sistemas hidrostaticos para maquinas concreteras

7/27/2019 Sistemas Hidrostaticos Para Maquinas Concreteras

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Brueninghaus Hydromatik

R E 98050/04.95

H ydrostatic D rive S ystems for M obile C oncrete M ixers


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Hydros tatic Drive S ystem s for Drum Drives

on Mobile Co ncrete Mixers

2

Hydrostatic transmissions from Brueninghaus

Hydromatik fulfill these requireme nts by offering

the following advantages :

stepless and sensitive setting of drum

speed

sm ooth reversal of drum direction for

mixing and emptying

High dem ands are placed today on modern

technology when designing drum drives for

mobile concrete mixers.

Hig h operat ional s afe ty

Easy handling

Hig h leve l o f e ffic ien cy

Environmental acceptability

Lo ng serv ice life

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Drives , Control, Movem ent.

A com plete trans m is s ion

sys tem from a single

supplier.


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The quality of the Brueninghaus Hydromatik

produc ts is along with the high level of

technologies the reason for content customers

worldwide.

The certification as to DIN ISO 9001 therefore

is the log ical result of our extensive quality

assurance strategy.

The Mannesm ann Rexroth group of companies

is able to offer a com plete solution for any

drive application.

Why not talk to our mob ile concrete mixer

sales department?

simplification of mob ile mixer design

mounting of internal combustion engine

independ ent of position of drum drive

simple operation of transmission from a

number of positions

reduction in noise

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Standard Mod elconventional des ign

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Our A4V variable pum ps are equiped with

hydraulic servo control. Actuation is distanc e

depen dent by m eans of a control lever. This

permits both the flow and thus the drum s peed

to be infinitely set between Q0and Qma xfor

mixing and emptying.

1,0 0,8 0,6 0,4 0,2 0,2 0,4 0,6 0,8 1,0

I in mA

VgVg max

VgVg max

I in mA

80 0

60 0

40 0

20 0

20 0

40 0

60 0

80 0

40

30

20

10

10

20

30

40

1,0 0,8 0,6 0,4 0,2 0,2 0,4 0,6 0,8 1,0

in

VgVg max

VgVg max

in

Strong end stops of the lever in the pump

eliminate the need for further end s tops in the

cable line for maximum drum s peeds . The cable

support is mounted on the pump u sing the

special bores provided.

Electrical control is also p oss ible if required

e.g. for a particular mixing prog ramme or for

remote control.

For this an amplifier card (a 12 or 24 V PVR,

see data s heet RE 95 02 2) is required together

with one or more potentiometers.

Hydraul ic co ntrol , m ec hanical s erv o, HW

Electrical con trol with proportional so lenoid, EP

Pump speeds down to 500 rpm are permit ted

with all un its.


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Standard Mod elconventional des ign

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All A4V variable displacem ent pu mp sizes are

available with S AE-A or SAE-B throu gh drives

or with a moun ted gear pum p (for operation of

a con veyor belt, chute or an au xiliary axle on

the vehicle).

Axial piston pumps may also be mou nted onto

the through drive for operating the distributor

mast on combination mixers/concrete pumps.

Axial piston p ump s s izes 71 and 90 are fitted

with drive flange s for the steering s haft (stand ard

flange 100 mm d ia.).


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Components

8

Series A2F fixed displacemen t motors in ben t

axis design are the best cho ice for the hydraulic

motor.

These motors are characterised by a high

starting torque and long s ervice life.

Dimensions co rrespond to standards for mixers.

All motors are e quipped with a flushing valve

for chang ing the oil in the main circuit.

For further information s ee data s heet

RE 91 00 1.

Any comb ination of the following pum ps and m otors m ay be us ed.

Pump

Shaften

dMo

unting

centeri

ngdia .

Suction

connec

tionfr

forboo

stpum

p

High p

ressure

ports

Weight

ofpum

p

(appro

x.)

Motor

Shaften

dMo

unting

centeri

ngdia.

Weigh

tof

motor

(appro

x.)

A2FM45 16/32 p itch , 21 s p lines 127 mm 13,5 kg

A2FM56 16/32 p itch , 21 s p lines 127 mm 18 kg



A2FM90 16/32 p itch , 21 s p lines 127 mm 23kg

A4V40 16/32 p itch, 21 s plines 127 mm M36x2 external thread 3/4" 30 kg

A4V56 16/32 p itch, 21 s plines 127 mm M36x2 external thread 3/4" 37 kg

A4VTG71 16/32 p itch, 21 s plineswith drive flange for 127 mm M42x2 internal thread 1" 48 kg

cardan shaft

A4VTG90 16/32 p itch, 23 s plines

with drive flange for 127 mm M42x2 internal thread 1" 50 kg

cardan shaft

A4VG125 SAE 1 3 /4", 13 s p lines 152 mm M48x2 internal thread 1 1/4" 80 kg


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S tand ard Drum Drives

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Either the vehicle engine (secon dary power

take-off) or a sep arate drive motor is used to

drive the variable pump .

In order to reduce n oise d uring filling, m ixing

and em ptying of the drum the vehicle engine

is normally run only at low speed (nma x= 1600

rpm), whereas with a se parate drive mo tor

speeds of up to 2500 rpm are poss ible.

To achieve the maximum d rum s peed, the

appropriate pump size must be selected.

4 m 3 14 18 rpm

6 m 3 13 16 rpm

7 m 3 12 15 rpm

8 m 3 11 14 rpm

9 m 3 10 12 rpm

10 m 3 9 12 rpm

12 m 3 8 12 rpm

Ag it at io n 1 5 r pm

The selection of the mixer drive depends

mainly on the required torque of the m ixer

drum.

Given a s tandard drum d iameter of 2200 -

2300 mm we can assu me a standard

value of

6000 Nm per m 3concrete.

This represents the m aximum value taking into

consideration peaks occuring when starting

up the d rum after a long journey (setting ofconcrete).

Furthermore the g ear ratio of the mixer drive

used is also decisive. The gear ratio of the

mixer transm ission varies co nsiderably from

one m anufacturer to an other, but lies within

the range of approx. i = 100 - 1 60.

From the maximum drum speeds the following

mixer sizes can b e ass umed:

S tandard transm ission for mobile concrete

mixer

Trans m ission with 2-s tage planetary gear with

axially mounted hydraulic motor.

Optional secondary power take-off for water

pu m p and spee d s en s ing dev ice .


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Selection of hydraulic motor

Example:

Mixer drum capacity 6 m3

Drum speed 14 rpm

Mixer trans m is s ion i = 141

Drive s peed (pump) 1500 rpm

Selection of hydraulic pump

To obtain a drum spe ed of 14 rpm a

pump d rive speed of 1725 rpm is

required.

A pum p drive speed o f 1500 rpm gives

a drum speed of 1716 rpm /141 = 12.2

rpm.

On request we can supply exact

dimensioning using CAD, stipulating the

most sui table hydraul ic com ponents.

nmotor= n drum. itransmission =

14 rp m . 141 = 1974 rpm

As a general rule the d rive of a mo bile

concrete mixer can be selected inaccordance with these diagrams.

40000 50000 60000 7000030000

= 255 Nm

10000

10

8

6

4

2Capacityofmixerdrum

(m3)

20000

100 200150 300 400350 500450

s e l e c t e d h y d r a u l i c m o t o r S iz e 5 6

600550

Size 80Size 63Size 56Size 45 Size 90450

400

300

200

100

Operatingpressureathydraulicmotor(bar)

250

Determination of hydraulic motor (mh=0,95)

Required drive torque atmixer drum

Hydraulic motor drive torque (Nm)

Drum drive torque (Nm)

Nm

Nm

20 40 60 80 100 120 140 160 180 200 220 240

4000

3000

2000

1000

v=0,95

1725

1500

20 40 60 80 100 120 140 160 180 200 220 240

4000

3000

2000

1000

Size 80Size 90

Motor displacement (l/min)

v=0,95

Size 125

Size 90

Size 40

116,3

Size 56Size 71

Size 32

Size 63

Size 56Size 45

Pump flow (l/min)

selec ted hydraulic pump Size 71

Determination of Qreq

Determination of hydraulic pump

19741716

Outputsp

eedhydraulicmotor(rpm)

Drivespeed

hydraulicpump(rpm)

36000 Nm

141 (itransmission)


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Cams haft drivenot s witchable, on ly part load transferable, Mdma xapprox. 600 Nm, short time 720 Nm

i = rev 1:1 motor speed, torque limitation necessary when using pumps > 90 cm3/ rev.

Separate motor

Pum p mo unted directly by means of elastic coupling, no torque limitation required

Front e ng ine p owe r take- off (FEPTO)

Md ma xdepending on design characteristics, i = 1:1

Drives for Low-no ise M ob ile Co nc rete Mixers

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HA1 HA2

HA1 HA2

Hydraulic pum ps

It is pos sible to reduce no ise with minimaleffect o n o perating efficiency.

Good resu lts were achieved at a drive speed

reduction of up to min. 800 rpm.

Naturally larger pumps are then necessary

which require higher drive torques a lthough

this can lead to overloading of the camsh aft

drive.

To prevent this the pum p m ust b e fitted with a

torque control (applies to pum ps > 90 cm3/r ev).

Our A4VG 125 pu mp is particularly suitable

and is available with the following control

characteristics:

On entering the speed reduction field the d rum

speed is automatically reduced in accordance

with the diagram .

Press ure relief valves 450 bar

Press ure cut-off 420 bar

S tart of of speed reduction ~ 300 b ar = 600 Nm

500

400

300

200

100

0,25 qv max

0,5 qv max

0,75 qv max

qv max

Flow qv

O

peratingpressurep(bar)


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"Low no ise" mob ile m ixer transm ission On request we can sup ply exact dimension ing

for devices with thes e drives us ing CAD.

Hydraulic motors

In these d ays of environmen tal awarenes s large

volume radial piston motors are com monly

used owing to their reduced noise. They are

either an integral part of the mixer trans miss ion

or are mounted such that the transm ission and

the motor build a s ingle unit. At the same time

a cooler and pump suction filter are mounted,

the housing also b eing used as an oil reservoir

for the hydraulic fluid.

The result is an extremely compact un it.

Such transmissions demonstrate an i of approx.

7:1 (planetary stage)

The highest sp eed of all rotating pa rts is less

than 100 rpm, making them quieter than

conventional mixer transmissions.

These transmissions could well be introduced

in the long term in standard devices.


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The New WayModel with EL constant speed drive (CSD)

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The electrical constant s peed d rive was

developed es pecially for use in m obile concrete

mixers.

The drive cons ists bas ically of the sam e

hydraulic components as with the standard

drive, but with the control via a control flow

(see c haracteristic EP, pag e 5).

Proportional so lenoids mou nted onto the d rive

(EP co ntrol) are used to co ntrol pump flow as

required.

The constant sp eed function effects a co nstant

drum s peed, even with varying sp eed of the

drive motor.

This function is b rough t about by determination

of the required pump swivel angle dependent

on the pre-selected drum and pump speeds .

From these two parame ters the electronics

calculate continuou sly the required control flow

and chang es the pum p swivel angle so that the

pump flow remains co nstant, corresponding to

the given value.

Even m ixing of the conc rete during travel, with

correct metering o f the water sup ply, eliminates

the need for additional fuel and wear-intensive

mixing at high drum speeds on site before

unloading.

Even for "kerbstone concreting" the con stant

drum s peed allows e ven flow of the con crete.

The electric CSD also permits com plete mixing

programm es to be c arried ou t with the aid of

additional devices i.e. by setting the no. o f

drum revolut ions and rpm a programme can

be produ ced to include s pecific intervals during

mixing.

As a general rule the ELCSD can be eas ily

operated by remote co ntrol, as only electrical

signals are required to operate the pump.

The drum s peed can be set by ramps, this

method o f operation being kinder to the

materials.

1

2

3

6

7

5

4

This drive offers the following advantages for

use in mixers:

The drum m ay be s et to agitate during travel

at a constant drum speed.

This has only a minimal effect on the

performance of the vehicle. The co ntinuous

acceleration and deceleration of the drum with

changing vehicle speeds is eliminated.

This means less wear of all rotating p arts

(transm ission, h ydraulics, d rum), longer s ervice

life and lower fuel cons ump tion.

When accelerating the vehicle no add itionalpower is necessary for simultaneous

acceleration of the mixer drum. The power

reserve of the prime m over is available for

acceleration o f the vehicle. This is of particular

advantage in vehicles with low engine po wer

and when travelling up hill.

300020001000

18

12

6

Diesel engine speed (rpm)

Potentiometersetting

Drivespeed(rpm)


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M = 1,59 x Vg maxx p

100

Function

See also data sh eet RE 95 075

Selection of drum speed can be m ade from on e

of two pos itions .

a) By potentiometer (3) in the driver's cab . This

is a potentiometer without housing and is

mounted on the dashboard.

b) By potentiometer (4), which is mou nted near

the chu te at the rear of the vehicle. This is built

into a water-resistant rubber hous ing (type SP,

see data sheet RE 95 040).

Speed feedback, which has to bear a fixed

relationship to the pump drive speed, can beeither by means of terminal W (5) on the

generator or, if not pos sible, via the speed

sens or on the starting g ear ring (6) or elsewhere.

If using terminal W as sp eed feedback an

electronic device with a frequency rang e of

100 - 1000 Hz must be used.

If a VDO is used for speed feedback at the

starter gearing, electronics with a frequen cy

range of 2000 - 8000 Hz must be used.

Torque limitation

If overloading of the camshaft drive or of the

drive motor is to be avoided, then mo del CSDwith torque limitation should be used (see data

shee t RE 95 075).

The relevant high pressure is measured by a

pressure sens or 7 and the torque l imited in

accordance with the following formula:

i.e. when the p re-set torque is exceede d the

control flow for the pum p is reduc ed, the pu mp

will swivel back and the torque m easu red is

reduced to prevent overloading.

The drum s peed will automatically be reduced

accordingly.

With vehicles in comm on us e today the current

max. Md at the cam sh aft drive is 60 0 Nm for

cont inuous operation and 72 0 Nm for short

periods.

Torque limitation of these vehicles h as been

shown to be only necessary when using pum ps

of over 90 cm 3/ re v (predomin an tly with lo w-

noise concrete mixers).

Both potentiometers are of the same design (1x

with ho using , 1x without ho using ). They are

fitted with strong mech anical end stop s to

prevent overspeed ing. Only one potentiometer

may be us ed at any one time. Switchover is by

means of switch 2, installed in the driver's cab.

After switchover the potentiom eter switched on

mus t first be set to the zero position to prevent

malfunctioning and accidents.


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Hydraulic fluids

Note: Environmen tally accep table fluids are

also subject to the relevant regulations regarding

disposal .k

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Plant Elchingen

Glockeraus trae 2

D89275 Elchingen

Telephone (0 73 08 ) 8 20

Telefax (0 73 08) 72 74

Plant Horb

An d en Kelterwiesen 14

D72160 Horb

Telephon e (0 74 51 ) 9 20

Telefax (0 74 51) 82 21

Brueningh aus Hydroma tik GmbH

D97813 Lohr am Main

Telephon e (0 93 52 ) 18 0

Telefax (0 9 3 52 ) 18 21 59

Telex 689 418 -12

Mannesm ann Rexroth GmbH

Our units are e qually suitable for use with

mineral oil based hydraulic fluids and

ecologically acceptable fluids.

When us ing fire resistant hydraulic fluids pleas e

consul t us.

Please also refer to our recommendations for

oils.

Mineral oil based hydraulic fluids

see data sheet RE 90 220

Ecologically acceptable fluids

HETG, HEPG, HEE


Axial piston u nits for us e with HF hydraulic

fluids


sistemas hidrostaticos para maquinas concreteras

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