Electric actuator
AssigneeNtn Corporation
InventorsShintarou Ishikawa, Takahide Saito
Life of this patent
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Abstract
A differential device (5) of an electric actuator (1) includes a driving rotary body (2), a driven rotary body (3), and a planetary rotary body (52). A first speed reducer (5a) is formed between the planetary rotary body (52) and the driving rotary body (2). A second speed reducer (5b) is formed between the planetary rotary body (52) and the driven rotary body (3). The electric actuator (1) includes a first bearing (53) configured to support the planetary rotary body (52) on an inner side of a rotor (42) of an electric motor (4), and a second bearing (54) configured to support the planetary rotary body (52) at a position shifted in an axial direction so as to be prevented from overlapping the rotor (42). The second bearing (54) is formed of a deep-groove ball bearing.
Claims20
An electric actuator, comprising:
- a differential device comprising:
- a driving rotary body rotatable about a rotation axis;
- a planetary rotary body capable of rotating on its axis and revolving about the rotation axis;
- a driven rotary body rotatable about the rotation axis,
- the planetary rotary body meshing with the driving rotary body and the driven rotary body;
- a first speed reducer formed between the planetary rotary body and the driving rotary body;
- and
- a second speed reducer formed between the planetary rotary body and the driven rotary body,
- the first speed reducer and the second speed reducer having different speed reduction ratios;
- an electric motor comprising a rotor configured to drive the planetary rotary body;
- a first bearing configured to support the planetary rotary body on an inner side of the rotor;
- and
- a second bearing configured to support the planetary rotary body at a position shifted in an axial direction so as to be prevented from overlapping the rotor,
- wherein the second bearing is a deep-groove ball bearing,
- wherein the first bearing comprises rolling elements that roll in contact with the planetary rotary body,
- wherein the planetary rotary body has an outer peripheral surface on which the rolling elements roll in contact with the outer peripheral surface, and
- wherein the outer peripheral surface of the planetary rotary body contacts the rolling elements on the inner side of the rotor.
An electric actuator, comprising:
- a differential device comprising:
- a driving rotary body rotatable about a rotation axis;
- a planetary rotary body capable of rotating on its axis and revolving about the rotation axis;
- a driven rotary body rotatable about the rotation axis,
- the planetary rotary body meshing with the driving rotary body and the driven rotary body;
- a first speed reducer formed between the planetary rotary body and the driving rotary body;
- and
- a second speed reducer formed between the planetary rotary body and the driven rotary body,
- the first speed reducer and the second speed reducer having different speed reduction ratios;
- an electric motor comprising a rotor configured to drive the planetary rotary body;
- a first bearing configured to support the planetary rotary body on an inner side of the rotor;
- and
- a second bearing configured to support the planetary rotary body at a position shifted in an axial direction so as to be prevented from overlapping the rotor,
- wherein the differential device further comprises an eccentric member configured to rotate integrally with the rotor and change a rotation phase difference of the driven rotary body with respect to the driving rotary body,
- wherein the second bearing is a deep-groove ball bearing, and
- wherein the second bearing comprises:
- an outer ring fixed to an inner periphery of the eccentric member;
- and
- an inner ring fixed to an outer periphery of the planetary rotary body.
Dependencies are inferred from the claim text.