The present disclosure relates to a limited-slip clutch system and method. In one aspect, the limited-slip clutch actuation system can include a hydraulic pump operated by a variable speed drive wherein the pump can be configured to generate hydraulic flow in a hydraulic circuit including an actuation branch line that actuates a clutch. The circuit may also include a flow regulating valve for regulating a hydraulic fluid flow rate through the hydraulic circuit wherein the flow regulating valve can be configured to prevent the hydraulic fluid flow rate from exceeding a set maximum flow rate regardless of a magnitude of the hydraulic pressure in the hydraulic circuit. In operation, the pump speed can be controlled based on a command pressure set point and the measured pressure in the actuation branch line and to minimize operational costs by operating the pump at a transition region of the system pressure-pump speed curve.

A method of operating a transmission of a vehicle drive train is provided. The transmission comprises at least one interlocking shift element and at least one frictional shift element. The method comprises receiving a command for the at least one interlocking shift element to move to an engaged position, and applying a first pressure of fluid to the at least one interlocking shift element. The first pressure of fluid is less than a maximum engagement pressure. A second pressure of fluid to the at least one frictional shift element is pulsed. It is then determined whether the interlocking shift element has moved to the engaged position. The first pressure of fluid is then increased towards the maximum engagement pressure once it has been determined that the shift element is in the engaged position.

A hydraulic circuit for a transmission includes a friction element that engages or disengages an operating element of the transmission, a pump that pumps oil to form preliminary pressure that allows the friction element to be maintained in a standby state in which the friction element is ready to operate, and a direct control valve that receives the oil that has passed through the pump and adjusts the preliminary pressure to form operating pressure that allows the friction element to operate, when operating the friction element. The friction element includes a hydraulic chamber into which the oil is introduced, a first supply hole through which the oil that has passed through the pump is supplied to the hydraulic chamber, and a second supply hole through which the oil that has passed through the direct control valve is supplied to the hydraulic chamber.

A hydraulic circuit for a transmission includes a friction element that engages or disengages an operating element of the transmission, a pump that pumps oil to form preliminary pressure that allows the friction element to be maintained in a standby state in which the friction element is ready to operate, and a direct control valve that receives the oil that has passed through the pump and adjusts the preliminary pressure to form operating pressure that allows the friction element to operate, when operating the friction element. The friction element includes a hydraulic chamber into which the oil is introduced, a first supply hole through which the oil that has passed through the pump is supplied to the hydraulic chamber, and a second supply hole through which the oil that has passed through the direct control valve is supplied to the hydraulic chamber.

A hydraulic control device with a second oil passage check valve provided in the second oil passage between a connection portion with the first oil passage and the second solenoid valve, the second oil passage check valve being configured such that a hydraulic pressure is supplied in a direction from the second solenoid valve toward the first oil passage and a hydraulic pressure is not supplied in the opposite direction.

A hydraulic control device for an automatic transmission including a valve device. The valve device comprising a switching valve, featuring a switching component and a check valve. The switching valve is formed in a housing and is hydraulically connected to a first pressure adjusting device and a second pressure adjusting device along with a shift element for transferring a certain torque. The switching valve is formed as a directional seat valve.

The invention relates to, in essence, a positive engaged infinitely variable transmission combining a 90 planetary axial gear (differential) with a double radial planetary gear so, the sun gear of the first planetary gear system is solidary to the second planetary gear assemblie sun gear, and that the ring gear of the first planetary gear system is solidary with the planet carrier of the second planetary gear system offering a inertial configuration, or. By combining an axial gear system at 180, equivalent to a double radial planetary gearbox (the second planet gear is used to change the motion vector between 90 and 180) to a second axial gear system, uniting the first sun gear with the second sun gear and, the first ring gear with the second planet carrier.

The first planet carrier, which is now the anchor point of the system, is geared to a hydraulic loop with a flow valve that controls it at will.