Conical crossed shaft internal gearing asymmetric double-screw rotor structure and design method thereof

Abstract

The invention relates to a conical crossed shaft inner gearing asymmetric double-screw rotor structure and a design method thereof, rotor molded lines adopted by different parts of an inner rotor and an outer rotor are generated by generating circles with different radiuses, an outer rotor curve section A2B2 is a circular arc section with the radius of r1, an inner rotor curve section A1B1C1 is an envelope line of the curve section A2B2, an outer rotor curve section B2C2 is an envelope line of the inner rotor curve section B1C1, and the radius of the inner rotor curve section B1C1 is r1. The outer rotor curve segment A2D2 is a circular arc segment with the radius r2, the inner rotor curve segment A1D1E1 is an envelope line of the curve segment A2D2, and the outer rotor curve segment D2E2 is an envelope line of the inner rotor curve segment D1E1; rotating and splicing the single-tooth tooth profiles of the molded lines of the inner and outer rotors to obtain the multi-tooth molded lines of the inner and outer rotors; similar rotor molded lines are arranged on spherical surfaces with different radiuses, and a spiral line is used for controlling the relation between the rotation angle and the axial position of the rotor molded lines. According to the invention, optimal combination of rotor transmission and sealing performance can be realized.

Description

Technical Field

[0001] The present invention belongs to the field of the structural design of a screw compressor rotor, and particularly relates to a conical crossed-axis internal meshing asymmetric twin-screw rotor structure and a design method thereof. Background Art

[0002] Compared with the traditional twin-screw compressor, the internal meshing screw compressor has the characteristics of a compact structure, a low sliding speed in the transmission contact area, a large communication area of the exhaust port, and no leakage triangle. At the same time, it inherits the characteristics of a reliable operation of the screw compressor, no vulnerable parts such as air valves, compatibility with liquids, and a high operation efficiency. It has great potential as the rotor structure of the next-generation screw compressor and can be widely used in industries such as refrigeration, compressed gas, and chemical medicine. Similar to the traditional external meshing twin-screw compressor, the parallel-axis internal meshing screw compressor can carry out a variable pitch design or a conical design to control the compression process of the internal gas. However, the variable pitch design often results in a smaller pitch on the exhaust side of the rotor, causing the teeth on the exhaust side of the internal meshing screw rotor to become thinner, and the sealing and machining performance to decrease significantly. And the conical design of the parallel axis makes the shape of the rotor profile need to change greatly at different axial positions of the rotor, and the relative sliding speed between the internal and external rotor profiles increases significantly, resulting in it being difficult to balance the transmission performance and the thermal performance of the profile. By adopting the meshing mode of the internal and external rotors with crossed axes, while realizing the conical structure of the rotor, the same rotor profile structure can be maintained at different axial positions of the rotor structure, and thus the disadvantage of being difficult to balance the transmission performance and the thermal performance can be effectively avoided. However, the existing conventional crossed-axis meshing rotor structures often adopt a symmetric structure in the upper and lower parts. For the internal meshing rotor, the upper and lower parts of its rotor structure are responsible for the sealing and transmission functions respectively. Therefore, the existing symmetric crossed-axis internal meshing rotor structure still cannot make the transmission and sealing performance of the rotor in the optimal state. Summary of the Invention

[0003] The purpose of the present invention is to provide a conical crossed-axis internal meshing asymmetric twin-screw rotor structure and a design method thereof for the above problems in the existing technology, and to realize the optimal combination of the transmission and sealing performance of the rotor through the asymmetric design of the internal and external rotor structures.

[0004] In order to achieve the above purpose, the present invention has the following technical solutions:

[0005] In the first aspect, a conical crossed-axis internal meshing asymmetric twin-screw rotor structure is provided. The rotor profiles of different parts of the inner and outer rotors are generated by generating circles with different radii. The single-tooth profile of the outer rotor is composed of curve segments A2B2, B2C2, A2D2, and D2E2 connected. The single-tooth profile of the inner rotor is composed of curve segments A1B1C1 and A1D1E1 connected. The curve segment A2B2 of the outer rotor is an arc segment with a radius of r1, and the curve segment A1B1C1 of the inner rotor is the envelope of the curve segment A2B2 of the outer rotor. The curve segment B2C2 of the outer rotor is the envelope of the curve segment B1C1 of the inner rotor. The curve segment A2D2 of the outer rotor is an arc segment with a radius of r2, and the curve segment A1D1E1 of the inner rotor is the envelope of the curve segment A2D2 of the outer rotor. The curve segment D2E2 of the outer rotor is the envelope of the curve segment D1E1 of the inner rotor. After rotating the single-tooth profile C1B1A1D1E1 of the inner rotor by an angle of 2π / N in sequence and splicing N segments, a complete multi-tooth inner rotor profile is formed. After rotating the single-tooth profile C2B2A2D2E2 of the outer rotor by an angle of 2π / (N + 1) in sequence and splicing N + 1 segments, a complete multi-tooth outer rotor profile is formed. Here, N represents the number of teeth of the inner rotor profile. The rotor profiles of the inner and outer rotors are located on a spherical surface with a radius of R s , and by setting similar rotor profiles on spherical surfaces with different radii and using a helix to control the relationship between the rotation angle of the rotor profile and the axial position, a complete surface structure of the inner and outer rotors is generated.

[0006] As a preferred solution, the rotor profile structures at different axial positions of the rotors are in a similar relationship with the inner and outer rotor profile structures on the spherical surface with a radius of R s . The reduction ratio of the rotor profile structures at different axial positions of the rotors is determined by the ratio of the spherical radius at the corresponding position to the radius R s . By defining the pitch of the helix, the rotation angle of the rotor profile structure at different axial positions of the rotors is determined to construct a complete rotor structure.

[0007] As a preferred solution, the center of the inner rotor profile is always located on the central axis O0O1, and the center of the outer rotor profile is always located on the central axis O0O2. The central axis O0O1 and the central axis O0O2 intersect at point O0, and the angle between the central axis O0O1 and the central axis O0O2 is α.

[0008] As a preferred solution, the radius of the first generating circle of the inner and outer rotor profiles on the spherical surface with a radius of R s is r1, the angle between the central axis O0O r1 of the first generating circle and the central axis O0O1 of the inner rotor profile is β2, the radius of the second generating circle is r2, and the angle between the central axis O0O r2 of the second generating circle and the central axis O0O1 of the inner rotor profile is β1; Initialize the spherical radius Rs The radius r1 of the first generating circle, the radius r2 of the second generating circle, and the central axis O0O of the second generating circle r2 If the included angle β1 between the central axis O0O of the first generating circle and the central axis O0O1 of the inner rotor profile is a design variable, then the central axis O0O of the first generating circle r1 The included angle β2 with the central axis O0O1 of the inner rotor profile is solved by the following formula:

[0009]

[0010] As a preferred solution, a coordinate system O0x r1 y r1 z r1 is established with the center of the first generating circle, then the position vector of the curve segment A2B2 of the outer rotor profile on the spherical surface with a radius of R s in the coordinate system O0x r1 y r1 z r1 is solved by the following formula:

[0011]

[0012] In the formula, θ is a parameter variable.

[0013] As a preferred solution, the position vector of the curve segment A1B1C1 of the inner rotor profile on the spherical surface with a radius of R s in the coordinate system O0x1y1z1 is solved by the following formula:

[0014]

[0015] In the formula, M i,r1 represents the unit rotation matrix of the coordinate system O0x r1 y r1 z r1 M 1r1 represents the transfer matrix when the coordinate is transformed from the coordinate system O0x r1 y r1 z r to the coordinate system O0x1y1z1, M i,1 represents the unit rotation matrix of the coordinate system O0x1y1z1, which is solved by the following formula:

[0016]

[0017] In the formula, is the rotation angle parameter, and N is the number of teeth of the inner rotor profile.

[0018] As a preferred solution, the position vector r 1 A1B1C1 of the curve segment A1B1C1 of the inner rotor, the rotation angle parameter The relationship with the parameter θ is obtained from the meshing relationship; the position vector of the curve segment B2C2 of the outer rotor is obtained from the curve segment B1C1 of the inner rotor through the meshing relationship.

[0019] As a preferred solution, the rotor profile generated by the second generating circle in the inner and outer rotor profiles is generated in the same way as the first generating circle.

[0020] In a second aspect, a design method for the conical cross-axis internal meshing asymmetric twin-screw rotor structure described above is provided, including the following steps:

[0021] According to the exhaust volume requirement, set the initial spherical radius R s , the central axis O0O of the second generating circle r2 The included angle β1 with the central axis O0O1 of the inner rotor profile, and the radius r1 of the curve segment A2B2 of the outer rotor;

[0022] According to the transmission requirement, set the radius r2 of the curve segment A2D2 of the outer rotor; according to the requirements of sealing performance and suction / discharge working conditions, set the number of teeth N of the inner rotor profile, the included angle α between the central axis O0O1 and the central axis O0O2, and the pitch of the outer rotor helix;

[0023] According to the set parameters, solve the included angle β2 between the central axis O0O of the first generating circle r1 and the central axis O0O1 of the inner rotor profile, and the position vector of the curve segment A2B2 of the outer rotor profile on the sphere with a radius of R s in the coordinate system O0x r1 y r1 z r1 and the position vector of the curve segment A1B1C1 of the inner rotor profile in the coordinate system O0x1y1z1, and determine the position vector r of the curve segment A1B1C1 of the inner rotor 1 A1B1C1 The relationship between the rotation angle parameter and the parameter θ;

[0024] Using the same method, the position vector of the curve segment B2C2 of the outer rotor is obtained from the curve segment B1C1 of the inner rotor through the meshing relationship;

[0025] The rotor profile generated by the second generating circle in the inner and outer rotor profiles is generated in the same way as the first generating circle.

[0026] As a preferred solution, according to the rotor profile structure at different rotor axial positions and the similarity relationship between the inner and outer rotor profile structures on the sphere with a radius of R s , the reduction multiple of the rotor profile structure at different rotor axial positions is determined by the ratio of the spherical radius at the corresponding position to the radius R s ;

[0027] Define the pitch of the helix to determine the rotation angle of the rotor profile structure at different axial positions of the rotor, and construct a complete rotor structure;

[0028] Adjust the number of teeth N of the inner rotor profile to adjust the number of teeth of the rotor profile, thereby realizing different rotor surface structures;

[0029] By changing the design parameters of the profiles of different parts of the inner and outer rotors, obtain the rotor geometric structures that meet different requirements.

[0030] Compared with the prior art, the present invention has at least the following beneficial effects:

[0031] Existing conventional cross-axis meshing rotor structures often adopt an upper and lower symmetric structure. For an internal meshing rotor, since its upper and lower halves are respectively responsible for the sealing and transmission functions, it is impossible to make the rotor transmission and sealing performances reach the optimal state. In the present invention, the rotor profiles of different parts of the inner and outer rotors are generated by generating circles with different radii. By setting similar rotor profiles on spherical surfaces with different radii and using a helix to control the relationship between the rotation angle of the rotor profile and the axial position, a complete inner and outer rotor surface structure is generated. Through the asymmetric design of the inner and outer rotor structures, the present invention realizes the optimal combination of rotor transmission and sealing performances. The cross-axis internal meshing inner and outer rotor profiles based on arc generation are adopted, and the relationship between the rotation angle of the rotor profile and the axial position is regulated by the designed helix. The radius of the rotor profile naturally decreases along the rotor axis, thereby realizing a gas space that gradually decreases from the suction section to the exhaust end along the rotor axis. Furthermore, while realizing the internal compression process of the gas, a certain rotor profile and pitch are ensured, and thus excellent rotor transmission and sealing performances are achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0033] Figure 1 Profile schematic diagram of the tapered cross-axis internal meshing asymmetric twin-screw rotor structure in the embodiment of the present invention;

[0034] Figure 2 Axial structure schematic diagram of the inner and outer rotors in the embodiment of the present invention;

[0035] FIG. 3(a) Schematic diagram of the rotor surface generation process in the embodiment of the present invention;

[0036] FIG. 3(b) Schematic diagram of the complete three-dimensional structure of the rotor in the embodiment of the present invention;

[0037] Figure 4(a) Schematic diagram of the profile of the inner and outer rotors with 3 / 4 teeth in the third embodiment of the present invention;

[0038] Figure 4(b) Schematic diagram of the surface structure of the inner and outer rotors with 3 / 4 teeth in the third embodiment of the present invention;

[0039] Figure 5(a) Schematic diagram of the profile of the inner and outer rotors with 4 / 5 teeth in the fourth embodiment of the present invention;

[0040] Figure 5(b) Schematic diagram of the surface structure of the inner and outer rotors with 4 / 5 teeth in the fourth embodiment of the present invention. Detailed implementation manners

[0041] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, those of ordinary skill in the art can also obtain other embodiments without creative efforts.

[0042] It should be noted that in the description of the embodiments of the present invention, the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0043] Please refer to Figure 1, an embodiment of the present invention proposes a conical crossed-axis internal meshing asymmetric twin-screw rotor structure. The upper and lower parts of the inner and outer rotors adopt rotor profiles generated by generating circles with different radii. Through the asymmetric design of the inner and outer rotor structures, the optimal combination of rotor transmission and sealing performance is achieved. Specifically, the single-tooth profile of the outer rotor is composed of the curve segments A2B2, B2C2, A2D2, and D2E2 connected. The single-tooth profile of the inner rotor is composed of the curve segments A1B1C1 and A1D1E1 connected. The curve segment A2B2 of the outer rotor is an arc segment with a radius of r1, and the curve segment A1B1C1 of the inner rotor is the envelope of the curve segment A2B2 of the outer rotor. The curve segment B2C2 of the outer rotor is the envelope of the curve segment B1C1 of the inner rotor. The curve segment A2D2 of the outer rotor is an arc segment with a radius of r2, and the curve segment A1D1E1 of the inner rotor is the envelope of the curve segment A2D2 of the outer rotor. The curve segment D2E2 of the outer rotor is the envelope of the curve segment D1E1 of the inner rotor; after rotating the single-tooth profile C1B1A1D1E1 of the inner rotor by 2π / N angles in sequence and splicing N segments, a complete multi-tooth inner rotor profile is formed; after rotating the single-tooth profile C2B2A2D2E2 of the outer rotor by 2π / (N + 1) angles in sequence and splicing N + 1 segments, a complete multi-tooth outer rotor profile is formed; where N represents the number of teeth of the inner rotor profile; the rotor profiles of the inner and outer rotors are located on a spherical surface with a radius of R s . By setting similar rotor profiles on spherical surfaces with different radii and using a helix to control the relationship between the rotation angle of the rotor profile and the axial position, a complete surface structure of the inner and outer rotors is generated. In the asymmetrically designed inner and outer rotor structures, by adjusting the center position of the generating circle, the generating circle radius r1 of the upper half of the rotor profile, and the generating circle radius r2 of the lower half of the rotor profile, the shape of the inner and outer rotor profiles can be flexibly adjusted.

[0044] Please refer to Figure 2 and FIGS. 3(a) and 3(b). The inner and outer rotor profiles generated in the embodiments of the present invention are located on a spherical surface with a radius of R s . The rotor profile structures at different rotor axial positions are in a similar relationship with the inner and outer rotor profile structures on the spherical surface with a radius of R s . The reduction ratio of the rotor profile structures at different rotor axial positions is determined by the ratio of the spherical radius at the corresponding position to the radius R s . By defining the pitch of the helix to determine the rotation angle of the rotor profile structure at different rotor axial positions, a complete surface structure of the inner and outer rotors can be generated, and then an inner and outer rotor structure that can be completely meshed on a crossed axis can be generated. Among them, the center of the inner rotor profile is always located on the central axis O0O1, the center of the outer rotor profile is always located on the central axis O0O2, the central axis O0O1 and the central axis O0O2 intersect at the point O0, and the included angle between the central axis O0O1 and the central axis O0O2 is α.

[0045] In a possible implementation, the radius is R s The radius of the first generating circle of the inner and outer rotor profiles on the spherical surface is r1, and the included angle between the central axis O0O of the first generating circle r1 and the central axis O0O1 of the inner rotor profile is β2. The radius of the second generating circle is r2, and the included angle between the central axis O0O of the second generating circle r2 and the central axis O0O1 of the inner rotor profile is β1; Initialize the spherical radius R s , the radius r1 of the first generating circle, the radius r2 of the second generating circle, and the included angle β1 between the central axis O0O of the second generating circle r2 and the central axis O0O1 of the inner rotor profile as design variables, then the included angle β2 between the central axis O0O of the first generating circle r1 and the central axis O0O1 of the inner rotor profile is solved by the following formula:

[0046]

[0047] Establish a coordinate system O0x r1 y r1 z r1 with the center of the first generating circle. Then, the position vector of the curve segment A2B2 of the outer rotor profile on the spherical surface with radius R s in the coordinate system O0x r1 y r1 z r1 is solved by the following formula:

[0048]

[0049] where θ is a parameter variable.

[0050] The position vector of the curve segment A1B1C1 of the inner rotor profile on the spherical surface with radius R s in the coordinate system O0x1y1z1 is solved by the following formula:

[0051]

[0052] where M i,r1 represents the unit rotation matrix of the coordinate system O0x r1 y r1 z r1 , M 1r1 represents the transfer matrix when the coordinate is transformed from the coordinate system O0x r1 y r1 z r to the coordinate system O0x1y1z1, and M i,1 represents the unit rotation matrix of the coordinate system O0x1y1z1, which is solved by the following formula:

[0053]

[0054] In the formula, is the rotation angle parameter, and N is the number of teeth of the inner rotor profile.

[0055] Furthermore, the position vector r of the curve segment A1B1C1 of the inner rotor in the embodiments of the present invention 1 A1B1C1 The rotation angle parameter The relationship between and the parameter variable θ is obtained from the meshing relationship.

[0056] In a similar manner, the position vector of the curve segment B2C2 of the outer rotor in the embodiments of the present invention is obtained from the curve segment B1C1 of the inner rotor through the meshing relationship.

[0057] According to the same method as the first generating circle, the rotor profiles generated by the second generating circle in the inner and outer rotor profiles can be generated.

[0058] As Figure 2 shown, the rotor profile structures at different rotor axial positions are in a similar relationship with the inner and outer rotor profile structures on the spherical surface with a radius of R s The reduction multiple is the ratio of the local spherical radius to the radius R s By defining the pitch of the helix, the rotation angle of the profile at different rotor axial positions can be defined, and then the rotor surface structure shown in Fig. 3(a) can be generated, and it can be used to construct a complete rotor structure, as shown in Fig. 3(b).

[0059] Please refer to Fig. 4(a) and Fig. 4(b) and Fig. 5(a) and Fig. 5(b). By reasonably adjusting the number of teeth of the inner rotor, the number of teeth of the rotor profile can be flexibly adjusted, so as to realize different rotor surface structures.

[0060] In the conical crossed-axis internal meshing asymmetric twin-screw rotor structure of the embodiments of the present invention, through the asymmetric design of the inner and outer rotor structures, the optimal combination of rotor transmission and sealing performance is achieved. The crossed-axis internal meshing inner and outer rotor profiles based on arc generation are adopted, and the relationship between the rotation angle of the rotor profile and the axial position is regulated by the designed helix. The radius of the rotor profile decreases naturally along the rotor axis, so as to realize the gas space that gradually decreases from the suction section to the exhaust end along the rotor axis, and then while realizing the internal compression process of the gas, a certain rotor profile and pitch are ensured, and excellent transmission and sealing performance of the rotor are achieved.

[0061] Another embodiment of the present invention also proposes a design method for the conical crossed-axis internal meshing asymmetric twin-screw rotor structure, including the following steps:

[0062] S1. According to the exhaust volume requirement, set the initial spherical radius R s , the central axis O0O of the second generating circle r2The included angle β1 with the central axis O0O1 of the inner rotor profile, and the radius r1 of the curve segment A2B2 of the outer rotor;

[0063] S2. Set the radius r2 of the curve segment A2D2 of the outer rotor according to the transmission requirements; set the number of teeth N of the inner rotor profile, the included angle α between the central axis O0O1 and the central axis O0O2, and the pitch of the outer rotor helix according to the requirements of sealing performance and intake and exhaust conditions.

[0064] S3. Solve the central axis O0O of the first generating circle according to the set parameters r1 The included angle β2 with the central axis O0O1 of the inner rotor profile, and on the sphere with radius R s The position vector of the curve segment A2B2 of the outer rotor profile in the coordinate system O0x r1 y r1 z r1 In, and the position vector of the curve segment A1B1C1 of the inner rotor profile in the coordinate system O0x1y1z1, determine the position vector r of the curve segment A1B1C1 of the inner rotor 1 A1B1C1 The relationship between the rotation angle parameter And the parameter variable θ is as follows:

[0065] (1) The included angle β2 between the central axis O0O of the first generating circle r1 And the central axis O0O1 of the inner rotor profile is obtained by the following formula:

[0066]

[0067] (2) The position vector of the curve segment A2B2 of the outer rotor profile on the sphere with radius R s In the coordinate system O0x r1 y r1 z r1 In is solved by the following formula:

[0068]

[0069] In the formula, θ is the parameter variable.

[0070] (3) The position vector of the curve segment A1B1C1 of the inner rotor profile on the sphere with radius R s In the coordinate system O0x1y1z1 is solved by the following formula:

[0071]

[0072] In the formula, M i,r1 Represents the unit rotation matrix of the coordinate system O0x r1 y r1 z r1 And M 1r1Indicates that the coordinates are transformed from the coordinate system O0x r1 y r1 z r to the transfer matrix M when transformed to the coordinate system O0x1y1z1 i,1 Indicates the unit rotation matrix of the coordinate system O0x1y1z1, which is solved by the following formula:

[0073]

[0074] In the formula, is the rotation angle parameter, and N is the number of teeth of the inner rotor profile. The position vector r of the curve segment A1B1C1 of the inner rotor 1 A1B1C1 The rotation angle parameter The relationship between and the parameter θ is obtained from the meshing relationship.

[0075] S4. Obtain the position vector of the curve segment B2C2 of the outer rotor from the curve segment B1C1 of the inner rotor through the meshing relationship; Generate the rotor profile generated by the second generating circle in the inner and outer rotor profiles in the same way as the first generating circle.

[0076] S5. According to the rotor profile structure at different rotor axial positions and the similarity relationship between the inner and outer rotor profile structures on the spherical surface with a radius of R s the reduction ratio of the rotor profile structure at different rotor axial positions is determined by the ratio of the spherical radius at the corresponding position to the radius R s ; Determine the rotation angle of the rotor profile structure at different rotor axial positions by defining the pitch of the helix, and it can be used to construct a complete rotor structure;

[0077] S6. Flexibly adjust the number of teeth of the rotor profile by reasonably adjusting the number of teeth N of the inner rotor profile, so as to realize different rotor surface structures. For the rotor structure obtained through the above design, by reasonably setting the design parameters, the optimal rotor geometric structure under different requirements can be obtained.

[0078] For those skilled in the art, it is obvious that the present invention is not limited to the details described in the above embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention, and any reference signs in the claims should not be regarded as limiting the scope of protection involved.

[0079] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A conical cross-axis internal meshing asymmetric twin-screw rotor structure, characterized in that: The rotor profiles used in different parts of the inner and outer rotors are generated by generating circles of different radii. The profile single tooth shape of the outer rotor is composed of curve segments A2B2, B2C2, A2D2, and D2E2. The profile single tooth shape of the inner rotor is composed of curve segments A1B1C1 and A1D1E1. The curve segment A2B2 of the outer rotor is an arc segment with a radius of r1. The curve segment A1B1C1 of the inner rotor is the envelope of the curve segment A2B2 of the outer rotor. The curve segment B2C2 of the outer rotor is the envelope of the curve segment B1C1 of the inner rotor. The curve segment A2D2 of the outer rotor is an arc segment with a radius of r2. The curve segment A1D1E1 of the inner rotor is the envelope of the curve segment A2D2 of the outer rotor, and the curve segment D2E2 of the outer rotor is the envelope of the curve segment D1E1 of the inner rotor; the single-tooth tooth profile C1B1A1D1E1 of the inner rotor is rotated by 2π / N angles in sequence and spliced ​​with N segments to form a complete multi-tooth inner rotor profile; the single-tooth tooth profile C2B2A2D2E2 of the outer rotor is rotated by 2π / (N+1) angles in sequence and spliced ​​with N+1 segments to form a complete multi-tooth outer rotor profile; wherein N represents the number of teeth of the inner rotor profile; the rotor profiles of the inner and outer rotors are located at a radius of R s By setting similar rotor profiles on spherical surfaces of different radii and using spiral lines to control the relationship between the rotor profile angle and the axial position, a complete inner and outer rotor surface structure is generated.

2. The conical cross-axis internal meshing asymmetric twin-screw rotor structure according to claim 1, characterized in that: The rotor profile structure at different rotor axial positions and the radius R s The inner and outer rotor profile structures on the spherical surface are similar, and the reduction factor of the rotor profile structure at different rotor axial positions is the spherical radius and radius R at the corresponding position. s The ratio is determined; the rotation angle of the rotor profile structure at different rotor axial positions is determined by defining the pitch of the helix to construct a complete rotor structure.

3. The conical cross-axis internal meshing asymmetric twin-screw rotor structure according to claim 1, characterized in that: The center of the inner rotor's profile is always located on the central axis O0O1, and the center of the outer rotor's profile is always located on the central axis O0O2. The central axis O0O1 intersects the central axis O0O2 at point O0, and the angle between the central axis O0O1 and the central axis O0O2 is α.

4. The conical cross-axis internal meshing asymmetric twin-screw rotor structure according to claim 3, characterized in that: The radius is R s The radius of the first generating circle of the inner and outer rotor profiles on the spherical surface is r1, and the central axis of the first generating circle is O0O r1 The included angle between the central axis O0O1 and the inner rotor profile is β2, the radius of the second generating circle is r2, and the central axis O0O r2 The angle between the inner rotor profile and the central axis O0O1 is β1; the initial spherical radius R s , the radius r1 of the first generating circle, the radius r2 of the second generating circle, and the central axis O0O of the second generating circle r2 The angle β1 between the center axis O0O1 of the inner rotor profile is the design variable, then the center axis O0O r1 The angle β2 with the central axis O0O1 of the inner rotor profile is solved by the following formula:

5. The conical cross-axis internal meshing asymmetric twin-screw rotor structure according to claim 4, characterized in that: Establish the coordinate system O0x with the center of the first generated circle r1 y r1 z r1 , then the radius is R s The curve segment A2B2 of the outer rotor profile on the spherical surface is in the coordinate system O0x r1 y r1 z r1 The position vector in is solved by the following formula: In the formula, θ is a parameter variable.

6. The conical cross-axis internal meshing asymmetric twin-screw rotor structure according to claim 5, characterized in that: The radius is R s The position vector of the curve segment A1B1C1 of the inner rotor profile on the spherical surface in the coordinate system O0x1y1z1 is solved by the following formula: Where M i,r1 Represents the coordinate system O0x r1 y r1 z r1 The unit rotation matrix, M 1r1 The coordinates are represented by the coordinate system O0x r1 y r1 z r The transfer matrix when transformed to the coordinate system O0x1y1z1, M i,1 The unit rotation matrix representing the coordinate system O0x1y1z1 is solved by the following formula: In the formula, is the rotation angle parameter, and N is the number of teeth on the inner rotor profile.

7. The conical cross-axis internal meshing asymmetric twin-screw rotor structure according to claim 6, characterized in that: The position vector r of the curve segment A1B1C1 of the inner rotor 1 A1B1C1 Middle turning angle parameters The relationship between and the parameter θ is obtained from the meshing relationship; the position vector of the curve segment B2C2 of the outer rotor is obtained from the curve segment B1C1 of the inner rotor through the meshing relationship.

8. The conical cross-axis internal meshing asymmetric twin-screw rotor structure according to claim 7, characterized in that: The rotor profile generated by the second generating circle among the inner and outer rotor profiles is generated in the same way as the first generating circle.

9. A method for designing a conical cross-shaft internal meshing asymmetric twin-screw rotor structure as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: According to the exhaust volume requirements, set the initial spherical radius R s , the central axis of the second generating circle is O0O r2 The angle β1 with the central axis O0O1 of the inner rotor profile, and the radius r1 of the curved segment A2B2 of the outer rotor; According to the transmission requirements, the radius r2 of the curve segment A2D2 of the outer rotor is set; according to the sealing and suction and exhaust working conditions, the number of teeth N of the inner rotor profile, the angle α between the central axis O0O1 and the central axis O0O2, and the pitch of the outer rotor helix are set; According to the set parameters, solve the central axis O0O of the first generated circle r1 The included angle β2 with the central axis O0O1 of the inner rotor profile, and the radius R s The curve segment A2B2 of the outer rotor profile on the spherical surface is in the coordinate system O0x r1 y r1 z r1 The position vector of the inner rotor profile curve segment A1B1C1 in the coordinate system O0x1y1z1 is determined by the position vector r of the inner rotor profile curve segment A1B1C1. 1 A1B1C1 Middle turning angle parameters The relationship between and parameter θ; In the same way, the position vector of the curve segment B2C2 of the outer rotor is obtained from the curve segment B1C1 of the inner rotor through the meshing relationship; The rotor profile generated by the second generating circle among the inner and outer rotor profiles is generated in the same way as the first generating circle.

10. The design method according to claim 9, characterized in that: According to the rotor profile structure at different rotor axial positions and the radius R s The inner and outer rotor profiles on the spherical surface are similar, and the spherical radius at the corresponding position and the radius R s The ratio determines the reduction multiple of the rotor profile structure at different rotor axial positions; Define the pitch of the helix to determine the rotation angle of the rotor profile structure at different rotor axial positions and construct a complete rotor structure; The number of teeth on the rotor profile is adjusted by adjusting the number of teeth N on the inner rotor profile, thereby achieving different rotor surface structures; By changing the design parameters of different parts of the inner and outer rotor profiles, the rotor geometry that meets different requirements can be obtained.

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