An oil-free screw compressor screw profile
By employing a double-sided asymmetric profile design and a smooth continuous curve in an oil-free twin-screw compressor, combined with sealing grooves and sealing ribs, the problems of low efficiency and insufficient sealing performance of the male and female rotors are solved, achieving high-efficiency and low-leakage compressor performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WUXI XIYA COMPRESSOR CO LTD
- Filing Date
- 2025-07-04
- Publication Date
- 2026-06-09
AI Technical Summary
In existing oil-free twin-screw compressors, the male and female rotors adopt symmetrical profiles, which result in insufficient efficiency, significant leakage, inadequate sealing performance, and poor gas dynamics of the profile.
It adopts a double-sided asymmetric profile design, with a tooth ratio of 6:4 between the male and female rotors. The meshing clearance is distributed through synchronous gears. The male and female rotors use smooth continuous curves and are equipped with sealing grooves and sealing ribs to improve sealing performance.
It effectively reduces leakage losses, improves volume utilization and efficiency, enhances sealing performance and profile gas dynamics, and reduces wear.
Smart Images
Figure CN224339169U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of compressor rotor technology, specifically to a screw profile for an oil-free screw compressor. Background Technology
[0002] Because dry screw compressors do not require the injection of oil or other coolants into the compressed medium during the compressor process, the compressed gas they deliver is clean and suitable for applications with high gas quality requirements, such as food, pharmaceuticals, and electronics. The rotor profile plays a decisive role in the machine's operating efficiency, transmission performance, and processing costs.
[0003] Existing patent document CN208169115U discloses an oil-free twin-screw compressor rotor profile, comprising a pair of meshing male and female rotors. The male rotor, connected to the drive shaft, meshes with the female rotor, connected to the driven shaft, forming a conventional compressor rotor structure. The tooth ratio of the male rotor to the female rotor is 4:6. At the meshing point, the end lines of the male teeth are in contact with the root lines of the female teeth. Simultaneously, adjacent end lines of two male teeth form a groove due to the spacing between the root lines, and the end lines of the female teeth respectively fit into the grooves with the end lines of two adjacent male teeth. Based on the specific profile equation of this invention, the meshing point ensures good fit. Specifically, its contact line remains continuous and is significantly shorter than that of a conventional profile, while minimizing the leakage triangle, thereby significantly reducing leakage loss. Furthermore, this rotor profile has a smaller enclosed volume and a larger inter-tooth area, which helps reduce wear and improve transmission efficiency.
[0004] Although the device has many beneficial effects, the following problems still exist: During the use of the device, both the male and female rotors adopt symmetrical profiles, resulting in insufficient efficiency and significant leakage; secondly, the device has insufficient sealing performance and poor gas dynamics of the profile, which need to be improved. In view of this, we propose a screw profile for an oil-free screw compressor. Utility Model Content
[0005] The purpose of this section is to outline some aspects of the embodiments of this utility model and to briefly introduce some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be used to limit the scope of this utility model.
[0006] 1. Technical problems to be solved:
[0007] To address the issues of insufficient efficiency, significant leakage, inadequate sealing performance, and poor aerodynamics of the aforementioned symmetrical rotor profiles, this invention is proposed.
[0008] Therefore, the purpose of this utility model is to provide an oil-free screw compressor screw profile, in which both the male and female rotors adopt a double-sided asymmetrical profile, resulting in higher efficiency, less leakage, higher volume utilization, better sealing performance, and better profile gas dynamics.
[0009] 2. Technical Solution:
[0010] To solve the above-mentioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution:
[0011] An oil-free screw compressor screw profile includes a screw compressor housing. A drive shaft is rotatably connected to the inner wall of the screw compressor housing. A male rotor is provided on the outer circumference of the drive shaft. The outer circumference of the male rotor is provided with multiple male rotor teeth. The end face lines of the male rotor teeth are male tooth end lines, and the end face lines of the male rotor are male tooth root lines. Multiple sets of male tooth end lines and male tooth root lines are connected end to end. A driven shaft is rotatably connected to the other side of the inner wall of the screw compressor housing. A female rotor is provided on the outer circumference of the driven shaft. The outer circumference of the female rotor is provided with multiple female rotor teeth. The end face lines of the female rotor teeth are female tooth end lines, and the end face lines of the female rotor are female tooth root lines. Multiple sets of female tooth end lines and female tooth root lines are connected end to end.
[0012] As a preferred embodiment of the screw profile of an oil-free screw compressor according to this utility model, a plurality of male tooth root lines are provided with sealing grooves on their sidewalls, and a plurality of female tooth root lines are provided with sealing ribs on their sidewalls. The male tooth end lines, male tooth root lines, female tooth end lines, female tooth root lines, sealing grooves, and sealing ribs are all smooth and continuous curves.
[0013] In a preferred embodiment of the screw profile of an oil-free screw compressor according to this utility model, the ratio of the number of teeth of the female rotor to the number of teeth of the male rotor is 6:4, and the meshing clearance between the male rotor and the female rotor is achieved by synchronous gear distribution.
[0014] As a preferred embodiment of the screw profile of an oil-free screw compressor according to this utility model, the distance between the center of the drive shaft and the center of the driven shaft is 136mm, and the meshing clearance between the male rotor teeth and the female rotor teeth is 0.30~0.55mm.
[0015] In a preferred embodiment of the screw profile of an oil-free screw compressor according to this utility model, the dimensions and position of the sealing groove match the dimensions and position of the sealing rib.
[0016] In a preferred embodiment of the screw profile of an oil-free screw compressor according to this utility model, both the male rotor and the female rotor are made of carbon steel, and the outer wall of the screw compressor housing is threaded with multiple bolts.
[0017] As a preferred embodiment of the screw profile of an oil-free screw compressor according to this utility model, the profiles of both the male rotor and the female rotor adopt a thermal compensation algorithm, and the male rotor and the female rotor mesh with each other.
[0018] 3. Beneficial effects:
[0019] Compared with the prior art, the beneficial effects of this utility model are:
[0020] The screw profile of this oil-free screw compressor forms a groove between adjacent male tooth end lines through the spacing of the male tooth root lines. The female tooth end lines fit into the male tooth root lines in the grooves, reducing leakage and leakage loss, and effectively improving volume utilization. The rotation of the drive shaft drives the male rotor to rotate, thereby causing the meshing female rotor to rotate. The use of double-sided asymmetrical profiles for both the male and female rotors effectively improves efficiency.
[0021] The screw profile of this type of oil-free screw compressor, when the male and female rotors mesh and rotate, allows the sealing ribs to enter the sealing groove, improving sealing performance. The smooth and continuous curves of the male tooth end line, male tooth root line, female tooth end line, female tooth root line, sealing groove, and sealing ribs facilitate better gas dynamics of the profile and make it convenient to use. Attached Figure Description
[0022] To more clearly illustrate the technical solutions of the embodiments of this utility model, the present utility model will be described in detail below with reference to the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them:
[0023] Figure 1 This is a schematic diagram of the male and female rotor structures of an oil-free screw compressor according to the present invention;
[0024] Figure 2 This is a schematic diagram of the female rotor structure of an oil-free screw compressor according to the present invention;
[0025] Figure 3 This is a schematic cross-sectional view of the overall structure of the screw profile of an oil-free screw compressor according to this utility model;
[0026] Figure 4 This is a schematic diagram of the main unit profile of the screw profile of an oil-free screw compressor according to this utility model.
[0027] The following are the labels in the diagram: 1. Screw compressor housing; 2. Drive shaft; 3. Male rotor; 4. Male rotor teeth; 5. Male tooth end line; 6. Male tooth root line; 7. Driven shaft; 8. Female rotor; 9. Female rotor teeth; 10. Female tooth end line; 11. Female tooth root line; 12. Sealing groove; 13. Sealing rib. Detailed Implementation
[0028] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.
[0029] This utility model is described in detail with reference to the schematic diagrams. When describing the embodiments of this utility model, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not be construed as limiting the scope of protection of this utility model. In actual manufacturing, the three-dimensional spatial dimensions of length, width, and depth should be included.
[0030] The orientation or positional relationship indicated in the terminology is based on the orientation or positional relationship shown in the accompanying drawings and is only for the convenience of describing the present invention and simplifying the description. It is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.
[0031] The term "connection method" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0032] The embodiments of this utility model will now be described in further detail with reference to the accompanying drawings.
[0033] This utility model provides an overall structural schematic diagram of an embodiment of the screw profile of an oil-free screw compressor, including:
[0034] Please see Figures 1-4This embodiment of an oil-free screw compressor screw profile includes a screw compressor housing 1. A drive shaft 2 is rotatably connected to the inner wall of the screw compressor housing 1. A male rotor 3 is fixedly mounted on the outer circumference of the drive shaft 2. Multiple male rotor teeth 4 are fixedly mounted on the outer circumference of the male rotor 3. The end face lines of the male rotor teeth 4 are male tooth end lines 5, and the end face lines of the male rotor 3 are male tooth root lines 6. Multiple sets of male tooth end lines 5 and male tooth root lines 6 are connected end to end. A driven shaft 7 is rotatably connected to the other side of the inner wall of the screw compressor housing 1. A female rotor 8 is fixedly mounted on the outer circumference of the driven shaft 7. Multiple female rotor teeth 8 are fixedly mounted on the outer circumference of the female rotor 8. The female rotor tooth 9 has an end face line 10, and the female rotor 8 has an end face line 11. Multiple sets of female tooth end lines 10 and female tooth root lines 11 are connected end to end. The male tooth root lines 6 are spaced to form grooves between adjacent male tooth end lines 5. The female tooth end lines 10 fit into the male tooth root lines 6 in the grooves to reduce leakage and leakage loss, and effectively improve volume utilization. The rotation of the drive shaft 2 drives the male rotor 3 to rotate, thereby causing the meshing female rotor 8 to rotate. Both the male rotor 3 and the female rotor 8 adopt double-sided asymmetrical profiles, which effectively improves efficiency.
[0035] It is worth noting that, in order to improve the sealing performance, specifically, sealing grooves 12 are provided on the side walls of multiple male tooth root lines 6, and sealing ribs 13 are provided on the side walls of multiple female tooth root lines 11. The male tooth end line 5, male tooth root line 6, female tooth end line 10, female tooth root line 11, sealing groove 12, and sealing rib 13 are all smooth and continuous curves. When the male rotor 3 and female rotor 8 mesh and rotate, the sealing rib 13 enters the sealing groove 12, improving the sealing performance. The smooth and continuous curves of the male tooth end line 5, male tooth root line 6, female tooth end line 10, female tooth root line 11, sealing groove 12, and sealing rib 13 facilitate better gas dynamics of the profile and make it convenient to use.
[0036] Next, in order to reduce rotor wear, specifically, the tooth ratio of the female rotor tooth 9 to the male rotor tooth 4 is 6:4. The meshing clearance between the male rotor 3 and the female rotor 8 is achieved through synchronous gear distribution. The tooth ratio of the female rotor tooth 9 to the male rotor tooth 4 of 6:4 facilitates the reduction of the enclosed volume and the increase of the inter-tooth area, which helps to reduce wear and improve transmission efficiency. The synchronous gear distribution between the male rotor 3 and the female rotor 8 facilitates transmission.
[0037] Meanwhile, in order to adapt to meshing transmission, specifically, the distance between the axis of the drive shaft 2 and the axis of the driven shaft 7 is 136mm, and the meshing clearance between the male rotor teeth 4 and the female rotor teeth 9 is 0.30~0.55mm.
[0038] Furthermore, in order to make the engagement and rotation of the male rotor 3 and the female rotor 8 smoother, the size and position of the sealing groove 12 are matched with the size and position of the sealing rib 13. The sealing groove 12, which matches the size and position of the sealing rib 13, prevents the engagement and rotation of the male rotor 3 and the female rotor 8 from being obstructed.
[0039] It is worth noting that, in order to improve the performance of the oil-free screw compressor, specifically, the male rotor 3 and the female rotor 8 are both made of carbon steel, and the outer wall of the screw compressor housing 1 is threaded with multiple bolts. The male rotor 3 and the female rotor 8 made of carbon steel are easy to process, have low cost, and better strength. By screwing in the bolts, the screw compressor housing 1 can be made more stable.
[0040] Finally, in order to ensure the profile gap under hot conditions, the profiles of both the male rotor 3 and the female rotor 8 adopt a thermal compensation algorithm. The male rotor 3 and the female rotor 8 mesh with each other. By using the thermal compensation algorithm to set the profiles of the male rotor 3 and the female rotor 8, the profile gap between the male rotor 3 and the female rotor 8 under hot conditions can be guaranteed.
[0041] Combination Figures 1-4 The screw profile of an oil-free screw compressor according to this embodiment is used in the following specific process:
[0042] 1: According to actual use, the spacing of the male tooth root line 6 makes the adjacent male tooth end line 5 form a groove, and the female tooth end line 10 fits into the male tooth root line 6 in the groove to reduce leakage. The rotation of the drive shaft 2 drives the male rotor 3 to rotate, thereby causing the meshing female rotor 8 to rotate. Both the male rotor 3 and the female rotor 8 adopt double-sided asymmetrical profile.
[0043] 2: When the male rotor 3 and female rotor 8 mesh and rotate, the sealing rib 13 enters the sealing groove 12, and the smooth and continuous curves of the male tooth end line 5, male tooth root line 6, female tooth end line 10, female tooth root line 11, sealing groove 12, and sealing rib 13 improve the gas dynamics of the profile.
[0044] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the features in the embodiments disclosed in this invention can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. An oil-free screw compressor screw profile, characterized in that, The screw compressor housing (1) is characterized in that: a drive shaft (2) is rotatably connected to the inner wall of the screw compressor housing (1), a male rotor (3) is provided on the outer circumference of the drive shaft (2), and a plurality of male rotor teeth (4) are provided on the outer circumference of the male rotor (3), the end face line of the male rotor teeth (4) is the male tooth end line (5), and the end face line of the male rotor (3) is the male tooth root line (6), and the plurality of sets of the male tooth end lines (5) and the male tooth root lines (6) The screw compressor housing (1) is connected end to end. A driven shaft (7) is rotatably connected to the other side of the inner wall. The driven shaft (7) has a female rotor (8) on its outer circumference. The female rotor (8) has multiple female rotor teeth (9) on its outer circumference. The end face line of the female rotor teeth (9) is the female tooth end line (10). The end face line of the female rotor (8) is the female tooth root line (11). Multiple sets of female tooth end lines (10) and female tooth root lines (11) are connected end to end.
2. The screw profile of the oil-free screw compressor according to claim 1, characterized in that, Each of the male tooth root lines (6) has a sealing groove (12) on its sidewall, and each of the female tooth root lines (11) has a sealing rib (13) on its sidewall. The male tooth end line (5), male tooth root line (6), female tooth end line (10), female tooth root line (11), sealing groove (12), and sealing rib (13) are all smooth and continuous curves.
3. The screw profile of the oil-free screw compressor according to claim 2, characterized in that, The ratio of the number of teeth of the female rotor (9) to the number of teeth of the male rotor (4) is 6:4, and the meshing gap between the male rotor (3) and the female rotor (8) is achieved by synchronous gear distribution.
4. The screw profile of the oil-free screw compressor according to claim 3, characterized in that, The distance between the center of the drive shaft (2) and the center of the driven shaft (7) is 136 mm, and the meshing clearance between the male rotor tooth (4) and the female rotor tooth (9) is 0.30 to 0.55 mm.
5. The screw profile of the oil-free screw compressor according to claim 4, characterized in that, The dimensions and position of the sealing groove (12) match the dimensions and position of the sealing rib (13).
6. The screw profile of the oil-free screw compressor according to claim 5, characterized in that, Both the male rotor (3) and the female rotor (8) are made of carbon steel, and the outer wall of the screw compressor housing (1) is threaded with multiple bolts.
7. The screw profile of the oil-free screw compressor according to claim 6, characterized in that, The profiles of the male rotor (3) and the female rotor (8) are both designed using a thermal compensation algorithm, and the male rotor (3) and the female rotor (8) mesh with each other.