Wheel assembly for robotic cleaner and robotic cleaner having the same

1. A wheel assembly for a robotic cleaner comprising:

a frame;

a moveable arm pivotally coupled to the frame;

a driven wheel rotatably coupled to the moveable arm such that the driven wheel pivots with the moveable arm;

a pin coupled to the frame; and

a torsion spring that includes a coiled portion that extends around the pin, the torsion spring configured to urge the driven wheel towards an extended position, the torsion spring being spaced apart from the moveable arm, wherein the moveable arm is configured to pivot such that a rotation axis of the driven wheel transitions between a position vertically above the pin and a position vertically below the pin.

2. The wheel assembly of claim 1 , further comprising a power train coupled to the moveable arm such that the power train pivots with the moveable arm, wherein the power train includes a drive motor and a drive train, the drive train including one or more gears.

3. The wheel assembly of claim 1 , wherein the torsion spring directly engages a bushing, the bushing extending around an axle coupled to the driven wheel.

4. The wheel assembly of claim 1 , wherein the torsion spring includes a first spring arm configured to urge the driven wheel towards the extended position and a second spring arm configured to engage the frame.

5. The wheel assembly of claim 4 , wherein the driven wheel includes an axle extending therefrom, the axle rotating with the driven wheel.

6. The wheel assembly of claim 5 , wherein a bushing extends around the axle.

7. The wheel assembly of claim 6 , wherein the first spring arm is configured to engage the bushing.

8. The wheel assembly of claim 7 , wherein the axle includes a first end and a second end and the driven wheel includes a hub configured to receive the second end.

9. The wheel assembly of claim 8 , wherein the hub is over-molded over at least a portion of the axle.

10. The wheel assembly of claim 8 further comprising a power train coupled to the moveable arm such that the power train pivots with the moveable arm, wherein the power train includes a drive train having a drive train cover.

11. The wheel assembly of claim 10 , wherein the first end of the axle extends from the drive train cover by an extension distance.

12. The wheel assembly of claim 11 , wherein the bushing is disposed between the drive train cover and the first end of the axle.

13. A robotic cleaner comprising:

a body;

a wheel assembly coupled to the body, the wheel assembly comprising:

a frame;

a pin coupled to the frame;

a moveable arm pivotally coupled to the frame; and

a driven wheel rotatably coupled to the moveable arm such that the driven wheel pivots with the moveable arm; and

a torsion spring configured to urge the driven wheel towards an extended position, the torsion spring including a coiled portion that extends around the pin, wherein the moveable arm is configured to pivot such that a rotation axis of the driven wheel transitions between a position vertically above the pin and a position vertically below the pin.

14. The robotic cleaner of claim 13 , wherein the torsion spring includes a first spring arm configured to urge the driven wheel towards the extended position and a second spring arm configured to engage the frame.

15. The robotic cleaner of claim 13 , wherein the driven wheel includes an axle extending therefrom, the axle rotating with the driven wheel.

16. The robotic cleaner of claim 15 , wherein a bushing extends around the axle.

17. The robotic cleaner of claim 16 , wherein the torsion spring includes a first spring arm configured to engage the bushing.

18. The robotic cleaner of claim 17 , wherein the axle includes a first end and a second end and the driven wheel includes a hub configured to receive the second end.

19. The robotic cleaner of claim 18 , wherein the hub is over-molded over at least a portion of the axle.