Rotating shaft torque measuring device and torque measuring method

Abstract

The present invention is applicable to the field of torque measurement technology and provides a rotating shaft torque measurement device and method. The device includes a detection disc and an inductive proximity sensor. The detection disc is mounted with a disc holder, and a magnet is provided at one end of the disc holder away from the detection disc, for attracting the measured shaft. The detection disc also has a fan-shaped window, and the detection probe of the inductive proximity sensor is aligned with the fan-shaped window. The inductive proximity sensor is mounted on a machine frame via a sensor holder, and the sensor holder is provided with a guide groove for mounting the inductive proximity sensor. The device can be installed at either end of any rotating shaft to measure torque without changing the transmission structure of the measured shaft itself or opening the machine for installation. It has a simple structure, takes up little space, and is easy to install. The inductive proximity sensor only senses metal and is not easily interfered with by other objects, allowing it to operate in complex environments.

Description

Technical Field

[0001] The present invention belongs to the technical field of torque measurement, and in particular relates to a rotating shaft torque measurement device and a torque measurement method. Background Art

[0002] Torque directly reflects the operating performance of a shaft and is the most important parameter to measure for rotating shafts. The challenge in measuring torque is how to quickly, reliably, accurately, and affordably measure this quantity while minimizing the impact of structural changes to the machine itself, which could affect the shaft's operating state, caused by installing a torque sensor.

[0003] Currently, the majority of torque measurement devices in China are contact-type devices, requiring direct connection to the shaft being measured to obtain the torque value. Depending on the operating state of the shaft being measured, these contact-type torque sensors can be divided into those requiring power transmission and those requiring non-power transmission. When measuring a drive shaft, because power transmission cannot be interrupted, the torque sensor must be installed somewhere between the shaft being measured and the next-level drive shaft, with a coupling installed between the sensor and the shaft. When measuring a driven shaft, the torque sensor must be installed at the end of the shaft being measured.

[0004] Installing these torque sensors requires modifying the transmission structure to reserve space for the sensor and installing a coupling to connect it to the shaft being measured. This occupies a large space, complicates the structure, and can affect the working state of the rotating shaft. These sensors require wireless transmission or conductive slip rings for energy and signal exchange. The conductive slip ring method is a contact measurement method, and prolonged contact between the conductive slip ring and the high-speed rotating shaft can easily damage the torque measurement device. Therefore, it is of great significance to develop a torque measurement device that is easy to install, simple in structure, and reliable in operation. Summary of the Invention

[0005] The purpose of the embodiments of the present invention is to provide a rotating shaft torque measurement device and a torque measurement method, aiming to solve the problems raised in the above background technology.

[0006] The embodiment of the present invention is implemented as follows: a rotating shaft torque measuring device includes a detection disc and an inductive proximity sensor;

[0007] A disc bracket is mounted on the detection disc, and a magnet is provided at one end of the disc bracket away from the detection disc, and the magnet is used to attract the shaft to be tested;

[0008] The detection disc is also provided with a fan-shaped window, and the detection probe of the inductive proximity sensor is aligned with the fan-shaped window;

[0009] The inductive proximity sensor is mounted on the rack via a sensor bracket, and the sensor bracket is provided with a guide groove for mounting the inductive proximity sensor.

[0010] According to a further technical solution, the sensor bracket is fixed to the frame by bolts.

[0011] According to a further technical solution, a boss is further provided on the detection disc bracket, and the boss cooperates with a nut to fasten the detection disc bracket to the detection disc.

[0012] According to a further technical solution, a set of measuring devices is provided at both ends of the measured shaft, and the two sets of measuring devices are installed symmetrically to keep the installation positions consistent.

[0013] Another object of an embodiment of the present invention is to provide a torque measurement method for a rotating shaft torque measurement device, based on the above-mentioned rotating shaft torque measurement device, comprising the following steps:

[0014] Step 1: Attach the magnets at the ends of the detection disc bracket to the two ends of the shaft to be measured, thereby installing the detection disc on the shaft to be measured; then install the inductive proximity sensor on the sensor bracket, and then install the sensor bracket on the frame of the shaft to be measured, and align the detection probe of the inductive proximity sensor with the fan-shaped window;

[0015] Step 2: When installing the detection disc, artificially delay the installation position of the detection disc at the end of the measured shaft; when the measured shaft is unloaded, the voltage pulse waveform detected by the inductive proximity sensor is obtained, and the time difference of the rising edge voltage signal is obtained. The time difference is recorded through the capture register of the microcontroller and recorded as the error calibration value , the calculation formula is:

[0016] ;

[0017] in: Timestamp recorded by the end proximity sensor, unit: ; Timestamp recorded by the front-end proximity sensor, unit: ; is the shaft speed, unit: r / s;

[0018] Finally, the recorded errors are accumulated 10 times and the average value is taken to ensure the accuracy of the error;

[0019] Step 3: When the measured shaft is loaded, the time difference between the rising edge voltage signals received by the inductive proximity sensors on both sides of the measured shaft will change with the load. The microcontroller reads the time difference between the rising edge voltage signals and obtains the torque value; the phase angle corresponding to the time difference between two adjacent rising edge pulse signals is The calculation formula is:

[0020] ;

[0021] in: Timestamp recorded by the end proximity sensor, unit: ; Timestamp recorded by the front-end proximity sensor, unit: ; is the shaft speed, unit: r / s;

[0022] Torque value The calculation formula is:

[0023] ;

[0024] in, is the elastic modulus of the measured shaft, unit: ; is the diameter of the shaft being measured, unit: ; is the length of the measured shaft, unit: .

[0025] The embodiments of the present invention provide a rotating shaft torque measurement device and a torque measurement method, which have the following beneficial effects:

[0026] (1) The structure of the device is simple and reliable. No electronic components or circuits need to be installed on the rotor, which will not cause wear.

[0027] (2) The device is easy to install without changing the original transmission structure. It has the characteristics of small space, low cost, easy to manufacture, and strong interchangeability. It effectively solves the problem of existing measuring devices that require changing the transmission structure, occupying a large space, poor interchangeability, and high cost when measuring torque.

[0028] (3) It can meet the torque measurement requirements of rotating shafts in harsh environments, with fast measurement and reliable results. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of a single-side structure of a rotating shaft torque measuring device provided by an embodiment of the present invention;

[0030] Figure 2 A schematic diagram of the installation of a rotating shaft torque measuring device provided by an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the sensor waveform when there is no load;

[0032] Figure 4 Schematic diagram of sensor waveform when there is load.

[0033] In the accompanying drawings: frame 1; detection disc 2; fan-shaped window 2-1; inductive proximity sensor 3; sensor bracket 4; guide groove 4-1; detection disc bracket 5; magnet 5-1; boss 5-2. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0035] The specific implementation of the present invention is described in detail below with reference to specific embodiments.

[0036] like Figure 1 and Figure 2 As shown, a rotating shaft torque measuring device provided by one embodiment of the present invention includes a detection disc 2 and an inductive proximity sensor 3;

[0037] A disc holder 5 is mounted on the detection disc 2. A magnet 5-1 is provided at one end of the disc holder 5 away from the detection disc 2. The magnet 5-1 is used to attract the shaft to be tested.

[0038] The detection disc 2 is also provided with a fan-shaped window 2-1, and the detection probe of the inductive proximity sensor 3 is aligned with the fan-shaped window 2-1;

[0039] The inductive proximity sensor 3 is mounted on the rack 1 via a sensor bracket 4 , and the sensor bracket 4 is provided with a guide groove 4 - 1 for mounting the inductive proximity sensor 3 .

[0040] In this embodiment of the present invention, the sensor bracket 4 is fixed to the frame 1 via bolts. During use, the magnets 5-1 at the ends of the detection disc bracket 5 are attached to the ends of the shaft being measured, thereby mounting the detection disc 2 on the shaft being measured. The inductive proximity sensor 3 is then mounted on the sensor bracket 4, which is then mounted on the frame 1 of the shaft being measured, with the detection probe of the inductive proximity sensor 3 aligned with the fan-shaped window 2-1. When the shaft is loaded, it undergoes circumferential torsional deformation, and the relative angle of the fan-shaped window 2-1 of the detection disc 2 also changes accordingly. This angle change is proportional to the torque, and the corresponding torque can be obtained by analyzing the relative angle change. When the inductive proximity sensor 3 approaches the fan-shaped window 2-1, the signal is low-level. When it rotates against the metal part, the signal changes from low to high. Due to the change in the relative angle of the fan-shaped window 2-1, the time difference between the rising edges of the signals received by the two inductive proximity sensors 3 also changes, which is linearly related to the axial torsional deformation of the shaft. The torsional angle is obtained by the time difference between the rising edge signals of the two inductive proximity sensors 3.

[0041] like Figure 1 and Figure 2 As shown in FIG. 5 , as a preferred embodiment of the present invention, the detection disc bracket 5 is further provided with a boss 5 - 2 , and the boss 5 - 2 cooperates with the nut 6 to fasten the detection disc bracket 5 to the detection disc 2 .

[0042] like Figure 2 As shown in FIG. 1 , as a preferred embodiment of the present invention, a set of measuring devices is provided at both ends of the measured shaft, and the two sets of measuring devices are symmetrically installed to keep the installation positions consistent.

[0043] Another embodiment of the present invention provides a torque measurement method for a rotating shaft torque measurement device, based on the above-mentioned rotating shaft torque measurement device, comprising the following steps:

[0044] Step 1: Attach the magnets 5-1 at the ends of the detection disc holder 5 to both ends of the shaft to be measured, thereby mounting the detection disc 2 on the shaft to be measured. Then, mount the inductive proximity sensor 3 on the sensor holder 4, which is then mounted on the frame 1 of the shaft to be measured, with the detection probe of the inductive proximity sensor 3 aligned with the fan-shaped window 2-1.

[0045] Step 2: The theoretical value of the rising edge signal time difference detected by the inductive proximity sensor 3 should be 0. However, in actual applications, it is impossible to guarantee that the parts processing and installation positions are absolutely accurate. Therefore, when installing the detection disc 2, the installation position of the detection disc 2 at the end of the measured shaft (the end corresponds to the front end and is only used to distinguish the two ends of the measured shaft) can be artificially delayed. When the measured shaft is not loaded, the voltage pulse waveform detected by the inductive proximity sensor 3 is as follows Figure 3 As shown, It is the time difference of the rising edge voltage signal. The capture register of the STM32F103 microcontroller (clock frequency is 1MHz) records the time difference and stores the value in the register as the error calibration value. , the calculation formula is:

[0046] ;

[0047] in: Timestamp recorded by the end proximity sensor, unit: ; Timestamp recorded by the front-end proximity sensor, unit: ; is the shaft speed, unit: r / s;

[0048] Finally, the recorded errors are accumulated 10 times and the average value is taken to ensure the accuracy of the error;

[0049] Step 3: When the measured shaft is loaded, the voltage pulse waveform detected by the inductive proximity sensor 3 is as follows: Figure 4 As shown, The time difference of the rising edge voltage signal will change with the load. The STM32F103 microcontroller reads the time difference of the rising edge voltage signal to obtain the torque value. The phase angle corresponding to the time difference of two adjacent rising edge pulse signals The calculation formula is:

[0050] ;

[0051] in: Timestamp recorded by the end proximity sensor, unit: ; Timestamp recorded by the front-end proximity sensor, unit: ; is the shaft speed, unit: r / s;

[0052] Torque value The calculation formula is:

[0053] ;

[0054] in, is the elastic modulus of the measured shaft, unit: ; is the diameter of the shaft being measured, unit: ; is the length of the measured shaft, unit: .

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A rotating shaft torque measuring device, characterized in that: Includes detection disc and inductive proximity sensor; A disc bracket is mounted on the detection disc, and a magnet is provided at one end of the disc bracket away from the detection disc, and the magnet is used to attract the shaft to be tested; The detection disc is also provided with a fan-shaped window, and the detection probe of the inductive proximity sensor is aligned with the fan-shaped window; The inductive proximity sensor is mounted on the rack via a sensor bracket, and the sensor bracket is provided with a guide groove for mounting the inductive proximity sensor.

2. The rotating shaft torque measuring device according to claim 1, characterized in that: The sensor bracket is fixedly connected to the frame by bolts.

3. The rotating shaft torque measuring device according to claim 1, wherein: The detection disc bracket is further provided with a boss, and the boss cooperates with a nut to fasten the detection disc bracket to the detection disc.

4. The rotating shaft torque measuring device according to claim 1, wherein: A set of measuring devices is provided at both ends of the measured shaft, and the two sets of measuring devices are symmetrically installed to keep the installation positions consistent.

5. A torque measurement method for a rotating shaft torque measurement device, based on the rotating shaft torque measurement device according to claim 4, characterized in that: The following steps are involved: Step 1: Attach the magnets at the ends of the detection disc bracket to the two ends of the shaft to be measured, thereby installing the detection disc on the shaft to be measured; Then install the inductive proximity sensor on the sensor bracket, and then install the sensor bracket on the rack of the shaft to be measured, and align the detection probe of the inductive proximity sensor with the fan-shaped window; Step 2: When installing the detection disc, artificially delay the installation position of the detection disc at the end of the measured shaft; When the measured shaft is unloaded, the inductive proximity sensor detects the voltage pulse waveform and obtains the time difference of the rising edge voltage signal. The time difference is recorded through the capture register of the microcontroller and recorded as the error calibration value. , the calculation formula is: ； in: Timestamp recorded by the end proximity sensor, unit: ; Timestamp recorded by the front-end proximity sensor, unit: ; is the shaft speed, unit: r / s; Finally, the recorded errors are accumulated 10 times and the average value is taken to ensure the accuracy of the error; Step 3: When the measured shaft is loaded, the time difference between the rising edge voltage signals received by the inductive proximity sensors on both sides of the measured shaft will change with the load. The microcontroller reads the time difference between the rising edge voltage signals and obtains the torque value; the phase angle corresponding to the time difference between two adjacent rising edge pulse signals is The calculation formula is: ； in: Timestamp recorded by the end proximity sensor, unit: ; Timestamp recorded by the front-end proximity sensor, unit: ; is the shaft speed, unit: r / s; Torque value The calculation formula is: ； in, is the elastic modulus of the measured shaft, unit: ; is the diameter of the shaft being measured, unit: ; is the length of the measured shaft, unit: .

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