High-compression-ratio single-tooth rotor, design method and dry compressor

Abstract

The invention relates to the field of compressors, in particular to a high-compression-ratio single-tooth rotor, a design method and a dry compressor. The high-compression-ratio single-tooth rotor comprises a male rotor and a female rotor conjugated with the male rotor; the molded line of the male rotor comprises an epicycloid AB, a tooth top arc BC, a line segment CD, a parabola DE, a tooth pitch arc EF, a parabola FG and a tooth bottom arc GA which are smoothly connected in sequence and form a closed loop; the molded line of the female rotor comprises an epicycloid ab, a tooth crest arc bc, an envelope line cd of a parabola, a tooth pitch arc de, an envelope line ef of the parabola, an envelope line fg of a line segment, an epicycloid gh and a tooth bottom arc ha which are smoothly connected in sequence and form a closed loop. By means of the two sets of asymmetric rotors, larger air suction and displacement and a higher compression ratio can be achieved, and the working requirements of wide working conditions and large air flow are met.

Description

Technical Field

[0001] The invention relates to the field of compressors, in particular to a high compression ratio single-tooth rotor, a design method and a dry compressor. Background Art

[0002] As a dry compressor with good performance, single-tooth compressor is currently widely used in high-tech fields such as aerospace, electronics, and medicine. It realizes compression, air intake, and exhaust by driving two sets of rotors to rotate synchronously in opposite directions at high speed through two meshing rotors without direct contact through a pair of screws with a certain gap. The design of the overall profile of the single-tooth compressor directly affects the performance of the compressor (such as compression ratio, operating noise, etc.).

[0003] The common rotor profiles in single-tooth compressors are as follows: Figure 4 As shown in the figure, it has an outward-extending tooth arm structure, and the two sets of meshing rotor teeth in the compressor are exactly the same. When the two sets of traditional symmetrical single-tooth rotors are working, the compression ratio is relatively low, and they can only adapt to the working environment of low suction and exhaust volume, and cannot meet the use requirements of special environments such as wide working conditions, large air volume, and high dynamic load. Once the suction and exhaust volume of the compressor is increased by increasing the speed, the dynamic load and stress on the root of the single-tooth rotor will increase accordingly, exceeding the maximum stress value it can withstand, and stress concentration is prone to occur at the root of the tooth, while generating greater turbulence and working noise, which need to be solved urgently. Summary of the invention

[0004] In order to avoid and overcome the technical problems existing in the prior art, the present invention provides a high compression ratio single-tooth rotor, a design method and a dry compressor. The present invention can achieve a larger suction and exhaust volume and a higher compression ratio through two sets of asymmetric rotors, meeting the working requirements of wide working conditions and large air volume.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A high compression ratio single-tooth rotor comprises a male rotor and a female rotor conjugated therewith;

[0007] The profile of the male rotor includes an epicycloid AB, a tooth top arc BC, a line segment CD, a parabola DE, a tooth pitch arc EF, a parabola FG and a tooth bottom arc GA which are smoothly connected in sequence and form a closed loop;

[0008] The profile of the female rotor includes the epicycloid ab, the tooth top arc bc, the parabola envelope cd, the tooth pitch arc de, the parabola envelope ef, the line segment envelope fg, the epicycloid gh and the tooth bottom arc ha which are smoothly connected in sequence to form a closed loop.

[0009] As a further solution of the present invention: the coordinate equation of the epicycloid AB is:

[0010]

[0011] Among them, R 1 is the radius of the tooth top arc BC;

[0012] R 2 is the radius of the pitch arc EF;

[0013] The coordinate equation of the tooth top arc BC is:

[0014]

[0015] The coordinate equation of line segment CD is:

[0016]

[0017] Among them, α is the arc angle of the tooth top arc BC;

[0018] The two end points of line segment CD are point C and point D, the rotation axis of the male rotor is point O, and γ is the angle between OC and OD;

[0019]

[0020] The coordinate equation of the parabola DE is:

[0021]

[0022] in,

[0023] l x1 =-R 2 sin(α+γ)cos2(α+γ);

[0024]

[0025] The coordinate equation of the pitch arc EF is:

[0026]

[0027] The coordinate equation of the parabola FG is:

[0028]

[0029] in, l x2 =-R 3 sinβcos2β;

[0030]

[0031] The coordinate equation of the tooth bottom arc GA is:

[0032]

[0033] Among them, R 3 is the radius of the arc GA at the tooth bottom;

[0034] In the female rotor, the coordinate equation of the epicycloid ab is:

[0035]

[0036] The radius of the tooth top arc bc is equal to the radius of the tooth top arc BC. The coordinate equation of the tooth top arc bc is:

[0037] The coordinate equation of the envelope cd of the parabola is:

[0038]

[0039] in,

[0040] The radius of the pitch arc de is equal to the radius of the pitch arc EF. The coordinate equation of the pitch arc de is:

[0041]

[0042] The coordinate equation of the envelope ef of the parabola is:

[0043]

[0044] in,

[0045] The coordinate equation of the envelope fg of the line segment is:

[0046]

[0047] in,

[0048] The coordinate equation of the epicycloid gh is:

[0049]

[0050] The radius of the tooth bottom arc ha is equal to the radius of the tooth bottom arc GA. The coordinate equation of the tooth bottom arc ha is:

[0051]

[0052] As a further embodiment of the present invention: R 3 =2R 2 -R 1 .

[0053] A design method for a high compression ratio single-tooth rotor comprises the following steps:

[0054] S1. Determine the radius R of the tooth tip arc BC of the male rotor according to the design compression ratio requirements. 1 , Radius R of pitch arc EF 2 And the arc angle α of the tooth top arc BC; according to the radius R of the tooth top arc BC 1 and the radius R of the pitch arc EF 2 Determine the radius R of the tooth bottom arc GA 3 ;

[0055] S2. Build a rectangular coordinate system for the male rotor plane, with the radius R of the tooth top arc BC 1 , Radius R of pitch arc EF 2 and the radius R of the tooth bottom arc GA 3 Draw the tooth addendum circle, tooth pitch circle and tooth bottom circle respectively, the centers of the tooth addendum circle, tooth pitch circle and tooth bottom circle coincide, and take the center point O as the coordinate origin of the positive rotor plane rectangular coordinate system; take the line connecting one of the end points of the tooth addendum arc BC and point O as the x-axis of the positive rotor plane rectangular coordinate system, and draw the tooth addendum arc BC in the first quadrant of the plane rectangular coordinate system according to the arc angle α of the tooth addendum arc BC;

[0056] S3. Draw an epicycloid AB in the plane rectangular coordinate system of the male rotor according to its coordinate equation. The two endpoints of the epicycloid AB intersect with the tooth top circle and the tooth bottom circle at the x-axis of the plane rectangular coordinate system. The intersection of the epicycloid AB and the tooth bottom circle is one of the endpoints A of the tooth bottom circular arc GA.

[0057] S4. Draw a parabola DE and a parabola FG in the plane rectangular coordinate system of the male rotor, use the intersection points E and F of the parabola DE and the parabola FG with the pitch circle as the endpoints of the pitch arc EF, use the intersection point of the parabola FG with the tooth bottom circle as the other endpoint G of the tooth bottom arc GA, and determine the positions of the pitch arc EF and the tooth bottom arc GA in the plane rectangular coordinate system;

[0058] S5. Draw a tangent on the parabola DE, passing through the end point C of the tooth tip arc BC. Take point C as the starting point, and the tangent point between the tangent and the parabola DE is point D. Connect points C and D to close the profile of the male rotor.

[0059] S6. Determine the radius R of the tooth top arc bc of the conjugate female rotor based on the profile of the male rotor. 1 , Radius R of pitch arc de 2 , Radius R of the arc ha at the tooth bottom 3 and the arc angle α of the tooth bottom arc ha;

[0060] S7, build the plane rectangular coordinate system of the female rotor, with the radius R of the tooth top arc bc 1 , Radius R of pitch arc de 2 And the radius R of the tooth bottom arc ha 3 Draw the tooth top circle, tooth pitch circle and tooth bottom circle respectively, the centers of the tooth top circle, tooth pitch circle and tooth bottom circle coincide, and the center point o is used as the coordinate origin of the female rotor plane rectangular coordinate system; the line connecting one of the end points a of the tooth bottom circular arc ha and point o is used as the x-axis of the female rotor plane rectangular coordinate system, and draw the tooth bottom circular arc ha in the fourth quadrant of the female rotor plane rectangular coordinate system according to the arc angle α of the tooth bottom circular arc ha;

[0061] S8. Draw an epicycloid ab in the plane rectangular coordinate system of the female rotor according to its coordinate equation. The two endpoints of the epicycloid ab intersect with the tooth top circle and the tooth bottom circle at the x-axis of the plane rectangular coordinate system. The intersection of the epicycloid ab and the tooth top circle is one of the endpoints b of the tooth top circle arc bc.

[0062] S9, draw the envelope of the parabola cd and the envelope of the parabola ef in the plane rectangular coordinate system of the female rotor, use the intersection points d and e of the envelope of the parabola cd and the envelope of the parabola ef with the pitch circle as the endpoints of the pitch arc de, use the intersection point of the envelope of the parabola cd and the addendum circle as the other endpoint c of the addendum arc bc, and determine the positions of the pitch arc de and the addendum arc bc in the plane rectangular coordinate system;

[0063] S10. According to the coordinate equation of the envelope line fg of the line segment and the coordinate equation of the epicycloid gh, draw the envelope line fg of the line segment and the epicycloid gh in the rectangular coordinate system of the female rotor plane, and smoothly connect the tooth bottom arc ha, the epicycloid gh, the envelope line fg of the line segment and the envelope line ef of the parabola in sequence to form the profile of the closed female rotor.

[0064] A dry compressor, wherein a high compression ratio single-tooth rotor is arranged in the dry compressor, the dry compressor comprises two sets of screws driven by gears, a male rotor and a female rotor are coaxially arranged on the two screws, respectively, mesh with each other and rotate synchronously inversely.

[0065] Compared with the prior art, the present invention has the following beneficial effects:

[0066] 1. The asymmetric yin-yang rotor design of the present invention can achieve a wider compression ratio and a larger intake and exhaust volume, reducing the air flow pulsation caused by gas turbulence, and meeting the working requirements of wide working conditions and large air volume.

[0067] 2. The stress distribution of the present invention is reasonable, which overcomes the stress concentration caused by the unevenness of the original rotor tooth arm. The overall stress distribution is more uniform and continuous, has a greater bearing capacity, and can be applied to working environments with higher pressure and speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 It is a schematic diagram of the meshing relationship between the male rotor and the female rotor of the present invention.

[0069] Figure 2 It is a schematic diagram of the profile of the male rotor in the present invention.

[0070] Figure 3 It is a schematic diagram of the profile of the female rotor in the present invention.

[0071] Figure 4 This is a stress analysis diagram of the existing single-tooth rotor when it is working.

[0072] Figure 5 It is a stress analysis diagram of the male rotor of the present invention when it is working.

[0073] Figure 6 This is a stress analysis diagram of the female rotor of the present invention when it is working. DETAILED DESCRIPTION

[0074] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0075] See also Figures 1 to 6 , In an embodiment of the present invention, a high compression ratio single-tooth rotor, a design method and a dry compressor include a male rotor and a female rotor conjugated therewith;

[0076] The profile of the male rotor includes an epicycloid AB, a tooth top arc BC, a line segment CD, a parabola DE, a tooth pitch arc EF, a parabola FG and a tooth bottom arc GA which are smoothly connected in sequence and form a closed loop;

[0077] The profile of the female rotor includes the epicycloid ab, the tooth top arc bc, the parabola envelope cd, the tooth pitch arc de, the parabola envelope ef, the line segment envelope fg, the epicycloid gh and the tooth bottom arc ha which are smoothly connected in sequence to form a closed loop.

[0078] The coordinate equation of the epicycloid AB is:

[0079]

[0080] Among them, R1 is the radius of the tooth top arc BC;

[0081] R 2 is the radius of the pitch arc EF;

[0082] The coordinate equation of the tooth top arc BC is:

[0083]

[0084] The coordinate equation of line segment CD is:

[0085]

[0086] Among them, α is the arc angle of the tooth top arc BC;

[0087] The two end points of line segment CD are point C and point D, the rotation axis of the male rotor is point O, and γ is the angle between OC and OD;

[0088]

[0089] The coordinate equation of the parabola DE is:

[0090]

[0091] in,

[0092] l x1 =-R 2 sin(α+γ)cos2(α+γ);

[0093]

[0094] The coordinate equation of the pitch arc EF is:

[0095]

[0096] The coordinate equation of the parabola FG is:

[0097]

[0098] in,

[0099] l x2 =-R 3 sinβcos2β;

[0100]

[0101] The coordinate equation of the tooth bottom arc GA is:

[0102]

[0103] Among them, R 3 is the radius of the arc GA at the tooth bottom; R 3 =2R 2 -R 1 .

[0104] In the female rotor, the coordinate equation of the epicycloid ab is:

[0105]

[0106] The radius of the tooth top arc bc is equal to the radius of the tooth top arc BC. The coordinate equation of the tooth top arc bc is:

[0107] The coordinate equation of the envelope cd of the parabola is:

[0108]

[0109] in, The radius of the pitch arc de is equal to the radius of the pitch arc EF. The coordinate equation of the pitch arc de is:

[0110] The coordinate equation of the envelope ef of the parabola is:

[0111]

[0112] in,

[0113] The coordinate equation of the envelope fg of the line segment is:

[0114]

[0115] in,

[0116] The coordinate equation of the epicycloid gh is:

[0117]

[0118] The radius of the tooth bottom arc ha is equal to the radius of the tooth bottom arc GA. The coordinate equation of the tooth bottom arc ha is:

[0119]

[0120] The following steps are involved in designing the rotor:

[0121] S1. Determine the radius R of the tooth tip arc BC of the male rotor according to the design compression ratio requirements. 1 , Radius R of pitch arc EF 2And the arc angle α of the tooth top arc BC; according to the radius R of the tooth top arc BC 1 and the radius R of the pitch arc EF 2 Determine the radius R of the tooth bottom arc GA 3 ;

[0122] S2. Build a rectangular coordinate system for the male rotor plane, with the radius R of the tooth top arc BC 1 , Radius R of pitch arc EF 2 and the radius R of the tooth bottom arc GA 3 Draw the tooth addendum circle, tooth pitch circle and tooth bottom circle respectively, the centers of the tooth addendum circle, tooth pitch circle and tooth bottom circle coincide, and take the center point O as the coordinate origin of the positive rotor plane rectangular coordinate system; take the line connecting one of the end points of the tooth addendum arc BC and point O as the x-axis of the positive rotor plane rectangular coordinate system, and draw the tooth addendum arc BC in the first quadrant of the plane rectangular coordinate system according to the arc angle α of the tooth addendum arc BC;

[0123] S3. Draw an epicycloid AB in the plane rectangular coordinate system of the male rotor according to its coordinate equation. The two endpoints of the epicycloid AB intersect with the tooth top circle and the tooth bottom circle at the x-axis of the plane rectangular coordinate system. The intersection of the epicycloid AB and the tooth bottom circle is one of the endpoints A of the tooth bottom circular arc GA.

[0124] S4. Draw a parabola DE and a parabola FG in the plane rectangular coordinate system of the male rotor, use the intersection points E and F of the parabola DE and the parabola FG with the pitch circle as the endpoints of the pitch arc EF, use the intersection point of the parabola FG with the tooth bottom circle as the other endpoint G of the tooth bottom arc GA, and determine the positions of the pitch arc EF and the tooth bottom arc GA in the plane rectangular coordinate system;

[0125] S5. Draw a tangent on the parabola DE, passing through the end point C of the tooth tip arc BC. Take point C as the starting point, and the tangent point between the tangent and the parabola DE is point D. Connect points C and D to close the profile of the male rotor.

[0126] S6. Determine the radius R of the tooth top arc bc of the conjugate female rotor based on the profile of the male rotor. 1 , Radius R of pitch arc de 2 , Radius R of the arc ha at the tooth bottom 3 and the arc angle α of the tooth bottom arc ha;

[0127] S7, build the plane rectangular coordinate system of the female rotor, with the radius R of the tooth top arc bc 1 , Radius R of pitch arc de 2 And the radius R of the tooth bottom arc ha 3Draw the tooth top circle, tooth pitch circle and tooth bottom circle respectively, the centers of the tooth top circle, tooth pitch circle and tooth bottom circle coincide, and the center point o is used as the coordinate origin of the female rotor plane rectangular coordinate system; the line connecting one of the end points a of the tooth bottom circular arc ha and point o is used as the x-axis of the female rotor plane rectangular coordinate system, and draw the tooth bottom circular arc ha in the fourth quadrant of the female rotor plane rectangular coordinate system according to the arc angle α of the tooth bottom circular arc ha;

[0128] S8. Draw an epicycloid ab in the plane rectangular coordinate system of the female rotor according to its coordinate equation. The two endpoints of the epicycloid ab intersect with the tooth top circle and the tooth bottom circle at the x-axis of the plane rectangular coordinate system. The intersection of the epicycloid ab and the tooth top circle is one of the endpoints b of the tooth top circle arc bc.

[0129] S9, draw the envelope of the parabola cd and the envelope of the parabola ef in the plane rectangular coordinate system of the female rotor, use the intersection points d and e of the envelope of the parabola cd and the envelope of the parabola ef with the pitch circle as the endpoints of the pitch arc de, use the intersection point of the envelope of the parabola cd and the addendum circle as the other endpoint c of the addendum arc bc, and determine the positions of the pitch arc de and the addendum arc bc in the plane rectangular coordinate system;

[0130] S10. According to the coordinate equation of the envelope line fg of the line segment and the coordinate equation of the epicycloid gh, draw the envelope line fg of the line segment and the epicycloid gh in the rectangular coordinate system of the female rotor plane, and smoothly connect the tooth bottom arc ha, the epicycloid gh, the envelope line fg of the line segment and the envelope line ef of the parabola in sequence to form the profile of the closed female rotor.

[0131] When the male rotor and the female rotor mesh with each other, the center distance between the two rotors is twice the pitch arc radius R 2 The two rotors are staggered by 180°, thus achieving synchronous reversal of the compressor rotors.

[0132] like Figure 4 As shown in FIG. 1 , the maximum stress value of the existing rotor at the end of exhaust is 73.6 MPa; Figure 5 As shown, the maximum stress value of the male rotor of the present invention under the same working conditions is 32.1MPa; Figure 6 As shown, the maximum stress value of the female rotor of the present invention under the same working conditions is 30.6MPa; the maximum stress value is significantly lower than that of the existing rotor. In addition, the stress distribution of the rotor of the present invention is more reasonable; the design of the straight line section on the male rotor has uniform stress distribution, which effectively improves the overall bearing capacity of the rotor.

[0133] The yin and yang rotors are not exactly the same, which helps to improve the flexibility of the rotor design, achieve a larger suction volume, a smaller relative clearance volume and internal compression volume, and improve the working efficiency of the single-tooth compressor and its adaptability to different working conditions.

[0134] When air is used as the conveying medium, Figure 4 The compression ratio of the existing rotor shown in the figure can only be adjusted between 2.2 and 3.7. The male rotor and the female rotor of the present invention can be adjusted by adjusting different design parameters (such as R 1 , R 1 and α), the compression ratio range can be dynamically adjusted between 1.4 and 5.7, with a more flexible wide compression ratio adjustment range, and a higher or lower compression ratio than the existing rotor can be obtained through adjustment.

[0135] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0136] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

Claims

1. A high compression ratio single-tooth rotor, characterized in that: It includes a male rotor and a female rotor conjugated therewith; The profile of the male rotor includes an epicycloid AB, a tooth top arc BC, a line segment CD, a parabola DE, a tooth pitch arc EF, a parabola FG and a tooth bottom arc GA which are smoothly connected in sequence and form a closed loop; The profile of the female rotor includes the epicycloid ab, the tooth top arc bc, the parabola envelope cd, the tooth pitch arc de, the parabola envelope ef, the line segment envelope fg, the epicycloid gh and the tooth bottom arc ha which are smoothly connected in sequence to form a closed loop.

2. A high compression ratio single-tooth rotor according to claim 1, characterized in that: The coordinate equation of the epicycloid AB is: Among them, R1 is the radius of the tooth top arc BC; R2 is the radius of the pitch arc EF; The coordinate equation of the tooth top arc BC is: The coordinate equation of line segment CD is: Among them, α is the arc angle of the tooth top arc BC; The two end points of line segment CD are point C and point D, the rotation axis of the male rotor is point O, and γ is the angle between OC and OD; The coordinate equation of the parabola DE is: in, l x1 =-R2 sin(α+γ)cos2(α+γ); The coordinate equation of the pitch arc EF is: The coordinate equation of the parabola FG is: in, l x2 =-R3 sinβcos2β; The coordinate equation of the tooth bottom arc GA is: Among them, R3 is the radius of the arc GA at the bottom of the tooth; In the female rotor, the coordinate equation of the epicycloid ab is: The radius of the tooth top arc bc is equal to the radius of the tooth top arc BC. The coordinate equation of the tooth top arc bc is: The coordinate equation of the envelope cd of the parabola is: in, The radius of the pitch arc de is equal to the radius of the pitch arc EF. The coordinate equation of the pitch arc de is: The coordinate equation of the envelope ef of the parabola is: in, The coordinate equation of the envelope fg of the line segment is: in, The coordinate equation of the epicycloid gh is: The radius of the tooth bottom arc ha is equal to the radius of the tooth bottom arc GA. The coordinate equation of the tooth bottom arc ha is:

3. A high compression ratio single-tooth rotor according to claim 2, characterized in that: R3=2R2-R1.

4. A design method for a high compression ratio single-tooth rotor according to any one of claims 1 to 3, characterized in that: The steps include: S1. Determine the radius R1 of the tooth tip arc BC, the radius R2 of the tooth pitch arc EF and the arc angle α of the tooth tip arc BC of the male rotor according to the design compression ratio requirements; determine the radius R3 of the tooth bottom arc GA according to the radius R1 of the tooth tip arc BC and the radius R2 of the tooth pitch arc EF; S2. Build a rectangular coordinate system for the male rotor plane. Use the radius R1 of the tooth tip arc BC, the radius R2 of the tooth pitch arc EF, and the radius R3 of the tooth bottom arc GA to draw the tooth tip circle, tooth pitch circle, and tooth bottom circle respectively. The centers of the tooth tip circle, tooth pitch circle, and tooth bottom circle coincide with each other. Use the center O as the origin of the coordinate system of the male rotor plane rectangular coordinate system. Use the line connecting one of the endpoints of the tooth tip arc BC and point O as the x-axis of the male rotor plane rectangular coordinate system. Draw the tooth tip arc BC in the first quadrant of the plane rectangular coordinate system according to the arc angle α of the tooth tip arc BC. S3. Draw an epicycloid AB in the plane rectangular coordinate system of the male rotor according to its coordinate equation. The two endpoints of the epicycloid AB intersect with the tooth top circle and the tooth bottom circle at the x-axis of the plane rectangular coordinate system. The intersection of the epicycloid AB and the tooth bottom circle is one of the endpoints A of the tooth bottom circular arc GA. S4. Draw a parabola DE and a parabola FG in the plane rectangular coordinate system of the male rotor, use the intersection points E and F of the parabola DE and the parabola FG with the pitch circle as the endpoints of the pitch arc EF, use the intersection point of the parabola FG with the tooth bottom circle as the other endpoint G of the tooth bottom arc GA, and determine the positions of the pitch arc EF and the tooth bottom arc GA in the plane rectangular coordinate system; S5. Draw a tangent on the parabola DE, passing through the end point C of the tooth tip arc BC. Take point C as the starting point, and the tangent point between the tangent and the parabola DE is point D. Connect points C and D to close the profile of the male rotor. S6. Determine the radius R1 of the tooth top arc bc, the radius R2 of the tooth pitch arc de, the radius R3 of the tooth bottom arc ha, and the arc angle α of the tooth bottom arc ha of the conjugate female rotor based on the profile of the male rotor; S7, build a female rotor plane rectangular coordinate system, and use the radius R1 of the tooth top arc bc, the radius R2 of the tooth pitch arc de, and the radius R3 of the tooth bottom arc ha to respectively draw the tooth top circle, the tooth pitch circle, and the tooth bottom circle. The centers of the tooth top circle, the tooth pitch circle, and the tooth bottom circle coincide with each other, and the center point o is used as the coordinate origin of the female rotor plane rectangular coordinate system; use the line connecting one of the end points a of the tooth bottom arc ha and the point o as the x-axis of the female rotor plane rectangular coordinate system, and draw the tooth bottom arc ha in the fourth quadrant of the female rotor plane rectangular coordinate system according to the arc angle α of the tooth bottom arc ha; S8. Draw an epicycloid ab in the plane rectangular coordinate system of the female rotor according to its coordinate equation. The two endpoints of the epicycloid ab intersect with the tooth top circle and the tooth bottom circle at the x-axis of the plane rectangular coordinate system. The intersection of the epicycloid ab and the tooth top circle is one of the endpoints b of the tooth top circle arc bc. S9, draw the envelope of the parabola cd and the envelope of the parabola ef in the plane rectangular coordinate system of the female rotor, use the intersection points d and e of the envelope of the parabola cd and the envelope of the parabola ef with the pitch circle as the endpoints of the pitch arc de, use the intersection point of the envelope of the parabola cd and the addendum circle as the other endpoint c of the addendum arc bc, and determine the positions of the pitch arc de and the addendum arc bc in the plane rectangular coordinate system; S10. According to the coordinate equation of the envelope line fg of the line segment and the coordinate equation of the epicycloid gh, draw the envelope line fg of the line segment and the epicycloid gh in the rectangular coordinate system of the female rotor plane, and smoothly connect the tooth bottom arc ha, the epicycloid gh, the envelope line fg of the line segment and the envelope line ef of the parabola in sequence to form the profile of the closed female rotor.

5. A dry compressor, characterized in that: A high compression ratio single-tooth rotor as described in any one of claims 1 to 3 is arranged in a dry compressor, and the dry compressor includes two sets of screws driven by gears, and the male rotor and the female rotor are coaxially arranged on the two screws, respectively, and mesh with each other and reverse synchronously.

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