Abstract: Drive assemblies with two novel aspects are disclosed. According to one aspect, the drive assembly is an eccentric drive assembly which is comprised of a crankshaft with eccentric journals, a split bearing and a split housing to encircle and clamp on to the bearing. The housing is joined to a connecting rod with translates the rotation of the crankshaft into a reciprocating motion. The split character permits the bearing and housing to be opened for inspection and, if necessary, removed for repair or replacement by access through a direction transverse to the crankshaft, so that these functions can be performed without disturbing the crankshaft itself or any other units positioned on it. According to the second aspect, the housing and bearing are constructed in a manner which permits variation of the housing position along the direction of the crankshaft axis with a clamping capability at any selected position.