one orbit motor Main quality problems and cause analysis

Low volumetric efficiency or rapid decline; Oil seepage; Bite to death; Broken shaft; noise

2. Volumetric efficiency

First, the volumetric efficiency is low; The second is that the volumetric efficiency decreases rapidly. The important reasons for harming volumetric efficiency are as follows:

1、 The assembly clearance is too large. Based on the constraints of China's machining manufacturing methods and standards, including facility level, processing technology, tooling level, and CNC tool level, the machining specifications and quality of mechanical parts in the same industry in China are low, so whether the side gap or end gap is tight, it will bite, loose, and the volumetric efficiency is low.

Secondly, rotate the stator.

(1) Based on the difficulty of rotor and stator processing, the level of facilities in the same industry in China is lower than that in the international industry (MAGLER powerful grinder and internal grinder in Switzerland). Based on the gap between traditional processing technologies, the surface roughness of rotor and stator is poor.

(2) As most domestic broaching machines are used in the same industry in our country, based on the position of domestic broaching machines, especially the poor perpendicularity, the processing level of the rotor and stator is too low. The side clearance between rotor and stator is difficult to obtain accurate adjustment. M+S company adopts the German KLINGER broaching machine, and selects the combination broach for sub forming broaching. High working efficiency, high position and verticality.

(3) In China, traditional surface grinding machines are often used to process the two end faces of the rotor and stator, which are so rough, flat and parallel that it is difficult to compare with foreign advanced technical standards.

(4) The verticality of the stator of White Company in the United States can reach 0. 5 MU, so it can rotate the motor to 1 revolution. It is a company that has a lower speed all over the world, and maintains a higher volumetric efficiency. They carried out special spraying treatment on the stator.

(5) The traditional method of measuring the verticality of the rotor stator is not very accurate. Japan NOP Company fixes the side of the stator and measures the perpendicularity of the stator on the side. Perpendicularity is one of the main reasons that endanger the volumetric efficiency of motors.

3. Oil leakage

Oil leakage is mainly concentrated in two aspects: - oil leakage from the junction surface at both ends of the rotor and stator, and oil leakage from the output shaft.

Important reasons for oil leakage of output shaft:

1) Specification of output shaft processing, out of round;

2) Size adjustment of front cover hole, out of round;

3) The matching size of the shaft and the body shell is not well controlled, and the clearance is too large, resulting in that the output shaft cannot bear excessive radial and axial forces. In case of slightly larger radial force, the shaft deviates from the position, resulting in oil seepage.

Oil leakage of output shaft

The oil leakage at both ends of the rotor stator refers to the poor flatness, parallelism and roughness of the two end faces of the rotor stator and the end faces of the spacer. To solve this problem, Zhenjiang Company bought SCHLEIFRING surface grinder to grind the stator surface. This disadvantage is that the parallelism is poor and the unity is poor. I bought a new double end grinder from Hangzhou to grind the partition plate. In this way, the flatness and parallelism are greatly improved. Second, the roughness of the bottom end face of the seal groove is poor, and there are rust and pollutants at the bottom. The depth of the seal groove is different, leading to the invalidity of the seal ring. Third, the quality of domestic seal rings is poor, aging early, and the elasticity is not enough. Invalid seal. Fourth, the burr of the seal groove will cause incalculable damage to the seal ring.

4. Bite to death

The biting is mainly reflected in two aspects: first, the output shaft and the body shell bite; Second, the rotor stator is seized.

The main factors causing the seizure problem of output shaft and body shell:

1) The output shaft is out of round, and the roughness is not good; (To solve this problem, Zhenjiang bought a German SCHLEIFRINGER grinder for online measurement to ensure that the concentricity of the three circles is good and the roughness is also improved, with a precision of 0.1.) 2) The out of roundness roughness of the main hole of the shell is not very good. (Zhenjiang has bought a new main hole boring machine with six processes of American ENGIS. The roundness and roughness of the main hole have been improved. Zhenjiang has to buy another eight processes and add two processes to deburr?) In view of the lifting of the main hole of the shaft and the body shell, the probability of the shaft and the body shell biting has been greatly reduced, and the volumetric efficiency has also been greatly improved. 3) There are too many pollutants. According to the standards for pollutant detection, the total weight of pollutants, the diameter of larger particles of pollutants, and the number of particles of pollutants shall be checked. In particular, major pollutants should be controlled.

Main factors of rotor stator seizure problem:

First, the problem of pollutants;

Second, there are many problems such as the control of rotor stator specifications, product shape, etc;

Third, the rotor stator, especially the small displacement rotor, is difficult to control.

Fourth, when the rotating speed is high, it is easy to get hot, deform and bite.

Fifth, the teeth of the linkage shaft are matched with the internal splines of the rotor. Zhenjiang uses 4 beds of Nanjing No.2 Machine Tool to produce and process the teeth of linkage shaft, and Siemens control technology. Japan NOP Company carried out straightening treatment for the linkage shaft. Both sides were supported by metal bars, and the center was pressed and straightened by extrusion.

5. Difficult problem of broken shaft

First, the head of the output shaft will break. Usually, during machining, the hidden destruction caused by the production and processing of the flat key of the shaft by the tool will lead to the accumulation of hard force. If there is a large radial force, the flat key of the shaft will break. More shaft breaks of BMH motor

Second, material defects

The third is the tooth shape design of the linkage shaft. The tool is easy to damage the root of the tooth when machining, and the hard force gathers. In case of large radial force, the linkage shaft will break.

6. Noise

In fact, noise and volumetric efficiency are comprehensive problems, usually due to poor grasp of parts specifications and large deviation of assembly clearance. In addition, the motor does not have its own right to research and develop its own products. Generally, it simply copies and imitates the measured dimensions. In view of the lack of measuring instruments, the production and processing specifications of the measured samples may be at the upper or lower limits, which will adversely affect the use performance of the motor itself.