Pump

Abstract

A pump includes a unit case, a volume-changing body, a support portion, a driver and a seal member. The volume-changing body is accommodated in the unit case for defining a pump chamber. The support portion is provided in the unit case. The driver is connected to the volume-changing body and slidably supported by the support portion. The driver is reciprocated to deform the volume-changing body thereby changing a volume of the pump chamber to perform a pumping action. The seal member is provided between the unit case and the driver for preventing lubricant from leaking from a sliding region between the driver and the support portion to the volume-changing body.

1 . A pump comprising: 
 a unit case;    a volume-changing body accommodated in the unit case for defining a pump chamber;    a support portion provided in the unit case;    a driver connected to the volume-changing body, the driver being slidably supported by the support portion, the driver being reciprocated to deform the volume-changing body thereby changing a volume of the pump chamber to perform a pumping action; and    a seal member provided between the unit case and the driver for preventing lubricant from leaking from a sliding region between the driver and the support portion to the volume-changing body.    
   
   
       2 . The pump according to  claim 1 , wherein the seal member has a fixed end and a movable end, the seal member being deformable in such a manner that the movable end is displaced relative to the fixed end, wherein the fixed end is fixed to the unit case, the movable end being fixed to the driver.  
   
   
       3 . The pump according to  claim 2 , wherein the driver includes a piston that is slidably supported by the support portion and a coupling member that connects the piston to the volume-changing body, the movable end of the seal member being held between the piston and the coupling member.  
   
   
       4 . The pump according to  claim 2 , wherein the volume-changing body and the seal member are elastically deformed by the reciprocating movement of the driver, the seal member having elastic coefficient that is smaller than that of the volume-changing body.  
   
   
       5 . The pump according to  claim 4 , wherein the seal member functions to change the volume of the pump chamber after the volume-changing body is broken to malfunction, so that the pump continuously performs the pumping action.  
   
   
       6 . The pump according to  claim 2 , wherein the seal member is in the form of a diaphragm or a bellows.  
   
   
       7 . The pump according to  claim 1 , wherein the support portion is formed in the unit case.  
   
   
       8 . The pump according to  claim 7 , wherein the support portion is a cylinder formed in the unit case.  
   
   
       9 . The pump according to  claim 1 , further comprising a rotary shaft having a protruding portion that protrudes into an accommodation chamber, the driver being fitted on the protruding portion as the support portion.  
   
   
       10 . The pump according to  claim 1 , wherein the seal member is placed adjacent to the volume-changing body.  
   
   
       11 . The pump according to  claim 1 , wherein the volume-changing body is a diaphragm or a bellows.  
   
   
       12 . A pump comprising: 
 a first volume-changing body in the form of a diaphragm or a bellows, the first volume-changing body being deformed thereby performing a pumping action; and    a second volume-changing body in the form of a diaphragm or a bellows, the second volume-changing body placed adjacent to the first volume-changing body, the second volume-changing body being deformed for backup of the pumping action when the first volume-changing body is broken to malfunction, thereby continuously performing the pumping action.