Dynamic balance test method for impeller assembly

Abstract

The invention provides a dynamic balance test method of an impeller assembly, and belongs to the technical field of impeller dynamic balance test. The test method comprises the steps that the magnitude and the direction of the unbalance amount of the impeller assembly during rotation are determined; according to the magnitude and the direction of the unbalance, a balancing weight is connected to the impeller assembly, so that the unbalance of the impeller assembly connected with the balancing weight meets the allowable unbalance theoretical requirement; and the balancing weight is detached, and the weight of the impeller assembly is reduced or increased according to the balancing weight. The impeller assembly dynamic balance test efficiency can be improved.

Description

Technical Field

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

[0002] When the propeller is working, the impeller assembly generates thrust by rotating at high speed, so that the propeller can achieve the propulsion function. The impeller assembly usually includes an impeller body and a motor rotor, and the motor rotor is integrated on the impeller body by assembly welding. Since the impeller assembly is an assembly welding structure, it is impossible to ensure that the imbalance of the impeller assembly is within the theoretical range of the allowable imbalance after forming. In order to avoid the imbalance of the impeller assembly exceeding the standard, a dynamic balancing test is usually carried out on the impeller assembly during the manufacturing stage to detect the imbalance of the impeller assembly.

[0003] In the related art, when the impeller assembly is subjected to a dynamic balancing test, the impeller assembly is generally connected to a dynamic balancing machine. The dynamic balancing machine drives the impeller assembly to rotate and detects the imbalance during rotation. If the imbalance of the impeller assembly exceeds the standard, the surface of the impeller assembly where the imbalance is located is polished to eliminate the imbalance.

[0004] However, in the above test process, the grinding amount is uncontrollable during the grinding process. It can only rely on the experience of the workers to grind once and calibrate once. It takes many repeated grinding and calibration to achieve the required balancing accuracy of the impeller assembly. Summary of the invention

[0005] The embodiment of the present disclosure provides a dynamic balancing test method for an impeller assembly, which can improve the efficiency of the dynamic balancing test of the impeller assembly. The technical solution is as follows:

[0006] An embodiment of the present disclosure provides a dynamic balancing test method for an impeller assembly, the test method comprising: determining the size and direction of the imbalance of the impeller assembly during rotation; connecting a counterweight to the impeller assembly according to the size and direction of the imbalance, so that the imbalance of the impeller assembly connected with the counterweight meets the theoretical requirement of allowable imbalance; removing the counterweight, and reducing or increasing the weight of the impeller assembly according to the counterweight.

[0007] In another implementation of the present disclosure, determining the size and direction of the imbalance of the impeller assembly during rotation includes: connecting the impeller assembly to a dynamic balancing machine via a fixing device to detect the size and direction of the imbalance of the impeller assembly during rotation; wherein the fixing device includes a support shaft, a pulley and an elastic sleeve, and the pulley is interference-fitted outside the middle portion of the support shaft; the elastic sleeve is sleeved outside the support shaft and spaced apart from the pulley, and the elastic sleeve is connected to the impeller assembly.

[0008] In another implementation of the present disclosure, the outer wall of the support shaft connected to the elastic sleeve has a conical surface, the inner wall of the elastic sleeve is fitted with the conical surface, and the outer diameter of the conical surface gradually increases along the direction from the first end to the second end of the elastic sleeve; the fixing device also includes a fastener, which is located on the side of the elastic sleeve away from the pulley and is connected to the support shaft, and the fastener is used to abut against the first end of the elastic sleeve.

[0009] In another implementation of the present disclosure, the dynamic balancing test method further includes: before connecting the impeller assembly to the dynamic balancing machine via a fixing device, detecting the unbalance amount of the fixing device, and ensuring that the unbalance amount of the fixing device is no greater than 1 / 10 of the theoretical requirement of the allowable unbalance amount of the impeller assembly.

[0010] In another implementation of the present disclosure, reducing or increasing the weight of the impeller assembly according to the counterweight block includes: connecting a balancing block at the position where the counterweight block is connected in the impeller assembly to increase the weight, or machining the position of the impeller assembly opposite to the counterweight block to reduce the weight, the relative position of the counterweight block and the position where the counterweight block is located being centrally symmetrically distributed about the center of the impeller assembly.

[0011] In another implementation of the present disclosure, the dynamic balancing test method further includes: detecting the imbalance amount of the impeller assembly after weight reduction or weight increase, and determining whether the imbalance amount of the impeller assembly after weight reduction or weight increase meets the theoretical requirement of allowable imbalance amount.

[0012] In another implementation of the present disclosure, the detecting the unbalance amount of the impeller assembly after weight reduction or weight increase, and judging whether the unbalance amount of the impeller assembly after weight reduction or weight increase meets the theoretical requirement of allowable unbalance amount, comprises: installing the impeller assembly after weight reduction or weight increase in the fixing device, and the two ends of the support shaft are rotatably connected to the dynamic balancing machine through bearings; according to the connection relationship between the support shaft and the dynamic balancing machine, determining two support planes, the two support planes are cross sections of the support shaft, and the support planes are located at the connection between the support shaft and the dynamic balancing machine; determining two correction planes in the impeller assembly, the two correction planes correspond to and are parallel to the two support planes one by one, and the two correction planes are respectively located on both sides of the center of mass of the impeller assembly; according to the unbalance amount detected at each correction plane in the two correction planes and the theoretical unbalance amount calculated by the correction planes, determining whether the unbalance amount of the impeller assembly after weight reduction or weight increase meets the theoretical requirement of allowable unbalance amount.

[0013] In another implementation of the present disclosure, the theoretical unbalance amount at the correction plane is calculated according to the following formula:

[0014]

[0015] Among them, U per1 is the theoretical unbalance at the correction plane; m′ is the equal-calibration mass at the correction plane; G is the balancing accuracy grade; n is the rotation speed of the impeller assembly; r is the shaft diameter of the support shaft corresponding to the correction plane.

[0016] In another implementation of the present disclosure, determining whether the unbalance amount of the impeller assembly after weight reduction or weight increase meets the theoretical requirement of allowable unbalance amount according to the unbalance amount detected at each of the two correction planes and the theoretical unbalance amount calculated by the correction plane includes:

[0017] If the unbalance amount detected at at least one of the correction planes is greater than the theoretical unbalance amount, it is determined that the unbalance amount of the impeller assembly after weight reduction or weight increase does not meet the theoretical requirement of the allowable unbalance amount.

[0018] In another implementation of the present disclosure, a counterweight is connected to the impeller assembly so that the imbalance of the impeller assembly connected with the counterweight meets the theoretical requirement of allowable imbalance, including: pasting the counterweight to the impeller assembly, and the direction of the counterweight relative to the impeller assembly is opposite to the direction of the imbalance of the impeller assembly; detecting the imbalance of the impeller assembly with the counterweight, and adjusting the size of the counterweight according to the detection result.

[0019] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects:

[0020] When the dynamic balancing test method provided by the embodiment of the present disclosure is used to perform a dynamic balancing test on the impeller assembly, the unbalance amount of the impeller assembly during rotation is first obtained, so that it can be determined whether the impeller assembly is unbalanced based on the unbalance amount. If the impeller assembly is unbalanced, the dynamic balancing test method connects a counterweight block to the impeller assembly, and the unbalance amount of the impeller assembly meets the theoretical requirement of the allowable unbalance amount through the setting of the counterweight block. Afterwards, the weight of the impeller assembly can be reduced or increased based on the position of the connected counterweight block and the size of the counterweight block, thereby avoiding repeated grinding of the impeller assembly and greatly improving the test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 It is a structural schematic diagram of an impeller assembly in the related art;

[0023] Figure 2 yes Figure 1 The left figure in ;

[0024] Figure 3 is a flow chart of a dynamic balancing test method of an impeller assembly provided by an embodiment of the present disclosure;

[0025] Figure 4 is a flow chart of another dynamic balancing test method of an impeller assembly provided by an embodiment of the present disclosure;

[0026] Figure 5 is a schematic diagram of the structure of a fixing device provided in an embodiment of the present disclosure;

[0027] Figure 6 It is a schematic diagram of the structure in which the impeller assembly is assembled in the fixture;

[0028] Figure 7 It is a simplified schematic diagram of the impeller assembly during inspection.

[0029] The symbols in the figure mean the following:

[0030] 1. Hub; 2. Rim; 3. Guide vane;

[0031] 100, support shaft; 101, first support section; 102, first connecting section; 1021, outer flange; 103, limit section; 104, second connecting section; 105, third connecting section; 106, second support section;

[0032] 200, pulley; 300, elastic sleeve;

[0033] 400, fastener; 401, bushing; 4011, outer flange; 402, locking nut; 403, fastening screw. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0035] Figure 1 It is a structural schematic diagram of an impeller assembly in the related art. Figure 2 yes Figure 1 The left figure in Figure 1 and Figure 2 The impeller assembly includes a hub body 1, a rim 2 and a plurality of guide vanes 3. The rim 2 is sleeved outside the hub body 1, and the plurality of guide vanes 3 are located between the rim 2 and the hub body 1, and are connected to the rim 2 and the hub body 1 respectively.

[0036] The interior of the hub body 1 is a hollow structure. The interior of the hub body 1 is used to connect with the shaft. The number of the guide vanes 3 is generally an odd number, and the impeller assembly is a non-axisymmetric structure.

[0037] The present disclosure provides a method for dynamic balancing of an impeller assembly. Figure 3 As shown, the test methods include:

[0038] S301: Determine the magnitude and direction of the imbalance of the impeller assembly during rotation.

[0039] S302: Connect a counterweight to the impeller assembly according to the magnitude and direction of the unbalance of the impeller assembly, so that the unbalance of the impeller assembly connected with the counterweight meets the theoretical requirement of the allowable unbalance.

[0040] S303: Remove the counterweight block, and reduce or increase the weight of the impeller assembly according to the counterweight block.

[0041] When the dynamic balancing test method provided by the embodiment of the present disclosure is used to perform a dynamic balancing test on the impeller assembly, the unbalance amount of the impeller assembly during rotation is first obtained, so that it can be determined whether the impeller assembly is unbalanced based on the unbalance amount. If the impeller assembly is unbalanced, the dynamic balancing test method connects a counterweight block to the impeller assembly, and the unbalance amount of the impeller assembly meets the theoretical requirement of the allowable unbalance amount through the setting of the counterweight block. Afterwards, the weight of the impeller assembly can be reduced or increased based on the position of the connected counterweight block and the size of the counterweight block, thereby avoiding repeated grinding of the impeller assembly and greatly improving the test efficiency.

[0042] On the other hand, the embodiment of the present disclosure also provides another dynamic balancing test method, such as Figure 4 As shown, the dynamic balance test method includes:

[0043] S401: Provide fixing device.

[0044] Figure 5 is a schematic diagram of the structure of the fixing device provided in the embodiment of the present disclosure, such as Figure 5 As shown, the fixing device includes a support shaft 100, a pulley 200 and an elastic sleeve 300. Both ends of the support shaft 100 are rotatably connected to the bracket in the dynamic balancing machine through bearings. The pulley 200 is sleeved outside the middle of the support shaft 100. The pulley 200 is used to be connected to the belt of the dynamic balancing machine.

[0045] The elastic sleeve 300 is sleeved on the outside of the supporting shaft 100 and is spaced apart from the pulley 200 . The elastic sleeve 300 is used to be connected to the impeller assembly.

[0046] Thus, when the dynamic balancing machine is started, the belt of the dynamic balancing machine will drive the pulley 200 to rotate, the pulley 200 will drive the support shaft 100 to rotate, and the support shaft 100 will drive the impeller assembly to rotate through the elastic sleeve 300, thereby detecting the impeller assembly.

[0047] Optionally, the outer wall of the support shaft 100 sleeved with the elastic sleeve 300 has a conical surface, the inner wall of the elastic sleeve 300 fits the conical surface, and the outer diameter of the conical surface gradually increases along the direction from the first end to the second end of the elastic sleeve 300.

[0048] The fixing device further comprises a fastener 400 , which is located on a side of the elastic sleeve 300 away from the pulley 200 and connected to the support shaft 100 . The fastener 400 is used to abut against a first end of the elastic sleeve 300 .

[0049] When the elastic sleeve 300 is squeezed by the locking piece 400, the elastic sleeve 300 will climb along the conical surface, and the outer circle of the elastic sleeve 300 will expand, thereby achieving the purpose of fixing the impeller assembly, so that the impeller assembly can be reliably installed on the fixing device.

[0050] In the disclosed embodiment, along the length direction of the support shaft 100 , the support shaft 100 includes a first supporting section 101 , a first connecting section 102 , a limiting section 103 , a second connecting section 104 , a third connecting section 105 and a second supporting section 106 which are connected in sequence.

[0051] The first support section 101 and the second support section 106 are coaxial and have the same outer diameter. The first support section 101 and the second support section 106 are used to be placed on bearings at both ends of the dynamic balancing machine so that the support shaft 100 can maintain balance after the fixing device is connected to the dynamic balancing machine.

[0052] The outer diameter of the first connecting section 102 is larger than the outer diameter of the first supporting section 101. The outer diameter of the limiting section 103 is larger than the outer diameter of the first connecting section 102. The outer diameter of the second connecting section 104 is smaller than the outer diameter of the limiting section 103 and larger than the outer diameter of the third connecting section 105. The outer diameter of the third connecting section 105 is larger than the outer diameter of the second supporting section 106.

[0053] The pulley 200 is sleeved outside the first connecting section 102 and has an interference fit with the first connecting section 102. The middle part of the first connecting section 102 has an outer flange 1021, and one side of the pulley 200 abuts against the outer flange 1021. The outer flange 1021 is used to limit the pulley 200, so as to facilitate the installation and positioning of the pulley 200 on the support shaft 100.

[0054] The conical surface is located in the second connecting section 104, and the outer diameter of the second connecting section 104 gradually decreases along the direction from the limiting section 103 to the second supporting section 106. The outer wall of the third connecting section 105 has an external thread, which cooperates with the internal thread of the fastener 400 so that the fastener 400 is installed on the support shaft 100.

[0055] The fastener 400 includes a bushing 401, a locking nut 402, and a fastening screw 403. One end of the bushing 401 is clamped between the third connecting section 105 and the elastic sleeve 300, and the locking nut 402 is sleeved outside the other end of the bushing 401. The end surface of the locking nut 402 contacts the end surface of the elastic sleeve 300. The locking nut 402 is threadedly connected to the third connecting section 105. The fastening screw 403 is located in the radial direction of the locking nut 402, one end of the fastening screw 403 is connected to the locking nut 402, and the other end is against the third connecting section 105.

[0056] The external thread of the outer wall of the third connecting section 105 is used to assemble the locking nut 402. The locking nut 402 is tightened by the thread and squeezes the elastic sleeve 300 to expand it. When the locking nut 402 is tightened to fix the impeller assembly, the fastening screw 403 can tighten the locking nut 402 to prevent the locking nut 402 from loosening during the dynamic balancing test.

[0057] Exemplarily, the bushing 401 and the elastic sleeve 300 are both hollow cylindrical structures. One end of the bushing 401 has an annular outer flange 4011. The inner wall of the first end of the elastic sleeve 300 has an inner flange. The inner flange is clamped between the outer flange and the locking nut 402. In this way, the elastic sleeve 300 can be firmly assembled on the support shaft 100.

[0058] S402: Check the unbalance amount of the fixture and ensure that the unbalance amount of the fixture is no greater than 1 / 10 of the allowable unbalance amount of the impeller assembly.

[0059] In the disclosed embodiment, before carrying out the dynamic balancing test, the imbalance amount of the fixture itself needs to be checked first.

[0060] During the inspection, the fixture is first installed on the dynamic balancing machine, so that both ends of the support shaft are connected to the dynamic balancing machine through bearings, and the pulley is connected to the belt of the dynamic balancing machine.

[0061] Then, the dynamic balancing machine is started to operate at the rated speed of the impeller assembly or the maximum speed of the dynamic balancing machine, and the unbalance value of the fixture is measured.

[0062] In order to accurately determine the dynamic balance of the impeller assembly being tested, it is stipulated that the unbalance detected by the fixture shall not be greater than 1 / 10 of the allowable unbalance of the impeller assembly. If the requirement is not met, the fixture is trimmed by removing mass or attaching a counterweight until it meets the allowable unbalance requirement. This can reduce the impact of the fixture on the detection of the impeller assembly's unbalance, thereby improving the accuracy of the detection of the impeller assembly's unbalance.

[0063] When the unbalance amount of the fixture meets the requirements, the impeller assembly is assembled to the fixture.

[0064] S403: Connect the impeller assembly to the dynamic balancing machine through the fixing device.

[0065] Figure 6 It is a schematic diagram of the structure of the impeller assembly assembled in the fixture, such as Figure 6 As shown, optionally, S403 includes the following steps:

[0066] 4031: Sleeve the impeller assembly outside the elastic sleeve, and make the end surface of one end of the impeller assembly contact the end surface of the limiting section 103.

[0067] 4032: Tighten the lock nut and then lock it with the set screw.

[0068] When the elastic sleeve 300 is tightened and squeezed by the locking nut 402, the elastic sleeve 300 will climb along the conical surface, and the outer circle of the elastic sleeve 300 will expand, thereby achieving the purpose of fixing the impeller assembly, so that the impeller assembly can be reliably installed on the fixing device.

[0069] S404: Detect and obtain the magnitude and direction of the imbalance of the impeller assembly during rotation.

[0070] In the disclosed embodiment, the impeller assembly and the fixing device are integrally placed on a dynamic balancing machine, and the dynamic balancing machine is started to drive the impeller assembly to rotate, thereby measuring the size and direction of the imbalance of the impeller assembly.

[0071] Optionally, step S404 includes the following steps:

[0072] 4041: Determine the two supporting planes based on the connection relationship between the support shaft and the dynamic balancing machine.

[0073] The support span is adjusted according to the length of the support shaft in the fixture, and the fixture and impeller assembly are placed as a whole on the brackets at both ends of the dynamic balancing machine.

[0074] The two support planes are cross sections of the support shaft, and the support planes are located at the connection between the support shaft and the dynamic balancing machine. The support plane can be a cross section through the support shaft and the bearing.

[0075] Figure 7 This is a simplified schematic diagram of the impeller assembly during inspection, see Figure 7 , measure the distance d between the first support plane and the end face of the first end of the support shaft; measure the distance f between the second support plane and the end face of the second end of the non-support shaft; measure the distance L1 from the center of mass of the impeller assembly to the first support plane, measure the distance L2 from the center of mass of the impeller assembly to the second support plane, and measure the span L between the two support planes, where L=LI+L2.

[0076] 4042: Determine the correction plane.

[0077] Generally speaking, the dynamic balance correction of the impeller assembly is performed as much as possible in the plane where the center of mass of the impeller assembly is located to reduce the imbalance of the couple. If the plane where the center of mass is located does not allow weight removal or weight addition, it should generally be performed in two planes located on both sides of the plane where the center of mass is located. Since the impeller assembly has a certain thickness, the plane where the center of mass of the impeller assembly is located may not be convenient for weight removal or weight addition. Therefore, in order to facilitate the balancing of the impeller assembly, it is necessary to determine two correction planes on the impeller assembly.

[0078] The two correction planes correspond to the two support planes one by one. The correction plane is parallel to the support plane. The correction plane is the plane where the counterweight is installed later.

[0079] Generally speaking, the correction plane can be any plane. The correction plane is a plane in the impeller assembly where the weight change position is convenient.

[0080] Measure the distance a from the first correction plane to the corresponding support plane, the correction radius r1, and the span b from the second correction plane. Determine the distance c from the second correction plane to the corresponding support plane, and the correction radius r2.

[0081] That is to say, the correction plane is used as the detection plane of the dynamic balancing machine, and the unbalance amount Urm1 in the correction plane is detected to obtain the unbalance amount.

[0082] 4043: Record balance parameters.

[0083] Wherein, m is the mass of the impeller assembly; n is the rated speed of the impeller assembly; a is the distance between the first correction plane and the first support plane; b is the distance between the first correction plane and the second correction plane; c is the distance between the second correction plane and the second support plane; r1 is the diameter of the first support plane; r2 is the diameter of the second support plane.

[0084] 4044: Install the drive belt.

[0085] Install the belt of the dynamic balancing machine onto the pulley in the fixing device and use the pressure wheel to press it tightly so that the pulley has a certain tension.

[0086] 4045: Records the imbalance of the impeller assembly.

[0087] After the inspection and confirmation is completed, personnel should stay away from the test equipment.

[0088] Start the dynamic balancing machine, input the above balancing parameters into the dynamic balancing machine, and gradually increase the speed of the dynamic balancing machine to the rated working speed of the impeller assembly, then maintain the rated speed for stable operation for 1 minute, and record the imbalance of the impeller assembly.

[0089] If the maximum speed of the dynamic balancing machine is less than the rated operating speed of the impeller assembly, start the dynamic balancing machine, gradually increase the speed of the dynamic balancing machine to its maximum speed, then maintain the maximum speed for 1 minute and record the imbalance of the impeller assembly.

[0090] As mentioned above, since the impeller assembly has a certain thickness, in order to more accurately reflect the imbalance of the impeller assembly, during detection, the imbalance Urm1 of the two correction planes is detected to reflect the imbalance of the impeller assembly.

[0091] That is to say, the correction plane is used as the detection plane of the dynamic balancing machine, and the unbalance amount of the impeller assembly can be obtained by detecting the unbalance amount Urm1 in the correction plane.

[0092] S405: Calculate the theoretical unbalance of the impeller assembly.

[0093] The theoretical unbalance of the impeller assembly is calculated using the general method of rotor dynamic balancing, thereby determining the mass of the impeller assembly and the estimated operating speed.

[0094] In the disclosed embodiment, the theoretical unbalance of the impeller assembly is calculated according to the following formula (1).

[0095]

[0096] Among them, U per is the theoretical unbalance of the impeller assembly; m is the mass of the impeller assembly; G is the balancing accuracy grade, which is 6.3; n is the rotation speed of the impeller assembly; r is the rotation radius of the impeller assembly.

[0097] In the disclosed embodiment, there are two cases when calculating the theoretical unbalance of the impeller assembly. One case is the theoretical unbalance corresponding to the rated speed of the impeller assembly. The other case is the theoretical unbalance corresponding to the maximum speed of the dynamic balancing machine. The smaller theoretical unbalance of the two cases is taken as the final theoretical unbalance.

[0098] Moreover, in combination with the foregoing, since the unbalance amounts of the two correction planes are detected respectively when detecting the unbalance amount of the impeller assembly, the theoretical unbalance amount calculated here is also the theoretical unbalance amount of the two correction planes.

[0099] In the embodiment of the present disclosure, the theoretical unbalance amount at each correction plane is calculated according to the following formula (2):

[0100]

[0101] Among them, U per1 is the theoretical unbalance at the correction plane; m' is the equal correction mass at the correction plane (including the equal correction mass m' at the first correction plane below) 1 and the equal calibration mass m′ at the second calibration plane 2 ); G is the balancing accuracy level, which is 6.3; n is the speed of the impeller assembly; r is the shaft diameter of the support shaft corresponding to the correction plane (including Figure 7 r1 and r2 in ).

[0102] See also Figure 7 , where m′ in Formula 2 can be obtained according to the following process.

[0103] Assume that the mass at the first support plane is m1 and the mass at the second support plane is m 2 Then m 1 and m2 Satisfies the following formula:

[0104]

[0105] Where, m is the mass of the impeller assembly; L 1 is the distance from the center of mass of the impeller assembly to the first support plane, L 2 is the distance from the center of mass of the impeller assembly to the second support plane, and L is the span between the two support planes.

[0106] The equal calibration mass at the first calibration plane is m′ 1 , the equal calibration mass at the second calibration plane is m′ 2 , m′ 1 and m′ 2 Satisfies the following formula:

[0107] m 1 L = m′ 1 (b+c)+m′ 2 ·c (5) m 2 L = m′ 2 (a+b)+m′ 1 ·a (6)

[0108] Wherein, formula (5) is calculated with the second support plane as the fulcrum, and formula (6) is calculated with the first support plane as the fulcrum. To simplify the calculation, m′ 1 and m′ 2 Take them equal. 1 =m′ 2 . So we can get:

[0109]

[0110] Substitute formula (3) into formula (5), and substitute formula (4) into formula (6) to obtain m′ 1 and m′ 2 .

[0111]

[0112] Finally, substitute formula (9) and formula (10) into formula (2) to obtain the imbalance of the correction plane.

[0113] S406: According to the theoretical unbalance amount of the impeller assembly and the detected unbalance amount, it is determined whether the impeller assembly meets the theoretical requirement of the allowable unbalance amount.

[0114] If the detected imbalance is greater than the theoretical imbalance, the impeller assembly does not meet the theoretical requirement for allowable imbalance and needs to be corrected.

[0115] If the detected unbalance is not greater than the theoretical unbalance, the impeller assembly meets the theoretical requirements for allowable unbalance.

[0116] That is to say, when the unbalance amount Urm1 detected at each correction plane is less than or equal to the theoretical unbalance amount Uper1, the impeller assembly does not need to be corrected, and the unbalance amount of the impeller assembly reaches the theoretical requirement of the allowable unbalance amount.

[0117] When the unbalance amount Urm1 detected at a correction plane is greater than the theoretical unbalance amount Uper1, the impeller assembly needs to be corrected, and the unbalance amount of the impeller assembly exceeds the theoretical requirement for the allowable unbalance amount.

[0118] If the impeller assembly does not meet the theoretical requirement of the allowable unbalance, step S407 is executed.

[0119] S407: Connect a counterweight to the impeller assembly according to the magnitude and direction of the unbalance of the impeller assembly, so that the unbalance of the impeller assembly connected with the counterweight meets the theoretical requirement of the allowable unbalance.

[0120] Optionally, step S407 includes the following steps:

[0121] 4071: Glue the counterweight block to the impeller assembly, and the direction of the counterweight block relative to the impeller assembly is opposite to the direction of the imbalance.

[0122] 4072: Detect the imbalance of the impeller assembly with the counterweight attached, and adjust the size of the counterweight according to the detection result.

[0123] According to the magnitude and direction of the unbalance of the impeller assembly measured in the previous step S404, the impeller assembly is balanced by pasting a counterweight in the opposite direction of the unbalance of the impeller assembly, so that its unbalance meets the theoretical requirement of the allowable unbalance. After the impeller assembly is balanced, the counterweight pasted thereto is weighed. The counterweight is pasted by gluing.

[0124] For example, during the test, the unbalance at the correction plane on the left side exceeds the standard by 10g, and the unbalance is located at 10° in the clockwise direction. In this way, a 10g counterweight can be pasted on the left side of the impeller assembly, and the counterweight is located at 190° in the clockwise direction. Similarly, the unbalance at the correction plane on the right side also exceeds the standard and is 10g, and the unbalance is located at 10° in the clockwise direction. In this way, a 10g counterweight can be pasted on the right side of the impeller assembly, and the counterweight is located at 190° in the clockwise direction.

[0125] That is to say, by sticking the counterweight in the direction opposite to the direction of the imbalance, the impeller assembly can be quickly balanced.

[0126] S408: dismantling the counterweight block, and reducing or increasing the weight of the impeller assembly according to the counterweight block, so that the unbalance amount of the impeller assembly meets the theoretical requirement of the allowable unbalance amount.

[0127] A balancing block is connected to the position where the counterweight block is connected in the impeller assembly to increase the weight, or the position of the impeller assembly opposite to the counterweight block is machined to reduce the weight, and the relative position of the counterweight block and the position where the counterweight block is located are centrally symmetrically distributed about the center of the impeller assembly.

[0128] In the disclosed embodiment, the weight removal method is adopted to correct the unbalance of the impeller assembly, and holes are drilled on the rim or hub of the impeller assembly to remove weight, and the drilling depth is less than 1 / 2 of the overall thickness of the impeller assembly. Alternatively, the weight increase method is adopted for correction, and each balancing block does not exceed 5g, so that the unbalance of the impeller assembly reaches the allowable unbalance.

[0129] During the calibration, the unbalance U of the two calibration planes is still detected. rm1 When the unbalance U detected at each correction plane is rm1 ≤Theoretical unbalance U per1 When , it indicates that the unbalance of the impeller assembly reaches the theoretical requirement of the allowable unbalance.

[0130] When detecting the unbalance U of the two correction planes rm1 , the detection is still carried out in the aforementioned step S404, except that the impeller assembly after weight reduction or weight increase is installed in the fixing device.

[0131] The above description is only an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A dynamic balancing test method for an impeller assembly, characterized in that: The test method includes: Determining the magnitude and direction of the unbalance of the impeller assembly during rotation; Connecting a counterweight to the impeller assembly according to the magnitude and direction of the unbalance, so that the unbalance of the impeller assembly connected with the counterweight meets the theoretical requirement of the allowable unbalance; The counterweight block is disassembled, and the weight of the impeller assembly is reduced or increased according to the counterweight block.

2. The dynamic balancing test method according to claim 1, characterized in that: Determining the magnitude and direction of the unbalance of the impeller assembly during rotation includes: Connecting the impeller assembly to a dynamic balancing machine via a fixing device to detect the magnitude and direction of the unbalance of the impeller assembly during rotation; The fixing device comprises a support shaft (100), a belt pulley (200) and an elastic sleeve (300), and the belt pulley (200) is interference-fitted on the outside of the middle portion of the support shaft (100); The elastic sleeve (300) is sleeved outside the support shaft (100) and is spaced apart from the pulley (200). The elastic sleeve (300) is connected to the impeller assembly.

3. The dynamic balancing test method according to claim 2, characterized in that: The outer wall of the support shaft (100) sleeved with the elastic sleeve (300) has a conical surface, the inner wall of the elastic sleeve (300) is in contact with the conical surface, and the outer diameter of the conical surface gradually increases along the direction from the first end to the second end of the elastic sleeve (300); The fixing device further comprises a fastener (400), wherein the fastener (400) is located on a side of the elastic sleeve (300) away from the pulley (200) and is connected to the support shaft (100), and the fastener (400) is used to abut against the first end of the elastic sleeve (300).

4. The dynamic balancing test method according to claim 2, characterized in that: The dynamic balancing test method further comprises: Before the impeller assembly is connected to the dynamic balancing machine via a fixture, the unbalance amount of the fixture is detected, and the unbalance amount of the fixture is made not greater than 1 / 10 of the theoretical requirement of the allowable unbalance amount of the impeller assembly.

5. The dynamic balancing test method according to claim 1, characterized in that: The step of reducing or increasing the weight of the impeller assembly according to the counterweight block comprises: A balancing block is connected to the position of the impeller assembly where the counterweight block is connected to increase the weight, or the position of the impeller assembly where the counterweight block is connected is machined to reduce the weight, and the relative position of the counterweight block and the position where the counterweight block is located are centrally symmetrically distributed about the center of the impeller assembly.

6. The dynamic balancing test method according to claim 5, characterized in that: The dynamic balancing test method further comprises: The unbalance amount of the impeller assembly after the weight reduction or weight increase is detected, and it is determined whether the unbalance amount of the impeller assembly after the weight reduction or weight increase meets the theoretical requirement of the allowable unbalance amount.

7. The dynamic balancing test method according to claim 6, characterized in that: The detecting the unbalance amount of the impeller assembly after weight reduction or weight increase, and judging whether the unbalance amount of the impeller assembly after weight reduction or weight increase meets the theoretical requirement of allowable unbalance amount, comprises: The impeller assembly after weight reduction or weight increase is installed in the fixing device, and both ends of the support shaft are rotatably connected to the dynamic balancing machine through bearings; According to the connection relationship between the support shaft and the dynamic balancing machine, two support planes are determined, the two support planes are cross sections of the support shaft, and the support planes are located at the connection between the support shaft and the dynamic balancing machine; Determine two correction planes in the impeller assembly, the two correction planes correspond to the two support planes one by one and are parallel, and the two correction planes are respectively located on both sides of the center of mass of the impeller assembly; According to the unbalance amount detected at each of the two correction planes and the theoretical unbalance amount calculated by the correction plane, it is determined whether the unbalance amount of the impeller assembly after weight reduction or weight increase meets the theoretical requirement of allowable unbalance amount.

8. The dynamic balancing test method according to claim 7, characterized in that: The theoretical unbalance at the correction plane is calculated according to the following formula: Among them, U per1 is the theoretical unbalance at the correction plane; m′ is the equal-calibration mass at the correction plane; G is the balancing accuracy grade; n is the rotation speed of the impeller assembly; r is the shaft diameter of the support shaft corresponding to the correction plane.

9. The dynamic balancing test method according to claim 7, characterized in that: The step of determining whether the unbalance amount of the impeller assembly after weight reduction or weight increase meets the theoretical requirement of allowable unbalance amount according to the unbalance amount detected at each of the two correction planes and the theoretical unbalance amount calculated by the correction planes comprises: If the unbalance amount detected at at least one of the correction planes is greater than the theoretical unbalance amount, it is determined that the unbalance amount of the impeller assembly after weight reduction or weight increase does not meet the theoretical requirement of the allowable unbalance amount.

10. The dynamic balancing test method according to any one of claims 1 to 9, characterized in that: The method of connecting a counterweight to the impeller assembly so that the unbalance amount of the impeller assembly connected with the counterweight meets the theoretical requirement of the allowable unbalance amount includes: The counterweight block is attached to the impeller assembly, and the direction of the counterweight block relative to the impeller assembly is opposite to the direction of the unbalance amount of the impeller assembly; The unbalance amount of the impeller assembly to which the counterweight block is attached is detected, and the size of the counterweight block is adjusted according to the detection result.

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