CN105181195A - Rotating shaft torque measurement device, torque measurement method and rotating speed measurement method - Google Patents

Abstract

The invention discloses a rotating shaft torque measuring device, a torque measuring method and a rotational speed measuring method, and belongs to the technical field of power machinery measurement and control. It consists of a left half shaft, a right half shaft, a detection block, and a position detection sensor. Connect the right half-shaft (7) to the transmission shaft in series, the left half-shaft (1) and the right half-shaft (7) are connected to transmit torque through the torsion spring (4), the left half-shaft (1) and the right half-shaft (7) can be opposite Circumferential movement, the torsion spring body rotates with the drive shaft, and the torsion spring is compressed when the torque is transmitted, so that the relative angle of the two semi-shafts changes, and the angle of change is proportional to the torque; by analyzing the relative angle change of the two semi-shafts, we can get corresponding torque. The invention effectively solves the problems of low reliability, low resolution and narrow working range when other devices measure the torque of a high-speed rotating shaft, and can also be used as a speed sensor to reduce the cost of the measurement system.

Description

Rotary shaft torque measuring device, torque measuring method, and rotational speed measuring method

technical field

The invention relates to torque measurement under the rotating state of a transmission shaft of a power device, in particular to a device for measuring the torque of a transmission shaft using a torsion spring phase method, belonging to the technical field of power machinery measurement and control.

Background technique

The speed and torque can reflect the performance of the mechanical transmission system and are the most important measurement parameters of the rotating shaft. How to measure these two quantities accurately, quickly, reliably and cheaply without affecting the working state of the rotating shaft due to the introduction of the measurement feedback link is the difficulty of torque measurement.

At present, there are mainly two methods for measuring the torque of the rotating shaft in China, and the phase method is widely used to measure the torque. Torque measurement by phase method is to install a flexible torsion bar in the coaxial direction of the rotating shaft. When the torque applied on the rotating shaft is greater, the relative angle change of the flexible torsion bar between two different positions in the axial direction will be greater. Through The sensor detects the relative angle change of two different axial positions, and the corresponding rotational shaft torque can be obtained. According to the different measurement sensors, it can be divided into electromagnetic type, photoelectric type, laser type and capacitive type. This method requires high strength and rigidity of the rotating shaft, so the cost is high, and the torsion angle when the shaft is torsion is small, so the measurement error is large. In addition, because the flexible torsion bar is a one-time molding structural part, the interchangeability poor.

The second method is the strain method. A strain bridge is installed on the rotating shaft. By measuring the stress and strain values on the surface of the rotating shaft, the measured value is substituted into the corresponding mechanical formula to calculate the torque on the rotating shaft. Since the strain bridge is installed on the high-speed rotating shaft, the energy and signal exchange between the strain bridge and the external conditioning circuit needs to be carried out through wireless transmission or conductive slip ring. The conductive slip ring method is a contact measurement method. The long-term contact of the conductive slip ring with the high-speed rotating shaft can easily cause damage to the torque measurement device and the device under test; while the wireless transmission method has complicated power transmission equipment and poor anti-interference ability, which cannot be used in harsh environments. normal work.

Contents of the invention

The present invention aims to solve many deficiencies in the current torque measurement, and invents a rotating shaft torque measurement device, a torque measurement method and a rotational speed measurement method, which have the characteristics of good interchangeability, strong versatility, good reliability and high precision.

A rotating shaft torque measuring device, characterized in that it includes a left half shaft, a right half shaft, a cage, and a torsion spring; the left end of the right half shaft has a central blind hole, and the right end of the left half shaft extends into the central blind hole The right end of the above-mentioned left half shaft has a central through hole; the right end of the above-mentioned cage is fixed in the central blind hole of the right half shaft, and the left end of the cage extends into the central through hole of the left half shaft and is installed in the center through a sliding bearing In the through hole; the above-mentioned torsion spring is installed on the cage, its right end is connected with the right half shaft, and its left end is connected with the left half shaft; N first detection blocks are evenly distributed around the right end of the left half shaft, and the left end of the right half shaft N second detection blocks are uniformly distributed in the direction; the first detection block and the second detection block are uniformly arranged along the circumferential interval in the initial state; N is 2-5; the rotating shaft torque measuring device also includes a square position detection sensor; the radial distances from the first detection block and the second detection block to the central axis of the system are equal; equal.

Utilize the torque measurement method of the rotating shaft torque measuring device, it is characterized in that: the right half shaft is connected in series with the drive shaft, the left half shaft and the right half shaft are connected to transmit torque through a torsion spring, and the left half shaft and the right half shaft can be relatively Circumferential movement, the torsion spring body rotates with the drive shaft, and the torsion spring is compressed when the torque is transmitted, so that the relative angle of the two semi-shafts changes, and the angle of change is proportional to the torque; by analyzing the relative angle change of the two semi-shafts, we can get corresponding torque.

The torque measurement method is characterized in that: when the torque transmitted by the shaft changes, the relative position of the first detection block and the second detection block changes, and when the rotating shaft rotates, the first detection block and the second detection block make the position The detection sensor generates a pulse voltage signal, and the rotating shaft rotates once to generate 2N voltage pulse waveforms, which correspond to the positions of the 2N detection blocks distributed on the circumference. By analyzing the phase changes of adjacent pulses in the voltage pulse waveform, the relative angle change of the two semi-axes is obtained. , so as to obtain the corresponding torque.

The torque measurement method is characterized in that: when the shaft rotates, under the condition of no torque loading, the evenly distributed N first detection blocks and N second detection blocks make the position detection sensor generate 2N time intervals with the same time interval Voltage pulse waveform, the relative phase of adjacent pulses is zero; when the loading torque is T, the relative phase change of adjacent pulses is a; the corresponding relationship between different a and T is calibrated in advance, and T can be obtained from the phase change a; In order to solve the problem that the N first detection blocks and N second detection blocks cannot be completely evenly arranged in the initial state due to installation and manufacturing errors, and thus bring about phase angle detection errors, in the calculation of the phase angle, Calculate the time interval t ₁ , t ₂ ,…,t _2N between two adjacent pulses in 2N voltage pulse waveforms, and sort them from large to small as t ₁ ', t ₂ ',...,t _2N ', the calculation formula of two adjacent pulse phases in the voltage pulse waveform is:

The torque measurement method is characterized in that: the above-mentioned N=2; the shaft rotates one cycle to generate 4 voltage pulse waveforms, corresponding to the positions of the four detection blocks distributed on the circumference, by analyzing the two adjacent pulse phases in the voltage pulse waveform The change method can obtain the relative change angle of the two semi-axes, and then obtain the torque proportional to the angle; when the torque is zero, calculate the time intervals t ₁ , t ₂ between adjacent 4 pulses in the voltage pulse waveform, respectively. t ₃ , t ₄ , and sort them from large to small as t ₁ ', t ₂ ', t ₃ ', t ₄ ', the calculation formula of two adjacent pulse phases in the voltage pulse waveform is:

When the torque is a non-zero value T, calculate the time intervals t ₅ , t ₆ , t ₇ , and t ₈ between four adjacent pulses in the voltage pulse waveform, and sort them as t from large to small ₅ ', t ₆ ', t ₇ ', t ₈ ', the calculation formula of two adjacent pulse phases in the voltage pulse waveform is:

Therefore, when the torque is T, the angle change of the two half shafts when the relative torque is zero is a ₁ -a ₀ ; the relationship between the angle change of the two half shafts and the torque can be obtained through calibration.

The rotational speed measurement method of the rotating shaft torque measuring device is characterized in that: when the shaft rotates, N first detection blocks and N second detection blocks cause the position detection sensor to generate 2N voltage pulse waveforms, and the voltage pulses are calculated respectively The time interval t ₁ ,t ₂ ,…,t _2N between adjacent 2N pulses in the waveform, the formula for calculating the speed n is:

In the formula, the units of t ₁ , t ₂ ,...,t _2N are seconds.

The integrated high-speed rotating shaft torque measuring device of the present invention is a torsion measuring method based on torsion springs, which are often used in balance mechanisms in machinery, and the torsion angle is proportional to the torque. The torsion spring is applied to the measurement of the rotor torque. By measuring the size of the torsion angle, the size of the torque can be well felt, and the appropriate torsion spring can be selected according to the measurement range, so that the change of the torsion angle is in a suitable range, and the measurement accuracy is improved. Better interchangeability. In order to solve the reliability problem of the sensor, in the structural design, the sliding bearing, the hard sleeve and the cage mechanism are cleverly designed, so that the installation of the torsion spring is reliable, the stress distribution of the contact part is uniform, and the circumferential friction is reduced.

The obvious advantages of the present invention are: the present invention is a non-contact torque measurement method with simple and reliable structure, no need to install electronic components and circuits on the rotor, and can meet the torque measurement requirements of high-speed rotating shafts in harsh environments, and the measurement is fast and the result accurate. The measuring device of the present invention uses a torsion spring to sense the torque, and has the characteristics of good linearity, high precision, strong interchangeability, and easy manufacture. The measuring range of the sensor can be changed by changing the torsion spring, and the working range is wide. The invention effectively solves the problems of low reliability, low resolution and narrow working range when other devices measure the high-speed rotor torque, and can also be used as a speed sensor to reduce the cost of the measurement system.

Description of drawings

Figure 1 is an external schematic diagram of an integrated high-speed rotating shaft torque measuring device;

Fig. 2 is a schematic diagram of the internal structure of the integrated high-speed rotating shaft torque measuring device;

Fig. 3 is the waveform diagram of the metal boss position sensor when the torque is zero;

Fig. 4 is a waveform diagram of the metal boss position sensor when the torque is not zero;

Label names in the figure: 1. Left half shaft, 2. Sliding bearing, 3. Hard sleeve for left half shaft, 4. Torsion spring, 5. Cage, 6. Hard sleeve for right half shaft, 7. Right half shaft Shaft, 8. First detection block, 9. Second detection block, 10. Position detection sensor, 1-1. Center through hole, 7-1. Center blind hole.

Detailed ways

As shown in Figure 1, the integrated high-speed rotating shaft torque measuring device is composed of a left half shaft 1, a right half shaft 7 and a non-contact metal detection block position sensor 10, and there are two first detection blocks 8 on the left half shaft 1 , there are two second detection blocks 9 on the right half shaft 7 .

As shown in Figure 2, the internal structure of the integrated high-speed rotating shaft torque measurement device includes left half shaft 1, sliding bearing 2, hard sleeve 3 for left half shaft, torsion spring 4, cage 5, hard sleeve for right half shaft 6. Right half shaft 7. The left half shaft 1 and the right half shaft 7 are connected by a torsion spring 4, and the connecting parts are respectively fixed on the left half shaft 1 and the right half shaft 7 by hard sleeves, so that the stress on the contact parts is evenly distributed. The cage 5 is located in the middle of the torsion spring 4, and is connected with the right half shaft 7 as a whole, and the cage 5 is connected with the left half shaft 1 through a sliding bearing 2 to reduce circumferential friction and improve measurement accuracy.

The integrated high-speed rotary shaft torque measuring device is connected in series with the transmission shaft. The left half shaft 1 and the right half shaft 2 can move relative to the circumferential direction. The two transmission half shafts are connected to transmit torque through the torsion spring 4. The torsion spring body rotates with the shaft to transmit the torque. When the torsion spring is compressed, the relative angle of the two semi-axes changes, and the relative positions of the first detection block 8 and the second detection block 9 also change simultaneously. When the rotor rotates, the first detection block 8 and the second detection block 9 make the position detection sensor 10 generate a pulse voltage signal.

As shown in Figure 3 and Figure 4, four voltage pulse waveforms are generated when the rotor rotates once, corresponding to the positions of the four detection blocks distributed on the circumference, and the two halves can be obtained by analyzing the phase changes of two adjacent pulses in the voltage pulse waveform. The angle at which the shafts change relative to each other results in a torque proportional to the angle. Figure 3 shows when the torque is zero, respectively calculate the periods t ₁ , t ₂ , t ₃ , t ₄ of the four adjacent pulses in the voltage pulse waveform, and sort them as t ₁ ', t ₂ ', t ₃ ', t ₄ ', the calculation formula of two adjacent pulse phases in the voltage pulse waveform is:

Figure 4 shows that when the torque is a non-zero value T, calculate the period t ₅ , t ₆ , t ₇ , t ₈ of the four adjacent pulses in the voltage pulse waveform, and sort them as t ₅ from large to small ',t ₆ ',t ₇ ',t ₈ ', the calculation formula of two adjacent pulse phases in the voltage pulse waveform is:

Therefore, when the torque is T, the angle change of the two semi-shafts when the relative torque is zero is a ₁ -a ₀ . The relationship between the angle change of the two half shafts and the torque can be obtained through calibration.

The integrated high-speed rotating shaft torque measuring device can also be used as a speed sensor, and the calculation formula of the speed n is:

In the formula, the units of t ₁ , t ₂ , t ₃ , and t ₄ are seconds.

Claims (6)

1. A rotating shaft torque measuring device, characterized in that: Including left half shaft (1), right half shaft (7), cage (5), torsion spring (4); The left end of the above-mentioned right half shaft (7) has a central blind hole (7-1), and the right end of the left half shaft (1) extends into the central blind hole (7-1); The right end of the left half shaft (1) has a central through hole (1-1); The right end of the above cage (5) is fixed in the central blind hole (7-1) of the right half shaft (7), and the left end of the cage (5) extends into the central through hole (1-1) of the left half shaft (1). 1) and installed in the central through hole (1-1) through the sliding bearing (2); The above-mentioned torsion spring (4) is installed on the cage (5), its right end is connected with the right half shaft (7), and its left end is connected with the left half shaft (1); N first detection blocks (8) are uniformly distributed circumferentially on the right end of the left semi-axis (1), and N second detection blocks (9) are evenly distributed circumferentially on the left end of the right semi-axis (7); the first detection block in the initial state (8) and the second detection block (9) are evenly arranged along the circumferential interval; N is 2-5; The rotating shaft torque measuring device also includes a position detection sensor (10) located on the left side of the right half shaft (7); The above-mentioned first detection block (8), the second detection block (9) have the same radial distance to the central axis of the system, and the above-mentioned first detection block (8), second detection block (9), position detection sensor (10) to The distance of the plane where the right end face of the right semi-axis (7) is located is equal. 2. Utilize the torque measuring method of the rotary shaft torque measuring device according to claim 1, characterized in that: The right half shaft (7) is connected in series with the transmission shaft, the left half shaft (1) and the right half shaft (7) are connected to transmit torque through the torsion spring (4), and the left half shaft (1) and the right half shaft (7) can be relatively Circumferential movement, the torsion spring body rotates with the drive shaft, and the torsion spring is compressed when the torque is transmitted, so that the relative angle of the two semi-shafts changes, and the angle of change is proportional to the torque; by analyzing the relative angle change of the two semi-shafts, we can get corresponding torque. 3. The torque measuring method according to claim 2, characterized in that: When the torque transmitted by the shaft changes, the relative position of the first detection block (8) and the second detection block (9) changes, and when the rotating shaft rotates, the first detection block (8) and the second detection block (9) make The position detection sensor (10) generates a pulse voltage signal, and the rotating shaft rotates once to generate 2N voltage pulse waveforms, which correspond to the positions of the 2N detection blocks distributed on the circumference. By analyzing the phase changes of adjacent pulses in the voltage pulse waveform, the two semi-axis The relative angle changes, so as to obtain the corresponding torque. 4. The torque measuring method according to claim 3, characterized in that: When the shaft rotates, under the condition of no torque loading, the evenly distributed N first detection blocks and N second detection blocks make the position detection sensor generate 2N voltage pulse waveforms with the same time interval, and the relative phase of adjacent pulses is zero; when the loading torque is T, the relative phase change of adjacent pulses is a; the corresponding relationship between different a and T is calibrated in advance, and T can be obtained from the phase change a; in order to solve the problem of N first detection blocks and N Due to the installation and manufacturing error of the second detection block, the circumferential interval of the detection block cannot be completely evenly arranged in the initial state, which brings about the problem of phase angle detection error. In the phase angle calculation, the adjacent 2 of the 2N voltage pulse waveforms are respectively calculated The time interval between t ₁ , t ₂ ,…,t _2N pulses, and sort them from large to small as t ₁ ', t ₂ ',…,t _2N ', two adjacent pulses in the voltage pulse waveform The phase calculation formula is: 5. The torque measuring method according to claim 4, characterized in that: The above N=2; The shaft rotates one revolution to generate 4 voltage pulse waveforms, which correspond to the positions of the four detection blocks distributed on the circumference. By analyzing the phase changes of two adjacent pulses in the voltage pulse waveform, the relative change angle of the two semi-axes can be obtained, and then obtained with the Torque proportional to angle; When the torque is zero, calculate the time intervals t ₁ , t ₂ , t ₃ , and t ₄ between four adjacent pulses in the voltage pulse waveform, and sort them as t ₁ ', t ₂ ' from large to small ,t ₃ ',t ₄ ', the calculation formula of two adjacent pulse phases in the voltage pulse waveform is: When the torque is a non-zero value T, calculate the time intervals t ₅ , t ₆ , t ₇ , and t ₈ between four adjacent pulses in the voltage pulse waveform, and sort them as t from large to small ₅ ', t ₆ ', t ₇ ', t ₈ ', the calculation formula of two adjacent pulse phases in the voltage pulse waveform is: Therefore, when the torque is T, the angle change of the two half shafts when the relative torque is zero is a ₁ -a ₀ ; the relationship between the angle change of the two half shafts and the torque can be obtained through calibration. 6. Utilize the method for measuring the rotational speed of the rotating shaft torque measuring device according to claim 1, characterized in that: When the shaft rotates, N first detection blocks (8) and N second detection blocks (9) make the position detection sensor (10) generate 2N voltage pulse waveforms, respectively calculate the adjacent 2N pulse waveforms in the voltage pulse waveform The time interval between t ₁ ,t ₂ ,…,t _2N , the calculation formula of speed n is: In the formula, the units of t ₁ , t ₂ ,...,t _2N are seconds.