Title:
STEM LOAD EVALUATING DEVICE FOR MOTOR-DRIVEN VALVE
Document Type and Number:
Japanese Patent JP3300386
Kind Code:
B2
Abstract:
PURPOSE: To reduce site works to be made by workmans and decrease risk of their exposure by calculating the thrust load applied to the stem of a motor- driven valve from an output signal of a frequency analyzing means, and furnishing a thrust calculating means to evaluate the valve operating condition on the basis of slip frequency and slip current signal in normal operation.
CONSTITUTION: The current in a motor 2 while a motor-driven valve 1 is in operation is measured by a current sensing means 12, and the current signal obtained is pased through a filter means 14 to extract only the current signal of slip frequency. This signal is converted into digital signal by an A/O converting means 15 to serve for frequency analysis with a frequency analyzing means 16 and also undergoing a comparison made by a thrust calculating means 17 with the data in normal operation of the valve 1 set and recorded previously, and thereupon the thrust load applied to the stem of the valve 1 is calculated and the valve operating condition evaluated. Then the outputs of the thrust calculating means 17 and frequency analyzing means 16 are displayed on a display means 18.
Inventors:
Chikako Iwaki
Fukuzo Shimizu
Fukuzo Shimizu
Application Number:
JP17264291A
Publication Date:
July 08, 2002
Filing Date:
July 12, 1991
Export Citation:
Assignee:
Toshiba Corporation
International Classes:
F16K31/04; F16K37/00; (IPC1-7): F16K37/00
Domestic Patent References:
| JP2307033A | ||||
| JP1311885A | ||||
| JP1105084A | ||||
| JP1190295A | ||||
| JP6455488A | ||||
| JP61167828A | ||||
| JP646547A | ||||
| JP63181837U | ||||
| JP316547B2 | ||||
| JP591052B1 |
Attorney, Agent or Firm:
Yoshiaki Inomata