CN116907847A - Device and method for testing axial and radial high-rotation-speed dynamic stiffness of bearing - Google Patents

Abstract

The invention discloses a bearing axial and radial high-speed dynamic stiffness testing device and method, and relates to the technical field of mechanical testing. The device includes: a transmission spindle, which drives the experimental bearing to rotate; and a bearing adapter block, which is provided on the transmission spindle. One end is rigidly connected to the transmission main shaft, and the other end of the bearing adapter block is rigidly connected to the inner ring of the experimental bearing; the load loading component is used to apply axial force and radial force to the experimental bearing; the balance force loading component is used to offset the applied radial force. The warpage caused by the force-rear transmission spindle; the displacement measurement component is used to measure the axial displacement and multiple radial displacements of the experimental bearing; the processing unit is used to measure the real-time radial force, real-time axial force, and axis The stiffness is calculated by radial displacement and multiple radial displacements; the invention can realize displacement measurement and collection under a radial and axial combined load, can realize continuous dynamic loading and perform real-time measurement, and has good real-time performance.

Description

A bearing axial and radial high-speed dynamic stiffness testing device and method

Technical field

The invention relates to the technical field of mechanical testing, and in particular to a device and method for testing the axial and radial high-speed dynamic stiffness of a bearing.

Background technique

Bearing stiffness is one of the important indicators to measure the dynamic characteristics of bearings. Bearing static stiffness analysis is divided into static analysis and dynamic analysis. The static analysis of bearing stiffness refers to the bearing's ability to resist deformation under static load when it is stationary, and the dynamic analysis of bearing stiffness (i.e., operating stiffness) refers to the bearing's ability to resist deformation under static load when it is running.

Static analysis of bearing stiffness can be obtained by empirical calculation formulas or measured by bearing static stiffness testing equipment. For example, the patent CN107462418A "A high-precision rolling bearing static stiffness testing device and method" tests the axial and radial static stiffness of rolling bearings under pure axial load, pure radial load and shaft-diameter combined load, but the device cannot test the bearing dynamic Calculation and analysis of stiffness.

As machine tool spindles and aero-engine output shaft systems develop toward high speed, high precision, and high stiffness, the theoretical calculation and experimental testing process of the dynamic characteristics of high-speed spindles have attracted much attention. As the core component of this type of spindle, the dynamic characteristics of bearings at high speeds are particularly important. Therefore, higher requirements are put forward for the dynamic stiffness index of the bearings. At the same time, higher requirements are put forward for the dynamic stiffness measurement of the bearings under high-speed rotation. High requirements.

The application method of radial load in the existing patents cannot be accurately measured, calculated and analyzed. Chinese patent CN217687779U "A Rolling Bearing Stiffness Testing Device" uses an eccentric loading component to calculate the centrifugal force generated by the rotation of the eccentric block acting on the bearing. radial force. In addition, the radial force is generated by the centrifugal force generated by the eccentric mass disk when the shaft rotates and acts on the inner ring of the bearing. The disadvantage of this method is that the calculation of the centrifugal force of the eccentric disk under high-speed rotation will introduce errors in the calculation of the bearing load and cannot be eliminated. At the same time, the load is linearly related to the rotational speed, so it cannot implement a measurement solution for different loads at a constant rotational speed.

In the existing patents, most of the displacement sensors are installed and fixedly connected to the experimental bearing seat. For example, in the patent CN113607416A "A three-dimensional dynamic stiffness test of rolling bearings and its testing method", when arranging the displacement sensor, the sensor support part is installed on the bearing of the experimental bearing. , the assembly gap between the outer ring of the experimental bearing and the housing of the experimental bearing will be introduced into the measurement due to the deviation of the measurement reference. The systematic error introduced by the displacement measurement leads to errors in the stiffness calculation, which cannot be eliminated.

In addition, among the testing solutions for dynamic analysis of bearing static stiffness, most of the solutions focus on stiffness testing in either the radial or axial direction of the bearing, and there are very few solutions that take into account both at the same time. A very small number of research works take into account both axial and radial dynamic stiffness testing methods. For example, Chinese patent CN108680357A "A device for measuring the axial and radial comprehensive dynamic stiffness of rolling bearings" uses axial and radial gas-liquid superchargers to test the axial and radial dynamic stiffness through sleeves. The test bearing applies axial force and radial force, and the axial and radial displacement sensors in the center through hole of the sleeve detect the axial displacement and radial displacement of the experimental bearing. The relative displacement of the inner and outer rings is measured through a displacement sensor embedded in the radial force loading device, and no measures are taken to prevent the spindle warping deformation caused by the loading process. At the same time, it does not limit the high degree of freedom of the bearing seat, which will cause deflection and vertical movement during force addition and spindle operation. In addition, when measuring displacement, the offset layout of the displacement sensor is not collinear with the radial load direction, which will introduce systematic errors that cannot be eliminated during the calculation process. Moreover, this solution will bring the gap between the bearing seat and the outer ring of the experimental bearing produced during the assembly process into the calculation. This is a systematic error and cannot be eliminated. Therefore, a radial displacement test sensor layout with displacement compensation is needed. Precise measurement solutions.

In addition, the current domestic research has not included the high degree of freedom (yaw and non-load direction displacement) of the bearing seat used to install the experimental bearing into the scope of research.

Finally, the existing test equipment cannot achieve accurate calculation and solution of the dynamic stiffness curve due to insufficient test plans and limitations of collected data, resulting in calculation errors in the stiffness solution that cannot be eliminated. Mainly due to the fact that the data is measured under the loading of some discrete forces. The small amount of discrete data means that when processing stiffness test data, only methods such as least squares fitting can be used for data fitting, while the traditional method is based on least squares fitting. The dynamic stiffness solution method assumes that the stiffness is a constant value and completely ignores the nonlinear characteristics of the bearing dynamic stiffness. For example, the patent CN113218603A "Rolling Bearing Dynamic-Static Stiffness Monitoring Device and Method" uses traditional methods when calculating stiffness. The method is used to fit the dynamic stiffness of rolling bearings. This method has poor stiffness calculation results due to less data and ignores the nonlinear characteristics of the bearing dynamic stiffness.

In summary, the existing technology lacks a device and method for testing the axial and radial high-speed dynamic stiffness of bearings. There is an urgent need for a testing device that can accurately measure the radial and axial stiffness of rolling bearings and a corresponding more accurate test device. dynamic stiffness calculation method.

Contents of the invention

Embodiments of the present invention provide a device and method for testing the axial and radial high-speed dynamic stiffness of a bearing, which solves the problem of low measurement accuracy in the prior art.

The invention provides a bearing axial and radial high-speed dynamic stiffness testing device, which includes:

The transmission main shaft, the experimental bearing is sleeved on the transmission main shaft, and the transmission main shaft drives the experimental bearing to rotate;

A bearing adapter block is provided at one end of the transmission main shaft and is rigidly connected to the transmission main shaft, and the other end of the bearing adapter block is rigidly connected to the inner ring of the experimental bearing;

A load loading component is provided outside the bearing adapter block and is used to apply axial force and radial force to the experimental bearing;

A balance force loading component is provided at the other end of the transmission spindle to offset the warpage of the transmission spindle after the radial force is applied;

The displacement measurement component is used to measure the axial displacement and multiple radial displacements of the experimental bearing;

The processing unit is used to collect the real-time radial force and real-time axial force exerted on the experimental bearing, as well as the axial displacement and multiple radial displacements of the experimental bearing, and collect the real-time radial force, real-time axial force, axial displacement and Multiple radial displacements are used to calculate stiffness;

The displacement measurement component includes a radial displacement measurement component, and the radial displacement measurement component includes:

The radial displacement sensor mounting plate is set outside the bearing adapter block;

The first radial displacement sensor, the second radial displacement sensor and the third radial displacement sensor are respectively installed at one end, the other end and the middle of the radial displacement sensor installation plate, and are respectively used to measure one end and the other end of the bearing adapter block. Radial displacement and measurement of the radial displacement of the outer ring of the experimental bearing.

Preferably, the transmission main shaft is supported by a main shaft support assembly, and the main shaft support assembly includes:

Experimental bearing support block, the internal rotation of which is provided with the transmission spindle;

The main shaft support sleeve is sleeved on the experimental bearing support block;

A first support bearing, a second support bearing and a third support bearing are installed in series inside the main shaft support sleeve.

Preferably, the load loading component includes a radial force loading component and an axial force loading component;

The radial force loading components include:

The floating bearing seat is rigidly connected to the outer ring of the experimental bearing;

Radial force loading device is used to apply radial force to the floating bearing seat.

Preferably, the axial force loading component includes:

Loading pad, set at the end of the floating bearing seat;

Axial force loading device is used to apply axial force to the loading pad.

Preferably, the balancing force loading component includes:

The shaft system is loaded with a balance block, which is set on the experimental bearing support block;

The balance force loading device is used to apply the same balance force as the radial force to the shaft system loading balance block.

Preferably, the displacement measurement component further includes an axial displacement measurement component, and the axial displacement measurement component includes:

The axial displacement sensor mounting plate is installed at the end of the floating bearing seat;

The axial displacement sensor is installed on the axial displacement sensor mounting plate;

Axial measuring pad, fixedly installed at the end of the bearing adapter block.

Preferably, it also includes:

Installation platform;

A high-speed drive motor is installed at one end of the top of the installation platform. The high-speed drive motor is connected to the transmission main shaft through a shaft system connecting block;

The installation bracket is fixed on the other end of the top of the installation platform;

The fine-tuning slide is set on the top of the installation bracket and is used to simultaneously adjust the installation positions of multiple radial displacement sensors;

The experimental bearing support sleeve is set on the top of the installation platform and is used to support the experimental bearing.

A testing method of a rolling bearing axial and radial high-speed dynamic stiffness testing device, including the following steps:

Collect the real-time radial force and real-time axial force exerted on the experimental bearing as well as the axial displacement of the experimental bearing;

The inner ring radial compensation calculation is performed based on the radial displacement measured by the third radial displacement sensor and the first radial displacement sensor, and combined with the radial displacement of the outer ring measured by the second radial displacement sensor, the radial direction of the inner and outer rings of the experimental bearing is obtained. Relative displacement;

According to the axial displacement of the experimental bearing, the relative axial displacement of the inner and outer rings is obtained;

Establish the load-displacement curve of the experimental bearing based on the real-time radial force, real-time axial force, radial relative displacement of the inner and outer rings of the experimental bearing, and axial relative displacement of the inner and outer rings of the experimental bearing;

Perform parameter identification of the load-displacement curve based on the bearing mechanics model;

Substitute the parameters into the bearing mechanics model to obtain the radial and axial load-displacement relationships of the experimental bearing;

The load-displacement relationship was derivationally calculated to obtain the radial and axial dynamic stiffness of the experimental bearing.

Preferably, the radial displacement compensation calculation formula is as follows:

In the formula, a is the distance between the third radial displacement sensor and the second radial displacement sensor, b is the distance between the first radial displacement sensor and the second radial displacement sensor, Δx ₃ is the distance measured by the third radial displacement sensor. Data, Δx ₁ is the data measured by the first radial displacement sensor, Δx ₂ is the compensation displacement of the inner ring of the experimental bearing to be calculated.

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

The invention can realize displacement measurement and acquisition under a combined radial and axial load, can realize continuous dynamic loading and conduct real-time measurement, and can provide real-time feedback of measurement data, thus having good real-time performance. The warpage caused by the radial force added to the spindle is offset by loading the balance block on the shaft system, thus solving the error caused by the deformation of the spindle. The radial displacement error is reduced through displacement compensation, which solves the problem that the radial and axial relative displacement between the inner and outer rings of the bearing cannot be accurately measured, and the measurement accuracy is good. Through the new stiffness solution method, the displacement and force test data are processed and the dynamic stiffness curve is calculated and solved, which accurately shows the nonlinear properties of the bearing stiffness, fills the current gap in this field, and has broad application prospects. The entire inventive device has a simple structure, is easy to use, has good robustness, high measurement accuracy and low cost. At the same time, it can realize the measurement of dynamic stiffness of different types of rolling bearings, has strong interchangeability and is easy to maintain.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a structural block diagram of a bearing axial and radial high-speed dynamic stiffness testing device of the present invention;

Figure 2 is a cross-sectional structural view of a bearing axial and radial high-speed dynamic stiffness testing device of the present invention;

Figure 3 is a structural diagram of a bearing axial and radial high-speed dynamic stiffness testing device of the present invention;

Figure 4 is a flow chart of a rolling bearing axial and radial high-speed dynamic stiffness testing method of the present invention;

Figure 5 is a schematic diagram of the radial displacement compensation scheme of the present invention;

Figure 6 is a schematic diagram of the radial and axial dynamic stiffness calculation scheme of the present invention;

Figure 7 is a data fitting diagram of different methods.

Among them, (a): traditional method, (b): method of the present invention;

Figure 8 is a structural diagram of the radial force loading device of the present invention.

In the picture: 1-High-speed drive motor, 2-Shaft system connecting block, 3-Shaft system loading balance block, 4-Balance force loading device, 5-Experimental bearing support block, 6-Spindle support sleeve, 7-First support Bearing, 8-second support bearing, 9-third support bearing, 10-bearing adapter block, 11-experimental bearing, 12-radial force loading device, 121-loading sleeve gasket, 122-force sensor, 123 -Support seat, 124-spring, 125-servo electric cylinder, 13-floating bearing seat, 14-loading pad, 15-axial force loading device, 16-axial displacement sensor mounting plate, 17-axial displacement sensor, 18 -Third radial displacement sensor, 19-axial measurement pad, 20-second radial displacement sensor, 21-radial displacement sensor mounting plate, 22-first radial displacement sensor.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

Referring to Figures 1-3, the present invention provides a bearing axial and radial high-speed dynamic stiffness testing device, including: an installation platform 23, a spindle support assembly, a high-speed drive motor 1, a bearing adapter block 10, and an experimental bearing 11. Radial force loading component, balance force loading component, controller, radial displacement measuring component, axial force loading component, axial displacement measuring component and processing unit.

The spindle support assembly is provided at one end of the top of the installation platform 23 and is used to support the transmission spindle. The spindle support assembly includes the experimental bearing support block 5 and the spindle support sleeve 6, which is equipped with a transmission spindle for internal rotation. The main shaft support sleeve 6 is set on the experimental bearing support block 5. The first support bearing 7, the second support bearing 8 and the third support bearing 9 are installed in series inside the main shaft support sleeve 6 for carrying larger axial loads. The load is fixed axially through end caps, locking nuts, spacers, etc.

The high-speed drive motor 1 is arranged at one end of the spindle support assembly and is used to drive the transmission spindle to rotate. The high-speed drive motor 1 is connected to the transmission main shaft through the shaft system connecting block 2.

The bearing adapter block 10 is installed at the other end of the main shaft support assembly and is rigidly connected to the transmission bearing. Different types and types of rolling bearings are assembled through different types of transfer modules 10 to achieve the versatility of the experimental testing device.

The experimental bearing 11 is sleeved on the bearing adapter block 10, and the bearing adapter block 10 is rigidly connected to the inner ring of the experimental bearing 11. The top of the installation platform 23 is provided with a test bearing support sleeve 26 for supporting the test bearing 11 .

The radial force loading assembly is used to apply radial force to the experimental bearing 11. The radial force loading assembly includes a floating bearing seat 13 and a radial force loading device 12. The floating bearing seat 13 is rigidly connected to the outer ring of the experimental bearing 11. The radial force loading device 12 is used to apply radial force to the floating bearing seat 13, thereby applying the force to the outer ring of the experimental bearing 11. The floating bearing seat includes a bearing seat and a cross sliding table, and the bearing seat and the slide block are rigidly connected. The floating bearing seat limits the high degree of freedom of the bearing seat at high rotational speeds and restricts it to movement within the force loading plane.

The radial force loading device 12 includes a servo cylinder 125, a loading sleeve gasket 121, a support base 123, a spring 124, and a force sensor 122. The servo cylinder 125 is fed at a uniform speed through the motor controller, and the force is transmitted at a uniform speed through the spring 124. To the sleeve gasket 121, the force is measured by the force sensor 122 (the device that provides force in this part can be replaced by a hydraulic cylinder, a booster pump, etc.). By controlling the force change curve with time to ensure a linear change, continuous measurement of force in the complete dynamic stiffness curve is achieved. The spring 124 mainly plays the role of buffering and damping and reducing the axial feed increment of the loading unit per unit time through its own deformation. The force sensor 122 is used to measure the axial load exerted by the loading device on the measured spindle.

Balanced force loading assemblies are used to balance applied radial forces. The balance force loading assembly includes a shaft system loading balance block 3 and a balance force loading device 4. The shaft system loading balance block 3 is set on the experimental bearing support block 5, and includes two bearings installed back to back, which increases rigidity. The balance force loading device 4 is used to apply the same balance force as the radial force to the shaft system loading balance weight 3. Ensure that the forces at the front end and rear end of the experimental bearing support block are the same and without deviation, so as to eliminate the error introduced by the bending of the main shaft on the radial displacement.

The axial force loading assembly includes a loading pad 14 and an axial force loading device 15 . The loading pad 14 is provided at the end of the floating bearing seat 13 . The axial force loading device 15 is used to apply axial force to the loading pad 14 . The force is transmitted to the floating bearing seat 13 through the loading pad 14, thereby acting on the outer ring of the experimental bearing 11.

The axial force loading device 15 is the same as the balance force loading device 4 and the radial force loading device 12 . Using the same structure for modular design makes the construction of the test bench more convenient and more portable. The axial force of the outer ring of the bearing acts on the loading pad through the axial force loading device, and the loading pad transmits the force to the bearing seat. The balancing force acts on the shaft system loading balance block through the balancing force loading device to achieve the function of balancing the spindle.

The radial displacement measurement assembly is used to measure multiple radial displacements of the experimental bearing 11, including a radial displacement sensor mounting plate 21, a third radial displacement sensor 18, a second radial displacement sensor 20 and a first radial displacement. Sensor 22. The radial displacement sensor mounting plate 21 is installed at the other end of the top of the mounting platform 23 . The first radial displacement sensor 22 is installed at one end of the radial displacement sensor mounting plate 21 for measuring the radial displacement at one end of the bearing adapter block 10 . The second radial displacement sensor 20 is installed in the middle of the radial displacement sensor mounting plate 21 and is used to measure the radial displacement of the outer ring of the experimental bearing 11 . The third radial displacement sensor 18 is installed at the other end of the radial displacement sensor mounting plate 21 and is used to measure the radial displacement of the other end of the bearing adapter block 10 . Three non-contact displacement sensors measure two measuring points on the bearing adapter block 10 and the measuring point on the outer ring of the experimental bearing 11 respectively. The displacement of the inner ring of the experimental bearing 11 is calculated through displacement compensation through two measuring points on the bearing adapter block 10, and the relative radial displacement of the inner and outer rings of the experimental bearing 11 is obtained. In addition, the radial displacement sensor mounting plate is installed on the base and is not connected to the floating bearing seat, which can eliminate the assembly gap between the floating bearing seat and the bearing outer ring during data collection.

In this embodiment, a mounting bracket 25 is fixed on the top of the mounting platform 23, and a fine-tuning sliding table 24 is provided on the mounting bracket 25. The fine-tuning sliding table 24 is used to synchronize and finely adjust the installation positions of multiple radial displacement sensors.

As shown in Figure 3, the radial displacement sensor mounting plate 21 is not connected to the floating bearing seat 13. It is slotted above the floating bearing seat 13 to pass through it to ensure that the direct measurement points of the sensor are two on the bearing adapter block 10. Measuring points and measuring points on the outer ring of the experimental bearing 11, the function of the fine-tuning sliding table 21-1 is to facilitate the adjustment of the sensor position, and the mounting bracket 21-2 is directly installed on the mounting platform 23 of the experimental bench. Avoid bringing the gap between the floating bearing seat 13 and the outer ring of the experimental bearing 10, that is, the systematic error generated during the assembly process, into the calculation.

The axial displacement measurement assembly includes an axial displacement sensor installation plate 16, an axial displacement sensor 17 and an axial measurement pad 19. The axial displacement sensor installation plate 16 is installed at the end of the floating bearing seat 13, and the axial displacement sensor 17 is installed on the shaft. On the displacement sensor mounting plate 16, the axial measuring pad 19 is fixedly installed on the end of the bearing adapter block 10. The displacement change of the axial displacement sensor mounting plate 16 and the axial measurement pad 19 can be used to directly represent the axial relative displacement of the inner and outer rings of the bearing, and measure the axial displacement of the outer ring relative to the inner ring of the experimental bearing 11.

The radial force loading component, the balance force loading component and the axial force loading component are all electrically connected to the controller.

The processing unit is used to collect the real-time radial force and real-time axial force exerted on the experimental bearing 11 as well as the axial relative displacement and radial relative displacement of the inner and outer rings of the experimental bearing 11, and collect the real-time radial force, the real-time axial force, and the inner and outer rings of the experimental bearing 11. The stiffness is calculated based on the axial relative displacement and radial relative displacement of the ring.

Referring to Figure 4, based on the above concept, the present invention also provides a testing method of a bearing axial and radial high-speed dynamic stiffness testing device, which includes the following steps:

The first step: collect the real-time radial force and real-time axial force exerted on the experimental bearing 11 and the axial displacement of the experimental bearing 11;

Step 2: Calculate the radial compensation of the inner ring based on the radial displacement measured by the third radial displacement sensor 18 and the first radial displacement sensor 22, and combine it with the radial displacement of the outer ring measured by the second radial displacement sensor 20 to obtain Experiment with the radial relative displacement of the inner and outer rings of bearing 11. The real-time radial force and real-time axial force exerted by the experimental bearing 11 as well as the axial relative displacement of the inner and outer rings of the experimental bearing 11 are collected through a multi-channel acquisition system.

Displacement compensation is shown in Figure 5. The calculation method of radial displacement compensation is as follows:

Where a and b are the distances between the sensors respectively, Δx ₃ is the data measured by the third sensor 18 , Δx ₁ is the data measured by the first sensor 22 , and Δx ₂ is the compensation displacement of the inner ring of the experimental bearing 11 to be calculated.

The expression for Δx ₂ is solved as follows:

Then, the calculated radial relative displacement of the inner and outer rings of the experimental bearing 11 is calculated by subtracting the compensated displacement Δx ₂ of the inner ring of the experimental bearing 11 from the displacement of the outer ring.

Step 3: Obtain the relative axial displacement of the inner and outer rings based on the axial displacement of the experimental bearing 11.

Step 4: Establish the load-displacement curve of the experimental bearing based on the real-time radial force, real-time axial force, radial relative displacement of the inner and outer rings of the experimental bearing, and axial relative displacement of the inner and outer rings of the experimental bearing.

Step 5: Identify the parameters of the load-displacement curve based on the bearing mechanics model. Taking the tapered roller bearing as an example, first the load-displacement relationship between the tapered roller and the raceway is deduced, and the balance equation of the tapered roller and the overall balance equation of the double-row tapered roller bearing are given. On this basis, a force-displacement calculation model of double-row tapered roller bearings is established to lay the foundation for subsequent parameter identification.

Step 6: Substitute the parameters into the bearing mechanics model to obtain the radial and axial load-displacement relationship expressions of the experimental bearing 11.

Step 7: Perform derivation of the load-displacement relationship to obtain the radial and axial dynamic stiffness of the experimental bearing 11.

As shown in Figure 4, the multi-channel data acquisition system collects each part of the data and delivers it to the computer part. The computer performs signal noise reduction methods such as filtering, decomposition and reconstruction of the measured data to obtain the experimentally measured load-displacement data and curves.

As shown in Figure 6, based on the established bearing mechanical model, a hybrid optimization algorithm is used to identify the corresponding parameters of the experimentally measured load-displacement curve, and then the identified parameters are substituted into the mechanical model to obtain the measured bearing radial and axial load-displacement data. The real value of this data, and then perform a differential solution on the real value of this data to obtain the corresponding radial and axial dynamic stiffness of the experimental bearing.

As shown in Figure 7, the force of the traditional testing method is discrete loading, so the measurement results are also discretely distributed. The less discrete data means that when processing the stiffness test data, only least squares fitting and other methods can be used for data fitting, while the traditional The dynamic stiffness solution method based on least squares fitting assumes that the stiffness is a constant value and completely ignores the nonlinear characteristics of the bearing dynamic stiffness. The new stiffness solution method proposed by the present invention uses the parameter identification method and introduces the mechanical equations of the bearing to process the test data, which more accurately displays the nonlinear properties of the dynamic stiffness of the bearing.

In summary, the invention describes a bearing axial and radial high-speed dynamic stiffness testing device and method that can realize simultaneous or separate measurement and continuous collection of displacement under a radial and axial combined load, and can achieve continuous dynamic loading and Real-time measurement is carried out, and the measurement data is fed back in real time, which has good real-time performance. The warpage caused by the radial force added to the spindle is offset by loading the balance block on the shaft system, thus solving the error caused by the deformation of the spindle. The radial displacement error is reduced through displacement compensation, which solves the problem that the radial and axial relative displacement between the inner and outer rings of the bearing cannot be accurately measured, and the measurement accuracy is good. Through the new stiffness solution method, the displacement and force test data are processed and the dynamic stiffness curve is calculated and solved, which accurately shows the nonlinear properties of the bearing stiffness, fills the current gap in this field, and has broad application prospects. The entire inventive device has a simple structure, is easy to use, has good robustness, high measurement accuracy and low cost. At the same time, it can realize the measurement of dynamic stiffness of different types of rolling bearings, has strong interchangeability and is easy to maintain.

Although the preferred embodiments of the present invention have been described, those skilled in the art will be able to make additional changes and modifications to these embodiments once the basic inventive concepts are apparent. Therefore, it is intended that the appended claims be construed to include the preferred embodiments and all changes and modifications that fall within the scope of the invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the invention. In this way, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims (9)

1. The utility model provides a bearing axial and radial high rotational speed dynamic rigidity testing arrangement which characterized in that includes:

the experimental bearing (11) is sleeved on the transmission main shaft, and the transmission main shaft drives the experimental bearing (11) to rotate;

the bearing adapter block (10) is arranged at one end of the transmission main shaft and is rigidly connected with the transmission main shaft, and the other end of the bearing adapter block (10) is rigidly connected with the inner ring of the experimental bearing (11);

the load loading assembly is arranged outside the bearing adapter block (10) and is used for applying axial force and radial force to the experimental bearing (11);

the balance force loading assembly is arranged at the other end of the transmission main shaft and is used for counteracting the warping generated by the transmission main shaft after the radial force is applied;

the displacement measuring assembly is used for measuring the axial displacement and a plurality of radial displacements of the experimental bearing (11);

the processing unit is used for collecting real-time radial force and real-time axial force applied to the experimental bearing (11) and axial displacement and multiple radial displacements of the experimental bearing (11), and calculating rigidity according to the real-time radial force, the real-time axial force, the axial displacement and the multiple radial displacements;

the displacement measurement assembly includes a radial displacement measurement assembly including:

a radial displacement sensor mounting plate (21) arranged outside the bearing adapter block (10);

the first radial displacement sensor (22), the second radial displacement sensor (20) and the third radial displacement sensor (18) are respectively arranged at one end, the other end and the middle part of the radial displacement sensor mounting disc (21) and are respectively used for measuring the radial displacement of one end and the other end of the bearing adapter block (10) and the radial displacement of the outer ring of the experimental bearing (11).

2. A bearing axial and radial high rotational speed dynamic stiffness testing apparatus according to claim 1, wherein the drive spindle is supported by a spindle support assembly comprising:

the experimental bearing supporting block (5) is internally provided with the transmission main shaft in a rotating way;

the main shaft supporting shaft sleeve (6) is sleeved on the experimental bearing supporting block (5);

the main shaft support shaft sleeve (6) is internally provided with a first support bearing (7), a second support bearing (8) and a third support bearing (9) in series.

3. A bearing axial and radial high rotational speed dynamic stiffness testing device as claimed in claim 2, wherein the load loading assembly includes a radial force loading assembly and an axial force loading assembly;

the radial force loading assembly comprises:

the floating bearing seat (13) is rigidly connected with the outer ring of the experimental bearing (11);

radial force loading means (12) for applying a radial force to the floating bearing block (13).

4. A bearing axial and radial high rotational speed dynamic stiffness testing apparatus as defined in claim 3 wherein said axial force loading assembly comprises:

a loading pad (14) arranged at the end part of the floating bearing seat (13);

an axial force loading device (15) for applying an axial force to the loading pad (14).

5. The device for testing the dynamic stiffness of the axial and radial high rotational speed of the bearing according to claim 4, wherein the balancing force loading assembly comprises:

the shafting loading balance block (3) is sleeved on the experimental bearing support block (5);

and the balance force loading device (4) is used for loading the balance weight (3) to the shafting to apply the same balance force as the radial force.

6. The device for testing the axial and radial high-speed dynamic stiffness of a bearing according to claim 5, wherein the displacement measuring assembly further comprises an axial displacement measuring assembly, the axial displacement measuring assembly comprising:

an axial displacement sensor mounting disc (16) mounted at the end of the floating bearing seat (13);

an axial displacement sensor (17) mounted on the axial displacement sensor mounting plate (16);

and the axial measuring pad (19) is fixedly arranged at the end part of the bearing adapter block (10).

7. The device for testing the dynamic stiffness of the axial and radial high rotational speed of the bearing according to claim 6, further comprising:

a mounting platform (23);

the high-speed driving motor (1) is arranged at one end of the top of the mounting platform (23), and the high-speed driving motor (1) is connected with the transmission main shaft through the shafting connecting block (2);

the mounting bracket (25) is fixedly arranged at the other end of the top of the mounting platform (23);

the fine adjustment sliding table (24) is arranged at the top of the mounting bracket (25) and is used for synchronously adjusting the mounting positions of the plurality of radial displacement sensors;

the experimental bearing supporting shaft sleeve (26) is arranged at the top of the mounting platform (23) and used for supporting the experimental bearing (11).

8. A method of testing a rolling bearing axial and radial high rotational speed dynamic stiffness testing apparatus according to claim 1, comprising the steps of:

collecting real-time radial force and real-time axial force applied to the experimental bearing (11) and axial displacement of the experimental bearing (11);

performing inner ring radial compensation calculation according to radial displacement measured by a third radial displacement sensor (18) and a first radial displacement sensor (22), and combining the outer ring radial displacement measured by a second radial displacement sensor (20) to obtain radial relative displacement of the inner ring and the outer ring of the experimental bearing (11);

obtaining the axial relative displacement of the inner ring and the outer ring according to the axial displacement of the experimental bearing (11);

establishing a load displacement curve of the experimental bearing (11) according to the real-time radial force, the real-time axial force and the radial relative displacement of the inner ring and the outer ring of the experimental bearing (11);

carrying out parameter identification on the load displacement curve according to the bearing mechanical model;

substituting the parameters into a bearing mechanical model to obtain a radial and axial load-displacement relation of the experimental bearing (11);

and carrying out derivative operation on the load-displacement relation to obtain the radial and axial dynamic rigidity of the experimental bearing (11).

9. A method of testing a rolling bearing axial and radial high rotational speed dynamic stiffness testing apparatus according to claim 8, wherein the radial displacement compensation calculation formula is as follows:

wherein a is the distance between the third radial displacement sensor and the second radial displacement sensor, b is the distance between the first radial displacement sensor and the second radial displacement sensor, and Deltax ₃ For data measured by a third radial displacement sensor, deltax ₁ For the data measured by the first radial displacement sensor, deltax ₂ And compensating displacement of the inner ring of the experimental bearing to be calculated.