Strain wave gear device
AssigneeRiken
InventorsSatoru Fujita, Kazuo Ishizuka, Tomoki Shirasawa, Ryo Kamiyama
Life of this patent
Estimating the term…
Abstract
It is included an internal gear (2), an external gear (3) having flexibility, and a wave generator (4) that forms a meshing part (P) with the internal gear (2) in the external gear (3) and moves the meshing part (P) in a circumferential direction of the internal gear (2). The wave generator (4) is configured such that the meshing part (P) is formed at three or more positions in a circumferential direction of the external gear (3). A value (DpF/ZF) obtained by dividing a working pitch diameter DpF of the external gear (3) by the number of teeth ZF is greater than a value (DpR/ZR) obtained by dividing a working pitch diameter DpR of the internal gear (2) by the number of teeth ZR.
Claims4
A strain wave gear device comprising:
- an internal gear;
- an external gear that has flexibility and is arranged at an inner circumference side of the internal gear;
- and
- a wave generator that is assembled to an inner circumference of the external gear to cause the external gear to noncircularly deflect to form a meshing part with the internal gear in the external gear and to move the meshing part in a circumferential direction of the internal gear, wherein
- the wave generator is configured such that the meshing part is formed at three or more positions in a circumferential direction of the external gear, and
- in a state before the external gear is assembled to the wave generator, a value (DpF/ZF) obtained by dividing a working pitch diameter DpF of the external gear by the number of teeth ZF of the external gear is greater than a value (DpR/ZR) obtained by dividing a working pitch diameter DpR of the internal gear by the number of teeth ZR of the internal gear and
- wherein
- a tip diameter DaR, a root diameter DdR, and the number of teeth ZR of the internal gear;
- a tip diameter DaF, a root diameter DdF, and the number of teeth ZF of the external gear;
- and
- a lift amount D of a working pitch circle of the external gear, the lift amount D being generated by assembling the external gear to the wave generator, satisfy a relation of:
- 1<{ZR·(DaR+DdR+DaF+DdF−4D)}/{ZF·(DaR+DdR+DaF+DdF+4D)}≤1.11.
Dependencies are inferred from the claim text.