초록

A motor-driven wheel driving apparatus has two planetary reduction gear mechanisms arranged within the outer member, forming a part of the wheel bearing. The apparatus is positioned at the outboard side end of the inner member.

대표청구항 ▼

What is claimed is: 1. 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 mem

What is claimed is: 1. 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. 2. The motor-driven wheel driving apparatus of claim 1, wherein a plurality of carrier pins are equidistantly in its circumferential direction secured on said input element, a second planetary reduction gear mechanism is additionally provided, said second planetary reduction gear mechanism including a plurality of planetary elements rotatably supported on said carrier pins, a stationary element secured on the inner circumference of said first inner ring member, and an input element projecting from the outboard side end of said supporting member, said planetary elements engaging with said input element and stationary element, and rotation of said electric motor being transmitted to said outer member via two planetary reduction gear means so as to drive the wheel. 3. The motor-driven wheel driving apparatus of claim 2, wherein a cup-shaped motor cover is fitted on the outer cylindrical portion of said stator housing and secured thereto by securing bolts, and said stator section is radially positioned and secured to said stator housing by arranging said securing bolts within semicircular axial grooves formed equidistantly in the outer circumferential direction of said stator section. 4. The motor-driven wheel driving apparatus of claim 2, wherein seals are arranged at either side of said bearing portions. 5. The motor-driven wheel driving apparatus of claim 1, wherein a cup-shaped motor cover is fitted on the outer cylindrical portion of said stator housing and secured thereto by securing bolts, and said stator section is radially positioned and secured to said stator housing by arranging said securing bolts within semicircular axial grooves formed equidistantly in the outer circumferential direction of said stator section. 6. The motor-driven wheel driving apparatus of claim 5, wherein seals are arranged at either side of said bearing portions. 7. The motor-driven wheel driving apparatus of claim 1, wherein seals are arranged at either side of said bearing portions. 8. A motor-driven wheel driving apparatus comprising: a driving section including a double row wheel bearing, planetary reduction gear mechanism, 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 including a first inner ring member formed with one inner raceway surface arranged opposite to one outer raceway surface and integrally formed with a cylindrical portion of smaller diameter axially extending from said one inner raceway surface, a second inner ring member 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: a stationary element mounted on said first inner ring member; input elements torque-transmittably arranged at an outboard side end of said supporting member; a plurality of planetary elements engaging said input elements and said stationary element; an output element supporting said planetary elements rotatably relative to a carrier; 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 and said carrier being torque-transmittably connected to said outer member to transmit the rotation of said electric motor to said outer member so as to drive the wheel. 9. The motor-driven wheel driving apparatus of claim 8, wherein a plurality of carrier pins are equidistantly in its circumferential direction secured on said input element, a second planetary reduction gear mechanism is additionally provided, said second planetary reduction gear mechanism including a plurality of planetary elements rotatably supported on said carrier pins, a stationary element secured on the inner circumference of said first inner ring member, and an input element projecting from the outboard side end of said supporting member, said planetary elements engaging with said input element and stationary element, and rotation of said electric motor being transmitted to said outer member via two planetary reduction gear means so as to drive the wheel. 10. The motor-driven wheel driving apparatus of claim 8, wherein a cup-shaped motor cover is fitted on the outer cylindrical portion of said stator housing and secured thereto by securing bolts, and said stator section is radially positioned and secured to said stator housing by arranging said securing bolts within semicircular axial grooves formed equidistantly in the outer circumferential direction of said stator section. 11. The motor-driven wheel driving apparatus of claim 2, wherein seals are arranged at either side of said bearing portions.