Speed reducer and motor with speed reducer
AssigneeShinano Kenshi Co., Ltd.
InventorHiroshi UEHARA
Life of this patent
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Abstract
To provide an inexpensive and thin motor with a speed reducer capable of elongating lifetime of bearings by reducing the effect of internal moments acting on an output member without using expensive bearings. A motor with a speed reducer performing output with a gear mechanism rotating to reduce speed around an electric motor M and an eccentric shaft driven to rotate by the electric motor M, in which a plurality of external gears are respectively assembled to the eccentric shaft at positions where moments obtained by multiplying distances in an axial direction from a position of a bearing provided in a speed reducer housing by magnitudes of loads acting on output pins at the positions are cancelled out with each other.
Claims6
A speed reducer performing output with a gear mechanism rotating to reduce speed around an eccentric shaft driven to rotate by a drive source comprising:
- the eccentric shaft driven and transmitted by a drive source;
- an internal gear provided around an inner peripheral surface of a speed reducer housing;
- a plurality of external gears eccentrically assembled to the eccentric shaft and revolving around the eccentric shaft by meshing with the internal gear;
- through holes piercing in an axial direction provided on the plural external gears;
- output pins piercing while externally contacting the through holes, provided at plural positions in a circumferential direction along the eccentric shaft;
- an output member to which end portions of the output pins are connected and rotating to reduce speed with the revolution of the plural external gears through an outer bearing provided in the speed reducer housing,
- wherein the plural external gears are respectively assembled to the eccentric shaft at positions where moments obtained by multiplying distances “a”, “b”, and “c” in the axial direction from the position of a bearing center line L of the outer bearing provided in the speed reducer housing to the center positions of the respective external gears by magnitudes of loads fa, fb and fc acting on the output pins at the positions are cancelled out with one another.
Dependencies are inferred from the claim text.