Wheel assembly with integral electric motor
View Patent ↗The subject invention provides a wheel assembly ( 20 ) having a spindle ( 26 ) for attachment to a vehicle along a rotational axis (R). An electric motor ( 22 ) is disposed radially about the spindle ( 26 ) and includes a stationary stator ( 34 ) and a rotor ( 36 ) rotatable about the rotational axis (R) relative to the stator ( 34 ). A rotor support ( 40 ) is disposed about the spindle ( 26 ) and includes a collar ( 42 ) rotatably supported by at least one rotor support bearing ( 46 ) on the spindle ( 26 ). The rotor support ( 40 ) includes a flange ( 44 ) disposed within a predetermined axial distance (D) and extending radially outward from the collar ( 42 ) to support the rotor ( 36 ). A planetary gear system ( 62 ) interconnects the rotor support ( 40 ) and a wheel drive ( 52 ) for reducing rotational speed of the rotor ( 36 ) and increasing the torque of the wheel assembly ( 20 ).
1. An electric drive wheel assembly ( 20 ) for a vehicle, said assembly ( 20 ) comprising;
a non-rotating spindle ( 26 ) having a first end ( 28 ) for attachment to the vehicle and a second end ( 30 ) spaced from said first end ( 28 ) along a rotational axis (R),
an electric motor ( 22 ) concentric with said spindle ( 26 ) and including a stator ( 34 ) surrounding and secured to said spindle ( 26 ) and a rotor ( 36 ) concentric with said stator ( 34 ) and rotatable about said rotational axis (R) relative to said stator ( 34 ),
said stator ( 34 ) and said rotor ( 36 ) extending a predetermined axial distance (D) along said rotational axis (R),
a wheel drive ( 52 ) rotatably supported by said spindle ( 26 ) for rotation about said rotational axis (R),
a rotor support ( 40 ) rotatably supported on said spindle ( 26 ) and extending to said electric motor ( 22 ) for rotatably supporting said rotor ( 36 ) for rotation about said rotational axis (R), and
a gear reduction system mechanically interconnecting said rotor support ( 40 ) and said wheel drive ( 52 ) for transmitting rotational movement of said rotor ( 36 ) to said wheel drive ( 52 ), said gear reduction system and said wheel drive ( 52 ) being at least partially disposed within said predetermined axial distance (D);
said assembly ( 20 ) characterized by said rotor support ( 40 ) having a radially extending flange ( 44 ) disposed within said predetermined axial distance (D).
2. An assembly ( 20 ) as set forth in claim 1 wherein said gear reduction system and said wheel drive ( 52 ) are disposed about said spindle ( 26 ) between said rotor support ( 40 ) and said second end ( 30 ) of said spindle ( 26 ).
3. An assembly ( 20 ) as set forth in claim 1 wherein said gear reduction system is further defined as a planetary gear system ( 62 ) including a sun gear ( 64 ), a plurality of planetary gears ( 66 ), and a ring gear ( 68 ) with said sun gear ( 64 ) engaging said plurality of planetary gears ( 66 ) and said plurality of planetary gears ( 66 ) engaging said ring gear ( 68 ) for reducing rotational speed between said rotor ( 36 ) and said wheel drive ( 52 ).
4. An assembly ( 20 ) as set forth in claim 1 wherein said rotor ( 36 ) includes a bracket ( 48 ) for attaching said rotor ( 36 ) to said flange ( 44 ).
5. An assembly ( 20 ) as set forth in claim 1 further including a braking system ( 104 ) at least partially disposed within said predetermined axial distance (D).
6. An assembly ( 20 ) as set forth in claim 1 wherein said stator ( 34 ) includes an inner surface ( 38 ) and said rotor ( 36 ) is disposed between said inner surface ( 38 ) of said stator ( 34 ) and said spindle ( 26 ) with said rotor ( 36 ) rotating about said spindle ( 26 ) adjacent said inner surface ( 38 ) of said stator ( 34 ).
7. An assembly ( 20 ) as set forth in claim 6 wherein said gear reduction system is further defined as a planetary gear system ( 62 ) including a sun gear ( 64 ), a plurality of planetary gears ( 66 ), and a ring gear ( 68 ) with said sun gear ( 64 ) engaging said plurality of planetary gears ( 66 ) and said plurality of planetary gears ( 66 ) engaging said ring gear ( 68 ) for reducing rotational speed between said rotor ( 36 ) and said wheel drive ( 52 ).
8. An assembly ( 20 ) as set forth in claim 7 wherein said ring gear ( 68 ) is non-rotatably attached to said spindle ( 26 ) adjacent said second end ( 30 ) of said spindle ( 26 ).
9. An assembly ( 20 ) as set forth in claim 8 wherein said rotor support ( 40 ) includes a collar ( 42 ) disposed radially about said spindle ( 26 ) within said predetermined axial distance (D).
10. An assembly ( 20 ) as set forth in claim 9 wherein said collar ( 42 ) of said rotor support ( 40 ) includes a splined end ( 77 ) extending axially along said rotational axis (R) and disposed radially about said spindle ( 26 ), and said sun gear ( 64 ) includes a splined portion ( 76 ) extending axially along said rotational axis (R) and disposed radially about said spindle ( 26 ) for mechanically engaging said collar ( 42 ) for transmitting rotational movement therebetween about said rotational axis (R).
11. An assembly ( 20 ) as set forth in claim 10 wherein said wheel drive ( 52 ) includes a carrier ( 54 ) rotatably mounted about said spindle ( 26 ) for rotation about said rotational axis (R).
12. An assembly ( 20 ) as set forth in claim 11 wherein said carrier ( 54 ) includes a bearing surface ( 78 ) and said assembly ( 20 ) includes at least one hub bearing ( 82 ) disposed between said bearing surface ( 78 ) and said splined portion ( 76 ) of said sun gear ( 64 ) and further including at least one rotor support bearing ( 46 ) disposed between said collar ( 42 ) of said rotor support ( 40 ) and said spindle ( 26 ) such that said at least one hub bearing ( 82 ) and said at least one rotor support bearing ( 46 ) are radially aligned along said spindle ( 26 ).
13. An assembly ( 20 ) as set forth in claim 11 further including a rear cover ( 90 ) attached to said carrier ( 54 ).
14. An assembly ( 20 ) as set forth in claim 13 further including a flexible member ( 92 ) disposed between said rear cover ( 90 ) and said carrier ( 54 ) for expanding in response to an internal pressure.
15. An assembly ( 20 ) as set forth in claim 11 wherein said wheel drive ( 52 ) includes a front cover ( 56 ) attached to said carrier ( 54 ) for rotation therewith about said rotational axis (R).
16. An assembly ( 20 ) as set forth in claim 15 further including a front cover bearing ( 60 ) disposed between said front cover ( 56 ) and said spindle ( 26 ) for rotatably supporting said front cover ( 56 ) on said spindle ( 26 ).
17. An assembly ( 20 ) as set forth in claim 15 wherein said front cover ( 56 ) includes a heat absorbing material for absorbing heat.
18. An assembly ( 20 ) as set forth in claim 17 wherein said heat absorbing material includes aluminum.
19. An assembly ( 220 ) as set forth in claim 1 wherein said stator ( 234 ) includes an outer surface ( 312 ) and is disposed between said rotor ( 236 ) and said spindle ( 226 ) with said rotor ( 236 ) rotating about said spindle ( 226 ) adjacent said outer surface ( 312 ) of said stator ( 234 ).
20. An assembly ( 220 ) as set forth in claim 19 wherein said wheel drive ( 252 ) includes a carrier ( 254 ) non-rotatably connected to said spindle ( 226 ) adjacent said second end ( 230 ) of said spindle ( 226 ).
21. An assembly ( 220 ) as set forth in claim 20 wherein said rotor support ( 240 ) includes a collar ( 242 ) disposed radially about said spindle ( 226 ) within said predetermined axial distance (D).
22. An assembly ( 220 ) as set forth in claim 21 wherein said wheel drive ( 252 ) includes an inner hub ( 318 ) at least partially disposed within said predetermined axial distance (D) and rotatably supported by said collar ( 242 ) of said rotor support.
23. An assembly ( 220 ) as set forth in claim 22 wherein said gear reduction system is further defined as a planetary gear system ( 262 ) including a sun gear ( 264 ), a plurality of planetary gears ( 266 ), and a ring gear ( 268 ) with said sun gear ( 264 ) engaging said plurality of planetary gears ( 266 ) and said plurality of planetary gears ( 266 ) engaging with said ring gears ( 268 ) for reducing rotational speed between said rotor ( 236 ) and said wheel drive ( 252 ).
24. An assembly ( 220 ) as set forth in claim 23 wherein said ring gear ( 268 ) is attached to said inner hub ( 318 ) for rotation therewith about said rotational axis (R).
25. An assembly ( 220 ) as set forth in claim 24 wherein said wheel drive ( 252 ) includes an outer hub ( 320 ) attached to said inner hub ( 318 ) for rotation about said rotational axis (R) with said ring gear ( 268 ) and said inner hub ( 318 ).
26. An assembly ( 220 ) as set forth in claim 21 further including at least one hub bearing ( 282 ) disposed between said inner hub ( 318 ) and said collar ( 242 ) of said rotor support ( 240 ) for rotatably supporting said inner hub ( 318 ) on said collar ( 242 ) of said rotor support ( 240 ) and at least one rotor support bearing ( 246 ) disposed between said collar ( 242 ) of said rotor support ( 240 ) and said spindle ( 226 ) such that said at least one hub bearing ( 282 ) and said at least one rotor support bearing ( 246 ) are radially aligned along said spindle ( 226 ).
27. An electric drive wheel assembly ( 20 ) for a vehicle, said assembly ( 20 ) comprising;
a non-rotating spindle ( 26 ) having a first end ( 28 ) for attachment to the vehicle and a second end ( 30 ) spaced from said first end ( 28 ) along a rotational axis (R),
an electric motor ( 22 ) concentric with said spindle ( 26 ) and including a stator ( 34 ) surrounding and secured to said spindle ( 26 ) and a rotor ( 36 ) concentric with said stator ( 34 ) and rotatable about said rotational axis (R) relative to said stator ( 34 ),
said stator ( 34 ) and said rotor ( 36 ) extending a predetermined axial distance (D) along said rotational axis (R),
a wheel drive ( 52 ) rotatably supported by said spindle ( 26 ) for rotation about said rotational axis (R),
a rotor support ( 40 ) rotatably supported on said spindle ( 26 ) and extending to said electric motor ( 22 ) for rotatably supporting said rotor ( 36 ) for rotation about said rotational axis (R),
a gear reduction system mechanically interconnecting said rotor support ( 40 ) and said wheel drive ( 52 ) for transmitting rotational movement of said rotor ( 36 ) to said wheel drive ( 52 ); and
a braking system ( 104 ) at least partially disposed within said predetermined axial distance (D);
said assembly ( 20 ) characterized by said rotor support ( 40 ) having a radially extending flange ( 44 ) disposed within said predetermined axial distance (D).
28. An assembly ( 20 ) as set forth in claim 27 wherein said gear reduction system is further defined as a planetary gear system ( 62 ) including a sun gear ( 64 ), a plurality of planetary gears ( 66 ), and a ring gear ( 68 ) with said sun gear ( 64 ) engaging said plurality of planetary gears ( 66 ) and said plurality of planetary gears ( 66 ) engaging said ring gear ( 68 ) for reducing rotational speed between said rotor ( 36 ) and said wheel drive ( 52 ).
29. An assembly ( 20 ) as set forth in claim 27 wherein said stator ( 34 ) includes an inner surface ( 38 ) and said rotor ( 36 ) is disposed between said inner surface ( 38 ) of said stator ( 34 ) and said spindle ( 26 ) with said rotor ( 36 ) rotating about said spindle ( 26 ) adjacent said inner surface ( 38 ) of said stator ( 34 ).
30. An assembly ( 220 ) as set forth in claim 27 wherein said stator ( 234 ) includes an outer surface ( 312 ) and is disposed between said rotor ( 236 ) and said spindle ( 226 ) with said rotor ( 236 ) rotating about said spindle ( 226 ) adjacent said outer surface ( 312 ) of said stator ( 234 ).