Hollow shaft rotor dynamic balancing tool and method

Abstract

This invention discloses a hollow shaft rotor dynamic balancing fixture and method, comprising: a first balancing dummy shaft with a central hole and a first conical surface at one end that mates with a centering conical hole at one end of the rotor shaft; a second balancing dummy shaft with a central hole and a second conical surface at one end that mates with a centering conical hole at the other end of the rotor shaft; a third balancing dummy shaft having the same central hole and centering conical hole as the rotor shaft; a tension bolt for passing through the central holes of the first balancing dummy shaft, the rotor shaft, or the third and second balancing dummy shafts; and a lock nut for engaging with the tension bolt to axially lock the first balancing dummy shaft, the rotor shaft, or the third and second balancing dummy shafts together. This invention not only provides reliable support during dual-rotor dynamic balancing but also ensures that the dynamic balancing fixture is concentric with the rotor, and the device is easy and convenient to install and disassemble.

Description

Technical Field

[0001] This invention relates to a dynamic balancing fixture for a hollow shaft rotor of an electric motor, specifically to a dynamic balancing fixture and method for a hollow shaft rotor. Background Technology

[0002] Rotor dynamic balancing is a technique that adjusts the mass distribution of a rotor by adding or removing weights, bringing the remaining imbalance below the allowable range. The core principle of rotor dynamic balancing is to reduce lateral vibration and dynamic loads generated during rotor rotation by balancing centrifugal force and torque, thereby improving the stability and lifespan of the equipment.

[0003] When performing dynamic balancing on a motor rotor, the bearing support of the rotor shaft is usually placed on the support rollers of the dynamic balancing machine. Due to the special structure of the product, some rotors have other components obstructing the bearing support or no shaft extension (for example, the two rotor discs of a dual-rotor axial flux motor are connected by a rotor connecting cylinder, and neither end of its shaft extends outward). These rotors cannot be directly used as dynamic balancing support positions. For these types of rotors, there are usually two methods of handling:

[0004] (1) The inner support roller mechanism of the rotor extends the roller into the bearing position of the rotor shaft for support. However, the inner support roller is a precision part of the dynamic balancing machine. It usually needs to be customized by the dynamic balancing equipment manufacturer. The customization cycle is long and the cost is high. Moreover, the inner support roller mechanism is only suitable for some rotors with sufficient installation and support space.

[0005] (2) Install an extended dummy shaft tooling at one end of the rotor as a support part: For solid shaft rotors with end faces, the connection between the extended dummy shaft and the rotor is usually made by bolts. It is difficult to ensure concentricity between the extended dummy shaft and the rotor when they are installed. For hollow shaft rotors, the extended dummy shaft is usually installed by cold pressing process mandrel (for example, Chinese patent CN112378580A). Its disadvantage is that the process mandrel is difficult to remove. Repeated installation and removal can easily cause wear and deformation of the process mandrel. Its own imbalance can easily affect the accuracy of the rotor dynamic balance result. Summary of the Invention

[0006] The technical problem to be solved by this invention is that, in the case of the inability to achieve reliable support when the two rotor discs of a dual-rotor axial flux motor are dynamically balanced, this invention provides a hollow shaft rotor dynamic balancing fixture and method, which can not only achieve reliable support when the hollow shaft rotor without shaft extension is dynamically balanced, but also ensure that the dynamic balancing fixture is concentric with the rotor. The device is easy and convenient to install and disassemble.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A hollow shaft rotor dynamic balancing fixture, wherein the hollow shaft rotor has a rotating shaft, a first central hole in the middle of the rotating shaft, and first centering cone holes are respectively provided at both ends of the first central hole. The fixture is characterized in that it comprises:

[0009] The first balancing dummy shaft is provided with a second center hole and a first conical surface at one end that mates with the first centering conical hole at one end of the rotating shaft.

[0010] The second balancing dummy shaft is provided with a third center hole and a second conical surface at one end that mates with the first centering conical hole at the other end of the rotating shaft.

[0011] The third balancing dummy shaft is provided with a fourth center hole, and second centering cone holes are respectively provided at both ends of the fourth center hole. The fourth center hole has the same specifications as the first center hole, and the second centering cone holes have the same specifications as the first centering cone holes. The hollow shaft rotor dynamic balancing fixture is assembled into a whole by means of the third balancing dummy shaft, so as to fix the dynamic balancing fixture and independently rotate the dynamic balancing fixture to detect the dynamic balance.

[0012] A tension bolt is used to pass through the center hole of the first balancing dummy shaft, the rotating shaft, or the third balancing dummy shaft and the second balancing dummy shaft;

[0013] A locking nut is used to cooperate with the tensioning bolt to axially lock the first balance dummy shaft, the rotating shaft, or the third balance dummy shaft and the second balance dummy shaft together.

[0014] During the dynamic balancing of the tooling, the tension bolt passes through the center holes of the first balancing dummy shaft, the third balancing dummy shaft, and the second balancing dummy shaft in sequence, and the locking nut cooperates with the tension bolt to axially lock the first balancing dummy shaft, the third balancing dummy shaft, and the second balancing dummy shaft together;

[0015] During the dynamic balancing of the rotor structure, the tension bolt passes through the center holes of the first balancing dummy shaft, the rotating shaft, and the second balancing dummy shaft in sequence, and the locking nut cooperates with the tension bolt to axially lock the first balancing dummy shaft, the rotating shaft, and the second balancing dummy shaft together.

[0016] A further improvement to the above scheme is that the first conical surface and the second conical surface each have an inclination angle consistent with the wall surface of the first centering conical hole, further ensuring that the first balancing dummy shaft and the second balancing dummy shaft are concentrically assembled with the rotating shaft.

[0017] A further improvement to the above solution is that the first balancing dummy shaft is interference-fitted with the nut end of the tensioning bolt, and the position between the first balancing dummy shaft and the tensioning bolt is fixed as a whole by heat fitting, so that the first balancing dummy shaft and the tensioning bolt will not have relative displacement in the axial and circumferential directions.

[0018] A further improvement to the above solution is that the second balancing dummy shaft and the tensioning bolt have a transition fit, and lubricating oil is applied between the second balancing dummy shaft and the tensioning bolt to facilitate installation and disassembly.

[0019] Based on the same inventive concept, the present invention also provides a method for dynamic balancing of a hollow shaft rotor, which includes the following steps:

[0020] S1. Before first use, the third balance dummy shaft is dynamically balanced separately. The initial imbalance is corrected by weight reduction based on the measured amount, so that the balance quality level of the third balance dummy shaft reaches G0.4 or above.

[0021] S2. Fit the conical surfaces of the first and second balancing dummy shafts with the second centering conical holes at both ends of the third balancing dummy shaft, and pass the tension bolts through the first, third, and second balancing dummy shafts in sequence;

[0022] S3. Tighten the lock nut onto the tension bolt, and axially lock the first balance dummy shaft, the second balance dummy shaft and the third balance dummy shaft to form a dynamic balancing fixture;

[0023] S4. Use a scribing pen to draw a straight line along the axial direction of the tension bolt in sequence on the first balance dummy shaft, the third balance dummy shaft, the second balance dummy shaft, the lock nut, and the tension bolt. Use the straight line to mark the assembly position relationship between the parts of the dynamic balancing fixture.

[0024] S5. Perform dynamic balancing test on the assembled dynamic balancing fixture with the third balancing dummy shaft as a whole. Based on the measured initial imbalance, perform weight reduction correction on the first and second balancing dummy shafts respectively. The weight reduction position avoids the rotating support area during the dynamic balancing of the dual rotor structure, so that the dynamic balancing fixture with the third balancing dummy shaft achieves a balance quality level of G0.4 or above.

[0025] S6. Insert the tension bolt with the first balancing dummy shaft through the first centering cone hole at the non-transmission end of the rotor structure shaft, so that the first balancing dummy shaft fits tightly with the first centering cone hole at the non-transmission end of the rotor structure shaft.

[0026] S7. Insert the second balancing dummy shaft into the tension bolt and tighten the lock nut onto the tension bolt;

[0027] S8. Adjust the positional relationship between the second balancing dummy shaft and the tension bolt and lock nut with the first balancing dummy shaft, and after aligning the straight line marked in step S4, tighten the lock nut;

[0028] S9. Perform dynamic balancing tests on the rotor structure according to the requirements of dynamic balancing operations;

[0029] S10. After the rotor structure dynamic balancing test and correction is completed, loosen the lock nut and remove the first and second balancing dummy shafts.

[0030] Each time dynamic balancing is performed on the rotor structure, only S6-S10 needs to be executed.

[0031] To further ensure the assembly positional relationship between the various parts of the dynamic balancing fixture, in step S4, two adjacent straight lines are drawn sequentially along the axial direction of the tension bolt on the first balancing dummy shaft, the third balancing dummy shaft, the second balancing dummy shaft, the lock nut, and the tension bolt using a scribing pen, and the two straight lines are colored with two different colored markers respectively; in step S8, the positional relationship between the second balancing dummy shaft and the tension bolt and lock nut with the first balancing dummy shaft is adjusted so that the two different colored straight lines marked in step S4 are aligned, and then the lock nut is tightened.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] 1) This invention has a simple structure and a short manufacturing cycle;

[0034] 2) This invention is particularly applicable to the dynamic balancing of a dual-rotor structure without shaft extension support. It can achieve reliable support for the dynamic balancing of the dual-rotor structure through the first and second balancing dummy shafts. At the same time, it cleverly utilizes the first centering cone hole of the shaft and the cone surface of the first and second balancing dummy shafts to ensure the concentricity of the assembly of the first and second balancing dummy shafts with the shaft, thereby ensuring the assembly accuracy of the dynamic balancing tooling and the rotor itself.

[0035] 3) This invention is quick and easy to install and disassemble, and is not easily worn or deformed even after repeated use;

[0036] 4) This invention not only ensures reusability accuracy by using dynamic balancing fixtures for self-balancing calibration and marking of relative assembly positions, but also enables rapid installation. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the structure of the present invention used for dynamic balance testing of a dual-rotor axial flux motor rotor.

[0039] Figure 2 This is a schematic diagram of the assembly structure for dynamic balancing testing of the tooling of the present invention.

[0040] Figure 3This is a schematic diagram showing the assembly position relationship between the various parts of the dynamic balancing fixture during dynamic balancing testing of the tooling of the present invention.

[0041] In the diagram: 1-First rotor disc; 2-Rotor connecting cylinder; 3-Second rotor disc; 4-Shaft; 5-First balancing dummy shaft; 6-Tightening bolt; 7-Second balancing dummy shaft; 8-Locking nut; 9-Third balancing dummy shaft. Detailed Implementation

[0042] The present invention will be further described below with reference to specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0043] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0045] Please see Figure 1 , Figure 2 In one embodiment of the hollow shaft rotor dynamic balancing fixture of the present invention, the hollow shaft rotor has a rotating shaft 4, a first central hole 41 in the middle of the rotating shaft 4, and first centering cone holes 42 respectively provided at both ends of the first central hole 41. The dynamic balancing fixture includes:

[0046] The first balancing dummy shaft 5 has a second center hole 52 in its middle part and a first conical surface 51 at one end that mates with the first centering conical hole 42 at one end of the rotating shaft 4.

[0047] The second balancing dummy shaft 7 has a third center hole 72 in its middle part and a second conical surface 71 at one end that mates with the first centering conical hole 42 at the other end of the rotating shaft 4.

[0048] The third balancing dummy shaft 9 has a fourth center hole 91 in its middle and second centering cone holes 92 at both ends. The specifications of the fourth center hole 91 (including length, shape, diameter, etc.) are the same as those of the first center hole 41 of the shaft 4. The specifications of the second centering cone holes 92 are the same as those of the first centering cone holes 42. That is, compared with the first center hole 41 and the first centering cone holes 42, the fourth center hole 91 and the second centering cone holes 92 belong to the third balancing dummy shaft 9, while the latter belong to the shaft 4 of the hollow shaft rotor. Therefore, the hollow shaft rotor dynamic balancing fixture can be assembled into one piece by means of the third balancing dummy shaft 9 to fix the dynamic balancing fixture and to rotate and test the dynamic balance of the dynamic balancing fixture separately.

[0049] The tension bolt 6 is used to pass through the center hole of the first balancing dummy shaft 5, the rotating shaft 4 or the third balancing dummy shaft 9 and the second balancing dummy shaft 7;

[0050] The locking nut 8 is used to cooperate with the tensioning bolt 6 to axially lock the first balancing dummy shaft 5, the rotating shaft 4 or the third balancing dummy shaft 9 and the second balancing dummy shaft 7 together.

[0051] In this embodiment, a rotor for a dual-rotor axial flux motor is used as an example for illustration, but the present invention is not limited to the use of this type of rotor. In this embodiment, the rotor for the dual-rotor axial flux motor includes a first rotor disk 1 and a second rotor disk 3, which are connected by a rotor connecting cylinder 2. The shaft 4 of the rotor connecting cylinder 2 is a hollow shaft with a first central hole 41, and its two ends each have a first centering conical hole 42.

[0052] The first conical surface 51 and the second conical surface 71 have an inclination angle consistent with the wall surface of the first centering conical hole 42 at both ends of the rotating shaft 4, so as to further ensure that the first balancing dummy shaft 5 and the second balancing dummy shaft 7 are concentrically assembled with the rotating shaft 4.

[0053] The first balancing dummy shaft 5 is interference-fitted with the nut end of the tension bolt 6, and is assembled by a heat sleeve (not shown in the figure) to fix the position of the first balancing dummy shaft 5 and the tension bolt 6 into a whole, so that the first balancing dummy shaft 5 and the tension bolt 6 will not have relative displacement in the axial and circumferential directions.

[0054] The second balancing dummy shaft 7 and the tension bolt 6 are in a transition fit, and lubricating oil is applied between the second balancing dummy shaft 7 and the tension bolt 6 to facilitate installation and disassembly.

[0055] When the tooling of this invention is used for dynamic balance testing of the rotor of a dual-rotor axial flux motor, it includes the following steps:

[0056] S1. Before first use, the third balancing dummy shaft 9 is dynamically balanced separately. The initial imbalance is corrected by weight reduction based on the measured amount, so that the balance quality level of the third balancing dummy shaft 9 reaches G0.4 or above.

[0057] S2. The conical surfaces of the first balancing dummy shaft 5 and the second balancing dummy shaft 7 are respectively fitted with the centering conical holes at both ends of the third balancing dummy shaft 9, and the tensioning bolt 6 is passed through the second center hole 52 of the first balancing dummy shaft 5, the fourth center hole 91 of the third balancing dummy shaft 9, and the third center hole 72 of the second balancing dummy shaft 7 in sequence.

[0058] S3. Tighten the locking nut 8 onto the tension bolt 6, and axially lock the first balancing dummy shaft 5, the second balancing dummy shaft 7 and the third balancing dummy shaft 9 to form a dynamic balancing fixture;

[0059] S4. Using a marking pen, draw two adjacent straight lines along the axis of the tension bolt 6, sequentially on the first balancing dummy shaft 5, the third balancing dummy shaft 9, the second balancing dummy shaft 7, the lock nut 8, and the tension bolt 6. Color the two straight lines with two different colored markers to mark the assembly positional relationships between the parts of the dynamic balancing fixture. Figure 3 As shown;

[0060] S5. Perform dynamic balancing test on the assembled dynamic balancing fixture with the third balancing dummy shaft 9 as a whole. Based on the measured initial imbalance, perform weight reduction correction on the first balancing dummy shaft 5 and the second balancing dummy shaft 7 respectively. The weight reduction position avoids the rotating support area during the dynamic balancing of the dual rotor structure, so that the dynamic balancing fixture with the third balancing dummy shaft 9 reaches the balance quality level of G0.4 or above. In this way, through the above S1-S5, the dynamic balancing fixture itself reaches the balanced state. Mark the assembly position relationship of the first balancing dummy shaft 5, the second balancing dummy shaft 7, the tension bolt 6, and the lock nut 8.

[0061] S6. Insert the tension bolt 6 with the first balancing dummy shaft 5 into the first centering cone hole 42 at the non-transmission end of the dual rotor structure shaft 4, so that the first balancing dummy shaft 5 fits tightly with the first centering cone hole 42 at the non-transmission end of the dual rotor structure shaft 4.

[0062] S7. Insert the second balancing dummy shaft 7 into the tension bolt 6, and tighten the lock nut 8 onto the tension bolt 6;

[0063] S8. Adjust the positional relationship between the second balancing dummy shaft 7 and the tension bolt 6 with the first balancing dummy shaft 5 and the locking nut 8, so that the two different colored straight lines marked in step S4 are aligned respectively, and then tighten the locking nut 8.

[0064] S9. Perform dynamic balancing tests on the dual-rotor structure according to the requirements of dynamic balancing operations;

[0065] S10. After the dynamic balancing test and correction of the dual rotor structure is completed, loosen the locking nut 8 and remove the first balancing dummy shaft 5 and the second balancing dummy shaft 7 to complete the process.

[0066] After the first use of the dynamic balancing fixture of the present invention, each time a dynamic balancing operation is performed on the dual rotor structure, only S6-S10 needs to be executed.

[0067] This invention is particularly applicable to the dynamic balancing of dual rotors in the field of axial flux motors without shaft extension.

[0068] After the hollow shaft rotor dynamic balancing fixture of the present invention completes its own balance calibration, the relative assembly position relationship of the tension bolt 6, the second balance dummy shaft 7, and the locking nut 8 with the first balance dummy shaft 5 is marked by scribing. When assembling the dynamic balancing fixture before the rotor dynamic balancing operation, the installation can be quickly achieved by simply aligning the marking lines on the parts.

[0069] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can make many possible variations and modifications to the technical solution of the present invention, or modify it into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention should fall within the scope of protection of the technical solution of the present invention.

Claims

1. A dynamic balancing fixture for a hollow shaft rotor, wherein the hollow shaft rotor has a rotating shaft, a first central hole in the middle of the rotating shaft, and first centering cone holes are respectively provided at both ends of the first central hole, characterized in that... The dynamic balancing fixture includes: The first balancing dummy shaft is provided with a second center hole and a first conical surface at one end that mates with the first centering conical hole at one end of the rotating shaft. The second balancing dummy shaft is provided with a third center hole and a second conical surface at one end that mates with the first centering conical hole at the other end of the rotating shaft. The third balancing dummy shaft is provided with a fourth center hole, and a second centering cone hole is provided at each end of the fourth center hole. The fourth center hole has the same specifications as the first center hole, and the second centering cone hole has the same specifications as the first centering cone hole. A tension bolt is used to pass through the center hole of the first balancing dummy shaft, the rotating shaft, or the third balancing dummy shaft and the second balancing dummy shaft; A locking nut is used to cooperate with the tensioning bolt to axially lock the first balance dummy shaft, the rotating shaft, or the third balance dummy shaft and the second balance dummy shaft together. During the dynamic balancing of the tooling, the tension bolt passes through the center holes of the first balancing dummy shaft, the third balancing dummy shaft, and the second balancing dummy shaft in sequence, and the locking nut cooperates with the tension bolt to axially lock the first balancing dummy shaft, the third balancing dummy shaft, and the second balancing dummy shaft together; During the dynamic balancing of the rotor structure, the tension bolt passes through the center holes of the first balancing dummy shaft, the rotating shaft, and the second balancing dummy shaft in sequence, and the locking nut cooperates with the tension bolt to axially lock the first balancing dummy shaft, the rotating shaft, and the second balancing dummy shaft together.

2. The hollow shaft rotor dynamic balancing fixture according to claim 1, characterized in that, The first conical surface and the second conical surface each have an inclination angle consistent with the wall surface of the first centering conical hole.

3. The hollow shaft rotor dynamic balancing fixture according to claim 1, characterized in that, The first balancing dummy shaft is interference-fitted with the nut end of the tensioning bolt, and the position of the first balancing dummy shaft and the tensioning bolt is fixed as a whole by heat fitting.

4. The hollow shaft rotor dynamic balancing fixture according to claim 1, characterized in that, The second balancing dummy shaft and the tensioning bolt are in a transition fit, and lubricating oil is applied between the second balancing dummy shaft and the tensioning bolt.

5. A dynamic balancing method based on the hollow shaft rotor dynamic balancing fixture according to any one of claims 1-4, characterized in that... Includes the following steps: S1. Before first use, the third balance dummy shaft is dynamically balanced separately. The initial imbalance is corrected by weight reduction based on the measured amount, so that the balance quality level of the third balance dummy shaft reaches G0.4 or above. S2. Fit the conical surfaces of the first and second balancing dummy shafts with the second centering conical holes at both ends of the third balancing dummy shaft, and pass the tension bolts through the first, third, and second balancing dummy shafts in sequence; S3. Tighten the lock nut onto the tension bolt, and axially lock the first balance dummy shaft, the second balance dummy shaft and the third balance dummy shaft to form a dynamic balancing fixture; S4. Use a scribing pen to draw a straight line along the axial direction of the tension bolt in sequence on the first balance dummy shaft, the third balance dummy shaft, the second balance dummy shaft, the lock nut, and the tension bolt. Use the straight line to mark the assembly position relationship between the parts of the dynamic balancing fixture. S5. Perform dynamic balancing test on the assembled dynamic balancing fixture with the third balancing dummy shaft as a whole. Based on the measured initial imbalance, perform weight reduction correction on the first and second balancing dummy shafts respectively. The weight reduction position avoids the rotating support area during the dynamic balancing of the dual rotor structure, so that the dynamic balancing fixture with the third balancing dummy shaft achieves a balance quality level of G0.4 or above. S6. Insert the tension bolt with the first balancing dummy shaft through the first centering cone hole at the non-transmission end of the rotor structure shaft, so that the first balancing dummy shaft fits tightly with the first centering cone hole at the non-transmission end of the rotor structure shaft. S7. Insert the second balancing dummy shaft into the tension bolt and tighten the lock nut onto the tension bolt; S8. Adjust the positional relationship between the second balancing dummy shaft and the tension bolt and lock nut with the first balancing dummy shaft, and after aligning the straight line marked in step S4, tighten the lock nut; S9. Perform dynamic balancing tests on the rotor structure according to the requirements of dynamic balancing operations; S10. After the rotor structure dynamic balancing test and correction is completed, loosen the lock nut and remove the first and second balancing dummy shafts.

6. The method for dynamic balancing of a hollow shaft rotor according to claim 5, characterized in that, Each time dynamic balancing is performed on the rotor structure, only S6-S10 needs to be executed.

7. The method for dynamic balancing of a hollow shaft rotor according to claim 5, characterized in that, In step S4, use a marking pen to draw two adjacent straight lines along the axial direction of the tension bolt, sequentially on the first balance dummy shaft, the third balance dummy shaft, the second balance dummy shaft, the lock nut, and the tension bolt. Color the two straight lines with two different colored markers. In step S8, adjust the positional relationship between the second balance dummy shaft and the tension bolt and lock nut with the first balance dummy shaft so that the two different colored straight lines marked in step S4 are aligned. Then tighten the lock nut.

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