Actuator for brake device

Abstract

An actuator for a brake device is disclosed. According to one aspect of the present invention, there may be provided an actuator for a brake device, the actuator comprising: a housing provided with a motor accommodating portion for accommodating a motor and a gear accommodating portion for accommodating a reduction gear; a power connection unit connected to the motor; and a reduction gear connected to the power connection unit in which the reduction gear is provided with a first reduction gear unit connected to the power connection unit and a second reduction gear unit connected to the first reduction gear unit, and the first reduction gear unit is arranged as a bevel gear assembly.

Description

[0001] This application is a divisional application of the original patent application No. 202080061128.2 (International Application No.: PCT / KR2020 / 010678, Application Date: August 12, 2020, Invention Title: Actuator for Braking Device). Technical Field

[0002] This disclosure relates to an actuator for a braking device, and more specifically, to an actuator for a braking device capable of achieving a parking function through the operation of a motor. Background Technology

[0003] Brakes are typically devices that prevent a vehicle from moving during braking or parking, and are used to keep the vehicle's wheels from rotating.

[0004] Recently, electronic parking brake (EPB) systems, used for the operation of electronically controlled parking brakes, have become widely used. EPBs are installed on conventional disc brakes to perform the functions of parking brakes. EPBs include cable-operated, caliper motor (MOC)-operated, and hydraulic parking brake types.

[0005] For example, Korean Patent Publication No. 10-2011-0072877 (June 29, 2011) relates to an MOC-type EPB actuator structure. This document discloses an actuator used in an EPB, wherein a motor that generates power is connected to the actuator, and the power generated from the motor is reduced in speed using multiple gears, while increasing the torque transmitted to the actuator and caliper, thereby performing a braking operation.

[0006] However, the actuators used in EPB cause large vibrations and noise, and also have disadvantages in terms of assembly and economic feasibility. Summary of the Invention

[0007] Technical issues

[0008] One aspect of this disclosure provides an actuator for a braking device, which can achieve miniaturization and operational stability by improving the structure of each component, while having a simple structure, each component being, for example, a power transmission unit that transmits the driving force of a motor and a reduction gear unit that reduces rotational force.

[0009] Technical solution

[0010] According to one aspect of this disclosure, an actuator for a braking device is provided, the actuator comprising: a housing including a motor housing configured to house a motor and a gear housing configured to house a reduction gear; a power connection unit connected to the motor; and a reduction gear connected to the power connection unit; wherein the reduction gear includes a first reduction gear unit connected to the power connection unit and a second reduction gear unit connected to the first reduction gear unit, and the first reduction gear unit is configured as a bevel gear assembly.

[0011] The power connection unit includes: a drive shaft having a predetermined length and disposed between the motor and the reduction gear; a first helical gear connected to the rotating shaft of the motor; a second helical gear mounted at one end of the drive shaft and meshing with the first helical gear; and a bearing portion disposed on the drive shaft to rotatably support the drive shaft.

[0012] The first reduction gear unit includes: a first bevel gear portion disposed at the other end of the drive shaft; and a second bevel gear portion formed as a cylinder with an open lower portion to have an internal receiving space, and including gear teeth that mesh with the first bevel gear portion along the edge of the upper surface.

[0013] The first bevel gear portion may include gear teeth formed on the outer surface of the other end of the drive shaft.

[0014] The second reduction gear unit includes: a sun gear connected to the lower center of the second bevel gear portion to rotate together with the rotation of the second bevel gear portion; a plurality of planet gears meshing with the outer side of the sun gear; a gear mounting portion having a gear ring on its inner circumference to accommodate the plurality of planet gears; and a planet carrier rotatably supporting the plurality of planet gears and mounted to rotate coaxially with the sun gear, the planet carrier being provided with an output gear for outputting rotational power.

[0015] The gear mounting portion can be accommodated in the accommodating space of the second bevel gear portion, and the plurality of planetary gears arranged to mesh with the sun gear and the ring gear may be rotatably disposed in the internal space of the gear mounting portion.

[0016] The gear receiving portion may be provided with an extension plate, the gear mounting portion is connected to the extension plate, and a plurality of hooks are provided at the lower end of the gear mounting portion to be detachably attached to the extension plate.

[0017] The extension plate may be provided with a plurality of locking ribs spaced apart from each other at a predetermined distance along its circumferential direction, and a plurality of connecting ribs that engage with the plurality of locking ribs protrude from the lower outer peripheral surface of the gear mounting portion.

[0018] The actuator may also include a bracket configured to support the power connection unit from above the motor and a cover configured to cover the top of the housing.

[0019] Beneficial effects

[0020] The actuator for braking devices according to embodiments of the present disclosure can effectively achieve compact size and low-noise operation by using helical and bevel gears in the power transmission process of the motor.

[0021] Furthermore, the actuator for the braking device according to the embodiments of this disclosure can ensure a compact assembly because the gear mounting portion provided with the sun gear, planet gear and ring gear is arranged and meshes within the second bevel gear portion, resulting in improved miniaturization and operational stability of the actuator. Attached Figure Description

[0022] Figure 1 This is a perspective view showing an actuator for a braking device according to an embodiment of the present disclosure;

[0023] Figure 2 This is an exploded perspective view showing an actuator for a braking device according to an embodiment of the present disclosure;

[0024] Figure 3 This is an exploded perspective view showing the connection relationship between the power connection unit and the first reduction gear unit of the actuator for a braking device according to an embodiment of the present disclosure;

[0025] Figure 4 This is an exploded perspective view showing a reduction gear for an actuator of a braking device according to an embodiment of the present disclosure; and

[0026] Figure 5 This is a partial cross-sectional perspective view showing an actuator for a braking device according to an embodiment of the present disclosure. Detailed Implementation

[0027] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be understood that the terminology used in the specification and appended claims should not be construed as limited to its general or dictionary meaning, but rather is interpreted based on the principle that inventors are permitted to appropriately define terms for best interpretation, and on the meaning and concepts corresponding to the technical aspects of the present disclosure. Therefore, the description presented herein is merely a preferred example for illustrative purposes and is not intended to limit the scope of the present disclosure; thus, it should be understood that other equivalents and modifications may be made thereto without departing from the spirit and scope of the present disclosure.

[0028] Figure 1 This is a perspective view showing an actuator for a braking device according to an embodiment of the present disclosure. Figure 2 This is an exploded perspective view showing an actuator for a braking device according to an embodiment of the present disclosure. Figure 3 This is an exploded perspective view showing the connection relationship between the power connection unit and the first reduction gear unit of the actuator for a braking device according to an embodiment of the present disclosure. Figure 4 This is an exploded perspective view showing a reduction gear for an actuator of a braking device according to an embodiment of the present disclosure, and Figure 5 This is a partial cross-sectional perspective view showing an actuator for a braking device according to an embodiment of the present disclosure.

[0029] See Figures 1 to 5 According to an embodiment of the present disclosure, the actuator 10 for a braking device includes a housing 100 housing a motor 300 and a reduction gear 600, a power connection unit 500 connected to the motor 300, and a reduction gear 600 connected to the power connection unit 500. Furthermore, the actuator 10 for the braking device also includes a bracket 400 supporting the power connection unit 500 above the motor 300, and a cover 200 covering the top of the housing 100.

[0030] The housing 100 has a motor housing 110 on one side that houses the motor 300 and a gear housing 120 on the other side that houses the reduction gear 600. The housing 100 is configured with an open top, in which the motor housing 110 and the gear housing 120 are formed. The open top of the housing 100 is closed by a cover 200.

[0031] The motor receiving portion 110 has a depth sufficient to accommodate the motor 300 and may be cylindrical with an open top. Therefore, the motor 300 can be inserted and installed through the open top of the motor receiving portion 110.

[0032] The damper component 140 supporting the lower end of the motor 300 can be disposed on the bottom surface of the motor housing 110.

[0033] The gear receiving portion 120 may be arranged horizontally adjacent to the open top of the motor receiving portion 110. The gear receiving portion 120 may accommodate the reduction gear 600 and includes an extension plate 126 connected to the gear mounting portion 623 of the reduction gear 600, which will be described later. The gear receiving portion 120 may be arranged in a vertically open form to output the reduced rotational force through the reduction gear 600. The structure of the gear mounting portion 623 connected to the extension plate 126 will be described again below.

[0034] The cover 200 is configured as a box with an open lower side, and forms a space therein when attached to the housing 100. The cover 200 and the housing 100 can be made of synthetic resin material. The bracket 400, the power connection unit 500, and the reduction gear 600 are fixedly installed in the housing 100, and then the cover 200 is joined to the housing 100 by ultrasonic welding, laser welding, or the like, thereby easily sealing the interior of the housing 100.

[0035] On the other hand, the housing 100 includes a connector unit 130 that supplies power to the motor 130. When the motor 300 is installed in the housing 100, the power terminal 330 of the motor 300 can be configured to connect to the terminal tap 133 of the connector unit 130.

[0036] The power transmission from the motor 300 to the reduction gear 600 is carried out by the power connection unit 500.

[0037] The power connection unit 500 directly connects the motor 300 and the reduction gear 600 to transmit the rotational force of the motor 300. For this purpose, the power connection unit 500 can be disposed between the motor 300 and the reduction gear 600. More specifically, the power connection unit 500 includes a drive shaft 530 of predetermined length, a first helical gear 510 connected to the rotating shaft of the motor 300, a second helical gear 520 mounted at one end of the drive shaft 530 and meshing with the first helical gear 510, and a bearing portion 540 disposed on the drive shaft 530 to rotatably support the drive shaft 530. In this case, the bearing portion 540 can be arranged between the first helical gear 510 and the second helical gear 520 and supported by a bracket 400. Furthermore, a first bevel gear portion 611 of the first reduction gear unit 610, which will be described later, can be disposed at the other end of the drive shaft 530.

[0038] The first helical gear 510 rotates while its center is connected to the rotating shaft of the motor 300. The second helical gear 520, which meshes with the first helical gear 510, rotates while changing its rotation direction to be perpendicular to the rotating shaft of the motor 300. Using helical gears to change the rotation direction can significantly reduce noise because the meshing ratio is better than that of spur gears. In addition, it can also be used for speed reduction when adjusting the transmission ratio.

[0039] The reduction gear 600 includes a first reduction gear unit 610 connected to the power connection unit 500 and a second reduction gear unit 620 connected to the first reduction gear unit 610.

[0040] The first reduction gear unit 610 may be configured as a bevel gear assembly. More specifically, the first reduction gear unit 610 includes a first bevel gear portion 611 disposed at the other end of the drive shaft 530 and a second bevel gear portion 612 meshing with the first bevel gear portion 611.

[0041] The first bevel gear portion 611 may include gear teeth formed on the outer surface of the other end of the drive shaft 530. Therefore, the first bevel gear portion 611 rotates in the same direction of rotation as the drive shaft 530 and transmits rotational force to the second bevel gear portion 612. Here, the first bevel gear portion 611 is shown and described as being formed on the outer surface of the drive shaft 530 by machining a conical shape with gear teeth, but is not limited thereto. In other words, the first bevel gear portion 611 may be formed as a separate bevel gear and coupled to the drive shaft 530.

[0042] The second bevel gear portion 612 meshes with and rotates with the first bevel gear portion 611. The second bevel gear portion 612 converts the direction of rotation to a vertical direction. In other words, the direction of rotation is changed to a direction parallel to the rotation axis of the motor 300. The second bevel gear portion 612 can be formed as a cylinder with an open lower portion to have a receiving space S1 therein. Furthermore, the second bevel gear portion 612 includes gear teeth that mesh with the first bevel gear portion 611 along the edge of its upper surface so as to mesh with the first bevel gear portion 611. Therefore, the second bevel gear portion 612 meshes with the first bevel gear portion 611 on its upper side to rotate.

[0043] The second reduction gear unit 620 includes a sun gear 621 that rotates together with the second bevel gear portion 612, a plurality of planet gears 622 that mesh with the outer side of the sun gear 621, a gear mounting portion 623 having a gear ring 624 on its inner circumference to accommodate the plurality of planet gears 622, and a planet carrier 628. The planet carrier 628 rotatably supports the plurality of planet gears 622 and is mounted to rotate coaxially with the sun gear 621 and output rotational power. In this case, the three planet gears 622 are arranged around the sun gear 621.

[0044] The sun gear 621 is disposed in the receiving space S1 of the second bevel gear portion 612. More specifically, the sun gear 621 may be integrally formed with the second bevel gear portion 612 at the lower center. Furthermore, the sun gear 621 may be mounted at the lower center of the second bevel gear portion 612 to rotate together with the second bevel gear portion 612.

[0045] Considering efficiency and economic feasibility, the multiple planetary gears 622 are arranged into three, and these planetary gears are rotatably mounted on the branch shafts 628a in three directions branching from the planet carrier 628.

[0046] The gear mounting portion 623 has a shaft hole 625 that extends vertically through its center, and a gear ring 624 is disposed on the inner surface of the gear mounting portion 623 in the circumferential direction. The gear ring 624 can be integrally formed with the gear mounting portion 623.

[0047] The second bevel gear portion 612 can be rotatably supported above the gear mounting portion 623. For example, the receiving space S1 of the second bevel gear portion 612 can have a shape corresponding to that of the gear mounting portion 622. Therefore, the gear mounting portion 623 is arranged in the receiving space S1 of the second bevel gear portion 612. In other words, the second bevel gear portion 612 is configured to cover the upper surface and side surface of the gear mounting portion 623. Therefore, when the second bevel gear portion 612 covers the upper part of the gear mounting portion 623, the sun gear 621 is arranged in the internal space S2 of the gear mounting portion 623 through the shaft hole 625 of the gear mounting portion 623.

[0048] Furthermore, the gear mounting portion 623 is configured as a hollow cylinder with an open lower portion and can be detachably connected to the extension plate 126 formed in the gear receiving portion 120. A plurality of hooks 626 may be provided at the lower end of the gear mounting portion 623 to be detachably attached to the extension plate 126.

[0049] In addition, in order to stably connect the gear mounting portion 623 to the extension plate 126, the extension plate 126 may be provided with a plurality of locking ribs 127 spaced apart from each other at a predetermined distance along its circumferential direction, and a plurality of connecting ribs 627 engaging with the plurality of locking ribs 127 may protrude from the lower outer peripheral surface of the gear mounting portion 623.

[0050] When the gear mounting portion 623 is mounted on the extension plate 126, a plurality of hooks 626 are inserted into and engaged with a plurality of hook slots 126a formed in the extension plate 126, and the rotation of the gear mounting portion 623 is restricted by the mutual engagement of a plurality of locking ribs 127 and a plurality of connecting ribs 627.

[0051] On the other hand, although the gear mounting portion 623 is shown and described as being detachably mounted on the extension plate 126, embodiments of the present disclosure are not limited thereto and may be integrally formed with the housing 100.

[0052] The planet carrier 628 can be formed in a disc shape, and a plurality of planetary gear branch shafts 628a are provided on the upper surface of the planet carrier 628, spaced apart from each other at a predetermined distance along its circumferential direction. A planet carrier shaft portion 628b, extending upward through the shaft hole 625 of the gear mounting portion 623, is located at the center of the upper surface of the planet carrier 628, and an output gear 629 is located at the center of the lower surface of the planet carrier 628. In this case, the output gear 629 can be integrally formed with the planet carrier 628 and rotate together with it.

[0053] When the planet carrier 628 is connected to the gear mounting portion 623, the planet carrier shaft portion 628b passes through the center of the second bevel gear portion 612 and the sun gear 621, and is then rotatably connected to the shaft support hole formed in the cover 200.

[0054] When the speed reduction device 600 as described above is installed on the gear receiving portion 120, the gear mounting portion 623 can be accommodated in the receiving space S1 of the second bevel gear portion 612, and the plurality of planetary gears 622 arranged to mesh with the sun gear 621 and the ring gear 624 can be configured to rotate in the internal space S2 of the gear mounting portion 623, thereby achieving a compact connection structure.

[0055] The operation of an actuator for a braking device according to embodiments of the present disclosure will be described below.

[0056] When the driver applies the parking brake after stopping the vehicle, the motor 300 is driven to rotate the rotating shaft of the motor 300. As a result, the first helical gear 510 connected to the rotating shaft of the motor 300 rotates together, causing the second helical gear 520 connected to the first helical gear 510 to rotate.

[0057] When the drive shaft 530 rotates together with the second helical gear 520, the second bevel gear portion 612, which meshes with the gear teeth of the first bevel gear portion 611 formed on the drive shaft 530, rotates.

[0058] The sun gear 621 is disposed on the inner lower side of the second bevel gear portion 612 and rotates together with the second bevel gear portion 612 to transmit rotational force to a plurality of planet gears 622, and the plurality of planet gears 622 rotate around the sun gear 621 along a gear ring 624 disposed along the inner circumference of the gear mounting portion 623.

[0059] As the planet carrier 628 rotates via a plurality of planetary gears 622 that move about an orbit in this manner, the output gear 629 rotates.

[0060] As described above, although several embodiments of the present disclosure have been shown and described, those skilled in the art will understand that changes can be made to these embodiments without departing from the principles and spirit of the present disclosure, the scope of which is defined by the claims and their equivalents.

Claims

1. An actuator for a braking device, the actuator comprising: The housing includes a motor housing configured to house a motor and a gear housing configured to house a reduction gear. A power connection unit, which is connected to the motor; as well as The speed reduction device is connected to the power connection unit. The reduction gear includes a first reduction gear unit connected to the power connection unit and a second reduction gear unit connected to the first reduction gear unit. The first reduction gear unit is configured as a bevel gear assembly. The second reduction gear unit includes a planetary gear assembly, which is housed within the receiving space of the bevel gear assembly. The power connection unit includes a first helical gear connected to the rotating shaft of the motor and a second helical gear mounted at one end of the transmission shaft and meshing with the first helical gear to change the direction of rotation. The housing is configured such that the motor and the reduction gear are integrally combined.

2. The actuator according to claim 1, wherein, The power connection unit includes: The drive shaft has a predetermined length and is disposed between the motor and the reduction gear; and A bearing portion is disposed on the drive shaft to rotatably support the drive shaft.

3. The actuator according to claim 2, wherein, The first reduction gear unit includes: A first bevel gear portion, wherein the first bevel gear portion is disposed at the other end of the drive shaft; and The second bevel gear portion is formed as a cylinder with an open lower portion to have an internal receiving space, and includes gear teeth that mesh with the first bevel gear portion along the edge of its upper surface.

4. The actuator according to claim 3, wherein, The first bevel gear portion includes gear teeth formed on the outer surface of the other end of the drive shaft.

5. The actuator according to claim 3, wherein, The second reduction gear unit includes: A sun gear, which is connected to the lower center of the second bevel gear portion to rotate together with the rotation of the second bevel gear portion; Multiple planetary gears, wherein the multiple planetary gears mesh with the outer side of the sun gear; A gear mounting portion, wherein a gear ring is provided on its inner circumference to accommodate the plurality of planetary gears; and A planetary carrier rotatably supports the plurality of planetary gears and is mounted to rotate coaxially with the sun gear. The planetary carrier is provided with an output gear for outputting rotational power.

6. The actuator according to claim 5, wherein, The gear mounting portion is accommodated in the second bevel gear portion of the accommodating space, and The plurality of planetary gears, which mesh with the sun gear and the ring gear, are capable of rotating within the internal space of the gear mounting portion.

7. The actuator according to claim 5, wherein, The gear receiving portion is provided with an extension plate, and the gear mounting portion is connected to the extension plate. Multiple hooks are provided at the lower end of the gear mounting portion to be detachably attached to the extension plate.

8. The actuator according to claim 7, wherein, The extension plate is provided with a plurality of locking ribs spaced apart from each other at a predetermined distance in its circumferential direction, and a plurality of connecting ribs that engage with the plurality of locking ribs protrude from the lower outer peripheral surface of the gear mounting portion.

9. The actuator of claim 1, further comprising a bracket configured to support the power connection unit from above the motor and a cover configured to cover the top of the housing.

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