Patent ID: 8678783

Claim:
A solution sending pump comprising: a pump head including a pump chamber and a solution inlet and outlet for drawing and discharging a solution into and out of the pump chamber; a plunger having a tip end inserted into the pump chamber and for sliding in the pump chamber; a driving portion including a motor for driving the plunger and a driving transmitting portion for converting rotary movement of the motor into reciprocating movement in a certain direction to transmit the movement to the plunger; and a retaining member made of heat-conductive material and for retaining the driving portion, wherein the motor is fixed to the retaining member with a clearance between a main body portion of the motor and the retaining member, the motor main body portion and the retaining member are fixed to each other by a well nut and a screw, the clearance is defined by a thickness of a flange portion of the well nut, and a heat-conductive elastic member is inserted into the clearance, wherein the motor and the driving portion are coupled indirectly to each other, and wherein a face of the motor main body portion facing the retaining member is planar and square, the motor main body portion and the retaining member are fixed to each other at four corner portions of the square, and the elastic member comprises a plurality of pieces and each piece is inserted adjacent to and along a respective side of the square, the elastic member being sandwiched between the planar and square face of the motor main body portion and the retaining member.