A calculation method for the tooth profile of the inner and outer rotors of a multi-arc compound cycloid rotor pump

Abstract

The present invention discloses a method for calculating the tooth profile of inner and outer rotors of a multi-arc composite cycloid rotor pump, comprising the following steps: inputting design parameters; calculating outer rotor size parameters; calculating outer rotor tooth profile coordinate sequence; calculating coordinate conversion matrix; calculating inner rotor tooth profile coordinate sequence A2B2, B2C2, C2D2; calculating inner rotor tooth profile coordinate sequence E2F2, F2G2; calculating inner rotor tooth profile intersection points; deleting redundant curves; calculating a complete outer rotor tooth profile curve; calculating a complete inner rotor tooth profile curve. The present invention can more easily calculate the various size parameters and inner and outer rotor tooth profile discrete points of a multi-arc cycloid rotor pump according to the input design parameters of the multi-arc cycloid rotor pump, and simultaneously solve the size design problem and the tooth profile calculation problem.

Description

Technical Field

[0001] The invention relates to the field of automobile cooling and lubrication system component design, and in particular to a method for calculating tooth profiles of inner and outer rotors of a multi-arc composite cycloid rotor pump with high volumetric efficiency and low machining accuracy requirements. Background Art

[0002] Cycloid rotor pumps are widely used in automotive cooling and lubrication systems due to their compact structure, stable operation, low pulsation, and high volumetric efficiency. Cycloid rotor pumps are mainly composed of inner and outer rotors, pump housings, pump covers, and other parts. The inner rotor is driven by the driving shaft and drives the outer rotor to rotate in the same direction. The cavity between the inner and outer rotors gradually increases on the oil inlet side, forming a vacuum to complete oil suction. On the oil discharge side, the cavity gradually decreases, generating a relatively high pressure to discharge the oil.

[0003] The inner and outer rotors of the cycloid rotor pump mesh at multiple points during the rotation process, so the machining accuracy of the inner and outer rotors is high and they are prone to wear. To address this problem, improvements are usually made to their profiles. Among them, the multi-arc composite cycloid rotor pump is a cycloid rotor pump with a special profile rotor. Compared with the traditional arc-cycloid rotor pump, it has fewer meshing points of the inner and outer rotors, so it has lower machining accuracy requirements and is not easy to wear. However, the prior art (Theoretical Analysis of an Original Rotary Machine) has the following problems: 1) The tooth profiles of the inner and outer rotors of the multi-arc cycloid rotor pump are complex and difficult to design and calculate. At present, there is no more convenient method for calculating the tooth profile at home and abroad; 2) The actual meshing trajectory of the inner and outer rotors cannot be calculated, resulting in the inability to determine the sealing oil line angle of the subsequent inlet and outlet oil chambers, and there is a risk of leakage in the inlet and outlet oil chambers; 3) The existing design method needs to calculate the formula curves of each tooth profile of the inner and outer rotors, and calculate the curve parameters, which is cumbersome when modeling using three-dimensional software. Summary of the invention

[0004] The technical problem solved by the present invention is: to provide a method for calculating the tooth profile profile of the inner and outer rotors of a multi-arc compound cycloid rotor pump, which is used to design and calculate the tooth profile profile of the inner and outer rotors of the multi-arc compound cycloid rotor pump. The method can calculate the tooth profile profile of the inner and outer rotors according to the input design parameters, and obtain the actual meshing trajectory of the inner and outer rotors and the tooth profile spline points of the inner and outer rotors with specified accuracy during the calculation process.

[0005] In order to achieve the purpose of the present invention, the present invention provides a method for calculating the tooth profile of the inner and outer rotors of a multi-arc compound cycloid rotor pump, comprising the following steps:

[0006] (1) Input design parameters, which include eccentricity e, tooth thickness coefficient k, side tooth profile circular position angle θ, top tooth profile circular arc radius r a、Radius of fillet arc r c , number of teeth of inner rotor z1, outer diameter of outer rotor r o and tooth root thickness d m ;

[0007] (2) Calculate the outer rotor size parameters and calculate the side tooth arc radius r based on the input design parameters and geometric relationships b , calculate the center of the top tooth arc O a , Side tooth arc center O b 、Rounded corner arc center O c The coordinates of are (x oa ,y oa )、(x ob ,y ob )、(x oc ,y oc );

[0008] (3) Calculate the coordinate sequence of the outer rotor tooth profile: The three arcs on the half tooth profile of the outer rotor: the top tooth arc Rounded Arc Side tooth arc Discretize into n1, n2, n3 points respectively, and obtain the position angle φ of all points on half of the outer rotor tooth profile a (1)~π a (n1),φ c (1)~φ c (n2),φ b (1)~φ b (n3), and then calculate the outer rotor tooth profile coordinate sequence r P1 (1)~r P1 (n1), r P2 (1)~r p2 (n2), r p3 (1)~r p3 (n3), where point A is the symmetric point of the tooth profile and the starting point of the top tooth profile arc coordinate sequence r P1 (1), point B is the intersection of the top tooth shape arc and the fillet arc, point C is the intersection of the side tooth shape arc and the fillet arc, and point D is the end point of the side tooth shape circle coordinate sequence;

[0009] (4) The coordinate transformation matrix from the point on the outer rotor to the point on the inner rotor and the coordinate transformation matrix from the outer rotor rotating coordinate system to the fixed coordinate system are calculated through the motion relationship between the inner and outer rotors:

[0010] (5) Calculate the inner rotor tooth profile coordinate sequence A2B2, B2C2, C2D2: Using the outer rotor tooth profile coordinate sequence in step (3), calculate the corresponding inner rotor tooth profile A2B2, B2C2, C2D2 coordinate sequence r by equations (1a) and (1b) respectively: Q1(1)~r Q1 (n1), r Q2 (1)~r Q2 (n2), r Q3 (1)~r Q3 (n3):

[0011] r c1 =M 12 r c2 (1a);

[0012] r cf =M f2 r c2 (1b);

[0013] r c1 、r c2 、r cf The coordinates of the corresponding points on the inner rotor tooth profile, outer rotor tooth profile, and meshing trajectory are calculated to calculate the corresponding outer rotor rotation angle sequence. And calculate the corresponding theoretical meshing point trajectory coordinate sequence r S1 (1)~r S1 (n1), r S2 (1)~r S2 (n2), r S3 (1)~r S3 (n3);

[0014] (6) Calculate the inner rotor tooth profile coordinate sequence E2F2, F2G2: Calculate the inner rotor tooth profile E2F2, F2G2 coordinate sequence r by equations (1a) and (1b): Q4 (1)~r Q4 (n2), r Q5 (1)~r Q5 (n1), calculate the corresponding outer rotor angle sequence Calculate the corresponding meshing point trajectory coordinate sequence r S4 (1)~r S4 (n2), r S5 (1)~r S5 (n1);

[0015] (7) Calculate the intersection point of the inner rotor tooth profile: Calculate the serial number m1 corresponding to the intersection point H2 of C2D2 and E2F2 on C2D2 and the serial number m2 corresponding to E2F2 according to the method of calculating the intersection point of the curve;

[0016] (8) Delete redundant curves: Delete the inner rotor coordinate sequence r corresponding to the inner rotor tooth profiles E2H2 and D2H2. Q3 (m1+1)~r Q3 (n3), r Q4 (m2+1)~rQ4 (n2), get the actual half tooth profile of the inner rotor, delete the corresponding meshing point trajectory coordinate sequence r S3 (m1+1)~r S3 (n3), r S4 (m2+1)~r S4 (n2), get the actual meshing point trajectory;

[0017] (9) Calculate the complete outer rotor tooth profile curve: Based on the obtained outer rotor half tooth profile curve Get the complete outer rotor tooth profile;

[0018] (10) Calculate the complete inner rotor tooth profile curve: Based on the half tooth profile curve of the inner rotor obtained in step (8), the complete inner rotor tooth profile is obtained.

[0019] Furthermore, in step (1), a circle is drawn with the center of the outer rotor as the center and the radius of the inner rotor tooth top circle as the radius, and the intersection with the side tooth profile circle is recorded as Q, and the angle between the line connecting the center of the side tooth profile circle and Q and the horizontal line is defined as the side tooth profile circle position angle. The top tooth profile arc refers to the tooth profile arc at the top of the single tooth profile of the outer rotor. The fillet arc refers to the arc of the single tooth profile of the outer rotor connecting the side tooth profile circle and the top tooth profile circle.

[0020] Further, in step (3), the outer rotor tooth profile coordinate sequence r is calculated using the following formulas: P1 (1)~r P1 (n1), r P2 (1)~r p2 (n2), r p3 (1)~r p3 (n3):

[0021]

[0022]

[0023]

[0024] In the formula, φ a ,φ c ,φ b They are the angles between the line connecting a point on the top tooth arc, corner arc and side tooth arc and the center of the arc on which they are located and the horizontal line.

[0025] Furthermore, in step (3), φ a ,φ b ,φ c The ranges are:

[0026]

[0027]

[0028]

[0029] Among them, x ac ,y ac is the horizontal and vertical coordinates of point B on the outer rotor tooth profile, x bc ,y bc is the horizontal and vertical coordinates of point C on the outer rotor tooth profile, x be ,y be are the horizontal and vertical coordinates of point D on the outer rotor tooth profile.

[0030] Furthermore, in step (4), the inner and outer rotor rotation coordinate systems are first established respectively, and the points on the outer rotor tooth profile become meshing points in sequence during the outer rotor rotation process. The meshing points are located on the outer rotor and inner rotor tooth profiles at the same time, and the meshing points are obtained.

[0031]

[0032]

[0033] Where M 12 is the coordinate transformation matrix from the point on the outer rotor to the point on the inner rotor, M f2 is the coordinate transformation matrix from the outer rotor rotating coordinate system to the fixed coordinate system, is the angle that the inner rotor rotates when a certain point on the inner rotor tooth profile becomes the meshing point, It is the angle that the outer rotor rotates when a certain point on the outer rotor tooth profile becomes the meshing point.

[0034] Furthermore, in step (5) and step (6), the motion trajectory of the meshing point on the outer rotor is "ABCDCBA". Therefore, when the outer rotor rotates 180°, the top tooth arc and the fillet arc mesh twice respectively, and the corresponding inner rotor also has two sections. Corresponding to the inner rotor tooth profile A2B2, F2G2, rounded arc Corresponding to the inner rotor tooth profiles B2C2 and E2F2.

[0035] Further, in step (9), the half tooth profile of the outer rotor is obtained After mirroring and array operations, the complete outer rotor tooth profile can be obtained.

[0036] Furthermore, in step (10), the half tooth profile of the inner rotor obtained in step (8) is subjected to mirroring and array operations to obtain a complete tooth profile of the inner rotor.

[0037] Furthermore, in step (5), the outer rotor angle Angle φ with meshing point aThe relationship is determined as follows:

[0038] When the meshing point is on the outer rotor top tooth arc When the inner rotor tooth profile is A2B2, the outer rotor angle Angle φ with meshing point a The relationship is:

[0039]

[0040] When the meshing point is on the outer rotor fillet arc When the inner rotor tooth profile is B2C2, the outer rotor angle Angle φ with meshing point b The relationship is:

[0041]

[0042] When the meshing point is on the outer rotor side tooth arc When the inner rotor tooth profile C2D2 is on, the outer rotor angle Angle φ with meshing point c The relationship is:

[0043]

[0044] Among them, Z2 refers to the number of teeth on the outer rotor.

[0045] Further, in step (6), the outer rotor angle Angle φ with meshing point a The relationship is determined as follows:

[0046] When the meshing point is on the outer rotor top tooth arc When the inner rotor tooth profile F2G2 is on, the outer rotor angle Angle φ with meshing point a The relationship is:

[0047]

[0048] When the meshing point is on the outer rotor fillet arc When the inner rotor tooth profile is E2F2, the outer rotor angle Angle φ with meshing point b The relationship is:

[0049]

[0050] Among them, Z2 refers to the number of teeth on the outer rotor.

[0051] Compared with the prior art, the present invention has at least the following beneficial effects:

[0052] 1) The present invention proposes a method for calculating the tooth profile of the inner and outer rotors of a multi-arc compound cycloid rotor pump, which solves the problem that the tooth profile of the inner and outer rotors of the multi-arc compound cycloid rotor pump is difficult to calculate, and can effectively improve the high processing accuracy requirements of the inner and outer rotors.

[0053] 2) The present invention can obtain the actual meshing trajectory of the inner and outer rotors and the angular range of the inner and outer rotors when they are meshing, providing data support for the subsequent sealing design of the oil inlet and outlet chambers, making it easier to manufacture a more efficient cycloid rotor pump.

[0054] 3) The inner and outer rotor tooth profiles obtained by the present invention are discrete points, which can be directly imported into the modeling software for sketching after selecting the accuracy as needed, thus saving the time cost of modeling. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a flow chart of a method for calculating the tooth profile of the inner and outer rotors of a multi-arc compound cycloid rotor pump provided in an embodiment of the present invention.

[0056] Figure 2 It is a schematic diagram of the size parameters of the multi-arc compound cycloid rotor pump in the present invention.

[0057] FIG. 3( a ) is a schematic diagram of the tooth profile and position angle of the outer rotor in the present invention.

[0058] FIG3( b ) is a partial enlarged view of the schematic diagram of the tooth profile and position angle of the outer rotor in the present invention.

[0059] Figure 4 It is a schematic diagram of the inner and outer rotor coordinate system in the present invention.

[0060] Figure 5 It is a schematic diagram of the tooth profile of the inner and outer rotors in the present invention.

[0061] FIG. 6( a ) is a diagram showing the theoretical meshing trajectories of the inner and outer rotors of the multi-arc compound cycloid rotor pump of the present invention.

[0062] FIG. 6( b ) is a diagram showing the actual meshing trajectories of the inner and outer rotors of the multi-arc compound cycloid rotor pump of the present invention. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0064] See also Figure 1The present invention provides a method for calculating the tooth profile of the inner and outer rotors of a multi-arc compound cycloid rotor pump, comprising the following steps:

[0065] Step 1: Input design parameters, including the eccentricity e of the inner rotor and the outer rotor, the tooth thickness coefficient k, the side tooth profile circular position angle θ, and the top tooth profile circular arc radius r a 、Radius of fillet arc r c , number of teeth of inner rotor z1, outer diameter of outer rotor r o , tooth root thickness d m .

[0066] In some embodiments of the present invention, the eccentricity e, the outer diameter r of the outer rotor o and tooth root thickness d m Meaning of reference Figure 2 , the eccentricity e is the distance between the inner and outer rotor centers, and the outer diameter r of the outer rotor o is the outer radius of the outer rotor, the tooth root thickness d m is the distance from the outer circle of the outer rotor to the root circle of the outer rotor teeth. Referring to Figure 3(a), the side tooth profile arc is the tooth profile arc on the side of the single tooth profile of the outer rotor. Its position angle θ is used to indicate the center position of the tooth profile circle. The definition is as follows: a circle is made with the center of the outer rotor as the center and the radius of the inner rotor tooth top circle as the radius. The intersection with the side tooth profile circle is marked as Q. The angle between the line connecting the center of the side tooth profile circle and Q and the horizontal line is defined as the side tooth profile circle position angle. The top tooth profile arc refers to the tooth profile arc at the top of the single tooth profile of the outer rotor. The fillet arc refers to the arc connecting the side tooth profile circle and the top tooth profile circle of the single tooth profile of the outer rotor.

[0067] Step 2: Calculate the outer rotor size parameters.

[0068] In some embodiments of the present invention, the side tooth profile arc radius r is calculated based on the input design parameters and geometric relationships. b , and calculate the center O of the top tooth arc a , Side tooth arc center O b 、Rounded corner arc center O c The coordinates of are (x oa ,y oa )、(x ob ,y ob )、(x oc ,y oc ). The center of the top tooth arc is O a , Side tooth arc center O b 、Rounded corner arc center O c 3(b), they are the centers of the top tooth arc, the side tooth arc and the fillet arc respectively.

[0069] Step 3: Calculate the coordinate sequence of the outer rotor tooth profile: The three arcs on the half tooth profile of the outer rotor: the top tooth arc Rounded Arc Side tooth arc Discretize into n1, n2, and n3 points respectively, and obtain the position angle φ of all points on the half tooth profile of the outer rotor a (1)~φ a (n1),φ c (1)~φ c (n2),φ b (1)~φ b (n3).φ a (1)~φ a (n1),φ c (1)~φ c (n2),φ b (1)~φ b (n3) are The position angle φ of all discrete points on a (1)φ a (2)…φ a (n1),φ c (1)φ c (2)…φ c (n2),φ b (1)φ b (2)…φ b (n3), that is, the sequence formed by the angles between the lines connecting all discrete points and the center of the arc where they are located and the horizontal line.

[0070] In some embodiments of the present invention, the corresponding outer rotor tooth profile coordinate sequence r is calculated according to equations (1), (2) and (3). P1 (1)~r P1 (n1), r P2 (1)~r p2 (n2), r p3 (1)~r p3 (n3);φ a ,φ c ,φ b The meanings are the angles between the line connecting a point on the top tooth arc, corner arc and side tooth arc and the center of the arc on which they are located and the horizontal line.

[0071]

[0072]

[0073]

[0074] Among them, φ a ,φb ,φ c The ranges are:

[0075]

[0076]

[0077]

[0078] Step 4: Calculate the coordinate transformation matrix.

[0079] In some embodiments of the present invention, reference is made to Figure 4 Establish the rotating coordinate systems of the inner and outer rotors respectively: establish the fixed coordinate system O1-x with the inner rotor center O1 as the origin f y f and O1-x1y1, and establish the outer rotor rotating coordinate system O2-x2y2 with the outer rotor center O2 as the origin. O1-x1y1 is fixedly connected to the inner rotor and rotates with the inner rotor. O2-x2y2 is fixedly connected to the outer rotor and rotates with the outer rotor. Since the points on the outer rotor tooth profile become meshing points in turn during the rotation of the outer rotor, the meshing points are located on the outer rotor and inner rotor tooth profiles at the same time. Therefore, the coordinate transformation matrix M from the points on the outer rotor to the points on the inner rotor can be calculated through the kinematic relationship between the inner and outer rotors. 12 And the coordinate transformation matrix M from the outer rotor rotating coordinate system to the fixed coordinate system f2 :

[0080]

[0081]

[0082] In the formula, is the angle that the inner rotor rotates when a certain point on the inner rotor tooth profile becomes the meshing point, It is the angle that the outer rotor rotates when a certain point on the outer rotor tooth profile becomes the meshing point.

[0083] Step 5: Calculate the inner rotor tooth profile coordinate sequence A2B2, B2C2, C2D2.

[0084] In some embodiments of the present invention, the motion trajectory of the meshing point on the outer rotor is "ABCDCBA". Therefore, when the outer rotor rotates 180°, the top tooth arc and the fillet arc mesh twice respectively, and the corresponding inner rotor also has two sections. The corresponding inner rotor tooth profile is A2B2, F2G2, with rounded corners and arcs The corresponding inner rotor tooth profile is B2C2, E2F2, and the side tooth profile is arc The corresponding inner rotor tooth profile is C2D2.

[0085] Using the outer rotor tooth profile coordinate sequence obtained in step 3, the corresponding inner rotor tooth profile A2B2, B2C2, C2D2 coordinate sequence r is calculated by equations (1a) and (1b): Q1 (1)~r Q1 (n1), r Q2 (1)~r Q2 (n2), r Q3 (1)~r Q3 (n3). Point A is the symmetry point of the tooth profile and the starting point of the coordinate sequence r P1 (1), point B is the intersection of the top tooth profile arc and the fillet arc, point C is the intersection of the side tooth profile arc and the fillet arc, and point D is the end point of the side tooth profile circle coordinate sequence.

[0086] r c1 =M 12 r c2 (1a)

[0087] r cf =M f2 r c2 (1b)

[0088] r c1 With r c2 、r cf are the coordinates of the corresponding points on the inner rotor tooth profile, outer rotor tooth profile and meshing trajectory respectively. Calculate the corresponding (Formula (7) corresponds to Formula (8) corresponds to Formula (9) corresponds to Outer rotor angle sequence The corresponding theoretical meshing point trajectory coordinate sequence r is calculated by equations (5a) and (5b): S1 (1)~r S1 (n1), r S2 (1)~r S2 (n2), r S3 (1)~r S3 (n3).

[0089] When the meshing point is on the outer rotor top tooth arc When the inner rotor tooth profile is A2B2, the outer rotor angle Angle φ with meshing point a The relationship is:

[0090]

[0091] Among them, Z2 refers to the number of teeth on the outer rotor.

[0092] When the meshing point is on the outer rotor fillet arc When the inner rotor tooth profile is B2C2, the outer rotor angle Angle φ with meshing point b The relationship is:

[0093]

[0094] When the meshing point is on the outer rotor side tooth arc When the inner rotor tooth profile C2D2 is on, the outer rotor angle Angle φ with meshing point c The relationship is:

[0095]

[0096] Step 6: Calculate the inner rotor tooth profile coordinate sequence E2F2, F2G2: Calculate the inner rotor tooth profile E2F2, F2G2 coordinate sequence r by formula (16): Q4 (1)~r Q4 (n2), r Q5 (1)~r Q5 (n1). The corresponding outer rotor angle sequence is calculated by equations (10) and (11): The corresponding meshing point trajectory coordinate sequence is calculated by equations (1a) and (1b): S4 (1)~r S4 (n2), r S5 (1)~r S5 (n1), and obtain the theoretical meshing trajectory 603.

[0097] When the meshing point is on the outer rotor top tooth arc When the inner rotor tooth profile F2G2 is on, the outer rotor angle Angle φ with meshing point a The relationship is:

[0098]

[0099] When the meshing point is on the outer rotor fillet arc When the inner rotor tooth profile is E2F2, the outer rotor angle Angle φ with meshing point b The relationship is:

[0100]

[0101] Step 7: Calculate the intersection of the inner rotor tooth profile: Calculate the serial number m1 corresponding to the intersection point H2 of C2D2 and E2F2 on C2D2 and the serial number m2 corresponding to E2F2 according to the method of calculating the intersection of curves.

[0102] Step 8: Delete redundant curves: Delete the inner rotor coordinate sequence r corresponding to the inner rotor tooth profiles E2H2 and D2H2Q3 (m1+1)~r Q3 (n3), r Q4 (m2+1)~r Q4 (n2), get the actual half tooth profile of the inner rotor. Delete the corresponding meshing point trajectory coordinate sequence r S3 (m1+1)~r S3 (n3), r S4 (m2+1)~r S4 (n2), and obtain the actual meshing point trajectory 604.

[0103] Step 9: Get the complete outer rotor tooth profile curve: Obtain the half outer rotor tooth profile curve obtained in step 3 After mirroring and array operations, a complete outer rotor tooth profile 602 is obtained;

[0104] Step 10: Obtaining a complete inner rotor tooth profile curve: The half inner rotor tooth profile curve obtained in step 8 is subjected to mirroring and array operations to obtain a complete inner rotor tooth profile 601.

[0105] By adopting the method of the present invention, various dimensional parameters and discrete points of the inner and outer rotor tooth profiles of the multi-arc cycloid rotor pump can be calculated more simply according to the input design parameters of the multi-arc cycloid rotor pump, and the dimensional design problem and the tooth profile calculation problem are solved at the same time; in the calculation of the inner and outer rotor tooth profiles, the actual meshing trajectories of the inner and outer rotors and the angular range of the inner and outer rotors when they are meshed can be obtained, providing data support for the subsequent seal design of the inlet and outlet oil chambers; the calculated inner and outer rotor tooth profiles are discrete points, which can be directly imported into the modeling software for sketching after the accuracy is selected as needed, saving the time cost of modeling.

[0106] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for calculating the tooth profile of the inner and outer rotors of a multi-arc compound cycloid rotor pump, characterized in that: The following steps are involved: (S1) Input design parameters, wherein the design parameters include eccentricity e, tooth thickness coefficient k, side tooth profile circular position angle θ, top tooth profile circular arc radius r a 、Radius of fillet arc r c , number of teeth on the inner rotor z1, outer diameter of the outer rotor r o and tooth root thickness d m ; A circle is constructed with the center of the outer rotor as the center and the radius of the inner rotor tooth top circle as the radius. The intersection point with the side tooth profile circle is recorded as Q. The angle between the line connecting the center of the side tooth profile circle and Q and the horizontal line is defined as the side tooth profile circle position angle. The top tooth profile arc refers to the tooth profile arc at the top of the single tooth profile of the outer rotor. The fillet arc refers to the arc of the single tooth profile of the outer rotor connecting the side tooth profile circle and the top tooth profile circle. (S2) Calculate the outer rotor size parameters and calculate the side tooth arc radius r based on the input design parameters and geometric relationships b , calculate the center of the top tooth arc O a , Side tooth arc center O b 、Rounded corner arc center O c The coordinates of are (x oa ,y oa )、(x ob ,y ob )、(x oc ,y oc ); (S3) Calculate the coordinate sequence of the outer rotor tooth profile: The three arcs on the half tooth profile of the outer rotor: the top tooth arc Rounded Arc Side tooth arc Discretize into n1, n2, n3 points respectively, and obtain the position angle φ of all points on half of the outer rotor tooth profile a (1)~φ a (n1),φ c (1)~φ c (n2),φ b (1)~φ b (n3), and then calculate the outer rotor tooth profile coordinate sequence r p1 (1)~r p1 (n1), r p2 (1)~r p2 (n2), r p3 (1)~r p3 (n3), where point A is the symmetric point of the tooth profile and the starting point of the top tooth profile arc coordinate sequence r p1 (1), point B is the intersection of the top tooth shape arc and the fillet arc, point C is the intersection of the side tooth shape arc and the fillet arc, and point D is the end point of the side tooth shape circle coordinate sequence; The outer rotor tooth profile coordinate sequence r is calculated using the following formulas: p1 (1)~r p1 (n1), r p2 (1)~r p2 (n2), r p3 (1)~r p3 (n3): In the formula, , , They are the angles between the line connecting a point on the top tooth arc, the fillet arc and the side tooth arc and the center of the arc where they are located and the horizontal line; (S4) Calculate the coordinate transformation matrix from the points on the outer rotor to the points on the inner rotor and the coordinate transformation matrix from the outer rotor rotating coordinate system to the fixed coordinate system through the motion relationship between the inner and outer rotors: First, establish the inner and outer rotor rotating coordinate systems respectively. The points on the outer rotor tooth profile become meshing points in turn during the rotation of the outer rotor. The meshing points are located on the tooth profiles of the outer rotor and the inner rotor at the same time. Where M 12 is the coordinate transformation matrix from the point on the outer rotor to the point on the inner rotor, M f2 is the coordinate transformation matrix from the outer rotor rotating coordinate system to the fixed coordinate system, is the angle that the inner rotor rotates when a certain point on the inner rotor tooth profile becomes the meshing point, It is the angle that the outer rotor rotates when a certain point on the outer rotor tooth profile becomes the meshing point; (S5) The motion trajectory of the meshing point on the outer rotor is "ABCDCBA". Therefore, when the outer rotor rotates 180°, the top tooth arc and the fillet arc mesh twice respectively, and the corresponding inner rotor also has two sections. Corresponding to the inner rotor tooth profile A2B2, F2G2, rounded arc Corresponding to the inner rotor tooth profile B2C2, E2F2; Calculate the inner rotor tooth profile coordinate sequence A2B2, B2C2, C2D2: Using the outer rotor tooth profile coordinate sequence in step (S3), the corresponding inner rotor tooth profile A2B2, B2C2, C2D2 coordinate sequence r is calculated by equations (1a) and (1b) respectively Q1 (1)~r Q1 (n1), r Q2 (1)~r Q2 (n2), r Q3 (1)~r Q3 (n3): r c1 =M 12 r c2 (1a); r cf =M f2 r c2 (1b); r c1 、r c2 、r cf The coordinates of the corresponding points on the inner rotor tooth profile, outer rotor tooth profile, and meshing trajectory are calculated to calculate the corresponding outer rotor rotation angle sequence. And calculate the corresponding theoretical meshing point trajectory coordinate sequence r S1 (1)~r S1 (n1), r S2 (1)~r S2 (n2), r S3 (1)~r S3 (n3); M 12 is the coordinate transformation matrix from the point on the outer rotor to the point on the inner rotor, M f2 The coordinate transformation matrix from the outer rotor rotating coordinate system to the fixed coordinate system; (S6) Calculate the inner rotor tooth profile coordinate sequence E2F2, F2G2: Calculate the inner rotor tooth profile E2F2, F2G2 coordinate sequence r by equations (1a) and (1b) Q4 (1)~r Q4 (n2), r Q5 (1)~r Q5 (n1), calculate the corresponding outer rotor angle sequence Calculate the corresponding meshing point trajectory coordinate sequence r S4 (1)~r S4 (n2), r S5 (1)~r S5 (n1); (S7) Calculating the intersection of the inner rotor tooth profile: Calculate the serial number m1 corresponding to the intersection H2 of C2D2 and E2F2 on C2D2 and the serial number m2 corresponding to E2F2 according to the method of calculating the intersection of curves; (S8) Delete redundant curves: Delete the inner rotor coordinate sequence r corresponding to the inner rotor tooth profiles E2H2 and D2H2 Q3 (m1+1)~r Q3 (n3), r Q4 (m2+1)~r Q4 (n2), get the actual half tooth profile of the inner rotor, delete the corresponding meshing point trajectory coordinate sequence r S3 (m1+1)~r S3 (n3), r S4 (m2+1)~r S4 (n2), get the actual meshing point trajectory line; (S9) Calculate the complete outer rotor tooth profile curve: Based on the obtained outer rotor half tooth profile curve Get the complete outer rotor tooth profile; (S10) Calculating the complete inner rotor tooth profile curve: Obtaining the complete inner rotor tooth profile based on the half inner rotor tooth profile curve obtained in step (S8).

2. The method for calculating the tooth profile of the inner and outer rotors of a multi-arc compound cycloid rotor pump according to claim 1, characterized in that: In step (S3) , , The ranges are: Among them, x ac ,y ac is the horizontal and vertical coordinates of point B on the outer rotor tooth profile, x bc ,y bc is the horizontal and vertical coordinates of point C on the outer rotor tooth profile, x be ,y be are the horizontal and vertical coordinates of point D on the outer rotor tooth profile.

3. The method for calculating the tooth profile of the inner and outer rotors of a multi-arc compound cycloid rotor pump according to claim 1, characterized in that: In step (S9), the half tooth profile of the outer rotor is obtained. After mirroring and array operations, the complete outer rotor tooth profile can be obtained.

4. The method for calculating the tooth profile of the inner and outer rotors of a multi-arc compound cycloid rotor pump according to claim 1, characterized in that: In step (S10), the half tooth profile of the inner rotor obtained in step (S8) is subjected to mirroring and array operations to obtain a complete tooth profile of the inner rotor.

5. The method for calculating the tooth profile of the inner and outer rotors of a multi-arc compound cycloid rotor pump according to claim 1, characterized in that: In step (S5), and The relationship is determined as follows: When the meshing point is on the outer rotor top tooth arc When the inner rotor tooth profile is A2B2, and The relationship is: When the meshing point is on the outer rotor fillet arc When the inner rotor tooth profile is B2C2, and The relationship is: When the meshing point is on the outer rotor side tooth arc When the inner rotor tooth profile C2D2 is on, and The relationship is: Among them, Z2 refers to the number of teeth on the outer rotor.

6. The method for calculating the tooth profile of the inner and outer rotors of a multi-arc compound cycloid rotor pump according to any one of claims 1 to 5, characterized in that: Step (S6), and The relationship is determined as follows: When the meshing point is on the outer rotor top tooth arc When the inner rotor tooth profile F2G2 is on, and The relationship is: When the meshing point is on the outer rotor fillet arc When the inner rotor tooth profile is E2F2, and The relationship is: Among them, Z2 refers to the number of teeth on the outer rotor.

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