Actuator for braking device

Abstract

An actuator for a braking device is disclosed. According to one aspect of the disclosure, an actuator for a braking device includes a motor; a first reduction gear unit connected to the motor; and a second reduction gear unit connected to the first reduction gear unit; wherein the first reduction gear unit is provided as a planetary gear arrangement and the second reduction gear unit is provided as a bevel gear.

Description

[Technical field]

[0001] The present disclosure relates to an actuator for a braking device and in particular to an actuator for a braking device which is capable of performing a parking function by operating a motor. [General state of the art]

[0002] In general, a braking device is a device for preventing a vehicle from moving during braking or parking, and serves to prevent a wheel of the vehicle from rotating.

[0003] Recently, an electric parking brake (EPB) system has been widely used to electronically control the application of a parking brake, and the EPB is mounted on a conventional disc brake to perform the function of a parking brake. The disc brake includes a cable-operated type, a motor-on-caliper (MOC) type, and a hydraulic parking brake type.

[0004] For example, documents disclosed in Korean patent publications KR 10 2011 0 072 877 A (June 29, 2011) and KR 10 2018 0 133 976 A (December 18, 2018) relate to a structure of an EPB actuator of the MOC type. This EPB actuator discloses an actuator used in an electronic disc brake that slows down power generated from a motor while increasing torque by using a variety of wheel devices, and transmits the power to a caliper for a parking brake to perform a braking operation.

[0005] Actuators used in such electronic disc brakes generate strong vibrations and noise and are inferior in terms of assembly and price competitiveness.

[0006] Furthermore, actuators used in such electronic disc brakes have the disadvantage that the structure between the wheelsets for transmitting a rotational force is complicated, and heat loss and loss of durability of performance due to friction increase with the number of connecting parts of the wheelsets. [Revelation][Technical Problem Statement]

[0007] One aspect of the revelation is to provide an actuator for a braking device that is able to accommodate a planetary gear and a bevel gear connected to a motor, in order to have a simple structure and miniaturization, thereby reducing weight and increasing efficiency. [Technical solution]

[0008] According to one aspect of the present disclosure, an actuator for a braking device comprises a motor; a first reduction gear unit connected to the motor; and a second reduction gear unit connected to the first reduction gear unit; wherein the first reduction gear unit is provided as a planetary gear arrangement, and the second reduction gear unit is provided as a bevel gear arrangement.

[0009] The actuator may further include a housing that has a motor housing section to accommodate the motor and a gearbox housing section to accommodate the first reduction gearbox unit.

[0010] The actuator may further include a support coupled to a top of the gearbox housing section, on which the second reduction gearbox unit is installed.

[0011] The first reduction gear unit may comprise a sun gear connected to a rotating shaft of the motor; a plurality of planetary gear sets engaging with an outside of the sun gear; a gear assembly section provided with a ring gear on an inner circumference thereof to accommodate the plurality of planetary gear sets; and a support rotatably carrying the plurality of planetary gear sets and installed to rotate coaxially with the sun gear set, and provided with an external shaft for outputting rotational power.

[0012] The gearbox mounting section can be provided integrally with the gearbox housing section of the enclosure.

[0013] The gearbox mounting section can be detachably coupled to the housing.

[0014] The gearbox housing section can be fitted with an extension plate to which the gearbox mounting section is coupled, and a hook is provided at an outer lower end of the gearbox mounting section to allow it to be detached from the extension plate.

[0015] The extension plate can be provided with a plurality of locking ribs spaced apart from each other by a predetermined distance along a circumferential direction thereof, and coupling ribs engaging between the plurality of locking ribs can be formed to project from a lower side of the gearbox mounting section.

[0016] The second reduction gear unit may include a first bevel gear provided on an output shaft of the carrier; and a second bevel gear that engages with the first bevel gear.

[0017] The second reduction gear unit may further include a power transmission shaft provided to pass through the second bevel gear and rotate together with the second bevel gear.

[0018] An output wheel for delivering rotational power can be provided at one end of the power transmission shaft.

[0019] The actuator may further include a bearing provided on the power transmission shaft to rotatably support the power transmission shaft.

[0020] The bearing can be provided to be supported by a prop that is provided to install the second reduction gear unit.

[0021] A damping element to support a lower end of the motor can be provided on the floor of the motor housing section. [Beneficial effects]

[0022] One embodiment of the disclosure can provide an actuator for a braking device that is capable of compactness by using a planetary gear and a bevel gear in the power transmission process of the motor and by reducing its weight.

[0023] Furthermore, one embodiment of the disclosure can provide an actuator for a braking device that has a simple wheel connection structure to increase efficiency and be able to effectively implement low-noise operation. [Description of the drawings] Fig. Figure 1 is a perspective view illustrating an actuator for a braking device according to an embodiment of the disclosure. Fig. Figure 2 is an expanded perspective view illustrating an actuator for a braking device according to an embodiment of the disclosure. Fig. 3. A stretched perspective view of a lower side Fig. 2. Fig. Figure 4 is an expanded perspective view illustrating a coupling state between a motor and a first reduction gear unit for an actuator for a braking device according to an embodiment of the disclosure. Fig. Figure 5 is an expanded perspective view illustrating a coupling state between a support and a second reduction gear unit of an actuator for a braking device according to an embodiment of the disclosure. Fig. Figure 6 is a partially perspective view illustrating a coupling state of a first reduction gear unit and a second reduction gear unit of an actuator for a braking device according to an embodiment of the disclosure. Fig. Figure 7 is a view illustrating a housing for an actuator for a braking device according to another embodiment of the disclosure. Fig. Figure 8 is a view illustrating an actuator for a braking device according to another embodiment of the disclosure. Fig. Figure 9 is a view illustrating an actuator for a braking device according to another embodiment of the disclosure. [Embodiments of the invention]

[0024] The embodiments of the disclosure are described in detail below with reference to accompanying drawings. It must be understood that the terms used in the patent specification and the attached claims are not to be interpreted as general or dictionary definitions, but rather based on the meanings and concepts corresponding to the technical aspects of the disclosure, on the basis of the concept that the inventor is permitted to define terms expediently for the best possible explanation. The description proposed herein is therefore only a preferred example for illustrative purposes, which is not intended to limit the scope of the disclosure, and it must therefore be understood that other equivalents or modifications could be made to it without departing from the spirit and scope of the disclosure.

[0025] Fig. Figure 1 is a perspective view illustrating an actuator for a braking device according to an embodiment of the disclosure. Fig. Figure 2 is an expanded perspective view illustrating an actuator for a braking device according to an embodiment of the disclosure. Fig. 3 is a stretched perspective view showing a lower side of the Fig. 2 illustrates, Fig. Figure 4 is an expanded perspective view illustrating a coupling state between a motor and a first reduction gear unit of an actuator for a braking device according to an embodiment of the disclosure. Fig. Figure 5 is an expanded perspective view illustrating a coupling state between a support and a second reduction gear unit of an actuator for a braking device according to an embodiment of the disclosure, and Fig. Figure 6 is a partially perspective view illustrating a coupling state of a first reduction gear unit and a second reduction gear unit of an actuator for a braking device according to an embodiment of the disclosure.

[0026] With reference to the Fig. Figures 1 to 6 comprise an actuator 10 for a braking device according to one embodiment of the disclosure, comprising a motor 200, a first reduction gear unit 300 connected to the motor 200, and a second reduction gear unit 400 connected to the first reduction gear unit 300, as well as a housing 100 that accommodates the motor 200 and the first reduction gear unit 300. Furthermore, the actuator 10 for a braking device according to one embodiment of the disclosure also comprises a support 500 coupled to the housing 100, on which the second reduction gear unit 400 is installed.

[0027] The housing 100 includes a motor housing section 120, which accommodates the motor 200, and a gearbox housing section 130, which accommodates the first reduction gearbox unit 300. The gearbox housing section 130 is located on top of the motor housing section 120, and one portion of the gearbox housing section 130 is provided in an open form. The open top of the housing 100 can be closed with the support 500, which is described below.

[0028] The motor housing section 120 has a depth capable of accommodating the motor 200 and can have a cylindrical shape with an open top. The motor 200 can therefore be inserted and mounted through the open top of the motor housing section 120.

[0029] Meanwhile, a damping element 140, capable of absorbing vibrations while a lower end of the engine 200 is supported, can be installed on a floor of the engine housing section 120, thereby reducing noise caused by vibration by the damping element 140.

[0030] The gearbox housing section 130 is provided integrally with the open top of the motor housing section 120. The first reduction gear unit 300 is housed within the gearbox housing section 130, and an extension plate 133, coupled to the gearbox mounting section 330 of the first reduction gear unit 300 as described below, can be formed on the gearbox housing section 130. The gearbox housing section 130 can be provided in a vertically open form to output a torque that is reduced by the first reduction gear unit 300. A structure in which the gearbox mounting section 330 is coupled to the extension plate 133 is also described below.

[0031] The support 500 is provided in the form of a box with an open bottom and forms a space within it that is coupled to the housing 100. Both the support 500 and the housing 100 can be made of a resin material. After the motor 200, the first reduction gear unit 300, and the second reduction gear unit 400 are securely installed within the housing 100 and the support 500, the housing 100 and the support 500 can be joined by ultrasonic or laser welding. The interior of the housing 100 can then be easily sealed.

[0032] On the other hand, a connector section 110 is formed for supplying power to the motor 200 in the housing 100, and when the motor 200 is installed in the housing 100, a power terminal (not shown) of the motor 200 can be provided to be connected to a terminal of the connector section 110.

[0033] The first reduction gear unit 300 transmits the rotational power of the motor 200 by directly connecting the motor 200 and the second reduction gear unit 400. The first reduction gear unit 300 can be provided as a planetary gear arrangement.

[0034] More precisely, the first reduction gear unit 300 includes a sun gear 310 connected to a rotating shaft 210 of the motor 200, a plurality of planet gears 320 engaging with an outside face of the sun gear 310, the gear assembly section 330, which is provided with a ring gear 332 on an inner circumference to accommodate the plurality of planet gears 320, and a carrier 340 rotatably supporting the plurality of planet gears 320 and installed to rotate coaxially with the sun gear 310.

[0035] The multitude of planet gears 320 is provided in triplicate and arranged to surround the sun gear 310. Initially, three planet gears 320 are provided for efficiency and economic feasibility, but four planet gears can be provided and used optionally. The multitude of planet gears 320 is rotatably coupled to a planet gear shaft section 342 formed on the carrier 340.

[0036] The gear mounting section 330 is provided with a shaft bore 331 that penetrates vertically into its center, and the ring gear 332 is connected along an inner circumferential direction of the gear mounting section 330. The ring gear 332 can be manufactured integrally with the gear mounting section 330. Accordingly, when the gear mounting section 330 is mounted onto the gear housing section 130, the sun gear 310 is arranged in an interior space of the gear housing section 330, which is provided with the ring gear 332.

[0037] The gearbox mounting section 330 is provided in a hollow cylindrical shape with an open top and can be detachably coupled to the extension plate 133 formed in the gearbox housing section 130. A hook 335 can be provided at an outer lower end of the gearbox mounting section 330 to allow it to be detached from the extension plate 133.

[0038] In order to stably couple the gearbox mounting section 330 to the extension plate 133, the extension plate 133 can be provided with a plurality of locking ribs 134 spaced apart from each other by a predetermined distance along a circumferential direction thereof, and coupling ribs 334, which engage between the plurality of locking ribs 134, can be formed to project from a lower outer circumferential surface of the gearbox mounting section 330.

[0039] When the gearbox mounting section 330 is mounted onto the extension plate 133, the hook 335 is inserted into a hook groove 135 formed in the extension plate 133 to be bound, and as a result the plurality of locking ribs 134 and coupling ribs 334 are mutually loaded, so that rotation and separation of the gearbox mounting section 330 are restricted.

[0040] On the other hand, although the gear mounting section 330 has been illustrated and described as detachable on the extension plate 133, it is not limited to this. The gear mounting section 330 can, for example, be formed integrally with the housing 100' such that the ring gear 332' is provided in the gear housing section 130, this embodiment being shown in Fig. Figure 7 illustrates this. Fig. Figure 7 shows another embodiment of the disclosure, wherein the same reference numerals as in the drawings shown above refer to elements with the same function. In other words, the actuator for the brake device shown in Fig. Figure 7 shows the embodiment described above only in that the ring gear 332' of the gear assembly section is integrally provided with the housing 100', but the rest of the configuration is the same, so a detailed description of it is omitted.

[0041] With renewed reference also to the Fig. 1 to 6, the carrier 340 can be formed in a disk shape, and the plurality of planetary gear shaft sections 342, spaced apart from one another in the circumferential direction, are provided on its lower surface, and an output shaft 341 is provided at the center of its upper surface. At this point, the output shaft 341 can be formed integrally with the carrier 340 in order to rotate with it.

[0042] The second reduction gear unit 400 can be provided to be supported by the support 500 in such a way that it is connected to the first reduction gear unit 300. The second reduction gear unit 400 can be provided as a bevel gear assembly.

[0043] More specifically, the second reduction gear unit 400 can include a first bevel gear 410 provided on the output shaft 341 of the carrier 340, a second bevel gear 420 engaging with the first bevel gear 410, and a power transmission shaft 430 installed through the second bevel gear 420.

[0044] The first bevel gear 410 is provided in a conical shape and is coupled to rotate coaxially with the output shaft 341 of the carrier 340. Accordingly, the first bevel gear 410 rotates in the same direction as the carrier 340 and transmits the rotational force to the second bevel gear 420.

[0045] The second bevel gear for 420 rotates while engaging with the first bevel gear 410, and continues to rotate while the direction of rotation is changed to a direction perpendicular to the rotating shaft 210 of the motor 200. The change in direction of rotation using bevel gears 410 and 420 has a better contact ratio than that of a spur gear, so that noise can be significantly reduced, and the reduction ratio can also be adjusted to perform an efficient deceleration function.

[0046] The power transmission shaft 430 passes through the second bevel gear 420 in such a way that the second bevel gear 420 maintains an engagement with the first bevel gear 410 for rotation with the second bevel gear 420. The power transmission shaft 430 has a predetermined length, and an output gear 440 for outputting rotational power is provided at one end of it. The end at which the drive gear 440 of the power transmission shaft 430 is formed can be arranged to be exposed on the outside of the support arm 500.

[0047] A bearing 450 is provided on the power transmission shaft 430 such that the power transmission shaft 430 rotates continuously. The bearings 450 are provided as a pair and installed on the support arm 500. One of the bearings 450 is provided at the other end of the power transmission shaft 430, and the other bearing 450 can be provided between the second bevel gear 420 and the output gear 440 to rotatably support the power transmission shaft 430.

[0048] On the other hand, the output gear 440 can be provided with teeth formed on one end of an outer surface of the power transmission shaft 430. The drive gear 440 accordingly outputs rotational power while rotating in the same direction as the power transmission shaft 430. The output gear 440 can, for example, be provided to transmit the rotational power to an electric parking brake device.

[0049] The actuator 10 for the braking device, as described above, can be coupled to a caliper by means of a mounting section 510 provided on an outside of the support 500 to transmit power to a caliper for a parking brake (not shown). The mounting section 510 is a section coupled to the caliper for the parking brake and can be formed on an outside of the housing 100 in the same way as the support 500. Furthermore, the shape or number of mounting sections 510 can be varied according to a mounting position in which the actuator 10 for the braking device is installed to transmit power to the caliper. Fig. Figure 8 shows the actuator 10 for the brake device, which has the mounting section 510, the position of which is changed to couple with the saddle. Fig. Figure 8 is a view illustrating another embodiment of the disclosure, and the same reference numerals as in the embodiment described above refer to elements that have the same function.

[0050] With reference to Fig. 8. The mounting section 510 can be formed on a distal end of the support 500 in the direction in which the output wheel 440 is positioned, in order to be tightly coupled to the saddle. In other words, the position at which the mounting section 510 is formed for coupling with the saddle is changed to ensure practical installation.

[0051] On the other hand, in embodiments of the disclosure, the first reduction gear unit 300, which receives the torque from the motor 200, is provided as a planetary gear assembly, and the second reduction gear unit 400, which is connected to the first reduction gear unit 300, is provided as a bevel gear assembly, so that the structure has been illustrated and described as transmitting power in a so-called L-shape, but is not limited to this. For example, the first reduction gear unit 300 is provided as a bevel gear assembly, and the second reduction gear unit 400 is provided as a planetary gear assembly, so that the power can be transmitted to the saddle. As in Fig. As shown in Figure 9, the power can be transmitted in a so-called C-shape structure by changing the position and structure in which the bevel gear assembly and the planetary gear assembly are assembled, as described above. Fig. Figure 9 is a view illustrating another embodiment of the disclosure, and the same reference numerals as in the embodiment described above refer to elements that have the same function.

[0052] With reference to Fig.9. The actuator 10 for the braking device according to the embodiment of the disclosure can be provided to transmit power in a C-shaped structure by modifying the assembly structure between the reduction gears of the embodiment described above. Although not shown, for example, the bevel gear is mounted on the motor's drive shaft, and the motor's torque is transmitted by the sun gear of the planetary gear assembly through the power transmission shaft and the plurality of other bevel gears, such that the direction of the output torque (i.e., towards a direction of the output shaft that is ultimately output) can be changed.In other words, according to one embodiment of the disclosure, the actuator 10 for the braking device can change the assembly method of the planetary gear arrangement and the bevel gear arrangement in different shapes to transmit power, and then adjust the directionality of the rotational power that is ultimately output.

[0053] The following describes an operation of the actuator for the brake device according to an embodiment of the disclosure.

[0054] When a driver applies the parking brake after the vehicle has come to a stop, the motor 200 is driven to rotate the motor 200's drive shaft 210. The sun gear 310, coupled to the motor 200's drive shaft 210, rotates accordingly and transmits the rotational force to the multitude of planet gears 320 that mesh with the sun gear 310. The multitude of planet gears 320 rotates and turns along the circumference of the sun gear 310 and along the ring gear 332, which is provided along a circumference of the inner surface of the transmission assembly section 330. As the carrier 340 rotates in the coaxial direction with the motor 200's drive shaft 310 by the rotation of the multitude of planet gears 320, the output shaft 341 rotates along with it.

[0055] When the carrier 340 rotates, the first bevel gear 410, which is coupled to the output shaft 341, rotates together with the carrier 340 and transmits the rotational force to the second bevel gear 420. The power transmission shaft 430, which is installed through the second bevel gear 420, rotates together with the second bevel gear 420. The output gear 420, which is provided at one end of the power transmission shaft 430, rotates accordingly together with the power transmission shaft 430 to output the rotational power.

[0056] As described above, although a few embodiments of the disclosure have been shown and described, the person skilled in the art would understand that changes can be made to these embodiments without departing from the concepts and spirit of the disclosure, the scope of which is defined in the following claims and their equivalents.

Claims

[1] Actuator (10) for a braking device comprising the following: a motor (200); a first reduction gear unit (300) which is connected to the motor (200); a second reduction gear unit (300) connected to the first reduction gear unit (300); a housing (100) comprising a motor housing section (120) that accommodates the motor (200) and a gearbox housing section (130) that accommodates the first reduction gearbox unit (300); wherein the first reduction gear unit (300) is provided as a planetary gear arrangement comprising: a sun gear (310) coupled to a rotating shaft of the motor (200); a plurality of planetary gears (320) that engage with an outer surface of the sun gear (310); a gear assembly section (330) which is provided with a ring gear (332) on an inner circumference thereof to accommodate the plurality of planet gears (320); and a carrier (340) rotatably supporting the plurality of planetary gears (320) and installed to rotate coaxially with the sun gear (310), and provided with an output shaft (341) for outputting rotational power; wherein the second reduction gear unit (400) is provided as a bevel gear assembly; and wherein the carrier (340) is formed in a disk shape and a plurality of planet gear shaft sections (342) are provided on the lower surface and the output shaft (341) is provided in a center of an upper surface. [2] Actuator (10) according to claim 1, further comprising a support (500) coupled to a top of the gearbox housing section (130) and on which the second reduction gearbox unit (400) is installed. [3] Actuator (10) according to claim 1, wherein the gear mounting section (330) is provided integrally with the gear housing section (130) of the housing (100). [4] Actuator (10) according to claim 1, wherein the gear assembly section (330) is detachably coupled to the housing (100). [5] Actuator (10) according to claim 4, wherein the gearbox housing section (130) is provided with an extension plate (133) to which the gearbox mounting section (330) is coupled, and a hook (335) is provided at an outer lower end of the gearbox mounting section (330) to be detachable from the extension plate (133). [6] Actuator (10) according to claim 5, wherein the extension plate (133) is provided with a plurality of locking ribs (134) spaced apart from each other by a predetermined distance along a circumferential direction therefrom, and coupling ribs (334) are formed which engage between the plurality of locking ribs (134) to project from a lower side of the gear mounting section (330). [7] Actuator according to claim 1, wherein the second reduction gear unit comprises: a first bevel gear provided on the output shaft of the carrier; and a second bevel gear that engages with the first bevel gear. [8] Actuator (10) according to claim 7, wherein the second reduction gear unit (400) further comprises a power transmission shaft (430) which is provided to pass through the second bevel gear (420) and rotate together with the second bevel gear (420). [9] Actuator (10) according to claim 8, wherein an output wheel (440) is provided for outputting rotational power at one end of the power transmission shaft (430). [10] Actuator (10) according to claim 8, further comprising a bearing (450) provided on the power transmission shaft (430) to rotatably support the power transmission shaft (430). [11] Actuator (10) according to claim 10, wherein the bearing (450) is provided to be supported by a support (500) which is provided to install the second reduction gear unit (300). [12] Actuator (10) according to claim 1, wherein a damping element is provided for supporting a lower end of the motor (200) on a base of the motor housing section (120).

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