DRIVING UNIT FOR ELECTRONIC PARKING BRAKE

1 . A driving unit for an electronic parking brake which drives a brake cable of the electronic parking brake comprising:

a motor;

a final gear;

a gear box assembly which transmits power output from the motor to the final gear;

a first power transmitting member which is connected to the final gear so as to rotate together with the final gear and to be movable in an axial direction relative to the final gear; and

a second power transmitting member which is connected to the first power transmitting unit so as to move in the axial direction in response to a rotation of the first power transmitting member.

2 . The driving unit for an electronic parking brake of claim 1 , wherein the first power transmitting member is inserted into a through hole of the final gear, wherein a groove is formed along an axial direction on a surface defining the through hole, and wherein a coupling protrusion which is inserted into the groove is formed on an outer circumferential surface of the first power transmitting member.

3 . The driving unit for an electronic parking brake of claim 1 , wherein a tool connection portion which is formed to be connected to a tool from an outside to forcibly rotate the first power transmitting member is formed to the first power transmitting member.

4 . The driving unit for an electronic parking brake of claim 1 , further comprising:

a first supporting member which is connected to the first power transmitting member so as to move together with the first power transmitting member in the axial direction;

a second supporting member which is fixed at a predetermined position to face the first supporting member;

an elastic member which is elastically interposed between the first supporting member and the second supporting member; and

a sensor module which senses a position in an axial direction of the first supporting member.

5 . The driving unit for an electronic parking brake of claim 4 , wherein the first supporting member is connected to the first power transmitting member so as not to rotate together with the first power transmitting member when the first power transmitting member rotates.

6 . The driving unit for an electronic parking brake of claim 4 , wherein the sensor module comprises:

a magnet which is mounted to the first supporting member; and

a sensor which is operated by a magnetic force of the magnet.

7 . The driving unit for an electronic parking brake of claim 6 , further comprising a case which houses the final gear, the first power transmitting member, the first supporting member and the second supporting member, wherein the case has a cover which covers upper portions of the final gear and the first supporting member, and wherein the sensor is inserted into an opening which is formed in the cover.

8 . The driving unit for an electronic parking brake of claim 1 , wherein the gear box assembly comprises a gear box housing, and wherein the gear box housing has an opening which is formed at a side toward the final gear.

9 . A driving unit for an electronic parking brake which drives a brake cable of the electronic parking brake comprising:

a motor;

a final gear;

a gear box assembly which transmits power output from the motor to the final gear;

a first power transmitting member which rotates together with the final gear;

a second power transmitting member which is connected to the first power transmitting unit so as to move in the axial direction in response to a rotation of the first power transmitting member;

a first supporting member which is connected to the first power transmitting member so as to move together with the first power transmitting member in the axial direction;

a second supporting member which is fixed at a predetermined position to face the first supporting member;

an elastic member which is elastically interposed between the first supporting member and the second supporting member; and

a sensor module which senses a position in an axial direction of the first supporting member.