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

Abstract

The ultra-miniature harmonic speed reducer with the double-flexible-gear structure comprises a steel wheel, an input shaft, a supporting bearing structure, a multi-stage flexible gear structure and an output shaft, an upper cover and a lower cover are fixedly installed on the upper side and the lower side of the steel wheel correspondingly, and the input shaft and the output shaft are rotationally connected with the steel wheel through the supporting bearing 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] The invention relates to the technical field of harmonic reducer structures, and in particular to an ultra-miniature double-flexible-wheel structure harmonic reducer. Background Art

[0002] Harmonic gear drive was invented by American inventor CW Musser in 1955. It is a new type of transmission method that uses the elastic deformation of flexible working components to transmit motion or power. It breaks through the mode of mechanical transmission using rigid components and uses a flexible component to achieve mechanical transmission, thereby obtaining a series of special functions that are difficult to achieve with other transmissions. Since the deformation process of the intermediate flexible component is basically a symmetrical harmonic, it is named so. Except for the Soviet Union, which calls this transmission wave drive or flexible wheel drive, the United States, Britain, Germany, Japan and other countries all call it "harmonic drive".

[0003] The principle of harmonic gear transmission speed reduction refers to the use of the relative movement of the flexible wheel, the rigid wheel and the wave generator, mainly the controllable elastic deformation of the flexible wheel to achieve motion and power transmission. The elliptical cam in the wave generator rotates in the flexible wheel to deform the flexible wheel. When the flexible wheel teeth and the rigid wheel teeth at both ends of the long axis of the elliptical cam of the wave generator enter into meshing, the flexible wheel teeth at both ends of the short axis are disengaged from the rigid wheel teeth. For the teeth between the long axis and the short axis of the wave generator, the semi-meshing state of gradually entering into meshing in different sections along the circumference of the flexible wheel and the rigid wheel is called meshing in; the semi-meshing state of gradually exiting meshing is called meshing out. When the wave generator rotates continuously, the flexible wheel continuously deforms, causing the two wheel teeth to continuously change their original working states in the four movements of meshing in, meshing, meshing out and disengaging, generating staggered tooth motion, and realizing the motion transmission from the active wave generator to the flexible wheel.

[0004] However, the existing harmonic reducer structure occupies a large volume and cannot be used in small spaces. It mostly adopts a single-stage flexible wheel transmission structure with a small specific speed and load torque, and the accuracy is not high enough to meet the needs of high specific speed and large torque output.

[0005] There is a need for an ultra-miniature double-flexible-wheel structure harmonic reducer that can solve the above-mentioned problems. Summary of the invention

[0006] The present invention provides an ultra-miniature double-flexible-wheel structure harmonic reducer, which solves the problem that the existing harmonic reducer cannot meet the use requirements of ultra-miniature, high precision, high specific speed and large torque by technically transforming the existing harmonic reducer.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] An ultra-miniature double-flexible-wheel structure harmonic reducer comprises a steel wheel, an input shaft, a supporting bearing structure, a multi-stage flexible-wheel structure and an output shaft, wherein an upper cover and a lower cover are fixedly mounted 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 supporting bearing structure, and the input shaft and the output shaft are drivingly connected through a multi-stage flexible-wheel structure, and the multi-stage flexible-wheel structure is composed of a plurality of flexible-wheel structures connected in series.

[0009] Preferably, a lower bearing seat is provided on the upper surface of the lower cover, a lower ball bearing is installed in the lower bearing seat, the input shaft is rotatably connected to the lower cover via the lower ball bearing, an upper bearing seat is provided on the bottom surface of the upper cover, an upper ball bearing is installed in the upper bearing seat, and the output shaft is rotatably connected to the upper cover via 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, and the first flexible bearing is installed in the inner cavity of the first-stage flexible wheel. A first outer tooth surface is provided on the outer periphery of the first-stage flexible wheel, and the first outer tooth surface is matched with 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, and the second flexible bearing is installed in the inner cavity of the second-stage flexible wheel. A second outer tooth surface is provided on the outer periphery of the second-stage flexible wheel, and the second outer tooth surface is matched with the inner tooth surface of the steel wheel, and 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 outer tooth surface of the first-stage flexible wheel relative to the major axis of the first cam is meshed with the inner tooth surface of the steel wheel, and the first outer 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 outer tooth surface of the second-stage flexible wheel relative to the major axis of the second cam is meshed with the inner tooth surface of the steel wheel, and the second outer 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 of the inner wall of the first-stage flexible wheel cavity, and the middle 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 through a second arc-shaped spring piece, the bottom of the second arc-shaped spring piece is connected to the top of the inner wall of the second-stage flexible wheel cavity, and the middle part of the second arc-shaped spring piece protrudes upward and is connected to the output shaft.

[0016] The beneficial effects of the present invention are:

[0017] The present application is provided with a double flexible wheel structure connected in series. The harmonic reducer has a large transmission ratio, high load-bearing capacity, and high transmission accuracy. Compared with traditional harmonic reducers, it can achieve an ultra-micro structure, with a high transmission ratio and large torque, and can be used in a small space environment. The overall size of the harmonic reducer in the present application can be as small as 5mm in diameter, and its applicability and application field are broader, and it has better market prospects for future AI artificial intelligence control miniaturized equipment.

[0018] In addition, the flexible wheel structure of the present application is provided with a floating arc-shaped spring structure, and a movable gap is reserved between the first-stage flexible wheel structure and the second-stage flexible wheel structure and 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, can perform elastic buffering, has a lower failure rate, and a longer service life. Compared with the traditional flexible wheel structure, the deformation area is narrower, so that the harmonic reducer occupies less space and does not increase the overall thickness. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the present invention;

[0020] Figure 2 It is a schematic diagram of the cross-sectional structure of the present invention;

[0021] Figure 3-Figure 4 It is a schematic diagram of the explosion structure of the present invention;

[0022] Figure 5 It is a schematic diagram of the input shaft and the first cam structure of the present invention;

[0023] Figure 6 It is a schematic diagram of the first-stage flexible pulley structure of the present invention;

[0024] Figure 7 It is a schematic diagram of the structure of the second-stage flexible wheel and the output shaft of the present invention;

[0025] Explanation of the accompanying drawings: steel wheel 1, upper cover 11, upper bearing seat 111, lower cover 12, lower bearing seat 121, input shaft 2, first cam 21, supporting 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 piece 6, second arc-shaped spring piece 7. DETAILED DESCRIPTION

[0026] The specific contents of the present invention are described in detail below with reference to the accompanying drawings and embodiments.

[0027] See also Figure 1-7 As shown, the present invention provides an ultra-micro double flexible wheel structure harmonic reducer, including a steel wheel 1, an input shaft 2, a supporting bearing structure 3, a multi-stage flexible wheel structure 4 and an output shaft 5, wherein an upper cover 11 and a lower cover 12 are fixedly installed on the upper and lower sides of the steel wheel 1 respectively, the input shaft 2 and the output shaft 5 are rotatably connected to the steel wheel 1 through the supporting bearing structure 3, and the input shaft 2 and the output shaft 5 are drivingly connected through the multi-stage flexible wheel structure 4, and the multi-stage flexible wheel structure 4 is composed of a plurality of flexible wheel structures connected in series.

[0028] Among them, the steel wheel 1 is used as the fixed part of the reducer and is provided with an internal tooth surface. The input shaft 2 is used to receive the power input. The support bearing structure 3 is used to ensure the smooth rotation of the input shaft 2 and the output shaft 5. The multi-stage flexible wheel structure 4 is composed of two or more flexible wheel structures connected in series to achieve multi-stage reduction. The output shaft 5 is used to output the reduced power. The upper cover 11 and the lower cover 12 are used to encapsulate the internal structure of the reducer.

[0029] Furthermore, in order to support the input shaft 2 and the output shaft 5, and the input shaft 2 and the output shaft 5 can be rotatably installed in the steel wheel 1, the supporting bearing structure 3 includes: a lower bearing seat 121 is arranged on the upper surface of the lower cover 12, a lower ball bearing 32 is installed in the lower bearing seat 121, the input shaft 2 is rotatably connected to the lower cover 12 through the lower ball bearing 32, an upper bearing seat 111 is arranged on the bottom surface of the upper cover 11, an upper ball bearing 31 is installed in the upper bearing seat 111, and the output shaft 5 is rotatably connected to the upper cover 11 through 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] Further, the first-stage flexible wheel structure 41 includes a first-stage flexible wheel 411 and a first flexible bearing 412, the second-stage flexible wheel structure 42 includes a second-stage flexible wheel 421 and a second flexible bearing 422, the upper end of the input shaft 2 is provided with a first cam 21, the outer circumference of the first cam 21 is sleeved with a first flexible bearing 412, the first flexible bearing 412 is installed in the inner cavity of the first-stage flexible wheel 411, the outer circumference of the first-stage flexible wheel 411 is provided with a first external tooth surface, the first external tooth surface is matched with the inner tooth surface of the steel wheel 1, the upper end of the first-stage flexible wheel 411 is also provided with a second cam 413, the outer circumference of the second cam 413 is sleeved with a second flexible bearing 422, the second flexible bearing 422 is installed in the inner cavity of the second-stage flexible wheel 421, the outer circumference of the second-stage flexible wheel 421 is provided with a second external tooth surface, the second external tooth surface is matched with the inner tooth surface of the steel wheel 1, and the upper end of the second-stage flexible wheel 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 gear 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 outer tooth surface of the first-stage flexible wheel 411 relative to the major axis of the first cam 21 is meshed with the inner tooth surface of the steel wheel 1, and the first outer tooth surface of the first-stage flexible wheel 411 relative to the minor axis of the first cam 21 is disengaged from the inner 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 outer tooth surface of the second-stage flexible wheel 421 at the major axis of the second cam 413 is meshed with the inner tooth surface of the steel wheel 1, and the second outer tooth surface of the second-stage flexible wheel 421 at the minor axis of the second cam 413 is disengaged from the inner tooth surface of the steel wheel 1.

[0035] Furthermore, in order to allow a floating active gap to exist between the first-stage flexible wheel structure 41 and the second-stage flexible wheel structure 42 to avoid hard collision and affect the service life and transmission accuracy, the first-stage flexible wheel 411 is connected to the second cam 413 through the first arc-shaped spring piece 6, and the bottom of the first arc-shaped spring piece 6 is connected to the top of the inner wall of the inner cavity of the first-stage flexible wheel 411, and the middle part of the first arc-shaped spring piece 6 protrudes upward and is connected to the second cam 413.

[0036] Furthermore, in order to allow a floating clearance to exist between the second-stage flexible wheel structure 42 and the upper ball bearing 31 of the steel wheel 1 to avoid hard collision and affect the service life and transmission accuracy, the second-stage flexible wheel 421 is connected to the output shaft 5 through a second arc-shaped spring piece 7, and the bottom of the second arc-shaped spring piece 7 is connected to the top of the inner wall of the inner cavity of the second-stage flexible wheel 421, and the middle part of the second arc-shaped spring piece 7 protrudes upward and is connected to the output shaft 5.

[0037] The overall diameter of the harmonic reducer of the present application can be as small as 5mm, the double flexible wheel structure can achieve a 225 speed ratio, and a flexible bearing with a diameter of 3mm can be used to achieve a large torque transmission effect of 2N.m.

[0038] The application principle is:

[0039] The input shaft 2 rotates driven by the motor. The first cam 21 arranged on the top of the input shaft 2 is provided with a first flexible bearing 412 and a first-stage flexible wheel 411. When the first cam 21 is installed in the first flexible bearing 412 and the first-stage flexible wheel 411, it is pressed against the inner wall of the first-stage flexible wheel 411, so that the first-stage flexible wheel 411 undergoes elastic deformation, forcing the cross-section of the first-stage flexible wheel 411 to change from the original circle to an ellipse. The first outer tooth surface of the first-stage flexible wheel 411 at the long axis of the first cam 21 is meshed with the inner tooth surface of the steel wheel 1, and the first outer tooth surface of the first-stage flexible wheel 411 at the short axis of the first cam 21 is disengaged from the inner tooth surface of the steel wheel 1, and the teeth of other sections on the circumference are in a transitional state of meshing and disengagement. When the input shaft 2 rotates continuously, the deformation of the first-stage flexible wheel 411 changes continuously, so that the meshing state of the first-stage flexible wheel 411 and the rigid wheel also changes continuously, from meshing in, meshing in, meshing out, disengaging, and then meshing in again, etc., in a cycle, thereby realizing the slow rotation of the first-stage flexible wheel 411 relative to the rigid wheel in the opposite direction of the input shaft 2;

[0040] The first-stage flexible wheel 411 is connected with a second cam 413, which is installed in the second flexible bearing 422 and the second-stage flexible wheel 421, and is pressed against the inner wall of the second-stage flexible wheel 421, so that the second-stage flexible wheel 421 undergoes elastic deformation, forcing the cross-section of the second-stage flexible wheel 421 to change from the original circle to an ellipse. The second outer tooth surface of the second-stage flexible wheel 421 at the long axis of the second cam 413 is meshed with the inner tooth surface of the steel wheel 1, and the second outer tooth surface of the second-stage flexible wheel 421 at the short axis of the second cam 413 is disengaged from the inner tooth surface of the steel wheel 1. The teeth of other sections on the circumference are in a transition state of meshing and disengagement. When working, the steel wheel 1 is fixed, the motor drives the input shaft 2 to rotate, the first-stage flexible wheel 411 and the second-stage flexible wheel 421 serve as driven wheels, and the output drives the output shaft 5 to rotate, thereby driving the load to rotate.

[0041] The present application is provided with a double flexible wheel structure connected in series with each other. The harmonic reducer has a large transmission ratio, high load-bearing capacity, and high transmission accuracy. Compared with traditional harmonic reducers, it can achieve an ultra-micro structure, have a high transmission ratio and large torque, can be used in a small space environment, and has stronger applicability.

[0042] In addition, the flexible wheel structure of the present application is provided with a floating arc-shaped spring structure, and a movable gap is reserved between the first-stage flexible wheel structure and the second-stage flexible wheel structure and 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, can perform elastic buffering, has a lower failure rate, and a longer service life. Compared with the traditional flexible wheel structure, the deformation area is narrower, so that the harmonic reducer occupies 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 solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

[0044] The standard parts used in the present invention can all be purchased from the market, and special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the prior art. Machinery, parts and equipment all adopt conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be described in detail here.

[0045] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Claims

1. An ultra-miniature double-flexure harmonic reducer, characterized in that: It includes a steel wheel, an input shaft, a supporting 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 supporting bearing structure, and the input shaft and the output shaft are drivingly connected through the multi-stage flexible wheel structure. The multi-stage flexible wheel structure is composed of a plurality of flexible wheel structures connected in series.

2. The ultra-miniature double-flex gear structure harmonic reducer according to claim 1, characterized in that: A lower bearing seat is arranged on the upper surface of the lower cover, a lower ball bearing is installed in the lower bearing seat, the input shaft is rotatably connected with the lower cover via the lower ball bearing, an upper bearing seat is arranged on the bottom surface of the upper cover, an upper ball bearing is installed in the upper bearing seat, and the output shaft is rotatably connected with the upper cover via the upper ball bearing.

3. The ultra-miniature double-flex gear structure 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 double-flex gear structure 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, and the second-stage flexible wheel structure includes a second-stage flexible wheel and a second flexible bearing. A first cam is arranged on 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 outer tooth surface is arranged on the outer periphery of the first-stage flexible wheel, and the first outer tooth surface is matched with the inner tooth surface of the steel wheel. A second cam is also arranged on 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. A second outer tooth surface is arranged on the outer periphery of the second-stage flexible wheel, and the second outer tooth surface is matched with the inner tooth surface of the steel wheel, and the upper end of the second-stage flexible wheel is connected to the output shaft.

5. The ultra-miniature double-flex gear structure 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 outer tooth surface of the first-stage flexible wheel relative to the major axis of the first cam is meshed with the inner tooth surface of the steel wheel, and the first outer 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 double-flex gear structure 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 outer tooth surface of the second-stage flexible wheel relative to the major axis of the second cam is meshed with the inner tooth surface of the steel wheel, and the second outer 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. According to the ultra-micro dual-flexible gear structure harmonic reducer of claim 4, the first cam is integrally formed with the input shaft, and the second-stage flexible gear is integrally formed with the output shaft.

8. The ultra-miniature double-flex gear structure harmonic reducer according to claim 4, characterized in that: The first-stage flexible wheel is connected to the second cam through 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 inner cavity, and the middle part of the first arc-shaped spring piece protrudes upward and is connected to the second cam.

9. The ultra-miniature double-flex gear structure harmonic reducer according to claim 4, characterized in that: The second stage flexible wheel is connected to the output shaft through a second arc spring piece. The bottom of the second arc spring piece is connected to the top of the inner wall of the second stage flexible wheel cavity, and the middle part of the second arc spring piece protrudes upward and is connected to the output shaft.

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