Compressor machining method

Abstract

The invention provides a compressor machining method. The compressor machining method comprises the steps of overall paint dipping, laser cleaning, laser welding and welding of a motor stator and a shell. According to the technical scheme, the motor iron loss can be reduced, and the motor efficiency is improved.

Description

Technical Field

[0001] The invention relates to the field of compressors, and in particular to a compressor processing method. Background Art

[0002] In the industry, in order to reduce the noise problem of the compressor motor during operation and the problem of the insulation paper in the motor stator moving in series, the painting process is often used to dip the enameled wire harness of the motor (stator) into paint, so that each enameled wire is connected by paint. After the paint is cured, it can prevent the enameled wires from vibrating and colliding with each other during the operation of the motor (stator) to generate noise. At the same time, the painting process can also solve the problem of the insulation paper moving in the motor stator: because the paint has a connection and fixing function after curing, it can prevent the slot wedge insulation paper from being displaced by the refrigerant, thereby avoiding the motor insulation withstand voltage failure and burning.

[0003] However, the existing painting process is difficult to completely remove the residual paint on the outer cylindrical surface of the motor stator, and there will still be a certain amount of residue on the outer cylindrical surface of the stator. Therefore, the motor stator and the housing can only be fixed by the traditional "housing shrink fit" process.

[0004] In the existing process, "shell shrinkage" is to heat the shell to plastic deformation, and then insert the motor into the shell after the shell inner diameter becomes larger. When the shell cools and the shell inner diameter shrinks, a clamping force is generated on the motor stator to fix the motor. However, due to the heat transfer and thermal deformation of the motor stator when the shell is heated, the motor iron loss increases and the motor efficiency decreases. Summary of the invention

[0005] In view of the problems in the prior art, the object of the present invention is to provide a compressor processing method, which can reduce the iron loss of the motor and improve the efficiency of the motor.

[0006] According to the present invention, a method for processing a compressor is provided, wherein the compressor includes a housing and a motor stator, and comprises the following steps:

[0007] Step 1, immersing the entire motor stator into paint to complete the overall painting of the motor stator;

[0008] Step 2, determining the laser welding part and the part to be cleaned on the surface of the motor stator, wherein the part to be cleaned covers the laser welding part and the area of ​​the part to be cleaned is not less than the area of ​​the laser welding part;

[0009] Step 3, removing the paint from the area to be cleaned by laser cleaning;

[0010] Step 4: Laser welding the laser welding part on the surface of the motor stator and the housing.

[0011] Preferably, after painting in step 1, the paint on the outer surface of the motor stator is shaken off by rotating the motor stator.

[0012] Preferably, the laser cleaning in step 3 includes linear scanning cleaning or point scanning cleaning.

[0013] Preferably, the length of the part to be cleaned in step 2 is within 3 times the length of the laser welding weld, and the width is within 10 times the width of the laser welding weld.

[0014] Preferably, when cleaning the residual paint on the outer surface of the motor stator in step 3, the cleaning depth is within 0.5 mm below the uncleaned portion of the outer surface of the motor stator.

[0015] Preferably, when cleaning the residual paint in the gaps between the motor stator laminations in step 3, the depth of the portion to be cleaned is within 2 mm below the uncleaned portion of the stator outer surface.

[0016] Preferably, step 3 further comprises sucking dust generated by laser cleaning by a dust suction device.

[0017] Preferably, the temperature of the laser cleaning in step 3 is 700°C to 1500°C.

[0018] Preferably, the power of the laser cleaning in step 3 is 100W-500W.

[0019] Preferably, the laser cleaning in step 3 is performed by pulsed laser irradiation cleaning.

[0020] A compressor processing method of the present invention performs laser cleaning and paint removal on the to-be-welded parts of the integrally dipped paint motor stator before welding, and then uses a laser welding method to complete the fixation of the stator and the housing, thereby improving the motor efficiency and the compressor performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features, objectives and advantages of the present invention will become more apparent from a reading of the detailed description of non-limiting embodiments made with reference to the following accompanying drawings.

[0022] Figure 1 is a schematic flow chart of a compressor processing method according to an embodiment of the present invention;

[0023] Figure 2 is a schematic structural diagram of a compressor according to an embodiment of the present invention; wherein the arrow shown is the direction of laser welding;

[0024] Figure 3 2 is a schematic structural diagram of an overall immersion paint of an embodiment of the present invention;

[0025] Figure 4 is a schematic diagram of the surface structure of a motor stator according to an embodiment of the present invention;

[0026] Figure 51 is a schematic diagram of the structure of laser cleaning according to an embodiment of the present invention; the arrows shown therein indicate the direction and route of laser movement;

[0027] Figure 6 Schematic diagram of the structure of the motor stator lamination according to an embodiment of the present invention.

[0028] Reference numerals

[0029] 1 Housing

[0030] 2 Motor stator

[0031] 3 Laser welding parts

[0032] 4 Areas to be cleaned

[0033] 5. Lamination DETAILED DESCRIPTION

[0034] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their repeated description will be omitted.

[0035] There are three types of painting processes for motor stators:

[0036] 1. Paint dripping: Use a paint gun to drip paint on the enameled wire of the motor stator;

[0037] 2. End face varnishing: immerse the enameled wire part of the motor stator in the paint tank;

[0038] 3. Overall immersion in paint: immerse the entire motor stator in the paint tank.

[0039] The above three painting processes for motor stators are all used in mass production. The "whole immersion painting" process has the advantages of more complete painting penetration and more efficient painting of the motor stator because the whole motor is immersed in the paint tank. Therefore, lower-cost water-based paint can be used to replace traditional oil-based paint. The equipment structure is simple and the equipment manufacturing cost is the lowest.

[0040] After the "overall immersion in paint", it is preferred to use the "paint throwing" method to remove the remaining paint on the outer cylindrical surface of the motor stator. However, there will still be a certain amount of residue on the outer cylindrical surface of the stator. The main component of these paints is epoxy resin, which is a non-metallic material. The presence of these paints makes it impossible to use laser welding of the motor stator and the compressor housing. If there is residual paint that has not been removed by the "paint throwing" process on the outer cylindrical surface of the motor stator to be welded, the chemical composition in the molten pool will be more complicated during laser welding, and welding instability will occur, resulting in welding defects: non-metallic materials (epoxy resin) invade the metal material (housing, stator) during welding.

[0041] In addition, the following methods cannot be used to clean the outer cylindrical surface of the motor stator: one is to apply a certain lipid material before the overall immersion in paint, so that the part cannot be painted, and use a rag to wipe off the lipid after the overall immersion in paint. This method requires the configuration of lipid materials during processing, which has material costs, and there are also processing costs for wiping after immersion in paint. The other is to use mechanical polishing to remove the outer cylindrical surface paint. The paint thickness is 0.001 accuracy level. Mechanical polishing must be able to remove the paint without damaging the substrate. It requires high polishing accuracy and large equipment investment. Moreover, the motor stator is a laminated structure, and there will be residual paint in the gaps between the laminates. Due to the small gap (within 0.1mm), it is difficult to remove it by mechanical polishing.

[0042] like Figure 1 As shown in, in an embodiment of the present invention, a compressor processing method is provided, such as Figure 2 As shown in , the compressor includes a housing 1 and a motor stator 2, and the method includes the following steps:

[0043] Step 1, such as Figure 3 As shown in , the motor stator 2 is immersed in paint as a whole to complete the overall painting of the motor stator 2; wherein the paint is preferably water-based paint, the main component of which is epoxy resin.

[0044] Step 2, such as Figure 4 As shown in , the laser welding part 3 and the part to be cleaned 4 on the surface of the motor stator 2 are determined. The part to be cleaned 4 covers the laser welding part 3 and the area of ​​the part to be cleaned 4 is not less than the area of ​​the laser welding part 3;

[0045] Step 3, such as Figure 5 As shown in , the paint on the part to be cleaned 4 is removed by laser cleaning;

[0046] Step 4, such as Figure 2 As shown in FIG. 1 , the laser welding portion 3 of the motor stator 2 and the housing 1 are welded by laser.

[0047] A compressor processing method according to an embodiment of the present invention performs laser cleaning and paint removal on the to-be-welded parts of the integrally-dipped-painted motor stator before welding, and then uses a laser welding method to complete the fixation of the stator and the housing, thereby improving the motor efficiency and the compressor performance.

[0048] In an embodiment of the present invention, the motor stator 2 preferably includes enameled wire, and step 1 further includes shaking off the paint on the outer surface of the motor stator 2 after the whole is painted. The paint on the outer surface of the motor stator 2 is preferably shaken off by rotating the motor stator.

[0049] That is, the motor stator 2 is painted as a whole by the method of overall immersion of the motor stator 2. The motor stator 2 is fixed by a clamp and rotated at high speed in a confined space to "spin the paint" to remove the useless paint on the outer surface of the motor stator 2, and the "spinned" paint can also be recycled and reused through a reflux pipe.

[0050] Afterwards, the residual paint is removed from the parts of the motor stator 2 to be laser welded by laser cleaning equipment.

[0051] Since the thermal decomposition temperature of epoxy resin is lower than 700℃, while the melting point of stator silicon steel sheet is over 1500℃, by adjusting the laser output parameters during laser cleaning to make the output heat greater than 700℃ and less than 1500℃, the epoxy resin can be decomposed and disappeared while the stator silicon steel sheet is not melted, so that the residual paint in the gap between the stator laminations can be removed. It has more advantages than mechanical polishing in terms of paint removal effect.

[0052] like Figure 4 As shown in , in the embodiment of the present invention, when laser cleaning technology is used to laser clean and remove paint from the to-be-welded part of the motor stator 2, the laser cleaning length is within 3 times of the laser welding weld length B. The laser cleaning width is within 10 times of the laser welding weld width A.

[0053] In the process flow proposed in the embodiment of the present invention, laser cleaning is the front process and laser welding is the back process. There are two positioning errors in the two processes. In order to ensure that the laser welding is within the laser cleaning range, the laser cleaning area needs to be enlarged in advance. Even in the case of large positioning errors (laser cleaning and laser welding on the assembly line, the assembly line fixture accuracy is not high), laser welding can be avoided in non-laser cleaned areas.

[0054] The laser cleaning depth is within 0.5mm below the uncleaned part of the motor stator outer surface; or. Figure 6 As shown in , when cleaning the residual paint in the gaps between the stator laminations 5, the cleaning depth is within 2 mm below the uncleaned portion of the stator outer surface.

[0055] Furthermore, in the embodiment of the present invention, the laser cleaning portion may be a flat surface or a curved surface of the motor stator.

[0056] Laser cleaning can be done in linear scanning or point scanning. Figure 5 As shown in , in the embodiment of the present invention, laser cleaning is a laser processing in the form of linear scanning. Since the laser beam has a certain radius, there will be repeated cleaning areas when the laser moves back and forth horizontally, so that the entire surface to be cleaned can be ensured to be completely cleaned, and based on the Gaussian characteristics of the laser beam, there will be no obvious difference in cleaning effect in the repeated cleaning areas.

[0057] In addition, in an embodiment of the present invention, the target cleaning area on the stator of the laser irradiated motor is edited by using the built-in software in the laser device. The target cleaning area can be square or rectangular, and the area size is set according to the weld length and width of the subsequent process (laser welding).

[0058] The laser in the laser cleaning equipment configuration is preferably a MOPA high-pulse laser, which can achieve 0.001mm high-precision cleaning; the optical fiber is preferably a step optical fiber or a ladder optical fiber; and the laser output head is preferably a galvanometer laser head.

[0059] MOPA (Master Oscillator Power Amplifier) ​​pulsed laser cleaning, under the action of high-frequency short pulses, the material heating and cooling process is extremely rapid. Because different materials have different thermal expansion coefficients, under the irradiation of short-pulse lasers, surface contaminants and the substrate will undergo high-frequency thermal expansion and contraction to varying degrees, generating an oscillation effect that causes the contaminants to be peeled off the material surface.

[0060] Since the laser emits light in short pulses, the laser irradiates the stator intermittently, which can greatly reduce the thermal impact and oxidation effect on the irradiated material on the stator surface when the laser is continuously irradiated for a long time for cleaning.

[0061] At the same time, combined with Figure 6As shown in , when the silicon steel sheets of the motor stator are stacked to form a stack 5, there is a certain probability that a gap (0.1-0.2mm) will be generated. When the motor is dipped in paint as a whole, the paint liquid will invade the gap. If mechanical paint removal is used, it is difficult to remove the residual paint in the gap. The focal spot diameter of the laser beam of the MOPA laser can reach 0.1mm. Reduce the spacing in the length direction of laser cleaning to ≤0.1mm, so that the paint in the gap can be directly removed. Since the paint is composed of epoxy resin, the thermal decomposition temperature is less than 700°, which is much lower than the melting point of the core silicon steel sheet (the melting point of silicon steel is about 1800°), so when the laser heats the residual paint in the gap, a deeper cleaning effect can be obtained. By setting the laser cleaning parameters, the residual paint cleaning depth is greater than the melting depth during the subsequent laser welding. In this way, the influence of the residual paint in the gap of the stack 5 on the laser welding can be avoided during laser welding.

[0062] In the embodiment of the present invention, the laser parameters during cleaning mainly involve: laser focal length, laser power, laser cleaning speed, and the angle between the laser and the workpiece.

[0063] Laser focal length: Set to the laser focus position. The laser cleaning thermal efficiency at the focus position is the highest.

[0064] Laser power and laser cleaning speed: The motor stator is cured after painting. The curing material is generally epoxy resin, and the special decomposition temperature is less than 700°. Using 100W-500W laser power can completely remove the paint layer.

[0065] The embodiments of the present invention have shown through multiple tests that a laser power exceeding 500 W may damage the substrate.

[0066] For cleaning of different paint layer thicknesses, the corresponding relationship between laser power and laser cleaning speed is shown in Table 1 below.

[0067] Table 1: Correspondence between paint layer thickness, laser power and laser cleaning speed

[0068] Paint layer thickness MM 0.001 0.003-0.005 0.005-0.01 0.01-0.15 0.015-0.025 Laser power W 100 200 300 400 500 Laser speed mm / s 4000 4500 5000 7000 8000

[0069] In addition, the angle between the laser and the surface of the workpiece to be cleaned is preferably 90±3°, at which time the energy is most concentrated and the cleaning effect is best.

[0070] It is also preferred that a dust suction device be arranged above the cleaning area during laser cleaning to prevent smoke and dust from entering the motor enameled wire area or other parts, causing a short circuit in the motor or bringing in dust when the motor is installed in the compressor, thereby affecting the performance of the compressor.

[0071] Finally, after laser cleaning is completed, Figure 2 As shown in , in an embodiment of the present invention, laser welding is performed.

[0072] After the laser cleaning is preferably completed, the motor is inserted into the housing. According to the preset cleaning position of the motor stator core, the external laser welding equipment performs targeted laser welding. The welding mode is the laser penetration welding mode, that is, the external laser heat source is aimed at the outer surface of the housing for heating. The laser welding has the characteristics of strong penetration. The laser irradiates the housing, melts through the housing, and then sinters with the motor stator into one.

[0073] Laser welding has the advantages of small heat-affected zone and small thermal deformation. Laser welding of the housing and the motor can reduce the iron loss of the motor and improve the efficiency of the motor.

[0074] The embodiment of the present invention adds a "laser cleaning" process before laser welding to laser clean the outer cylindrical surface of the motor stator (the part to be laser welded). In this way, the residual paint (epoxy resin) on the part to be welded of the stator can be removed before laser welding, thereby ensuring the quality of laser welding.

[0075] In summary, the compressor processing method of the embodiment of the present invention reduces the iron loss of the motor and improves the efficiency of the motor.

[0076] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A method for processing a compressor, wherein the compressor comprises a housing and a motor stator, characterized in that: The following steps are involved: Step 1, immersing the entire motor stator into paint to complete the overall painting of the motor stator; Step 2, determining the laser welding part and the part to be cleaned on the surface of the motor stator, wherein the part to be cleaned covers the laser welding part and the area of ​​the part to be cleaned is not less than the area of ​​the laser welding part; Step 3, removing the paint from the area to be cleaned by laser cleaning; Step 4: Laser welding the laser welding part on the surface of the motor stator and the housing.

2. The compressor processing method according to claim 1, characterized in that: After painting in step 1, the paint on the outer surface of the motor stator is shaken off by rotating the motor stator.

3. The compressor processing method according to claim 1, characterized in that: The laser cleaning in step 3 includes linear scanning cleaning or point scanning cleaning.

4. The compressor processing method according to claim 1, characterized in that: The length of the part to be cleaned in step 2 is within 3 times the length of the laser welding weld, and the width is within 10 times the width of the laser welding weld.

5. The compressor processing method according to claim 1, characterized in that: When cleaning the residual paint on the outer surface of the motor stator in step 3, the cleaning depth is within 0.5 mm below the uncleaned part of the outer surface of the motor stator.

6. The compressor processing method according to claim 1, characterized in that: When cleaning the residual paint in the gaps between the motor stator laminations in step 3, the depth of the portion to be cleaned is within 2 mm below the uncleaned portion of the stator outer surface.

7. The compressor processing method according to claim 1, characterized in that: The step 3 also includes sucking dust generated by laser cleaning by a dust suction device.

8. The compressor processing method according to claim 1, characterized in that: The temperature of the laser cleaning in step 3 is 700°C to 1500°C.

9. The compressor processing method according to claim 1, characterized in that: The power of the laser cleaning in step 3 is 100W-500W.

10. The compressor processing method according to claim 1, characterized in that: The laser cleaning in step 3 is performed by pulsed laser irradiation cleaning.

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