| 摘要 |
A two mass vibratory material handling apparatus has a first mass that includes a vibration exciter of the rotary eccentric weight type and a second mass that includes an object to be vibrated. The two masses are interconnected by resilient elements designed to permit a desired vibration amplification from the vibration exciter to the object to be vibrated. The vibration exciter has a drive with an adjustable drive ratio located between a fixed r.p.m. at full voltage motor drive shaft and a shaft that rotatably supports eccentric weights. Variable pitch pulleys or a set of pulleys having various pitch diameters and provided so that pitch diameters can be selected therefrom for mounting one pulley on each shaft with a drive belt trained about the pulleys and thus, provide a drive ratio enabling the fixed frequency motor to drive the eccentric weights at a selected operating frequency. The resilient elements can be designed to amplify vibration along a predetermined line of attack or to flex in that direction while amplifying vibration perpendicularly thereto or to provide a combination of such vibration amplifications to impart an elliptical motion to the second mass. The apparatus can be manufactured without undue care in maintaining a designed spring rate for the resilient elements or maintaining the designed weight of the two masses since after manufacture and assembly, the apparatus can be fine tuned by weighing the two masses, measuring the amplitude of vibration of the mass including the object to be vibrated at a known frequency, selecting an operating frequency for obtaining a desired vibration stroke, and adjusting the drive ratio to operate at that frequency. |
