TRANSMISSION FOR A POWERTRAIN SYSTEM

摘要

A transmission includes an input member, a hydraulic pump, a hydraulic circuit, a clutch assembly for transferring torque between the input member and an output member. A mechanically-driven hydraulic pump is rotatably coupled to the input member and is fluidly connected to the hydraulic circuit. The clutch assembly includes a friction clutch pack, a clutch-apply piston, a clutch-release piston and a coned-disc spring. The clutch-release piston is fluidly coupled to a first hydraulic chamber that is fluidly coupled to the hydraulic circuit. The clutch-apply piston is fluidly coupled to a second hydraulic chamber that is selectively fluidly coupled to the hydraulic circuit. A second spring urges the clutch-apply piston and the coned-disc spring urges the clutch-release piston. When the hydraulic pump is not rotating, the clutch assembly is activated by the coned-disc spring urging the clutch-release piston.

主权项

1. A transmission for a powertrain system, comprising:
an input member, a hydraulic pump, a hydraulic circuit, a clutch assembly for transferring torque between the input member and an output member; the hydraulic pump being a mechanically-driven hydraulic pump rotatably coupled to the input member, the hydraulic pump being fluidly connected to the hydraulic circuit; the clutch assembly including a friction clutch pack, a clutch-apply piston, a clutch-release piston and a coned-disc spring; the clutch-release piston being fluidly coupled to a first hydraulic chamber that is fluidly coupled to the hydraulic circuit; the clutch-apply piston being fluidly coupled to a second hydraulic chamber that is selectively fluidly coupled to the hydraulic circuit; a second spring urging the clutch-apply piston; and the coned-disc spring urging the clutch-release piston; wherein when the hydraulic pump is not rotating, the clutch assembly is activated by the coned-disc spring urging the clutch-release piston.