Actuator comprising speed reducer

Abstract

An actuator according to the present invention comprises a motor and a speed reducer for controlling the rotation of the motor. The speed reducer includes: a harmonic drive including a wave generator; a plurality of spur gears connected to a cam plate of the wave generator; and an input gear which extends in the axial direction so as to pass through the central portion of the cam plate and which is gear-coupled to the plurality of spur gears, wherein the wave generator includes: a circular central part; three protruding parts formed on the outer peripheral surface of the central part; and a ball bearing disposed to encompass the cam plate, and elastically deformed by means of the three protruding parts. The actuator according to the present invention prevents a dedoidal state, remarkably increases a gear tooth engagement rate, greatly improves performance factors of the speed reducer such as rated torque and peak torque and, simultaneously, maximizes a reduction ratio.

Description

Actuator including reducer

[0001] The present invention relates to an actuator applied to a vehicle such as an electric vehicle, and more particularly, to an actuator having a reducer having both a gear structure and a three-point harmonic drive.

[0002] An actuator controls the movement of the center or links of a vehicle's stabilizer bar. It is a mechanical component that converts electrical energy into mechanical force, such as an electric motor, hydraulic motor, or electromagnet. Actuators used in vehicles consist of a motor, reducer, and other components.

[0003] At this time, the reducer is coupled to the motor, the power source, to reduce the output rotational speed, thereby achieving high rotational torque and reducing speed. The reducer can be selected based on factors such as reduction ratio, output torque, backlash, and rotational accuracy. With the development of electric vehicles and autonomous vehicles, demand for reducers, which are essential components for these vehicles, is steadily increasing. Research and development of reducers to match vehicle specifications and performance is also actively underway.

[0004] Reducers are used not only in vehicles but also in robots. Robots include domestic robots used for tasks such as caring for patients or children, or assisting with cooking and cleaning, as well as industrial robots such as vertical / horizontal multi-joint robots and mobile robots with robot arms used in industrial manufacturing. Reducers are a critical component in the joint drive mechanisms of these robots.

[0005] Gear reducers used in various industrial fields come in various types, such as planetary gear reducers, spherical gear reducers, cycloidal gear reducers, harmonic gear reducers, and hybrid gear reducers, depending on their shape, configuration, and operating principles. Planetary gear reducers have a very high power transmission ratio per unit volume, enabling greater power transmission than gear reducers of the same size. Furthermore, planetary gear reducers can have concentric drive and driven shafts, and offer a variety of reduction ratios and high power transmission efficiency.

[0006] At this time, backlash generated by the reducer causes instability in the vehicle's operation and posture, so various efforts are being made to reduce backlash. Korean Patent Publication No. 10-1504253 (Title: Vehicle Actuator) describes a backlash reduction mechanism that controls the vehicle body's posture in a vehicle capable of active roll control, reducing the backlash of the reducer. However, the backlash reduction mechanism has the disadvantage of being very complex and bulky.

[0007] Meanwhile, a harmonic reducer is a reducer that uses the bending of a rigid body to mesh with planetary gears, and is very advantageous in miniaturizing high-rigidity, high-output devices due to its large basic reduction ratio and low backlash, so it is widely used in ultra-precision positioning mechanisms, multi-joint robots, etc. Conventional harmonic reducers are two-point reducers and include a wave generator such as that disclosed in Korean Patent No. 10-1557677 (Title of the invention: Noncircular bearing, wave generator, and wave gear device). The wave generator includes a plug inside, and the plug has an oval shape and is connected to the input shaft of the drive system to transmit rotational motion, and at the same time, the plug shape of the wave generator elastically deforms a thin cup-shaped flex spline, causing the flex spline to generate a decelerating rotational motion in the opposite direction. The harmonic reducer receives rotational force from the input shaft of the drive system, and the wave generator rotates. The flex spline changes shape to be the same as the plug, that is, in an elliptical shape, so that the positions of the teeth that mesh with the circular splines in the long axis of the ellipse sequentially move. When the wave generator makes a complete rotation, the flex spline rotates in the opposite direction by the difference in the number of teeth, and deceleration is achieved due to this rotation in the opposite direction. Since the conventional harmonic reducer operates with a symmetrical tooth meshing structure in the long axis of the ellipse, a problem called dedoidal often occurs in which the teeth mesh state is momentarily disengaged when the assembly is forced or a ratcheting shock with a large external force occurs.

[0008] With the rapid development of electric vehicles, robots, etc., there is a growing demand for performance improvement in reducers, and in particular, research and development is needed on ways to maximize reduction ratios while resolving the problems of conventional reducers mentioned above.

[0009] The present invention has been conceived in consideration of the above-described technical needs, and an object of the present invention is to provide an actuator having a reducer capable of preventing a dead-end state, significantly increasing its biting rate, and significantly improving reducer performance items such as rated torque and peak torque, while maximizing the reduction ratio.

[0010] According to the present invention for achieving the above object, an actuator comprises: a motor; and a reducer for controlling rotation of the motor; wherein the reducer comprises: a harmonic drive including a wave generator; a plurality of spur gears connected to a cam plate of the wave generator; and an input gear extending in the axial direction and penetrating the central portion of the cam plate and gear-engaged with the plurality of spur gears; wherein the wave generator comprises: a central portion having a circular shape; three protrusions formed on an outer peripheral surface of the central portion; and a ball bearing arranged to surround the cam plate and elastically deformed by the three protrusions.

[0011] And, the above motor can transmit rotational force to the vehicle's stabilizer bar.

[0012] In addition, it may include a cover flange including a hole through which the input gear passes; an output side flange arranged to face the cover flange; and a fixed flange arranged between the cover flange and the output side flange.

[0013] In addition, the output side flange includes a receiving space in which the tip of the input gear is received, and a ball bearing can be arranged between the inner surface of the receiving space and the tip of the input gear.

[0014] Additionally, the cam plate may include a cam plate extension extending in the axial direction, and a ball bearing may be provided between the cam plate extension and the output side flange.

[0015] And, the output side flange includes a side wall protruding in the axial direction, and the ball bearing can be provided between the cam plate extension and the side wall.

[0016] Additionally, the cover flange may include a side wall protruding in the axial direction, and a ball bearing may be arranged between the side wall of the cover flange and the input gear.

[0017] And, the gear of the input gear can be arranged to mesh with the gears of the plurality of spur gears.

[0018] Meanwhile, an actuator according to the present invention for achieving the above object includes: a motor; and a reducer for controlling rotation of the motor; wherein the reducer includes: an output-side flange; a harmonic drive disposed spaced apart from the output-side flange and including a wave generator; a shaft extending in the axial direction and penetrating the output-side flange and the cam plate of the wave generator; a bevel gear fastened to one end of the shaft; and an input-side cover flange having an accommodation space formed therein for accommodating the other end of the shaft.

[0019] And, the above motor can transmit rotational force to the vehicle's stabilizer bar.

[0020] Additionally, the input side cover flange may include a side wall protruding in the axial direction, and the receiving space may be formed by the side wall.

[0021] And, it may further include a tapered roller bearing arranged between the inside of the receiving space and the tip of the shaft.

[0022] Additionally, the output side flange may include a through hole through which the shaft passes, and a bearing may be provided between the inner wall of the through hole and the shaft.

[0023] And, the distance between the cam plate of the wave generator and the output side flange may be closer than the distance between the cam plate and the input side cover flange.

[0024] Meanwhile, an actuator according to the present invention for achieving the above object includes: a motor; and a reducer for controlling rotation of the motor; wherein the reducer includes: an input-side cover flange; a harmonic drive disposed spaced apart from the input-side cover flange and including a wave generator; a shaft extending in the axial direction and penetrating the input-side cover flange and the cam plate of the wave generator; a bevel gear fastened to one end of the shaft; and an output-side flange having an accommodation space formed therein for accommodating the other end of the shaft.

[0025] And, the output side flange includes a side wall protruding in the axial direction, and the receiving space can be formed by the side wall.

[0026] In addition, it may further include a tapered roller bearing disposed between the inner side of the receiving space and the tip of the shaft.

[0027] In addition, the input side cover flange includes a through hole through which the shaft passes, and a bearing may be provided between the inner wall of the through hole and the shaft.

[0028] The reducer included in the actuator according to the present invention simultaneously includes a planetary gear structure / bevel gear structure and a three-point drive harmonic drive, thereby preventing a dead-end state, significantly increasing the teeth engagement ratio, and greatly improving reducer performance items such as rated torque and peak torque, while maximizing the reduction ratio.

[0029] Figure 1 illustrates various embodiments to which the actuator according to the present invention can be applied.

[0030] Figure 2 is a conceptual diagram for explaining a harmonic drive, which is a component of a reducer applied to an actuator according to the present invention.

[0031] Figures 3 to 5 are drawings showing the shape of a wave generator, which is a component of the harmonic drive illustrated in Figure 2.

[0032] Figure 6 is a drawing showing a state in which the wave generator illustrated in Figure 2 is installed on a flex spline.

[0033] Figure 7 is a drawing showing a state in which the flex spline illustrated in Figure 6 is installed on a circular spline.

[0034] Figure 8 is a drawing for explaining a deceleration operation by a harmonic drive, which is a component of a reducer according to the present invention.

[0035] Figures 9 and 10 are internal structural drawings and front views of a harmonic drive, which is a three-point drive reducer applied to an actuator according to the present invention.

[0036] Figures 11 and 12 illustrate a structure in which a harmonic drive, which is a three-point drive reducer, and a planetary gear structure are combined in a reducer applied to an actuator according to the present invention.

[0037] Figures 13 and 14 illustrate a structure in which a harmonic drive, which is a three-point drive reducer, and a bevel gear are combined in a reducer applied to an actuator according to the present invention.

[0038] Figure 15 illustrates an embodiment in which an actuator according to the present invention is applied to a vehicle stabilizer.

[0039] Fig. 16 is a block diagram showing the configuration of an actuator applied to a vehicle stabilizer.

[0040] Figure 17 is a measurement result testing the performance of a reducer used in an actuator according to the present invention.

[0041] Figure 18 illustrates an embodiment in which an actuator according to the present invention is applied to an air conditioning device for a vehicle.

[0042] The following detailed description of the present invention refers to the accompanying drawings, which illustrate specific embodiments in which the present invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present invention. It should be understood that the various embodiments of the present invention, while different from each other, are not necessarily mutually exclusive. For example, specific shapes, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the present invention. Furthermore, it should be understood that the positions or arrangements of individual components within each disclosed embodiment may be modified without departing from the spirit and scope of the present invention. Accordingly, the following detailed description is not intended to be limiting, and the scope of the present invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly described. Like reference numerals in the drawings designate the same or similar functionality throughout the several aspects.

[0043] Hereinafter, a reducer according to an exemplary embodiment of the present invention will be described with reference to the attached drawings. The reducer according to the present invention can simultaneously perform reduction using a planetary gear structure and reduction using a three-point drive wave generator. The three-point drive wave generator coupled to the planetary gear reducer having a planetary gear structure has three protrusions formed at regular intervals on the outer surface, and the teeth of a flex spline on which the three protrusions are located are simultaneously engaged with the teeth of a circular spline.

[0044] In addition, a reducer according to another embodiment of the present invention may be implemented to enable bevel gear driving by installing a spline on the input drive shaft.

[0045] Figure 1 illustrates various embodiments to which the actuator according to the present invention can be applied. First, the actuator according to the present invention can be applied to a vehicle in various ways. First, the actuator according to the present invention can be applied to a vehicle stabilizer. A stabilizer is a posture stabilization device installed to reduce the left and right tilt of a vehicle body. The actuator according to the present invention is connected to a stabilizer bar and facilitates the posture stabilization of the vehicle through the configuration of a reducer described below. In addition, the actuator according to the present invention can be used in an active suspension for a vehicle. An active suspension is a suspension that actively suppresses vibration by applying a control force using a hydraulic or pneumatic actuator. This can obtain a stable posture and ride quality in response to various driving situations such as on-road and off-road by controlling a shock absorber or spring using an actuator operated by hydraulic or pneumatic pressure, and has the function of contacting the tires with the road surface. In addition, the actuator according to the present invention can be used in a steering system for a vehicle. The steering system is a device for controlling the direction of travel of a vehicle, and is composed of a gear device that transmits the steering force of a driver to a gear device, changes the direction of the steering force, and simultaneously increases the rotational force and transmits it to a driving link mechanism, and a link that transmits the operation of the gear device to the front wheels and correctly supports the positional relationship of the left and right wheels. Currently, steering devices are evolving from hydraulic power steering devices to electronic / mechanical power steering devices, and the steering torque generated by the motor is transmitted to the rack-and-pinion steering gear through a worm gear and a steering column. In addition, the actuator according to the present invention can be used in a vehicle air conditioning system.For example, a vehicle air conditioner uses a compressor to compress refrigerant to lower its temperature and generate cool air through a heat exchanger. The compressor converts rotational energy into reciprocating energy through a cylinder to compress the refrigerant. In this case, an actuator according to the present invention can be used. In addition, the actuator according to the present invention can be applied to engine variable speed devices and various vehicle mechatronics, and is not limited to the embodiments mentioned above.

[0046] Hereinafter, with reference to FIGS. 2 to 5, a three-point drive wave generator equipped in a reducer applied to an actuator according to the present invention and a harmonic drive including the same will be described.

[0047] FIG. 2 is a conceptual diagram for explaining a harmonic drive, which is one component of a reducer applied to an actuator according to the present invention, and FIGS. 3 to 5 are drawings showing the shape of a wave generator, which is one component of the harmonic drive illustrated in FIG. 2.

[0048] Referring to FIG. 2, a harmonic drive, which is a component of a reducer applied to an actuator according to the present invention, may include a wave generator (100), a flex spline (200), and a circular spline (300).

[0049] The wave generator (100) is formed in an overall triangular shape and is connected to an input shaft to perform rotational motion. The wave generator (100) is installed on the inside of the flex spline (200) and elastically deforms the flex spline (200) to cause the flex spline (200) to perform a decelerating rotational motion in the opposite direction.

[0050] Referring to FIGS. 3 to 5, a wave generator (100) included in a harmonic drive, which is a component of a reducer applied to an actuator according to the present invention, includes a cam plate (110) and a ball bearing (120) formed on the outside to surround the cam plate (110).

[0051] The cam plate (110) has a circular central portion (111) and crescent-shaped protrusions (110a, 110b, 110c) formed at least three points on the outer surface of the central portion (111), and is connected to an input shaft to perform rotational movement. The crescent-shaped protrusions (110a, 110b, 110c) formed at least at three points are formed at regular intervals, so that they can correspond to the vertices of a triangle as a whole. The cam plate (110) can be formed of a rigid material that does not deform in shape.

[0052] The ball bearing (120) may be formed on the outside so that a plurality of balls (130) in a ring shape surround the cam plate (110). The inside of the ball bearing (120) may be in contact with the outside of the cam plate (110), and a portion of the outside of the ball bearing (120) may be in contact with a portion of the inside of the flex spline (200).

[0053] Since the ball bearing (120) is elastically deformed by the shape of the cam plate (110), protrusions (120a, 120b, 120c) may be formed on the outer circumferential surface corresponding to each of the protrusions (110a, 110b, 110c) of the cam plate (110). The protrusions (120a, 120b, 120c) formed at at least three points corresponding to the protrusions (110a, 110b, 110c) of the cam plate (110) are formed at regular intervals, so that they may correspond to the vertices of a triangle as a whole.

[0054] The protrusions (120a, 120b, 120c) of the ball bearing (120) elastically deform the flex spline (200) so that at least three points of the flex spline (200) come into contact with the inside of the circular spline (300), and the teeth can be engaged simultaneously at the three points in contact.

[0055] In this way, since crescent-shaped protrusions are formed at least at three points on the outer surface of the circular cam plate (110), the flex spline (200) and circular spline (300) that are combined therewith can mesh with each other at three points simultaneously.

[0056] The flex spline (200) is formed in a cup shape, and a wave generator (100) can be installed on the inside. Teeth can be formed on the outer surface of the flex spline (200).

[0057] Referring to FIG. 5, each of the protrusions (110a, 110b, 110c) formed on the outer surface of the central portion (111) of a circular shape is included in three different circles and forms a part of the circles, and the diameters of the three different circles can all be formed to be the same.

[0058] The radius R2 of the three circles including each of the protrusions (110a, 110b, 110c) is smaller than the radius R1 of the central portion (111) of the circular shape, and the relationship is defined as in the following [Mathematical Formula 1].

[0059] [Mathematical Formula 1]

[0060] R2 = k × R1

[0061] Here, k is a proportional constant, and is in the range of 0.6 to 0.8, with k = 0.7 being most preferable. When k < 0.6, the overall shape of the cam plate (110) does not become a circle, so the movement of the ball (130) does not become smooth, which may cause a rotational problem. On the other hand, when k > 0.8, the overall shape of the cam plate (110) becomes almost a circle, so there is a problem that the meshing portion at the three points becomes too wide.

[0062] Figure 6 is a drawing showing a state in which the wave generator illustrated in Figure 2 is installed on a flex spline.

[0063] Referring to FIG. 6, the flex spline (200) is formed of a metal elastic body, has a wave generator (100) installed inside, and can be elastically deformed by the shape of the wave generator (100).

[0064] Among the elastically deformed portions of the flex spline (200), the portions that are elastically deformed by the protrusions (120a, 120b, 120c) of the wave generator can rotate the circular spline (300) by interlocking the teeth by contacting the inner side of the circular spline (300).

[0065] The circular spline (300) is formed in a ring shape, and a flex spline (200) can be installed on the inside. The circular spline (300) is formed of a rigid material whose shape does not change, and teeth that mesh with the teeth of the flex spline (200) can be formed on the inner surface.

[0066] The number of teeth formed on the inner surface of the circular spline (300) can be designed to be greater than the number of teeth formed on the outer surface of the flex spline (200) for the purpose of reduction ratio.

[0067] Figure 7 is a drawing showing a state in which the flex spline illustrated in Figure 6 is installed on a circular spline.

[0068] Referring to Fig. 7, a flex spline (200) is installed on the inner side of a circular spline (300) having a ring shape, and can engage teeth at at least three points (A1, A2, A3). Teeth formed on the outer surface of the flex spline, which is elastically deformed by the shape of the wave generator, can engage teeth formed on the inner surface of the circular spline.

[0069] Since the teeth formed on the outer surface of the flex spline mesh with the teeth formed on the inner surface of the circular spline at three different points with equal intervals, a deadoidal state in which the teeth are misaligned may not occur. Here, deadoidal state refers to a state in which the meshing of the teeth is shifted to one side when a ratcheting phenomenon occurs or parts are forcibly assembled. Ratcheting phenomenon refers to a state in which the meshing of the teeth between the flex spline and the circular spline is momentarily misaligned when excessive impact torque is applied during operation, even though the flex spline, etc., is not damaged.

[0070] FIG. 8 is a drawing for explaining a deceleration operation by a harmonic drive, which is a component of a reducer applied to an actuator according to the present invention.

[0071] Referring to Fig. 8, (a) the flex spline (200) is elastically deformed by the wave generator (100), and the teeth (210) located at three points are engaged with the teeth (310) formed on the inner surface of the circular spline (300), and in other areas, the teeth are completely separated.

[0072] (b) When the circular spline (300) is fixed and the wave generator (100) is rotated 90 degrees clockwise, the flex spline (200) is elastically deformed and the meshing of the teeth with the circular spline (300) moves sequentially.

[0073] (c) When the wave generator (100) rotates 180 degrees clockwise, the flex spline (200) moves counterclockwise.

[0074] (d) When the wave generator (100) rotates 360 degrees, the flex spline (200) moves counterclockwise. At this time, the flex spline (200) moves counterclockwise by the difference between the number of teeth of the flex spline (200) and the number of teeth of the circular spline (300).

[0075] In the conventional two-point drive differential reducer, when the number of teeth is two, more than 200 teeth must be formed to implement a reduction ratio of 100:1, and in the case of the three-point drive differential reducer, more than 300 teeth must be formed when the number of teeth is three. In this case, the tooth module becomes too small, so tooth processing is not easy. Considering this, the present invention utilizes a front planetary gear structure to overcome the high-ratio reduction limit while maintaining the unique characteristics and reduction ratio characteristics of the three-point drive differential reducer, thereby maximizing the reduction ratio. That is, by inserting a planetary gear reducer capable of a front reduction of 2:1 to 4:1 or more into the three-point drive differential reducer, the performance of the reducer is maximized.

[0076] FIGS. 9 and 10 are internal structural drawings and front views of a harmonic drive, which is a three-point drive reducer applied to an actuator according to the present invention, and FIGS. 11 and 12 illustrate a structure in which a harmonic drive, which is a three-point drive reducer, and a planetary gear structure are combined in a reducer applied to an actuator according to the present invention.

[0077] First, referring to FIGS. 9 and 10, the reducer with the planetary gear structure omitted has an input gear shaft (400) extended in the direction of the central axis (C), and the harmonic drive structure described above is arranged between the cover flange (410) and the output flange (421).

[0078] The cover flange (410) has a hole formed through which the input gear shaft (400) passes, and the end of the input gear shaft (400) is connected to the output flange (421) through the hole. Meanwhile, a main ball bearing (402) for supporting the input gear may be provided between the cover flange (410) and the input gear shaft (400). In addition, a fixing seal (C ring) (403) for fixing the outer diameter of the input gear and the inner ring of the ball bearing (402), and a fixing seal (404) for fixing the cover flange (410) and the outer ring of the ball bearing (402) may be provided.

[0079] The harmonic drive structure is composed of a circular spline (300), a flex spline (200), and a wave generator (100) as described above, and the wave generator (100) has a ball bearing (120) including a plurality of balls (130). The inner teeth (310) of the circular spline (300) and the outer teeth (210) of the flex spline (200) can be arranged on the same plane as the wave generator (100). At this time, the wave generator (100) is a three-point drive wave generator as illustrated in FIGS. 2 to 5, and a duplicate description thereof will be omitted. The input gear shaft (400) passes through the center of the cam plate (110) of the wave generator (100) and is connected to the output side flange (421), and the output side flange (421) is provided with a ball bearing (422) for supporting the cam plate (110) of the wave generator (100) and / or the input gear shaft (400). A through hole may be formed in the center of the wave generator (110) for passing the input gear shaft (400).

[0080] More specifically, a space is formed in the output side flange (421) to accommodate a portion of the end of the input gear shaft (400), and a ball bearing (422) for supporting the cam plate (110) of the wave generator (100) and the input gear shaft (400) can be arranged to surround the end of the input gear shaft (400) within the space.

[0081] Meanwhile, a cross roller bearing (411) for supporting the output stage may be arranged between the cover flange (410) and the output side flange (421), and a fixed flange (412) for supporting the cross roller bearing and the harmonic drive structure may be arranged. The fixed flange (412) surrounds the side of the reducer applied to the actuator according to the present invention.

[0082] One or more oil chambers (413) (two at the top and bottom in FIG. 9) may be provided between the cover flange (410) and the fixed flange (412) to prevent oil leakage. In addition, the fixed flange (412) may be provided with an oil chamber (414) to prevent oil leakage from a cross roller bearing, etc.

[0083] As illustrated in Fig. 9, a reducer including a harmonic drive has a cavity formed therein by a cover flange (410), a fixed flange (412), and an output flange (421). In the reducer applied to the actuator according to the present invention, a planetary gear structure is arranged within the cavity, as illustrated in Figs. 11 and 12.

[0084] Referring to FIGS. 11 and 12, the output-side flange (421) is formed with a receiving space (H) for receiving the end of the input gear shaft (400). Here, the input gear tooth (401) may be directly formed on the input gear shaft (400), or the input gear tooth (401) may be fastened to the input gear shaft (400) as a separate component. Hereinafter, the input gear tooth (401) and the input gear shaft (400) will be collectively referred to as an input gear. The tip of the input gear received in the receiving space (H) of the output-side flange (421) is supported by a ball bearing (407). In other words, the ball bearing (407) is provided between the tip of the input gear and the inner surface of the receiving space (H) to ensure smooth rotation of the input gear.

[0085] Meanwhile, the cam plate (110) of the wave generator (100) may be provided with a fastening hole for fastening a spur gear (500) of a planetary gear. Although three spur gears (500a to 500c) are illustrated in FIG. 12, a greater number of spur gears may be provided. A ball bearing (408) may be provided between the cam plate (100) of the wave generator (100) and the output flange (421). Specifically, the cam plate (110) of the wave generator (100) may be provided with a cam plate extension portion (110a) extending in the direction of the output flange (421). That is, the cam plate extension portion (110a) may extend in the direction of the axis (C). In addition, the accommodation space (H) for accommodating the tip of the input gear can be formed by a side wall (421a) protruding from the output-side flange (421) toward the cover flange (410). That is, the side wall (421a) can also extend in the direction of the axis (C). Consequently, when viewed in a direction perpendicular to the axis (C), the cam plate extension (110a) and the side wall (421a) can overlap each other with a predetermined distance apart. The ball bearing (408) for supporting the cam plate of the wave generator (100) is arranged between the cam plate extension (110a) and the side wall (421a) of the output-side flange (421), thereby supporting the wave generator (100) and ensuring smooth operation thereof.

[0086] Meanwhile, the gear (401) of the input gear may be arranged to mesh with the gear (501) of the spur gear. That is, as illustrated in FIG. 12, the gears (501) of three spur gears (500a to 500c) are arranged to mesh with the gear (401) of the input gear. Accordingly, the position of the fastening hole formed in the cam plate (110) of the wave generator (100) may be determined by the diameter of the spur gears (500a to 500c), the distance between the spur gears (500a to 500c), the diameter of the input gear, and the depth of each gear (401, 501). In relation to fastening of the spur gears (500a to 500c), the cam plate (110) of the wave generator (100) and the spur gears (500a to 500c) can be connected through pin bolts (520) or the like. The pin bolts (520) pass through fastening holes formed in the cam plate (110) to rotatably fasten the spur gears (500a to 500c) to the cam plate (100).

[0087] The cover flange (410) includes a side wall (410a) protruding toward the output flange (421). In other words, the side wall (410a) can extend in the axial direction, and a ball bearing (402) for supporting the input gear can be arranged between the side wall (410a) of the cover flange (410) and the input gear. A ball bearing (402) for supporting the input gear is provided on the upper side of the input gear, a ball bearing (407) for supporting the tip of the input gear is provided on the lower side (tip) of the input gear, and a gear (401) located on the middle side of the input gear is arranged to mesh with a spur gear gear (501) of a planetary gear. By this structure, the input gear is aligned in the axial direction and can rotate freely.

[0088] Figures 13 and 14 illustrate a drive module structure in which a harmonic drive, which is a three-point drive reducer, and a bevel gear are combined in a reducer applied to an actuator according to the present invention.

[0089] First, referring to FIG. 13, the tip of the shaft (650) in the axial direction to which the bevel gear (600) is fastened is connected to the input-side cover flange (620). The input-side cover flange (620) includes a side wall (620a) protruding in the axial direction, and the tip of the shaft (650) is received in an accommodation space (L) formed by the side wall (620a). A tapered roller bearing (610) is provided between the inner side of the accommodation space (L) and the tip of the shaft (650), thereby facilitating rotation of the shaft (650) to which the bevel gear (600) is fastened. Meanwhile, the device (reducer and / or drive module) according to the present embodiment may further include a sealing ring (611) for supporting the outer ring of the tapered roller bearing (610).

[0090] The thrust generated by employing the bevel gear (600) is received by the tapered roller bearing (610) arranged at the tip of the shaft (650). In addition, the device (reducer and / or drive module) according to the present embodiment provides an accommodation space (L) for accommodating the tapered roller bearing (610) by modifying the structure of the input side cover flange (620).

[0091] Meanwhile, a bevel gear (600) is fastened to one end of the shaft (650), and the bevel gear (600) is fixed by a U-nut (601) and a tap screw (602). The output flange (621) faces the harmonic drive including the wave generator (100) and can be arranged to have a predetermined distance. The output flange (621) includes a through hole through which the shaft (650) passes, and a bearing (603) can be provided between the inner wall of the through hole of the output flange (621) and the shaft (650). The shaft (650) passing through the through hole of the output flange (621) also passes through the through hole formed in the center of the cam plate (110) of the harmonic drive, and is ultimately accommodated in the accommodation space (L) of the input cover flange (620).

[0092] The device (reducer and / or drive module) illustrated in FIG. 13 may have a harmonic drive structure arranged closer to the output flange (621) due to a structural deformation of the input-side cover flange (620). That is, the distance between the cam plate (110) of the wave generator (100) and the output-side flange (621) may be closer than the distance between the cam plate (110) of the wave generator (100) and the input-side cover flange (620). More specifically, the input-side cover flange (620) includes a base and a protrusion (620a) protruding from the base, and the distance between the cam plate (110) of the wave generator (100) and the output-side flange (621) may be closer than the distance between the cam plate (110) of the wave generator (100) and the base of the input-side cover flange (620). Additionally, the distance between the cam plate (110) of the wave generator (100) and the output side flange (621) may be closer than the distance between the cam plate (110) of the wave generator (100) and the end of the protrusion (620a) of the input side cover flange (620).

[0093] The device (reducer and / or drive module) illustrated in Fig. 13 enables bevel gear driving by attaching a spline to the input drive shaft. Specifically, the device (reducer and / or drive module) illustrated in Fig. 13 has a structure in which, in addition to the structure of the device (reducer and / or drive module) employing the three-point support wave generator described above, a tapered roller bearing is inserted to receive the axial force of the five-axis reducer that generates thrust. In addition, the output flange (621) is designed so that the input shaft passes through it, and a structure is adopted in which the input gear can be fixed with a spline by modifying it.

[0094] The device (reducer and / or drive module) illustrated in Fig. 14 is designed to enable bevel gear drive by attaching a spline to the input drive shaft in a three-point drive reducer. The device (reducer and / or drive module) illustrated in Fig. 14 is designed so that the shaft (750) passes through the input side cover flange (720), unlike the device (reducer and / or drive module) illustrated in Fig. 13. That is, a spline is formed on the input drive shaft, a bevel gear is assembled, and the bevel gear is then fixed with a unit nut. Meanwhile, a tapered roller bearing is inserted to receive the axial force generated from the bevel gear, and an ISO tool flange is attached to the end of the six-axis to improve user convenience and reduce the number of parts.

[0095] Referring to Fig. 14, a shaft (750) extends in the axial direction, a bevel gear (700) is fastened to one end of the shaft (750), and the bevel gear (700) is fixed by a U-nut (701) and a tap screw (702). An input-side cover flange (720) may be positioned to face the harmonic drive and have a predetermined distance therebetween. The input-side cover flange (720) may include a through-hole through which the shaft (750) passes, and a bearing (703) may be provided between the inner wall of the through-hole of the input-side cover flange (720) and the shaft (750). The shaft (750) passing through the through-hole of the input-side cover flange (720) also passes through a through-hole formed in the center of the cam plate (110) of the harmonic drive, and is ultimately accommodated in the accommodation space (L) of the output-side flange (721).

[0096] The tip of the shaft (750) in the axial direction to which the bevel gear (700) is fastened is connected to the output flange (721). The output flange (721) includes a side wall (721a) protruding in the axial direction, and the tip of the shaft (750) is received in a receiving space (L) formed by the side wall (721a). The side wall (721a) may be formed to a predetermined depth toward the input side cover flange (720). A tapered roller bearing (710) is provided between the inner side of the receiving space (L) and the tip of the shaft (750), thereby ensuring smooth rotation of the shaft (750) to which the bevel gear (700) is fastened. Although not shown in the drawing, a sealing ring (not shown) may be further provided to support the outer ring of the tapered roller bearing (710).

[0097] The thrust generated by employing the bevel gear (700) is received by the tapered roller bearing (710) arranged at the tip of the shaft (750). In addition, the device (reducer and / or drive module) according to the present embodiment provides a receiving space (L) to accommodate the tapered roller bearing (710) by modifying the structure of the output side flange (721).

[0098] In the device (reducer and / or drive module) illustrated in FIG. 14, the distance between the cam plate (110) of the wave generator (100) and the output side flange (721) may be closer than the distance between the cam plate (110) of the wave generator (100) and the input side cover flange (720).

[0099] FIG. 15 illustrates an embodiment in which an actuator according to the present invention is applied to a vehicle stabilizer, and FIG. 16 is a block diagram showing the configuration of an actuator applied to a vehicle stabilizer.

[0100] As illustrated in FIG. 15, the vehicle's stability and ride comfort are enhanced by varying the stiffness of the stabilizer bars (20, 30). Specifically, when the vehicle turns, the vehicle roll is suppressed to enhance safety, or the lateral attitude of the vehicle is controlled by distributing the roll stiffness of the front and rear wheels. The actuator (10) may be arranged between two stabilizer bars (20, 30). The first stabilizer bar (20) may be fixed, and the second stabilizer bar (30) may be rotatable. However, depending on the embodiment, both the first and second stabilizer bars (20, 30) may be implemented as rotatable.

[0101] As illustrated in Fig. 16, the actuator (10) includes a motor (11) and a reducer (12). The motor (11) generally includes a stator that generates magnetic force and a rotor that rotates with the magnetic force generated thereby.

[0102] The reducer (12) can be implemented in various embodiments described above. That is, the reducers illustrated in FIGS. 10, 11, and 12 can be used in the actuator (10).

[0103] Fig. 17 shows the measurement results of the performance of the reducer used in the actuator according to the present invention. As shown in Fig. 17, the stiffness test measurement results show that the lost motion was improved by approximately 3.5 times, the hysteresis was improved by 2.4 times, and the torsional stiffness was also improved by 1.4 times. In addition, the angular transmission error measurement results show that the angular transmission error CW was improved by 2.2 times (error amount reduced by 45%, i.e., by more than 55%), and the angular transmission error CCW was improved by 2.6 times (error amount reduced by 38%, i.e., by more than 62%). Accordingly, the actuator including the reducer according to the present invention can have superior performance compared to the prior art, and in particular, it can provide stability to the operation and posture of the vehicle due to the improvement in backlash.

[0104] Fig. 18 illustrates an embodiment in which an actuator according to the present invention is applied to a vehicle air conditioning system. As illustrated in Fig. 18, the vehicle air conditioning system includes an air conditioning ECU (40), an actuator (60) for controlling various doors, various sensors (70), and a compressor (80).

[0105] The air conditioner ECU (40) controls the indoor temperature by controlling the supply of air for air conditioning based on the determined discharge mode, discharge temperature, discharge direction, and discharge volume based on the measured values ​​of various sensors, and controls the internal / external door (intake door) actuator, the temperature control door (temperature door) actuator, the wind direction control door (mode door) actuator, the dehumidification (defog) door actuator, etc. In addition, the air conditioner ECU (40) controls the components such as the compressor (60), the air conditioner blower (not shown), and the electric heater (not shown). That is, a vehicle air conditioning system is equipped with a number of doors, such as an inside / outside door that determines the inflow of inside / outside air to control the wind direction, temperature, and air volume inside the vehicle, a temperature control door (temp door) that determines the flow rate passing through the heater core and the flow rate bypassing it, a wind direction control door (mode door) that determines the mode such as Face, Floor, Mix, and Bi-Level, and a dehumidification door, which can be driven by an actuator (60). At this time, the actuator (60) may include a reducer according to the various embodiments described above.

[0106] Various sensors (70) may include, but are not limited to, an irradiance sensor that detects irradiance, an outside temperature sensor that detects outside temperature, an indoor temperature sensor that detects the vehicle interior temperature, an exhaust temperature sensor, a heater temperature sensor, an evaporator temperature sensor, etc.

[0107] The compressor (80) compresses the refrigerant into a high-temperature, high-pressure gaseous state. At this time, the compressor (80) may include a reducer and a motor according to the various embodiments described above. The compressor (80) regulates the refrigerant supply amount of the air conditioner.

[0108] In addition, although not shown in Fig. 18, it may further include a condenser that cools compressed refrigerant using outside air to create a high-pressure liquid, an expansion valve that rapidly expands the cooled refrigerant to create a low-temperature, low-pressure mist, and an evaporator that evaporates the refrigerant by exchanging heat with air and creates a low-temperature, low-pressure gas.

[0109] The features, structures, effects, etc. described in the embodiments above are included in one embodiment of the present invention, and are not necessarily limited to that one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified to implement other embodiments by those skilled in the art. Therefore, the contents related to such combinations and modifications should be construed as being included within the scope of the present invention.

[0110] In addition, although the above description focuses on examples, these are merely examples and do not limit the present invention. Those skilled in the art to which the present invention pertains will appreciate that various modifications and applications not exemplified above are possible without departing from the essential characteristics of the present invention. For example, each component specifically shown in the examples can be modified and implemented. In addition, differences related to such modifications and applications should be interpreted as being included within the scope of the present invention defined in the appended claims.

Claims

1. Motor; and including a reducer for controlling the rotation of the above motor; The above reducer is, Harmonic drive including wave generator; A plurality of spur gears connected to the cam plate of the above wave generator; and An input gear extending in the axial direction, penetrating the center of the cam plate, and gear-engaged with the plurality of spur gears; The above wave generator, A central portion of a circular shape and three protrusions formed on the outer surface of the central portion; and An actuator comprising a ball bearing arranged to surround the cam plate and elastically deformed by the three protrusions.

2. In paragraph 1, The above motor is an actuator that transmits rotational force to the vehicle's stabilizer bar.

3. In paragraph 1, A cover flange including a hole through which the input gear passes; An output side flange positioned opposite the above cover flange; and An actuator comprising a fixed flange disposed between the cover flange and the output side flange.

4. In paragraph 3, The above output side flange includes a receiving space in which the tip of the input gear is received, An actuator in which a ball bearing is arranged between the inner surface of the above-mentioned accommodation space and the tip of the above-mentioned input gear.

5. In paragraph 3, The above cam plate includes a cam plate extension extending in the axial direction, An actuator having a ball bearing provided between the cam extension and the output flange.

6. In paragraph 5, The above output side flange includes a side wall protruding in the axial direction, An actuator in which the above ball bearing is provided between the cam plate extension and the side wall.

7. In paragraph 3, The above cover flange includes a side wall protruding in the axial direction, An actuator in which a ball bearing is arranged between the side wall of the cover flange and the input gear.

8. In paragraph 1, An actuator in which the gears of the above input gear are arranged to mesh with the gears of the above plurality of spur gears.

9. Motor; and including a reducer for controlling the rotation of the above motor; The above reducer is, Output side flange; A harmonic drive disposed spaced apart from the output side flange and including a wave generator; A shaft extending axially and penetrating the output flange and the cam plate of the wave generator; A bevel gear connected to one end of the above shaft; and An actuator including an input side cover flange having a receiving space formed therein for receiving the other end of the shaft.

10. In paragraph 9, The above motor is an actuator that transmits rotational force to the vehicle's stabilizer bar.

11. In paragraph 9, The above input side cover flange includes a side wall protruding in the axial direction, The above-mentioned accommodation space is an actuator formed by the side wall.

12. In paragraph 9, An actuator further comprising a tapered roller bearing disposed between the inner side of the receiving space and the tip of the shaft.

13. In paragraph 9, The above output side flange includes a through hole through which the shaft passes, An actuator having a bearing provided between the inner wall of the above through hole and the above shaft.

14. In paragraph 9, An actuator in which the distance between the cam plate of the wave generator and the output side flange is shorter than the distance between the cam plate and the input side cover flange.

15. Motor; and including a reducer for controlling the rotation of the above motor; The above reducer is, Input side cover flange; A harmonic drive disposed spaced apart from the input side cover flange and including a wave generator; A shaft extending axially and penetrating the input side cover flange and the cam plate of the wave generator; A bevel gear connected to one end of the above shaft; and An actuator including an output side flange having a receiving space formed therein for receiving the other end of the shaft.

16. In paragraph 15, The above output side flange includes a side wall protruding in the axial direction, The above-mentioned accommodation space is an actuator formed by the side wall.

17. In paragraph 15, An actuator further comprising a tapered roller bearing disposed between the inner side of the receiving space and the tip of the shaft.

18. In paragraph 15, The above input side cover flange includes a through hole through which the shaft passes, An actuator having a bearing provided between the inner wall of the above through hole and the above shaft.

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