Method for adjusting gravity center coincidence after rotor and impeller are disassembled and assembled

Abstract

The invention discloses a method for adjusting gravity center coincidence after disassembly and assembly of a rotor and an impeller. The method comprises the following steps: marking a vertical line on the rotor which completes dynamic balance and fixing the rotor; and marking a mark line passing through the circle center on the impeller by using a marking tool. During installation, the rotor marking line is vertically and upwards fixed and aligned with the impeller marking line, and the fit clearance is automatically adjusted to be vertically below under the action of gravity so as to ensure that the installation eccentricity is consistent. During final assembly, the rotor mark extends to the end cover, the impeller mark extends to the outer circle, and press fitting is performed when the two lines coincide and are vertically upward. According to the method, the problem that in the mounting process of the high-speed rotor dynamic balance accessory, due to the fact that mark lines are inaccurate, the center of gravity shifts after repeated disassembly and assembly, and the allowed maximum residual unbalance amount is out of tolerance is solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high-speed rotor dynamic balancing, in particular, relates to a method for adjusting the coincidence of the center of gravity after disassembling the rotor and impeller. BACKGROUND

[0002] The high-speed permanent magnet motor rotor is usually provided with single-stage or double-stage impellers. Generally, after the single-rotor dynamic balancing is completed, the impellers are respectively installed on the corresponding end faces, and then the impellers are taken down for assembly process after the dynamic balancing is completed. However, the cooperation between most impellers and rotors is gap cooperation. It is found through multiple verifications that the balance amount is seriously out of tolerance when the impellers disassembled after dynamic balancing are assembled again. The assembly process is completed for secondary assembly, and the test is carried out under the condition that whether the remaining balance amount is qualified is uncertain, which leads to the vibration out of tolerance of the motor during the load test. The motor can only be disassembled to find the reason, which consumes labor cost, time cost and even causes product scrap.

[0003] The prior art is to clean the impeller and the rotor only when the impeller is installed, without fixing the installation direction. After the impeller is pressed and installed, a mark line is drawn at any position connected by the rotor and the impeller. The angle of the mark line is far away from the center of the impeller, which makes it difficult to find the accurate position of the mark line without seeing the rotor during the assembly process, resulting in low restoration degree of secondary installation. Before the marking tool is not used, only the naked eye is used to compare the angle of the marking line with the mark line drawn by the marking tool, and the deviation angle between them is between 10° and 30°. This method cannot make the mark line of the rotor and the impeller coincide with the center, cannot guarantee that the center of the impeller coincides with the installation position of the previous time after the impeller is disassembled and installed, and cannot guarantee that the repeatability of the unbalance amount meets the design requirements. The existing installation method does not fix the position of the rotor, does not determine the consistent installation direction of the rotor and the impeller, and randomly places the position for installation under the condition of aligning the mark line. Therefore, the position of the center cannot be determined, the position of the center is inconsistent after each disassembly and assembly, and the result is that the unbalance amount is out of tolerance, which affects the overall test effect.

[0004] The existing patent application CN115638923A discloses a dynamic balancing method for a propeller impeller, including the following steps: first, manufacturing the impeller, then measuring the impeller, and then machining the impeller surface; assembling the impeller onto a dynamic balancing fixture; machining the outer cylindrical surface of the impeller using a two-pronged clamping method; attaching a fixture weight to the inner arc surface of the impeller, calculating the impeller's dynamic imbalance, and inputting the values ​​into a dynamic balancing machine for an initial dynamic balancing test to ensure the impeller and dynamic balancing fixture achieve initial dynamic balancing; removing the fixture weight and welding a titanium alloy counterweight of the same material as the impeller; repositioning the impeller and dynamic balancing fixture onto the dynamic balancing machine for a dynamic balancing test to obtain the impeller's imbalance value; and using tools to grind the surface of the titanium alloy counterweight and the inner arc surface of the impeller to achieve overall dynamic balancing of the impeller and dynamic balancing fixture. The impeller mounting section, keyway, balance block groove and other structures of the patented dynamic balancing shaft need to be matched with specific impeller dimensions. When changing impellers of different specifications, the tooling needs to be redesigned, resulting in poor adaptability. Summary of the Invention

[0005] This invention addresses the problem that existing technologies cannot ensure that the markings on the rotor and impeller coincide with the center of the circle, thus failing to guarantee that the impeller center remains aligned with the previous installation position after each disassembly and reassembly, and consequently failing to guarantee the repeatability of the unbalance to meet design requirements. The invention proposes a method for adjusting the center of gravity to coincide after the rotor and impeller are disassembled and reassembled.

[0006] A method for aligning the centers of gravity of a rotor and impeller after disassembly and assembly includes the following steps: S1. Support the dynamically balanced rotor on the dynamic balancing machine, and mark a longitudinal line at the end of the rotor-impeller mating surface, so that the mark line always faces vertically upward. S2. Two triangular blocks of equal height are placed at the angle between the belt of the dynamic balancing machine and the two driven wheels, and the rotor rotation is restricted by the fixed belt. S3. Construct an impeller scribing fixture, which consists of two cuboid blocks and a ruler. According to the tangent length theorem (two tangents drawn from a point outside a circle are of equal length, and the connection between the center of the circle and the point bisects the angle between the two tangents), the outer circle of the impeller is considered as a circle, the two right-angled sides of the scribing fixture are considered as two tangents, and the scale edge of the ruler is a line passing through the center of the circle and bisecting the 90° angle. Place the outer circle of the impeller within the vertical angle of the scribing fixture, ensuring that the outer circle is in close contact with the right-angled side, and then scribing a marking line passing through the center of the impeller along the scale edge of the ruler, so that the marking line can disperse through the center of the impeller. S4. Install the impeller using the gravity influence method. The gravity influence method includes: aligning the markings on the impeller with the markings on the rotor, both of which are vertically upward. Press the impeller in the aligned state, while checking the tightness of the clearance fit. This ensures that the clearance between the impeller and the rotor is automatically adjusted to be directly below the connection between the rotor and the impeller due to the influence of gravity, thus ensuring that the eccentricity is consistent each time it is installed. S5. During assembly, fix the rotor with the marking lines facing vertically upwards, extend the marking lines on the rotor to the end cover using the marking fixture, and extend the marking lines on the impeller to the outer circumference of the impeller. Press the impeller in place when the marking lines on the impeller and the marking lines on the end cover coincide and are both vertically upwards.

[0007] Furthermore, the scribing fixture consists of two 145mm×28mm×20mm plastic plates and a ruler. First, the two plastic plates are spliced ​​together to form a right-angle structure, and then the ruler is glued in the middle of the right angle, so that the scale edge of the ruler and a right-angle edge form a 45° angle.

[0008] Furthermore, the ruler is fixed between the right-angle structures by bolt fastening or snap-fit ​​connection, and the perpendicularity error between the ruler's scale edge and the perpendicular edge of the right-angle structure is ≤0.5°.

[0009] Furthermore, in step S2, the height of the triangular equal-height block is adapted to the fit clearance between the dynamic balancing machine belt and the driven wheel, so that the belt is completely limited without damaging the belt surface.

[0010] Furthermore, the triangular contour block is a triangular contour block made of rubber.

[0011] Furthermore, in step S5, the method of extending the marking line on the rotor to the end cover is as follows: the scribing tool is attached to the surface of the end cover, and an extension mark is drawn along the direction of the rotor marking line. The extension mark is coplanar with the rotor marking line and faces vertically upward.

[0012] Furthermore, it also includes impeller installation anomaly detection and handling, including the following steps: S6. Abnormal Judgment: After the impeller is installed and dynamic balancing is completed, record the unbalance data. Then, according to the requirements, remove the impeller and reinstall it with the same pressure at the original marked line position. Measure and record the unbalance data again. Compare the unbalance data before and after the impeller is removed. If the two data deviate from the design requirements by more than the preset range, it is judged that there is an abnormality in the impeller installation. S7. Troubleshooting: First, remove the impeller and check for foreign objects at the joint between the impeller and the rotor; check if the impeller markings meet the requirements, ensuring that the markings coincide with the center of the circle; then check if the rotor is fixed and if the markings on the rotor are pointing directly upwards. S8. Reinstall the impeller following steps S1 to S5.

[0013] Furthermore, the preset range is: the remaining imbalance of the impeller after disassembly and assembly is ≤400mg, and the difference between the impeller and the initial dynamic balance data is ≤300mg.

[0014] Furthermore, in step S4, the deviation of the alignment of the marking lines is ≤0.5°.

[0015] Furthermore, step S5 also includes the initial installation of the high-speed permanent magnet rotor system and at least one repeated disassembly and assembly; after each installation, the remaining imbalance is measured; and it is verified whether the remaining imbalance data before and after the repeated disassembly and assembly are within the range of the maximum allowable imbalance calculated based on the target balance level.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention solves the problem of excessive maximum residual imbalance caused by inaccurate marking lines during the installation of dynamic balancing accessories for high-speed rotors, resulting in center of gravity shift after repeated disassembly and reassembly. This invention designs and manufactures a marking line scribing fixture to solve the marking line eccentricity problem, and proposes a gravity-based method for impeller installation, ensuring consistent center of gravity after each disassembly and reassembly, thus resolving the problem of excessive maximum allowable imbalance after disassembly and reassembly.

[0017] 2. This invention, through its rotor fixing device, marking line alignment mechanism, and gravity-based automatic gap adjustment design, ensures that the impeller center remains consistent with the original installation position regardless of the number of disassembly and assembly cycles. It also features high eccentricity repeatability, eliminating the need for repeated dynamic balancing corrections and significantly reducing rework rates.

[0018] 3. The tooling structure can be adapted to impellers and rotors of different diameters by adjusting the size. The operation process does not rely on the special functions of dedicated dynamic balancing equipment. It is suitable for disassembly and assembly of various rotating machinery such as high-speed permanent magnet rotors, motor rotors, pump and valve impellers, and has outstanding practicality and compatibility. Attached Figure Description

[0019] Figure 1 This is a flowchart of the present invention; Figure 2 This is a schematic diagram of the structure of the high-speed permanent magnet rotor fixed on the dynamic balancing machine in this invention; Figure 3 This is a schematic diagram of the longitudinal marking line at the end of the mating surface between the rotor and the impeller in this invention; Figure 4 This is a schematic diagram of the rubber triangular contour block of the present invention; Figure 5 This is a schematic diagram of the fixed belt and rotor in this invention; Figure 6 This is a schematic diagram of the impeller scribing tooling structure of the present invention; Figure 7This is a schematic diagram of scribing the impeller using a scribing tool according to the present invention; Figure 8 This is a schematic diagram showing the markings on the impeller of the present invention pointing vertically upwards and coinciding with the markings on the rotor; Figure 9 This is a schematic diagram of the structure in this invention that fixes the rotor and extends the rotor markings to the end cap; Figure 10 This is a schematic diagram illustrating the alignment and installation of the impeller markings and volute markings according to the present invention; In the above diagram, 1. Rotor; 2. Impeller; 3. Marking lines on the rotor; 4. Marking lines on the impeller; 5. Rubber triangular contour block; 6. Marking fixture. Detailed Implementation

[0020] To clearly illustrate the technical features of the present invention, the invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the invention; however, the invention may be implemented in other ways different from those described herein, and therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below. In the present invention, unless otherwise expressly specified and limited, the first feature "on" or "below" the second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0021] Example 1 like Figure 1 As shown, a method for aligning the centers of gravity of a rotor and impeller after disassembly and assembly includes the following steps: S1. Support the dynamically balanced rotor 1 on the dynamic balancing machine, and mark a longitudinal line at the end of the mating surface between the rotor 1 and the impeller 2, so that the mark line always faces vertically upward. S2. Two triangular blocks of equal height are placed at the angle between the belt of the dynamic balancing machine and the two driven wheels, and the rotor rotation is restricted by the fixed belt. S3. Construct the impeller scribing fixture 6, which consists of two cuboid blocks and a ruler. According to the tangent length theorem of a circle (two tangents drawn from a point outside a circle are of equal length, and the connection between the center of the circle and the point bisects the angle between the two tangents), the outer circle of the impeller 2 is regarded as a circle, the two right-angled sides of the scribing fixture 6 are regarded as two tangents, and the scale edge of the ruler is a line that passes through the center of the circle and bisects the 90° angle. Place the outer circle of the impeller 2 into the vertical angle of the scribing fixture 6, ensuring that the outer circle of the impeller 2 is in close contact with the right-angled side, and then scribing a marking line passing through the center of the impeller 2 along the scale edge of the ruler, so that the marking line can disperse through the center of the impeller 2. S4. Install the impeller 2 using the gravity influence method. The gravity influence method includes: aligning the marking line 4 on the impeller 2 with the marking line 3 on the rotor, both of which are vertically upward. Press the impeller 2 while maintaining the alignment, and at the same time check the tightness of the clearance fit. This ensures that the clearance between the impeller 2 and the rotor 1 is automatically adjusted to directly below the connection between the rotor and the impeller due to the influence of gravity, thus ensuring that the eccentricity is consistent each time it is installed. S5. During assembly, the marking line 3 on the rotor is vertically upward and the rotor 1 is fixed. The marking line 3 on the rotor is extended to the end cover through the marking tool. At the same time, the marking line 4 on the impeller is extended to the outer surface of the impeller 2. When the marking line 4 on the impeller coincides with the marking line on the end cover and both are vertically upward, the impeller 2 is pressed in.

[0022] This embodiment applies to the dynamic balancing and assembly process of a high-speed permanent magnet motor rotor system. It aims to ensure that the center of gravity of the impeller after repeated disassembly and assembly is basically coincident with the initial balance center of gravity of the rotor through precise marking and alignment, thereby controlling the remaining imbalance within the allowable range.

[0023] like Figure 2 As shown, in this embodiment, the rotor 1 (considered a standard workpiece) that has undergone single-piece dynamic balancing and meets design requirements is supported on a dynamic balancing machine. At the end of the mating surface between the rotor 1 and the impeller 2, a clear marking line is made axially using a scribing tool, as shown... Figure 3 As shown. When marking, use a level to ensure the marking line is always vertically upward.

[0024] like Figure 4 and Figure 5 As shown, to prevent rotor 1 from rotating unexpectedly on the dynamic balancing machine, two rubber triangular blocks 5 with a height of 8mm and adapted to the clearance between the dynamic balancing machine belt and the driven pulley are used. These two triangular blocks are precisely inserted into the angular gap formed between the dynamic balancing machine drive belt and the two driven pulleys. The height of the triangular blocks and the clearance are matched so that they can completely restrict belt displacement, thereby firmly locking the position of rotor 1 without damaging the belt surface.

[0025] like Figure 6As shown, a simple impeller scribing fixture 6 is constructed. The fixture consists of two 145mm × 28mm × 20mm plastic plates and a ruler. First, the two plastic plates are joined to form a right angle. Then, the ruler is glued to the center of the right angle, making the ruler's graduated edge and one right-angled edge form a 45° angle. During scribing, the outer circle of the impeller is embedded within the vertical angle of the scribing fixture 6, ensuring a tight fit between the outer circle of the impeller 2 and the inner wall of the fixture. A marker is used to draw a line passing through the center of the impeller along the edge of the ruler's graduated edge, with the scribing deviation controlled within 0.3°. Theoretically, the line containing the ruler's graduated edge must pass through the center of the impeller 2. The operator uses a marker, close to the edge of the ruler, to draw the corresponding line on the end face or outer circle of the impeller 2. This fixture ensures the accuracy of the marking lines, allowing them to disperse through the center of the impeller 2.

[0026] like Figure 8 As shown, the impeller 2 is installed using the "gravity influence method". First, ensure that the marking line on the rotor 1 in step S1 is vertically upward. Then, pick up the impeller 2, which has been marked in step S3, and adjust its marking line to be vertically upward as well, precisely aligning it with the marking line 3 on the rotor. While maintaining this alignment, apply a preset pressure to press the impeller 2 onto the rotor 1, while simultaneously checking the tightness of the clearance with a feeler gauge. During the pressing process, due to gravity, the clearance between the impeller 2 and the rotor 1 mating surface will automatically adjust to be vertically downward, which is equivalent to fixing the orientation of the mating clearance. This method ensures that no matter how many times the assembly and disassembly are repeated, as long as this alignment is maintained, the eccentric position (eccentricity) of the impeller 2 relative to the rotor 1 will remain essentially consistent.

[0027] During the final assembly stage, the installation of impeller 2 differs from the dynamic balancing process. Because rotor 2 is inside the base, the portion exposed above the end cover and volute is very small, making it impossible to observe the markings on the shaft during installation, which easily leads to misalignment. Therefore, the base (along with the internal rotor 1) must first be adjusted and fixed so that the marking line 3 on the rotor is vertically upward. Then, using the impeller marking fixture 6, its reference edge is aligned with the visible plane of the end cover, and the marking line 3 on the rotor is precisely extended and marked onto the end cover, such as... Figure 9 As shown. Similarly, using a tool, the marking line 4 on the impeller is also clearly extended and marked onto its visible outer surface. During installation, adjust the impeller 2's orientation so that the extended marking line on its outer circumference and the extended marking line on the end cap are simultaneously perpendicularly upward and aligned, as shown. Figure 10 As shown, pressing is then performed. This achieves precise restoration of the original rotor markings that are not visible.

[0028] This embodiment systematically solves the problem of center of gravity shift after disassembly and assembly caused by inaccurate marking and arbitrary alignment through the above steps.

[0029] Example 2 like Figure 1As shown, a method for aligning the centers of gravity of a rotor and impeller after disassembly and assembly includes the following steps: S1. Support the dynamically balanced rotor 1 on the dynamic balancing machine, and mark a longitudinal line at the end of the mating surface between the rotor 1 and the impeller 2, so that the mark line always faces vertically upward. S2. Two triangular blocks of equal height are placed at the angle between the belt of the dynamic balancing machine and the two driven wheels, and the rotor rotation is restricted by the fixed belt. S3. Construct the impeller scribing fixture 6, which consists of two cuboid blocks and a ruler. According to the tangent length theorem of a circle (two tangents drawn from a point outside a circle are of equal length, and the connection between the center of the circle and the point bisects the angle between the two tangents), the outer circle of the impeller 2 is regarded as a circle, the two right-angled sides of the scribing fixture 6 are regarded as two tangents, and the scale edge of the ruler is a line that passes through the center of the circle and bisects the 90° angle. Place the outer circle of the impeller 2 into the vertical angle of the scribing fixture 6, ensuring that the outer circle of the impeller 2 is in close contact with the right-angled side, and then scribing a marking line passing through the center of the impeller 2 along the scale edge of the ruler, so that the marking line can disperse through the center of the impeller 2. S4. Install the impeller 2 using the gravity influence method. The gravity influence method includes: aligning the marking line 4 on the impeller 2 with the marking line 3 on the rotor, both of which are vertically upward. Press the impeller 2 while maintaining the alignment, and at the same time check the tightness of the clearance fit. This ensures that the clearance between the impeller 2 and the rotor 1 is automatically adjusted to the vertical position directly below the connection point of the two workpieces due to the influence of gravity, thus ensuring that the eccentricity is consistent each time it is installed. S5. During assembly, the marking line 3 on the rotor is vertically upward and the rotor 1 is fixed. The marking line 3 on the rotor is extended to the end cover through the marking tool. At the same time, the marking line 4 on the impeller is extended to the outer surface of the impeller 2. When the marking line 4 on the impeller coincides with the marking line on the end cover and both are vertically upward, the impeller 2 is pressed in.

[0030] In this embodiment, the impeller installation anomaly detection and handling process is also included, comprising the following steps: S6. Abnormal Judgment: After installing impeller 2 and completing dynamic balancing, record the unbalance data. Then, according to the requirements, remove impeller 2 and reinstall it with the same pressure at the original marked line position. Measure and record the unbalance data again. Compare the unbalance data before and after removing and installing impeller 2. If the two data deviate from the design requirements by more than the preset range, it is judged that there is an abnormality in the installation of impeller 2. S7. Troubleshooting: First, remove the impeller 2 and check if there are any foreign objects at the joint between the impeller 2 and the rotor 1; check if the marking line 4 on the impeller meets the requirements, requiring the marking line to coincide with the center of the circle; then check if the rotor 1 is fixed and if the marking line 3 on the rotor is facing directly upward. S8. Reinstall the impeller following steps S1 to S5.

[0031] Taking the dynamic balancing practice data of a certain type of high-speed permanent magnet rotor as an example, the total weight of the rotor is angular velocity The impeller dynamic balance radius is The design requires the impeller to have a dynamic balance rating of [level missing] upon initial installation. The permissible imbalance level after disassembling and assembling the impeller is: Based on the available information, the calculations are as follows: angular velocity ; (1) Calculation of the maximum allowable imbalance after the initial installation of the impeller: The dynamic balance vector is ; The maximum allowable unbalanced weight is ; (2) Calculation of the maximum allowable imbalance after disassembling and assembling the impeller: Dynamic balance vector: ; The maximum allowable unbalanced weight is ; Table 1 below shows a comparison of the remaining imbalance data after the initial dynamic balancing and after disassembly and assembly of the impeller when using existing technical methods to install the impeller.

[0032] Table 1

[0033] When the impeller was installed using existing technical methods, the results showed that 607mg > 400mg, which did not meet the design requirements.

[0034] The following table 2 shows a comparison of the remaining imbalance data after the initial dynamic balancing and the impeller disassembly / reassembly when using this embodiment to install and disassemble the impeller.

[0035] Table 2

[0036] The results showed that 178mg < 400mg, which meets the design requirements.

[0037] In this embodiment, after the rotor and impeller are repeatedly disassembled and reassembled three times, the remaining imbalance is stable between 150mg and 190mg, which meets the design requirement of G6.3 balance level (maximum allowable imbalance of 400mg). Compared with the prior art (imbalance of 607mg after disassembly and reassembly), the imbalance fluctuation range is significantly reduced, and the assembly accuracy and repeatability are greatly improved.

[0038] Example 3 In this embodiment, for application scenarios with higher requirements for balance grade (such as better than G6.3) or rotor systems that are more sensitive to the fluctuation of unbalance, based on the basic method of Embodiment 1, more stringent alignment control standards and auxiliary measurement links are added.

[0039] In this embodiment, in step S4 (press-fitting in the dynamic balancing process) and step S5 (press-fitting in the assembly process), the requirement of aligning vertically upward is quantified into more precise angular deviation control. A high-precision digital level or a centering instrument with a cross laser line is used to assist the operation. The specific requirement is that when the marking line 4 on the impeller is aligned with the marking line 3 on the rotor, the relative angular deviation is not greater than 0.5°. This ensures that the positioning of the two parts in the circumferential direction reaches a very high repeatability accuracy.

[0040] During the press-fitting process, instead of relying solely on gravity to naturally adjust the clearance, a pre-tightening fine-tuning step is added. That is, after the marking line 4 on the impeller is initially aligned with the marking line on the rotor 1 (or end cover) and the press-fitting starts, before the final pressing, the impeller 2 is allowed to have a small free swing under its own weight. The operator observes at this moment and ensures that after the swing stops, the two marking lines still remain within the above-mentioned 0.5° deviation requirement, and then the final press-fitting pressure is applied. This step further utilizes the self-aligning effect of gravity and eliminates the deviation caused by the small lateral force introduced by the installation tool or operation method.

[0041] In this embodiment, for each set of high-speed permanent magnet rotor systems applying this method, not only the initial installation and balance test are carried out, but also at least one complete disassembly and reassembly cycle test is compulsorily required. The remaining unbalance data (M1) after the initial installation and the data (M2, M3...) after each disassembly and reassembly are recorded in detail and compared. All data need to be compared with the theoretically allowed maximum unbalance calculated according to the target balance grade (such as G1 level for the initial time and G6.3 level for after disassembly and reassembly). Only when all measurement data meet the design requirements can the installation operation be determined to be qualified.

[0042] Obviously, the above-described embodiments are only examples for clearly explaining the present invention and are not limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A method for aligning the center of gravity of a rotor and impeller after disassembly and assembly, characterized in that, Includes the following steps: S1. Support the dynamically balanced rotor on the dynamic balancing machine, and mark a longitudinal line at the end of the rotor-impeller mating surface, so that the mark line always faces vertically upward. S2. Two triangular blocks of equal height are placed at the angle between the belt of the dynamic balancing machine and the two driven wheels, and the rotor rotation is restricted by the fixed belt. S3. Construct an impeller scribing fixture, which consists of two cuboid blocks and a ruler. According to the tangent length theorem, the outer circle of the impeller is considered as a circle, the two right-angled sides of the scribing fixture are considered as two tangents, and the scale edge of the ruler is a line that passes through the center of the circle and bisects the 90° angle. Place the outer circle of the impeller into the vertical angle of the scribing fixture, ensuring that the outer circle is in close contact with the right-angled side, and then scribing a marking line that passes through the center of the impeller along the scale edge of the ruler, so that the marking line can disperse through the center of the impeller. S4. Install the impeller using the gravity influence method. The gravity influence method includes: aligning the markings on the impeller with the markings on the rotor, both of which are vertically upward. Press the impeller in the aligned state, while checking the tightness of the clearance fit. This ensures that the clearance between the impeller and the rotor is automatically adjusted to be directly below the connection between the rotor and the impeller due to the influence of gravity, thus ensuring that the eccentricity is consistent each time it is installed. S5. During assembly, fix the rotor with the marking lines facing vertically upwards, extend the marking lines on the rotor to the end cover using the marking fixture, and extend the marking lines on the impeller to the outer circumference of the impeller. Press the impeller in place when the marking lines on the impeller and the marking lines on the end cover coincide and are both vertically upwards.

2. The method for adjusting the center of gravity to coincide after disassembling and assembling the rotor and impeller, as described in claim 1, is characterized in that... The marking fixture consists of two 145mm×28mm×20mm plastic plates and a ruler. First, the two plastic plates are spliced ​​together to form a right angle structure, and then the ruler is glued in the middle of the right angle so that the scale edge of the ruler and one right angle edge form a 45° angle.

3. The method for adjusting the center of gravity to coincide after disassembling and assembling the rotor and impeller, as described in claim 2, is characterized in that... The ruler is fixed to the right-angle structure by bolts or clips, and the perpendicularity error between the ruler's scale edge and the perpendicular edge of the right-angle structure is ≤0.5°.

4. The method for adjusting the center of gravity to coincide after disassembling and assembling the rotor and impeller, as described in claim 1, is characterized in that... In step S2, the height of the triangular equal-height block is adapted to the fit clearance between the dynamic balancing machine belt and the driven wheel, so that the belt is completely limited and the belt surface is not damaged.

5. A method for adjusting the center of gravity to coincide after disassembling and assembling the rotor and impeller, as described in claim 4, characterized in that... The triangular contour blocks are made of rubber.

6. A method for adjusting the center of gravity to coincide after disassembling and assembling the rotor and impeller, as described in claim 1, characterized in that... In step S5, the method of extending the marking line on the rotor to the end cover is as follows: the scribing tool is attached to the surface of the end cover, and an extension mark is drawn along the direction of the rotor marking line. The extension mark is coplanar with the rotor marking line and faces vertically upward.

7. A method for adjusting the center of gravity to coincide after disassembling and assembling the rotor and impeller, as described in claim 1, characterized in that... It also includes handling impeller installation anomalies, including the following steps: S6. Abnormal Judgment: After the impeller is installed and dynamic balancing is completed, record the unbalance data. Then, according to the requirements, remove the impeller and reinstall it with the same pressure at the original marked line position. Measure and record the unbalance data again. Compare the unbalance data before and after the impeller is removed. If the two data deviate from the design requirements by more than the preset range, it is judged that there is an abnormality in the impeller installation. S7. Troubleshooting: First, remove the impeller and check for foreign objects at the joint between the impeller and the rotor; check if the impeller markings meet the requirements, ensuring that the markings coincide with the center of the circle; then check if the rotor is fixed and if the markings on the rotor are pointing directly upwards. S8. Reinstall the impeller following steps S1 to S5.

8. A method for adjusting the center of gravity to coincide after disassembling and assembling the rotor and impeller, as described in claim 7, characterized in that... The preset range is: the remaining imbalance of the impeller after disassembly and assembly is ≤400mg, and the difference between the impeller and the initial dynamic balance data is ≤300mg.

9. A method for adjusting the center of gravity to coincide after disassembling and assembling the rotor and impeller, as described in claim 1, characterized in that, In step S4, the deviation of the alignment of the marking lines is ≤0.5°.

10. A method for adjusting the center of gravity to coincide after disassembling and assembling the rotor and impeller, as described in claim 1, characterized in that... Step S5 also includes the initial installation of the high-speed permanent magnet rotor system and at least one repeated disassembly and assembly; after each installation, the remaining imbalance is measured; and it is verified whether the remaining imbalance data before and after repeated disassembly and assembly are within the range of the maximum allowable imbalance calculated based on the target balance level.

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