Molded line design method of wear-resistant elastoplastic body plum blossom pump

Abstract

The invention discloses a molded line design method of a wear-resistant elastoplastic body plum pump. The molded line design method comprises the following steps: S1, designing molded line parameters; s2, designing an outer rotor; s3, designing an inner rotor; and S4, conjugating and meshing the inner rotor and the outer rotor to form a quincunx pump profile. According to the steps of the design method, the characteristic that the involute is adopted for accurate conjugate meshing and point contact at the position where the rotor contact stress is maximum, the sealing requirement is highest and the movement is most complex can be achieved, compared with line contact of other molded lines, friction abrasion between the rotors is reduced, and under the working condition of high-pressure conveying, the service life of the rotors is prolonged. The sealing effect with the inner wall of the pump body is good, lasting and stable conveying pressure is guaranteed, pulsation is reduced, and working efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of positive displacement pump profile design technology, and in particular to a profile design method for a wear-resistant elasto-plastic body plum blossom pump. Background Technology

[0002] In data center thermal management systems and liquid cooling solutions, the reliability, efficiency, and stability of fluid transport equipment (such as pumps) are crucial. These applications typically require pumps to operate stably under high pressure for extended periods, while also exhibiting low vibration and low noise characteristics to ensure that the working environment of precision electronic equipment remains undisturbed.

[0003] Existing pumps used in this field, such as common gear pumps and vane pumps, often employ cycloidal, circular, or a combination thereof profiles for their core component rotors. These traditional profiles are designed with line contact in mind, aiming for better sealing. However, in actual operation, especially in areas with the highest rotor contact stress, the most stringent sealing requirements, and the most complex movements, line contact can lead to the following significant problems: 1. Severe friction and wear: The line contact design results in a large specific pressure over the contact area. Especially under high-pressure transmission conditions, the friction and wear between rotors are aggravated, which not only reduces the service life of the pump and increases maintenance costs, but also the particles generated by wear may contaminate the transported medium, posing a threat to the precision cooling system of the data center.

[0004] 2. Pressure pulsation and vibration noise: During the meshing process, traditional profiles are prone to rapid changes in the closed volume, resulting in significant pulsations in outlet flow and pressure. These pressure pulsations can cause vibration and noise in the pipeline and system, which does not meet the requirements of data centers for a low-noise operating environment. At the same time, continuous pulsation impacts can also affect the structural integrity of the pump and its connecting components.

[0005] 3. Insufficient high-pressure sealing performance: With the pursuit of higher efficiency and the continuous increase in power density in data centers, pumps need to operate at higher output pressures. Traditional pump profiles may deform or wear under high pressure, leading to increased meshing clearance, reduced sealing effect, increased internal leakage, decreased volumetric efficiency, and difficulty in ensuring sustained stability of the delivery pressure. Summary of the Invention

[0006] The purpose of this invention is to provide a technical solution for the profile design method of a wear-resistant elasto-plastic body plum blossom pump, addressing the shortcomings of existing technologies. This design method not only utilizes the characteristics of precise conjugate meshing and point contact of involute curves at the points of highest rotor contact stress, highest sealing requirements, and most complex movement, reducing friction and wear between rotors compared to line contact of other profiles, but also provides a good sealing effect between the involute curve and the pump body wall under high-pressure conveying conditions, ensuring long-term stable conveying pressure, reducing pulsation, and improving working efficiency.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for designing the profile of a wear-resistant elasto-plastic composite plum blossom pump, characterized by the following steps: S1, Profile Parameter Design Determine the number of blades for the inner and outer rotors of the plum blossom pump, and design the profile design parameters for the inner and outer rotors. S2, External Rotor Design Based on the profile design parameters, the profile of the first worm claw of the outer rotor is designed. The first worm claw profile is composed of the circular arc segment AB, the circular arc segment BC, the transition cubic curve segment CD, the involute segment DE, the transition cubic curve segment EF, and the arc segment FG connected in sequence. The equation of the circular arc AB is: ; Where, θ 12 θ is a constant. 11 Let L1 be the straight-line distance from the center O of the base circle of the involute to the circular arc segment AB O1, and R1 be the radius of the circular arc segment AB. The equation of the circular arc BC is: ; Where, θ 21 θ is a constant. 22 Let L2 be the straight-line distance from the center O of the base circle of the involute to the center O2 of the arc segment BC, and R2 be the radius of the arc segment BC. The equation of the transition cubic curve segment CD is: ; Where a, b, c, and d are the equation coefficients of the outer rotor; The equation of the involute segment DE is: ; Where e is the eccentricity and t1 is the development angle of the involute; S3, Internal Rotor Design Based on the profile design parameters, the profile of the second worm claw of the inner rotor is designed. The profile of the second worm claw is composed of a circular arc segment ab, a circular arc segment bc, a transition cubic curve segment cd, an involute segment de, a transition cubic curve segment ef, and an arc segment fg connected in sequence. The equation of the circular arc segment ab is: ; Where, θ 12 θ is a constant. 11 Let L1 be the straight-line distance from the center O of the base circle of the involute to the circular arc segment AB O1, R1 be the radius of the circular arc segment AB, and e be the eccentricity. The equation of the circular arc segment bc is: ; Where, θ 21 θ is a constant. 22 Let L2 be the straight-line distance from the center O of the base circle of the involute to the center O2 of the arc segment BC, R2 be the radius of the arc segment BC, and e be the eccentricity. The equation of the transition cubic curve segment cd is: ; Where k is the scaling factor, (x0, y0) is the center of the scaling circle, and a, b, c, d are the equation coefficients of the outer rotor; The equation of the involute segment de is: ; Where e is the eccentricity, t1 is the involute development angle, and t2 is the involute development angle; S4, the conjugate meshing of the inner and outer rotors forms a plum blossom pump profile. The outer rotor is fixed in place, while the inner rotor moves eccentrically along the inner side of the outer rotor, forming the desired plum blossom pump profile through conjugate meshing.

[0008] This design method not only utilizes the precise conjugate meshing and point contact characteristics of involute curves at the points of greatest rotor contact stress, highest sealing requirements, and most complex motion, reducing friction and wear between rotors compared to line contact with other profiles, but also provides a good sealing effect with the pump body wall under high-pressure conveying conditions, ensuring long-term stable conveying pressure, reducing pulsation, and improving working efficiency.

[0009] Furthermore, the equation of the inner rotor's arc segment ab is obtained by translating the equation of the outer rotor's arc segment AB, and the equation of the inner rotor's arc segment bc is obtained by translating the equation of the outer rotor's arc segment BC.

[0010] Furthermore, the equation of the involute segment de differs from the equation of the involute segment DE by a phase difference.

[0011] Furthermore, the plum blossom pump profile is an axisymmetric structure.

[0012] Furthermore, a cubic curve is added between the involute segment DE and the circular arc segment BC to achieve a smooth transition; At point C: ; At point D: .

[0013] Furthermore, the equation for the transition cubic curve segment cd of the inner rotor is obtained through three steps, specifically including the following steps: (1) Translation of the coordinate system: Translate each point on the outer rotor so that the center (x0, y0) becomes the new origin of the coordinate system. ; (2) Proportional scaling: The translated coordinates are scaled proportionally. ; (3) Restoring the translation: The scaled coordinates are restored to the original coordinate system by restoring the translation. ; Substituting the transformation formula into the equation of the outer rotor: ; The equation for the transition cubic curve segment cd of the inner rotor is obtained by expansion: ; Where k is the scaling factor, (x0, y0) is the center of the scaling circle, and a, b, c, d are the equation coefficients of the outer rotor.

[0014] Furthermore, the equations for the transition cubic curve EF and arc segment FG on the outer rotor are derived in the same way as those for the transition cubic curve segment CD and the circular arc segment AB, and the equations for the transition cubic curve ef and arc segment fg on the inner rotor are derived in the same way as those for the transition cubic curve segment cd and the circular arc segment ab.

[0015] The present invention, by adopting the above-described technical solution, has the following beneficial effects: The design method of this invention not only utilizes the characteristics of precise conjugate meshing and point contact using involute curves at the points of greatest rotor contact stress, highest sealing requirements, and most complex motion, thus reducing friction and wear between rotors compared to line contact with other profiles, but also provides a good sealing effect with the pump body wall under high-pressure conveying conditions, ensuring long-term stable conveying pressure, reducing pulsation, and improving working efficiency. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings: Figure 1 This is a flowchart illustrating the profile design method for a wear-resistant elasto-plastic composite plum blossom pump according to the present invention. Figure 2 This is a transformation diagram of the linear coordinates in this invention; Figure 3 This is a schematic diagram of the connection between the outer rotor and the inner rotor in this invention; Figure 4 This is a schematic diagram showing the involute wrap angle α of the inner and outer rotors in this invention when it is 60°, 70°, 80°, or 90°. Figure 5 This is a schematic diagram showing the eccentricity between the inner and outer rotors in this invention when it is 1mm, 1.5mm, or 2mm. Figure 6 This is a schematic diagram of the worm gear assembly of both the inner rotor and the outer rotor in this invention, which has 2, 3, or 4 blades.

[0017] In the figure: 1-Outer rotor; 101-First worm claw portion; 102-First worm claw groove; 2-Inner rotor; 201-Second worm claw part; 202-Second worm claw groove. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0021] like Figures 1 to 2 As shown, this invention provides a profile design method for a wear-resistant elasto-plastic body plum blossom pump, comprising the following steps: S1, Profile Parameter Design Determine the number of blades for the inner rotor 2 and outer rotor 1 of the plum blossom pump, and design the profile design parameters for the inner rotor 2 and outer rotor 1; the profile of the plum blossom pump is an axisymmetric structure.

[0022] S2, External Rotor 1 Design Based on the profile design parameters, the profile of the first worm claw 101 of the outer rotor 1 is designed. The first worm claw 101 profile is composed of the arc segment AB, the arc segment BC, the transition cubic curve segment CD, the involute segment DE, the transition cubic curve segment EF and the arc segment FG connected in sequence. The equation of the circular arc AB is: ; Where, θ 12 θ is a constant. 12 =1.32, θ 11 As a variable, 0 < θ 11 <2.72, L1 is the straight-line distance from the center O of the base circle of the involute to the circular arc O1 of the arc segment AB, and R1 is the radius of the arc segment AB; The equation of the circular arc BC is: ; Where, θ 21 θ is a constant. 21 =0.31, θ 22 As a variable, -0.68 < θ 22 <0, L2 is the straight-line distance from the center O of the base circle of the involute to the center O2 of the arc segment BC, L 2, =1.05, R2 is the radius of the arc segment BC, R2=3; The equation of the transition cubic curve segment CD is: ; Where a, b, c, and d are the equation coefficients of the outer rotor 1, a = -0.0003, b = -0.0015, c = 0.0022, and d = 0.86; The equation of the involute segment DE is: ; Where e is the eccentricity, t1 is the involute development angle, e=1, 12.56<t1<14.13; S3, Inner Rotor 2 Design Based on the profile design parameters, the profile of the second worm claw 201 of the inner rotor 2 is designed. The second worm claw 201 profile is composed of the arc segment ab, the arc segment bc, the transition cubic curve segment cd, the involute segment de, the transition cubic curve segment ef, and the arc segment fg connected in sequence. The equation of the circular arc segment ab of the inner rotor 2 is obtained by translational transformation of the equation of the circular arc segment AB of the outer rotor 1. The equation of the circular arc segment ab is: ; Where, θ 12 θ is a constant. 12=1.32, θ 11 As a variable, 0 < θ 11 <2.72, L1 is the straight-line distance from the center O of the involute base circle to the circular arc segment AB O1, L 1, =4.14, R1 is the radius of the arc segment AB, R1=1.78, R1 is the radius of the arc segment AB, e is the eccentricity, e=1; The equation of the circular arc segment bc of the inner rotor 2 is obtained by translating the equation of the circular arc segment BC of the outer rotor 1. The equation of the circular arc segment bc is: ; Where, θ 21 θ is a constant. 21 =0.31, θ 22 As a variable, -0.68 < θ 22 <0, L2 is the straight-line distance from the center O of the base circle of the involute to the center O2 of the arc segment BC, L 2, =1.05, R2 is the radius of the arc segment BC, R2=3, e is the eccentricity, e=1; A smooth connection is achieved by adding a cubic curve between the involute segment DE and the circular arc segment BC; At point C: ; At point D: .

[0023] The equation for the transition cubic curve segment cd of the inner rotor 2 is obtained through three steps, specifically including the following steps: (1) Translation of the coordinate system: Translate each point on the outer rotor 1 so that the center (x0, y0) becomes the new origin of the coordinate system. ; (2) Proportional scaling: The translated coordinates are scaled proportionally. ; (3) Restoring the translation: The scaled coordinates are restored to the original coordinate system by restoring the translation. ; Substituting the transformation formula into the equation of outer rotor 1: ; Expanding, we obtain the equation for the transition cubic curve segment cd of the inner rotor 2: ; Where k is the scaling factor, (x0, y0) is the center of the scaling circle, and a, b, c, d are the equation coefficients of the outer rotor 1, a=-0.0015, b=0.0017, c=0.0039, d=-7.25, x0=-17.19, y0=-17.44, k=0.95.

[0024] The equation of the transition cubic curve segment cd is: ; Where k is the scaling factor, (x0, y0) is the center of the scaling circle, and a, b, c, d are the equation coefficients of the outer rotor 1.

[0025] The equation of the involute segment *de* differs from the equation of the involute segment *DE* by a phase difference. The equation of the involute segment *de* is: ; Where e is the eccentricity, t1 is the involute development angle, t2 is the involute development angle, e=1, 12.56<t1<14.13, 9.42<t2<10.99.

[0026] The equations for the transition cubic curve EF and arc segment FG on the outer rotor 1 are derived in the same way as those for the transition cubic curve segment CD and the circular arc segment AB. The equations for the transition cubic curve ef and arc segment fg on the inner rotor 2 are derived in the same way as those for the transition cubic curve segment cd and the circular arc segment ab.

[0027] S4, the conjugate meshing of the inner and outer rotors forms a plum blossom pump profile. The outer rotor 1 is fixed in place, while the inner rotor 2 moves eccentrically along the inner side of the outer rotor 1, forming the required plum blossom pump profile through conjugate meshing.

[0028] This design method not only utilizes the precise conjugate meshing and point contact characteristics of involute curves at the points of greatest rotor contact stress, highest sealing requirements, and most complex motion, reducing friction and wear between rotors compared to line contact with other profiles, but also provides a good sealing effect with the pump body wall under high-pressure conveying conditions, ensuring long-term stable conveying pressure, reducing pulsation, and improving working efficiency.

[0029] The present invention discloses a method for determining the profile of a wear-resistant elasto-plastic body plum blossom pump as follows: First, set the outer diameter of inner rotor 2 to 22.5mm, the outer diameter of outer rotor 1 to 23.5mm, and the eccentricity e between inner rotor 2 and outer rotor 1 to 1mm. Then, draw the tooth root circle AB and tooth root circle ab according to the following two equations: The equation of the root circle AB is: ; Where, 0 < θ 11 <2.72.

[0030] The equation for the root circle ab is: ; Where, 0 < θ 11 <2.72.

[0031] 2) Then, take the radius of the root circle BC as 3mm, and draw the root circle BC and root circle bc respectively according to the following two equations: The equation for the root circle BC is: ; Where -0.68 < θ 22 <0.

[0032] The equation for the root circle bc is: ; Where -0.68 < θ 22 <0.

[0033] 3) Next, to ensure a smooth connection between the involute and the circular arc, a transition cubic curve segment CD and a transition cubic curve segment cd are added in between: The equation of the transition cubic curve segment CD is: ; The equation of the transition cubic curve segment cd is: ; 4) Finally, at the point where the rotor experiences the greatest contact stress, the highest sealing requirements, and the most complex motion, the characteristics of precise conjugate meshing and point contact of the involute curve are utilized. Based on the following two equations, the involute segment DE and the involute segment de are drawn respectively: The equation of the involute segment DE is: ; Among them, 12.56 < t1 < 14.13; The equation of the involute segment de is: ; Among them, 9.42 < t2 < 10.99.

[0034] The equations for transition cubic curve segment EF and arc segment FG are derived in the same way as those for transition cubic curve segment CD and arc segment AB. The equations for transition cubic curve segment ef and arc segment fg are derived in the same way as those for transition cubic curve segment cd and arc segment ab. The corresponding inner rotor 2 arc is derived in the same way. Draw these arc segments using the same method.

[0035] like Figure 3As shown, this invention provides a plum blossom pump, comprising an outer rotor 1 and an inner rotor 2. The outer rotor 1 includes at least two sets of first worm gear assemblies, each set of first worm gear assemblies including two first worm gear portions 101 arranged in opposite directions, with adjacent first worm gear portions 101 cooperating to form a first worm gear groove 102. The inner rotor 2 includes at least two sets of second worm gear assemblies, each set of second worm gear assemblies including two second worm gear portions 201 arranged in opposite directions, with adjacent second worm gear portions 201 cooperating to form a second worm gear groove 202. The outer rotor 1 is fixed, and the inner rotor 2 moves eccentrically along the inner side of the outer rotor 1, forming a tooth profile through conjugate meshing. The tooth profile adopts the wear-resistant elastoplastic plum blossom pump profile as described above.

[0036] The rotor involute wrap angle of this application is 90°, but the involute wrap angle can also be changed, such as... Figure 4 a, b, c, and d in the figure represent the inner and outer rotors 1 with different involute wrap angles α.

[0037] The eccentricity between the inner rotor 2 and the outer rotor 1 in this application is 1 mm, but the eccentricity between the rotors can also be changed, such as... Figure 5 a, b, and c in the figure represent inner and outer rotors 1 with different eccentricities.

[0038] The number of blades in the worm gear assembly of the inner and outer rotors 1 of this application can also be changed, such as... Figure 6 a, b, and c in the figure represent inner and outer rotors 1 with different numbers of blades.

[0039] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to achieve substantially the same technical effect are all covered within the protection scope of the present invention.

Claims

1. A profile design method for a wear-resistant elasto-plastic body plum blossom pump, characterized in that... Includes the following steps: S1, Profile Parameter Design Determine the number of blades for the inner and outer rotors of the plum blossom pump, and design the profile design parameters for the inner and outer rotors. S2, External Rotor Design Based on the profile design parameters, the profile of the first worm claw of the outer rotor is designed. The first worm claw profile is composed of a circular arc segment AB, a circular arc segment BC, a transition cubic curve segment CD, an involute segment DE, a transition cubic curve segment EF, and an arc segment FG connected in sequence. The equation of the circular arc segment AB is: ； Where, θ 12 θ is a constant. 11 Let L1 be the straight-line distance from the center O of the base circle of the involute to the circular arc segment AB O1, and R1 be the radius of the circular arc segment AB. The equation of the circular arc segment BC is: ； Where, θ 21 θ is a constant. 22 Let L2 be the straight-line distance from the center O of the base circle of the involute to the center O2 of the arc segment BC, and R2 be the radius of the arc segment BC. The equation of the transition cubic curve segment CD is: ； Where a, b, c, and d are the equation coefficients of the outer rotor; The equation of the involute segment DE is: ； Where e is the eccentricity and t1 is the development angle of the involute; S3, Internal Rotor Design Based on the profile design parameters, the profile of the second worm claw of the inner rotor is designed. The second worm claw profile is composed of a circular arc segment ab, a circular arc segment bc, a transition cubic curve segment cd, an involute segment de, a transition cubic curve segment ef, and an arc segment fg connected in sequence. The equation of the circular arc segment ab is: ； Where, θ 12 θ is a constant. 11 Let L1 be the straight-line distance from the center O of the base circle of the involute to the circular arc segment AB O1, R1 be the radius of the circular arc segment AB, and e be the eccentricity. The equation of the circular arc segment bc is: ； Where, θ 21 θ is a constant. 22 Let L2 be the straight-line distance from the center O of the base circle of the involute to the center O2 of the arc segment BC, R2 be the radius of the arc segment BC, and e be the eccentricity. The equation of the transition cubic curve segment cd is: ； Where k is the scaling factor, (x0, y0) is the center of the scaling circle, and a, b, c, d are the equation coefficients of the outer rotor; The equation of the involute segment de is: ； Where e is the eccentricity, t1 is the involute development angle, and t2 is the involute development angle; S4, the conjugate meshing of the inner and outer rotors forms a plum blossom pump profile. The outer rotor is fixed in place, while the inner rotor moves eccentrically along the inner side of the outer rotor, forming the desired plum blossom pump profile through conjugate meshing.

2. The profile design method for a wear-resistant elasto-plastic body plum blossom pump according to claim 1, characterized in that: The equation of the arc segment ab of the inner rotor is obtained by translating the equation of the arc segment AB of the outer rotor, and the equation of the arc segment bc of the inner rotor is obtained by translating the equation of the arc segment BC of the outer rotor.

3. The profile design method for a wear-resistant elasto-plastic body plum blossom pump according to claim 1, characterized in that: The equation of the involute segment de differs from the equation of the involute segment DE by a phase difference.

4. The profile design method for a wear-resistant elasto-plastic body plum blossom pump according to claim 1, characterized in that: The plum blossom pump profile is an axisymmetric structure.

5. The profile design method for a wear-resistant elasto-plastic body plum blossom pump according to claim 1, characterized in that: A smooth connection is achieved by adding a cubic curve between the involute segment DE and the circular arc segment BC; At point C: ； At point D: 。 6. The profile design method for a wear-resistant elasto-plastic body plum blossom pump according to claim 5, characterized in that: The equation for the transition cubic curve segment cd of the inner rotor is obtained through three steps, specifically including the following steps: (1) Translation of the coordinate system: Each point on the outer rotor is translated so that the center (x0, y0) becomes the new origin of the coordinate system. ； (2) Proportional scaling: The translated coordinates are scaled proportionally. ； (3) Restoring the translation: The scaled coordinates are restored to the original coordinate system by restoring the translation. ； Substituting the transformation formula into the equation of the external rotor: ； The equation for the transition cubic curve segment cd of the inner rotor is obtained by expansion: ； Where k is the scaling factor, (x0, y0) is the center of the scaling circle, and a, b, c, d are the equation coefficients of the outer rotor.

7. The profile design method for a wear-resistant elasto-plastic body plum blossom pump according to claim 6, characterized in that: The equations for the transition cubic curve EF and the arc segment FG on the outer rotor are derived in the same way as those for the transition cubic curve segment CD and the circular arc segment AB. The equations for the transition cubic curve ef and the arc segment fg on the inner rotor are derived in the same way as those for the transition cubic curve segment cd and the circular arc segment ab.

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