Universal driving device

1. A universal driving apparatus comprising:

a sun gear rotatably provided;

a ring gear in which a ring gear axis is moveable relative to a sun gear axis; and

a gear train engaging the sun gear to the ring gear and configured to allow a relative motion between the sun gear axis and the ring gear axis and to define a continuous power transmission state between the sun gear and the ring gear.

2. The universal driving apparatus of claim 1 , wherein the gear train includes a plurality of links having connection angles that vary depending on the relative motion between the sun gear axis and the ring gear axis.

3. The universal driving apparatus of claim 2 ,

wherein the plurality of links includes:

a first link, a first end of which is connected to a rotation shaft of the sun gear; and

a second link, a first end of which is connected to a second end of the first link, and

wherein a joint pinion having a same number of teeth as the sun gear is provided on a connecting portion of the second end of the first link and the first end of the second link.

4. The universal driving apparatus of claim 3 , wherein a final pinion is disposed on a second end of the second link and engages with the ring gear, and the final pinion has a same number of teeth as the sun gear.

5. The universal driving apparatus of claim 4 ,

wherein the gear train further includes a series of gears, and

wherein the final pinion is configured to transmit power to the ring gear through the series of gears connected from the sun gear to the joint pinion.

6. The universal driving apparatus of claim 4 , wherein the gear train is provided in plural.

7. The universal driving apparatus of claim 6 , wherein rotation shafts of the final pinions of the plurality of gear trains are supported on a carrier.

8. The universal driving apparatus of claim 2 ,

wherein the gear train further includes a series of gears, and

wherein the plurality of links includes:

a first link connected to a rotation shaft of the sun gear; and

a second link connected to the first link, and

wherein rotation shafts of the series of gears are provided on the first link and the second link to transmit power from the sun gear to the ring gear.

9. The universal driving apparatus of claim 8 , wherein gears, which are disposed at even-numbered positions from the sun gear among the series of gears forming the gear train, have a same number of teeth as the sun gear.

10. The universal driving apparatus of claim 9 , wherein a gear, which is disposed at a second position from the sun gear, is a joint pinion provided coaxially with a rotation shaft of the first link and a rotation shaft of the second link, and a gear, which is disposed at a fourth position from the sun gear, is a final pinion that engages with the ring gear.

11. The universal driving apparatus of claim 10 , wherein a first intermediate pinion having a rotation shaft provided on the first link engages with the sun gear and the joint pinion, and a second intermediate pinion having a rotation shaft provided on the second link engages with the joint pinion and the final pinion.

12. The universal driving apparatus of claim 10 , wherein the gear train is provided in plural, and the final pinions of the gear trains are supported on a carrier so that relative positions between the final pinions are constantly maintained and only rotations of the final pinions about their own axes are allowed.

13. The universal driving apparatus of claim 2 , wherein the gear train includes at least four pinions continuously engaging with one another, and rotation shafts of the at least four pinions are rotatably supported on the plurality of links connected continuously.

14. The universal driving apparatus of claim 13 , wherein the gear train is configured to constantly maintain a relative phase between the sun gear and the ring gear with respect to the relative motion in an upward/downward direction between a rotation shaft of the sun gear and a rotation shaft of the ring gear.

15. The universal driving apparatus of claim 13 , wherein a final pinion, which is a pinion engaging with the ring gear among the at least four pinions, is supported on a carrier so that the final pinion is inhibited from rotating about the sun gear and only allowed to rotate about an axis of the final pinion.

16. The universal driving apparatus of claim 1 , wherein the gear train is provided in plural, and the plurality of gear trains is symmetric in a circumferential direction of the sun gear.

17. The universal driving apparatus of claim 1 , wherein the gear train is provided in plural, and the plurality of gear trains is asymmetric in a circumferential direction of the sun gear.

18. The universal driving apparatus of claim 1 , wherein a power source is connected to the sun gear, a load is connected to the ring gear, and a rotation speed from the power source is decelerated and transmitted to the load.

19. The universal driving apparatus of claim 1 , wherein a power source is connected to the ring gear, a load is connected to the sun gear, and a rotation speed from the power source is accelerated and transmitted to the load.

20. The universal driving apparatus of claim 1 , wherein a rotation shaft of a motor is connected to the sun gear, and a wheel is connected to the ring gear.