A system for cooling and lubricating a rotor shaft bearing of an electric machine is provided. In one example, the system includes a plurality of oil passages that extend axially through a rotor shaft and open into a sealed cavity near a housing interface between an electric machine housing and gearbox housing to route oil to the rotor shaft bearing for cooling and lubrication thereof.

Disclosed is a driving system having an oil circulation structure in which churned oil is collected in a housing and in which the collected oil is efficiently distributed to driving structures, which include a motor and a speed reducer, thereby smoothly cooling and lubricating the respective driving structures. In addition, it is possible to adjust the level of the oil depending on whether the driving structures are in a low-load state or a high-load state, thereby improving lubrication and cooling performance.

A vehicle includes a motor, a gear mechanism connected downstream of the motor, a box that has a motor chamber that houses the motor, a gear chamber that houses the gear mechanism and lubricating oil, and an exhaust pipe. A first cooling box, in which cooling liquid that cools the motor is introduced, is configured on an outer circumference of the motor. A second cooling box, which is connected so that cooling liquid can circulate between the second cooling box and the first cooling box, is configured on an outer circumference of the box. The motor chamber is arranged at a position spaced further apart from the exhaust pipe than the gear chamber.

A transmission device includes a power-transmission case having a carrier of a reduction gear and a differential case joined to the carrier is supported in a transmission case via case support bearings, a specific planetary gear portion of a planetary gear is disposed on one side of a differential mechanism in an axial direction, and the specific case support bearing is disposed on the other side thereof An oil passage-forming body is provided on an inner wall of the transmission case, the oil passage-forming body comprising an oil collection part that opens upward and can collect lubricating oil splashed up in an area around the specific planetary gear portion within the transmission case accompanying rotation of the power-transmission case, and an oil reservoir part that is continuous from the oil collection part, stores lubricating oil collected by the oil collection part, and supplies the lubricating oil to the specific case support bearing.

A transmission device is formed by combining a planetary gear-type reduction gear and a differential device, wherein at least one of first and second planetary gear portions in a two-stage planetary gear has gear teeth that receive a thrust load due to meshing with opposing gear, a power-transmission case formed by joining a carrier to a differential case is rotatably supported on a transmission case. A pivot shaft of the planetary gear has one end thereof on the first planetary gear portion side supported on the power-transmission case via a first bearing and the other end on the second planetary gear portion side supported on the power-transmission case via a second bearing, and the thrust loads on one side and on the other side in an axial direction are supported only by the first bearing among the first and second bearings. Thus, a wall portion of the power-transmission case pivotably supporting the second planetary gear portion is reduced in size in the radial direction, contributing to a reduction in size of the transmission case in the radial direction.

A powertrain assembly includes one or several electric motors, a gearbox comprising a gearbox housing, an axle comprising: an axle housing, movable parts inside axle housing, comprising a shaft for a wheel, a lubricating system comprising an axle lubricating device comprising an axle oil sump and a gearbox lubricating device comprising a gearbox oil sump inside the gearbox housing which is a dry sump having an oil storage area which is separate from said gearbox oil sump, a scavenge pump and a first duct configured to retrieve oil from gear box oil sump and to convey the retrieved oil up to the oil storage area, and a main pump and a second duct configured to convey oil from the storage oil area to lubricate the gears of the gearbox.

A rotating electrical machine and an input member are placed on a first axis, a counter gear mechanism is placed on a second axis, and a differential gear mechanism is placed on a third axis. The input member, the counter gear mechanism, and the differential gear mechanism have portions placed on an axial first side with respect to the rotating electrical machine. A pump portion is placed on the opposite side of an imaginary plane passing through the first axis and the third axis from the second axis, and is placed at a location that overlaps at least one of the rotating electrical machine and the differential gear mechanism in an axial view. The pump portion is placed on the axial first side with respect to the rotating electrical machine.

A differential device is provided with: a ring gear having a tooth row arranged around an axis to mesh with an input gear; an outer case combined with the ring gear and rotatable about the axis; an inner case rotatable about the axis relative to the outer case and having a toothed end with axially projecting dog teeth; a differential gear set supported by the inner case and to be coupled with a pair of axles to allow differential motion between the axles; a clutch member engaging with the outer case and disconnectably connecting with the dog teeth so as to prevent the inner case from rotating relative to the outer case; and perforations penetrating the outer case and opened on an outer face of the outer case, the perforations being so disposed as to expose the dog teeth radially outwardly from the outer case.

A lubrication structure for a vehicle includes: a first lubrication pipe through which lubricating oil is supplied to a rotary machine disposed in a case; a second lubrication pipe through which lubricating oil is supplied to a bearing member disposed in the case; and an oil pump that supplies lubricating oil to the first and second lubrication pipes. The lubrication structure includes a first oil hole in the case that is connected to the first oil hole, and a second oil hole in the case, lubricating oil flowing into the second oil hole from the second lubrication pipe. A connection portion between the first lubrication pipe and the first oil hole is located above an opening portion of the second oil hole such that at least a part of lubricating oil that has flowed out from the connection portion flows into the second oil hole.

A transmission device is formed by combining a planetary gear-type reduction gear and a differential device, wherein at least one of first and second planetary gear portions in a two-stage planetary gear has gear teeth that receive a thrust load due to meshing with opposing gear, a power-transmission case formed by joining a carrier to a differential case is rotatably supported on a transmission case. A pivot shaft of the planetary gear has one end thereof on the first planetary gear portion side supported on the power-transmission case via a first bearing and the other end on the second planetary gear portion side supported on the power-transmission case via a second bearing, and the thrust loads on one side and on the other side in an axial direction are supported only by the first bearing among the first and second bearings. Thus, a wall portion of the power-transmission case pivotably supporting the second planetary gear portion is reduced in size in the radial direction, contributing to a reduction in size of the transmission case in the radial direction.