A platform for testing dynamic balance of a rotor of a mine energy-saving motor

Abstract

The present application relates to the technical fields of dynamic balance test, in particular to a kind of mining energy-saving motor rotor dynamic balance test platform, including casting base, excitation column, force sensor assembly, swing frame and gyro wheel, the swing frame is installed at the top of force sensor assembly, and swing frame includes support seat, limiting crossbeam, the both ends of limiting crossbeam are slidably connected with the two side vertical arms of support seat, and the bottom surface of limiting crossbeam and the highest point of the rotor to be measured after assembly are reserved play clearance;The gyro wheel is at least two, and gyro wheel includes outer rim, inner hub;Multiple elastic rib plates radially distributed between the outer rim and inner hub are arranged.The present application is reserved by adding porous limiting crossbeam with play clearance, double-layer gyro wheel with S-shaped elastic rib plate and support seat with vibration isolation slit;Realize the safety protection under extreme conditions, and ensure the purpose of dynamic balance test signal pure and stable.

Description

Technical Field

[0001] This invention relates to the field of dynamic balancing testing technology, specifically to a dynamic balancing testing platform for the rotor of an energy-saving electric motor used in mining. Background Technology

[0002] In the field of mining heavy equipment manufacturing and maintenance, electric motor rotor dynamic balancing test platforms are mainly used for the precise measurement and correction of the dynamic centrifugal force of heavy rotors with large inertia. In existing technologies, for mining rotors weighing several tons, such test platforms typically employ a rigid support structure, using a large-diameter rigid spherical roller pendant to mechanically support the rotor journal. The core technology lies in relying on high-rigidity physical boundaries to isolate low-frequency micro-vibrations from the external ground, and obtaining the rotor structure's vibration response characteristics under controlled rotation, thereby calculating the rotor imbalance in reverse.

[0003] However, the aforementioned technologies still face the problem of dynamic constraint failure under extreme working conditions in practical applications. Existing technologies generally assume that for large-tonnage mining motors, the weight of the heavy rotor itself is sufficient to maintain stable contact between the rotor and the roller frame. Therefore, conventional platforms often rely on a static gravity field to maintain the contact between the rotor and the roller surface. However, mining motor rotors have extremely large inertia, requiring extremely high tangential drive torque during startup or braking. At this time, the rotor's stress state abruptly changes from a single static gravity field to a complex three-dimensional vector field containing centrifugal force and transient tangential torsional force. Constraint mechanisms relying solely on gravity clamping have a potential risk of failure.

[0004] Specifically, on a hard-bearing test platform, when a heavy rotor with a large initial imbalance crosses the static friction dead zone and undergoes low-speed transient acceleration or emergency braking, the nonlinear angular acceleration caused by the enormous driving torque generated by the motor will be superimposed on the transient centrifugal force generated by the rotor's unbalanced mass. When the resultant force of the transient centrifugal force component and the tangential force component exceeds the rotor's equivalent radial gravity in a very short time, the rotor journal will experience high-frequency mechanical vibration and microscopic slippage on the contact surface of the rigid spherical roller pendulum. This manifests as a momentary detachment and impact of the journal, leading to localized extreme Hertzian stress concentration. This defect not only causes irreversible indentation damage to the surface of the ultra-high precision cylindrical roller bearing, but the nonlinear mechanical impact also destroys the stiffness decoupling characteristics of the hard-bearing system, resulting in severe baseline drift and phase distortion in the vibration signals acquired by the mechanical sensors, thus causing the dynamic balance matrix calculation to fail.

[0005] To address this, a dynamic balancing test platform for the rotor of an energy-saving electric motor used in mining is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a dynamic balancing test platform for energy-saving electric motor rotors used in mining, which solves the problems of equipment damage and signal distortion during the start and stop of dynamic balancing tests of large inertia motor rotors. By adding a multi-hole limiting beam with reserved clearance, a double-layer roller with S-shaped elastic ribs, and a support base with vibration isolation slits, safety protection under extreme working conditions is achieved, and the purpose of ensuring the purity and stability of the dynamic balancing test signal is ensured.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A dynamic balancing test platform for a mining energy-saving electric motor rotor includes a cast base, an excitation column mounted on the cast base, a force sensor assembly located at the end of the excitation column, and a swing frame and rollers supporting the rotor under test. The swing frame is mounted on top of the force sensor assembly and includes a U-shaped support base and a limiting beam spanning above the support base. The two ends of the limiting beam are slidably connected to the two side arms of the support base to accommodate the nominal shaft diameters of different rotors under test. A clearance is reserved between the bottom surface of the limiting beam and the highest point of the assembled rotor under test. Existing safety clamping mechanisms typically use auxiliary rollers to press against the rotor journal to prevent jump-out. This contact-type protection inevitably introduces contact stiffness and parasitic friction damping into the vibration system. This solution, by reserving clearance, avoids contact above the rotor during steady-state testing, enabling zero-loss transmission of the rotor excitation force. The limiting beam only provides a blocking boundary when the rotor jumps out beyond the limit, thus balancing high signal fidelity and safety protection under extreme conditions.

[0008] The rollers are of at least two types, each rotatably mounted on the inner side of the support base. The rollers are configured with a double-layer nested structure, and each roller includes an outer rim for contacting the rotor under test and an inner hub rotatably connected to the support base. Multiple elastic ribs are provided between the outer rim and the inner hub, arranged radially along the circumference, and connected to the inner hub via these ribs. The elastic ribs are configured to undergo tangential elastic deformation to absorb transient impact energy during rotor start-up and shutdown. The double-layer nested structure of the rollers, in conjunction with the elastic ribs, achieves primary mechanical filtering. During startup transients, the elastic deformation of the ribs absorbs a large amount of nonlinear torsional impact energy, preventing destructive stress on the underlying rigid support network. During steady-state testing, it can restore and transmit the same-frequency excitation force.

[0009] Preferably, the support base has a through-hole slit, and the groove wall of the slit forms a discontinuous barrier interface inside the support base. The slit allows the part of the support base to make a slight opening and closing motion along the radial direction of the slit when it encounters an impact from the rotor, using its own expansion and contraction to buffer the energy of the impact. In addition, since metal is a good medium for transmitting vibration and sound, efforts should be made to weaken the propagation of vibration. The air filling the slit interrupts the continuous state of the metal, so that the high-frequency noise generated by the rotor rubbing against the rollers is blocked by the air gap before it is transmitted downward to the sensor, so that the force sensor can only receive the pure swaying signal generated by the rotor's unstable center of gravity.

[0010] Preferably, the extended end of the slit has a release hole, which is configured as a teardrop shape, with the tip of the release hole located on the surface of the support base. A straight slit is prone to cracking at its very end when subjected to repeated pulling. By making its end a rounded teardrop-shaped cavity, the destructive force that was originally concentrated at one point is dispersed to a longer arc edge, preventing the metal frame from being torn apart under long-term pulling. Furthermore, the direction of the teardrop-shaped tip pointing towards the surface of the support base follows the diffusion direction of force within the metal. The impact will be smoothly dispersed into the surrounding thicker solid metal block along the direction of the tip, avoiding deformation caused by localized stress accumulation.

[0011] Preferably, the support base includes an upper part for bearing rollers and a lower part installed inside the vibration column. Multiple slits are distributed in the upper part, and the lower part is set as a continuous solid section without gaps. The slits are concentrated in the upper part, making the upper part relatively soft to absorb vibrations. At the same time, the lower part is kept in a solid state without cutting to maintain rigidity and support the crossbeam.

[0012] Preferably, the upper part is provided with outwardly protruding heat dissipation ribs, and an open guide groove is formed between two adjacent heat dissipation ribs; the heat dissipation ribs increase the thickness and volume of the upper outer side, change the shaking frequency of the entire support base, and thus prevent the shaking rhythm of the test platform itself from colliding with the rotation rhythm of the rotor, preventing the two from resonating and causing the equipment to shake violently; and the outwardly protruding heat dissipation ribs and the open grooves between the heat dissipation ribs increase the contact area between the metal surface and the surrounding air, thereby allowing cold air to quickly pass through the grooves to remove the heat generated by the friction between the rotor and the roller.

[0013] Preferably, the elastic rib is configured as an S-shaped bent cantilever structure, with the convex crest of the elastic rib extending toward the rotational tangent of the roller, and both ends of the elastic rib smoothly transitioning to the inner peripheral wall of the outer rim and the outer peripheral wall of the inner hub, respectively. The S-shaped bent cantilever utilizes its large geometric deformation characteristics to exhibit extremely low tangential stiffness (flexible energy absorption) during minor frictional slippage, while its structural stiffness increases sharply and nonlinearly when encountering a limiting torque that causes the crest to flatten (rigid load bearing). In addition, the heat generated by a traditional metal roller under heavy-load friction is rapidly conducted radially to the core bearing. The S-shaped bend structure of the elastic rib extends the heat conduction path, and combined with the rotating air convection during the test, effectively reduces the temperature rise of the inner precision bearing, preventing thermal strain from causing the dynamic balance calibration matrix to drift.

[0014] Preferably, the wall thickness of the elastic rib decreases from the connection end of the inner hub to the connection end of the outer rim, and the side of the elastic rib closest to the outer rim and the inner hub respectively forms a follower section and a base section; the base section near the central axis is thicker, providing a solid grip, which can firmly anchor the entire structure and prevent the rib from being broken off at the root during violent torsion and tension; the follower section near the outer edge is relatively thin, and when the outer rim contacts the uneven surface of the old mining rotor, the softer edge allows the rim surface to be locally concave, thus more closely wrapping the rough rotor surface.

[0015] Preferably, the outer rim has two parallel V-shaped grooves on its outer circumferential surface. The radial depth of the bottom of the V-shaped groove is less than the thickness of the solid outline of the outer rim. The V-shaped groove provides a space for the outer rim to accommodate the rollers. If the old rotor is repaired and leaves protruding welding scars or burrs on the shaft, these protrusions will gradually move into the V-shaped groove during operation, thus avoiding damage to the smooth contact surface of the roller.

[0016] Preferably, the width of the V-groove opening is greater than the width of its bottom; the outwardly expanding inclined groove wall uses the centrifugal force generated by the high-speed rotation of the rotor to automatically throw out the iron filings and impurities that are crushed and peeled off during operation, preventing the secondary accumulation of debris into the contact surface and causing high-frequency pulse interference, thus ensuring the continuous self-cleaning of the force measuring system.

[0017] Preferably, the bottom surface of the limiting beam is an arc surface, and the bottom surface of the limiting beam is made of a porous material. If traditional solid metal or hard rubber is used as the limiting block, the heavy rotor will not only cause irreversible indentation on the journal surface during extreme bounce impact, but will also easily trigger a strong secondary rebound. The porous material undergoes irreversible plastic crushing and collapse at the moment of impact, converting huge kinetic energy into deformation energy through the destruction of the microstructure, thereby reducing the probability of damage to the rotor journal and the main body of the beam.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention addresses the issue of rotor slippage during testing of high-inertia motor rotors by changing the traditional rigid support platform's reliance solely on rotor weight for support. The pre-existing clearance between the limiting beam and the rotor ensures that the rotor is not contacted by the upper structure during stable testing, avoiding the introduction of additional frictional resistance that could interfere with sensor measurements. Simultaneously, the elastic ribs connecting the inner hub and outer rim of the rollers deform during the intense torque generated by the heavy rotor's start-up and braking, absorbing the energy of the rotor's instantaneous impact, protecting the bottom structure from damage, and restoring support after stable operation, thus transmitting the swaying force caused by rotor instability.

[0019] 2. The through slit at the top of the support base of this invention uses the air in the slit to cut off the solid continuity of the metal, intercepting the high-frequency vibration generated by the rotor friction roller, making the signal received by the force sensor below purer; the teardrop-shaped release hole design at the end of the slit disperses the destructive force originally concentrated at the end of the slit to the arc edge, preventing the support base from cracking under long-term tension; in addition, the heat dissipation ribs on the outside increase the air contact area to dissipate frictional heat, while also changing the overall mass and shape of the upper part of the support base, avoiding the resonant frequency of the rotor rotation, preventing the equipment from shaking violently, and at the same time reducing the external cooling energy consumption of the testing system.

[0020] 3. The design of the elastic ribs of this invention, which gradually thins from the inside to the outside, makes the outer rim edge relatively soft, which can create local concavity to fit the uneven surface of the old rotor; the V-shaped groove with a large opening on the outer rim provides space for the electric welding protrusions on the surface of the old rotor and the iron filings that fall off during operation to be accommodated and discharged, preventing the flat surface of the roller from being scratched; the porous material used on the bottom surface of the limiting beam can be crushed when the rotor experiences a severe jump impact, and absorbs kinetic energy through its own destruction, preventing the rotor journal from being indented and from experiencing secondary rebound.

[0021] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show a certain embodiment of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1This is a schematic diagram of the overall isometric structure of the present invention; Figure 2 This is a schematic diagram of the overall right-side structure of the present invention; Figure 3 This is a schematic diagram of the overall internal section isometric structure of the present invention; Figure 4 This is a schematic diagram of the overall internal cross-section right view of the present invention; Figure 5 For the present invention Figure 1 Enlarged diagram of part A in the middle; Figure 6 For the present invention Figure 3 Enlarged diagram of section B; Figure 7 For the present invention Figure 4 Enlarged diagram of section C.

[0024] In the diagram: 1. Cast base; 2. Vibration column; 3. Force sensor assembly; 4. Swing frame; 41. Support base; 411. Slit; 412. Release hole; 413. Upper part; 414. Lower part; 415. Heat dissipation ribs; 42. Limiting beam; 5. Roller; 51. Outer rim; 511. V-groove; 52. Inner hub; 53. Elastic rib; 531. Follower section; 532. Base section Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Please see Figures 1 to 7 This invention provides a dynamic balancing test platform for the rotor of an energy-saving electric motor used in mining. The technical solution is as follows: A dynamic balancing test platform for a mining energy-saving electric motor rotor includes a cast base 1, an excitation column 2 mounted on the cast base 1, a force sensor assembly 3 located at the end of the excitation column 2, and a swing frame 4 and rollers 5 supporting the rotor to be tested. The bottom surface of the excitation column 2 is provided with a slide table, and the cast base 1 is provided with corresponding slide rails so that the swing frame 4 and rollers 5 can move laterally through the cooperation of the slide table and slide rails. In addition, the motor to be tested is fastened to the support plate of the cast base 1 by bolts. The support plate can move up and down to adjust the position of the motor rotor. Then, through the lateral adjustment of the rollers 5 and the lifting adjustment of the motor, the initial alignment is completed (so that the motor rotor is located between the two rollers 5 and in contact with the surface of the rollers 5).

[0027] To ensure the benchmark stability of the dynamic balancing test, the casting base 1 is preferably made of HT250 or higher grade gray cast iron through integral casting and hot aging. The flake graphite distributed inside the gray cast iron is used to achieve low-frequency vibration attenuation of the base. The slide rail adopts a high-precision linear guide rail, which is driven by a ball screw mechanism driven by a servo motor to improve the positioning accuracy of lateral movement, thereby eliminating the assembly eccentricity error introduced in the initial alignment stage.

[0028] The pendulum frame 4 is installed on top of the force sensor assembly 3. The pendulum frame 4 includes a U-shaped support base 41 and a limiting beam 42 spanning above the support base 41. The two ends of the limiting beam 42 are slidably connected to the two side arms of the support base 41 to accommodate the nominal shaft diameter of different rotors to be tested. A clearance is reserved between the bottom surface of the limiting beam 42 and the highest point of the assembled rotor to be tested. The sliding connection is specifically achieved by opening dovetail grooves on the inner side of the two side arms of the support base 41 and setting matching dovetail sliders at both ends of the limiting beam 42, and using a self-locking screw and handwheel for height adjustment. The reserved clearance is usually set within the range of 0.5mm to 1.5mm. This threshold ensures that the rotor does not make contact above under normal micron-level steady-state amplitude caused by unbalance, and also ensures instantaneous intervention and constraint before destructive jump-off.

[0029] There are at least two rollers 5, and each roller 5 is rotatably mounted on the inner side of the support base 41. The rollers 5 are configured with a double-layer nested structure, and each roller 5 includes an outer rim 51 for contacting the rotor under test and an inner hub 52 rotatably connected to the support base 41. Multiple elastic ribs 53 are provided between the outer rim 51 and the inner hub 52 in a radially distributed manner along the circumference, and the outer rim 51 and the inner hub 52 are connected by multiple elastic ribs 53. The elastic ribs 53 are configured to undergo tangential elastic deformation to absorb the transient impact energy during the start-up and shutdown of the rotor under test. In terms of manufacturing process, the outer rim 51, the inner hub 52 and the elastic ribs 53 can be integrally cast using high-strength polyurethane elastomer material, or integrally formed using 65Mn spring steel through precision slow wire cutting and then subjected to overall quenching and tempering treatment. In this approach, by matching the elastic modulus of the material with the cross-sectional area of ​​the stiffener, the equivalent radial stiffness of the double-layer nested structure is set to be much greater than its equivalent tangential stiffness, so as to ensure the lossless transmission of steady-state radial excitation force.

[0030] As one embodiment of the present invention, refer to Figures 4-6A slit 411 is formed through the support base 41, and the groove wall of the slit 411 forms a discontinuous barrier interface inside the support base 41. The specific width of the slit 411 is preferably 1mm to 2mm, and it is machined on the support base 41 blank using an electrical discharge wire cutting process. The width of the slit 411 is sufficient to block the direct transmission of high-frequency sound waves and micro-stress waves between the metal lattice. At the same time, the air medium inside the slit 411 forms a layer of abrupt change in acoustic impedance, effectively constituting a high-frequency mechanical filtering barrier and preventing parasitic high-frequency noise from interfering with the piezoelectric ceramic wafer of the bottom force sensor.

[0031] As one embodiment of the present invention, refer to Figure 3 and Figure 6 The extended end of the slit 411 has a release hole 412, which is designed as a teardrop shape and the tip of the release hole 412 is located on the surface of the support 41. The teardrop shape of the release hole 412 smooths out the strange stress field that was originally concentrated at the tip of the slit 411, and the stress concentration factor (Kt) is effectively reduced. The design of the tip pointing to the outer surface utilizes the compressive stress layer that is usually present on the metal surface (e.g., after surface shot blasting), which further suppresses the initiation and propagation of fatigue cracks.

[0032] As one embodiment of the present invention, refer to Figure 4 The support base 41 includes an upper part 413 for bearing the roller 5 and a lower part 414 installed inside the vibrating column 2. Multiple slits 411 are distributed in the upper part 413, and the lower part 414 is set as a continuous solid section without gaps.

[0033] As one embodiment of the present invention, refer to Figure 1 and Figure 5 The upper part 413 is provided with heat dissipation ribs 415 protruding outward, and an open guide groove is formed between two adjacent heat dissipation ribs 415. When the rotor rotates at high speed, the boundary layer airflow driven by its surface is guided into the open guide groove, forming a forced convection heat transfer channel. Thus, the heat generated by the friction pair of the roller 5 can be quickly dissipated without the need for an external cooling power source, maintaining the elastic modulus of the material from decreasing due to temperature rise. This eliminates the need for the forced water cooling / air cooling external system that is usually required in traditional heavy-duty test platforms, as well as the additional power consumption required to overcome contact resistance, thereby reducing the overall operating power consumption and achieving energy saving.

[0034] As one embodiment of the present invention, refer to Figure 2 and Figure 4The elastic stiffener 53 is configured as an S-shaped bent cantilever structure, and the convex section of the elastic stiffener 53 extends toward the rotational tangent of the roller 5. The two ends of the elastic stiffener 53 are smoothly connected to the inner peripheral wall of the outer rim 51 and the outer peripheral wall of the inner hub 52, respectively. When the rotor rotates at a normal uniform speed, the small tangential fluctuations only cause small deflection bending of the S-shaped structure, and the system is in a low-stiffness flexible energy absorption state. When a huge tangential slippage tendency occurs at the moment of start-stop, the S-shaped structure is quickly straightened (or crushed to the trough and fits), and the stress mode of the structure changes instantly from bending-dominated to axial tension (or compression-dominated). The system stiffness shows an exponential leap and enters a high-stiffness rigid load-bearing state, thereby preventing the roller 5 from disintegrating.

[0035] As one embodiment of the present invention, refer to Figure 7 The wall thickness of the elastic stiffener 53 decreases from the connecting end of the inner hub 52 to the connecting end of the outer rim 51. The side of the elastic stiffener 53 closest to the outer rim 51 and the inner hub 52 forms a follower section 531 and a base section 532, respectively. The ratio of the thickness of the base section 532 to the thickness of the follower section 531 is preferably between 3:1 and 5:1, so that the stress distribution of the entire stiffener is more uniform under load, avoiding excessive stress concentration at the root. The thinner follower section 531 reduces the local polar moment of inertia of the outer rim 51, allowing it to flexibly cover old rotor journals with minor rust or machining marks on the surface.

[0036] As one embodiment of the present invention, refer to Figures 5-7 The outer rim 51 has two parallel V-shaped grooves 511 on its outer circumferential surface. The radial depth of the bottom of the V-shaped grooves 511 is less than the solid contour thickness of the outer rim 51. The annular arrangement ensures that the roller 5 maintains continuous line or surface contact with the rotor journal during rolling, avoiding periodic vibration impacts when crossing the groove opening. The radial depth of the groove bottom is usually set to 1 / 3 to 1 / 2 of the solid contour thickness to maximize the accommodating space while ensuring structural strength. The groove opening width of the V-shaped groove 511 is greater than its own groove bottom width. The included angle of the V-shaped groove 511 is set between 60° and 90°. This inclined angle forms a centrifugal chip removal slope. When the roller 5 rotates at high speed, because the density of metal chips is much greater than that of air, the impurities generate a radially outward sliding force along the inclined groove wall under the action of centrifugal force, thereby overcoming friction and being automatically thrown out. In addition, in view of the harsh working conditions in which the surface of mining equipment is usually covered with sticky oil stains, the inclined groove wall surface of the V-shaped groove 511 can preferably be sprayed with a low surface energy anti-adhesion coating such as polytetrafluoroethylene, so as to significantly reduce the static friction coefficient and adhesion force between iron filings and metal groove wall, and ensure that even when the rotor is running at low speed and the centrifugal force is weak during the test stage, the impurities can still slide outward along the inclined surface and be thrown out, thus ensuring the absolute reliability of the self-cleaning function.

[0037] As one embodiment of the present invention, refer to Figure 1 and Figure 2 The bottom surface of the limiting beam 42 is set as an arc surface, and the bottom surface of the limiting beam 42 is made of a porous material; the radius of curvature of the arc surface is slightly larger than the journal radius of the largest rotor measured to provide the optimal contact wrap angle. The porous material is preferably a closed-cell aluminum foam alloy plate; when the rotor experiences an extreme bounce impact, the closed-cell aluminum foam relies on the plastic buckling, crushing and collapse of its tens of thousands of tiny pore walls to absorb a huge amount of impact kinetic energy with a constant plateau stress.

[0038] Working principle: Refer to Figure 1 and Figure 2 Before conducting the dynamic balancing test, the heavy-duty motor rotor to be tested is stably placed on the rollers 5 on both sides, and the limiting beam 42 is adjusted downward to leave a small clearance between the porous material at its bottom and the highest point of the rotor. During the stable test operation phase, the rotor's own weight and the pure centrifugal force generated due to the instability of the center of gravity are stably transmitted downward through the rollers 5 to the force sensor assembly 3 at the end of the excitation column 2. The compliance judgment of the dynamic balancing test is based on whether the real-time feedback value of the force sensor assembly 3 located between the excitation column 2 and the pendulum frame 4 is within the preset range. It should be clarified that in this application, the elastic stiffener 53 and the slit 411 are both structural features of the pendulum frame 4 and its internal assembly, located in the force transmission path between the rotor and the sensor assembly 3. Since the motor is bolted to the cast base 1, the torque change caused by rotor dynamic imbalance will increase or decrease the centrifugal force on the pendulum frame 4. Although the elastic stiffener 53 and the slit 411 will trigger a local buffering effect against this force, this buffering is a self-coordinating structural feature within the pendulum frame 4 and does not affect the interaction force between the pendulum frame 4 as a whole under stress and the external excitation column 2. Therefore, this scheme, while utilizing internal micro-deformation to intercept high-frequency mechanical interference, ensures the complete mapping of the macroscopic dynamic balance measurement signal at the sensor interface, achieving a balance between detection accuracy and equipment protection. At this stage, refer to Figure 7 If the surface of the old rotor has iron filings or repair protrusions, these impurities will be initially squeezed into the V-groove 511 on the outer circumference of the outer rim 51. As the rotor rotates at high speed, the inclined groove wall of the V-groove 511 expands outward and uses centrifugal force to automatically throw the impurities outward along the inclined surface of the groove wall, thereby achieving continuous self-cleaning of the contact surface of the roller 5 and preventing high-frequency pulse interference.

[0039] Reference Figure 4 and Figure 7When the motor rotor is in a rapid acceleration or emergency braking phase, it generates a huge nonlinear tangential torque. At this time, the force transmission changes drastically: the huge tangential cutting force first acts on the outer rim 51 of the roller 5. The S-shaped elastic rib 53 located between the outer rim 51 and the inner hub 52 acts like an energy buffer. Its convex crest section rapidly undergoes a large-deflection tangential flexible bending, converting the destructive transient impact kinetic energy into its own elastic potential energy. When the torque approaches the limit and causes the S-shaped crest to flatten, the rib instantly enters a rigid stress state of axial tension, anchoring the inner and outer structures, preventing the roller 5 from disintegrating, and thus smoothly passing through the kinetic energy burst period.

[0040] Reference Figure 3 and Figure 6 The high-frequency mechanical friction noise and residual stress waves generated during the operation of roller 5 are intercepted by the through slit 411 as they continue to propagate downwards to the upper part 413 of support base 41. The air medium inside slit 411 interrupts the continuity of the metal lattice, forming a natural acoustic impedance shielding layer that intercepts high-frequency noise at the upper part 413, ensuring that the force sensor below only receives the valuable, pure low-frequency shaking signal. Simultaneously, the tearing stress transmitted to the end of slit 411 is evenly dispersed to the surrounding solid area along the rounded edge of the teardrop-shaped release hole 412, preventing fatigue fracture. Furthermore, referring to... Figure 5 The heat generated by the friction of the roller 5 is conducted outward to the heat dissipation ribs 415 on the surface of the support 41. The boundary layer airflow generated by the high-speed rotation of the rotor passes through the guide grooves between the ribs and is quickly dispersed by convection.

[0041] Finally, refer to Figure 1 and Figure 4 If, during the test, the initial imbalance is extremely large, causing the rotor journal to jump upwards against gravity, the rotor will instantly cross the preset clearance and collide with the limiting beam 42. At this moment, the porous material on the bottom surface of the limiting beam 42 undergoes irreversible plastic crushing and internal pore wall collapse upon impact, instantly converting the rotor's violent impact kinetic energy into the material's deformation and destructive energy, thereby eliminating the rotor's secondary rebound path and protecting the motor rotor and high-precision bearings under extreme operating conditions.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A dynamic balancing test platform for a mining energy-saving electric motor rotor, comprising a cast base, a vibration column mounted on the cast base, a force sensor assembly disposed at the end of the vibration column, and a swing frame and rollers supporting the rotor to be tested, characterized in that: The pendulum frame is installed on top of the force sensor assembly, and the pendulum frame includes a support base with a U-shaped bottom and a limiting beam spanning above the support base. The two ends of the limiting beam are slidably connected to the two side arms of the support base to accommodate the nominal shaft diameter of different rotors to be tested. A clearance is reserved between the bottom surface of the limiting beam and the highest point of the assembled rotor to be tested. The rollers are at least two in number, and each roller is rotatably mounted on the inner side of the support base. The rollers are configured with a double-layer nested structure, and each roller includes an outer rim for contacting the rotor under test and an inner hub rotatably connected to the support base. The outer rim and the inner hub are provided with multiple elastic ribs that are radially distributed along the circumference, and the outer rim and the inner hub are connected by the multiple elastic ribs; the elastic ribs are configured to undergo tangential elastic deformation to absorb the transient impact energy when the rotor under test starts and stops.

2. The testing platform for dynamic balancing of the rotor of the energy-saving electric motor for mining as described in claim 1, characterized in that: The support base has a through slit, and the groove wall of the slit forms a discontinuous barrier interface inside the support base.

3. The testing platform for dynamic balancing of the rotor of the energy-saving electric motor for mining as described in claim 2, characterized in that: The extended end of the slit has a release hole, which is configured as a teardrop shape and the tip of the release hole is located on the surface of the support.

4. The testing platform for dynamic balancing of the rotor of the energy-saving electric motor for mining as described in claim 2, characterized in that: The support base includes an upper part that carries the rollers and a lower part that is installed inside the vibrating column. Multiple slits are distributed in the upper part, and the lower part is configured as a continuous solid cross-section without gaps.

5. The testing platform for dynamic balancing of the rotor of the energy-saving electric motor for mining as described in claim 4, characterized in that: The upper part is provided with outwardly protruding heat dissipation ribs, and an open guide groove is formed between two adjacent heat dissipation ribs.

6. The testing platform for dynamic balancing of the rotor of the energy-saving electric motor for mining as described in claim 1, characterized in that: The elastic rib is configured as an S-shaped bent cantilever structure, and the convex section of the elastic rib extends toward the rotational tangent of the roller, and the two ends of the elastic rib are smoothly connected to the inner peripheral wall of the outer rim and the outer peripheral wall of the inner hub, respectively.

7. The testing platform for dynamic balancing of the rotor of the energy-saving electric motor for mining as described in claim 6, characterized in that: The wall thickness of the elastic rib plate decreases from the connection end of the inner hub to the connection end of the outer rim, and the side of the elastic rib plate closest to the outer rim and the inner hub respectively forms a follower section and a base section.

8. The testing platform for dynamic balancing of the rotor of the energy-saving electric motor for mining as described in claim 1, characterized in that: The outer rim has two parallel V-shaped grooves on its outer circumferential surface, and the radial depth of the bottom of the V-shaped grooves is less than the solid contour thickness of the outer rim.

9. The testing platform for dynamic balancing of the rotor of an energy-saving electric motor for mining as described in claim 8, characterized in that: The width of the V-shaped groove opening is greater than the width of its own bottom.

10. The testing platform for dynamic balancing of the rotor of the energy-saving electric motor for mining as described in claim 1, characterized in that: The bottom surface of the limiting beam is set as an arc surface, and the bottom surface of the limiting beam is made of a porous material.

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