Generator dynamic balance testing device

Abstract

The invention relates to the technical field of dynamic balance testing, in particular to a generator dynamic balance testing device which is configured to be capable of performing dynamic balance testing on a rotor of a generator and comprises a testing platform, a supporting assembly, a limiting synchronous belt and a belt wheel assembly. The support assembly is arranged on the test platform and is configured to support the rotor to rotate; the limiting synchronous belt is arranged on the test platform, a closed motion loop is formed on the test platform, and the belt wheel assembly is arranged on the test platform and is configured to enable the limiting synchronous belt to form the closed motion loop; the limiting synchronous belt is provided with a fixed section, and the outer side of the fixed section wraps the top of the rotor and is in friction contact with the rotor when the fixed section is used, so that when the rotor rotates, the rotor can be externally restrained through the fixed section, stable supporting conditions needed by dynamic balance testing are guaranteed, and the accuracy of a testing result is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of dynamic balance testing, and in particular to a generator dynamic balance testing device. Background Art

[0002] The dynamic balancing test of the generator is an important step to ensure that the vibration and noise are minimized when it rotates at high speed. By adjusting the mass distribution of the rotor, the unbalanced force can be eliminated or reduced, thereby improving the stability and service life of the generator.

[0003] When performing a dynamic balance test on a generator rotor, a dynamic balance test equipment is required; in the related art, for example, Chinese patent application CN118882917A discloses a rotor dynamic balance test mechanism, which first places the rotor on a belt during the dynamic balance test on the rotor. Since the belt is initially in a tensioned state, the belt is deformed after being pressed down by the gravity of the rotor. The belt applies a force to the third driven wheel, and the third driven wheel drives the first slider to move on the slide rail, thereby changing the tension of the belt, so that the belt can deform differently according to the rotor mass, thereby avoiding the influence of insufficient belt tension on the test results.

[0004] However, the above-mentioned rotor dynamic balancing test mechanism also has some problems in the actual testing process: the essence of this mechanism is to combine the adaptive tensioning mechanical transmission mechanism with the free support state of the rotor, but due to the lack of external constraints on the rotor movement under the vibration state, the stiffness of the support system will change dynamically with the rotor vibration, destroying the stable support conditions required for the dynamic balancing test, which will affect the test results. Summary of the Invention

[0005] Based on this, it is necessary to provide a generator dynamic balance test device to address the problem of poor test result accuracy in the current rotor dynamic balance test process.

[0006] The above purpose is achieved through the following technical solutions: A generator dynamic balance test device is configured to perform a dynamic balance test on a generator rotor; the generator dynamic balance test device comprises: test platform; a support assembly, disposed on the test platform and configured to support the rotation of the rotor; a limiting synchronous belt, disposed on the test platform and forming a closed motion loop on the test platform, the limiting synchronous belt having a fixed section, the fixed section being wrapped around the top of the rotor when in use and in frictional contact with the rotor; A pulley assembly is arranged on the test platform and configured to enable the limiting synchronous belt to form a closed motion loop.

[0007] Further, the pulley assembly includes a bracket, on which an active pulley, an elastic tension pulley, a first driven pulley, two second driven pulleys and two active tension pulleys are rotatably arranged about their own axes. The active pulley, the elastic tension pulley, the first driven pulley and the two active tension pulleys are all located inside the limiting synchronous belt and are in frictional contact with the limiting synchronous belt; the two second driven pulleys are located outside the limiting synchronous belt and are in frictional contact with the limiting synchronous belt; the elastic tension pulley is configured to elastically tension the limiting synchronous belt; the two active tension pulleys are symmetrically arranged with respect to the rotor.

[0008] Further, the limiting synchronous belt is configured to have an acceleration state and a stable state. When in the acceleration state, the limiting synchronous belt is configured to be able to drive the rotor to accelerate; when in the stable state, the limiting synchronous belt is configured to be able to drive the rotor to rotate at a constant speed; and when in the acceleration state, the area of the fixed section wrapping the rotor is larger than the area of the fixed section wrapping the rotor when in the stable state; the generator dynamic balance test device further includes an adjustment mechanism configured to be able to adjust the state of the limiting synchronous belt.

[0009] Further, the active tension pulley can slide in the vertical direction; the adjustment mechanism includes two third driven pulleys and two driving members. The two third driven pulleys are both arranged on the bracket and are both located inside the limiting synchronous belt and are symmetrically arranged with respect to the rotor; the driving member is arranged on the bracket and is configured to be able to provide the driving force for the active tension pulley to slide in the vertical direction; the active tension pulley has corresponding first and second positions before and after sliding. When in the first position, the limiting synchronous belt is in a first state, and the limiting synchronous belt is wound around the active pulley, the elastic tension pulley, the first driven pulley, the two second driven pulleys and the two active tension pulleys; when in the second position, the limiting synchronous belt is in a second state, and the limiting synchronous belt is wound around the active pulley, the elastic tension pulley, the first driven pulley, the two second driven pulleys and the two third driven pulleys.

[0010] Further, the active tension pulley has a first sub-pulley and two second sub-pulleys that are fixedly and coaxially arranged. The two second sub-pulleys are located on both sides of the first sub-pulley, and their diameters are both larger than that of the first sub-pulley. The third driven pulley has a third sub-pulley and two fourth sub-pulleys that are fixedly and coaxially arranged. The two fourth sub-pulleys are located on both sides of the third sub-pulley, and their diameters are both smaller than that of the third sub-pulley. There are three limiting synchronous belts, and the three limiting synchronous belts are arranged side by side. The limiting synchronous belt in the middle is configured to be able to cooperate with the first sub-pulley or the third sub-pulley, and the limiting synchronous belts on both sides are configured to be able to cooperate with the second sub-pulley or the fourth sub-pulley.

[0011] Further, the diameter difference between the first sub-pulley and the second sub-pulley is less than the belt thickness of the limiting synchronous belt; the diameter difference between the third sub-pulley and the fourth sub-pulley is less than the belt thickness of the limiting synchronous belt.

[0012] Further, a first support is also provided on the test platform, and the bracket is hinged on the first support; the generator dynamic balance test device further includes a driving component, and the driving component is configured to be able to provide a driving force for the rotation of the bracket.

[0013] Further, the first support can slide in a direction parallel to the axis of the rotor.

[0014] Further, the support assembly includes two second supports, and the two second supports are arranged at intervals in a direction parallel to the axis of the rotor; two rotating wheels are provided on each second support, the axis of the rotating wheel is parallel to the axis of the rotor, the rotating wheel can rotate around its own axis, the rotating wheels on different second supports are correspondingly arranged, the two rotating wheels on the same second support are arranged in a direction perpendicular to the axis of the rotor, and a support area is formed therebetween, and the support area is configured to be able to support the rotor.

[0015] Further, the two second supports can both slide in a direction parallel to the axis of the rotor.

[0016] The beneficial effects of the present invention are: The present invention relates to a generator dynamic balance test device. By setting that the limiting synchronous belt has a fixed section, the fixed section is wrapped around the top of the rotor on the outside during use and is in frictional contact with the rotor, so that it can not only drive the rotor to rotate, but also apply an external constraint to the rotor, thereby ensuring the stable support conditions required for dynamic balance testing and ensuring the accuracy of the test results.

[0017] Further, by setting the limiting synchronous belt to have an accelerating state and a stable state, in the accelerating state, since the area of the fixed section wrapping the rotor is larger, the interaction force between the fixed section and the rotor is larger, thus ensuring that the fixed section can stably drive the rotor to speed up, which is beneficial to improving the test efficiency; in the stable state, since the area of the fixed section wrapping the rotor is smaller, the interaction force between the fixed section and the rotor is smaller. On the one hand, it ensures that the rotor can rotate stably, and on the other hand, it can reduce the vibration effect of the rotor caused by the inconsistent thickness of the belt body, which is beneficial to improving the accuracy of the test results.

[0018] Further, by setting the active tensioning pulley to have a first sub-wheel and two second sub-wheels that are fixedly and coaxially arranged, and the diameter of the first sub-wheel is smaller than that of the second sub-wheel, and setting the number of limiting synchronous belts to be three, and the three limiting synchronous belts are arranged side by side. When the limiting synchronous belt is in the accelerating state, the tension of the limiting synchronous belts on both sides is greater, and the frictional force provided when contacting the rotor is greater, thus ensuring the stability when the rotor speeds up; by setting the third driven pulley to have a third sub-wheel and two fourth sub-wheels that are fixedly and coaxially arranged, and the diameter of the third sub-wheel is larger than that of the fourth sub-wheel. When the limiting synchronous belt is in the stable state, the tension of the limiting synchronous belt in the middle is greater, and the frictional force provided when contacting the rotor is greater, thereby reducing the vibration influence on the rotor dynamic balance test caused by the wear of the limiting synchronous belt.

[0019] Further, by setting the diameter difference between the first sub-wheel and the second sub-wheel to be smaller than the belt thickness of the limiting synchronous belt, and the diameter difference between the third sub-wheel and the fourth sub-wheel to be smaller than the belt thickness of the limiting synchronous belt, there are overlapping regions in the thickness direction of the three limiting synchronous belts before and after the limiting synchronous belt switches states, so that the three limiting synchronous belts can limit each other, preventing polarization from affecting the rotor dynamic balance test. Description of the Drawings

[0020] Figure 1 Schematic three-dimensional structure diagram of the generator dynamic balance test device provided by the embodiment of the present invention; Figure 2 Schematic side view structure diagram of the generator dynamic balance test device provided by the embodiment of the present invention; Figure 3 Schematic three-dimensional structure diagram of the generator dynamic balance test device provided by the embodiment of the present invention when performing a dynamic balance test on the rotor; Figure 4 Schematic side view structure diagram of the generator dynamic balance test device provided by the embodiment of the present invention when performing a dynamic balance test on the rotor; Figure 5 Schematic front view structure diagram of the generator dynamic balance test device provided by the embodiment of the present invention when performing a dynamic balance test on the rotor; Figure 6 is Figure 5 the three-dimensional sectional view in the A-A direction in Figure 7 is Figure 6 the schematic diagram of the enlarged local structure at X in Figure 8 the three-dimensional sectional structure diagram when the generator dynamic balance test device provided by the embodiment of the present invention performs dynamic balance test on the rotor; Figure 9 is Figure 8 the schematic diagram of the enlarged local structure at Y in Figure 10 the three-dimensional structure diagram of the third driven wheel of the generator dynamic balance test device provided by the embodiment of the present invention; Figure 11 the three-dimensional structure diagram when the active tensioning wheel and the first driving cylinder of the generator dynamic balance test device provided by the embodiment of the present invention are assembled.

[0021] Wherein: 1. Test platform; 101. Second chute; 2. Support assembly; 201. Second support; 202. Runner; 3. Limiting synchronous belt; 401. Bracket; 4011. First chute; 402. Driving wheel; 403. Elastic tensioning wheel; 4031. Support rod; 4032. Compression spring; 404. First driven wheel; 405. Second driven wheel; 406. Active tensioning wheel; 4061. First sub-wheel; 4062. Second sub-wheel; 407. First driving motor; 501. Third driven wheel; 5011. Third sub-wheel; 5012. Fourth sub-wheel; 502. First driving cylinder; 6. First support; 7. Driving assembly; 701. Second driving motor; 702. Transmission belt; 703. Fixed pulley; 8. Rotor. Detailed implementation manners

[0022] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below through embodiments and in conjunction with the drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0023] The serial numbers assigned to components in this text, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meaning. The terms "connected" and "coupled" as used herein, unless otherwise specified, both include direct and indirect connection (coupling). In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0024] In the present invention, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0025] The following refers to Figures 1 to 11 to describe a generator dynamic balance test device provided by an embodiment of the present invention, which is particularly suitable for the dynamic balance test of a generator rotor 8. Of course, it can also be suitable for the dynamic balance test of other shaft-like and rotor 8-like components.

[0026] Specifically, when the rotor 8 is installed, its axis extends horizontally in the left-right direction. The generator dynamic balance test device is arranged to include a test platform 1, a support assembly 2, a limiting synchronous belt 3 and a pulley assembly. Among them, the support assembly 2 is arranged on the test platform 1 and configured to be able to support the rotation of the rotor 8, and can be arranged to include two second supports 201. The two second supports 201 are horizontally arranged at intervals in the left-right direction. Two runners 202 are hingedly connected to each second support 201. The two runners 202 on the same second support 201 are arranged horizontally in the front-rear direction. The axis of the runner 202 is parallel to the axis of the rotor 8. The runners 202 on different second supports 201 are correspondingly arranged to ensure that the rotor 8 can be supported along its axial direction.

[0027] The limiting synchronous belt 3 is a ring structure and is arranged on the test platform 1, and a closed motion loop is formed on the test platform 1. The limiting synchronous belt 3 is located above the rotor 8 to ensure that an external constraint can be formed on the rotor 8 from top to bottom. The pulley assembly is arranged on the test platform 1 and is configured to enable the limiting synchronous belt 3 to form a closed motion loop, and can be set to include a bracket 401 and a first driving motor 407. A driving wheel 402, an elastic tensioning wheel 403, a first driven wheel 404, two second driven wheels 405 and two driving tensioning wheels 406 are rotatably arranged on the bracket 401 around its own axis; as Figure 6 shown, wherein the elastic tensioning wheel 403 is located at the rear upper part of the driving wheel 402; the first driven wheel 404 and the elastic tensioning wheel 403 are at the same horizontal height, and the first driven wheel 404 is located behind the elastic tensioning wheel 403; the two second driven wheels 405 are at the same horizontal height and are located between the driving wheel 402 and the first driven wheel 404. One of the second driven wheels 405 is located at the lower front of the first driven wheel 404, and the other second driven wheel 405 is located at the lower rear of the elastic tensioning wheel 403; the two driving tensioning wheels 406 are at the same horizontal height, are symmetrically arranged with respect to the rotor 8, and are both located below the driving wheel 402. One of the driving tensioning wheels 406 is located at the lower front of the second driven wheel 405 arranged at the rear, and the other driving tensioning wheel 406 is located at the lower rear of the second driven wheel 405 arranged at the front; the driving wheel 402, the elastic tensioning wheel 403, the first driven wheel 404 and the two driving tensioning wheels 406 are all located inside the limiting synchronous belt 3 and are in frictional contact with the limiting synchronous belt 3, and the two second driven wheels 405 are located outside the limiting synchronous belt 3 and are in frictional contact with the limiting synchronous belt 3; when the first driving motor 407 is installed, the motor shaft is coaxially and fixedly inserted into the wheel shaft of the driving wheel 402 to ensure that the driving wheel 402 can be driven to rotate, and then the limiting synchronous belt 3 forms a closed motion loop.

[0028] A support rod 4031 is also inserted into the bracket 401. The support rod 4031 extends horizontally in the front-rear direction and is at the same horizontal height as the elastic tensioning wheel 403. The front end of the support rod 4031 is hinged to the wheel shaft of the elastic tensioning wheel 403 to ensure that the elastic tensioning wheel 403 can rotate freely. A compression spring 4032 is sleeved on the support rod 4031. The two ends of the compression spring 4032 respectively abut against the bracket 401 and the elastic tensioning wheel 403. Under the action of the compression spring 4032, the support rod 4031 has a tendency to drive the elastic tensioning wheel 403 to move forward, so as to be able to elastically tension the limiting synchronous belt 3. Optionally, to improve the stability of the elastic tensioning wheel 403 during movement, the number of the support rods 4031 can be set to two, and the two support rods 4031 are symmetrically arranged with respect to the elastic tensioning wheel 403, and a compression spring 4032 is sleeved on each support rod 4031.

[0029] In the field of dynamic balance testing of generator rotors 8, the testing mechanism based on restricting the adaptive tension of the synchronous belt 3 realizes the adjustment of the tension through mechanical conduction. Its core logic is to utilize the gravity of the rotor 8 to cause the deformation of the restricting synchronous belt 3. Through the mechanical linkage between the driven wheel and the slider, the tension of the restricting synchronous belt 3 is dynamically adapted to the mass of the rotor 8. Although it solves the problem of the mismatch between the pre-tension of the restricting synchronous belt 3 and the weight of the rotor 8 in the traditional fixed tension structure, in the scenario of unbalanced vibration of the rotor 8, there is a fundamental contradiction between its mechanical conduction mechanism and the motion state of the rotor 8.

[0030] From the perspective of the mechanical conduction path, the existing testing mechanism places the rotor 8 completely on the freely supported restricting synchronous belt 3. When the rotor 8 generates centrifugal force to excite vibration due to uneven mass distribution, the rotor 8 will generate periodic displacement in the radial direction. At this time, the restricting synchronous belt 3 not only needs to bear the static gravity of the rotor 8 but also needs to cope with the dynamic vibration load. Since the rotor 8 is in an unconstrained free state, the radial force generated by the vibration will directly act on the supporting surface of the restricting synchronous belt 3, resulting in asymmetric deformation of the restricting synchronous belt 3. This deformation will push the slider to reciprocate on the slide rail through the driven wheel, converting the mechanical structure originally used for adaptive tension adjustment into a conduction path for vibration energy. The reciprocating motion of the slider not only changes the tension of the restricting synchronous belt 3 but also introduces additional mechanical interference.

[0031] From the perspective of the stability of the testing system, dynamic balance testing requires the rotor 8 to maintain a relatively stable supporting state during rotation to ensure the accuracy of vibration signal acquisition. In the existing testing mechanism, the dynamic change in the tension of the restricting synchronous belt 3 caused by the vibration of the rotor 8 will form a positive feedback effect of "vibration - tension change - vibration intensification": when the unbalance of the rotor 8 causes vibration, the tension of the restricting synchronous belt 3 changes due to the movement of the slider, and the change in the supporting stiffness will also change the vibration characteristics of the rotor 8, causing the original single unbalanced vibration to be superimposed with parametric vibration caused by the change in supporting stiffness. This composite vibration state will make the vibration signal of the testing system contain interference components unrelated to the unbalance amount, making it difficult to accurately separate the characteristic frequency corresponding to the unbalance amount during spectrum analysis, thereby affecting the calculation accuracy of the dynamic balance correction amount.

[0032] From the perspective of the mechanical constraint principle, the lack of a limiting mechanism for the radial movement of the rotor 8 in the free support structure is the essential reason for the deviation of the test results. During the dynamic balance test, the vibration displacement of the rotor 8 needs to be constrained within a reasonable range to ensure that the signal collected by the vibration sensor only reflects the vibration caused by the unbalance. In the existing test mechanism, the radial displacement generated when the rotor 8 vibrates directly acts on the limiting synchronous belt 3. Although the flexible deformation of the limiting synchronous belt 3 can adapt to the tension, it cannot provide sufficient radial constraint stiffness. When the vibration amplitude is large, the rotor 8 may partially lose contact due to the radial displacement exceeding the support range of the limiting synchronous belt 3, resulting in discontinuous support force. This non-steady-state support will cause sudden noises in the vibration signal, interfere with the phase detection of the unbalance amount, and further affect the azimuth judgment of the counterweight correction.

[0033] In addition, there is a problem of dynamic response lag in the mechanical conduction chain of the existing test mechanism. When the instantaneous load generated by the vibration of the rotor 8 is transmitted through the mechanical link of the limiting synchronous belt 3 - driven wheel - slider, the inertial mass and elastic deformation of each link will cause the tension adjustment to lag behind the change of the vibration load. This lag effect will keep the tension of the limiting synchronous belt 3 in continuous dynamic adjustment, unable to form a stable support state within the vibration cycle, resulting in the dynamic characteristics of the test system changing with time, which does not meet the basic requirements of the dynamic balance test for the stability of system parameters.

[0034] Based on this, in the generator dynamic balance test device provided in the embodiment of the present invention, the limiting synchronous belt 3 is set to have a fixed section, and the outer side of the fixed section is wrapped around the top of the rotor 8 and is in frictional contact with the rotor 8 during use.

[0035] Specifically, the part of the limiting synchronous belt 3 between the two active tension wheels 406 is the fixed section, which is in an inverted U shape during use and is wrapped around the top of the rotor 8. This geometric configuration realizes the directional constraint of the contact interface: the two sides of the inverted U-shaped structure form an arc-shaped contact surface with the top of the rotor 8, forming a continuous frictional force transmission path in the circumferential direction, while the top arc segment constitutes the radial constraint surface, forming a "driving - constraint" composite mechanical relationship between the fixed section and the rotor 8.

[0036] In terms of the driving mechanism, the inverted U-shaped fixed segment utilizes the friction coupling principle to limit the transmission of the synchronous belt 3. When the driving wheel 402 drives the limited synchronous belt 3 to move, the friction contact between the fixed segment and the top of the rotor 8 will generate a tangential driving torque. The inverted U-shaped structure improves the friction transmission efficiency by increasing the contact arc length. Compared with the point contact or line contact between the belt and the rotor 8 in the traditional free support, the surface contact formed by the inverted U-shaped wrapping can make the tangential stress distribution more uniform, and can provide a greater ultimate friction force under the same tension, thereby avoiding the slippage of the rotor 8 during the acceleration phase. This surface contact drive mechanism can also disperse the driving force to a larger contact interface, reduce local stress concentration, and enable the rotor 8 to obtain a smoother driving torque, providing stable speed conditions for dynamic balancing tests.

[0037] In terms of the constraint mechanism, the inverted U-shaped topology of the fixed segment creates a rigid constraint boundary for the radial movement of rotor 8. When rotor 8 experiences radial vibration due to imbalance, the top arc of the fixed segment directly limits the upward displacement of rotor 8. This limiting effect differs from the flexible constraint that relies on belt deformation in existing technologies. Instead, it provides a rigid constraint through the structural rigidity of the fixed segment.

[0038] Specifically, the fixed section maintains a nearly constant tension under the preload of the elastic tensioning wheel 403, forming a constrained surface with a certain degree of rigidity in the top arc section of the inverted U-shaped structure. When the vibration displacement of the rotor 8 reaches this constrained surface, it is subjected to a constraining force in the opposite direction of the vibration, thereby limiting the radial vibration of the rotor 8 to the constrained range of the fixed section. This rigid constraint mechanism effectively prevents the rotor 8 from separating from the support surface due to excessive vibration amplitude, ensuring the continuity of the supporting force.

[0039] Therefore, through the inverted U-shaped structure of the fixed section, the driving function and the constraint function are integrated into the same mechanical interface: in the driving dimension, a stable driving torque is provided by surface contact friction transmission; in the constraint dimension, a stable radial constraint boundary is constructed by a rigid topological structure, which not only solves the vibration instability problem caused by free support in the existing technology, but also ensures the dynamic stability of the test system through a stable tensioning force mechanism, and in principle achieves the dual goals of "stable support-precise vibration measurement" required for dynamic balancing testing.

[0040] In a further embodiment, due to the processing error of the limiting synchronous belt 3, there is inconsistency in its thickness, and the inconsistent thickness will lead to uneven distribution of belt stiffness. When the limiting synchronous belt 3 runs at high speed, this uneven stiffness will induce periodic exciting force, which will cause abnormal vibration of the rotor 8 and affect the accuracy of the test results.

[0041] Based on this, in the generator dynamic balance test device provided by the embodiments of the present invention, the limiting synchronous belt 3 is configured to have an acceleration state and a stable state, and the generator dynamic balance test device further includes an adjustment mechanism configured to be able to adjust the state of the limiting synchronous belt 3. During the speed-up stage of the rotor 8, the limiting synchronous belt 3 is in the acceleration state and is configured to be able to drive the rotor 8 to rotate at an accelerated speed. At this time, the area of the fixed section wrapping the rotor 8 is relatively large. The change in this geometric constraint essentially improves the transmission efficiency of the frictional torque by increasing the contact arc length. According to the principle of friction mechanics, the increase in the contact area will make the distribution of the tangential contact stress more uniform. Under the condition of the same pre-tightening force, a larger contact area can provide a higher limiting frictional force, thus avoiding the slipping phenomenon during the acceleration stage of the rotor 8. At the same time, the interaction force between the fixed section and the rotor 8 realizes the distributed conduction of force through a larger contact interface. This distributed force transmission mechanism can reduce the local stress concentration, enable the rotor 8 to obtain a more stable driving torque during the acceleration process, and thus shorten the speed-up time and improve the test efficiency.

[0042] When the rotor 8 accelerates to the preset speed and enters the stable state, the limiting synchronous belt 3 is in the stable state and is configured to be able to drive the rotor 8 to rotate at a constant speed. At this time, the area of the fixed section wrapping the rotor 8 is relatively small, and this state transition contains the optimization logic of dynamic characteristics.

[0043] Specifically, reducing the wrapping area can effectively reduce the action intensity of the exciting force: on the one hand, the reduction of the contact area reduces the action range of the radial force caused by the thickness difference of the belt body, and reduces the excitation effect of the non-uniform stiffness on the vibration of the rotor 8; on the other hand, the reduction of the radial constraint force weakens the coupled vibration between the belt body and the rotor 8, making the vibration characteristics of the rotor 8 closer to the natural vibration state caused by its own unbalance amount, thus avoiding the interference of the belt body defect on the test signal.

[0044] Therefore, by switching the state of the limiting synchronous belt 3, using the coupling relationship between the contact area and the mechanical characteristics: in the acceleration stage, the force transmission efficiency is strengthened by increasing the contact area, and the linear growth characteristic of the frictional torque is used to achieve fast and stable speed-up; in the stable stage, the unnecessary coupling effect is weakened by reducing the contact area, so that the vibration signal of the rotor 8 more purely reflects its own unbalance characteristics.

[0045] Specifically, to facilitate the state switching of the limiting synchronous belt 3, two first sliding grooves 4011 are provided on the bracket 401. The first sliding grooves 4011 extend in the up and down direction and are respectively arranged corresponding to the two active tensioning wheels 406. When the active tensioning wheels 406 are installed, their axles are slidably inserted into the first sliding grooves 4011 to ensure that they can slide along the first sliding grooves 4011; the adjustment mechanism is configured to include two third driven wheels 501 and two driving members. The two third driven wheels 501 are both arranged on the bracket 401, as Figure 6As shown, the two third driven wheels 501 are at the same horizontal height, symmetrically arranged with respect to the rotor 8, and are both located between the second driven wheel 405 and the driving wheel 402. One of the third driven wheels 501 is located in front of and below the second driven wheel 405 arranged at the rear, and the other second driven wheel 405 is located behind and below the second driven wheel 405 arranged at the front; the driving member is the first driving cylinder 502. The two first driving cylinders 502 are both arranged on the bracket 401. The two first driving cylinders 502 and the two first sliding grooves 4011 are correspondingly arranged. When the first driving cylinder 502 is installed, the output shaft is arranged downward and is hinged on the axle of the driving tensioning wheel 406 to ensure that the driving tensioning wheel 406 can be driven to slide along the first sliding groove 4011.

[0046] Optionally, to improve the stability of the driving tensioning wheel 406 during movement, the number of the first driving cylinders 502 can be set to four. The four first driving cylinders 502 are evenly divided into two groups. The two first driving cylinders 502 in the same group are symmetrically arranged with respect to the bracket 401, and their output shafts are respectively hinged at both ends of the same driving tensioning wheel 406.

[0047] It can be understood that the first driving cylinder 502 can be set as any one of a hydraulic cylinder, a pneumatic cylinder or an electric cylinder.

[0048] During the use process, the driving tensioning wheel 406 has corresponding first and second positions before and after sliding. During the speed-up stage of the rotor 8, the driving tensioning wheel 406 is in the first position. As Figure 6 and Figure 7 shown, at this time, the driving tensioning wheel 406 is located at the bottom end of the first sliding groove 4011, restricting the synchronous belt 3 to be in the first state, restricting the synchronous belt 3 to be wound around the driving wheel 402, the elastic tensioning wheel 403, the first driven wheel 404, the two second driven wheels 405 and the two driving tensioning wheels 406. At this time, the area of the fixed section wrapping the rotor 8 is relatively large, so that the interaction force between the fixed section and the rotor 8 is relatively large, thereby ensuring that the fixed section can stably drive the rotor 8 to speed up and facilitating the improvement of the test efficiency; when the rotor 8 accelerates to the preset speed and enters the stable state, the driving tensioning wheel 406 is in the second position. As Figure 8 and Figure 9 shown, at this time, the driving tensioning wheel 406 is located at the top end of the first sliding groove 4011, restricting the synchronous belt 3 to be in the second state, restricting the synchronous belt 3 to be wound around the driving wheel 402, the elastic tensioning wheel 403, the first driven wheel 404, the two second driven wheels 405 and the two third driven wheels 501. At this time, the area of the fixed section wrapping the rotor 8 is relatively small, so that the interaction force between the fixed section and the rotor 8 is relatively small. On the one hand, it ensures that the rotor 8 can rotate stably, and on the other hand, it can reduce the vibration effect of the rotor 8 caused by the inconsistent thickness of the belt body, which is conducive to improving the accuracy of the test results.

[0049] Thus, through the continuous action of the adjustment mechanism, the state of the limiting synchronous belt 3 can be automatically switched.

[0050] In a further embodiment, when the rotor 8 generates irregular vibrations due to the unbalance amount, the contact area between the fixed section of the limiting synchronous belt 3 and the rotor 8 will bear periodically changing radial and tangential forces. The spatio-temporal difference of this dynamic load distribution will cause non-uniform deformation at different positions of the limiting synchronous belt 3, and further lead to differences in the thickness direction of the limiting synchronous belt 3: the bending stiffness of the thinner area of the belt body is lower, and greater bending deformation occurs when passing through the active tensioning pulley 406. This deformation will generate an additional radial impact force on the rotor 8; while the thicker area of the belt body has a greater stiffness, and a sudden contact force will be generated when contacting the rotor 8. The exciting force caused by the difference in belt body thickness has a definite periodicity, and its frequency is related to the belt speed and the thickness fluctuation period, thus superimposing interference components unrelated to the unbalance amount in the vibration signal of the rotor 8.

[0051] Based on this, in the generator dynamic balance test device provided in the embodiment of the present invention, the active tensioning pulley 406 is provided with a first sub-pulley 4061 and two second sub-pulleys 4062 that are fixedly and coaxially arranged. The two second sub-pulleys 4062 are located on both sides of the first sub-pulley 4061, and their diameters are both larger than that of the first sub-pulley 4061; the third driven pulley 501 is provided with a third sub-pulley 5011 and two fourth sub-pulleys 5012 that are fixedly and coaxially arranged. The two fourth sub-pulleys 5012 are located on both sides of the third sub-pulley 5011, and their diameters are both smaller than that of the third sub-pulley 5011; the number of the limiting synchronous belts 3 is three, and the three limiting synchronous belts 3 are arranged side by side. The limiting synchronous belt 3 in the middle is configured to be able to cooperate with the first sub-pulley 4061 or the third sub-pulley 5011, and the limiting synchronous belts 3 on both sides are configured to be able to cooperate with the second sub-pulley 4062 or the fourth sub-pulley 5012.

[0052] During use, when the limiting synchronous belt 3 is in an accelerating state, at this time, the limiting synchronous belt 3 is wound around the driving pulley 402, the elastic tensioning pulley 403, the first driven pulley 404, the two second driven pulleys 405 and the two active tensioning pulleys 406. Supported by the second sub-pulley 4062, the tension of the limiting synchronous belts 3 on both sides is greater, resulting in a greater frictional force provided when contacting the rotor 8. Thus, it serves as the main power source for driving the rotor 8 to speed up. Correspondingly, it is more affected by the influence of the rotor 8's irregular vibrations caused by the unbalance amount on the belt thickness; while the tension of the limiting synchronous belt 3 in the middle is smaller, resulting in a smaller frictional force provided when contacting the rotor 8. Thus, it serves as an auxiliary power source for driving the rotor 8 to speed up. Correspondingly, it is less affected by the influence of the rotor 8's irregular vibrations caused by the unbalance amount on the belt thickness.

[0053] When the limiting synchronous belt 3 is in a stable state, the limiting synchronous belt 3 is wound around the driving wheel 402, the elastic tensioning wheel 403, the first driven wheel 404, two second driven wheels 405 and two third driven wheels 501. Supported by the third sub-wheel 5011, the tension of the limiting synchronous belt 3 in the middle is greater, resulting in a greater frictional force when it contacts the rotor 8, thus serving as the main power source for driving the rotor 8 to rotate stably. While the tension of the limiting synchronous belt 3 on both sides is smaller, resulting in a smaller frictional force when it contacts the rotor 8, thus serving as an auxiliary power source for driving the rotor 8 to rotate stably. Therefore, the limiting synchronous belt 3 with less affected belt thickness can be used to drive the rotor 8 to rotate stably, and further reduce the influence on the dynamic balance test result of the rotor 8 caused by inconsistent belt thickness.

[0054] In a further embodiment, to improve the stability of the limiting synchronous belt 3 during operation, it is set that the diameter difference between the first sub-wheel 4061 and the second sub-wheel 4062 is less than the belt thickness of the limiting synchronous belt 3; the diameter difference between the third sub-wheel 5011 and the fourth sub-wheel 5012 is less than the belt thickness of the limiting synchronous belt 3. The essence of this size constraint is to construct an overlapping interference region in the belt body thickness direction, thereby forming a self-limiting mechanical coupling mechanism.

[0055] Specifically, when the limiting synchronous belt 3 bypasses the sub-wheels, the radial displacement of the belt body cross-section due to bending is directly related to the diameter of the sub-wheels. Among them, the sub-wheel with a smaller diameter will cause greater bending deformation of the belt body. And the constraint condition that the diameter difference is less than the belt thickness ensures that the bending trajectories of the belt body under the action of different sub-wheels have an intersection in the thickness direction. The existence of this overlapping region enables multiple limiting synchronous belts 3 to form an interlocking structural relationship in the thickness direction, restricting the independent offset of a single limiting synchronous belt 3 like a mechanical limiting device, thereby improving the stability of the limiting synchronous belt 3 during operation.

[0056] In some other embodiments, to improve the convenience of loading and unloading the rotor 8, it is set that a first support 6 is further provided on the test platform 1. The first support 6 is located between two second supports 201 and is on the same straight line as the two second supports 201, ensuring that the dynamic balance test of the rotor 8 can be carried out stably. The bracket 401 is hinged on the first support 6, enabling the angle between the bracket 401 and the first support 6 to be changed. In this way, when installing or disassembling the rotor 8, a larger angle can be formed between the bracket 401 and the first support 6, as Figure 1 shown, so as to facilitate placing the rotor 8 on the four runner wheels 202 or taking the rotor 8 off the four runner wheels 202. When performing the dynamic balance test on the rotor 8, a smaller angle can be formed between the bracket 401 and the first support 6, as Figure 3As shown, the outer side of the fixed section can wrap around the top of the rotor 8 and be in frictional contact with the rotor 8, ensuring that it can drive the rotor 8 to rotate and apply an external constraint to the rotor 8. The generator dynamic balance test device is further provided with a driving assembly 7, and the driving assembly 7 is configured to be able to provide the driving force for the rotation of the bracket 401.

[0057] Specifically, the driving assembly 7 is provided to include a second driving motor 701, a transmission belt 702, and a fixed pulley 703. Among them, the second driving motor 701 is arranged on the first support 6, and a pulley is fixedly sleeved on the motor shaft of the second driving motor 701; the fixed pulley 703 is fixedly arranged on the bracket 401; the transmission belt 702 is wound around the pulley and the fixed pulley 703. In this way, the second driving motor 701 can drive the pulley to rotate, and the pulley drives the fixed pulley 703 to rotate through the transmission belt 702, so as to change the included angle between the bracket 401 and the first support 6 through the hinge connection between the bracket 401 and the first support 6.

[0058] In a further embodiment, to improve the convenience of adjusting the alignment of the limiting synchronous belt 3 and the middle part of the rotor 8, the first support 6 is arranged to be able to slide in a direction parallel to the axis of the rotor 8.

[0059] Specifically in this embodiment, a second chute 101 is opened at the top of the test platform 1, and the second chute 101 extends in a direction parallel to the axis of the rotor 8; a first slider is arranged at the bottom of the first support 6, and the first slider is slidably inserted into the second chute 101 during installation to ensure that the first support 6 can be driven to slide in a direction parallel to the axis of the rotor 8, and further the relative position between the limiting synchronous belt 3 and the middle part of the rotor 8 can be adjusted; a first locking bolt is threaded through the first support 6, and the first locking bolt is configured to be able to form a frictional locking fit with the test platform 1, so that after the limiting synchronous belt 3 and the middle part of the rotor 8 are aligned, the first support 6 can be locked on the test platform 1, thereby locking the position of the limiting synchronous belt 3 and improving the stability of the limiting synchronous belt 3 during movement.

[0060] It can be understood that the relative position between the limiting synchronous belt 3 and the middle part of the rotor 8 can also be adjusted by directly moving the rotor 8.

[0061] In other embodiments, to realize the sliding of the first support 6, it can also be arranged that a second driving cylinder is provided on the test platform 1, the output shaft of the second driving cylinder extends in a direction parallel to the axis of the rotor 8, and is fixed on the first support 6, ensuring that the first support 6 can be driven to slide in a direction parallel to the axis of the rotor 8, and further the relative position between the limiting synchronous belt 3 and the middle part of the rotor 8 can be adjusted.

[0062] It can be understood that the second driving cylinder can be any one of a hydraulic cylinder, a pneumatic cylinder, or an electric cylinder.

[0063] In other embodiments, to achieve the sliding of the first support 6, it can also be arranged that a lead screw is provided on the test platform 1. The lead screw extends along a direction parallel to the axis of the rotor 8, and the lead screw can rotate around its own axis. When the first support 6 is installed, it is sleeved on the lead screw and forms a transmission fit with the lead screw to ensure that the first support 6 can be driven to slide along a direction parallel to the axis of the rotor 8, thereby adjusting the relative position between the limiting synchronous belt 3 and the middle part of the rotor 8. Optionally, the lead screw can be rotated manually. Optionally, a third driving motor can also be provided to drive the lead screw to rotate.

[0064] In other embodiments, the specifications of the rotor 8 are diverse, resulting in different lengths. To improve the versatility of the generator dynamic balance test device, it is arranged that both second supports 201 can slide along a direction parallel to the axis of the rotor 8, so that the distance between the two second supports 201 can be adjusted according to the length of different rotors 8, thereby adapting to rotors 8 of different lengths.

[0065] Specifically in this embodiment, a second sliding groove 101 is formed at the top of the test platform 1. The second sliding groove 101 extends along a direction parallel to the axis of the rotor 8. Second sliding blocks are arranged at the bottom of each second support 201. When installed, the second sliding blocks are slidably inserted into the second sliding groove 101 to ensure that the second supports 201 can be driven to slide along a direction parallel to the axis of the rotor 8, thereby adjusting the distance between the two second supports 201. A second locking bolt is threaded through each second support 201, and the second locking bolt is configured to form a friction locking fit with the test platform 1, so that after the two second supports 201 are adjusted in place, the second supports 201 can be locked on the test platform 1, thereby locking the position of the runner 202 and improving the support stability of the rotor 8.

[0066] In other embodiments, to achieve the sliding of the second support 201, two third driving cylinders can also be provided. The principle is the same as above and will not be elaborated here.

[0067] It can be understood that the third driving cylinder can be any one of a hydraulic cylinder, a pneumatic cylinder or an electric cylinder.

[0068] In other embodiments, to achieve the sliding of the second support 201, a lead screw can also be provided. The principle is the same as above and will not be elaborated here.

[0069] In other embodiments, the support assembly 2 can also be arranged to adopt a structure in which the runner 202 is replaced by a bearing.

[0070] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

Claims

1. A dynamic balance testing device for a generator, characterized in that The generator dynamic balance test device is configured to be able to perform a dynamic balance test on the rotor of the generator; The generator dynamic balance test device includes: A test platform; A support assembly, which is arranged on the test platform and is configured to be able to support the rotation of the rotor; A limiting synchronous belt, which is arranged on the test platform and forms a closed motion loop on the test platform. The limiting synchronous belt has a fixed section, and the outer side of the fixed section wraps around the top of the rotor during use and is in frictional contact with the rotor; A pulley assembly, which is arranged on the test platform and is configured to be able to make the limiting synchronous belt form a closed motion loop.

2. The generator dynamic balance test device according to claim 1, wherein The pulley assembly includes a bracket. On the bracket, a driving wheel, an elastic tensioning wheel, a first driven wheel, two second driven wheels and two driving tensioning wheels are rotatably arranged around its own axis. The driving wheel, the elastic tensioning wheel, the first driven wheel and the two driving tensioning wheels are all located inside the limiting synchronous belt and are in frictional contact with the limiting synchronous belt; the two second driven wheels are located outside the limiting synchronous belt and are in frictional contact with the limiting synchronous belt; the elastic tensioning wheel is configured to be able to elastically tension the limiting synchronous belt; the two driving tensioning wheels are symmetrically arranged with respect to the rotor.

3. The generator dynamic balance test device according to claim 2, characterized in that, The limiting synchronous belt is configured to have an acceleration state and a stable state. When in the acceleration state, the limiting synchronous belt is configured to be able to drive the rotor to rotate at an accelerated speed; when in the stable state, the limiting synchronous belt is configured to be able to drive the rotor to rotate at a constant speed; and when in the acceleration state, the area of the fixed section wrapping the rotor is larger than the area of the fixed section wrapping the rotor when in the stable state; the generator dynamic balance test device further includes an adjusting mechanism, and the adjusting mechanism is configured to be able to adjust the state of the limiting synchronous belt.

4. The generator dynamic balance test device according to claim 3, characterized in that, The driving tensioning wheel can slide in the vertical direction; the adjusting mechanism includes two third driven wheels and two driving members. The two third driven wheels are both arranged on the bracket and are both located inside the limiting synchronous belt and are symmetrically arranged with respect to the rotor; the driving member is arranged on the bracket and is configured to be able to provide the driving force for the driving tensioning wheel to slide in the vertical direction; the driving tensioning wheel has corresponding first and second positions before and after sliding. When in the first position, the limiting synchronous belt is in a first state, and the limiting synchronous belt is wound around the driving wheel, the elastic tensioning wheel, the first driven wheel, the two second driven wheels and the two driving tensioning wheels; when in the second position, the limiting synchronous belt is in a second state, and the limiting synchronous belt is wound around the driving wheel, the elastic tensioning wheel, the first driven wheel, the two second driven wheels and the two third driven wheels.

5. The generator dynamic balance test device according to claim 4, wherein, The active tension pulley has a first sub-pulley and two second sub-pulleys that are fixedly and coaxially arranged. The two second sub-pulleys are located on both sides of the first sub-pulley and have diameters larger than that of the first sub-pulley. The third driven pulley has a third sub-pulley and two fourth sub-pulleys that are fixedly and coaxially arranged. The two fourth sub-pulleys are located on both sides of the third sub-pulley and have diameters smaller than that of the third sub-pulley. There are three limiting synchronous belts, and the three limiting synchronous belts are arranged side by side. The limiting synchronous belt in the middle is configured to be able to cooperate with the first sub-pulley or the third sub-pulley, and the limiting synchronous belts on both sides are configured to be able to cooperate with the second sub-pulley or the fourth sub-pulley.

6. The generator dynamic balance testing device according to claim 5, characterized in that The diameter difference between the first sub-pulley and the second sub-pulley is smaller than the belt thickness of the limiting synchronous belt; the diameter difference between the third sub-pulley and the fourth sub-pulley is smaller than the belt thickness of the limiting synchronous belt.

7. The generator dynamic balance test device according to claim 2, characterized in that, A first support is further provided on the test platform, and the bracket is hinged on the first support; the generator dynamic balance test device further includes a driving component, and the driving component is configured to be able to provide a driving force for the rotation of the bracket.

8. The generator dynamic balance testing device according to claim 7, wherein, The first support can slide in a direction parallel to the axis of the rotor.

9. The generator dynamic balance test device according to claim 1, characterized in that The support component includes two second supports, and the two second supports are arranged at intervals in a direction parallel to the axis of the rotor; two rotating wheels are provided on each second support, the axis of the rotating wheel is parallel to the axis of the rotor, the rotating wheel can rotate around its own axis, the rotating wheels on different second supports are correspondingly arranged, the two rotating wheels on the same second support are arranged in a direction perpendicular to the axis of the rotor, and a support area is formed therebetween, and the support area is configured to be able to support the rotor.

10. The generator dynamic balance testing device according to claim 9, characterized in that, Both of the two second supports can slide in a direction parallel to the axis of the rotor.

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