Electric torque wrench capable of sensing manual operating torque

1. An electric torque wrench capable of sensing a manual operating torque, comprising:

an outer housing having an accommodating space at an internal thereof and a front end with an opening;

a motor having a driving shaft arranged inside the accommodating space of the outer housing;

a reduction device arranged inside the accommodating space of the outer housing and positioned at a front end of the motor; the reduction device having a reduction gear assembly connected to the driving shaft; the reduction gear assembly having a front end with a transmission shaft arranged thereon; the reduction gear assembly having an outer circumferential surface with a hollow ring gear member arranged thereon;

the ring gear member having a front end with at least one extension arm arranged thereon, and the extension arm having at least one sensing plane formed thereon; the transmission shaft configured to extend outward from the ring gear member;

at least one torque sensing unit arranged on the sensing plane of the at least one extension arm;

a driving device installed at the front end of the outer housing and configured to be driven by the transmission shaft; the front end having a working head, and the working head configured to be driven by the transmission shaft to generate a rotation with an axial direction of the working head as a center of rotation; the front end of the ring gear member secured and attached onto the driving device.

2. The electric torque wrench as claimed in claim 1 , further comprising an operating plane arranged perpendicular to the axial direction of the working head, and a non-zero degree angle is formed between the sensing plane on the extension arm of the ring gear member and the operating plane.

3. The electric torque wrench as claimed in claim 2 , wherein the angle between the operating plane of the working head and the sensing plane of the ring gear member is 1 degree°˜90 degrees.

4. The electric torque wrench as claimed in claim 1 , wherein front end of the ring gear member includes an extension arm.

5. The electric torque wrench as claimed in claim 1 , wherein the front end of the ring gear member includes two extension arms, and the two extension arms are positioned at two sides of the front end of the ring gear member respectively.

6. The electric torque wrench as claimed in claim 1 , wherein a free end of the extension arm includes a circular ring installed thereon, and the circular ring is secured and attached onto the driving device.

7. The electric torque wrench as claimed in claim 6 , wherein an outer side of the ring gear member includes at least one fastening piece.

8. The electric torque wrench as claimed in claim 7 , wherein the driving device includes a fastening slot and a retaining slot; the fastening piece of the ring gear member is secured inside the fastening slot, and the extension arm is positioned inside the retaining slot.

9. The electric torque wrench as claimed in claim 2 , wherein a free end of the extension arm includes a circular ring installed thereon, and the circular ring is secured and attached onto the driving device.

10. The electric torque wrench as claimed in claim 9 , wherein an outer side of the ring gear member includes at least one fastening piece.

11. The electric torque wrench as claimed in claim 10 , wherein the driving device includes a fastening slot and a retaining slot; the fastening piece of the ring gear member is secured inside the fastening slot, and the extension arm is positioned inside the retaining slot.

12. The electric torque wrench as claimed in claim 3 , wherein a free end of the extension arm includes a circular ring installed thereon, and the circular ring is secured and attached onto the driving device.

13. The electric torque wrench as claimed in claim 12 , wherein an outer side of the ring gear member includes at least one fastening piece.

14. The electric torque wrench as claimed in claim 13 , wherein the driving device includes a fastening slot and a retaining slot; the fastening piece of the ring gear member is secured inside the fastening slot, and the extension arm is positioned inside the retaining slot.

15. The electric torque wrench as claimed in claim 4 , wherein a free end of the extension arm includes a circular ring installed thereon, and the circular ring is secured and attached onto the driving device.

16. The electric torque wrench as claimed in claim 5 , wherein a free end of the extension arm includes a circular ring installed thereon, and the circular ring is secured and attached onto the driving device.

17. The electric torque wrench as claimed in claim 1 , wherein a rear end of the driving device includes a hollow mounting portion; the mounting portion is installed between the outer housing and the ring gear member.

18. The electric torque wrench as claimed in claim 1 , wherein the torque sensing unit is a strain gauge.

19. The electric torque wrench as claimed in claim 1 , wherein the torque sensing unit is electrically connected to a human-machine interface.

20. The electric torque wrench as claimed in claim 1 , wherein the transmission shaft of the reduction device is formed by a first shaft and a second shaft; the first shaft is engaged with the reduction gear assembly, and the second shaft is connected to the driving device; a universal joint is arranged between the first shaft and the second shaft.