Abstract: A planetary cam phaser for varying the timing of an engine camshaft is provided with oppositely tapered teeth on the planet gear(s) and the mating ring and sun gears and biasing means for urging the mating gears axially into lash free engagement. The tapered teeth may be formed on constant pitch circles or on conical pitch circles of conical gears and the teeth of at least one of a pair of mating gears may be crowned to control loading and wear. The taper angles of the teeth and/or the conical pitch circles of the conical gears are preferably made small enough to avoid gear drive forces from developing gear separation forces greater than restraining friction forces.

Abstract: A valve actuating mechanism for an internal combustion engine is provided including an integrally formed stop element to limit the axial travel of the valves toward the piston to a predetermined maximum extent in the event an adjacent associated valve becomes stuck and unmovable. The present invention further provides a valve actuating mechanism including a guideless valve bridge with specifically configured contact faces which prevents both the excess axial movement of the valve stem and the transfer of undesired loads to the valve stem or adjacent structures.

Abstract: The design and construction of past pushrod retainers has required complex components, sliding relationships and additional assembly time and expense. The present invention overcomes these problems by using a retainer attached to a first end of the rocker arm. Thus, the components are simple to install, imexpensive to manufacture and do not increase assembly time since there is no adjustment necessary when using the device. The present pushrod retainer provides a device which retains the cupped end of the pushrod in a pre-established proximity to the first end of the rocker arm and prevents extensive damage to the engine caused by a large separation between the cupped end of the pushrod and the first end of the rocker arm which allows the pushrod to fall into other components and resulting in malfunction of the engine. The device cradles the cupped end and prevents the pushrod from tipping or falling to one side.