Variable vibratory mechanism

Abstract

A vibratory mechanism includes a motor, and a clutch having first and second output shafts. The first and second output shafts are connected with first and second eccentric weights. The clutch is operative to engage and disengage the inner and outer drive shafts from each other to change a phase difference between the first and second eccentric weights.

What is claimed is:  
     
         1 . A vibratory mechanism, comprising: 
 a motor;    a clutch having first and second output shafts, said clutch being connected to said motor;    a first eccentric weight connected to the first output shaft of said clutch;    a second eccentric weight connected to the second output shaft of said clutch; and    wherein said clutch is operative to engage and disengage said first and second output shafts from each other to change a phase difference between said first and second eccentric weights.    
     
     
         2 . The vibratory mechanism of  claim 1 , wherein said clutch includes a hydraulic piston for engaging and disengaging said inner and outer output shafts of said clutch.  
     
     
         3 . The vibratory mechanism of  claim 1 , including an inner drive shaft connected between said first output shaft and said first eccentric weight and an outer drive shaft connected between said outer drive shaft and said second eccentric weight.  
     
     
         4 . The vibratory mechanism of  claim 1 , further including a controller for controlling said clutch based on detected operating conditions.  
     
     
         5 . The vibratory mechanism of  claim 4 , further including a rotation sensing device for detecting a position of each of said first and second eccentric weights.  
     
     
         6 . The vibratory mechanism of  claim 4 , wherein the detected operating conditions correspond to the position detected by said rotation sensing device.  
     
     
         7 . The vibratory mechanism of  claim 4 , wherein the detected operating conditions correspond to conditions detected by an accelerometer.  
     
     
         8 . The vibratory mechanism of  claim 4 , including means for detection compaction of a material being compacted by the vibratory mechanism.  
     
     
         9 . The vibratory mechanism of  claim 4 , wherein said controller is operative to be controlled by manual operation of at least three positions of vibration amplitude settings  
     
     
         10 . A work machine, comprising: 
 a compacting drum supporting said work machine; and    a vibratory mechanism as set for in  claim 1 .    
     
     
         11 . A method for adjusting amplitude of a vibratory mechanism, the vibratory mechanism including first and second eccentric weights, a motor for driving the first and second eccentric weights, and a clutch connected to the motor and having first and second output shafts connected to the first and second eccentric weights, respectively, comprising: 
 activating the clutch to change a phase difference between the first and second eccentric weights in order to change the vibration amplitude.    
     
     
         12 . The method according to  claim 11 , wherein said activating step includes disengaging a one of the first and second output shafts from another one of the first and second output shafts so that the one of the first and second output shafts slips relative to the other one of the first and second output shafts, thereby changing the phase difference of the first and second eccentric weights.  
     
     
         13 . The method according to  claim 12 , wherein said disengaging step includes momentarily actuating a hydraulic piston for disengaging the one of the first and second output shafts from the other one of the first and second output shafts.  
     
     
         14 . A method for adjusting amplitude of a vibratory mechanism as it makes a plurality of passes over a compactable material, the vibratory mechanism including first and second eccentric weights, a motor for driving the first and second eccentric weights, and a clutch connected to the motor and having first and second output shafts connected to the first and second eccentric weights, respectively, comprising: 
 monitoring a speed and position of the output shafts via a computer controller;    engaging or disengaging the clutch to cause the first and second eccentric weights to be 180° out of phase; and    engaging or disengaging the clutch to increase the vibration amplitude to a desired level after a desired RPM is reached.    
     
     
         15 . The method according to  claim 14 , further comprising: 
 monitoring the vibration speed and amplitude via the controller; and    controlling the clutch to decrease the vibration amplitude to substantially zero at the end of each pass.