Hydro-mechanical clutch for a hybrid transmission and method for operating the same
View Patent ↗A clutch assembly and method of operating the clutch assembly to start an engine of a hybrid vehicle includes a first clutch and a first clutch actuator for selectively engaging the first clutch. The first actuator has a first at-rest position engaging the clutch and a hydraulically charged position disengaged from the first clutch. The clutch assembly further includes a second clutch actuator having a second at-rest position away disengaged from the first clutch and a second hydraulically charged position engaged with the first clutch.
1. A clutch assembly comprising:
a first clutch disk;
a first clutch actuator for selectively engaging the first clutch disk, said first clutch actuator having a first at-rest position engaging the first clutch disk and a first hydraulically-charged position disengaged from the first clutch disk; and
a second clutch actuator having a second at-rest position away disengaged from the first clutch and a second hydraulically-charged position engaged with the first clutch disk, wherein the first clutch actuator contacts the first clutch disk independent from the second clutch actuator.
2. A clutch assembly as recited in claim 1 wherein the first clutch actuator comprises a first spring, said first spring positioning the first clutch actuator to the first at-rest position.
3. A clutch assembly as recited in claim 2 wherein the first at-rest position corresponds to an engine starting position.
4. A clutch assembly as recited in claim 1 wherein the first clutch actuator comprises a first piston and a first spring, said first spring biasing the piston to the at-rest position.
5. A clutch assembly as recited in claim 1 wherein the second clutch actuator comprises a second spring, said second spring positioning the second actuator to the second at-rest position.
6. A clutch assembly as recited in claim 1 wherein the second clutch actuator comprises a second piston and a second spring, said second spring biasing the piston to the at-rest position.
7. A clutch assembly as recited in claim 6 wherein the second at rest position corresponds to an engine starting position.
8. A clutch assembly as recited in claim 1 further comprising a second clutch and a third clutch actuator engaging the second clutch.
9. A transmission assembly comprising:
a clutch assembly as recited in claim 1 ;
a transmission shaft; and
a plurality of gears selectively coupled to the transmission shaft by the clutch assembly.
10. A transmission assembly as recited in claim 9 comprising:
a first electric motor; and
a second electric motor.
11. A transmission assembly as recited in claim 10 wherein the clutch assembly is disposed axially between the first electric motor and the second electric motor.
12. A hybrid vehicle comprising:
an engine; and
the transmission of claim 11 disposed within the first housing.
13. A hybrid vehicle as recited in claim 12 wherein the first clutch actuator comprises a first spring, said first spring biasing the first clutch actuator toward said first clutch disk to start the engine.
14. A hybrid vehicle as recited in claim 12 wherein the first clutch actuator is hydraulically biased away from the first clutch disk after the engine started.
15. A method of starting a vehicle having an engine comprising:
engaging a first clutch disk in a transmission with a first clutch actuator when the engine is not started;
starting the engine;
generating a hydraulic force to move the first clutch actuator after starting the engine; and
operating the transmission by selecting engaging the first clutch disk with a second clutch actuator, said first clutch actuator having an at-rest position in which the first clutch actuator contacts the first clutch disk independent from the second clutch actuator.
16. A method as recited in claim 15 wherein engaging a first clutch disk comprises engaging the first clutch disk with a piston positioned by a spring force.
17. A method as recited in claim 16 wherein generating a hydraulic force comprises generating the hydraulic force to overcome the spring force after the engine is started.
18. A method as recited in claim 16 wherein in response to the hydraulic force, disengaging the piston from the first clutch disk.
19. A method as recited in claim 16 wherein starting the engine comprises starting the engine with a motor located in transmission housing with the first clutch disk.
20. A method as recited in claim 16 further comprising operating the transmission with the first clutch disk and a second clutch after disengaging the first clutch disk.