RV speed reducer and industrial robot

Abstract

The invention discloses an RV speed reducer and an industrial robot, and relates to the technical field of speed reducers. The RV speed reducer comprises a pin wheel housing, a planet carrier and a main bearing; the main bearing is used for supporting relative movement of the planet carrier and the pin wheel housing and comprises an inner ring, an outer ring and a rolling body clamped between the inner ring and the outer ring, the inner ring is formed on the planet carrier, the outer ring is fixedly connected with the pin wheel housing, the outer ring is provided with a track, the track comprises an arc-shaped section and a straight section, and the straight section is connected to the side, close to the open end face, of the arc-shaped section; the minimum diameter of the straight section is larger than or equal to the maximum diameter of the arc-shaped section, and a chamfer is formed between the track and the open end face. When the RV reducer is assembled with the main bearing, the rolling body enters the straight section through the chamfer and then is assembled into the arc-shaped section, so that the assembly difficulty of the rolling body is reduced, the assembly efficiency is improved, and the rolling body can be effectively prevented from damaging the track during installation.

Description

[0001] This application is a divisional application with the application date of "2023.10.11", application number "202311318451.5", and application name "RV reducer and industrial robot". Technical Field

[0002] The present invention relates to the technical field of reducers, and in particular to an RV reducer and an industrial robot. Background Art

[0003] RV reducers are widely used in industrial robots, machine tools, medical testing equipment, satellite receiving systems and other fields due to their many advantages such as small size, strong impact resistance, large torque, high positioning accuracy, low vibration, and large reduction ratio. In RV reducers, a main bearing needs to be set between the pinion housing and the planetary carrier to ensure the power output of the planetary carrier. As a key component of the RV reducer, the main bearing must bear axial loads, radial loads, and overturning loads at the same time. While ensuring rigidity, it needs to have high rotation accuracy. In related technologies, the rolling elements of the main bearing are prone to collide with the track of the main bearing during assembly, causing damage to the track, resulting in abnormal wear of the track and rolling elements, and shortening the life of the main bearing. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an RV reducer, which is convenient for assembling rolling elements and can effectively prevent the rolling elements from damaging the main bearing.

[0005] The present invention also provides an industrial robot having the RV reducer.

[0006] According to an RV reducer of an embodiment of the first aspect of the present invention, the reducer comprises: a pinion housing, a planetary carrier and a main bearing; the planetary carrier is rotatably arranged in the pinion housing; the main bearing is used to support the relative movement of the planetary carrier and the pinion housing, the main bearing comprises an inner ring, an outer ring and a rolling body sandwiched between the inner ring and the outer ring, the inner ring is formed on the planetary carrier, the outer ring is fixedly connected to the pinion housing, the two end faces of the outer ring along the axial direction of the main bearing are respectively an open end face and a closed end face, the outer ring is provided with a track, the track comprises an arc segment and a straight segment, the straight segment is connected to a side of the arc segment close to the open end face, the minimum diameter of the straight segment is greater than or equal to the maximum diameter of the arc segment, a transition section is formed between the track and the open end face, the transition section is configured as a chamfer, and the two ends of the chamfer are respectively connected to the straight segment and the open end face.

[0007] The RV reducer according to the embodiment of the present invention has at least the following beneficial effects:

[0008] By arranging a track including an arc section and a straight section on the outer ring, a chamfer is formed between the track and the open end face of the outer ring. When the RV reducer is assembled with the main bearing, the rolling element enters the straight section through the chamfer and is then installed into the arc section. This reduces the difficulty of assembling the rolling element and improves the assembly efficiency. It can also effectively prevent the rolling element from damaging the track during installation, inhibit abnormal wear between the track and the rolling element, and extend the service life of the main bearing.

[0009] According to some embodiments of the present invention, the height of the outer ring along the axial direction is H, the length of the straight section along the axial direction is L, the radius of the arc section is R, and the dimension of the chamfer along the axial direction is C, satisfying: (R+L+C+2.2mm)≤H≤(R+L+C+3mm).

[0010] According to some embodiments of the present invention, a dimension of the chamfer along the axial direction is C, which satisfies: 1 mm ≤ C ≤ 1.5 mm.

[0011] According to some embodiments of the present invention, the length of the straight section along the axial direction is L, satisfying: 0.5 mm ≤ L ≤ 1.5 mm.

[0012] According to some embodiments of the present invention, the outer ring is further provided with an annular avoidance groove, and along the radial direction of the outer ring, one end of the avoidance groove is connected to the track, and the other end is connected to the inner hole wall of the outer ring.

[0013] According to some embodiments of the present invention, the bottom diameter of the track is φ2, the radius of the arc segment is R, and the maximum diameter of the avoidance groove is φ5, satisfying: (φ2-2*R+0.5mm)≤φ5≤(φ2-2*R+1.5mm).

[0014] According to some embodiments of the present invention, the bottom diameter of the track is φ2, the radius of the arc segment is R, and the inner diameter of the outer ring is φ4, satisfying: (φ2-2*R-2.5mm)≤φ4≤(φ2-2*R-1mm).

[0015] According to some embodiments of the present invention, the needle gear housing is provided with an annular groove, and the outer circumferential wall of the outer ring is interference fit with the inner circumferential wall of the annular groove.

[0016] According to some embodiments of the present invention, a positioning platform is formed in the annular groove, and the outer ring is positioned and connected to the positioning platform.

[0017] The industrial robot according to the second embodiment of the present invention comprises the RV reducer described in the above embodiment.

[0018] The industrial robot according to the embodiment of the present invention has at least the following beneficial effects:

[0019] The RV reducer adopts the first aspect of the embodiment. The RV reducer is provided with a track including an arc segment and a straight segment on the outer ring, and a chamfer is formed between the track and the open end face of the outer ring. When the RV reducer is assembled with the main bearing, the rolling element enters the straight section through the chamfer and is then installed into the arc segment, which reduces the difficulty of assembling the rolling element and improves the assembly efficiency. It can also effectively prevent the rolling element from damaging the track during installation, inhibit abnormal wear between the track and the rolling element, and extend the service life of the main bearing.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0022] Figure 1 A schematic diagram of the structure of an RV reducer according to an embodiment of the present invention;

[0023] Figure 2 A schematic structural diagram of a planet carrier according to an embodiment of the present invention;

[0024] Figure 3 for Figure 1 The enlarged view of point A in the middle;

[0025] Figure 4 This is a schematic diagram of the structure of an outer ring of an embodiment of the present invention;

[0026] Figure 5 for Figure 4 Enlarged view of point B in the middle.

[0027] Figure Number:

[0028] Pin gear housing 100; annular groove 101; planet carrier 110; output shaft 111; support flange 112; support column 113; fixing pin 114; pin gear pin 120; positioning platform 130; oil seal 140; baffle 150;

[0029] Main bearing 200; outer ring 210; inner hole 2101; avoidance groove 2102; open end surface 211; closed end surface 212; track 213; arc section 2131; straight section 2132; transition section 214; rolling element 220; inner ring 230; cage 240;

[0030] Crankshaft 300; input end 310; first bearing 311; output end 320; second bearing 321; gasket 322; eccentric portion 330; third bearing 331;

[0031] Cycloid wheel 400. DETAILED DESCRIPTION

[0032] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0033] In the description of the present invention, it should be understood that descriptions involving orientation, such as orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0034] In the description of the present invention, "a plurality" means more than two. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0035] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0036] In the design of the outer ring of the main bearing in the prior art, too much emphasis is usually placed on the ability to withstand various types of loads. The load on the rolling element in the outer ring is increased as much as possible within the allowable range, that is, the contact area between the rolling element and the inner wall of the outer ring after the main bearing is pre-loaded is increased, which will increase the friction loss of the outer ring track, causing accelerated wear of the rolling element and the track, and shortening the life of the main bearing; and the contact area between the rolling element and the inner wall of the outer ring is increased. In order to ensure the strength of the outer ring and bear the contact stress of the rolling element, the size of the outer ring is also designed to be larger, which can easily cause the outer ring to be more easily deformed during installation, increase the deformation of the track caused by the assembly of the main bearing, and the accuracy of the track size cannot be guaranteed, further shortening the life of the main bearing.

[0037] Reference Figure 1 and Figure 2As shown, an RV reducer according to an embodiment of the present invention comprises: a pin gear housing 100, a planetary carrier 110 and a main bearing 200; the planetary carrier 110 comprises an output shaft 111 and a supporting flange 112, a pillar 113 is provided on the side of the output shaft 111 facing the supporting flange 112, the pillar 113 is connected to the supporting flange 112 through a fixing pin 114, the planetary carrier 110 is rotatably arranged in the pin gear housing 100, the main bearing 200 is used to support the relative movement of the planetary carrier 110 and the pin gear housing 100, that is, the output shaft 111 and the supporting flange 112 are rotatably installed on the planetary carrier 110 through two symmetrical main bearings 200 respectively, an oil seal 140 for improving the internal sealing of the pin gear housing 100 is also provided between the output shaft 111 and the pin gear housing 100, and a baffle 150 for radially limiting the crankshaft 300 along the outer ring 210 is provided on the side of the supporting flange 112 away from the output shaft 111. The main bearing 200 includes an inner ring 230, an annular outer ring 210, and a rolling body 220 sandwiched between the inner ring 230 and the outer ring 210. The rolling body 220 is a plurality of steel balls arranged along the circumference of the outer ring 210, wherein the steel balls can also be replaced by rollers such as cylindrical rollers, tapered rollers, and needle rollers as required. The main bearing is described below using steel balls as an example, which is specially explained here and will not be repeated hereafter. The inner ring 230 is formed on the planetary carrier 110. Specifically, the inner ring 230 is an annular groove formed on the outer peripheral wall of the output shaft 111 and the support flange 112, and the groove wall of the annular groove is in an arc shape matching the steel balls. The inner ring 230 is directly formed on the outer peripheral wall of the planetary carrier 110, which can effectively improve the structural tightness of the RV reducer and facilitate power transmission.

[0038] Reference Figure 1 and Figure 3 As shown, it can be understood that a positioning platform 130 is provided in the pin gear housing 100, and the end faces on both sides of the positioning platform 130 respectively form an annular groove 101 with the inner wall of the pin gear housing 100, and the annular groove 101 and the main bearing 200 are arranged in a one-to-one correspondence, and the outer circumferential wall of the outer ring 210 and the inner circumferential wall of the annular groove 101 are interference fit, that is, the outer circumferential wall size of the outer ring 210 is slightly larger than the inner circumferential wall size of the annular groove 101. When assembling the RV reducer, the outer ring 210 is knocked and pressed into the annular groove 101 by a pressing device and contacts the positioning platform 130. The size of the outer circumferential wall of the outer ring 210 that is larger than the inner circumferential wall of the annular groove 101 is the interference amount of the outer ring 210. By reserving a certain amount of interference, the outer wall of the outer ring 210 is interference fit with the inner wall of the annular groove 101, which can effectively improve the installation stability of the outer ring 210, and evenly distribute the various loads of the steel balls carried by the outer ring 210 to the entire pinion housing 100, effectively improving the working stability of the RV reducer.

[0039] Reference Figure 1As shown, a crankshaft 300 and a cycloidal wheel 400 are installed in the planetary carrier 110. Specifically, an input end 310 and an output end 320 are respectively provided at both ends of the crankshaft 300. The input end 310 is rotatably connected to the support flange 112 through a first bearing 311 and a transmission connection with an external motor (not shown in the figure). The output end 320 is rotatably connected to the output shaft 111 through a second bearing 321. An eccentric portion 330 is provided in the middle section of the crankshaft 300. The eccentric portion 330 is rotatably connected to the cycloidal wheel 400 through a third bearing 331. A gasket 332 is provided between the second bearing 321 and the third bearing 331. The gasket 332 can prevent the second bearing 321 and the third bearing 331 from rubbing against each other. The cycloidal wheel 400 is meshed with a needle pin 120 in the needle gear housing 100. The needle pin 120 is located between the two outer rings 210 and is arranged around the cycloidal wheel 400. After the external motor drives the input end 310 to rotate, the input end 310 controls the eccentric part 330 to rotate. Since the positions of the needle gear housing 100 and the needle gear pin 120 in the needle gear housing 100 relative to the cycloid wheel 400 remain unchanged, under the squeezing action of the needle gear pin 120, the eccentric part 330 drives the cycloid wheel 400 to do eccentric motion, and the cycloid wheel 400 drives the crank shaft 300 to revolve, and the crank shaft 300 transmits the torque to the output shaft 111 through the second bearing 321 of the output end 320, so that the planetary carrier 110 rotates, thereby realizing the power output of the RV reducer.

[0040] Reference Figure 3 and Figure 4As shown, it can be understood that the two end faces of the outer ring 210 along the axial direction of the main bearing 200 are respectively an open end face 211 and a closed end face 212. For the two symmetrical outer rings 210 in the pin gear housing 100, the open end face 211 is the end face of one of the outer rings 210 away from the other outer ring 210, and the closed end face 212 is the end face of one of the outer rings 210 facing the other outer ring 210. The outer ring 210 is provided with a track 213, and the track 213 includes an arc segment 2131 and a straight segment 2132. The straight segment 2132 is connected to the side of the arc segment 2131 close to the open end face 211. The minimum diameter of the straight segment 2132 is greater than or equal to the maximum diameter of the arc segment 2131. The straight segment 2132 is an annular plane, or a straight segment. 2132 is a trumpet-shaped inclined surface which is inclined outwardly along the radial direction of the outer ring 210 at one end away from the arc section 2131, so as to avoid the straight section 2132 interfering with the movement of the steel ball, and a transition section 214 is formed between the track 213 and the open end surface 211 to facilitate the processing of the outer ring 210; wherein, the outer diameter of the outer ring 210 is φ3, and the bottom diameter of the track 213 is φ2. Since the minimum diameter of the straight section 2132 is greater than or equal to the maximum diameter of the arc section 2131, φ2 is the maximum diameter of the straight section 2132 in the track 213 along the radial direction of the outer ring 210, the radius of the arc section 2131 is R, and the diameter of the rolling element 220 is S, which satisfies: (S*1.015) / 2≤R≤(S*1.025) / 2, and (φ2+4.6mm)≤φ3≤(φ2+6mm).

[0041] It is understandable that, under the premise of determining the steel ball diameter S, the number of steel balls Q, and the diameter of the steel ball distribution circle according to the load and life requirements, the numerical range of the radius R of the arc segment 2131 can be further limited according to the steel ball diameter S. When assembling the RV reducer, the multiple steel balls in the main bearing 200 can first be close to the straight section 2132, so that the steel balls are positioned in the radial direction of the outer ring 210 and then pressed into the arc segment 2131. While improving the assembly efficiency, it prevents the rolling body 220 from directly impacting the arc segment 2131 and causing damage to the track 213. The radius R of the arc segment 2131 is limited to between (S*1.015) / 2 and (S*1.025) / 2, that is, the radius R of the arc segment 2131 is within 1 / 100 of the radius of the rolling body 220. .015 times or more, it can avoid that the radius R of the arc segment 2131 is too small, resulting in excessive contact area between the steel ball and the arc segment 2131 after the main bearing 200 is pre-loaded, resulting in increased friction and wear, shortening the life of the main bearing 200, and other problems; at the same time, the radius R of the arc segment 2131 is limited to less than 1.025 times the radius of the rolling element 220, which can avoid the problems of increased contact stress of the steel ball and insufficient rigidity of the main bearing 200 due to the small contact angle between the steel ball and the arc segment 2131 after the main bearing 200 is pre-loaded. By reasonably limiting the radius R of the arc segment 2131, it is ensured that the steel ball and the arc segment 2131 are in reasonable contact, so that the main bearing 200 can bear various loads while reducing friction losses and extending the service life of the main bearing 200.

[0042] The outer diameter φ3 of the outer ring 210 is limited to between φ2+4.6mm and φ2+6mm, that is, along the radial direction of the outer ring 210, the thickness of the outer ring 210 outside the track 213 in the outer ring 210 is limited to more than 4.6mm, so as to avoid the problems of the outer ring 210 wall thickness being too thin, the track 213 being greatly deformed during processing, and the dimensional accuracy cannot be guaranteed, etc. At the same time, the thickness of the outer ring 210 outside the track 213 is limited to less than 6mm. Under the premise of ensuring a certain assembly interference, the deformation of the track caused by assembly can be well controlled, and when the outer ring 210 is knocked, the outer ring 210 with too large wall thickness will not produce a large installation deformation, resulting in the dimensional accuracy of the track 213 cannot be guaranteed, and the service life of the main bearing 200 will be shortened. In addition, the outer ring 210 with a reasonable size can save processing materials and reduce the processing cost of the outer ring 210. By reasonably limiting the radius R of the arc segment 2131 and the outer diameter φ3 of the outer ring 210, the friction loss is reduced, the dimensional accuracy of the track 213 is ensured, and the service life of the main bearing 200 is further extended while ensuring simple assembly, stable operation, and low production cost of the main bearing 200.

[0043] It should be noted that the radius R of the arc segment 2131 is positively correlated with the steel ball diameter S, while the steel ball diameter S is usually negatively correlated with the number of steel balls Q, and the number of steel balls Q is usually positively correlated with the size of the pin gear housing 100. Therefore, when designing the RV reducer, the larger the size of the pin gear housing 100, the more the number of steel balls Q, and the smaller the diameter S of the steel balls, so that the radius R of the arc segment 2131 is smaller. Similarly, the smaller the size of the pin gear housing 100, the larger the radius R of the arc segment 2131. The radius R of the arc segment 2131 is not specifically limited here, as long as it can support the stable movement of the steel balls. In addition, the outer diameter φ3 of the outer ring 210 is usually positively correlated with the size of the pin gear housing 100. The outer diameter φ3 of the outer ring 210 is not specifically limited here, as long as it can be stably installed on the pin gear housing 100.

[0044] Reference Figure 1 and Figure 4 As shown, it can be understood that the inner diameter of the outer ring 210 is φ4, that is, the diameter of the inner hole 2101 of the outer ring 210 is φ4, which satisfies: (φ2-2*R-2.5mm)≤φ4≤(φ2-2*R-1mm), and the above formula is converted into the following form: 1mm≤(φ2-2*R-φ4)≤2.5mm, wherein the bottom diameter φ2 of the track 213 minus the radius R of the double arc segment 2131 minus the inner diameter φ4, is the thickness of the outer ring 210 between the inner side of the track 213 and the outer side of the inner hole 2101 along the radial direction of the outer ring 210, and the thickness here can also approximately represent the width of the closed end face 212 at the inner side of the track 213. The thickness of the outer ring 210 on the inner side of the track 213 is limited to more than 1 mm, ensuring that the closed end surface 212 has sufficient width to limit the needle pin 120 and the cycloidal wheel 400 along the radial direction of the outer ring 210, avoiding the axial displacement of the needle pin 120 and the cycloidal wheel 400 during the operation of the RV reducer, effectively improving the overall structural compactness of the RV reducer, and improving the installation stability of the needle pin 120 and the cycloidal wheel 400; the outer side of the steel ball is usually provided with a retainer 240 for maintaining the relative position between multiple steel balls, and the thickness of the outer ring 210 on the inner side of the track 213 is limited to less than 2.5 mm, avoiding interference between the outer ring 210 and the retainer 240 or the third bearing 331, affecting the rotation of the crankshaft 300, and effectively improving the structural rationality of the outer ring 210. The inner diameter φ4 of the outer ring 210 is not specifically limited here, as long as it can make the RV reducer work stably.

[0045] Reference Figure 3 and Figure 4As shown, it can be understood that the transition section 214 is configured as a chamfer, and the two ends of the chamfer are respectively connected to the straight section 2132 and the open end surface 211. The chamfered transition straight section 2132 and the open end surface 211 are provided to remove burrs generated by processing, facilitate the processing of the housing, and also facilitate the subsequent assembly and use of the main bearing 200. In addition, the transition section 214 can also be configured as a fillet, and the connection and effect of the fillet can refer to the above description of the chamfer, which will not be repeated here.

[0046] Reference Figure 5 As shown, it can be understood that the dimension of the chamfer along the axial direction is C, which satisfies: 1mm≤C≤1.5mm. The chamfer dimension is limited to 1mm to 1.5mm, which can avoid the chamfer being too small, which can not play a good role in convenient processing and assembly, and avoid the chamfer being too large to squeeze the open end face 211 and affect the strength of the outer ring 210.

[0047] Continue to refer to Figure 5 As shown, it can be understood that the length of the straight section 2132 along the axial direction is L, which satisfies: 0.5mm≤L≤1.5mm. As a part of the track 213 connected to the arc section 2131, the size of the straight section 2132 will directly affect the performance of the track 213. If the length L of the straight section 2132 along the axial direction is less than 0.5mm, the contact length between the straight section 2132 and the steel ball will be too short, making it difficult to position the steel ball and prevent the rolling element 220 from damaging the track 213. If the length L of the straight section 2132 along the axial direction is greater than 1.5mm, the track 213 will be too deep, which will not only increase the difficulty of assembling the main bearing 200, but also increase the volume of the outer ring 210 and the production cost of the outer ring 210. The length L of the straight section 2132 along the axial direction is limited to 0.5 mm to 1.5 mm, the size of the straight section 2132 is reasonably limited, the structure of the track 213 is optimized, and the problem of structural invalidity caused by insufficient length of the straight section 2132 of the track 213 is avoided, or the problem of structural redundancy caused by excessive length of the straight section 2132 is avoided.

[0048] Reference Figure 3 and Figure 5 As shown, it can be understood that the diameters of the straight section 2132 in the axial direction are all equal, that is, the track 213 is in a circular hole shape at the straight section 2132. At this time, the projection of the straight section 2132 in the direction perpendicular to the axial direction is parallel to the axial line. The straight section 2132 is arranged straight along the axial direction of the outer ring. On the one hand, it can facilitate the processing and forming of the straight section 2132 and improve the production efficiency of the outer ring 210; on the other hand, it can facilitate the movement of the steel ball against each other and further improve the assembly efficiency of the main bearing 200.

[0049] Continue to refer to Figure 4 and Figure 5As shown, it can be understood that the height of the outer ring 210 along the axial direction is H, the length of the straight section 2132 along the axial direction is L, and the dimension of the chamfer along the axial direction is C, satisfying: (R+L+C+2.2mm)≤H≤(R+L+C+3mm), the height H of the outer ring 210 along the axial direction is mainly composed of the radius R of the arc section 2131, the length L of the straight section 2132 along the axial direction, the dimension C of the chamfer along the axial direction and the height of the inner hole 2101 of the outer ring 210 along the axial direction. The height of the inner hole 2101 along the axial direction can approximately represent the thickness of the outer ring 210 on the side where the steel ball is away from the inner ring 230. The height H of the outer ring 210 along the axial direction is limited to more than R+L+C+2.2mm, ensuring that the outer ring on the side where the steel ball is away from the inner ring 230 has sufficient strength, thereby ensuring that the track 213 can stably bear the axial load of the steel ball on the outer ring 210, and meet the bearing requirements of the outer ring 210 for the axial load; the height H of the outer ring 210 along the axial direction is limited to less than R+L+C+3mm, that is, the height of the inner hole 2101 of the outer ring 210 is limited to less than 3mm, avoiding the problems of increased material cost and processing cost caused by the excessive size of the outer ring 210. By reasonably limiting the height of the inner hole 2101 along the axial direction, the design requirements are met, the structural stability of the RV reducer is improved, and the material cost and processing cost are saved. The height of the inner hole 2101 along the axial direction is not specifically limited here, as long as the RV reducer can be stably assembled while saving materials.

[0050] Reference Figure 4 and Figure 5As shown, it can be understood that the outer ring 210 is also provided with an annular avoidance groove 2102, and the avoidance groove 2102 is formed between the track 213 and the inner hole 2101 of the outer ring 210. The avoidance groove 2102 can avoid the tool (not shown in the figure) when the tool is processed to the end of the track 213, so as to facilitate the tool to retract. The maximum diameter of the avoidance groove 2102 is φ5, which satisfies: (φ2-2*R+0.5mm)≤φ5≤(φ2-2*R+1.5m m), convert the above formula into the following form: 0.5mm≤φ5-(φ2-2*R)≤1.5mm, wherein the bottom diameter φ2 of the track 213 minus twice the radius R of the arc segment 2131 is the diameter of the outer ring 210 excluding the track 213 and the outer part of the track 213, and the maximum diameter φ5 of the avoidance groove 2102 minus this diameter is the depth of the arc segment 2131 of the track 213 occupied by the avoidance groove 2102 along the radial direction of the outer ring 210. By limiting the depth of the arc segment 2131 occupied by the avoidance groove 2102 to more than 0.5 mm, the processing area of ​​the arc segment 2131 can be reduced, and the processing of the track 213 is convenient, thereby further reducing the processing cost of the outer ring 210; by limiting the depth of the arc segment 2131 occupied by the avoidance groove 2102 to less than 1.5 mm, sufficient arc segment 2131 structure is retained to ensure that after the main bearing 200 is pre-pressed, the arc segment 2131 has enough area to contact the steel ball, thereby avoiding the accelerated wear and aging of the track 213. By reasonably limiting the maximum diameter φ5 of the avoidance groove 2102, while facilitating the processing of the track 213 and saving processing costs, the track 213 and the steel ball are in stable contact, the working stability of the RV reducer is improved, and the service life of the main bearing 200 is further extended. Here, the maximum diameter φ5 of the avoidance groove 2102 is not specifically limited, as long as the track 213 is easy to process and in stable contact with the steel ball.

[0051] Reference Figure 5 As shown, it can be understood that, along the radial direction of the outer ring 210, one end of the avoidance groove 2102 is connected to the track 213, and the other end is connected to the wall surface of the inner hole 2101. The two ends of the avoidance groove 2102 are respectively connected to the track 213 and the wall surface of the inner hole 2101, and the position of the avoidance groove 2102 is reasonably designed by using the space between the track 213 and the wall surface of the inner hole 2101, so as to avoid redundant structure at one end of the arc section 2131 of the track 213 away from the straight section 2132, and further reduce the processing cost of the track 213.

[0052] An industrial robot according to an embodiment of the second aspect of the present invention comprises the RV reducer of the embodiment of the first aspect.

[0053] The industrial robot adopts the RV reducer of the first aspect embodiment. The RV reducer reasonably limits the radius R of the arc segment 2131 and the outer diameter φ3 of the outer ring 210, thereby reducing friction loss while ensuring simple assembly and stable operation of the main bearing 200, controlling the deformation of the track 213 caused by assembly, ensuring the dimensional accuracy of the track 213, and extending the service life of the main bearing 200.

[0054] Since the industrial robot adopts all the technical solutions of the RV reducer of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment, which will not be repeated here.

[0055] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. RV reducer, characterized in that: include: Needle tooth shell; A planet carrier rotatably disposed in the pin gear housing; A main bearing is used to support the relative movement of the planetary carrier and the pin gear housing, the main bearing comprises an inner ring, an outer ring and a rolling body sandwiched between the inner ring and the outer ring, the inner ring is formed on the planetary carrier, the outer ring is fixedly connected to the pin gear housing, the two end faces of the outer ring along the axial direction of the main bearing are an open end face and a closed end face respectively, the outer ring is provided with a track, the track comprises an arc section and a straight section, the straight section is connected to a side of the arc section close to the open end face, the minimum diameter of the straight section is greater than or equal to the maximum diameter of the arc section, a transition section is formed between the track and the open end face, the transition section is configured as a chamfer, and the two ends of the chamfer are respectively connected to the straight section and the open end face.

2. The RV reducer according to claim 1, characterized in that: The height of the outer ring along the axial direction is H, the length of the straight section along the axial direction is L, the radius of the arc section is R, and the dimension of the chamfer along the axial direction is C, satisfying: (R+L+C+2.2mm)≤H≤(R+L+C+3mm).

3. The RV reducer according to claim 1 or 2, characterized in that: The dimension of the chamfer along the axial direction is C, which satisfies: 1mm≤C≤1.5mm.

4. The RV reducer according to claim 1 or 2, characterized in that: The length of the straight section along the axial direction is L, which satisfies: 0.5 mm ≤ L ≤ 1.5 mm.

5. The RV reducer according to claim 1, characterized in that: The outer ring is also provided with an annular avoidance groove, and along the radial direction of the outer ring, one end of the avoidance groove is connected to the track, and the other end is connected to the inner hole wall of the outer ring.

6. The RV reducer according to claim 5, characterized in that: The bottom diameter of the track is φ2, the radius of the arc segment is R, and the maximum diameter of the avoidance groove is φ5, satisfying: (φ2-2*R+0.5mm)≤φ5≤(φ2-2*R+1.5mm).

7. The RV reducer according to claim 1, characterized in that: The bottom diameter of the track is φ2, the radius of the arc segment is R, and the inner diameter of the outer ring is φ4, satisfying: (φ2-2*R-2.5mm)≤φ4≤(φ2-2*R-1mm).

8. The RV reducer according to claim 1, characterized in that: The needle gear housing is provided with an annular groove, and the outer peripheral wall of the outer ring is interference-fitted with the inner peripheral wall of the annular groove.

9. The RV reducer according to claim 8, characterized in that: A positioning platform is formed in the annular groove, and the outer ring is positioned and connected to the positioning platform.

10. An industrial robot, characterized in that: Including the RV reducer as described in any one of claims 1 to 9.

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