Flexible bearing, speed reducer and robot

Abstract

The invention discloses a flexible bearing, a speed reducer and a robot. The flexible bearing comprises a bearing inner ring, a bearing outer ring and a first ball, the bearing outer ring sleeves the bearing inner ring, and the first ball is arranged between the bearing outer ring and the bearing inner ring; the bearing outer ring comprises a first outer ring, and the first outer ring is provided with an outer spherical surface. Through rolling of the first balls between the bearing inner ring and the bearing outer ring, sliding friction between a shaft and a hole can be converted into rolling friction, and therefore friction resistance and abrasion are reduced. Importantly, the bearing outer ring comprises a first outer ring, and the first outer ring is provided with an outer spherical surface. Thus, when the flexible bearing is applied to a harmonic reducer, the outer spherical surface can be matched with an inner hole of a flexible gear, traditional rotary sliding friction can be converted into rolling friction, friction force generated by relative displacement of the inner hole of the flexible gear and the outer ring of the bearing is reduced, and therefore the influence of axial force on the bearing structure is eliminated; axial movement of the flexible bearing and the cam is avoided, bearing capacity of the reducer is improved, and service life of the reducer is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of reducers and relates to a flexible bearing, a reducer and a robot. Background Art

[0002] The harmonic reducer has many advantages such as high transmission accuracy, large speed ratio, small size, simple structure and wide application. The reducer is mainly composed of three basic components, namely, a rigid wheel, a flexible wheel and a wave generator. The working process is generally that the rigid wheel is fixed, and when the wave generator rotates, the flexible wheel is forced to produce elastic deformation, so that the teeth of the flexible wheel and the teeth of the rigid wheel enter a meshing state, thereby realizing transmission.

[0003] The wave generator of the harmonic reducer is an elliptical structure, and its elliptical major axis is slightly larger than the inner diameter of the flexible wheel. Therefore, after the wave generator is installed in the flexible wheel, the flexible wheel will deform according to the contour shape of the wave generator at the open end of the flexible wheel. The flexible wheel will be stretched outward near the long axis of the wave generator at the open end, and because the circumference of the flexible wheel basically does not change, the flexible wheel will shrink inward near the short axis of the wave generator at the open end. At the same time, the diameter of the bottom of the flexible wheel has not changed or has only a small change, so the flexible wheel will present a complex deformation form, but there is a maximum inclination value outward and inward near the long axis and short axis of the wave generator, respectively. In addition, the diaphragm part of the bottom of the flexible wheel produces axial deformation in the direction of the flange near the long axis and axial deformation in the direction of the gear near the short axis, and the inner hole of the entire flexible wheel cup mouth presents a saddle-shaped structure. Because the outer ring of the flexible bearing works with the inner hole of the flexible wheel, the outer ring of the flexible bearing is subjected to the friction force of the flexible wheel toward the bottom of the cylinder near the long axis, resulting in the flexible bearing presenting a saddle-shaped structure close to the inner hole of the flexible wheel. The friction force is transmitted to the ball through the outer ring groove, and then transmitted to the inner ring of the bearing through the inner ring groove, so that the entire flexible bearing is subjected to an axial force toward the bottom of the flexible wheel cylinder. This axial force is proportional to the load torque. When the torque exceeds a certain range, the reducer will be at risk of axial movement of the bearing and cam. Summary of the invention

[0004] In view of this, the present invention provides a flexible bearing, a reducer and a robot to solve the problem of axial movement of the flexible bearing and the cam due to axial force.

[0005] In order to solve the above problems, according to one aspect of the present application, an embodiment of the present invention provides a flexible bearing, which includes a bearing inner ring, a bearing outer ring and a first ball, the bearing outer ring is sleeved on the bearing inner ring and the first ball is arranged between the two; the bearing outer ring includes a first outer ring, and the first outer ring has an outer spherical surface.

[0006] In some embodiments, the bearing outer ring further includes a second outer ring, the second outer ring has an inner spherical surface, the second outer ring is sleeved on the first outer ring and the two are matched through the outer spherical surface and the inner spherical surface.

[0007] In some embodiments, the bearing outer ring further includes a rolling unit, and the rolling unit is disposed between the first outer ring and the second outer ring.

[0008] In some embodiments, the rolling unit includes a first groove arranged on the outer surface of the first outer ring, a second groove arranged on the inner surface of the second outer ring, and a second ball. The first groove and the second groove are spliced ​​to form a accommodating cavity. There are at least two second balls, and at least two of the second balls are movably arranged in the accommodating cavity.

[0009] In some embodiments, the first groove penetrates the axial direction of the outer surface of the first outer ring, and the second groove penetrates the axial direction of the outer surface of the second outer ring, so that the first groove and the second groove are spliced ​​to form a plurality of the accommodating cavities, and the second balls correspond to the accommodating cavities one by one.

[0010] In some embodiments, the inner surface of the first outer ring has a first deep groove ball bearing groove structure, and the outer surface of the bearing inner ring has a second deep groove ball bearing groove structure, and the first deep groove ball bearing groove structure and the second deep groove ball bearing groove structure can be spliced ​​into a track for the first ball to roll.

[0011] According to another aspect of the present application, an embodiment of the present invention provides a reducer, which includes the above-mentioned flexible bearing.

[0012] In some embodiments, the reducer also includes a cam, a rigid wheel and a flexible wheel, the flexible bearing is sleeved on the cam, the flexible wheel is sleeved on the flexible bearing and the inner hole of the flexible wheel cooperates with the outer spherical surface of the first outer ring, the rigid wheel is sleeved on the flexible wheel, and the inner teeth of the rigid wheel are meshed with the outer teeth of the flexible wheel.

[0013] In some embodiments, the number of the inner teeth is greater than the number of the outer teeth.

[0014] According to another aspect of the present application, an embodiment of the present invention provides a robot comprising the above-mentioned reducer.

[0015] Compared with the prior art, the flexible bearing of the present invention has at least the following beneficial effects:

[0016] The flexible bearing provided by the present invention comprises a bearing inner ring, a bearing outer ring and a first ball, wherein the bearing outer ring is sleeved on the bearing inner ring and the first ball is arranged between the two; the bearing outer ring comprises a first outer ring having an outer spherical surface.

[0017] The flexible bearing includes a bearing inner ring, which is an annular structure; and also includes a bearing outer ring, which is sleeved on the bearing inner ring and has a gap between the two, and the first ball is arranged in the gap along the circumferential direction. In this way, after adopting this structure, the sliding friction between the shaft and the hole can be converted into rolling friction by the rolling of the first ball between the bearing inner ring and the bearing outer ring, thereby reducing friction resistance and wear, which is also the role of the bearing as a mechanical component. Importantly, the bearing outer ring in the present invention includes a first outer ring, and the first outer ring has an outer spherical surface. In this way, when the flexible bearing is used in a harmonic reducer, the outer spherical surface can cooperate with the inner hole of the flexible wheel, and the traditional rotational sliding friction can be converted into rolling friction, reducing the friction force generated by the relative displacement between the inner hole of the flexible wheel and the outer ring of the bearing, thereby eliminating the influence of the axial force on the bearing structure, avoiding the axial movement of the flexible bearing and the cam of the harmonic reducer, and improving the load-bearing capacity and life of the reducer.

[0018] The reducer provided by the present invention is designed based on the above-mentioned flexible bearing. Its beneficial effects refer to the beneficial effects of the above-mentioned flexible bearing, which will not be described in detail here.

[0019] The robot provided by the present invention is designed based on the above-mentioned reducer. Its beneficial effects refer to the beneficial effects of the above-mentioned reducer, which will not be described in detail here.

[0020] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0022] Figure 1 is a cross-sectional view of a flexible bearing provided by an embodiment of the present invention;

[0023] Figure 2 is another cross-sectional view of a flexible bearing provided by an embodiment of the present invention;

[0024] Figure 3 yes Figure 2A partial enlarged view of the middle A;

[0025] Figure 4 It is a partial cross-sectional view of a flexible bearing provided by an embodiment of the present invention when no second ball is placed in the accommodating cavity;

[0026] Figure 5 is a cross-sectional view of a reducer provided by an embodiment of the present invention;

[0027] Figure 6 yes Figure 5 A partial enlarged view of point B in the middle;

[0028] Figure 7 It is a schematic diagram of the meshing of internal teeth and external teeth in a reducer in the prior art;

[0029] Figure 8 It is a schematic diagram of the contraction and expansion of the flexible wheel in the reducer in the prior art;

[0030] Fig. 9 is a cross-sectional view of a flexible wheel in a reducer provided by an embodiment of the present invention;

[0031] Fig.10 is a cross-sectional view of a deformation of a flexible bearing in a reducer provided by an embodiment of the present invention;

[0032] Fig.11 is another cross-sectional view showing deformation of a flexible bearing in a reducer provided by an embodiment of the present invention;

[0033] Fig.12 is a cross-sectional view of the deformation of a flexible bearing in a reducer in the prior art;

[0034] Fig.13 It is another cross-sectional view of the deformation of the flexible bearing in the reducer in the prior art.

[0035] in:

[0036] 1. Flexible bearing; 11. Bearing inner ring; 12. Bearing outer ring; 13. First ball; 14. Cage; 121. First outer ring; 122. Second outer ring; 123. Rolling unit; 1231. First groove; 1232. Second groove; 1233. Second ball; 1234. Accommodating chamber; 2. Cam; 3. Rigid wheel; 31. Internal teeth; 4. Flexible wheel; 41. External teeth; 42. Inner hole; 43. Thin-walled cylinder; 44. Thin-walled diaphragm; 45. Flange; 5. Rigid bearing. DETAILED DESCRIPTION

[0037] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention application are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

[0038] In the description of the present invention, it should be clarified that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, but are not necessarily used to describe a specific order or sequence; the terms "vertical", "lateral", "longitudinal", "front", "rear", "left", "right", "up", "down", "horizontal", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention, and do not mean that the referred device or element must have a specific direction or position, and therefore cannot be understood as a limitation on the present invention.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] Example 1

[0041] This embodiment provides a flexible bearing, such as Figure 1-Figure 4 As shown, the flexible bearing includes a bearing inner ring 11, a bearing outer ring 12 and a first ball 13, the bearing outer ring 12 is sleeved on the bearing inner ring 11 and the first ball 13 is arranged between the two; the bearing outer ring 12 includes a first outer ring 121, and the first outer ring 121 has an outer spherical surface.

[0042] Flexible bearings are a special type of bearings that have good radial flexibility and axial flexibility and can adapt to the displacement and vibration of moving parts of equipment within a certain range. Flexible bearings refer to a structural form that uses the elastic deformation of materials to produce relative rotation between adjacent components under the action of external forces or moments.

[0043] The flexible bearing 1 includes a bearing inner ring 11, which is an annular structure; and a bearing outer ring 12, which is sleeved on the bearing inner ring 11 with a gap between the two, and a first ball 13 is circumferentially arranged in the gap. In this way, after adopting this structure, the sliding friction between the shaft and the hole can be converted into rolling friction by the rolling of the first ball 13 between the bearing inner ring 11 and the bearing outer ring 12, thereby greatly reducing friction resistance and wear.

[0044] In this embodiment, if Figure 1 As shown, the outer ring 12 of the bearing includes a first outer ring 121, and the first outer ring 121 has an outer spherical surface. In this way, when the flexible bearing is used in the harmonic reducer, the outer spherical surface can cooperate with the inner hole 42 of the flexible wheel 4, converting the traditional sliding friction into rolling friction, reducing the friction generated by the displacement, thereby eliminating the influence of the axial force on the bearing structure, avoiding the axial movement of the flexible bearing 1 and the cam 2 of the harmonic reducer, and improving the load-bearing capacity and life of the reducer.

[0045] In a specific embodiment, the bearing outer ring 12 further includes a second outer ring 122 . The second outer ring 122 has an inner spherical surface. The second outer ring 122 is sleeved on the first outer ring 121 and the two are matched through the outer spherical surface and the inner spherical surface.

[0046] Specifically, in this embodiment, the outer ring 12 of the bearing includes not only the first outer ring 121, but also the second outer ring 122, that is, the first outer ring 121 and the second outer ring 122 together constitute the outer ring 12 of the bearing. Among them, the first outer ring 121 has an outer spherical surface, the second outer ring 122 has an inner spherical surface, the second outer ring 122 is sleeved on the first outer ring 121 and the two are matched through the outer spherical surface and the inner spherical surface, that is, the first outer ring 121 and the second outer ring 122 constitute a joint bearing. Joint bearings are spherical sliding bearings, whose sliding contact surfaces are an inner spherical surface and an outer spherical surface, and can rotate and swing at any angle during movement. Joint bearings have the characteristics of large load capacity, impact resistance, corrosion resistance, wear resistance, self-aligning, good lubrication, etc., and can withstand radial loads, axial loads or combined loads of radial and axial loads. In this embodiment, when the inner wall of the flexible wheel 4 is axially displaced due to the inclination of the wide mouth, the joint bearing can convert the sliding friction between the outer ring of the bearing and the inner hole of the flexible wheel into rolling friction.

[0047] The two friction surfaces of sliding friction are fixed, while one of the friction surfaces of rolling friction is changing, and the contact point is constantly changing. Rolling friction refers to the friction generated when an object rolls on another object. Sliding friction refers to the friction generated when an object slides along the surface of another object. Rolling friction is much smaller than the maximum static friction and sliding friction. Under normal circumstances, rolling friction is only 1 / 40 to 1 / 60 of the sliding friction resistance. Therefore, the shutdown bearing provided in this embodiment reduces the friction generated by the displacement, thereby eliminating the influence of axial force on the deep groove ball bearing, avoiding axial movement of the bearing and cam, and improving the load-bearing capacity and life of the reducer.

[0048] In a specific embodiment, Figure 2-Figure 4 As shown, in order to reduce the friction between the first outer ring 121 and the second outer ring 122 , the bearing outer ring 12 further includes a rolling unit 123 , and the rolling unit 123 is disposed between the first outer ring 121 and the second outer ring 122 .

[0049] In a specific embodiment, the rolling unit 123 includes a first groove 1231 disposed on the outer surface of the first outer ring 121, a second groove 1232 disposed on the inner surface of the second outer ring 122, and a second ball 1233, wherein the first groove 1231 and the second groove 1232 are spliced ​​to form a receiving cavity 1234, such as Figure 4 As shown, there are at least two second rolling balls 1233 , and at least two second rolling balls 1233 are movably disposed in the accommodating cavity 1234 .

[0050] More specifically, a first groove 1231 is provided on the outer surface of the first outer ring 121, a first groove is provided on the first groove 1231, a second groove 1232 is provided on the inner surface of the second outer ring 122, and a second groove is provided on the second groove 1232. Thus, when the first outer ring 121 and the second outer ring 122 are matched, the first groove and the second groove are just butted together to form a receiving cavity 1234. The second ball 1233 is provided in the receiving cavity 1234 and can roll in the receiving cavity 1234. In a conventional flexible bearing, the outer ring of the flexible bearing 1 cooperates with the inner hole 42 of the flexible wheel 4. The outer ring of the flexible bearing is subjected to the friction force of the flexible wheel on the direction of the cylinder bottom near the long axis, so that the flexible bearing presents a saddle-shaped structure close to the inner hole of the flexible wheel. The friction force is transmitted to the ball through the outer ring groove, and then transmitted to the inner ring of the bearing through the inner ring groove, so that the entire flexible bearing is subjected to an axial force toward the direction of the flexible wheel cylinder bottom flange, such as Fig.12 and Fig.13As shown. The axial force is proportional to the load torque. When the torque exceeds a certain range, the reducer will have the risk of axial movement of the flexible bearing and the cam. In this embodiment, the second ball 1233 between the first outer ring 121 and the second outer ring 122 reduces the friction generated by the displacement, thereby eliminating the influence of the axial force on the bearing structure. Fig.10 and Fig.11 shown.

[0051] In a specific embodiment, the first groove 1231 penetrates the axial direction of the outer surface of the first outer ring 121, and the second groove 1232 penetrates the axial direction of the outer surface of the second outer ring 122, so that the first groove 1231 and the second groove 1232 are spliced ​​to form a plurality of the accommodating cavities 1234, and the second balls 1233 correspond one-to-one to the accommodating cavities 1234.

[0052] The inner surface of the first outer ring 121 has a first deep groove ball bearing groove structure, and the outer surface of the bearing inner ring 11 has a second deep groove ball bearing groove structure, and the first deep groove ball bearing groove structure and the second deep groove ball bearing groove structure can be spliced ​​into a track for the first ball 13 to roll. In addition, a retainer 14 is provided between the first outer ring 121 and the bearing inner ring 11.

[0053] That is to say, the first outer ring 121, the bearing inner ring 11, the first ball 13 and the retainer 14 constitute a deep groove ball bearing. The deep groove ball bearing mainly bears radial loads, and can also bear radial loads and axial loads at the same time. When it only bears radial loads, the contact angle is zero. When the deep groove ball bearing has a large radial clearance, it has the performance of an angular contact bearing and can bear a large axial load.

[0054] The flexible bearing provided in this embodiment mainly has the following specific structures:

[0055] The first type is a flexible bearing comprising a bearing inner ring 11, a bearing outer ring 12 and a first ball 13. The bearing outer ring 12 is sleeved on the bearing inner ring 11 and the first ball 13 is arranged between the two. The bearing outer ring 12 comprises a first outer ring 121, and the first outer ring 121 has an outer spherical surface. The flexible bearing of this structure realizes the matching with the inner hole of the flexible wheel through the outer spherical surface, and converts the traditional sliding friction into rolling friction.

[0056] The second type, the flexible bearing includes a bearing inner ring 11, a bearing outer ring 12 and a first ball 13, the bearing outer ring 12 is sleeved on the bearing inner ring 11 and the first ball 13 is arranged between the two; the bearing outer ring 12 includes a first outer ring 121 and a second outer ring 122, the first outer ring 121 has an outer spherical surface, the second outer ring 122 has an inner spherical surface, the second outer ring 122 is sleeved on the first outer ring 121 and the two are matched by the outer spherical surface and the inner spherical surface, that is, the first outer ring 121 and the second outer ring 122 constitute a joint bearing. Joint bearings can withstand radial loads, axial loads or combined loads of radial and axial loads. In this embodiment, when the inner wall of the flexible wheel is axially displaced due to the inclination of the wide mouth, the joint bearing can convert the sliding friction between the outer ring of the bearing and the inner hole of the flexible wheel into rolling friction.

[0057] The third type, the flexible bearing includes a bearing inner ring 11, a bearing outer ring 12 and a first ball 13, the bearing outer ring 12 is sleeved on the bearing inner ring 11 and the first ball 13 is arranged between the two; the bearing outer ring 12 includes a first outer ring 121, a second outer ring 122, a first groove 1231 arranged on the outer surface of the first outer ring 121, a second groove 1232 arranged on the inner surface of the second outer ring 122, and a second ball 1233, the first groove 1231 and the second groove 1232 are spliced ​​to form a accommodating cavity 1234, and the second ball 1233 is movably arranged in the accommodating cavity 1234. That is to say, on the basis of the second spherical bearing, the third structure adds grooves (the first groove 1231 and the second groove 1232) and the second ball along the axial direction of the spherical bearing structure. The second ball and the groove fit tightly together, and the second ball can roll freely in the groove. The number of grooves is the same as the number of second balls in the internal deep groove ball structure, usually twenty-three. The number of balls in each groove is greater than or equal to 2, which will be more conducive to the spherical bearing to eliminate the friction caused by deformation.

[0058] In addition, in the flexible bearing provided in this embodiment, under the condition of the same rotation speed, the distribution diameter of the first ball 13 is reduced, and the linear velocity between the first ball 13 and the inner and outer diameters is reduced. Under the condition of the same linear velocity between the first ball 13 and the inner and outer diameters, the smaller the distribution diameter of the first ball 13, the higher the limit rotation speed. That is, this embodiment also reduces the distribution diameter of the deep groove ball bearing ball (first ball), which can increase the limit operating speed of the harmonic reducer.

[0059] Example 2

[0060] This embodiment provides a reducer, such as Figure 5-Figure 13 As shown, the reducer includes the flexible bearing 1 described in Example 1.

[0061] In a specific embodiment, Figure 5As shown, the reducer further includes a cam 2, a rigid wheel 3 and a flexible wheel 4, the flexible bearing 1 is sleeved on the cam 2, the flexible wheel 4 is sleeved on the flexible bearing 1 and the inner hole 42 of the flexible wheel 4 is matched with the outer spherical surface of the first outer ring 121, the rigid wheel 3 is sleeved on the flexible wheel 4, and the inner teeth 31 of the rigid wheel 3 are meshed with the outer teeth 41 of the flexible wheel 4. Specifically, the reducer in this embodiment refers to a harmonic reducer.

[0062] It should be noted that, when the bearing outer ring 12 in the flexible bearing 1 further includes a second outer ring 122 , the inner hole 42 of the flexible wheel 4 cooperates with the second outer ring 122 .

[0063] A harmonic reducer, also known as a harmonic gear reducer, is a transmission device that utilizes the meshing of a rigid wheel 3 and a flexible wheel 4 to transmit power and motion. It is mainly composed of a wave generator (a cam 2 and a flexible bearing 1 constitute a wave generator), a flexible wheel 4, and a rigid wheel 3. The wave generator is usually elliptical or hyperbolic, and the change in its shape causes the outer teeth 41 of the flexible wheel 4 to produce periodic elastic deformation, which in turn produces a process of meshing and disengagement with the inner teeth 31 of the rigid wheel 3, thereby transmitting power.

[0064] In this embodiment, the structure of the flexible wheel 4 is a top hat type or a cup type. Fig. 9 As shown, it includes a thin-walled cylinder 43, a thin-walled diaphragm 44 and a flange 45, wherein the cup, corner, diaphragm, flange and other joints of the flexible wheel 4 are all smoothly transitioned to ensure that no cutting edges appear on the elastic element to avoid stress concentration; the wave generator includes a smooth and continuously conductive outer circular profile to drive the outer teeth 41 of the flexible wheel 4 to mesh with the inner teeth 31 of the rigid wheel 3; the relative position between the rigid wheel 3 and the flexible wheel 4 is constrained by a rigid bearing 5.

[0065] In a specific embodiment, the number of the internal teeth 31 is greater than the number of the external teeth 41. Specifically, the number of the internal teeth 31 is two, three or four more than the number of the external teeth 41. The specific number depends on the reduction ratio, which is determined according to the formula reduction ratio = number of external teeth / (number of internal teeth - number of external teeth).

[0066] The wave generator of the harmonic reducer is an elliptical structure, and its elliptical major axis is slightly larger than the inner diameter of the flexible wheel. Therefore, after the wave generator is installed in the flexible wheel, the flexible wheel will deform according to the contour shape of the wave generator at the open end of the flexible wheel. The flexible wheel will be stretched outward near the major axis of the wave generator at the open end. Figure 8 At Z in the figure, because the circumference of the flexible wheel does not change basically, the flexible wheel shrinks inward near the short axis of the wave generator at the open end, such as Figure 8At S in the middle. At the same time, the diameter of the bottom of the flexible wheel 4 has not changed or has only a small change, so the flexible wheel 4 will present a complex deformation form. Since the flexible bearing 1 works in conjunction with the inner hole 42 of the flexible wheel 4, the flexible bearing 1 is subjected to the friction force of the flexible wheel on the bottom of the cylinder near the long axis, which causes the flexible bearing to present a saddle-shaped structure close to the inner hole of the flexible wheel. The friction force is transmitted to the ball through the outer ring groove, and then transmitted to the inner ring of the bearing through the inner ring groove, so that the entire flexible bearing is subjected to an axial force toward the bottom of the flexible wheel cylinder. The axial force is proportional to the load torque. When the torque exceeds a certain range, the reducer will have the risk of axial movement of the bearing and the cam. After adopting the flexible bearing in Example 1, when the inner wall of the flexible wheel 4 is axially displaced due to the wide mouth tilt of the reducer provided in this embodiment, the flexible bearing 1 can convert the sliding friction between the outer ring of the bearing and the inner hole 42 of the flexible wheel 4 into rolling friction, reduce the friction generated by the displacement, and thus eliminate the influence of the axial force on the deep groove ball bearing. Avoid axial movement of the bearing and the cam 2, and improve the load-bearing capacity and life of the reducer.

[0067] Example 3

[0068] This embodiment provides a robot, which includes the reducer described in Example 2.

[0069] In summary, it is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous technical features can be freely combined and superimposed.

[0070] The above are only preferred embodiments of the present invention and are not intended to limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A flexible bearing, comprising a bearing inner ring, a bearing outer ring and a first ball, wherein the bearing outer ring is sleeved on the bearing inner ring and the first ball is arranged between the two; characterized in that: The bearing outer ring includes a first outer ring having an outer spherical surface.

2. The flexible bearing according to claim 1, characterized in that: The bearing outer ring further comprises a second outer ring, the second outer ring has an inner spherical surface, the second outer ring is sleeved on the first outer ring and the two are matched through the outer spherical surface and the inner spherical surface.

3. The flexible bearing according to claim 2, characterized in that: The bearing outer ring further includes a rolling unit disposed between the first outer ring and the second outer ring.

4. The flexible bearing according to claim 3, characterized in that: The rolling unit includes a first groove arranged on the outer surface of the first outer ring, a second groove arranged on the inner surface of the second outer ring, and a second ball. The first groove and the second groove are spliced ​​to form a accommodating cavity. There are at least two second balls, and at least two of the second balls are movably arranged in the accommodating cavity.

5. The flexible bearing according to claim 4, characterized in that: The first groove runs through the axial direction of the outer surface of the first outer ring, and the second groove runs through the axial direction of the outer surface of the second outer ring, so that the first groove and the second groove are spliced ​​to form a plurality of the accommodating cavities, and the second balls correspond to the accommodating cavities one by one.

6. The flexible bearing according to any one of claims 1 to 5, characterized in that: The inner surface of the first outer ring has a first deep groove ball bearing groove structure, and the outer surface of the bearing inner ring has a second deep groove ball bearing groove structure. The first deep groove ball bearing groove structure and the second deep groove ball bearing groove structure can be spliced ​​into a track for the first ball to roll.

7. A reducer, characterized in that: The flexible bearing comprises any one of claims 1-6.

8. The reducer according to claim 7, characterized in that: The reducer also includes a cam, a rigid wheel and a flexible wheel. The flexible bearing is sleeved on the cam, the flexible wheel is sleeved on the flexible bearing and the inner hole of the flexible wheel matches the outer spherical surface of the first outer ring, the rigid wheel is sleeved on the flexible wheel, and the inner teeth of the rigid wheel are meshed with the outer teeth of the flexible wheel.

9. The reducer according to claim 8, characterized in that: The number of the inner teeth is greater than the number of the outer teeth.

10. A robot, characterized in that: Including the reducer described in claims 7-9.

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