A power transmission device includes a pinion gear having a large pinion gear and a small pinion gear, a carrier that supports the pinion gear, a ring gear that engages with the small pinion gear, an oil supply unit positioned above a horizontal line that passes through a revolution center of the pinion gear, and a downstream side wall part facing a gear surface of the large pinion gear. The downstream side wall part is arranged to be adjacent to the oil supply unit further downstream in a revolution direction of the pinion gear than the oil supply unit when viewed from an axial direction.

A power transmission device includes a box, a case disposed in the box, a differential mechanism housed in the case, and a planetary gear mechanism disposed in the box and supported by the case. The planetary gear mechanism includes a sun gear and a pinion gear that engages with the sun gear. The box has a shelf part above a horizontal line that passes through a revolution center of the pinion gear. The shelf part is arranged at a position that does not overlap the sun gear when viewed from radially above.

A stub shaft assembly for an outer planetary axle (1) of a motor vehicle includes an inner shaft (9) and an outer shaft (10) comprising a helically toothed sun gear (4). A pair of toothings (11) with a first helical toothing and a second helical toothing is effective between the inner shaft (9) and the outer shaft (10). Also disclosed is an outer planetary axle (1) for a motor vehicle comprising at least one such stub shaft assembly.

An electric drive unit and method of assembling the same is disclosed. The electric drive unit includes a rotor having a rotor shaft, and gear shaft, where the rotor shaft is inserted into the gear shaft. The gear shaft is supported by two bearings, while the rotor shaft supported directly at one end by a bearing and at the other by the gear shaft. A wave spring is also disclosed that provides an axial loading to the rotor shaft. Also disclosed is a balancing ring secured to an end of the rotor via a locknut. The balancing ring can be machined in order to balance the rotor. The rotor shaft can be connected to the gear shaft via a spline connection. The rotor shaft can bear against the gear shaft via a pilot journal and pilot bore defined on the rotor shaft and gear shaft respectively.

A dual transmission with input shafts, output shafts, a transmission case and two separate single transmissions arranged in the transmission case is described. Each single transmission is a two-stage spur gear transmission with three positions for gear centers. A first position is occupied by an input shaft and a second position by an output shaft. A third position is for a middle stationary axle fixed to the transmission case. The three positions define a triangular arrangement having a first side defined by a distance between the first position and the second position, a second side defined by a distance between the first position and the third position, and a third side defined by a distance between the second position and the third position. The second side and the third side form respective angles with the first side. At least one of these angles has a value ranging between 5° and 70°.

A method of manufacturing a torsion bar for a steering system is provided. The method includes supporting a torsion bar blank on a cold forming machine with a plurality of dies at a first end region of the torsion bar blank and a second end region of the torsion bar blank. The method also includes rolling the torsion bar blank to form an end region having a cylindrical outer surface extending from an axial end surface and a serrated portion disposed proximate the end region and axially offset from the axial end surface.

A transaxle includes a planetary gear reducer and a differential device. The planetary gear reducer includes a stepped pinion, a first needle bearing, a second needle bearing, and a carrier. The stepped pinion includes a pinion shaft with which a large diameter pinion and a small diameter pinion are integrated. The first needle bearing is fitted to a part of the pinion shaft outside the large diameter pinion. The second needle bearing is fitted to a part of the pinion shaft outside the small diameter pinion. The carrier is configured to support the stepped pinion via the first needle bearing and the second needle bearing such that the stepped pinion is rotatable with respect to the carrier, and to couple the stepped pinion and the differential device.

Systems and method for cooling and lubricating power transmission systems include providing oil to an oil tube and then to a rotor shaft via the oil tube. Oil may also be provided through at least one channel defined in an end of the oil tube inserted into an annular region of the rotor shaft, through at least one channel defined in an end of the gear shaft and between the end and a shoulder of the rotor shaft and through at least one channel defined in side surface of the rotor shaft in a region of rotor shaft inserted into the gear shaft. Such systems and method can also include providing oil a fluid passageway in a bearing shim plate via an inlet tube. Oil may also be provided through a radial gap adjacent a bearing shim plate outlet and chamber defined in the bearing shim plate.

Systems and methods for cooling power transmission systems are include providing oil through an aperture defined in a housing to a stator cooling ring, through the stator cooling ring and into stator cooling channels, through the stator cooling channels and into spaces defined between the housing and jet rings, and through holes in the jet rings and onto the end-windings. The stator cooling ring, stator cooling channels and jet rings can encircle the stator and end-windings and, via the holes in the jet rings, spray pressurized jets of oil from various angles onto the end-windings, and in particular middle regions thereof. Seals may be used between the jet rings and housing, and between the jet rings and stator ends. The seals may be compressed so as to form an interference fit between the jet rings and housing or stator ends as the case may be.

A transaxle includes a planetary gear reducer and a differential device. The planetary gear reducer includes a stepped pinion, a first needle bearing, a second needle bearing, and a carrier. The stepped pinion includes a pinion shaft with which a large diameter pinion and a small diameter pinion are integrated. The first needle bearing is fitted to a part of the pinion shaft outside the large diameter pinion. The second needle bearing is fitted to a part of the pinion shaft outside the small diameter pinion. The carrier is configured to support the stepped pinion via the first needle bearing and the second needle bearing such that the stepped pinion is rotatable with respect to the carrier, and to couple the stepped pinion and the differential device.