Double-screw rotor and mechanical equipment

Abstract

The invention discloses a double-screw rotor and mechanical equipment, and belongs to the technical field of screw rotors. The rotor molded line double-screw rotor comprises a first rotor and a second rotor which are meshed with each other; the single-tooth molded line of the first rotor comprises an elliptic arc line segment, a hyperbolic curve segment, a first arc envelope line segment, a second arc line segment and a third arc line segment which are smoothly connected in sequence; and the single-tooth molded line of the second rotor comprises an elliptic arc envelope line section, a hyperbolic envelope line section, a first arc line section, a second arc envelope line section and a fourth arc line section which are smoothly connected in sequence. Based on the multi-curve-section structure of the single-tooth profile of the first rotor and the single-tooth profile of the second rotor, the first rotor and the second rotor can be well meshed in the working process, the conditions of small pressure ratio and large pressure difference can be borne, inter-tooth leakage can be reduced, and then the compression efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of screw rotors, and in particular to a twin-screw rotor and mechanical equipment. Background Art

[0002] Research on rotor profile technology has always been a core content and one of the fundamental tasks of screw compressor / expander technology. However, when a small pressure ratio is required while a large pressure differential is required, leakage between the rotor teeth may occur, resulting in reduced compression efficiency. Summary of the Invention

[0003] The embodiments of the present application provide a twin-screw rotor and mechanical equipment, which reduce inter-tooth gap leakage under conditions of a small pressure ratio and a large pressure difference, thereby improving compression efficiency.

[0004] In order to achieve the above objectives, according to a first aspect of the present application, a twin-screw rotor is provided, comprising:

[0005] a first rotor and a second rotor meshing with each other;

[0006] The single tooth profile of the first rotor includes an elliptical arc segment, a hyperbola segment, a first circular arc envelope segment, a second circular arc segment, and a third circular arc segment that are smoothly connected in sequence;

[0007] The single tooth profile of the second rotor includes an elliptical arc envelope segment, a hyperbolic envelope segment, a first circular arc segment, a second circular arc envelope segment, and a fourth circular arc segment that are smoothly connected in sequence.

[0008] In some embodiments, the number of teeth of the first rotor is M, the number of teeth of the second rotor is N, and M>N and MN≤2 are satisfied.

[0009] In some embodiments, the torsion angle α of the second rotor satisfies 280°≤α≤325°;

[0010] The torsion angle β of the first rotor satisfies β=α*N / M.

[0011] In some embodiments, the torsion angle α of the second rotor satisfies 300°≤α≤310°;

[0012] The torsion angle β of the first rotor satisfies β=α*N / M.

[0013] In some embodiments, the major semi-axis of the ellipse corresponding to the ellipse arc segment is located on the line connecting the starting point of the ellipse arc segment and the center of the first rotor pitch circle, or,

[0014] The minor semi-axis of the ellipse corresponding to the ellipse arc segment is located on a line connecting the starting point of the ellipse arc segment and the center of the first rotor pitch circle.

[0015] In some embodiments, the length m of the major semi-axis of the ellipse satisfies 0.08*A≤m≤0.1*A, where A represents the distance between the center of the first rotor pitch circle and the center of the second rotor pitch circle;

[0016] The length n of the minor semi-axis of the ellipse satisfies 0.04*A≤n≤0.05*A, where A represents the distance between the center point of the first rotor pitch circle and the center point of the second rotor pitch circle.

[0017] In some embodiments, the focus of the hyperbola segment is located on a line connecting the center of the first rotor pitch circle and the center of the second rotor pitch circle.

[0018] In some embodiments, the center of the first arc segment is located on a line connecting the center of the first rotor pitch circle and the center of the second rotor pitch circle.

[0019] In some embodiments, the arc radius r1 corresponding to the first arc segment satisfies 0.025*A≤r1≤0.065*A, where A represents the distance between the center of the first rotor pitch circle and the center of the second rotor pitch circle.

[0020] In some embodiments, the center of the second arc segment is located on a line connecting the end point of the second arc segment and the center of the first rotor pitch circle.

[0021] In some embodiments, the arc radius r2 corresponding to the second arc segment satisfies 0.025*A≤r2≤0.065*A, where A represents the distance between the center of the first rotor pitch circle and the center of the second rotor pitch circle.

[0022] In some embodiments, the center of the third arc segment is located at the center of the first rotor pitch circle.

[0023] In some embodiments, the arc center angle δ corresponding to the third arc segment satisfies 0°≤t2≤10°.

[0024] In some embodiments, the center of the fourth arc segment is located at the center of the second rotor pitch circle.

[0025] In some embodiments, the number of teeth of the first rotor is at least six.

[0026] The number of teeth of the second rotor is at least five.

[0027] According to a second aspect of the present application, a mechanical device is also provided, comprising the twin-screw rotor in the above embodiment.

[0028] In the twin-screw rotor of the embodiment of the present application, through the above technical solution, the twin-screw rotor includes: a first rotor and a second rotor that mesh with each other; the single tooth profile of the first rotor includes an elliptical arc segment, a hyperbolic curve segment, a first circular arc segment, a second circular arc segment, and a third circular arc segment that are smoothly connected in sequence; the single tooth profile of the second rotor includes an elliptical arc segment, a hyperbolic curve segment, a first circular arc segment, a second circular arc segment, and a fourth circular arc segment that are smoothly connected in sequence. Based on the multi-segment curve segment structure included in the single tooth profile of the first rotor and the single tooth profile of the second rotor, the present application can achieve better meshing of the first rotor and the second rotor during operation, can withstand small pressure ratios and large pressure differences, can reduce inter-tooth leakage, and thus improve compression efficiency.

[0029] In addition, the mechanical equipment of the embodiment of the present application includes the above-mentioned twin-screw rotor, so the mechanical equipment can have all the technical features and beneficial effects of the above-mentioned twin-screw rotor, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] To more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0031] Figure 1 A schematic diagram of a single tooth profile of the first rotor and the second rotor provided in an embodiment of the present application;

[0032] Figure 2 A schematic diagram of a twin-screw rotor profile with a gear ratio of 5:7 provided in an embodiment of the present application;

[0033] Figure 3 A geometric diagram of a single tooth profile of the first rotor and the second rotor provided in an embodiment of the present application;

[0034] Figure 4 A schematic diagram of a twin-screw rotor profile with a gear ratio of 5:6 provided in an embodiment of the present application;

[0035] Figure 5 Schematic diagram of the profile coordinates of a twin-screw rotor with a gear ratio of 5:7 provided in an embodiment of the present application.

[0036] Description of reference numerals: 10, first rotor; 20, second rotor. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0038] Research on rotor profile technology has always been a core and fundamental aspect of screw compressor / expander technology. Major domestic and international manufacturers of specialty screw compressors generally utilize a 4:6 rotor profile technology, achieving the required pressure through multi-stage or single-stage compression.

[0039] In recent years, with the continuous expansion of the application field of process screw compressors / expanders, large pressure differential applications such as hydrogen boosting, exhaust steam boosting, and helium compression have become increasingly common. This has brought new opportunities for process screw compressors, but it has also exposed many problems with existing profiles when dealing with large pressure differential conditions, such as low efficiency, high vibration and noise. These problems are particularly prominent when a large pressure differential is required despite a small pressure ratio.

[0040] In applications with low pressure ratios and large pressure differentials, although multi-stage compression can reduce the pressure differential between each stage, the low pressure ratio makes it difficult to arrange the exhaust orifices, making it difficult to match the internal and external pressure ratios, resulting in significant over-compression between stages. Furthermore, multi-stage compression significantly increases system complexity and initial investment costs. If single-stage compression is used, the conventional profile design results in a large pressure differential between teeth. Severe leakage between tooth slots can lead to a significant decrease in machine operating efficiency and a greater risk of vibration and noise. Furthermore, the large pressure differential places higher demands on the rigidity and strength of the rotor.

[0041] In addition, driven by the "dual carbon" goals, the market urgently needs a rotor and profile technology solution suitable for large pressure difference conditions in order to achieve the best balance between cost and efficiency.

[0042] In view of this, the embodiments of the present application propose a twin-screw rotor and mechanical equipment, aiming to solve at least one of the above-mentioned technical problems.

[0043] See also Figure 1 As shown, Figure 1 Schematic diagram of single tooth profiles of the first rotor 10 and the second rotor 20 provided in an embodiment of the present application.

[0044] The present application provides a twin-screw rotor, comprising: a first rotor 10 and a second rotor 20 meshing with each other; a single tooth profile of the first rotor 10 comprises an elliptical arc segment, a hyperbolic curve segment, a first circular arc envelope segment, a second circular arc segment, and a third circular arc segment that are smoothly connected in sequence; a single tooth profile of the second rotor 20 comprises an elliptical arc envelope segment, a hyperbolic curve segment, a first circular arc segment, a second circular arc envelope segment, and a fourth circular arc segment that are smoothly connected in sequence.

[0045] In the present application, the first rotor 10 can be a female rotor, and the second rotor 20 can be a male rotor; in the process of the twin-screw rotor rotating and meshing, in the single tooth profiles of the first rotor 10 and the second rotor 20, the elliptical arc segment is meshed with the elliptical arc envelope segment, the hyperbola segment is meshed with the hyperbola envelope segment, the first circular arc envelope segment is meshed with the first circular arc segment, the second circular arc segment is meshed with the second circular arc envelope segment, and the third circular arc segment is meshed with the elliptical arc envelope segment; the rotor profile corresponding to the first rotor 10 is the rotor end profile, that is, the single tooth profile of the first rotor 10 is rotated around the center of the first rotor 10 circle O2 and connected end to end, that is, a first rotor 10 is connected to the first rotor 10. The starting end of the elliptical arc segment of a single tooth profile in the corresponding rotor profile is connected to the ending end of the third arc segment of another adjacent single tooth profile, and so on, the rotor profile corresponding to the first rotor 10 is obtained by connecting end to end; similarly, the rotor profile corresponding to the second rotor 20 is the rotor end face profile, and similarly, it is obtained by rotating the single tooth profile of the second rotor 20 around the center point O1 of the second rotor 20 pitch circle and connecting end to end, that is, the starting end of the elliptical arc envelope segment of a single tooth profile in the rotor profile corresponding to the second rotor 20 is connected to the ending end of the fourth arc segment of another adjacent single tooth profile, and so on, the rotor profile corresponding to the second rotor 20 is obtained by connecting end to end.

[0046] Among them, an elliptical arc segment is a part of an ellipse; an elliptical arc envelope segment is an outer contour segment surrounding the elliptical arc segment, and the elliptical arc envelope segment and the elliptical arc segment satisfy the conjugate envelope principle; a hyperbola segment refers to a curve on a hyperbola; a hyperbola envelope segment refers to an outer contour segment surrounding the hyperbola segment, and the hyperbola envelope segment and the hyperbola segment satisfy the conjugate envelope principle; a circular arc segment is an arc on a circle; a circular arc envelope segment refers to an outer contour segment surrounding the circular arc segment, and the circular arc envelope segment and the circular arc segment satisfy the conjugate envelope principle.

[0047] For example, see Figure 1As shown, the single tooth profile of the first rotor 10 includes an elliptical arc segment connected in sequence and smoothly as the curve segment a2b2, a hyperbolic curve segment as the curve segment b2c2, a first circular arc envelope segment as the curve segment c2d2, a second circular arc segment as the curve segment d2e2, and a third circular arc segment as the curve segment e2f2; the single tooth profile of the second rotor 20 includes an elliptical arc envelope segment connected in sequence and smoothly as the curve segment a1b1, a hyperbolic curve segment as the curve segment b1c1, a first circular arc segment as the curve segment c1d1, a second circular arc envelope segment as the curve segment d1e1, and a fourth circular arc segment as the curve segment e1f1. Furthermore, during the rotation and meshing process of the twin-screw rotor, the curved segment a2b2 meshes with the curved segment a1b1, the curved segment b2c2 meshes with the curved segment b1c1, the curved segment c2d2 meshes with the curved segment c1d1, the curved segment d2e2 meshes with the curved segment d1e1, and the curved segment e2f2 meshes with the curved segment e1f1; then, in the rotor profile corresponding to the first rotor 10, the starting end a2 of the elliptical arc segment a2b2 of a single tooth profile serves as the starting end of the single tooth profile and is connected to the adjacent other single tooth profile. The termination end f2 of the third circular arc segment e2f2 of the profile is connected as the tail end of the single tooth profile, and so on, the end to end are connected to obtain the rotor profile corresponding to the first rotor 10; the starting end a1 of the elliptical arc envelope segment a1b1 of a single tooth profile in the rotor profile corresponding to the second rotor 20 is used as the starting end of the single tooth profile and is connected to the termination end f1 of the fourth circular arc segment e1f1 of another adjacent single tooth profile as the tail end of the single tooth profile, and so on, the end to end are connected to obtain the rotor profile corresponding to the second rotor 20.

[0048] Through the above technical solution, the twin-screw rotor in the embodiment of the present application includes: a first rotor 10 and a second rotor 20 that are meshed with each other; the single tooth profile of the first rotor 10 includes an elliptical arc segment, a hyperbolic curve segment, a first circular arc envelope segment, a second circular arc segment, and a third circular arc segment that are smoothly connected in sequence; the single tooth profile of the second rotor 20 includes an elliptical arc envelope segment, a hyperbolic curve segment, a first circular arc segment, a second circular arc envelope segment, and a fourth circular arc segment that are smoothly connected in sequence. This application is based on the five-segment curved line structure of the single tooth profile of the first rotor 10 and the single tooth profile of the second rotor 20, wherein the elliptical arc envelope segment meshes with the elliptical arc segment, the hyperbolic envelope segment meshes with the hyperbolic segment, the first circular arc envelope segment meshes with the first circular arc segment, the second circular arc segment meshes with the second circular arc envelope segment, and the third circular arc segment meshes with the fourth circular arc segment. This enables the first rotor 10 and the second rotor 20 to achieve better meshing during operation, can withstand small pressure ratios and large pressure differences, can reduce inter-tooth leakage, and thus improve compression efficiency. In addition, the single tooth profile of the first rotor 10 and the single tooth profile of the second rotor 20 are both smoothly connected in sequence, ensuring a smooth transition of the profile and improving the overall performance of the rotor.

[0049] See also Figure 2 As shown, Figure 2 Schematic diagram of the twin-screw rotor profile with a gear ratio of 5:7 provided in the embodiments of the present application.

[0050] In some embodiments, the torsion angle α of the second rotor 20 satisfies 280°≤α≤325°; and the torsion angle β of the first rotor 10 satisfies β=α*N / M.

[0051] That is, in some embodiments, the torsion angle α of the second rotor 20 can range from 280° to 325°. This means that the torsion angle α of the second rotor 20 can be any angle among 280°, 290°, 300°, 310°, 320°, and 325°, or a range between any two angles. Since the two rotors mesh and rotate synchronously, their torsion angles must be coordinated. The torsion angle of the first rotor 10 can be calculated based on the gear ratio of the twin-screw rotors and the known torsion angle of the second rotor 20. That is, the first rotor torsion angle β and the second rotor torsion angle α are constrained by the mathematical relationship β = α * M / N. It should be noted that, typically, the torsion angles of the first and second rotors 10, 20 in a twin-screw extruder are not identical. The torsion angles of the first and second rotors 10, 20 can be determined based on specific application requirements and performance objectives to achieve optimal compression efficiency and system performance. By adjusting the torsion angle of the two rotors, designers can better control the gas flow and compression process to meet different operating conditions and process requirements.

[0052] It can be understood that the torsion angle refers to the angle that any point on the tooth-shaped spiral surface of the screw rotor rotates when it moves along the spiral line from one end face of the rotor to the other end face. Figure 2As shown, the first rotor 10 and the second rotor 20 rotate in the direction shown. The twist angle refers to the angle of rotation required to complete a working cycle. Taking a screw air compressor as an example, the twist angle is the angle of rotation from the end of the intake position to the end of the discharge position. This angle describes how the rotor twists relative to its initial position during rotation. Specifically, the larger the rotor twist angle, the more inclined the helix or tooth profile during rotation, causing the gas to flow along a longer path, thereby affecting the efficiency of the compression process and the internal compression angle. The internal compression angle refers to the angle of rotation of the meshed screw rotors from the moment the intake ends to the moment the discharge begins. It reflects the rotor's operation during the gas compression phase. A larger internal compression angle generally means that the gas undergoes a longer compression path within the rotor, resulting in a smoother pressure change and higher compression efficiency. It should be understood that the rotor has multiple tooth slots where the gas is compressed. For example, an internal compression angle of 200 degrees means that the gas rotates 200 degrees from the end of intake and the beginning of compression to discharge.

[0053] Furthermore, in some embodiments, the torsion angle α of the second rotor 20 satisfies 300°≤α≤310°; and the torsion angle β of the first rotor 10 satisfies 300°≤β≤310°.

[0054] That is, in some embodiments, the torsion angle α of the second rotor 20 can range from 300° to 310°, meaning that the torsion angle α of the second rotor 20 can be any angle among 310°, 311°, 312°, 313°, 314°, 315°, 316°, 317°, 318°, 319°, and 310°, or a range between any two angles. Similarly, since the two rotors mesh with each other and rotate synchronously, their torsion angles must be coordinated. Based on the gear ratio set for the twin-screw rotors and the known torsion angle of the second rotor 20, the torsion angle of the first rotor 10 can be calculated using the gear ratio. That is, the first rotor torsion angle β and the second rotor torsion angle α are constrained by the mathematical relationship β = α * M / N.

[0055] It should be noted that the 5:7 gear ratio refers to the ratio of the number of teeth on the male rotor to the number of teeth on the female rotor. However, the torsion angle α of the second rotor 20 and the torsion angle β of the first rotor 10 in this application are not limited to twin-screw rotors with a gear ratio of 5:7 and can also be applied to twin-screw rotors with other gear ratios, such as 5:6, depending on the specific implementation.

[0056] Through the above technical solution, a moderate torsion angle can help the rotor disperse stress when it is under load, reduce local stress concentration, and thus improve stability. In addition, an appropriate torsion angle can help reduce vibration of the rotor during operation, reduce noise, and improve operational smoothness. In addition, the larger the torsion angle, the longer the compression process, and the larger the internal compression angle must be. Therefore, a higher torsion angle can provide a larger internal compression angle. The internal compression angle determines the compression path and compression ratio of the gas inside the rotor. Increasing the internal compression angle means that the gas undergoes a longer compression path inside the rotor. A longer compression path allows the gas to be gradually compressed over a larger volume change, thereby reducing instantaneous pressure changes. This can reduce the pressure difference between the teeth because the gas pressure changes more gently and evenly, thereby reducing leakage between the teeth, and thus improving compression efficiency.

[0057] See also Figure 3 As shown, Figure 3 Schematic diagram of the single tooth profile geometry of the first rotor and the second rotor provided in an embodiment of the present application.

[0058] In some embodiments, the major semi-axis of the ellipse corresponding to the elliptical arc segment a2b2 is located on the line connecting the starting point of the elliptical arc segment a2b2 and the center of the first rotor 10 section circle, or the minor semi-axis of the ellipse corresponding to the elliptical arc segment a2b2 is located on the line connecting the starting point of the elliptical arc segment a2b2 and the center of the first rotor 10 section circle.

[0059] That is, in some embodiments, the semi-major axis of the ellipse corresponding to elliptical arc segment a2b2 lies on the line connecting the starting point of elliptical arc segment a2b2 and the center of the pitch circle of the first rotor 10. It will be understood that the pitch circle refers to an imaginary circle on the rotor. For a pair of meshing rotors, the pitch circle is the circle to which the two rotors are tangent when meshing. The pitch circles of the two rotors in a twin-screw extruder must be precisely matched to ensure proper meshing of the rotor teeth. The semi-major axis of the ellipse corresponding to elliptical arc segment a2b2 lies on the line connecting the starting point of elliptical arc segment a2b2 and the center of the pitch circle of the first rotor 10, making elliptical arc segment a2b2 relatively gentle, that is, having a smaller curvature. A gentler elliptical arc segment a2b2 can make the rotor mesh smoother, reducing shock and vibration, helping to reduce operating noise, minimize gas leakage, and improve compression efficiency. Furthermore, the smaller curvature can more evenly distribute contact stress across the rotor surface, thereby reducing localized wear. This helps extend the rotor's service life and reduce maintenance requirements. Under high load conditions, the gentler curvature provides better structural strength and stability, reducing the possibility of deformation. This is very beneficial in compressor applications that need to handle high pressures or high loads.

[0060] In some embodiments, the minor semi-axis of the ellipse corresponding to elliptical arc segment a2b2 lies on the line connecting the starting point of elliptical arc segment a2b2 and the center of the pitch circle of the first rotor 10. It will be appreciated that the minor semi-axis of the ellipse corresponding to elliptical arc segment a2b2 lies on the line connecting the starting point of elliptical arc segment a2b2 and the center of the pitch circle of the first rotor 10, making elliptical arc segment a2b2 relatively steep, that is, the curvature of elliptical arc segment a2b2 is relatively large. A larger curvature can provide a shorter sealing line when the rotors are engaged, thereby improving sealing performance. This is very important for applications requiring high sealing to prevent gas leakage. Furthermore, a larger curvature can enable faster rotor response during engagement and disengagement, reducing the pumping effect when the rotors disengage or enter engagement, thereby reducing vibration and noise.

[0061] Specifically, the position of point b2 in the elliptical arc segment a2b2 in the present application is determined by the condition that the curve segment a2b2 and the curve segment b2c2 are tangent at the connection point b2, and point a2 is determined by the condition that the curve segment e2f2 of another adjacent single tooth profile is tangent at the connection point f2(a2). It can be understood that the two connected curve segments in the present application are tangent at the connection point, that is, the two connected curve segments have the same tangent direction at the connection point. Specifically, the tangent slopes of the two connected curve segments at the connection point are the same. This means that the two connected curve segments are smoothly connected, and the two tangent curve segments form a smooth transition at the connection point without sharp angles or discontinuities. In addition, based on the fact that during the rotation and meshing process of the twin-screw rotor, the curve segment a2b2 meshes with the curve segment a1b1, and then the elliptical arc envelope segment a1b1 can be formed according to the conjugate envelope principle. In this application, the position of point b1 in the elliptical arc envelope segment a1b1 is determined by the condition that the curve segment a1b1 and the curve segment b1c1 are tangent at the connection point b1, and point a1 is determined by the condition that the curve segment e1f1 of another adjacent single tooth profile is tangent at the connection point f1(a1).

[0062] Through the above technical solution, the present application provides two forms of elliptical arc segments a2b2. The long semi-axis of the ellipse corresponding to the elliptical arc segment a2b2 is located on the line connecting the starting point of the elliptical arc segment a2b2 and the center of the first rotor 10 section circle, making the elliptical arc segment a2b2 relatively gentle and with a small curvature, which is suitable for application scenarios that need to reduce noise, reduce wear and improve efficiency. The short semi-axis of the ellipse corresponding to the elliptical arc segment a2b2 is located on the line connecting the starting point of the elliptical arc segment a2b2 and the center of the first rotor 10 section circle, which makes the elliptical arc segment a2b2 relatively steep and with a large curvature, which is suitable for application scenarios that need to improve sealing performance, increase compression ratio and process high-viscosity fluids. The parameters of the two elliptical arc segments a2b2 can be flexibly selected and adjusted according to the needs of the actual solution to optimize the performance of the compressor and adapt to specific operating conditions.

[0063] In some embodiments, the length m of the major semi-axis of the ellipse satisfies 0.08*A≤m≤0.1*A, where A represents the distance between the center of the node circle of the first rotor 10 and the center of the node circle of the second rotor 20; the length n of the minor semi-axis of the ellipse satisfies 0.04*A≤n≤0.05*A, where A represents the distance between the center of the node circle of the first rotor 10 and the center of the node circle of the second rotor 20.

[0064] It can be understood that the center of the node circle of the first rotor 10 is O2, and the center of the node circle of the second rotor 20 is O1. In this application, the length m of the major semi-axis of the ellipse corresponding to the elliptical arc segment a2b2 satisfies 0.08*A≤m≤0.1*A, and the length n of the minor semi-axis of the ellipse satisfies 0.04*A≤n≤0.05*A, thereby providing sufficient structural strength and stability for the tooth profile of the first rotor 10. In some embodiments, n=0.042*A,m=0.0836*A, providing a balanced design solution that meets the requirements of structural strength while maintaining manufacturing feasibility and cost-effectiveness. It should be noted that the units of length in this application can be millimeters (mm), centimeters (cm), meters (m), etc., which are set according to the actual implementation plan.

[0065] In some embodiments, the focus of the hyperbola segment b2c2 is located on a line connecting the center of the first rotor 10 pitch circle and the center of the second rotor 20 pitch circle.

[0066] like Figure 3 As shown, hyperbola segment b2c2 can be a partial curve segment in the right branch of the hyperbola. The focus of the hyperbola corresponding to hyperbola segment b2c2 is located on the line connecting the center of the first rotor 10 and the center of the second rotor 20, and the focus of the hyperbola branch where hyperbola segment b2c2 is located is located outside the rotor profile corresponding to the first rotor 10. Furthermore, based on the meshing of curve segment b2c2 with curve segment b1c1, a hyperbola envelope segment b1c1 can be formed according to the conjugate envelope principle. It is understandable that, based on the shape of the preset hyperbola corresponding to hyperbola segment b2c2, the curve segment in the right branch of the hyperbola can be intersected with the elliptical arc segment a2b2, and the point where curve segments a2b2 and b2c2 are tangent at the connection point b2 is used as the interception position of the starting point b2 of hyperbola segment b2c2. The position of point c2 is determined by the condition that the first circular arc envelope segment c2d2 and hyperbola segment b2c2 are tangent at the connection point c2. It should be noted that the preset hyperbola curvature corresponding to the hyperbola segment b2c2 is specifically set according to the actual implementation plan. In addition, the position of c1 in the hyperbola envelope segment b1c1 is determined by the condition that the hyperbola envelope segment b1c1 and the first circular arc segment c1d1 are tangent at the connection point c1.

[0067] In some embodiments, the center of the first arc segment c1d1 is located on a line connecting the center of the first rotor 10 section circle and the center of the second rotor 20 section circle.

[0068] like Figure 3 As shown, the first arc segment c1d1 can be a partial arc on a circle. The center of the circle corresponding to the first arc segment c1d1 is located on the line connecting the center of the first rotor 10 section circle and the center of the second rotor 20 section circle. The center of the circle corresponding to the first arc segment c1d1 is also located within the rotor profile corresponding to the second rotor 20. Based on the meshing of the curved segments c1d1 and c2d2, a first arc envelope segment c2d2 can be formed according to the conjugate envelope principle. It will be understood that the position of point d2 in the first arc envelope segment c2d2 is determined by the tangency between the first arc envelope segment c2d2 and the second arc segment d2e2 at the connection point d2. Furthermore, the position of point d1 in the first arc segment c1d1 is determined by the tangency between the first arc segment c1d1 and the second arc envelope segment d1e1 at the connection point d1.

[0069] In some embodiments, the arc radius r1 corresponding to the first arc segment c1d1 satisfies 0.025*A≤r1≤0.065*A, where A represents the distance between the center of the first rotor 10 pitch circle and the center of the second rotor 20 pitch circle. It is understood that the arc radius r1 corresponding to the first arc segment c1d1 can be determined by the continuous and differentiable geometric relationship of the profile at points d1 and c1. That is, the first arc segment c1d1 and the hyperbolic envelope segment b1c1 are tangent at the connection point c1, and the first arc segment c1d1 and the second arc envelope segment d1e1 are tangent at the connection point d1. This ensures that the two ends of the first arc segment c1d1 are smoothly connected to the hyperbolic envelope segment b1c1 and the second arc envelope segment d1e1, respectively.

[0070] In some embodiments, the center of the second arc segment d2e2 is located on a line connecting the end point of the second arc segment d2e2 and the center of the section circle of the first rotor 10 .

[0071] like Figure 3 As shown, the second arc segment d2e2 can be a partial arc on a circle. The center of the circle corresponding to the second arc segment d2e2 is located on the line connecting the end point e2 of the second arc segment d2e2 and the center of the pitch circle O2 of the first rotor 10, and the center of the second arc segment d2e2 is located inside the corresponding rotor profile of the first rotor 10. Based on the meshing of the curved segment d2e2 and the curved segment d1e1, the second arc envelope segment d1e1 can be formed according to the conjugate envelope principle. It can be understood that the position of point e2 in the second arc segment d2e2 is determined by the condition that the second arc segment d2e2 and the third arc segment e2f2 are tangent at the connection point e2. In addition, point e1 in the second arc envelope segment d1e1 is determined by the condition that the second arc envelope segment d1e1 and the fourth arc segment e1f1 are tangent at the connection point e1.

[0072] In some embodiments, the arc radius r2 corresponding to the second arc segment d2e2 satisfies 0.025*A≤r2≤0.065*A, where A represents the distance between the center of the pitch circle of the first rotor 10 and the center of the pitch circle of the second rotor 20. For example, r2 may be 0.05*A. It will be appreciated that by varying the arc radius corresponding to the second arc segment d2e2, the pitch circle pressure angle of the profile can be adjusted, thereby making the profile more suitable for compressor or expander applications.

[0073] In some embodiments, the center of the circle corresponding to the third arc segment e2f2 is located at the center of the section circle of the first rotor 10. It is understandable that the center radius r3 corresponding to the third arc segment e2f2 is equal to the outer diameter of the first rotor 10. It is understandable that the tooth top refers to the outermost edge of the rotor gear. The third arc segment e2f2 represents the position of the first rotor tooth top, which means that it is part of the rotor outer diameter. The rotor outer diameter refers to the circumferential diameter of the outermost layer of the rotor. Furthermore, when the rotor rotates in the housing, the third arc segment e2f2 can form a sealing area between the first rotor tooth top and the housing, which can reduce the leakage of fluid or gas and improve mechanical efficiency and performance. In some embodiments, the arc center angle t2 corresponding to the third arc segment e2f2 satisfies 0°≤t2≤10°. That is, the value range of the arc center angle δ corresponding to the third arc segment e2f2 can be 0° to 10°, which means that the value of the arc center angle δ corresponding to the third arc segment e2f2 can be any angle among 0°, 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, and 10°, or a range between any two angles. It is understandable that the third arc segment e2f2 can effectively form a sealing band between the tooth top and the housing. However, for a liquid injection compressor, an overly wide sealing band will result in greater power consumption, and thus the gap between the tooth top and the housing needs to be controlled within a smaller range to prevent leakage and ensure effective sealing.

[0074] In some embodiments, the center of the circle corresponding to the fourth arc segment e1f1 is located at the center of the second rotor 20 section circle. It will be appreciated that the center radius r4 corresponding to the fourth arc segment e1f1 is equal to the base diameter of the second rotor 20. Similarly, the fourth arc segment e1f1 represents the position of the second rotor tooth tip. Furthermore, when the rotor rotates within the housing, the fourth arc segment e1f1 can form a sealing area between the second rotor tooth tip and the housing, thereby reducing fluid or gas leakage and improving mechanical efficiency and performance. Furthermore, since the third arc segment e2f2 is controlled within a relatively small range, based on the conjugate envelope relationship, the arc center angle t1 corresponding to the fourth arc segment e1f1 also controls the fourth arc segment e1f1 within a relatively small range. Consequently, the gap between the tooth tip corresponding to the fourth arc segment e1f1 and the housing is also controlled within a relatively small range, thereby preventing leakage and ensuring effective sealing. It should be noted that in this application, based on the meshing of curve segments e2f2 and e1f1, the third arc segment e2f2 can form the fourth arc segment e1f1 according to the conjugate envelope principle. Point f2 in the third arc segment e2f2 is determined by the condition that the curve segment a2b2 of the adjacent single-tooth profile is tangent to the connection point f2(a2). Furthermore, point f1 in the fourth arc segment e1f1 is determined by the condition that the curve segment a1b1 of the adjacent single-tooth profile is tangent to the connection point f1(a1).

[0075] Through the above technical solution, the rotor profile twin-screw rotor of the present application includes: a first rotor 10 and a second rotor 20 that mesh with each other; the single tooth profile of the first rotor 10 includes a smoothly connected sequence of elliptical arc segments a2b2, a hyperbolic segment b2c2, a first circular arc segment c2d2, a second circular arc segment d2e2, and a third circular arc segment e2f2; the single tooth profile of the second rotor 20 includes a smoothly connected sequence of elliptical arc segments a1b1, a hyperbolic segment b1c1, a first circular arc segment c1d1, a second circular arc segment d1e1, and a fourth circular arc segment e1f1. The configuration of these curved segments allows for better meshing of the first and second rotors 10, 20 during operation, and the combination of multiple curved segments reduces inter-tooth leakage. Furthermore, the larger torsion angle and higher tooth ratio result in a larger internal compression angle, thereby increasing the internal volume ratio, making it easier to match the exhaust port to the required pressure ratio and improving under- and over-compression. This application can withstand small pressure ratios and large pressure differences, can reduce inter-tooth leakage, and thus improve compression efficiency. It is worth noting that the connection between adjacent curved segments is processed through a smooth transition to achieve a tangential connection, ensuring the continuity and smoothness of the rotor profile.

[0076] See also Figure 2 、 Figure 4 and Figure 5 As shown, Figure 4A schematic diagram of a twin-screw rotor profile with a gear ratio of 5:6 provided in an embodiment of the present application; Figure 5 Schematic diagram of the profile coordinates of a twin-screw rotor with a gear ratio of 5:7 provided in an embodiment of the present application.

[0077] In some embodiments, the number of teeth of the first rotor 10 is M, the number of teeth of the second rotor 20 is N, and M>N and MN≤2 are satisfied.

[0078] In some embodiments, the number of teeth of the first rotor 10 is at least six, and the number of teeth of the second rotor 20 is at least five.

[0079] For example, Figure 2 As shown, in some embodiments, the gear ratio of the second rotor 20 to the first rotor 10 can be 5:7, that is, the gear ratio of the male rotor to the female rotor can be 5:7, the number of teeth of the male rotor can be 5, and the number of teeth of the female rotor can be 7.

[0080] like Figure 4 As shown, in other embodiments, the gear ratio of the second rotor 20 to the first rotor 10 can be 5:6, that is, the gear ratio of the male rotor to the female rotor can be 5:6, the male rotor can have 5 teeth, and the female rotor can have 6 teeth. The above is only a partial illustration of the embodiments of the present application and does not limit the present application.

[0081] As you can understand, the gear ratio refers to the ratio of the number of teeth on the male rotor to the number of teeth on the female rotor of a twin-screw rotor. Increasing the gear ratio means more teeth on each rotor participate in the gas compression process. More teeth distribute the gas pressure more evenly, reducing pressure differences within each tooth slot. This helps to smoothly compress the gas and minimize local pressure fluctuations. Furthermore, an appropriate gear ratio optimizes the internal compression angle, allowing the compressor to achieve optimal efficiency under specific operating conditions. Avoiding an excessively large internal compression angle can lead to overcompression and increased energy loss, while avoiding an excessively small internal compression angle can result in incomplete compression and reduced efficiency. The gear ratio influences the meshing and sealing between the rotors. A suitable gear ratio reduces leakage and backflow, thereby optimizing the internal compression angle and ensuring that the gas is compressed and discharged at the appropriate time and location. It also increases the internal volume ratio, making it easier to match the exhaust port to the required pressure ratio, reducing under- and overcompression.

[0082] Furthermore, in this application, the first rotor 10 has at least six teeth, and the second rotor 20 has at least five teeth. This allows for more even distribution of gas pressure, thereby reducing pressure differences within each tooth slot. It is understood that, for example, a 5:6 or 5:7 tooth ratio, as proposed in this application for high pressure differentials, increases the internal compression angle and thus improves the internal volume ratio.

[0083] In some embodiments, the twin-screw rotor profile provided herein is suitable for high-pressure differential operating conditions. The maximum discharge pressure applicable to the twin-screw rotor profile in this application can be 40 barA, and the suction and exhaust pressure differential can be 10 bar to 35 bar. This means that the suction and exhaust pressure differential of the twin-screw rotor in this application can be any pressure differential of 10 bar, 15 bar, 20 bar, 25 bar, 30 bar, or 35 bar, or a range between any two pressure differentials.

[0084] Please refer to Table 1, which shows the comparison relationship between the leakage amount and the female rotor tooth root strength when the gear ratios of the second rotor 20 to the first rotor 10 are 4:5, 5:6 and 5:7 provided in the embodiment of the present application. It should be noted that the percentages in the table are relative values based on the 4:6 gear ratio as the comparison benchmark.

[0085] Table 1

[0086]

[0087] Furthermore, the contact line is the most impactful leakage channel. While triangular leakage does have an impact, it is not the primary issue. The data in the table above shows that contact line leakage is significantly reduced when the gear ratio of the second rotor 20 to the first rotor 10 is 5:7, indicating that contact line leakage is effectively controlled at a gear ratio of 5:7. Furthermore, the female rotor tooth root strength increases to 105% at a gear ratio of 5:7, indicating enhanced tooth root strength at this ratio. Therefore, in some embodiments, selecting a gear ratio of 5:7 may be a better choice for optimizing leakage control and structural strength.

[0088] For example, see Table 2 and Figure 5 As shown, Table 2 shows the coordinate parameters of the partial positions of the rotor profile corresponding to the first rotor 10 and the rotor profile corresponding to the second rotor 20 when the gear ratio of the second rotor 20 to the first rotor 10 is 5:7 provided in an embodiment of the present application.

[0089] Table 2

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108] Understandably, Figure 5 The two-dimensional coordinate system is based on the line containing the center O2 of the first rotor 10 and the center O1 of the second rotor 20 as the x-axis, and the line perpendicular to the x-axis and passing through the center O2 of the first rotor 10 as the y-axis. The data shown in Table 2 above are the coordinates of the single tooth profile of the first rotor and the corresponding single tooth profile of the second rotor, that is, Figure 5 The curves a1-b1-c1-d1-e1-f1 and a2-b2-c2-d2-e2-f2 are shown in Table 2. The positions in Table 2 are the coordinates of the single tooth profile in the first rotor in the order of the curve points a2-b2-c2-d2-e2-f2, and the coordinates of the single tooth profile in the second rotor in the order of the curve points a1-b1-c1-d1-e1-f1. It should be noted that the coordinate data points of the profile that can be generated by arranging different gaps may also be different. In addition, the lengths of the tooth profiles of the yin and yang rotors may be different, and thus the number of coordinate data points of the profile derived based on the same gap may also be different. In addition, this embodiment can be scaled proportionally to obtain other embodiments.

[0109] The single tooth profile of the first rotor and the single tooth profile of the second rotor in the present application both include a multi-segment curved segment structure, and the multi-segment curved segments transition smoothly and connect tangentially. The overall profile adopts a fluid dynamics design, which enables the first rotor and the second rotor to achieve better meshing during operation, can withstand small pressure ratios and large pressure differences, can reduce inter-tooth leakage, and thus improve compression efficiency. According to the second aspect of the present application, a mechanical device is also provided, including the twin-screw rotor in the above embodiment. The mechanical device of the present application can be used for a compressor or an expander.

[0110] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0111] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0112] The embodiments, implementation methods and related technical features of the present application can be combined and replaced with each other without conflict.

[0113] The above are merely preferred embodiments of the present application and do not constitute any form of limitation to the present application. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A twin-screw rotor, characterized in that: include: A first rotor (10) and a second rotor (20) meshing with each other; The single tooth profile of the first rotor (10) comprises an elliptical arc segment, a hyperbola segment, a first circular arc envelope segment, a second circular arc segment, and a third circular arc segment that are smoothly connected in sequence; The single tooth profile of the second rotor (20) comprises an elliptical arc envelope segment, a hyperbolic envelope segment, a first circular arc segment, a second circular arc envelope segment, and a fourth circular arc segment that are smoothly connected in sequence.

2. The twin-screw rotor according to claim 1, characterized in that The number of teeth of the first rotor (10) is M, and the number of teeth of the second rotor (20) is N, satisfying: M>N, and MN≤2.

3. The twin-screw rotor according to claim 2, characterized in that The torsion angle α of the second rotor (20) satisfies 280°≤α≤325°; The torsion angle β of the first rotor (10) satisfies β=α*N / M.

4. The twin-screw rotor according to claim 2, characterized in that The torsion angle α of the second rotor (20) satisfies 300°≤α≤310°; The torsion angle β of the first rotor (10) satisfies β=α*N / M.

5. The twin-screw rotor according to claim 1, wherein The major semi-axis of the ellipse corresponding to the elliptical arc segment is located on the line connecting the starting point of the elliptical arc segment and the center of the pitch circle of the first rotor (10), or, The minor semi-axis of the ellipse corresponding to the ellipse arc segment is located on a line connecting the starting point of the ellipse arc segment and the center of the pitch circle of the first rotor (10).

6. The twin-screw rotor according to claim 5, characterized in that The length m of the major semi-axis of the ellipse satisfies 0.08*A≤m≤0.1*A, wherein A represents the distance between the center of the pitch circle of the first rotor (10) and the center of the pitch circle of the second rotor (20); The length n of the minor semi-axis of the ellipse satisfies 0.04*A≤n≤0.05*A, wherein A represents the distance between the center of the pitch circle of the first rotor (10) and the center of the pitch circle of the second rotor (20).

7. The twin-screw rotor according to claim 1, characterized in that The focus of the hyperbola segment is located on a line connecting the center of the pitch circle of the first rotor (10) and the center of the pitch circle of the second rotor (20).

8. The twin-screw rotor according to claim 1, wherein The center of the circle corresponding to the first arc segment is located on a line connecting the center of the pitch circle of the first rotor (10) and the center of the pitch circle of the second rotor (20).

9. The twin-screw rotor according to claim 8, characterized in that The arc radius r1 corresponding to the first arc segment satisfies 0.025*A≤r1≤0.065*A, wherein A represents the distance between the center of the pitch circle of the first rotor (10) and the center of the pitch circle of the second rotor (20).

10. The twin-screw rotor according to claim 1, wherein The center of the circle corresponding to the second arc segment is located on the line connecting the end point of the second arc segment and the center of the pitch circle of the first rotor (10).

11. The twin-screw rotor according to claim 10, characterized in that The arc radius r2 corresponding to the second arc segment satisfies 0.025*A≤r2≤0.065*A, wherein A represents the distance between the center of the pitch circle of the first rotor (10) and the center of the pitch circle of the second rotor (20).

12. The twin-screw rotor according to claim 1, wherein The center of the circle corresponding to the third arc segment is located at the center of the pitch circle of the first rotor (10).

13. The twin-screw rotor according to claim 12, characterized in that The arc center angle δ corresponding to the third arc segment satisfies 0°≤t2≤10°.

14. The twin-screw rotor according to claim 1, wherein The center of the circle corresponding to the fourth arc segment is located at the center of the pitch circle of the second rotor (20).

15. The twin-screw rotor according to claim 2, characterized in that The number of teeth of the first rotor (10) is at least six, The number of teeth of the second rotor (20) is at least five.

16. A mechanical device, characterized in that: Comprising the twin-screw rotor according to any one of claims 1 to 15.

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