A method for designing a wear-resistant low-pulsation traveling wave pump

Abstract

The application discloses a kind of wear-resistant low pulsation traveling wave pump's type line design method, comprising the following steps: S1, type line parameter design and S2, rotor body design.The type line design method of the application is simple, the contact stress reaches maximum at the beginning and end of the modified cycloid segment BC, the rotor is at the maximum contact stress, and the modified cycloid is used.The effect of the modified cycloid is that the acceleration at the starting point and ending point of the stroke is zero, thereby eliminating the soft impact and changing the jump to a finite value.Finally, the extremely smooth, stable, very suitable for high-speed motion dynamics characteristics are obtained.Under high-pressure conveying conditions, the sealing effect between the pump body and the inner wall is good, the conveying pressure is stable and durable, the pulsation is reduced, and the work efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of traveling wave pump profile design technology, and in particular to a profile design method for a wear-resistant, low-pulsation traveling wave pump. Background Technology

[0002] In the field of microfluidics, applications such as precision drug delivery, lab-on-a-chip (Lab-on-a-Chip), biochemical analysis, and micro / nanoliter liquid handling utilize micropumps, which drive the fluid and are the core actuators for achieving their functions. These applications place extreme demands on the performance of micropumps: not only do they need to be tiny enough to fit into integrated systems, but more importantly, they must possess extremely low flow pulsation, ultra-high operational stability, and long-term reliability. Even minute flow fluctuations can directly interfere with the mixing ratio of reaction reagents, affect the precision of cell-level operations, and even lead to a deterioration in the signal-to-noise ratio of detection signals. Furthermore, wear on the moving parts inside the micropump can generate particulate contaminants and alter the sealing characteristics of the microchannels, which is fatal for channels with a scale of only micrometers, ultimately causing the entire microfluidic chip to malfunction.

[0003] Currently, the core moving parts (such as rotors and cams) of positive displacement micropumps (e.g., piezoelectric pumps, gear pumps) widely used in the microfluidics field are mostly designed based on traditional cycloidal, involute, or simple circular arc profiles. However, the inherent defects of these traditional profiles are drastically amplified at the microscale and under high-speed operating conditions. 1. Significant flow and pressure pulsations: Traditional profiles are prone to sudden acceleration changes during meshing or motion, triggering so-called "soft impacts" or "rigid impacts." This dynamic discontinuity translates into periodic pressure spikes and flow fluctuations in the fluid, severely disrupting the stable, laminar flow state sought by microfluidic systems and greatly limiting their application in precision analysis and transport.

[0004] 2. Intractable Wear Problems: In areas of highest contact stress (usually the start and end points of the profile), traditional profiles, due to design flaws, lead to stress concentration. Under the high-frequency, long-life operation requirements of micropumps, these areas become the hardest hit by wear. Wear not only shortens the service life of the micropump but also gradually increases internal leakage over time, leading to a decrease in output flow and pressure, making it impossible to guarantee the stability and consistency of long-term operation.

[0005] 3. Poor dynamic characteristics limit high-speed performance: Many traditional profiles exhibit discontinuous acceleration curves during motion, and may even have infinitely large jumps (derivatives of acceleration). These undesirable dynamic characteristics cause vibration and noise in the rotor during high-speed operation, limiting the increase in the operating speed of the micropump and thus restricting its application potential in small-volume, high-flow-rate microfluidic systems.

[0006] Traveling wave pumps are a type of micro pump. In existing technologies, the profile of traveling wave pumps has not been corrected, resulting in non-zero acceleration at the beginning and end of the stroke, leading to soft impacts. This makes it impossible to obtain smooth, stable dynamic characteristics that are well-suited for high-speed motion. At the same time, under large pressure differences, the speed difference is also large, resulting in significant friction and wear. When the rotor is under high pressure, the large speed difference will affect the rotor's lifespan. Furthermore, under high-pressure conveying conditions, the sealing effect between the pump and the inner wall of the pump body is poor and cannot be constant, leading to increased pulsation and low efficiency. Summary of the Invention

[0007] The purpose of this invention is to provide a technical solution for the profile design method of a wear-resistant, low-pulsation traveling wave pump, addressing the shortcomings of existing technologies. This profile design method is simple in steps. At the beginning and end of the modified cycloidal segment BC, the contact stress reaches its maximum. When the rotor is at the point of maximum contact stress, a modified cycloidal segment is used. Since the modified cycloidal segment ensures that the acceleration at the beginning and end of the stroke is zero, soft impacts are eliminated, and the jump is reduced to a finite value. Ultimately, extremely smooth and stable dynamic characteristics suitable for high-speed motion are obtained. Under high-pressure conveying conditions, the sealing effect between the pump and the inner wall of the pump body is good, ensuring long-term stable conveying pressure, reducing pulsation, and improving working efficiency.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A profile design method for a wear-resistant, low-pulsation traveling wave pump, characterized by the following steps: S1, Profile Parameter Design Determine the rotor dimensions of the traveling wave pump and design the profile parameters of the rotor body; S2, Rotor Body Design Based on the profile design parameters, the rotor body profile is designed. One-quarter of the profile consists of the first transition curve AB, the modified cycloidal segment BC, the higher-order transition curve CD, and the second transition curve DE. The first transition curve AB is connected to the second transition curve DE through the modified cycloidal segment BC and the higher-order transition curve CD. a. First, set the base circle radius R of the rotor sleeve and draw the first transition curve AB. The equation of the first transition curve AB is: ; Where R is the radius of the base circle; b. Then, take the total lift of segment BD, and determine the lift of the corrected cycloidal segment BC as h1. By providing a smooth motion transition through the corrected cycloidal curve, the curve BC is determined to be the corrected cycloidal segment. The equation of the corrected cycloidal segment BC is: ; Where R is the base circle radius and h1 is the lift of the corrected cycloidal segment BC; c. Next, draw the higher-order transition curve CD. The higher-order transition curve CD is a fifth-order polynomial curve. The initial velocity is the final velocity of the corrected cycloidal segment BC. The fifth-order polynomial equation of the higher-order transition curve CD is: ; Where R is the radius of the base circle; ; 0.9549 is the final velocity of the corrected cycloidal segment BC, and a3, a4, and a5 are the coefficients of the fifth-degree polynomial. d. Draw the second transition curve DE connecting the segment to the fifth-degree polynomial curve. The initial velocity is 0. The equation of the second transition curve DE is: ; Where R is the radius of the base circle.

[0009] The design method of this profile is simple. Since the contact stress reaches its maximum at the beginning and end of the corrected cycloidal segment BC during the rotor's ascending phase, a corrected cycloidal curve is used. This corrected cycloidal curve ensures zero acceleration at the start and end of the stroke, eliminating soft impacts and reducing the jump to a finite value. Ultimately, this results in extremely smooth, stable dynamic characteristics ideal for high-speed motion. Compared to other profiles, this profile reduces the velocity difference under maximum pressure conditions, thus reducing friction and wear between the rotor and vanes. Under high-pressure conveying conditions, it provides a good seal with the pump body wall, ensuring sustained and stable conveying pressure, reducing pulsation, and improving working efficiency. The lift of the corrected cycloidal segment BC is h1, and the lift of the higher-order transition curve CD is 10-h1.

[0010] Furthermore, both the first transition curve AB and the second transition curve DE are straight line segments.

[0011] Furthermore, in the equation of the first transition curve AB, 0 < t < π / 24.

[0012] Furthermore, in the corrected equation for the cycloid segment BC, π / 24 < t < 6*π / 24.

[0013] Furthermore, in the equation of the higher-order transition curve CD, 5*π / 12<t<10*π / 12.

[0014] Furthermore, in the s(t) equation, 6*π / 24 < t < 11*π / 24.

[0015] Furthermore, in the equation of the second transition curve DE, 11*π / 24<t<12*π / 24.

[0016] Furthermore, the profile is an axisymmetric structure.

[0017] The present invention, by adopting the above-described technical solution, has the following beneficial effects: The profile design method of this invention has simple steps. At the beginning and end of the modified cycloidal segment BC, the contact stress reaches its maximum. When the rotor is at the point of maximum contact stress, the modified cycloidal segment is used. Since the function of the modified cycloidal segment is to make its acceleration zero at the beginning and end of the stroke, soft impact is eliminated and the jump is made into a finite value. Finally, extremely smooth and stable dynamic characteristics that are very suitable for high-speed motion are obtained. Under high-pressure conveying conditions, the sealing effect between the rotor and the pump body wall is good, ensuring the long-term stability of the conveying pressure, reducing pulsation, and improving working efficiency. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings: Figure 1 This is a flowchart of a profile design method for a wear-resistant, low-pulsation traveling wave pump according to the present invention; Figure 2 This is a schematic diagram of the shape line in this invention; Figure 3 This is a schematic diagram of the rotor structure in this invention; Figure 4 This is a schematic diagram of the base circle radius of the rotor in this invention; Figure 5 This is a schematic diagram of the rotor design principle in MATLAB in this invention; Figure 6 This is a schematic diagram of the space curve of the rotor in this invention; Figure 7 This is a rendering of the rotor in this invention.

[0019] In the figure: 1-sleeve; 2-rotor body; 3-shaft hole; 4-stepped hole. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] 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.

[0022] 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.

[0023] like Figures 1 to 6 As shown, this invention provides a profile design method for a wear-resistant, low-pulsation traveling wave pump, characterized by the following steps: S1, Profile Parameter Design Determine the rotor dimensions of the traveling wave pump and design the profile parameters of the rotor body; such as Figure 7 As shown, the rotor includes an integrally formed sleeve 1 and a rotor body 2. The rotor body 2 is distributed on the outer circumferential side of the sleeve 1. The sleeve 1 is provided with an interconnected shaft hole 3 and a stepped hole 4.

[0024] S2, Rotor Body Design Based on the profile design parameters, the rotor body profile is designed, and the profile is an axisymmetric structure. One-quarter segment of the profile consists of the first transition curve AB, the modified cycloidal segment BC, the higher-order transition curve CD, and the second transition curve DE. The first transition curve AB connects to the second transition curve DE through the modified cycloidal segment BC and the higher-order transition curve CD; both the first transition curve AB and the second transition curve DE are straight line segments.

[0025] a. First, set the base circle radius R of the rotor sleeve, R = 16mm, and draw the first transition curve AB. The equation of the first transition curve AB is: ; Where R is the radius of the base circle, and 0 < t < π / 24.

[0026] b. Then, taking the total lift of segment BD as 10mm, determine the lift of the corrected cycloidal segment BC as h1. By providing a smooth motion transition through the corrected cycloidal curve, curve BC is determined to be the corrected cycloidal segment. The equation of the corrected cycloidal segment BC is: ; Where R is the base circle radius, and h1 is the lift of the corrected cycloid segment BC; π / 24 < t < 6*π / 24. The purpose of using the corrected cycloid is to make its acceleration zero at the beginning and end of its stroke, thereby eliminating soft impacts and turning the jump into a finite value.

[0027] c. Next, draw the higher-order transition curve CD. The higher-order transition curve CD is a fifth-order polynomial curve. The initial velocity is the final velocity of the corrected cycloidal segment BC, and the final velocity is 0. The fifth-order polynomial equation of the higher-order transition curve CD is: ; Where R is the radius of the base circle; 5*π / 12<t<10*π / 12.

[0028] ; 0.9549 is the final velocity of the corrected cycloidal segment BC; 6*π / 24 < t < 11*π / 24. a3, a4, and a5 are the coefficients of the fifth-order polynomial, a3 is -0.0087079143, a4 is 0.0004157723, and a5 is -0.00000000000000000007. By setting the high-order transition curve CD, the initial velocity can be 0 when reaching the next straight segment, and the velocity will not change abruptly, thus achieving a smoother transition to the next second transition curve DE.

[0029] d. Draw the second transition curve DE connecting the segment to the fifth-degree polynomial curve. The initial velocity is 0. The equation of the second transition curve DE is: ; Where R is the radius of the base circle, and 11*π / 24 < t < 12*π / 24.

[0030] The design method for this profile is simple. The contact stress reaches its maximum at the beginning and end of the modified cycloidal segment BC. When the rotor reaches this maximum contact stress, a modified cycloidal curve is used. Because the modified cycloidal curve ensures zero acceleration at the start and end of its stroke, soft impacts are eliminated, and the jump becomes a finite value. This results in extremely smooth, stable dynamic characteristics highly suitable for high-speed motion. Under high-pressure conveying conditions, it provides excellent sealing with the pump body wall, ensuring stable and sustained conveying pressure, reducing pulsation, and improving working efficiency. The lift of the modified cycloidal segment BC is h1, and the lift of the higher-order transition curve CD is 10-h1.

[0031] 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, low-pulsation traveling wave pump, characterized in that... Includes the following steps: S1, Profile Parameter Design Determine the rotor dimensions of the traveling wave pump and design the profile parameters of the rotor body; S2, Rotor Body Design Based on the profile design parameters, the rotor body profile is designed. One-quarter segment of the profile is composed of a first transition curve AB, a modified cycloid segment BC, a higher-order transition curve CD, and a second transition curve DE. The first transition curve AB is connected to the second transition curve DE through the modified cycloid segment BC and the higher-order transition curve CD. a. First, set the base circle radius R of the rotor sleeve and draw the first transition curve AB. The equation of the first transition curve AB is: ； Where R is the radius of the base circle; b. Then, take the total lift of segment BD, and determine the lift of the corrected cycloidal segment BC as h1. By providing a smooth motion transition through the corrected cycloidal curve, the curve BC is determined to be the corrected cycloidal segment. The equation of the corrected cycloidal segment BC is: ； Where R is the base circle radius and h1 is the lift of the corrected cycloidal segment BC; c. Next, draw the higher-order transition curve CD. The higher-order transition curve CD is a fifth-order polynomial curve. The initial velocity is the final velocity of the modified cycloidal segment BC. The fifth-order polynomial equation of the higher-order transition curve CD is obtained as follows: ； Where R is the radius of the base circle; ； 0.9549 is the final velocity of the corrected cycloidal segment BC, and a3, a4, and a5 are the coefficients of the fifth-degree polynomial. d. Draw the second transition curve DE connecting the segment to the fifth-degree polynomial curve. The initial velocity is 0. The equation of the second transition curve DE is: ； Where R is the radius of the base circle.

2. The profile design method for a wear-resistant, low-pulsation traveling wave pump according to claim 1, characterized in that: Both the first transition curve AB and the second transition curve DE are straight line segments.

3. The profile design method for a wear-resistant, low-pulsation traveling wave pump according to claim 1, characterized in that: In the equation of the first transition curve AB, 0 < t < π / 24.

4. The profile design method for a wear-resistant, low-pulsation traveling wave pump according to claim 1, characterized in that: In the equation of the modified cycloid segment BC, π / 24 < t < 6*π / 24.

5. The profile design method for a wear-resistant, low-pulsation traveling wave pump according to claim 1, characterized in that: In the equation of the higher-order transition curve CD, 5*π / 12 < t < 10*π / 12.

6. The profile design method for a wear-resistant, low-pulsation traveling wave pump according to claim 1, characterized in that: In the s(t) equation, 6*π / 24 < t < 11*π / 24.

7. The profile design method for a wear-resistant, low-pulsation traveling wave pump according to claim 1, characterized in that: In the equation of the second transition curve DE, 11*π / 24<t<12*π / 24.

8. The profile design method for a wear-resistant, low-pulsation traveling wave pump according to claim 1, characterized in that: The profile is an axisymmetric structure.

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