Bearing monitoring apparatus and method for monitoring bearing

Patent metadata

Field	Value
Publication number	US-11867227-B2
Application number	US-202017596755-A
Country	US
Kind code	B2
Filing date	Jun 11, 2020
Priority date	Jun 21, 2019
Publication date	Jan 9, 2024
Grant date	Jan 9, 2024

Abstract

A bearing monitoring apparatus includes a rolling bearing, multiple rolling elements, a strain gauge configured to detect strain of the outer ring or the inner ring, the strain gauge including at least two resistors, and the resistors being arranged in a same direction as an arrangement direction of the rolling elements so as to correspond to spacing between rolling elements that are next to each other. The bearing monitoring apparatus includes a first circuit configured to generate a first distorted waveform based on an output of one resistor and to generate a second distorted waveform based on an output of another resistor. The bearing monitoring apparatus includes a second circuit configured to subtract the second distorted waveform from the first distorted waveform to generate a differential waveform. The second circuit is configured to compare the differential waveform against a reference value to detect a wear state of the rolling bearing.

First claim

The invention claimed is:

1. A bearing monitoring apparatus comprising:
a rolling bearing including
an outer ring,
an inner ring disposed coaxially with the outer ring, the inner ring being on an inner peripheral side of the outer ring,
multiple rolling elements disposed between the outer ring and the inner ring, and
a strain gauge configured to detect strain of the outer ring or the inner ring, the strain gauge including at least two resistors, and the resistors being arranged in a same direction as an arrangement direction of the rolling elements so as to correspond to spacing between rolling elements that are next to each other;

a first circuit configured to generate a first distorted waveform based on an output of one resistor of the at least two resistors and to generate a second distorted waveform based on an output of another resistor of the at least two resistors; and
a second circuit configured to:
subtract the second distorted waveform from the first distorted waveform to generate a differential waveform; and
compare the differential waveform against a reference value to detect a wear state of the rolling bearing.

2. The bearing monitoring apparatus according to claim 1 , wherein the at least two resistors in the rolling bearing are disposed on an outer peripheral surface of the outer ring or an inner peripheral surface of the inner ring.

3. The bearing monitoring apparatus according to claim 2 , wherein the at least two resistors in the rolling bearing are disposed on a side opposite a preload.

4. The bearing monitoring apparatus according to claim 1 , wherein the at least two resistors in the rolling bearing are disposed on an end surface of the outer ring or an end surface of the inner ring.

5. The bearing monitoring apparatus according to claim 1 , wherein the rolling bearing includes a housing disposed in contact with the outer periphery of the outer ring, and
wherein the at least two resistors are disposed on an outer peripheral surface of the housing.

6. The bearing monitoring apparatus according to claim 1 , wherein the rolling bearing includes a housing disposed in contact with the outer periphery of the outer ring, and
wherein the at least two resistors are disposed on an end surface of the housing.

7. The bearing monitoring apparatus according to claim 1 , wherein the at least two resistors in the rolling bearing are arranged such that a longitudinal direction of each resistor is directed in a circumferential direction of the outer ring or the inner ring.

8. The bearing monitoring apparatus according to claim 1 , wherein each of the at least two resistors in the rolling bearing is formed of a Cr composite film.

9. A method for monitoring a bearing, the method comprising:
generating a first distorted waveform based on an output of one resistor of at least two resistors in a rolling bearing, and generating a second distorted waveform based on an output of another resistor of the at least two resistors, the rolling bearing including
an outer ring;
an inner ring disposed coaxially with the outer ring, the inner ring being on an inner peripheral side of the outer ring,
multiple rolling elements disposed between the outer ring and the inner ring, and
a strain gauge configured to detect strain of the outer ring or the inner ring, the strain gauge including the at least two resistors, and the resistors being arranged in a same direction as an arrangement direction of the rolling elements so as to correspond to spacing between rolling elements that are next to each other;

subtracting the second distorted waveform from the first distorted waveform to generate a differential waveform; and
comparing the differential waveform against a reference value to detect a wear state of the rolling bearing.

Assignees

• Minebea Mitsumi Inc

Inventors

• Fujiura Hideo
• Hirai Yukinori
• Takata Shintaro

Classifications

• F16C19/06 Primary

  with a single row or balls · CPC title

• F16C19/522

  related to load on the bearing, e.g. bearings with load sensors or means to protect the bearing against overload · CPC title

• F16C33/586

  outside the space between the races, e.g. end faces or bore of inner ring · CPC title

• F16C35/073

  between shaft and inner race ring · CPC title

• F16C35/077

  between housing and outer race ring · CPC title