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EP-4741674-A1 - BEARING RACE INCLUDING INTEGRATED PIEZOELECTRIC SENSOR

EP4741674A1EP 4741674 A1EP4741674 A1EP 4741674A1EP-4741674-A1

Abstract

A bearing race for a rolling element bearing (130) is described. The bearing race includes a metal region having an outer surface and an inner surface. The race has a groove in at least one of the outer surface and the inner surface. The groove extends around at least part of a circumference the outer surface or the inner surface. A piezoelectric layer (110) and a resistive layer (112) are located in the groove.

Inventors

  • Grießbach, Jan
  • MAROTZKE, ADRIAN

Assignees

  • NXP B.V.

Dates

Publication Date
20260513
Application Date
20241112

Claims (15)

  1. A bearing race for a rolling element bearing, the bearing race comprising: a metal region having an outer surface and an inner surface and further comprising a groove in at least one of the outer surface and the inner surface, the groove extending around at least part of a circumference of the at least one of the outer surface and the inner surface; and a piezoelectric layer and a resistive layer in the groove.
  2. The bearing race of claim 1, wherein the groove extends around at least half of the circumference of at least one of the outer surface and the inner surface.
  3. The bearing race of any preceding claim, wherein the groove extends around the circumference of at least one of the outer surface and the inner surface.
  4. The bearing race of any preceding claim, wherein the groove extends substantially in a direction of rotation of the bearing race.
  5. A rolling element bearing comprising an inner race and an outer race, wherein at least one of the inner race and the outer race comprises the bearing race of any preceding claim.
  6. The rolling element bearing of claim 5, wherein the outer race comprises the bearing race and wherein the groove is in the outer surface of the metal region.
  7. The rolling element bearing of claim 5 or claim 6, wherein the inner race comprises the bearing race and wherein the groove is in the inner surface of the metal region.
  8. The rolling element bearing of any of claims 5 to 7 configured as a ball bearing.
  9. The rolling element bearing of any of claims 5 to 7 configured as a roller bearing.
  10. An electric motor comprising the rolling element bearing of claim 8.
  11. A sensor system comprising a controller coupled to the rolling element bearing of any of claims 5 to 9, the controller having a first terminal coupled to a first contact point on the resistive layer and a second terminal coupled to a second contact point on the resistive layer, wherein the controller is configured to measure a resistance value between the first contact point and the second contact point and to determine a manufacturing fault condition depending on the resistance value.
  12. A sensor system comprising a controller coupled to the rolling element bearing of any of claims 5 to 9, the controller having a first terminal coupled to a first contact point on the resistive layer and a second terminal coupled to a second contact point on the metal region, wherein the controller is configured to measure a piezoelectric voltage between the first point and the second point and to determine at least one of a fault condition and a vibration level of the ball bearing depending on a piezoelectric voltage value.
  13. A sensor system comprising a controller coupled to the rolling element bearing of any of claims 5 to 9, the controller comprising a plurality of terminals connected to a plurality of contact points on the resistance layer and a further terminal connected to a contact point on the metal region, wherein the controller is configured to measure a plurality of voltage values between each of the plurality of terminals and the further terminal and to determine at least one of a fault condition and a fault location of the rolling element bearing depending on the plurality of voltage values.
  14. The sensor system of claim 13, wherein the controller is further configured to measure a resistance value between a first point of the plurality of contact points and a second contact point of the plurality of points and to determine a manufacturing fault condition depending on the resistance value.
  15. A method of sensing an operating status of a bearing race for a rolling element bearing, the bearing race comprising: a metal region having an outer surface and an inner surface and further comprising a groove in at least one of the outer surface and the inner surface, the groove extending around at least part of a circumference of the at least one of the outer surface and the inner surface; and a piezoelectric layer and a resistive layer in the groove; the method comprising: measuring a piezo-electric voltage between at least one point on the resistive layer and a point of the metal region.

Description

FIELD This disclosure relates to a bearing race for a rolling element bearing including an integrated piezoelectric sensor. BACKGROUND Rolling element bearings which may be either ball bearings or roller bearings are used in a wide variety of applications such as motors, vehicles, industrial machinery, centrifuges, engines, and aircraft. Rolling element bearings include an inner race and an outer race with either bearing balls or rollers between. The bearing balls and rollers may be retained in position by a cage structure. Detecting faults and anomalies in such bearings is a critical part for example in preventing damage to electric motors and monitoring wear in critical components. External sensors, such as vibration sensors, can provide an indication of anomalies but may not give an accurate indication of the condition of the bearing. SUMMARY Aspects of the disclosure are defined in the accompanying claims. In a first aspect, there is provided. A bearing race for a rolling element bearing, the bearing race comprising: a metal region having an outer surface and an inner surface and further comprising a groove in at least one of the outer surface and the inner surface, the groove extending around at least part of a circumference of the at least one of the outer surface and the inner surface; and a piezoelectric layer and a resistive layer in the groove. In some embodiments, the groove extends around at least half of the circumference of at least one of the outer surface and the inner surface. In some embodiments, the groove extends around the circumference of at least one of the outer surface and the inner surface. In some embodiment, the groove extends substantially in a direction of rotation of the bearing race. Embodiments of the bearing race may be included in a rolling element bearing comprising an inner race and an outer race, wherein at least one of the inner race and the outer race comprises the bearing race. In some embodiments, the outer race comprises the bearing race and wherein the groove is in the outer surface of the metal region. In some embodiments, the inner race comprises the bearing race and wherein the groove is in the inner surface of the metal region. In some embodiments, the rolling element bearing is configured as a ball bearing. In some embodiments, the rolling element bearing is configured as a roller bearing. Embodiments of the rolling element bearing may be included in an electric motor. Embodiments of the rolling element bearing may be included in a sensor system comprising a controller coupled to the rolling element bearing, the controller having a first terminal coupled to a first contact point on the resistive layer and a second terminal coupled to a second contact point on the resistive layer, wherein the controller is configured to measure a resistance value between the first contact point and the second contact point and to determine a manufacturing fault condition depending on the resistance value. Embodiments of the rolling element bearing may be included in a sensor system comprising a controller coupled to the rolling element bearing, the controller having a first terminal coupled to a first contact point on the resistive layer and a second terminal coupled to a second contact point on the metal region, wherein the controller is configured to measure a piezoelectric voltage between the first point and the second point and to determine at least one of a fault condition and a vibration level of the ball bearing depending on a piezoelectric voltage value. Embodiments of the rolling element bearing may be included in a sensor system comprising a controller coupled to the rolling element bearing, the controller comprising a plurality of terminals connected to a plurality of contact points on the resistance layer and a further terminal connected to a contact point on the metal region, wherein the controller is configured to measure a plurality of voltage values between each of the plurality of terminals and the further terminal and to determine at least one of a fault condition and a fault location of the rolling element bearing depending on the plurality of voltage values. In some embodiments, the controller is further configured to measure a resistance value between a first point of the plurality of contact points and a second contact point of the plurality of points and to determine a manufacturing fault condition depending on the resistance value. In a second aspect, there is provided a method of detecting a manufacturing fault in a bearing race for a rolling element bearing, the bearing race comprising: a metal region having an outer surface and an inner surface and further comprising a groove in at least one of the outer surface and the inner surface, the groove extending around at least part of a circumference of the at least one of the outer surface and the inner surface; and a piezoelectric layer and a resistive layer in the groove; the method comprising: measurin