Abstract: A pump device includes a housing, a pump element, and an on-off valve. The housing includes a suction passage defining a suction port at an upstream end, a discharge passage defining a discharge port at a downstream end, and a return passage returning a part of a fluid flowing through the discharge passage to midway of the suction passage. The pump element is accommodated in the housing and rotates around a predetermined axis to suck, pressurize, and discharge a fluid. The on-off valve opens and closes the return passage. In the suction passage upstream of an opening at which the return passage is opened to the suction passage, the housing includes a directional wall which directs a flow of a suction fluid sucked into the suction passage from the suction port to divert from a flow of a return fluid returned from the return passage.

Abstract: The pump device includes a housing defining insertion holes for a rotation shaft, inlets and outlets, and an internal passage; a first pump element; and a second pump element. The internal passage includes first suction passages communicating from the inlet to a first suction port facing the first end surface of the first pump element directed to one end side; first discharge passages communicating from a first discharge port facing the first end surface to the outlet; second suction passages passing around the first pump element to communicate from the inlet to a second suction port facing the second end surface of the second pump element; and second discharge passages passing around the first pump element to communicate from a second discharge port facing the second end surface to the outlet.

Abstract: The disclosure provides a pump device and an outboard motor equipped with the same. The pump device to be applied to an outboard motor includes a housing that has an insertion hole into which a drive shaft driven by an engine is to be inserted; and a resin cover member that is fixed to the housing to cover an outer wall surface of the housing in a region having the insertion hole. The cover member has a small-diameter insertion hole having an inner diameter smaller than the insertion hole to allow the drive shaft to be rotatably inserted thereto.

Abstract: A pump device includes a housing, a pump element, and an on-off valve. The housing includes a suction passage defining a suction port at an upstream end, a discharge passage defining a discharge port at a downstream end, and a return passage returning a part of a fluid flowing through the discharge passage to midway of the suction passage. The pump element is accommodated in the housing and rotates around a predetermined axis to suck, pressurize, and discharge a fluid. The on-off valve opens and closes the return passage. In the suction passage upstream of an opening at which the return passage is opened to the suction passage, the housing includes a directional wall which directs a flow of a suction fluid sucked into the suction passage from the suction port to divert from a flow of a return fluid returned from the return passage.

Abstract: A wave absorber comprising semiconductive ceramic short fibers having defined diameter, aspect ratio and volume resistivity dispersed in polymer materials. The dispersion is usually formed on a sheet or film base as a layer. A method for making the wave absorber is also described.