A mechanical integrated joint with force sensing function

Abstract

The present invention discloses a mechanical integrated joint with a force sensing function, wherein a torque sensor can be movably mounted on an input shaft and located between a flexible wheel and a motor, the inner side of the torque sensor is fixedly matched with the flexible wheel, and the outer side of the torque sensor is fixed to the stator of the motor. The present invention has a torque sensing function, can accurately sense the torque applied to the joint, has higher transmission accuracy, and avoids cantilever installation of the torque sensor, and has a compact structure and high rigidity, thereby improving the overall accuracy of the mechanical arm.

Description

Technical Field

[0001] The invention relates to a mechanical joint structure, in particular to a mechanical integrated joint with a force sensing function. Background Art

[0002] Articulated robots, also known as articulated arm robots or articulated robotic arms, are one of the most common forms of industrial robots in today's industrial field and are suitable for mechanical automation operations in many industrial fields.

[0003] Robots are widely used in the automation industry to reduce human labor intensity. In order to reduce costs and shorten production cycles and adapt to large-scale production, harmonic reducers, motors, brakes, encoders, and torque sensors are integrated into the robot's joints. Mechanical joints are used to connect various robotic arms and drive the robotic arms to adjust angles.

[0004] However, current integrated joints either have a low degree of integration and lack components such as torque sensors, or the torque sensors are installed at the ends of the integrated joints. This results in the torque sensors being supported on only one side, forming a cantilever structure. This causes the rigidity of the integrated joints to be low, thereby reducing the overall accuracy of the robot. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a mechanical integrated joint with force sensing function, load the torque sensor inside the harmonic reducer, avoid cantilever installation of the torque sensor, and improve the overall structural compactness and accuracy of the mechanical integrated joint.

[0006] The purpose of the present invention is achieved by the following technical solutions:

[0007] A mechanical integrated joint with a force sensing function comprises a joint housing, wherein a mounting inner cavity is formed in the joint housing, and an opening communicating with the mounting inner cavity is formed on the joint housing; a motor and a drive control unit connected to the motor are arranged in the mounting inner cavity, wherein the motor has a stator and a rotor, and the rotor of the motor comprises a first output end, and the first output end is arranged toward the opening; the mounting inner cavity is also provided with a harmonic reducer and a torque sensor, wherein the harmonic reducer comprises a flexible wheel, a rigid wheel and a wave generator; the rigid wheel is sleeved on the outer periphery of the flexible wheel and meshes with the flexible wheel, the wave generator cooperates with the flexible wheel driving so that the flexible wheel drives the rigid wheel to realize a reduction transmission, and the wave generator comprises an input shaft, wherein one end of the input shaft forms a connection end connected to the first output end, and the other end of the input shaft extends toward the opening direction and forms a transmission end; the torque sensor is movably sleeved on the input shaft and is located between the flexible wheel and the motor, the inner side of the torque sensor is fixedly matched with the flexible wheel, and the outer side of the torque sensor is fixed to the stator of the motor.

[0008] Furthermore, the flexible wheel has a first end and a second end, and is rotatably sleeved on the input shaft. The inner sides of the first and second ends of the flexible wheel are matched with the input shaft, and the other side of the first end of the flexible wheel is meshed with the rigid wheel.

[0009] Furthermore, a cross roller bearing is arranged between the rigid wheel and the torque sensor, and two side surfaces of the cross roller bearing are respectively abutted against the rigid wheel and the torque sensor; the inner ring of the cross roller bearing is fixedly connected to the rigid wheel, and the outer ring of the cross roller bearing is fixedly connected to the torque sensor.

[0010] Furthermore, a gap is formed between the second end of the flexible wheel and the input shaft; a connecting flange is also provided between the torque sensor and the stator of the motor, the connecting flange is rotatably sleeved on the input shaft, and two side surfaces of the connecting flange are respectively fixedly connected to the torque sensor and the stator of the motor; a supporting bearing is provided between the connecting flange and the input shaft, the inner ring of the supporting bearing is fixedly sleeved on the input shaft, and the outer ring of the supporting bearing is fixed to the connecting flange.

[0011] Furthermore, the wave generator also includes a flexible bearing, which is arranged between the transmission end of the input shaft and the first end of the flexible wheel and has a shape matching the transmission end; the inner ring of the flexible bearing is fixedly sleeved on the transmission end of the input shaft, and the outer ring of the flexible bearing abuts against the inner side of the first end of the flexible wheel.

[0012] Furthermore, the rotor of the motor also includes a second output end, and the second output end and the first output end are respectively located at opposite ends of the motor; the second output end is provided with a connecting shaft, one end of the connecting shaft is connected to the second output end, and the other end of the connecting shaft extends in a direction opposite to the input shaft.

[0013] Furthermore, the mechanical integrated joint with force sensing function also includes a braking device, which is fixed to the installation inner cavity and sleeved on the connecting shaft; the braking device includes an operating state and a braking state. When the braking device is in the operating state, the braking device releases the connecting shaft, and when the braking device is in the braking state, the braking device holds the connecting shaft.

[0014] Furthermore, the drive control unit includes a drive controller and an encoder, the encoder is sleeved on the connecting shaft and electrically connected to the drive controller; the drive controller is electrically connected to the motor and the torque sensor respectively.

[0015] Furthermore, the mechanical integrated joint with force sensing function also includes an output flange, and the output flange is fixedly connected to the rigid wheel.

[0016] Furthermore, a first wire passing channel is formed in the input shaft, a second wire passing channel is formed in the connecting shaft, a third wire passing channel is formed in the rotor of the motor, and the first wire passing channel, the third wire passing channel and the second wire passing channel are connected in sequence; a wire passing channel connected to the first wire passing channel, the second wire passing channel and the third wire passing channel is formed on the output flange.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The mounting cavity is also provided with a harmonic reducer and a torque sensor, so that the mechanical integrated joint of the present invention has a torque sensing function, can accurately sense the torque applied to the joint, and has a higher transmission accuracy;

[0019] The torque sensor can be movably mounted on the input shaft and is located between the flexible pulley and the motor. The inner side of the torque sensor is fixedly matched with the flexible pulley, and the outer side of the torque sensor is fixed to the stator of the motor. The torque sensor is installed inside the harmonic reducer, which avoids the cantilever installation of the torque sensor. It has a compact structure and high rigidity, thereby improving the overall accuracy of the robot arm. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the overall structure of a mechanical integrated joint with force sensing function of the present invention;

[0021] Figure 2 It is a schematic diagram of the structure of the harmonic reducer of the present invention.

[0022] In the figure: 10, joint housing; 11, mounting inner cavity; 12, opening; 211, fixing block; 20, motor; 21, stator; 22, rotor; 221, first output end; 222, second output end; 223, third wire-passing channel; 30, drive control unit; 31, encoder; 32, drive controller; 33, cover; 40, harmonic reducer; 41, flexible wheel; 411, first end; 412, second end; 42, rigid wheel; 43, wave generator; 431, input shaft; 4311, connecting end; 4312, transmission end; 4313, first wire-passing channel; 432, flexible bearing; 50, torque sensor; 51, cross roller bearing; 52, connecting flange; 521, supporting bearing; 60, connecting shaft; 61, brake device; 62, second wire-passing channel; 70, output flange; 71, threading channel; 80, threading tube. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0024] like Figure 1-2 As shown, in order to improve the overall transmission accuracy of the robotic arm and make the mechanical integrated joint structure more compact and more accurate, the present invention provides a mechanical integrated joint with a force sensing function, which includes a joint housing 10. The joint housing 10 serves as the housing of the mechanical integrated joint with a force sensing function of the present invention, and an installation cavity 11 for installing joint components is formed therein. An opening 12 connected to the installation cavity 11 is formed on the joint housing 10. During the actual use of the present invention, the opening 12 is used to extend the joint driving end to connect with the robotic arm, so that the robotic arms can swing relative to each other to adjust the angle. In order to achieve this effect, a motor 20 and a drive control unit 30 connected to the motor 20 are arranged in the installation cavity 11. The motor 20 has a stator 21 and a rotor 22. The rotor 22 of the motor 20 includes a first output terminal 221, and the first output terminal 221 is arranged toward the opening 12. The rotor 22 is used to connect with an external robotic arm. The stator 21 is fixed to the installation cavity 11 to achieve the effect of relative movement with the rotor 22. Another robotic arm can be installed on the joint housing 10, and the drive control unit 30 is used to transmit a control signal to the motor 20 to make the robotic arms swing relative to each other.

[0025] In order to solve the technical problem to be solved by the present invention, the mounting cavity 11 is further provided with a harmonic reducer 40 and a torque sensor 50, wherein the harmonic reducer 40 includes a flexible wheel 41, a rigid wheel 42 and a wave generator 43; the rigid wheel 42 is sleeved on the outer periphery of the flexible wheel 41 and meshes with the flexible wheel 41, the wave generator 43 drives and cooperates with the flexible wheel 41 so that the flexible wheel 41 drives the rigid wheel 42 to realize the reduction transmission, the wave generator 43 includes an input shaft 431, one end of the input shaft 431 forms a connecting end 4311 driven and connected to the first output end 221, and the other end of the input shaft 431 extends toward the opening 12 and forms a transmission end 4312; the torque sensor 50 is movably sleeved on the input shaft 431 and is located between the flexible wheel 41 and the motor 20, the inner side of the torque sensor 50 is fixedly matched with the flexible wheel 41, and the outer side of the torque sensor 50 is fixed to the stator 21 of the motor 20. In practical applications of the present invention, the torque sensor 50 is located between the motor 20 and the rigid wheel 42. Specifically, the torque sensor 50 can be regarded as being installed on the harmonic reducer 40, so that it has the function of torque sensing. At the same time, the torque sensor 50 can be used to fix the flexible wheel 41 and connect the motor 20, and has the advantages of simple and compact structure, easy installation, small size and light weight.

[0026] During use of the present invention, the first output end 221 of the motor 20 drives the input shaft 431 , so that the transmission end 4312 of the input shaft 431 drives the flexible wheel 41 , and the flexible wheel 41 and the rigid wheel 42 are meshed for transmission.

[0027] Moreover, the force exerted by the torque sensor 50 on the workpiece or load due to its own weight cantilever only acts on the inside of the harmonic reducer. In practical applications, the torque sensor 50 can be supported by installing bearings, thus avoiding the cantilever installation of the torque sensor 50, which not only increases the accuracy of torque sensing but also increases the service life of the torque sensor 50.

[0028] Specifically, the flexible spline 41 has a first end 411 and a second end 412 , and is rotatably sleeved on the input shaft 431 . The inner sides of the first end 411 and the second end 412 of the flexible spline 41 are matched with the input shaft 431 , and the other side of the first end 411 of the flexible spline 41 is meshed with the rigid wheel 42 .

[0029] A cross roller bearing 51 is provided between the rigid wheel 42 and the torque sensor 50, and the two side surfaces of the cross roller bearing 51 are respectively in contact with the rigid wheel 42 and the torque sensor 50, so that the rigid wheel 42 and the torque sensor 50 can be accurately positioned; the inner ring of the cross roller bearing 51 is fixedly connected to the rigid wheel 42, and the outer ring of the cross roller bearing 51 is fixedly connected to the torque sensor 50, so as to make the transmission stability between the rigid wheel 42 and the torque sensor 50 higher.

[0030] A gap is formed between the second end 412 of the flexible wheel 41 and the input shaft 431 to prevent the second end 412 of the flexible wheel 41 from rubbing against each other when the input shaft 431 rotates. A connecting flange 52 is also provided between the torque sensor 50 and the stator 21 of the motor 20. The connecting flange 52 is rotatably sleeved on the input shaft 431. The two side surfaces of the connecting flange 52 are respectively fixedly connected to the torque sensor 50 and the stator 21 of the motor 20. The connecting flange 52 is connected to the torque sensor 50, and the torque sensor 50 is connected to the flexible wheel 41. The connecting flange 52 indirectly becomes a component for supporting the second end 412 of the flexible wheel 41. Therefore, a supporting bearing 521 is arranged between the connecting flange 52 and the input shaft 431. The inner ring of the supporting bearing 521 is fixedly sleeved on the input shaft 431, and the outer ring of the supporting bearing 521 is fixed to the connecting flange 52. In this example, the motor 20 adopts a torque motor 20. Since the torque motor 20 is relatively small in size, a fixing block 211 for fixing the stator 21 of the motor 20 is also arranged between the motor 20 and the cavity wall of the mounting inner cavity 11.

[0031] The wave generator 43 also includes a flexible bearing 432, which is arranged between the transmission end 4312 of the input shaft 431 and the first end 411 of the flexible wheel 41 and has a shape matching the transmission end 4312; the inner ring of the flexible bearing 432 is fixedly sleeved on the transmission end 4312 of the input shaft 431, and the outer ring of the flexible bearing 432 abuts against the inner side of the first end 411 of the flexible wheel 41, so that the output end of the input shaft 431 can transmit the torsional force more smoothly and accurately.

[0032] The rotor 22 of the motor 20 also includes a second output end 222, and the second output end 222 and the first output end 221 are respectively located at opposite ends of the motor 20; the second output end 222 is provided with a connecting shaft 60, one end of the connecting shaft 60 is connected to the second output end 222, and the other end of the connecting shaft 60 extends in a direction opposite to the input shaft 431, and the connecting shaft 60 provided at the second output end 222 can be used to install other components.

[0033] The mechanical integrated joint with force sensing function also includes a braking device 61, which is fixed to the mounting inner cavity 11 and sleeved on the connecting shaft 60; the braking device 61 includes an operating state and a braking state. When the braking device 61 is in the operating state, the braking device 61 releases the connecting shaft 60, and when the braking device 61 is in the braking state, the braking device 61 holds the connecting shaft 60. In this example, the braking device 61 includes a brake disc sleeved on the connecting shaft 60 and a brake pin fixed to the mounting inner cavity 11 and capable of reciprocating in the direction of approaching and moving away from the brake disc. The braking state is achieved by driving the brake pin close to and against the brake disc, and the operating state is achieved by driving the brake pin away from the brake disc to form a gap between the brake pin and the brake disc.

[0034] Specifically, the drive control unit 30 includes a drive controller 32 and an encoder 31. The encoder 31 is sleeved on the connecting shaft 60 and electrically connected to the drive controller 32, and is used to obtain the connecting shaft 60, that is, the rotational speed of the motor 20 and feed back the speed signal to the drive controller 32 so that the drive controller 32 can monitor and control the rotational speed of the motor 20 in real time; the drive controller 32 is electrically connected to the motor 20 and the torque sensor 50 respectively, and the torque sensor 50 will also transmit the torque signal to the drive controller 32, so that the drive controller 32 can pass through the rotational speed of the motor 20 and the torque borne by the joint. In this example, the drive controller 32 is arranged at one end of the joint housing 10 away from the opening 12, and a threading port for threading is opened on the joint housing 10, and a cover 33 for protecting the drive controller 32 is arranged on the outside of the joint housing 10.

[0035] The mechanical integrated joint with force sensing function further includes an output flange 70 , which is fixedly connected to the rigid wheel 42 . The output flange 70 is used to be connected to an external mechanical arm to achieve driving.

[0036] In order to make threading of the present invention more convenient, a first wire passing channel 4313 is provided in the input shaft 431, a second wire passing channel 62 is provided in the connecting shaft 60, and a third wire passing channel 223 is formed in the rotor 22 of the motor 20. The first wire passing channel 4313, the third wire passing channel 223 and the second wire passing channel 62 are connected in sequence; a threading channel 71 connected to the first wire passing channel 4313, the second wire passing channel 62 and the third wire passing channel 223 is provided on the output flange 70, and in this example, a threading tube 80 is also included. The threading tube 80 passes through the first wire passing channel 4313, the third wire passing channel 223 and the second wire passing channel 62 from the threading channel 71 of the output flange 70. In actual use, the wires pass through the threading tube 80 and are connected to the drive controller 32.

[0037] Through the above technical solution, the transmission process of the mechanical integrated joint with force sensing function can be made more stable, and the gravity of the torque sensor 50 is directly applied to the harmonic reducer 40, avoiding the generation of a cantilever structure.

[0038] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A mechanical integrated joint with a force sensing function, comprising a joint housing, a mounting inner cavity formed in the joint housing, and an opening communicating with the mounting inner cavity is formed on the joint housing; a motor and a drive control unit connected to the motor are arranged in the mounting inner cavity, the motor has a stator and a rotor, the rotor of the motor includes a first output end, and the first output end is arranged toward the opening; characterized in that: The mounting inner cavity is also provided with a harmonic reducer and a torque sensor, the harmonic reducer includes a flexible wheel, a rigid wheel and a wave generator; the rigid wheel is sleeved on the outer periphery of the flexible wheel and meshes with the flexible wheel, the wave generator cooperates with the flexible wheel driving so that the flexible wheel drives the rigid wheel to realize the reduction transmission, the wave generator includes an input shaft, one end of the input shaft forms a connecting end driven and connected to the first output end, and the other end of the input shaft extends toward the opening direction and forms a transmission end; the torque sensor is movably sleeved on the input shaft and is located between the flexible wheel and the motor, the inner side of the torque sensor is fixedly matched with the flexible wheel, and the outer side of the torque sensor is fixed to the stator of the motor; The flexible wheel has a first end and a second end, and the flexible wheel is rotatably sleeved on the input shaft. The inner sides of the first end and the second end of the flexible wheel are matched with the input shaft, and the other side of the first end of the flexible wheel is meshed with the rigid wheel; A cross roller bearing is arranged between the rigid wheel and the torque sensor, and two side surfaces of the cross roller bearing are respectively in contact with the rigid wheel and the torque sensor; the inner ring of the cross roller bearing is fixedly connected to the rigid wheel, and the outer ring of the cross roller bearing is fixedly connected to the torque sensor; A gap is formed between the second end of the flexible wheel and the input shaft; a connecting flange is further provided between the torque sensor and the stator of the motor, the connecting flange is rotatably sleeved on the input shaft, and two side surfaces of the connecting flange are respectively fixedly connected to the torque sensor and the stator of the motor; a supporting bearing is provided between the connecting flange and the input shaft, the inner ring of the supporting bearing is fixedly sleeved on the input shaft, and the outer ring of the supporting bearing is fixed to the connecting flange; The wave generator also includes a flexible bearing, which is arranged between the transmission end of the input shaft and the first end of the flexible wheel and has a shape matching the transmission end; the inner ring of the flexible bearing is fixedly sleeved on the transmission end of the input shaft, and the outer ring of the flexible bearing abuts against the inner side of the first end of the flexible wheel.

2. The mechanical integrated joint with force sensing function as claimed in claim 1, characterized in that: The rotor of the motor also includes a second output end, and the second output end and the first output end are respectively located at opposite ends of the motor; the second output end is provided with a connecting shaft, one end of the connecting shaft is connected to the second output end, and the other end of the connecting shaft extends in a direction opposite to the input shaft.

3. The mechanical integrated joint with force sensing function as claimed in claim 2, characterized in that: The mechanical integrated joint with force sensing function also includes a braking device, which is fixed to the installation inner cavity and sleeved on the connecting shaft; the braking device includes an operating state and a braking state. When the braking device is in the operating state, the braking device releases the connecting shaft, and when the braking device is in the braking state, the braking device holds the connecting shaft.

4. The mechanical integrated joint with force sensing function as claimed in claim 2, characterized in that: The drive control unit includes a drive controller and an encoder. The encoder is sleeved on the connecting shaft and electrically connected to the drive controller. The drive controller is electrically connected to the motor and the torque sensor respectively.

5. The mechanical integrated joint with force sensing function as claimed in claim 2, characterized in that: The mechanical integrated joint with force sensing function also includes an output flange, and the output flange is fixedly connected to the rigid wheel.

6. The mechanical integrated joint with force sensing function as claimed in claim 5, characterized in that: A first wire passing channel is formed in the input shaft, a second wire passing channel is formed in the connecting shaft, a third wire passing channel is formed in the rotor of the motor, and the first wire passing channel, the third wire passing channel and the second wire passing channel are connected in sequence; a wire passing channel connected to the first wire passing channel, the second wire passing channel and the third wire passing channel is formed on the output flange.

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