Abstract: A belt tensioner comprises a shaft which is eccentrically mounted on a stud bolt so as to be rotatable thereon when a lock nut is loosened. A pulley is concentrically mounted on the shaft by means of a bearing and rotatable thereon. The shaft is urged by a spring in the direction to cause the pulley to move toward a drive belt. The shaft is fixed to a stationary member when the lock nut is tightened.

Abstract: A plate spring is formed to have a "spider-like" configuration with pairs of bent "spider leg-like" flexible fingers. The spring is fixed to the top of a rocker arm shaft mounting bracket so that each pair of fingers straddles the rocker arm shaft and biasingly contacts a lateral surface of a rocker arm pivotally mounted on said shaft. The fingers have a length adequate to allow for mass production tolerances while simultaneously biasing the rocker arm uniformly along the rocker arm shaft preventing any unwanted uneven wearing of the shaft or rocker arm. The spring may be replaced simply by removing a single bolt.

Abstract: An internal combustion engine equipped with a blowby gas recirculation system is provided with a jackshaft which is driven by a crankshaft and rotatably supported in a crankcase to operate engine accessories. A rotational part of a centrifugal oil separator is securely connected to an end of the jackshaft to be rotatable with the jackshaft, thereby effectively separating engine oil mist from blowby gas which is sucked through the oil separator to an intake manifold.