Power Flow During Forward Travel, Function - GF27.10-P-3035RFH
Transmission 724.2 in model 205, 253
Power flow with forward travel, general
Power flow refers to the transmission paths of driving powers and torques. The engine torque is transferred to the drive wheels by the mechanical connection of the combustion engine, the electric machine (A79/1), the wet clutch, the automatic transmission and transfer case (model 253), the front axle differential (model 253) and the rear axle differential. Power transmission in the wet clutch ensues through the non-positive connection of the internal and external plates, which are pressed together by the clutch piston. The pressure in the clutch piston is regulated via the wet clutch control solenoid valve (Y3/8y9). The torques generated by the wet clutch are forwarded onto the main shaft via the gear wheels of the individual planetary gear sets with the help of the multidisk clutches and multidisk brakes to match the transmission ratio and actuated shift elements.
A reduction of the output speed in the low gears provides lower vehicle speeds while at the same time increasing drive torques at the drive wheels.
Depending on the operating condition of the hybrid drive system, the vehicle is driven by either the combustion engine or the electric machine or through a combination from both major assemblies.
Shown is power flow in 1st gear
1st gear power flow
The following multidisk brakes and multidisk clutches are engaged:
- Multidisk brake B2 (43)
- Multidisk brake B3 (45)
- Multidisk clutch K3 (48)
In 1st gear, the power flows through the following gear sets:
- Ravigneaux gear set
The small annulus gear (5) is driven via the drive shaft. The long planetary gears (50) drive the short planetary gears (49) which roll in the stalled large ring gear (8). An increased torque and reduced RPM occur as a result which are transmitted to the dual planet carrier (6).
- Rear single planetary gear set
The ring gear (9) rotates at the same speed due to the mechanical connection to the dual planet carrier (6). The planetary gears (51) roll over the stalled sun gear (11) and transmit the rotary motion to the planet carrier (10).
- Front single planetary gear set
The ring gear (12) has a mechanical connection to the planet carrier (10) and rotates at the same speed. The planetary gears (52) roll on the stalled sun gear (14) and transfer the subsequently increased torque and reduced rotational speed to the main shaft via the planet carrier (13). The main shaft therefore rotates in the direction of engine rotation with reduced input speed.
Shown is power flow in 2nd gear
2nd gear power flow
The following multidisk brakes and multidisk clutches are engaged:
- Multidisk brake B1 (42)
- Multidisk brake B2 (43)
- Multidisk clutch K3 (48)
Power flow in 2nd gear takes place via the following gear sets:
- Ravigneaux gear set
The small annulus gear (5) is driven via the drive shaft. The long planetary gears (50) roll over the stalled sun gear (7) and transmit the increased torque and reduced rotational speed as a result to the dual planet carrier (6).
- Rear single planetary gear set
The ring gear (9) rotates at the same speed due to the mechanical connection to the dual planet carrier (6). The planetary gears (51) roll over the stalled sun gear (11) and transmit the rotary motion to the planet carrier (10).
- Front single planetary gear set
The ring gear (12) has a mechanical connection to the planet carrier (10) and rotates at the same speed. The planetary gears (52) roll on the stalled sun gear (14) and transfer the subsequently increased torque and reduced rotational speed to the main shaft via the planet carrier (13). The main shaft therefore rotates in the direction of engine rotation with reduced input speed.
Shown is power flow in 3rd gear
3rd gear power flow
The following multidisk brakes and multidisk clutches are engaged:
- Multidisk brake B2 (43)
- Multidisk clutch K1 (46)
- Multidisk clutch K3 (48)
Power flow in 3rd gear takes place via the following gear sets:
- Ravigneaux gear set
The components of the Ravigneaux gear set are interlocked with each other by the switched multidisk clutch K1 (46) and pass on the transmission input torque and the input speed unchanged to the ring gear (9).
- Rear single planetary gear set
The ring gear (9) drives the planetary gears (51). These roll over the stalled sun gear (11) and transmit the rotary motion to the planet carrier (10).
- Front single planetary gear set
The ring gear (12) has a mechanical connection to the planet carrier (10) and rotates at the same speed. The planetary gears (52) roll on the stalled sun gear (14) and transfer the subsequently increased torque and reduced rotational speed to the main shaft via the planet carrier (13). The main shaft therefore rotates in the direction of engine rotation with reduced input speed.
Shown: power flow in 4th gear
4th gear power flow
The following multidisk brakes and multidisk clutches are engaged:
- Multidisk brake B2 (43)
- Multidisk clutch K1 (46)
- Multidisk clutch K2 (47)
In 4th gear, the power flows through the following gear sets:
- Ravigneaux gear set
The components of the Ravigneaux gear set are interlocked with each other by the switched multidisk clutch K1 (46) and pass on the transmission input torque and the input speed unchanged to the ring gear (9).
- Rear single planetary gear set
The engaged multidisk clutch K2 (47) means that the RPM of the ring gears (9, 12) are the same. As a result the rear single planetary gear set is locked and not actively involved in the gear ratio.
- Front single planetary gear set
The closed multidisk clutch K2 (47) is used to drive the ring gear (12) with the input speed. The planetary gears (52) roll on the stalled sun gear (14) and transfer the subsequently increased torque and reduced rotational speed to the main shaft via the planet carrier (13). The main shaft therefore rotates in the direction of engine rotation with reduced input speed.
Shown: power flow in 5th gear
5th gear power flow
The following multidisk clutches are engaged:
- Multidisk clutch K1 (46)
- Multidisk clutch K2 (47)
- Multidisk clutch K3 (48)
In 5th gear, power flows from the input shaft through the blocked Ravigneaux gear set and blocked front single planetary gear set to the main shaft. This rotates at the input speed in the direction of engine rotation.
Shown is power flow in 6th gear
Power flow in 6th gear
The following multidisk brakes and multidisk clutches are engaged:
- Multidisk brake B1 (42)
- Multidisk clutch K2 (47)
- Multidisk clutch K3 (48)
The power flow in 6th gear takes place via the following gear sets:
- Ravigneaux gear set
The small annulus gear (5) is driven via the drive shaft. The long planetary gears (50) roll over the stalled sun gear (7) and transmit the increased torque and reduced rotational speed as a result to the dual planet carrier (6).
- Rear single planetary gear set
The ring gear (9) rotates at the same speed due to the mechanical connection to the dual planet carrier (6). The planetary gears (51) transmit the rotary motion to the sun gear (11). Sun gear (11) passes on the rotational speed to sun gear (14) via the closed multidisk clutch K3 (48).
- Front single planetary gear set
The transmission input torque and input speed are transmitted to the ring gear (12) by the closed multidisk clutch K2 (47). The speed difference between the sun gear (14) and ring gear (12) results in a speed increase and torque reduction. These are passed on via the planet carrier (13) to the main shaft. The main shaft therefore rotates with an increased input speed in the direction of engine rotation.
Shown: Power flow in 7th gear
7th gear power flow
The following multidisk brakes and multidisk clutches are engaged:
- Multidisk brake B3 (45)
- Multidisk clutch K2 (47)
- Multidisk clutch K3 (48)
In 7th gear, the power flow occurs through the following gear sets:
- Ravigneaux gear set
The small annulus gear (5) is driven via the drive shaft. The long planetary gears (50) drive the short planetary gears (49) which roll in the stalled large ring gear (8). The increased torque and reduced rotational speed as a result are transmitted to the dual planet carrier (6).
- Rear single planetary gear set
The ring gear (9) rotates at the same speed due to the mechanical connection to the dual planet carrier (6). The planetary gears (51) transmit the rotary motion to the sun gear (11). Sun gear (11) passes on the rotational speed to sun gear (14) via the closed multidisk clutch K3 (48).
- Front single planetary gear set
The transmission input torque and input speed are transmitted to the ring gear (12) by the closed multidisk clutch K2 (47). The speed difference between the sun gear (14) and ring gear (12) results in a speed increase and torque reduction. These are passed on via the planet carrier (13) to the main shaft. The main shaft therefore rotates with an increased input speed in the direction of engine rotation.
| Overview of system components for automatic transmission hybrid drive | GF27.10-P-9993RFH |