US 11,852,049 B2
Electric actuator
Shintarou Ishikawa, Shizuoka (JP); and Takahide Saito, Shizuoka (JP)
Assigned to NTN CORPORATION, Osaka (JP)
Appl. No. 17/435,882
Filed by NTN CORPORATION, Osaka (JP)
PCT Filed Feb. 26, 2020, PCT No. PCT/JP2020/007744
§ 371(c)(1), (2) Date Sep. 2, 2021,
PCT Pub. No. WO2020/189200, PCT Pub. Date Sep. 24, 2020.
Claims priority of application No. 2019-049763 (JP), filed on Mar. 18, 2019; and application No. 2019-059054 (JP), filed on Mar. 26, 2019.
Prior Publication US 2022/0145783 A1, May 12, 2022
Int. Cl. F01L 1/352 (2006.01); F01L 1/344 (2006.01); F01L 1/047 (2006.01); H02K 7/08 (2006.01); H02K 7/116 (2006.01); H02K 21/16 (2006.01); F16C 19/54 (2006.01); F16H 57/021 (2012.01)
CPC F01L 1/344 (2013.01) [F01L 1/047 (2013.01); F01L 1/352 (2013.01); F16C 19/54 (2013.01); F16H 57/021 (2013.01); H02K 7/083 (2013.01); H02K 7/116 (2013.01); H02K 21/16 (2013.01); F01L 2820/032 (2013.01); F16C 2380/27 (2013.01)] 20 Claims
OG exemplary drawing
 
1. 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.