A rotary joint module

Abstract

A rotary joint module comprises a rotary joint module output end, a rotary joint module motor end and a rotary joint module position detection end. The rotary joint module of the present invention has strong external force perception capability, high control feedback accuracy, high electromagnetic shielding and compact structure. It is a high-performance force-controlled mechanical arm rotary joint; the encoder position, torque sensor position and communication line position of the rotary joint are all electromagnetically shielded and protected, which can be better adapted to harsh electromagnetic environments. The rotary joint module is designed with a torque sensor for precise force feedback. The rotary joint module is designed with a harmonic reducer, which is mainly composed of a flexible wheel, a steel wheel, a wave generator and a cross roller bearing. The harmonic reducer is mainly used to increase the output torque of the module.

Description

Technical Field

[0001] The present invention belongs to the field of machinery, and specifically relates to a new type of rotary joint module applicable to a surgical robot. Background Art

[0002] The joint module is the main component of a multi-joint robot arm, which is mainly used in collaborative robots. Six-axis or seven-axis multi-joint collaborative robot arms are more common in the market. Collaborative robots are mostly reflected in human-machine collaboration, that is, the safety of the robot arm when it actually comes into physical contact with people. Typical scenes in work production include drag teaching and collision detection. Based on this application, the rotary joint of the collaborative robot arm should have high-performance motion capabilities, which are specifically reflected in the high-precision perception of external forces, the high compactness and lightweight of the overall hardware, the high-precision control feedback and the strong torque output capability.

[0003] For precise external force sensing solutions, the current mainstream approach is to use current loop feedback or integrated torque sensors for rotary joint modules. For compact and lightweight design, most rotary joints on the market are made of magnesium-aluminum alloy and carbon fiber materials, and the weight is reduced and the compactness of the design is improved through finite element analysis of metal parts and integrated design. The mainstream solution for high-precision control feedback is that rotary joints mostly use single-turn absolute encoders with batteries, or compare the readings of multiple single-turn absolute encoders to ensure the accuracy of the rotary joint position information. For strong torque output capability, the mainstream design solution is to use a high-reduction ratio harmonic reduction unit combined with a large torque motor torque motor, while strictly controlling the weight of the joint itself. Summary of the invention

[0004] As mentioned above, although existing technologies have proposed a variety of solutions to improve the performance of joint modules, they are all applied in the industrial field and lack consideration for the special requirements of the medical surgery industry.

[0005] An embodiment of the present invention provides a rotary joint module applied to the medical surgery industry. The rotary joint module has strong external force perception capability, high control feedback accuracy, high electromagnetic shielding, and compact structure. It is a high-performance force-controlled robotic arm rotary joint.

[0006] The rotary joint module provided by the embodiment of the present invention is mainly used in surgical robots. This application scenario requires good adaptability to harsh electromagnetic environments. The encoder position, torque sensor position and communication line position of the rotary joint are all electromagnetically shielded, which can better adapt to harsh electromagnetic environments.

[0007] The rotary joint module provided in the embodiment of the present invention is designed with a torque sensor for precise force feedback. The outer ring of the torque sensor is connected to the output end of the harmonic reducer, and the inner ring of the torque sensor is connected to the output flange of the output rotary joint.

[0008] In the rotary joint module provided by the embodiment of the present invention, an independent cross roller bearing is designed between the torque sensor and the harmonic reducer housing, and the cross roller bearing is used to assist the torque sensor in bearing bending moment.

[0009] The rotary joint module provided in the embodiment of the present invention is designed with a harmonic reducer, which is mainly composed of a flexible wheel, a steel wheel, a wave generator and a cross roller bearing. The harmonic reducer is mainly used to increase the output torque of the module.

[0010] The rotary joint module provided in the embodiment of the present invention is designed with a hollow motor shaft, one end of the hollow motor shaft is connected to the harmonic reducer through a connecting sleeve, the hollow motor shaft is connected to the brake block and the power-off brake, and the brake side of the hollow motor shaft is supported by a deep groove ball bearing.

[0011] The rotary joint module provided in the embodiment of the present invention is designed with two pairs of encoder components, and the outer sides of the encoders are electromagnetically shielded with ferromagnetic shielding materials.

[0012] The rotary joint module provided in the embodiment of the present invention is designed with a zero-point sensor, and the zero-point sensor cooperates with the induction block to realize zero-point feedback of the rotary joint.

[0013] The rotary joint module provided in the embodiment of the present invention is designed with a limit block, and the limit block cooperates with the arm rod of the mechanical arm to achieve mechanical limit.

[0014] An embodiment of the present invention provides a rotary joint module, which includes a rotary joint module output terminal 1, a rotary joint module motor terminal 2 and a rotary joint module position detection terminal 3.

[0015] According to one embodiment of the present invention, for example, the output end 1 of the rotary joint module includes an output connecting flange 101, an output flange 102, a torque sensor 103, a torque sensor connecting plate 104, a cross roller bearing 105, a harmonic reducer 106, a limit block 107, a connecting sleeve 108, a connecting sleeve 109, a sensing block 110, an output sleeve 111 and a bearing support sleeve 112.

[0016] According to an embodiment of the present invention, for example, the output end flange of the harmonic reducer 106 is fixedly connected to the torque sensor connecting plate 104, and the outer ring 1032 of the torque sensor 103 (see the attached Figure 6 ) is fixedly connected to the torque sensor connecting plate 104, and the output flange 102 is connected to the inner ring 1031 of the torque sensor 103 (see the attached Figure 6 ) is fixedly connected, the output sleeve 111 is fixedly connected to the output flange 102, and the output sleeve 111 is fixedly connected to the mechanical arm arm outside the rotary joint module;

[0017] Preferably, a torque sensor 103 is fixedly connected between the output flange 102 and the harmonic reducer 106, and the torque sensor 103 has a cross roller bearing 105, and the cross roller bearing 105 is configured to assist the torque sensor 103 in bearing bending moment, thereby improving the reliability of the torque sensor 103 during use; the outer ring of the cross roller bearing 105 is fixedly connected to the output sleeve 111 and the output flange 102, and the inner ring of the cross roller bearing 105 is fixedly connected to the torque sensor connecting plate 104 and the bearing support sleeve 112;

[0018] Preferably, the limit block 107 is fixedly connected to the output sleeve 111 , the limit block 107 moves in the limit groove on the arm of the robot arm, the sensing block 110 is fixedly connected to the output sleeve 111 , and the sensing block 110 is used in conjunction with the zero position sensor 207 .

[0019] According to one embodiment of the present invention, for example, the motor end 2 of the rotary joint module includes a torque motor 201, a motor shaft 202, a motor housing 203, a first deep groove ball bearing 204, a first bearing end cover 205, a power-off brake 206, a zero position sensor 207 and a sensor fixing block 208.

[0020] According to an embodiment of the present invention, for example, the stator of the torque motor 201 is fixedly connected to the motor housing 203, the rotor of the torque motor 201 is fixedly connected to the motor shaft 202, the first deep groove ball bearing 204 is fixed on the motor shaft 202, the first bearing end cover 205 is fixedly connected to the motor housing 203, and the first deep groove ball bearing 204 is installed in the bearing seat hole of the first bearing end cover 205; the power-off brake 206 is fixedly connected to the first bearing end cover 205, and the zero position sensor 207 is fixedly connected to the motor housing 203 through the sensor fixing block 208;

[0021] Preferably, the motor end 2 of the rotary joint module and the output end 1 of the rotary joint module are connected and assembled by fixing the motor housing 203 with the bearing support sleeve 112 by screws, and the motor shaft 202 is inserted into the inner hole of the connecting sleeve 108 to realize the transmission of the power of the torque motor 201 to the harmonic reducer 106.

[0022] According to one embodiment of the present invention, for example, the rotary joint module position detection end 3 includes a support sleeve 301, a brake block 302, a motor end encoder magnetic ring 303, a motor end encoder circuit board 304, an encoder support frame 305, a second deep groove ball bearing 306, a second bearing end cover 307, a third bearing end cover 308, a support ring 309, an output end encoder magnetic ring 310, an output end encoder circuit board 311 and a wire guard plate 312.

[0023] According to one embodiment of the present invention, for example, the motor end encoder magnetic ring 303 is fixedly connected to the brake block 302, the motor end encoder circuit board 304 is fixedly connected to the support sleeve 301, the brake block 302 is fixedly connected to the motor shaft 202, and the brake block 302 cooperates with the brake pad of the power-off brake 206;

[0024] Preferably, the output end encoder circuit board 311 is fixedly connected to the encoder support frame 305, and the output end encoder magnetic ring 310 is fixedly connected to the support ring 309; the connecting sleeve 109 is connected to the support ring 309, the connecting sleeve 109 is fixedly connected to the connecting flange 101, the connecting flange 101 is fixedly connected to the inner ring of the torque sensor 103, and the output flange 102 drives the support ring 309 and the output end encoder magnetic ring 310 to rotate together through the connecting sleeve 109.

[0025] According to one embodiment of the present invention, for example, the support ring 309 is connected to the encoder support frame 305 through the second deep groove ball bearing 306, the second deep groove ball bearing 306 ensures the stability of the support ring 309 and the coaxiality with the encoder support frame 305, the support frame 305 is fixedly connected to the support sleeve 301, and the support sleeve 301 is fixedly connected to the motor housing 203.

[0026] According to one embodiment of the present invention, for example, the support sleeve 301, the brake block 302 and the encoder support frame 305 are all made of iron shielding material, and the motor housing 203 is also made of iron material.

[0027] Preferably, the motor housing 203 is made of iron material, and the connecting sleeve 109 is made of steel material. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the appearance structure of a rotary joint module provided by an embodiment of the present invention.

[0029] Figure 2 It is a cross-sectional view of a rotary joint module provided by an embodiment of the present invention.

[0030] Figure 3 It is a cross-sectional view of the output end of the rotation joint module provided in an embodiment of the present invention.

[0031] Figure 4 It is a cross-sectional view of the motor end of the rotary joint module provided in an embodiment of the present invention.

[0032] Figure 5 It is a cross-sectional view of the position detection end of the rotary joint module provided in an embodiment of the present invention.

[0033] Figure 6 Schematic diagram of a torque sensor provided by an embodiment of the present invention.

[0034] Figure 7It is an exploded view of the rotary joint module provided by an embodiment of the present invention.

[0035] Figure 8 It is a connection relationship diagram between the output sleeve and the arm rod of the mechanical arm in the rotary joint module provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0036] To make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. However, those skilled in the art will appreciate that the present invention is not limited to the accompanying drawings and the following embodiments.

[0037] In the description of the invention, it should be noted that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "far", "near", etc. is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and cannot be understood as limiting the specific protection scope of the invention. In addition, the terms "first" and "second" are only used for descriptive purposes to distinguish technical features, and do not have substantial meanings, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features.

[0038] Figure 1 The figure shows the appearance structure of a rotary joint provided by an embodiment of the present invention. Figure 1 As shown, viewed from the outside, the rotary joint module includes a rotary joint module output terminal 1, a rotary joint module motor terminal 2 and a rotary joint module position detection terminal 3. Figure 2 It is a cross-sectional view of a rotary joint module provided by an embodiment of the present invention, which shows the internal structure of the rotary joint module.

[0039] Figure 3 A cross-sectional view of an output end of a rotary joint module provided by an embodiment of the present invention is shown. Figure 7 FIG. 1 is an exploded view of a rotary joint module provided by an embodiment of the present invention. Figure 3 , Figure 7 As shown, the output end 1 of the rotary joint module includes an output connecting flange 101, an output flange 102, a torque sensor 103, a torque sensor connecting plate 104, a cross roller bearing 105, a harmonic reducer 106, a limit block 107, a connecting sleeve 108, a connecting sleeve 109, a sensing block 110, an output sleeve 111 and a bearing support sleeve 112.

[0040] like Figure 3As shown, the output end flange of the harmonic reducer 106 is fixedly connected to the torque sensor connecting plate 104, the outer ring of the torque sensor 103 is fixedly connected to the torque sensor connecting plate 104, the output flange 102 is fixedly connected to the inner ring of the torque sensor 103, the output sleeve 111 is fixedly connected to the output flange 102, and the output sleeve 111 is fixedly connected to the mechanical arm arm 400 (see Figure 8 ). In this way, the rotational power and torque output by the output end 1 can drive the mechanical arm to rotate. The torque sensor 103 is fixedly connected between the output flange 102 and the harmonic reducer 106, which can detect the dynamic state of the mechanical arm during the movement process in real time. Because the torque sensor 103 is mainly used to bear torque, and has a weak ability to withstand the bending moment applied to the torque sensor 103, a cross roller bearing 105 is designed to assist the torque sensor 103 in bearing the bending moment, thereby improving the reliability of the torque sensor 103 during use. The outer ring of the cross roller bearing 105 is fixedly connected to the output sleeve 111 and the output flange 102, and the inner ring of the cross roller bearing 105 is fixedly connected to the torque sensor connecting plate 104 and the bearing support sleeve 112. Such a structure is used to assist the torque sensor 103 in bearing the bending moment. The cross roller bearing 105 is small in size, can withstand large torque, and has a high rotation speed. It can not only reliably assist the torque sensor 103 in bearing the bending moment, but also reduce the volume of the rotary joint module, making its structure more compact. The limit block 107 is fixedly connected to the output sleeve 111, and the limit block 107 moves in the limit slot 401 on the robot arm 400. The connection relationship is as follows: Figure 8 As shown, the output end of the rotary joint module stops rotating after the limit block 107 contacts the limit groove 401. The sensing block 110 is fixedly connected to the output sleeve 111, and the sensing block 110 is used in conjunction with the zero position sensor 207 (see below). When the sensing block 110 moves to the upper end of the sensing block 110, the output end of the rotary joint module stops rotating, and the rotary joint returns to the set zero position, and the arm of the robot also returns to the set zero position.

[0041] Figure 4 The figure shows a cross-sectional view of a motor end of a rotary joint module provided by an embodiment of the present invention. Figure 4 , Figure 7 As shown, the motor end 2 of the rotary joint module mainly includes a torque motor 201, a motor shaft 202, a motor housing 203, a first deep groove ball bearing 204, a first bearing end cover 205, a power-off brake 206, a zero position sensor 207 and a sensor fixing block 208.

[0042] like Figure 4As shown, the stator of the torque motor 201 is fixedly connected to the motor housing 203, the rotor of the torque motor 201 is fixedly connected to the motor shaft 202, the first deep groove ball bearing 204 is fixed on the motor shaft 202, the first bearing end cover 205 is fixedly connected to the motor housing 203, and the first deep groove ball bearing 204 is installed in the bearing seat hole of the first bearing end cover 205, which supports the motor shaft 202 and also ensures the coaxiality of the motor shaft 202 and the motor housing 203. The power-off brake 206 is fixedly connected to the first bearing end cover 205, and the zero position sensor 207 is fixedly connected to the motor housing 203 through the sensor fixing block 208. The motor end of the rotary joint module and the output end of the rotary joint module are fixedly connected to the motor housing 203 and the bearing support sleeve 112 by screws to achieve connection and assembly, and the motor shaft 202 is inserted into the inner hole of the connecting sleeve 108 to realize the transmission of the torque motor 201 power to the harmonic reducer 106.

[0043] Figure 5 The figure shows a cross-sectional view of a rotary joint module position detection end provided by an embodiment of the present invention. Figure 5 , Figure 7 As shown, the rotary joint module position detection end 3 includes a support sleeve 301, a brake block 302, a motor end encoder magnetic ring 303, a motor end encoder circuit board 304, an encoder support frame 305, a second deep groove ball bearing 306, a second bearing end cover 307, a third bearing end cover 308, a support ring 309, an output end encoder magnetic ring 310, an output end encoder circuit board 311 and a wire guard plate 312.

[0044] like Figure 5 As shown, the motor end encoder magnetic ring 303 is fixedly connected with the brake block 302, the motor end encoder circuit board 304 is fixedly connected with the support sleeve 301, the brake block 302 is fixedly connected with the motor shaft 202, and the brake block 302 is also matched with the brake pad of the power-off brake 206. When the motor shaft 202 rotates, the brake block 302 and the motor end encoder magnetic ring 303 rotate together with the motor shaft 202, so that the speed of the motor shaft 202 can be detected in real time. The output end encoder circuit board 311 is fixedly connected with the encoder support frame 305, and the output end encoder magnetic ring 310 is fixedly connected with the support ring 309. The connecting sleeve 109 is connected with the support ring 309, and the connecting sleeve 109 is fixedly connected with the connecting flange 101, and the connecting flange 101 is fixedly connected with the inner ring of the torque sensor 103. The output flange 102 drives the support ring 309 and the output end encoder magnetic ring 310 to rotate together through the connecting sleeve 109, so that the output end position information and the position information of the connecting arm tube can be detected in real time. The support ring 309 is connected to the encoder support frame 305 through the second deep groove ball bearing 306 , and the second deep groove ball bearing 306 ensures the stability of the support ring 309 and the coaxiality with the encoder support frame 305 . The support frame 305 is fixedly connected to the support sleeve 301 , and the support sleeve 301 is fixedly connected to the motor housing 203 .

[0045] The support sleeve 301, the brake block 302 and the encoder support frame 305 are all made of iron shielding materials, which can effectively shield the influence of the external magnetic field on the magnetic ring. At the same time, the motor housing 203 is also made of iron material, which can effectively shield the leakage of the magnetic field of the torque motor 201 and further shield the influence on the encoder magnetic ring. The motor housing 203 is made of iron material, and the wall thickness can be made thinner, which can further achieve a compact structure. The connecting sleeve 109 is also made of steel material, which can effectively shield the magnetic field and achieve a good electromagnetic shielding effect on the communication cable inside the connecting sleeve 109.

Claims

1. A rotary joint module, characterized in that: The rotary joint module comprises a rotary joint module output end (1), a rotary joint module motor end (2) and a rotary joint module position detection end (3); The rotary joint module output end (1) comprises an output connecting flange (101), an output flange (102), a torque sensor (103), a torque sensor connecting plate (104), a cross roller bearing (105), a harmonic reducer (106), a limit block (107), a connecting sleeve (108), a connecting sleeve (109), a sensing block (110), an output sleeve (111) and a bearing support sleeve (112); The output end flange of the harmonic reducer (106) is fixedly connected to the torque sensor connecting plate (104), the outer ring of the torque sensor (103) is fixedly connected to the torque sensor connecting plate (104), the output flange (102) is fixedly connected to the inner ring of the torque sensor (103), the output sleeve (111) is fixedly connected to the output flange (102), and the output sleeve (111) is fixedly connected to the arm of the mechanical arm outside the rotary joint module; the output flange (102) and the harmonic reducer (106) are fixedly connected to the torque sensor. The torque sensor (103) comprises a cross roller bearing (105), the cross roller bearing (105) is configured to assist the torque sensor (103) in bearing bending moment, thereby improving the reliability of the torque sensor (103) during use; the outer ring of the cross roller bearing (105) is fixedly connected to the output sleeve (111) and the output flange (102), and the inner ring of the cross roller bearing (105) is fixedly connected to the torque sensor connecting plate (104) and the bearing support sleeve (112); The limit block (107) is fixedly connected to the output sleeve (111), the limit block (107) moves in the limit groove on the arm of the mechanical arm, the sensing block (110) is fixedly connected to the output sleeve (111), and the sensing block (110) is used in conjunction with the zero position sensor (207); The rotary joint module motor end (2) comprises a torque motor (201), a motor shaft (202), a motor housing (203), a first deep groove ball bearing (204), a first bearing end cover (205), a power-off brake (206), a zero position sensor (207) and a sensor fixing block (208); The stator of the torque motor (201) is fixedly connected to the motor housing (203), the rotor of the torque motor (201) is fixedly connected to the motor shaft (202), the first deep groove ball bearing (204) is fixed on the motor shaft (202), the first bearing end cover (205) is fixedly connected to the motor housing (203), and the first deep groove ball bearing (204) is installed in the bearing seat hole of the first bearing end cover (205); the power-off brake (206) is fixedly connected to the first bearing end cover (205), and the zero position sensor (207) is fixedly connected to the motor housing (203) via a sensor fixing block (208); The rotary joint module position detection end (3) comprises a support sleeve (301), a brake block (302), a motor end encoder magnetic ring (303), a motor end encoder circuit board (304), an encoder support frame (305), a second deep groove ball bearing (306), a second bearing end cover (307), a third bearing end cover (308), a support ring (309), an output end encoder magnetic ring (310), an output end encoder circuit board (311) and a wire guard plate (312); The output end encoder circuit board (311) is fixedly connected to the encoder support frame (305), and the output end encoder magnetic ring (310) is fixedly connected to the support ring (309); the connecting sleeve (109) is connected to the support ring (309), the connecting sleeve (109) is fixedly connected to the connecting flange (101), the connecting flange (101) is fixedly connected to the inner ring of the torque sensor (103), and the output flange (102) drives the support ring (309) and the output end encoder magnetic ring (310) to rotate together through the connecting sleeve (109); The connecting sleeve (109) is made of steel material.

2. The rotary joint module according to claim 1, characterized in that: The motor housing (203) and the bearing support sleeve (112) are fixedly connected by screws between the rotary joint module motor end (2) and the rotary joint module output end (1) to achieve connection and assembly, and the motor shaft (202) is inserted into the inner hole of the connecting sleeve (108) to achieve transmission of power from the torque motor (201) to the harmonic reducer (106).

3. The rotary joint module according to claim 1, characterized in that: The motor end encoder magnetic ring (303) is fixedly connected to the brake block (302), the motor end encoder circuit board (304) is fixedly connected to the support sleeve (301), the brake block (302) is fixedly connected to the motor shaft (202), and the brake block (302) cooperates with the brake pad of the power-off brake (206).

4. The rotary joint module according to claim 1, characterized in that: The support ring (309) is connected to the encoder support frame (305) via a second deep groove ball bearing (306), and the second deep groove ball bearing (306) ensures the stability of the support ring (309) and the coaxiality with the encoder support frame (305). The encoder support frame (305) is fixedly connected to the support sleeve (301), and the support sleeve (301) is fixedly connected to the motor housing (203).

5. The rotary joint module according to claim 4, characterized in that: The support sleeve (301), the brake block (302) and the encoder support frame (305) are all made of iron shielding material, and the motor housing (203) is also made of iron material.

Images