Abstract: A variable displacement hydraulic pump or motor includes: a swash plate; a lever supported by a housing and configured to rotate in conjunction of tilting of the swash plate; and a sensor configured to detect a displacement amount of the lever.

Abstract: A variable displacement hydraulic pump or motor (10) includes: a swash plate (13); a lever (22) supported by a housing (21) and configured to rotate in conjunction of tilting of the swash plate (13); and a sensor (23) configured to detect a displacement amount of the lever (22).

Abstract: A fan drive system includes a hydraulic pump, a hydraulic motor that rotates a fan on the basis of hydraulic oil supplied from the hydraulic pump, a data acquisition unit that acquires an actual fan speed of the fan, a target amount determination unit that determines a target fan speed of the fan on the basis of a state of an object to be cooled of the fan, and an estimating unit that estimates a state of the hydraulic pump or a state of the hydraulic motor on the basis of a change of a feedback amount that indicates a difference between the target fan speed and the actual fan speed.

Abstract: A fan drive system includes a hydraulic pump, a hydraulic motor that rotates a fan on the basis of hydraulic oil supplied from the hydraulic pump, a data acquisition unit that acquires an actual fan speed of the fan, a target amount determination unit that determines a target fan speed of the fan on the basis of a state of an object to be cooled of the fan, and an estimating unit that estimates a state of the hydraulic pump or a state of the hydraulic motor on the basis of a change of a feedback amount that indicates a difference between the target fan speed and the actual fan speed.

Abstract: In a variable displacement hydraulic pump/motor, a casing includes a tapered roller bearing supporting a rotating shaft near supports, the support has a sliding protruding portion in a spherical shape at a shaft portion, and a through oil path extending from the shaft portion to the sliding protruding portion, the support being fitted, at the shaft portion, in a mounting hole in the casing and being fitted, at the sliding protruding portion, in a sliding recessed portion in the swash plate to cover an opening of the through oil path, a communicating oil path is between a space in which a tapered roller of the tapered roller bearing is disposed and the mounting hole, and a lubrication groove constantly connecting the opening of the through oil path to an outside of a sliding contact area between the sliding protruding portion and the sliding recessed portion.

Abstract: In a variable displacement hydraulic pump/motor, a casing includes a tapered roller bearing supporting a rotating shaft near supports, the support has a sliding protruding portion in a spherical shape at a shaft portion, and a through oil path extending from the shaft portion to the sliding protruding portion, the support being fitted, at the shaft portion, in a mounting hole in the casing and being fitted, at the sliding protruding portion, in a sliding recessed portion in the swash plate to cover an opening of the through oil path, a communicating oil path is between a space in which a tapered roller of the tapered roller bearing is disposed and the mounting hole, and a lubrication groove constantly connecting the opening of the through oil path to an outside of a sliding contact area between the sliding protruding portion and the sliding recessed portion is between the sliding protruding portion and the sliding recessed portion.