Reciprocating pump

Abstract

The present invention is aimed to provide a pump which can not only obtain high discharging pressure and large capacity but obtain a substantially non-pulsating flow with a miniaturized configuration and even if the pump is operated with low power. To achieve the object, a pump of the present invention is characterized in including a pump chamber ( 17 ), an intake passage ( 34 ) for taking liquid into the pump chamber via an intake valve (V 1 ) being opened when liquid is taken into the pump chamber, a discharge passage ( 43 ) for discharging liquid to an outside of the pump chamber via a discharge valve (V 2 ) being opened when liquid is discharged from the pump chamber, a cylinder ( 11 ) in communication with the pump chamber, a plunger ( 12 ) slidably provided within the cylinder and biased toward a bottom dead center side by a spring ( 16 ), and a moving element (P) being brought in contact with the plunger and stroking the plunger upward, wherein the moving element moves upward and downward via a motion conversion means ( 20 a , 20 b , 20 c ) for transforming rotary motion of a rotary shaft ( 21 ) of an electric motor ( 22 ) into upward and downward motion, the plunger in descending motion and moving element are spaced apart.

1 . A pump comprising:
 a pump chamber;   an intake passage for taking liquid into the pump chamber via an intake valve being opened when liquid is taken into the pump chamber;   a discharge passage for discharging liquid to an outside of the pump chamber via a discharge valve being opened when liquid is discharged from the pump chamber;   a cylinder in communication with the pump chamber;   a plunger slidably provided within the cylinder and biased toward a bottom dead center side by a spring; and   a moving element being brought in contact with the plunger and stroking the plunger upward;   wherein the moving element moves upward and downward via a motion conversion means for transforming rotary motion of a rotary shaft of an electric motor into upward and downward motion;   the plunger in descending motion and moving element are spaced apart.   
   
   
       2 . The pump according to  claim 1 , wherein the discharge passage is connected to an elastic resin tube. 
   
   
       3 . The pump according to  claim 1 , wherein the motion conversion means and moving element are an eccentric cam being coupled with the rotary shaft of the electric motor. 
   
   
       4 . The pump according to  claim 1 , wherein the motion conversion means comprises a crank arm of which an end is coupled with the rotary shaft of the electric motor and a connecting rod of which an end is swingably attached to the other end of the crank arm via a crank pin, wherein the moving element is swingably attached to the other end of the connecting rod and is guided to a guide member extending to a vertical direction. 
   
   
       5 . The pump according to  claim 1 , wherein the intake valve and discharge valve are check valves comprising:
 a lower passage and upper passage which are in communication with each other and through which liquid flows;   a valve seat provided at a connecting portion of the lower passage and upper passage;   a valve plug provided within the upper passage; and   a movement restricting means for restricting moving distance of the valve plug;   wherein the valve plug comprises a body supportably provided on the valve seat and an adjusting means for adjusting opening/closing response of the check valves which is provided at a lower side of the body.   
   
   
       6 . The pump according to  claim 2 , wherein the motion conversion means and moving element are an eccentric cam being coupled with the rotary shaft of the electric motor. 
   
   
       7 . The pump according to  claim 2 , wherein the motion conversion means comprises a crank arm of which an end is coupled with the rotary shaft of the electric motor and a connecting rod of which an end is swingably attached to the other end of the crank arm via a crank pin, wherein the moving element is swingably attached to the other end of the connecting rod and is guided to a guide member extending to a vertical direction. 
   
   
       8 . The pump according to  claim 2 , wherein the intake valve and discharge valve are check valves comprising:
 a lower passage and upper passage which are in communication with each other and through which liquid flows;   a valve seat provided at a connecting portion of the lower passage and upper passage;   a valve plug provided within the upper passage; and   a movement restricting means for restricting moving distance of the valve plug;   wherein the valve plug comprises a body supportably provided on the valve seat and an adjusting means for adjusting opening/closing response of the check valves which is provided at a lower side of the body.   
   
   
       9 . The pump according to  claim 3 , wherein the intake valve and discharge valve are check valves comprising:
 a lower passage and upper passage which are in communication with each other and through which liquid flows;   a valve seat provided at a connecting portion of the lower passage and upper passage;   a valve plug provided within the upper passage; and   a movement restricting means for restricting moving distance of the valve plug;   wherein the valve plug comprises a body supportably provided on the valve seat and an adjusting means for adjusting opening/closing response of the check valves which is provided at a lower side of the body.   
   
   
       10 . The pump according to  claim 4 , wherein the intake valve and discharge valve are check valves comprising:
 a lower passage and upper passage which are in communication with each other and through which liquid flows;   a valve seat provided at a connecting portion of the lower passage and upper passage;   a valve plug provided within the upper passage; and   a movement restricting means for restricting moving distance of the valve plug;   wherein the valve plug comprises a body supportably provided on the valve seat and an adjusting means for adjusting opening/closing response of the check valves which is provided at a lower side of the body.