A lubrication and hydraulic actuation system for a transfer case (120) includes a pump (220), a pump sump (210) formed in the transfer case (120), and having an opening (430) in communication with an interior of the transfer case (120), and a fluid retention element (510, 710). The fluid retention element (510, 710) is disposed in the opening (430) of the pump sump (210) and has at least one baffle structure (550) to allow fluids to enter the pump sump (210) through the fluid retention element (510, 710) and restrain fluids from exiting the pump sump (210) through the fluid retention element (510, 710).

A hydraulic pump with an integrated clutch includes an outer cone coupled to a drive gear or a driven gear and having a frictional inner surface, and an inner cone arranged inside the outer cone, coupled to the drive gear or the driven gear and having a frictional outer surface, wherein the inner and outer cones are rotationally and axially movable with respect to each other. A spring is coupled to the inner cone or the outer cone and acts to axially displace the inner cone with respect to the outer cone in a first direction. An actuator including a rod and a piston is coupled to the inner cone or the outer cone and acts to overcome the force of the spring to axially displace the inner cone with respect to the outer cone in a second direction being axially opposite to the first direction.

Actual pressure of a hydraulic clutch of a motor vehicle can be regulated by: a) providing a value for a desired pressure to be present in a clutch cylinder; b) filling the clutch cylinder with hydraulic fluid to achieve the desired pressure; c) wherein, if the desired pressure lies between 0 and 7 bar, the actual pressure in the clutch cylinder is adjusted by regulating a rotational speed of the pump of the electric motor, and if the desired pressure is greater than 7 bar, the actual pressure in the clutch cylinder is adjusted by regulating a motor current of the electric motor; d) regulating the actual pressure until the desired pressure is achieved.

The invention relates to a hydraulic assembly for driving a friction clutch, comprising a hydraulically driveable actuator cylinder, a pump driving the actuator cylinder, wherein the actuator cylinder has a working piston with a working chamber and the working piston moveably arranged in the working chamber divides said working chamber into a main chamber and an auxiliary chamber, at least one control valve which is designed as a multi-port valve and arranged in the line path between the actuator cylinder and the pump, wherein a first supply line leads from the pump to the control valve, whereby a line path is created via a second supply line in a first valve position of the control valve, which leads to the main chamber of the actuator cylinder. In addition, in a second valve position of the control valve, the auxiliary chamber of the working chamber can be fluidically connected to the line path of the first and second supply lines via a first discharge line, while simultaneously, in the second valve position, the main chamber is connected via the first and second supply lines by means of the pump.

A hydraulic control device for an automatic transmission includes a shut-off valve arranged between a first pressure adjusting device and a respective shifting element cylinder of a plurality of shifting elements. In the first shifting position of the shut-off valve, the first pressure adjusting device is hydraulically connected to the respective shifting element cylinder through the shut-off valve. In the second shifting position of the shut-off valve, the shifting element cylinder is sealed by the shut-off valve relative to the first pressure adjusting device. The shut-off valve is an releasable check valve. The releasable check valve includes a check valve and an unblocking device. The unblocking device is actuatable by a control pressure from a second pressure adjusting device.

A hydraulic pump with an integrated clutch includes an outer cone coupled to a drive gear or a driven gear and having a frictional inner surface, and an inner cone arranged inside the outer cone, coupled to the drive gear or the driven gear and having a frictional outer surface, wherein the inner and outer cones are rotationally and axially movable with respect to each other. A spring is coupled to the inner cone or the outer cone and acts to axially displace the inner cone with respect to the outer cone in a first direction. An actuator including a rod and a piston is coupled to the inner cone or the outer cone and acts to overcome the force of the spring to axially displace the inner cone with respect to the outer cone in a second direction being axially opposite to the first direction.

A device is disclosed that performs highly accurate control in a low-torque region and improves the response of the hydraulic system, taking advantage of hydraulic sealed-type hydraulic control devices. The hydraulic sealed-type hydraulic control device includes: a first characteristic (sealed pressurization) obtained by closing an on-off valve and driving an oil pump; a second characteristic (sealed depressurization) obtained by disabling drive of the oil pump and opening the on-off valve; and a third characteristic (flow-rate control) obtained by opening the on-off valve and driving the oil pump. In a low-torque region, the device performs control according to the third characteristic. In a high-torque region, the device performs control according to the second characteristic. In the process of depressurization, the device performs control according to the second characteristic. Moreover, the device performs control to increase commanded hydraulic pressure in immediate response to an accelerator's change amount larger than a predetermined value.

A multi-pressure hydraulic control system (66, 166) for use with a dual clutch automatic transmission (14) of a vehicle powertrain system (10) includes a least one pump (28) including a rotatable pump member (34), at least one inlet region (40) for receiving fluid to be pumped by the pump member (34), and at least one outlet region (42) for outputting fluid pumped by the pump member (34), and a switching valve (78, 178) receiving at least two separate outputs of fluid pumped by the at least one pump (28) for allowing the at least two separate outputs to be selectively combined and/or separated, the switching valve (78, 178) having a valve member being movable between at least three positions that produces fluid outputs having at least three fluid pressures of a high fluid pressure, a medium fluid pressure, and a low fluid pressure to one or more portions of the dual clutch automatic transmission (14).

An electronically operated autonomous manual transmission clutch system and a second electronically operated vehicle system, such as a belted alternator starter system (BAS), in which the ECU and micro controller of the second electronic system are utilized for both systems.

A device is disclosed that performs highly accurate control in a low-torque region and improves the response of the hydraulic system, taking advantage of hydraulic sealed-type hydraulic control devices. The hydraulic sealed-type hydraulic control device includes: a first characteristic (sealed pressurization) obtained by closing an on-off valve and driving an oil pump; a second characteristic (sealed depressurization) obtained by disabling drive of the oil pump and opening the on-off valve; and a third characteristic (flow-rate control) obtained by opening the on-off valve and driving the oil pump. In a low-torque region, the device performs control according to the third characteristic. In a high-torque region, the device performs control according to the second characteristic. In the process of depressurization, the device performs control according to the second characteristic. Moreover, the device performs control to increase commanded hydraulic pressure in immediate response to an accelerator's change amount larger than a predetermined value.