PURPOSE: To enable measurement of high precision by a method wherein the main shaft supporting a rotary body and rotating unitarily with the rotary body is provided, the fitting part of the rotary body on the main shaft is constituted by an aerostatic bearing and at least a radial bearing out of radial and thrust bearings supporting the main shaft is constituted by the aerostatic bearing.
CONSTITUTION: The main shaft 11 is rotated by a motor 21 through the intermediary of a belt 22, while a rotary body 10 is rotated unitedly with the main shaft 11. When there is any imbalance in the rotary body 10, vibrations are caused in a frame 17 supported by a plate spring 18 by the centrifugal force due to the imbalance, and the vibrations are detected by a pickup, thus the imbalance of the rotary body 10 being measured. The fitting part of the rotary body 10 on the main shaft 11 is constituted by an aerostatic bearing and connected with an air pipe 12. At a rotating joint 14, the air pipe 12 is connected with an air pump. The main shaft 11 is supported in the thrust and radial directions by an aerostatic bearing 15 and also is supported in the radial direction by another aerostatic bearing 16. Thereby, the measurement of imbalance can be performed with high precision.
SUZUKI MASAKI
NAGANO HIROYUKI
HARA YOSHIBUMI
Next Patent: WORK LIFT DEVICE FOR DYNAMIC BALANCE TESTER