Functional Description - Engagement Elements (Brakes And Clutches)
There are five engagement elements divided as follows:
| Brakes | A | B | |
| Clutches | C | D | E |
The clutches and brakes operate as follows:
- Multiple-disc clutches C, D and E transmit the engine torque to the epicyclic gear train while brakes A and B offload the engine torque to the transmission housing.
- The engagement elements are hydraulically closed. The fluid pressure compresses the disc pack to engage the clutch. When the hydraulic pressure decreases, the diaphragm spring pushes the piston into its rest position.
- The engagement elements serve to engage the gears under load without interrupting the traction force.
- For each gear, three engagement elements are always closed while two engagement elements will always remain open. Each open engagement element creates drag torque which allows an increase in transmission efficiency.
BRAKES
| 1 | Brake B Piston |
| 2 | B1 Chamber |
| 3 | Return Spring |
| 4 | Brake B |
| 5 | Brake A |
| 6 | Return Spring |
- Brake B has a spring pack to return the piston into position.
- Brake A has a diaphragm return spring.
CLUTCHES
| 1 | Piston |
| 2 | Pressure chamber |
| 3 | Hydraulic compensation chamber |
| 4 | Diaphragm |
| 5 | Diaphragm spring |
The dynamic pressure of clutches C, D and E is compensated. The increase in dynamic hydraulic pressure at high speeds is due to the fact that the transmission fluid in the clutch cylinder is subject to considerable centrifugal forces created by the rotation. As a result, the pressure in the clutch cylinder increases in the direction of the maximum radius. This "dynamic pressure generation" is undesirable because increases the pressure and obstructs the defined increase or decrease in the pressure chamber. For the best clutch control, even at high speeds, oil is supplied to both sides of the clutch piston creating a pressure chamber and a pressure compensation chamber. The transmission fluid in the pressure compensation chamber comes from the lubrication ducts and is therefore at low pressure. However, it is subject to the same dynamic pressure increase during rotation due to the centrifugal forces. In this way, the clutch piston contact pressure is balanced, the shift comfort is significantly improved and safe opening and closing of the clutch is ensured at all speeds.