Gearless harmonic reducer

Abstract

The present invention discloses a toothless harmonic reducer comprising an inner flexspline, an outer flexspline, and a wave generator. Neither the inner flexspline nor the outer flexspline has teeth. Under the action of the wave generator, the inner flexspline partially protrudes radially outward, and its outer wall compresses a friction ring against the inner wall of the outer flexspline, transmitting torque through friction. The reduction ratio is achieved by the circumference difference between the outer and inner walls of the inner flexspline. Furthermore, to enhance friction, a friction ring is provided between the inner and outer flexsplines. The elastic modulus of the friction ring is lower than that of steel, allowing for minimal compression deformation to ensure contact.

Description

Technical Field

[0001] The present invention relates to a reducer, in particular to a toothless harmonic reducer. Background Art

[0002] The principle of harmonic gear transmission deceleration utilizes the relative motion of the flexspline, rigid pulley, and wave generator, primarily the controllable elastic deformation of the flexspline, to achieve motion and power transmission. The elliptical cam within the wave generator rotates within the flexspline, causing the flexspline to deform. As the flexspline teeth at both ends of the wave generator's elliptical cam's major axis engage with the rigid pulley teeth, the flexspline teeth at both ends of the minor axis disengage from the rigid pulley teeth. The teeth between the major and minor axes of the wave generator are in a semi-meshing state, gradually entering engagement, within different sections along their circumferences (called engagement), and a semi-meshing state, gradually exiting engagement, known as disengagement. As the wave generator rotates continuously, the flexspline continuously deforms, causing the teeth on both wheels to continuously change their original working states through four motions: engagement, engagement, disengagement, and disengagement. This produces staggered tooth motion, achieving motion transmission from the active wave generator to the flexspline. Existing harmonic gear transmissions primarily consist of a rigid spline, a flexspline, and a wave generator. The rigid internal gear typically has two more teeth than the flexspline and is typically fixed to the housing. The flexspline is a thin, cup-shaped metal elastic component with a gear on its outer ring. It deforms as the wave generator rotates and is typically connected to the output shaft. The wave generator consists of an elliptical cam and a flexible bearing, typically connected to the input shaft. The inner ring of the flexible bearing is fixed to the cam, while the outer ring is elastically deformed into an elliptical shape by a ball bearing.

[0003] In patent CN109356992A applied for by the applicant in 2018, a double-flexible harmonic reducer with limited deformation was disclosed, which includes a strong flexible pulley, a weak flexible pulley, a wave generator and a strong flexible pulley deformation limiting part. The strong flexible pulley and the weak flexible pulley are respectively provided with teeth that can mesh with each other, and there is a difference in the number of teeth between the strong flexible pulley and the weak flexible pulley. Summary of the Invention

[0004] On this basis, the present invention provides a toothless harmonic reducer, in which the contact surfaces of the inner and outer flexible gears of the toothless harmonic reducer are not provided with teeth and are transmitted through contact friction, so that it can be used in some harmonic reducers that need to reduce speed and increase torque but have low requirements for reduction ratio and precision, thereby reducing manufacturing costs.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] The present invention provides a toothless harmonic reducer, comprising an inner flexspline, an outer flexspline, a limiting ring, a wave generator, a housing, and an elastic element. Neither the inner flexspline nor the outer flexspline has a toothed wall. The inner flexspline is sheathed on the outer wall of the wave generator, and the outer flexspline is sheathed on the outer wall of the inner flexspline. The outer wall of the outer flexspline is sheathed on the outer wall of the outer flexspline. The limiting ring is used to limit the deformation of the outer flexspline. The elastic element is compressed and installed between the limiting ring and the housing to apply an elastic axial force to the limiting ring. The housing is directly or indirectly fixedly connected to the outer flexspline. The limiting ring always maintains contact with the outer flexspline under the action of the thrust of the elastic element. The elastic element is used to apply an axial force to the limiting ring, and the limiting ring can move axially under the action of the force of the elastic element. The outer wall of the inner flexspline partially protrudes radially outward under the action of the wave generator, and its outer wall is pressed against the inner wall of the outer flexspline, transmitting torque through friction, and achieving a reduction ratio through the circumference difference between the outer wall of the inner flexspline and the inner wall of the outer flexspline.

[0007] Optionally, a friction ring is provided between the inner flexible wheel and the outer flexible wheel. The friction ring is made of a material with a high friction coefficient with metal, that is, the friction coefficient between the friction ring and the flexible wheel surface is greater than the friction coefficient between metal and metal, that is, 0.1-0.5. At the same time, the elastic modulus of the material of the friction ring is lower than that of steel, and the thickness can be compressed by a small amount to maintain contact and friction pressure.

[0008] Furthermore, the contact surface between the outer flexspline and the retaining ring serves as a retaining contact surface. A conical surface is provided on a portion of the outer wall of the outer flexspline as the retaining contact surface, and a conical surface with a matching angle is also provided on the inner wall of the retaining ring at a corresponding position. These conical surfaces are not strictly geometrically defined; their purpose is to ensure that the retaining ring maintains contact with the outer wall of the outer flexspline during axial displacement. To reduce contact pressure on the retaining surfaces, the retaining contact surface on the outer flexspline and the surface on the retaining ring that contacts the outer flexspline are machined to mate with each other, with one end larger than the other. These surfaces, such as chamfered surfaces with similar angles or filleted surfaces with similar corner radii, are designed to mate with each other.

[0009] Furthermore, the elastic element is an axial spring ring or a polymer elastic washer.

[0010] The elastic element is compressed and installed, and its expansion elastic force can axially push the limit ring to move in the direction of smaller radius of the contact area between it and the outer flexible wheel. When the deformation of the outer flexible wheel decreases due to wall wear and other reasons, the limit ring will move axially under the action of the elastic element. The angle between the limit contact surface on the outer flexible wheel and the axis of the outer flexible wheel should be less than 10 degrees. In this way, the axial component of the contact pressure between the outer flexible wheel and the limit ring is as small as possible, thereby minimizing or avoiding the axial movement of the elastic part caused by the limit ring compressing the elastic part due to this pressure.

[0011] Furthermore, the contact surfaces of the inner flexible spline and the outer flexible spline are smooth surfaces.

[0012] Furthermore, a friction ring is provided between the inner flexible wheel and the outer flexible wheel, and a friction ring groove is provided on the friction inner wall of the outer flexible wheel. The friction ring is arranged in the friction ring groove. Under the action of the wave generator, the friction ring is pressed between the outer wall of the inner flexible wheel and the inner wall of the outer flexible wheel, and the friction force between the inner flexible wheel and the outer flexible wheel is increased by the friction ring.

[0013] Furthermore, an annular boss is provided in the contact area between the outer flexible spline and the inner flexible spline, and the contact surface thereof is textured to increase the friction coefficient.

[0014] Furthermore, the friction ring is made of a polymer material, and the friction coefficient between the friction ring and the surface of the metal flexible wheel is greater than the friction coefficient between metals.

[0015] Furthermore, the friction ring is a rubber ring.

[0016] Furthermore, the outer flexspline and the inner flexspline are made of materials with similar or identical elastic moduli. In this case, the wall thickness of the outer flexspline is greater than 1.2 times the wall thickness of the inner flexspline and less than 4 times the wall thickness of the inner flexspline.

[0017] Furthermore, the wave generator is a multi-wave generator with three or more cams, with each cam equally spaced along the circumference. In conventional toothed harmonic reducers, the wave generator is typically designed as an elliptical cam (two waves). In the present invention, it can also be a multi-wave generator with three or more waves, as long as the spacing between the waves is evenly distributed.

[0018] Furthermore, the outer flexible wheel and the inner flexible wheel are made of a thermoplastic elastomer selected from one of PEEK (polyetheretherketone plastic), PPS (polyphenylene sulfide plastic) and PI (polyimide plastic).

[0019] In one embodiment, the outer flex spline and the inner flex spline are made of a plastic material that is injection molded or a plastic material that is injection molded and then subjected to a small amount of processing.

[0020] In one embodiment, the material elasticity of the inner flexspline is greater than that of the outer flexspline. In this case, the aforementioned wall thickness limits should be calculated based on the difference in material elastic modulus. The highly elastic inner flexspline provides a cushioning effect. The wave generator compresses the outer flexspline with the highly elastic inner flexspline, increasing friction and reducing noise.

[0021] Furthermore, the toothless harmonic reducer is also provided with a slewing bearing, and the inner and outer flexible pulleys are respectively connected and fixed to the inner and outer rings of the slewing bearing. In the present invention, the radius of the cylindrical tubular inner wall of the outer flexible pulley before assembly is smaller than the long axis radius of the outer wall of the inner flexible pulley after deformation under the action of the wave generator. Generally, it is recommended that the value greater than is at least 0.05mm, and in some cases, the value greater than is even required to be greater than 0.1mm. The value less than is the flexible deformation of the outer flexible pulley after assembly. The flexible deformation of the outer flexible pulley is related to the outer flexible pulley radius, material, and processing accuracy. In theory, the larger the outer flexible pulley radius, the larger the outer flexible pulley design deformation should be. The softer the material, the larger the above-mentioned deformation should be designed to be. In theory, the lower the processing accuracy requirement, the larger the above-mentioned deformation should be designed to be.

[0022] The wave generator includes a flexible bearing and a cam. Most of the time, an elliptical cam is used and a rolling bearing is provided on the outer ring of the cam. The elliptical cam is a two-head cam that can contact and rub with the outer flexible wheel at both ends of the short axis of the inner flexible wheel. Theoretically, a single-head cam or a multi-head cam with more than three heads can also be used to make the inner flexible wheel and the outer flexible wheel contact at one or more points.

[0023] In one embodiment, the limiting ring can adjust its axial position to achieve different diameters of its annular limiting surface in contact with the outer flexspline limiting contact surface, thereby adjusting the outer flexspline deformation limit value. In other words, the outer flexspline deformation limit value can be adjusted by adjusting the axial position of the limiting ring.

[0024] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0025] The inner and outer flexible pulleys of the toothless harmonic reducer described in the present invention are not provided with meshing teeth. The inner flexible pulley rolls smoothly inside the outer flexible pulley, which greatly improves the transmission smoothness. Moreover, the radius of the inner and outer flexible pulleys is not affected by the size of the meshing teeth, which allows for a very large range of transmission ratio selection. Moreover, compared with the preparation of meshing teeth, the manufacturing difficulty is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a cross-sectional view of the toothless double-flexible harmonic reducer described in Example 1;

[0027] Figure 2 2 is a cross-sectional view of the toothless double flexspline harmonic reducer according to Example 2, wherein a friction ring is provided between the inner flexspline and the outer flexspline;

[0028] Figure 3 is a cross-sectional view of the toothless double-flexible harmonic reducer described in Example 3;

[0029] Figure 41 is a cross-sectional view of the toothless double flexspline harmonic reducer according to Example 4, wherein a friction ring is provided between the inner flexspline and the outer flexspline;

[0030] Figure 5 is a cross-sectional view of the toothless double-flexible harmonic speed reducer described in Example 5;

[0031] Figure 6 It is a cross-sectional view of the toothless double flexible spline harmonic reducer described in Example 6, wherein a friction ring is provided between the inner flexible spline and the outer flexible spline.

[0032] in,

[0033] 13: Outer flexible spline; 14: Inner flexible spline; 15: Wave generator; 16: Limiting ring; 17: Elastic element; 21: Friction ring. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions, beneficial effects and significant improvements of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the drawings provided in the examples of the present invention. Obviously, all the described embodiments are only partial embodiments of the present invention, rather than all embodiments; based on the demonstrations made in the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field based on the content, implementation methods and drawings of the present invention without making any creative work shall fall within the scope of protection of the present invention.

[0035] It should be noted that the terms "first", "second", "third", etc. in the description and claims of the present invention are only used to distinguish different objects, rather than to describe a specific order.

[0036] It should also be noted that the following specific embodiments may be combined with each other, and the same or similar concepts or processes therein may not be repeated in some embodiments.

[0037] Example 1

[0038] like Figure 1 As shown (the housing and main bearings are not shown), a toothless dual-flexspline harmonic reducer comprises a cup-shaped inner flexspline 14, a hat-shaped outer flexspline 13, and a wave generator 15. The wave generator 15 is embedded in the inner cavity of the inner flexspline 14, while the outer flexspline 13 is sleeved on the outer wall of the inner flexspline 14. The inner walls of the outer flexspline 13 and the inner flexspline 14 can contact each other, and the opposing walls of the outer flexspline 13 and the inner flexspline 14 are not provided with intermeshing teeth but are machined into smooth surfaces that contact each other.

[0039] The wave generator 15 comprises an elliptical cam and a flexible bearing, and is coaxially arranged with the inner and outer flexsplines. The outer wall of the wave generator 15 is sheathed with an inner flexspline 14, which is connected to the wave generator shaft. The outer wall of the inner flexspline 14 is sheathed with an outer flexspline 13, which is bolted to the outer ring of the main bearing (not shown). The outer flexspline 13 is coaxially and axially fixed to the housing (not shown) via bolts. Both the inner and outer flexsplines 14 and 13 are manufactured using the same processing techniques and steel commonly used for flexsplines in harmonic reducers. The opposing walls of the inner and outer flexsplines 14 and 13 do not have intermeshing teeth. The inner flexspline 14 uses the same thin-walled cup shape as most existing flexsplines in harmonic reducers, while the outer flexspline 13 uses a tubular shape with an outer flange and a wall thickness twice that of the inner flexspline 14.

[0040] A limit ring 16 is mounted on the outer wall of the outer flexible wheel 13. The limit ring is in coaxial contact with the outer flexible wheel and is used to limit the deformation of the outer flexible wheel 13. The limit ring is made of high-hardness steel and is machined. The flexible tubular outer wall of the outer flexible wheel 13 is machined with a limit contact surface to reduce the contact pressure of the limit surface. Figure 3 As shown, the lower edge of the outer wall of the outer flexspline is processed with a chamfered surface with an angle of 5 degrees, and the inner wall of the limiting ring 16 is also processed with a chamfered surface with an angle of 5 degrees. When the inner flexspline, the wave generator and the outer flexspline are assembled, the outer flexspline undergoes elliptical deformation. After the deformation, the two 5-degree chamfered surfaces of the elliptical major axis of the outer flexspline contact the 5-degree chamfered surfaces of the limiting ring 16. The inner flexspline always maintains a portion of its wall surface continuously contacting and pressing the wall surface of the outer flexspline along the rotation direction of the wave generator. Due to the circumference difference between the outer diameter of the inner flexspline and the inner diameter of the outer flexspline, the rotation of the wave generator drives the major axis of the inner flexspline to partially roll inside the outer flexspline, and the inner flexspline and the outer flexspline rotate relative to each other, achieving a speed reducer effect of speed reduction and torque increase.

[0041] Furthermore, an elastic element 17 is sleeved onto the outer wall of the retaining ring 16. This elastic element 17 is located between the opposing walls of the housing and the retaining ring 16, applying an axial force to the retaining ring. This force allows the retaining ring to move axially. This elastic element 17 is a spring washer with an inner petal shape. The elastic element 17 is installed in a compression manner, and the retaining ring 16 maintains contact with the outer flexible spline under the thrust of the elastic element 17.

[0042] The wave generator 15 uses an elliptical cam with an external ball bearing commonly used in existing harmonic reducers. The elliptical cam is a two-head cam that can make the two ends of the short shaft of the inner flexible wheel contact with the outer flexible wheel and press the inner wall of the outer flexible wheel. The wave generator is provided with a keyway shaft hole connected to the input torque. The wave generator is installed in the inner flexible wheel 14. The wall surface of the wave generator is against the wall surface of the inner flexible wheel 14, causing the inner flexible wheel 14 to undergo elliptical elastic deformation and become elliptical. At the two ends of the elliptical short end shaft, the wave generator is provided with a keyway shaft hole connected to the input torque. The wave generator is installed in the inner flexible wheel 14. The wall surface of the wave generator is against the wall surface of the inner flexible wheel 14, causing the inner flexible wheel 14 to undergo elliptical elastic deformation and become elliptical. The opposite side walls of the inner flexible wheel 14 and the outer flexible wheel 13 are completely separated; and the outer walls of the elliptical inner flexible wheel 14 at both ends of the elliptical major axis contact and press the inner wall of the outer flexible wheel, so that the contact portion of the outer flexible wheel 13 and the inner flexible wheel 14 is subjected to the radial pressure of the inner flexible wheel to produce an elliptical elastic deformation, and the outer flexible wheel 13 is subjected to the radial pressure of the inner flexible wheel 14 so that its elliptical major axis area contacts the annular limiting surface of the limit ring 16, thereby limiting the deformation of the outer flexible wheel 13.

[0043] The rigidity of the limiting ring 16 is greater than that of the outer flexspline 13 , and the rigidity of the outer flexspline 13 is greater than that of the inner flexspline 14 .

[0044] When the wave generator 15 is driven by the motor connected to it and rotates, it is squeezed by the cams at both ends, producing a synchronized periodic elliptical deformation. The inner and outer flexsplines 14, 13, simultaneously deform into ellipses. The outer walls of the inner flexspline 14 at both ends of its elliptical major axis contact and compress the inner walls of the outer flexspline 13, generating friction. As the wave generator 15 rotates, a portion of the inner flexspline 14's major axis rolls within the outer flexspline 13. Due to the circumference difference between the inner and outer flexspline's outer diameters, the inner and outer flexsplines rotate relative to each other.

[0045] The inner and outer flexible pulleys of the harmonic reducer described in the present invention are not provided with meshing teeth. The inner flexible pulley rolls smoothly inside the outer flexible pulley, which greatly improves the stability. Moreover, the radius of the inner and outer flexible pulleys is not affected by the size of the meshing teeth, which allows for a very large range of transmission ratio selection. Moreover, compared with the preparation of meshing teeth, the manufacturing difficulty is greatly reduced.

[0046] Example 2

[0047] like Figure 2 As shown, a toothless dual-flexspline harmonic speed reducer includes a cup-shaped inner flexspline 14, a hat-shaped outer flexspline 13, and a wave generator 15. The structure of this toothless dual-flexspline harmonic speed reducer is essentially the same as that of Example 1 and will not be further described here. The only difference is that a friction ring 21 is provided between the contact surfaces of the outer flexspline 13 and the inner flexspline 14.

[0048] Specifically, a friction ring groove is provided on the friction inner wall of the outer flexible wheel 13, and the friction ring 21 is arranged in the friction ring groove. Under the action of the wave generator, the friction ring 21 is pressed between the outer wall of the inner flexible wheel 14 and the inner wall of the outer flexible wheel 13, and the friction force between the inner flexible wheel 14 and the outer flexible wheel 13 is increased by the friction ring 21.

[0049] When the wave generator 15 is actuated, the inner flexible wheel 14 undergoes elliptical elastic deformation and becomes an elliptical shape. At the short and long ends of the ellipse, the opposite side walls of the inner flexible wheel 14 and the friction ring 21 are completely separated. At the two ends of the elliptical major axis of the elliptical inner flexible wheel 14, the outer wall contacts and presses the inner wall of the outer flexible wheel 13 through the friction ring 21, and the inner wall of the outer flexible wheel is pressed. The torque is transmitted through friction, so that the contact part of the outer flexible wheel 13 and the inner flexible wheel 14 is subjected to the radial pressure of the inner flexible wheel to produce elliptical elastic deformation. The elliptical major axis area of ​​the outer flexible wheel 13 deformed by the radial pressure of the inner flexible wheel 14 contacts the annular limiting surface of the limit ring 16, thereby limiting the deformation of the outer flexible wheel 13.

[0050] Example 3

[0051] like Figure 3 As shown, a toothless double flexspline harmonic speed reducer includes a cup-shaped inner flexspline 14, a cup-shaped outer flexspline 13, and a wave generator 15. The remaining structure of the toothless double flexspline harmonic speed reducer is basically the same as that of embodiment 1 and will not be repeated here.

[0052] Example 4

[0053] like Figure 4 As shown, a toothless double flexspline harmonic speed reducer includes a cup-shaped inner flexspline 14 , a cup-shaped outer flexspline 13 and a wave generator 15 , and a friction ring 21 is provided between the contact surfaces of the outer flexspline 13 and the inner flexspline 14 .

[0054] The remaining structure of the toothless double-flexible harmonic reducer is basically the same as that of Example 3 and will not be repeated here.

[0055] Example 5

[0056] like Figure 5 As shown, a toothless double flexspline harmonic speed reducer includes a cap-shaped inner flexspline 14, a cap-shaped outer flexspline 13, and a wave generator 15. The remaining structure of the toothless double flexspline harmonic speed reducer is basically the same as that of embodiment 3 and will not be repeated here.

[0057] Example 6

[0058] like Figure 6 As shown, a toothless double flexspline harmonic speed reducer includes a hat-shaped inner flexspline 14 , a hat-shaped outer flexspline 13 and a wave generator 15 , and a friction ring 21 is provided between the contact surfaces of the outer flexspline 13 and the inner flexspline 14 .

[0059] The remaining structure of the toothless double-flexible harmonic reducer is basically the same as that of Example 3 and will not be repeated here.

[0060] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents, and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention. Non-essential improvements, adjustments or replacements made by those skilled in the art based on the contents of this specification are all within the scope of protection required by the present invention.

Claims

1. A toothless harmonic reducer, characterized in that: The invention comprises an inner flexible wheel (14), an outer flexible wheel (13), a limiting ring (16), a wave generator (15), a shell and an elastic element (17), wherein the wall surfaces of the inner flexible wheel (14) and the outer flexible wheel (13) are not provided with teeth, and the outer wall of the outer flexible wheel (13) is provided with a limiting ring (16), and the limiting ring (16) is used to limit the deformation of the outer flexible wheel (13); the elastic element (17) is compressed and installed between the limiting ring and the shell, and applies an elastic axial force to the limiting ring; the shell and the outer flexible wheel are directly connected to each other. The limiting ring (16) is always in contact with the outer flexible wheel under the action of the thrust of the elastic element (17); the elastic element (17) is used to apply an axial force to the limiting ring, and the limiting ring can move axially under the action of the force of the elastic element; the outer wall of the inner flexible wheel is partially radially protruded outward under the action of the wave generator, and the outer wall is pressed against the inner wall of the outer flexible wheel, and the torque is transmitted by friction, and the reduction ratio is achieved by the circumference difference between the outer wall of the inner flexible wheel and the inner wall of the outer flexible wheel; A friction ring (21) is further provided between the inner flexible wheel (14) and the outer flexible wheel (13), and a friction ring groove is provided on the friction inner wall of the outer flexible wheel. The friction ring is arranged in the friction ring groove, and the friction ring is pressed between the outer wall of the inner flexible wheel and the inner wall of the outer flexible wheel under the action of the wave generator; the friction coefficient between the friction ring (21) and the surface of the inner flexible wheel is greater than the friction coefficient between metals, the elastic modulus is lower than that of steel, and the thickness can be compressed slightly to maintain contact and friction pressure; and the material elasticity of the inner flexible wheel is greater than the material elasticity of the outer flexible wheel.

2. The toothless harmonic reducer according to claim 1, characterized in that: The friction ring (21) is a rubber ring.

3. The toothless harmonic reducer according to claim 1, characterized in that: The elastic element (17) is an axial spring ring or a polymer material elastic washer.

4. The toothless harmonic reducer according to claim 1, characterized in that: The outer flexible wheel (13) and the inner flexible wheel (14) are made of materials with similar or identical elastic moduli. In this case, the wall thickness of the outer flexible wheel (13) is greater than 1.2 times the wall thickness of the inner flexible wheel (14) and less than 4 times the wall thickness of the inner flexible wheel.

5. The toothless harmonic reducer according to claim 1, characterized in that: The contact surfaces of the inner flexible wheel (14) and the outer flexible wheel (13) are smooth surfaces.

6. The toothless harmonic reducer according to claim 1, characterized in that: The wave generator (15) has three or more heads, and each protrusion is equally divided along the circumference.

7. The toothless harmonic reducer according to claim 1, characterized in that: The harmonic reducer is also provided with a slewing support, and the inner flexible wheel (14) and the outer flexible wheel (13) are respectively connected and fixed to the inner ring and the outer ring of the slewing support.

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