Actuator for braking devices

Abstract

This invention discloses an actuator for a braking device. According to an embodiment of the invention, the actuator includes: a housing having a motor housing and a gear housing; a motor, housed in the motor housing; and a reduction gear, housed in the gear housing. The reduction gear includes: a crossed helical gear comprising a drive helical gear coupled to the shaft of the motor and an annular gear having a driven helical gear meshing with the drive helical gear on its outer periphery; and a planetary gear comprising a sun gear rotating with the annular gear, an annular gear formed as an internal gear, a plurality of planetary gears meshing with the sun gear and the annular gear, and a bracket having an output shaft and rotatably supporting the plurality of said planetary gears.

Description

Technical Field

[0001] The present invention relates to an actuator for a braking device, and more specifically, to an actuator for a braking device capable of realizing a parking function through the operation of a motor. Background Technology

[0002] Generally, a braking device is a device that stops a vehicle from moving when braking or parking, and is used to prevent the vehicle's wheels from turning.

[0003] Recently, electronic parking brake (EPB) systems, which are driven by electronically controlled parking brakes, have been widely used. These EPBs are installed on top of traditional disc brakes to perform the functions of parking brakes. Electronic disc brakes include cable puller types, motor-on-caliper (MOC) types, and hydraulic parking brake types.

[0004] Korean Patent Publication No. 10-2011-0072877 (June 29, 2011) relates to an actuator structure for an MOC type electronic parking brake and discloses an actuator for an electronic disc brake, wherein a motor that generates power is connected to the actuator, and the torque is increased while the power generated by the motor is decelerated by using multiple gears, and the power is transmitted to the actuator and caliper to perform the braking operation. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] Embodiments of the present invention aim to provide an actuator for a braking device that can improve production efficiency by reducing the number of actuator components and increasing design freedom.

[0007] (II) Technical Solution

[0008] According to one aspect of the invention, an actuator for a braking device can be provided, comprising: a housing having a motor housing and a gear housing; a motor housing in the motor housing; and a reduction gear housing in the gear housing, the reduction gear comprising: a crossed helical gear including a drive helical gear coupled to the shaft of the motor and an annular gear having a driven helical gear meshing with the drive helical gear on its outer periphery; and a planetary gear including a sun gear rotating with the annular gear, an annular gear formed as an internal gear, a plurality of planetary gears meshing with the sun gear and the annular gear, and a bracket having an output shaft and rotatably supporting the plurality of planetary gears.

[0009] In addition, the driven threaded gear can be configured as a spur gear.

[0010] In addition, the ring wheel can be formed into a cylindrical shape with an open bottom and accommodate the ring gear on the inside, and the sun gear can pass through the shaft hole of the ring gear and be inserted into the inside of the ring gear.

[0011] In addition, the ring gear can be fastened to the gear housing by a hook fastening method.

[0012] In addition, the outer periphery of the ring gear may be provided with multiple locking ribs, which restrict and constrain the rotation of the ring gear in the gear housing.

[0013] In addition, the reduction device may include a primary reduction structure of the threaded gear reduction section and a secondary reduction structure of the planetary gear reduction section.

[0014] In addition, the shaft of the motor and the shaft of the annular wheel can be orthogonally arranged.

[0015] In addition, the rotational force of the driving threaded gear can be directly transmitted to the annular wheel through the driven threaded gear.

[0016] In addition, the shaft of the annular wheel can be set vertically, while the shaft of the motor can be set at an angle.

[0017] (III) Beneficial Effects

[0018] In embodiments of the present invention, the motor output is achieved through a two-stage reduction structure consisting of a threaded gear reduction section and a planetary gear reduction section. This reduces the number of components, thereby improving production efficiency by reducing weight and cost.

[0019] Furthermore, in embodiments of the present invention, by using a threaded gear reduction section, the power transmission of the motor can be engaged at any angle. Therefore, compared with the structure that is always orthogonally engaged according to the characteristics of the existing worm gear power transmission structure, the actuator can be manufactured so that the caliper and the motor do not interfere with each other due to the increased design freedom. Attached Figure Description

[0020] Figure 1 This is a partial cross-sectional view of an actuator for a braking device according to an embodiment of the present invention.

[0021] Figure 2 This is an exploded perspective view of an actuator for a braking device according to an embodiment of the present invention.

[0022] Figure 3 A threaded gear reduction section for an actuator of a braking device according to an embodiment of the present invention is shown.

[0023] Figure 4 A planetary gear reduction section for an actuator of a braking device according to an embodiment of the present invention is shown.

[0024] Figure 5 This is an exploded perspective view of a planetary gear reduction section according to an embodiment of the present invention.

[0025] Figure 6 A threaded gear reduction section for an actuator of a braking device according to another embodiment of the present invention is shown. Detailed Implementation

[0026] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below are examples provided to fully convey the spirit of the invention to those skilled in the art. The present invention is not limited to the embodiments described below and may be embodied in other forms. For clarity of explanation, parts unrelated to the description have been omitted from the drawings, and the width, length, thickness, etc., of components may be enlarged in the drawings for ease of explanation. Throughout the specification, the same reference numerals denote the same components.

[0027] Figure 1 This is a partial cross-sectional view of an actuator for a braking device according to an embodiment of the present invention. Figure 2 This is an exploded perspective view of an actuator for a braking device according to an embodiment of the present invention. Figure 3 A threaded gear reduction section for an actuator of a braking device according to an embodiment of the present invention is shown. Figure 4 A planetary gear reduction section for an actuator of a braking device according to an embodiment of the present invention is shown. Figure 5 This is an exploded perspective view of a planetary gear reduction section according to an embodiment of the present invention.

[0028] Reference Figures 1 to 5 According to an embodiment of the present invention, the actuator 10 for a braking device includes a housing 20 having a motor housing 21 and a gear housing 22.

[0029] One side of the housing 20 may have a motor housing 21 that is open on one side to accommodate the motor 30, and the other side of the housing 20 may have a cylindrical gear housing 22 that is open at the top and bottom to accommodate the speed reduction device.

[0030] The speed reduction device is installed into the gear receiving portion 22 through the open portion of the gear receiving portion 22, and the open portion of the gear receiving portion 22 can be sealed by the cover 25.

[0031] The power of motor 30 is amplified and output through the reduction gear and output shaft 55.

[0032] The reduction gear is equipped with a two-stage reduction structure including a crossed helical gear reduction section 40 and a planetary gear reduction section 50.

[0033] The threaded gear reduction unit 40 includes: a driving threaded gear 41, which is coupled to the shaft 31 of the motor 30; and an annular wheel 43, on the outer periphery of which a driven threaded gear 42 is disposed, which meshes with the driving threaded gear 41.

[0034] The driving threaded gear 41 and the driven threaded gear 42 can be configured as helical gears, or, as... Figure 6 As shown, the driving threaded gear 41 can be configured as a helical gear, while the driven threaded gear 42 can be configured as a spur gear.

[0035] Since the threaded gear reducer 40 can engage at any angle when transmitting power from the motor 30 to the annular wheel 43 (i.e., it can realize motion transmission between intersecting shafts), the design freedom is increased. As a result, the caliper and motor 30 installed in the narrow space of the vehicle will not interfere with each other.

[0036] That is, such as Figure 3 As shown, the shaft 31 of the motor 30 and the shaft of the annular wheel 43 can be orthogonally arranged, or, as... Figure 6 As shown, the shaft 31 of the motor 30 intersects the shaft of the annular wheel 43 at any angle; that is, the shaft of the annular wheel 43 can be set vertically, while the shaft 31 of the motor 30 can be set at an angle.

[0037] The planetary gear reducer 50 includes: a sun gear 51 that rotates together with a ring gear 43; a ring gear 52 that is formed as an internal gear; a plurality of planetary gears 53 that mesh with the sun gear 51 and the ring gear 52; and a bracket 54 having an output shaft 55, wherein the plurality of planetary gears 53 are rotatably supported by the bracket 54.

[0038] The annular wheel 43 is formed into a hollow cylinder with one side open. A driven threaded gear 42 is provided on its outer periphery to mesh with a drive threaded gear 41 mounted on the shaft 31 of the motor 30, and a sun gear 51 is fixedly provided in the center of the inner receiving space 44.

[0039] The ring gear 52 is formed as a hollow cylinder with one side open, and is rotatably supported in the inner receiving space 44 of the ring wheel 43.

[0040] The inner circumference of the ring gear 52 is formed with an inner gear 52a that meshes with a plurality of planetary gears 53, and the outer circumference of the ring gear 52 is provided with a plurality of locking ribs 60 for limiting rotation when the ring gear 52 is installed in the gear receiving part 22.

[0041] The lower end of the ring gear 52 is provided with a hook 61 for engaging when the ring gear 52 is installed into the gear receiving part 22, so the ring gear 52 can be detachably engaged into the gear receiving part 22 by means of hook fastening.

[0042] The other side of the seal of the ring gear 52 has a shaft hole 52b formed at its center, which allows the sun gear 51 to pass through and be inserted when the ring wheel 43 is installed.

[0043] When the ring gear 52 is installed into the gear receiving part 22, the hook 61 is inserted into and engaged in the hook groove 62 provided in the gear receiving part 22, and the locking rib 60 can be placed in the rib groove 63 provided in the gear receiving part 22 and supported therein.

[0044] The bracket 54 can be formed in the shape of a disc, with a plurality of planetary gear shafts 54a spaced at predetermined intervals along the circumference on its upper surface, and a bracket shaft 54b at the center of its upper surface.

[0045] Multiple planetary gears 53 are rotatably supported by multiple planetary gear shafts 54a, and the bracket shaft 54b can pass through the center of the sun gear 51 and be rotatably coupled into the shaft support hole 25a formed on the cover 25.

[0046] An output shaft 55 is disposed at the center of the lower surface of the bracket 54. The output shaft 55 can rotate integrally with the bracket 54.

[0047] The operation of the actuator for the braking device according to an embodiment of the present invention will be described below.

[0048] When the driver applies the parking brake after stopping the vehicle, the motor 30 is driven to rotate the shaft 31 of the motor 30, and the drive threaded gear 41 mounted on the shaft 31 of the motor 30 will rotate together. Therefore, the annular wheel 43 rotates according to the rotation of the driven threaded gear 42 meshing with the drive threaded gear 41, thereby achieving a first-stage reduction.

[0049] Furthermore, the rotational force of the ring gear 43 is transmitted to multiple planetary gears 53 via the sun gear 51, and the multiple planetary gears 53 revolve around the sun gear 51 along the inner gear 52a of the ring gear 52. As described above, the bracket 54 rotates through the revolving multiple planetary gears 53, thereby rotating the output shaft 55 in a state of achieving two-stage reduction.

[0050] That is, since the rotational force of the drive threaded gear 41 coupled to the shaft 31 of the motor 30 is directly transmitted to the ring wheel 43 through the driven threaded gear 42, compared with the existing structure composed of a three-stage reduction structure, not only can the reduction efficiency be improved, but the operating time of the actuator 10 can also be significantly reduced due to the reduction of the total reduction ratio.

[0051] Furthermore, since the threaded gear reduction section 40, which can mesh at any angle as a first-stage reduction structure, is provided, the design freedom is increased, thus providing the advantage of significantly improving vehicle installability when installed in the narrow space of a vehicle.

[0052] The above description illustrates and describes specific embodiments. However, the present invention is not limited to the above embodiments, and those skilled in the art should be able to make various modifications and implement the invention without departing from the spirit and intent of the technical concept set forth in the claims.

Claims

1. An actuator for a braking device, comprising: The housing has a motor housing and a gear housing; The motor is housed in the motor housing. as well as The speed reduction device is housed in the gear receiving portion. The speed reduction device includes: A threaded gear reduction unit includes a drive threaded gear coupled to the shaft of the motor and an annular wheel with a driven threaded gear meshing with the drive threaded gear on its outer periphery; and The planetary gear reducer includes a sun gear that rotates together with the ring gear, a ring gear formed as an internal gear, a plurality of planet gears meshing with the sun gear and the ring gear, and a bracket having an output shaft and rotatably supporting the plurality of planet gears. The driving threaded gear is configured as a helical gear, and the driven threaded gear is configured as a spur gear. The shaft of the annular wheel is vertically arranged, and the shaft of the motor is inclined, so that the threaded gear reduction unit can mesh at any angle when transmitting power from the motor to the annular wheel, and the shaft of the motor and the shaft of the annular wheel can intersect at any angle other than a right angle.

2. The actuator for a braking device according to claim 1, wherein, The ring wheel is formed into a cylindrical shape with an open lower part to accommodate the ring gear on the inside, and the sun gear passes through the shaft hole of the ring gear and is inserted into the inside of the ring gear.

3. The actuator for a braking device according to claim 2, wherein, The ring gear is fastened to the gear housing by a hook fastening method.

4. The actuator for a braking device according to claim 3, wherein, The outer periphery of the ring gear is provided with multiple locking ribs, which restrict the rotation of the ring gear in the gear housing.

5. The actuator for a braking device according to claim 1, wherein, The speed reduction device includes a primary speed reduction structure of the threaded gear speed reduction section and a secondary speed reduction structure of the planetary gear speed reduction section.

6. The actuator for a braking device according to claim 1, wherein, The motor shaft and the annular wheel shaft are orthogonally arranged.

7. The actuator for a braking device according to claim 1, wherein, The rotational force of the driving threaded gear is directly transmitted to the annular wheel through the driven threaded gear.

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