A hydraulically actuatable shift element (100) includes a clutch piston (101), a fast fill piston (102), a fast fill valve (103), a fast fill pressure chamber (126), and a clutch pressure chamber (117). The fast fill valve (103) includes a sealing body (132) and a control body (131). Before the actuation of the shift element (100), the sealing body (132) is in a first switching position, in which the fast fill pressure chamber (126) is connected to a pressurized oil source (108) and, after the actuation of the shift element (100) in a second switching position, seals off the fast fill pressure chamber (126) with respect to the rest of the hydraulic system. The control body (131) has a first pressure surface (A18) and a second pressure surface (A19), wherein, in the first switching position, only the first pressure surface (A18) is pressurizable from the pressurized oil source (108). The fast fill valve (103) is configured such that, in the second switching position or between the first switching position and the second switching position of the control body (131), the second pressure surface (A19), in addition to the first pressure surface (A18), is pressurizable.

An automatic transmission with a brake is provided, the brake including a hub member coupled to a transmission case. The hub member includes a first hub member having a cylindrical part spline-engaged with friction plates and the transmission case, and forming a disengagement hydraulic chamber, a second hub member disposed at one side of the first hub member in the axial direction, fitted into the transmission case, and coupled to the one side of the first hub member in the axial direction by a first coupling member, and a third hub member disposed at the other side of the first hub member in the axial direction, coupled to the other side of the first hub member in the axial direction by a second coupling member, and forming an engagement hydraulic chamber. The first coupling member and the second coupling member are disposed radially inward of the disengagement hydraulic chamber.

An automatic transmission with a brake is provided, the brake including a hub member coupled to a transmission case. The hub member includes a first hub member having a cylindrical part spline-engaged with friction plates and the transmission case, and forming a disengagement hydraulic chamber, a second hub member disposed at one side of the first hub member in the axial direction, fitted into the transmission case, and coupled to the one side of the first hub member in the axial direction by a first coupling member, and a third hub member disposed at the other side of the first hub member in the axial direction, coupled to the other side of the first hub member in the axial direction by a second coupling member, and forming an engagement hydraulic chamber. The first coupling member and the second coupling member are disposed radially inward of the disengagement hydraulic chamber.

A control method of a continuously variable transmission includes supplying oil pressure to a secondary pulley oil chamber by a source pressure oil pump, and controlling a flow of oil into and from a primary pulley oil chamber by an electric oil pump arranged in an oil passage between the primary pulley oil chamber and the secondary pulley oil chamber. After start-up of the source pressure oil pump, an operation of the electric oil pump is restricted until the oil is filled in the oil passage on the secondary pulley oil chamber side of the electric oil pump. The operation of the electric oil pump is permitted when rotation speed of the electric oil pump reaches a predetermined rotation speed.

A hydraulic controller for a vehicle gearbox is provided. The controller includes a hydraulic actuator which has an oil supply port, a high-pressure hydraulic pump for providing a feed to a high-pressure line, a low-pressure hydraulic pump for providing a feed to a low-pressure line, a hydraulic reservoir for receiving the hydraulic medium from a return line, and a hydraulic control valve. The control valve includes at least three control positions and at least four valve ports. In a first control position, the high-pressure line is fluidly connected to the oil supply port for the regulation of the actuating force of the hydraulic actuator. In a second control position, the low-pressure line is fluidly connected to the oil supply port for the pre-charging of the hydraulic actuator. In a third control position, the hydraulic actuator is fluidly connected to the return line for the return of the hydraulic medium.

A control method of a continuously variable transmission includes supplying oil pressure to a secondary pulley oil chamber by a source pressure oil pump, and controlling a flow of oil into and from a primary pulley oil chamber by an electric oil pump arranged in an oil passage between the primary pulley oil chamber and the secondary pulley oil chamber. After start-up of the source pressure oil pump, an operation of the electric oil pump is restricted until the oil is filled in the oil passage on the secondary pulley oil chamber side of the electric oil pump. The operation of the electric oil pump is permitted when rotation speed of the electric oil pump reaches a predetermined rotation speed.

A work vehicle includes a restrainer vehicle speed setter to set a restrainer vehicle speed, and a switch restrainer to permit switching of the forward/backward travel switching device while a detected vehicle speed is lower than the restrainer vehicle speed and prevent switching of the forward/backward travel switching device while the detected vehicle speed is a high speed not lower than the restrainer vehicle speed.

Methods and systems for improving operation of a vehicle driveline that includes an engine and an automatic transmission with a torque converter are presented. In one non-limiting example, the engine may be stopped while a vehicle in which the engine operates is rolling. A transmission coupled to the engine may be shifted as the vehicle rolls so that vehicle response may be improved if a driver requests an increase of engine torque.

A hydraulic controller for a vehicle gearbox is provided. The controller includes a hydraulic actuator which has an oil supply port, a high-pressure hydraulic pump for providing a feed to a high-pressure line, a low-pressure hydraulic pump for providing a feed to a low-pressure line, a hydraulic reservoir for receiving the hydraulic medium from a return line, and a hydraulic control valve. The control valve includes at least three control positions and at least four valve ports. In a first control position, the high-pressure line is fluidly connected to the oil supply port for the regulation of the actuating force of the hydraulic actuator. In a second control position, the low-pressure line is fluidly connected to the oil supply port for the pre-charging of the hydraulic actuator. In a third control position, the hydraulic actuator is fluidly connected to the return line for the return of the hydraulic medium.

A hydraulically actuatable shift element (100) includes a clutch piston (101), a fast fill piston (102), a fast fill valve (103), a fast fill pressure chamber (126), and a clutch pressure chamber (117). The fast fill valve (103) includes a sealing body (132) and a control body (131). Before the actuation of the shift element (100), the sealing body (132) is in a first switching position, in which the fast fill pressure chamber (126) is connected to a pressurized oil source (108) and, after the actuation of the shift element (100) in a second switching position, seals off the fast fill pressure chamber (126) with respect to the rest of the hydraulic system. The control body (131) has a first pressure surface (A18) and a second pressure surface (A19), wherein, in the first switching position, only the first pressure surface (A18) is pressurizable from the pressurized oil source (108). The fast fill valve (103) is configured such that, in the second switching position or between the first switching position and the second switching position of the control body (131), the second pressure surface (A19), in addition to the first pressure surface (A18), is pressurizable.