Abstract: An apparatus that functions as a linear bearing for supporting a reciprocating structure that reciprocates along a linear path includes a first body including a pinion gear with a first diameter and a first number of teeth for engagement with a second number of teeth that is twice the first number and on an interior ring gear of a second body. The interior ring gear is disposed within an interior cavity. The first body also includes a support member connected to the pinion gear with a crank, the support member being aligned with a point at the periphery of the pinion gear so that it will, upon rotation of the pinion gear while engaged with the ring gear, cyclically reciprocate along a linear path. The apparatus can be used to support reciprocating structures such as, for example, a reciprocating conveyor.