A dynamic balancing mandrel for dynamic balancing test of an impeller assembly and a manufacturing method thereof

Abstract

The present invention discloses a dynamic balancing mandrel for dynamic balancing test of an impeller assembly and a manufacturing method thereof. The dynamic balancing mandrel is mainly assembled from a shaft body, a pulley and a cylindrical pin. The shaft body includes a micro-conical cylindrical surface that is in assembly contact with the impeller assembly, a shaft shoulder at the large end of the micro-conical cylindrical surface, and a cylindrical surface at the other end of the shaft shoulder; the pulley includes a second cylindrical hole, and the second cylindrical hole is assembled with an interference fit with the cylindrical surface on the shaft body. A cylindrical hole for dynamic balancing test mandrel is provided on the axial end face of the shaft body close to the pulley, and the depth of the cylindrical hole for dynamic balancing test mandrel is used to adjust the center of gravity of the dynamic balancing mandrel. The present invention adjusts the center of gravity of the dynamic balancing mandrel to within the mounting support surface of the impeller assembly without a locating key, and minimizes the distance between the center of gravity of the impeller assembly and the center of gravity of the dynamic balancing mandrel as much as possible to ensure that the dynamic balancing quality of the impeller assembly meets the design requirements.

Description

Technical Field

[0001] The present invention relates to a core shaft for dynamic balance testing of an impeller, in particular to a dynamic balance core shaft for dynamic balance testing of an impeller assembly and a manufacturing method thereof, belonging to the technical field of dynamic balance testing. Background Art

[0002] In order to cool down the working environment temperature of the airborne radar and enable the radar to work normally, a cooling fan is used as a solution. In order to evaluate the matching impeller assembly of the cooling fan ( Figure 1 ) To ensure the reliability of the welding structure, the impeller assembly is required to undergo an overspeed test during the manufacturing process, and then undergo a dynamic balance retest after the overspeed test. After the cooling fan is installed on the aircraft, the impeller assembly is driven by the motor to rotate. In order to obtain the required flow rate and pressure rise of cold air, the impeller assembly is designed as an ultra-thin large-diameter impeller (an ultra-thin large-diameter impeller refers to an impeller with an impeller diameter ≥ 200mm and an impeller thickness ÷ impeller diameter ≤ 0.15), and there is no keyway in the impeller inner hole. When the impeller is assembled on the motor shaft, it is assembled without a locating key. The operating speed of the impeller is 11000rpm, and the overspeed test speed is 13200rpm. It runs at this speed for 5 minutes. Before the test, the impeller assembly is dimensional inspected and dynamically balanced. The allowable unbalance is no more than 0.2g·cm. After the overspeed test, the impeller assembly is retested for size and dynamic balance quality. The result is that the size of the impeller assembly has not changed significantly, but the unbalance has changed greatly. The change in unbalance is specifically manifested in the following aspects:

[0003] 1) Before and after the overspeed test, the residual unbalance values ​​of the same impeller assembly vary, with the largest exceeding +15% of the allowable measurement value. That is, the measurement result before the overspeed test was 0.2g·cm, and the measurement result after the overspeed test was 0.23g·cm.

[0004] 2) Before the overspeed test, the residual unbalance value of the impeller assembly was remeasured several times, and the measurement results were recorded each time; after the overspeed test, the residual unbalance value of the impeller assembly was remeasured several times. Compared with the data before the overspeed test, the difference in the residual unbalance value was large or small, and some exceeded the allowable error value of the two measurements;

[0005] 3) Before assembling the impeller assembly onto the dynamic balancing test shaft, mark lines on the surface of the impeller assembly and the dynamic balancing test shaft. After consciously changing the relative angular positions of the impeller assembly and the dynamic balancing test shaft one by one, perform a dynamic balancing test. The difference in the residual unbalance of the impeller assembly varies, but it is always possible to find an angular position where the residual unbalance before and after the overspeed test is basically equal. Then, at this angular position, remove the impeller assembly from the dynamic balancing shaft, and then reinstall the impeller assembly in its original position on the dynamic balancing test shaft for dynamic balancing retest. Repeat this several times, and the residual unbalance has good repeatability.

[0006] 4) In practice, when dynamically balancing an impeller with a key, the key ensures the unique installation position between the impeller and the balancing shaft, thus ensuring good repeatability of the residual unbalance. The magnitude of the impeller assembly unbalance varies with the distance and angular position (i.e., the angle between the impeller assembly unbalance and the balancing shaft unbalance) between them.

[0007] The fundamental reason for these variations is that the residual unbalance of the impeller assembly, as measured in the past, is actually the vector sum U0 of the impeller assembly's residual unbalance U1 and the residual unbalance U2 of the dynamic balancing test shaft. This vector sum U0 changes with the angular position (i.e., the angle between) between the impeller assembly's unbalance and the dynamic balancing test shaft's unbalance.

[0008] The solution to this problem [see Figures 4 to 8 ] It can be found on pages 89-90 of "Principles of Dynamic Balancing and Dynamic Balancing Machine" (edited by Ye Neng'an and Yu Rusheng, published by Huazhong University of Science and Technology Press, first edition in December 1985, first printing in December 1985); it can also be found on pages 38-40 of "Balancing Technology" (edited by Heppnheim 1991 and Hatto Schneider, Shanghai Schenck Machinery Co., Ltd.). The two solutions are actually one. Theoretically, they are valid, but it is very troublesome to implement them in practice.

[0009] Figure 4 In the figure, an auxiliary shaft with an unbalance U1 is shown, with eccentricity e at the rotor mounting and axial runout;

[0010] Figure 5 A rotor with an unbalance U is shown in FIG;

[0011] Figure 6 The figure shows a rotor with an unbalance U, mounted on an auxiliary shaft with an unbalance U1, which also generates an unbalance U due to the mounting eccentricity e.偏 , the unbalance U caused by the rotor displacement of half a gap on the auxiliary shaft 间 The unbalanced amount U converted from the unbalanced couple caused by axial runout 轴 , so the total unbalance is U 合 =U1+U+U 偏 +U 间 +U 轴 .

[0012] Figure 7 The figure shows that the rotor rotates 180° on the auxiliary shaft. At this time, U1 and U 偏 、U 间 、U 轴 The magnitude and direction of U remain unchanged, and U rotates 180° to become U', that is, U = -U'. Total unbalance U' 合 =U1+U'+U 偏 +U 间 +U 轴 .

[0013] Figure 8 The unbalance U measured by the secondary method is shown in 合 , U' 合 Subtract U 合 -U' 合 =2U'. The size and direction of U' can be obtained from the vector diagram.

[0014] It is obviously unrealistic to directly use the above solution for batch dynamic balancing of impeller rotors because its operability is too poor. The appearance of the parts will become very ugly due to the removal of excess metal during the 180° dynamic balancing, and the quality will be difficult to be recognized.

[0015] Can a good and easy-to-implement solution be found? After repeated research and verification, the applicant discovered that the magnitude of the impeller assembly's imbalance varies with the distance and angular position (i.e., the angle between) between the impeller assembly's imbalance and the imbalance of the dynamic balancing test shaft. The solution to this problem is to focus on the design of the dynamic balancing shaft, adjust the center of gravity of the dynamic balancing shaft to within the impeller assembly's mounting support surface, and minimize the distance between the impeller assembly's center of gravity and the center of gravity of the dynamic balancing shaft. Summary of the Invention

[0016] In order to overcome the defects existing in the existing impeller assembly dynamic balancing technology, the present invention aims to provide a dynamic balancing mandrel and a manufacturing method thereof that can be used for the dynamic balancing test of the impeller assembly, adjust the center of gravity of the dynamic balancing mandrel to within the mounting support surface of the impeller assembly (or adjust the center of gravity of the dynamic balancing mandrel to within the spatial area formed by the mounting support surface of the impeller assembly), and minimize the distance between the center of gravity of the impeller assembly and the center of gravity of the dynamic balancing mandrel to ensure that the dynamic balancing quality of the impeller assembly meets the design requirements.

[0017] To achieve the above object, the present invention adopts the following technical solutions:

[0018] A dynamic balancing mandrel for dynamic balancing test of an impeller assembly:

[0019] The impeller assembly is an impeller without a positioning key;

[0020] The center of gravity of the dynamic balancing core shaft is located in the spatial area formed by the installation support surface of the impeller assembly, and the center of gravity of the dynamic balancing core shaft coincides with or tends to coincide with the center of gravity of the impeller assembly. The installation support surface is the surface on which the impeller assembly is supported by the dynamic balancing core shaft when the impeller assembly and the dynamic balancing core shaft are assembled without a locating key.

[0021] As a solution, the impeller assembly is an impeller with a diameter ≥ 200 mm and an impeller thickness ÷ impeller diameter ≤ 0.15.

[0022] As a solution, the impeller assembly includes a mounting cylindrical hole, and the cylindrical surface of the inner wall of the mounting cylindrical hole serves as the mounting support surface.

[0023] As a solution, the dynamic balancing core shaft includes a shaft body, a pulley and a cylindrical pin, wherein the pulley is coaxially assembled on the shaft body, and the pulley is connected to the shaft body through a cylindrical pin perpendicular to the shaft body.

[0024] further,

[0025] The shaft body includes a micro-conical cylindrical surface that is in assembly contact with the impeller assembly, with a shaft shoulder at the large end of the micro-conical cylindrical surface and a cylindrical surface at the other end of the shaft shoulder. It should be pointed out that the micro-conical cylindrical surface is actually a conical surface, but because the taper is small, for example, the taper of the micro-conical cylindrical surface in the present invention is 1:3000, and it looks close to a cylinder from the appearance, so it is expressed as a micro-conical cylindrical surface.

[0026] The pulley includes a second cylindrical hole, and the second cylindrical hole is assembled with the cylindrical surface on the shaft body by interference fit.

[0027] Furthermore, the pulley further includes a first cylindrical hole inside for reducing weight.

[0028] As a solution, a cylindrical hole for a dynamic balancing test mandrel is provided on the axial end face of the shaft body close to the pulley, and the depth of the cylindrical hole for the dynamic balancing test mandrel is used to adjust the center of gravity of the dynamic balancing mandrel.

[0029] A method for manufacturing a dynamic balancing mandrel for dynamic balancing testing of an impeller assembly comprising a shaft, a pulley, and a cylindrical pin as described above, comprising:

[0030] S1, according to the diameter of the cylindrical hole for installing the impeller assembly, a micro-conical cylindrical surface is machined on the shaft body, and a shoulder and cylindrical surface are machined on the shaft body;

[0031] S2, machining a second cylindrical hole on the pulley according to the outer diameter of the cylindrical surface;

[0032] S3, assemble the shaft and the pulley, and drill pin holes at the matching positions of the two. Then, according to the diameter of the pin hole, a cylindrical pin is matched to ensure that the cylindrical pin and the pin hole have an interference fit. Finally, the cylindrical pin is inserted into the pin hole to complete the assembly of the dynamic balancing core shaft;

[0033] S4. A cylindrical hole for a dynamic balancing test mandrel is machined on the axial end face of the shaft body close to the pulley. By controlling the hole depth of the cylindrical hole for the dynamic balancing test mandrel, the center of gravity of the dynamic balancing mandrel is adjusted to a position close to half of the axial length of the micro-cone cylindrical surface.

[0034] Furthermore, the method for manufacturing a dynamic balancing core shaft for dynamic balancing test of an impeller assembly also includes S5: performing a dynamic balancing test on the dynamic balancing core shaft that has completed S4, and removing material from the surface of the pulley so that the residual unbalance amount of the dynamic balancing core shaft is less than or equal to the residual unbalance amount of the impeller assembly specified in the design.

[0035] Compared to existing technologies, the present invention provides a novel solution to the dynamic balancing problem of ultra-thin, large-diameter impellers without locating keys. The present invention is easy to implement and, when implemented according to the present invention, demonstrates excellent repeatability in the residual imbalance of the impeller assembly during dynamic balancing tests before and after overspeed testing. Furthermore, the present invention's dynamic balancing mandrel has a simple structure, is easy to manufacture and use, and offers high positioning and testing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The figure is a schematic diagram of the structure of an ultra-thin large-diameter impeller assembly without a locating key;

[0037] Figure 2 This is a schematic diagram of the structure of a core shaft used in an existing dynamic balancing test;

[0038] Figure 3 This is a schematic diagram of the structure of the assembly of the core shaft and impeller assembly for the existing dynamic balancing test;

[0039] Figures 4 to 8 Schematic diagram of the theoretical method for removing the shaft imbalance from the impeller imbalance for dynamic balancing test;

[0040] Figure 9 This is a schematic diagram of the structural requirements for the center of gravity design of the dynamic balancing core shaft in the present invention;

[0041] Figure 10 Schematic diagram of the shaft structure of the dynamic balancing core shaft in the present invention;

[0042] Figure 11 Schematic diagram of the pulley structure of the dynamic balancing mandrel in the present invention;

[0043] Figure 12 Schematic diagram of the cylindrical pin structure of the dynamic balancing mandrel in the present invention;

[0044] Figure 13 This is a schematic diagram of the assembly of the dynamic balancing core shaft and the impeller assembly in the present invention;

[0045] In the figure, 1 is an existing core shaft for dynamic balancing test, 2 is a dynamic balancing core shaft, 3 is a shaft body, 4 is a pulley, 5 is a cylindrical pin, 6 is an impeller assembly, 101 is a micro-conical cylindrical surface of an existing core shaft for dynamic balancing test, 102 is a center of gravity of an existing core shaft for dynamic balancing test, 201 is a center of gravity of a dynamic balancing core shaft, 202 is a cylindrical hole of a core shaft for dynamic balancing test, 301 is a micro-conical cylindrical surface, 302 is a cylindrical surface, 303 is a shaft shoulder, 401 is a first cylindrical hole, 402 is a second cylindrical hole, 601 is a mounting cylindrical hole, and 602 is a center of gravity of an impeller assembly. DETAILED DESCRIPTION

[0046] The present invention is further described below with reference to the accompanying drawings and specific embodiments. However, it should not be understood that the scope of the subject matter described in the present invention is limited to the following embodiments. Without departing from the above technical ideas of the present invention, various modifications, substitutions and changes made according to common technical knowledge and customary means in the field are included in the scope of the present invention.

[0047] In order to solve the dynamic balance test problem of ultra-thin large diameter impeller without positioning key, the present invention will Figure 2 The existing dynamic balance test core shaft 1 shown is modified to be Figure 9 The dynamic balancing mandrel 2 is shown.

[0048] The center of gravity 102 of the conventional dynamic balance test core shaft is located at the same position as the impeller assembly 6 (see Figure 1 ) of the mounting cylindrical hole 601 for assembling and positioning the existing dynamic balance test core shaft with a micro-conical cylindrical surface 101 (see Figure 2), after the impeller assembly 6 is assembled on the existing dynamic balancing test core shaft 1, the center of gravity 102 of the existing dynamic balancing test core shaft is outside the axial thickness range of the impeller assembly 6, and the center of gravity 102 of the dynamic balancing test core shaft is far away from the center of gravity 602 of the impeller assembly. The positional relationship between the center of gravity 102 of the dynamic balancing test core shaft and the center of gravity 602 of the impeller assembly is shown in FIG. Figure 3 .

[0049] As a comparison, the modified dynamic balancing core shaft 2 is mainly composed of the shaft body 3 (see Figure 10 ), pulley 4 (see Figure 11 ) and cylindrical pin 5 (see Figure 12 ) assembled.

[0050] According to the impeller assembly 6 (see Figure 1 ) of the cylindrical hole 601, the positioning micro-conical cylindrical surface 301 of the shaft body 3 is designed (see Figure 10 ), the micro-cone cylindrical surface 301 is a conical surface, the outer diameter of the large end of which is equal to the maximum inner diameter of the mounting cylindrical hole 601, and the taper of the micro-cone cylindrical surface is 1:3000. A shaft shoulder 303 is designed at the large end of the micro-cone cylindrical surface 301 (see Figure 10 ), a cylindrical surface 302 is designed at the other end of the shoulder 303 (see Figure 10 ), used for interference fit assembly with the second cylindrical hole 402 of the pulley 4.

[0051] The second cylindrical hole 402 on the pulley 4 is designed according to the cylindrical surface 302 of the shaft body 3 (see Figure 11 ), so that an interference fit is formed between the two, and under the premise of meeting the strength requirements of the dynamic balance test, a first cylindrical hole 401 (see Figure 11 ).

[0052] After the shaft 3 and pulley 4 are processed, Figure 9 Assemble the pulley 4 on the shaft 3, and drill a pin hole at the matching position between the shaft 3 and the pulley 4, and make a cylindrical pin 5 according to the actual size of the pin hole (see Figure 12 ) to ensure that an interference fit is formed between the cylindrical pin 5 and the pin hole. After the cylindrical pin 5 is assembled, press the cylindrical pin 5 into the pin hole to strengthen the positioning.

[0053] After the shaft 3, pulley 4 and cylindrical pin 5 are assembled together to form the dynamic balance shaft 2 (see Figure 9), then punch a balancing test mandrel cylindrical hole 202 at the shaft end of the dynamic balancing mandrel 2, and by changing the depth of the dynamic balancing test mandrel cylindrical hole 202 at the shaft end, adjust the center of gravity 201 of the dynamic balancing mandrel to approximately one-half of the axial length of the micro-conical cylindrical surface 301. It should be pointed out that the reason for adjusting to approximately one-half of the axial length of the micro-conical cylindrical surface 301 is that there are manufacturing deviations in the actual processing process, and it is relatively difficult to accurately adjust the center of gravity 201 of the dynamic balancing mandrel to one-half of the axial length of the micro-conical cylindrical surface 301. Generally, it is sufficient to adjust the center of gravity 201 of the dynamic balancing mandrel to a point close to one-half of the axial length of the micro-conical cylindrical surface 301.

[0054] After the impeller assembly 6 is assembled on the dynamic balancing core shaft 2, the center of gravity 602 of the impeller assembly and the center of gravity 201 of the dynamic balancing core shaft are both located within the axial thickness range of the impeller assembly 6 (equivalent to adjusting the center of gravity 201 of the dynamic balancing core shaft to be within the mounting support surface of the impeller assembly 6, Figure 13 The axial thickness is more intuitive in the description), and the positional relationship between the two is shown in Figure 13 .

[0055] Compared with the prior art, due to the solution of the present invention, the impeller assembly 6 and the dynamic balance shaft 2 can be assembled into a whole by inserting the micro-conical cylindrical surface 301 on the shaft body 3 into the mounting cylindrical hole 601 of the impeller assembly 6 for positioning (installation support) (see FIG. Figure 13 By changing the depth of the core shaft cylindrical hole 202 for dynamic balancing test at the shaft end, the center of gravity 201 of the dynamic balancing shaft can be adjusted to about half the axial length of the installation cylindrical hole 601 of the impeller assembly 6 (see Figure 13 ) effectively solves the problem of the center of gravity 102 of the existing dynamic balancing test mandrel deviating from the cylindrical mounting hole 601 of the impeller assembly 6, which results in large systematic errors in the dynamic balancing test. This allows dynamic balancing tests of the impeller assembly 6 to be performed in accordance with process specifications. Dynamic balancing tests are performed before and after the impeller assembly 6 overspeed test, and the residual imbalance of the impeller assembly 6 is highly repeatable. The dynamic balancing mandrel 2 of the present invention has a simple structure, is easy to manufacture and use, and offers high positioning and testing accuracy.

[0056] The manufacturing method of the dynamic balancing mandrel 2 is as follows:

[0057] 1) According to the impeller assembly 6 (see Figure 1 ) of the cylindrical hole 601, the positioning micro-conical cylindrical surface 301 of the shaft body 3 (see Figure 10 ), a shoulder 303 is machined at the large end of the micro-cone cylindrical surface 301 (see Figure 10 ), a cylindrical surface 302 is machined at the other end of the shoulder 303 (see Figure 10), used for interference fit assembly with the second cylindrical hole 402 of the pulley 4.

[0058] 2) Design the second cylindrical hole 402 on the pulley 4 according to the cylindrical surface 302 of the shaft 3 (see Figure 11 ), so that an interference fit is formed between the two, and under the premise of meeting the strength requirements of the dynamic balance test, a first cylindrical hole 401 (see Figure 11 ).

[0059] 3) After the shaft 3 and pulley 4 are processed, Figure 9 , assemble the pulley 4 on the shaft 3, and drill the pin hole at the matching position between the shaft 3 and the pulley 4, and make a cylindrical pin 5 according to the actual size of the pin hole (see Figure 12 ) to ensure that an interference fit is formed between the cylindrical pin 5 and the pin hole. After the cylindrical pin 5 is assembled, press the cylindrical pin 5 into the pin hole to strengthen the positioning.

[0060] 4) After the shaft 3, pulley 4 and cylindrical pin 5 are assembled together to form the dynamic balancing core shaft 2 (see Figure 9 ), and then punch a cylindrical hole 202 for a dynamic balancing test core shaft at the shaft end of the dynamic balancing core shaft 2, and adjust the center of gravity 201 of the dynamic balancing core shaft to approximately one-half of the axial length of the micro-conical cylindrical surface 301 by changing the depth of the cylindrical hole 202 for a dynamic balancing test core shaft at the shaft end.

[0061] 5) Perform a dynamic balancing test on the dynamic balancing core shaft 2 and remove unbalanced metal on the pulley 4 so that the remaining unbalance of the dynamic balancing core shaft 2 is no more than one tenth of the remaining unbalance value of the impeller assembly 6 specified in the design.

[0062] The method for performing an overspeed test and a dynamic balancing test using the dynamic balancing mandrel 2 of the present invention is as follows:

[0063] 1) Assemble the impeller assembly 6 on the dynamic balancing core shaft 2, and perform dynamic balancing test and correction on the impeller assembly 6 according to the requirements of the process regulations so that its residual unbalance reaches the technical indicators specified in the design;

[0064] 2) According to the requirements of the process regulations, the impeller assembly 6 that has passed the dynamic balance test is subjected to an overspeed test;

[0065] 3) The impeller assembly 6 that has completed the overspeed test is assembled on the dynamic balancing core shaft 2, and the impeller assembly 6 is dynamically balanced again according to the requirements of the process regulations. The residual unbalance amount reaches the technical indicators specified in the design, indicating that the residual unbalance amount of the impeller assembly 6 has good repeatability.

[0066] After adopting the dynamic balancing mandrel 2 of the present invention, the dynamic balance of the impeller assembly 6 meets the design technical specifications. When assembled in a cooling fan for qualification testing, the fan passed the long-term operating life test and also passed the field installation and use test, demonstrating that the dynamic balancing quality of the impeller assembly 6 has been fully verified. This invention improves the dynamic balancing technology for ultra-thin, large-diameter impellers without locating keys and provides a simple, economical, and practical solution for the dynamic balancing of similar impellers.

[0067] The above is only one specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A dynamic balancing mandrel for dynamic balancing test of an impeller assembly, characterized by: The impeller assembly (6) is an impeller without a positioning key; The center of gravity (201) of the dynamic balancing core shaft is located within the spatial area formed by the mounting support surface of the impeller assembly (6), and the center of gravity (201) of the dynamic balancing core shaft coincides with or tends to coincide with the center of gravity (602) of the impeller assembly, and the mounting support surface is the surface on which the impeller assembly (6) is supported by the dynamic balancing core shaft (2) when the impeller assembly (6) and the dynamic balancing core shaft (2) are assembled without a locating key; The impeller assembly (6) comprises a mounting cylindrical hole (601), wherein the cylindrical surface of the inner wall of the mounting cylindrical hole (601) serves as a mounting support surface; The dynamic balancing core shaft (2) comprises a shaft body (3), a pulley (4) and a cylindrical pin (5), wherein the pulley (4) is coaxially assembled on the shaft body (3), and the pulley (4) is connected to the shaft body (3) via the cylindrical pin (5) perpendicular to the shaft body (3); The shaft body (3) includes a micro-conical cylindrical surface (301) in contact with the impeller assembly (6), a shaft shoulder (303) at the large end of the micro-conical cylindrical surface (301), and a cylindrical surface (302) at the other end of the shaft shoulder (303); A dynamic balancing test core shaft cylindrical hole (202) is provided on the axial end face of the shaft body (3) close to the pulley (4), and the depth of the dynamic balancing test core shaft cylindrical hole (202) is used to adjust the center of gravity (201) of the dynamic balancing core shaft; The pulley (4) comprises a second cylindrical hole (402), and the second cylindrical hole (402) is assembled with the cylindrical surface (302) on the shaft body (3) by interference fit.

2. The dynamic balancing mandrel for dynamic balancing test of an impeller assembly according to claim 1, characterized in that: The impeller assembly (6) is an impeller with a diameter of ≥200 mm and an impeller thickness ÷ impeller diameter ≤0.

15.

3. The dynamic balancing mandrel for dynamic balancing test of an impeller assembly according to claim 1, characterized in that: The pulley (4) further comprises a first cylindrical hole (401) inside for reducing weight.

4. A method for manufacturing a dynamic balancing mandrel for dynamic balancing test of an impeller assembly as claimed in claim 1, characterized in that: include: S1, machining a micro-conical cylindrical surface (301) on the shaft body (3) according to the aperture of the mounting cylindrical hole (601) of the impeller assembly (6), and machining a shaft shoulder (303) and a cylindrical surface (302) on the shaft body (3); S2, machining a second cylindrical hole (402) on the pulley (4) according to the outer diameter of the cylindrical surface (302); S3, assemble the shaft (3) and the pulley (4), and drill a pin hole at the matching position of the two, then make a cylindrical pin (5) according to the hole diameter of the pin hole, ensure that the cylindrical pin (5) and the pin hole have an interference fit, and finally insert the cylindrical pin (5) into the pin hole to complete the assembly of the dynamic balancing core shaft (2); S4, a dynamic balancing test core shaft cylindrical hole (202) is machined on the axial end face of the shaft body (3) close to the pulley (4), and the center of gravity (201) of the dynamic balancing test core shaft is adjusted to a position close to half of the axial length of the micro-cone cylindrical surface (301) by controlling the hole depth of the dynamic balancing test core shaft cylindrical hole (202).

5. The method for manufacturing a dynamic balancing mandrel for dynamic balancing test of an impeller assembly according to claim 4, characterized in that: The method further includes S5: performing a dynamic balancing test on the dynamic balancing core shaft (2) that has completed S4, and removing material from the surface of the pulley (4) so ​​that the residual unbalance of the dynamic balancing core shaft (2) is less than or equal to one tenth of the residual unbalance value of the impeller assembly (6) specified in the design.

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