Speed reducer and robot
AssigneeMitsubishi Electric Corporation
InventorsAkiko HAMADA, Mineo HIGUCHI
Life of this patent
Estimating the term…
Abstract
The speed reducer includes: a first sun gear; a second sun gear arranged coaxially with the first sun gear and having a different number of teeth from the first sun gear; a first planetary gear to engage with the first sun gear; a second planetary gear to engage with both the second sun gear and the first planetary gear and having an equal number of teeth to the first planetary gear; and a carrier part to rotatably fix relative positions of shafts of the first sun gear, the first planetary gear, and the second planetary gear and to rotate at a lower rotational speed than the first sun gear. The first sun gear and the second sun gear are rotated in opposite directions at an equal rotational speed.
Claims3
1:
- A speed reducer comprising:
- a first sun gear;
- a second sun gear arranged coaxially with the first sun gear and having a different number of teeth from the first sun gear;
- a first planetary gear to engage with the first sun gear;
- a second planetary gear to engage with both the second sun gear and the first planetary gear and having an equal number of teeth to the first planetary gear;
- and
- a carrier part to rotatably fix relative positions of shafts of the first sun gear, the first planetary gear, and the second planetary gear and to rotate at a lower rotational speed than the first sun gear, wherein
- the first sun gear and the second sun gear are rotated in opposite directions at an equal rotational speed.
2:
- The speed reducer according to claim 1, further comprising:
- a first bevel gear rotated by an electric motor;
- a second bevel gear rotated by the first bevel gear about a shaft perpendicular to a rotating shaft of the electric motor;
- and
- a third bevel gear to rotate in a direction opposite to a direction of rotation of the second bevel gear, the third bevel gear engaging with the first bevel gear and being arranged coaxially with the second bevel gear, wherein
- the first sun gear is fixed to the second bevel gear and rotates coaxially with the second bevel gear, and
- the second sun gear is fixed to the third bevel gear and rotates coaxially with the third bevel gear.
3:
- A robot comprising:
- the speed reducer according to claim 2;
- and
- a stationary part housing that fixes the electric motor, wherein
- the carrier part rotates or linearly moves with respect to the stationary part housing and forms an articulated shaft having a reduction ratio with respect to rotation of the electric motor.