Spraying method of screw rotor
By using screw size design software to calculate and machined the male and female rotors in the screw compressor, high-temperature oil removal treatment is carried out, and Teflon spraying is assembled on the spray base, the problems of uneven spray thickness and rotor bite are solved, and balanced spraying and rotor performance are improved.
Patent Information
- Application Number
- CN202411488057.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-24
- Publication Date
- 2025-03-07
AI Technical Summary
In the spraying process of existing screw compressors, the female rotor and the male rotor are sprayed separately, resulting in uneven spraying thickness and different meshing gaps, which may cause the rotor to bite and affect the normal use of the screw compressor.
The theoretical 0 meshing gap and pattern line data of the female and male rotors are calculated through the screw size design software. After machining, the female and male rotors are baked and removed from oil at high temperature, and they are assembled on the spray base respectively. Teflon spraying equipment is set up. The female and male rotors mesh and rotate each other for spraying. After the spraying is completed, dry and mold them.
The uniform spray coating of the female and male rotors is achieved, which avoids the rotor's bite, ensures the normal use of the screw compressor, and improves the corrosion resistance, non-stick properties, wear resistance and high temperature resistance of the rotor.
Smart Images
Figure CN119565878A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of spray coating on the surface of a screw rotor, and specifically to a method for spraying a screw rotor. Background Art
[0002] Due to the factors of compressed gas medium and working environment, the screw rotor of the screw compressor main engine needs to have excellent corrosion resistance, good non-stick performance, wear resistance and impact resistance, excellent high temperature resistance, insulation, reduced friction coefficient, etc. These properties can be achieved by spraying Teflon material on the surface of the screw rotor.
[0003] However, in the process of making Teflon sprayed rotors, the general spraying process is as follows: first, the female rotor or the male rotor is processed according to the gap without Teflon spraying, and then it is baked in an oven for degreasing process, and then the surface is sprayed with Teflon respectively, and finally it is oven dried after the spraying is completed; however, in this process, because the female and male rotors are sprayed separately during the spraying process, and the female rotor or the male rotor does not move evenly during the spraying process, the spraying thickness at different positions on the female rotor or the male rotor is different, so that the meshing gaps between the female rotor and the male rotor at different axial points are different, and the driven gas volume is also different, and even the female rotor and the male rotor may mesh and bite each other, which affects the normal use of the screw compressor. Summary of the invention
[0004] In view of the above-mentioned deficiencies in the prior art, the present application provides a method for spraying a screw rotor that can achieve balanced spray coating of the yin and yang rotors and can also prevent the rotor from being stuck during use in the main engine.
[0005] In order to solve the above technical problems, the technical solution adopted in this application is: a method for spraying a screw rotor, the steps of the method comprising:
[0006] (1) First, the theoretical zero meshing clearance, high temperature profile, and profile data of 0.1 mm clearance of the female and male rotors are calculated using screw size design software;
[0007] (2) machining a pair of female and male rotors according to the size specifications calculated and designed by the software in step (1) to obtain female and male rotors of designed size;
[0008] (3) then baking the processed female rotor and male rotor at high temperature to remove oil;
[0009] (4) Assemble the deoiled female rotor and the male rotor on the spray-coated base at the same time, and assemble them in such a way that the female rotor and the male rotor are located at the same orientation at the intake end and the exhaust end of the main unit of the screw compressor;
[0010] (5) Then, Teflon spraying equipment is arranged on the outer sides of the female rotor and the male rotor, and the female rotor and the male rotor are started at the same time so that they mesh with each other and rotate, and Teflon spraying is performed during the meshing and rotating process;
[0011] (6) After the spraying is completed, the obtained female rotor and male rotor are dried and shaped.
[0012] Furthermore, the high temperature baking to remove oil in step (3) is specifically to place one or more female rotors and male rotors in a baking device and bake them at 260-300° C. for 2-2.5 hours.
[0013] Furthermore, the Teflon spraying equipment described in step (5) moves back and forth along the axial direction of the female rotor and the male rotor during the spraying process.
[0014] Furthermore, the spraying range of the Teflon spraying equipment is consistent with the extended length of the screw part on the female rotor and the male rotor; that is, the Teflon coating is only sprayed on the screw part of the female rotor and the male rotor, that is, the part where the meshing teeth are set, and the shaft section is not sprayed.
[0015] Furthermore, the drying and shaping in step (6) is specifically performed by placing one or more female rotors and male rotors in a baking device and baking them at 260-280° C. for 3-3.5 hours.
[0016] Furthermore, the center distance between the air inlet ends of the female rotor and the male rotor in step (4) is greater than the center distance between the air exhaust ends.
[0017] Furthermore, the center distance between the air inlet ends of the female rotor and the male rotor in step (4) is consistent with the center distance between them in the main unit of the screw compressor.
[0018] Furthermore, after the spraying is completed, the female rotor and the male rotor are assembled in the main body of the screw compressor and are arranged axially parallel to each other.
[0019] Furthermore, the present application describes that a needle seat and a spray rack are arranged on the spray base, the axial ends of the female rotor and the male rotor are respectively connected to the needle seats on the corresponding sides, the needle seat is connected to a driving mechanism, and the driving mechanism is used to drive the female rotor and the male rotor to rotate circumferentially; the spray rack is provided with a guide rail, and a Teflon spray gun is slidably fitted on the guide rail, and the Teflon spray gun can move back and forth along the guide rail.
[0020] Furthermore, the female rotor and the male rotor are assembled between the ejector seats according to the positions where the female rotor and the male rotor are located at the same position at the intake end and the exhaust end in the screw compressor.
[0021] Furthermore, the center distance between the air inlet ends of the female rotor and the male rotor is greater than the center distance between the air exhaust ends.
[0022] Advantages and beneficial effects of this application:
[0023] 1. The present application firstly calculates the theoretical zero meshing clearance, high temperature profile, and profile data of 0.1mm clearance of the female and male rotors through software; later, the dimensions before the process are achieved through exquisite processing technology, and then the oil is removed in an oven; then the key point is to clamp the female and male rotors with the center distance required by the host on the rotary spraying station, and then achieve the purpose of uniformly spraying Teflon on the outer surfaces of the female and male rotors through uniform rotation and uniform spraying; this spraying process can realize the spraying of the outer surfaces of the female and male rotors at the same time, without the need for a separate one. processing; more importantly, the female rotor and the male rotor rotate at a uniform speed in the spraying process, so the sprayed coating is more balanced, and the female rotor and the male rotor are set in the same direction as the exhaust end and the intake end of the main engine, so that the spraying process can effectively avoid the rotor from getting stuck, and provide a guarantee for the stable use of the subsequent rotor in the main engine; the male and female rotors after spraying have a coating of Teflon material, so they have excellent corrosion resistance, good non-stick performance, wear resistance and impact resistance, excellent high temperature resistance, insulation, and reduced friction coefficient.
[0024] 2. This application is the first to set the spraying process of Teflon on the outer surfaces of the female and male rotors of the screw compressor to achieve spraying by setting the female and male rotors to rotate circumferentially with respect to the center distance of the air inlet end (intake end) required by the main engine. Compared with traditional static single-root spraying, the obtained coating is sprayed more evenly and is more adaptable to the use requirements in the main engine.
[0025] 3. In the present application, during the spraying process, the center distance between the air inlet end of the female rotor and the male rotor is greater than the center distance between the air outlet end. During the spraying process, the thickness of the spraying is controlled to ensure that the female rotor and the male rotor will not bite each other. After the spraying is completed, the female rotor and the male rotor are assembled into the main unit of the screw compressor in a manner that they are axially parallel to each other. The reason for this arrangement is that after the female and male rotors are installed in the screw chamber of the screw compressor, during the operation of the screw compressor, low-temperature gas is absorbed from the intake end and transported to the outlet end (exhaust end) after the two rotors are meshed and driven. The temperature of the gas will increase. Under normal circumstances, the female and male rotors are located in an environment surrounded by such high-temperature gas, and they will expand and the gap will become smaller, which may cause the rotors to bite or scrape the cylinder. However, after adopting the above-mentioned scheme of the present application, When spraying, the center distance between the female and male rotors at the exhaust end is set smaller. After the spraying process is completed, the rotors are controlled not to bite each other. Then, after being assembled into the main engine, since the female and male rotors are arranged axially parallel to each other, compared with the process of spraying the coating, the center distance of the intake end remains unchanged, while the center distance of the exhaust end becomes larger. In this way, even if the outer diameter of the rotor at the exhaust end expands and becomes larger in a high-temperature gas environment, since the gap between the female and male rotors becomes larger than when spraying, the smaller gap caused by high-temperature expansion can be offset, thereby ensuring that the female and male rotors at the exhaust end in a high-temperature environment will not bite each other or scratch the cylinder body, thereby ensuring stable operation of the rotors. The difference in the center distances at both ends of the specific spraying process can be adjusted according to the needs of screw compressors of different specifications. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 A structural schematic diagram of the first view of the equipment used in the spraying method of the screw rotor of the present application.
[0027] Figure 2 A structural schematic diagram of the first view of the equipment used in the spraying method of the screw rotor of the present application.
[0028] Figure 3 A schematic diagram of the structure of the rotor and the spraying equipment in the spraying method of the screw rotor of the present application.
[0029] As shown in the attached figure: 1. Spraying base, 2. Ejector seat, 3. Spraying rack, 4. Female rotor, 5. Male rotor, 6. Guide rail, 7. Teflon spray gun. DETAILED DESCRIPTION
[0030] The following will combine the embodiments and drawings to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only preferred embodiments, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention;
[0031] It should also be noted that: when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may be another intermediate component, fixed through the intermediate component. When a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be another intermediate component at the same time. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be another intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only; the front and rear ends of this application are the front end when the pen tip is extended in the use state, and the rear end where the pressing part is located. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by technicians in the technical field of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.
[0032] As attached Figure 1-3 As shown, it is a schematic diagram of the structure of the equipment used in the spraying method of the screw rotor of the present application, the equipment includes a spraying base 1, a ejector seat 2 and a spraying frame 3 arranged on the spraying base 1, and the two axial ends of the female rotor 4 and the male rotor 5 are respectively connected to the ejector seat 2 on the corresponding side (the ejector seat can be fixed on the spraying base at the lower end, and the abutting end thereof with the female and male rotors can be set to a sharp end, which can achieve abutment with the female and male rotors, and at the same time will not increase the friction resistance due to the excessive contact surface). 2 is also connected with a driving mechanism (such as a driving motor and a gear plate, similar to the gear plate in the gear box of a screw compressor, so that the female and male rotors can be driven to rotate synchronously; not shown in the figure, it is a conventional driving mechanism and driving method of the female and male rotors), and the driving mechanism is used to drive the circumferential rotation of the female rotor 4 and the male rotor 5; the spraying frame 3 is provided with a guide rail 6, and a Teflon spraying gun 7 is slidably matched on the guide rail 6, and the Teflon spraying gun 7 can move back and forth along the guide rail 6.
[0033] Specifically, as attached Figure 1-3As shown, a set of Teflon spray guns 7 (which can be existing guns for spraying Teflon coatings on screw rotors) are arranged on both sides of the radial direction of the female rotor 4 and the male rotor 5, and two guide rails 6 are arranged in parallel up and down on each side. The Teflon spray gun 7 is slidably mounted on the two guide rails 6 arranged in parallel up and down, and can run back and forth along the length direction of the guide rails 6. The operation process can be achieved by conventional driving motors and corresponding driving components in the industry, such as screws, stepping motors, etc.; here, it will not be described in detail; the installation height of the ejector seat 2 of the present application must ensure that the female and male rotors will not contact or collide with the spray base during the rotation process.
[0034] As attached Figure 3 As shown, the female rotor 4 and the male rotor 5 described in the present application are assembled between the ejector pin seats 2 according to the arrangement of the intake end and the exhaust end of the screw compressor main unit assembly; that is, the orientation of the female and male rotors in the screw compressor main unit is consistent with the orientation of the coating sprayed thereon; the ejector pin seat of the present application has a tip that cooperates with the concave hole on the axial end faces of the female and male rotors, so that the friction between the female and male rotors can be reduced during the rotation of the female and male rotors, making the rotation smoother, thereby ensuring that the coating is sprayed more evenly.
[0035] The Teflon coating of the present application is only sprayed on the screw parts of the female rotor and the male rotor, while the shaft sections are not sprayed; this can effectively protect and spray the meshing parts of the female and male rotors, and can also save costs.
[0036] As an example, in the spraying process of the Teflon spray gun 7 described in the present application, the center distance between the female rotor 4 and the male rotor 5 at the air inlet end is consistent with the center distance between them in the main body of the screw compressor, and the center distance between their exhaust ends is slightly smaller than the center distance between their air inlet ends; after the spraying is completed, the female rotor 4 and the male rotor 5 are assembled into the main body of the screw compressor, and they are axially parallel to each other, that is, the center distance between the air inlet end and the exhaust end is consistent with the center distance of the air inlet end during spraying, and the center distance of the exhaust end at this time is larger than the center distance between the exhaust ends when the coating is sprayed; the reason for this arrangement is that: after the female and male rotors are installed in the screw chamber of the screw compressor, during the operation of the screw compressor, low-temperature gas is absorbed from the intake end, and is transported to the outlet end (exhaust end) after being driven by the meshing of the two rotors. The temperature of the gas will increase. Under normal circumstances, the female and male rotors are located in such an environment surrounded by high-temperature gas, and they will expand, the gap will become smaller, and it is very likely that the rotors will The situation of biting or scraping the cylinder; after adopting the above-mentioned scheme of the present application, since the center distance of the female and male rotors at the exhaust end is set to be smaller when spraying the coating, the control process of controlling the rotors to prevent biting occurs during the spraying process, and then after being assembled into the main engine, since the female and male rotors are set axially parallel to each other, compared with the process of spraying the coating, the center distance of the intake end remains unchanged, while the center distance of the exhaust end becomes larger, so that even if the outer diameter of the rotor at the exhaust end expands and becomes larger in a high-temperature gas environment, since the gap between the female and male rotors becomes larger than when the coating is sprayed, the reduction in the gap caused by the high-temperature expansion can be offset, thereby ensuring that the female and male rotors at the exhaust end in a high-temperature environment will not bit each other or scrape against the cylinder body, thereby ensuring the stable operation of the rotors. The difference in the center distances at both ends of the specific spraying process can be adjusted according to the needs of screw compressors of different specifications. It is a very small adjustment, which can be adjusted specifically according to parameters such as the expansion coefficient.
[0037] The present application adopts the above-mentioned equipment to carry out the spraying method of the screw rotor, and the steps of the method include:
[0038] (1) First, the theoretical zero meshing clearance, high temperature profile, and profile data of 0.1 mm clearance of the female and male rotors are calculated by screw size design software; that is, the Rongguo design software technology obtains the specification size of a pair of female and male rotors that need to be prepared and processed for meshing with each other;
[0039] The screw size design software mentioned in this application is a well-known calculation software in the industry. This application does not make any protection requirements for the specific software and the corresponding algorithm. It can be designed and developed by those skilled in the art according to the selected design software and the specifications of the yin and yang rotors, and will not be described in detail here.
[0040] (2) machining a pair of female and male rotors according to the size specifications calculated and designed by the software in step (1) to obtain female and male rotors of designed size; the machining process of the female and male rotors is also a conventional processing method for screw rotors in the art, which will not be described in detail here;
[0041] (3) Then the processed female rotor and male rotor are placed in a high temperature environment for baking and degreasing to provide a guarantee for the subsequent coating and bonding of the Teflon coating;
[0042] (4) The deoiled female rotor and the male rotor are fixed on the spray base at the same time, and the arrangement and layout of the female rotor and the male rotor on the spray base are consistent with the orientation of the air inlet end and the air outlet end after they are assembled to the main unit of the screw compressor; and the center distance between the air inlet ends of the female and male rotors at this time is also consistent with the center distance required when they are assembled to the main unit of the screw compressor, while the center distance between the exhaust ends is slightly smaller than the center distance between the air inlet ends at this time;
[0043] (5) Then, on the outside of the female rotor and the male rotor (see Appendix for details) Figure 1-3 , that is, Teflon spraying equipment is arranged on both sides of the female and male rotors in the radial direction, and the female rotor and the male rotor are started at the same time so that they mesh with each other and rotate, and Teflon is sprayed during the meshing and rotating process;
[0044] (6) After the spraying is completed, the obtained female rotor and male rotor are dried and shaped.
[0045] The high temperature baking and degreasing described in the above step (3) of the present application specifically involves placing one or more female rotors and male rotors in a baking device and baking them at 260-300° C. for 2-2.5 hours.
[0046] The formula of the Teflon coating of the present application mainly includes ingredients such as polytetrafluoroethylene resin, additives and solvents; commercially available Teflon coatings can be used, and the type and parameters of the spraying equipment will be adjusted according to the specific application scenarios and needs to achieve the required coating thickness and uniformity requirements.
[0047] More specifically, the high-temperature baking and degreasing of step (3) is performed by placing one or more female rotors and male rotors in a baking device and baking them at 280° C. for 2-2.5 hours. The female and male rotors can be placed in an oven for baking at a rate of 8-12 rotors per oven at a time.
[0048] The Teflon spraying equipment described in the above step (5) of the present application moves back and forth along the axial direction of the female rotor and the male rotor during the spraying process.
[0049] The spraying range of the Teflon spraying equipment described above in the present application is consistent with the extension length of the screw parts of the female rotor and the male rotor.
[0050] The drying and shaping described in the above step (6) of the present application specifically includes placing one or more female rotors and male rotors in a baking device and baking them at 260-280° C. for 3-3.5 hours.
[0051] More specifically, the drying and shaping in step (6) is performed by placing one or more female rotors and male rotors in a baking device and baking them at 270° C. for 3-3.5 hours. The female and male rotors can be placed in an oven for baking at a rate of 8-12 rotors per oven.
[0052] The most important innovation of the present application is that the Teflon coating is sprayed while the female and male rotors of the screw compressor are rotating circumferentially, and the center distance between the inlet ends of the female and male rotors during the spraying rotation is consistent with the actual axial distance in the cavity of the specific screw compressor, while the center distance of the exhaust ends is smaller than the center distance of the inlet ends; after the spraying coating is completed, the female and male rotors are assembled into the main unit of the screw compressor in parallel with each other axially. At this time, the center distance between the inlet ends of the female and male rotors remains unchanged, while the center distance of the exhaust ends becomes larger than that in the process of spraying the coating, that is, the meshing clearance between the female and male rotors is smaller than that in the spraying coating. The meshing gap becomes larger during coating; in this way, in actual use, due to the compression and extrusion of other temperatures at the exhaust end and the steady increase, the outer diameters of the exhaust ends of the negative and positive rotors will expand and become larger, and the meshing gap between the negative and positive rotors caused by the above-mentioned adjustment method becomes larger, which makes up for the smaller meshing gap caused by thermal expansion. Therefore, even if expansion occurs, it is not easy for the negative and positive rotors to bite each other or scratch the cylinder body during actual use; obviously, the coating process of the present application, which is set according to the actual use scenarios of the negative and positive rotors, is more advantageous than the traditional negative and positive rotors sprayed separately.
Claims
1. A method for spraying a screw rotor, characterized in that: The steps of the method include: (1) First, the theoretical zero meshing clearance, high temperature profile, and profile data of 0.1 mm clearance of the female and male rotors are calculated using screw size design software; (2) machining a pair of female and male rotors according to the size specifications calculated and designed by the software in step (1) to obtain female and male rotors of designed size; (3) then baking the processed female rotor and male rotor at high temperature to remove oil; (4) Assemble the deoiled female rotor and the male rotor on the spray-coated base at the same time, and assemble them in such a way that the female rotor and the male rotor are located at the same orientation at the intake end and the exhaust end of the main unit of the screw compressor; (5) Then, Teflon spraying equipment is arranged on the outer sides of the female rotor and the male rotor, and the female rotor and the male rotor are started at the same time so that they mesh with each other and rotate, and Teflon spraying is performed during the meshing and rotating process; (6) After the spraying is completed, the obtained female rotor and male rotor are dried and shaped.
2. The method for spraying a screw rotor according to claim 1, characterized in that: The high temperature baking to remove oil in step (3) is specifically to place one or more female rotors and male rotors in a baking oven and bake them at 260-300° C. for 2-2.5 hours.
3. The method for spraying a screw rotor according to claim 1, characterized in that: The Teflon spraying equipment described in step (5) moves back and forth along the axial direction of the female rotor and the male rotor during the spraying process.
4. The method for spraying a screw rotor according to claim 1, characterized in that: The spraying range of the Teflon spraying equipment is consistent with the extension length of the screw parts of the female rotor and the male rotor.
5. The method for spraying a screw rotor according to claim 1, characterized in that: The drying and shaping in step (6) is specifically to place one or more female rotors and male rotors in a baking oven and bake them at 260-280° C. for 3-3.5 hours.
6. The method for spraying a screw rotor according to claim 1, characterized in that: The center distance between the intake ends of the female rotor and the male rotor described in step (4) is greater than the center distance between the exhaust ends.
7. The method for spraying a screw rotor according to claim 6, characterized in that: The center distance between the air inlet ends of the female rotor and the male rotor described in step (4) is consistent with the center distance between them in the main unit of the screw compressor.
8. The method for spraying a screw rotor according to claim 6, characterized in that: After the spraying is completed, the female rotor and the male rotor are assembled in the main body of the screw compressor and are arranged axially parallel to each other.
9. The method for spraying a screw rotor according to claim 6, characterized in that: The spray base is provided with an ejector seat and a spray rack, the axial ends of the female rotor and the male rotor are respectively connected to the ejector seats on the corresponding sides, the ejector seat is connected with a driving mechanism, and the driving mechanism is used to drive the female rotor and the male rotor to rotate circumferentially; the spray rack is provided with a guide rail, and a Teflon spray gun is slidably fitted on the guide rail, and the Teflon spray gun can move back and forth along the guide rail.
10. The method for spraying a screw rotor according to claim 9, characterized in that: The female rotor and the male rotor are assembled between the ejector seats according to the positions where the air inlet and the air outlet ends of the female rotor and the male rotor are located in the screw compressor in the same manner; the center distance between the air inlet ends of the female rotor and the male rotor is greater than the center distance between the air outlet ends.