Electromechanical actuator

Patent metadata

Field	Value
Publication number	US-9685838-B2
Application number	US-201414503830-A
Country	US
Kind code	B2
Filing date	Oct 1, 2014
Priority date	Oct 8, 2013
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

An electromechanical actuator is provided whose structure is simplified and made small, and with which an output portion can be driven even if a jammed state occurs in a screw mechanism. An electromechanical actuator is configured that includes an electric motor having a first rotor portion and a second rotor portion capable of relative rotation with respect to each other, and a jam relief mechanism having a first conversion portion having a first screw mechanism capable of converting rotational force of the first rotor portion into thrust force and moving an output portion back and forth, a sliding support mechanism which can transmit the rotational force of the first rotor portion to the first conversion portion, and a second conversion portion having a second screw mechanism which moves the output portion back and forth together with the first conversion portion.

First claim

What is claimed is:

1. An electromechanical actuator comprising:
an electric motor having a first rotor portion and a second rotor portion that serve as a pair of rotor portions, which are each formed in a cylindrical shape, are arranged within a cylindrical stator fixed to a housing, in an axial direction of the stator, and can relatively rotate with respect to each other;
an output portion that outputs driving force; and
a jam relief mechanism having a first conversion portion that has a first screw mechanism capable of converting rotational force of the first rotor portion into thrust force and moving the output portion back and forth, a sliding support mechanism provided between the first rotor portion and the first conversion portion, the sliding support mechanism supporting the first conversion portion so as to be able to be displaced in an axial direction with respect to the first rotor portion and being able to transmit the rotational force of the first rotor portion to the first conversion portion, and a second conversion portion that has a second screw mechanism which converts rotational force of the second rotor portion into thrust force and moves the output portion back and forth together with the first conversion portion.

2. The electromechanical actuator according to claim 1 ,
further comprising a rotation member that moves the output portion back and forth by rotating together with the first rotor portion, and also moves the output portion back and forth together with the first conversion portion by the second rotor portion rotating,
wherein the rotation member has a sliding portion that is accommodated in the first rotor portion so as to be coaxial with the first rotor portion, the sliding portion being unable to rotate with respect to the first rotor portion and being able to slide in the axial direction by means of the sliding support mechanism.

3. The electromechanical actuator according to claim 2 ,
wherein the rotation member is provided with a second screw portion that is integrated with the sliding portion so as to be coaxial with the sliding portion, can relatively rotate with respect to a first screw portion formed in an inner circumferential portion of the second rotor portion, around an axis of the first screw portion, and can be relatively displaced in the axial direction with respect to the first screw portion, and
the second screw mechanism has the first screw portion and the second screw portion.

4. The electromechanical actuator according to claim 2 ,
wherein the first screw mechanism has a third screw portion in which a screw channel is formed, and a fourth screw portion to which the output portion is connected or in which the output portion is provided, the fourth screw portion being attached so as to be able to relatively rotate around an axis of the third screw portion and being able to be relatively displaced in the axial direction with respect to the third screw portion.

5. The electromechanical actuator according to claim 4 ,
wherein the rotation member is formed in a cylindrical shape, and
the fourth screw portion is accommodated within the rotation member.

6. The electromechanical actuator according to claim 5 ,
wherein the fourth screw portion is arranged radially inward of the sliding portion.

7. The electromechanical actuator according to claim 1 ,
further comprising a bearing portion that is provided between the pair of rotor portions and allows the pair of rotor portions to rotate with respect to each other.

8. The electromechanical actuator according to claim 1 ,
wherein the output portion is provided with a connected portion with which rotation of the output portion with respect to the housing is restricted by the connected portion being connected to equipment driven by the driving force that is output by the output portion.

Assignees

• Nabtesco Corp

Inventors

• Ueyama Masayoshi
• Higuchi Ryoichi

Classifications

• F16H2025/2078

  the rotor being integrated with the nut or screw body · CPC title

• H02K2213/06

  Machines characterised by the presence of fail safe, back up, redundant or other similar emergency arrangements · CPC title

• H02K7/06 Primary

  Means for converting reciprocating motion into rotary motion or vice versa · CPC title

• F16H25/205

  comprising alternate power paths, e.g. for fail safe back-up · CPC title

• H02K16/02

  Machines with one stator and two {or more} rotors · CPC title