Multi-stage power transmission system with tension compensation

Abstract

The invention discloses a multi-stage power transmission system with tension compensation, which comprises a mounting base, a first wheel set and a second wheel set, and further comprises a bearing piece fixedly connected to the mounting base, and an arc-shaped guide part is arranged on the bearing surface of the bearing piece; the deflection seat is fixedly connected to the axial bearing end of the first wheel set and / or the second wheel set, the deflection seat is provided with a deflection part, and the deflection part can rotate in the extending direction of the arc-shaped guide part; the adjusting assembly is used for applying an actuating force between the deflection seat and the bearing piece, and the actuating force drives the deflection part to rotate around the arc-shaped guide part and generate relative angular displacement; the adjusting assembly drives the deflection base to deflect to a preset angle and is fixed to the bearing piece. By the adoption of the scheme, the belt wheel shaft is in the preset correction state all the time in actual operation, then uneven radial loads caused by superposition of multi-stage tensioning force can be eliminated, and the accumulative effect of the offset of the belt wheel shaft is restrained from the source.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor wafer conveying equipment, and in particular to a multi-stage power transmission system with tension compensation. Background Art

[0002] In the semiconductor manufacturing process, the precise transfer of wafers is of great significance to ensure the stability and yield of each process. In order to meet the dual requirements of transmission accuracy and efficiency, wafer transfer robots are widely used in packaging, lithography, etching and other process links as key equipment. It uses multi-degree-of-freedom robotic arms to achieve automatic and high-precision transfer of wafers between different chambers or workstations.

[0003] As the structure of semiconductor devices develops towards higher density and finer line width, higher requirements are placed on the dynamic performance of the wafer transfer system. The wafer transfer robot needs to operate in an environment with an extremely high cleanliness level. The system must have strong dynamic response capabilities and anti-disturbance performance to adapt to the complex and changeable work rhythm and collaborative control requirements. This has prompted the transmission system of the robot to gradually evolve towards a multi-level, multi-joint, and multi-actuator structure, thereby achieving more sophisticated motion control and positioning accuracy. However, in order to achieve independent drive of multiple robotic arms and end effectors, the transmission system often needs to introduce a multi-level transmission structure consisting of multiple synchronous belts and pulleys. In actual working conditions, the increase in the transmission level will cause the tension of each level of the synchronous belt to be superimposed step by step, thereby subjecting some pulley bearings to greater radial loads. This load may cause a slight angular offset of the pulley shaft and accumulate during the multi-level transmission process, ultimately affecting the transmission accuracy of the end of the robot, becoming one of the potential hidden dangers that need to be urgently addressed in high-precision wafer handling systems.

[0004] Therefore, it is necessary to provide a multi-stage power transmission system with tension compensation to solve the above-mentioned problems existing in the prior art. Summary of the invention

[0005] The object of the present invention is to provide a multi-stage power transmission system with tension compensation, so as to compensate for the axle angle deviation caused by the multi-stage synchronous belt in the power transmission system and increase the transmission accuracy of the robot end.

[0006] To achieve the above object, the technical solution of the present invention is as follows: A multi-stage power transmission system with tension compensation, comprising a mounting base, a first wheel set coaxially arranged with the center of the shoulder joint of the mounting base, a second wheel set coaxially arranged with the center of the elbow joint of the mounting base, and a multi-stage synchronous belt connecting the first wheel set and the second wheel set, comprising: A supporting member, fixedly connected to the mounting base, wherein an arc-shaped guide portion is provided on a bearing surface of the supporting member; A deflection seat, fixedly connected to the axial bearing end of the first wheel set and / or the second wheel set, wherein the deflection seat has a deflection portion, and the deflection portion can rotate along the extension direction of the arc-shaped guide portion; An adjusting assembly, used for applying an actuating force between the deflection seat and the supporting member, wherein the actuating force drives the deflection portion to rotate around the arc-shaped guide portion and cause relative angular displacement; Among them, the adjustment component drives the deflection seat to deflect to a preset angle and is fixed to the supporting member. The adjustment component can generate a compensation torque on the first wheel group and / or the second wheel group that is opposite to the direction of the multi-stage synchronous belt tension accumulation and has the same magnitude as that to offset the radial load offset of the pulley shaft.

[0007] The beneficial effect of a multi-stage power transmission system with tension compensation provided by the present invention is that by arranging an active angle compensation device composed of an arc-shaped guide, an adjustable deflection seat and an adjustment component at the axial load-bearing end of the first wheel group and / or the second wheel group, accurate correction of the slight deviation of the wheel shaft caused by the tension gradient of the multi-stage synchronous belt is achieved. By locking the adjustment component, the pulley shaft is always in a preset correction state in actual operation, thereby eliminating the uneven radial load caused by the superposition of multi-stage tension forces, and suppressing the cumulative effect of the pulley shaft deviation from the source.

[0008] Preferably, the arc-shaped guide portion is provided with an arc-shaped guide groove, the horizontal extension direction of the arc-shaped guide groove is parallel to the main tension direction of the multi-level synchronous belt, and the deflection seat includes an integrally formed deflection body and an arc-shaped guide block, and the arc-shaped guide block slides along the curved surface of the arc-shaped guide groove.

[0009] By adopting the above technical solution, an arc-shaped guide groove parallel to the main force direction of the synchronous belt is opened on the supporting part, and the deflection body is tightly matched with the integrally formed arc-shaped guide block, so that the deflection bearing seat only slides along a predetermined trajectory, thereby ensuring the positioning accuracy of the compensation mechanism during the angle adjustment process and effectively eliminating the swing error of the traditional guide part caused by assembly tolerance or wear.

[0010] Preferably, at least two adjusting screw holes are provided on the supporting member, and the at least two adjusting screw holes are spaced apart along the horizontal extension direction of the arc-shaped guide groove. The adjusting assembly includes an adjusting top screw, and after the adjusting top screw is screwed into the adjusting screw hole, the end of the adjusting top screw abuts against the deflection seat.

[0011] By adopting the above technical solution and using the adjusting top screw for angle compensation, the deflection angle of the pulley shaft can be accurately achieved by adjusting the screw-in depth of the top screw, and rigid contact can be formed after the adjusting top screw is locked, ensuring that the compensation angle is stable for a long time without rebound.

[0012] Preferably, a plurality of kidney-shaped holes are formed in the supporting member, locking screw holes corresponding to and communicating with the kidney-shaped holes are formed in the deflection main body, the adjusting assembly further includes a pre-tightening positioning bolt, and the pre-tightening positioning bolt passes through the kidney-shaped hole and is screwed into the locking screw hole of the deflection main body.

[0013] By adopting the above technical solution, the kidney-shaped hole is matched with the pre-tightening positioning bolt. During installation, the pre-tightening positioning bolt can be first screwed into the kidney-shaped hole and locked into the locking screw hole of the deflection main body; the pre-tightening positioning bolt cooperates with the kidney-shaped hole and the locking screw hole to accurately constrain the supporting member at a predetermined horizontal position during the installation stage, realizing the positioning in the horizontal direction; secondly, when the pre-tightening positioning bolt is screwed into the locking screw hole, the supporting member is combined with the deflection main body to realize preliminary locking.

[0014] Preferably, the kidney-shaped holes are symmetrically and spaced apart on both sides of the arc-shaped guide groove, and the adjusting screw hole is located between adjacent kidney-shaped holes.

[0015] By adopting the above technical solution, the kidney-shaped holes are symmetrically arranged on both sides of the arc-shaped guide groove, and the adjusting screw hole is arranged between adjacent kidney-shaped holes, which can achieve more balanced horizontal pre-positioning and mechanical support in the overall structure: the symmetrical distribution of the kidney-shaped holes ensures that the supporting member is evenly stressed during installation, is not prone to tilt, and improves the stability during the pre-locking stage; and placing the adjusting screw hole between adjacent kidney-shaped holes makes the acting point of the adjusting jackscrew centered, shortens the lever arm length of the deflection seat, and further improves the sensitivity and positioning accuracy of the angle fine adjustment.

[0016] Preferably, the deflection main body includes an integrally formed upper column body and a lower column body, and an annular boss is formed between the upper column body and the lower column body.

[0017] Preferably, both the first pulley group and the second pulley group include at least three pulley groups axially distributed, and adjacent pulley groups are axially staggered respectively.

[0018] By adopting the above technical solution, by arranging at least three pulleys in the first pulley group and the second pulley group in multiple axial staggered arrangements, not only the axial cross-sectional thickness of the robotic arm is significantly reduced on the premise of ensuring the balanced distribution of multi-stage transmission levels and tension, but also a more compact overall layout is achieved, meeting the space utilization efficiency required for semiconductor manufacturing.

[0019] Preferably, the first pulley group includes a first pulley group, a second pulley group and a third pulley group, and the second pulley group includes a fourth pulley, a fifth pulley and a sixth pulley; the first pulley group and the fourth pulley are connected by a synchronous belt; the second pulley group and the fifth pulley are connected by a synchronous belt; the third pulley group and the sixth pulley are connected by a synchronous belt.

[0020] Preferably, the first pulley set includes a first pulley and a first link plate. The first pulley is hollow inside, and the first pulley is provided with a first clamping groove. The first link plate is provided with a second clamping groove. The first clamping groove and the second clamping groove form a clamping space for clamping a bearing. The bottom of the first link plate is provided with a first space for accommodating a second pulley set.

[0021] Preferably, the second pulley set includes a second pulley and a second link plate. The second pulley is hollow inside, and the second link plate is provided with a first support portion which extends into the first space. The second pulley is provided with a third clamping groove, and the second link plate is provided with a fourth clamping groove. The third clamping groove and the fourth clamping groove form a clamping space for clamping a bearing. The bottom of the second link plate is provided with a second space for accommodating a third pulley set.

[0022] Preferably, the third pulley set includes a third pulley, and the top of the third pulley has a second support portion which is arranged in the second space. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a top view of a multi-stage power transmission system with tension compensation according to the present invention; Figure 2 is a cross-sectional view of a multi-stage power transmission system with tension compensation according to the present invention; Figure 3 is a schematic structural view of a deflection seat and a support member according to an embodiment of the present invention; Figure 4 is a schematic structural view of a deflection seat according to an embodiment of the present invention; Figure 5 is a schematic structural view of a support member according to an embodiment of the present invention; Figure 6 is a cross-sectional view of a deflection seat and a support member according to an embodiment of the present invention; Figure 7 is a cross-sectional view of a first pulley set and a second pulley set according to an embodiment of the present invention; Figure 8 is a top view of a first pulley set according to an embodiment of the present invention; Figure 9 is a cross-sectional view of a first pulley set according to an embodiment of the present invention; Figure 10 is a cross-sectional view of a first pulley set according to an embodiment of the present invention; Figure 11 is a cross-sectional view of a second pulley set according to an embodiment of the present invention; Figure 12 is a cross-sectional view of a third pulley set according to an embodiment of the present invention.

[0024] Reference numerals: 1, mounting base; 2, first pulley set; 21, first pulley; 211, first card slot; 22, first link plate; 221, second card slot; 222, first space; 23, second pulley; 231, third card slot; 24, second link plate; 241, fourth card slot; 242, second space; 243, first support portion; 25, third pulley; 251, second support portion; 26, bearing; 261, gland; 3, second pulley set; 31, fourth pulley; 32, fifth pulley; 33, sixth pulley; 4, support member; 41, arc-shaped guide groove; 42, adjustment screw hole; 43, kidney-shaped hole; 5, deflection seat; 51, arc-shaped guide block; 52, upper column; 53, lower column; 531, locking screw hole; 54, annular boss; 6, first power shaft; 7, second power shaft; 8, third power shaft. Detailed implementation manners

[0025] For the purposes, technical solutions and advantages of the embodiments of the present invention to be more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings understood by those of ordinary skill in the art in the field to which the present invention belongs. The words such as "including" used herein mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0026] The following combines the attached Figure 1 -attached Figure 12 , and further elaborates on the specific implementation manners of the present invention in detail.

[0027] Referring to Figures 1 - 3 , in an embodiment of the present invention, a multi-stage power transmission system with tension compensation includes a mounting base 1, a first pulley set 2 and a second pulley set 3 disposed on the mounting base 1 and connected by a multi-level synchronous belt drive, as well as a support member 4, a deflection seat 5 and an adjustment assembly.

[0028] Referring to Figure 2 and Figure 3, in some embodiments of the present invention, the mounting base 1 is a frame body with an accommodation space inside, and the first pulley group 2 and the second pulley group 3 are installed in the accommodation space. The first pulley group 2 and the second pulley group 3 are a shoulder joint pulley group and an elbow joint pulley group or any other adjacent joint pulley groups. Taking the shoulder joint pulley group and the elbow joint pulley group as an example, the shoulder pulley and the elbow pulley are driven by a double relative belt drive, and there are at least three transmission levels between the shoulder joint pulley group and the elbow joint pulley group. One of the transmission levels is used to drive the forearm of the manipulator to rotate independently, and at least two other transmission levels drive at least two end effectors to rotate relatively independently.

[0029] Refer to Figure 2 , in some embodiments of the present invention, the supporting member 4 is fixedly connected to the mounting base 1, and an arc-shaped guiding portion is provided on the top bearing surface of the supporting member 4. The deflection seat 5 is fixedly connected to the axial bearing end of the first pulley group 2 or the second pulley group 3; in some other embodiments, deflection seats 5 are provided at the axial bearing ends of both the first pulley group 2 and the second pulley group 3. The bottom of the deflection seat 5 has a deflection portion, and the deflection portion can rotate along the extending direction of the arc of the arc-shaped guiding portion of the supporting member 4.

[0030] Refer to Figures 4 - 6 , in some specific embodiments of the present invention, an arc-shaped guiding groove 41 is formed at the arc-shaped guiding portion, and the horizontal extending direction of the arc-shaped guiding groove 41 is parallel to the main tension direction of the multi-level synchronous belt, thereby ensuring that the main tension generated when the multi-level synchronous belt works is parallel to the adjustment direction of the pulley shaft formed by the arc-shaped guiding groove 41. The deflection seat 5 includes an integrally formed deflection main body and an arc-shaped guiding block 51, and the arc-shaped guiding portion is located on the arc-shaped guiding block. The arc-shaped guiding block 51 is slidably fitted along the curved surface of the arc-shaped guiding groove 41. By forming an arc-shaped guiding groove 41 parallel to the main tension direction of the synchronous belt on the supporting member 4 and tightly fitting the deflection main body with the integrally formed arc-shaped guiding block 51, the deflection bearing seat can only slide along a predetermined track, ensuring the positioning accuracy of the compensation mechanism during the angle adjustment process and effectively eliminating the swing error caused by assembly tolerance or wear of traditional guiding members; in addition, the integrally formed deflection main body and arc-shaped guiding block 51 simplify the number of parts and the assembly process, improving the overall rigidity and cleanliness of the power transmission system.

[0031] Refer to Figure 4 , in some specific embodiments of the present invention, the deflection main body includes an integrally formed upper cylinder 52 and a lower cylinder 53, and an annular boss 54 is formed between the upper cylinder 52 and the lower cylinder 53. The annular stepped groove formed by the annular boss 54 is used to carry the axial bearing end of the first pulley group 2 or the second pulley group 3.

[0032] Refer to Figures 3 - 5, in some embodiments of the present invention, the adjusting assembly is used to apply a driving force between the deflection seat 5 and the supporting member 4, and the driving force drives the deflection part to rotate around the arc-shaped guiding part and generate a relative angular displacement; the adjusting assembly is used to deflect the deflection seat 5 to a preset angle and fix it to the supporting member 4, and the adjusting assembly can generate a compensation torque on the first pulley set 2 and / or the second pulley set 3 that is opposite to the cumulative direction of the multi-stage synchronous belt tension and has the same magnitude. The arc-shaped guiding part, the adjustable deflection seat 5 and the adjusting assembly together constitute a tension compensation device for the pulley shaft, realizing precise correction of the small offset of the pulley shaft caused by the tension gradient of the multi-stage synchronous belt. During the assembly or maintenance stage, the deflection seat 5 can be preset to a preset compensation angle according to the tension accumulation of each transmission level and locked by the adjusting assembly, so that the pulley shaft is always in the preset correction state during actual operation, thereby eliminating the uneven radial load caused by the superposition of multi-stage tension forces, suppressing the cumulative effect of the offset amount of the pulley shaft from the source, and ensuring the smooth movement of the end effector along the predetermined trajectory; and compared with the traditional passive bearing or adding spring and damping elements, the present invention does not require additional sensor control or real-time monitoring, has a simple structure and is convenient for maintenance, and is more suitable for high-cleanliness semiconductor production environments.

[0033] Referring to Figures 3 - 5 , in some specific embodiments of the present invention, at least two adjusting screw holes 42 are provided on the supporting member 4, and the at least two adjusting screw holes 42 are spaced apart along the horizontal extension direction of the arc-shaped guiding groove 41. The adjusting assembly includes a plurality of adjusting set screws. After the adjusting set screws are screwed into the adjusting screw holes 42, the ends of the adjusting set screws abut against the deflection seat 5. Angle compensation is performed by using the adjusting set screws. The deflection angle of the pulley shaft can be accurately adjusted by adjusting the screwing depth of the adjusting set screws, and a rigid contact can be formed after the adjusting set screws are locked to ensure that the compensation angle is stable and does not rebound for a long time. In addition, a plurality of adjusting set screws are arranged at both ends of the arc-shaped guiding groove 41, and differential fine adjustment can be performed on the angle deviation to effectively eliminate the assembly error and further improve the end positioning accuracy of the power transmission system.

[0034] Referring to Figures 3 - 5, in some specific embodiments of the present invention, a plurality of waist-shaped holes 43 are formed in the supporting member 4, and locking screw holes 531 corresponding to and communicating with the waist-shaped holes 43 are formed in the lower cylinder 53 of the deflection body. The adjusting assembly further includes a pre-tightening positioning bolt, and the pre-tightening positioning bolt passes through the waist-shaped hole 43 and is screwed into the locking screw hole 531 of the deflection body. By using the waist-shaped hole 43 in cooperation with the pre-tightening positioning bolt, during installation, the pre-tightening positioning bolt can be first screwed into the waist-shaped hole 43 and locked into the locking screw hole 531 of the deflection body; the pre-tightening positioning bolt cooperates with the waist-shaped hole 43 and the locking screw hole 531. First, by fixing the number of turns of the pre-tightening positioning bolt screwed into the locking screw hole 531, the supporting member 4 can be accurately constrained to a predetermined horizontal position during the installation stage, thereby realizing the positioning of the supporting member 4 in the horizontal direction, which is convenient for subsequent adjustment of the set screw for fine angle adjustment; secondly, when the pre-tightening positioning bolt is screwed into the locking screw hole 531, the supporting member 4 and the deflection body are combined to achieve preliminary locking; wherein the pre-tightening positioning bolt is not fully locked in the initial state, and the micro-sliding space in the horizontal direction provided by the waist-shaped hole is used to establish a stable reference support for the subsequent fine adjustment of the set screw, avoiding positioning drift caused by component movement during the fine angle compensation process. Among them, the axial angle adjustment range of the adjusting assembly for the first wheel set 2 or the second wheel set 3 is between 0.05° and 0.15°.

[0035] Refer to Figures 3 - 5 , in some specific embodiments of the present invention, there are six waist-shaped holes 43, which are symmetrically and spaced apart on both sides of the arc-shaped guide groove 41, and three are distributed on each side of the arc-shaped guide groove 41. There are four adjusting screw holes 42, and they are all located between adjacent waist-shaped holes 43. By symmetrically arranging the waist-shaped holes 43 on both sides of the arc-shaped guide groove 41 and arranging the adjusting screw holes 42 between adjacent waist-shaped holes 43, more balanced horizontal pre-positioning and mechanical support can be achieved in the overall structure: the symmetrical distribution of the waist-shaped holes 43 ensures that the supporting member 4 is evenly stressed during installation, is not prone to tilting, and improves the stability during the pre-locking stage; and placing the adjusting screw holes 42 between adjacent waist-shaped holes 43 makes the acting point of the adjusting set screw centered, shortens the lever arm length of the deflection seat 5, and further improves the sensitivity and positioning accuracy of the angle fine adjustment.

[0036] Specific angle adjustment process: First, the pre-tightening positioning bolt is passed through the waist-shaped hole 43 on the support member 4 and screwed into the locking screw hole 531 corresponding to the deflection body to achieve horizontal pre-positioning of the deflection seat 5; then, the adjusting top screw is screwed into the adjusting screw hole 42 located on the deflection body, and its end extends out and abuts against the bottom surface of the deflection body. The further screwing in of the top screw end generates a torque opposite to the tensioning force of the synchronous belt, driving the deflection body to rotate clockwise around the arc-shaped guide portion to a preset compensation angle of between 0.05° and 0.15°; finally, the pre-tightening positioning bolt and the locking screw hole 531 are locked again to fix the deflection seat 5 at the adjusted angle position. This process not only ensures the initial horizontal positioning, but also realizes fine angle compensation by adjusting the top screw, and finally ensures the long-term stability of the compensation state by locking the pre-tightening bolt.

[0037] Reference Figure 7 and Figure 8 In some specific embodiments of the present invention, the first wheel set 2 and the second wheel set 3 each include at least three axially distributed pulley sets, and the adjacent pulley sets are axially staggered. By arranging at least three pulleys in the first wheel set 2 and the second wheel set 3 in a multiple staggered manner along the axial direction, not only the axial cross-sectional thickness of the robot arm is significantly reduced under the premise of ensuring the multi-stage transmission level and balanced distribution of the tension force, but also a more compact overall layout is achieved to meet the space utilization efficiency required for semiconductor manufacturing. The first wheel set 2 and the second wheel set 3 are located at the same transmission height, and the power is transmitted through a synchronous belt.

[0038] Reference Figure 9 and Figure 10 In some specific embodiments of the present invention, the first wheel group 2 includes a first pulley group 21, a second pulley group and a third pulley group, and the second wheel group 3 includes a fourth pulley 31, a fifth pulley 32 and a sixth pulley 33; the first pulley group 21 and the fourth pulley 31 are connected by a synchronous belt transmission; the second pulley group and the fifth pulley 32 are connected by a synchronous belt transmission; the third pulley group and the sixth pulley 33 are connected by a synchronous belt transmission. Three transmission levels are formed between the first wheel group 2 and the second wheel group 3, the first transmission level is composed of the first pulley 21, the synchronous belt and the fourth pulley 31; the second transmission level is composed of the second pulley 23, the synchronous belt and the fifth pulley 32; the third transmission level is composed of the third pulley 25, the synchronous belt and the sixth pulley 33. Multiple transmission levels will produce multiple tensioning forces when transmitting power. The multiple tensioning forces are accumulated step by step, resulting in an increase in the radial load on the pulley bearing 26 of the first wheel group 2 or the second wheel group 3, which in turn causes a slight angular deviation of the pulley shaft; after multiple levels of amplification, it affects the terminal transmission positioning accuracy.

[0039] In some specific embodiments of the present invention, the first pulley set includes a first pulley 21 and a first link plate 22, and the interior of the first pulley 21 is hollow. Taking the longitudinal section of the first pulley set as the direction reference, an annular first clamping groove 211 is provided in the upper right part of the inner ring surface of the first pulley 21, and an annular second clamping groove 221 is provided in the lower left part of the first link plate 22. The first clamping groove 211 and the second clamping groove 221 form a clamping space for clamping the bearing 26 to press and fix the outer ring of the bearing 26. A first space 222 for accommodating the second pulley set is provided at the bottom of the first link plate 22. Among them, a bearing 26 is provided between the first pulley set and the second pulley set; a bearing 26 is provided between the second pulley set and the third pulley set; a bearing 26 is provided at the bottom of the third pulley set.

[0040] Referring to Figure 11 , in some specific embodiments of the present invention, the second pulley set includes a second pulley 23 and a second link plate 24, and the interior of the second pulley 23 is hollow. Taking the longitudinal section of the second pulley set as the direction reference, the second link plate 24 is provided with a first support portion 243, and the first support portion 243 extends into the first space 222; an annular third clamping groove 231 is provided in the upper right part of the inner ring of the second pulley 23, and an annular fourth clamping groove 241 is provided in the lower left part of the second link plate 24. The third clamping groove 231 and the fourth clamping groove 241 form a clamping space for clamping the bearing 26 to press and fix the outer ring of the bearing 26. A second space 242 for accommodating the third pulley set is provided at the bottom of the second link plate 24. Among them, a bearing 26 is provided between the fourth pulley 31 and the fifth pulley 32; a bearing 26 is provided between the fifth pulley 32 and the sixth pulley 33; a bearing 26 is provided at the bottom of the sixth pulley 33. In some specific embodiments of the present invention, a gland 261 is provided on the bearing 26 to ensure the stable operation of the bearing 26.

[0041] Referring to Figure 12 , in some specific embodiments of the present invention, the third pulley set includes a third pulley 25, and the top of the third pulley 25 has a second support portion 251, and the second support portion 251 is arranged in the second space 242. In some other embodiments of the present invention, a first power shaft 6 is provided at the bottom of the first link plate 22, a second power shaft 7 is provided at the bottom of the second link plate 24, and a third power shaft 8 is provided at the bottom of the third pulley 25. The power shafts are used to drive the first pulley 21, the second pulley 23 and the third pulley 25 to rotate. In some specific embodiments of the present invention, receiving cavities are provided at both the upper and lower ends of the inner ring of the first link plate 22, and a through hole is provided in the middle. The receiving cavities and the through hole are used to accommodate the first power shaft 6; a receiving cavity is provided at the bottom of the inner ring of the second link plate 24 for accommodating the second power shaft 7; a receiving cavity is provided at the bottom of the third pulley 25 for accommodating the third power shaft 8.

[0042] By arranging the first pulley set 21, the second pulley set and the third pulley set axially staggered and matching them with the corresponding link plates and power shafts, not only a compact integration of the three-stage synchronous belt drive levels is achieved within a limited installation height, but also a clamping space is formed by the hollow pulley and the card slots on the link plate to firmly press the bearing 26 within the pulley set, ensuring the support of axial and radial loads; in addition, the power shafts established at the bottoms of the first link plate 22, the second link plate 24 and the third pulley 25 directly drive the corresponding pulleys, reducing the transmission losses in the power transmission path.

[0043] Although the embodiments of the present invention have been described in detail above, it is obvious to those skilled in the art that various modifications and changes can be made to these embodiments. However, it should be understood that such modifications and changes are all within the scope and spirit of the present invention. Moreover, the present invention described herein can have other embodiments and can be implemented or realized in various ways.

Claims

1. A multi-stage power transmission system with tension compensation, comprising a mounting base (1), a first wheel set (2) coaxially arranged with the shoulder joint center of the mounting base (1), a second wheel set (3) coaxially arranged with the elbow joint center of the mounting base (1), and a multi-level synchronous belt connecting the first wheel set (2) and the second wheel set (3), characterized in that, Comprising: A supporting member (4) fixedly connected to the mounting base (1), and an arc-shaped guiding portion is provided on the bearing surface of the supporting member (4); A deflection seat (5) fixedly connected to the axial bearing end of the first pulley group (2) and / or the second pulley group (3), the deflection seat (5) has a deflection portion, and the deflection portion can rotate along the extending direction of the arc-shaped guiding portion; An adjusting assembly for applying an actuating force between the deflection seat (5) and the supporting member (4) to drive the deflection portion to rotate around the arc-shaped guiding portion and generate a relative angular displacement; Wherein, by driving the deflection seat (5) to deflect to a preset angle and fixing it to the supporting member (4), the adjusting assembly can generate a compensation torque on the first pulley group (2) and / or the second pulley group (3) that is opposite to the cumulative direction of the multi-stage synchronous belt tension and has the same magnitude, so as to offset the radial load offset of the pulley shaft.

2. The multi-stage power transmission system with tension compensation according to claim 1, wherein, The arc-shaped guiding portion is provided with an arc-shaped guiding groove (41), the horizontal extending direction of the arc-shaped guiding groove (41) is parallel to the main tension direction of the multi-layer synchronous belt, the deflection seat (5) includes an integrally formed deflection main body and an arc-shaped guiding block (51), and the arc-shaped guiding block (51) is slidably fitted along the curved surface of the arc-shaped guiding groove (41).

3. A multi-stage power transmission system with tension compensation according to claim 2, characterized in that, At least two adjusting screw holes (42) are provided on the supporting member (4), and at least two adjusting screw holes (42) are spaced apart along the horizontal extending direction of the arc-shaped guiding groove (41). The adjusting assembly includes an adjusting setscrew. After the adjusting setscrew is screwed into the adjusting screw hole (42), the end of the adjusting setscrew abuts against the deflection seat (5).

4. A multi-stage power transmission system with tension compensation according to claim 3, characterized in that, A plurality of waist-shaped holes (43) are provided on the supporting member (4), and locking screw holes (531) corresponding to and communicating with the waist-shaped holes (43) are provided on the deflection main body. The adjusting assembly further includes a pre-tightening positioning bolt, and the pre-tightening positioning bolt passes through the waist-shaped hole (43) and is screwed into the locking screw hole (531) of the deflection main body.

5. A multi-stage power transmission system with tension compensation according to claim 4, characterized in that The waist-shaped holes (43) are symmetrically and spaced apart on both sides of the arc-shaped guiding groove (41), and the adjusting screw holes (42) are located between adjacent waist-shaped holes (43).

6. A multi-stage power transmission system with tension compensation according to claim 2, characterized in that, The deflection main body includes an integrally formed upper cylinder (52) and a lower cylinder (53), and an annular boss (54) is formed between the upper cylinder (52) and the lower cylinder (53).

7. A multi-stage power transmission system with tension compensation according to claim 1, characterized in that, Both the first pulley group (2) and the second pulley group (3) include at least three pulley groups axially distributed, and adjacent pulley groups are axially staggered respectively.

8. A multi-stage power transmission system with tension compensation according to claim 7, characterized in that, The first pulley group (2) includes a first pulley group, a second pulley group and a third pulley group, and the second pulley group (3) includes a fourth pulley (31), a fifth pulley (32) and a sixth pulley (33); the first pulley group and the fourth pulley (31) are connected by a synchronous belt; the second pulley group and the fifth pulley (32) are connected by a synchronous belt; the third pulley group and the sixth pulley (33) are connected by a synchronous belt.

9. A multi-stage power transmission system with tension compensation according to claim 8, characterized in that, The first pulley set includes a first pulley (21) and a first connecting disk (22). The first pulley (21) has a hollow interior. The first pulley (21) is provided with a first clamping groove (211). The first connecting disk (22) is provided with a second clamping groove (221). The first clamping groove (211) and the second clamping groove (221) form a clamping space for clamping a bearing (26). The bottom of the first connecting disk (22) is provided with a first space (222) for accommodating a second pulley set.

10. A multi-stage power transmission system with tension compensation according to claim 9, characterized in that, The second pulley set includes a second pulley (23) and a second connecting disk (24). The second pulley (23) has a hollow interior. The second connecting disk (24) is provided with a first supporting portion (243). The first supporting portion (243) extends into the first space (222). The second pulley (23) is provided with a third clamping groove (231). The second connecting disk (24) is provided with a fourth clamping groove (241). The third clamping groove (231) and the fourth clamping groove (241) form a clamping space for clamping a bearing (26). The bottom of the second connecting disk (24) is provided with a second space (242) for accommodating a third pulley set.

11. A multi-stage power transmission system with tension compensation according to claim 10, characterized in that, The third pulley set includes a third pulley (25). The top of the third pulley (25) has a second supporting portion (251). The second supporting portion (251) is arranged in the second space (242).

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