Condition monitoring system

Patent metadata

Field	Value
Publication number	US-11320446-B2
Application number	US-201916423350-A
Country	US
Kind code	B2
Filing date	May 28, 2019
Priority date	Jun 22, 2018
Publication date	May 3, 2022
Grant date	May 3, 2022

Abstract

A condition monitoring system for monitoring a rolling element bearing. The system includes a signal processing unit and a vibration energy harvester. The vibration energy harvester provides an electromagnetic transducer. When vibrated, a coil moves relative to a static electromagnetic field to create power. To create a compact and efficient condition monitoring system, it uses the electromagnetic transducer also as a vibration sensor, a velocity sensor. The signal processing unit determines if the bearing has been damaged and in some embodiments also the extent of the damage. The electromagnetic transducer is attached directly or indirectly to the rolling element bearing.

First claim

What is claimed is:

1. A condition monitoring system of a rolling element bearing, the system comprising:
an energy harvester comprising an electromagnetic transducer, where the electromagnetic transducer transduces vibrations subjected to it, over a frequency bandwidth of 100 Hz or more, to an electrical voltage by means of a coil moving relative to a static electromagnetic field due to vibrations;
a signal processing unit that determines a condition of the rolling element bearing;
the electromagnetic transducer being attached directly or indirectly to the rolling element bearing, wherein
the signal processing unit determines the condition of the rolling element bearing by means of the electrical voltage from the electromagnetic transducer, wherein the signal processing unit determines or calculates a vibration level and a base vibration level the electromagnetic transducer is and has been subjected to by means of the electrical voltage from the electromagnetic transducer.

2. The condition monitoring system according to claim 1 , wherein the system further comprises a GPS to attain speed and location, or the system attains at least one of the group of speed and location from an external device, and in that the signal processing unit determines the base vibration level also in dependence of speed.

3. The condition monitoring system according to claim 1 , wherein the signal processing unit determines that there is damage if the vibration level rises.

4. The condition monitoring system according to claim 3 , wherein if the rolling element bearing is a railway bearing then the signal processing unit determines that:
if there is a first cyclical rise in the vibration level above the base vibration level by at least a first predetermined value up to a second predetermined value then the damage is a bearing damage;
if there is a second cyclical rise in the vibration level above the base vibration level by an amount greater than the second predetermined value up to a third predetermined value then the damage is a wheel flat damage, the second cyclical rise being at least twice the first cyclical rise; and
if there is a third rise in the vibration level above the base vibration level by an amount greater than a third predetermined value then the damage is a track damage.

5. A condition monitoring system of a rolling element bearing, the system comprising:
an energy harvester comprising an electromagnetic transducer, where the electromagnetic transducer transduces vibrations subjected to it, over a frequency bandwidth of 100 Hz or more, to an electrical voltage by means of a coil moving relative to a static electromagnetic field due to vibrations;
a signal processing unit that determines a condition of the rolling element bearing;
the electromagnetic transducer being attached directly or indirectly to the rolling element bearing, wherein
the signal processing unit determines the condition of the rolling element bearing by means of the electrical voltage from the electromagnetic transducer, wherein the signal processing unit or the energy harvester determines or calculates a power level of the electromagnetic transducer by means of the electrical voltage from the electromagnetic transducer, and the signal processing unit or the energy harvester determines a base power level from the electrical voltage from the electromagnetic transducer.

6. The condition monitoring system according to claim 5 , further comprising a GPS to attain speed and location, or the system attains at least one of the group of speed and location from an external device, and in that the signal processing unit determines the base power level in dependence of speed.

7. The condition monitoring system according to claim 5 , wherein the signal processing unit determines that there is a damage if the power level rises.

8. The condition monitoring system according to claim 7 , wherein if the rolling element bearing is a railway bearing then the signal processing unit determines that:
if there is a first cyclical rise in the power level above the base power level by at least a first predetermined value up to a second predetermined value then the damage is a bearing damage;
if there is a second cyclical rise in the power level above the base power level by an amount greater than the second predetermined value up to a third predetermined value then the damage is a wheel flat damage, the second cyclical rise being at least twice the first cyclical rise; and
if there is a third rise in the power level above the base power level by an amount greater than a third predetermined value then the damage is a track damage.

9. A condition monitoring system of a rolling element bearing, the system comprising:
an energy harvester comprising an electromagnetic transducer, where the electromagnetic transducer transduces vibrations subjected to it, over a frequency bandwidth of 100 Hz or more, to an electrical voltage by means of a coil moving relative to a static electromagnetic field due to vibrations;
a signal processing unit that determines a condition of the rolling element bearing;
the electromagnetic transducer being attached directly or indirectly to the rolling element bearing, wherein
the signal processing unit determines the condition of the rolling element bearing by means of the electrical voltage from the electromagnetic transducer, wherein the electromagnetic transducer acts as a velocity sensor thereby enabling the signal processing unit to integrate the electrical voltage of the electromagnetic transducer to get a change in displacement enabling the signal processing unit to determine a size of a damage by determining when a damage starts and when a damage ends.

10. A condition monitoring system of a rolling element bearing, the system comprising:
an energy harvester comprising an electromagnetic transducer, where the electromagnetic transducer transduces vibrations subjected to it, over a frequency bandwidth of 100 Hz or more, to an electrical voltage by means of a coil moving relative to a static electromagnetic field due to vibrations, wherein the electrical voltage represents both the vibrations to which an associated bearing is subject;
a signal processing unit that determines a condition of the rolling element bearing;
the electromagnetic transducer being attached directly to the rolling element bearing, wherein the signal processing unit determines the condition of the rolling element bearing based on the vibrations of the bearing by means of the electrical voltage from the electromagnetic transducer;
wherein the system further comprises a GPS to attain speed and location and the signal processing unit determines a base vibration level also in dependence of speed and location.

11. The condition monitoring system according to claim 10 , wherein the signal processing unit determines that there is damage if the vibration level exceeds a predetermined threshold.

12. The condition monitoring system according to claim 11 , wherein the rolling element bearing is a railway bearing, the signal processing unit determines that:
if there is a cyclical rise in the vibration level by a first predetermined amount above the base vibration level then the damage is a bearing damage;
if there is a cyclical rise in the vibration level above the base vibration level by a second predetermined amount then the damage is a wheel flat damage, the cyclical large rise being at least twice the cyclical moderate rise; and
if there is a rise in the vibration level above the base vibration level which is not cyclical then the damage is a track damage.

Assignees

• Skf Ab

Inventors

• Tatar Florin
• Martinez Victor
• Mol Hendrik Anne
• Qiu Feng

Classifications

• H02K7/08

  Structural association with bearings · CPC title

• B61L2205/04

  Satellite based navigation systems, e.g. global positioning system [GPS] · CPC title

• G01H11/02

  by magnetic means, e.g. reluctance · CPC title

• B61L15/0018

  Communication with or on the vehicle or train · CPC title

• G01M13/045 Primary

  Acoustic or vibration analysis · CPC title