DE-112024002924-T5 - ELECTRO ACTUATOR

Abstract

An electric actuator comprises a first unit containing an electric motor, a first reduction gear, and a first housing, and a second unit containing a fourth reduction gear, a rotary-to-linear motion conversion mechanism, and a second housing in which these components are enclosed. The first and second units are detachably connected. This allows the electric actuator to be more easily mounted on a vehicle.

Inventors

• Ryohei MARUO
• Ryuya EZAKI

Assignees

• ASTEMO, LTD.

Dates

Publication Date

20260513

Application Date

20240610

Priority Date

20230707

Claims (8)

1. Electric actuator comprising: a first unit comprising an electric motor, an input element to which a rotation is transmitted from the electric motor, and a first housing accommodating the electric motor and the input element; a second unit comprising an output element to which a rotation is transmitted from the input element, a rotary-to-linear motion conversion mechanism configured to convert a rotary motion from the output element into a linear motion, and a second housing containing the output element and the rotary-to-linear motion conversion mechanism, the first unit and the second unit being detachably connected to one another.
2. electric actuator after Claim 1 , wherein the first unit and the second unit are detachably connected to each other on a surface parallel to a direction of movement of a linear motion element of the rotary-linear motion conversion mechanism.
3. Electric actuator according to Claim 1 or 2 , wherein the first unit and the second unit can be connected in such an orientation that a rotary shaft of the electric motor of the first unit and the direction of movement of the linear motion element of the rotary-linear motion conversion mechanism of the second unit are parallel or orthogonal to each other.
4. Electric actuator according to Claim 3 , wherein the first unit and the second unit can be connected such that the rotary shaft of the electric motor of the first unit and the direction of movement of the linear motion element of the rotary-linear motion conversion mechanism of the second unit are parallel to each other, and a main body section of the electric motor of the first unit and the rotary-linear motion conversion mechanism of the second unit are arranged on opposite sides of the output element of the second unit.
5. Electric actuator according to Claim 1 , wherein the first unit further comprises: an adapter unit section comprising an adapter housing rotatably supporting a rotating shaft of the electric motor, and a motor unit section comprising a motor housing containing a main body part of the electric motor.
6. Electric actuator according to Claim 5 , wherein the motor unit section and the adapter unit section are detachably connected to each other.
7. electric actuator after Claim 5 , wherein the adapter unit section has a connecting element for supplying an energy source to the electric motor.
8. electric actuator after Claim 1 , wherein the rotation of the input element is transmitted to the output element via an intermediate transmission element, and the intermediate transmission element is supported by the first housing and/or the second housing.

Description

TECHNICAL FIELD The present invention relates to an electric actuator, which is used, for example, for a disc brake or a drum brake to brake a vehicle. TECHNICAL BACKGROUND An electric parking brake device disclosed in PTL 1 uses an electric actuator which transmits a rotational input from an electric motor via a reduction gear mechanism to a rotary-to-linear motion conversion mechanism to advance or retract a linear motion element (a screw shaft) of the rotary-to-linear motion conversion mechanism, and engages or disengages a parking brake by pulling or unwinding a brake cable coupled to the linear motion element of the rotary-to-linear motion conversion mechanism by means of an action of this electric actuator. CITATION LIST PATENT LITERATURE PTL 1: Japanese Disclosure Document No. 2023-67950 PRESENTATION OF THE INVENTION TECHNICAL PROBLEM Generally, an electric actuator is directly or indirectly connected to a braking device, such as a drum brake equipped with an electric parking brake. In other words, the electric actuator should be located in or near a wheel of the vehicle to which it is attached. This means that the shape of the electric actuator is subject to significant limitations due to the wheel size, the type of suspension, and the chassis shape of the vehicle to which it is attached. However, in the electric actuator described above, as detailed in PTL 1, the electric motor, reduction gear mechanism, and rotary-to-linear motion conversion mechanism are contained and integrally designed within the same actuator housing. Consequently, this electric actuator requires its shape to be modified each time it is installed, according to the available space, to avoid interfering with various vehicle-side structures. This presents a challenge regarding its fitment into a vehicle and leaves room for improvement. One of the objectives of the present invention is to provide an electric actuator whose installability in a vehicle is improved. SOLUTION TO THE PROBLEM According to one aspect of the present invention, an electric actuator comprises a first unit comprising an electric motor, an input element to which rotation is transmitted from the electric motor, and a first housing containing the electric motor and the input element, and a second unit comprising an output element to which rotation is transmitted from the drive element, a rotary-to-linear motion conversion mechanism configured to convert a rotary motion from the output element into a linear motion, and a second housing containing the output element and the rotary-to-linear motion conversion mechanism. The first unit and the second unit are detachably connected to one another. According to one aspect of the present invention, the electric actuator can be improved with regard to its mountability on a vehicle. BRIEF DESCRIPTION OF THE DRAWINGS 1 is a front view of a drum brake for which an electric actuator according to an embodiment of the present invention is used.2 is a rear view of the drum brake for which the electric actuator is used according to the present embodiment.3 This is a perspective view of the electric actuator according to the present embodiment.4 is a cross-sectional view of the electric actuator according to the present embodiment (an electric motor is omitted).5 is a perspective view of an adapter unit section of a first unit used for the electric actuator according to the present embodiment.6 is an exploded view of the adapter unit section of the first unit used for the electric actuator according to the present embodiment.7 is an exploded view of a motor unit section of the first one unit, which is used for the electric actuator according to the present embodiment.8 is an exploded view of the adapter unit section and part of the motor unit section of the first unit used for the electric actuator according to the present embodiment.9 is an exploded view of a second unit used for the electric actuator according to the present embodiment.10 is a partially enlarged perspective view of the second unit used for the electric actuator according to the present embodiment.11 Diagrams are to be presented to illustrate the electric actuator according to the present embodiment and to illustrate a connection configuration between the first unit and the second unit according to a first embodiment, and 11(a) and 11(b) These are perspective views before and after assembly. 12 are diagrams for representing a connection configuration between the first unit and the second unit according to a second embodiment, and 12(a) and 12(b) These are perspective views before and after assembly.13 are diagrams for representing a connection configuration between the first unit and the second unit according to a third embodiment, and 13(a) and 13(b) These are perspective views before and after assembly. DESCRIPTION OF EXECUTION FORMS In the following description, embodiments of the present invention are described with reference to the 1 to 13 described in det