In-wheel working device

1. An in-wheel working device, comprising:

a motor part configured to generate power;

a first speed reduction part comprising a sun gear connected to a driving shaft of the motor part and configured to rotate with the driving shaft, a planetary gear configured to rotate along a circumference of the sun gear, and a carrier configured to rotate with the planetary gear;

a second speed reduction part installed in series to the first speed reduction part, and configured to perform speed reduction through a gear ratio while rotating with the carrier axially connected to the second speed reduction part;

a hub part spline-coupled to the second speed reduction part, and configured to rotate with the second speed reduction part; and

a wheel member connected to the hub part, and configured to rotate with the hub part.

2. The in-wheel working device of claim 1 , wherein a center axis of the motor part is installed at a position separated by a preset distance from a rotational center axis of the wheel member.

3. The in-wheel working device of claim 1 , wherein the first speed reduction part comprises a ring gear located outside the planetary gear, and the ring gear is fixed to a housing part which is restricted from rotating and is coupled to the motor part while surrounding the outside of the first speed reduction part.

4. The in-wheel working device of claim 3 , wherein the first speed reduction part is disposed closer to the outside of a vehicle than the motor part, and a rotational center of the first speed reduction part is disposed in the same axis line as the driving shaft of the motor part.

5. The in-wheel working device of claim 3 , wherein the second speed reduction part comprises:

a small-diameter gear shaft axially coupled to the carrier;

a small-diameter gear installed in a ring shape outside the small-diameter gear shaft and configured to rotate with the small-diameter gear shaft; and

a large-diameter gear having a larger diameter than the small-diameter gear and configured to engage and rotate with the small-diameter gear.

6. The in-wheel working device of claim 5 , wherein the second speed reduction part is disposed closer to the outside of a vehicle than the first speed reduction part.

7. The in-wheel working device of claim 5 , wherein the hub part comprises:

a hub outer race fixed to the housing part and restricted from rotating;

a hub inner race spline-coupled to the large-diameter gear, configured to receive rotation power from the large-diameter gear, connected to the wheel member, and configured to rotate with the wheel member; and

a hub bearing located between the hub outer race and the hub inner race.

8. The in-wheel working device of claim 7 , further comprising:

a braking disk connected to the hub inner race, and configured to rotate with the hub inner race; and

a caliper part installed in the housing part, and configured to generate a braking force while coming in contact with the braking disk.

9. The in-wheel working device of claim 5 , wherein the carrier and the small-diameter gear shaft are formed as separate members, and axially connected to each other by a spline coupling.

10. The in-wheel working device of claim 5 , further comprising a bearing part configured to reduce friction when the motor part, the first speed reduction part, and the second speed reduction part are rotated.

11. The in-wheel working device of claim 10 , wherein the bearing part comprises a first bearing, located between the driving shaft and the carrier, configured to reduce friction between the driving shaft and the carrier.

12. The in-wheel working device of claim 11 , wherein the sun gear comprises:

a sun gear body located between the driving shaft and the planetary gear; and

an extension protrusion extended from the sun gear body and located between the driving shaft and the first bearing.

13. The in-wheel working device of claim 11 , wherein the bearing part comprises:

a second bearing located between the housing part and the small-diameter gear shaft, and configured to support a first side of the small-diameter gear shaft; and

a third bearing located between the small-diameter gear shaft and a speed reducer cover coupled to the housing part, and configured to support a second side of the small-diameter gear shaft.

14. The in-wheel working device of claim 13 , wherein the bearing part further comprises a fourth bearing located between the housing part and the large-diameter gear, and configured to support one side of the large-diameter gear.