Grip apparatus and robot apparatus including the same

1. A grip apparatus comprising:

a first finger;

a second finger configured to face the first finger;

a first link configured to have a first end connected to the first finger;

a second link configured to have a first end connected to the second finger; and

a differential apparatus configured to connect a second end of the first link and a second end of the second link, the differential apparatus comprising:

a motor;

a first shaft;

a side gear connected to the first shaft;

a second gear coaxial with the side gear;

a first spider shaft and a second spider shaft in parallel with the first shaft, the first spider shaft and the second spider shaft spanning the second gear and the side gear;

a first spider gear engaged with the side gear and rotatably supported on the first spider shaft; and

a second spider gear engaged with the first spider gear and the second gear, the second spider gear being rotatably supported on the second spider shaft,

wherein the differential apparatus rotates the first link and the second link in different directions when the motor is driven, and

wherein the differential apparatus rotates the first link in a first direction when the second link rotates in the first direction by an external force.

2. The grip apparatus of claim 1 ,

wherein the first link includes a first gear region at the second end thereof and the second link includes a second gear region at the second end thereof,

wherein the differential apparatus further comprises:

a first gear configured to be engaged with the first gear region, and

a third gear configured to be engaged with the second gear region and the second gear, and

wherein the second gear is configured to be interlocked with the first gear and rotate with respect to the first gear.

3. The grip apparatus of claim 2 , wherein the differential apparatus further comprises a ring gear configured to be disposed between the first gear and the second gear, and configured to be rotated by the motor.

4. The grip apparatus of claim 2 , wherein the first gear region and the second gear region have the same gear ratio.

5. The grip apparatus of claim 2 ,

wherein the differential apparatus further comprises a second shaft configured to have a first end connected to the second gear and rotate integrally with the second gear,

wherein the first shaft is configured to have a first end connected to the first gear and rotate integrally with the first gear, and

wherein the first shaft and the second shaft are coaxially disposed.

6. The grip apparatus of claim 2 ,

wherein the differential apparatus further comprises a ring gear configured to be disposed between the first gear and the second gear and configured to be rotated by the motor,

wherein the side gear is configured to be connected to a second end of the first shaft and configured to be rotated integrally with the first shaft, and

wherein the first spider shaft and the second spider shaft are configured to be rotated integrally with the ring gear.

7. The grip apparatus of claim 5 , wherein the first gear region and the third gear are disposed on opposite sides with respect to a central axis of the first shaft and the second shaft.

8. The grip apparatus of claim 2 ,

wherein the differential apparatus further comprises a ring gear configured to be disposed between the first gear and the second gear and configured to be rotated by the motor, and

wherein the first shaft penetrates the ring gear.

9. The grip apparatus of claim 5 , wherein the differential apparatus further comprises:

a first cam member configured to be connected in parallel to the first shaft, and

a second cam member configured to be connected in parallel to the second shaft and in contact with the first cam member.

10. The grip apparatus of claim 9 , wherein the differential apparatus further comprises:

a bolt configured to be fixedly disposed inside at least one of the first shaft and the second shaft, and

a pressing member configured to connect at least one of the first cam member and the second cam member with the bolt.

11. The grip apparatus of claim 10 , wherein the pressing member comprises a compression spring.

12. The grip apparatus of claim 9 ,

wherein the first shaft and the second shaft include key grooves formed on inner surfaces thereof, and

wherein the first cam member and the second cam member are respectively inserted along the key grooves formed in the first shaft and the second shaft.

13. The grip apparatus of claim 9 , wherein the first cam member and the second cam member include concave surfaces facing each other.

14. The grip apparatus of claim 1 , further comprising a housing configured to rotatably support the first end of each of the first link and the second link.

15. A robot apparatus comprising:

an image sensor configured to detect of a shape of an object;

a grip apparatus comprising:

a first finger;

a second finger, finger;

a first link configured to have a first end connected to the first finger;

a second link configured to have a first end connected to the second finger; and

a differential apparatus configured to connect a second end of the first link and a second end of the second link, the differential apparatus comprising:

a motor;

a first shaft;

a side gear connected to the first shaft;

a second gear coaxial with the side gear;

a first spider shaft and a second spider shaft in parallel with the first shaft, the first spider shaft and the second spider shaft spanning the second gear and the side gear;

a first spider gear engaged with the side gear and rotatably supported on the first spider shaft; and

a second spider gear engaged with the first spider gear and the second gear, the second spider gear being rotatably supported on the second spider shaft; and

a processor configured to control the grip apparatus such that the first finger and the second finger are spaced apart by a distance corresponding to a thickness of the object detected by the image sensor.