Processing method for reducing rotor loss and stray loss

Abstract

The invention relates to a processing method for reducing rotor loss and stray loss, belongs to the technical field of motors, solves the technical problem that the rotor loss is still large due to the fact that a motor rotor adopts a turning mode, and comprises the steps of grinding the motor rotor and singeing the motor rotor. The method further comprises the following steps: S1, performing a B-method type test on the motor; s2, performing rotor grinding treatment and singeing treatment on the motor rotor, and then performing the type test in the step S1 again; s3, comparing the proportion relation between the stray loss and the total loss of the two-time type test of the motor to determine the validity of the stray loss data; and S4, comparing the change rules of the stray loss after the two types of tests, thereby judging the reason causing the large loss of the rotor. According to the rotor processing method, the electromagnetic loss of the surface of the motor rotor can be reduced, the stray loss of the whole motor is further reduced, and the efficiency of the motor is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of motors, and particularly relates to a processing method for reducing rotor loss and stray loss. Background Art

[0002] The existing method for reducing motor rotor loss is turning. After the motor rotor is processed by this method, burrs are easily formed on the surface of the motor rotor, resulting in still large rotor loss and even affecting the electrical performance and vibration of the motor. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a processing method for reducing rotor loss and stray loss, thereby solving the technical problem that the rotor loss of the motor is still large due to turning.

[0004] In order to solve the above problems, the technical solution of the present invention is: a method for reducing rotor loss and stray loss, comprising grinding the motor rotor and singeing the motor rotor; The mill rotor processing includes the following steps: Step 1: Use a lathe to roughly turn the motor rotor; Step 2: Use a lathe to fine-turn the motor rotor; Step 3: Use a grinder to grind the motor rotor until it reaches the target size; Step 4: Place the motor rotor in an oven to dry the grinding fluid remaining in the motor rotor; Step 5: Check the size of the motor rotor after taking it out of the oven; Step 6: Use an air pump to blow away foreign matter inside and outside the motor rotor.

[0005] The singeing process includes the following steps: Step 1: Lift the motor rotor onto the rolling support. The bearing step of the motor rotor must not be stressed or damaged, and the motor rotor can rotate freely on the rolling support. Step 2: Use a cutting torch to locally heat each aluminum guide bar and notch of the motor rotor. The cutting torch needs to be adjusted to an oxygen-rich state, with the flame 10mm-15mm away from the surface of the motor rotor to ensure that the aluminum guide bar does not melt. The moving speed of the cutting torch is 130mm / s-160mm / s.

[0006] Optionally, the operation steps further include: S1. The motor shall be subjected to type test of method B in accordance with the requirements of GB / T1032-2012; S2. After the B-type test in step S1 is completed, the motor rotor is subjected to rotor grinding and singeing treatments, and then the B-type test in step S1 is performed again; S3. Compare the ratio of stray loss to total loss of the motor in two B-method type tests to determine the validity of the stray loss data; the smaller the ratio of stray loss to total loss, the better. The present invention aims to reduce losses, and the validity of the data is verified by calculating whether the ratio of stray loss increases or decreases.

[0007] S4. When the stray loss data is confirmed to be valid, compare the changing patterns of the stray loss after two B-method type tests to determine the cause of the large rotor loss.

[0008] Optionally, the front and rear bearing seals of the motor need to be removed before performing the B-type test.

[0009] Optionally, the motor is subjected to factory tests in advance, and two motors with similar factory data are selected from the motor prototypes, one as the tested motor and the other as the accompanying test motor, and the operations of steps S1 to S4 are performed using the two selected motors.

[0010] Optionally, before performing the B-method type test in step S1 , the reliability of the torque and speed sensor used in the B-method type test should be tested, and the B-method type test can be performed only after the reliability meets the requirements.

[0011] Optionally, in step S2, after the motor is subjected to a B-type test, the remaining loss P L The stray loss data can be considered reliable and can be used as comparative data only when the correlation coefficient γ obtained by linear regression of T² reaches above 0.95; where T is the motor shaft torque.

[0012] Optionally, the processing method adopts a static variable frequency test power supply device to supply power to the test motor and the accompanying test motor respectively, and the frequency and speed of the accompanying test motor are reduced, while the frequency of the test motor remains unchanged, thereby achieving a full load state of the test motor, and the load state is adjustable in real time.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention greatly reduces the occurrence of faults such as burrs on the surface of the motor rotor by grinding the motor rotor. The motor rotor is singed after being ground, so as to further remove the burrs on the surface of the motor rotor, thereby reducing rotor loss and stray loss, which is of great significance to improving motor efficiency and reducing costs and increasing efficiency. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below in conjunction with embodiments.

[0015] Embodiment: This embodiment provides a method for reducing rotor loss and stray loss, including grinding the motor rotor and singeing the motor rotor.

[0016] Specifically, the specific steps and equipment used for grinding the motor rotor are as follows: 1. Equipment used: lathe, grinder, oven.

[0017] 2. Operation process: 1. Use a lathe to roughly turn the motor rotor according to the requirements of the motor rotor drawing; 2. According to the requirements of the motor rotor drawing, use a lathe to fine-turn the motor rotor and leave a margin; 3. According to the requirements of the motor rotor drawing, use a grinder to grind the motor rotor until it reaches the target size; 4. Place the motor rotor in an oven at a temperature of about 100°C to dry the grinding fluid remaining in the motor rotor.

[0018] 3. Quality inspection: 1. After taking the motor rotor out of the oven, check the size of the motor rotor; 2. Use an air pump to blow away foreign matter inside and outside the motor rotor.

[0019] 4. Technical safety and precautions: 1. Pay attention to the correct use of oven temperature and subsequent drying inspection of grinding fluid during the operation process.

[0020] 2. Operate smoothly as required to ensure personal safety. Clean the equipment after the operation.

[0021] The specific steps and equipment used for singeing the motor rotor are as follows: 1. Equipment used: cutting torch and rolling support.

[0022] 2. Operation process: 1. Adjust the distance between the rolling brackets according to the motor rotor after fine turning in the metalworking branch.

[0023] 2. Hang the motor rotor onto the rolling bracket. Do not allow the bearing step of the motor rotor to be stressed or damaged, and the motor rotor can rotate freely on the rolling bracket.

[0024] 3. Use a cutting torch to locally heat each aluminum guide bar and notch of the motor rotor. The cutting torch needs to be adjusted to an oxygen-rich state, with the flame 10mm-15mm away from the surface of the motor rotor to ensure that the aluminum guide bar does not melt. The moving speed of the cutting torch is 130mm / s-160mm / s.

[0025] 3. Quality inspection: Complete the "singeing" treatment of the motor rotor according to the operating procedures, and visually check that there are no residual burrs on the surface of the motor rotor after machining.

[0026] 4. Technical safety and precautions: 1. Pay attention to the correct use of the cutting torch during the operation process.

[0027] 2. Operate smoothly as required to ensure personal safety. Clean up the equipment after the operation.

[0028] This embodiment combines the shelling process before turning the motor rotor, and then turns the motor rotor, and then grinds it, that is, grinds the rotor, and then performs a surface singeing process on the processed motor rotor. Compared with the current turning process, the processing method of this embodiment can reduce the electromagnetic loss on the surface of the motor rotor, further reduce the overall stray loss of the motor, and thus improve the efficiency of the motor, which is of great significance for the research and development of ultra-high efficiency motors; on the other hand, with the improvement of efficiency, the measures for saving materials in the motor can be further improved. After the stray loss is reduced, the motor efficiency increases. When the efficiency is guaranteed to be within the range specified by the national standard, the number of motor silicon steel sheets and copper wires used can be appropriately reduced, thereby achieving the effect of reducing the cost of the motor and improving market competitiveness.

[0029] In a processing method for reducing rotor loss and stray loss in this embodiment, the operation steps further include: S1. The motor shall be subjected to type test of method B in accordance with the requirements of GB / T1032-2012; S2, after the B-type test in step S1 is completed, the motor rotor is subjected to rotor grinding and singeing treatment, and then the B-type test in step S1 is performed again; S3. Compare the ratio of stray loss to total loss of the motor in two B-method type tests to determine the validity of the stray loss data; the smaller the ratio of stray loss to total loss, the better. The present invention aims to reduce losses, and the validity of the data is verified by calculating whether the ratio of stray loss increases or decreases.

[0030] S4. When the stray loss data is confirmed to be valid, compare the change pattern of stray loss after two B-method type tests to determine the cause of the large rotor loss. For example, after the rotor is processed according to this process, the stray loss value becomes smaller, indicating that the effect of singeing and grinding is obvious. The cause of the large rotor loss is the large rotor surface loss, such as: protruding burrs, uneven stacking, deformation of silicon steel sheets on the rotor surface, etc. Whether the stray loss is valid is determined based on the correlation coefficient of the B-method test.

[0031] In a processing method for reducing rotor loss and stray loss in this embodiment, the front and rear bearing seals of the motor need to be removed before the B-type test is performed. This can avoid friction between the seal and the bearing cover, which will generate additional mechanical loss and affect the actual efficiency of the motor.

[0032] In a processing method for reducing rotor loss and stray loss in the present embodiment, the motor is subjected to factory testing in advance, and two motors with similar factory data are selected from a number of motor prototypes, one of which is used as the tested motor and the other as the accompanying test motor. The operations of steps S1 to S4 are performed using the two selected motors.

[0033] In a processing method for reducing rotor loss and stray loss of the present embodiment, before performing the B-method type test in step S1, the reliability of the torque and speed sensor used in the B-method type test is tested. The B-method type test can be performed only after the reliability meets the requirements.

[0034] The reliability requirements of the torque and speed sensor are as follows: the nominal torque of the torque and speed sensor and the measuring instrument should not exceed twice the rated torque of the motor under test. The windage loss of the coupling and the dynamometer (or load motor) measured when the motor under test is at the rated speed should not be greater than 15% of the rated output of the motor under test, and the sensitivity of the torque change should reach 0.25% of the rated torque. The mechanical power should be measured very carefully and accurately.

[0035] In a processing method for reducing rotor loss and stray loss of this embodiment, in step S2, after the motor is subjected to a B-type test, the remaining loss P L The linear regression of T² results in a correlation coefficient γ of 0.95 or above, and the stray loss data can be considered reliable and can be used as comparative data; where T is the motor shaft torque, and the residual loss P is L It is linearly related to T². Whether the stray loss is effective is determined based on the correlation coefficient of the B method test.

[0036] In a processing method for reducing rotor loss and stray loss in the present embodiment, the processing method adopts a static variable frequency test power supply device to supply power to the test motor and the accompanying test motor respectively, and reduces the frequency and speed of the accompanying test motor, while the frequency of the test motor remains unchanged, thereby achieving a full load state of the test motor, and the load state is adjustable in real time.

[0037] The rotor grinding and singeing steps can be performed at the same time. The following table shows the statistical data of the motor rotor before and after the rotor grinding and singeing treatments:

[0038] From the above table, it can be concluded that after the motor rotor is processed by the two processes of rotor grinding and singeing, the rotor loss and stray loss are significantly reduced, and the efficiency is significantly improved, which has extremely important guiding significance for the development and research of ultra-high efficiency motors and capacity-enhanced motors; in addition, the rotor processing technology has also been significantly improved. In terms of economy, the present invention can help enterprises reduce costs and increase efficiency, and increase the market competitiveness of products.

Claims

1. A method for reducing rotor loss and stray loss, characterized in that: The method comprises grinding the motor rotor and singeing the motor rotor; the grinding rotor comprises the following steps: Step 1: Use a lathe to roughly turn the motor rotor; Step 2: Use a lathe to fine-turn the motor rotor; Step 3: Use a grinder to grind the motor rotor until it reaches the target size; Step 4: Place the motor rotor in an oven to dry the grinding fluid remaining in the motor rotor; Step 5: Check the size of the motor rotor after taking it out of the oven; Step 6: Use an air pump to blow away foreign matter inside and outside the motor rotor; The singeing process includes the following steps: Step 1: Lift the motor rotor onto the rolling support. The bearing step of the motor rotor must not be stressed or damaged, and the motor rotor can rotate freely on the rolling support. Step 2: Use a cutting torch to locally heat each aluminum guide bar and notch of the motor rotor. The cutting torch needs to be adjusted to an oxygen-rich state, with the flame 10mm-15mm away from the surface of the motor rotor to ensure that the aluminum guide bar does not melt. The moving speed of the cutting torch is 130mm / s -160mm / s.

2. A method for reducing rotor loss and stray loss according to claim 1, characterized in that: The steps also include: S1. The motor shall be subjected to type test of method B in accordance with the requirements of GB / T1032-2012; S2. After the B-type test in step S1 is completed, the motor rotor is subjected to the rotor grinding and singeing treatments, and then the B-type test in step S1 is performed again; S3. Compare the ratio of stray loss to total loss of the motor in two B-method type tests to determine the validity of the stray loss data; S4. When the stray loss data is confirmed to be valid, compare the changing patterns of the stray loss after two B-method type tests to determine the cause of the large rotor loss.

3. A method for reducing rotor loss and stray loss according to claim 2, characterized in that: Before conducting the B-type test, the front and rear bearing seals of the motor must be removed.

4. A method for reducing rotor loss and stray loss according to claim 2, characterized in that: The motor is subjected to factory tests in advance, and two motors with similar factory data are selected from the motor prototypes, one as the tested motor and the other as the accompanying test motor. The operations of steps S1 to S4 are performed using the two selected motors.

5. A method for reducing rotor loss and stray loss according to claim 2, characterized in that: Before performing the B-method type test in step S1 , the reliability of the torque and speed sensor used in the B-method type test must be tested. The B-method type test can be performed only after the reliability meets the requirements.

6. A method for reducing rotor loss and stray loss according to claim 2, characterized in that: In step S2, after the motor is subjected to the B-type test, the remaining loss P L The stray loss data can be considered reliable and can be used as comparative data only when the correlation coefficient γ obtained by linear regression of T² reaches above 0.95; where T is the motor shaft torque.

7. A method for reducing rotor loss and stray loss according to claim 4, characterized in that: The processing method adopts a static variable frequency test power supply device to supply power to the tested motor and the accompanying tested motor respectively, and the frequency and speed of the accompanying tested motor are reduced while the frequency of the tested motor remains unchanged, thereby achieving a full load state of the tested motor, and the load state is adjustable in real time.

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