A method of determining automatic transmission lubrication fluid flow rates corresponding to a running vehicle without direct oil flow measurements is disclosed. A set of in-vehicle clutch torques for a chosen clutch pack during a gear shift event for a set of shift conditions is obtained. A series of bench tests at various clutch-pack clearances and oil-flow rates for the set of shift conditions are performed. The clearances and oil-flow rates are adjusted in response to the measured magnitudes exceeding thresholds. In-vehicle transmission lubrication oil-flow rates are estimated at the chosen clutch pack for the set of shift conditions when the bench-test and in-vehicle clutch torques are less than the thresholds. The steps are reproduced for other engine conditions and fluid temperatures corresponding to other transmission gear positions. A functional map of in-vehicle oil flow rates are produced, and the transmission is adjusted based on the map.

A vehicle driving force distribution device includes: a differential gear; a driving force transmission device; and a case member having a first accommodating chamber accommodating the differential gear and a second accommodating chamber accommodating the driving force transmission device. The case member has a first flow passage that allows lubricating oil to flow from the first accommodating chamber into the second accommodating chamber, and a second flow passage that allows lubricating oil to flow from the second accommodating chamber into the first accommodating chamber. In a two-wheel drive mode, lubricating oil flows from the second accommodating chamber into the first accommodating chamber through the second flow passage. In a four-wheel drive mode, lubricating oil flows from the first accommodating chamber into the second accommodating chamber through the first flow passage.

A drive system with an electric machine and two gear stages, formed by gearwheels and clutches, the rotor shaft of the electric machine defining an axial overall length, within which the predominant axial length component of an intermediate shaft which runs parallel to the former with gearwheels and an oil pump and the predominant axial length component of a split output shaft which runs parallel to the other shafts with two clutches run.

Provided is an automatic transmission with a compact arrangement that prevents rotation of a hub member, and efficiently supplies lubrication hydraulic oil to the friction plates. The automatic transmission comprises a brake in which a plurality of friction plates are arranged between the hub member and a drum member, wherein a biasing member, an engagement hydraulic pressure chamber, and a disengagement hydraulic pressure chamber are arranged radially inward of the friction plates at positions radially overlapping each other. The hub member comprises: a first hub member comprising a cylindrical portion having a splined region with which the friction plates are spline-engaged, wherein the first hub member s spline-engaged with a transmission casing; and a second hub member formed with a part of a lubrication oil supply passage, wherein the second hub member is fittingly engaged with the transmission casing such that it is connected to a valve body.

A drive assembly for a motor vehicle includes a housing having a transmission housing chamber, a reservoir, and a clutch housing chamber. At least one of the transmission housing chamber or the clutch housing chamber are fluidically connected to the reservoir. A transmission is disposed in the transmission housing chamber. A clutch is disposed in the clutch housing chamber. The clutch is drivingly connected to the transmission. An actuator has an actuating element engaged with the clutch. The clutch is moveable by the actuating element between a disengaged position and an engaged position. A valve is operatively connected to the actuating element of the actuator to allow lubricant flow from the reservoir to at least one of the transmission housing chamber and the clutch housing chamber when the clutch is in the engaged position and to prevent lubricant flow from the reservoir when the clutch is in the disengaged position.

An object of the present invention is to provide a one-way clutch capable of preventing wear on radially inner engagement surfaces and radially outer engagement surfaces of cams in periods of high-speed freewheeling. The one-way clutch includes an inner race (110) and an outer race (150), a plurality of cams (140) provided between the inner race (110) and the outer race (150), and side plates (120, 130) provided to at least one of the inner race (110) and outer race (150) and positioned on both sides in an axial direction of the cams (140). The plurality of cams (140) are each configured to receive a predetermined centrifugal force to turn in an engaging direction in which the cams engage the inner race (110) and outer race (150) when the inner race (110) and outer race (150) rotate together in the same direction.

A shaft (W) for a motor vehicle transmission (G) may have axial bore holes positioned within the shaft and configured to guide fluid within the shaft. The shaft may have first, second, and third axial sections (W1, W2, W3), the second axial section being axially between the first and third axial sections. Fluid enters the axial bore holes in the second axial section and exits the axial bore holes in the first and third axial sections. One of the axial bore holes (B2; B1, B1a) is arranged, at least partially, in the first axial section and is radially spaced from an axis of rotation (WA) of the shaft. Another of the axial bore holes (B1RS; B_SE5, B3a) is arranged, at least partially, in the third axial section. The one of the axial bore holes (B2; B1, B1a) is coaxial with the other of the axial bore holes (B1RS; B_SE5, B3a).

An oil supply device has: a first hydraulic pump driven by power transmitted through a power transmission path; a second hydraulic pump driven by a second driving force source independent from the power transmission path; and a hydraulic circuit. In a specific state in which a first forward speed is formed by oil discharged from the second hydraulic pump being supplied to a hydraulic drive portion, when a failure occurs in which a discharge pressure of the second hydraulic pump is decreased, a state of the hydraulic circuit is switched from a first state in which oil discharged from the second hydraulic pump is supplied to the hydraulic drive portion to a second state in which oil discharged from the first hydraulic pump is supplied to the hydraulic drive portion.

A front wheel clutch and a front wheel acceleration clutch are supported to a front wheel transmission shaft. Between the front wheel clutch and the front wheel acceleration clutch, there is provided a holder supporting the front wheel transmission shaft. A first operational oil passage for switching over the front wheel clutch is defined respectively in and between the holder and the front wheel transmission shaft. A second operational oil passage for switching over the front wheel acceleration clutch is defined respectively in and between the holder and the front wheel transmission shaft.

An automatic transmission includes a starting clutch which connects and disconnects motive power between an engine and a transmission mechanism. The starting clutch includes a clutch hub connected to the engine, a clutch drum connected to the transmission mechanism, a friction plate provided between the clutch hub and the clutch drum, and a piston which presses the friction plate. The clutch drum has a radial-direction portion extending from an end portion of the outer-side cylindrical portion on a first axial-direction side to the radial-direction inner side, and an annular oil dam member extending from an end portion of the outer-side cylindrical portion on a second axial-direction side to the radial-direction inner side to immerse the friction plate in oil supplied from the radial-direction inner side toward the outer side, together with the outer-side cylindrical portion and the radial-direction portion.