Hydraulic pump/motor and fan driving device

A fan driving device, comprising:

• a hydraulic motor including a rotational shaft, both of whose ends are rotatably attached to a casing and an end cover closing an opening of the casing via a. bearing in a casing in a state in which a tip end of the rotational shaft protrudes from the casing, a cylinder block rotating together with the rotational shaft, a plurality of pistons fittedly inserted into a plurality of cylinder holes formed on the cylinder block so as to be able to reciprocate, a swash plate provided in the casing so as to be tilted relative to the rotational shaft to allow tip ends of the pistons to slide so as to be able to slidingly contact the swash plate, and a valve plate slidingly contacting a rear end face of the cylinder block, the hydraulic motor for distributing oil in the cylinder holes through a port provided on the valve plate;
• a bracket provided with a planar base portion having a through-hole to which the hydraulic motor is attached in a state in which a tip end of the rotational shaft is arranged on a surface side of the base portion by fittedly inserting the casing into the through-hole;
• and
• a fan attached to the tip end of the rotational shaft and is driven by the hydraulic motor, wherein
• the hydraulic motor includes a plurality of detected units provided on an outer circumferential surface of the cylinder block, and a rotation sensor arranged in the casing in a state opposed to a portion between a deepest portion of the cylinder hole and the rear end face of the cylinder block in an axial direction of the cylinder block for detecting the detected units, and
• the fan driving device attached to the bracket in a state in which the rotation sensor is located on a rear surface side of the base portion.