Vibratory system for a compactor

Abstract

A vibratory system for a compactor is provided. The vibratory system has a first eccentric, a second eccentric, and a drive shaft. The second eccentric is rotatably and coaxially positioned with respect to the first eccentric. The drive shaft is rotatably coupled to the second eccentric and rotatably coupled to the first eccentric through a helical spline.

1 . A vibratory system for a compactor, comprising:
 a first eccentric;   a second eccentric rotatably and coaxially positioned with respect to the first eccentric; and   a key shaft rotatably coupled to the second eccentric and rotatably coupled to the first eccentric.   
     
     
         2 . The vibratory system of  claim 1 , wherein the key shaft comprises
 an axial spline portion;   a helical spline portion, and   wherein the first eccentric is rotatably coupled to the first eccentric through the helical spline portion.   
     
     
         3 . The vibratory system of  claim 2 , further comprising:
 an actuator having an extension and a retraction stroke and coupled to the key shaft, and   wherein the second eccentric rotates in a first angular direction with respect to the first eccentric on the extension stroke and rotates in a second angular direction opposite the first angular direction with respect to the first eccentric on the retraction stroke.   
     
     
         4 . The vibratory system of  claim 3 , further comprising:
 an adapter coupling the actuator to the key shaft, the adapter including at least one bearing.   
     
     
         5 . The vibratory system of  claim 2 , wherein the second eccentric is positioned within the first eccentric. 
     
     
         6 . The vibratory system of  claim 5 , wherein the axial portion of the key shaft slides within the second eccentric. 
     
     
         7 . The vibratory system of  claim 5 , further comprising:
 an actuator having an extension and a retraction stroke and coupled to the key shaft, and   wherein the second eccentric rotates in a first angular direction with respect to the first eccentric on the extension stroke and rotates in a second angular direction opposite the first angular direction with respect to the first eccentric on the retraction stroke,   wherein the first and the second eccentric each have a radial alignment hole, and the axes of the radial alignment holes align when the first eccentric and the second eccentric are in phase.   
     
     
         8 . The vibratory system of  claim 5 , further comprising:
 an actuator having an extension and a retraction stroke and coupled to the key shaft, and   wherein the second eccentric rotates in a first angular direction with respect to the first eccentric on the extension stroke and rotates in a second angular direction opposite the first angular direction with respect to the first eccentric on the retraction stroke,   wherein the first and the second eccentric each have a radial alignment hole, and the axes of the radial alignment holes align when the first eccentric and the second eccentric are 180 degrees out of phase.   
     
     
         9 . The vibratory system of  claim 2 , wherein the first eccentric has a helical bore and further comprising:
 a helical screw positioned in the helical bore and coupled to the key shaft, the helical spline positioned on the helical screw.   
     
     
         10 . The vibratory system of  claim 2 , further comprising:
 a motor coupled to the first eccentric and configured to rotate the first eccentric about an axis.   
     
     
         11 . The vibratory system of  claim 2 , further comprising:
 a motor coupled to the second eccentric and configured to rotate the second eccentric about an axis.   
     
     
         12 . A compactor, comprising:
 a drum having a drum axis; and   a vibratory system rotatably positioned within the drum about the drum axis and having:
 a first eccentric; 
 a second eccentric rotatably and coaxially positioned with respect to the first eccentric; and 
 a key shaft rotatably coupled to the second eccentric and rotatably coupled to the first eccentric through a helical spline. 
   
     
     
         13 . The compactor of  claim 12 , wherein the key shaft comprises
 an axial spline portion;   a helical spline portion; and   wherein the first eccentric is rotatably coupled to the first eccentric through the helical spline portion.   
     
     
         14 . The compactor of  claim 13 , wherein the vibratory system further includes:
 an actuator having an extension and a retraction stroke and coupled to the key shaft, and   wherein the second eccentric rotates in a first angular direction with respect to the first eccentric on the extension stroke and the second eccentric rotates in a second angular direction opposite the first angular direction with respect to the first eccentric on the retraction stroke.   
     
     
         15 . The compactor of  claim 12 , wherein the vibratory system further includes:
 an adapter coupling the actuator to the key shaft, the adapter including at least one bearing.   
     
     
         16 . The compactor of  claim 12 , wherein the second eccentric is positioned within the first eccentric. 
     
     
         17 . The compactor of  claim 16 , wherein the axial portion of the key shaft slides within the second eccentric. 
     
     
         18 . The compactor of  claim 16 , wherein the vibratory system further includes:
 an actuator having an extension and a retraction stroke and coupled to the key shaft, and   wherein the second eccentric rotates in a first angular direction with respect to the first eccentric on the extension stroke and rotates in a second angular direction opposite the first angular direction with respect to the first eccentric on the retraction stroke, and   wherein the first and the second eccentric each have a radial alignment hole, and the axes of the radial alignment holes align when the first eccentric and the second eccentric are in phase.   
     
     
         19 . The compactor of  claim 16 , wherein the vibratory system further includes:
 an actuator having an extension and a retraction stroke and coupled to the key shaft, and   wherein the second eccentric rotates in a first angular direction with respect to the first eccentric on the extension stroke and rotates in a second angular direction opposite the first angular direction with respect to the first eccentric on the retraction stroke, and   wherein the first and the second eccentric each have a radial alignment hole, and the axes of the radial alignment holes align when the first eccentric and the second eccentric are 180 degrees out of phase.   
     
     
         20 . The compactor of  claim 13 , wherein the first eccentric has a helical bore and the vibratory system further includes:
 a helical screw positioned in the helical bore and coupled to the key shaft, the helical spline positioned on the helical screw.   
     
     
         21 . The compactor of  claim 13 , wherein the vibratory system further includes:
 a motor coupled to the first eccentric and configured to rotate the first eccentric about the drum axis.   
     
     
         22 . The compactor of  claim 13 , wherein the vibratory system further includes:
 a motor coupled to the second eccentric and configured to rotate the second eccentric about the drum axis.   
     
     
         23 . A method for providing a vibratory system for a compactor, comprising:
 providing a first eccentric, a second eccentric, and a key shaft;   rotatably and coaxially positioning the second eccentric with respect to the first eccentric;   rotatably coupling the key shaft to the second eccentric; and   rotatably coupling the key shaft to the first eccentric.   
     
     
         24 . The method of  claim 23 , wherein the key shaft comprises
 an axial spline portion;   a helical spline portion; and   
       wherein the step of rotatably coupling the key shaft to the first eccentric is done through the helical spline portion. 
     
     
         25 . The method of  claim 23 , further comprising:
 coupling a motor to the first eccentric, the motor configured to rotate the first eccentric about an axis; and   coupling an actuator to the key shaft, the actuator having an extension and a retraction stroke, wherein the second eccentric rotates in a first angular direction with respect to the first eccentric on the extension stroke and rotates in a second angular direction opposite the first angular direction with respect to the first eccentric on the retraction stroke.   
     
     
         26 . The method of  claim 23 , further comprising:
 coupling a motor to the second eccentric, the motor configured to rotate the second eccentric about an axis; and   coupling an actuator to the key shaft, the actuator having an extension and a retraction stroke, wherein the second eccentric rotates in a first angular direction with respect to the first eccentric on the extension stroke and rotates in a second angular direction opposite the first angular direction with respect to the first eccentric on the retraction stroke.