A valve timing controller is provided with a first rotary element
including a first gear part, a second rotary element including a second
gear part, and a third rotary element including a third gear part and a
fourth gear part. The third gear part and the fourth gear part are meshed
respectively with the first gear part and the second gear part. A stopper
is provided so as to extend in the first rotary element in the radial
direction for regulating a relative rotational phase shift angle between
the first rotary element and the second rotary element. An interposing
assembler is provided on the second rotary element for rotatably
interposing the stoppers in an axial direction.