Motor with worm reduction gear
AssigneeMitsuba Electric Manufacturing Co., Ltd.
InventorKatsuyoshi Kitada
Life of this patent
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Abstract
In the motor with the worm reduction gear, wherein a worm is provided at an end portion of a rotary shaft, a worm wheel is in meshing engagement with the worm and rotation of the rotary shaft is reduced in speed and transmitted to load, such an arrangement is adopted that a first damper and a second damper, which are different in elasticity from each other, are provided at end portions in the axial direction of the rotary shaft, and, at an initial stage where the thrust force from the rotary shaft is low, only the elastic force of the first damper lower in elasticity acts on the rotary shaft and, at a stage where the thrust force becomes high, both the elastic forces of the first damper and the second damper act on the rotary shaft.
Claims11
A motor comprising a rotary shaft having first and second end faces and a first end portion located adjacent said first end face;
- a worm reduction gear including a worm on said first end portion of said rotary shaft and a worm wheel in meshing engagement with said worm whereby rotation of said rotary shaft is reduced in speed and transmitted to a load;
- and a plurality of elastic members different in elasticity from each other located adjacent said first end face of said rotary shaft in the axial direction of said rotary shaft to support thrust forces tending to move said rotary shaft in the direction toward said first end face, said elastic members including at least one elastic member of lower elasticity and one elastic member of higher elasticity, said elastic members being positioned so that said elastic member of lower elasticity urges said rotary shaft in the direction away from said first end face without said member of higher elasticity contributing to the force urging said rotary shaft away from said first end face when small thrust forces in the direction toward said first end face are applied to said rotary shaft and so that when higher thrust forces are applied to said shaft tending to move it toward said first end face both said member of lower elasticity and said member of higher elasticity in combination support the thrust force by both of them urging said rotary shaft in the direction away from said first end face.
Dependencies are inferred from the claim text.