Differential drive system, more particularly for use in a power train of a motor vehicle
A differential drive system for a vehicle includes a differential drive device, a dog clutch device, and an electromagnetic actuator. The axis of rotation of the differential drive device is situated outside of the annular electromagnet of the electromagnetic actuator.
1. A differential drive system for a vehicle, comprising:
a differential drive device comprising a differential casing housing a differential gearset, the differential gearset being able to transmit torque from the differential casing to a first output side shaft and a second output side shaft which each drive a wheel of the vehicle, the first output side shaft and the second output side shaft extending along an axis of rotation X,
a dog clutch device comprising a first coupling member and a second coupling member, the second coupling member being able to be rotationally driven about the axis of rotation X and being able to move axially along the axis of rotation X with respect to the first coupling member so as to engage with the first coupling member or disengage therefrom, the first coupling member being formed by a toothed torque-transmission member of the differential drive device,
an electromagnetic actuator comprising an annular electromagnet able to generate a magnetic field to move a mobile element between a first position associated with the engaged state of the dog clutch device, and a second position associated with the disengaged state of the dog clutch device,
wherein the axis of rotation X is situated outside of the annular electromagnet of the electromagnetic actuator, and the differential drive system further comprises a force-transfer mechanism designed to transfer the forces of actuation of the mobile element of the electromagnetic actuator to the second coupling member of the dog clutch device,
wherein the force-transfer mechanism comprises a pressure plate mounted to slide axially on the differential casing,
wherein the differential casing forms a torque input member of the differential drive device and the differential drive device further comprises a first output member able to be coupled to the first output side shaft, and a second output member able to be coupled to the second output side shaft,
wherein the differential drive system is provided with a disconnection mechanism configured to interrupt the transmission of torque between the differential casing and the differential gearset when the dog clutch device is open,
wherein the first coupling member is radially encompassed by the differential casing, and
wherein the first coupling member forms an auxiliary input member of the differential drive device, the differential gearset being configured to transmit torque between the auxiliary input member and the first and second output members of the differential drive device, the auxiliary input member being mounted with the freedom to rotate with respect to the differential casing and being secured in terms of rotation to the differential casing only when the dog clutch device is closed.
2. The differential drive system as claimed in claim 1 , wherein the second coupling member is able to be rotationally driven about the axis of rotation X with the differential casing.
3. The differential drive system as claimed in claim 1 , wherein the differential casing has holes distributed about the axis of rotation X, and the second coupling member has fingers passing axially through these holes so as to secure, in terms of rotation about the axis of rotation X, the second coupling member and the differential casing.
4. The differential drive system as claimed in claim 1 , wherein the electromagnetic actuator is positioned in such a way that the mobile element moves parallel to the axis of rotation X; and the force-transfer mechanism is mobile, in axial translation along the axis.
5. The differential drive system as claimed in claim 1 , wherein the differential drive system comprises a plurality of electromagnetic actuators, the force-transfer mechanism connecting each electromagnetic actuator to the second coupling member.
6. The differential drive system as claimed in claim 1 , wherein the force-transfer mechanism comprises a pressure plate positioned outside of the differential casing.
7. The differential drive system as claimed in claim 1 , wherein the force-transfer mechanism is configured to increase the force of actuation generated by the actuator by means of a lever arm.
8. The differential drive system as claimed in claim 1 , wherein the actuator is a linear actuator.
9. A differential drive system for a vehicle, comprising:
a differential drive device comprising a differential casing housing a differential gearset, the differential gearset being able to transmit torque from the differential casing to a first output side shaft and a second output side shaft which each drive a wheel of the vehicle, the first output side shaft and the second output side shaft extending along an axis of rotation X,
a dog clutch device comprising a first coupling member and a second coupling member, the second coupling member being able to be rotationally driven about the axis of rotation X and being able to move axially along the axis of rotation X with respect to the first coupling member so as to engage with the first coupling member or disengage therefrom, the first coupling member being formed by a toothed torque-transmission member of the differential drive device,
an electromagnetic actuator comprising an annular electromagnet able to generate a magnetic field to move a mobile element between a first position associated with the engaged state of the dog clutch device, and a second position associated with the disengaged state of the dog clutch device,
wherein the axis of rotation X is situated outside of the annular electromagnet of the electromagnetic actuator, and the differential drive system further comprises a force-transfer mechanism designed to transfer the forces of actuation of the mobile element of the electromagnetic actuator to the second coupling member of the dog clutch device,
wherein the differential casing forms a torque input member of the differential drive device and the differential drive device further comprises a first output member able to be coupled to the first output side shaft, and a second output member able to be coupled to the second output side shaft,
wherein the differential drive system is provided with a disconnection mechanism configured to interrupt the transmission of torque between the differential casing and the differential gearset when the dog clutch device is open,
wherein the first coupling member is positioned inside of the differential casing, and
wherein the first coupling member forms an auxiliary input member of the differential drive device, the differential gearset being configured to transmit torque between the auxiliary input member and the first and second output members of the differential drive device, the auxiliary input member being mounted with the freedom to rotate with respect to the differential casing and being secured in terms of rotation to the differential casing only when the dog clutch device is closed,
wherein the force-transfer mechanism comprises a pressure plate positioned outside of the differential casing, and
wherein the force-transfer mechanism comprises a pivoting lever able to push the pressure plate.
10. The differential drive system as claimed in claim 9 , wherein the force-transfer mechanism comprises a first contact zone collaborating with the mobile element of the electromagnetic actuator and moving with same; and a second contact zone collaborating with the second coupling member and moving axially with same.
11. The differential drive system as claimed in claim 9 , wherein the pivoting lever comprises an annular portion arranged around the axis of rotation X.
12. The differential drive system as claimed in claim 9 , wherein the force-transfer mechanism comprises a first part and a second part able to rotate relative to one another about the axis of rotation X.
13. The differential drive system as claimed in claim 9 , wherein the annular electromagnet is positioned around an axis, this axis being offset from the axis of rotation X and the axis of rotation X being positioned, with respect to the axis of the electromagnet, radially outside of the annular electromagnet.
14. A transmission system comprising a reduction gearbox housed in a reduction gearbox casing and a differential drive system as claimed in claim 9 , the electromagnetic actuator being positioned outside of the reduction gearbox casing.
15. The differential drive system as claimed in claim 9 , wherein the differential casing has holes distributed about the axis of rotation X, and the second coupling member has fingers passing axially through these holes so as to secure, in terms of rotation about the axis of rotation X, the second coupling member and the differential casing.
16. The transmission system as claimed in claim 14 , wherein the differential casing is configured to be guided in the reduction gearbox casing by a rolling contact bearing.
17. The differential drive system as claimed in claim 9 , wherein the actuator is a linear actuator.