Large hollow shaft cycloid joint module

Abstract

The invention discloses a large hollow shaft cycloid joint module which comprises a shell internally provided with a mounting space. The eccentric crankshaft is arranged in the mounting space of the shell in a penetrating manner and is provided with an eccentric structure; the output end cover is arranged on the outer side of the eccentric crankshaft in a sleeving mode, and a first needle bearing is arranged between the eccentric crankshaft and the output end cover. The first cycloid gear assembly comprises a first cycloid gear and a first inner gear, the first cycloid gear is arranged on the outer side of the eccentric crankshaft in a sleeving mode through a second needle bearing, and the first inner gear is formed on the inner side face of the output end cover; the second cycloid gear assembly comprises a second cycloid gear and a second inner gear, the second cycloid gear is fixedly arranged at the bottom of the outer side of the first cycloid gear in a sleeving mode, and the second inner gear is formed on the inner wall of the shell; the eccentric balance weight wheel is fixedly arranged on the outer side of the eccentric crankshaft in a sleeving mode. The hollow shaft is fixedly arranged in the eccentric crankshaft in a penetrating mode, and a cable channel is formed in the hollow shaft. Through layout optimization of the cycloid gear and the bearing, the problems of poor rigidity and low precision in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of robots, and particularly to a large hollow shaft cycloidal joint module. Background Art

[0002] Currently, robots need to achieve two key technical requirements in the joint module: a large hollow shaft and high rigidity. The large hollow shaft is used to accommodate various cables to meet the complex wiring requirements of the robot, such as power, signal, and data lines, etc., while the high rigidity is to meet the robot's requirement for control accuracy.

[0003] There are two mainstream solutions for the existing robot joint modules: the first is the harmonic joint module, and the other is the cycloidal joint module. The existing harmonic drive module has the advantage of a large hollow shaft and can meet the complex wiring requirements, but its structural limitations result in low rigidity and cannot meet the requirements of high-precision control. The existing cycloidal reducer has high rigidity and precision due to the design of its cycloidal gears, but due to its design characteristics, it cannot be adapted to a large hollow shaft and thus cannot adapt to application scenarios that require a large amount of wiring. Therefore, the existing robot joint modules have the problem of functional singularity. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a large hollow shaft cycloidal joint module, which realizes the design of a large hollow shaft and improves the rigidity through structural optimization, so as to balance the wiring flexibility and the motion control accuracy, and can solve the problem of single function in the past.

[0005] To solve the above technical problems, the present invention discloses a large hollow shaft cycloidal joint module, which includes a housing with an installation space formed inside; an eccentric crankshaft that passes through the installation space of the housing, and the eccentric crankshaft is provided with an eccentric structure for transmitting power and driving the cycloidal gear to move; an output end cover that is sleeved outside the eccentric crankshaft, and a first needle roller bearing is provided between the eccentric crankshaft and the output end cover so that the output end cover can rotate around the eccentric crankshaft, and an angular contact ball bearing is provided between the output end cover and the housing; a first cycloidal gear assembly, including a first cycloidal gear and a first internal gear, the first cycloidal gear is sleeved outside the eccentric crankshaft through a second needle roller bearing so that the first cycloidal gear can rotate self and revolve around the axis, the first internal gear is formed on the inner side surface of the output end cover, and the first internal gear meshes with the outer bottom of the first cycloidal gear so that the first internal gear drives the output end cover to rotate; a second cycloidal gear assembly, including a second cycloidal gear and a second internal gear, the second cycloidal gear is fixedly sleeved on the outer bottom of the first cycloidal gear so that when the first cycloidal gear rotates self and revolves around the axis, it drives the second cycloidal gear to rotate self and revolve around the axis, the second internal gear is formed on the inner wall of the housing to limit the movement track of the second cycloidal gear; an eccentric counterweight wheel that is fixedly sleeved outside the eccentric crankshaft for compensating the inertial torque generated by the eccentric structure and the movement of the cycloidal gear; a hollow shaft that is fixedly passed through the inside of the eccentric crankshaft, and a cable channel is formed inside the hollow shaft for accommodating power lines, signal lines and data lines.

[0006] Wherein, a bearing seat is fixedly installed at the middle position inside the housing, and a third needle roller bearing sleeved outside the eccentric crankshaft is provided between the bearing seat and the eccentric crankshaft so that the eccentric crankshaft can rotate relative to the housing.

[0007] Wherein, a rotor assembly is fixedly installed at the bottom of the eccentric crankshaft, and the rotor assembly is located inside the housing.

[0008] Wherein, an output flange is fixedly installed at the top of the output end cover, and a through hole communicating with the hollow shaft is opened in the middle of the output flange.

[0009] Wherein, the housing includes a fixed flange, an upper housing, a lower housing and a motor bearing bracket fixedly connected in sequence from top to bottom, and the bearing seat is clamped between the upper housing and the lower housing.

[0010] Wherein, a clamping portion extends radially along the bottom of the first cycloidal gear, and a plurality of circumferentially continuously arranged teeth are formed on the outer peripheral side surface of the clamping portion, and a plurality of circumferentially continuously arranged slots are formed on the inner side wall of the second cycloidal gear. In the assembled state, the teeth are inserted into the slots.

[0011] Wherein, the eccentric structure is an eccentric wheel sleeved on the eccentric crankshaft or an eccentric shaft section formed on the eccentric crankshaft.

[0012] Among them, the tooth profile of the first cycloidal gear, the tooth profile of the first internal gear, the tooth profile of the second cycloidal gear, and the tooth profile of the second internal gear are cycloidal teeth or involute teeth.

[0013] Among them, an isolation protection layer is provided on the inner wall of the cable channel.

[0014] Among them, the eccentric counterweight wheel is provided with a mounting hole for the eccentric crankshaft to pass through. A clamping convex is extended radially inward along the hole wall of the mounting hole, and a limiting groove for the clamping convex to insert is provided on the outer peripheral side of the eccentric crankshaft.

[0015] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0016] (1) Through the layout optimization of the cycloidal gear and the bearing, the rigidity of the module is significantly improved, supporting high-precision control, and solving the problems of poor rigidity and low precision in the past;

[0017] (2) The volume of the hollow shaft increases by more than 30%, meeting the requirements of complex cable routing, and solving the problem of cable routing obstruction in the past;

[0018] (3) The eccentric counterweight effectively compensates for the inertia imbalance, reduces vibration, and extends the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 It is a schematic structural diagram of the joint module in the present invention;

[0021] Figure 2 It is an exploded view of the joint module in the present invention;

[0022] Figure 3 It is an exploded view of the housing in the present invention;

[0023] Figure 4 It is a cross-sectional view of the joint module in the present invention;

[0024] Figure 5 It is a schematic structural diagram of the eccentric crankshaft in the present invention;

[0025] Figure 6 It is a schematic structural diagram of the output end cover in the present invention;

[0026] Figure 7 It is a schematic structural diagram of the assembled first cycloidal gear and second cycloidal gear in the present invention;

[0027] Figure 8 Structural schematic diagram of the eccentric counterweight wheel in the present invention. Specific embodiments

[0028] In order to enable those skilled in the art to better understand the solution of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0029] The terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, device, product or server that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or servers.

[0030] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments may be included in at least one embodiment of the present invention. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0031] The present invention discloses a specific embodiment of a large hollow shaft cycloid joint module, please refer to Figure 1 and Figure 2 , which includes a housing 1, an output flange 21, an output end cover 4, a first cycloid gear 61 assembly, a second cycloid gear 62 assembly, an eccentric crankshaft 3, a hollow shaft 9 and a rotor assembly 22. An installation space is formed inside the housing 1, and the output flange 21, the output end cover 4, the first cycloid gear 61 assembly, the second cycloid gear 62 assembly, the eccentric crankshaft 3, the hollow shaft 9 and the rotor assembly 22 are all installed in the installation space inside the housing 1.

[0032] Combined with Figure 3 , the housing 1 includes a fixed flange 11, an upper housing 12, a bearing seat 13, a lower housing 14 and a motor bearing bracket 15 fixedly connected in sequence from top to bottom, and the bearing seat 13 is clamped between the upper housing 12 and the lower housing 14. Optionally, the sequential fixed connection can be achieved by sequentially fixing with screws, which is convenient for disassembly, assembly and maintenance of the module.

[0033] Combined with Figure 4 and Figure 5 ,the eccentric crankshaft 3 is inserted into the installation space of the housing 1. The eccentric crankshaft 3 is provided with an eccentric structure 31, and the eccentric structure 31 is used to transmit power and drive the cycloidal gear to move. In this embodiment, the eccentric structure 31 is an eccentric shaft section formed on the eccentric crankshaft 3. In other embodiments, the eccentric structure 31 can also be an eccentric wheel sleeved on the eccentric crankshaft 3.

[0034] Combined with Figure 4 and Figure 6 ,the output end cover 4 is sleeved on the outside of the eccentric crankshaft 3. A first needle roller bearing 51 is provided between the eccentric crankshaft 3 and the output end cover 4, and an angular contact ball bearing 54 is provided between the output end cover 4 and the housing 1, so that the output end cover 4 can rotate around its own axis. The top of the output end cover 4 is fixedly installed with an output flange 21 for connecting with an external module. When the output end cover 4 rotates, it will drive the output flange 21 to rotate, realizing the output of power.

[0035] Combined with Figure 4 、 Figure 6 and Figure 7 ,the first cycloidal gear 61 assembly includes a first cycloidal gear 61 and a first internal gear 71. The first cycloidal gear 61 is sleeved on the outside of the eccentric crankshaft 3 through a second needle roller bearing 52. It can be understood that the outer side surface of the second needle roller bearing 52 is in close contact with the inner side surface of the first cycloidal gear 61, and the inner side surface of the second needle roller bearing 52 is in close contact with the outer side surface of one of the shaft ends of the eccentric crankshaft 3, so that the first cycloidal gear 61 can rotate self and revolve around the axis. The first internal gear 71 is formed on the inner side surface of the output end cover 4. It can be understood that the first internal gear ring is opened on the inner side surface of the output end cover 4, and the first internal gear 71 meshes with the outer bottom of the first cycloidal gear 61, so that the first internal gear 71 drives the output end cover 4 to rotate, realizing the output of power.

[0036] Combined with Figure 3 、 Figure 4 and Figure 7 ,the second cycloidal gear 62 assembly includes a second cycloidal gear 62 and a second internal gear 72. The second cycloidal gear 62 is fixedly sleeved on the outer bottom of the first cycloidal gear 61, so that when the first cycloidal gear 61 rotates self and revolves around the axis, it drives the second cycloidal gear 62 to rotate self and revolve around the axis. Please refer to Figure 3 ,the second internal gear 72 is formed on the inner wall of the housing 1. It can be understood that the inner wall of the housing 1 is provided with a second internal gear ring, and the second internal gear 72 meshes with the second cycloidal gear 62, which can limit the movement track of the second cycloidal gear 62.

[0037] In this embodiment, please refer to Figure 7, a clamping portion extends radially along the bottom of the first cycloid gear 61, and a plurality of circumferentially continuous clamping teeth 63 are formed on the outer peripheral side of the clamping portion. A plurality of circumferentially continuous clamping grooves 64 are formed on the inner side wall of the second cycloid gear 62. In the assembled state, the clamping teeth 63 are inserted into the clamping grooves 64, so that the first cycloid gear 61 and the second cycloid gear 62 are rigidly connected, effectively improving the stiffness.

[0038] Please refer to Figure 3 , the eccentric counterweight wheel 8 is fixedly sleeved on the outside of the eccentric crankshaft 3 and is used to compensate for the inertial moment generated by the movement of the eccentric structure 31 and the cycloid gear. The hollow shaft 9 is fixedly inserted inside the eccentric crankshaft 3, and a cable channel is formed inside the hollow shaft 9 for accommodating power lines, signal lines and data lines. In addition, a through hole communicating with the hollow shaft 9 is opened in the middle of the output flange 21. In order to improve the service life, an isolation protection layer is provided on the inner wall of the cable channel to prevent the cables from contacting the moving parts.

[0039] In this embodiment, please refer to Figure 4 , the bearing seat 13 is fixedly installed at the middle position inside the housing 1. A third needle roller bearing 53 sleeved on the outside of the eccentric crankshaft 3 is provided between the bearing seat 13 and the eccentric crankshaft 3, so that the eccentric crankshaft 3 can rotate relative to the housing 1. The rotor assembly 22 is fixedly installed at the bottom of the eccentric crankshaft 3, and the rotor assembly 22 is located inside the housing 1.

[0040] As a preferred solution, the tooth profile of the first cycloid gear 61, the tooth profile of the first internal gear 71, the tooth profile of the second cycloid gear 62, and the tooth profile of the second internal gear 72 are cycloid teeth or involute teeth. Please refer to Figure 8 , the eccentric counterweight wheel 8 is provided with a mounting hole 81 for the eccentric crankshaft 3 to pass through, and the aperture of the mounting hole 81 is larger than the outer diameter of the first cycloid gear 61. Combining Figure 5 and Figure 8 , a clamping protrusion 82 extends radially inwards along the hole wall of the mounting hole 81, and a limiting groove 32 for the clamping protrusion 82 to insert is opened on the outer peripheral side of the eccentric crankshaft 3. The cooperation of the clamping protrusion 82 and the limiting groove 32 can play an anti-mistake role, facilitate installation, and in addition, can also limit the offset of the eccentric counterweight wheel 8 relative to the eccentric crankshaft 3 to ensure the working accuracy.

[0041] The transmission process of the large hollow shaft cycloidal joint module in this embodiment is as follows: An external power source (such as a servo motor) drives the eccentric crankshaft 3 to rotate. The eccentric structure 31 provided on the eccentric crankshaft 3 drives the first cycloidal gear 61 and the second cycloidal gear 62 to revolve around the axis of the eccentric crankshaft 3. Due to the existence of the eccentric structure 31, the cycloidal gears generate self-rotation while revolving. Since the second internal gear 72 (second internal gear ring) is fixed on the housing 1 and meshes with the external teeth of the second cycloidal gear 62, restricting the movement trajectory of the second cycloidal gear 62, the first cycloidal gear 61 is installed on the eccentric crankshaft 3 through a needle bearing, and the first cycloidal gear 61 can freely rotate around the axis. The output end cover 4 is installed in the housing 1 through an angular contact bearing, and the first internal gear 71 (first internal gear ring) is provided on the inner side wall of the output end cover 4. The revolution and self-rotation of the first cycloidal gear 61 drive the output end cover 4 to rotate around the axis through tooth meshing. The rotation of the output end cover 4 is transmitted to the external robot joint to achieve power output. Due to the high reduction ratio characteristic of the cycloidal gear, the output speed is significantly reduced while the torque is greatly increased.

[0042] In the large hollow shaft cycloidal joint module of this embodiment, the hollow shaft 9 runs through the entire module, and the internal space accommodates power lines, signal lines, and data lines. During the transmission process, the cables bend freely with the movement of the joint, avoiding affecting the flexibility of the robot due to wiring restrictions. The eccentric balance block on the eccentric crankshaft 3 offsets the inertial torque generated by the movement of the eccentric structure 31 and the cycloidal gears through reverse mass balancing, reducing vibration and ensuring the smoothness and accuracy of the transmission. Through the layout optimization of the cycloidal gears and bearings, the rigidity of the module is significantly improved, supporting high-precision control and solving the problems of poor rigidity and low accuracy in the past.

[0043] Finally, it should be noted that: What is disclosed in the large hollow shaft cycloidal joint module disclosed in the embodiments of the present invention is only the preferred embodiments of the present invention, which are only used to illustrate the technical solutions of the present invention and are not intended to limit them; Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: They can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; And these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A large hollow shaft cycloidal joint module, characterized in that Comprising: A housing, within which an installation space is formed; An eccentric crankshaft, which is disposed within the installation space of the housing, and the eccentric crankshaft is provided with an eccentric structure; An output end cover, which is sleeved outside the eccentric crankshaft, a first needle roller bearing is provided between the eccentric crankshaft and the output end cover, and an angular contact ball bearing is provided between the output end cover and the housing; A first cycloid gear assembly, including a first cycloid gear and a first internal gear, the first cycloid gear is sleeved outside the eccentric crankshaft through a second needle roller bearing, the first internal gear is formed on the inner side surface of the output end cover, and the first internal gear meshes with the outer bottom of the first cycloid gear; A second cycloid gear assembly, including a second cycloid gear and a second internal gear, the second cycloid gear is fixedly sleeved on the outer bottom of the first cycloid gear, and the second internal gear is formed on the inner wall of the housing; An eccentric counterweight wheel, which is fixedly sleeved outside the eccentric crankshaft; A hollow shaft, which is fixedly disposed inside the eccentric crankshaft, and a cable channel is formed inside the hollow shaft.

2. The large hollow shaft cycloidal joint module according to claim 1, wherein A bearing seat is fixedly installed at the middle position inside the housing, and a third needle roller bearing sleeved outside the eccentric crankshaft is provided between the bearing seat and the eccentric crankshaft, so that the eccentric crankshaft can rotate relative to the housing.

3. A large hollow shaft cycloid joint module according to claim 1 or 2, characterized in that, A rotor assembly is fixedly installed at the bottom of the eccentric crankshaft, and the rotor assembly is located inside the housing.

4. A large hollow shaft cycloidal joint module according to claim 1 or 2, characterized in that, An output flange is fixedly installed at the top of the output end cover, and a through hole communicating with the hollow shaft is opened in the middle of the output flange.

5. A large hollow shaft cycloidal joint module according to claim 2, characterized in that, The housing includes a fixed flange, an upper housing, a lower housing, and a motor bearing bracket fixedly connected in sequence from top to bottom, and the bearing seat is clamped between the upper housing and the lower housing.

6. A large hollow shaft cycloidal joint module according to claim 1, characterized in that, A clamping portion extends radially along the bottom of the first cycloid gear, a plurality of circumferentially continuously arranged teeth are formed on the outer peripheral side surface of the clamping portion, and a plurality of circumferentially continuously arranged clamping grooves are formed on the inner side wall of the second cycloid gear. In the assembled state, the teeth are inserted into the clamping grooves.

7. A large hollow shaft cycloidal joint module according to claim 1, characterized in that, The eccentric structure is an eccentric wheel sleeved on the eccentric crankshaft or an eccentric shaft section formed on the eccentric crankshaft.

8. A large hollow shaft cycloid joint module according to claim 1, characterized in that, The tooth profiles of the first cycloid gear, the first internal gear, the second cycloid gear, and the second internal gear are cycloid teeth or involute teeth.

9. The large hollow shaft cycloid joint module according to claim 1, wherein An isolation protection layer is provided on the inner wall of the cable channel.

10. A large hollow shaft cycloidal joint module according to claim 1, characterized in that, The eccentric counterweight wheel is provided with an installation hole for the eccentric crankshaft to pass through, a clamping convex extends radially inwards along the hole wall of the installation hole, and a limiting groove for the clamping convex to insert is opened on the outer peripheral side surface of the eccentric crankshaft.

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