recirculating ball bearing.12. Power Rack and Pinion steering assembly.13. Hydraulic power steering.14. Electrical steering system in Automobile.15. Electrical power steering.16. System structure of safe electrical steering system.17. Active steering.18. Actual photo presenting location and view of active steering. 19. Sbw explanatory sketch.
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CHAPTER 1
INTRODUCTION
1.1 Aim of The Project
To design and fabricate electrical steering system mechanism.
To achieve higher safety and reduce the man power as well.
To increase the efficiency of the vehicle and to reduce workload.
1.2 Need Of The Project
In past years without power steering technique, although large reduction ratio
can alleviate the driving torque of drivers, it is still very tiring in fact. Thereafter,
hydraulic power steering (HPS) improves this problem. In a hydraulic power steering
system, driving a steering wheel is to control a pressure valve, which causes straight line
motion of a rack mechanism to change tires direction through link sticks. However,
environmental consciousness has been paid attention in nowadays with technique
progress. Even though the HPS possesses large power and smooth output, there are still
some drawbacks, such as (1) Pipes may leak. (2) Hydraulic oil may deteriorate since
rising temperature when pipes and hydraulic oil rub against. (3) Check and change power
steering wheel oil on a regular time. (4) Pipes are complex. (5) A hydraulic pump, a
hydraulic oil storage tank, and pipes, etc, increase weight and occupy space. (6) Extra
engine power is needed to drive a hydraulic pump, i.e., oil consumption will be increased.
(7) A holding pressure is necessary when a vehicle moves on a straight line.
Electrical steering system does not possess all above drawbacks like
power steering. Additionally there are some advantages.
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1.3 WORKING PRINCIPLE
In our project lead-acid 12 Volt batteries is used. The lead-acid batteries output is
given to the limit switch. There are two Limit switches are used in this project. These
switch outputs are connected to the steering D.C motor in Forward and reverse rotation of
operation.
The rack and pinion arrangement is used to turn the wheel in left and right
direction. The Rack is connected to the wheel with the help of liver mechanism and the
pinion is coupled to the permanent magnet D.C motor shaft. The Motor is drawn supply
from the battery through limit switch arrangement.
When the steering is turn in the left direction, it pushes the left side limit switches,
so that the D.C motor rotate in forward direction to move the wheel in left side. Similarly
When the steering is turn in the right direction, it pushes the right side limit switches, so
that the D.C motor rotate in reverse direction to move the wheel in right side
Basic steering components
99% of the world's car steering systems are made up of the same three or four
components. The steering wheel, which connects to the steering system, which connects
to the track rod, which connects to the tie rods, which connect to the steering arms. The
steering system can be one of several designs, which we'll go into further down the page,
but all the designs essentially move the track rod left-to-right across the car. The tie rods
connect to the ends of the track rod with ball and socket joints, and then to the ends of the
steering arms, also with ball and socket joints. The purpose of the tie rods is to allow
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suspension movement as well as an element of adjustability in the steering geometry. The
tie rod lengths can normally be changed to achieve these different geometries.
Figure 1.1: Basic Components Of Steering System
In the simplest form of steering, both the front wheels always point in the same
direction. You turn the wheel, they both point the same way and around the corner you
go. Except that by doing this, you end up with tyres scrubbing, loss of grip and a vehicle
that 'crabs' around the corner. So why is this? Well, it's the same thing you need to take
into consideration when looking at transmissions. When a car goes around a corner, the
outside wheels travel further than the inside wheels. In the case of a transmission, it's why
you need a differential (see the Transmission Bible), but in the case of steering, it's why
you need the front wheels to actually point in different directions. This is the diagram
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from the Transmission Bible. You can see the inside wheels travel around a circle with a
smaller radius (r2) than the outside wheels (r1):
Figure 1.2: Wheel path while turning
In order for that to happen without causing undue stress to the front wheels and tyres,
they must point at slightly different angles to the centerline of the car. The following
diagram shows the same thing only zoomed in to show the relative angles of the tyres to
the car. It's all to do with the geometry of circles:
Figure 1.3: Off-centerline angle
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This difference of angle is achieved with a relatively simple arrangement of
steering components to create a trapezoid geometry (a parallelogram with one of the
parallel sides shorter than the other). Once this is achieved, the wheels point at different
angles as the steering geometry is moved. Most vehicles now don't use 'pure' Ackermann
steering geometry because it doesn't take some of the dynamic and compliant effects of
steering and suspension into account, but some derivative of this is used in almost all
steering systems:
Figure1.4: Steering geometry parallelogram
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CHAPTER 2
LITERATURE REVIEW
2.1 Steering System designs: Rack and pinion
This is by far the most common type of steering you'll find in any car today due to
its relative simplicity and low cost. Rack and pinion systems give a much better feel for
the steering, and there isn't the slop or slack associated with steering box pitman arm type
systems. The downside is that unlike those systems, rack and pinion designs have no
adjustability in them, so once they wear beyond a certain mechanical tolerance, they need
replacing completely. In a rack and pinion system, the track rod is replaced with the
steering rack which is a long, toothed bar with the tie rods attached to each end. On the
end of the steering shaft there is a simple pinion gear that meshes with the rack. When
you turn the steering wheel, the pinion gear turns, and moves the rack from left to right.
Changing the size of the pinion gear alters the steering ratio. It really is that simple. The
diagram below shows an example rack and pinion system as well as a close-up cutaway
of the steering rack itself.
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Figure 2.1: rack and pinion steering
This is a simple variation on the above design. All the components are the same,
and it all works the same except that the spacing of the teeth on the rack varies depending
on how close to the centre of the rack they are. In the middle, the teeth are spaced close
together to give slight steering for the first part of the turn - good for not over steering at
speed. As the teeth get further away from the centre, they increase in spacing slightly so
that the wheels turn more for the same turn of the steering wheel towards full lock.
Vehicle dynamics and steering
Generally speaking, when you turn the steering wheel in your car, you typically expect it
to go where you're pointing it. At slow speed, this will almost always be the case but once
you get some momentum behind you, you are at the mercy of the chassis and suspension
designers. In racing, the aerodynamic wings, air splitters and under trays help to maintain
an even balance of the vehicle in corners along with the position of the weight in the
vehicle and the suspension setup. The two most common problems you'll run into are
under steer and over steer.
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Under steer
Under steer is so called because the car steers less than you want it to. Under steer
can be brought on by all manner of chassis, suspension and speed issues but essentially it
means that the car is losing grip on the front wheels. Typically it happens as you brake
and the weight is transferred to the front of the car. At this point the mechanical grip of
the front tyres can simply be overpowered and they start to lose grip (for example on a
wet or greasy road surface). The end result is that the car will start to take the corner very
wide. In racing, that normally involves going off the outside of the corner into a catch
area or on to the grass. In normal you-and-me driving, it means crashing at the outside of
the corner. Getting out of under steer can involve letting off the throttle in front-wheel-
steering vehicles (to try to give the tires chance to grip) or getting on the throttle in rear-
wheel-steering vehicles (to try to bring the back end around). It's a complex topic more
suited to racing driving forums but suffice to say that if you're trying to get out of under
steer and you cock it up, you get.....
Figure2.2:Under steer
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Over steer
The bright ones amongst you will probably already have guessed that over steer is
the opposite of under steer. With over steer, the car goes where it's pointed far too
efficiently and you end up diving into the corner much more quickly than you had
expected. Over steer is brought on by the car losing grip on the rear wheels as the weight
is transferred off them under braking, resulting in the rear kicking out in the corner.
Without counter-steering (see below) the end result in racing is that the car will spin and
end up going off the inside of the corner backwards. In normal you-and-me driving, it
means spinning the car and ending up pointing back the way you came.
Figure2.3: Over steer
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Counter-steering
Counter-steering is what you need to do when you start to experience over steer. If
you get into a situation where the back end of the car loses grip and starts to swing out,
steering opposite to the direction of the corner can often 'catch' the over steer by directing
the nose of the car out of the corner. In drift racing and demonstration driving, it's how
the stirrings are able to smoke the rear tires and power-slide around a corner. They will
use a combination of throttle, weight transfer and handbrake to induce over steer into a
corner, then flick the steering the opposite direction, honk on the accelerator and try to
hold a slide all the way around the corner. It's also a widely-used technique in rally
racing. Tiff Need ell - a racing steering who also works on some UK motoring programs -
is an absolute master at counter-steer power sliding.
Figure2.4: Counter steer
This paperwork deals with the details of four wheels steering (4ws) system.
According to this mechanism in a four wheels steering system, all the four wheels are
steered, thus can turn the vehicle easily to either lift or right using the steering wheel.
This system serves more effective and stability in controlling the vehicle at cornering and
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at parking .The operation of this system take change as the speed of vehicle increase or
decrease.
At low speed motion of the vehicle, the front wheels turn to the direction of the
steering wheel, at the same time the rear wheels turn in the opposite direction .Four
wheel mechanism is active only in position when the vehicle moves at low speed and
below 35 km .There after the rear wheels follow in the same direction of the print wheels.
There are three types of 4 wheels steering system
Ø Mechanical
Ø Hydraulic
Ø Electro-hydraulic
2.2STEERING SYSTEM
In earlier days of automobile development, in most of the cars the engine was on the
rear axle, steering was a simple matter of turning a tiller that pivoted the entire front axle.
When the engine was moved to the front of the car, complex steering systems had to
evolve. The modern automobile has come a long way since the days when "being self-
propelled" been enough to satisfy the car owner. Improvements in suspension and
steering system, increased strength and durability of components, and advances in tyre
design and construction have made large contributions to riding comfort and to safe
driving. Cadillac allegedly produced the first American car to use a steering wheel
instead of a tiller. Two of the most common steering mechanisms are the "rack and
pinion" and the standard (or recirculation-ball) systems, that can be either manual or
assisted by power. The rack and pinion was designed for sports cars and requires too
much steering muscle at low speeds to be very useful in larger, heavier cars. However,
power steering makes a heavy car respond easily to the steering wheel, whether at
highway speeds or inching into a narrow parking place and it is normal equipment for
large automobiles.
The manual steering system incorporates:
1. Steering wheel and column,
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2. A manual gearbox and pitman arm or a rack and pinion assembly,
3. Linkages; steering knuckles and ball joints; and
4. The wheel spindle assemblies.
Power steering systems add a hydraulic pump; fluid reservoir; hoses; lines; and
either a power assist unit mounted on, or integral with, a power steering-gear-assembly.
There are several different manual steering gears in current use. The "rack and
pinion" type is the choice of most manufacturers. The "recirculation ball" type is a past
favorite because the balls act as a rolling thread between the worm shaft and the ball nut.
Another manual steering gear once popular in imported cars is the "worm and sector"
type. Other manual gears are the "worm and tapered pin steering gear" and the "worm
and roller steering gear."
STEERING LINKAGE
The steering linkage is made of interconnected parts which move every time the
steering wheel is turned. The rotating movement of the steering column activates
mechanisms inside the steering box. Tie rod ends, which join the key parts, pass on the
steering wheel's motion no matter what the angle of the linkage or the vibration from the
road. In a pitman arm steering setup, the movement inside the steering box causes the
Pitman shaft and arm to rotate, applying leverage to the relay rod, which passes the
movement to the tie rods. The steering arms pick up the motion from the tie rods and
cause the steering knuckles to turn the wheels. The steering linkages need regular
maintenance for safe operation, such as lubrication and inspection.
2.3 TURNING THE CAR
For a car to turn smoothly, each wheel must follow a different circle. Since the inside
wheel is following a circle with a smaller radius, it is actually making a tighter turn than
the outside wheel. If you draw a line perpendicular to each wheel, the lines will intersect
at the center point of the turn. The geometry of the steering linkage makes the inside
wheel turn more than the outside wheel.
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To understand turning of a car we will take look at some definitions,
Steering ratio-
The steering ratio is the ratio of how far you turn the steering wheel to how far the
wheels turn. For instance, if one complete revolution (360 degrees) of the steering wheel
results in the wheels of the car turning 20 degrees, then the steering ratio is 360 divided
by 20, or 18:1. A higher ratio means that you have to turn the steering wheel more to get
the wheels to turn a given distance. However, less effort is required because of the higher
gear ratio.
Figure2.5: turning the car
Generally, lighter, sportier cars have lower steering ratios than larger cars and
trucks. The lower ratio gives the steering a quicker response -- you don't have to turn the
steering wheel as much to get the wheels to turn a given distance – which is a desirable
trait in sports cars. These smaller cars are light enough that even with the lower ratio, the
effort required to turn the steering wheel is not excessive. There are a couple different
types of steering gears. The most common are rack-and-pinion and recirculating ball.
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STEERING COLUMNS
Special steering columns have been employed in many foreign made cars which provide
safety and ease of operation to the steering. Various types of which are:
Energy absorbing steering column
This type of column provides safety by collapsing during impact in a front end crash.
Also the column incorporates ball bearings fitted between two overlapping tubes. These
tubes groove in under impact resulting in efficient energy absorption
Tilt wheel steering column
This type of steering allows the steering to tilt the steering wheel for ease
during entry or exit. Even while driving, the steering can adjust it at convenient angle.
This can be done easily by releasing a lever on the side of steering column and moving
the wheel into the desired position, where it locks itself in place.
Tilt and telescopic steering column
This type of steering has all features of the tilt wheel steering explained above in
addition to convenience of telescopic steering, which adds to steeringr’s comfort. The
telescopic motion is under steering wheel, but telescopic and tilting adjustment can be
made with no loss of steering control.
Steering column with anti-theft lock
This type of arrangement provides additional safety against theft. By simply
turning the ignition to the lock position and removing the key, the ignition and steering
wheel and on some models, the gearshift levers of the transmission are locked
simultaneously. In Maruti 800 car the steering lock is provided when the ignition key is
removed and the steering gets locked. When the ignition key is removed and the steering
wheel is turned to one extreme, the steering gets locked. When the ignition key is inserted
in its slot and turned the lock is off.
2.4 MECHANICAL STEERINGS
The different types of mechanical steering used in modern cars are:
RACK AND PINION STEERING
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RECIRCULATING BALL BEARING
MANUAL WORM AND SECTOR STEERING
WORM AND TAPERED PEG STEERING
MANUAL WORM AND ROLLER STEERING
WORM AND WHEEL STEERING
WORM AND NUT STEERING
RACK AND PINION STEERING
Rack-and-pinion steering is quickly becoming the most common type of steering
on cars, small trucks and SUVs. It is actually a pretty simple mechanism. A rack-and-
pinion gear set is enclosed in a metal tube, with each end of the rack protruding from the
tube. A rod, called a tie rod, connects to each end of the rack.
The pinion gear is attached to the steering shaft. When you turn the steering wheel,
the gear spins, moving the rack. The tie rod at each end of the rack connects to the
steering arm on the spindle.
Figure 2.6: rack and pinion steering
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The rack-and-pinion gear set does two things:
It converts the rotational motion of the steering wheel into the linear motion
needed to turn the wheels.
It provides a gear reduction, making it easier to turn the wheels.
On most cars, it takes three to four complete revolutions of the steering wheel to make
the wheels turn from lock to lock (from far left to far right).
Some cars have variable-ratio steering, which uses a rack-and-pinion gear set that has a
different tooth pitch (number of teeth per inch) in the center than it has on the outside.
This makes the car respond quickly when starting a turn (the rack is near the center), and
also reduces effort near the wheels turning limits.
RECIRCULATING BALL STEERING
Recirculating-ball steering is used on many trucks and SUVs (sport utility vehicle)
today. The linkage that turns the wheels is slightly different than on a rack and pinion
system. The recirculating ball steering gear contains a worm gear. You can imagine the
gear in two parts. The first part is a block of metal with a threaded hole in it.
Figure 2.7: recirculating ball bearing steering
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This block has gear teeth cut into the outside of it, which engage a gear that moves
the pitman arm. The steering wheel connects to a threaded rod, similar to a bolt that sticks
into the hole in the block. When the steering wheel turns, it turns the bolt. Instead of
twisting further into the block the way a regular bolt would, this bolt is held fixed so that
when it spins, it moves the block, which moves the gear that turns the wheels.
Instead of the bolt directly engaging the threads in the block, all of the threads are
filled with ball bearings that recirculate through the gear as it turns. The balls actually
serve two purposes: First, they reduce friction and wear in the gear; second, they reduce
slop in the gear. Slop would be felt when you change the direction of the steering wheel
without the balls in the steering gear, the teeth would come out of contact with each other
for a moment, making the steering wheel feel loose.
MANUAL WORM AND SECTOR STEERING
The manual worm and sector steering gear assembly uses a steering shaft with a
three-turn worm gear supported and straddled by ball bearing assemblies. The worm
meshes with a 14-tooth sector attached to the top end of the pitman arm shaft. In
operation, a turn of the steering wheel causes the worm gear to rotate the sector and the
pitman arm shaft. This movement is transmitted to the pitman arm and throughout the
steering train to the wheel spindles.
WORM AND TAPERED PEG STEERING
The manual worm and tapered peg steering gear has a three-turn worm gear at the
lower end of the steering shaft supported by ball bearing assemblies. The pitman shaft
has a lever end with a tapered peg that rides in the worm grooves. When the movement of
the steering wheel revolves the worm gear, it causes the tapered peg to follow the worm
gear grooves. Movement of the peg moves the lever on the pitman shaft, which in turn
moves the pitman arm and the steering linkage.
MANUAL WORM AND ROLLER STEERING
Various manufacturers use the manual worm and roller steering gear. This steering
gear has a three-turn worm gear at the lower end of the steering shaft. Instead of a sector
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or tapered peg on the pitman arm shaft, the gearbox has a roller assembly (usually with
two roller teeth) that engages the worm gear. The assembly is mounted on anti-frictional
bearings. When the roller teeth follow the worm, the rotary motion is transmitted to the
pitman arm shaft, pitman arm and into the steering linkage.
WORM AND WHEEL STEERING GEAR
The movement of the steering wheel turns the worm, which in turn steering the
worm wheel. Attached to the wheel spindle rigidly is drop arm, so that a rotation of
steering wheel corresponds to a linear motion of the drop arm end, which is connected to
the link rod as has already been discussed. In place of worm wheel, only a sector is also
sometimes used, but the complete wheel has an advantage over the later in that in this
case backlash due wearing of the tooth of the worm and worm wheel can be easily
adjusted. For this purpose the worm wheel is mounted over an eccentric bush. When the
teeth worn out problem is how to bring the worm and the wheel together to take up the
wear. This is done by rotating the bush through a certain angle.
WORM AND NUT STEERING GEAR
Here the steering wheel rotation rotates the worm, which in turn moves the nut
along its length. This cause the drop arm ends to move linearly, further moving the link
rod and thus steering the wheel.
2.5 POWER STEERING
POWER RACK AND PINION STEERING
POWER RECIRCULATING BALL BEARING STEERING
HYDRAULIC POWER STEERING
ELECTROHYDRAULIC POWER STEERING
ELECTRIC POWER STEERING
ACTIVE STEERING
STEER BY WIRE
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POWER RACK AND PINION
When the rack-and-pinion is in a power-steering system, the rack has a slightly
different design as shown in figure no. 4.
Figure 2.7: power rack and pinion steering assembly
Part of the rack contains a cylinder with a piston in the middle. The piston is
connected to the rack. There are two fluid ports, one on either side of the piston.
Supplying higher-pressure fluid to one side of the piston forces the piston to move, which
in turn moves the rack, providing the power assist.
POWER RECIRCULATING BALL BEARING SYSTEM
Power steering in a recirculating-ball system works similarly to a rack-and-pinion
system. Supplying higher-pressure fluid (fluid is always a oil) to one side of the block
provides assist.
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HYDRAULIC POWER STEERING SYSTEM
The hydraulic power steering system today (fig. 5) is the most used steering
system. It is based on the components of the mechanical steering system, in addition there
is a hydraulic system, usually consisting of hydro pump with V-belt steering, hydraulic
lines, oil reservoir and steering valve. The essential new function of this power steering is
the hydraulic support of the steering movement, so that the steeringr’s steering-wheel
effort is reduced.
Figure 2.8: hydraulic power steering
Therefore in the event of failure, the loss of steering boost arises as a new safety
aspect in comparison to purely manual steering. This can be caused by a leakage of the
hydraulic system or by a hydro pump failure. Since by design the manual steering system
is further available, in case of a failure the steering function is further available and the
steering can adapt himself by the usually slowly rising steering-wheel effort in good time
to the missing steering boost.
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Eelectrical Steering System in Automobile
CHAPTER 3
CONCEPT AND ITS DEVELOPMENT
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Eelectrical Steering System in Automobile
3.1 ELECTRIC POWER STEERING SYSTEM
The electric power steering system (Fig.3.1) combines a mechanical steering
system with an electronically controlled electric motor to a dry power steering. The
hydraulic system, which so far delivered the steering boost, is substituted by an electrical
system. For this, a torque sensor measures the steering wheel torque and an electronic
control unit calculates the necessary servo torque. This is delivered by an electric motor
in such a way that the desired torque curve at the steering wheel is created.
Depending on the necessary steering forces the electric motor engages by a worm gear at
the steering column or at the pinion and for high forces directly at the rack by a ball-and-
nut gear. In above figure.10 the pinion-solution is represented, which is intended for
middle class vehicles.
Figure.3.1: electric power steering
The components involved in the electrical power steering are besides the mechanical
steering components:
Electric motor,
Electronic control unit,
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Power electronics,
Steering wheel torque sensor and
CAN data bus to other systems
The electrical power steering system offers large benefits compared to the
hydraulic power steering. Apart from about 80% lower energy consumption the omission
of the hydraulic fluid increases the environmental compatibility. The electrical power
steering is delivered to the car manufacturer as a complete system module ready-to
install. The adaptation of the servo power assistance to certain vehicle types as well as the
modification of the control strategy dependent on different parameters and vehicle sizes
are easily and rapidly feasible.
From the safety point of view as with the other power steering systems due to
failures in electrical components, again the steering boost can be impaired, here by faults
of components of the electrical servo system. The steering system’s unintentional self
activity as well as too strong steering boosts is to be concerned as new potential safety
critical effects, which must be avoided by appropriate countermeasures.
FUNCTIONAL DESCRIPTION OF ELECTRICAL STEERING SYSTEMS
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Figure3.2: System structures of safe electrical steering systems
In an electrical power steering system the steering torque initiated by the steering
(Fig.3.2) is measured by a steering wheel torque sensor and is fed into an electronic
control unit. The later then calculates along with the driving speed a reference torque for
the steering motor, which, however, can optionally also depend on the steering angle and
steering angle velocity. By means of the calculated reference torque the currents of the
steering motor are actuated. Figure 8 shows the pinion-type realization; where at the
pinion the electrical torque is superimposed to the torque initiated by the steering. In
further versions both torques can be superimposed either on the steering column or on the
rack. In case of a failing electrical component of this steering system the non-boosted
mechanical intervention by the steering is maintained.
3.2 SAFETY FEATURES
Detecting and evaluating all electrical failures accomplish the system’s fail-safe
behavior concerning electrical faults. In case of major electrical faults the electrical
power steering system is switched off.
Sensor failures or failures in the electronic control unit might be considered as an
example, resulting in an unintentional self-activity of the steering or in a too strong
steering boost. Risks of that kind are avoided by an effective monitoring strategy where
failures are detected on time and the power steering system is switched-off. One detection
method for this constitutes checking sensor signals and motor currents for plausible
system conditions on a second path.
3.3 BMW Active Steering
BMW's Active Steering, a true breakthrough in steering technology, supports the
steering at all speeds, particularly in the lower and medium speed range where dynamic
steering offers a genuine increase in driving pleasure.
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In a situation like where one quality is of particular significance: the correct
steering response this car must meet a wide range of different requirements. At medium
speeds, for example, the front wheels must respond as directly as possible to the steering
commands. With increasing road speeds on the other hand, the steering transmission
should become less direct. The demands made on the steering system therefore vary most
significantly from case to case, with the overriding requirement that the steering always
receives authentic feedback from the steering system itself.
Figure 3.3. Active steering
On a conventional steering system the steeringr's steering commands are always
conveyed the same way due to the strictly defined transmission ratio between the steering
wheel and the front wheels of the car (even if the transmission becomes more progressive
with increasing wheel lock). Direct steering that would be ideal at low speeds remains
direct, although a much more indirect steering transmission ratio would be appropriate at
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high speeds in order to compensate for the physically induced increase in steering
sensitivity as a function of higher speeds on the road. Conversely, the same also applies
to indirect steering: The ideal steering transmission ratio at high speeds makes the
process of steering hard work at lower speeds, requiring the steering to turn the steering
wheel much more and with much higher forces than necessary related to the position of
the wheels on the road. Conventional steering systems, therefore, are always a
compromising of these two extremes.
BMW's innovative Active Steering now revolutionizes the entire steering process
by overriding this seemingly insoluble conflict of interests, varying the steering angle of
the front wheels specifically according to the steering’s requirements. In this process,
Active Steering combines the advantages of all electronic steer-by-wires steering without
any mechanical link between the steering wheel and the front wheels (purely electronic
transmission of signals) with the authentic steering feedback that only a mechanical
steering system is currently able to provide. Accordingly, Active Steering sets a new
standard in agility, comfort and safety on the road.
Figure 3.4: actual photo presenting location and view of active steering
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In technical terms the various functions and benefits offered by Active Steering are
based on the principle of overlapping steering angles: An electromechanical adjuster
between the steering wheel and the steering gearbox adds an additional steering angle to
the angle predetermined by the steering. The core element of BMW's revolutionary
Active Steering is therefore the override steering effect provided by the planetary gearing
with two incoming and one outgoing shaft integrated in the split steering column. One
incoming shaft is connected with the steering wheel; the second is steering by an electric
motor via a self-inhibiting gear wheel transmission and thus serving to reduce the
transmission ratio. The overall steering angle finally coming out on the outgoing shaft is
made up of the angle determined by the steering on the steering wheel and the angle
determined by the electric motor. Steering forces when turning the wheels, however, are
not determined by the electric motor, but rather by conventional power steering
assistance. Additional components of Active Steering are the separate control unit and
various sensors for determining both current driving conditions and the steeringr's
commands. And last but not least, Active Steering communicates directly with the DSC
control unit through the car's on-board communication network.
Depending on driving conditions, Active Steering either increases or reduces the
steering angle on the front wheels. At low speeds the actuator follows the steeringr's
steering commands, increasing wheel lock at the front and reducing the effort required in
steering. On the road this means a far more direct steering transmission ratio than with
conventional cars up to a medium speed level, steering forces remaining comfortably low
as with BMW's well-known Servotronic.
At high speeds the actuator operates by reducing the steering angle. This reduces
the steering lock on the front wheels and makes the steering transmission ratio more
indirect, thus providing the high standard of a conventional BMW steering on fast
stretches of the Autobahn. Steering forces are increased in the process in order to prevent
any undesired movement of the steering-wheel.
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In critical situations on the road Active Steering modifies the position of the
steering wheels determined by the steering, thus stabilizing the car much faster and more
efficiently than the steering would be able to do himself.
Active Steering enhances the typical virtues of BMW steering, making the car
even more agile and nimble at low and medium speeds while retaining that authentic
steering feedback and even offering a genuine "kart" feeling at low speed-levels. Active
Steering also serves to enhance steering comfort. While the steering has to turn the
steering wheel approximately three times in a current BMW from lock to lock, active
steering reduces this control process to just two turns of the steering wheel by cutting
back the steering wheel angle at low and medium road speeds.
The steering will immediately enjoy the reduced steering force, for example when
maneuvering in confined parking spaces or when taking a sharp turn in town. Crossing
over your hands on the steering wheel, for example on a winding mountain pass, is hardly
necessary any more with Active Steering. So while the steering often has no choice in a
car with conventional steering but to cross over his arms, in a BMW equipped with
Active Steering his hands will always remain where they should be: in exactly the right
position on the steering wheel. This guarantees unrestricted, smooth and easy operation
of the multifunction buttons and SMG paddles shifting the Sequential Manual Gearbox
directly on the steering wheel, ensuring superior safety and response in every situation on
the road.
The greater agility and enhanced dynamic performance provided by Active
Steering comes out particularly clearly in the slalom test, simulating sudden steering
maneuvers at low and medium speeds: Active Steering gives the steering much better
control of the car than conventional steering, combined with significantly enhanced
steering precision and an equally significant reduction of steering forces. And ultimately,
the greater comfort and control provided by Active Steering helps to keep the steering fit
and avoid any fatigue at the wheels.
With increasing road speeds, Active Steering reduces the steering wheel lock and
makes the steering transmission ratio more indirect. To put it in simple terms, the steering
would now have to move the steering wheel further than at low speeds in order to obtain
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the same lock on the front wheels. This efficiently avoids common mistakes at the wheel,
for example with the steering abruptly wrenching round the steering wheel when
panicking at high speeds. A further advantage of an indirect steering transmission ratio at
high speeds, finally, is the perfect straight line tracking stability.
3.4 STEER BY WIRE SYSTEMS
The main feature of future steering systems is the missing direct mechanical link
between steering wheel and steered wheels. With such a steer-by-wire steering system
(Fig.3.5) the missing steering column’s function must be reproduced in both directions of
action. In forward direction the angle set by the steering at the steering wheel is measured
by a steering angle sensor and transferred with the suitable steering ratio to the wheels. In
reverse direction the steering torque occurring at the wheels is picked up via a torque
sensor and attenuated respectively, modified fed back to the steering as a counter torque
on the steering wheel.
Figure 3.5.sbw explanatory sketch
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First, steering wheel module and steering module are implemented with familiar
components of mechanical and electrical steering systems, like: Steering wheel, gearbox,
electrical motors, rack. The operational principle is, however, in principle open for more
futuristic designs like side stick operation on the steeringr’s side and single wheel
steering on the wheel side. While in systems with mechanical connection in the case of
electrical errors only the steering boost is concerned, corresponding measures must be
taken with steer-by-wire systems, that in case of any electrical failure steering control is
always guaranteed.
ADVANTAGES OF STEER-BY-WIRE SYSTEMS
Steer by-wire is a universal actuator for automatic steering intervention. For
vehicle dynamic steering intervention a steering angle actuator is needed which does not
affect the steering wheel while rapidly correcting the vehicle wheels. On the other hand, a
torque actuator will be needed for automatic lateral guidance interference and future
steering systems of autonomous driving, thus imparting a superimposed torque onto the
steering wheel and letting the steering with that know the intended direction, evaluated by
the lateral guidance control system. Steer-by-wire meets both requirements ideally. Along
with "steering by wire” and "brake by wire“it provides the condition to materialize
vehicle dynamics and comfort oriented automatic controls in one system. Design
advantages for the automaker –the rigid steering column curbs the design freedom for the
engine compartment. On either side space has to be provided (left-hand or right-hand
driving). Steer-by-wire implies that no steering column impairs the good usage of engine
compartment.
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CHAPTER 4
DESIGN
Design consists of application of scientific, principles, technical information and
imagination for development of new or improvised machine or mechanism to perform a
specific with maximum economy & efficiency.
Hence a careful design approach has to be adopted. The total design work has been
split up into two parts;
System design
Mechanical Design
System design mainly concerns the various physical constraints and ergonomics,
space requirements, arrangement of various components on main frame at system, man +
machine interaction, No. of controls, position of controls, working environment of
machine, chances of failure, safety, measures to be provided, servicing aids, ease of
maintenance, scope of improvement, weight of machine from ground level, total weight
of machine and a lot more.
In mechanical design the components are listed down and stored on the basis of
their procurement, design in two categories namely,
Designed Parts
Parts to be purchased
For designed parts detached design is done & distinctions thus obtained are
compared to next highest dimensions which are readily available in market. This
amplifies the assembly as well as postproduction servicing work. The various tolerances
on the works are specified. The process charts are prepared and passed on to the
manufacturing stage.
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The parts which are to be purchased directly are selected from various catalogues &
specified so that anybody can purchase the same from the retails shop with given
specifications.
4.1 SYSTEM DESIGN
In system design we mainly concentrated on the following parameters:-
1. System Selection Based on Physical Constraints
While selecting any machine it must be checked whether it is going to be used in a
large scale industry or a small scale industry. In our case it is to be used by a small scale
industry .So space is a major constrain. The system is to be very compact so that it can be
adjusted to corner of a room.
The mechanical design has direct norms with the system design. Hence the
foremost job is to control the physical parameters, so that the distinctions obtained after
mechanical design can be well fitted into that.
2. Arrangements of Various Components
Keeping into view the space restrictions the components should be laid such that
their easy removal or servicing is possible. More over every component should be easily
seen none should be hidden. Every possible space is utilized in components
arrangements.
3. Components of System
As already stated the system should be compact enough so that it can be
accommodated at a corner of a room. All the moving parts should be well closed &
compact. A compact system design gives a high weighted structure which is desired.
Man Machine Interaction. The friendliness of a machine with the operator that is an
important criteria of design. It is the application of anatomical & psychological principles
to solve problems arising from Man Machine relationship. Following are some of the
topics included in this section.
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4. Chances of Failure
The losses incurred by owner in case of any failure are important criteria of design.
Factor safety while doing mechanical design is kept high so that there are
Less chances of failure. Moreover periodic maintenance is required to keep unit healthy.
5. Servicing Facility
The layout of components should be such that easy servicing is possible. Especially
those components which require frequents servicing can be easily disassembled.
Scope of Future Improvement
Arrangement should be provided to expand the scope of work in future.
Such as to convert the machine motor operated; the system can be easily configured to
required one. The die & punch can be changed if required for other shapes of notches etc.
6. Height of Machine from Ground
For ease and comfort of operator the height of machine should be properly decided
so that he may not get tried during operation. The machine should be slightly higher than
the waist level, also enough clearance should be provided from the ground for cleaning
purpose.
7. Weight of Machine
The total weight depends upon the selection of material components as well as the
dimension of components. A higher weighted machine is difficult in transportation & in
case of major breakdown; it is difficult to take it to workshop because of more weight
.
4.2 MECHANICAL DESIGN
Mechanical design phase is very important from the view of designer as whole
success of the project depends on the correct design analysis of the problem. Many
preliminary alternatives are eliminated during this phase Designer should have adequate
knowledge above physical properties of material, loads stresses, deformation, and failure.
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Theories and wear analysis. He should identify the external and internal force acting on
the machine parts.
This force may be classified as;
1] Dead weigh forces
2] Friction forces
3] Inertia forces
4] Centrifugal forces
5] Forces generated during power transmission etc.
Designer should estimate these forces very accurately by using design equations. If
he does not have sufficient information to estimate them he should make certain practical
assumptions based on similar conditions. This will almost satisfy the functional needs.
Assumptions must always be on the safer side.
Selection of factors of safety to find working or design stress is another important
step in design of working dimensions of machine elements. The corrections in the
theoretical stress value are to be made according in the kinds of loads, shape of parts &
service requirements.
Selection of material should be made according to the condition of loading shapes
of products environments conditions & desirable properties of material
Provision should be made to minimize nearly adopting proper lubrications methods.
In, mechanical design the components are listed down & stored on the basis of their
procurement in two categories.
1] Design parts
2] Parts to be purchased
For design parts a detailed design is done & designation thus obtain are compared
to the next highest dimension which is ready available in market.
This simplification the assembly as well as post production service work. The various
tolerances on the work are specified. The processes charts are prepared & passed on to
the work are specified. The parts to be purchased directly are selected from various
catalogues & specification so that anybody can purchase the same from retail shop with
the given specifications.
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MOTOR SELECTION
1- PHASE INDUCTION MOTOR ( 2 POLE )
MAKE:- REVOLUTION TECHNOLOGY
VOLTS, 0.05 Hp
SPEED = 30 rpm ( DC MOTOR )
FRAME SIZE = 71
CURRENT = 1.70 AMP
TORQUE = O.17 kg .M
TEFC CONSTRUCTION.
DETAILS OF FRAME SIZE: 71
(FOOT MOUNTED)
A) TORQUE ANALYSIS :-
Torque at spindle is given by
P = 2 N T
60
Where;
T = Torque at spindle (Nm)
P = POWER (kw)
N = Speed (rpm)
T = 185 x 60
2 x 600
T = 2.94 N.m
Considering 25% overload;
T design = 1.25 T
= 1.25x 2.94
=3.68 N.m
T design = 3.68 N.m
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4.3 DESIGN OF MAIN SPINDLE.
T Design = 1.5234 Nm.
= 1.5234 x 10 3 N.mm
Selection of main spindle material
Ref: - PSG Design Data
Pg No.:- 1.10 & 1.12.
1.17
Designation Ultimate Tensile
Strength N/mm2
Yield strength N/mm
EN 24(40 N; 2 cr 1 Mo28) 720 600
Using ASME code of design
Allowable shear stress;
Fs all is given stress;
Fs all = 0.30 syt = 0.30 x 600
= 180N/mm2
Fs all = 0.18 x Sult = 0.18 x720
= 130 N/mm2
Considering minimum of the above values;
fs all =130 N/mm2
a) Considering pure torsional load;
T design = II fs all d3
----
16
d 3 = 16 x 3.68 x 10 3
II x 97.5
d = 5.77 mm
Selecting minimum diameter of spindle = 10 mm
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4.4 Selection of Bearing
Spindle bearing will be subjected to purely medium radial loads; hence we shall
use ball bearings for our application.
Selecting; single Row deep groove ball bearing as follows;
Series 62
I S I No. Bearing of Basic design No.
( SKF )
d D1 D D2 B Basic Capacity
20 BC02 6000 10 12 26 22 10 10000 6550
P = X F + Y F a
For our application F a = o
P = X F r
Where F r = 204.5 N
As; F r < e X = 1
P = F r
Max radial load = F r = 204.5 N
P = 204.5 N
Calculation dynamic load capacity of bearing
L = (C) p where p =3 for ball bearings
P
When P for ball Bearing
For m/c used for eight hr of service per day;
L h = 12000- 20000 hr
But; L = 60 n L h/10
L = 600 million rev
Now; 600 = ( C )3/( 204.5)3
C =1724.8 N
As the required dynamic capacity of bearing is less than the rated dynamic capacity of
bearing
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SR NO. PART
CODE
DESCRIPTION QTY MATERIAL
1 FRAME 1 MS
2 GEAR MOTORS 1 STD
3 WHEELS 2 RUBBER
4 SHAFT 2 40C8
5 BALL BEARINGS 4 STD
6 AXLE SHAFT 2 C30
7 BEARING MOUNTER 2 STD
8 BEARING
SUPPORTER1
2 STD
9 NUT AND BOLT STD
10 RACK AND PINION 1 STD
CHAPTER 5
COMPONENTS USED IN SYSTEM AND ITS PROPERTIE
5.1 USED MATERIALS AND THEIR PROPERTIES
The materials used in this project are detailed as follows
FERROUS MATERIALS
A ) Mild steel – EN – 4 to EN – 6
Carbon – 0.15% to 0.35%
Tensile strength –1200/1420MPA
Yield strength – 750/1170 MPA
B) C30 Carbon – 0.25% to 0.35%
Tensile strength – 620 MPA
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Yield strength – 400 MPA
Izod Impact Value – 55 Nm
% Minimum Elongation – 21
C30 material is generally used for cold formed levers, hardened and
tempered tie rods, Cables, Sprockets, Hubs and Bushes –Steel Tubes.
C) 40C8 Carbon – 0.25% to 0.35%
Tensile strength – 620 MPA
Yield strength – 400 MPA
Izod Impact Value – 55 Nm
5.2 NON METALLIC MATERIALS
The non-metallic materials are used in engineering practice due to their low
density, low cost, flexibility, resistance to heat and electricity. Though there are many
non-metallic materials, important materials used in our project are listed below:
A) PLASTIC (NYLON):
The plastics are synthetic materials which are molded into shape under pressure
with or without the application of heat. These can also be cast, rolled, extruded,
laminated, and machined. Following are the two types of plastics;
(a) Thermosetting plastics
(b) Thermoplastics.
The thermosetting plastics are those which are formed into shape under heat and
pressure is applied, it becomes hard by a chemical change known as phenol formaldehyde
(Bakelite), phenol-furfural (Durite), urea-formaldehyde (Plaskon), etc.
2. RUBBER:
It is one of the most important natural plastics. It resists abrasion, heat, strong
alkalies, and fairly strong acids. Soft rubber is used for electrical insulations. It is also
used for power transmission belting, being applied to woven cotton as a base. The hard
rubber is used for piping and as lining for pickling tanks.
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CHAPTER 6
FABRICATION DETAILS
6.1 PART NAME: SHAFT
Part weight – 1kg
Part material – C30
Part quantity – 4
Part size – Φ20 x 110 mm.
Sr. No. Operation Machine Tool Time
1 Cutting the material as per our
required size.
Power
Hacksaw
Hacksaw Blade 10 min
2 Facing both side Lathe
machine
facing tool 10 min
3 After inserting the Bering
knurling at distance 35mm
Lathe
machine
Knurling tool 10 min
6.2 PART NAME: BEARING MOUNTER-1
Part weight – 1 kg
Part material – M.S
Part quantity – 4
Part size – 60 x 10 x 60 mm.
Sr. No. Operation Machine Tool Time
1 Cutting the material as per our
required size.
Power
Hacksaw
Hacksaw Blade 10 min
2 Drilling 10mm hole Lathe
machine
Drilling Bit
10mm
10 min
3 Make Φ42mm Lathe Boring tool 15 min
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Eelectrical Steering System in Automobile
machine
6.3 PART NAME: BEARING MOUNTER-2
Part weight – 1 kg
Part material – M.S
Part quantity – 4
Part size – 40 x 16 x 160mm.
Sr. No. Operation Machine Tool Time
1 Cutting the material as per our
required size.
Power
Hacksaw
Hacksaw Blade 10 min
2 Drilling 10mm Lathe
machine
Drilling Bit
10mm
10 min
3 Make Φ42mm Lathe
machine
Boring tool 15 min
6.4 PART NAME: LOWER FRAME
Part material – M.S
Part quantity – 1
Part size –
2. Lower Part – 300 x 600 x 80 mm, t = 15 mm
Sr. No. Operation Machine Tool Time
1 Cutting the material as per our
required size.
Power
Hacksaw
Hacksaw Blade 40 min
2 Welding of a frame Arc welding Welding
holder
40 min
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CHAPTER 7
COST ESTIMATION
7.1 COST OF MATERIAL:
Sr.No Part Name Weight Rate/kg Total Cost
1 Shaft 1 kg 60 180
2 Bearing Mounter plate 3 kg 60 30
3 Motor Mounter plate 3 kg 60 15
4 Frame 2 kg 60 240
Rs. 555
7.2 COST OF STANDARD PARTS:
Sr.No Part Quantity Rate/unit Total Cost
1 Gear Motor 1 2700 2700
2 Rack and pinion 1 100 100
3 Bearing holder 4 500 1000
4 Ball Bearing 4 30 150
5 Wheel 2 500 1000
6 Nut and bolt 20 1 20
Rs.
7.3 OTHER COST:
Sr. No Details Total Cost
1 Painting 150
2 Transport 300
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3 Other/overhead 700
Rs. 1150
7.4 TOTAL PROJECT COST:
Cost of material + Cost of machining + Cost of std. part + other Cost
= 555 + 1710 + 12190 + 1150
= 15605/-
Total project cost = Rs. 15700/-
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CHAPTER 8
APPLICATIONS
It is very much useful for heavy load vehicles. This Electrical steering system can
be used for smooth steering of the vehicles.
Thus it can be useful for many automobile companies such as TATA, FIAT,
MAHHINDRA etc.
8.1 ADVANTAGES
It gives smooth and effortless steering system.
It also provides a steering system with less linkages and moving parts. .
Low Cost Automation Project
8.2 DISADVANTAGES
To apply this steering systems to automobile vehicles, lot of
improvements is required which may increase the cost of system.
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CHAPTER 9
CONCLUSION
This contribution presented various types of electrical steering systems and their
safety aspects. Rather, an electric motor is used, yielding energy savings and flexibility of
installation.
Electrical power steering pursues this trend and offers additional advantages since
no hydraulic system is required. A steer-by-wire system with hydraulic backup and a
purely electrical system were discussed. It had been stated that redundant fail-safe
structures for electric and electronic components are to be established due to the fact that
no mechanical or hydraulic connection between steering wheel and vehicle wheels are
available. Future innovative steering functions, such as vehicle dynamic interventions,
collision avoidance, individual wheel steering, tracking assistance, automatic lateral
guidance, and finally autonomous driving functions will be implemented in a system
compound of various vehicle systems. Future steering systems will thus have to be
integrated into a system compound, in terms of interfaces and functions. The steer-by-
wire principle becomes absolutely necessary when those innovative functions are to be
achieved.
The transition to purely electrical steering systems will proceed step by step, both
for safety reasons and acceptance by the customer. The path will lead from electrical
power steering via a steer-by-wire system with a hydraulic or mechanical backup towards
purely electrical steer-by-wire systems.
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CHAPTER 10
. REFERENCES
Internet : Automotive Engineering International Online, Delphi Automotive
Systems;
Joseph, Heitner.Automotive Mechanics, CBS Publishers and Distribution.
Narang G.B.S.Automobile Engineering, S.Chand and Company Ltd.
Crouse, W.H.Automotive Mechanics, TATA McGraw Hill Publishing Company Ltd.
1. Vering on narrow roads and during parking becomes easier.
T.K.I.E.T. Warananagar. Page 55
Eelectrical Steering System in Automobile
T.K.I.E.T. Warananagar. Page 56