Double clutch system
| Item | Description |
|---|---|
| 1 | Clutch unit |
| 2 | Clutch A actuator lever |
| 3 | Guide sleeve |
| 4 | Clutch B actuator lever |
| 5 | Engagement bearing |
| 6 | Snap ring |
The clutch system consists of:
- the clutch unit
- the engaging unit
- the two lever actuators, each of which is actuated by a brushless DC clutch actuator motor.
The clutch unit is connected to the two input shafts of the transmission and attached to the drive plate with nuts. The nuts need to be removed from the drive plate if the transmission is removed.
Clutch unit
Sectional view
| Item | Description |
|---|---|
| 1 | Drive plate |
| 2 | Pressure Plate A - 1st gear, 3rd gear and 5th gear. |
| 3 | Driving disc |
| 4 | Clutch discs |
| 5 | Pressure Plate B - 2nd gear, 4th gear, 6th gear and reverse gear. |
| 6 | Torsion damper |
| 7 | Input shaft B hub |
| 8 | Input shaft A hub |
| 9 | Bearings of the driving disc |
The double clutch is designed to be open in the rest state. This type of clutch is referred to as an "active clutch". On an active clutch, the contact pressure is zero if no force or only a small force is applied at the lever springs.
The clutches are equipped with an internal travel-controlled wear adjustment system in order to keep the necessary actuator travel paths and therefore the required packaging space within tight limits.
Similar to many other dry clutch designs, torsional vibration dampers are integrated in the clutch discs.
The driving disc of the double clutch rides on a bearing that is pressed on the end of Input shaft B.
Schematic diagram of the open and closed clutch
| Item | Description |
|---|---|
| A | Clutch in the rest state (open) |
| B | Clutch A closed |
| 1 | Pressure plate B |
| 2 | Clutch disc B |
| 3 | Driving disc |
| 4 | Pressure plate A |
| 5 | Clutch disc A |
| 6 | Input shaft A |
| 7 | Input shaft B |
| 8 | Lever spring B |
| 9 | Lever spring A |
The two lever springs open the clutches in the rest state. They are closed through actuation of the relevant engaging bearing, which acts on the corresponding lever spring. By pressing the lever springs, the relevant pressure plate is pressed against the clutch disc and the driving disc.
Engaging unit
Sectional view
| Item | Description |
|---|---|
| 1 | Engaging bearing B Comments: Actuates the lever spring B of clutch |
| 2 | Engaging bearing A Comments: Actuates the lever spring A of clutch |
| 3 | Compensating element |
| 4 | Guide sleeve |
The two engaging bearings are accommodated by the guide sleeve in such a way that they can be moved independently of each other. The sliding sleeves are slotted for this purpose and engage in segments in each other. The compensating element is used to compensate for any offset to the actuating levers.
The two engaging bearings are each equipped with a hardened engaging disc. This lies loose on the engaging bearing and transmits the axial forces.
Electromechanical lever actuator
| Item | Description |
|---|---|
| 1 | Brushless DC clutch actuator motor |
| 2 | Pressure spring |
| 3 | Recirculating ball nut |
| 4 | Rollers |
| 5 | Engagement lever |
The force required to close the clutches is largely generated by a compression spring via the mechanical system of the lever actuator. This force acts on the outer end of the engaging lever. This has the form of a rocker. The rollers form the central point of contact of the engagement lever.
The brushless DC clutch actuator motors are bolted directly onto the transmission clutch housing. The DC clutch actuator motor drives the threaded bar of the ball screw via gear teeth. Through rotation of the threaded rod, the recirculating ball nuts and thus the rollers are moved in an axial direction.
Function of the electromechanical lever actuator
| Item | Description |
|---|---|
| A | Clutches open Comments: Brushless DC clutch actuator motor de-energized |
| B | Clutch B closed Comments: Brushless DC clutch actuator motor energized |
| 1 | Brushless DC clutch actuator motor |
| 2 | Pressure spring |
| 3 | Ball screw drive |
| 4 | Rollers |
| 5 | Engagement lever |
When the DC clutch actuator motor is de-energized the clutch is open. In order to close the clutch, the DC clutch actuator motor is actuated by the TCM. As a result of the rotation of the ball screw, the roller is moved downwards via the recirculating ball nut. Due to this axial movement of the rollers, the central support point of the engaging lever is displaced, as a result of which the leverage is altered. The change in leverage in turn causes the force which acts via the engaging lever and the engaging bearing on the lever spring of the clutch to be increased. The engaging bearing presses against the lever spring and the clutch is pressed into the closed position.
In order to hold the clutch in the closed position, a holding current is applied to the DC clutch actuator motor.
As soon as the holding current is switched off by the TCM, the lever springs will slacken and the clutch will open. Through the release of the lever springs, the engaging bearing and the engaging lever are rotated back. When the engaging lever is rotated back, the shape of the engaging lever ensures that the rollers return to their starting position.