Patent ID: 7530416

Claim:
A motor-driven wheel driving apparatus comprising: a driving section including a double row wheel bearing, planetary reduction gear mechanisms, an electric motor, and a cylindrical supporting member for supporting said electric motor; said wheel bearing including an outer member integrally formed with a wheel mounting flange on its outer circumference and formed with double row outer raceway surfaces; an inner member includes a first inner ring member formed with one inner raceway surface arranged opposite to one outer raceway surface, said inner ring is integrally formed with a cylindrical portion of smaller diameter axially extending from said one inner raceway surface, a second inner ring member is press fit onto said cylindrical portion of smaller diameter of said first inner ring member and formed with another inner raceway surfaces arranged opposite to the other outer raceway surface, said second inner ring member integrally formed with a cup-shaped stator housing extending radially outward from an inboard side end of said other inner raceway surface; a plurality of rolling elements rollably arranged between said outer and inner raceway surfaces, respectively, of said outer and inner members; said planetary reduction gear mechanism including an output element mounted on said outer member and input elements torque-transmittably arranged at an outboard side end of said supporting member; a plurality of planetary elements rotatably supported on supporting pins secured on said first inner ring member and adapted to engage said input elements and said output element; said driving section including said electric motor including a stator section secured on an inner circumferential surface of said stator housing, and a rotor section secured on the outer circumferential surface of said supporting member opposing said stator section via a predetermined radial gap; and said supporting member being rotatably supported relative to shaft portions of said inner member via a pair of rolling bearings to transmit the rotation of said electric motor to said outer member so as to drive the wheel.