MACHINE AND METHOD FOR MONITORING THE STATE OF A SAFETY BEARING OF A MACHINE

• US 20120126648A1
• Filed: 04/16/2010
• Published: 05/24/2012
• Est. Priority Date: 05/27/2009
• Status: Active Grant

• Current Assignee: Innomotics GmbH
• Original Assignee: Schaeffler Technologies GmbH & Co. KG (INA-Holding Schaeffler GmbH & Co. KG), Siemens AG
• Inventors: Walter, Hartmut, Georgi, Jan
• Granted Patent: US 9,279,735 B2
• Time in Patent Office: Days
• US Class Current: 310/90.5
• CPC Class Codes: F16C 19/18 with two or more rows of balls
• CPC Class Codes: F16C 19/522 related to load on the bearing, e.g. bearings with load sensors or means to protect the bearing against overload
• CPC Class Codes: F16C 19/525 related to temperature and heat, e.g. insulation
• CPC Class Codes: F16C 32/0442 with devices affected by abnormal, undesired or non-standard conditions such as shock-load, power outage, start-up or touchdown
• CPC Class Codes: F16C 32/0444 Details of devices to control the actuation of the electromagnets
• CPC Class Codes: F16C 32/048 with active support of two degrees of freedom, e.g. radial magnetic bearings
• CPC Class Codes: F16C 39/02 using mechanical means
• CPC Class Codes: F16C 41/007 Encoders, e.g. parts with a plurality of alternating magnetic poles
• CPC Class Codes: G01L 5/0009 Force sensors associated with a bearing testing of bearings G01M13/04
• CPC Class Codes: G01M 13/04 Bearings
• CPC Class Codes: H02K 7/09 with magnetic bearings

Abstract

The invention relates to a method for monitoring the state of a safety bearing (14) of a machine (12), wherein the safety bearing (14) catches a rotor shaft (1) of the machine (12) in case of failure of a magnetic bearing (6) of the machine (12), wherein the safety bearing (14) has an outer ring (3) and an inner ring (2) that is arranged rotatably in relation to the outer ring (3), wherein the magnetic bearing (6) is switched off, wherein the rotor shaft (1) is rotationally moved with a defined course of movement, wherein a physical variable (G) of the safety bearing (14) is measured by means of a sensor (5). The invention further relates to a corresponding machine. The invention allows for monitoring the state of a safety bearing (14) installed in a machine (12).

Claims

1-15. -15. (canceled)

16. A method for monitoring a state of a safety bearing of a machine, the safety bearing having an outer ring and an inner ring arranged for rotation with respect to the outer ring, the method comprising the steps of:

catching a rotor shaft of the machine with the safety bearing when a magnetic bearing of the machine fails,

switching the magnetic bearing off,

rotating the rotor shaft with a defined motion sequence, and

measuring a physical variable of the safety bearing with a sensor.

17. The method of claim 16, further comprising the steps of:

comparing the measured physical variable or a variable derived from the measured physical variable with a target variable, and

generating a warning message, if a deviation of the physical variable or the derived variable exceeds a threshold value.

18. The method of claim 16, wherein the safety bearing is attached in the machine with a safety bearing carrier arranged around the outer ring, and wherein the sensor is arranged on a side of the outer ring facing the safety bearing carrier.

19. The method of claim 16, wherein the physical variable comprises a variable selected from the group consisting of a temperature of the safety bearing, a force between the outer ring and the safety bearing carrier, oscillations of the safety bearing, and a pressure between outer ring and the safety bearing carrier.

20. The method of claim 16, wherein the sensor is arranged between the outer ring and the safety bearing carrier.

21. The method of claim 16, wherein the sensor has a flat configuration and is embedded in or arranged on a film.

22. The method of claim 18, wherein at least a part of the sensor is arranged in a recess disposed on the side of the outer ring facing the safety bearing carrier.

23. The method of claim 16, wherein the physical variable is a distance between the outer ring and the inner ring.

24. The method of claim 23, wherein at least part of the sensor is arranged inside the inner ring.

25. The method of claim 16, wherein roller bearings are arranged between the outer ring and inner ring, or wherein the inner ring slides directly in the outer ring.

26. The method of claim 16, wherein the physical variable is transmitted via a data link to a computer arranged remote from the machine.

27. The method of claim 16, wherein the machine is embodied as an electric motor, a generator, a compressor, or a turbine.

28. The method of claim 27, wherein the machine is embodied as a wind power generator.

29. A machine, comprising

a rotor shaft,

a magnetic bearing supporting the rotor shaft and configured to be switched off,

a safety bearing comprising an outer ring and an inner ring arranged for rotation relative to the outer ring, the safety bearing constructed to catch the rotor shaft when the magnetic bearing fails, wherein when the magnetic bearing is switched off, the rotor shaft is rotated with a defined motion sequence, and

a sensor measuring a physical variable of the safety bearing.

30. The machine of claim 29, wherein the measured physical variable or a variable derived from the measured physical variable is compared with a target variable, and a warning message is generated, if a deviation of the physical variable or the derived variable exceeds a threshold value.