Patent ID: 8267590
Filing Date: 2012-09-18
Classification: F02M,F04B

Abstract:
1. A plunger driving structure comprising: a rotation shaft having a single eccentric part; a roller bearing comprising an outer ring and a plurality of rollers arranged along the track surface of said outer ring, and supporting said single eccentric part, a peripheral edge of the outer ring of the roller bearing supporting the single eccentric part and configured so as not to cover an end of the rollers; a balancer arranged at a position adjacent to said roller bearing at said rotation shaft, a side face of the balancer abutting an end face of at least a portion of the outer ring and limiting movement of the rollers in the axial direction; and a plunger abutting on said outer ring and reciprocated by the rotation of said rotation shaft, wherein the balancer has a shaped configuration wherein a portion of the balancer has a shape not coincident with a shape of the outer ring so that when the balancer is arranged at the position adjacent to the roller bearing and the outer ring does not cover the end of the roller, a portion of one or more of the rollers of the roller bearing is exposed so that lubricant can be supplied in an axial direction to the roller bearing and the balancer with its shape covers all or a portion of the ends of the rollers facing the balancer.