roller gearing and power transmission mechanism · settimo torinese ( torino) italia • tel. +39...

Settimo Torinese ( Torino) Italia • tel. +39 (0) 11 800 29 84 ‐mobile +39 3356763554 • [email protected] 1

Roller Gearing and Power Transmission Mechanism

Galli Dario

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Currently the transmission of rotary motion between two perpendicular axes, it makes use of kinematic helical pairs, consisting of a toothed wheel associated with a worm‐shaped substantially cylindrical in shape Described: An incident that occurs through the system known is that the conjugate profiles of the worm and gear are subject to wear by friction.

The profile of the worm steel tends to dig the profile of the conjugate gear, which as you see in the pictures is usually in bronze. So over time is due to problems of inaccuracy of the angular position, and in some cases in which the system is subjected to mechanical strain, even at break, and for that to wear fatigue.The system must also be lubricated with oils or fats, this makes it sensitive to temperatures, both high and low. In general this applies to the requirements for the lubrication of gears. Particularly in the case of high speed and / or high loads, lubrication is especially important to avoid raising the temperature and thermal expansion such as to reduce the accuracy of position and length of the screw. A striking example are the many aviation accidents occurring to aircraft Md. 80, where 's gear in question was placed on the tail of the aircraft, and ordered the flaps control flight.

Settimo Torinese ( Torino) Italia • tel. +39 (0) 11 800 29 84 ‐mobile +39 3356763554 • [email protected]

3Settimo Torinese ( Torino) Italia • tel. +39 (0) 11 800 29 84 ‐mobile +39 3356763554 • [email protected]

Products currently produced worldwide


Products currently produced worldwide


All these profiles of non‐rectifiable tracks, with machine tool, and therefore material not suitable for thermal treatments, and therefore the material does not have the mechanical characteristics required in certain particular applications.In fact if you notice the crown is made of bronze material, therefore soft material, and the curvature of the screw and the profiles does not allow the final grinding work.You can notice the particular configuration of the gears that to work must have for a game, determined by various factors, according to gear theory

The Innovative Idea - what new do we do

Realisation of the Idea - how do we do it

Design Examples - what variety can we do

Concept Prototype Tests - facts and proofs so far

Benefits and Advantages - why should it be used

Potential Applications - where could it be used

Running Application Projects - who got interested so far

The Galli Industry Company - our business, skills and facilities


Brand new technology- 8 months in the market

Trivial problem – non-trivial solution

Rollers connect the wheels wheels do not connect directly there are no “teeth”

Rollers roll along the grooves on both wheels simultaneously rigid coupling between the wheels

Rollers do pure rolling motion without sliding ensured by the shape of the grooves

The Innovative Idea


Forces transmit via “single” contact points between rollers and grooves lines of contact points determine the

lines of the grooves and the shape of the wheels

cross-sectional shape of the grooves is irrelevant

lines of grooves are key to ensure proper forces for pure rolling motion

Hertzian stress is well contained curvatures of rollers and grooves are

similar near the contact point

Realisation of the Idea

• More like a ball screw than a conventional toothed-wheel gear

8www.galli‐industry.com • tel. +39 (0) 11 800 29 84 • [email protected]

Realisation of the Idea (cont’d)

Complex physics

G: roller (ball)

P1, P2: contact points between the balls and the wheels

gp: path travelled by the ball’s centre when in coupling

g1, g2: paths travelled by the contact points

u, v: various velocity vectors

1, 2: angular velocity vectors of the two wheels

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Settimo Torinese ( Torino) Italia • tel. +39 (0) 11 800 29 84 ‐mobile +39 3356763554 • [email protected] https://it.linkedin.com/in/dario‐galli‐61050654

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The technology is …

• universally applicable to any gearing problem– any shaft angles– crossing or non-crossing axes– internal or external coupling– planetary systems and worm gears– linear drives and gear racks

• highly flexible and rich in design– for any given gearing problem,

provides a variety of solutions – highly optimisable and customisable

• very different from conventional – it is more like a generalised ball

screw or roller bearing

Design Examples


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worm gearaxes angle = 90o

gearing ratio = 1:50ball diameter = 4mmcontact factor = n/a


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Concept Prototype Tests

The prototype tested was the 1:10 non-intersecting axes, 45o setup Made of steel with nitriding finish of grooves surfaces

Tests performed: All this was done: Basic checks of operations - With and without back-lash Kinematics and noise checks - For both directions of rotation Static power efficiency - For both directions of load Dynamic power efficiency - For various angular velocities Movement precision Reliability


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Summary of Test Results

• Basic operations, kinematics, noise and reliability – no particular issues, performance was quite good in all respect

• All tests were insensitive (in terms of statistical significance) to– changing direction of rotation– changing the direction of the load– and whether the back-lash was eliminated or not

• Static efficiency at least 98% - this was independent of – roller recycling device being in place or not – back-lash has been eliminated or not (surprise!)

• Dynamic efficiency at least 94%– groove surfaces were sub-optimal as a result of nitriding– we will re-test again soon with polished groove finish and improved roller

recycling device


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Summary of Test Results (cont’d)

• Movement precision showed a periodic structure where the periodicity was the same as the period of revolutions of the larger wheel in the gear. This shows there was a manufacturing error in the larger wheel. – the error was about +/- 0.2 degrees – looks like a normal amount of

inaccuracy and should not be a cause for alarm– we want to retest with a higher precision electronics to see if anything else

besides the larger wheel has an effect on precision


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parallel axes A L U M I N I U M P R O T O T Y P Eaxes angle = 0o ( n o t t e s t e d )gearing ratio = 26:23ball diameter = 4mmcontact factor = 8


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WORM BALL


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Describes a pair kinematic ball for transmitting rotary motion from a first axis, a second axis, perpendicular to the first. The invention is intended to apply in the field of machine tools in the first, aircraft auto motive, and generally in all areas in which you request a particular accuracy and reliability of machinery and large load capacity, and duration of mechanical system. As the name in itself, a ball screw actuator is composed of a threaded shaft, a nut and a number of spheres placed between 'set-screw nut who ride their propellers. The transformation of motion is achieved by rolling balls interposed between the thread of the spiral and that of the screw.The ball screw is a screw type, so called because of the screw and spiral steel balls are placed with the task of transforming the sliding friction into rolling friction, this treatment as a rolling bearing . Inside the spiral groove is carved a hemispherical helical section having the same pitch diameter of the screw but well above average.The mechanical efficiency of a screw ball goes up 96% since the friction due to sliding between the contact surfaces, present in conventional screws (trapezoidal screw) is replaced by the friction between the ball rolling and slopes as happens in the rolling ball bearings. reduction of friction in the game involves less power dissipated in heat and less wear of the walls. low operating temperatures translatecontained in thermal expansion and high positioning accuracy. reduced wear, coupled with the quality of raw materials and appropriate heat treatment, ensures a long life ball screws. It is the mechanism most frequently used to convert rotary motion into a translational motion, it can be seen as a refinement of the "screw-nut", against which it is more accurate and has a much higher yield (yield = 90% Approx. )


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Some of the benefits guaranteed by the use of ball screws are: • high yield and very high wear durability • • • significant axial stiffness significantly reduce friction between parts in contact Technological development has generally sought to Manufacturers of components a continuous investment in research and development. With this patented recirculation we achieved the following significant results:1) We increased the threshold of the maximum speed of rotation of the screw than traditional systems. 2) We obtained the lower wear of the switches and thanks to the ideal angle of the ball recirculation and particulars "calls" of the diverter. With extensive experience in over thirty years with major manufacturers in the industry, we designed and implemented a new system of internal recirculation which offers the following advantages:

• Increased load capacity • large increase in the rotational speed of the system • Better response in short strokes with high levels of acceleration

• Roll at low speed devoid of obstinate • Considerable reduction in system noise at high travel speed

• Separation of the linear trajectory of balls taken from those in back • Elimination of each leg broken in the grinding thread nut

• Exclusive use of liners or steel dividers

With this system the spheres are located along a three-dimensional curve placed tangentially to their path so as to ensure a course without interruptions, with the maximum quiet tire. The ball screws are then able to reach a large number of rotations and allow the achievement of a factor of speed limit (D x N) maximum of 120,000 and in some cases 150,000. So, even the screws ball rolling follow the laws of friction, thanks to which we obtain the following benefits:• High efficiency, particularly in relation to an acme screw • Reduction of engine power required • Travel speeds greater• Less friction and therefore less heat development • Increased positioning accuracy • Less wear and therefore increase the operating lifetime• No lubricationne


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MATERIALS AND HEAT TREATMENTIn the construction of a recirculating ball screws are used certified specialty steel, high physical and mechanical properties. Generally are used reclaimed steel with high carbon content. To ensure the constant reliability exasperated cycles machine today, the steels are subjected to various heat treatments, in order to increase the surface hardness and thus make them suitable to the demands that come from various application areas, requiring different environmental

A pair of recirculating ball and 'rolling a mechanical system composed of a threaded shaft or screw, and a crown, which is committed to the first element, not directly, but through the interposition of a number of spheres. E ', then obviously such a scheme, based on the law of rolling, have enormous advantages over traditional systems of kinematic pairs, which yield high, three to five times in different angles resulting from the ratio of diameter vite.Dell-step of 'inclination of the propeller, a lower content of dimensions, a reduction of torque applied and reduced wear. The performance, in particular, is equal to 0.9 in the case of rotational movement translatory or slightly below 0.8 in the case of translational motion

www.galli‐industry.com • tel. +39 (0) 11 800 29 84 • [email protected]

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CHARACTERISTICS. Non-grinding profileThe ability 'to rotate heavy loads for thousands of hours of operation in difficult conditions makes this system particularly suitable for heavy applications. The robustness of sliding tracks, can withstand shock loads, while the synchronization system of balls or rollers, ensures high reliability 'is accelerating, which in any other condition of employment, the significant length of runways allows high speed 'rotation. The presence of games in a recirculating ball screw is easily eliminated by preloading, ie moving away or approaching the two lead screws or by inserting ball ring selected with the greatest centesimal or even micron in diameter.If you opt for the former and, in particular, the preload, generally performed in tension, ie run away both mother and placing a spacer ring screws until you get a predetermined load value. This value is calculated taking into account the dynamic load characteristic of the lives and where there is any information about it, taking into account the conditions of use (actual working loads, speed, temperature and time required). Load capacity and stiffness. The figure clearly shows how the cylindrical roller, thanks to the large contact area, have the highest capacity 'drops. Also the stiffness of the roller and 'clearly greater than for other types of rolling elements. In practice the guideway rollers for cylindrical roller bearings have the following advantages over conventional guidance systems supported ball with the same overall dimensions, a capacity 'of increased capacity. increased stiffness. With the linear contact the cylindrical rollers roll without slipping. In contrast with the balls and rollers barrel microstrip occur which increase the rolling friction. The system once started, keeps the value of the initial preload and, consequently, the desired stiffness without the need for periodic adjustments. For the accuracy of this system must be defined several parameters, especially the parallel slip between the side of the reference guide and the axis of the system.


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APPLICATIONS OF THE SYSTEM

are provided for use as a swivel axis and positioning in machine tools, such as machining centers, cells and complex production machines, circular, and installations for the manufacture of all kinds.

ROTARY TABLES


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Aerospace industryYoung-kinematic stainless steel, can operate accurately and reliably and can be used on board satellites.

Plans aircraft tail-flaps


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AUTOMOTIVE INDUSTRYpossible use on the boxes of transmission and steering control, with applications of kinematic pairs unadjusted.

Certainly with degrees of precision machining the raceway lighter than other applications.


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Applicable Industries

Cement, stone and ore industries Grinding machines, rolling mills, presses, separators, mixers,

elevators etc Chemical and environmental industries

Agitators, mixers, pumps and compressors, cooling towers, dryers, turbines, aerators and thickeners in sewage treatment etc.

Electric power generation Wind, gas, coal, oil, water and nuclear power generators etc.

Food and agri industries Cutters, feeders, mixers, harvesters, combines, sewage treatment

machinery etc. Machine tools industries

Table movers, rotators, dividers, gear racks, spindle drives etc.


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Benefits and Advantages

Power efficiency close to 100% due to pure rolling motion done by the rollers sliding friction is practically eliminated

Contact factor up to 20 or more load distributes over many rollers

Back-lash eliminated easy to eliminate back-lash by forcing the wheels together efficiency loss is in-significant

… and implications of these


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Implied Advantages (Expected)

High power efficiency

No sliding friction Lower energy losses Lower starting torque Smaller motor needed Friendlier to the

environment – a green technology

Lower operating costs Reduced heating up Reduced abrasion Less cooling and

lubrication needed Less wear and

deterioration Longer lifetime Less vibration and noise

High contactor factor

• Smaller size• Higher power density• Smoother and steadier

movements• Precise movements• Lower noise• Greater reliability

No back-lash

• Precise movements• Less vibrations and

resonances• Longer lifetime


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• High-power drives– due to low operating costs, small

size and good reliability• All vehicles

– due especially to high efficiency, high power density, special shape and long lifetime

• Material handling machines– due especially to smaller

actuating torque and reliability

• Machine tools– due to eliminated back-lash– alternative to ball-screw drives

• Wind power generators– due to high energy efficiency,

high gear-up ratio, no back-lash• Standard gear families

– especially worm gears and bevel gears due to high efficiency and compact size, respectively

Potential Applications

Applicable in all areas of mechanical gearing and power transmission Including any / high or low:

o torque o ratio o precision o rpm o size

For example:


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• Wind turbines– Yaw and pitch drives– Main gearbox

• Machine tools– Turning tables

• Aviation– Flight control drives/actuators

• General industrial– Worm gears– Parallel-shaft gears– Planetary gears– Right-angle “bevel” gears– Linear actuators– Precision drives– Plastic gears– Miniature gears

• Car transmission, 5 fwd+1 back– Parallel axes, complex setup

• Car rear axle hypoid gearsRight-angle

– Intersecting axes– Non-intersecting axes– Twin-wheel

• Car parts– Window lifter– Engine starter

• Truck rear axle hypoid gears– Same as car hypoid gears

• Railway traction drives– Same as car hypoid gears– Also parallel axes

Running Application Projects


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Our primary businessof the new roller gear technology research and development commercialisation and transfer

Our design and development skills twenty years of experience in scientific research computer aided design and simulations applications design and development, evaluation and testing

Our management skills twenty years of experience in scientific research corporate management entrepreneurial and start-up management


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Access to machining facilities manufacture of high-quality prototypes build test equipment and perform basic tests produce on a relatively small scale, pilot runs

Access to suppliers local market knowledge supplier contacts, networks and relationships twenty years of experience, track record

Wide range of services basic R&D, theoretical and experimental work specifications and analysis, advisory and design prototype and applications manufacture and testing production advisory and outsourcing technology licensing


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Looking for a partner is a new idea we came to the market four months ago only Following about five years of intensive R&D

We believe the technology is mature enough now to be successfully applied in commercial applications

We need partners to help us to find the best applications that we can develop with the ultimate target of a commercial product in the focus

We also need partners to contribute in the partnership with production capacity and skills as well as market knowledge, sales and marketing networks and customer relationships

Potential for Collaboration


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In return we provide the technology through e.g. a licence agreement as well as our R&D and pilot production services in order to progress the developments of the technology further

Potential for Collaboration


roller gearing and power transmission mechanism · settimo torinese ( torino) italia • tel. +39...

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