Positive displacement hydraulic pumps

Abstract

This invention presents several configuration of a new positive displacement pump with variable geometric volume for hydraulic drive and control system or else, this pump consists of one more pumping groups. When one pumping group is used an external energy storage system is to be utilized. This is not necessary in the case when the pump has two or more pumping groups. A pumping group consists of a cam that pushes one or more followers, which encircle the cam to form enclosed chamber. During the cam rotation the followers rise and fall. During the followers rise, the encircled volume between the cam and the followers expands, and sucks oil. The rising followers push control oil that exists in a control chamber behind them. In a pump with more than one pumping group, e.g. two pumping groups, this control oil is fed to the control chamber of the other pumping group, with followers in opposite phase with respect to those of the first pumping group. The second pumping group followers thus are pushed to fall towards their cam. The falling followers contract the encircled chamber to cause the discharge stroke of the second group. By controlling the control oil volume flowing between the two groups, the stroke of the followers is controlled and hence the pump geometric volume is controlled. The followers can be rigid components which slide relative to each there, or alternatively flexible.

1 . A hydraulic positive displacement pump with a pumping group comprising of a cam completely encircled by followers to form an enclosed chamber 
     
     
         2 . A pumping group according to  claim 1  in which the followers rise and fall during cam rotation.  3  (currently amended) A pumping group according to  claim 1  in which the volume of the enclosed chamber increases and such liquid during the followers rise. 
     
     
         4 . A pumping group according to  claim 1  in which the volume of the enclosed chamber decreases and discharges the liquid to the pump delivery line during the followers fall. 
     
     
         5 . A pumping group according to  claim 1  as on item 1 and with the followers rise by means of the action of the cam. 
     
     
         6 . A pumping group according to  claim 1  with the followers fall by the action of pressurized control fluid, springs, mechanisms, or any combination of these means. 
     
     
         7 . A pump according to  claim 1  further including a plurality of pumping groups. 
     
     
         8 . A pump according to  claim 1  where the pressurized control fluid is provided internally or from out sources. 
     
     
         9 . A pump according to  claim 1  with rigid or flexible followers. 
     
     
         10 . A pump according to  claim 1  with rigid followers distributed around the cam, and each follower slides with respect to the adjacent components. 
     
     
         11 . A pump according to  claim 1  in which buckets could be formed between the adjacent followers and components. 
     
     
         12 . A pump according to  claim 1  in which the buckets may be governed by guides. 
     
     
         13 . A pump according to  claim 1  with the follower sliding motion can be governed by guides. 
     
     
         14 . A pump according to  claim 13  with the guide having cylindrical shape or else. 
     
     
         15 . A pump according to  claim 14  with the guides having lips or else for sealing purposes. 
     
     
         16 . A pump according to  claim 1  wherein the with the flexible followers made of one or more pieces. 
     
     
         17 . A pump according to  claim 1  with each cam has one or more rises per one drive shaft revolution. 
     
     
         18 . A pump according to  claim 1  where the cam push the followers directly or through rollers or pads or else. 
     
     
         19 . A pump according to  claim 1  with rollers may have their own separation bearings. 
     
     
         20 . A pump according to  claim 18  with rollers running over bridges in the separation zones between the followers or followers segments. 
     
     
         21 . A pump according to  claim 1  with the followers of a pumping group while rising during suction sweep control liquid in a control chamber behind the followers. 
     
     
         22 . A pump according to  claim 21  where the swept, pressurized control liquid can be stored under pressure. 
     
     
         23 - 24 . (canceled)