Pump apparatus with improved coupling between the pump and motor

摘要

A pump apparatus includes a plunger, an eccentric cam for moving the plunger toward a pressure chamber, a drive shaft supporting the eccentric cam, and an output shaft of a motor for imparting a rotational force to the drive shaft. A convex portion is formed on one end of one of the drive shaft and the output shaft whereas a concave portion is formed in one end of the other of the two shafts. The convex portion is fitted in the concave portion to interconnect the drive shaft and the output shaft. The convex portion is fitted in the concave portion with a clearance therebetween. A holder member for always holding the convex portion and the concave portion in engagement with each other in the direction of rotation of the drive shaft is provided at an area of fitting between the convex portion and the concave portion. With this arrangement, noises resulting from the impingement of one of the convex portion and the concave portion upon the other during the operation of the pump apparatus are eliminated.