Overrunning alternator damping pulley

1. An overrunning alternator damping pulley comprising:

a pulley body;

two ball bearings provided on both ends of a shaft hole of the pulley body; and

a hub for supporting the two ball bearings;

wherein at least one spring holder is provided on the hub, at least one friction spring is installed on the spring holder; one end of the friction spring is inserted into the spring holder; another end of the friction spring forms a free end spirally extending along an axial direction of the hub; the outer ring of the friction spring is in contact with an inner wall of the pulley body;

wherein a damping groove corresponding to the friction spring is provided on the inner wall of the pulley body;

wherein the damping groove is in an annular shape, the damping groove has a variable width according to a bumping requirement;

the damping groove is provided near an end portion of the spring holder;

wherein the spring holder has an arc groove, one end of the friction spring which inserts to the spring holder is clamped in the arc groove;

wherein two sides of the spring holder are inserted to two friction spring respectively, the two friction springs are concentrically set at the two sides of the spring holder with an opposite rotation direction; wherein the spring holder has two arc groove, and the friction spring has two arc grooves, two friction springs are opposite disposed in the spring holder correspondingly; and

wherein two locking blocks are set on an opposite sides of the hub respectively; two locking grooves corresponding to the two locking blocks are set in the spring holder, the locking blocks are locked in the locking grooves;

wherein the locking blocks are located in a middle of the hub.

2. An overrunning alternator damping pulley comprising:

a pulley body;

two ball bearings provided on both ends of a shaft hole of the pulley body; and

a hub for supporting the two ball bearings;

wherein at least one spring holder is provided on the hub, at least one friction spring is installed on the spring holder; one end of the friction spring is inserted to the spring holder; another end of the friction spring forms a free end spirally extending along an axial direction of the hub; the outer ring of the friction spring is in contact with an inner wall of the pulley body; and

wherein a damping groove corresponding to the friction spring is provided on the inner wall of the pulley body;

wherein the damping groove is in an annular shape, the damping groove has a variable width according to a damping requirement; and

wherein the spring holder has an arc groove, one end of the friction spring which connects to the spring holder is clamped in the arc groove;

wherein two sides of the spring holder are inserted to two friction spring respectively, the two friction springs are concentrically set at the two sides of the spring holder with an opposite rotation direction.

3. The overrunning alternator damping pulley of claim 2 , wherein a number of the spring holder is two and a number of the friction spring is two, two friction springs are opposite disposed in the spring holder correspondingly.

4. The overrunning alternator damping pulley of claim 2 , wherein two locking blocks are set on an opposite sides of the hub respectively; two locking grooves corresponding to the two locking blocks are set in the spring holder, the locking blocks are locked in the locking grooves.

5. The overrunning alternator damping pulley of claim 4 , wherein the locking blocks are located in a middle of the hub.

6. The overrunning alternator damping pulley of claim 2 , wherein the damping groove is provided near an end portion of the spring holder.

7. The overrunning alternator damping pulley of claim 2 , wherein the spring holder and the hub are integrated.

8. An overrunning alternator damping pulley comprising:

a pulley body;

two ball bearings provided on both ends of a shaft hole of the pulley body; and

a hub for supporting the two ball bearings;

wherein at least one spring holder is provided on the hub, at least one friction spring is installed on the spring holder; one end of the friction spring is inserted to the spring holder; another end of the friction spring forms a free end spirally extending along an axial direction of the hub; the outer ring of the friction spring is in contact with an inner wall of the pulley body; and

wherein a damping groove corresponding to the friction spring is provided on the inner wall of the pulley body, wherein two sides of the spring holder are inserted to two friction spring respectively, the two friction springs are concentrically set at the two sides of the spring holder with an opposite rotation direction.

9. The overrunning alternator damping pulley of claim 8 , wherein the damping groove is in an annular shape, the damping groove has a variable width according to a damping requirement.

10. The overrunning alternator damping pulley of claim 9 , wherein the damping groove is provided near an end portion of the spring holder.

11. The overrunning alternator damping pulley of claim 8 , wherein the spring holder has an arc groove, one end of the friction spring which connects to the spring holder is clamped in the arc groove.

12. The overrunning alternator damping pulley of claim 8 , wherein the spring holder and the hub are integrated.

13. An overrunning alternator damping pulley comprising:

a pulley body;

two ball bearings provided on both ends of a shaft hole of the pulley body; and

a hub for supporting the two ball bearings;

wherein at least one spring holder is provided on the hub, at least one friction spring is installed on the spring holder; one end of the friction spring is inserted to the spring holder; another end of the friction spring forms a free end spirally extending along an axial direction of the hub; the outer ring of the friction spring is in contact with an inner wall of the pulley body; and

wherein a damping groove corresponding to the friction spring is provided on the inner wall of the pulley body, wherein a number of the spring holder is two and a number of the friction spring is two, two friction springs are opposite disposed in the spring holder correspondingly.

14. An overrunning alternator damping pulley comprising:

a pulley body;

two ball bearings provided on both ends of a shaft hole of the pulley body; and

a hub for supporting the two ball bearings;

wherein at least one spring holder is provided on the hub, at least one friction spring is installed on the spring holder; one end of the friction spring is inserted to the spring holder; another end of the friction spring forms a free end spirally extending along an axial direction of the hub; the outer ring of the friction spring is in contact with an inner wall of the pulley body; and

wherein a damping groove corresponding to the friction spring is provided on the inner wall of the pulley body, wherein two locking blocks are set on an opposite sides of the hub respectively; two locking grooves corresponding to the two locking blocks are set in the spring holder, the locking blocks are locked in the locking grooves.

15. The overrunning alternator damping pulley of claim 14 , wherein the locking blocks are located in a middle of the hub.