Abstract: An air pump structured to facilitate the installation of a pair of pistons includes a casing (17) having a pair of cylinder chambers (14) slidably accommodating a pair of pistons (16), respectively, and a drive chamber accommodating electromagnets between the pair of cylinder chambers. The pump casing has mutually opposing side walls and a cylindrical peripheral wall defining the drive chamber. The side walls have circular cylindrical inner peripheral surfaces (28-1) of the cylinders defined therein, respectively. A piston assembly having the pistons connected to the opposite ends of an armature (34) is inserted into the pump casing through one of the cylindrical inner peripheral surfaces and installed therein. The peripheral wall has an electromagnet-loading opening (26-2) through which electromagnet pedestal members (26-7) and the electromagnets are inserted into the casing and secured therein.

Abstract: There is provided an air pump in which vibration noise generated in a drive unit of the pump is suppressed from being transmitted to the outside through a suction passage. A casing of the air pump has a suction port extending from an outer peripheral surface to inner peripheral surface of the casing, a noise reduction wall annularly formed on the outer peripheral surface of the casing such that the suction port opens in a region of the outer peripheral surface of the casing surrounded by the noise reduction wall, and a lid member closing the opening of the top of the noise reduction wall and cooperating with the noise reduction wall and the outer peripheral surface of the casing to define a noise reduction chamber communicating with the suction port. The noise reduction wall has an elongated noise reduction passage extending circumferentially in the noise reduction wall.

Abstract: An electromagnetic reciprocating fluid device in which a movable member is equipped with permanent magnets, resists a torque rotating the movable member about an axis thereof in the reciprocating direction. The electromagnetic reciprocating fluid device has a pair of electromagnets facing each other, and permanent magnets disposed in a space between the opposed electromagnets and held by a movable member. When an alternating current is applied to coils formed in the electromagnets, a magnetic force is generated between the electromagnets and the permanent magnets, whereby a driving force for reciprocation is applied to the movable member. One end of the movable member is connected to a piston of a first piston-cylinder assembly, while the other end is connected to a piston of a second piston-cylinder assembly.

Abstract: An air pump has an air tank (20) for temporarily storing air from a pump unit (12) before discharging the air. The air tank has a tank body having a top wall (40) on which the pump unit is placed, and a peripheral wall (42) extending downward from the top wall. The tank body has a downward facing opening. The air tank further has a metallic bottom wall member (46) engaged with the bottom surface of the peripheral wall so as to close the opening of the tank body. Bolts are passed through the metallic bottom wall member and into a metallic part of the pump unit and tightened to connect and secure the pump unit and the air tank to each other.

Abstract: An air pump has an air tank (20) for temporarily storing air from a pump unit (12) before discharging the air. The air tank has a tank body having a top wall (40) on which the pump unit is placed, and a peripheral wall (42) extending downward from the top wall. The tank body has a downward facing opening. The air tank further has a metallic bottom wall member (46) engaged with the bottom surface of the peripheral wall so as to close the opening of the tank body. Bolts are passed through the metallic bottom wall member and into a metallic part of the pump unit and tightened to connect and secure the pump unit and the air tank to each other.

Abstract: An air pump structured to facilitate the installation of a pair of pistons includes a casing (17) having a pair of cylinder chambers (14) slidably accommodating a pair of pistons (16), respectively, and a drive chamber accommodating electromagnets between the pair of cylinder chambers. The pump casing has mutually opposing side walls and a cylindrical peripheral wall defining the drive chamber. The side walls have circular cylindrical inner peripheral surfaces (28-1) of the cylinders defined therein, respectively. A piston assembly having the pistons connected to the opposite ends of an armature (34) is inserted into the pump casing through one of the cylindrical inner peripheral surfaces and installed therein. The peripheral wall has an electromagnet-loading opening (26-2) through which electromagnet pedestal members (26-7) and the electromagnets are inserted into the casing and secured therein.

Abstract: There is provided an air pump in which vibration noise generated in a drive unit of the pump is suppressed from being transmitted to the outside through a suction passage. A casing (17) of the air pump has a suction port (26-12) extending from an outer peripheral surface to inner peripheral surface of the casing, a noise reduction wall (26-9) annularly formed on the outer peripheral surface of the casing such that the suction port opens in a region of the outer peripheral surface of the casing surrounded by the noise reduction wall, and a lid member closing the opening of the top of the noise reduction wall and cooperating with the noise reduction wall and the outer peripheral surface of the casing to define a noise reduction chamber (26-14) communicating with the suction port. The noise reduction wall has an elongated noise reduction passage (26-11) extending circumferentially in the noise reduction wall. One end of the noise reduction passage opens on the outer surface of the noise reduction wall.

Abstract: An electromagnetic reciprocating fluid device in which a movable member is equipped with permanent magnets, resists a torque rotating the movable member about an axis thereof in the reciprocating direction. The electromagnetic reciprocating fluid device has a pair of electromagnets facing each other, and permanent magnets disposed in a space between the opposed electromagnets and held by a movable member. When an alternating current is applied to coils formed in the electromagnets, a magnetic force is generated between the electromagnets and the permanent magnets, whereby a driving force for reciprocation is applied to the movable member. One end of the movable member is connected to a piston of a first piston-cylinder assembly, while the other end is connected to a piston of a second piston-cylinder assembly.

Abstract: An electromagnetic reciprocating fluid device in which a movable member is equipped with permanent magnets, resists a torque rotating the movable member about an axis thereof in the reciprocating direction. The electromagnetic reciprocating fluid device has a pair of electromagnets facing each other, and permanent magnets disposed in a space between the opposed electromagnets and held by a movable member. When an alternating current is applied to coils formed in the electromagnets, a magnetic force is generated between the electromagnets and the permanent magnets, whereby a driving force for reciprocation is applied to the movable member. One end of the movable member is connected to a piston of a first piston-cylinder assembly, while the other end is connected to a piston of a second piston-cylinder assembly.

Abstract: It is an object of the present invention, in an electromagnetic reciprocating fluid device in which a movable member is equipped with permanent magnets, to resist a torque rotating the movable member about an axis thereof in the reciprocating direction. The electromagnetic reciprocating fluid device has a pair of electromagnets 28, 28? facing each other, and permanent magnets 26, 26? disposed in a space between the opposed electromagnets and held by a movable member 27. When an alternating current is applied to coils 34 formed in the electromagnets, a magnetic force is generated between the electromagnets and the permanent magnets, whereby a driving force for reciprocation is applied to the movable member. One end of the movable member is connected to a piston 18 of a first piston-cylinder assembly 12, while the other end is connected to a piston 18? of a second piston-cylinder assembly 12?.

Abstract: A compact air massage system is provided which enables the user to receive a comfortable feeling of massage on each part of the limbs. The system includes massage bodies having a plurality of air-tight chambers, a compressed air supply source supplying compressed air to the massage body, and a compressed air distribution apparatus arranged between the compressed air supply source and the massage body and having a plurality of switching valves each allowing the respective air-tight chambers to communicate with one of the compressed air supply source and an outer atmosphere. The system further includes a controller controlling the respective switching valves to allow the respective chambers to be expanded or contracted and check valves each arranged between the compressed air supply source and the switching valve and openable from the compressed air supply source toward the direction of the switching valve, by which it is possible to individually adjust pressure in the respective chambers.