초록

An alternator assembly for a motor vehicle is disclosed. The alternator assembly includes a rotor including a shaft. A torsion member is disposed inside a central cavity of the shaft. A pulley is connected to the torsion member to allow some decoupling between the pulley and the shaft.

대표청구항 ▼

1. An alternator assembly for a motor vehicle, comprising: a housing;a shaft configured to rotate with respect to the housing, the shaft being associated with a rotor;the shaft including a central cavity, a first end portion, and a second end portion;a torsion member including a first end portion an

1. An alternator assembly for a motor vehicle, comprising: a housing;a shaft configured to rotate with respect to the housing, the shaft being associated with a rotor;the shaft including a central cavity, a first end portion, and a second end portion;a torsion member including a first end portion and a second end portion;the torsion member being disposed within the central cavity of the shaft so that the second end portion of the torsion member is attached to the second end portion of the shaft;a pulley associated with a belt, the pulley being disposed radially around the first end portion of the shaft;wherein the first end portion of the torsion member is fastenably attached to the pulley;wherein the first end portion of the shaft provides rotating support for the pulley;a pulley bearing assembly disposed radially between the pulley and the first end portion of the shaft, wherein the pulley bearing assembly allows the pulley to rotate with respect to first end portion of shaft; andwherein the pulley bearing assembly is in rotating contact with an internal cylindrical surface of the pulley and an external cylindrical surface of the first end portion of the shaft. 2. The alternator assembly according to claim 1, wherein the torsion member is a torsion bar. 3. The alternator assembly according to claim 1, wherein the torsion member is a torsion spring. 4. The alternator assembly according to claim 1, wherein the first end portion of the torsion member is decoupled from the first end portion of the shaft. 5. The alternator assembly according to claim 1, wherein the torsion member is fastenably attached to the pulley using a bolt. 6. The alternator assembly according to claim 1, wherein the second end portion of the torsion member is connected to the second end portion of the shaft using a one way bearing assembly. 7. The alternator assembly according to claim 1, wherein the pulley defines an outer cylindrical belt receiving surface for receiving the belt, wherein the outer cylindrical belt receiving surface has an axial length, and wherein the external cylindrical surface of the first end portion of the shaft extends axially inside the pulley through a majority of the axial length of the outer cylindrical belt receiving surface of the pulley. 8. An alternator assembly for a motor vehicle, comprising: a housing;a shaft configured to rotate with respect to the housing, the shaft being associated with a rotor;the shaft including a first end portion, a second end portion opposite to the first end portion in an axial direction, and a wall defining a central cavity;a pulley disposed radially around the wall at the first end portion of the shaft, the pulley being associated with a belt;a torsion member disposed in the central cavity of the shaft;wherein the pulley is connected to the second end portion of the shaft by the torsion member and wherein torque is transferred directly between the pulley and the second end portion of the shaft by the torsion member;a first bearing assembly disposed at the second end portion of the shaft radially between the wall of the shaft and the housing, wherein the first bearing assembly allows the shaft to rotate with respect to the housing;a second bearing assembly disposed at the first end portion of the shaft radially between the wall of the shaft and the pulley, wherein the second bearing assembly allows the shaft to rotate with respect to the pulley, and wherein the second bearing assembly is in rotating contact with an internal cylindrical surface of the pulley and an external cylindrical surface of the wall of the shaft at the first end portion of the shaft; anda third bearing assembly disposed at a portion of the shaft in between the first and second end portions of the shaft in the axial direction and radially between the wall of the shaft and the housing, wherein the third bearing assembly allows the shaft to rotate with respect to the housing. 9. The alternator assembly according to claim 8, wherein the torsion member is configured to partially decouple the pulley from the shaft. 10. The alternator assembly according to claim 8, wherein the torsion member extends beyond the wall in an axial direction away from the second end portion of the shaft and is attached to an outermost radially extending wall of the pulley. 11. The alternator assembly according to claim 8, wherein the torsion member extends through a substantial majority of the length of the central cavity. 12. The alternator assembly according to claim 8, wherein the torsion member includes an intermediate portion disposed between the first end portion and the second end portion. 13. The alternator assembly according to claim 12, wherein a first radius of the intermediate portion is less than a second radius associated with the first end portion. 14. The alternator assembly according to claim 8, wherein torsion member helps to reduce stiffness of a drive system that includes the pulley and the belt. 15. The alternator assembly according to claim 8, wherein the pulley defines an outer cylindrical belt receiving surface for receiving the belt, wherein the outer cylindrical belt receiving surface has an axial length, and wherein the external cylindrical surface of the wall of the shaft at the first end portion of the shaft extends in the axial direction inside the pulley a majority of the axial length of the outer cylindrical belt receiving surface of the pulley. 16. An alternator assembly for a motor vehicle, comprising: a housing;a shaft configured to rotate with respect to the housing, the shaft being associated with a rotor;the shaft including a central cavity, a first end portion, and a second end portion;a torsion member including a first end portion and a second end portion;a pulley attached to the first end portion of the torsion member and disposed radially around the first end portion of the shaft;wherein the first end portion of the shaft provides rotating support for the pulley;the torsion member being disposed within the central cavity of the shaft so that the second end portion of the torsion member is coupled to the second end portion of the shaft;wherein the second end portion of the torsion member is coupled to the second end portion of the shaft in a manner so that the torsion member transfers torque to the shaft while rotating at a speed greater or equal to the speed of the shaft and wherein the torsion member rotates independently of the shaft while rotating at a speed that is less than the speed of the shaft;a pulley bearing assembly disposed radially between the pulley and the first end portion of the shaft, wherein the pulley bearing assembly allows the pulley to rotate with respect to first end portion of shaft; andwherein the pulley bearing assembly is in rotating contact with an internal cylindrical surface of the pulley and an external cylindrical surface of the first end portion of the shaft. 17. The alternator assembly according to claim 16, wherein the second end portion of the torsion member is coupled to the second end portion of the shaft using a one way bearing assembly. 18. The alternator assembly according to claim 17, wherein the one way bearing assembly is a press fit bearing assembly. 19. The alternator assembly according to claim 16, wherein the torsion member is a torsion bar. 20. The alternator assembly according to claim 16, wherein the torsion member is a torsion spring. 21. The alternator assembly according to claim 16, wherein the first end portion of the torsion member is configured to twist with respect to the second end portion of the torsion member. 22. The alternator assembly according to claim 16, wherein the first end portion of the torsion member is decoupled from the first end portion of the shaft. 23. The alternator assembly according to claim 16, wherein the pulley defines an outer cylindrical belt receiving surface for receiving a belt, wherein the outer cylindrical belt receiving surface has an axial length, and wherein the external cylindrical surface of the first end portion of the shaft extends axially inside the pulley through a majority of the axial length of the outer cylindrical belt receiving surface of the pulley.