Interconnecting rotary and reciprocating motion

An apparatus for converting reciprocating motion to rotary motion and vice-versa, comprising a reciprocatory assembly guided for reciprocation in a first direction and comprising first and second reciprocating members respectively terminating in first and second planar guide surfaces which extend transverse to the direction of reciprocation, and spacing tie means interconnecting the two reciprocatory members at opposite ends of the guide surfaces to maintain the guide surfaces parallel, spaced apart and facing each other, a drive block having opposed guide faces each slidably engaged with a respective one of the guide surfaces of the reciprocatory members, a rotary member mounted for rotation about an axis transverse to said direction of reciprocation and having an eccentric portion rotatably engaged in a plain bearing in the drive block, and a lubrication system for supplying lubricant under pressure through the rotary member to a plurality of outlet portions defined in a surface of the eccentric portion, the drive block having a respective passage leading to the respective guide face from a respective window in the plain bearing and positioned to communicate with the outlet ports of the eccentric portion as the latter rotates in said bearing, wherein each said window in the bearing lies within a quadrant of the plain bearing, two said quadrants each containing a said window being on opposite sides of the axis of the bearing, and the outlet ports in the eccentric portion all lie in a sector thereof smaller than the angular extent of an unported portion of the bearing which separates the windows as connected to different said guide faces of the drive block.