Abstract: The friction engagement device connects the input shaft and the output shaft to transmit a driving force from a driving source from the input shaft to the output shaft. The friction engagement device includes a housing, a friction engagement portion, a piston, an oil pump, and a motor. The housing is disposed between the input shaft and the output shaft. The friction engagement portion is disposed in the housing and composed of a plurality of friction components. The piston is disposed at one side of the friction engagement portion for pressing the friction engagement portion. The oil pump is used to operate the piston. The motor is used to drive the oil pump. In the friction engagement device, abnormal wear of the friction components of the friction engagement portion is detected by monitoring a value of an operation parameter of the friction engagement device.

Abstract: The friction engagement device connects the input shaft and the output shaft to transmit a driving force from a driving source from the input shaft to the output shaft. The friction engagement device includes a housing, a friction engagement portion, a piston, an oil pump, and a motor. The housing is disposed between the input shaft and the output shaft. The friction engagement portion is disposed in the housing and composed of a plurality of friction components. The piston is disposed at one side of the friction engagement portion for pressing the friction engagement portion. The oil pump is used to operate the piston. The motor is used to drive the oil pump. In the friction engagement device, abnormal wear of the friction components of the friction engagement portion is detected by monitoring a value of an operation parameter of the friction engagement device.

Abstract: A hydraulic engagement device includes a first friction engagement element, a second friction engagement element, a cylinder, a piston, an oil chamber, hydraulic oil, and a release groove. The first friction engagement element and the second friction engagement element are to rotate around a third rotational axis. The piston is slidably provided in the cylinder. The oil chamber is defined between the piston and the cylinder. The hydraulic oil is supplied to the oil chamber to move the piston to push the first friction engagement element or the second friction engagement element so that the first friction engagement element engages the second friction engagement element. The release groove is provided on the cylinder or the piston. The hydraulic oil in the oil chamber is released through the release groove when a stroke of the piston exceeds a predetermined level.

Abstract: An oil strainer includes a main body, a tubular suction protrusion, and a partition. The main body has a bottom and is configured to filter an oil in an oil storage. The tubular suction protrusion protrudes from the bottom of the main body downward in a height direction along a height of the oil storage and has a suction port at a bottom end of the tubular suction protrusion. The main body is configured to suction the oil in the oil storage via the suction port. The partition protrudes downward in the height direction from the bottom of the main body and is provided apart from the suction port.

Abstract: A power transmission system includes a first rotating shaft and a second rotating shaft, a first fastening element including multiple first friction members and rotating integrally with the first rotating shaft, a second fastening element including multiple second friction members and rotating integrally with the second rotating shaft, a frictional engagement portion in which the first fastening element and the second fastening element are alternately stacked in an axial direction, and a pressing member disposed movable in the axial direction and pressing the frictional engagement portion to engage the first friction members and the second friction members with each other. The first fastening element is supported in the axial direction by an internal thrust bearing and an external thrust bearing that have different diameters.

Abstract: A power transmission system includes a rotating shaft, a power transmission component, a pressing member, and a wave spring. The rotating shaft is rotatable about a rotating axis. The power transmission component includes a frictional engagement portion that includes a plurality of friction members alternately stacked in an axial direction along the rotating axis. The pressing member has a contact portion and is disposed to be movable in the axial direction to press the frictional engagement portion such that the plurality of friction members engage with each other. The wave spring is to press the pressing member at the contact portion in the axial direction away from the frictional engagement portion. The contact portion of the pressing member has a reduced friction between the contact portion and the wave spring along a circumference of the wave spring.

Abstract: A driving force distributing device includes a single pump for supplying control hydraulic pressure to each of first and second hydraulic clutches, an electric motor for driving the pump, a flow rate variable mechanism for changing a ratio of flow rate of hydraulic fluid supplied to each of the first and second hydraulic clutches and a controlling means for controlling the electric motor and the flow rate variable mechanism. The driving force distributing device can variably control a flow rate of hydraulic fluid supplied to first and second hydraulic clutches based on changing a ratio of flow rate of hydraulic fluid supplied to the first and second hydraulic clutches in the flow rate variable mechanism and a control of changing rotational speed of the pump using the motor.

Abstract: A drive force distribution device for an automobile is provided in which a hydraulic clutch includes an annular oil groove opposing a clutch piston in an inner wall face of a clutch oil chamber, and a hydraulic oil supply port and a hydraulic oil discharge port communicating with the oil groove. Since when the hydraulic oil supply port of the oil groove is a starting end and the hydraulic oil discharge port of the oil groove is a finishing end, a cross-sectional area of a longer oil groove section of the annular oil groove is set to be larger than a cross-sectional area of a shorter oil groove section, the flow path resistance of the oil groove sect of the respective hydraulic clutches made to be uniform. This enables smooth operation, improvement of the engagement responsiveness and uniformization of the engagement responsiveness of the hydraulic clutches to be achieved.

Abstract: A drive force distribution device for an automobile is provided in which a hydraulic clutch includes an annular oil groove opposing a clutch piston in an inner all face of a clutch oil chamber, and a hydraulic oil supply port and a hydraulic oil discharge port communicating with the oil groove. Since when the hydraulic oil supply port of the oil groove is a starting end and the hydraulic oil discharge port of the oil groove is a finishing end, a cross-sectional area of a longer oil groove section of the annular oil groove is set to be larger than a cross-sectional area of a shorter oil groove section, the flow path resistance of the oil groove sect of the respective hydraulic clutches made to be uniform. This enables smooth operation, improvement of the engagement responsiveness and uniformization of the engagement responsiveness of the hydraulic clutches to be achieved.

Abstract: A driving force distributing device includes a single pump for supplying control hydraulic pressure to each of first and second hydraulic clutches, an electric motor for driving the pump, a flow rate variable mechanism for changing a ratio of flow rate of hydraulic fluid supplied to each of the first and second hydraulic clutches and a controlling means for controlling the electric motor and the flow rate variable mechanism. The driving force distributing device can variably control a flow rate of hydraulic fluid supplied to first and second hydraulic clutches based on changing a ratio of flow rate of hydraulic fluid supplied to the first and second hydraulic clutches in the flow rate variable mechanism and a control of changing rotational speed of the pump using the motor.

Abstract: A hydraulic engagement device includes a first friction engagement element, a second friction engagement element, a cylinder, a piston, an oil chamber, hydraulic oil, and a release groove. The first friction engagement element and the second friction engagement element are to rotate around a third rotational axis. The piston is slidably provided in the cylinder. The oil chamber is defined between the piston and the cylinder. The hydraulic oil is supplied to the oil chamber to move the piston to push the first friction engagement element or the second friction engagement element so that the first friction engagement element engages the second friction engagement element. The release groove is provided on the cylinder or the piston. The hydraulic oil in the oil chamber is released through the release groove when a stroke of the piston exceeds a predetermined level.