A streamlined adjustable twin-screw rotor and its profile design method

Abstract

A streamlined design adjustable twin-screw rotor and its profile design method, the rotor includes a female rotor and a male rotor that mesh with each other, according to the meshing relationship, the A on the rack curve r B r , B r C r , C r D r , D r E r , E r F r , F r G r , G r H r , H r I r , I r J r The curve segments in the yin and yang rotor profiles are generated by the segment A. r B r Segment is a Bezier curve segment, B r C r The segment is a straight line segment, C r D r The segment is an equidistant curve segment of the trochoid, D r E r The segment is an equidistant curve segment of the trochoid, E r F r The segment is an arc segment, F r G r The segment is a Bezier curve segment, G r H r The segment is a straight line segment, H r I r The segment is a Bezier curve segment, I r J r The segments are straight segments, and the slopes of the curve segments on the rack curve are continuous. The present invention can flexibly adjust the streamline design, transmission design and sealing performance of the twin-screw rotor, thereby achieving the regulation of the thermal performance, power performance and mechanical efficiency of the twin-screw machine.

Description

Technical Field

[0001] The invention belongs to the technical field of rotary machinery design, and particularly relates to a streamlined adjustable twin-screw rotor and a profile design method thereof. Background Art

[0002] Twin-screw extruders are positive displacement rotary machines with forced intake and exhaust functions. They are widely used in modern industry as gas compressors or expanders. Compared to dynamic compression and expansion machines, they offer numerous advantages, including reliable operation, wide adaptability to operating conditions, and low cost. Compared to other positive displacement machines, they lack vulnerable parts such as air valves, are liquid compatible, and offer high operating efficiency. They are core components in systems such as medium- and low-pressure air supply, steam cycle refrigeration, and organic Rankine cycle waste heat recovery.

[0003] The core design element of a twin-screw extruder is the rotor profile, which directly determines the overall thermodynamic performance of the machine. Advanced rotor profile design requires a comprehensive consideration of both thermal and dynamic performance. The selection of rotor profile parameters directly determines geometric characteristics such as the leakage triangle, contact line length, and area utilization. An excellent rotor profile can optimize the area of ​​each leakage channel by properly manipulating these parameters, thereby reducing the relative leakage rate and improving thermal performance. Furthermore, the rotor profile design also determines the gas torque experienced by the female rotor, which in turn determines the transmission performance between the male and female rotors. An excellent rotor profile can minimize the total torque experienced by the female rotor. Furthermore, by reducing the relative sliding velocity and transmission pressure angle at the actual transmission contact zone between the male and female rotors, smoother operation can be achieved, reducing wear and power consumption, and increasing overall machine energy efficiency and reliability. Finally, the streamlined design of the rotor profile can also reduce liquid and gas agitation losses caused by rotor rotation, thereby increasing the overall mechanical efficiency of the machine. To achieve these goals, direct rotor curve generation and rack curve generation are commonly used methods for generating twin-screw rotor profiles. The rotor profile generated by the direct rotor curve generation method relies on directly designing the component curves of the yin and yang rotor profiles to generate the complete rotor profile. This generation process is simple and clear, and the generated curves are relatively intuitive. Existing rotor profiles generated by direct rotor curve generation methods all incorporate complex quadratic curves, such as relatively complex elliptical curve segments, enabling flexible and adjustable profiles, allowing for the proper adjustment of leakage triangles, contact line length, and area utilization. However, this generation method struggles with the introduction of involutes, making it impossible to properly control the transmission performance of the rotor profile. The rack curve generation method, on the other hand, designs a rack curve that meshes with the yin and yang rotors, and then generates the yin and yang rotor profiles based on this meshing relationship. While the generation process easily identifies undercutting and allows for the introduction of transmission curves such as involutes, the rotor profiles currently generated using this method suffer from the drawbacks of a single curve type and a limited number of adjustable parameters, making it difficult to adjust the leakage triangle, contact line length, area utilization, and profile streamline. Summary of the Invention

[0004] The object of the present invention is to address the above-mentioned problems in the prior art and provide a streamlined design of an adjustable twin-screw rotor and a profile design method thereof, so that the generated twin-screw rotor profile can more easily and flexibly adjust the transmission pressure angle, leakage triangle, area utilization and contact line length, thereby improving the performance of the twin-screw rotor profile.

[0005] In order to achieve the above object, the present invention has the following technical solutions:

[0006] A streamlined design adjustable twin-screw rotor, comprising a female rotor and a male rotor meshing with each other, according to the meshing relationship, by the A on the rack curve r B r , B r C r , C r D r , D r E r , E r F r , F r G r , G r H r , H r I r , I r J r A in the male rotor profile is generated by segment m B m , B m C m , C m D m , D m E m , E m F m , F m G m , G m H m , H m I m , I m J m Segment and A in the female rotor profile f B f , B f C f , C f D f , D f E f , E f F f , F f G f , G f Hf , H f I f , I f J f Segment A of the rack curve r B r Segment is a Bezier curve segment, B r C r The segment is a straight line segment, C r D r The segment is an equidistant curve segment of the trochoid, D r E r The segment is an equidistant curve segment of the trochoid, E r F r The segment is an arc segment, F r G r The segment is a Bezier curve segment, G r H r The segment is a straight line segment, H r I r The segment is a Bezier curve segment, I r J r Segment A is a straight line segment. r B r , B r C r , C r D r , D r E r , E r F r , F r G r , G r H r , H r I r , I r J r The slope is continuous between segments.

[0007] As a preferred solution, in the generated male rotor profile, A m B m Segment A is the same as the Bezier curve segment r B r The curve segment generated by meshing, B m C m The segment is an involute segment, C m D m The segment is the arc envelope, D m F m The segment is an arc segment, E m F m Segment is the arc segment of pin tooth, F m G m Segment F is the same as the Bezier curve segment r G rThe curve segment generated by meshing, G m H m The segment is an involute segment, H m I m Segment H is the same as the Bezier curve segment r I r The curve segment generated by meshing, I m J m The segment is the tooth root arc segment.

[0008] As a preferred solution, in the generated female rotor profile, A f B f Segment A is the same as the Bezier curve segment r B r The curve segment generated by meshing, B f C f The segment is an involute segment, C f D f The segment is an arc, D f F f The segment is the arc envelope segment, E f F f Segment is the arc segment of pin tooth, F f G f Segment F is the same as the Bezier curve segment r G r The curve segment generated by meshing, G f H f The segment is an involute segment, H f I f Segment H is the same as the Bezier curve segment r I r The curve segment generated by meshing, I f J f The segment is the tooth top arc segment.

[0009] As a preferred solution, the meshing relationship between the rack curve and the profiles of the female rotor and the male rotor conforms to the following expression:

[0010]

[0011]

[0012] Where r m With r f They represent the position vectors of points on the yin and yang rotor lines respectively. The yin and yang rotor coordinate systems are fixed on the rotating yin and yang rotors respectively. r with y r Respectively represent the horizontal and vertical coordinates of the position vector of each curve segment on the rack curve, r p1 Indicates the pitch radius of the male rotor, r p2represents the pitch radius of the female rotor; φ2 represents the rotation angle of the female rotor profile corresponding to the position of the points on the meshing line; φ2 represents the rotation angle of the male rotor profile corresponding to the position of the points on the meshing line.

[0013] As a preferred solution, r p1 Indicates the pitch radius of the male rotor, r p2 It represents the pitch radius of the female rotor and is calculated by the following formula:

[0014]

[0015] Where m1 and m2 represent the number of teeth on the male and female rotors respectively, and A is the center distance between the male and female rotors.

[0016] As a preferred solution, the rotation angle φ2 of the female rotor profile corresponding to the position of the point on the different meshing line and the rotation angle φ1 of the male rotor profile satisfy the following relationship:

[0017]

[0018] As a preferred solution, the Bezier curve segment A r B r The expression is:

[0019]

[0020] Where r bezier,AB Represents Bezier curve segment A r B r The position vector of the upper point, r A With r B Represents the position vectors of point A and point B respectively, r P1,AB With r P2,AB Represent the selected set point P 1,AB With P 2,AB The position vector of

[0021] Click P 1,AB and point P 2,AB Select line segment A r P 0,AB With line segment B r P 0,AB For a point on , the direction vector expression is:

[0022]

[0023] Where i 1,AB with i 2,AB The decision points P 1,AB With P 2,AB The position parameter, r P0,AB Represents point P0,AB Position vector of point P 0,AB For straight line A r P 0,AB With line B r P 0,AB The intersection of straight line A r P 0,AB Passing through a given point A r , straight line A r P 0,AB The slope is from point A r Determined by the tangent vector, straight line B r P 0,AB Passing through given point B r , the slope is from point B r Determined by the tangent vector;

[0024] Bezier curve segment F r G r With Bezier curve segment H r I r The calculation method is the same as that of Bezier curve segment A r B r same.

[0025] A method for designing the profile of a streamlined adjustable twin-screw rotor comprises the following steps:

[0026] According to the processing performance requirements, design the straight line segment B on the rack curve r C r , the equidistant curve segment C of the trochoid r D r , the equidistant curve segment D of the trochoid r E r , arc segment E r F r , straight line segment G r H r , straight line segment I r J r ;

[0027] Design Bezier curve segment A according to thermal performance requirements r B r , realize the optimal allocation of leakage triangle and contact line length; design Bezier curve segment F according to transmission performance requirements r G r , adjust the meshing line shape to reduce the total resistance torque of the female rotor; design the Bezier curve segment H according to the streamline design requirements r I r , adjust the rotor shape to achieve a streamlined design of the rotor profile;

[0028] According to the meshing relationship, the A on the rack curve r Br , B r C r , C r D r , D r E r , E r F r , F r G r , G r H r , H r I r , I r J r A in the male rotor profile is generated by segment m B m , B m C m , C m D m , D m E m , E m F m , F m G m , G m H m , H m I m , I m J m A in the segment and the female rotor profile f B f , B f C f , C f D f , D f E f , E f F f , F f G f , G f H f , H f I f , I f J f part.

[0029] As a preferred solution, the yin and yang rotor profiles under different gear ratios are obtained based on the relationship between the rotation angle φ2 of the yin rotor profile and the rotation angle φ1 of the yang rotor profile corresponding to the point positions on different meshing lines.

[0030] Compared with the prior art, the present invention has at least the following beneficial effects: the rack curve is formed by using the Bezier curve, and then the yin and yang rotor profiles of the twin-screw rotor are generated by the rack curve according to the meshing relationship. r Br Segment is a Bezier curve segment, B r C r The segment is a straight line segment, C r D r The segment is an equidistant curve segment of the trochoid, D r E r The segment is an equidistant curve segment of the trochoid, E r F r The segment is an arc segment, F r G r The segment is a Bezier curve segment, G r H r The segment is a straight line segment, H r I r The segment is a Bezier curve segment, I r J r Segment A is a straight line segment. r B r , B r C r , C r D r , D r E r , E r F r , F r G r , G r H r , H r I r , I r J r The slopes between segments are continuous, so that the transmission curves close to the pitch circles in the yin and yang rotor profiles adopt involutes, the upper sealing surface adopts arc segments and arc envelopes, and the connection of each curve adopts Bezier curves. The generated rotor profiles are easier to flexibly adjust the transmission pressure angle, leakage triangle, area utilization and contact line length, thereby improving the thermal performance, power performance and mechanical efficiency of the twin-screw machinery. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of the composition structure of a rack curve according to an embodiment of the present invention;

[0032] Figure 2 Schematic diagram of the relationship between the yin and yang rotor profiles and the rack curve in an embodiment of the present invention;

[0033] Figure 3 Schematic diagram of the changes in the profile and meshing line caused by changing the Bezier curves of the AB segment, FG segment, and HI segment;

[0034] Figure 4 Schematic diagram of the changes in contact line and leakage triangle caused by changing the Bezier curves of the AB segment, FG segment, and HI segment;

[0035] Figure 5 Schematic diagram of the yin and yang rotor profile structure with different numbers of teeth of the present invention:

[0036] (a) 3-5 tooth profile line; (b) 4-5 tooth profile line; (c) 4-6 tooth profile line;

[0037] (d) 5-6 tooth profile line; (e) 5-7 tooth profile line; (f) 6-8 tooth profile line. DETAILED DESCRIPTION

[0038] The present invention will be described in further detail below with reference to the accompanying drawings.

[0039] like Figure 1 As shown, the streamlined design of the embodiment of the present invention can adjust the twin-screw rotor to divide the rack curve into multiple parts, and the curve A on the rack curve r B r , B r C r , C r D r , D r E r , E r F r , F r G r , G r H r , H r I r , I r J r The parts are generated in sequence as Figure 2 Curve A in the male rotor profile shown m B m , B m C m , C m D m , D m E m , E m F m , F m G m , G m H m , H m I m , I m J m Part A of the female rotor profile f B f , B f C f , C f D f , D f E f , E f Ff , F f G f , G f H f , H f I f , I f J f All curves are designed in the rack curve and then solved based on the meshing relationship between the rack curve and the yin and yang rotor profiles.

[0040] like Figure 1 As shown, the curve segment A in the rack curve of the embodiment of the present invention r B r is a Bezier curve segment, B r C r is a straight line segment, C r D r is the equidistant curve segment of the trochoid, D r E r is the equidistant curve segment of the trochoid, E r F r is an arc segment, F r G r is a Bezier curve segment, G r H r is a straight line segment, H r I r is a Bezier curve segment, I r J r It is a straight line segment, and the slopes between the curve segments are continuous.

[0041] like Figure 2 As shown, the male rotor segment A generated by the rack curve m B m is the Bezier curve segment A in the rack curve r B r The curve segment generated by meshing, B m C m is an involute segment, C m D m is the arc envelope, D m F m is an arc segment, E m F m is the arc segment of the pin tooth, F m G m is the Bezier curve segment F in the rack curve r G r The curve segment generated by meshing, G m H m is an involute segment, H m I m is the Bezier curve segment H in the rack curve rI r The curve segment generated by meshing, I m J m It is the tooth root arc segment.

[0042] like Figure 2 As shown, the negative rotor segment A generated by the rack curve f B f is the Bezier curve segment A in the rack curve r B r The curve segment generated by meshing, B f C f is an involute segment, C f D f is an arc line, D f F f is the arc envelope segment, E f F f is the arc segment of the pin tooth, F f G f is the Bezier curve segment F in the rack curve r G r The curve segment generated by meshing, G f H f is an involute segment, H f I f is the Bezier curve segment H in the rack curve r I r The curve segment generated by meshing, I f J f It is the tooth top arc segment.

[0043] exist Figure 1 and Figure 2 In the figure, the transformation relationship between the rack curve and the yin-yang rotor profile is:

[0044]

[0045]

[0046] Where r m With r f They represent the position vectors of points on the yin and yang rotor lines respectively. The yin and yang rotor coordinate systems are fixed on the rotating yin and yang rotors respectively. r with y r Respectively represent the horizontal and vertical coordinates of the position vector of each curve segment on the rack curve, r p1 Indicates the pitch radius of the male rotor, r p2 It represents the pitch radius of the female rotor and is calculated by the following formula:

[0047]

[0048] Where m1 and m2 represent the number of teeth on the male and female rotors respectively, and A is the center distance between the male and female rotors.

[0049] In the expression of the yin-yang rotor profile, φ2 represents the rotation angle of the yin rotor profile corresponding to the position of the point on the meshing line, and the rotation angle φ1 of the yang rotor profile corresponding to the position of the point on the meshing line satisfies the following relationship:

[0050]

[0051] exist Figure 1 and Figure 2 In the figure, Bezier curve segment A r B r The expression is:

[0052]

[0053] Where r bezier,AB Represents Bezier curve segment A r B r The position vector of the upper point, r A With r B Represents the position vectors of point A and point B respectively, r P1,AB With r P2,AB Represent the selected set point P 1,AB With P 2,AB The position vector of .

[0054] Click P 1,AB and point P 2,AB Select line segment A r P 0,AB With line segment B r P 0,AB The direction vector of a point on is expressed as:

[0055]

[0056] Among them, i 1,AB with i 2,AB The decision points P 1,AB With P 2,AB The position parameter, r P0,AB Represents point P 0,AB Position vector of point P 0,AB For straight line A r P 0,AB With line B r P 0,AB The intersection of straight line A r P 0,AB Passing through a given point A r , whose slope is from point A r Determined by the tangent vector, straight line B r P0,AB Passing through given point B r , the slope is from point B r Determined by the tangent vector.

[0057] Bezier curve segment F r G r With curve segment H r I r The determination method of curve segment A r B r same.

[0058] By adjusting the parameters of the AB segment Bezier curve, the following Figure 3 The yin and yang rotor profiles shown are flexibly adjusted, thereby achieving flexible adjustment such as Figure 4 The leakage triangle and contact line shown in the figure can realize the flexible allocation of leakage channel area, thereby obtaining better thermal performance. By adjusting the parameters of the FG segment Bezier curve, the following can be achieved: Figure 3 The yin and yang rotor profiles and meshing line shapes can be flexibly adjusted to achieve the following Figure 4 The contact line and the lower leakage triangle can be adjusted flexibly. By adjusting the parameters of the HI segment Bezier curve, the following can be achieved: Figure 3 The flexible adjustment of the yin and yang rotor profile shape and meshing line shape can realize the streamline design of the profile and achieve the following Figure 4 Flexible adjustment of the contact line shape is shown.

[0059] The method for designing a streamlined profile of an adjustable twin-screw rotor according to an embodiment of the present invention comprises the following steps:

[0060] Curve B on the rack curve is designed based on processing performance requirements r C r , C r D r , D r E r , E r F r , G r H r , I r J r Part. Among them, the curve segment B in the rack curve r C r is a straight line segment, C r D r is the equidistant curve segment of the trochoid, D r E r is the equidistant curve segment of the trochoid, E r F r is an arc segment, G r H r is a straight line segment, I r Jr is a straight line segment.

[0061] Design curve A according to thermal performance requirements r B r The Bezier curve parameters are optimized to achieve the optimal allocation of leakage triangle and contact line length. Curve F is designed according to transmission performance requirements. r G r The parameters of the Bezier curve are optimized to adjust the meshing line shape to reduce the total resistance torque of the female rotor. Curve H is designed according to the streamline design requirements. r I r The rotor shape is adjusted by optimizing the Bezier curve parameters to realize the streamlined design of the rotor profile.

[0062] The corresponding rack curve generated by the above Bezier curve is combined with the curve part on the previously defined rack curve to solve the yin and yang rotor profile. The transformation relationship between the rack curve and the yin and yang rotor profile is:

[0063]

[0064]

[0065] Where r m With r f They represent the position vectors of points on the yin and yang rotor lines respectively. The yin and yang rotor coordinate systems are fixed on the rotating yin and yang rotors respectively. r with y r Respectively represent the horizontal and vertical coordinates of the position vector of each curve segment on the rack curve, r p1 Indicates the pitch radius of the male rotor, r p2 It represents the pitch radius of the female rotor and is calculated by the following formula:

[0066]

[0067] Where m1 and m2 represent the number of teeth on the male and female rotors respectively, and A is the center distance between the male and female rotors.

[0068] In the expression of the yin and yang rotor profiles, φ2 represents the rotation angle of the yin rotor profile corresponding to the position of the point on the different meshing lines, and the rotation angle φ1 of the yang rotor profile satisfies the following relationship:

[0069]

[0070] The above method can also be used to obtain the yin and yang rotor profiles under different gear ratios, such as Figure 5 As shown in Figures (a) to (f) in.

[0071] The twin-screw rotor profile produced by the method of the present invention can flexibly adjust the streamline design, transmission design and sealing performance of the twin-screw rotor, thereby achieving flexible regulation of the thermal performance, power performance and mechanical efficiency of the twin-screw machinery.

[0072] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A streamlined design adjustable twin-screw rotor, characterized in that: It includes the female rotor and the male rotor that mesh with each other. According to the meshing relationship, the gears on the rack curve are A r B r , B r C r , C r D r , D r E r , E r F r , F r G r , G r H r , H r I r , I r J r The segment generates the male rotor profile A m B m , B m C m , C m D m , D m E m , E m F m , F m G m , G m H m , H m I m , I m J m Segment and the female rotor profile A f B f , B f C f , C f D f , D f E f , E f F f , F f G f , G f H f , H f I f , I f J f segment, the rack curve A r B r Segments are Bezier curve segments, B r C r Segment is a straight line segment, C r D r The segment is an equidistant curve segment of the trochoid. D r E r The segment is an equidistant curve segment of the trochoid. E r F r Segment is an arc segment, F r G r Segments are Bezier curve segments, G r H r Segment is a straight line segment, H r I r Segments are Bezier curve segments, I r J r Segment is a straight line segment, A r B r , B r C r , C r D r , D r E r , E r F r , F r G r , G r H r , H r I r , I r J r The slope is continuous between segments; The meshing relationship between the rack curve and the profiles of the female rotor and the male rotor conforms to the following expression: Where r m With r f They represent the position vectors of points on the yin and yang rotor lines respectively. The yin and yang rotor coordinate systems are fixed on the rotating yin and yang rotors respectively. x r and y r Respectively represent the horizontal and vertical coordinates of the position vector of each curve segment on the rack curve, r p1 represents the pitch radius of the male rotor, r p2 Indicates the pitch radius of the female rotor; Indicates the rotation angle of the female rotor profile corresponding to the position of the point on the meshing line. Indicates the rotation angle of the male rotor profile corresponding to the point position on different meshing lines; The Bezier curve segment A r B r The expression is: Where r bezier,AB Represents a Bezier curve segment A r B r The position vector of the upper point, r A With r B Respectively A Point and B The position vector of the point, r P1,AB With r P2,AB Respectively represent the selected set points P 1,AB and P 2,AB The position vector of point P 1,AB with dot P 2,AB Select as line segments A r P 0,AB With line segment B r P 0,AB For a point on , the direction vector expression is: Where, i 1,AB and i 2,AB Decision points P 1,AB and P 2,AB The position parameter, r P0,AB Indicates a point P 0,AB Position vector of point P 0,AB For a straight line A r P 0,AB With straight line B r P 0,AB The intersection of the straight line A r P 0,AB Passing a given point A r ,straight line A r P 0,AB The slope is determined by the point A r The straight line is determined by the tangent vector B r P 0,AB Passing a given point B r , the slope is determined by the point B r Determined by the tangent vector; Bezier curve segments F r G r With Bezier curve segments H r I r The calculation method is the same as that of Bezier curve segments A r B r same.

2. The streamlined adjustable twin-screw rotor according to claim 1, characterized in that: In the generated male rotor profile, A m B m Bezier curve segment A r B r The curve segments produced by meshing, B m C m Segment is an involute segment, C m D m The segment is the arc envelope, D m F m Segment is an arc segment, E m F m Segment is the arc segment of pin tooth, F m G m Bezier curve segment F r G r The curve segments produced by meshing, G m H m Segment is an involute segment, H m I m Bezier curve segment H r I r The curve segments produced by meshing, I m J m The segment is the tooth root arc segment.

3. The streamlined adjustable twin-screw rotor according to claim 1, characterized in that: In the generated female rotor profile, A f B f Bezier curve segment A r B r The curve segments produced by meshing, B f C f Segment is an involute segment, C f D f The segment is an arc line, D f F f Segment is the arc envelope segment, E f F f Segment is the arc segment of pin tooth, F f G f Bezier curve segment F r G r The curve segments produced by meshing, G f H f Segment is an involute segment, H f I f Bezier curve segment H r I r The curve segments produced by meshing, I f J f The segment is the tooth top arc segment.

4. The streamlined adjustable twin-screw rotor according to claim 1, characterized in that: r p1 represents the pitch radius of the male rotor, r p2 It represents the pitch radius of the female rotor and is calculated by the following formula: Where, m 1 and m 2 represents the number of teeth of the male and female rotors respectively, A is the center distance between the male and female rotors.

5. The streamlined adjustable twin-screw rotor according to claim 4, characterized in that: The rotation angle of the female rotor profile corresponding to the position of the point on the meshing line ϕ 2 Rotation angle with the male rotor profile ϕ 1 satisfy the following relationship: 。 6. A method for designing a streamlined adjustable twin-screw rotor according to claim 1, characterized in that: The following steps are involved: Design the straight line segment on the rack curve according to the processing performance requirements B r C r , the equidistant curve segments of the trochoid C r D r , the equidistant curve segments of the trochoid D r E r , arc segment E r F r , straight line segment G r H r , straight line segment I r J r ; Design Bezier curve segments based on thermal performance requirements A r B r , realize the optimal allocation of leakage triangle and contact line length; design Bezier curve segment according to transmission performance requirements F r G r , adjust the meshing line shape to reduce the total resistance torque of the female rotor; Design Bezier curve segments according to streamline design requirements H r I r , adjust the rotor shape to achieve a streamlined design of the rotor profile; According to the meshing relationship, the A r B r , B r C r , C r D r , D r E r , E r F r , F r G r , G r H r , H r I r , I r J r The segment generates the male rotor profile A m B m , B m C m , C m D m , D m E m , E m F m , F m G m , G m H m , H m I m , I m J m Segment and the female rotor profile A f B f , B f C f , C f D f , D f E f , E f F f , F f G f , G f H f , H f I f , I f J f part.

7. The profile design method according to claim 6, characterized in that: According to the rotation angle of the female rotor profile corresponding to the position of different points on the meshing line Rotation angle with the male rotor profile The relationship between them is used to obtain the yin and yang rotor profiles under different gear ratios.

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