| 摘要 |
PURPOSE:To increase a speed to the required number of rotation by suppressing vibration when the high vibration occurs, by coupling rubber tires on bush metals, which support a rotary shaft from the outside, applying hydraulic fluid to the tires, and changing the constant of a spring. CONSTITUTION:The lower side of a rotary shaft 2 is supported by bush metals 19 and 20, and the upper side thereof is supported by ball bearings 21 and 22. Rubber tires 24 and 25 are coupled to the bush metals 19 and 20 from the outside, and hydraulic oil can be supplied to the tires. At the time of overspeed test, oil is supplied to various friction parts from an oil feeding path 17. The vibration of the shaft 2 is suppressed by the damping function of the oil. When the required number of rotation is high, however, high vibration sometimes occurs. At this time, hydraulic oil is supplied to the tires 24 and 25, in order to increase the internal pressure and also to increase the spring constant of the metals 19 and 20, and the vibration of the shaft 2 is suppressed to low amplitude. Thus the required number of rotation is achieved, and the specified strength test can be performed. |
