Abstract:
An eccentric assembly for a compaction machine comprises an outer eccentric member that is longitudinally elongated cylinder shaped and has a partial longitudinal opening through the length; an inner eccentric member that is longitudinally elongated cylinder shaped and has a partial longitudinal opening through the length and rotatably connected inside of said outer eccentric member so that the inner eccentric member can rotate with respect to the outer eccentric member around the same axis of rotation.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a national phase entry under 35 U.S.C. §371 of International Application No. PCT/US2014/015527 filed Feb. 10, 2014, published in Korean, the disclosure of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a construction machine, in particular, relates to a simple structured eccentric assembly with enhanced lubrication, for a construction machine. 
     BACKGROUND OF THE INVENTION 
     Construction machines, especially compaction machines, usually include a frame and one or two vibrating drums rotatably mounted to the frame, whereby the drums compact the surfaces as the machine moves thereon. Compacting machines often include a vibration assembly that generates vibrations and transfer these vibrations via the drum to the work surface. These eccentric assemblies are used to provide vibratory impact for compaction and also sometimes for oscillation effects for some types of compaction machines. Usually a vibration assembly for compaction machines has two eccentric weights that are adjustable relative to each other to vary the amplitude of the vibrations that are generated by rotating the eccentric assembly. 
     SUMMARY OF THE INVENTION 
     In order to achieve the aforementioned objectives, the present invention employs the following arrangement. 
     According to one aspect of the present disclosure, the present disclosure provides an eccentric assembly for vibratory compaction comprising: an outer eccentric member that is longitudinally elongated cylinder shaped and has a partial longitudinal opening through the length; and an inner eccentric member that is longitudinally elongated cylinder shaped and has a partial longitudinal opening through the length and rotatably connected inside of said outer eccentric member so that the inner eccentric member can rotate with respect to the outer eccentric member around the same axis of rotation. 
     It is preferable that a pin member that fitted into the bores of the inner eccentric member and outer eccentric member thus rotatably connects said inner eccentric member and said outer eccentric member together. 
     It is also preferable that bushings that are press fitted between the inner eccentric member and said pin member so that the bushings give enough friction to the inner eccentric member to rotate with respect to the outer eccentric member. 
     It is also preferable that a snap ring fitted at the inner eccentric member side end of the pin member so that the pin member does not move away. 
     It is also preferable that thrust washers on the pin member between the inner eccentric member and the outer eccentric member and between said snap ring and said inner eccentric member so that the friction between the elements can be absorbed by the washers. 
     It is also preferable that the outer eccentric member and said inner eccentric member overlaps downward in high amplitude position and said inner eccentric member rotates upward not to overlap much in low amplitude position. 
     It is also preferable that bearings connected to the outer ends the outer eccentric member at the same axis of rotation with the outer eccentric member and the inner eccentric member. 
     It is also preferable that the bearings are directly connected to the outer ends of the outer eccentric member without journals so that oil flows easily into the rolling part of the bearings without interference of the journals. 
     It is also preferable that the inner surface of the outer eccentric member works as a stopper so an additional stopper for the inner eccentric member is not needed. 
     It is also preferable that at least one protruded stopper for the inner eccentric member at the inner surface of the outer eccentric member so that wear to the outer eccentric member is minimized. 
     According to another aspect of the present disclosure, the present disclosure discloses an eccentric assembly for a compaction machine comprising: an outer eccentric member that is longitudinally elongated cylinder shaped and has a partial longitudinal opening through the length; an inner eccentric member that is longitudinally elongated cylinder shaped and has a partial longitudinal opening through the length and rotatably connected inside of said outer eccentric member so that the inner eccentric member can rotate with respect to the outer eccentric member around the same axis of rotation; and bearings connected to the outer ends the outer eccentric member at the same axis of rotation with the outer eccentric member and the inner eccentric member. 
     It is preferable that the bearings are directly connected to the outer ends of the outer eccentric member without journals so that oil flows easily into the rolling part of the bearings without interference of the journals. 
     It is also preferable that a pin member that fitted into the bores of the inner eccentric member and outer eccentric member thus rotatably connects said inner eccentric member and said outer eccentric member together. 
     It is also preferable that bushings that are press fitted between the inner eccentric member and said pin member so that the bushings give enough friction to the inner eccentric member to rotate with respect to the outer eccentric member. 
     It is also preferable that a snap ring fitted at the inner eccentric member side end of the pin member so that the pin member does not move away. 
     It is also preferable that thrust washers on the pin member between the inner eccentric member and the outer eccentric member and between said snap ring and said inner eccentric member so that the friction between the elements can be absorbed by the washers. 
     It is also preferable that the outer eccentric member and said inner eccentric member overlaps downward in high amplitude position and said inner eccentric member rotates upward not to overlap much in low amplitude position. 
     It is also preferable that the inner surface of the outer eccentric member works as a stopper so an additional stopper for the inner eccentric member is not needed. 
     It is also preferable that at least one protruded stopper for the inner eccentric member at the inner surface of the outer eccentric member so that wear to the outer eccentric member is minimized. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a perspective view of a compactor machine according to prior arts. 
         FIG. 2  illustrates a perspective view of an eccentric assembly according to prior arts. 
         FIG. 3  shows a cross-sectional view of the eccentric assembly according to  FIG. 2 . 
         FIG. 4  shows a perspective view of the eccentric assembly according to the present disclosure, when it is in high amplitude. 
         FIG. 5  shows a perspective view of the eccentric assembly according to the present disclosure, when it is in low amplitude. 
         FIG. 6  shows a cross-sectional view of locking state of the eccentric assembly according to the present disclosure. 
         FIG. 7  shows a side view of the eccentric assembly according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While this invention is illustrated and described in a preferred embodiment, the device may be produced in many different configurations, forms and materials. There is depicted in the drawings, and will hereinafter be described in detail, a preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and the associated functional specifications for its construction and is not intended to limit the invention to the embodiment illustrated. Those skilled in the art will envision many other possible variations within the scope of the present invention. 
     Referring to  FIGS. 1-3 , the present disclosure describes an eccentric assembly according to prior arts. 
     Compacting machines usually have at least one roller or drum  12  and drum frames  16 ,  18  to control and move the vehicle along with the drums  12 . There is an operator&#39;s platform  14  for the operator on top of the vehicle. A compacting machine  10  usually has at least one vibratory eccentric assembly in a drum  12  which used to compact the grounds. These eccentric assembly  100  is usually have an outer eccentric member  104 , inner eccentric member  102 , a mechanical stopper  106 , journals  108  coupling the outer eccentric member  104  and the inner eccentric member  102  together at the end of the outer eccentric member  104 , and a bearing  110  at the outer ends of the journals  108 . 
     The outer eccentric member  104  is a rigid cylinder having added thickness around the lower part of it. The added thickness works as a mass so it can have eccentric mass that is lighter at one part and heavier at the other part. The shape of the added thickness can be varied but in this prior art, it is a half cylinder located partially on the lower part of the outer eccentric member  104 . At the upper part of the outer eccentric member  104 , there is a stopper  106  to mechanically stop the rotation of the inner eccentric member  102 . In the prior art, the stopper  106  is quarter arc shaped bar protruded toward inside of the outer eccentric member  104  with a small thickness so that it can prevent the movement of the inner eccentric member  102 . However, the weight of the stopper  106  is not substantial enough to prevent the outer eccentric member  104  from working as eccentric member since the additional mass of the outer eccentric member  104  is much larger than that of the stopper  106 . 
     The inner eccentric member  102  is rotatably connected to the axis of the rotation. In this prior art, it is almost a half cylinder shaped with slighter protrusion on each end sides so that the inner eccentric member  102  can be securely fastened to the axis of rotation.  FIG. 3  shows how the inner eccentric member  102  can rotate and stopped by the stopper  106 . When the inner eccentric member  102  rotates to the bottom, the mass of the inner eccentric member  102  can be added to the eccentric mass of the outer eccentric member  104  at the bottom. Thus, the drums  12  of the compaction machine can provide high amplitude vibration to the work surface. When the inner eccentric member  102  rotates upward as shown in  FIG. 3 , the mass of the eccentric assembly  100  is dispersed. Thus, the drums  12  of the compaction machine will provide low amplitude vibration to the work surface. 
     The end of the outer eccentric member  104  and the inner eccentric member  102 , there are journals  108  that can seal and support the eccentric members  102 ,  104 . The journals  108  would also connect the inner eccentric member  102  to bearings  110  so that the friction would be handled by the bearings  110 . However, as shown in  FIG. 2 , the presence of the journals  108  would limit | [HS1]  lubrication oil mist or splash from reach well to the balls of the bearings  110 . Bearings  110  can be ball bearings or any type of bearings that can facilitate rotation and minimize friction. 
     Referring to  FIGS. 4 and 5 , the eccentric assembly according to the present disclosure is explained, when it is in high amplitude and low amplitude. 
     The eccentric assembly  2  according to the present disclosure has much simpler structure than that of the prior arts explained above. The outer eccentric member  200  shaped as an open cylinder which has approximately half circle as its cross section, although it does not have to be a half circle but a cylinder having some open space so that the inner eccentric member  202  can be located into and rotate in it. The outer eccentric member  200  has its protrusion parts  200   a  at each end of it. The protrusion parts  200   a  can be fastened with the bearings  206  so that the inner eccentric member  204  can rotate with respect to the outer eccentric member  200 . Detailed structure of fastening will be explained later when referring to  FIG. 5 . 
     The inner eccentric member  202  is shaped as approximately quarter-arced open cylinder which can be rotatably fastened inside the outer eccentric member  200 .  FIG. 4  shows the outer eccentric member  200  and the inner eccentric member  202  overlaps downward so that they can give high amplitude vibration to the drum. As previously stated, the shape or the arc size of the outer and inner eccentric members  200 ,  202  can be varying according to the design or specification of a drum or a compactor machine. As shown in  FIG. 5 , the inner eccentric member  202  rotates with respect to the outer eccentric member  200  so that the mass can be more evenly distributed. In this case, it gives low amplitude vibration to the drum thus impact to the work surface is minimized. 
       FIG. 6  shows a cross-sectional view of locking state of the eccentric assembly according to the present disclosure. A pin member  204  press fitted into the bore of the inner eccentric member  202  and extended through the bore of the outer eccentric member  200 . The pin member  204  has a stepped end so that it can be fastened to the stepped part of the bore of the outer eccentric  200  and would not moving backward toward the inner eccentric member  202 . Also, the pin member  204  is connected to a shaft, which located in the bore  200   b  and extended outside of the bore  200   b , so that it can be rotatably connected to the rotating axis of the bearings  206 . In other words, the inner and outer eccentric members  200 ,  202  are connect together by means of the pin member  204  which is press fitted into the outer eccentric member  200 . Bushings  205  are press fitted between the pin member  204  and the inner eccentric member  202 , which allow the inner eccentric member  202  to rotate with respect to the outer eccentric member  200 . Washers  204   a ,  204   b  are located on the pin member  204  on each sides of the inner eccentric member  202 . A snap ring  204   c  is put on pin member  204  adjacent to washer  204   a  so as to ensure the inner and outer eccentric members  200 ,  202  do not become separated. 
     In referring to  FIG. 7 , the oil flow and improved lubrication effect according to the present disclosure are explained. The improved lubrication effect is a combination of factors. The first of these is that the oil is struck closer to the eccentric bearing  206  than prior art eccentric assemblies the outer eccentric  200  extends closer to the bearings  206  than in the prior art. The open design according to the present disclosure also creates less of an obstruction in front of the bearing  206  which allows for a more direct path of the oil mist to contact the bearing  206 . There is a greater exposed surface area of the bearing  206  which allows for increased lubrication. Thus, the eccentric assembly according to the present disclosure provides simpler construction with higher lubrication efficiency without deteriorating vibration effectiveness. Manufacturing, assembly, or maintenance would be much easier due to the simple structure. 
     The foregoing description of the embodiments of the invention has been presented for the purpose of illustration; it is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Persons skilled in the relevant art can appreciate that many modifications and variations are possible in light of the above teachings. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.