A large-scale compressor test stand torque meter field calibration system and method

Abstract

The application provides a large-scale compressor test bench torque tester field calibration system and method, relates to the field of test bench torque test calibration, and comprises a torque tester field static calibration system and a torque tester field dynamic calibration system, realizes static calibration and dynamic zero point calibration under the condition of a field transmission shaft system, and eliminates the influence of torque tester torque shaft stiffness variation, zero point drift and other factors on torque measurement; meanwhile, for a two-way rotatable compressor test bench, static and dynamic calibration of the torque tester is completed before reversing for testing. The application can conveniently realize static calibration and dynamic calibration of the compressor test bench torque tester under the field condition, is favorable for high-precision measurement of the compressor test bench shaft system torque, and can meet more frequent torque calibration requirements of the two-way rotatable compressor test bench.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of test bench torque test calibration, in particular to a large-scale compressor test bench torque transducer field calibration system and method. BACKGROUND

[0002] As a key component of an aero-engine and a gas turbine, a compressor must be tested on a test bench during development and improvement, and a large amount of test data is needed to solve many basic scientific problems. The torque of a transmission shaft is one of the key parameters obtained by testing, and the measurement principle mainly includes shear strain and torsion phase. A phase-type torque transducer with a base is usually used to obtain the torque parameter on a large-scale compressor test bench. In order to obtain high-precision measurement results, the torque transducer needs to be calibrated regularly and on demand. For a phase-type torque transducer, static calibration is mainly completed by calibrating the shaft stiffness (the torque required for the torsion shaft to generate a signal pitch). If the torque transducer is disassembled and returned to the factory for calibration, problems such as inconvenient disassembly and assembly, long period, and high calibration cost will be encountered. In addition to static calibration, dynamic zero-point calibration under the condition of a transmission shaft system on site is also needed to eliminate the influence of zero-point drift caused by power loss and other factors between the torque transducer and the load test piece. For a compressor test bench that can rotate in both directions, static and dynamic calibration of the torque transducer is also needed before reversing for testing. Therefore, it is of great significance to study the static and dynamic calibration technology of the torque transducer on site to solve the above problems. SUMMARY

[0003] To solve the above technical problems, the present application provides a large-scale compressor test bench torque transducer field calibration system and method, which realizes static calibration and dynamic zero-point calibration under the condition of a transmission shaft system on site to eliminate the influence of torque shaft stiffness variation, zero-point drift and other factors on torque measurement. At the same time, for a compressor test bench that can rotate in both directions, static and dynamic calibration of the torque transducer is completed before reversing for testing.

[0004] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0005] A large-scale compressor test bench torque transducer field calibration system, comprising a torque transducer field static calibration system and a torque transducer field dynamic calibration system, which realizes static calibration and dynamic calibration of the torque transducer of the compressor test bench under the condition of a transmission shaft system on site;

[0006] The torque transducer field static calibration system comprises a torque loading device and a force sensor; the torque loading device applies force through a hydraulic loading assembly, and then applies torque to the to-be-calibrated torque transducer through a force arm; one end of the hydraulic loading assembly is connected with the force sensor, and the other end is connected with a support base; the force sensor is connected with a display instrument to read the loading force value; one end of a torque shaft of the to-be-calibrated torque transducer is fixed through a support base, and the other end is connected with the force arm;

[0007] The torque transducer field dynamic calibration system comprises a variable frequency speed regulation subsystem, a motor, a shaft transmission device, a to-be-calibrated torque transducer, a hydraulic lubrication subsystem, an electrical control subsystem and a vibration monitoring subsystem; the variable frequency speed regulation subsystem provides a power source for the motor and adjusts the rotating speed of the motor; the shaft transmission device is installed between the motor and the to-be-calibrated torque transducer; the hydraulic lubrication subsystem provides bearing lubrication and jacking for the motor, the shaft transmission device and the to-be-calibrated torque transducer; the electrical control subsystem realizes operation control, state monitoring, safety protection, storage and management of operation data of the torque transducer field dynamic calibration system; and the vibration monitoring subsystem is used for monitoring vibration data of the motor, the shaft transmission device and the to-be-calibrated torque transducer in real time.

[0008] The to-be-calibrated torque transducer reads the values of phase, torque, rotating speed and torque shaft temperature through a torque transducer signal processor.

[0009] Further, the hydraulic loading assembly comprises a hydraulic oil cylinder, a hydraulic hose and a pump; force loading is realized by pumping high-pressure hydraulic oil into the hydraulic oil cylinder; and a pressure gauge is installed at a pump outlet of the pump to observe the change of oil pressure in real time.

[0010] The present application also provides a calibration method of the large-scale compressor test bench torque transducer field calibration system, which comprises the following steps: first, torque transducer field static calibration, and then torque transducer field dynamic calibration.

[0011] Further, the static calibration comprises the following steps:

[0012] Step 1.1: pre-load torque, load torque to above the rated torque of the to-be-calibrated torque transducer, then unload, and repeat multiple times;

[0013] Step 1.2: apply torque from zero to the rated torque of the to-be-calibrated torque transducer, load gradually at equal intervals, and read the phase of the to-be-calibrated torque transducer under each loading force;

[0014] Step 1.3: unload gradually at equal intervals, and read the phase value of the to-be-calibrated torque transducer under the same force as in step 1.2;

[0015] Step 1.4: Establish a linear regression model about the loading force-phase, solve it using the least square method, calculate the torsional stiffness value of the torsion meter shaft in Nm / 100%PD according to the slope value, and calculate the maximum value and root mean square value of the deviation;

[0016] Step 1.5: If the maximum value and root mean square value of the deviation calculated in step 1.4 are within the allowable error range, and the relative error of the torsional stiffness values of the two consecutive calibrations is within the allowable error range, the static calibration is completed; otherwise, the static calibration is re-performed.

[0017] Further, in step 1.2, the maximum force required to be loaded is calculated according to the rated torque of the torsion meter to be calibrated and the length of the force arm.

[0018] Further, in step 1.4, the slope value is K and the torsional stiffness value is S, and the calculation formula is as follows:

[0019] ;

[0020] ;

[0021] In the formula, n is the number of data points, W is the reading of the loading force, R is the reading of the phase value, L is the length of the force arm, and C is the unit conversion coefficient.

[0022] Further, considering the influence of the torque shaft temperature of the torsion meter to be calibrated on the stiffness value, the calculated stiffness value is corrected, and the corrected stiffness value The calculation formula is as follows:

[0023] ;

[0024] In the formula, is the shaft temperature during the test of the torsion meter to be calibrated, if the torsion meter to be calibrated has temperature compensation function, then is the shaft temperature required to be input to the torsion meter to be calibrated; is the shaft temperature during the calibration of the torsion meter to be calibrated, is the temperature correction coefficient.

[0025] Further, in step 1.5, the limit value of the maximum value of the deviation is 0.05%PD, the limit value of the root mean square value of the deviation is 0.02%PD, and the limit value of the relative error of the stiffness values of the two consecutive calibrations is 0.04%.

[0026] Further, the dynamic calibration includes the following steps:

[0027] Step 2.1: Arrange the on-site dynamic calibration system, connect the motor, shaft transmission equipment, and torsion meter to be calibrated, and start the related supporting equipment;

[0028] Step 2.2: start the motor, read the phase and speed value at the 1st speed of the to-be-calibrated torque transducer through the torque transducer signal processor; then increase the speed to the 2nd speed, the 3rd speed and the nth speed, and read the phase and speed value;

[0029] Step 2.3: input the read phase value at each speed into the torque transducer signal processor as the zero torque reference under the field condition of the test bench;

[0030] Step 2.4: read the torque and speed value of the to-be-calibrated torque transducer at each speed again, if the torque value is within the allowable error range, the dynamic calibration is completed; otherwise, the dynamic calibration is performed again.

[0031] Further, in the step 2.2, the number of speed points and the speed value are determined according to the speed at which the test needs to be stopped and the data needs to be recorded.

[0032] Further, in the step 2.4, the allowable error limit value of the torque is 0.05% PD.

[0033] Beneficial effects:

[0034] The present application can conveniently realize the static calibration and dynamic calibration of the torque transducer of the compressor test bench under the field condition, is beneficial to the high-precision measurement of the shaft torque of the compressor test bench, and can meet the more frequent torque calibration requirements of the bidirectional rotating compressor test bench. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 Fig. 1 is a structural schematic diagram of a torque transducer field static calibration system of a large-scale compressor test bench torque transducer field calibration system according to the present application;

[0036] Figure 2 Fig. 2 is a structural schematic diagram of a torque transducer field dynamic calibration system of a large-scale compressor test bench torque transducer field calibration system according to the present application.

[0037] Wherein, the reference signs are: 1, frequency conversion speed regulation subsystem; 2, motor; 3, low-speed coupling; 4, gear box; 5, high-speed coupling; 6, to-be-calibrated torque transducer; 7, electrical control subsystem; 8, vibration monitoring subsystem; 9, hydraulic lubrication subsystem; 10, shaft end fixed support; 11, force arm; 12, force sensor; 13, force sensor display instrument; 14, hydraulic loading assembly; 15, hydraulic oil cylinder; 16, hydraulic hose; 17, pump; 18, support seat. DETAILED DESCRIPTION

[0038] In order to make the technical scheme of the present application clearer, the specific implementation process of the technical scheme of the present application will be introduced below in combination with the drawings and specific embodiments. It should be noted that the following embodiments are only for the purpose of facilitating the understanding of the technical scheme of the present application, and do not limit the implementable scope of the present application.

[0039] It should be understood that, in the description used in the present application, orientation terms such as "upper", "lower", "left", "right", "transverse", "longitudinal", "horizontal", "vertical", "center", "top", "bottom", etc. are based on the orientation relationship shown in the drawings and cannot be understood as necessarily required orientations. The structural and dimensional relationships shown in the drawings of the present application are only for the purpose of illustrative description in the present application and do not limit the implementation scope of the present application. The terms "first", "second", "third" are only for the purpose of description, and do not indicate or imply other special meanings unless otherwise stated. The terms "mounting", "connecting", "connecting" are broadly described, and those skilled in the art should understand the meaning of the above terms in the present application according to the specific circumstances. In addition, the same reference numerals in the drawings represent the same items.

[0040] The large-scale compressor test bed torque transducer field calibration system of the present application includes a torque transducer field static calibration system and a torque transducer field dynamic calibration system, which realizes the static calibration and dynamic calibration of the compressor test bed torque transducer under field conditions.

[0041] As shown in Figure 1 The present embodiment provides a torque transducer field static calibration system, which mainly includes a shaft end fixed support 10, a force arm 11, a force sensor 12, a hydraulic loading assembly 14, and a support seat 18. The hydraulic loading assembly 14 includes a hydraulic cylinder 15, a hydraulic hose 16, a pump 17, etc. Preferably, the force arm 11 is triangular. One end of the torque shaft of the torque transducer 6 to be calibrated is fixed through the shaft end fixed support 10, and the other end is connected to the bottom end of the triangle of the force arm 11. The force arm 11 is installed horizontally. The top of the force sensor 12 is connected to the tip of the triangle of the force arm 11 through a top connecting block, and the bottom of the force sensor 12 is connected to the hydraulic cylinder 15. The force sensor display instrument 13 is connected to the force sensor 12 and reads the data through the force sensor display instrument 13 at the same time. The hydraulic cylinder 15 is installed on the support seat 18. The force sensor 12, the hydraulic cylinder 15, the support seat 18, and the related connecting parts are vertically installed on the same center line.

[0042] After the torque transducer static calibration system is arranged, the torque transducer 6 to be calibrated is calibrated according to the following steps:

[0043] Step 1: Preload torque, i.e. load torque to the rated torque of the torque transducer 6 to be calibrated, then unload, and repeat five times.

[0044] Step 2: Apply torque from zero to the rated torque of the torque transducer 6 to be calibrated, load at equal intervals, and read the phase displacement (PD) of the torque transducer 6 to be calibrated at each load;

[0045] In the above step 2, by pumping high-pressure hydraulic oil into the hydraulic cylinder 15, the vertical downward pulling force is generated by the movement of the piston in the hydraulic cylinder, and then the torque is applied to the torque transducer 6 to be calibrated through the horizontally installed force arm 11. The type of pump 17 can be selected from manual pump, electric pump, pneumatic pump, etc., and the change of oil pressure can be observed in real time by installing a pressure gauge at the outlet of the pump. The display value of the force sensor 12 is observed and the force is loaded at equal intervals from zero, and the maximum load required can be calculated according to the rated torque of the torque transducer 6 to be calibrated and the length of the force arm 11. After the reading is stable, the data is read at each loading step, and generally 8-10 equal interval points of loading force and PD value data can be taken.

[0046] Step 3: Perform equal interval step-by-step unloading, i.e. read the PD value of the torque transducer 6 to be calibrated at the same force as step 2;

[0047] Step 4: Establish a linear regression model for the load force-phase, solve using the least squares method, and calculate the torsional stiffness value (unit: Nm / 100%PD) of the torque axis of the torque transducer 6 to be calibrated according to the slope value obtained; At the same time, calculate the maximum value and root mean square value of the deviation.

[0048] In the above step 4, the calculation formula of the slope value K and the stiffness value S is as follows:

[0049] ;

[0050] ;

[0051] In the formula, n is the number of data points, W is the reading of the load force; R is the reading of the PD value; L is the length of the force arm; C is the unit conversion coefficient.

[0052] Further, considering the influence of the torque axis temperature of the torque transducer 6 to be calibrated on the stiffness value, the stiffness value can be corrected according to the torque axis temperature of the torque transducer 6 to be calibrated, and the corrected stiffness value The calculation formula of the corrected stiffness value is as follows:

[0053] ;

[0054] In the formula, is the axis temperature during the test of the torque transducer to be calibrated, and if the torque transducer 6 to be calibrated has a temperature compensation function, is the axis temperature required to be input to the torque transducer to be calibrated; the shaft temperature at the time of calibration for the to-be-calibrated torque transducer, the temperature correction coefficient, which is generally 2.45%.

[0055] Step 5: If the maximum value and the root mean square value of the deviation calculated in Step 4 are within the allowable error range, and the relative error of the stiffness values of the two consecutive calibrations is within the allowable error range, the static calibration is completed, otherwise, the static calibration is re-performed.

[0056] In Step 5, the limit value of the maximum value of the deviation is 0.05% PD, the limit value of the root mean square value of the deviation is 0.02% PD, and the limit value of the relative error of the stiffness values of the two consecutive calibrations is 0.04%.

[0057] When reverse rotation is required for the on-site static calibration of the torque transducer, the devices connected to the two ends of the torque shaft of the to-be-calibrated torque transducer 6 in Figure 1 are exchanged, and the static calibration is performed according to the above calibration steps,

[0058] After the on-site static calibration of the torque transducer is completed, on-site dynamic calibration of the torque transducer is performed.

[0059] As shown in Figure 2 , the on-site dynamic calibration system of the torque transducer includes a variable frequency speed regulation subsystem 1, a motor 2, a low-speed coupling 3, a gear box 4, a high-speed coupling 5, an electrical control subsystem 7, a vibration monitoring subsystem 8, and a hydraulic lubrication subsystem 9. The variable frequency speed regulation subsystem 1 provides a power source for the motor 2 and adjusts the speed of the motor 2. The driving end of the motor 2 is connected to the gear box 4 through the low-speed coupling 3. The output end of the gear box 4 is connected to the to-be-calibrated torque transducer 6 through the high-speed coupling 5. The to-be-calibrated torque transducer 6 reads values such as phase, torque, speed, and torque shaft temperature through a matching signal processor. The electrical control subsystem 7 realizes operation control, state monitoring, safety protection, storage and management of running data of the entire on-site dynamic calibration system of the torque transducer. The vibration monitoring subsystem 8 is used for real-time monitoring of vibration data of the motor 2, the gear box 4, and the to-be-calibrated torque transducer 6. The hydraulic lubrication subsystem 9 provides bearing lubrication for the motor 2, the gear box 4, and the to-be-calibrated torque transducer 6, and provides a bearing jacking oil source for the motor 2 and the gear box 4.

[0060] The on-site dynamic calibration system of the torque transducer according to the present application, and the corresponding dynamic calibration method, include the following steps:

[0061] Step 1: Arrange the on-site dynamic calibration system. Connect the motor 2, the low-speed coupling 3, the gear box 4, the high-speed coupling 5, and the to-be-calibrated torque transducer 6, and start the relevant matching equipment.

[0062] In step 1 above, the coaxiality of the shafting composed of motor 2, low-speed coupling 3, gear box 4, high-speed coupling 5 and the to-be-calibrated torque transducer 6 is controlled within 0.05 mm.

[0063] In step 1 above, the relevant auxiliary equipment includes frequency conversion speed regulation, electrical control, vibration monitoring, hydraulic lubrication, cooling water, auxiliary air and other auxiliary equipment.

[0064] Step 2: Start motor 2 and adjust the speed, and read the phase and speed value at the 1st speed of the to-be-calibrated torque transducer 6 through the signal processor. Then increase the speed to the 2nd speed, the 3rd speed, …, the nth speed, and similarly read the phase and speed value;

[0065] In step 2 above, the number of speed points and the speed value can be determined according to the speed at which the test needs to be stopped and the data recorded, and generally 8-10 speed points can be taken to read the phase and speed value.

[0066] In step 2 above, during the speed increase process, the temperature, vibration and other state parameters of the system equipment are monitored in real time through the electrical control subsystem 7 and the vibration monitoring subsystem 8, and appropriate safety protection measures are taken in a timely manner in case of abnormal conditions. After the fault is eliminated, step 2 is performed again.

[0067] Step 3: The phase value at each speed read is input into the torque transducer signal processor as the Zero Torque Datum (ZTD) under the test bench field conditions;

[0068] In step 3 above, the ZTD value is the initial phase difference of the electrical signals generated at both ends of the torque shaft of the torque transducer when the torque shaft is rotating but not transmitting torque. Because it is performed under no load, the phase value at each speed is the ZTD value corresponding to the speed under the test bench field conditions. For a compressor test bench requiring bidirectional rotation, the ZTD value is generally set between 45% and 55%.

[0069] Step 4: The torque and speed value of the to-be-calibrated torque transducer 6 at each speed are read again, and if the torque value is within the allowable error range, the dynamic calibration is completed. Otherwise, the dynamic calibration is performed again.

[0070] In step 4 above, the allowable error limit value of the torque is 0.05% PD.

[0071] For a compressor test bench requiring bidirectional rotation, the ZTD values in the forward and reverse directions are different, so when the direction is changed, the ZTD value needs to be determined again through dynamic calibration and input into the torque transducer signal processor of the to-be-calibrated torque transducer 6.

[0072] It should be noted that the present application is not limited to the exemplary technical details of the above embodiments, and those skilled in the art can make equivalent replacements or modifications to the related technical features without departing from the technical solutions of the present application. The embodiments after the replacements or modifications still belong to the protection scope of the present application.

Claims

1. A calibration method for a large compressor test stand torque meter field calibration system, characterized by, The on-site static calibration of the torque transducer is performed first, and then the on-site dynamic calibration of the torque transducer is performed; the on-site calibration system of the torque transducer of the large-scale compressor test bed comprises an on-site static calibration system of the torque transducer and an on-site dynamic calibration system of the torque transducer, and realizes the static calibration and dynamic calibration of the torque transducer of the compressor test bed under on-site conditions; The on-site static calibration system of the torque transducer comprises a torque loading device and a force sensor; the torque loading device applies force through a hydraulic loading assembly, and then applies torque to the torque transducer to be calibrated through a force arm; one end of the hydraulic loading assembly is connected with the force sensor, and the other end is connected with a support seat; the force sensor is connected with a display instrument to read the loading force value; one end of the torque shaft of the torque transducer to be calibrated is fixed through a support, and the other end is connected with the force arm; The on-site dynamic calibration system of the torque transducer comprises a variable frequency speed regulation subsystem, a motor, a shaft transmission device, a torque transducer to be calibrated, a hydraulic lubrication subsystem, an electrical control subsystem and a vibration monitoring subsystem; the variable frequency speed regulation subsystem provides a power source for the motor and adjusts the rotating speed of the motor; the shaft transmission device is installed between the motor and the torque transducer to be calibrated; the hydraulic lubrication subsystem provides bearing lubrication and jacking for the motor, the shaft transmission device and the torque transducer to be calibrated; the electrical control subsystem realizes the operation control, state monitoring, safety protection, storage and management of the running data of the on-site dynamic calibration system of the torque transducer; the vibration monitoring subsystem is used for monitoring the vibration data of the motor, the shaft transmission device and the torque transducer to be calibrated in real time; The torque transducer to be calibrated reads the values of phase, torque, rotating speed and torque shaft temperature through a torque transducer signal processor; The static calibration comprises the following steps: Step 1.1: preloading torque, loading torque to above the rated torque of the torque transducer to be calibrated, then unloading, and repeating multiple times; Step 1.2: applying torque from zero to the rated torque of the torque transducer to be calibrated, loading at equal intervals, and reading the phase of the torque transducer to be calibrated under each loading force; Step 1.3: unloading at equal intervals, and reading the phase value of the torque transducer to be calibrated under the same force as in step 1.2; Step 1.4: establishing a linear regression model about loading force-phase, solving by using the least square method, calculating the torsional stiffness value of the torque transducer shaft in units of Nm / 100%PD according to the slope value obtained, and calculating the maximum value and root mean square value of the deviation; The slope value is K and the torsional stiffness value is S, and the calculation formula is as follows: ； ； In the formula, n is the number of data points, W is the reading of the loading force, R is the reading of the phase value, L is the length of the force arm, and C is the unit conversion coefficient; Considering the influence of the torque shaft temperature of the to-be-calibrated torque transducer on the stiffness value, the calculated stiffness value is corrected, and the corrected stiffness value The calculation formula of the corrected stiffness value is as follows: ； In the formula, is the shaft temperature at the time of the test of the torque transducer to be calibrated, and if the torque transducer to be calibrated has a temperature compensation function, then is the shaft temperature that needs to be input to the torque transducer to be calibrated; is the shaft temperature at the time of the calibration of the torque transducer to be calibrated, is the temperature correction coefficient; Step 1.5: if the maximum value and root mean square value of the deviation calculated in step 1.4 are within the allowable error range, and the relative error of the torsional stiffness values of two consecutive calibrations is within the allowable error range, the static calibration is completed; otherwise, the static calibration is performed again.

2. The calibration method of claim 1, wherein, The hydraulic loading assembly comprises a hydraulic oil cylinder, a hydraulic hose and a pump; the loading of force is realized by pumping high-pressure hydraulic oil into the hydraulic oil cylinder; a pressure gauge is installed at the pump outlet of the pump for observing the change of oil pressure in real time.

3. The method of calibration of claim 2, wherein, In the step 1.2, the maximum force required to be loaded is calculated according to the rated torque of the torque transducer to be calibrated and the length of the force arm.

4. The method of calibration of claim 1, wherein, In the step 1.5, the limit value of the maximum value of the deviation is 0.05%PD, the limit value of the root mean square value of the deviation is 0.02%PD, and the limit value of the relative error of the stiffness value of the two consecutive calibrations is 0.04%.

5. The method of calibration of claim 1, wherein, The dynamic calibration comprises the following steps: Step 2.1: arranging the on-site dynamic calibration system, connecting the motor, shaft transmission equipment, and torque transducer to be calibrated, and starting the related auxiliary equipment; Step 2.2: starting the motor, reading the phase and speed values at the first speed of the torque transducer to be calibrated through the torque transducer signal processor, then increasing the speed to the second speed, the third speed, and the nth speed, and similarly reading the phase and speed values; Step 2.3: inputting the phase values at each speed read as the zero torque reference under the on-site conditions of the test bench into the torque transducer signal processor; Step 2.4: reading the torque and speed values of the torque transducer to be calibrated at each speed again, if the torque value is within the allowable error range, the dynamic calibration is completed, otherwise the dynamic calibration is performed again.

6. The method of calibration of claim 5, wherein, In the step 2.2, the number of speed points and the speed values are determined according to the speeds required to be stopped and data recorded during the test.

7. The method of calibration of claim 5, wherein, In the step 2.4, the allowable error limit value of the torque is 0.05%PD.

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