| 摘要 |
<p>PURPOSE:To regularize the motion of a piston in a cylinder, to eliminate the fluctuation of a frictional load and to fix a discharge pressure, by a construction wherein a piston guide made of a low-friction member and a elastic member is provided concentrically with the cylinder and the reciprocating motion of the piston is guided flexibly by said piston guide in an ink feeding pump of an ink jet recording apparatus. CONSTITUTION:A guide element 24 of a pump driving part is provided with a through hole 36b having a stepped part 36a in the center of a lower casing 36, and a cylinder 37 is accommodated in said through hole 36b in the state wherein it is pressed on the stepped part 36a. Then, a ring-shaped piston guide 38 is inserted into a inner peripheral groove 37a opened on the upper side, so that it is concentric with the cylinder 37. The piston guide 38 is constructed of a thin-wall low-friction member 39 and an elastic member 40 which is provided on the outer periphery of the low-friction member 39 and tighten the same. Teflon resin is used, for instance, for the low-friction member 39, while an O ring made of rubber us used, for instance, for the elastic member 40. The reciprocation motion of a piston 28 is guided by the piston guide 38 having flexibility, the motion of the piston 26 in the cylinder 37 is regularized, and thereby the fluctuation of a frictional load is eliminated.</p> |
