Dual piston transmission clutch
AssigneeCaterpillar Inc.
InventorsKevin G. Meyer, Peter A. Bezjak, Jason R. Allen
Life of this patent
Estimating the term…
Abstract
A transmission assembly may include a first clutch and a second clutch. The second clutch may include a clutch pack, a pressure chamber, a first piston, and a second piston. The first piston may be configured to push against the clutch pack when pressurized fluid is directed into the pressure chamber. The second piston may be configured to push against the first piston when pressurized fluid is directed into the pressure chamber at a time when the first clutch is unactuated and inhibited from pushing against the first piston at a time when the first clutch is actuated.
Claims17
A transmission assembly, comprising:
- a transmission housing;
- a first rotating member disposed radially inward of the transmission housing;
- a second rotating member disposed radially inward of the transmission housing;
- a first clutch, the first clutch including
- a first planet carrier;
- a second planet carrier;
- and
- a first clutch pack configured to rotationally lock the first planet carrier to the second planet carrier when actuated;
- and
- a second clutch, the second clutch including
- a second clutch pack;
- a pressure chamber;
- a first piston configured to push against the second clutch pack when pressurized fluid is directed into the pressure chamber and the second clutch pack being configured to rotationally lock the first rotating member to the second rotating member when pushed on by the first piston;
- and
- a second piston configured to push against the first piston when pressurized fluid is directed into the pressure chamber at a time when the first clutch is unactuated and inhibited from pushing against the first piston at a time when the first clutch is actuated.
A method of operating a transmission, the transmission including a transmission housing, a first rotating member disposed radially inward of the transmission housing, and a second rotating member disposed radially inward of the transmission housing, the method comprising:
- actuating a first clutch by pressurizing a first chamber of a first clutch to generate a first resistive torque on a first clutch pack during a transmission operation in a first gear, the first clutch pack being configured to rotationally lock the first rotating member to the second rotating member when pushed on by a first piston;
- and
- actuating the first clutch and a second clutch during a transmission operation in a second gear to generate a second resistive torque on the first clutch pack less than the first resistive torque, the second clutch including a first planet carrier, a second planet carrier, and a second clutch pack configured to rotationally lock the first planet carrier to the second planet carrier when actuated, by
- pressurizing the first chamber;
- and
- actuating a control valve to direct pressurized fluid to both the second clutch and a second chamber of the first clutch, the pressurized fluid in the second chamber inhibiting a force applied to the first clutch pack to generate the second resistive torque.
A transmission assembly, comprising:
- a housing;
- a sun gear;
- a ring gear;
- a first planet carrier;
- a second planet carrier;
- a first clutch configured to selectively lock the first planet carrier to the sun gear and the ring gear in a first gear and a second gear;
- a second clutch configured to selectively lock the first planet carrier to the second planet carrier in the second gear;
- a first chamber;
- a second chamber;
- a control valve configured to direct pressurized fluid to both the second clutch and the second chamber when the second clutch is activated;
- a first piston configured to push against the first clutch pack with a first force when pressurized fluid is directed into the first chamber during operation of the transmission in the first gear and the second gear;
- and
- a second piston configured to push against the first piston with a second force when pressurized fluid is directed into the first chamber during operation of the transmission in the first gear, and inhibited from pushing against the first piston when pressurized fluid is directed into the second chamber during operation in the second gear, the second force being supplemental to the first force.
Dependencies are inferred from the claim text.