Patent ID: 11971042
Assignee: EDWARDS JAPAN LIMITED
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  G | IPC F  G

Claim 3:
4. A control device for a vacuum pump having a rotor blade which is provided in a vacuum pump main body and at least two sensors disposed in the vacuum pump main body and configured to measure physical quantities related to the rotor blade, the control device comprising:
a physical quantity extraction means for extracting the physical quantities which are measured during an operation of the vacuum pump;
a time acquisition means for acquiring total time of each of a plurality of stages when the physical quantity belongs to the stage during the operation of the vacuum pump and total time of all of the stages,
wherein each stage comprises a range of current value as measured by the current amount measurement means, and
wherein the total time of each stage comprises the total time for which the current value is within the range of current values associated with each stage;

a storage means for storing the total time of each stage and the total time of all of the stages which are acquired by the time acquisition means; and
wherein the control device is configured to determine a ratio of the total time of each stage to the total time of all of the stages, wherein a first sensor of the at least two sensors is a temperature measurement means for measuring a temperature of the rotor blade and a second sensor of the at least two sensors is a current amount measurement means for measuring a current amount of a current flowing through a motor which drives the rotor blade, and
wherein the control device is configured to determine timing of replacement of the rotor blade based on the total time of each stage or the ratio of the total time of each stage to the total time of all of the stages.