Pump

Abstract

A double action rotary pump forcibly delivers fluid such as liquid or gas. A transmission unit operates at uniform or non-uniform angular speeds using driving force transmitted from a motor via a power transmission system. An operating unit is provided in series with the transmission unit. A piston of the operating unit has a pair of heads, which rotate at non-uniform angular speeds in a counteracting fashion while maintaining the distance between shafts, and divides the spaces inside cylinders. The volumes of the divided spaces of the cylinders are repeatedly and alternately contracted and expanded in response to the rotation of the piston, so that the cylinders counteractively and continuously perform intake and exhaust operations, thereby forcibly delivering fluid. The structure of the power transmission system is improved such that the sum of flow rates that are pumped by the piston at a predetermined time point stays uniform.

1 . A pump comprising:
 a transmission unit including a pair of crank-type first and second shafts, which operates at uniform or non-uniform angular speeds using driving force that is transmitted from a motor via a power transmission system, which includes a combination of concentric and eccentric gears;   an operating unit provided in series with the transmission unit, wherein the operating unit comprises:
 an intake port and an exhaust port on both sides thereof; 
 first and second cylinders in upper and lower portions thereof, wherein the first and second cylinders are divided from each other, and are connected to each other via a through-hole; 
 a piston including a pair of heads, each of which is provided in a corresponding one of the first and second cylinders using a corresponding one of the first and second shafts such that the each head is eccentric from a center of the corresponding cylinder, the heads rotating at the non-uniform angular speeds in a counteracting fashion while maintaining a distance between the shafts, and a connector, which extends through the through-hole and connects the heads to each other; and 
 wherein volumes of spaces inside the cylinders, which are divided by the piston, are repeatedly and alternately contracted and expanded in response to a rotation of the piston, so that the cylinders counteractively and continuously perform intake and exhaust operations, thereby forcibly delivering fluid; 
   a main drive shaft provided between the first and second shafts, wherein the main drive shaft is associated with each of the first and second shafts, and comprises a distribution stage, which supplies the driving force introduced from the motor to the first and second shafts by distributing the driving force;   a first input stage provided on the first shaft, the first input stage being associated with the distribution stage of the main drive shaft, and receiving the distributed driving force;   a second input stage provided on the second shaft, the second input stage being associated with the distribution stage of the main drive shaft, and receiving the distributed driving force; and   a delivery stage interposed between the distribution stage of the main drive shaft and the first stage on the first shaft or between the distribution stage of the main drive shaft and the second stage on the second shaft in order to cause the first and second shafts to operate in opposite directions,   wherein the driving force introduced to the main drive shaft is distributed by the distribution stage and supplied by the delivery stage, so that the first and second shafts operate at the non-uniform angular speeds so as to counteract each other.   
     
     
         2 . The pump of  claim 1 , wherein the distribution stage comprises an eccentric gear, which is associated with the second input stage of the second shaft and the delivery stage, and distributes the driving force. 
     
     
         3 . The pump of  claim 1 , wherein the distribution stage comprises a first transmission element associated with the second input stage of the second shaft and a second transmission element associated with the first input sage of the first shaft. 
     
     
         4 . The pump of  claim 1 , wherein the distribution stage comprises a first transmission element associated with the second input stage of the second shaft and a second transmission element to and from which the driving force from the second input stage is input and output. 
     
     
         5 . The pump of  claim 4 , wherein the second transmission element comprises an input section, a delivery section and an output section. 
     
     
         6 . The pump of  claim 1 , wherein the delivery stage comprises an input section, which is provided on an idle shaft between the main drive shaft and the first shaft so as to be associated with the distribution stage of the main drive shaft, and an output section, which is associated with the first input stage of the first shaft. 
     
     
         7 . The pump of  claim 1 , wherein the delivery stage comprises a chain, which directly connects between the distribution stage of the main drive shaft and the first input stage of the first shaft. 
     
     
         8 . The pump of  claim 1 , wherein the delivery stage comprises an idle gear provided on an idle shaft between the main drive shaft and the first shaft, the idle gear being associated with the delivery section of the second transmission element of the distribution stage of the main drive shaft and the first input stage of the first shaft. 
     
     
         9 . The pump of  claim 5 , wherein the delivery stage comprises an idle gear provided on an idle shaft between the main drive shaft and the first shaft, the idle gear being associated with the delivery section of the second transmission element of the distribution stage of the main drive shaft and the first input stage of the first shaft. 
     
     
         10 . The pump of  claim 1 , wherein the power transmission system comprises:
 a worm having one end, which is fixed by a support piece such that the driving force from an output shaft of the motor, and the other end, which is a free end; and   worm gears engaged with both sides of the worm such that the worm is disposed in a middle between the worm gears, the worm gears being eccentrically provided on the first and second shafts, respectively,   wherein the worm moves like a pendulum between the eccentric worm gears while supplying the driving force from the motor to the worm gears by distributing the driving force.   
     
     
         11 . The pump of  claim 10 , further comprising a flexible delivery element interposed between the output shaft of the motor and the worm, the delivery element transmitting the driving force of the motor toward the worm.