Rolling bearing power consumption measurement testing machine under combined load and power consumption measurement calculation method

Abstract

The invention discloses a rolling bearing power consumption measurement tester under combined load and a power consumption measurement calculation method, and belongs to the technical field of bearing performance testing, the tester comprises a test bench, a bearing test device, a torque and temperature measurement system, a thermal management system, and an external lubricant supply and circulation system; a pair of center bearings is installed on a center shaft section of an output main shaft of the bearing test device, a pair of test bearings are installed on shaft shoulders on the two sides, the test bearings apply axial loads through end covers on the outer sides, a center block is arranged above the output main shaft and located in the axial center of the output main shaft, and radial loads 2Fr are applied to the center block. Applying a radial load Fr to each set of test bearing and central bearing; the paths of the axial load and the radial load are completely independent, so that the central bearing is only loaded in the radial direction. According to the invention, under the condition of strictly controlling the overall temperature of the bearing, the temperature of the oil inlet and the oil supply flow, the power consumption irrelevant to the load and the power consumption relevant to the load of the rolling bearing under the radial and axial combined load can be accurately measured in a wide rotating speed range.

Description

Technical Field

[0001] This invention belongs to the field of bearing performance testing, specifically relating to a rolling bearing power consumption measurement test machine under combined load and a power consumption measurement and calculation method. Background Technology

[0002] Rolling bearings have the advantage of low friction, but the friction in rolling bearings cannot be ignored. There are extremely complex friction phenomena in rolling bearings. Friction in rolling bearings leads to bearing wear and temperature rise. Excessive friction not only consumes energy, but also leads to bearing failure.

[0003] Palmgren first derived an empirical formula for the frictional torque of rolling bearings through extensive experimental research. Based on this formula, a frictional power consumption calculation model could be obtained, but this model was only applicable to calculating the overall frictional power consumption of the bearing under low-speed conditions. Astridge and Smith, through extensive experimental research, improved upon Palmgren's calculation model and proposed a frictional torque calculation model applicable to high-speed operating conditions. Kazuo Kakuta proposed a more accurate frictional torque calculation model based on theoretical analysis and introduced a local calculation method for bearing frictional torque. Harris proposed a local frictional power consumption calculation model based on bearing dynamics analysis, calculating the frictional power consumption generated by sliding between the rolling elements and raceways, the frictional power consumption generated by the viscous resistance of the lubricant on the rolling elements, the frictional power consumption between the cage and the raceways, the frictional power consumption between the rolling elements and the cage, and the frictional power consumption between the rolling elements and the inner end face of the raceways. Iqb, through experiments, found that grease-lubricated needle roller bearings have greater frictional power consumption than oil-lubricated needle roller bearings, and modified the Palmgren and SKP models based on experimental data. Chao WY studied the influence of the circumferential radial preload generated by the interference fit of the bearing on the bearing frictional power consumption and bearing life. Gloeckner analyzed the influence of the bearing radius of curvature on the bearing frictional power consumption and temperature rise under the operating conditions of high speed, high load and high temperature.

[0004] The power consumption of rolling bearings under combined axial and radial loads is affected by various operating conditions, such as inner ring speed, lubricating oil temperature, overall bearing temperature, and oil supply rate. In other words, the actual operating conditions of the bearing will increase the error of the results calculated by existing widely accepted bearing power consumption calculation methods (such as Palmgren's mechanical power consumption equation). Therefore, it is of great significance to study a method that can accurately measure the power consumption of rolling bearings under combined axial and radial loads and improve the accuracy of rolling bearing power consumption calculation. Summary of the Invention

[0005] The purpose of this invention is to provide a rolling bearing power consumption measurement test machine and a power consumption measurement and calculation method under combined loads. Under strict control of the overall bearing temperature, oil inlet temperature (viscosity) and oil supply flow rate, the power consumption of rolling bearings under combined radial and axial loads can be accurately measured within a wide speed range, both load-independent and load-dependent.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A rolling bearing power consumption measurement test machine under combined load includes a test bench, a bearing test device mounted on the test bench, a torque and temperature measurement system, a thermal management system, and an external lubricant supply and circulation system;

[0008] The bearing testing device includes an output spindle driven by a motor. A pair of central bearings are mounted on the central shaft section of the output spindle, and a pair of test bearings are mounted on the shoulders on both sides of the output spindle. The test bearings apply axial loads through left and right end caps I located on their axial outer sides. A central block is located above the output spindle at its axial center, and the central block is connected to the outer radial surface of the outer ring of the two central bearings. A radial load 2F is applied to the central block. r To apply a radial load F to each set of test bearings and center bearings r ;

[0009] The bearing testing device is located below the output spindle and is equipped with axial sliding body and radial sliding body to ensure that the paths of axial load and radial load are completely independent and that the central bearing is only subjected to radial load.

[0010] The torque and temperature measurement system includes a torque sensor and an integrated data acquisition system. The torque sensor is mounted coaxially with the output spindle, and the integrated data acquisition system is used to acquire the bearing's torque, speed, and thermocouple signals.

[0011] The thermal management system is used to control the overall temperature of the bearing.

[0012] The external lubricant supply and circulation system is used to provide the bearing with the required flow rate and temperature of lubricant.

[0013] In one embodiment, the bearing testing device is supported by a test bench, the base of the bearing testing device is connected to the bearing testing device guide rail set on the test bench, the bearing housing of the bearing testing device is connected to the base of the bearing testing device by bolts, the left end cover I and the right end cover I are respectively slidably engaged with the bearing housing of the bearing testing device to realize its free movement in the axial direction, and both the left end cover I and the right end cover I are provided with keyways to prevent their own rotation.

[0014] Preferably, the axial sliding body and the radial sliding body are low-friction linear guides, and their sliding directions are aligned with the directions of application of the axial load and the radial load, respectively.

[0015] Preferably, the center block is located on the axial sliding body and is not axially constrained, and the center bearing does not bear axial load.

[0016] Preferably, the external lubricant supply and circulation system uses a heated reservoir and an integral J-type thermocouple to control the oil tank temperature. The oil tank is equipped with stirring blades, and a thermocouple is inserted into the oil inlet of each bearing lubrication channel to monitor the lubricant inlet temperature. The bearing testing device is equipped with a cylindrical heater to ensure that the overall bearing temperature is as close as possible to the set oil inlet temperature value.

[0017] A method for measuring and calculating the power consumption of rolling bearings under combined loads, the method utilizing the aforementioned rolling bearing power consumption measurement test machine under combined loads, includes the following steps:

[0018] S1, obtains torque loss signal T through sensor. L (F r ,F a The total power consumption P is obtained from the formula for calculating total power consumption (Ω).

[0019] S2, three bearing rotation and mechanical loss layouts for the testing machine are set according to different radial loads, axial loads, and rotational speeds: layout A, layout B, and layout C. Layout A consists of a pair of identical central bearings and a pair of test bearings with different inner and outer diameters from the central bearings, applying 2F... r Total radial load, applied F a Axial load; Layout B replaces a pair of test bearings with a pair of center bearings based on Layout A, making all four sets of bearings identical, and applies 2F. r The total radial load is not applied, and no axial load is applied; layout C is based on layout A but does not have a central bearing and does not apply radial or axial loads.

[0020] S3, obtain the bearing power consumption P of layout A. A (F r ,F a The power consumption P of the bearing in layout B (Ω) B (F r ,0,Ω), and then calculate the total power consumption P of a single test bearing. (t) (F r ,F a ,Ω); Obtain the bearing power consumption P of C layout. C (0,0,Ω);

[0021] S4, determine the rotational power consumption P of a single test bearing. s (t) (Ω) and mechanical power consumption P m (t) (F r ,F a ,Ω);

[0022] S5, the actual total power consumption of a single set of test bearings is obtained from the above three layout schemes:

[0023] Furthermore, in step S3, the bearing power consumption P of layout A is... A : P A (F r ,F a ,Ω)=2P (t) (F r ,F a ,Ω)+2P (C) (F r ,0,Ω) In the formula: P (t) P represents the total power consumption of a single test bearing. (C) The total power consumption of a single set of central bearings;

[0024] The power consumption P of the bearing in layout B B : P B (F r ,0,Ω)=4P (C) (F r ,0,Ω)

[0025] Based on layouts A and B, the total power consumption of a single set of test bearings is:

[0026] C-layout bearing power consumption P C : P C (0,0,Ω)=2P s (t) (Ω) In the formula, s is the rotation loss component.

[0027] Furthermore, in step S5, the rotational power consumption of a single test bearing is:

[0028] The mechanical power consumption of a single test bearing is:

[0029] Furthermore, in the experiment, by setting different cage speeds, viscosities, and oil flow rates for comparative analysis, the rotational power consumption P was obtained. s (t) The formula is: In the formula: u is the cage speed, η is the viscosity, The oil flow rate of the bearing is given by indices a≈0.4~4.0, b≈0.4~0.5, c≈1.6~2.0, and d≈0.1.

[0030] Furthermore, mechanical losses are based on parameter F. r F a ,u and η for each bearing P m (t) The measured values ​​were fitted to a curve to obtain the mechanical power consumption P. m (t) The formula is: In the formula, u is the cage speed, η is the viscosity, and F is the viscosity. r For radial load, F a For axial loads, the exponents are e≈0.4~4.0, f≈0.25~0.28, g≈0.92~0.97, h≈1.8~2.9, and i≈0.4~1.1.

[0031] By adopting the above technical solution, the present invention can achieve the following beneficial effects:

[0032] (1) This invention innovatively proposes an experimental mechanism for measuring the load-independent and load-dependent power consumption of a bearing under combined radial and axial loads over a wide range of speeds, under strict control of the overall bearing temperature, oil inlet temperature (viscosity) and oil supply flow rate.

[0033] (2) The test machine can remove the loss of the central bearing and measure the mechanical power consumption and rotational power consumption of three independent test bearings under different hardware and loading conditions. It quantifies the sensitivity of the rotational power consumption P of the two test bearings to the rotational speed, oil viscosity and oil supply flow rate, as well as the sensitivity of the mechanical power consumption to the loading conditions, oil viscosity and rotational speed.

[0034] (3) During the measurement process, this invention innovatively quantifies the rotational power consumption P of the two types of test bearings. s (t) Sensitivity to rotational speed, oil viscosity, and oil supply flow rate, as well as mechanical power consumption P m (t)The study investigated the sensitivity of the bearings to loading conditions, oil viscosity, and rotational speed. Specifically, the effects of four flow rates, six viscosity values, and twelve rotational speeds on the two test bearings were studied in the rotational power consumption test. In the mechanical power consumption test, 25 loading conditions under five rotational speeds and two viscosity values ​​were measured for each bearing, resulting in 522 rotational power consumption test points and 500 mechanical power consumption data points. This comprehensive approach fully considered various operating conditions of rolling bearings under combined axial and radial loads, improving the accuracy of power consumption calculations.

[0035] (4) This invention empirically evaluates the power consumption under actual loading and lubrication conditions, and uses the measured Ps (t) and Pm (t) Compared to the widely used Palmgren bearing power consumption measurement formula, which underestimates bearing power consumption in some cases, this invention considers more factors, calculates power consumption more accurately, and conforms to actual operating conditions. This provides insights for improving rolling bearing performance, incorporating design considerations, and offering a reliable basis for improving manufacturing processes. Attached Figure Description

[0036] Figure 1 This is a schematic cross-sectional view of the testing machine in this invention;

[0037] Figure 2 This is a schematic diagram of the loading mechanism for the combined axial and radial loads in this invention;

[0038] Figure 3 Flowchart of the method for measuring and calculating the power consumption of rolling bearings under combined axial and radial loads;

[0039] Figure 4 To determine three configurations for the test bearing's rotation and mechanical losses;

[0040] Figure 5 This is a schematic diagram of the A-layout test mechanism in this invention;

[0041] Figure 6 This is a schematic diagram of the B-layout test mechanism in this invention;

[0042] Figure 7 This is a schematic diagram of the C-layout test mechanism in this invention;

[0043] Figure 8 This is a schematic diagram illustrating the variation patterns of T and Ω in this invention;

[0044] Figure 9 This is a schematic diagram illustrating the variation of radial and axial loads 2Fr(t) and Fa(t) in this invention;

[0045] Figure 10The specific structural parameters of test bearing 1 and test bearing 2 are as follows;

[0046] Figure 11 The change of Ps(t) was measured for bearing 1 in the experiment;

[0047] Figure 12 The change of Ps(t) was measured for test bearing 2;

[0048] Figure 13 This is a reference table of power consumption regression coefficients in this invention;

[0049] Figure 14 For the actual measured P of test bearing 1 m (t) and P s (t) With F r and γ=F a / F r Changes;

[0050] Figure 15 For the actual measured P of test bearing 2 m (t) and P s (t) With F r and γ=F a / F r Changes;

[0051] The markings in the diagram are: 1-Test bench; 2-Bearing test device base; 3-Axial sliding body; 4-Left sleeve; 5-Radial sliding body; 6-Torque sensor; 7-Output spindle; 8-Test bearing I; 9-Center bearing I; 10-Left end cover I; 11-Left end cover II; 12-Center block; 13-Cylinder heater I; 14-Cylinder heater II; 15-Cylinder heater III; 16-Cylinder heater IV; 17-Right end cover II; 18-Center bearing II; 19-Right sleeve; 20-Right end cover I; 21-Motor housing; 22-Test bearing II; 23-Motor; 24-Bearing test device bearing seat; 25-Bearing test device guide rail; 26-Spacer; 27-Locking nut; 28-Shaft section spacer; 29-Center bearing III; 30-Center bearing IV. Detailed Implementation

[0052] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0053] The structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0054] It should also be noted that, unless otherwise stated, "multiple" means two or more; the terms "upper," "lower," "left," "right," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the present invention.

[0055] Example 1

[0056] A rolling bearing power consumption measurement test machine under combined axial and radial loads can simulate the load, speed, and temperature conditions experienced by gearbox bearings. It includes a test bench, torque and temperature measurement systems, bearing testing equipment, a thermal management system for controlling the overall bearing temperature, and an external lubricant supply and circulation system.

[0057] like Figure 1 As shown, the testing machine includes a test bench 1 and a bearing testing device mounted on the test bench 1. The bearing testing device includes an output spindle 7 driven by a motor 23, and a motor housing 21 is provided outside the motor 23. Preferably, the output spindle 7 adopts a 30HP AC motor 23 and a frequency converter drive.

[0058] Furthermore, a speed-increasing pulley set was used in the belt drive, allowing the output spindle 7 to rotate at a maximum speed of Ω = 12000 r / min.

[0059] The torque and temperature measurement system includes a torque sensor 6 and an integrated data acquisition system.

[0060] Torque sensor 6 uses Interface T11 and is coaxially mounted with output spindle 7 to provide high-resolution torque and speed measurement.

[0061] The torque sensor 6 is used for measuring bearing torque loss in this application. Its torque capacity is 50N, resolution is 0.0015N·m, and accuracy is ±0.05N·m.

[0062] The integrated data acquisition system can measure the torque of the sample at up to 100 kHz and has sufficient capacity to record the rotational speed and all thermocouple signals.

[0063] It should be noted that measurement errors are unavoidable, and the sources of these errors are the torque sensor 6 and the integrated data acquisition system.

[0064] The integrated data acquisition system acquires torque signals through the NIPXIe-4497 dynamic signal acquisition module, which has a maximum DC coupling gain accuracy of 0.5% and a maximum voltage bias difference of ±0.00005V.

[0065] Furthermore, when the applied torque is 1 N·m, considering the maximum error of torque sensor 6, the maximum error is 0.0555 N·m or 5.55%. Since the error in the instrument depends on the distribution of environmental and manufacturing errors, the expected error of the device is relatively small. The method proposed in this study can also be used with torque sensor 6 and a data analysis system for even better accuracy.

[0066] like Figure 2 As shown, the output spindle 7 of the bearing testing device has central bearings I 9 and II 18 distributed on its left and right sides via a mating arrangement. Test bearings I 8 and II 22 are installed at the shoulders on both sides of the output spindle. A center block 12 is located above the output spindle 7 at its axial center position.

[0067] The outer radial surfaces of the outer rings of the central bearings I 9 and II 18 are connected to the central block 12. The central block presses the central bearings I 9 and II 18 onto the output spindle 7 via a threaded connection. The outer ring end faces of the two central bearings I 9 and II 18 are axially pressed by the left end cover II 11 and the right end cover II 17. These measures are to ensure that slippage does not occur at the contact point between the central bearings I 9 and II 18 and the output spindle 7.

[0068] At the shoulders of the two slender ends of the output spindle 7, test bearings I8 on the left and II 22 on the right are fitted together. Test bearings I8 and II 22 are respectively connected to the left sleeve 4 and the right sleeve 19. The left sleeve 4 and the right sleeve 19 are simultaneously axially pressed together by the left end cap I10 and the right end cap I 20 via threaded connections. The test bearings apply axial loads through the left end cap I and the right end cap I. In specific implementation, the inner rings of the left test bearing I8 and the right test bearing II 22 are clamped onto the output spindle 7 by locking nuts 27 and spacers 26 located on their outer sides, and the outer rings are fixed to their respective bearing seats by fixing screws. A shaft segment spacer 28 is provided around the central shaft section of the output spindle 7.

[0069] Heaters are respectively provided at the center block 12, the left sleeve 4 and the right sleeve 19. Specifically, the heaters are cylindrical heater I13 embedded in the left sleeve 4, cylindrical heater II 14 located on the left side of the center block 12, cylindrical heater III 15 located on the right side of the center block 12, and cylindrical heater IV 16 embedded in the right sleeve 19. Each heater is connected to the above-mentioned tooling parts by threads.

[0070] The left sleeve 4 and the right sleeve 19 are connected to the bearing housing 24 of the bearing testing device by bolts. The bearing housing 24 of the bearing testing device is connected to the base 2 of the bearing testing device by bolts, and the base 2 of the bearing testing device is connected to the guide rail 25 of the bearing testing device. The bottom of the entire bearing testing device is supported by the test bench 1.

[0071] A schematic diagram of the loading mechanism for combined axial and radial loads is shown below. Figure 2 As shown. A radial load 2F is applied to the center block 12. r Radial load F is applied to test bearing I 8, test bearing II 22, center bearing I 9, and center bearing II 18. r Simultaneously, an axial load F is applied to the right end cap I 20. a The outer ring of the right-side test bearing II 22 is pushed to the left, while the left end cap I10 of the other left-side test bearing I 8 applies F to both sets of test bearings. a The reaction force during the process is applied to the axial load. The left end cover I10 and the right end cover I20 are respectively slidably engaged with the bearing seat 24 of the bearing test device, so as to realize its free axial movement. Both the left end cover I10 and the right end cover I20 are provided with keyways to prevent them from rotating.

[0072] The bearing testing device is located below the output spindle 7 and is equipped with an axial sliding body 3 and a radial sliding body 5 to ensure that the paths of axial and radial loads are completely independent. The center block 12 is located on the axial sliding body 3 and is not subject to axial constraints. The center bearings I 9 and II 18 do not bear axial loads, but are only subjected to radial loads. Therefore, under combined loads, when the actuator uses load 2F... r and F a At that time, each set of test bearings was subjected to a load (F) r F a ), and when F a When F = 0, each set of central bearings only bears F. r .

[0073] The hydraulic actuator used to apply the required radial and axial loads has a maximum rated force of 39 kN and is equipped with a force sensor rated at 44 kN.

[0074] Without axial load, the operation of center bearings I 9 and II 18 can eliminate the losses associated with the center bearings.

[0075] Radial slider 5 and axial slider 3 ensure that the radial and axial load paths are completely independent. Specifically, low-friction linear guides are used for radial slider 5 and axial slider 3, and their sliding directions are precisely aligned with the radial and axial load directions, respectively. Furthermore, the loading in the test is performed in the following order: the axial load is always applied before the radial load to prevent increased friction in the axial slider 3 due to radial loading. Any considerable shaft bending deformation will introduce some degree of undesirable coupling between the axial and radial loads.

[0076] Furthermore, in the finite element analysis of the output spindle 7, the radial deformation of the shaft was less than 4 μm under the maximum load condition, thus ruling out this possibility.

[0077] The thermal management system controls the overall bearing temperature. The repeatability and accuracy of power consumption measurements largely depend on maintaining the overall temperature of the test bearing and the reaction bearing at the same level as the oil inlet temperature. Specifically, four cylindrical heaters are embedded in the bearing testing apparatus to control the overall bearing temperature. Under feedback control, these heaters ensure that the overall bearing temperature is as close as possible to the set oil inlet temperature value so that power consumption measurements can be correlated with a single operating temperature condition (oil inlet temperature and overall bearing temperature). Thermocouples are installed on the outer ring of the bearing for measuring the overall bearing temperature.

[0078] The external lubricant supply and circulation system employs a 5-gallon heated reservoir and an integrated J-type thermocouple to control the oil tank temperature, providing precise lubricant flow to the bearings. Agitator blades are installed inside the oil tank to maintain a constant temperature of the lubricant through stirring.

[0079] A thermocouple is inserted into the oil inlet of the bearing lubrication channel to monitor the lubricant inlet temperature. Each lubrication channel delivers lubricant to its respective bearing via a continuous droplet method. Oil pumped to the outer chamfer of the bearing passes through the bearing and is discharged by gravity to a reservoir below the machine.

[0080] In practice, a thin disc is placed between the test bearing and the central bearing to ensure that the lubricant in the oil flow path does not mix until it reaches the return reservoir. The gap between the thin disc and the bearing housing of the bearing test device is very small, preventing lubricant from entering the area of ​​other bearings, but allowing it to drain downwards into the return tank.

[0081] Example 2

[0082] like Figure 3 As shown, a method for measuring and calculating the power consumption of a rolling bearing under combined axial and radial loads, using the testing machine in Example 1, includes the following steps:

[0083] Step 1: Obtain the torque loss signal T through the sensor. L (F r ,F a ,Ω), the obtained T L (F r ,F a Substitute the data (Ω) into the total power consumption calculation formula to obtain the total power consumption P.

[0084] Furthermore, schematic diagrams of the application of radial and axial loads are shown below. Figure 2 As shown. In this general layout, when the output spindle and the inner rings of all four sets of bearings rotate at a set speed Q, a 2F load is applied by two independent load actuators. r Total radial load and F a The axial load. In this configuration, each set of test bearings is subjected to a combined load (F). r ,F a Each set of central bearings only bears a radial load Fr. After removing the bearing losses from the torque sensor, the measured torque loss signal T... L (F r ,F a The total power consumption P is determined by (Ω) as follows:

[0085] Step 2: Based on different radial loads, axial loads, and rotational speeds, three bearing rotation and mechanical loss layouts for the testing machine were determined: Layout A, Layout B, and Layout C, as follows: Figure 4 As shown. Layout A consists of a pair of identical central bearings and a pair of test bearings with different inner and outer diameters from the central bearings, with a 2F applied. r Total radial load, applied F a Axial load; Layout B replaces a pair of test bearings with a pair of center bearings based on Layout A, making all four sets of bearings identical, and applies 2F. r The total radial load is not applied, and no axial load is applied; the C layout is based on the A layout but does not have a central bearing and does not apply radial or axial loads.

[0086] Furthermore, the bearings used in the experiment were the same type of rolling bearings, such as deep groove ball bearings and angular contact ball bearings. The center bearing I 9 and center bearing II 18 were the same, and the test bearing I 8 and test bearing II 22 were the same. The center bearings and test bearings had different basic dimensions of inner and outer diameters, but had the same clearance and could be fitted with cages of different or the same materials.

[0087] Furthermore, before applying all test conditions to the test facility, several preliminary tests are conducted under the same operating conditions used in the final test to ensure that many different parts function properly.

[0088] Step 3: Experimentally obtain the bearing power consumption under three bearing layouts, and obtain the bearing power consumption P of layout A. A (F r ,F a The power consumption P of the bearing in layout B (Ω) B (F r ,0,Ω), and then calculate the total power consumption P of a single test bearing. (t) (F r ,F a ,Ω); Obtain the bearing power consumption P of C layout. C (0,0,Ω).

[0089] The following details how to measure and obtain the rotational power consumption, mechanical power consumption, and total power consumption of the test bearing based on three different layouts.

[0090] Furthermore, in the experiment, the automatic transmission fluid was supplied with different flow rates and supply temperatures.

[0091] Specifically, the rotational power consumption P of a single test bearing s (t) The rotational speed Ω, oil viscosity η (which varies with the inlet temperature), and oil flow rate into each bearing are all factors that influence this. And change. Figure 4Layout C in the diagram is used for each set of test bearing pairs.

[0092] Furthermore, under the given loading conditions (F) r ,F a Under these conditions, a single test should include multiple speed increments. Each speed increment should last for 1 minute, and for load tests, each batch of tests should include 5 minutes of testing.

[0093] In (F) r ,F a When )=(2,0)kN, the measured speed Ω(t) and torque loss signal T are obtained from the experiment. L (t), including five speed increments between 1000 and 8000 r / min (1000 r / min, 2000 r / min, 4000 r / min, 6000 r / min, 8000 r / min), precisely maintains the speed for each speed increment, except for instantaneous peaks during acceleration. L The value is also relatively stable, such as Figure 8 As shown.

[0094] steady-state T of speed increment L The value is defined as T within the last 3 / 4 of each speed increment. L The time average of (t) is maintained throughout the experiment. r ,F a The set value is used to obtain the following: Figure 9 The results are shown.

[0095] To ensure the accuracy of the experiment, the oil temperature supplied at the inlet is θ. oil Temperature θ of a single set of central bearings b To maintain consistency, ensure that the overall bearing temperature is as close as possible to the set inlet temperature value so that power consumption measurements can be correlated with a single operating temperature condition (inlet temperature and overall bearing temperature).

[0096] like Figure 5 As shown, in layout A, P consists of the power consumption of two sets of test bearings and two sets of central bearings. Test bearings I 8 and II 22 are deemed to have the same power consumption value because they are identical and subjected to the same load, speed, lubrication, and temperature conditions. The same assumptions are made for central bearings I 9 and II 18, thus obtaining the power consumption P of layout A. A : P A (F r ,F a ,Ω)=2P (t) (F r ,F a ,Ω)+2P (C) (F r,0,Ω) P (t) P represents the total power consumption of a single test bearing. (C) This represents the total power consumption of a single set of central bearings.

[0097] A single measurement of layout A is insufficient to determine P. (t) Because it cannot be with P A In the power consumption formula, P (C) Separation. Therefore, in layout B, a pair of test bearings are replaced by a pair of center bearings, so that all four sets of bearings are identical. Figure 6 In the middle, the output spindle 7 is equipped with center bearings III 29, I 9, II 18, and IV 30 from left to right. It is only subjected to radial loads, achieving the power consumption P of the B layout. B : P B (F r ,0,Ω)=4P (C) (F r ,0,Ω)

[0098] From the first two measured values ​​P A and P B The calculated total power consumption P of the test bearing was obtained. (t) (F r ,F a ,Ω):

[0099] like Figure 7 As shown, the output spindle of the C layout is supported by only a pair of test bearings without a central bearing. The C layout is designed to measure the rotational losses of the test bearings without any radial or axial loads. Therefore, the central bearing is not mounted on the shaft for measurement, and the power consumption P of the C layout is obtained. C : P C (0,0,Ω)=2P s (t) (Ω) In the formula, the subscript s represents the rotation loss component.

[0100] Step 4: Determine the rotational power consumption P of a single test bearing. s (t) (Ω) and mechanical power consumption Pm (t) (F r ,F a ,Ω).

[0101] Rotational speed Ω, viscosity η, and bearing oil flow rate Varying it over a wide range to quantify its impact on the spin power P of the test bearing. s (t)The combined impact.

[0102] In the experiment, Ω represents the inner race rotational speed (r / min), while the outer race remains stationary. To better understand the size effect, the cage speed... Ω c To determine the cage rotational speed (r / min), d m This indicates the diameter of the bearing pitch circle.

[0103] For test bearings 1 and 2, the temperature increment is 10°C, at θ oil =Within the range of 90 to 40℃, the viscosity can be adjusted by changing the inlet temperature.

[0104] Furthermore, during the experiment, the box heater was activated, raising the overall temperature θ of the experimental setup. b Maintain the same value. For the flow rate of each bearing, when the increment for the two test bearings is 0.1 L / min,

[0105] For the rotational speed of test bearing 1 The increment is 1000 r / min, corresponding to the cage speed. For test bearing 2, Ω was varied between 1000 and 12000 r / min in increments of 1000 r / min, corresponding to the cage speed. The parameters of test bearing 1 and test bearing 2 are as follows: Figure 10 As shown.

[0106] During the tests, no additional load was applied to the bearings other than the mass of the output spindle. This should have caused the bearings to operate below the minimum radial load requirement given by the manufacturer under certain test conditions. Assuming the conditions resulting from the mass of the shaft on the bearings are approximately the same as the rotational speed of the rolling elements under load, this effect is considered negligible.

[0107] Furthermore, the cage speed u, viscosity η, and bearing oil flow rate were tested. All combinations, considering several data points from test bearing 1 and test bearing 2 respectively in the rotation loss, illustrate the cage speed u, viscosity η, and bearing oil flow rate. Regarding the self-rotation power consumption P s (t) The impact, such as Figure 11 and Figure 12 As shown.

[0108] Furthermore, Figure 11 a1 and Figure 11 a2 and Figure 12 a1 and Figure 12 a2 shows that and Oil flow rate and P at all 6 viscosities η s (t) As the cage speed u changes; Figure 11 b1 and Figure 11 b2 and Figure 12 b1 and Figure 12 b2 shows test bearing 1 and test bearing 2 in... and Oil flow rate and discrete u level P s (t) As viscosity η changes; Figure 11 c1 and Figure 11 c2 and Figure 12 c1 and Figure 12 c2 shows P at the same cage speed increments u, η = 7.3 cSt and η = 29.6 cSt (inlet temperatures of 90°C and 40°C). s (t) Follow The changes.

[0109] Furthermore, by comparing and analyzing the experimental results and regressing all data points for each type of bearing, P was obtained. s (t) The cage speed u, viscosity η, and bearing oil flow rate vary. The equation is given, where the unit of η is cSt and the unit of u is m / s. The unit is L / min, P s (t) The unit is W, that is

[0110] The coefficients a to d for each bearing are as follows: Figure 13 As shown, the formulas for the listed coefficients apply only to the cage speed u, viscosity η, and bearing oil flow rate mentioned above. The expected bearing within the range, the self-rotation power consumption P s (t) With respect to cage speed u, viscosity η, and bearing oil flow rate The associated indices are a≈0.4~4.0, b≈0.4~0.5, c≈1.6~2.0, and d≈0.1.

[0111] like Figure 13 As shown, these power consumption regression determination coefficients R 2 ≥0.995, its value is close to 1, indicating It fits the rotation loss very well.

[0112] Determine the self-rotation power consumption P s (t) The calculation formula is as follows: P C (0,0,Ω)=2P s (t) (Ω)

[0113] The following section continues with the measurement and calculation of mechanical power consumption P. m (t) .

[0114] To quantify the mechanical power consumption P m (t) This assumes there is sufficient oil for elastohydrodynamic lubrication of the bearing contacts, and the oil flow rate... It should not affect P m (t) Each type of bearing can be used Single oil flow rate.

[0115] Furthermore, the load test was conducted at two temperature values ​​θ. oi1 =θ b The tests were conducted at 40℃ and 90℃ (corresponding to η = 29.6 cSt and 7.3 cSt, respectively). Therefore, P... m (t) Quantified as follows F r F a And change with u.

[0116] rotational speed Five increments were set, corresponding to the cage speeds of test bearing 1 and test bearing 2. and

[0117] Furthermore, radial loads on test bearing 1 and test bearing 2 (Incremental 2kN) and (Increment 1kN). For each F r Values, implementing a set of 5 F a Value. Therefore, the load ratio is defined as γ = F a / F r The selected F a The value is: The increment is 0.25 (i.e., axial load). The increment is 1 / 4F r ).

[0118] For F r , γ (i.e., F a The total number of data points obtained by evaluating the mechanical power consumption of each bearing will be several, based on all combinations of each increment of u and η.

[0119] Figure 14 and Figure 15This represents the measured values ​​P of bearings 1 and 2 under different cage speeds u and viscosities η. m (t) With F r And the changes in γ.

[0120] Similar to the regression analysis of rotation loss described earlier, mechanical loss is based on parameter F. r F a ,u and η for each bearing P m (t) The measured values ​​are then subjected to curve fitting. The mechanical power consumption P is determined. m (t) The regression formula is: The regression coefficients e~i and R for each bearing 2 For the root mean square error value, please refer to Figure 13 .

[0121] Mechanical loss P m (t) Related to cage speed u, viscosity η, and bearing oil flow rate Radial load F r and axial load F a The associated indices are e≈0.4~4.0, f≈0.25~0.28, g≈0.92~0.97, h≈1.8~2.9, and i≈0.4~1.1.

[0122] like Figure 13 As shown, these power consumption regression determination coefficients R 2 ≥0.97, its value is close to 1, indicating It can be used to fit mechanical losses.

[0123] Step 5, by Figure 4 The power consumption calculation formulas for the bearing under combined radial load are obtained from the three layout schemes shown:

[0124] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope. All such changes and modifications fall within the scope of the present invention as claimed, which is defined by the appended claims and their equivalents.

Claims

1. A rolling bearing power consumption measurement and testing machine under combined load, characterized in that: This includes a test bench, a bearing testing device mounted on the test bench, a torque and temperature measurement system, a thermal management system, and an external lubricant supply and circulation system; The bearing testing device includes an output spindle driven by a motor. A pair of central bearings are mounted on the central shaft section of the output spindle, and a pair of test bearings are mounted on the shoulders on both sides of the output spindle. The test bearings apply axial loads through left and right end caps I located on their axial outer sides. A central block is located above the output spindle at its axial center, and the central block is connected to the outer radial surface of the outer ring of the two central bearings. A radial load 2F is applied to the central block. r To apply a radial load F to each set of test bearings and center bearings r ; The bearing testing device is located below the output spindle and is equipped with axial sliding body and radial sliding body to ensure that the paths of axial load and radial load are completely independent and that the central bearing is only subjected to radial load. The torque and temperature measurement system includes a torque sensor and an integrated data acquisition system. The torque sensor is mounted coaxially with the output spindle, and the integrated data acquisition system is used to acquire the bearing's torque, speed, and thermocouple signals. The thermal management system is used to control the overall temperature of the bearing. The external lubricant supply and circulation system is used to provide the bearing with the required flow rate and temperature of lubricant.

2. The rolling bearing power consumption measurement test machine under combined load as described in claim 1, characterized in that: The bearing testing device is supported by a test bench. The base of the bearing testing device is connected to the guide rail of the bearing testing device set on the test bench. The bearing seat of the bearing testing device is connected to the base of the bearing testing device by bolts. The left end cover I and the right end cover I are respectively slidably engaged with the bearing seat of the bearing testing device to realize its free movement in the axial direction. Both the left end cover I and the right end cover I are provided with keyways to prevent their own rotation.

3. The rolling bearing power consumption measurement test machine under combined load as described in claim 2, characterized in that: The axial and radial sliding bodies are low-friction linear guides, and their sliding directions are aligned with the directions of application of the axial and radial loads, respectively.

4. The rolling bearing power consumption measurement test machine under combined load as described in claim 3, characterized in that: The central block is located on the axial sliding body and is not subject to axial constraints, and the central bearing does not bear axial load.

5. The rolling bearing power consumption measurement test machine under combined load as described in claim 4, characterized in that: The external lubricant supply and circulation system uses a heated reservoir and an integral J-type thermocouple to control the oil tank temperature. The oil tank is equipped with stirring blades, and a thermocouple is inserted into the oil inlet of each bearing lubrication channel to monitor the lubricant inlet temperature. The bearing testing device is equipped with a cylindrical heater to ensure that the overall bearing temperature is as close as possible to the set oil inlet temperature value.

6. A method for measuring and calculating the power consumption of rolling bearings under combined loads, characterized in that: This method utilizes the rolling bearing power consumption measurement test machine under combined load as described in any one of claims 1 to 5, and includes the following steps: S1, obtains torque loss signal T through sensor. L (F r ,F a The total power consumption P is obtained from the formula for calculating total power consumption (Ω). S2, three bearing rotation and mechanical loss layouts for the testing machine are set according to different radial loads, axial loads, and rotational speeds: layout A, layout B, and layout C. Layout A consists of a pair of identical central bearings and a pair of test bearings with different inner and outer diameters from the central bearings, applying 2F... r Total radial load, applied F a Axial load; Layout B replaces a pair of test bearings with a pair of center bearings based on Layout A, making all four sets of bearings identical, and applies 2F. r The total radial load is not applied, and no axial load is applied; layout C is based on layout A but does not have a central bearing and does not apply radial or axial loads. S3, obtain the bearing power consumption P of layout A. A (F r ,F a The power consumption P of the bearing in layout B (Ω) B (F r ,0,Ω), and then calculate the total power consumption P of a single test bearing. (t) (F r ,F a ,Ω); Obtain the bearing power consumption P of C layout. C (0,0,Ω); S4, determine the rotational power consumption P of a single test bearing. s (t) (Ω) and mechanical power consumption P m (t) (F r ,F a ,Ω); S5, the actual total power consumption of a single set of test bearings is obtained from the above three layout schemes:

7. The method for measuring and calculating the power consumption of rolling bearings under combined loads according to claim 6, characterized in that: In step S3, the bearing power consumption P of layout A is... A : P A (F r ,F a ,Ω)=2P (t) (F r ,F a ,Ω)+2P (C) (F r ,0,Ω) In the formula: P (t) P represents the total power consumption of a single test bearing. (C) The total power consumption of a single set of central bearings; The power consumption P of the bearing in layout B B : P B (F r ,0,Ω)=4P (C) (F r ,0,Ω) Based on layouts A and B, the total power consumption of a single set of test bearings is: C-layout bearing power consumption P C : In the formula, s is the rotation loss component.

8. The method for measuring and calculating the power consumption of rolling bearings under combined loads according to claim 7, characterized in that: In step S5, The power consumption of a single test bearing during rotation is: The mechanical power consumption of a single test bearing is:

9. The method for measuring and calculating the power consumption of rolling bearings under combined loads according to claim 8, characterized in that: In the experiment, comparative analysis was conducted by setting different cage speeds, viscosities, and oil flow rates. The self-rotation power consumption P is obtained s (t) The formula is: In the formula, u is the cage speed, and η is the viscosity. The oil flow rate of the bearing is given by indices a≈0.4~4.0, b≈0.4~0.5, c≈1.6~2.0, and d≈0.

1.

10. The method for measuring and calculating the power consumption of rolling bearings under combined loads according to claim 9, characterized in that: Mechanical loss is based on parameter F r F a u and η for each bearing P m (t) The measured values ​​were fitted to a curve to obtain the mechanical power consumption P. m (t) The formula is: In the formula, u is the cage speed, η is the viscosity, and F is the viscosity. r For radial load, F a For axial loads, the exponents are e≈0.4~4.0, f≈0.25~0.28, g≈0.92~0.97, h≈1.8~2.9, and i≈0.4~1.1.

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