Ultra-miniature harmonic speed reducer with double-flexible-gear structure

Abstract

The utility model provides an ultraminiature double flexible gear structure harmonic wave speed reducer, including steel wheel, input shaft, support bearing structure, multistage flexible gear structure and output shaft, said steel wheel upper side and lower side are respectively and fixedly equipped with upper cover and lower cover, input shaft and output shaft pass through support bearing structure and steel wheel rotary connection arrangement, the multistage flexible gear structure is equipped with multistage flexible gear structure. The input shaft and the output shaft are in driving connection through a multi-stage flexible gear structure, and the multi-stage flexible gear structure is formed by connecting a plurality of flexible gear structures in series. The harmonic speed reducer is provided with the double flexible gear structures which are connected in series, the harmonic speed reducer is large in transmission ratio, high in bearing capacity and high in transmission precision, and compared with a traditional harmonic speed reducer, the harmonic speed reducer can be of an ultra-micro structure, has the high transmission ratio and large torque, can be suitable for the small-space use environment, is higher in applicability and has the good market prospect in the field of miniature equipment.

Description

Technical Field

[0001] This utility model relates to the field of harmonic reducer structure technology, and in particular to an ultra-miniature double flexible wheel structure harmonic reducer. Background Technology

[0002] Harmonic gear transmission was invented by American utility model inventor C.W. Musser in 1955. It is a novel transmission method that utilizes the elastic deformation of a flexible working component to transmit motion or power. It breaks away from the rigid component mechanism used in mechanical transmission, using a flexible component to achieve mechanical transmission, thereby obtaining a series of special functions that are difficult to achieve with other transmission methods. It is named after the fact that the deformation process of the intermediate flexible component is basically a symmetrical harmonic.

[0003] The harmonic gear transmission reduction principle refers to the use of the relative motion of a flexible wheel, a rigid wheel, and a wave generator, primarily through the controllable elastic deformation of the flexible wheel, to achieve motion and power transmission. An elliptical cam inside the wave generator rotates within the flexible wheel, causing it to deform. When the teeth of the flexible wheel at both ends of the elliptical cam's major axis engage with the teeth of the rigid wheel, the teeth of the flexible wheel at both ends of the minor axis disengage from the rigid wheel. For the teeth between the major and minor axes of the wave generator, they are in a semi-engaged state gradually entering engagement (called engagement) or gradually disengaging (called disengagement) along different sections of the circumference of the flexible and rigid wheels. As the wave generator rotates continuously, the flexible wheel continuously deforms, causing the teeth of both wheels to constantly change their original working states through four motions: engagement, disengagement, and retraction, producing a tooth-shifting motion, thus realizing the motion transmission from the active wave generator to the flexible wheel.

[0004] However, existing harmonic reducers occupy a large volume and are not suitable for use in small spaces. They also mostly adopt a single-stage flexible gear transmission structure, which has a small specific speed, low load torque, and insufficient precision, failing to meet the needs of high specific speed and high torque output.

[0005] There is a need for an ultra-miniature dual-flexible-wheel harmonic reducer that can solve the problems mentioned above. Utility Model Content

[0006] This utility model provides an ultra-miniature dual-flexible-wheel structure harmonic reducer. By technically modifying existing harmonic reducers, it solves the problem that existing harmonic reducers cannot meet the requirements of ultra-miniature, high precision, high specific speed and large torque applications.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0008] An ultra-miniature dual-flexible-wheel harmonic reducer includes a steel wheel, an input shaft, a support bearing structure, a multi-stage flexible wheel structure, and an output shaft. An upper cover and a lower cover are fixedly installed on the upper and lower sides of the steel wheel, respectively. The input shaft and the output shaft are rotatably connected to the steel wheel through the support bearing structure. The input shaft and the output shaft are driven and connected by the multi-stage flexible wheel structure, which consists of several flexible wheel structures connected in series.

[0009] Preferably, a lower bearing seat is provided on the upper surface of the lower cover, and a lower ball bearing is installed in the lower bearing seat. The input shaft is rotatably connected to the lower cover through the lower ball bearing. An upper bearing seat is provided on the bottom surface of the upper cover, and an upper ball bearing is installed in the upper bearing seat. The output shaft is rotatably connected to the upper cover through the upper ball bearing.

[0010] Preferably, the multi-stage flexible wheel structure includes a first-stage flexible wheel structure and a second-stage flexible wheel structure. The input shaft is connected to the input end of the first-stage flexible wheel structure, the output end of the first-stage flexible wheel structure is connected to the input end of the second-stage flexible wheel structure, and the output end of the second-stage flexible wheel structure is connected to the output shaft.

[0011] Preferably, the first-stage flexible wheel structure includes a first-stage flexible wheel and a first flexible bearing, and the second-stage flexible wheel structure includes a second-stage flexible wheel and a second flexible bearing. A first cam is provided at the upper end of the input shaft, and a first flexible bearing is sleeved and installed on the outer periphery of the first cam. The first flexible bearing is installed in the inner cavity of the first-stage flexible wheel. A first external tooth surface is provided on the outer periphery of the first-stage flexible wheel, and the first external tooth surface matches the inner tooth surface of the steel wheel. A second cam is also provided at the upper end of the first-stage flexible wheel, and a second flexible bearing is sleeved and installed on the outer periphery of the second cam. The second flexible bearing is installed in the inner cavity of the second-stage flexible wheel, and a second external tooth surface is provided on the outer periphery of the second-stage flexible wheel, and the second external tooth surface matches the inner tooth surface of the steel wheel. The upper end of the second-stage flexible wheel is connected to the output shaft.

[0012] Preferably, the first cam is an elliptical cylinder with a major axis and a minor axis, the first external tooth surface of the first stage flexible wheel relative to the major axis of the first cam meshes with the inner tooth surface of the steel wheel, and the first external tooth surface of the first stage flexible wheel relative to the minor axis of the first cam is disengaged from the inner tooth surface of the steel wheel.

[0013] Preferably, the second cam is an elliptical cylinder with a major axis and a minor axis. The second external tooth surface of the second stage flexible wheel relative to the major axis of the second cam meshes with the inner tooth surface of the steel wheel, and the second external tooth surface of the second stage flexible wheel relative to the minor axis of the second cam is disengaged from the inner tooth surface of the steel wheel.

[0014] Preferably, the first-stage flexible wheel is connected to the second cam via a first arc-shaped spring piece. The bottom of the first arc-shaped spring piece is connected to the top periphery of the inner wall of the first-stage flexible wheel cavity, and the middle part of the first arc-shaped spring piece protrudes upward and is connected to the second cam.

[0015] Preferably, the second-stage flexible wheel is connected to the output shaft via a second arc-shaped spring. The bottom of the second arc-shaped spring is connected to the top periphery of the inner wall of the second-stage flexible wheel, and the middle of the second arc-shaped spring protrudes upward and is connected to the output shaft.

[0016] The beneficial effects of this utility model are as follows:

[0017] This application features a dual-flexible gear structure connected in series, resulting in a harmonic reducer with a high transmission ratio, high load-bearing capacity, and high transmission accuracy. Compared to traditional harmonic reducers, it achieves an ultra-miniature structure, possessing a high transmission ratio and large torque, making it suitable for use in confined spaces. The overall diameter of the harmonic reducer in this application can be as small as 5mm, broadening its applicability and application areas. It also has a better market prospect for future AI-controlled miniaturized equipment.

[0018] Furthermore, the flexible wheel structure of this application is equipped with a floating arc-shaped spring structure. There are reserved movable gaps between the first-stage flexible wheel structure and the second-stage flexible wheel structure, as well as between the second-stage flexible wheel structure and the upper ball bearing, so that the flexible wheel has a certain deformation area in the axial direction, which can perform elastic buffering, resulting in a lower failure rate and a longer service life. Moreover, the deformation area is narrower than that of traditional flexible wheel structures, which makes the harmonic reducer occupy less space and does not increase the overall thickness. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model;

[0020] Figure 2 This is a schematic cross-sectional view of the present invention;

[0021] Figures 3-4 This is a schematic diagram of the exploded structure of this utility model;

[0022] Figure 5 This is a schematic diagram of the input shaft and the first cam structure of this utility model;

[0023] Figure 6 This is a schematic diagram of the first-stage flexible wheel structure of this utility model;

[0024] Figure 7 This is a schematic diagram of the second-stage flexible wheel and output shaft structure of this utility model;

[0025] Reference numerals: 1. Steel wheel, 11. Upper cover, 111. Upper bearing seat, 12. Lower cover, 121. Lower bearing seat, 2. Input shaft, 2. First cam, 21. Support bearing structure, 3. Upper ball bearing, 31. Lower ball bearing, 32. Multi-stage flexible wheel structure, 4. First-stage flexible wheel structure, 41. First-stage flexible wheel, 411. First flexible bearing, 412. Second cam, 413. Second-stage flexible wheel structure, 42. Second-stage flexible wheel, 421. Second flexible bearing, 422. Output shaft, 5. First arc-shaped spring, 6. Second arc-shaped spring, 7. Detailed Implementation

[0026] The specific content of this utility model will be described in detail below with reference to the accompanying drawings and embodiments.

[0027] Please see Figure 1-7 As shown, this utility model provides an ultra-miniature dual-flexible-wheel harmonic reducer, including a steel wheel 1, an input shaft 2, a support bearing structure 3, a multi-stage flexible wheel structure 4, and an output shaft 5. The upper and lower sides of the steel wheel 1 are respectively fixedly installed with an upper cover 11 and a lower cover 12. The input shaft 2 and the output shaft 5 are rotatably connected to the steel wheel 1 through the support bearing structure 3, and the input shaft 2 and the output shaft 5 are driven and connected by the multi-stage flexible wheel structure 4, which consists of several flexible wheel structures connected in series.

[0028] The reducer is comprised of a steel wheel 1, which is a fixed part with internal gears; an input shaft 2, which receives power input; a support bearing structure 3, which ensures smooth rotation of the input shaft 2 and the output shaft 5; a multi-stage flexible gear structure 4, which consists of two or more flexible gear structures connected in series to achieve multi-stage speed reduction; and an output shaft 5, which outputs the reduced power. The upper cover 11 and the lower cover 12 enclose the internal structure of the reducer.

[0029] Furthermore, in order to support the input shaft 2 and the output shaft 5, and to enable the input shaft 2 and the output shaft 5 to be rotatably mounted in the steel wheel 1, the support bearing structure 3 includes: a lower bearing seat 121 provided on the upper surface of the lower cover 12, a lower ball bearing 32 installed in the lower bearing seat 121, the input shaft 2 being rotatably connected to the lower cover 12 via the lower ball bearing 32; an upper bearing seat 111 provided on the bottom surface of the upper cover 11, an upper ball bearing 31 installed in the upper bearing seat 111, the output shaft 5 being rotatably connected to the upper cover 11 via the upper ball bearing 31.

[0030] Furthermore, the multi-stage flexible gear structure 4 includes a first-stage flexible gear structure 41 and a second-stage flexible gear structure 42. The input shaft 2 is connected to the input end of the first-stage flexible gear structure 41, the output end of the first-stage flexible gear structure 41 is connected to the input end of the second-stage flexible gear structure 42, and the output end of the second-stage flexible gear structure 42 is connected to the output shaft 5.

[0031] Furthermore, the first-stage flexible gear structure 41 includes a first-stage flexible gear 411 and a first flexible bearing 412, and the second-stage flexible gear structure 42 includes a second-stage flexible gear 421 and a second flexible bearing 422. A first cam 21 is provided at the upper end of the input shaft 2, and a first flexible bearing 412 is sleeved on the outer periphery of the first cam 21. The first flexible bearing 412 is installed in the inner cavity of the first-stage flexible gear 411. A first external tooth surface is provided on the outer periphery of the first-stage flexible gear 411, and the first external tooth surface is matched with the inner tooth surface of the steel wheel 1. A second cam 413 is also provided at the upper end of the first-stage flexible gear 411, and a second flexible bearing 422 is sleeved on the outer periphery of the second cam 413. The second flexible bearing 422 is installed in the inner cavity of the second-stage flexible gear 421, and a second external tooth surface is provided on the outer periphery of the second-stage flexible gear 421, and the second external tooth surface is matched with the inner tooth surface of the steel wheel 1. The upper end of the second-stage flexible gear 421 is connected to the output shaft 5.

[0032] The first cam 21 is integrally formed with the input shaft 2, and the second-stage flexible wheel 421 is integrally formed with the output shaft 5.

[0033] Furthermore, the first cam 21 is an elliptical cylinder with a major axis and a minor axis. The first external tooth surface of the first stage flexible wheel 411 relative to the major axis of the first cam 21 is engaged with the internal tooth surface of the steel wheel 1, and the first external tooth surface of the first stage flexible wheel 411 relative to the minor axis of the first cam 21 is disengaged from the internal tooth surface of the steel wheel 1.

[0034] Furthermore, the second cam 413 is an elliptical cylinder with a major axis and a minor axis. The second external tooth surface of the second stage flexible wheel 421 relative to the major axis of the second cam 413 is engaged with the internal tooth surface of the steel wheel 1, and the second external tooth surface of the second stage flexible wheel 421 relative to the minor axis of the second cam 413 is disengaged from the internal tooth surface of the steel wheel 1.

[0035] Furthermore, in order to create a floating clearance between the first-stage flexible wheel structure 41 and the second-stage flexible wheel structure 42 to avoid hard collisions that could affect service life and transmission accuracy, the first-stage flexible wheel 411 is connected to the second cam 413 via a first arc-shaped spring piece 6. The bottom of the first arc-shaped spring piece 6 is connected to the top periphery of the inner wall of the first-stage flexible wheel 411, and the middle of the first arc-shaped spring piece 6 protrudes upward and is connected to the second cam 413.

[0036] Furthermore, in order to allow for a floating clearance between the second-stage flexible wheel structure 42 and the upper ball bearing 31 of the steel wheel 1, thus avoiding hard collisions that could affect service life and transmission accuracy, the second-stage flexible wheel 421 is connected to the output shaft 5 via a second arc-shaped spring 7. The bottom of the second arc-shaped spring 7 is connected to the top periphery of the inner wall of the second-stage flexible wheel 421, and the middle of the second arc-shaped spring 7 protrudes upward and is connected to the output shaft 5.

[0037] The harmonic reducer of this application has an overall diameter as small as 5mm, a dual flexible wheel structure that can achieve a specific speed of 225, and uses a flexible bearing with a diameter of 3mm to achieve a large torque transmission effect of 2N.m.

[0038] The principle behind this application is:

[0039] The input shaft 2 rotates under the drive of the motor. The first cam 21 at the top of the input shaft 2 is fitted with a first flexible bearing 412 and a first-stage flexible wheel 411. When the first cam 21 is installed inside the first flexible bearing 412 and the first-stage flexible wheel 411, it presses against the inner wall of the first-stage flexible wheel 411, causing the first-stage flexible wheel 411 to undergo elastic deformation. This forces the cross-section of the first-stage flexible wheel 411 to change from a circle to an ellipse. The first external tooth surface of the first-stage flexible wheel 411 at the long axis of the first cam 21 meshes with the inner tooth surface of the steel wheel 1. The first external tooth surface of the first-stage flexible wheel 411 at the short axis of the first cam 21 disengages from the inner tooth surface of the steel wheel 1. The teeth in other sections of the circumference are in a transitional state between meshing and disengagement. When the input shaft 2 rotates continuously, the deformation of the first-stage flexible wheel 411 changes continuously, causing the meshing state between the first-stage flexible wheel 411 and the rigid wheel to change continuously, from meshing, meshing, meshing out, disengaging, and meshing again... repeating in a cycle, thereby realizing the slow rotation of the first-stage flexible wheel 411 relative to the rigid wheel in the opposite direction to the input shaft 2.

[0040] A second cam 413 is connected to the first-stage flexible wheel 411. The second cam 413 is installed inside the second flexible bearing 422 and the second-stage flexible wheel 421, pressing against the inner wall of the second-stage flexible wheel 421. This causes the second-stage flexible wheel 421 to undergo elastic deformation, forcing its cross-section to change from a circle to an ellipse. The second external tooth surface of the second-stage flexible wheel 421 at the long axis relative to the second cam 413 meshes with the inner tooth surface of the steel wheel 1, while the second external tooth surface of the second-stage flexible wheel 421 at the short axis relative to the second cam 413 disengages from the inner tooth surface of the steel wheel 1. The teeth in other sections of the circumference are in a transitional state between engagement and disengagement. During operation, the steel wheel 1 is fixed, and the motor drives the input shaft 2 to rotate. The first-stage flexible wheel 411 and the second-stage flexible wheel 421 act as driven wheels, driving the output shaft 5 to rotate, thereby driving the load to rotate.

[0041] This application features a dual-flexible gear structure connected in series, resulting in a harmonic reducer with a high transmission ratio, high load-bearing capacity, and high transmission accuracy. Compared to traditional harmonic reducers, it achieves an ultra-miniature structure, possesses a high transmission ratio and large torque, and is suitable for use in small spaces, making it more versatile.

[0042] Furthermore, the flexible wheel structure of this application is equipped with a floating arc-shaped spring structure. There are reserved movable gaps between the first-stage flexible wheel structure and the second-stage flexible wheel structure, as well as between the second-stage flexible wheel structure and the upper ball bearing, so that the flexible wheel has a certain deformation area in the axial direction, which can perform elastic buffering, resulting in a lower failure rate and a longer service life. Moreover, the deformation area is narrower than that of traditional flexible wheel structures, which makes the harmonic reducer occupy less space and does not increase the overall thickness.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

[0044] All standard parts used in this utility model can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art. In addition, the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0045] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or a connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

Claims

1. A miniature dual-flexible gear harmonic reducer, characterized in that, It includes a steel wheel, an input shaft, a support bearing structure, a multi-stage flexible wheel structure, and an output shaft. The upper and lower sides of the steel wheel are respectively fixedly installed with an upper cover and a lower cover. The input shaft and the output shaft are rotatably connected to the steel wheel through the support bearing structure. The input shaft and the output shaft are driven and connected by the multi-stage flexible wheel structure, which consists of several flexible wheel structures connected in series.

2. The ultra-miniature dual-flexible-wheel harmonic reducer according to claim 1, characterized in that, The lower cover has a lower bearing seat on its upper surface, and a lower ball bearing is installed inside the lower bearing seat. The input shaft is rotatably connected to the lower cover through the lower ball bearing. The upper cover has an upper bearing seat on its bottom surface, and an upper ball bearing is installed inside the upper bearing seat. The output shaft is rotatably connected to the upper cover through the upper ball bearing.

3. The ultra-miniature dual-flexible-wheel harmonic reducer according to claim 1, characterized in that, The multi-stage flexible wheel structure includes a first-stage flexible wheel structure and a second-stage flexible wheel structure. The input shaft is connected to the input end of the first-stage flexible wheel structure, the output end of the first-stage flexible wheel structure is connected to the input end of the second-stage flexible wheel structure, and the output end of the second-stage flexible wheel structure is connected to the output shaft.

4. The ultra-miniature dual-flexible-wheel harmonic reducer according to claim 3, characterized in that, The first-stage flexible wheel structure includes a first-stage flexible wheel and a first flexible bearing. The second-stage flexible wheel structure includes a second-stage flexible wheel and a second flexible bearing. A first cam is provided at the upper end of the input shaft. A first flexible bearing is sleeved on the outer periphery of the first cam and installed in the inner cavity of the first-stage flexible wheel. A first external tooth surface is provided on the outer periphery of the first-stage flexible wheel, which matches the inner tooth surface of the steel wheel. A second cam is also provided at the upper end of the first-stage flexible wheel. A second flexible bearing is sleeved on the outer periphery of the second cam and installed in the inner cavity of the second-stage flexible wheel. A second external tooth surface is provided on the outer periphery of the second-stage flexible wheel, which matches the inner tooth surface of the steel wheel. The upper end of the second-stage flexible wheel is connected to the output shaft.

5. A miniature dual-flexible gear harmonic reducer according to claim 4, characterized in that, The first cam is an elliptical cylinder with a major axis and a minor axis. The first external tooth surface of the first stage flexible wheel relative to the major axis of the first cam meshes with the inner tooth surface of the steel wheel. The first external tooth surface of the first stage flexible wheel relative to the minor axis of the first cam is disengaged from the inner tooth surface of the steel wheel.

6. The ultra-miniature dual-flexible-wheel harmonic reducer according to claim 4, characterized in that, The second cam is an elliptical cylinder with a major axis and a minor axis. The second external tooth surface of the second stage flexible wheel relative to the major axis of the second cam meshes with the inner tooth surface of the steel wheel. The second external tooth surface of the second stage flexible wheel relative to the minor axis of the second cam is disengaged from the inner tooth surface of the steel wheel.

7. A micro dual-flexible gear harmonic reducer according to claim 4, characterized in that, The first cam is integrally formed with the input shaft, and the second-stage flexible wheel is integrally formed with the output shaft.

8. A miniature dual-flexible gear harmonic reducer according to claim 4, characterized in that, The first stage flexible wheel is connected to the second cam via a first arc-shaped spring piece. The bottom of the first arc-shaped spring piece is connected to the top of the inner wall of the first stage flexible wheel. The middle part of the first arc-shaped spring piece protrudes upward and is connected to the second cam.

9. A micro dual-flexible gear harmonic reducer according to claim 4, characterized in that, The second-stage flexible wheel is connected to the output shaft via a second arc-shaped spring. The bottom of the second arc-shaped spring is connected to the top periphery of the inner wall of the second-stage flexible wheel, and the middle of the second arc-shaped spring protrudes upward and is connected to the output shaft.

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