CN221033616U - Needle bearing, speed reducer and industrial robot - Google Patents

Abstract

The utility model discloses a needle bearing, a speed reducer and an industrial robot. The needle bearing includes a cage and a plurality of rolling elements. The plurality of rolling bodies are uniformly arranged in the retainer around the axis of the needle bearing, and the number of the rolling bodies is determined according to the diameter of the circumscribed circle of the rolling bodies and the diameter of the inscribed circle of the rolling bodies. The needle roller bearing has the maximum rolling body quantity under the sizes of the circumscribed circle diameter and the inscribed circle diameter, and is beneficial to reducing the maximum contact stress of the needle roller bearing, so that the abrasion of the needle roller bearing can be reduced, and the service life of the needle roller bearing is prolonged.

Description

Needle bearing, speed reducer and industrial robot

Technical Field

The utility model relates to the technical field of motors, in particular to a needle bearing, a speed reducer and an industrial robot.

Background

In the related art, the bearing design of the cycloidal transmission device on the crank shaft part mainly comprises a needle bearing, wherein the needle bearing is most widely applied. However, when the needle roller bearing is used for a cycloid transmission device, the contact stress is large, so that the noise of the needle roller bearing is increased after the needle roller bearing is used for a long time, the vibration is aggravated, the abrasion is accelerated, and finally the needle roller bearing is invalid.

Disclosure of utility model

The embodiment of the utility model provides a needle bearing, a speed reducer and an industrial robot to solve at least one technical problem.

A needle bearing of an embodiment of the present utility model includes a cage and a plurality of rolling elements. The plurality of rolling bodies are uniformly arranged in the retainer around the axis of the needle bearing, and the number of the rolling bodies is determined according to the diameter of the circumscribed circle of the rolling bodies and the diameter of the inscribed circle of the rolling bodies.

The needle roller bearing has the maximum rolling body quantity under the sizes of the circumscribed circle diameter and the inscribed circle diameter, and is beneficial to reducing the maximum contact stress of the needle roller bearing, so that the abrasion of the needle roller bearing can be reduced, and the service life of the needle roller bearing is prolonged.

In some embodiments, the rolling elements have an inscribed circle diameter D2, the rolling elements have an circumscribed circle diameter D3, the number of rolling elements is N,

In some embodiments, the needle bearing comprises a cage and a plurality of rolling bodies, wherein pockets for accommodating the rolling bodies are formed in the cage, the pockets are uniformly arranged around the axis of the needle bearing, the number of the pockets corresponds to the number of the rolling bodies, and the rolling bodies are arranged in the pockets.

In certain embodiments, the diameter of the distribution circle of the rolling elements is equal to half of the sum of the diameter of the inscribed circle of the rolling elements and the diameter of the circumscribed circle of the rolling elements.

In some embodiments, the difference between the inner diameter of the needle bearing and the inscribed circle diameter of the rolling element is in the range of [0,3mm ].

In some embodiments, the difference between the outer diameter of the needle bearing and the diameter of the circumscribed circle of the rolling element is in the range of [0,3mm ].

In some embodiments, the distance between the rolling elements and the wall of the pocket along the circumferential direction of the needle bearing is in the range of (0, 1 mm).

In some embodiments, the distance between the rolling elements and the wall of the pocket is C0, the minimum distance between every two rolling elements is C1, and the minimum distance between every two pockets is C2,2×c0+c2=c1 along the circumferential direction of the needle bearing.

A speed reducer according to an embodiment of the present utility model includes the needle bearing according to any one of the above embodiments.

An industrial robot according to an embodiment of the present utility model includes the speed reducer of the above embodiment.

In the above-described speed reducer and industrial robot, the actual maximum number of rolling elements at the diameter is determined based on the diameter of the inscribed circle and the diameter of the circumscribed circle of the needle bearing. The number of the rolling bodies is increased, and the maximum contact stress of the needle bearing is reduced, so that the abrasion of the needle bearing can be reduced, and the service life of the needle bearing is prolonged.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.

Drawings

The foregoing and/or additional aspects and advantages of the present utility model will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic view of a needle bearing according to an embodiment of the present utility model;

FIG. 2 is a schematic cross-sectional view of a needle bearing according to an embodiment of the present utility model;

Fig. 3 is a schematic diagram showing the relationship between the number of rolling elements and the maximum contact stress of the rolling elements according to the embodiment of the present utility model.

Description of main reference numerals:

needle bearings-10, retainers-12, rolling bodies-14, pockets-16.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present utility model and are not to be construed as limiting the present utility model.

In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present utility model, it should be noted that the terms "mounted," "connected," and "coupled" are to be construed broadly, as well as, for example, fixedly coupled, detachably coupled, or integrally coupled, unless otherwise specifically indicated and defined. Either mechanically or electrically. Can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present utility model, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

The disclosure herein provides many different embodiments or examples for implementing different structures of the utility model. To simplify the present disclosure, components and arrangements of specific examples are described herein. They are, of course, merely examples and are not intended to limit the utility model. Furthermore, the present utility model may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not themselves indicate the relationship between the various embodiments and/or arrangements discussed. In addition, the present utility model provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

Referring to fig. 1 and 2, the needle bearing 10 according to the embodiment of the present utility model includes a cage 12 and a plurality of rolling elements 14, wherein the rolling elements 14 are uniformly disposed in the cage 12 around the axis of the needle bearing 10, and the number of the rolling elements 14 is determined according to the diameter of the circumscribed circle of the rolling elements 14 and the diameter of the inscribed circle of the rolling elements 14.

The needle roller bearing has the maximum number of rolling elements 14 under the sizes of the outside circle diameter and the inside circle diameter of the needle roller bearing 10, which is beneficial to reducing the maximum contact stress of the needle roller bearing 10, thereby reducing the abrasion of the needle roller bearing 10 and prolonging the service life of the needle roller bearing 10.

Specifically, the needle bearing 10 may be applied to a speed reducer, alternatively, the speed reducer may be an RV (rotation Vector) speed reducer, which is a core component of an industrial robot, and has advantages of high accuracy, high rigidity, long life, and the like. The RV reducer consists of a planetary gear transmission assembly and a cycloid gear transmission assembly.

The motion transmission path of the RV speed reducer starts from the input shaft, motion and stress are transmitted to the planetary gear through the meshing of the input shaft and the planetary gear, the planetary gear is connected with the crankshaft, and the crankshaft and the planetary gear do the same motion. The cycloid gear is provided with a through hole, the cycloid gear is sleeved on the flange of the crankshaft through the through hole, and the crankshaft drives the cycloid gear to do eccentric motion and mesh with the pin teeth, and finally, load and motion are transmitted to the output shaft.

Needle bearing 10 is disposed between the cycloid gear and the crank shaft and is an important carrier for RV reducers. At present, the rolling elements 14 in the needle bearing 10 are limited by using the retainer 12 in the development of uncapping of the needle bearing 10, so that the size of the needle bearing 10 can be increased. However, after the size of the needle bearing 10 is changed, if the number of the rolling elements 14 is not reasonably designed, the maximum contact stress of the rolling elements 14 in the working process is increased, so that the problems of noise increase, vibration aggravation, accelerated wear and the like of the needle bearing 10 after long-time use are caused, and finally the needle bearing 10 is disabled.

As shown in fig. 1, the needle bearing 10 includes a cage 12 and a plurality of rolling elements 14, the rolling elements 14 being disposed within the cage 12, the cage 12 being configured to restrict the positions of the rolling elements 14 in the axial direction of the needle bearing 10. The plurality of rolling elements 14 are uniformly arranged around the axis of the needle bearing 10, the diameter of the circle around which the rolling elements 14 are distributed is denoted as D1, the diameter of the circle inscribed by the rolling elements 14 is denoted as D2, and the diameter of the circle circumscribed by the rolling elements 14 is denoted as D3. Here, the circumscribed circle of the rolling element 14 is a circle in which the axial center of the needle bearing 10 and the surface of the rolling element 14 are tangent to each other on the side close to the outer diameter of the needle bearing 10. The inscribed circle of the rolling element 14 is a circle in which the axial center of the needle bearing 10 and the surface of the rolling element 14 are tangent to each other on the side close to the inner diameter of the needle bearing 10.

In the needle bearing 10, increasing the number of the rolling elements 14 is advantageous in reducing the maximum contact stress of the rolling elements 14, so that the wear of the needle bearing 10 can be reduced, and the life of the needle bearing 10 can be prolonged. As shown in fig. 3, the relationship between the number N of rolling elements 14 and the maximum contact stress Qmax is shown.

In some embodiments, the diameter of the inscribed circle of the rolling elements 14 is D2, the diameter of the circumscribed circle of the rolling elements 14 is D3, the number of rolling elements 14 is N,

In this way, the needle bearing 10 can be provided with the largest number of rolling elements 14.

Specifically, the needle bearing 10 has the maximum number of rolling elements 14 at the sizes of the circumscribed circle diameter and the inscribed circle diameter, which is advantageous in reducing the maximum contact stress of the needle bearing 10, so that the wear of the needle bearing 10 can be reduced, and the life of the needle bearing 10 can be prolonged.

In some embodiments, the needle bearing 10 includes a cage 12 and a plurality of rolling elements 14, the cage 12 is provided with pockets 16 for accommodating the rolling elements 14, the pockets 16 are uniformly arranged around the axis of the needle bearing 10, the number of the pockets 16 corresponds to the number of the rolling elements 14, and the plurality of rolling elements 14 are installed in the pockets 16.

In this way, the cage 12 can restrict the position of the rolling elements 14, preventing the rolling elements 14 from coming out.

Specifically, as shown in fig. 1, the needle bearing 10 includes a cage 12 and a plurality of rolling elements 14, the cage 12 is provided with pockets 16, the pockets 16 are uniformly arranged around the axis of the needle bearing 10, and the plurality of rolling elements 14 are mounted in the pockets 16. The number of pockets 16 and rolling elements 14 may be determined according to the method of designing the needle bearing 10 described above.

The cage 12 can limit the position of the rolling element 14 in the axial direction of the needle bearing 10, so that the needle bearing 10 can eliminate the inner and outer ferrules, the size of the needle bearing 10 is increased, the structure of the needle bearing 10 is simpler, and the processing difficulty is reduced.

In one embodiment, the rolling elements 14 are cylindrical. In other embodiments, the rolling elements 14 may be spheres or cones. The shape of the pocket 16 corresponds to the shape of the rolling element 14.

Alternatively, the cage 12 may be of a resin, nylon or steel material. The cage 12 of resin or nylon material has good sliding and self-lubricating properties while allowing the needle bearing 10 to be lightweight overall. The steel holder 12 has the advantages of high strength, good toughness, easy processing, etc. The application can be selected according to the use scene and the actual requirement of the needle bearing 10.

In some embodiments, the diameter of the distribution circle of the rolling elements 14 is equal to half of the sum of the inscribed circle of the rolling elements 14 and the circumscribed circle of the rolling elements 14.

In this way, the rolling element 14 is uniformly stressed on each surface during rolling, and the abrasion to the rolling surface on the rolling element 14 during stress is reduced.

Specifically, as shown in fig. 1, the center of the rolling element 14 is located on the distribution circle of the rolling element 14, the diameter of the distribution circle of the rolling element 14 is D1, and the diameter D1 of the distribution circle of the rolling element 14 is equal to half of the sum of the diameter D2 of the inscribed circle of the rolling element 14 and the diameter D3 of the circumscribed circle of the rolling element 14, that is, d1=1/2 (d2+d3). In this way, the rolling element 14 is uniformly stressed on each surface during rolling, and the abrasion to the rolling surface on the rolling element 14 during stress is reduced. In the actual production and processing process, a certain error may be allowed, and a specific error range is required, and the setting is performed according to the application scenario of the needle bearing 10, which is not specifically limited herein.

In some embodiments, the difference between the outer diameter of the needle bearing 10 and the diameter of the circumscribed circle of the rolling elements 14 is in the range of [0,3mm ].

In this way, the rolling elements 14 can be prevented from falling off the cage 12 while ensuring high rotational accuracy of the needle bearing 10.

Specifically, as shown in fig. 1, the difference between the outer diameter D4 of the needle bearing 10 and the diameter D3 of the circumscribed circle of the rolling element 14 is in the range of [0,3mm ]. For example, the difference between the outer diameter D4 of the needle bearing 10 and the diameter D3 of the circumscribed circle of the rolling element 14 may be 0, 0.5mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.3mm, 2.7mm or 3mm, and if the difference between the outer diameter D4 of the needle bearing 10 and the diameter D3 of the circumscribed circle of the rolling element 14 is greater than 3mm, the function of limiting the rolling element 14 in the axial direction of the needle bearing 10 may be disabled, or even the rolling element 14 may be separated from the cage 12 when operating. Limiting the difference between the outer diameter D4 of the needle bearing 10 and the diameter D3 of the circumscribed circle of the rolling element 14 to a value within the range of 0,3mm prevents the rotation of the needle bearing 10 from being affected after the rolling element 14 is mounted to the cage 12.

In some embodiments, the difference between the inner diameter of the needle bearing 10 and the diameter of the inscribed circle of the rolling elements 14 is in the range of [0,3mm ].

In this way, the rolling elements 14 can be prevented from falling off the cage 12 while ensuring high rotational accuracy of the needle bearing 10.

Specifically, as shown in fig. 1, the difference between the inner diameter D5 of the needle bearing 10 and the inscribed circle diameter D2 of the rolling element 14 is in the range of [0,3mm ]. For example, the difference between the inner diameter D5 of the needle bearing 10 and the inscribed circle diameter D2 of the rolling element 14 may be 0, 0.5mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.3mm, 2.7mm or 3mm, and if the difference between the inner diameter D5 of the needle bearing 10 and the inscribed circle diameter D2 of the rolling element 14 is greater than 3mm, the stopper function of the rolling element 14 in the axial direction of the needle bearing 10 may be disabled, or even the rolling element 14 may be separated from the cage 12 when operated. Limiting the difference between the inner diameter D5 of the needle bearing 10 and the inscribed circle diameter D2 of the rolling element 14 to a value within [0,3mm ] can prevent the rotation of the needle bearing 10 from being affected after the rolling element 14 is mounted to the cage 12.

In some embodiments, the distance between the rolling elements 14 and the walls of the pockets 16 along the circumference of the needle bearing 10 can range from (0, 1 mm).

In this way, rolling elements 14 are not affected to roll in pockets 16, and excessive gaps between rolling elements 14 and walls of pockets 16 are avoided, and rolling elements 14 rock in pockets 16.

Specifically, as shown in fig. 2, along the circumferential direction of the needle bearing 10, the distance between the rolling element 14 and the wall of the pocket 16 is C0, and the range of the value of C0 is (0, 1 mm). For example, along the circumferential direction of the needle bearing 10, the distance C0 between the rolling element 14 and the wall of the pocket 16 may be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm, and if the distance between the rolling element 14 and the wall of the pocket 16 is equal to zero, the friction force between the rolling element 14 and the wall of the pocket 16 is large, which may make the abrasion during operation of the needle bearing 10 serious, and is inconvenient for processing and assembly.

In some embodiments, the distance between the rolling elements 14 and the walls of the pockets 16 is C0, the minimum distance between two adjacent rolling elements 14 in the circumferential direction of the needle bearing 10 is C1, and the minimum distance between the walls of two adjacent pockets 16 is C2,2×c0+c2=c1.

In this way, the wall of the pocket 16 can be ensured to have a certain structural strength, and the pocket 16 and the rolling elements 14 are compact in structure.

Specifically, as shown in fig. 2, in the circumferential direction of the needle bearing 10, the minimum distance between two adjacent rolling elements 14 is C1, the minimum distance between the wall of two adjacent pockets 16 is C2, and the distance between the rolling elements 14 and the wall of the pockets 16 is C0, that is, 2×c0+c2=c1. In this way, the wall of the pocket 16 can be ensured to have a certain structural strength, and the pocket 16 and the rolling elements 14 are compact in structure.

It should be noted that the above dimensional requirements may have a certain degree of error in the actual machining process, and the specific error requirements may be set according to the specific use of the needle bearing 10 and the machining equipment, and are not particularly limited herein.

A speed reducer according to an embodiment of the present utility model includes the needle bearing 10 according to any of the above embodiments.

An industrial robot according to an embodiment of the present utility model includes the speed reducer of the above embodiment.

In the above-described speed reducer and industrial robot, the actual maximum number of rolling elements 14 at the diameter is determined based on the diameter of the inscribed circle and the diameter of the circumscribed circle of the needle bearing 10. Increasing the number of rolling elements 14 advantageously reduces the maximum contact stress of the needle bearing 10, so that wear of the needle bearing 10 can be reduced and the life of the needle bearing 10 can be increased.

The explanation of the embodiment and advantageous effects of the needle bearing 10 described above is also applicable to the speed reducer and the industrial robot used in the embodiment of the present utility model, and is not developed in detail here to avoid redundancy.

In the description of the present specification, reference is made to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., meaning that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present utility model have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the utility model, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the utility model.

Claims (9)

1. The needle bearing is characterized by comprising a retainer and a plurality of rolling bodies, wherein the rolling bodies are uniformly arranged in the retainer around the axis of the needle bearing, the number of the rolling bodies is determined according to the diameter of an inscribed circle of the rolling bodies and the diameter of an inscribed circle of the rolling bodies, the diameter of the inscribed circle of the rolling bodies is D2, the diameter of the inscribed circle of the rolling bodies is D3, the number of the rolling bodies is N,

2. The needle bearing of claim 1, wherein the cage is provided with pockets for accommodating the rolling elements, the pockets are uniformly arranged around the axis of the needle bearing, the number of the pockets corresponds to the number of the rolling elements, and the plurality of rolling elements are arranged in the pockets.

3. The needle bearing of claim 1, wherein the diameter of the distribution circle of the rolling elements is equal to half of the sum of the diameter of the inscribed circle of the rolling elements and the diameter of the circumscribed circle of the rolling elements.

4. The needle bearing according to claim 1, wherein the difference between the inner diameter of the needle bearing and the inscribed circle diameter of the rolling element is in the range of [0,3mm ].

5. The needle bearing according to claim 1, wherein the difference between the outer diameter of the needle bearing and the diameter of the circumscribed circle of the rolling element is in the range of [0,3mm ].

6. The needle bearing according to claim 2, wherein the distance between the rolling elements and the wall of the pocket hole in the circumferential direction of the needle bearing has a value in the range of (0, 1 mm).

7. The needle bearing according to claim 2, wherein a distance between the rolling elements and a wall of the pocket is C0, a minimum distance between each two rolling elements is C1 along a circumferential direction of the needle bearing, and a minimum distance between each two pockets is C2,2 xc0+c2=c1.

8. A speed reducer comprising the needle bearing according to any one of claims 1 to 7.

9. An industrial robot comprising the speed reducer according to claim 8.