CAPACITY DETECTING DEVICE FOR SWASH PLATE TYPE VARIABLE DISPLACEMENT HYDRAULIC PRESSURE DEVICE

PROBLEM TO BE SOLVED: To prevent wear and seizure by a simple construction to make a high-speed capacity control possible. SOLUTION: At a position which is spaced a distance R apart from the center shaft A of rotation of a swash plate 30 of a swash plate type variable displacement piston pump, and deflected by θ degrees in the reversely tilt-turning direction, a pin member 32 is planted-provided on an end face of the swash plate 30 to form a spherical part 32a on its tip. The nearly central part of one end of a guide rod 41 crossing the axis-line of the pin member 32 at about right angles is pressed against the spherical part 32a by a weak spring 45, and the other end of the guide rod 41 is connected to a core 43 through a connecting rod 42 made of non-magnetic material to build up a differential transformer 44 together with three coil members 44a. Thus, the amount of movement of the pin member 32 is electrically detected through the guide rod 41.