METHOD FOR PREDICTING A FAILURE IN THE ROTATION OF THE ROTOR OF A VACUUM PUMP AND ASSOCIATED PUMPING DEVICE

• US 20120209569A1
• Filed: 06/24/2010
• Published: 08/16/2012
• Est. Priority Date: 06/26/2009
• Status: Active Grant

• Current Assignee: Pfeiffer Vacuum
• Original Assignee: Adixen Vacuum Products
• Inventors: Becourt, Nicolas, Martin, Florent, Pariset, Cecile, Galichet, Sylvie, Meger, Nicolas
• Granted Patent: US 9,534,609 B2
• Time in Patent Office: Days
• US Class Current: 702/183
• CPC Class Codes: F04B 51/00 Testing machines, pumps, or pumping installations
• CPC Class Codes: F04C 2220/10 Vacuum
• CPC Class Codes: F04C 2270/07 Electric current
• CPC Class Codes: F04C 2270/12 Vibration
• CPC Class Codes: F04C 2270/80 Diagnostics
• CPC Class Codes: F04D 19/04 specially adapted to the production of a high vacuum, e.g. molecular pumps
• CPC Class Codes: F04D 27/001 Testing thereof; Determination or simulation of flow characteristics; Stall or surge detection, e.g. condition monitoring
• CPC Class Codes: F05D 2260/607 Preventing clogging or obstruction of flow paths by dirt, dust, or foreign particles
• CPC Class Codes: G01H 1/003 of rotating machines G01H1/10 takes precedence
• CPC Class Codes: G01H 1/14 Frequency
• CPC Class Codes: G05B 23/0245 based on a qualitative model, e.g. rule based; if-then decisions
• CPC Class Codes: G05B 23/0283 Predictive maintenance, e.g. involving the monitoring of a system and, based on the monitoring results, taking decisions on the maintenance schedule of the monitored system; Estimating remaining useful life [RUL] preventive maintenance, i.e. planning maintenance according to the available resources without monitoring the system G06Q10/06

Abstract

The invention pertains to a method for predicting a failure in the rotation of the rotor of a vacuum pump, comprising the following steps:

• • sequences of events related to the change over time of the vacuum pump functional signals are recorded (101),
  • a match is sought between at least one sequence of events and at least one pre-established association rule precursory pattern of a vacuum pump behavior model within the recorded sequences of events, said pre-established association rule'"'"'s precursory patterns involving a failure in the rotor rotation (102), and
  • a time prediction window is deduced during which a failure in the rotor rotation will occur in a vacuum pump (103).

The invention also pertains to a pumping device comprising:

• • a vacuum pump (7) comprising at least one rotor and one pump body, said rotor having the potential to be driven rotationally within said pump body by a motor of said pump (7),
  • a functional signal sensor (9) of said pump (7), and
  • a means of predicting (10) a time prediction window during which a failure in the rotor rotation will occur in the vacuum pump (7), said means for prediction (10) calculating the predictive time window based on measurements provided by said functional signal sensor (9).

Claims

1-10. -10. (canceled)

11. A method for predicting a failure in the rotation of the rotor of a vacuum pump, comprising the following steps:

recording sequences of events related to the change over time of the vacuum pump functional signals (101),

seeking a match between at least one sequence of events and at least one precursory pattern of pre-established association rule of a vacuum pump behavior model within the recorded sequences of events, said association rules being established by extracting knowledge with the restriction of one or more extraction parameters and said precursory patterns of pre-established association rule involving a failure in the rotor rotation (102), and

deducing a time prediction window during which a failure in the rotor rotation will occur in a vacuum pump (103).

12. A prediction method according to claim 11, wherein sequences of events related to the change over time of vibration signals in the pump body of the vacuum pump are recorded (101).

13. A prediction method according to claim 11, wherein sequences of events related to the change over time of the vacuum pump motor current signals are recorded. (101).

14. A prediction method according to claim 11, wherein the functional signals may be transformed into a frequency spectrum, and frequency bands may be selected around the frequencies characteristic of the vacuum pump kinematics within said spectrum.

15. A prediction method according to claim 11, wherein association rules are established describing the vacuum pump behavior model by extracting knowledge from a learning database comprising a plurality of sequences of events, obtained from a set of vacuum pumps over the vacuum pumps life span running from startup to failure of the rotor rotation.

16. A prediction method according to claim 15, wherein said association rules are extracted with the restriction of one or more extraction parameters chosen from among:

the support, confidence, and maximum duration between each event of the association rule.

17. A prediction method according to claim 15, wherein one or more association rules are extracted from N−

1 sequences of events from the learning database, recorded from N vacuum pumps, and said association rules are verified against the sequence of events which was not used for extraction.

18. A prediction method according to claim 14, wherein from said learning database, a sequence of events is determined, on the one hand by the selection from among said frequency bands of a reference level and intermediate operating levels corresponding to a multiple of the reference level, and characteristics of the vacuum pump operation, and on the other hand, by a duration characteristic of said levels.

19. A pumping device comprising:

a vacuum pump (7) comprising at least one rotor and one pump body, said rotor having the potential to be driven rotationally within said pump body by a motor of said pump (7),

a functional signal sensor (9) of said pump (7), and

a means of predicting (10) a time prediction window during which a failure in the rotor rotation will occur in the vacuum pump (7), said means for prediction (10) being configured to implement a method for predicting a failure in the rotation of a vacuum pump rotor according to 11 in order to calculate the predictive time window based on measurements provided by said functional signal sensor (9).

20. A pumping device according to claim 19, wherein said functional signal sensor (9) is a vibration sensor fixed onto a bearing of said pump body.