Condition monitoring

Patent metadata

Field	Value
Publication number	US-11054338-B2
Application number	US-201916375960-A
Country	US
Kind code	B2
Filing date	Apr 5, 2019
Priority date	Apr 10, 2018
Publication date	Jul 6, 2021
Grant date	Jul 6, 2021

Abstract

Condition monitoring a cage to detect cage damage by detecting if a conducting material applied to a cage is unbroken or broken. The basic principle of the invention is to integrate a completely passive LC circuit, having the conductive material, on the cage. The LC circuit is magnetically activated and it is externally detectable when conducting material is unbroken or broken. The conducting material of the passive LC circuit is easily broken or worn, being weaker than the cage material. The cage material is non-metallic, such as a polymer material or other suitable synthetic materials.

First claim

What is claimed is:

1. A method of condition monitoring a bearing cage by determining if the cage has a positive or negative status, the cage having a cage body with pockets for rolling elements, the method comprising the following steps: providing the cage with a Wiegand wire, providing the cage with an electrical loop comprising a pulse coil, a capacitor, and a conducting track, magnetizing and triggering a Wiegand wire by subjecting the Wiegand wire to two magnetic fields of opposite polarity, creating voltage pulses in the pulse coil, measuring and determining if there is an emission of electromagnetic radiation emitted by an LC resonant circuit created by the electrical loop, determining if the electrical loop is intact or broken, providing a positive status of the cage if it is determined that the electrical loop is intact, and providing a negative status of the cage if it is determined that the loop is broken.

2. The method of condition monitoring according to claim 1 , wherein the cage body is made from a nonmetallic material.

3. The method of condition monitoring according to claim 1 , further comprising the step of at least in part embedding the conducting track in the cage body and/or at least in part onto the cage body.

4. The method of condition monitoring according to claim 1 , further comprising the step of at least in part embedding the conducting track under surfaces subjected to wear.

5. The method of condition monitoring according to claim 4 , wherein the step of at least in part embedding the conducting track under surfaces subjected to wear further comprises embedding the conducting track to a depth that is equal to a depth bordering on an acceptable wear.

6. A bearing cage arranged for condition monitoring of the bearing cage, comprising: a cage body with a plurality of pockets for rolling elements of a bearing, wherein the cage further comprises: a Wiegand wire, a pulse coil arranged such that it generates a voltage pulse when the magnetic field of the Wiegand wire changes, an electrical loop comprising the pulse coil, a capacitor and a conducting track, the electrical loop is arranged to create an LC resonant circuit with the pulse coil and the conducting track creating providing the inductance, L, and the capacitor the capacitance, C.

7. The bearing cage according to claim 6 , wherein the cage body is made from a nonmetallic material.

8. The bearing cage according to claim 6 , wherein the conducting track is at least in part embedded in the cage body and/or the conducting track is at least in part placed on the cage body.

9. The bearing cage to claim 8 , wherein the conducting track is at least in part embedded under surfaces of the cage subjected to wear to a depth that is equal to a depth bordering on an acceptable wear level.

10. A condition monitoring device arranged to monitor the condition of a bearing cage by determining if the cage has a positive or negative status, wherein the device comprises a bearing cage according to claim 6 , wherein the device further comprises: a processing unit, a reception coil connected to the processing unit, the reception coil being arranged in proximity to the cage when in use, two permanent magnets arranged such that when the device is in use and the cage rotates the Wiegand wire is alternatively subjected to a negative magnetic field and a positive magnetic field, and the processing unit determines that the cage has a positive status as long as it also determines that the reception coil captures electromagnetic radiation emitted by the LC resonant circuit when the cage is rotating, and the processing unit determines that the cage has a negative status as long as it also determines that the reception coil does not capture electromagnetic radiation emitted by the LC resonant circuit when the cage is rotating.

Assignees

• Skf Ab

Inventors

• Lang Defeng
• Mol Hendrik Anne
• Tatar Florin

Classifications

• F16C2233/00

  Monitoring condition, e.g. temperature, load, vibration · CPC title

• G01R27/2611

  Measuring inductance · CPC title

• F16C19/525

  related to temperature and heat, e.g. insulation · CPC title

• F16C33/46 Primary

  Cages for rollers or needles · CPC title

• F16C33/38

  Ball cages · CPC title