A contactless brushless torque sensor based on axial measurement

Abstract

The present invention discloses a contactless brushless torque sensor based on axial measurement, which includes a torsion transmission unit, including a transmission shaft, a steel belt, a rotating body, a deformation conversion mechanism and a housing structure, and all exist in pairs; the rotating body is fixedly connected to the transmission shaft, and the paired rotating bodies are connected by a steel belt; the deformation conversion mechanism rotates synchronously with the rotating body, and the height change side of the deformation conversion mechanism is in close contact with the housing; a strain detection unit, which includes 4 strain gauges forming a full-bridge form, and 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, and the voltage signal processing unit is connected to the strain detection unit, and the voltage signal processing unit converts the collected electrical signal into a digital signal. The present invention can realize the long-term accurate measurement of the torque received by the high-speed rotating shaft by measuring the voltage signal generated by the electrical strain gauges arranged on the outer shell and performing conversion.

Description

Technical Field

[0001] The present invention relates to the technical field of brushless torque sensors, and particularly to a contactless brushless torque sensor based on axial measurement. Background Art

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

[0003] Limitations of contact measurement: Traditional contact torque measurement methods, such as strain gauge torque testing methods, may have large signal errors due to poor brush contact or detachment. In addition, contact measurement may be affected by shaft deflection and axial offset, affecting measurement accuracy. Challenges brought by high-speed rotation: In the case of high-speed rotation, due to strong vibrations, problems such as test failure may occur in methods such as magnetoelastic and magnetoelectric methods. Signal transmission problems: Conductive slip rings in contact measurement have problems of wear and heat generation, which limit the rotational speed and service life of the rotating shaft and may cause measurement errors. Influence of environmental factors: The performance of the torque sensor may be affected by external environments such as temperature, humidity, and vibration, 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 complex and requires professional technical personnel to operate. Nonlinear error: The torque sensor may have nonlinear errors after long-term use and requires regular calibration and maintenance. Challenges in dynamic measurement: For dynamic or time-varying torque measurement, traditional methods may not be applicable and more advanced technologies are needed 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 problems in torque measurement of high-speed rotating shafts in large-scale heavy industrial complex equipment and the defects existing in existing torque sensing technologies, there is an urgent need for a sensor that can solve these problems. Summary of the Invention

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

[0006] To this end, the present invention provides a contactless brushless torque sensor based on axial measurement. By converting the torque deformation of the rotating shaft into axial tension of the sensor housing, and measuring the voltage signal generated by the electrical strain gauges arranged on the housing and performing conversion, long-term and accurate measurement of the torque received by the high-speed rotating shaft can be achieved.

[0007] To achieve the above object, on the one hand, the present invention provides a contactless brushless torque sensor based on axial measurement, including: a torsion transmission unit, a strain detection unit, and a voltage signal processing unit, wherein,

[0008] The torsional transmission unit includes a transmission shaft, a steel belt, a rotating body, a deformation conversion mechanism, and a housing structure, and all exist in pairs; the rotating body is fixedly connected to the transmission shaft, and the paired rotating bodies are connected by the steel belt; the deformation conversion mechanism rotates synchronously with the rotating body;

[0009] The strain detection unit includes 4 strain gauges that form a full-bridge configuration. The strain gauges are evenly pasted on the housing of the torsional 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 the voltage signal processing unit 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 contactless brushless torque sensor based on axial measurement according to the embodiment of the present invention may further have the following additional technical features:

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

[0013] In an embodiment of the present invention, the rotating body is provided with a threaded connection hole for connecting with the steel belt.

[0014] In an embodiment of the present invention, both ends of the deformation conversion mechanism are spherical surfaces, and the complete spherical surfaces corresponding to the two ends intersect.

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

[0016] In an embodiment of the present invention, the deformation conversion mechanism rotates with the rotation angle generated by the rotating body; the increase in the height of the deformation conversion mechanism in the direction of the rotating shaft causes the housing to generate tensile deformation in the direction of the rotating shaft.

[0017] In an embodiment of the present invention, the two sides of the housing are connected by a flange, and both sides of the housing have extension strips. The extension strips connect the near-axis end and the far-axis end of the housing by a flange and are arranged at intervals of 90 degrees along the circumferential direction.

[0018] In one embodiment of the present invention, let R1, R2, R3, and R4 be strain gauges pasted on the housing, where R1 and R3 are fixed along the transmission shaft direction, and R2 and R4 are fixed perpendicular to the transmission shaft direction. The deformation of the housing is converted into a change in resistance by the four strain gauges, and then converted into a voltage signal by a bridge to obtain a voltage change amount. The maximum strain of the housing is obtained through the voltage signal processing unit. The relationship is as follows:

[0019]

[0020] Where, is the input voltage, is the sensitivity coefficient of the resistance strain gauge, is the Poisson's ratio of the housing material, and the maximum strain , is the length of the extension strip, is the height increase value of the deformation conversion mechanism in the direction of the rotation axis.

[0021] In one embodiment of the present invention, when the deformation conversion mechanism has a deflection angle with the initial position, at this time, the preset line segment is parallel to the rotation axis direction, and the height increase of the deformation conversion mechanism in the direction of the rotation axis , , and the spherical radii at both ends are both , where , is the center point of the preset line segment . Then:

[0022] .

[0023] In one embodiment of the present invention, the vertical distance from the installation position of the deformation conversion mechanism to the axis of the rotation axis is . When the deformation conversion mechanism has a deflection angle with the initial position, the disk rotation angle , and the deformation amount generated by the steel belt under force is:

[0024]

[0025] When the steel belt generates a deformation amount , the tension force on the steel belt is:

[0026]

[0027] Where, is the original length of the steel belt, is the cross-sectional area of the steel belt, is the elastic modulus of the steel strip material;

[0028] The torque received by the transmission shaft is:

[0029] 。

[0030] The contactless brushless torque sensor based on axial measurement in the embodiment of the present invention has the housing and strain gauges of the device not rotating with the transmission shaft, convenient power supply, excellent guarantee of rotational dynamic balance, and the present invention is a contact type strain measurement, having the advantages of simple 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, become apparent in part from the following description, or be understood through the 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 be readily understood from the following description of the embodiments in conjunction with the drawings, wherein:

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

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

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

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

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

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

[0039] Reference numerals: 1, transmission shaft; 2, steel strip; 3, rotating body; 4, deformation conversion mechanism; 5, housing; 6, strain gauge; 7, extension strip. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] It should be noted that, without conflict, the embodiments in 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 drawings and in conjunction with the embodiments.

[0041] To enable those skilled in the art to better understand the solution of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0042] The following describes a contactless brushless torque sensor based on axial measurement according to an embodiment of the present invention with reference to the accompanying drawings.

[0043] Figure 1 It is a structural diagram of a contactless 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. Among them, as Figure 1 shown, the contactless 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; among them

[0044] The torsion transmission unit 100 includes structures such as a transmission shaft 1, a steel belt 2, a rotating body 3, a deformation conversion mechanism 4, and a housing 5, and all exist in pairs; the rotating body 3 is fixedly connected to the transmission shaft 1, and at the same time, the two rotating bodies are connected by the steel belt 2; the deformation conversion mechanism 4 rotates synchronously with the rotating body 3;

[0045] The strain detection unit 200 contains 4 strain gauges 6 and forms a full-bridge form; 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 with an interval of 180 degrees are in 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] Further, the rotation center axes of the transmission shaft 1, the rotating body 3, and the housing 5 are all coaxial.

[0048] Further, the rotating body 3 is provided with a threaded connection hole for connecting with the steel belt 2.

[0049] Further, both ends of the deformation conversion mechanism 4 are spherical surfaces, and the complete spherical surfaces corresponding to the two ends intersect.

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

[0051] Further, the deformation conversion mechanism rotates with the rotation angle generated by the rotating body; the increase in the height of the deformation conversion mechanism in the direction of the rotating shaft causes the housing to generate tensile deformation in the direction of the rotating shaft.

[0052] Further, the two side housings 5 are connected by flanges, and both side housings 5 are provided with extension strips 7. The extension strips connect the proximal end and the distal end of the housing 5 by flanges and are arranged at intervals of 90 degrees in the circumferential direction, which is convenient for the positioning and installation of the strain gauges 6 in the strain detection unit.

[0053] It can be understood that flange connection is a widely used connection method in industrial pipelines, which realizes the connection between pipelines or equipment through the combination of flange plates, bolts and gaskets. The embodiments of the present invention will not be elaborated further.

[0054] Further, Figure 4 is a schematic diagram of the pasting positions of the strain gauges on the torque sensor housing according to the embodiments of the present invention. As Figure 4 shown, R1, R2, R3 and R4 are resistance strain gauges pasted on the outer shell. Among them, R1 and R3 are fixed along the direction of the transmission shaft, and R2 and R4 are fixed perpendicular to the direction of the transmission shaft. The 4 strain gauges are formed into a full-bridge form. The 4 strain gauges convert the deformation of the outer shell into a change in resistance and convert it into a voltage signal by the bridge, so as to obtain the voltage change amount , and through the voltage signal processing unit, the maximum strain of the housing 5 can be obtained , and the relationship between the two parameters is as follows:

[0055]

[0056] Among them, is the input voltage, is the sensitivity coefficient of the resistance strain gauge, is the Poisson's ratio of the housing material, and the maximum strain , is the length of the extension strip 7, is the height increase value of the deformation conversion mechanism 4 in the direction of the rotating shaft.

[0057] Further, Figure 5 is a schematic diagram of the principle of the torque sensor deformation conversion mechanism. As Figure 5 shown, when the deformation conversion mechanism 4 generates a deflection angle with the initial position, at this time is parallel to the direction of the rotating shaft, and the height of the deformation conversion mechanism 4 in the direction of the rotating shaft rises , , and the spherical radii at both ends are both , where , is 's center point, then:

[0058]

[0059] Furthermore, Figure 6 is a schematic diagram of the principle of the steel strip of the torque sensor according to an embodiment of the present invention. As Figure 6 shown, the perpendicular distance from the installation position of the deformation conversion mechanism to the axis of the rotating shaft is . When the deformation conversion mechanism 4 has a deflection angle with the initial position, then the disk rotation angle , and the deformation amount generated by the force on the steel strip is:

[0060]

[0061] When the steel strip generates a deformation amount , the tensile force on the steel strip is:

[0062]

[0063] where is the original length of the steel strip; is the cross-sectional area of the steel strip; is the elastic modulus of the steel strip material.

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

[0065] The contactless brushless torque sensor based on axial measurement according to an 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. It can be used for torque detection on the high-speed rotating transmission shafts of heavy industrial complex equipment such as large generator sets, continuous rolling mills, and wind power generation equipment. The sensor adopts a unique deformation conversion mechanism, so that the housing and the strain gauge do not rotate with the transmission shaft, and the torsional displacement is converted into an axial displacement. Therefore, the problems of difficult power supply and difficult to ensure rotational dynamic balance of the existing torque sensor are solved.

[0066] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection 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, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0067] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

Claims

1. A contactless 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. Among them, the torsion transmission unit includes a transmission shaft, a steel belt, a rotating body, a deformation conversion mechanism, and a housing structure, and all exist in pairs; the rotating body is fixedly connected to the transmission shaft, and the paired rotating bodies are connected by the steel belt; the deformation conversion mechanism rotates synchronously with the rotating body; the strain detection unit includes 4 strain gauges that form a full-bridge configuration. 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. 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. The voltage signal processing unit 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; both ends of the deformation conversion mechanism are spherical surfaces, and the complete spherical surfaces corresponding to the spherical surfaces at both ends intersect; the deformation conversion mechanism rotates with the rotation angle generated by the rotating body; the increase in the height of the deformation conversion mechanism in the direction of the rotation axis causes the housing to produce tensile deformation in the direction of the rotation axis.

2. The contactless brushless torque sensor based on axial measurement according to claim 1, wherein the rotation axes of the transmission shaft, the rotating body, and the housing are all coaxial.

3. The contactless brushless torque sensor based on axial measurement according to claim 1, characterized in that, threaded connection holes are provided on the rotating body, and the threaded connection holes are used to connect with the steel belt.

4. The contactless brushless torque sensor based on axial measurement according to claim 2, wherein the vertical distances from the installation positions of the two endpoints of the steel belt to the axis of the rotation axis are equal, and when the rotation axis to be measured rotates, the steel belt is stretched by force and causes the rotating body to rotate.

5. The contactless brushless torque sensor based on axial measurement according to claim 1, characterized in that the two side housings are connected by flanges, and both side housings have extension strips. The extension strips connect the near-axis end and the far-axis end of the housing by flanges and are arranged at intervals of 90 degrees along the circumferential direction.

6. The contactless brushless torque sensor based on axial measurement according to claim 1, characterized in that, Let R1, R2, R3, and R4 be strain gauges pasted on the housing, where R1 and R3 are fixed along the direction of the transmission shaft, and R2 and R4 are fixed perpendicular to the direction of the transmission shaft. The deformation of the housing is converted into a change in resistance through the four strain gauges, and is converted into a voltage signal by a bridge to obtain a voltage change amount , and the maximum strain of the housing is obtained through the voltage signal processing unit , and the relationship is as follows Among them, is the input voltage, is the sensitivity coefficient of the resistance strain gauge, is the Poisson's ratio of the housing material, and the maximum strain , is the length of the extension strip, is the height increase value of the deformation conversion mechanism in the direction of the rotation axis.

7. The contactless brushless torque sensor based on axial measurement according to claim 1, characterized in that When the deformation conversion mechanism has an angular deviation from the initial position At this time, the preset line segment is parallel to the direction of the rotation axis, and the height of the deformation conversion mechanism in the direction of the rotation axis increases , , and the spherical radii at both ends are both , where , is the center point of the preset line segment , then: 。 8. The contactless brushless torque sensor based on axial measurement according to claim 7, characterized in that, The vertical distance from the installation position of the deformation conversion mechanism to the axis of the rotating shaft is , when the deformation conversion mechanism generates a deflection angle with the initial position, the rotation angle of the disc , and the deformation amount generated by the steel belt under force is: When the steel strip has a deformation the tensile force on the steel strip is: Among them, is the original length of the steel strip, is the cross-sectional area of the steel strip, is the elastic modulus of the steel strip material; The torque received by the transmission shaft is: 。

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