Pump monitoring device, vacuum processing device, and vacuum pump

Abstract

Provided is a pump monitoring device for detecting abnormalities of multiple vacuum pumps connected to the same chamber, the pump monitoring device being configured to estimate occurrence of the abnormality at any of the multiple vacuum pumps based on a comparison result of signals indicating rotation states of pump rotors of the multiple vacuum pumps.

1 . A pump monitoring device for detecting abnormalities of multiple vacuum pumps connected to an identical chamber, comprising:
 a calculation section that calculates a value corresponding to a comparison result of signals indicating rotation states of pump rotors of the multiple vacuum pumps included in the multiple vacuum pumps and that calculates a degree of scatter of a plurality of values each constituted of the value corresponding to the comparison result based on the signals acquired over time; and   a determination section that sets a threshold value based on the degree of scatter and that estimates occurrence of the abnormality at any of the multiple vacuum pumps based on the comparison result.   
     
     
         2 . The pump monitoring device according to  claim 1 , wherein
 each signal indicating the rotation state is a motor current value of a motor configured to rotatably drive the pump rotor, and   based on a difference between the different motor current values of the vacuum pumps, the determination section estimates that the abnormality has been caused at any of the multiple vacuum pumps.   
     
     
         3 . The pump monitoring device according to  claim 1 , wherein
 each pump rotor is magnetically levitated and supported by a magnetic bearing, and   each signal indicating the rotation state is calculated based on a magnetic bearing control amount of the magnetic bearing.   
     
     
         4 . The pump monitoring device according to  claim 1 , further comprising:
 an input section configured to receive, from one or more vacuum processing devices including multiple vacuum pumps configured to perform vacuum pumping for chambers, signals indicating rotation states of the multiple vacuum pumps,   wherein for each vacuum processing device, the determination section estimates that an abnormality has been caused at any of the multiple vacuum pumps.   
     
     
         5 . A vacuum processing device comprising:
 a chamber;   multiple vacuum pumps configured to perform vacuum pumping for the chamber; and   the pump monitoring device according to  claim 1 .   
     
     
         6 . A vacuum pump comprising:
 the pump monitoring device according to  claim 1 ;   a pump rotor to be rotatably driven by a motor; and   an input section configured to receive signals indicating rotation states from other vacuum pumps,   wherein the calculation section in the pump monitoring device compares a signal indicating a rotation state of the pump rotor and the signals input through the input section and indicating the rotation states and calculates the value corresponding to the comparison result; and   the determination section in the pump monitoring device estimates a pump abnormality based on the value corresponding to the comparison result.   
     
     
         7 . The pump monitoring device according to  claim 1 , wherein
 the multiple vacuum pumps include a first vacuum pump and a second vacuum pump; and   the value corresponding to the comparison result corresponds to a difference between the signals respectively representing the rotation states of the pump rotors respectively included in the first vacuum pump and the second vacuum pump.   
     
     
         8 . The pump monitoring device according to  claim 1 , wherein
 the degree of scatter corresponds to a standard deviation of the plurality of values.