A test bearing dynamic friction torque test tool and a test method thereof

Abstract

A test tool for testing bearing dynamic friction torque and a test method thereof belong to the technical field of bearing testing, and comprise a fixing base, a test bearing, a positioning disc and a loading disc A, a circular recess is formed on the inner side surface of the loading disc A, the test bearing is arranged in the circular recess of the loading disc A, the fitting surface at one end of the test bearing is connected with the fixing base through the positioning disc, the fitting surface at the other end of the test bearing is provided with a bolt fixed with the outer side surface of the loading disc A, a plurality of openings are uniformly formed on the inner side surface of the loading disc A along the circumferential direction, a proximity switch is installed on the upper end surface of the fixing base, the proximity switch is arranged in correspondence with the plurality of openings, and is connected with an external PLC controller through a signal line; the collected signal is transmitted to the PLC controller to calculate the actual running speed, the angular velocity of two time periods is measured to calculate the angular acceleration, and the bearing dynamic friction torque value is obtained through the rotational inertia value; the test method is simple and intuitive, convenient to test, and the result is accurate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bearing test, in particular to a test tool for testing dynamic friction torque of bearing and a test method thereof. BACKGROUND

[0002] It is known that with the improvement of industrial level in China, bearings are widely used in aerospace, precision machine tools, high-speed electric spindles, rail transit, ultra-precision medical machinery and other fields. The friction torque of the bearing is a comprehensive performance of the lubrication state and running performance of the bearing. Due to the influence of various uncertain factors on the rolling bearing, the friction torque presents a random and unstable change trend, and it is difficult to accurately calculate by using the calculation formula. At present, some test methods can only measure the static friction torque, and some testers can only test small ball bearings under light load. Therefore, it is the basic demand of the technical personnel in the field to propose a method for testing the dynamic friction torque of the bearing which is convenient and accurate. SUMMARY

[0003] In order to overcome the deficiencies in the background art, the present application discloses a test tool for testing dynamic friction torque of bearing and a test method thereof.

[0004] In order to achieve the object of the application, the following technical solutions are adopted:

[0005] A test tool for testing dynamic friction torque of bearing, comprising a fixed seat, a test bearing, a positioning disc and a loading disc A, a circular recess is formed on the inner side surface of the loading disc A, the test bearing is arranged in the circular recess of the loading disc A, and the mating surface at one end of the test bearing is connected with the fixed seat through the positioning disc, the mating surface at the other end of the test bearing is provided with a bolt fixed on the outer side surface of the loading disc A, a loading disc B is installed on the outer circular surface of the loading disc A, a plurality of holes are uniformly formed on the inner side surface of the loading disc A along the circumferential direction, a proximity switch is installed on the upper end surface of the fixed seat, the proximity switch is arranged corresponding to the plurality of holes, and is connected with an external PLC controller through a signal line, and the PLC controller controls the display of the proximity switch to display the data measured by the proximity switch.

[0006] The number of holes in the test tool for testing dynamic friction torque of bearing is determined according to the actual speed range and the required accuracy.

[0007] The test tool for testing dynamic friction torque of bearing, the loading disc A and the loading disc B are in transition fit.

[0008] The test tool for testing dynamic friction torque of bearing, the fixed seat is in the shape of a right triangle, the lower surface is fixed on the experimental table surface through bolts, and a plurality of screws for fixing the positioning disc are arranged on the vertical surface.

[0009] The test tool for testing the dynamic friction torque of the bearing, the size of the opening is 15mm in diameter and 5mm in depth.

[0010] The test tool for testing the dynamic friction torque of the bearing, the outer circular surface of the positioning disc is matched with the circular recess of the loading disc A to be fixed.

[0011] The method for testing the dynamic friction torque of the bearing, the gravity of the loading disc A is the load borne by the test bearing, and the loading disc B is installed to obtain different loads.

[0012] A method for testing the dynamic friction torque of a bearing, the specific testing method comprises the following steps:

[0013] (1) manually rotating the loading disc A to 150-200 revolutions per minute, then loosening, the loading disc A rotates by inertia, the proximity switch arranged at the upper end of the fixed seat collects signals and transmits the signals to the PLC controller, the PLC controller collects multiple signals in a fixed time interval and converts the signals into rotational speed;

[0014] The actual running speed in an arbitrary time period is automatically calculated by the PLC controller, and the angular velocity in a certain time period is calculated by the formula ω=2×π×n / 60, wherein n is the rotational speed, and the unit is revolutions per minute;

[0015] (2) the angular acceleration is calculated by measuring the angular velocities in two time periods and using the formula β=Δω / Δt= (ω2- ω1) / (t2-t1);

[0016] (3) a three-dimensional model is drawn by a design software, the material of the loading disc A is set, and the moment of inertia J is measured by a quality attribute function;

[0017] (4) the dynamic friction torque of the bearing is calculated by the formula M=J·β.

[0018] Due to the adoption of the above technical scheme, the present application has the following beneficial effects:

[0019] The test tool for testing the dynamic friction torque of the bearing and the testing method thereof collect signals and transmit the signals to the PLC controller to calculate the actual running speed, measure the angular velocities in two time periods to calculate the angular acceleration, and finally obtain the dynamic friction torque value of the bearing through the moment of inertia value; the test method is simple and intuitive, convenient to test, and the result is accurate. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a structural schematic view of the test tool of the present application.

[0021] Figure 2 is Figure 1 the sectional view of A-A in

[0022] Figure: 1, fixed seat; 2, test bearing; 3, screw; 4, bolt; 5, positioning disc; 6, loading disc A; 7, loading disc B; 8, opening; 9, proximity switch. DETAILED DESCRIPTION

[0023] The application can be explained in detail by the following examples, and the purpose of disclosing the application is to protect all technical improvements within the scope of the application.

[0024] The accompanying drawings Figure 1 The test tool for testing dynamic friction torque of the test bearing comprises a fixed seat 1, a test bearing 2, a positioning disc 5 and a loading disc A 6, a circular recess is formed on the inner side surface of the loading disc A 6, the test bearing 2 is arranged in the circular recess of the loading disc A 6, and the matching surface at one end of the test bearing 2 is connected with the fixed seat 1 through the positioning disc 5, the matching surface at the other end of the test bearing 2 is provided with the bolt 4 for fixing the outer side surface of the loading disc A 6, the loading disc B 7 is installed on the outer surface of the loading disc A 6, a plurality of openings 8 are uniformly formed on the inner side surface of the loading disc A 6 along the circumferential direction, the proximity switch 9 is installed on the upper end surface of the fixed seat 1, the proximity switch 9 is arranged corresponding to the plurality of openings 8, and is connected with the external PLC controller through a signal line, and the PLC controller controls the display of the proximity switch to display the data measured by the proximity switch.

[0025] The number of the openings 8 is determined according to the actual speed range and the required accuracy.

[0026] The test tool for testing dynamic friction torque of the test bearing, the loading disc A 6 and the loading disc B 7 are in transition fit.

[0027] The test tool for testing dynamic friction torque of the test bearing, the fixed seat 1 is in the shape of a right triangle, the lower part is fixed on the experimental table surface through the bolt, and a plurality of screws 3 for fixing the positioning disc 5 are arranged on the vertical surface.

[0028] The test tool for testing dynamic friction torque of the test bearing, the size of the opening 8 is 15 mm in diameter and 5 mm in depth.

[0029] The test tool for testing dynamic friction torque of the test bearing, the outer surface of the positioning disc 5 is matched and fixed with the circular recess of the loading disc A 6.

[0030] The method for testing dynamic friction torque of the test bearing, the gravity of the loading disc A 6 is the load borne by the test bearing 2, and different loads are obtained by installing the loading disc B 7.

[0031] A method for testing dynamic friction torque of a test bearing, the specific testing method comprises the following steps:

[0032] (1), manually rotate the loading disc A6 to 150-200 rpm, then release, the loading disc A6 rotates by inertia, the proximity switch 9 arranged on the upper end of the fixed seat 1 collects signals and transmits them to the PLC controller, the PLC controller collects multiple signals in a fixed time interval and converts them into rotational speed;

[0033] The actual running speed in any time period is automatically calculated by the PLC controller, and the angular velocity in a certain time period is calculated by the formula ω=2×π×n / 60, wherein n is the rotational speed, unit: rpm;

[0034] (2), the angular acceleration is calculated by the formula β=Δω / Δt= (ω2- ω1) / (t2-t1) through the angular velocity of two time periods;

[0035] (3), a three-dimensional model is drawn by the design software, and the material of the loading disc A6 is set, and the moment of inertia J is measured by the quality attribute function;

[0036] (4), the dynamic friction torque of the bearing is calculated by the formula M=J·β. EMBODIMENT

[0037] The inner side of the loading disc A6 is provided with 36 holes 8 evenly spaced in the circumferential direction, the gravity of the loading disc A6 is 100KG, that is, the load borne by the test bearing 2 is 100KG, the upper end of the fixed seat 1 is provided with a proximity switch 9, the proximity switch 9 is connected with the external PLC controller through a signal line, and the PLC controller controls the display of the proximity switch to display the data measured by the proximity switch; in this embodiment, 360 signals are collected at intervals of 10 seconds in a fixed time, and 36 signals are for one rotation, so 360 divided by 36 is 10 rotations, 10 rotations in 10 seconds, which is converted to 10×(60÷10)=60 rpm per minute; manually rotate the loading disc A6 to 200 rpm, then release, the loading disc A6 rotates by inertia, the signals of the proximity switch obtained by the PLC controller are used to calculate the actual running speed in the t1, t2 time period:

[0038] The rotational speed measured at time point t1 is 187 rpm,

[0039] The angular velocity is 19.58259387 rad / s according to ω=2×π×n / 60;

[0040] The rotational speed measured at time point t2 is 173 rpm,

[0041] The angular velocity is 18.11651733 rad / s according to ω=2×π×n / 60;

[0042] The angular acceleration is:

[0043] β = (19.58259387 - 18.11651733) / 5

[0044] = 0.293215309 rad / s²

[0045] The three-dimensional model is drawn by SolidWorks design software, and the material of the loading disc A6 is set as Q235A. The moment of inertia J measured by the quality attribute function is 2.60135593 kg·㎡;

[0046] Then the torque M = J·β = 0.762757384 N.M. Embodiment

[0047] The inner side surface of the loading disc A6 is uniformly and circumferentially provided with 36 openings 8. The gravity of the loading disc A6 and the loading disc B7 is 100 KG, that is, the load borne by the test bearing 2 is 200 KG. The upper end of the fixed seat 1 is provided with a proximity switch 9. The proximity switch 9 is connected with an external PLC controller through a signal line. The PLC controller controls the display of the proximity switch to display the data measured by the proximity switch. In this embodiment, 360 signals are collected at intervals of 10 seconds within a fixed time. 36 signals are for one rotation. Therefore, 360 divided by 36 is equal to 10 rotations. 10 rotations in 10 seconds are equal to 60 rotations per minute. After the loading disc A6 and the loading disc B7 are manually rotated to 150 rotations per minute, they are loosened. The loading disc rotates by inertia. The signals of the proximity switch obtained by the PLC controller are used to calculate the actual running speed in the time period t1 and t2.

[0048] The rotation speed measured at the time point t1 is 138 rotations per minute,

[0049] The angular velocity obtained from ω = 2 × π × n / 60 is 14.45132596 rad / s;

[0050] The rotation speed measured at the time point t2 is 133 rotations per minute,

[0051] The angular velocity obtained from ω = 2 × π × n / 60 is 13.92772719 rad / s;

[0052] The time interval between t2 and t1 is 5 seconds. The angular acceleration is:

[0053] β = (14.45132596 - 13.92772719) / 5

[0054] = 0.104719753 rad / s²

[0055] Draw three-dimensional model by SolidWorks design software, set material of loading disc A6, B7 as Q235A, measured moment of inertia J by quality attribute function as: 8.2895341 kg·㎡;

[0056] Then, torque M=J·β=0.868077966 N.M.

[0057] The parts of the application not described in detail are prior art.

[0058] The examples selected herein for the purpose of disclosing the application are presently considered to be the most practical and preferred, it being understood, however, that this application is intended to cover all embodiments which come within the scope of the concept and the application.

Claims

1. A test tool for testing dynamic friction torque of a bearing, comprising a fixed seat, a test bearing, a positioning disc and a loading disc A, a circular recess is formed on the inner side of the loading disc A, the test bearing is arranged in the circular recess of the loading disc A, and the matching surface at one end of the test bearing is connected with the fixed seat through the positioning disc, the matching surface at the other end of the test bearing is provided with a bolt fixed on the outer side of the loading disc A, a loading disc B is installed on the outer circular surface of the loading disc A, the gravity of the loading disc A is the load borne by the test bearing, the different loads are obtained by installing the loading disc B, a plurality of openings are uniformly formed on the inner side of the loading disc A along the circumferential direction, a proximity switch is installed on the upper end surface of the fixed seat, the proximity switch is arranged corresponding to the plurality of openings, and is connected with an external PLC controller through a signal line, the PLC controller controls the display of the proximity switch to display the data measured by the proximity switch.

2. A test rig for testing the dynamic friction torque of a bearing according to claim 1, characterized in that The number of openings is determined according to the actual speed range and the required accuracy.

3. The test fixture for testing the dynamic friction torque of a bearing of claim 1, wherein: The loading disc A and the loading disc B are in transition fit.

4. The test fixture of claim 1, wherein: The fixed seat is in the shape of a right triangle, the lower surface is fixed on the experimental table surface through a bolt, and a plurality of screws for fixing the positioning disc are arranged on the vertical surface.

5. The test fixture of claim 1 wherein: The size of the opening is 15mm in diameter and 5mm in depth.

6. The test fixture of claim 1 wherein: The outer circular surface of the positioning disc is matched and fixed with the circular recess of the loading disc A.

7. A method of testing a test bearing dynamic friction torque test rig as claimed in any one of claims 1 to 6, characterised by: The specific test method comprises the following steps: (1) manually rotate the loading disc A to 150-200 revolutions per minute, then loosen it, the loading disc A rotates by inertia, the proximity switch arranged on the upper end of the fixed seat collects signals and transmits them to the PLC controller, the PLC controller collects a plurality of signals in a fixed time interval and converts them into speed; The actual running speed in any time period is automatically calculated by the PLC controller, and the angular velocity in a certain period is calculated by the formula ω=2×π×n / 60, wherein n is the speed, unit: revolutions per minute; (2) the angular acceleration is calculated by the formula β=Δω / Δt= (ω2- ω1) / (t2-t1) through the measurement of the angular velocities of two time periods; (3) a three-dimensional model is drawn by a design software, the material of the loading disc A is set, and the moment of inertia J is measured by the mass attribute function; (4) the bearing dynamic friction torque is calculated by the formula M=J·β.

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