Patent ID: 9500273
Filing Date: 2016-11-22
CPC Classification: B60K,B60L,B60Y,F16H,H02K,Y02T

Claim Text:
1. An in-wheel motor drive device, comprising: a motor portion having a cylindrical motor casing, a motor rear cover that covers an opening located on one side in an axial direction of said motor casing, a plurality of cooling fins that are formed on at least one of an outer peripheral surface of said motor casing and an outer surface of said motor rear cover, and a motor rotation shaft that is provided in said motor casing to output rotation to the other side in said axial direction of said motor casing; a speed reduction portion which has a cylindrical speed-reduction-portion casing having its one side in said axial direction connected to the other side in said axial direction of said motor casing, an input shaft provided in said speed-reduction-portion casing and coupled to said motor rotation shaft, and an output shaft, and which reduces a speed of rotation of said input shaft to transmit said rotation having the reduced speed to said output shaft; a wheel hub that is rotatably supported in an opening located on the other side of said speed-reduction-portion casing, and is fixed and coupled to said output shaft; a lubricant oil passage, which includes a lubricant pump, a discharge oil passage, a motor-casing oil passage, and a motor-rear-cover oil passage, the motor-rear-cover oil passage provided in said motor rear cover; a motor-casing ridge formed on said outer peripheral surface of said motor casing, extending radially outwardly from said outer peripheral surface, and having a thickness, said motor-casing ridge further extending in said axial direction of said motor casing, a motor-casing oil passage provided in said thickness of said motor casing ridge, and cooling fins formed in a region of said outer peripheral surface of said motor casing where said motor-casing oil passage is provided, the cooling fins extending from said motor casing ridge and extending in a circumferential direction of said motor casing, one end of the motor casing oil passage is connected to the discharge oil passage extending from a discharge port of the lubricant pump, the other end of the motor-casing oil passage is connected to the motor-rear-cover oil passage, the lubricant oil circulating through the lubricant pump, the discharge oil passage, the motor-casing oil passage, the motor-rear-cover oil passage, and the speed reduction portion sequentially, so as to cool the speed reduction portion.