drive and control systems for loaders

Drive and Control Systems for Loaders

2

Drive and control systems for loaders

Comfort

Efficiency

Environmentprotection

Operationalsafety

Optimum ergonomic

Functional operation

Low mechanical forces

Optimum power utilisation

Optimum machine utilisation

High availability

Reduced fuel consumption

Reduced exhaust emissions

Reduced noise emissions

Standardised components

Modular design

Reduction of mechanical components

Advantages of hydrostatic drive systems

Very high demands are placed on the drivetechnology of mobile loading machines withregard to efficiency and driver comfort.

The Mannesmann Rexroth Group of companies, with its business sectors of Brueninghaus Hydromatikand Rexroth Hydraulics, supply complete drive and control systemsthat fully meet these requirements.

For loaders in the power range of up to 60 kW purely hydrostaticdrives are the norm.

For the higher power range (> 60 kW) as well as the hydrostaticdrives with a subsequent power shift gearbox, multiple motordrives with a summation gearbox are also utilised.

With multiple motor drives two hydraulic motors operate in paralleland are connected to the drive shaft via a mechanical summationgearbox.

For the power range above 125 kW multi-motor concepts withswitchable summation gearboxes provide the ideal solution.

The management of the entire drive train is controlled via a micro-controller.

As with the travel drives the efficiency, high performance andoperator comfort of the service hydraulics is of equal importance.

As well as the conventional open center controls and load sensingsystems with fixed or variable displacement pumps the LUDVcontrol, which has been developed and patented by RexrothHydraulics, is being increasingly applied.

4

K1 K2 K3 K4

30

25

20

15

10

5

30 60 90 120 150 180 210 250

6

5

4

3

2

10,5

An overview of travel drive systems

Correlation of drive systems to power range

Hydrostatictransmission

Unl

aden

wei

ght o

f uni

t (t)

Buck

et v

olum

e (m

3)

Drive power (kW)

withsummationgearboxk 2 motors

withpower shiftgearbox

withsummationgearboxk 2 motorsk 1 coupling

withsummationgearboxk 2 motorsk 3 couplings

with mecha-nical dircetthroughdrive

5

Hydrostatic

k Hydraulic conversion, stepless

k Shift (hydraulic motor) shock-free

k No interruption of tractive effort

A4VG + A6VM

DrivePower range < 60 kW

Hydrostatic + power shift gearbox

k Hydraulic conversion,stepless + mechanical switching stages

k Shift (gearbox) virtually shock-freek Brief interruption of the tractive effort

A4VG + A6VM + power shift gearbox

Hydrostatic + summation gearbox

k Hydraulic conversion, stepless

k Shift (hydraulic motor) shock-free

k No interruption of tractive effort

A4VG + 2 x A6VM + summation gearbox(without/with gear shift coupling)

Power range > 50 kW

Power range > 60 kW

Power range 50 – 100 kW

Hydrostatic + mechanical

k Hydraulic conversion,stepless + mechanical direct through drive

k Shift virtually shock-free

k Brief interruption of the tractive effort

A4VG + A6VM + summation gearbox(with gear shift clutch)

6

1 2

Variable displacement pump A4VG...DAData sheet RE 92003

Variable displacement pump A10VG...DAData sheet RE 92750

Drive direction valve

DA control valve forRPM related speed definitionLoad limitation controlIntegrated inching function,inching valve can beoptionally controlled by thebrake pressure

Pressure cut-off

Variable displacement motorA6VM...HA1RData sheet RE 91604

Load dependent control (HA1)

Vg max circuit:Motor can be held in the Vg max

position via a switching solenoid

Valve for direction of travel signalsensing

Hydrostatic transmission

Mechanicalinjection pump

Acceleratorpedal

Inchingpedal

Brakes

Directionof travel

Override

A4VG..DA

A6VM..HA1R

Trac

tive

effo

rt

Vehicle velocity

Motor

Pump

7

MC+

SoftwareLSG

BB-3

RS 232

K1

K2

STM

Trac

tive

effo

rt

Vehicle speed

1. Gear

2. Gear

Actu

al R

PM

Posi

tion

com

man

d va

lue

Posi

tion

actu

al v

alue

RPM

Gea

r 2

Gea

r 1

Hydrostatic transmission with a power shift gearbox

Variable displacement motorA6VM...DA2Data sheet RE 91604

RPM dependent speed selection

Vg max circuit:Motor can be held in the Vg max

position via a switching solenoid

Valve for direction of travel signalsensing

Power shift gearbox with an A6VMData sheet RE 91604

Direction oftravel

Acceleratorpedal

Gearselection

Changemanual/

automatic

BB-3 SoftwareBodem

Inching

A6VM..DAA4VG..DAMechanicalinjection pump

Electricalactuator

DiagnosticsParameter settingProcess monitoring

8

1 2

STM

K2K1

K3

MC+

SoftwareBB-3

RS 232

Summation gearbox with/without coupling

Summation gearbox with 3 gear shift clutches

RPM

Hydrostatic transmission with summation gearbox


A4VG..DA

A6VM..HA1U

A6VM..HA1R

Acceleratorpedal

Inchingpedal

Brakes

Directionof travel

Override

Direction oftravel

Acceleratorpedal

Gearselection

Inchingpedal

BB-3 SoftwareBodem

A6VM2

A4VG

A6VM1

Vehicle speed

Trac

tive

effo

rt

A6VM1 x i1A6VM2 x i3

A6VM1 /De-coupledA6VM2 x i3

A6VM1 x i2A6VM2 /De-coupled

Posi

tion

com

man

d va

lue

Posi

tion

actu

al v

alue


Electricalactuator


Vehicle speed

Trac

tive

effo

rt

9

PnL

STM

K2

K1

MC+

SoftwareBB-3

RS 232

Trac

tive

effo

rt

Vehicle speed

Switching point

Hydrostatic

Hydromechanical drive - force transmission

Mechanical

Hydromechanical drive

RPM

Hydrostatic transmission with a mechanical directthrough drive

Hydromechanical drive

k Combines the advantages of thehydrostatic drive with that of themechanical drive

Hydrostatic drive (working range)

k Maximum tractive effort at low dieselspeeds

k High start-up efficiency

k Jerk-free change of travel direction

k Load limiting control also with powerconsumed by auxiliary actuators

k Requirement dependent powerdistribution between the travel drive andservice hydraulics

Mechanical drive (changing theoperating location)

k Low efficiency losses

k Reduced noise emissions

BKM

BKM

BB-3 SoftwareBodem

A6VM

A4VG

Hydrostaticdrive

Mechanicaldirect drive

Direction oftravel

Acceleratorpedal

Gearselection

Inchingpedal

Posi

tion

com

man

d va

lue

Posi

tion

actu

al v

alue


Electricalactuator


10

n1

n2

n1 = n2n1 < n2n1 = – n2

BKM

A10VG

MCR

G2G3

MCR4TH64TH6

3 SM12

Opt

ion

Buck

et

Boom

Steering via speed differences at the wheels on each side

Control of the implement hydraulics and the hydrostatic transmission via a joy-stick

Wheel drive via MCR radial piston motor

Hydrostatic transmission for compact loaders

2 circuit drive with a compact tandem pumpspecial design for compact loaders

Tandem pump A10VG + A10VG

12

STM

MC+

SoftwareFGRBB-3

RS 232

Acceleratorpedal

Inchingpedal

Travel direction:forwards/neutral/

reverse

Tractive effortlimitation

ConstantSpeed Drive

Control block M7Load sensing and LUDV– Anti-cavitation - pre-charge valve– Electrical float position– Separate tank line with regeneration

Data sheet RE 64291

Variable displacement pump A4VGFor closed circuit travel drives with electro-proportional control. The pump for theimplement hydraulics is fitted to the throughdrive (100% through drive torque).

Data sheet RE 92003

Variable displacement pumpA10VO/A11VOFor open circuit implement hydraulicscontrolled via a microcontroller

Data sheets RE 92701 (A10VO)and RE 92500 (A11VO)

Variable displacement motor A6VMFor closed circuit transmission with electro-proportional control

Data sheet RE 91604

Implement hydraulics

RPM

Electronic control

Electronics for travel controls

Electronic control for implement hydraulics

A4VG A10VO/A11VO A6VM

BB-3 SoftwareBodem

Controlblock M7 Micro-

controller

Dieselmotor

A4VG A10VO/A11VO

Posi

tion

com

man

d va

lue

Posi

tion

actu

al v

alue


Electricalactuator


13

BB-3

BODEM

Microcontroller MC7 + Software FGREncapsulated microcontroller for mobileapplicationsSoftware with load limiting control for hydro-static transmission with automotive speedcontrol

Data sheets RE 95050, RE 95057

Electronic amplifier cards MHVA, MHVT

Data sheets, RE 29875, RE 29880,RE 29882, RE 29883

Electronic travel controlsk Direction of travel pre-selection

k Pre-set speed

k Acceleration/deceleration pre-selection

k Drive characteristics

– Working mode: flat characteristic curve

– Travel mode: steep characteristic curve

k Load limiting control

k Inching/braking function

k Over-speed safety for the engine

k Hydraulic motor adjustment device

– Electronic DA control

– Vg max circuit

Additional functions

k Tractive effort limitation

k Speed limitation

– Crawl gear

– Constant speed drive (CSD)

k Fuel economizing driving

k Integration of the service hydraulics

Network via a CAN-bus

Acceleratorpedal

Inchingpedal

Servicehydraulics

SteeringTraveldirection

Tractiveeffort

CSD Dieselmotor

Variabledisplacement

pump

Variabledisplacement

motor

MC + FGRTravel controls

MCService

hydraulics

DisplayProcess monitoring(actual values)

CAN-Bus

PC + Software Bodem

Control panel BB-3

DiagnosticsParameter settingProcessmonitoring

Electronic implement hydraulicsk Optimum levelling capability even due to the Z-kinematics

k Load limitation, i.e. protection against over-loading the bucket

k Weighting facility for the bucket contents

k Diesel motor load limitation

k Matching the working speed to the operator

k Steering control via a joy-stick with a safety switch

k Networking the diesel motor and travel hydraulics via a CAN-bus is possible (see below)

14

80 KW

60 KW

100 KW

30 60 90 120 150 180 210 250

30

25

20

15

10

5

6

5

4

3

2

10,5

Fixed displacement pumps Variable displacement pumps

Fixed displacementpump G2/G3

For further information see datasheets RE 10030 and RE 10039

Variable displacementpump A10VO/3

For further information seedata sheet RE 92701

Implement hydraulics for wheel loaders

Boom

Buck

et

Stee

ring

Boom

Buck

et

Stee

ring

Unl

aden

wei

ght o

f uni

t (t)

Buck

et v

olum

e (m

3)

Drive power (kW)

15

Fixed or variable displacement pumpsfor the implement hydraulics can be mountedonto the through drive of (100% throughdrive torque) the variable displacement traveldrive pump. A splitter box is not required.

Control block M7Load sensing and LUDV– Electrical float position– Separate tank line with regenerationData sheet RE 64291

Control block M1 and MOOpen center control– Electrical float position– Regeneration valveData sheets RE 64263 and RE 64266

Pilot control units 4THF6, 5THF6, 4TH6,2TH6– Electrical or mechanical detent– Float position functionData sheets RE 64522, 64553, 64555

Steering units LAGUV and LSPSD– Amplification and conversion for emergency operation– Priority valveData sheet RE 14365

Cartridge valves and complete controlblocks Data sheet RE 00182

Drive with variable displacement pump

Drive with fixed displacement pump

Controlblock

Dieselmotor

Priorityvalve

Dieselmotor

Priorityvalve

Controlblock

16

Slew

Support

Boom

Dipper

BucketH

oist

Buck

et

Addi

tiona

leq

uipm

ent

Fixed displacement pumps G2/G3

For further information see data sheetsRE 10030 and RE 10039

Variable displacement pumps A10VO/3

For further information see data sheetRE 92701

Fixed or variable displacement pumpsfor the implement hydraulics can be mountedonto the through drive of (100% throughdrive torque) the variable displacement traveldrive pump

A splitter box is not required

Control block M1 and MOOpen center control– Electrical float position– Regeneration valve

For further information see data sheetsRE 64263 and RE 64266

Control block M7Load sensing and LUDV– Electrical float position– Separate tank line with regeneration


Pilot control units 4THF6, 5THF6, 4TH6,2TH6– Electrical or mechanical detent– Float position function

For further information see data sheetsRE 64522, RE 64553, RE 64555

Steering units LAGUV and LSPSD– Amplification and conversion for emergency operation– Priority valve


Cartridge valves and complete controlblocks


Boom

/tilt

Tele

scop

e

Leve

l com

pens

atio

n

Addi

tiona

l equ

ipm

ent

Supp

ort

Implement hydraulics for backhoe loaders

Service hydraulics for telescopic loaders



Dieselmotor

Loader control blockwith priority valve

Cont

rol b

lock

exc

avat

or

Loader control blockwith priority valve

Dieselmotor

17

Diesel

Diesel

Diesel

Hydraulic remotely powered brake

Brake lightswitch

Accumulator pressurewarning switch

Brake pedal

Accumulatorpressure warning

Accumulatorloading valve

Additional (optional)actuators

Brake pedal

Spring loadedaccumulator

2 circuit brakevalve

Parking brakevalve

Additional (optional)actuators

2 circuit brakevalve

Brake lightswitch

Parking brakevalve

Accumulatorloading valve

Spring loadedaccumulator

Compact design

k Piping reduced to a minimum

k Parking brake electrically actuated

k Possibility of directly mounting the accumulator

k Sensitive metering

Compact brake blockLT13, Data sheet RE 66220

Accumulator loadingvalve LT06, Data sheetRE 66191

Compact brake blockLT17, (for mounting inthe drivers cab) Data sheet RE 66222

1 circuit remotelypowered brake valveLT05, Data sheet RE 66144

Inching brake valveLT31, Data sheet RE 66226

Modular design

k Components have a low space requirement

k Components can be located wherever required

k Sensitive metering

k Quickly ready for operation

18

EF

P

1234

6

5

Service hydraulicsPriority valve

High pressure (not metered)High pressure (metered)Low pressureSuction pressureEntrapped oilAmbient pressure

Steering systems

k Open centre steering with non reaction

k Closed centre steering with non reaction (load sensing dynamic)

Non reaction means that the occurring wheelforces do not act on the steering wheel viathe steering hydraulics

LAG and LAS

Steering with chamber isolation - servo operation

RSM valve

Logic valve

LFA-D2 valve4/2-way directionalvalveDBD valve(design tested)Accumulator

The Rexroth stabilisation system RSM is builtinto the lift cylinders of the wheeled loadersand dampens out the pitching oscillationswhich occur whilst the vehicle is moving.The installation of the RSM system in wheelloaders result in the following furtheradvantages:

k Shorter braking distances

k Stable steering characteristics

k Higher transport speeds

k Higher transfer rates

k Greater comfort for driver

k Lower repair costs or idle times

Steering

Stabilisation module RSMFor further information see data sheetRE 64615

RSM System

19

B

A

B

A

B

A

Filter ratingTo guarantee the functional safety of the axialpiston units the following cleanlinessclasses are the minimum requirementsnecessary of the pressure fluids

k 9 to NAS 1638k 6 to SAEk 18/15 to ISO/DIS 4406

For very high pressure fluid temperatures(90° C up to a maximum of 115°C) thefollowing cleanliness classes are the minimumrequirement

k 8 to NAS 1638k 5 to SAEk 17/14 to ISO/DIS 4406

The finer the filtration the better the fluidcleanliness class obtained and the higher theservice life of the axial piston units.

Use filter without bypass.Recommendation: use clogging indicators.

Further information regarding filtration of thepressure fluids can be found in the pumpdata sheets.

Standard: suction filtration(A4VG / A10VG)

Variant: pressure filtration(A4VG / A10VG)

Optimum cold start conditions for pressure filtration isachieved via the integrated filter short circuit valve

Variant: suction/return filtration

Advantages k Low space requirementsk Improved suction characteristics

Return oil from theimplement hydraulics

FiltrationCriteria for the functional safety of axial piston units

Drive and Control

Stabilisation module RSMFor dampening the pitchingmovements which occur duringoperation


Components

Variable displacement pumpA4VGClosed circuitNominal pressure 400 barPeak pressure 450 bar

For further information see data sheet RE 92003

Variable displacement pumpA10VOOpen circuitNominal pressure 280 barPeak pressure 350 bar


Variable displacement motorA6VMOpen and closed circuitNominal pressure 400 barPeak pressure 450 bar


Variable displacement pumpA11VOOpen circuitNominal pressure 350 barPeak pressure 400 bar


Control blocksSM 12/18 RE 64122/124SP 12/18 RE 64145/148SX 18 RE 64127M1-16/22/32 RE 64263M7-22 RE 64287

Pilot control units4/5THF6 RE 645534TH6 RE 645552-2TH6 RE 64552

Brueninghaus Hydromatik GmbHGlockeraustraße 2D–89275 Elchingen, GermanyTel +49 (0) 7308 820Fax +49 (0) 7308 7274

Mannesmann Rexroth AGRexroth HydraulicsJahnstraße 3-5D–97816 Lohr am Main, GermanyTel +49 (0) 9352 180Fax +49 (0) 9352 181040

Control block M7Load sensing and LUDV


Radial piston motor MCRClosed circuitNominal pressure 400 barPeak pressure 450 bar

For further information seedata sheets RE 15205to 15210

RE 9

8056

/04.

98

drive and control systems for loaders

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