US-12618461-B2 - Actuator and method of manufacturing the same

Abstract

An actuator may include a motor generating a rotational force, a gear assembly transmitting the rotational force of the motor, and a housing accommodating the gear assembly therein. The gear assembly includes a driving gear provided on a driving shaft of the motor, a first gear unit connected with the driving gear, and a second gear unit connected with the first gear unit to transmit the rotational force transmitted from the first gear unit to a power conversion unit, and the first gear unit includes a gear shaft, a first driven gear provided on one side of the gear shaft and meshed with the driving gear, a second driven gear provided on the other side of the gear shaft and meshed with the second gear unit, and a bearing provided on the gear shaft between the first driven gear and the second driven gear.

Inventors

• Jaehyun Lee

Assignees

• HL MANDO CORPORATION

Dates

Publication Date

20260505

Application Date

20240416

Priority Date

20230706

Claims (19)

1. 1 . An actuator comprising: a motor configured to generate a rotational force; a gear assembly configured to transmit the rotational force of the motor; and a housing accommodating the gear assembly therein, wherein: the gear assembly includes a driving gear provided on a driving shaft of the motor, a first gear unit rotatably connected with the driving gear, and a second gear unit rotatably connected with the first gear unit to transmit the rotational force transmitted from the first gear unit, the first gear unit includes a gear shaft, a first driven gear provided on one portion of the gear shaft and rotatably coupled with the driving gear provided on the driving shaft of the motor, a second driven gear provided on an other portion of the gear shaft and rotatably coupled with the second gear unit, the actuator further comprises a bearing positioned on the gear shaft of the first gear between the first driven gear and the second driven gear, and a support member coupled to an outer circumferential surface of the gear shaft of the first gear unit to support the bearing positioned between the first driven gear and the second driven gear, and wherein the bearing is press-fitted onto the gear shaft of the first gear unit.
2. 2 . The actuator of claim 1 , wherein the housing includes a bearing accommodation portion supporting one end portion and an other end portion of the bearing positioned between the first driven gear and the second driven gear.
3. 3 . The actuator of claim 1 , wherein: the housing includes at least one pair of mounting parts protruding from an outer surface of the housing and fixed to a structure of a vehicle; and the pair of mounting parts are positioned symmetrically with respect to the second gear unit.
4. 4 . The actuator of claim 3 , wherein: at least one protruding portion of the housing protruding outward accommodates at least a part of the first gear unit therein; and an outer end of at least one of the pair of mounting parts fixed to the structure of the vehicle is located further outward than an outer end of the protruding portion accommodating the at least a part of the first gear unit.
5. 5 . The actuator of claim 1 , wherein the gear shaft of the first gear unit is fixedly inserted in a coupling hole of an inner ring of the bearing.
6. 6 . The actuator of claim 5 , wherein the support member is a clip member.
7. 7 . The actuator of claim 5 , wherein the first driven gear is a helical gear molded on the gear shaft.
8. 8 . The actuator of claim 7 , wherein the support member is a support ring provided on the gear shaft between the helical gear and the bearing to support the bearing.
9. 9 . The actuator of claim 8 , wherein one end portion of the bearing is supported by the support ring provided on the gear shaft and an other end portion of the bearing is supported by a latching step formed on the gear shaft.
10. 10 . The actuator of claim 5 , wherein the first driven gear is a helical gear coupled on the gear shaft by a rivet.
11. 11 . The actuator of claim 1 , wherein the second driven gear is a worm gear integrally formed on the gear shaft.
12. 12 . The actuator of claim 11 , wherein the second gear unit includes a worm wheel rotatably meshed with the worm gear.
13. 13 . The actuator of claim 1 , wherein the housing includes: at least one pair of mounting parts protruding from an outer surface of the housing and fixed to a structure of a vehicle; and at least one protruding portion protruding outward to accommodate at least a part of the gear assembly therein, and wherein an outer end of at least one of the pair of mounting parts fixed to the structure of the vehicle is located further outward than an outer end of the at least one protruding portion accommodating the at least a part of the first gear unit.
14. 14 . The actuator of claim 13 , wherein the pair of mounting parts are provided symmetrically with respect to the second gear unit.
15. 15 . A method of manufacturing an actuator, the method comprising: providing a motor configured to generate a rotational force; and providing a gear assembly, configured to transmit the rotational force of the motor, into a housing, wherein: the providing of the gear assembly includes providing a driving gear on a driving shaft of the motor, providing a helical gear rotatably coupled with the driving gear on one portion of a worm shaft, providing a worm gear on an other portion of the worm shaft, and providing a bearing on the worm shaft, and the providing of the bearing includes press-fitting the bearing onto an outer circumferential surface of the worm shaft between the helical gear and the worm gear, the method further comprises providing a clip member on the worm shaft to support the bearing after the press-fitting of the bearing onto the worm shaft.
16. 16 . The method of claim 15 , wherein the providing of the helical gear includes injection-molding the helical gear on the worm shaft after the press-fitting of the bearing onto the worm shaft.
17. 17 . The method of claim 16 , wherein the injection-molding of the helical gear comprises injection-molding the helical gear with a support ring on the worm shaft between the helical gear and the bearing.
18. 18 . The method of claim 15 , wherein the providing of the helical gear includes fixedly riveting the helical gear to the worm shaft after the press-fitting of the bearing onto the worm shaft.
19. 19 . The method of claim 15 , wherein the worm gear provided in the providing of the worm gear is integrated with the worm shaft.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims the priority to and the benefit of Korean Patent Application No. 10-2023-0087930, filed on Jul. 6, 2023 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. BACKGROUND 1. Field Some embodiments of the present disclosure generally relate to an actuator and a method of manufacturing the same, and more specifically, to an actuator for a brake system, of which a shape and a structure are simplified to improve applicability and assemblability to a vehicle, and a method of manufacturing the same. 2. Description of the Related Art Brake systems are necessarily mounted in vehicles to perform braking, and various types of brake systems have been developed for the safety of drivers and passengers. The conventional brake system uses a mechanically connected booster when a driver presses a brake pedal in order to supply a hydraulic pressure necessary for braking to a wheel cylinder. However, for a driver's convenience, an electromechanical braking system receives a driver's braking intention using an electrical signal and operates a power transmission device such as a motor to brake a vehicle based on the electrical signal. Such an electromechanical brake system receives power from an actuator including a motor and a reducer to provide a clamping pressure of a brake disc and perform service braking or parking braking of a vehicle. Meanwhile, the actuator which provides the power for braking may be mounted to a caliper housing provided on a side of each wheel. Typically, the actuator includes a plurality of gear elements, and an internal structure and an external shape are asymmetrical shapes in many cases. Accordingly, when the actuator is installed on each wheel, since mounting directions of a left wheel and a right wheel are different, there may be problems that the actuator interferes with components therearound and mountability and applicability to a vehicle are degraded. When the actuator of the left wheel and the actuator of the right wheel are designed or manufactured differently or separately in order to solve these problems, there are problems that a production efficiency of the product decreases, and a manufacturing cost increases. In addition, as the conventional actuator has the asymmetrical shape, a direction of a thrust applied to the gear elements may change, a wear portion may be changed according to a position of the wheel on which the actuator is mounted, and thus the durability of the product may be degraded. SUMMARY Therefore, it is one aspect of the present disclosure to provide an actuator of which mountability and applicability to a vehicle are improved, and a method of manufacturing the same. It is another aspect of the present disclosure to provide an actuator that improves space utilization of a vehicle body, and a method of manufacturing the same. It is still another aspect of the present disclosure to provide an actuator that improves the durability and performance of a product, and a method of manufacturing the same. It is yet another aspect of the present disclosure to provide an actuator which stably generates and provides braking power regardless of a position of a wheel which is mounted to a vehicle, and a method of manufacturing the same. It is yet another aspect of the present disclosure to provide an actuator that simplifies a structure and a shape of a product to improve assemblability and productivity, and a method of manufacturing the same. It is yet another aspect of the present disclosure to provide an actuator of which a design is simplified and a manufacturing cost is reduced, and a method of manufacturing the same. In accordance with one aspect of the present disclosure, an actuator includes a motor configured to provide a driving force, a gear assembly configured to transmit the driving force of the motor, and a housing in which the gear assembly is accommodated, wherein the gear assembly includes a driving gear provided on a driving shaft of the motor, a first gear unit connected to the driving gear to transmit a rotational force, and a second gear unit connected to the first gear unit to transmit the rotational force transmitted from the first gear unit to a power conversion unit, and the first gear unit includes a gear shaft, a first driven gear provided on one side of the gear shaft and meshed with the driving gear, a second driven gear provided on the other side of the gear shaft and meshed with the second gear unit, and a bearing provided between the first driven gear and the second driven gear on the gear shaft. The housing may include a bearing accommodation part provided to surround one end portion and the other end portion of the bearing. The housing may include at least one pair of mounting parts protruding from an outer surface of the housing and mounted on a supportable structure using a fastening member, and the pair of mounting par