Built-in motor torque sensor and motor

Abstract

The utility model provides a built-in motor torque sensor and a motor, which comprise a measuring device arranged on an output shaft of the motor, a stator connected with a shell of the motor, a signal processing device arranged on the output shaft of the motor and a rotor arranged on the output shaft of the motor, the measuring device and the signal processing device are both arranged in a space formed by the stator and the rotor, and the signal processing device receives and processes a deformation signal generated by the measuring device and outputs a torque measuring result. The beneficial effects of the utility model are that the torque sensor is coupled and integrated on the output shaft of the motor, and the rotation of the rotor of the sensor depends on the output shaft of the motor, thereby omitting a high-speed bearing during the installation of a conventional torque sensor, simplifying the installation structure of the torque sensor, shortening the length of the output shaft of the motor, and reducing the cost. The weight of the measuring device and the signal processing device is light, the influence on the dynamic balance of the motor rotor is small, the dynamic problem of the motor rotor is improved, and the occurrence of a critical rotating speed resonance point is delayed.

Description

Technical Field

[0001] The utility model belongs to the technical field of motors, and in particular relates to a built-in motor torque sensor and a motor. Background Art

[0002] The motor needs to be tested for its performance before leaving the factory, one of which is the motor output torque, which is an important indicator of motor design. For the torque test of the motor, the technology that needs to be applied is the torque sensor. The torque sensor has its factory range, which includes the torque range and the speed range. The research and development of high-speed motors requires both high speed and high power, which requires a torque sensor with high speed and high torque. Through product research on the market, it is found that high-torque sensors are limited by speed, and the measurement range is restricted by its structural factors. The most commonly used torque sensor at present is installed in the form of flange connection, and the length and volume are too large, so it needs to be equipped with bearings as rotational support separately, and the bearings are a factor that restricts the high-speed rotation of the rotor. In order to solve the research and development and application problems of high-speed motors, a torque sensor is now needed to meet the performance calibration of high-speed motors. Summary of the invention

[0003] In view of the above problems, the utility model provides a built-in motor torque sensor and a motor to solve the above or other problems existing in the prior art.

[0004] In order to solve the above technical problems, the technical solution adopted by the utility model is: a built-in motor torque sensor, including a measuring device arranged on the motor output shaft, a stator connected to the motor housing, a signal processing device arranged on the motor output shaft and a rotor arranged on the motor output shaft, the rotor can rotate relative to the stator, the measuring device and the signal processing device are both arranged in the space formed by the stator and the rotor, the signal processing device receives and processes the deformation signal generated by the measuring device, and outputs the torque measurement result.

[0005] Furthermore, a plane structure is provided on the outer side of the motor output shaft, and the measuring device is attached to the plane structure.

[0006] Furthermore, the measuring device is a strain gauge.

[0007] Furthermore, a positioning structure is provided at the contact point between the motor housing and the stator to perform positioning during the stator installation process.

[0008] Furthermore, a positioning hole is provided on the motor housing and a positioning piece is provided on the stator, the stator piece corresponds to the positioning hole, and the positioning piece is plug-fitted with the positioning hole to control the coaxiality of the stator and the rotor.

[0009] Furthermore, the positioning structure is a stopper structure.

[0010] Furthermore, a mounting groove is provided on the output shaft of the motor, and the signal processing device is arranged in the mounting groove.

[0011] Furthermore, a sealing structure is provided at the connection between the stator and the motor housing to seal the contact between the stator and the motor housing.

[0012] Furthermore, the signal processing device includes a signal processing module and a signal transmission module connected to each other. The signal processing module receives the deformation signal of the measuring device and processes the deformation signal. The processed signal is output via the signal transmission module.

[0013] A motor comprises the above-mentioned built-in motor torque sensor, wherein the torque sensor is arranged at one side of the motor output shaft and is respectively connected to the motor output shaft and the motor housing.

[0014] Due to the adoption of the above technical solution, the torque sensor has a connected measuring device and a signal processing device, both of which are installed on the motor output shaft, the rotor of the torque sensor is fixedly installed on the motor output shaft, the sensor rotor rotates with the motor rotor, the stator of the torque sensor is penetrated through the motor output shaft and fixedly connected to the motor housing, the stator protects the measuring device, the signal processing device and the rotor located in its internal space, the torque sensor is coupled and integrated on the motor output shaft, the rotation of the sensor rotor relies on the motor output shaft, the high-speed bearing when the traditional torque sensor is installed is omitted, the installation structure of the torque sensor is simplified, and the length of the motor output shaft is shortened;

[0015] The measuring device is a strain gauge, and the signal processing device is a control board with components. The components are of patch type, so that the measuring device and the signal processing device are light in weight, have little effect on the dynamic balance of the motor rotor, improve the dynamic problems of the motor rotor, and delay the occurrence of the critical speed resonance point.

[0016] The motor and the standard motor output shaft are directly connected through a coupling, which avoids the transition of the flanges at both ends of the traditional torque sensor and reduces the couplings used when connecting the motor and the standard motor, making the alignment of the two motor shafts better. During high speed and torque transmission, the vibration is small, and there is no sharp noise at the coupling, which reduces the cost of motor alignment and reduces noise at the same time.

[0017] During the torque transmission process, the vibration is small, the loss of accuracy of the torque sensor is small, and the drift of the torque sensor is zero when recalibrated, which improves the accuracy of repeated test data, improves the accuracy of motor test parameters, reduces the impact of dynamic balance of the motor rotor, and ensures the stability of the motor at high speed;

[0018] The bearings of the torque sensor are simplified, the supporting points of the rotor are reduced, and the maintenance cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of a motor with a torque sensor installed in one embodiment of the utility model;

[0020] Figure 2 It is a schematic diagram of the motor cross-sectional structure of a torque sensor according to an embodiment of the utility model;

[0021] Figure 3 It is a schematic diagram of the stator structure of a torque sensor according to an embodiment of the utility model.

[0022] In the figure:

[0023] 1. Motor body 2. Motor rotor 3. Torque sensor

[0024] 201, measuring device 301, rotor 101, motor housing

[0025] 302, stator 303, signal processor 304, power board

[0026] 305. Signal receiving board DETAILED DESCRIPTION

[0027] The utility model is further described below in conjunction with the accompanying drawings and specific embodiments.

[0028] Figure 1 A structural schematic diagram of an embodiment of the utility model is shown. This embodiment relates to a built-in motor torque sensor and a motor. The torque sensor is coupled and installed on the output shaft of the motor, so that the torque sensor is integrated inside the motor and integrated with the motor as a whole, occupying a small space, shortening the overall length of the motor output shaft, and omitting the arrangement of the rotor bearing when installing a traditional torque sensor.

[0029] A built-in motor torque sensor, such as Figure 1-3 As shown, it includes a measuring device 201 arranged on the motor output shaft, a stator 302 connected to the motor housing 101, a signal processing device and a rotor 301 arranged on the motor output shaft, wherein the signal processing device is arranged on the motor output shaft, the rotor 301 rotates with the motor output shaft, the rotor 301 can rotate relative to the stator 302, and the stator 302 will not interfere with the rotation of the rotor 301. The measuring device 201 and the signal processing device are both arranged in a space formed by the stator 302 and the rotor 301, and the stator 302 protects the measuring device 201 and the signal processing device in the space. The measuring device 201 is used to measure the output torque of the motor output shaft, and the signal processing device receives the deformation signal generated by the measuring device 201 and outputs the torque measurement result.

[0030] Specifically, the above-mentioned measuring device 201 is fixedly installed on the motor output shaft, so that the measuring device 201 can rotate with the motor output shaft. When the motor output shaft is subjected to external force, the motor output shaft rotates, causing the measuring device 201 located on the motor output shaft to produce mechanical deformation, causing the resistance of the measuring device 201 to change, thereby measuring the output torque of the motor output shaft.

[0031] When the measuring device 201 is installed, it is bonded to the motor output shaft by pasting, and the bonding method is preferably to bond by adhesive, so that the measuring device 201 is fixed to the motor output shaft, so that the measuring device 201 will not fall off from the motor output shaft when the motor output shaft rotates and is subjected to centrifugal force. Based on the use requirements of the measuring device 201, and in order to ensure the measurement accuracy of the measuring device 201, a plane structure is provided on the outer side of the motor output shaft, and the measuring device 201 is pasted on the plane structure to keep the state of the measuring device 201 after installation in a plane state. The plane structure is arranged on the outer side of the motor output shaft, and the plane structure is formed by plane processing the outer diameter of the motor output shaft, and the area of ​​the plane structure is not less than the area of ​​the measuring device 201, so that the measuring device 201 can be installed at the plane structure.

[0032] In some feasible embodiments, the above-mentioned measuring device 201 is a strain gauge, which is a commercially available product and is selected according to actual needs. The strain gauge is light in weight and has little effect on the dynamic balance of the motor rotor 2 after being pasted on the motor output shaft. It can ensure that the motor rotor 2 is in a stable state during the entire speed-up process of the motor, generates less vibration, and can quickly pass the critical speed resonance point.

[0033] The above-mentioned signal processing device is fixedly installed on the motor output shaft. In order to facilitate the installation of the signal processing device, the motor output shaft is provided with a mounting groove, and the signal processing device is arranged in the mounting groove. The signal processing device is a circuit board structure with multiple components installed, and in order to reduce the length of the motor output shaft occupied, multiple components are mounted on the surface of the circuit board, and the circuit board is fixedly installed in the mounting groove. In order to prevent the signal processing device from being detached from the motor output shaft due to centrifugal force during the rotation of the motor output shaft, the signal processing device can be bonded by glue, and the signal processing device is firmly and reliably fixed in the mounting groove to prevent measurement deviation and parts damage caused by centrifugal force. At the same time, the signal processing device is light in weight and has little effect on the dynamic balance of the motor rotor 2. During the entire speed-up process of the motor, the motor rotor 2 is in a stable state, generates less vibration, and can quickly pass the critical speed resonance point. The mounting groove can be formed separately by processing, or the mounting groove can be the shaft groove of the motor output shaft.

[0034] The measuring device 201 and the signal processing device can be arranged in sequence along the axial direction of the motor output shaft, and the signal processing device is arranged outside the measuring device 201, that is, the signal processing device is arranged on a side close to the motor output shaft.

[0035] The above-mentioned signal processing device includes a signal processing module and a signal transmission module connected to each other. The signal processing module receives the deformation signal of the measuring device 201 and processes the deformation signal. The processed signal is output through the signal transmission module. The signal processing module filters, amplifies or converts the deformation signal to form a signal form that is easy to process, such as a digital signal. The signal transmission module transmits the processed signal and can transmit the processed signal to a computer, PLC or other control system to display the output torque of the motor output shaft. The signal processing module can be an amplifier, a filter or an A / D converter, and the signal output module can be a serial port or a USD.

[0036] Specifically, Figure 2 As shown, the signal processing module includes a signal processor 303, a power board 304 and a signal receiving board 305. The signal processor 303 and the power board 304 are respectively installed on the rotor 301, and the signal receiving board 305 is installed on the stator. The signal receiving board 305 is connected to the signal transmission module, the signal processor 303 is connected to the power board 304, the power board 304 provides power for the signal processor 303, the signal processor 303 is connected to the signal receiving board 305, and the signal receiving board 305 receives the signal processed by the signal processor 303 and transmits the signal through the signal processing module. The connection method between the signal processor 303 and the power board 304 can be a wire connection, and the connection method between the signal processor 303 and the signal receiving board 305 can be a wireless communication connection.

[0037] The above-mentioned signal processor 303, power board 304 and signal receiving board 305 are all commercially available products, which can be selected according to actual needs, and no specific requirements are made here.

[0038] like Figure 2 and 3 As shown, the above-mentioned stator 302 is fixedly connected to the motor housing 101, so that the stator 302 does not rotate with the motor output shaft, and protects the measuring device 201, the signal processing device and the rotor 301 located in the internal space of the stator 302. When the stator 302 is installed with the motor housing 101, the stator 302 can be fixedly installed on the end cover of the motor, so that the torque sensor 3 is installed as a whole on the end side of the motor. The fixed connection method can be riveting, or it can be connected by connecting parts such as bolts and screws, or other fixed connection methods, which can be selected according to actual needs.

[0039] The stator 302 is a shell structure with one end open and a hollow interior, which protects the signal processing device and the measuring device 201 located in the internal space thereof, and protects the electronic components of the measuring device 201 and the signal processing device from being affected by external factors and avoiding damage. The stator 302 is an axisymmetric structure so as to cooperate with the rotor 301, and includes an end shell and a side shell connected to each other. The side shell is arranged on either side of the end shell. The side shell is a curved surface structure, preferably a cylindrical structure with a certain length, with two ends open. One end of the side shell is fixedly connected to the end shell and arranged along the circumferential direction of the end shell. The fixed connection method is preferably integrally formed to enhance the stability of the stator 302 structure and extend the service life of the stator 302.

[0040] In order to facilitate the rapid and accurate installation of the torque sensor 3, a positioning stop structure is provided at the contact point between the motor housing 101 and the stator 302 for positioning. The positioning stop structure may be a step structure, and the free end of the side shell of the stator 302 is also a corresponding step structure. The step structure at the end of the side shell is engaged with the step structure at the corresponding position on the motor housing 101, and the stator 302 is positioned during the process to achieve rapid and accurate installation of the stator 302; alternatively, the positioning stop structure may also be a groove structure, and the free end of the side shell of the stator 302 is directly inserted into the groove structure for plugging. In the present embodiment, preferably, the cross-sectional shape of the groove structure is adapted to the shape of the free end of the side shell of the stator 302, so that the stator 302 can be quickly and accurately installed on the motor housing 101, while ensuring the coaxiality of the stator 302 and the rotor 301. After the stator 302 is plugged into the motor housing 101 , the stator 302 is connected to the motor housing 101 by screws to be fixed, so as to ensure that the stator 302 and the motor housing 101 will not become loose when the motor is vibrated during operation.

[0041] Further optimization scheme, in some feasible embodiments, the other end of the side shell is also provided with a connecting piece, the connecting piece is coaxially arranged with the side shell, and the connecting piece protrudes from the peripheral side of the side shell, that is, the other end of the side shell is provided with a flange, the connection piece is arranged so that the stator 302 is connected to the motor housing 101, and the connecting piece is fixedly connected to the end of the side shell, and the fixing method is preferably integrally formed. Along the circumferential direction of the side shell, a plurality of positioning pieces are arranged on the connecting piece, and a positioning hole is arranged at a corresponding position of the motor housing 101, and the positioning piece is plugged and matched with the positioning hole, so as to quickly position the stator 302 during the installation process, and at the same time control the coaxiality of the stator 302 and the rotor 301, ensure the coaxiality relationship between the stator 302 and the rotor 301, and then ensure the coaxiality relationship between the stator 302 and the motor output shaft, so that the stator 302 will not interfere with the rotation of the rotor 301.

[0042] The positioning member is a column structure, such as a cylinder, and the positioning hole is a hole structure. The cross-sectional shape of the positioning member is adapted to the cross-sectional shape of the positioning hole. When the stator 302 is installed, the positioning member on the stator 302 is directly inserted into the positioning hole on the motor housing 101 for positioning. After the positioning is completed, the stator 302 and the motor housing 101 are fixedly connected together by bolts and other connecting members to ensure that the stator 302 and the motor housing 101 will not loosen when the motor is vibrated during operation, thereby ensuring the reliability of the connection between the stator 302 and the motor housing 101.

[0043] In order to protect the measuring device 201 and the signal processing device located in the internal space of the stator 302 and prevent the measuring device 201 and the signal processing device from being affected by external factors such as dripping, the connection between the stator 302 and the motor housing 101 is sealed. The sealing treatment can be performed by sealing with a sealant or by setting a sealing ring at the connection for sealing.

[0044] A center hole is provided at the center of the end shell of the stator 302, which passes through the end shell so that when the stator 302 is installed, the motor output shaft can pass through the through hole, so that the stator 302 is passed on the motor output shaft and fixedly connected to the motor housing 101. The diameter of the through hole is not less than the diameter of the motor output shaft and will not interfere with the rotation of the motor output shaft.

[0045] The above-mentioned rotor 301 is an annular plate structure with a center hole. The rotor 301 is mounted on the motor output shaft and fixed on the motor output shaft by a key, so that the rotor 301 rotates with the rotation of the motor output shaft. The diameter of the rotor 301 is not greater than the inner diameter of the stator 302, so that the rotor 301 can rotate relative to the stator 302, and the stator 302 will not interfere with the rotation of the rotor 301. The rotor 301 is located in the internal space of the stator 302, and the stator 302 protects the rotor 301 to prevent the rotation of the rotor 301 from causing harm to the user when the torque sensor 3 is in use.

[0046] In some feasible embodiments, the number of rotors 301 can be one or more. When the number of rotors 301 is multiple, the multiple rotors 301 are arranged in sequence along the axial direction of the motor output shaft, and the multiple rotors 301 can be arranged at equal intervals or at non-equal intervals. The number and arrangement method of the rotors 301 are selected and set according to actual needs, and no specific requirements are made here.

[0047] A motor, such as Figure 1 As shown, it includes the built-in motor torque sensor 3 as mentioned above. The torque sensor 3 is arranged on the motor and is located on one side of the output shaft. The output shaft installed on the motor rotor 2 extends out of the motor body 1. The torque sensor 3 is installed on the motor output shaft and is connected to the motor housing 101.

[0048] When installing the torque sensor 3, the measuring device 201 is pasted on the plane structure on the motor output shaft, the signal processing device is connected to the measuring device 201, and the signal processing device is installed in the installation groove of the motor output shaft and fixed; then the rotor 301 is installed, the rotor 301 and the motor output shaft are matched by keys, the rotor 301, the signal processing device and the measuring device 201 are arranged in sequence along the axial direction of the motor output shaft, the rotor 301 is arranged on the free end side close to the motor output shaft, and then the stator 302 is installed, the open end of the stator 302 faces the motor body 1, the end shell of the stator 302 is penetrated on the motor output shaft through the center hole, and the free end of the side shell of the stator 302 and the motor housing are quickly positioned through the positioning structure, the stator 302 is plugged into the motor housing 101, and fixedly connected by screws, the stator 302 is fixed to the motor housing 101, and the torque sensor 3 is installed.

[0049] The measuring device 201 is attached to the motor output shaft, and the stator 302 is connected to the housing, so that the torque sensor 3 can be integrated on the motor. By arranging the strain gauge and the signal processing device in the space formed by the stator 302 and the rotor 301, the torque sensor 3 is small in size and occupies a small space when installed, thereby shortening the overall length of the motor output shaft; the rotation of the rotor 301 of the torque sensor 3 is carried on the motor output shaft, omitting the arrangement of the rotor 301 bearing when installing the traditional torque sensor 3, thereby simplifying the installation structure of the torque sensor 3;

[0050] The length of the motor output shaft and the weight of the rotor 301 of the torque sensor 3 are important factors affecting the dynamics of the motor rotor 2. The dynamics of the motor rotor 2 affects the high speed of the motor. The specifications and speed of the motor rotor 2 have a direct impact on the vibration of the motor. The vibration of the motor will directly affect the performance of the motor. The torque sensor 3 is integrated on the motor to shorten the length of the motor output shaft, and also reduces the overall weight of the motor rotor 2, thereby improving the curve parameters of the dynamics of the motor rotor 2.

[0051] When verifying the motor performance parameters, it is necessary to connect it with the standard motor so that the two form a dragging relationship. When connecting, the output shafts of the two motors need to be connected through a coupling. The connection process needs to ensure the coaxiality of the shaft (motor alignment). The integrated design of the torque sensor 3 and the motor output shaft simplifies the two alignments into one alignment, which saves time while also improving the alignment accuracy and reducing noise and vibration.

[0052] Due to the adoption of the above technical solution, the torque sensor has a connected measuring device and a signal processing device, both of which are installed on the motor output shaft, the rotor of the torque sensor is fixedly installed on the motor output shaft, the sensor rotor rotates with the motor rotor, the stator of the torque sensor is penetrated through the motor output shaft and fixedly connected to the motor housing, the stator protects the measuring device, signal processing device and rotor located in its internal space, the torque sensor is coupled and integrated on the motor output shaft, the rotation of the sensor rotor relies on the motor output shaft, the high-speed bearing when the traditional torque sensor is installed is omitted, the installation structure of the torque sensor is simplified, and the length of the motor output shaft is shortened; the measuring device is a strain gauge, and the signal processing device is a control board with components, the components are of patch type, so that the measuring device and the signal processing device are light in weight and have little effect on the movement of the motor rotor. The balance has little impact, improves the dynamics of the motor rotor, and delays the occurrence of the critical speed resonance point; the motor and the standard motor output shaft are directly connected through a coupling, avoiding the transition of the flanges at both ends of the traditional torque sensor, reducing the coupling used when connecting the motor to the standard motor, and making the alignment of the two motor shafts better. During high speed and torque transmission, the vibration is small, and there is no sharp noise at the coupling, which reduces the motor alignment cost and noise; during torque transmission, the vibration is small, the accuracy loss of the torque sensor is small, and the drift of the torque sensor is zero when recalibrated, which improves the accuracy of repeated test data, improves the accuracy of the motor's test parameters, reduces the impact of the dynamic balance of the motor rotor, and ensures the stability of the motor at high speed; the torque sensor bearings are streamlined, the support points of the rotor are reduced, and the maintenance cost is reduced.

[0053] The above is a detailed description of the embodiments of the utility model, but the contents are only preferred embodiments of the utility model and cannot be considered to limit the scope of implementation of the utility model. All equivalent changes and improvements made within the scope of application of the utility model should still fall within the scope of the patent coverage of the utility model.

Claims

1. A built-in motor torque sensor, characterized in that: The invention comprises a measuring device arranged on the output shaft of the motor, a stator connected to the motor housing, a signal processing device arranged on the output shaft of the motor and a rotor arranged on the output shaft of the motor, wherein the rotor can rotate relative to the stator, the measuring device and the signal processing device are both arranged in a space formed by the stator and the rotor, and the signal processing device receives and processes the deformation signal generated by the measuring device and outputs the torque measurement result.

2. The built-in motor torque sensor according to claim 1, characterized in that: A plane structure is provided on the outer side of the motor output shaft, and the measuring device is pasted on the plane structure.

3. The built-in motor torque sensor according to claim 2, characterized in that: The measuring device is a strain gauge.

4. The built-in motor torque sensor according to any one of claims 1 to 3, characterized in that: A positioning structure is provided at the contact point between the motor housing and the stator for positioning during the stator installation process.

5. The built-in motor torque sensor according to claim 4, characterized in that: The positioning structure includes: a positioning hole provided on the motor housing and a positioning piece provided on the stator, the stator piece corresponds to the positioning hole, and the positioning piece is plugged and matched with the positioning hole to control the coaxiality of the stator and the rotor.

6. The built-in motor torque sensor according to claim 4, characterized in that: The positioning structure is a stopper structure.

7. The built-in motor torque sensor according to any one of claims 1-3 and 5-6, characterized in that: The motor output shaft is provided with a mounting groove, and the signal processing device is arranged in the mounting groove.

8. The built-in motor torque sensor according to claim 7, characterized in that: A sealing structure is provided at the connection between the stator and the motor housing to seal the contact between the stator and the motor housing.

9. The built-in motor torque sensor according to claim 1, characterized in that: The signal processing device comprises a signal processing module and a signal transmission module connected to each other. The signal processing module receives the deformation signal of the measuring device and processes the deformation signal. The processed signal is outputted via the signal transmission module.

10. A motor, characterized in that: It comprises a built-in motor torque sensor as described in any one of claims 1 to 9, wherein the torque sensor is arranged on one side of the motor output shaft and is respectively connected to the motor output shaft and the motor housing.

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