Vacuum pump with back-up bearing contact sensor

Patent metadata

Field	Value
Publication number	US-9822788-B2
Application number	US-201314438148-A
Country	US
Kind code	B2
Filing date	Oct 14, 2013
Priority date	Oct 30, 2012
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

The present invention relates to a vacuum pump comprising a vacuum pumping mechanism comprising a rotor supported for rotation by a drive shaft, a first bearing assembly for controlling movement of the rotor during rotation of the drive shaft, a back-up bearing assembly for limiting said movement and a sensor for sensing when said movement is limited by the back-up bearing assembly.

First claim

The invention claimed is:

1. A vacuum pump comprising a vacuum pumping mechanism comprising a rotor supported for rotation by a drive shaft, a first bearing assembly for controlling movement of the rotor during rotation of the drive shaft, a back-up bearing assembly for limiting said movement and a sensor for sensing when said movement is limited by the back-up bearing assembly wherein the sensor is arranged to output a signal to a counter for counting the number of events when the back-up bearing assembly has limited said movement.

2. The vacuum pump as claimed in claim 1 , wherein movement of the drive shaft is generally in the radial direction relative to the axis of the drive shaft.

3. The vacuum pump as claimed in claim 1 , wherein the back-up bearing assembly is arranged to limit said movement by contact with the rotor or the drive shaft, and the sensor is arranged to sense each contact event between the back-up bearing assembly and the rotor or the drive shaft.

4. The vacuum pump as claimed in claim 1 , wherein the first bearing assembly is a non-contact bearing assembly which controls said movement without contacting the rotor or the drive shaft.

5. The vacuum pump as claimed in claim 4 , wherein the first bearing assembly is a magnetic bearing assembly.

6. The vacuum pump as claimed in claim 1 , wherein the first bearing assembly is spaced from the rotor or the drive shaft by a distance which is greater than the distance which the back-up bearing assembly is spaced from the rotor or the drive shaft.

7. The vacuum pump as claimed in claim 1 , wherein the sensor is arranged to sense a force imparted to the rotor or drive shaft sufficient to cause the back-up bearing to limit said movement resulting from the force.

8. The vacuum pump as claimed in claim 7 , wherein the sensor is an accelerometer.

9. The vacuum pump as claimed in claim 1 , wherein the sensor is fixed relative to a pump housing.

10. The vacuum pump as claimed in claim 1 , comprising an indicator for indicating to a user when the number of events exceeds a predetermined value predictive of a failure of the back-up bearing assembly.

11. The vacuum pump as claimed in claim 10 , wherein the indicator is a display for displaying the number of events.

12. The vacuum pump as claimed in claim 1 , wherein the indicator comprises a transmitter for transmitting the number of events to a remote location by wired or wireless connection.

13. The vacuum pump as claimed in claim 1 , comprising a turbo molecular vacuum pumping mechanism.

14. A vacuum pump comprising a vacuum pumping mechanism comprising a rotor supported for rotation by a drive shaft, a first bearing assembly for controlling movement of the rotor during rotation of the drive shaft, a back-up bearing assembly for limiting said movement and a sensor for sensing when said movement is limited by the back-up bearing assembly wherein the sensor is arranged to output a sensed magnitude of force applied to the vacuum pump and the vacuum pump further aggregates a plurality of sensed magnitudes of force applied to the vacuum pump to form a total magnitude of force applied to the vacuum pump over time.

Assignees

• Edwards Ltd

Inventors

• Bahrami Mohammad Eghtesadi
• Horler Richard Glyn

Classifications

• F04D29/059

  Roller bearings · CPC title

• F16C2360/45

  Turbo-molecular pumps · CPC title

• F04D19/048

  comprising magnetic bearings · CPC title

• F16C19/52

  with devices affected by abnormal or undesired conditions · CPC title

• F04D29/058 Primary

  magnetic; electromagnetic · CPC title