Robot, gear device, and gear device unit

1. A robot comprising:

a first member;

a second member configured to pivot with respect to the first member;

a gear device configured to transmit, from one side to another side of the first member and the second member, a driving force for pivoting the second member with respect to the first member; and

a driving source configured to generate the driving force, wherein

the gear device includes:

an internal gear including internal teeth; and

an external gear including external teeth, which partially mesh with the internal gear, and having flexibility, the external gear relatively rotating around a rotation axis with respect to the internal gear; and

a wave motion generator configured to come into contact with an inner circumferential surface of the external gear and move a meshing position of the internal gear and the external gear in a circumferential direction around the rotation axis,

the gear device further includes a wall section disposed at an end portion of tooth width of the internal gear and coupled to two dedenda adjacent to each other in the circumferential direction of the internal gear and a tooth bottom present between the two, and

wherein length in a tooth depth direction from the tooth bottom of the wall section is equal to or smaller than tooth depth of the internal gear.

2. The robot according to claim 1 , wherein the wall section is formed in an annular shape along a circumferential direction of the internal gear.

3. The robot according to claim 1 , wherein the wall section is integrated with the internal gear.

4. The robot according to claim 1 , further comprising a case configured to house the gear device, wherein

the wall section is integrated with the case.

5. The robot according to claim 1 , wherein

the external gear includes:

a tubular opening section including external teeth, which center on the rotation axis and mesh with the internal gear, and opened on one side; and

a tubular body section coupled to another side of the opening section,

the wave motion generator is coupled to the driving source, and

the wall section is disposed at an end portion on the body section side of the internal gear.

6. The robot according to claim 1 , wherein

the external gear includes:

a tubular opening section including external teeth, which center on the rotation axis and mesh with the internal gear, and opened on one side; and

a tubular body section coupled to another side of the opening section,

the external gear is coupled to the driving source, and

the end portion where the wall section is disposed is an opposite side of the body section side.

7. A gear device comprising:

an internal gear including internal teeth;

an external gear including external teeth, which partially mesh with the internal gear, and having flexibility, the external gear relatively rotating around a rotation axis with respect to the internal gear; and

a wave motion generator configured to come into contact with an inner circumferential surface of the external gear and move a meshing position of the internal gear and the external gear in a circumferential direction around the rotation axis, wherein

the internal gear includes a wall section coupled to two dedenda adjacent to each other in the circumferential direction and a tooth bottom present between the two dedenda and disposed at an end portion of tooth width, and

wherein length in a tooth depth direction from the tooth bottom of the wall section is equal to or smaller than tooth depth of the internal gear.

8. A gear device unit comprising:

a gear device including:

an internal gear including internal teeth;

an external gear including external teeth, which partially mesh with the internal gear, and having flexibility, the external gear relatively rotating around a rotation axis with respect to the internal gear; and

a wave motion generator configured to come into contact with an inner circumferential surface of the external gear and move a meshing position of the internal gear and the external gear in a circumferential direction around the rotation axis; and

a wall section disposed at an end portion of tooth width of the internal gear and coupled to two dedenda adjacent to each other in the circumferential direction of the internal gear and a tooth bottom present between the two dedenda, and

wherein the length in a tooth depth direction from the tooth bottom of the wall section is equal to or smaller than tooth depth of the internal gear.