Abstract: In order to improve operation efficiency, there is provided a method for assembling two assemblies together through a rotating medium, in which all the processes are automated except for fitting engagement of the spline portions. The method comprises a first manual operational step and a second automatic operational step. The first manual operational step includes a process for connecting a first rotating shaft member of a first assembly and the rotating medium while adjusting phases thereof. The second step includes a process for fitting a plurality of split knock-pins provided on the rotating medium into corresponding fitting holes of a second rotating shaft member of a second assembly, and thereafter spreading the front end of each split knock-pin so as to fix the rotating medium to the second rotating shaft, and assembling the first assembly with the second assembly.

Abstract: When a valve 10 is opened, a locking ball 8 moves upward with respect to a rocker arm 3 and the locking ball is located between the rocker arm 3 and a push rod 5. The push rod 5 moves downward integral with the rocker arm 3 in a condition the push rod 5 is locked. When a valve 10 is closed, the locking ball 8 moves downward with respect to the rocker arm 3 and the push rod 5 is placed in unlocked condition. A retaining member 3A in the rocker arm 3 contacts the circlip 9 and the push rod 5 moves upward. By this construction, it becomes possible to eliminate adjustment work of tappet clearances and also unfavorable conditions caused by adjustment work of tappet clearances.