Damping coupler of electronic power steering apparatus

1. A damping coupler of an electronic steering apparatus, comprising:

a first spline having a first shaft hole such that a worm shaft is inserted therein, with a first serration being formed in the first shaft hole to engage with a serration of the worm shaft;

a second spline directly coupled to a side of the first spline, and having a second shaft hole such that the worm shaft is inserted therein, with a second serration being formed in the second shaft hole to engage with a serration of the worm shaft; and

a molding surrounding outsides of the first and second splines, and coupled to a motor shaft.

2. The damping coupler according to claim 1 , wherein a first phase adjustment part is formed on a surface of the first spline, and a second phase adjustment part is formed on a surface of the second spline facing the first spline to be coupled to the first phase adjustment part.

3. The damping coupler according to claim 2 , wherein the first phase adjustment part is a recess that is concavely formed in the first spline, and the second phase adjustment part is a protuberance that protrudes out from the second spline.

4. The damping coupler according to claim 2 , wherein the first phase adjustment part is a protuberance that protrudes out from the first spline, and the second phase adjustment part is a recess that is concavely formed in the second spline.

5. The damping coupler according to claim 2 , wherein a first protrusion is formed on an outside of the first spline, a second protrusion corresponding to the first protrusion is formed on an outside of the second spline, and a third protrusion is formed on an outside of the molding to surround the first protrusion and the second protrusion.

6. The damping coupler according to claim 5 , wherein the first serration and the second serration have different phases.

7. The damping coupler according to claim 6 , wherein the first phase adjustment part is formed on a line connecting a center of the first shaft hole with a center of the first protrusion, and the second phase adjustment part is formed on a line connecting a center of the second shaft hole with a center of the second protrusion.

8. The damping coupler according to claim 5 , wherein the first serration and the second serration have the same phase.

9. The damping coupler according to claim 8 , wherein the first phase adjustment part is formed on a line connecting a center of the first shaft hole with a center of the first protrusion, and the second phase adjustment part is formed at a position deviating from a line connecting a center of the second shaft hole with a center of the second protrusion.

10. The damping coupler according to claim 5 , wherein an uneven part is formed on an outside of the third protrusion.

11. The damping coupler according to claim 1 , wherein the motor shaft has a shaft hole, and the molding is inserted into the shaft hole.

12. The damping coupler according to claim 1 , wherein the molding is made of a rubber material.

13. A damping coupler of an electronic steering apparatus, comprising:

a first spline having a first shaft hole such that a worm shaft is inserted therein, with a first serration being formed in the first shaft hole to engage with a serration of the worm shaft;

a second spline coupled to a side of the first spline, and having a second shaft hole such that the worm shaft is inserted therein, with a second serration being formed in the second shaft hole to engage with a serration of the worm shaft; and

a molding surrounding outsides of the first and second splines, and coupled to a motor shaft,

wherein the motor shaft has a shaft hole, and the molding is inserted into the shaft hole.

14. The damping coupler according to claim 13 , wherein a first phase adjustment part is formed on a surface of the first spline, and a second phase adjustment part is formed on a surface of the second spline facing the first spline to be coupled to the first phase adjustment part.

15. The damping coupler according to claim 14 , wherein the first phase adjustment part is a recess that is concavely formed in the first spline, and the second phase adjustment part is a protuberance that protrudes out from the second spline.

16. The damping coupler according to claim 14 , wherein the first phase adjustment part is a protuberance that protrudes out from the first spline, and the second phase adjustment part is a recess that is concavely formed in the second spline.

17. A damping coupler of an electronic steering apparatus, comprising:

a first spline having a first shaft hole such that a worm shaft is inserted therein, with a first serration being formed in the first shaft hole to engage with a serration of the worm shaft;

a second spline coupled to a side of the first spline, and having a second shaft hole such that the worm shaft is inserted therein, with a second serration being formed in the second shaft hole to engage with a serration of the worm shaft; and

a molding surrounding outsides of the first and second splines, and coupled to a motor shaft,

wherein the molding is made of a rubber material.

18. The damping coupler according to claim 17 , wherein a first phase adjustment part is formed on a surface of the first spline, and a second phase adjustment part is formed on a surface of the second spline facing the first spline to be coupled to the first phase adjustment part.

19. The damping coupler according to claim 18 , wherein the first phase adjustment part is a recess that is concavely formed in the first spline, and the second phase adjustment part is a protuberance that protrudes out from the second spline.

20. The damping coupler according to claim 18 , wherein the first phase adjustment part is a protuberance that protrudes out from the first spline, and the second phase adjustment part is a recess that is concavely formed in the second spline.