Contact type brushless torque sensor based on axial measurement

Abstract

The invention discloses a contact-type brushless torque sensor based on axial measurement, and the sensor comprises a torsion transmission unit which comprises a transmission shaft, a steel belt, a rotating body, a deformation conversion mechanism, and a housing structure, and the transmission shaft, the steel belt, the rotating body, the deformation conversion mechanism, and the housing structure exist in pairs. The rotating bodies are fixedly connected with the transmission shaft, and the paired rotating bodies are connected through a steel belt; the deformation conversion mechanism and the rotating body rotate synchronously, and the height change side of the deformation conversion mechanism is tightly attached to the shell. The strain detection unit comprises four strain gauges forming a full-bridge form, the strain gauges are uniformly pasted on a shell of the torsion transmission unit at intervals of 90 degrees in the circumferential direction and are divided into two groups according to the installation direction, the two groups are fixed in the axial direction and the direction perpendicular to the axial direction respectively, and the voltage signal processing unit is connected with the strain detection unit. The voltage signal processing unit converts the collected electric signals into digital signals. According to the invention, the torque borne by the high-speed rotating shaft can be accurately measured for a long time by measuring and converting the voltage signal generated by the electric strain gauge arranged on the shell.

Description

Technical Field

[0001] The invention relates to the technical field of brushless torque sensors, and in particular to a contact-type brushless torque sensor based on axial measurement. Background Art

[0002] The existing torque measurement problems of high-speed rotating shafts in large-scale heavy industrial complex equipment and the problems existing in the existing torque sensing technology may include the following defects:

[0003] Limitations of contact measurement: Traditional contact torque measurement methods, such as strain gauge torque test methods, may cause large signal errors due to poor contact or falling of the brush. In addition, contact measurement may be affected by the deflection and axial offset of the shaft, affecting the measurement accuracy. Challenges brought by high-speed rotation: In the case of high-speed rotation, strong vibration may cause test failure, such as magnetoelastic, magnetoelectric and other methods. Signal transmission problems: The conductive slip ring in contact measurement has wear and heating problems, which limits the speed and service life of the rotating shaft and may cause measurement errors. Environmental factors: The performance of the torque sensor may be affected by the external environment, such as temperature, humidity, vibration, etc., which may lead to unstable measurement results. Cost and installation complexity: The manufacturing and maintenance costs of torque sensors are relatively high, and the installation process is complicated and requires professional technicians to operate. Nonlinear error: Torque sensors may have nonlinear errors after long-term use and require regular calibration and maintenance. Challenges of dynamic measurement: For dynamic or time-varying torque measurement, traditional methods may not be applicable, and more advanced technologies are required to achieve accurate measurement. Measurement difficulties in special environments: In extreme environments such as high temperature, high humidity, and dust, electromagnetic torque sensors may face measurement difficulties.

[0004] In view of the problem of torque measurement of high-speed rotating shafts in large-scale heavy industrial complex equipment and the defects of existing torque sensing technology, a sensor that can solve the problems is urgently needed. Summary of the invention

[0005] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0006] To this end, the present invention proposes a contact-type brushless torque sensor based on axial measurement, which converts the torque deformation of the rotating shaft into the axial tension of the sensor housing, and measures and converts the voltage signal generated by the electric strain gauge arranged on the housing to achieve long-term and accurate measurement of the torque exerted on the high-speed rotating shaft.

[0007] To achieve the above-mentioned object, the present invention proposes a contact-type brushless torque sensor based on axial measurement, comprising: a torsion transmission unit, a strain detection unit and a voltage signal processing unit, wherein:

[0008] The torsion transmission unit comprises a transmission shaft, a steel belt, a rotating body, a deformation transformation mechanism and a shell structure, and all of them exist in pairs; the rotating body is fixedly connected to the transmission shaft, and the paired rotating bodies are connected through the steel belt; the deformation transformation mechanism rotates synchronously with the rotating body, and the height change side of the deformation transformation mechanism is in close contact with the shell;

[0009] The strain detection unit comprises four strain gauges forming a full bridge, the strain gauges are evenly pasted on the housing of the torsion transmission unit at intervals of 90 degrees along the circumferential direction, and are divided into two groups according to the installation direction, and the two groups are fixed along the axial direction and perpendicular to the axial direction respectively;

[0010] The voltage signal processing unit is connected to the strain detection unit, and is used to convert the collected electrical signal into a digital signal; the voltage signal processing unit includes a signal conditioner, a data acquisition card and a computer.

[0011] The contact-type brushless torque sensor based on axial measurement in the embodiment of the present invention may also have the following additional technical features:

[0012] In one embodiment of the present invention, the transmission shaft, the rotating body and the rotating axis of the housing are all coaxial.

[0013] In one embodiment of the present invention, a threaded connection hole and a cylindrical hole are provided on the rotating body, the threaded connection hole is used to connect with the steel belt, and the cylindrical hole is used to install the deformation conversion mechanism.

[0014] In one embodiment of the present invention, the two ends of the deformation transformation mechanism are spherical surfaces, the middle is a cylinder, and the complete spherical surfaces corresponding to the two end spherical surfaces intersect.

[0015] In one embodiment of the present invention, the installation positions of the two end points of the steel belt are at equal vertical distances from the axis of the rotating shaft, and when the rotating shaft to be measured rotates, the steel belt is stretched and causes the rotating body to rotate.

[0016] In one embodiment of the present invention, the deformation transformation mechanism rotates with the rotation angle generated by the rotating body; the height of the deformation transformation mechanism along the rotation axis direction increases so that the shell generates tensile deformation along the rotation axis direction.

[0017] In one embodiment of the present invention, the shells on both sides are connected by flanges, and both shells have extended slats, which connect the proximal end and the distal end of the shells through flanges and are arranged at 90 degrees in the circumferential direction.

[0018] In one embodiment of the present invention, R1, R2, R3 and R4 are strain gauges attached to the housing, wherein R1 and R3 are fixed along the transmission axis, and R2 and R4 are fixed perpendicular to the transmission axis. The deformation of the housing is converted into a change in resistance through the four strain gauges, and then converted into a voltage signal by a bridge to obtain a voltage change ΔU. The maximum strain ε of the housing is obtained by the voltage signal processing unit, and the relationship is as follows:

[0019]

[0020] Among them, U is the input voltage, K is the sensitivity coefficient of the resistance strain gauge, μ is the Poisson's ratio of the shell material, the maximum strain ε=ΔH / 2L0, L0 is the length of the extended strip, and ΔH is the height rise value of the deformation transformation mechanism along the rotation axis direction.

[0021] In one embodiment of the present invention, when the deformation transformation mechanism has a deviation angle α from the initial position, the preset line segment BB′ is parallel to the rotation axis direction, and the height of the deformation transformation mechanism along the rotation axis direction rises by ΔH, ΔH=BB'-H, and the spherical radii at both ends are R, wherein BO1=B'O2=R, O is the center point of the preset line segment AA′, then:

[0022]

[0023] In one embodiment of the present invention, the vertical distance between the installation position of the deformation transformation mechanism and the axis of the rotating shaft is r'. When the deformation transformation mechanism has an angle α with the initial position, the disc rotation angle The deformation of the steel belt caused by the force is:

[0024]

[0025] When the steel belt is deformed by ΔL, the tension on the steel belt is:

[0026]

[0027] Wherein, L is the original length of the steel strip, A is the cross-sectional area of ​​the steel strip, and E is the elastic modulus of the steel strip material;

[0028] The torque on the drive shaft is:

[0029] T = 2·cos45°·Fr.

[0030] The contact-type brushless torque sensor based on axial measurement in the embodiment of the present invention has a housing and a strain gauge that do not rotate with the transmission shaft, is easily powered, and can excellently ensure rotational dynamic balance. In addition, the present invention is a contact-type strain measurement, which has the advantages of easy installation, good reliability, and high measurement accuracy.

[0031] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0033] Figure 1 is a structural schematic diagram of a contact-type brushless torque sensor based on axial measurement according to an embodiment of the present invention;

[0034] Figure 2 is an overall assembly diagram of a contact-type brushless torque sensor structure based on axial measurement according to an embodiment of the present invention;

[0035] Figure 3 is a semi-assembly diagram of a contact-type brushless torque sensor structure based on axial measurement according to an embodiment of the present invention;

[0036] Figure 4 is a schematic diagram of the pasting position of the strain gauge on the housing of the torque sensor according to an embodiment of the present invention;

[0037] Figure 5 is a schematic diagram of the principle of a deformation conversion mechanism of a torque sensor according to an embodiment of the present invention;

[0038] Figure 6 is a schematic diagram of the principle of a torque sensor steel strip according to an embodiment of the present invention;

[0039] Explanation of reference numerals: 1. Transmission shaft; 2. Steel belt; 3. Rotating body; 4. Deformation transformation mechanism; 5. Housing; 6. Strain gauge; 7. Extension strip. DETAILED DESCRIPTION

[0040] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0041] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0042] The contact-type brushless torque sensor based on axial measurement according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0043] Figure 1 This is a structural diagram of a contact-type brushless torque sensor based on axial measurement of the present invention. Figure 2 and Figure 3 It is an assembly diagram of the present invention. Figure 1 As shown, the contact-type brushless torque sensor 10 based on axial measurement includes a torsion transmission unit 100, a strain detection unit 200 and a voltage signal processing unit 300; wherein

[0044] The torsion transmission unit 100 includes a transmission shaft 1, a steel belt 2, a rotating body 3, a deformation transformation mechanism 4 and a shell 5, and all of them exist in pairs; the rotating body 3 is fixedly connected to the transmission shaft 1, and the two rotating bodies are connected by the steel belt 2; the deformation transformation mechanism 4 rotates synchronously with the rotating body 3; the height change side of the deformation transformation mechanism 4 is in close contact with the shell 5;

[0045] The strain detection unit 200 includes four strain gauges 6, which form a full bridge. The strain gauges 6 are evenly pasted on the housing 5 of the torsion transmission unit 100 at intervals of 90 degrees along the circumferential direction, and are divided into two groups according to their installation directions. The two groups are fixed along the axial direction and perpendicular to the axial direction, respectively, and the strain gauges 6 at intervals of 180 degrees form one group.

[0046] The voltage signal processing unit 300 includes a signal conditioner, a data acquisition card and a computer, and is connected to the strain detection unit. The voltage signal processing unit 300 can convert the electrical signal into a digital signal.

[0047] Furthermore, the rotation center axes of the transmission shaft 1, the rotating body 3 and the housing 5 are all coaxial.

[0048] Furthermore, a threaded connection hole and a cylindrical hole are provided on the rotating body 3. The threaded connection hole is used for connection with the steel belt 2, and the cylindrical hole is used for installation of the deformation conversion mechanism.

[0049] Furthermore, the two ends of the deformation transformation mechanism 4 are spherical surfaces, the middle is a cylinder, and the complete spherical surfaces corresponding to the two end spherical surfaces intersect.

[0050] Furthermore, the installation positions of the two end points of the steel belt 2 are at equal vertical distances from the axis of the rotating shaft, and when the rotating shaft to be measured rotates, the steel belt 2 is stretched and causes the rotating body 3 to rotate.

[0051] Furthermore, the deformation transformation mechanism rotates with the rotation angle generated by the rotating body; the height of the deformation transformation mechanism along the rotation axis direction increases so that the shell generates tensile deformation along the rotation axis direction.

[0052] Furthermore, the two side shells 5 are connected by flanges, and both side shells 5 have extended strips 7, which connect the proximal end and the distal end flanges of the shells 5 and are arranged at 90 degrees in the circumferential direction, so as to facilitate the positioning and installation of the strain gauge 6 in the strain detection unit.

[0053] It is understandable that flange connection is a widely used connection method in industrial pipelines, which realizes the connection between pipelines or equipment by combining components such as flanges, bolts and gaskets. The embodiments of the present invention will not be described in detail.

[0054] Further, Figure 4 Schematic diagram of the pasting position of the strain gauge on the housing of the torque sensor according to an embodiment of the present invention. Figure 4 As shown, R1, R2, R3 and R4 are resistance strain gauges pasted on the housing, wherein R1 and R3 are fixed along the transmission axis, and R2 and R4 are fixed perpendicular to the transmission axis. The four strain gauges form a full bridge, and the four strain gauges convert the deformation of the housing into a change in resistance, which is then converted into a voltage signal by the bridge, thereby obtaining a voltage change ΔU. The maximum strain ε of the housing 5 can be obtained through the voltage signal processing unit. The relationship between the two parameters is as follows:

[0055]

[0056] Among them, U is the input voltage, K is the sensitivity coefficient of the resistance strain gauge, μ is the Poisson's ratio of the shell material, the maximum strain ε=ΔH / 2L0, L0 is the length of the extension strip 7, and ΔH is the height rise value of the deformation transformation mechanism 4 along the rotation axis direction.

[0057] Further, Figure 5 This is a schematic diagram of the principle of the torque sensor deformation conversion mechanism, such as Figure 5 As shown, when the deformation transformation mechanism 4 has a deviation angle α from the initial position, BB′ is parallel to the rotation axis direction, and the height of the deformation transformation mechanism 4 along the rotation axis direction rises by ΔH, ΔH=BB′-H, and the spherical radii at both ends are R, where BO1=B′O2=R, and O is the center point of AA′, then:

[0058]

[0059] Further, Figure 6 Schematic diagram of the principle of the torque sensor steel belt according to an embodiment of the present invention. Figure 6 As shown, the vertical distance between the installation position of the deformation transformation mechanism and the axis of the rotating shaft is r'. When the deformation transformation mechanism 4 has an angle α with the initial position, the rotation angle of the disk The deformation of the steel belt caused by the force is:

[0060]

[0061] When the steel belt is deformed by ΔL, the tension on the steel belt is:

[0062]

[0063] Where L is the original length of the steel strip; A is the cross-sectional area of ​​the steel strip; and E is the elastic modulus of the steel strip material.

[0064] At the same time, the torque on the transmission shaft is:

[0065] T=2·cos45°·Fr

[0066] According to the contact-type brushless torque sensor based on axial measurement in the embodiment of the present invention, the torque sensor of the present invention has the advantages of compact structure, high sensitivity, high measurement accuracy and high reliability, etc., and can be used for torque detection on high-speed rotating transmission shafts of complex heavy industrial equipment such as large-scale generator sets, continuous rolling mills and wind power generation equipment. The sensor adopts a unique deformation conversion mechanism, so that the housing and strain gauge do not rotate with the transmission shaft, and the torsional displacement is converted into axial displacement, thereby solving the problems of difficulty in power supply and difficulty in ensuring rotational dynamic balance of existing torque sensors.

[0067] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0068] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

Claims

1. A contact-type brushless torque sensor based on axial measurement, characterized in that: It includes a torsion transmission unit, a strain detection unit and a voltage signal processing unit, wherein: The torsion transmission unit comprises a transmission shaft, a steel belt, a rotating body, a deformation transformation mechanism and a shell structure, and all of them exist in pairs; the rotating body is fixedly connected to the transmission shaft, and the paired rotating bodies are connected through the steel belt; the deformation transformation mechanism rotates synchronously with the rotating body, and the height change side of the deformation transformation mechanism is in close contact with the shell; The strain detection unit comprises four strain gauges forming a full bridge, the strain gauges are evenly pasted on the housing of the torsion transmission unit at intervals of 90 degrees along the circumferential direction, and are divided into two groups according to the installation direction, and the two groups are fixed along the axial direction and perpendicular to the axial direction respectively; The voltage signal processing unit is connected to the strain detection unit, and is used to convert the collected electrical signal into a digital signal; the voltage signal processing unit includes a signal conditioner, a data acquisition card and a computer.

2. The contact-type brushless torque sensor based on axial measurement according to claim 1, characterized in that: The transmission shaft, the rotating body and the rotating shaft of the housing are all coaxial.

3. The contact-type brushless torque sensor based on axial measurement according to claim 1, characterized in that: The rotating body is provided with a threaded connection hole and a cylindrical hole, the threaded connection hole is used to be connected with the steel belt, and the cylindrical hole is used to install the deformation conversion mechanism.

4. The contact-type brushless torque sensor based on axial measurement according to claim 1, characterized in that: The two ends of the deformation transformation mechanism are spherical surfaces, the middle is a cylinder, and the complete spherical surfaces corresponding to the two end spherical surfaces intersect.

5. The contact-type brushless torque sensor based on axial measurement according to claim 2, characterized in that: The installation positions of the two end points of the steel belt are at equal vertical distances from the axis of the rotating shaft, and when the rotating shaft to be measured rotates, the steel belt is stretched by force and causes the rotating body to rotate.

6. The contact-type brushless torque sensor based on axial measurement according to claim 2, characterized in that: The deformation transformation mechanism rotates with the rotation angle generated by the rotating body; the height of the deformation transformation mechanism increases along the rotation axis direction, so that the shell generates tensile deformation along the rotation axis direction.

7. The contact-type brushless torque sensor based on axial measurement according to claim 1, characterized in that: The shells on both sides are connected by flanges, and both shells have extended strips, which connect the proximal end and the distal end of the shells through flanges and are arranged at intervals of 90 degrees in the circumferential direction.

8. The contact-type brushless torque sensor based on axial measurement according to claim 1, characterized in that: Assume that R1, R2, R3 and R4 are strain gauges attached to the housing, wherein R1 and R3 are fixed along the transmission axis, and R2 and R4 are fixed perpendicular to the transmission axis. The deformation of the housing is converted into a change in resistance through the four strain gauges, and then converted into a voltage signal by the bridge to obtain a voltage change ΔU. The maximum strain ε of the housing is obtained by the voltage signal processing unit, and the relationship is as follows: Among them, U is the input voltage, K is the sensitivity coefficient of the resistance strain gauge, μ is the Poisson's ratio of the shell material, the maximum strain ε=ΔH / 2L0, L0 is the length of the extended strip, and ΔH is the height rise value of the deformation transformation mechanism along the rotation axis direction.

9. The contact-type brushless torque sensor based on axial measurement according to claim 4, characterized in that: When the deformation transformation mechanism has a deviation angle α from the initial position, the preset line segment BB′ is parallel to the rotation axis, and the height of the deformation transformation mechanism along the rotation axis rises by ΔH, ΔH=BB'-H, and the spherical radii at both ends are R, where BO1=B'O2=R, and O is the center point of the preset line segment AA′, then:

10. The contact-type brushless torque sensor based on axial measurement according to claim 9, characterized in that: The vertical distance between the installation position of the deformation transformation mechanism and the axis of the rotating shaft is r'. When the deformation transformation mechanism has an angle α with the initial position, the disc rotation angle The deformation of the steel belt caused by the force is: When the steel belt is deformed by ΔL, the tension on the steel belt is: Wherein, L is the original length of the steel strip, A is the cross-sectional area of ​​the steel strip, and E is the elastic modulus of the steel strip material; The torque on the drive shaft is: T = 2·cos45°·Fr.

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