JP2018040770A5

JP2018040770A5 -

Info

Publication number: JP2018040770A5
Application number: JP2016176954A
Authority: JP
Filing date: 2016-09-09
Publication date: 2019-10-10
Anticipated expiration: 2036-09-09

Description

好ましくは、Ｓ−Ｎ曲線は、複数個の第１種定数と、故障破壊までの負荷回数Ｎと、合成応力Ｓを含む式で表される。合成応力Ｓを表す式は、複数個の第２種定数を含む。Ｓ−Ｎ曲線を求めるステップは、各試験用の軸受部品について、故障破壊するまでの複数回の転動疲労試験の負荷回数の合計をＮとし、故障破壊したときの合成応力をＳとした１つのサンプルを得るステップと、複数個の試験用の軸受部品についてのサンプルを用いて、複数個の第１種定数および複数個の第２種定数を推定するステップとを含む。 Preferably, the SN curve is represented by an expression including a plurality of first type constants, the number of times N of loads until failure and a composite stress S. The formula representing the composite stress S includes a plurality of second type constants. Determining a S- N curve, for bearing components for each test, a total of multiple loads the number of rolling contact fatigue test until failure fracture is N, the synthesis stress when failed disrupted is S Obtaining a single sample and estimating a plurality of first type constants and a plurality of second type constants using samples for a plurality of bearing parts for testing.

好ましくは、式は、式（１）で表される。Ａ、Ｂ、Ｓｆは定数である。 Preferably, the formula is represented by formula (1). A, B, and Sf are constants.

Claims

A life diagnosis method for bearing parts,
Performing a plurality of rolling fatigue tests on each of the plurality of test bearing parts until failure failure,
In each of the plurality of rolling fatigue tests on the plurality of test bearing parts, the combined stress of the test bearing parts, which is the sum of the residual stress and the micro stress of the test bearing parts, is calculated. Seeking steps,
In each of the plurality of rolling fatigue tests for the plurality of test bearing parts, X-ray analysis data is obtained from an X-ray diffraction ring detected by irradiating the test bearing parts with X-rays. Seeking steps,
S based on the relationship between the total number of loads in the multiple rolling fatigue tests for the plurality of test bearing parts and the combined stress of the test bearing parts when the failure occurs. Obtaining a -N curve;
Obtaining a cumulative fatigue degree in each of the plurality of rolling fatigue tests for the plurality of test bearing parts based on the SN curve;
Creating a correspondence table representing the relationship between the X-ray analysis data of the bearing component for the test and the cumulative fatigue level;
Determining a combined stress of the diagnostic bearing component that is the sum of the residual stress and the microstress of the diagnostic bearing component;
Determining the life of the diagnostic bearing component based on the combined stress of the diagnostic bearing component and the SN curve;
Obtaining X-ray analysis data from an X-ray diffraction ring detected by irradiating the diagnostic bearing component with X-rays;
Obtaining a cumulative fatigue level of the diagnostic bearing part based on the X-ray analysis data of the diagnostic bearing part and the correspondence table;
A method for diagnosing the life of a bearing component, comprising: determining the remaining life of the bearing component for diagnosis based on the life of the bearing component for diagnosis and the cumulative fatigue level.

The step of obtaining the composite stress of the bearing component for testing is as follows:
The bearing part life diagnosis method according to claim 1, further comprising a step of obtaining a micro stress of the test bearing part from a measurement result of a surface shape of the test bearing part.

The step of obtaining the composite stress of the bearing component for testing is as follows:
The bearing part life diagnosis method according to claim 1, further comprising: obtaining a residual stress of the test bearing part from an X-ray diffraction result of the test bearing part.

The step of obtaining the composite stress of the diagnostic bearing component is as follows:
The bearing part life diagnosis method according to claim 1, further comprising a step of obtaining a micro stress of the diagnostic bearing part from a measurement result of a surface shape of the diagnostic bearing part.

The step of obtaining the composite stress of the diagnostic bearing component is as follows:
The bearing part life diagnosis method according to claim 1, further comprising a step of obtaining a residual stress of the diagnostic bearing part from an X-ray diffraction result of the diagnostic bearing part.

The SN curve is expressed by a formula including a plurality of first type constants, a load count N until failure, and the composite stress S. Including two constants,
Determining the S- N curve is
Obtaining a sample for each bearing component for each test, where N is the total number of loads in the multiple rolling fatigue tests until failure failure, and S is the combined stress when failure occurs. ,
2. The bearing according to claim 1, further comprising: estimating values of the plurality of first type constants and the plurality of second type constants using the samples of the plurality of test bearing parts. Life diagnosis method for parts.

Before following formula is represented by the formula (1), A, B, Sf is a constant,

The bearing part life diagnosis method according to claim 6.

The step of obtaining the cumulative fatigue level includes:
Based on the SN curve, obtaining the number of loads until failure failure at the combined stress in each of the multiple rolling fatigue tests;
In each of the plurality of rolling fatigue tests, a step of obtaining a fatigue level represented by a ratio of an actual load number and a load number until failure failure,
The sum of the fatigue level of the rolling fatigue test and the fatigue levels of all the rolling fatigue tests before the rolling fatigue test in each of the plurality of rolling fatigue tests is calculated as the cumulative fatigue level. The method for diagnosing the life of a bearing component according to claim 1, comprising: a step.

The bearing part life diagnosis method according to claim 1, wherein the X-ray analysis data is data representing a relationship between a central angle and an intensity of an annular diffraction X-ray.

The bearing part life diagnosis method according to claim 1, wherein the X-ray analysis data is residual stress of six components acting on the bearing part.

The bearing part life diagnosis method according to claim 1, wherein the X-ray analysis data is a half-value width of a peak obtained corresponding to a central angle of an annular diffraction X-ray.

The bearing part life diagnosis method according to claim 1, wherein the X-ray analysis data is retained austenite of the bearing part.

The X-ray analysis data is obtained corresponding to the data representing the relationship between the center angle and intensity of the annular diffraction X-ray, the six-component residual stress acting on the bearing part, and the center angle of the annular diffraction X-ray. The bearing part life diagnosis method according to claim 1, wherein the bearing part life is a value expressed by a combination of two or more of a half width of a peak and a retained austenite of the bearing part.

The step of obtaining the remaining life includes
Including a step of calculating the remaining life according to equation (2), where D is the cumulative fatigue level, L is the life, and R is the remaining life,
R = L (1-D) (2)
The bearing part life diagnosis method according to claim 1.

When the oil film parameter obtained from the measurement result of the thickness of the oil film present on the surface of the test bearing part and the shape of the surface is equal to or less than a predetermined value, the step of obtaining the combined stress of the bearing part for test is executed. The bearing part life diagnosis method according to claim 1.

When the oil film parameter obtained from the measurement result of the thickness of the oil film present on the surface of the diagnostic bearing part and the shape of the surface is equal to or less than a predetermined value, a step of obtaining a composite stress of the bearing part for diagnosis is executed. The bearing part life diagnosis method according to claim 1.

The bearing component life diagnosis method is:
The bearing part life diagnosis method according to claim 1, further comprising a step of notifying whether or not the diagnosis bearing part requires replacement based on the remaining life, or a replacement time.

A life diagnosis device for bearing parts,
Each of the plurality of rolling fatigue tests on the plurality of test bearing parts when each of the plurality of test bearing parts is subjected to a plurality of rolling fatigue tests until failure. In the above, the composite stress of the test bearing part which is the sum of the residual stress and the micro stress of the test bearing part is obtained, and the diagnostic A combined stress calculation unit for determining a combined stress of the bearing parts of
In each of the plurality of rolling fatigue tests for the plurality of test bearing parts, X-ray analysis data is obtained from an X-ray diffraction ring detected by irradiating the test bearing parts with X-rays. An X-ray analysis data calculating unit for obtaining X-ray analysis data from an X-ray diffraction ring detected by irradiating the diagnostic bearing component with X-rays;
S based on the relationship between the total number of loads in the multiple rolling fatigue tests for the plurality of test bearing parts and the combined stress of the test bearing parts when the failure occurs. An SN curve calculation unit for obtaining an -N curve;
Based on the SN curve, a cumulative fatigue degree calculation unit for obtaining a cumulative fatigue degree in each of the plurality of rolling fatigue tests for the plurality of test bearing parts;
A correspondence table creation unit for creating a correspondence table representing the relationship between the X-ray analysis data of the bearing component for the test and the cumulative fatigue level;
Based on the X-ray analysis data of the diagnostic bearing part and the correspondence table, a cumulative fatigue level of the diagnostic bearing part is obtained, and based on the combined stress of the diagnostic bearing part and the SN curve. A diagnostic unit for obtaining a life of the diagnostic bearing component and obtaining a remaining life of the diagnostic bearing component based on a life of the diagnostic bearing component and a cumulative fatigue level of the diagnostic bearing component; A life diagnosis device for bearing parts, comprising:

A life diagnosis program for bearing parts,
On the computer,
Each of the plurality of rolling fatigue tests on the plurality of test bearing parts when each of the plurality of test bearing parts is subjected to a plurality of rolling fatigue tests until failure. A step of obtaining a composite stress of the test bearing part which is a sum of a residual stress and a micro stress of the test bearing part;
In each of the plurality of rolling fatigue tests for the plurality of test bearing parts, X-ray analysis data is obtained from an X-ray diffraction ring detected by irradiating the test bearing parts with X-rays. Seeking steps,
S based on the relationship between the total number of loads in the multiple rolling fatigue tests for the plurality of test bearing parts and the combined stress of the test bearing parts when the failure occurs. Obtaining a -N curve;
Obtaining a cumulative fatigue degree in each of the plurality of rolling fatigue tests for the plurality of test bearing parts based on the SN curve;
Creating a correspondence table representing the relationship between the X-ray analysis data and the cumulative fatigue level;
Determining a combined stress of the diagnostic bearing component that is the sum of the residual stress and the microstress of the diagnostic bearing component;
Estimating the life of the diagnostic bearing component based on the combined stress of the diagnostic bearing component and the SN curve;
Obtaining X-ray analysis data from an X-ray diffraction ring detected by irradiating the diagnostic bearing component with X-rays;
Based on the X-ray analysis data of the diagnostic bearing component and the correspondence table, obtaining a cumulative fatigue level of the diagnostic bearing component;
A bearing part life diagnosis program for executing a step of obtaining a remaining life of the diagnostic bearing part based on the life of the diagnostic bearing part and the cumulative fatigue level.