gearbox of tractor puma 210hp

 Gearbox overview

Splitter clutches A-B

Gear clutch C-D-E

Range clutch  F1-F2- F3-R

Clutch 40km ECO 50Km (19th Gear)

Clutch FWD

Clutch PTO                      

                Gears v clutches

• 9 Electro-hydraulically operated clutches

• A, B clutches – Provide high and low output ratios to “speed” section of gearbox.

• C, D, E clutches – Provide 6 speeds in conjunction with A and B clutches.

• S (slow), M (medium), F (fast) and R (reverse) are Range clutches.

Power Flow

5 major groups of components transfer drive from the engine to the rear axle.  This diagram shows the R clutch assembly and idler gear on top of the gearbox for clarity although in reality these are on the right hand side in the gearbox.

• Drive is transferred from the input shaft to the blue components either directly ( if clutch A is engaged ) or via the yellow components  ( if clutch B is engaged ).

•The blue components are coupled to the green components via clutches C, D or E.  When either A or B plus C, D or E are engaged, all the green components will be rotating.  Note that the M clutch assembly is permanently meshed to the R clutch assembly so when reverse is engaged, the M clutch assembly is being used as an idler gear. 

• The green components are linked to the purple components through clutches S, M, F and R.  Note that when S ( slow ) is engaged, the drive is transferred through the M and R clutch assemblies and back through an idler gear to achieve forwards.

• Feathering of drive is controlled by the Range clutches ( S, M, F, R )

Schematic of Clutch pack usage

Power Flow - 1st gear

Engage A clutch

Engage C clutch

Through M clutch assembly

Through R clutch assembly

Through idler gear

Engage S clutch

Output shaft to rear axle

 Power Flow - Reverse 5th gear

Engage A clutch

Engage E clutch

Through M clutch assembly which acts as an idler gear

Engage R clutch

Output shaft to rear axle 

3D of Speed Gears

3D of Range Gears

Torque sensing damper disc

( Shown looking backwards towards the transmission )

 Flywheel lug ( 1 ), Torque / rpm sensor ( 2 ), Transmission input shaft ( 3 ), Damper disc finger ( 4 ), Damper disc spring ( 5 )

• Drive from the engine transferred to the flywheel ( 1 ) which has 4 lugs on its outer edge

• Drive between flywheel and damper disc transferred through the damping springs ( 5 ), through the damper disc to the transmission input shaft ( 3 )

• Damper disc has 4 fingers ( 4 ) which are riveted to its rearward side

• As the transmission spins, the torque / rpm sensor ( 2 ) emits a signal every time a damper disc finger or flywheel lug passes it.

No load

• The damping springs will transfer drive without being compressed

• The short signals produced by the torque / rpm sensor will be half way between the long signal produced by the lugs.

Maximum Torque

• The damping springs will be compressed as the engine “pushes” the transmission round. 

• The short signals produced by the torque / rpm sensor will be shortly before the long signal produced by the flywheel.

• As the torque increases, there will be less time between the damper disc signal and the flywheel signal

• In this way the processor knows the amount of torque being transferred through the transmission

 Overspeed 

• The damping springs will be compressed as the transmission is “pushing”  the engine to go faster e.g. when driving down a hill with a heavily loaded trailer 

• The short signals produced by the torque / rpm sensor will be shortly after the long signal produced by the flywheel.

• As the torque increases, there will be less time between the flywheel signal and the damper disc signal

 In this way the processor knows the amount of torque being transferred back to the engine

TM Transmission Top Cover

1. From steering pump flow divider (lubrication oil)

2. Return from steering motor

3. To oil cooler

4. Return from oil cooler

5. Supplementary lubrication oil from charge circuit

6. To lubrication circuit

7. Low pressure feed for transmission

8. Feed to 19th gear dump solenoid

9. Low pressure supply to brake booster circuit

10. Low pressure oil – low pressure warning switch

11. Transmission oil temperature sensor

12. Range clutches pressure sensors

A. Transmission Clutch A solenoid

B. Transmission Clutch B solenoid

C. Transmission Clutch C solenoid

D. Transmission Clutch D solenoid

E. Transmission Clutch E solenoid

M Medium Range clutch solenoid

F High range clutch solenoid

S Low range clutch solenoid

R Reverse range clutch solenoid

19 19th gear clutch solenoid (50Km/h)

T7000 Transmission Top Cover

Revised pipe routing and connections

Switches have changed position

Transmission oil flows

Make reference to slide 16 ( PWM manifold ) and 17 ( Top cover schematic ).

• Clutches A, E, M  ( 11th gear ) supplied with low pressure oil ( 16 - 18 bar ) via manifolds.  Oil ways in manifolds separated by sealing rings.

• All other clutch oil ways open to sump and have no residual pressure

NB: In neutral, approx. 4 bar of pressure is supplied to the C, D and E clutches.  This locks the gearbox to prevent spin / creep.

Transmission lubrication circuit

•Oil supplied by the steering pump.

•Over pressure is controlled by lubrication relief valve

•Supplied to moving components via manifolds and internal galleries within the gearbox shafts.

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