Positive displacement piston pump, for lubication

Abstract

A positive displacement pump whose structure allows to increase the pressure of the lubricant taken from the oil sump, wherein the free level surface of the lubricant could even be located far away from the rotating members of the machine. This applies specifically to reciprocating, air compressors, which generally have an oil sump arranged very distant from the drive shaft used to transmit the motion needed for the actuation of the pump. The pump is based on a crank mechanism (7, 7′, 7″; 13; 13′) that sucks the lubricant and delivers it under pressure, in a target-oriented manner, to the components which require lubrication.

1 - 9 . (canceled) 
   
   
       10 . A positive displacement piston pump, for performing a target-oriented lubrication, comprising a crank mechanism ( 7 ;  13 ), which for its motion takes directly advantage of the motion of a drive shaft ( 13 ) to suck and compress a lubricant, characterized in that it comprises: a cylinder body ( 1 ) pivoted to an oil sump and receiving a sliding piston ( 2 ); a check valve ( 3 ); a suction duct ( 4 ) located in the lower part of said cylinder body ( 1 ), a link rod ( 5 ) interconnecting said piston ( 2 ) and said cylinder body ( 1 ); a crank ( 7 ) rigidly and eccentrically coupled with said drive shaft ( 13 ). 
   
   
       11 . A positive displacement piston pump according to  claim 10 , characterized in that only the suction duct ( 4 ) is at least partially located below the free upper surface level of lubricant introduced inside the oil sump. 
   
   
       12 . A positive displacement piston pump according to  claim 10 , characterized in that it includes a pressure-relief valve. 
   
   
       13 . A positive displacement piston pump according to  claim 11 , characterized in that it includes a pressure-relief valve. 
   
   
       14 . A positive displacement piston pump according to  claim 10 , characterized in that the check valve ( 3 ) has a spring ( 11 ) whose preloading is adjustable by means of a regulation plug ( 6 ) located inside the piston ( 2 ). 
   
   
       15 . A positive displacement piston pump according to  claim 11 , characterized in that the check valve ( 3 ) has s spring ( 11 ) whose preloading is adjustable by means of a regulation plug ( 6 ) located inside the piston ( 2 ). 
   
   
       16 . A positive displacement piston pump, for performing a target-oriented lubrication, comprising a crank mechanism ( 7 ′,  7 ″;  13 ′), which for its motion takes directly advantage of the motion of a drive shaft ( 13 ′) to suck and compress a lubricant, characterized in that the lower part of the pump forms a cylinder body ( 1 ′;  1 ″) which is substantially totally immersed in the lubricant and which is pivotally connected ( 15 ′;  15 ″) to an oil sump, a piston ( 2 ′;  2 ″) sliding inside said cylinder body ( 1 ′;  1 ″) and performing a reciprocating motion originated by said crank mechanism ( 7 ′  7 ″;  13 ′), and said cylinder body ( 1 ′;  1 ″) being internally provided with a check valve ( 3 ′;  3 ″) and with a connection to a delivery tube ( 4 ′;  4 ″) of the lubricant. 
   
   
       17 . A positive displacement piston pump according to  claim 16 , characterized in that a pressure-relief valve ( 8 ′;  8 ″) is also provided inside said cylinder body ( 1 ′;  1 ″). 
   
   
       18 . A positive displacement piston pump according to  claim 16 , characterized in that said delivery tube ( 4 ′) for supplying the lubricant is flexible. 
   
   
       19 . A positive displacement piston pump according to  claim 17 , characterized in that said delivery tube ( 4 ′) for supplying the lubricant is flexible. 
   
   
       20 . A positive displacement piston pump according to  claim 16 , characterized in that said delivery tube ( 4 ″) for supplying the lubricant is rigid and slides inside an element ( 14 ″) which is connected with said crank ( 7 ″) of said crank mechanism. 
   
   
       21 . A positive displacement piston pump according to  claim 17 , characterized in that said delivery tube ( 4 ″) for supplying the lubricant is rigid and slides inside an element ( 14 ″) which is connected with said crank ( 7 ″) of said crank mechanism.