Monitoring method and monitoring apparatus for determining remaining life of a bearing

Patent metadata

Field	Value
Publication number	US-10823638-B2
Application number	US-201716318142-A
Country	US
Kind code	B2
Filing date	Sep 6, 2017
Priority date	Sep 19, 2016
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

A monitoring method and monitoring apparatus for the remaining life of a bearing are provided. The monitoring method comprises: during the operation of a bearing, determining a position where a defect of the bearing is located, and determining a size of the defect (S10); according to the position where the defect is located and a set condition, determining a failure mode of the bearing as well as an expansion rate and a failure value of the defect in the failure mode (S20), the failure value being a maximum value that the defect can reach when the bearing fails; and based on the size, expansion rate and failure value of the defect, obtaining the remaining life of the bearing (S30). The monitoring method and monitoring apparatus determine the remaining service life of a bearing, so that maintenance personnel can arrange a maintenance plan and counter measures in advance.

First claim

The invention claimed is:

1. A monitoring method for determining a remaining life of a bearing, comprising:
during operation of the bearing, determining:
a position where a defect of the bearing is located; and
a size of the defect;

according to the position where the defect is located and a set condition, determining:
a failure mode of the bearing;
an expansion rate of the defect in the failure mode; and
a failure value of the defect in the failure mode, the failure value being a maximum value that the defect can reach when the bearing fails; and

based on the size, the expansion rate and the failure value of the defect, calculating a remaining life of the bearing.

2. The monitoring method according to claim 1 , wherein determining the position where the defect of the bearing is located comprises:
acquiring a vibration signal of the bearing, the vibration signal comprising:
a vibration frequency of the bearing; and
a vibration amplitude of the bearing; and

performing a frequency domain analysis on the vibration signal to determine the position where the defect is located.

3. The monitoring method according to claim 1 , wherein determining the position where the defect of the bearing is located comprises:
acquiring an acoustic emission signal of the bearing, the acoustic emission signal comprising:
a frequency of an acoustic wave generated by the bearing; and
an amplitude of the acoustic wave generated by the bearing; and

performing a frequency domain analysis on the acoustic emission signal to determine the position where the defect is located.

4. The monitoring method according to claim 1 , wherein determining the size of the defect comprises:
determining a relative rotational speed of a rolling element of the bearing with respect to an inner race of the bearing or an outer race of the bearing;
determining a time required for the rolling element to go through the defect; and
calculating the size of the defect according to the relative rotational speed and the time.

5. The monitoring method according to claim 4 , wherein determining the time required for the rolling element to go through the defect comprises:
acquiring a vibration signal of the bearing, the vibration signal comprising:
a vibration frequency of the bearing and an amplitude of the bearing; and

performing a time domain analysis on the vibration signal to determine a time required for the rolling element to go through the defect, the time being an interval between a moment at which the rolling element reaches the defect and a moment at which the rolling element leaves the defect.

6. The monitoring method according to claim 4 , wherein determining the time required for the rolling element to go through the defect comprises:
acquiring an acoustic emission signal of the bearing, the acoustic emission signal comprising:
a frequency of an acoustic wave generated by the bearing; and
an amplitude of the acoustic wave generated by the bearing; and

performing a time domain analysis on the acoustic emission signal to determine the time required for the rolling element to go through the defect, the time being an interval between a moment at which the rolling element reaches the defect and a moment at which the rolling element leaves the defect.

7. The monitoring method according to claim 1 , further comprising, before determining the position where the defect of the bearing is located, and before determining the size of the defect:
determining whether the bearing has the defect by:
detecting a value of an operating parameter of the bearing, the operating parameter of the bearing comprising one or more of a temperature of the bearing, a vibration frequency of the bearing, an amplitude of the bearing, and a rotational speed of the bearing;
acquiring the value of the operating parameter of the bearing during an operation of the bearing;
acquiring a criterion value of the operating parameter;
diagnosing whether the value of the operating parameter is abnormal by:
comparing the value of the operating parameter and the criterion value of the operating parameter to obtain a difference; and
when the difference exceeds a set range, determining that the operating parameter is abnormal; and

determining that the bearing has a defect when one or more of the values of the operating parameters are abnormal.

8. The monitoring method according to claim 7 , further comprising:
when the bearing has no defect,
determining a load of the bearing, and
calculating the remaining life of the bearing according to the load and a dynamic load rating of the bearing.

9. The monitoring method according to claim 8 , wherein determining the load of the bearing comprises:
determining an equivalent load on the bearing during the operation; and
using the equivalent load as the load.

10. The monitoring method according to claim 8 , wherein determining the load of the bearing comprises:
determining a real-time load on the bearing during the operation; and
using the real-time load as the load.

11. A monitoring apparatus for determining a remaining life of a bearing, comprising:
a defect determining unit configured to, during an operation of the bearing, determine:
a position where a defect of the bearing is located; and
determine a size of the defect;

a failure determining unit configured to, according to the position where the defect is located and a set condition, determine:
a failure mode of the bearing;
an expansion rate of the defect in the failure mode; and
a failure value of the defect in the failure mode, the failure value being a maximum value that the defect can reach when the bearing fails; and

a first calculation unit configured to obtain the remaining life of the bearing based on:
the size of the defect determined by the defect determining unit;
the expansion rate of the defect in the failure mode determined by the failure determining unit; and
the failure value determined by the failure determining unit.

12. The monitoring apparatus according to claim 11 , wherein the defect determining unit comprises:
a vibration acquiring module configured to acquire a vibration signal of the bearing, the vibration signal comprising a vibration frequency of the bearing and amplitude of the bearing;
a vibration analysis module configured to perform frequency domain analysis on the vibration signal acquired by the vibration acquiring module to determine the position where the defect is located;
an acoustic wave acquiring module configured to acquire an acoustic emission signal of the bearing, the acoustic emission signal comprising a frequency of an acoustic wave generated by the bearing and amplitude of the acoustic wave generated by the bearing; and,
an acoustic wave analysis module configured to perform a frequency domain analysis on the acoustic emission signal acquired by the acoustic wave acquiring module to determine the position where the defect is located.

13. The monitoring apparatus according to claim 11 , wherein the defect determining unit further comprises:
a rotational speed determining module configured to determine a relative rotational speed of a rolling element of the bearing with respect to an inner race or outer race of the bearing;
a time determining module configured to determine a time required for the rolling element to go through the defect; and
a calculation module configured to calculate the size of the defect based on the relative rotational speed determined by the rotational speed determining module and the time determined by the time determining module.

14. The monitoring apparatus accord

Assignees

• Schaeffler Technologies Ag

Inventors

• Guo Lei
• Bu Gefei

Classifications

• G01M13/04 Primary

  Bearings · CPC title

• G01N2291/2696

  Wheels, Gears, Bearings · CPC title

• G01M13/045 Primary

  Acoustic or vibration analysis · CPC title

• F16C19/527

  related to vibration and noise · CPC title