Screw rotor and compressor

Abstract

The present application provides a screw rotor and a compressor. The screw rotor includes a female rotor and a male rotor meshing with the female rotor. The number of teeth of the female rotor is equal to the number of teeth of the male rotor, and the number of teeth of the female rotor and the number of teeth of the male rotor are both greater than or equal to 6. By applying the technical solution of the present invention, the noise of the screw rotor can be reduced from both mechanical noise and fluid dynamic noise.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration equipment, and in particular to a screw rotor and a compressor. Background Art

[0002] The screw compressor achieves volume change through the periodic meshing rotation of a pair of parallel arranged female and male rotors, thereby completing the suction, compression and exhaust processes. In a screw compressor, the male rotor is usually driven by an electric motor to rotate, and the male rotor then drives the female rotor to rotate. The friction noise generated by the female and male rotors during the meshing process is the main source of mechanical noise in the screw compressor. The exhaust airflow pulsation caused by the periodic change of the exhaust port area is the main source of fluid dynamic noise. The end profile of the screw rotor is the core technology of the screw compressor, which largely determines the size of the mechanical noise and fluid dynamic noise during the meshing process of the screw compressor rotor.

[0003] In addition, the machining accuracy of the screw rotor will also have a great impact on the smooth meshing of the rotor. The general machining process of the screw rotor is to trim the grinding wheel to the required blade shape with a fine steel stone knife, and grind the rotor spiral tooth surface to the required accuracy through the grinding wheel. However, the grinding process will inevitably produce insufficient machining accuracy on both sides of the grinding wheel, making it impossible to trim the small section of the tooth top in the male rotor grinding process to the required profile, and the actual measurement point deviates seriously from the theoretical profile point, affecting the meshing between the rotors.

[0004] The gear ratio of the traditional screw rotor is generally 5:6. The male rotor drives the female rotor. When the male rotor teeth mesh with the female rotor tooth grooves, the number of teeth of the male and female rotors is different. If the machining accuracy of a tooth is insufficient, during operation, the tooth will cause grinding deviations in the tooth grooves of the female or male rotor, resulting in meshing instability. Especially when variable frequency screw compressors are used, sudden changes in speed will aggravate this effect, leading to severe vibration and noise problems. In addition, during the exhaust process of the screw compressor, the inter-tooth volume is periodically connected and disconnected from the exhaust chamber, resulting in severe exhaust airflow pulsation and large fluid dynamic noise. Summary of the invention

[0005] The embodiment of the present invention provides a screw rotor and a compressor to solve the technical problem of high noise during use of the screw rotor in the prior art.

[0006] An embodiment of the present application provides a screw rotor, including a female rotor and a male rotor meshing with the female rotor, wherein the number of teeth of the female rotor is equal to the number of teeth of the male rotor, and the number of teeth of the female rotor and the number of teeth of the male rotor are both greater than or equal to 6.

[0007] In one embodiment, the driving side tooth root position of the female rotor is a tooth root arc.

[0008] In one embodiment, the end point of the tooth root arc is D, the center of the female rotor is O1, the center of the male rotor is O2, the line connecting the center of the female rotor and the center of the male rotor is O1O2, the line connecting the end point of the tooth root arc and the center of the female rotor is DO1, and the angle between DO1 and O1O2 is 2 to 10°.

[0009] In one embodiment, the tip arc width of the male rotor is at least 1.5 mm.

[0010] In one embodiment, the gap between the driving side pitch circle K1K2 of the female rotor and the male rotor is 0.

[0011] In one embodiment, the gap between the sealing side pitch circle L1L2 of the female rotor and the male rotor is 0.01 mm to 0.03 mm.

[0012] In one embodiment, the gap between the driving side pitch circle K1K2 of the female rotor and the sealing side pitch circle L1L2 of the female rotor and the male rotor is 0.005 mm to 0.05 mm.

[0013] In one embodiment, there is one male rotor and at least two female rotors, and the female rotor is meshed around the male rotor.

[0014] In one embodiment, there are two female rotors, the two female rotors are respectively engaged with the two sides of the male rotor, and the line connecting the centers of the two female rotors passes through the center of the male rotor.

[0015] The present application also provides a compressor, including a screw rotor, and the screw rotor is the screw rotor mentioned above.

[0016] In the above embodiment, the number of teeth of the female rotor is equal to the number of teeth of the male rotor, and the teeth of the male rotor correspond to the tooth grooves of the female rotor and the teeth of the female rotor correspond to the tooth grooves of the male rotor during the meshing process. Even if the machining accuracy of one tooth is insufficient, during the operation, the tooth will only affect the tooth groove corresponding to the tooth, and there will be no grinding deviation on other tooth grooves, thereby reducing the influence of the machining deviation on the meshing of the teeth and the tooth grooves to a certain extent, so that the meshing of the female rotor and the male rotor is smooth and the mechanical noise is reduced. In addition, in the technical solution of the present invention, the number of teeth of the female rotor and the number of teeth of the male rotor are both greater than or equal to 6, which is more than the number of teeth of the traditional screw rotor, so that the volume value between a single tooth is relatively small, and the mass and energy exchange between the tooth volume and the exhaust chamber during the exhaust process is reduced, and the pulsation amplitude of the exhaust airflow is reduced, thereby reducing the fluid dynamic noise. In this way, the technical solution of the present invention can reduce the noise of the screw rotor from both mechanical noise and fluid dynamic noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 is a schematic diagram of the three-dimensional structure of an embodiment of a screw rotor according to the present invention;

[0019] Figure 2 yes Figure 1 A schematic diagram of the tooth curve formed on the driving side of the female rotor of the screw rotor;

[0020] Figure 3 yes Figure 1 The clearance distribution diagram of the female rotor of the screw rotor;

[0021] Figure 4 yes Figure 1 The end profile diagram of the screw rotor;

[0022] Figure 5 yes Figure 1 A diagram of exhaust pressure pulsation amplitude of a screw rotor compared to a screw rotor in the prior art;

[0023] Figure 6 yes Figure 1 A diagram showing a change in inter-tooth volume of a screw rotor compared to a screw rotor in the prior art;

[0024] Figure 7 yes Figure 1 The blade shape diagram of the male rotor dressing wheel of the screw rotor;

[0025] Figure 8 FIG. 1 is an end profile diagram of another embodiment of a screw rotor according to the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0027] Figure 1 An embodiment of the screw rotor of the present invention is shown, which includes a female rotor 10 and a male rotor 20 meshing with the female rotor 10. The number of teeth of the female rotor 10 is equal to the number of teeth of the male rotor 20, and the number of teeth of the female rotor 10 and the number of teeth of the male rotor 20 are both greater than or equal to 6.

[0028] By applying the technical solution of the present invention, the number of teeth of the female rotor 10 and the number of teeth of the male rotor 20 are equal, and the teeth of the male rotor 20 and the tooth grooves of the female rotor 10 and the teeth of the female rotor 10 and the tooth grooves of the male rotor 20 correspond one to one during the meshing process. Even if the machining accuracy of one tooth is insufficient, during the operation, the tooth will only affect the tooth groove corresponding to the tooth, and there will be no grinding deviation on other tooth grooves, thereby reducing the influence of the machining deviation on the meshing of the teeth and the tooth grooves to a certain extent, so that the meshing of the female rotor 10 and the male rotor 20 is smooth, and the mechanical noise is reduced. In addition, in the technical solution of the present invention, the number of teeth of the female rotor 10 and the number of teeth of the male rotor 20 are both greater than or equal to 6, which is more than the number of teeth of the traditional screw rotor, so that the volume value between a single tooth is relatively small, and the mass and energy exchange between the tooth volume and the exhaust chamber during the exhaust process is reduced, and the pulsation amplitude of the exhaust airflow is reduced, thereby reducing the fluid dynamic noise. In this way, the technical solution of the present invention can reduce the noise of the screw rotor from both mechanical noise and fluid dynamic noise.

[0029] Optionally, in the technical solution of this embodiment, if Figure 4 As shown, the number of teeth of the female rotor 10 and the number of teeth of the male rotor 20 are both equal to 6, the gear ratio is 1, the center distance A = 116mm, the rotor length L = 206mm, the torsion angle is 300deg, and the theoretical gas transmission capacity is 352m 3 / h, contact line length 138mm, leakage triangle area 1.8mm 2 .like Figure 6 As shown, compared with the prior art where the male rotor / female rotor has 5 / 6 teeth, after the number of teeth of the male rotor in this embodiment is increased to 6, the volume value between a single tooth is reduced, which effectively reduces the mass and energy exchange degree during the exhaust process. Figure 5 As shown, compared with the 5 / 6 tooth combination of the male rotor / female rotor in the prior art, the 6 / 6 tooth combination of the male rotor / female rotor in this embodiment can effectively reduce the exhaust airflow pulsation amplitude, so that the pressure pulsation amplitude in the exhaust chamber is further reduced, thereby reducing the fluid dynamic noise.

[0030] In the technical solution of this embodiment, the tooth root position of the driving side of the female rotor 10 is a tooth root arc. Figure 2As shown, the end point of the tooth root arc is D, the center of the female rotor 10 is O1, the center of the male rotor 20 is O2, the line connecting the center of the female rotor 10 and the center of the male rotor 20 is O1O2, the line connecting the end point of the tooth root arc and the center of the female rotor 10 is DO1, and the angle between DO1 and O1O2 is 2-10°. More preferably, the width of the tooth top arc of the male rotor 20 is at least 1.5 mm. Compared with the prior art, the technical solution of this embodiment can fully realize the "curved surface to curved surface" sealing, and the contact line has a good shape, which ensures the smooth meshing of the male and female rotors under small gaps and effectively reduces noise and vibration.

[0031] Optionally, in one embodiment, the angle between DO1 and O1O2 is 5°, and the tooth top arc at the corresponding meshing position of the male rotor is obtained according to the including principle, and the tooth top circle chord height is 1.5 mm, forming a tooth top circle area with a certain width, which fits the extended arc surface of the grinding wheel during the rotor grinding process.

[0032] like Figure 3 As shown, in the technical solution of this embodiment, the gap between the driving side pitch circle K1K2 of the female rotor 10 and the male rotor 20 is 0. Optionally, the gap between the sealing side pitch circle L1L2 of the female rotor 10 and the male rotor 20 is 0.01mm-0.03mm. More preferably, the gap between the driving side pitch circle K1K2 of the female rotor 10 and the sealing side pitch circle L1L2 of the female rotor 10 and the male rotor 20 is 0.005mm-0.05mm.

[0033] After reserving the gap, the actual line coordinate reference Figure 4 As shown in the following table:

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045] like Figure 7 As shown, the rotor can be ground according to the above data, and the rolling arc can be introduced, which is beneficial to the rotor grinding process, improves the processing accuracy, helps to smoothly mesh between the rotors, and reduces mechanical noise. After forming, the female rotor and the male rotor are paired, and the six teeth of the male rotor are meshed with the tooth grooves of the female rotor in turn. The reverse clearance of the female rotor is measured and the mechanism is used. The pairing method with the smallest reverse clearance is selected to ensure the smooth meshing of the male and female rotors during the operation of the compressor to the greatest extent.

[0046] The present invention also provides another embodiment of a screw rotor, in which there is one male rotor 20 and at least two female rotors 10, the female rotor 10 is meshed around the male rotor 20, and the remaining features are the same as those of the above embodiments. With this embodiment, one male rotor 20 can simultaneously drive multiple female rotors 10 to rotate, thereby significantly increasing the rotor exhaust volume.

[0047] like Figure 8 As shown, in a specific embodiment, there are two female rotors 10, and the two female rotors 10 are respectively meshed on both sides of the male rotor 20, and the line connecting the centers of the two female rotors 10 passes through the center of the male rotor 20. In this embodiment, since the two female rotors 10 are respectively meshed on both sides of the male rotor 20, and the centers of the three rotors are located on the same straight line, the torque applied by the male rotor 20 relative to the female rotor 10 on the left will be balanced by the torque applied by the female rotor 10 on the right, thereby reducing the radial force on the male rotor 20. At the same time, this embodiment can also significantly increase the rotor exhaust volume, and the compressor volume is reduced with the same exhaust volume.

[0048] The present invention also provides a compressor, which includes the screw rotor. The compressor using the screw rotor can significantly reduce the noise of the compressor and ensure the performance of the compressor.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the embodiments of the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A screw rotor, comprising a female rotor (10) and a male rotor (20) meshing with the female rotor (10), characterized in that: The number of teeth of the female rotor (10) is equal to the number of teeth of the male rotor (20), and the number of teeth of the female rotor (10) and the number of teeth of the male rotor (20) are both greater than or equal to 6; The tooth root position of the driving side of the female rotor (10) is a tooth root arc; The end point of the tooth root circular arc is D, the center of the circle of the female rotor (10) is O1, the center of the male rotor (20) is O2, the line connecting the center of the circle of the female rotor (10) and the center of the male rotor (20) is O1O2, the line connecting the end point of the tooth root circular arc and the center of the circle of the female rotor (10) is DO1, and the angle between DO1 and O1O2 is 2 to 10 degrees.

2. The screw rotor according to claim 1, characterized in that The tooth tip arc width of the male rotor (20) is at least 1.5 mm.

3. The screw rotor according to claim 1, characterized in that The clearance between the driving side pitch circle K1K2 of the female rotor (10) and the male rotor (20) is 0.

4. The screw rotor according to claim 3, characterized in that: The gap between the sealing side pitch circle L1L2 of the female rotor (10) and the male rotor (20) is 0.01 mm to 0.03 mm.

5. The screw rotor according to claim 4, characterized in that: The gap between the portion between the driving side pitch circle K1K2 of the female rotor (10) and the sealing side pitch circle L1L2 of the female rotor (10) and the male rotor (20) is 0.005 mm to 0.05 mm.

6. The screw rotor according to claim 1, characterized in that There is one male rotor (20), there are at least two female rotors (10), and the female rotor (10) is meshed around the male rotor (20).

7. The screw rotor according to claim 6, characterized in that There are two female rotors (10), the two female rotors (10) are respectively meshed on both sides of the male rotor (20), and a line connecting the centers of the two female rotors (10) passes through the center of the male rotor (20).

8. A compressor comprising a screw rotor, characterized in that: The screw rotor is the screw rotor according to any one of claims 1 to 7.

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