Hollow harmonic joint module with novel structure

Abstract

The invention relates to the technical field of robot joint structures, in particular to a hollow harmonic joint module with a novel structure, which comprises a motor, a rotor of the motor is connected through a harmonic reducer and drives an output flange to synchronously rotate, the harmonic reducer comprises a wave generator, a flexible gear and a rigid gear, and the wave generator synchronously rotates along with the rotor; the flexible gear comprises a straight cylinder part, a stress releasing part and a connecting part, the straight cylinder part is matched with the wave generator and acts along with the wave generator to transmit torque to the rigid gear, the stress releasing part extends to the connecting part from the straight cylinder part and forms an axial annular recess, and the connecting positions of the stress releasing part, the straight cylinder part and the connecting part are in smooth transition; and the connecting part extends towards the periphery and is fixed. By improving the flexible gear structure, the overall strength of the flexible gear structure is improved, and the overall reliability of the joint module can be improved. And the overall structure is simplified, so that the axial size and the radial size of the joint module are integrally reduced, and the use requirements of bionic robots and other small automatic robots can be met.

Description

Technical Field

[0001] The invention relates to the technical field of robot joint structures, and in particular to a hollow harmonic joint module with a novel structure. Background Art

[0002] With the continuous development of robot technology, especially in the wide application of service robots, humanoid robots and industrial robots, higher requirements are placed on the performance of joint modules. Harmonic joint modules have become a hot topic in current research and application due to their advantages such as high torque density, high transmission accuracy and compact structure.

[0003] As the core component of the harmonic reducer, the flexspline is divided into two types according to its shape: cup type and hat type. In the prior art, the bottom flange of the hat-type flexspline is thicker on the outside, while the inner part connected to the thin-walled cylinder is thinner, and the smooth rounded transition can absorb the deformation stress of the flexspline, but it also increases the difficulty and cost of processing; at the same time, it reduces the load-bearing capacity and has the risk of fracture failure under high torque output.

[0004] At the same time, the current joint modules are not perfect in terms of motor-end signal detection and output-end signal detection. Generally, signal detection is only performed on the output end or the motor end. If detection is performed simultaneously, the overall size of the joint module will be larger, and the overall structural size of the joint module cannot be effectively controlled, making it difficult to apply to bionic robots and small automation equipment.

[0005] It can be seen that there is still room for improvement in the current harmonic joint module. The overall mechanical properties of the harmonic joint module should be optimized and improved to maintain the structural strength during operation. At the same time, the structure of the joint module needs to be simplified and the overall size needs to be reduced. Therefore, a more reasonable technical solution needs to be proposed to solve the technical problems existing in the prior art. Summary of the invention

[0006] In order to overcome at least one of the defects mentioned above, the present invention proposes a hollow harmonic joint module with a new structure. By adjusting the flexible wheel structure in the joint module, the overall mechanical properties are improved and the overall strength is maintained. At the same time, the overall structure can be streamlined and the size of the joint module can be reduced, making it convenient for the joint module to be used in more bionic robots and automation equipment.

[0007] In order to achieve the above purpose, the hollow harmonic joint module disclosed in the present invention can adopt the following technical solutions:

[0008] A hollow harmonic joint module with a novel structure includes a motor, the rotor of the motor is connected through a harmonic reducer and drives the output flange to rotate synchronously, the harmonic reducer includes a wave generator, a flexible wheel and a rigid wheel, the wave generator rotates synchronously with the rotor; the flexible wheel includes a straight tube part, a stress release part and a connecting part, the straight tube part cooperates with the wave generator and moves with the wave generator to transmit torque to the rigid wheel, the stress release part extends from the straight tube part to the connecting part and forms an axial annular depression, the connection between the stress release part, the straight tube part and the connecting part is smoothly transitioned, and the connecting part extends to all sides and is fixed.

[0009] The above-disclosed harmonic joint module has improved and adjusted the flexible wheel structure, and the overall mechanical structure strength of the flexible wheel has been enhanced, thereby improving the overall working performance of the joint module. The increased strength of the flexible wheel structure can reduce the size of the flexible wheel structure itself, thereby also reducing the overall size of the joint module.

[0010] Furthermore, the structure of the rigid wheel can also be adjusted to simplify the overall structure of the joint module and reduce the overall size of the joint module: the rigid wheel cooperates with the reducer housing and rotates relatively, a cross roller bearing structure is formed between the rigid wheel and the reducer housing, and the inner ring of the cross roller bearing structure is integrally formed with the rigid wheel. When the above scheme is adopted, the overall size of the rigid wheel and the cross roller bearing structure is reduced, thereby facilitating the reduction of the overall structure of the joint module, and facilitating its application in bionic robots and small automation equipment.

[0011] Furthermore, after the output flange is connected to the rigid wheel, in order to facilitate the detection of the actual working condition of the output flange, the output flange can be adjusted, and its structure is not limited to a single one. Here, an optimization is made and one of the feasible options is proposed: an extension cylinder is formed on the output flange, and the extension cylinder extends from the upper part of the joint module to the lower part of the joint module. When the above scheme is adopted, the extension cylinder can be integrally formed with the output flange, and the extension cylinder can be used to connect the magnetic ring for detection, which is conducive to reducing the size of the magnetic ring in the axial direction.

[0012] Furthermore, a gap is formed between the extension cylinder and the rotor. To prevent external impurities from entering and affecting the motion sensitivity of the joint module, an optimization is performed here: a skeleton oil seal is provided between the extension cylinder and the rotor. When the above solution is adopted, the skeleton oil seal can be a rubber ring.

[0013] Furthermore, the joint module monitors the operating status of the motor end and the output end. Here, an optimization is performed and one of the feasible options is proposed: the joint module also includes a main control board, and a motor end encoder and an output end encoder are arranged on the main control board. A motor end magnetic ring is arranged on the rotor and is arranged opposite to the motor end encoder. The extension cylinder is provided with an output end magnetic ring and is arranged opposite to the output end encoder. The motor end magnetic ring and the output end magnetic ring are on the same plane. When the above scheme is adopted, the motor end encoder is used to monitor the operating status of the motor end magnetic ring, and the output end encoder is used to monitor the operating status of the output flange. Setting the motor end magnetic ring and the output end magnetic ring on the same plane is conducive to reducing the overall axial size of the joint module.

[0014] Furthermore, when setting the output end magnetic ring, a variety of methods can be used for fixed connection, and its structure is not limited to a single one. Here, optimization is performed and one feasible option is proposed: a motor end speed ring mounting disk is provided on the rotor, the motor end speed ring mounting disk rotates coaxially with the rotor, and the motor end magnetic ring is provided on the motor end speed ring mounting disk and rotates synchronously. When the above scheme is adopted, the motor end speed ring mounting disk rotates with the rotor, and the motor end magnetic ring is connected and fixed by gap gluing and then attached to the magnetic disk, thereby realizing the synchronous rotation of the motor end magnetic ring and the motor end speed ring mounting disk.

[0015] Furthermore, the joint module is a modular structure as a whole, and the motor and other components are integrated through an external closed structure. Modularization can be achieved through a variety of schemes, and its structure is not limited to a single one. Here, it is optimized and one of the feasible options is proposed: the joint module includes a motor housing and a back cover, the motor housing and the back cover are matched and connected, and the back cover forms an internal channel, and the internal channel extends from the back cover to the motor housing and passes through the joint module. When the above scheme is adopted, the motor housing and the back cover are connected by bolts, and the two parts are connected by cylindrical pins for centering.

[0016] Furthermore, the externally closed motor housing can be adjusted to improve the overall stability of the joint module. The structure is not limited to a single one. Here, an optimization is made and one of the feasible options is proposed: the reducer housing is connected to the motor housing, and the flexible wheel is clamped and fixed by the reducer housing and the motor housing. When the above scheme is adopted, the reducer housing is arranged after the motor housing to improve the overall integration of the joint module and maintain the output stability of the output flange. In some schemes, the outer ring of the cross roller bearing can be integrally formed with the reducer housing.

[0017] Furthermore, the motor housing is used to accommodate a variety of components, and its structure is not limited to a single one. Here, an optimization is made and one of the feasible options is proposed: a mounting cavity is formed in the motor housing, and a support boss and a support end plate for matching the motor are formed in the mounting cavity. A first bearing is arranged between the rotor and the support end plate, and a second bearing is arranged between the rotor and the support boss. When the above scheme is adopted, the cooperation of the first bearing and the second bearing enables the rotor to rotate smoothly, and the first bearing and the second bearing can adopt deep groove ball bearings.

[0018] Furthermore, in order to reduce leakage inside and outside the joint module, a sealing structure is provided to block it, and its structure is not limited to a single one. Here, an optimization is made and one of the feasible options is proposed: an oil seal is provided between the internal channel and the output flange. When the above solution is adopted, the oil seal adopts a skeleton seal.

[0019] Compared with the prior art, some beneficial effects of the technical solution disclosed in the present invention include:

[0020] The present invention improves the flexible wheel structure and enhances the overall strength of the flexible wheel structure, thereby improving the overall reliability of the joint module; the overall size of the flexible wheel structure is also streamlined, which is also convenient for streamlining the structure of the joint module, thereby reducing the axial and radial dimensions of the joint module as a whole. The optimized joint module can meet the use requirements of bionic robots and other small automated robots. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only represent some embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 This is a schematic diagram of the overall structure of the joint module (excluding the output flange).

[0023] Figure 2 This is a top view of the joint module (excluding the output flange).

[0024] Figure 3 This is an isometric diagram of the internal structure of the joint module.

[0025] Figure 4 This is a cross-sectional diagram of the internal structure of the joint module.

[0026] Figure 5 This is a cross-sectional structural diagram of a harmonic reducer.

[0027] Figure 6 It is the overall schematic diagram of the flexible wheel structure.

[0028] Figure 7 It is a cross-sectional schematic diagram of the flexible wheel structure.

[0029] Figure 8 It is a schematic diagram of the overall structure of the reducer housing.

[0030] Fig. 9 It is a cross-sectional schematic diagram of the reducer housing.

[0031] Fig.10 Schematic diagram of the overall structure of the back cover.

[0032] Fig.11 This is the stress cloud diagram of the flexible wheel structure.

[0033] In the above drawings, the meanings of the symbols are as follows:

[0034] 1. Reducer housing; 2. Motor housing; 3. Back cover; 301. Internal channel; 4. Motor; 5. Oil seal; 6. Output flange; 601. Extended cylinder; 7. Rigid wheel; 8. Flexible wheel structure; 801. Straight cylinder; 802. Stress extension part; 803. Connecting part; 804. Connecting port; 9. Wave generator; 10. Rotor; 11. Skeleton oil seal; 12. Motor end speed ring mounting plate; 13. Output end position ring mounting plate; 14. Output end magnetic ring; 15. Motor end magnetic ring; 16. Main control board. DETAILED DESCRIPTION

[0035] The present embodiment is further explained below in conjunction with the accompanying drawings and specific embodiments.

[0036] In view of the fact that the harmonic joint module in the prior art has low overall mechanical strength, complex structure, and large overall size, making it difficult to be applied to bionic robots and other small-scale automated equipment, the following embodiments are optimized and overcome the defects in the prior art.

[0037] Example

[0038] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, this embodiment provides a hollow harmonic joint module of a novel structure, including a motor 4, a rotor 10 of the motor 4 is connected through a harmonic reducer and drives the output flange 6 to rotate synchronously, the harmonic reducer includes a wave generator 9, a flexible wheel and a rigid wheel 7, and the wave generator 9 rotates synchronously with the rotor 10; Figure 6 , Figure 7As shown, the flexible wheel includes a straight cylinder portion 801, a stress release portion and a connecting portion 803. The straight cylinder portion 801 cooperates with the wave generator 9 and moves with the wave generator 9 to transmit the torque to the rigid wheel 7. The stress release portion extends from the straight cylinder portion 801 to the connecting portion 803 and forms an axial annular depression. The connection between the stress release portion and the straight cylinder portion 801 and the connecting portion 803 is smoothly transitioned. The connecting portion 803 extends to all sides and is fixed. A plurality of connecting ports 804 are provided on the connecting portion 803.

[0039] The above-disclosed harmonic joint module has improved and adjusted the flexible wheel structure 8, and the overall mechanical structure strength of the flexible wheel has been enhanced, thereby improving the overall working performance of the joint module. The increased strength of the flexible wheel structure 8 can reduce the size of the flexible wheel structure 8 itself, and thus can also reduce the overall size of the joint module.

[0040] Preferably, the flexible wheel in this embodiment adopts a cap-shaped flexible wheel. The motor 4 selects a frameless torque motor 4, the stator is fixed to the motor 4 housing, and the rotor 10 is designed as a hollow structure and interference fits with the wave generator 9. The flexible wheel in this embodiment is loaded with a torque of 150Nm. Fig.11 For the simulated stress cloud diagram, the maximum stress on the flexspline flange is 519.5MPa.

[0041] The 7 structures of the rigid wheel can also be adjusted to simplify the overall structure of the joint module and reduce the overall size of the joint module: Figure 5 , Figure 8 and Fig. 9 As shown, the rigid wheel 7 cooperates with the reducer housing 1 and rotates relatively, a cross roller bearing structure is formed between the rigid wheel 7 and the reducer housing 1, and the inner ring of the cross roller bearing structure is integrally formed with the rigid wheel 7. When the above scheme is adopted, the overall size of the rigid wheel 7 and the cross roller bearing structure is reduced, so that the overall structure of the joint module is reduced, which is convenient for application in bionic robots and small automation equipment.

[0042] After the output flange 6 is connected to the rigid wheel 7, in order to facilitate the detection of the actual working condition of the output flange 6, the output flange 6 can be adjusted, and its structure is not limited to a single one. This embodiment is optimized and adopts one of the feasible options: an extension cylinder 601 is formed on the output flange 6, and the extension cylinder 601 extends from the upper part of the joint module to the lower part of the joint module. When the above scheme is adopted, the extension cylinder 601 can be integrally formed with the output flange 6, and the extension cylinder 601 is provided with an output end position ring mounting disk 13, and the output end position ring mounting disk 13 is used to connect the output end magnetic ring 14 for detection, which is conducive to reducing the axial size of the output end magnetic ring 14.

[0043] A gap is formed between the extension cylinder 601 and the rotor 10. To prevent external impurities from entering and affecting the motion sensitivity of the joint module, this embodiment is optimized: a skeleton oil seal 11 is provided between the extension cylinder 601 and the rotor 10. When the above solution is adopted, the skeleton oil seal 11 can be a rubber ring.

[0044] The joint module monitors the operating status of the motor 4 and the output end. This embodiment is optimized and adopts one of the feasible options: Figure 3 , Figure 4 , Fig.10 As shown, the joint module also includes a main control board 16, on which a motor 4-end encoder and an output-end encoder are disposed, a motor-end magnetic ring 15 is disposed on the rotor 10 and is disposed opposite to the motor 4-end encoder, an output-end magnetic ring 14 is disposed on the extension cylinder 601 and is disposed opposite to the output-end encoder, and the motor-end magnetic ring 15 and the output-end magnetic ring 14 are on the same plane. When the above scheme is adopted, the motor 4-end encoder is used to monitor the operating state of the motor-end magnetic ring 15, and the output-end encoder is used to monitor the operating state of the output flange 6. Setting the motor-end magnetic ring 15 and the output-end magnetic ring 14 on the same plane is conducive to reducing the overall axial size of the joint module.

[0045] When setting the output end magnetic ring 14, a variety of methods can be used for fixed connection, and its structure is not limited to a single one. This embodiment optimizes and adopts one of the feasible options: Figure 4 As shown, the rotor 10 is provided with a motor end speed ring mounting disk 12, which rotates coaxially with the rotor 10, and the motor end magnetic ring 15 is provided on the motor end speed ring mounting disk 12 and rotates synchronously. When the above scheme is adopted, the motor end speed ring mounting disk 12 rotates with the rotor 10, and the motor end magnetic ring 15 is connected and fixed by means of snap-fitting, bonding, etc. and then attached to the magnetic disk, so as to realize the synchronous rotation of the motor end magnetic ring 15 and the motor end speed ring mounting disk 12.

[0046] The joint module is a modular structure as a whole, and the components such as the motor 4 are integrated through an external closed structure. Modularization can be achieved through a variety of schemes, and its structure is not limited to a single one. This embodiment is optimized and adopts one of the feasible options: Figure 1 , Figure 2 As shown, the joint module includes a motor housing 2 and a rear cover 3, the motor housing 2 is connected with the rear cover 3, and the rear cover 3 forms an internal channel 301, and the internal channel 301 extends from the rear cover 3 into the motor housing 2 and passes through the joint module. When the above solution is adopted, the motor housing 2 and the rear cover 3 are connected by screws and are centered by cylindrical pins.

[0047] On the externally closed motor housing 2, adjustments can also be made to improve the overall stability of the joint module. Its structure is not limited to a single one. This embodiment is optimized and adopts one of the feasible options: the reducer housing 1 is connected with the motor housing 2, and the flexible wheel is clamped and fixed by the reducer housing 1 and the motor housing 2. When the above scheme is adopted, the reducer housing 1 is arranged on the motor housing 2 to improve the overall integration of the joint module and maintain the output stability of the output flange 6. In some schemes, the outer ring of the cross roller bearing can be integrally formed with the reducer housing 1.

[0048] The motor housing 2 is used to accommodate a variety of components, and its structure is not limited to a single one. This embodiment is optimized and adopts one of the feasible options: the motor housing 2 forms an installation cavity, and the installation cavity forms a support boss and a support end plate for matching the motor 4. A first bearing is provided between the rotor 10 and the support end plate, and a second bearing is provided between the rotor 10 and the support boss. When the above scheme is adopted, the cooperation of the first bearing and the second bearing enables the rotor 10 to rotate smoothly, and the first bearing and the second bearing can adopt deep groove ball bearings.

[0049] In order to reduce leakage inside and outside the joint module, a sealing structure is provided to block the leakage, and its structure is not limited to a single one. This embodiment is optimized and adopts one of the feasible options: an oil seal 5 is provided between the internal channel 301 and the output flange 6. When the above solution is adopted, the oil seal 5 adopts an oil seal ring.

[0050] The above are the implementation methods listed in this embodiment, but this embodiment is not limited to the above optional implementation methods. Those skilled in the art can arbitrarily combine the above methods to obtain other various implementation methods. Anyone can derive other various implementation methods under the inspiration of this embodiment. The above specific implementation methods should not be understood as limiting the protection scope of this embodiment. The protection scope of this embodiment should be based on the definition in the claims.

Claims

1. A new type of hollow harmonic joint module, characterized by: The invention comprises a motor (4), wherein a rotor (10) of the motor (4) is connected via a harmonic reducer and drives an output flange (6) to rotate synchronously, wherein the harmonic reducer comprises a wave generator (9), a flexible wheel and a rigid wheel (7), wherein the wave generator (9) rotates synchronously with the rotor (10); the flexible wheel comprises a straight tube portion (801), a stress release portion and a connection portion (803), wherein the straight tube portion (801) cooperates with the wave generator (9) and moves with the wave generator (9) to transmit torque to the rigid wheel (7), wherein the stress release portion extends from the straight tube portion (801) to the connection portion (803) and forms an axial annular depression, wherein the connection between the stress release portion and the straight tube portion (801) and the connection portion (803) is smoothly transitioned, and the connection portion (803) extends in all directions and is fixed.

2. The hollow harmonic joint module of the novel structure according to claim 1 is characterized in that: The rigid wheel (7) cooperates with the reducer housing (1) and rotates relatively to each other, a cross roller bearing structure is formed between the rigid wheel (7) and the reducer housing (1), and the inner ring of the cross roller bearing structure is integrally formed with the rigid wheel (7).

3. The hollow harmonic joint module of the novel structure according to claim 1 is characterized in that: An extension cylinder (601) is formed on the output flange (6), and the extension cylinder (601) extends from the upper part of the joint module to the lower part of the joint module.

4. The hollow harmonic joint module of the novel structure according to claim 3 is characterized in that: A skeleton oil seal (11) is provided between the extension cylinder (601) and the rotor (10).

5. The hollow harmonic joint module of the novel structure according to claim 3 is characterized in that: The joint module also includes a main control board (16), on which a motor (4) end encoder and an output end encoder are arranged, a motor end magnetic ring (15) is arranged on the rotor (10) and is arranged opposite to the motor (4) end encoder, and an output end magnetic ring (14) is arranged on the extension cylinder (601) and is arranged opposite to the output end encoder, and the motor end magnetic ring (15) and the output end magnetic ring (14) are on the same plane.

6. The hollow harmonic joint module of the novel structure according to claim 5 is characterized in that: The rotor (10) is provided with a motor end speed ring mounting disk (12), the motor end speed ring mounting disk (12) rotates coaxially with the rotor (10), and the motor end magnetic ring (15) is arranged on the motor end speed ring mounting disk (12) and rotates synchronously.

7. The hollow harmonic joint module of the novel structure according to claim 1 is characterized in that: The joint module comprises a motor housing (2) and a rear cover (3), wherein the motor housing (2) and the rear cover (3) are cooperatively connected, and the rear cover (3) forms an internal channel (301), and the internal channel (301) extends from the rear cover (3) into the motor housing (2) and passes through the joint module.

8. The hollow harmonic joint module of the novel structure according to claim 7 is characterized in that: The reducer housing (1) is connected in a cooperative manner with the motor housing (2), and the flexible wheel is clamped and fixed by the reducer housing (1) and the motor housing (2).

9. The hollow harmonic joint module of the novel structure according to claim 7 or 8, characterized in that: An installation cavity is formed in the motor housing (2), and a support boss and a support end plate for matching the motor (4) are formed in the installation cavity. A first bearing is arranged between the rotor (10) and the support end plate, and a second bearing is arranged between the rotor (10) and the support boss.

10. The hollow harmonic joint module of the novel structure according to claim 7 is characterized in that: An oil seal (5) is provided between the internal channel (301) and the output flange (6).

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