A line pressure control method for a double clutch transmission (DCT) includes estimating a line pressure, which decreases with stoppage of an electric oil pump, based on a linear regression model using state variables of the DCT that are related to a line pressure change, and driving the electric oil pump when the line pressure estimated based on the linear regression model reaches a predetermined lower limit.

A hydraulic transformer clutch employs radial hydraulic piston assemblies with integrated electrohydraulic actuation. The hydraulic transformer clutch includes: an output shaft, an output disc affixed to the output shaft for rotation therewith, an input shaft, a rotatable housing affixed to one of the input shaft or the output shaft for rotation therewith, a plurality of hydraulic cylinders, and a plurality of working pistons. The hydraulic cylinders are operatively connected to the rotatable housing, and are spaced about the rotatable housing. Each working piston is slidably mounted within a corresponding hydraulic cylinder of the plurality of hydraulic cylinders, and is positioned to be selectively pushed, when actuated, to create a rigid connection between the input shaft and the output shaft. One or more actuator pistons are pushed by an electromagnet and create pressure that is distributed on working piston surfaces and generates active torque.

An electric oil pump for automobile transmission clutch engagement includes: a temperature sensor that measures a temperature of oil supplied to an oil supply destination relating to clutch engagement of an automobile transmission; an oil pump drive motor; a current determination part that determines a current value output to the oil pump drive motor to a predetermined current value determined such that the oil pump drive motor is capable of being driven without stopping in a case where the temperature is equal to or less than a predetermined temperature at which a torque of the oil pump drive motor becomes smaller than a load of the oil pump drive motor; and an oil pump that supplies oil to the oil supply destination by the oil pump drive motor being driven based on the determined current value.

A motorcycle clutch assist device including a spring arm arranged for rotation or pivoting inside a housing, a biasing device coupled at one end thereof to an axle of the spring arm and at an opposite end thereof to a spring adaptor, and a shaft, one end of which is fixed to the spring arm and an opposite end of which is fixable to the clutch handle, such that the clutch handle rotates about a central longitudinal axis of the shaft and squeezing the clutch handle transfers torque to the spring arm via the shaft, wherein when the biasing device is aligned with the central longitudinal axis no torque is applied by the biasing device, and squeezing the clutch handle causes the biasing device to move past the central longitudinal axis so that the biasing device applies an auxiliary torque to torque applied by squeezing the clutch handle.

A line pressure control method for a double clutch transmission (DCT) includes estimating a line pressure, which decreases with stoppage of an electric oil pump, based on a linear regression model using state variables of the DCT that are related to a line pressure change, and driving the electric oil pump when the line pressure estimated based on the linear regression model reaches a predetermined lower limit.

A hydraulic transformer clutch employs radial hydraulic piston assemblies with integrated electrohydraulic actuation. The hydraulic transformer clutch includes: an output shaft, an output disc affixed to the output shaft for rotation therewith, an input shaft, a rotatable housing affixed to one of the input shaft or the output shaft for rotation therewith, a plurality of hydraulic cylinders, and a plurality of working pistons. The hydraulic cylinders are operatively connected to the rotatable housing, and are spaced about the rotatable housing. Each working piston is slidably mounted within a corresponding hydraulic cylinder of the plurality of hydraulic cylinders, and is positioned to be selectively pushed, when actuated, to create a rigid connection between the input shaft and the output shaft. One or more actuator pistons are pushed by an electromagnet and create pressure that is distributed on working piston surfaces and generates active torque.

A drive force transmission apparatus is mountable on a four-wheel drive vehicle switchable between a four-wheel drive mode that transmits a drive force of an engine to front wheels and rear wheels, and a two-wheel drive mode that transmits the drive force to only the front wheels. The drive force transmission apparatus allows adjustment of the drive force to the rear wheels, and includes a multi-plate clutch, a piston for axially pressing the multi-plate clutch, an actuator for axially moving the piston, and a control unit for controlling the actuator. Upon satisfaction of a predetermined condition that indicates a high probability of the vehicle needing to be switched from the two-wheel drive mode to the four-wheel drive mode, the control unit causes the actuator to displace the piston by a predetermined amount with respect to an initial position of the piston toward the multi-plate clutch.

In a coasting control process, an ECU increases line pressure PL of a hydraulic path to predetermined pressure P1 such that discharge pressure of an MOP becomes higher than that before a C1 clutch is disengaged at timing when an executing condition of coasting control is satisfied (time t=t1). According to such coasting control process, driving torque of the MOP increases, so that deceleration (deceleration G) caused by driving of the MOP by a drive wheel becomes larger than that in conventional coasting control in which the discharge pressure of the MOP is not increased. As a result, it is possible to inhibit a driver from feeling discomfort due to free-running feeling generated during the coasting control.

A transmission includes a selectable one-way clutch with active and passive states. Successful transition from the active state to the passive state is only possible when there is no torque tending to cause overrunning. After commanding a transition from the active state to the passive state, a controller partially engages a first friction clutch to induce a torque tending away from overrunning until a lash crossing is detected. Then, the controller releases the first clutch and partially applies a second clutch to induce a torque toward overrunning. When slip is detected, indicating successful achievement of the passive state, the second clutch is released.

A clutch actuating device has an actuating cylinder with piston and rod-side chamber, a multiplier cylinder with piston-side and rod-side chambers separated by a piston, a rod(s) interconnecting the pistons, and a directional control valve. The valve has a pilot port, ports in fluid connection with piston-side and rod-side chambers of the multiplier cylinder, and a port in fluid connection with a secondary source. When a first fluid pressure (P1) from a first pressure source is applied to the pilot port and rod-side chamber of the actuating cylinder, a second fluid pressure (P2) is applied to the piston-side chamber of the multiplier cylinder by the secondary source. This results in the first and second fluid pressures (P1 and P2) acting on the piston of the actuating cylinder to produce a clutch actuation fluid pressure.