Musashi Seimitsu Industry Co., Ltd.

Naofumi Butta

Ryosuke Asai

Hoa Binh Nguyen

Shiryu Kato

Provided is a transmission device in which pinion and a large diameter gear each comprise a helical gear and are arranged such that an oil on a tooth surface is pushed from a mutual meshing portion to one side in an axial direction of the pinion during the forward rotation of the large diameter gear, and a fluid restriction wall configured to oppose the oil pushed from the meshing portion to the one side in the axial direction is arranged adjacent to an end face of teeth of the pinion on the one side in the axial direction, the fluid restriction wall being formed in a shape that allows a tooth tip portion of the end face to be covered.

Transmission device

A breather structure in a power unit is provided. The power unit includes a motor and a transmission device. The transmission device includes a gear transmission mechanism and a transmission case. The transmission case and a motor case forms a unit case. The unit case includes an oil supply passage, an oil return passage, and a partition wall. One side face of the partition wall and a lid coupled to the one side face define a breather chamber. The breather chamber includes an inlet that is open to the other side face of the partition wall and that communicates with a motor space.

Breather structure in power unit

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.

Growing community of inventors

Toyohashi, Japan

Naofumi Butta