A high-precision multi-stage servo reducer

Abstract

The present invention provides a high-precision multi-stage servo reducer, belonging to the technical field of reducers. This high-precision multi-stage servo reducer includes a harmonic reduction structure, a gear reduction structure, and a servo housing structure; the harmonic reduction structure mainly includes a fixed rigid gear, a driven flexible gear, and a wave generator nested and installed in sequence, and the gear reduction structure mainly includes a driving gear, a first-stage reduction gear, and a second-stage reduction gear; the fixed rigid gear and the driven flexible gear are meshed and connected to each other, and the wave generator is fitted and installed with fastening bolts on both sides and the top of the cylinder long axis and is closely fitted with the driven flexible gear, and is connected with the second-stage reduction gear at the bottom. The driving gear is sleeved on the working shaft of the DC motor, and the DC motor is regulated by the control circuit board. When running, it drives the driving gear, the first-stage reduction gear, the second-stage reduction gear, and the wave generator step by step in sequence. The present invention has the advantages of high transmission ratio, high transmission precision, strong load-bearing capacity, stable transmission, strong practicability, and long service life.

Description

Technical Field

[0001] The present invention belongs to the technical field of speed reducers, and particularly relates to a high-precision multi-stage servo speed reducer. Background Art

[0002] With the rapid development of industrialization and the aviation industry, small unmanned aerial vehicles (UAVs) have been widely used in various industries due to their unique advantages in military and civilian applications. The miniaturization, light weight, and large output torque of their structures are important trends in the development of small UAV technology. A servo is one of the core components for controlling small UAVs, and its main structure includes a housing, a DC motor, a speed reducer, a potentiometer, and a control circuit. Among them, the gear transmission ratio of the speed reducer determines the torque and speed of the servo. Generally, the larger the transmission ratio, the greater the torque but the slower the speed; the smaller the transmission ratio, the faster the speed but the smaller the torque. For equipment such as small UAVs with relatively high requirements for motion accuracy, a servo speed reducer is required to provide a large torque and transmission ratio.

[0003] Most existing servos use gear speed reducers, which have problems such as a relatively large backlash in the output shaft, low motion accuracy, and small load-bearing capacity. In this regard, the patent with the application number CN202111383058.5 discloses a compact servo equipped with a harmonic speed reducer. The main shaft of its motor and the harmonic speed reducer are arranged in parallel, and the housing of the harmonic speed reducer and the housing of the motor form an integrated housing space that communicates at the top. The output shaft of the motor is provided with a driving pulley, and the driving pulley forms a belt drive with the driven pulley at the top of the harmonic speed reducer through a synchronous belt. The harmonic speed reducer has the advantages of high precision, high transmission ratio, and strong load-bearing capacity. However, the flexspline of the harmonic speed reducer is prone to fatigue damage, and the belt drive mode of this patent has problems such as inaccurate transmission ratio, low transmission efficiency, and short service life. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-precision multi-stage servo speed reducer for the above problems existing in the prior art.

[0005] The purpose of the present invention can be achieved by the following technical solutions: A high-precision multi-stage servo speed reducer includes a harmonic reduction structure, a gear reduction structure, and a servo housing structure;

[0006] The harmonic reduction structure is installed on the top of the servo housing structure and mainly includes a fixed rigid gear, a driven flexspline, and a wave generator; the fixed rigid gear is integrally presented as a cylindrical tubular structure, and an upper end of an inner side wall thereof forms a rigid gear bearing seat, a first bearing is fitted and installed in the rigid gear bearing seat, and a continuous circle of internal teeth of the rigid gear is formed at a lower end;

[0007] A steering wheel mounting seat is formed at the upper end of the driven flexspline. A flexspline bolt hole is provided at the center of the steering wheel mounting seat. A plurality of steering wheel mounting holes are circumferentially provided at the top of the steering wheel mounting seat around the flexspline bolt hole. The lower end of the driven flexspline is formed with a flexspline connecting cover that expands outward from the bottom of the steering wheel mounting seat and opens downward. A continuous circle of flexspline external teeth is formed at the bottom of the outer side wall of the flexspline connecting cover;

[0008] The base of the wave generator is an elliptical cylinder, and a conical head is formed at the upper end. Mounting bolt seats are formed on both sides and at the top of the long axis of the cylinder body of the conical head. Tightening bolts are fitted and installed in the mounting bolt seats. A gear hole connecting to the gear reduction structure is provided at the bottom of the wave generator from bottom to top. A continuous circle of generator internal teeth is formed on the inner side wall of the gear hole;

[0009] The steering gear housing structure is jointly composed of a housing upper cover, a housing main body, and a housing base. An upper cover bearing seat is provided at the top of the housing upper cover. A second bearing is fitted and installed in the upper cover bearing seat. The harmonic reduction structure is fixedly connected to the top of the upper cover bearing seat;

[0010] The gear reduction structure is mainly installed at the top of the housing main body and inside the housing upper cover, and includes a driving gear, a first-stage reduction gear, and a second-stage reduction gear. The driving gear is sleeved on the working shaft of the DC motor. Both the first-stage reduction gear and the second-stage reduction gear are double-layer gears with a smaller outer diameter and a consistent tooth thickness from top to bottom. Among them, the lower end of the first-stage reduction gear meshes with the driving gear, the lower end of the second-stage reduction gear meshes with the upper end of the first-stage reduction gear, and the upper end of the second-stage reduction gear extends into the gear hole at the bottom of the wave generator and meshes with the generator internal teeth.

[0011] In the above-mentioned high-precision multi-stage steering gear reducer, a plurality of rigid gear screw holes are circumferentially provided inside the pipe wall of the fixed rigid gear from bottom to top. A plurality of upper cover screw holes corresponding to the rigid gear screw holes are circumferentially provided on the upper cover bearing seat of the housing upper cover. The harmonic reduction structure is fixedly connected to the housing upper cover by screws passing through the upper cover screw holes and the rigid gear screw holes from bottom to top.

[0012] In the above-mentioned high-precision multi-stage steering gear reducer, the tightening bolt at the top of the conical head of the wave generator extends into the flexspline bolt hole and cooperates with it. The outer side walls of the nuts of the tightening bolts on both sides are closely fitted with the lid-shaped inner side wall of the flexspline connecting cover.

[0013] In the above-mentioned high-precision multi-stage steering gear reducer, mounting extension blocks bulge outward on both sides of the housing main body, and steering gear mounting holes are provided on the mounting extension blocks.

[0014] In the above-mentioned high-precision multi-stage servo reducer, motor shaft holes, first-stage gear shafts, and second-stage support columns are respectively opened or formed at the top of the housing main body corresponding to the driving gear, first-stage reduction gear, and second-stage reduction gear. The working shaft of the DC motor passes through the motor shaft hole, the first-stage reduction gear is sleeved on the first-stage gear shaft, and the second-stage reduction gear is installed on the top of the second-stage support column to form a stepped installation with the first-stage reduction gear.

[0015] In the above-mentioned high-precision multi-stage servo reducer, an installation shaft passes through the centers of the second-stage reduction gear and the second-stage support column together, and a potentiometer is fixedly connected to the lower end of the installation shaft inside the housing main body.

[0016] In the above-mentioned high-precision multi-stage servo reducer, a control circuit board is connected and installed at the bottom of the DC motor inside the bottom of the housing. Several data lines are externally connected to the control circuit board, and a wire outlet hole is opened on the side of the housing base, and the data lines are led out from the wire outlet hole.

[0017] Compared with the prior art, the high-precision multi-stage servo reducer provided by the present invention has the following advantages: First, by setting a harmonic reduction structure and a gear reduction structure, the servo reducer can first increase the transmission torque and transmission ratio through multi-stage gear reduction, and then improve the transmission accuracy and bearing strength through harmonic reduction, thereby improving the functionality and practicality of the servo reducer; Second, the driven flexible gear is firmly supported by the wave generator, thereby preventing the driven flexible gear from suffering fatigue damage, ensuring the transmission stability of the servo reducer and increasing its service life. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of the present high-precision multi-stage servo reducer;

[0019] Figure 2 is a structural sectional view of the present high-precision multi-stage servo reducer;

[0020] Figure 3 is an exploded structural view of the harmonic reduction structure in the present high-precision multi-stage servo reducer;

[0021] Figure 4 is a partial structural sectional view of the harmonic reduction structure in the present high-precision multi-stage servo reducer;

[0022] Figure 5 is a schematic structural diagram of the gear reduction structure and the partial servo housing structure in the present high-precision multi-stage servo reducer.

[0023] In the above figures, 100 is a harmonic reduction structure; 110 is a fixed rigid gear; 111 is a rigid gear bearing seat; 112 is internal teeth of the rigid gear; 113 is a screw hole of the rigid gear; 120 is a first bearing; 130 is a driven flexible gear; 131 is a rudder disc mounting seat; 132 is a rudder disc mounting hole; 133 is a flexible gear bolt hole; 134 is a flexible gear connecting cover; 135 is external teeth of the flexible gear; 140 is a second bearing; 150 is a wave generator; 151 is a conical head; 152 is a mounting bolt seat; 153 is a fastening bolt; 154 is internal teeth of the generator;

[0024] 200 is a gear reduction structure; 210 is a driving gear; 211 is a DC motor; 220 is a primary reduction gear; 230 is a secondary reduction gear; 231 is a mounting shaft; 232 is a potentiometer; 240 is a control circuit board; 241 is a data line;

[0025] 300 is a steering gear housing structure; 310 is an upper housing cover; 311 is an upper housing bearing seat; 312 is a screw hole of the upper housing; 320 is a housing main body; 321 is a mounting extension block; 322 is a steering gear mounting hole; 323 is a motor shaft hole; 324 is a primary gear shaft; 325 is a secondary support column; 330 is a housing base; 331 is a wire outlet hole. Specific embodiments

[0026] The following are specific embodiments of the present invention and, in conjunction with the accompanying drawings, further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments. Embodiment 1:

[0027] As Figures 1 to 5 shown, this high-precision multi-stage steering gear reducer includes a harmonic reduction structure 100, a gear reduction structure 200, and a steering gear housing structure 300. The steering gear housing structure 300 is composed of an upper housing cover 310, a housing main body 320, and a housing base 330 connected by bolts from top to bottom. Among them, the harmonic reduction structure 100 is installed on the top of the upper housing cover 310, and the gear reduction structure 200 is mainly installed inside between the top of the housing main body 320 and the upper housing cover 310 and is connected and linked with the harmonic reduction structure 100.

[0028] As Figures 2 to 4 shown, the harmonic reduction structure 100 mainly includes a fixed rigid gear 110, a driven flexible gear 130, and a wave generator 150. The fixed rigid gear 110 is integrally in a cylindrical tubular structure. An upper end of its inner side wall forms a rigid gear bearing seat 111, and a lower end forms a circle of uniform and continuous internal teeth 112 of the rigid gear. An arc-shaped transition is formed between the rigid gear bearing seat 111 and the internal teeth 112 of the fixed rigid gear 110 on the inner side wall of the fixed rigid gear 110 to form a flexible gear fitting space.

[0029] At the upper end of the driven flexspline 130, a rudder disc mounting seat 131 is formed. A flexspline bolt hole 133 is provided at the center of the rudder disc mounting seat 131. Around the flexspline bolt hole 133 on the top of the rudder disc mounting seat 131, a number of rudder disc mounting holes 132 are circumferentially provided. The rudder disc mounting holes 132 are used to connect the working rudder disc of the reducer. At the lower end of the driven flexspline 130, a flexspline connection cover 134 with an opening downward is integrally formed by expanding outward from the bottom of the rudder disc mounting seat 131. The inner part of the cover shape of the flexspline connection cover 134 is a mating space for the wave generator 150. A uniform and continuous outer flexspline teeth 135 are formed at the bottom of the outer side wall of the flexspline connection cover 134. The outer flexspline teeth 135 are meshed and mated with the inner rigid teeth 112 in the long axis direction and separated from the inner rigid teeth 112 in the short axis direction.

[0030] The base of the wave generator 150 is an elliptical cylinder. A gear hole connecting the gear reduction structure 200 is provided from bottom to top at the bottom. A uniform and continuous inner generator teeth 154 are formed on the inner side wall of the gear hole. At the upper end of the wave generator 150, a conical head 151 is formed. Mounting bolt seats 152 are formed on both sides and at the top of the long axis of the column body of the conical head 151. Tightening bolts 153 are fitted and installed in the mounting bolt seats 152. The tightening bolt 153 at the top of the conical head 151 extends into the flexspline bolt hole 133 of the driven flexspline 130 to be in limit fit with it. The outer side walls of the nuts of the tightening bolts 153 on both sides are closely fitted with the inner side wall of the cover shape of the flexspline connection cover 134. Since the driven flexspline 130 is prone to fatigue damage, the tightening bolts 153 on both sides play a role in firmly supporting the driven flexspline 130 from the inside and relatively fixing the wave generator 150 and the driven flexspline 130, thereby ensuring the transmission stability of the steering gear reducer and improving its service life.

[0031] Furthermore, the harmonic reduction structure 100 is integrally installed in a nested manner on the top of the upper cover 310 of the housing structure 300 of the steering gear. An upper cover bearing seat 311 is provided on the top of the upper cover 310 of the housing. A mounting flange surface is formed by the top convexity of the outer edge of the upper cover bearing seat 311. A number of upper cover screw holes 312 are circumferentially provided on it. A number of rigid wheel screw holes 113 from bottom to top are circumferentially provided inside the pipe wall of the fixed rigid wheel 110. The upper cover screw holes 312 and the rigid wheel screw holes 113 are correspondingly matched.

[0032] The installation process of the harmonic reduction structure 100 is as follows: The second bearing 140 is fitted and installed in the upper cover bearing seat 311. The second bearing 140 is sleeved on the elliptical cylindrical base at the bottom of the conical head 151 of the wave generator 150. The driven flexible gear 130 is sleeved outside the wave generator 150 from top to bottom. The fixed rigid gear 110 is sleeved outside the driven flexible gear 130 from top to bottom and meshes with it at the bottom. A first bearing 120 is fitted and installed between the fixed rigid gear 110 and the driven flexible gear 130 in the rigid gear bearing seat 111. The fixing screw passes through the upper cover screw hole 312 and the rigid gear screw hole 113 from bottom to top to fixedly connect the harmonic reduction structure 100 with the housing upper cover 310.

[0033] As Figure 2 and Figure 5 shown, the gear reduction structure 200 is a multi-stage gear structure, mainly including a driving gear 210, a first-stage reduction gear 220, and a second-stage reduction gear 230. Among them, both the first-stage reduction gear 220 and the second-stage reduction gear 230 are double-layer gears with a smaller outer diameter at the top and a larger outer diameter at the bottom. The tooth thicknesses of the driving gear 210, the first-stage reduction gear 220, and the second-stage reduction gear 230 are the same and can mesh with each other. A DC motor 211 is provided on one side inside the housing main body 320 to provide power. Motor shaft holes 323, a first-stage gear shaft 324, and a second-stage support column 325 are respectively opened or formed at the top of the housing main body 320 corresponding to the driving gear 210, the first-stage reduction gear 220, and the second-stage reduction gear 230.

[0034] When installing the gear reduction structure 200, the working shaft of the DC motor 211 passes through the motor shaft hole 323, and the driving gear 210 is sleeved on the working shaft of the DC motor 211; the first-stage reduction gear 220 is sleeved on the first-stage gear shaft 324, so that the lower end of the first-stage reduction gear 220 meshes with the driving gear 210; the second-stage reduction gear 230 is installed on the top of the second-stage support column 325 to form a stepped installation with the first-stage reduction gear 220, so that the lower end of the second-stage reduction gear 230 meshes with the upper end of the first-stage reduction gear 220, and the upper end of the second-stage reduction gear 230 extends into the gear hole at the bottom of the wave generator 150 to mesh with the internal teeth 154 of the generator.

[0035] Further explanation, a potentiometer 232 is arranged on the other side of the housing body 320, and the center of the secondary reduction gear 230 and the secondary support column 325 passes through a mounting shaft 231, and the mounting shaft 231 is the resistance rod of the potentiometer 232, and the potentiometer 232 is fixedly connected to the lower end of the mounting shaft 231. The potentiometer 232 can convert mechanical motion into an electrical signal, thereby realizing angle position measurement and control. The bottom of the DC motor 211 is connected and installed with a control circuit board 240 in the bottom of the housing, and the control circuit board 240 is externally connected with a plurality of data lines 241. The side of the housing base 330 is provided with an outlet hole 331, and the data line 241 is connected from the outlet hole 331. When the control circuit board 240 sends an instruction to require the steering gear reducer to rotate to a specific angle, the potentiometer 232 will automatically adjust the angle position and generate a corresponding feedback signal. In addition, the control circuit board 240 can also adjust the running speed of the DC motor 211 according to actual needs, thereby realizing flexible control of the steering gear.

[0036] The working principle of the high-precision multi-stage steering gear reducer is as follows: the control circuit board 240 receives and sends operation instructions, controls the DC motor 211 to operate, so that the driving gear 210 drives the primary reduction gear 220 and the secondary reduction gear 230 to rotate in sequence, and the secondary reduction gear 230 drives the wave generator 150 and the driven flexible wheel 130 to rotate in conjunction. Since the cross-section of the wave generator 150 and the driven flexible wheel 130 is elliptical as a whole, when the wave generator 150 rotates, the driven flexible wheel 130 meshes with the fixed rigid wheel 110 in the long axis direction and separates from each other in the short axis direction, and with the continuous rotation of the wave generator 150, the movement process from meshing to separation and from separation to meshing is continuously cycled.

[0037] Compared with the steering gear reducer in the prior art, the present invention provides a linked harmonic reduction structure 100 and a gear reduction structure 200, so that the steering gear reducer can first increase the transmission torque and transmission ratio through multi-stage gear reduction, and then improve the transmission accuracy and bearing strength through harmonic reduction, thereby improving the functionality and practicality of the steering gear reducer. Embodiment 2:

[0038] like Figure 1 and Figure 5 As shown, based on a high-precision multi-stage servo reducer in Example 1, in order to facilitate its overall fixed installation in equipment with high motion precision requirements such as small unmanned aerial vehicles, the top sides of the shell body 320 in the servo shell structure 300 are extended outward to form installation extension blocks 321, and the installation extension blocks 321 on both sides are respectively provided with servo mounting holes 322. The servo mounting holes 322 are semi-open holes in the shape of a lock core, which can be snapped or screwed according to actual needs during installation.

[0039] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains may make various modifications or supplements to the described specific embodiments or use similar means for substitution, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0040] Although various terms are used more frequently herein, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; any interpretation of them as an additional limitation is contrary to the spirit of the present invention.

Claims

1. A high-precision multi-stage steering gear reducer, comprising a harmonic reduction structure (100), a gear reduction structure (200) and a steering gear housing structure (300); It is characterized in that The harmonic reduction structure (100) is installed on the top of the steering gear housing structure (300), and mainly comprises a fixed rigid wheel (110), a driven flexible wheel (130) and a wave generator (150); The fixed rigid wheel (110) is in the form of a cylindrical tubular structure as a whole, and a rigid wheel bearing seat (111) is formed at the upper end of its inner side wall, a first bearing (120) is mounted in the rigid wheel bearing seat (111), and a circle of continuous rigid wheel internal teeth (112) is formed at the lower end; A steering disc mounting seat (131) is formed at the upper end of the driven flexible wheel (130), a flexible wheel bolt hole (133) is provided at the center of the steering disc mounting seat (131), a plurality of steering disc mounting holes (132) are provided around the flexible wheel bolt hole (133) at the top of the steering disc mounting seat (131) in a circumferential direction, and a flexible wheel connecting cover (134) with an opening facing downward is formed at the lower end of the driven flexible wheel (130) by expanding outward from the bottom of the steering disc mounting seat (131), and a circle of continuous flexible wheel external teeth (135) is formed at the bottom of the outer side wall of the flexible wheel connecting cover (134); The base of the wave generator (150) is an elliptical cylinder, with a conical head (151) formed at the upper end. The conical head (151) is provided with mounting bolt seats (152) on both sides of the long axis of the cylinder and at the top. A fastening bolt (153) is mounted in the mounting bolt seat (152). The fastening bolt (153) at the top of the conical head (151) of the wave generator (150) extends into the flexible wheel bolt hole (133) to match it. The outer nut walls of the fastening bolts (153) on both sides are tightly matched with the cover-shaped inner wall of the flexible wheel connection cover (134). The bottom of the wave generator (150) is provided with a gear hole connected to the gear reduction structure (200) from bottom to top, and a circle of continuous generator internal teeth (154) is formed on the inner wall of the gear hole. The steering gear housing structure (300) is composed of a housing upper cover (310), a housing body (320) and a housing base (330); a housing upper cover bearing seat (311) is provided on the top of the housing upper cover (310); a second bearing (140) is mounted in the upper cover bearing seat (311); and the harmonic reduction structure (100) is fixedly connected to the top of the upper cover bearing seat (311); The gear reduction structure (200) is mainly installed on the top of the housing body (320) and inside the housing upper cover (310), and comprises a driving gear (210), a primary reduction gear (220) and a secondary reduction gear (230). The driving gear (210) is sleeved on the working shaft of the DC motor (211). The primary reduction gear (220) and the secondary reduction gear (230) are both double-layer gears with a smaller outer diameter at the top and a larger outer diameter at the bottom and uniform tooth thickness. The lower end of the primary reduction gear (220) is meshed with the driving gear (210), the lower end of the secondary reduction gear (230) is meshed with the upper end of the primary reduction gear (220), and the upper end of the secondary reduction gear (230) extends into the gear hole at the bottom of the wave generator (150) and is meshed with the internal teeth (154) of the generator.

2. A high-precision multi-stage steering gear reducer according to claim 1, characterized in that: A plurality of rigid wheel screw holes (113) are circumferentially opened inside the tube wall of the fixed rigid wheel (110) from bottom to top, and a plurality of upper cover screw holes (312) are circumferentially opened on the upper cover bearing seat (311) of the housing upper cover (310) corresponding to the rigid wheel screw holes (113), and the harmonic reduction structure (100) is fixedly connected to the housing upper cover (310) by screws passing through the upper cover screw holes (312) and the rigid wheel screw holes (113) from bottom to top.

3. A high-precision multi-stage steering gear reducer according to claim 1, characterized in that: Both sides of the housing body (320) are protruded outward to form installation extension blocks (321), and the installation extension blocks (321) are provided with steering gear installation holes (322).

4. The high-precision multi-stage steering gear reducer according to claim 1, characterized in that: The top of the housing body (320) is respectively provided with or formed with a motor shaft hole (323), a first-stage gear shaft (324) and a second-stage support column (325) corresponding to the driving gear (210), the first-stage reduction gear (220) and the second-stage reduction gear (230); the working shaft of the DC motor (211) passes through the motor shaft hole (323); the first-stage reduction gear (220) is sleeved on the first-stage gear shaft (324); and the second-stage reduction gear (230) is installed on the top of the second-stage support column (325) to form a stepped installation with the first-stage reduction gear (220).

5. A high-precision multi-stage steering gear reducer according to claim 4, characterized in that: A mounting shaft (231) passes through the centers of the secondary reduction gear (230) and the secondary support column (325), and a potentiometer (232) is fixedly connected to the lower end of the mounting shaft (231) inside the housing body (320).

6. The high-precision multi-stage steering gear reducer according to claim 1, characterized in that: The bottom of the DC motor (211) is connected to a control circuit board (240) installed in the bottom of the housing, and the control circuit board (240) is externally connected to a plurality of data lines (241). A wire outlet hole (331) is provided on the side of the housing base (330), and the data lines (241) are connected through the wire outlet hole (331).

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