JP5659481B2 - Bearing test method - Google Patents

Description

  The present invention relates to a bearing test method for testing the rolling life and the durable life of a rolling element constituting a rolling bearing.

Bearings used in automotive auxiliary equipment such as alternators, tension pulleys, idler pulleys, timing belt pulleys, electromagnetic clutches, compressors, water pumps, bearings supporting shafts incorporated in engines such as crankshafts and camshafts, and various motors In addition, as a factor that affects the durability life of a rolling bearing such as a bearing that supports a rotating shaft of a machine tool, there is a white peeling problem due to static electricity charged on the bearing from the rotation transmission path. As a bearing test apparatus for testing the bearing durability life due to the white peeling, a rotation shaft for mounting the inner ring of the test bearing, a housing for fixing the outer ring of the test bearing, and a rotation driving means for rotating the rotation shaft, Many of the test bearings are provided with a load loading means for applying a load. These bearing test apparatuses are used for endurance life testing, bearing design, development, quality assurance, trouble investigation, and the like.
As a typical prior art of such a test apparatus, for example, Patent Document 1 can be cited.

JP 2006-317273 A

In Patent Document 1, as shown in FIG. 2, a rotating shaft 200 to which an inner ring 100 n of a test bearing 100 is attached, a housing 300 a that fixes an outer ring 100 g of the test bearing 100, a dummy bearing 400, and a housing 300 b that holds the dummy bearing 400. And a rotational drive means (not shown) that rotationally drives the rotary shaft 200, and a load applied to the test bearing via a pulley 600 that is integrally fixed to the rotary shaft, and the rotational force of the rotary drive means is An endless belt (not shown) that transmits to the pulley 600 is provided.

According to this test apparatus, the white peeling of the test bearing 100 is reproduced by connecting one end of the electrode of the DC external power supply 500 to the housing 300a and the housing 300b and applying a voltage to make the test bearing 100 an energization path. And endurance life.

However, while most of the white peeling phenomenon on the market is due to static electricity, in the above known technique, the white peeling of the test bearing 100 is reproduced using a DC power source, and thus the current value becomes extremely large. . Therefore, there is a fear that the test bearing 100 may be eroded and cause a peeling phenomenon different from the actual peeling state in the market. In addition, since the test bearing 500 becomes a source of vibration due to electrolytic corrosion, the vibration of the entire testing machine is increased, making it difficult to detect the peeling of the test bearing 100. Further, the grease deterioration of the test bearing 100 was promoted, and there was a fear that the test bearing 100 would be seized.

Furthermore, in Patent Document 1, it is possible to reproduce the separation of the rolling surface on which the rolling element 100t rolls on the outer ring 100g and the inner ring 100n of the test bearing 100, but it is difficult to reproduce the white separation of the rolling element 100t itself. There was a limit to elucidating the whole picture.

In view of the above circumstances, the present invention suppresses unexpected vibrations caused by electrolytic corrosion of test bearings and peculiar delamination phenomenon by supplying static electricity to the test bearings. It is an object of the present invention to provide a bearing test method that enables accurate reproduction and white reproduction of the bearing rolling surface and rolling elements.

According to a first aspect of the present invention, there is provided a bearing test method comprising: a test bearing comprising an inner ring, an outer ring and a rolling element; a rotary shaft penetratingly fixed to the inner ring of the test bearing; and a pulley attached to one end of the rotary shaft. And a support bearing which is opposite to the pulley across the test bearing and in which the rotating shaft penetrates and is fixed, and an outer ring of the test bearing is fixed and supported by a base via an insulator. In a bearing test method using a bearing test apparatus comprising a housing, a rotation drive means, and an endless belt that transmits the rotational force of the rotation drive means to the pulley,
A static electricity generator is provided as an external power source, a convex portion is provided at the rotation center of the end of the rotary shaft, one of the negative pole and the positive pole of the static electricity generator is connected to the outer ring of the test bearing, and the other is Using a bearing test device that is slidably contacted with a convex portion, a voltage is increased by static electricity while rotating the test bearing to cause dielectric breakdown, and white peeling of the test bearing can be reproduced .

The bearing test method according to claim 2 is characterized in that a plurality of the rolling elements are provided, and at least one of the rolling elements uses a bearing test apparatus constituted by an insulator.

By adopting this test apparatus, it is possible to avoid abnormal vibrations and peculiar delamination phenomenon caused by electrolytic corrosion of the test bearing due to direct current, and to accurately reproduce white delamination of the test bearing due to static electricity. In addition, it is possible to reproduce white peeling at an arbitrary part with respect to the rolling surface and rolling element of the test bearing.

It is the schematic of the testing apparatus of this invention. It is the schematic of the conventional test apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view of an embodiment of the present bearing test apparatus. The test bearing 1 and the support bearing 2 are arranged at intervals in the axial direction. An inner ring 1n, which is a rotating ring of the test bearing 1, is fitted on a shaft 3 as a support body common to the test bearing 1 and the support bearing 2 so as to be integrally rotatable. The outer ring 1g of the test bearing 1 is fitted into the sub aluminum housing 4 and fixedly held. The sub-aluminum housing 4 is prevented from rotating by driving a plurality of fixing pins 6 into the end face of the aluminum housing 5.

A vibration sensor 13 is attached to the sub-aluminum housing 4 to monitor the vibration of the test bearing 1, and a hole is provided in a part of the outer peripheral surface where the vibration sensor 13 is not attached. The outer peripheral surface of the outer ring of the test bearing 1 incorporated in the sub aluminum housing 4 is exposed through the hole.

Further, the shaft 3 is provided with an iron pulley 11 at a slight interval outside the test bearing 1, and the rotational force of a driving source (not shown) is transmitted through an endless V-groove belt 12. It has come to be.

A housing 5 is fixed to the base 7 of the test apparatus provided with the insulator 8. In addition, as a power source for charging the test bearing 1, an electrostatic generator 10 is used as an external power source. The negative pole of the static electricity generator 10 is connected to the outer peripheral surface of the outer ring 1g of the test bearing 1 through the sub-aluminum housing 4 of this test equipment, and the positive pole of the static electricity generator 10 is connected to the end of the shaft 3 through the hole. Thus, the test bearing 1 is negatively charged. When the voltage of the test bearing 1 increases and reaches a certain value, dielectric breakdown occurs, and a current flows through a path of “external power source minus pole → test bearing 1 → shaft 3 → external power source plus pole”.

(Static generator)
As the static electricity generator, a mechanical static electricity generator (for example, VG-250 manufactured by Shimadzu Rika Co., Ltd.) is used. Since the amount of static electricity cannot be measured with a bulk metal, it is difficult to measure the absolute value of the amount of static electricity charged on the outer ring of the test bearing. However, when the amount of static electricity around the negative pole of the static electricity generating device was measured with a static electricity measuring device (for example, FMX-003 manufactured by SIMCO, etc.) in the operating state, a measurement limit of −20000 V was shown. Therefore, it is estimated that a considerable amount of static electricity is charged in the test bearing.

(Contact of shaft end)
A curved circuit 3a is provided at the center of the shaft end surface, and a current flowing from the test bearing 1 is drawn from the shaft 3 by contacting the carbon plate 10a at the electrode end of the external power source. The protrusion 3a and the carbon plate 10a constitute a so-called slip ring. Since the protrusion 3a is in contact with the carbon plate 10a at the center of the shaft 3 at a point, the peripheral speed is as close to zero as possible, and the wear of the protrusion 3a does not occur and the evaluation accuracy is good.
In the present invention, the protrusion 3a is provided on the shaft 3, but it may be provided on the carbon plate 10a side.

(Test bearings with rolling elements made of insulating material)
When all the rolling elements 1a provided on the test bearing 1 are made of steel balls as a white peel test using the device of the present invention, the white peel of the rolling surface can be reproduced. If one of the plurality of rolling elements 1a of the test bearing 1 is made of steel balls and the remaining rolling elements 1a are made of an insulating ceramic or the like, the current flows to the rolling elements made of steel balls of the test bearings 1. Aggregated. Therefore, white peeling can be reproduced on the rolling element. In the present embodiment, the number of rolling elements to be steel balls is set to 1 for reproduction of white separation of the rolling elements 1a. However, the number of steel balls may be appropriately increased under various conditions such as voltage.

(White peel test)
A deep groove ball bearing with a contact seal (inner diameter φ17 mm, outer diameter φ47 mm, width 14 mm) is filled with 2.3 g of grease shown in Table 1 under the conditions of a radial load of 1300 N, an inner ring rotational speed of 10500 min ⁻¹ , and an ambient temperature: room temperature. The test was conducted. The test was stopped when it reached three times the initial vibration value of the bearing, and the life was determined by confirming white flaking. The test results are shown in Table 2.

(Test results)
According to the test apparatus of the present invention, the white separation of the raceway and the white separation of the rolling element can be accurately reproduced without causing the test bearing to generate unexpected vibration due to electrolytic corrosion or the like. . In addition, the test time can be greatly shortened compared to the comparative example.

DESCRIPTION OF SYMBOLS 1 Test bearing 2 Support bearing 3 Shaft 4 Sub aluminum housing 5 Housing 10 Static electricity generator 11 Pulley 12 V groove belt

Claims (2)

A test bearing composed of an inner ring, an outer ring, and rolling elements, a rotating shaft that is fixedly inserted into the inner ring of the test bearing, a pulley attached to one end of the rotating shaft, and a direction opposite to the pulley across the test bearing A support bearing in which the rotating shaft is fixed in a penetrating manner, a housing for fixing an outer ring of the test bearing and supported by a base via an insulator, a rotation driving means, and a rotation driving means. In a bearing test method using a bearing test apparatus provided with an endless belt for transmitting rotational force to the pulley,
A static electricity generator is provided as an external power source, a convex portion is provided at the rotation center of the end of the rotary shaft, one of the negative pole and the positive pole of the static electricity generator is connected to the outer ring of the test bearing, and the other is A bearing test method characterized in that, using a bearing test device slidably in contact with a convex portion, a voltage is increased by static electricity while causing the dielectric breakdown to occur while rotating the test bearing, and white peeling of the test bearing can be reproduced . The bearing test method according to claim 1 , wherein a plurality of the rolling elements are provided, and a bearing test apparatus in which at least one of the rolling elements is made of an insulator is used .

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