A positive displacement pump is provided which is especially suited to be used as a left ventricle assist device (LVAD) The pump is electromagnetically actuated An electromagnet produces a pulse which repels a magnet mounted in a diaphragm which forms one wall of a pumping chamber The pumping chamber thereby constricts and fluid is expelled The electromagnet has a reverse taper core and core cup magnet which produce a bipolar field effect upon a diaphragm magnet to cause the return of the diaphragm to its starting position, without the application of external power

Magnetically actuated positive displacement pump

An electromagnet includes a coil, a movable iron core adapted to move on the center axis of the coil, and a stationary iron core provided so as to cover the upper and lower surfaces and the outer peripheral surface of the coil. A permanent magnet is arranged in a gap surrounded by the movable iron core and the stationary core.

Electromagnet and actuating mechanism for switch device, using thereof

An electromagnetic linear drive has a stationary unit, a mobile unit centered and coaxially placed with respect to the stationary unit and an enclosing assembly made of diamagnetic material to support and protect the stationary unit and the mobile unit. The stationary unit contains a coil, wound around a bobbin made of non-conductive and diamagnetic material including a stationary magnet coaxially attached to the lateral face of the bobbin. The mobile unit includes a mobile magnet fastened to a shaft made of diamagnetic material which holds, positions and further transfer the linear motion of the mobile magnet to the driven device. Two stationary units are used to obtain controlled movement in both direction. The permanent magnets are magnetized in the direction of their thickness, coaxially positioned and arranged to repulse each other. The coils are connected in series with the magnetic fields opposed. The mobile unit is moved by synergetic attraction and repulsive forces of a bi-directional rectangular electric current, generated by a bridge type circuit through the coils of the stationary units. This invention has higher output force and operating frequency created by eliminating ferromagnetic materials. This linear drive directly converts electric energy to linear motion. It can be used where precise movement is required or in applications such as pumps, robotics, loudspeakers and underwater communications.

Electromagnetic linear drive

An attraction blade plate is disposed on a plunger of a plunger type electromagnet to improve the shape of the plunger and the shape of a fixed core, or a cylinder equipped with a single flange and made of a magnetic material is fitted to the axial-direction end portion of a coil bobbin. According to each technical means, the change rate of permeance of a magnetic path at the time of attraction can be made great and high sensitivity of the electromagnet can be accomplished. Attraction retention force is controlled by adjusting the area of the contact surface between the fixed core and a movable core. A permanent magnet is shaped in a toroidal shape and the direction of magnetization is formed in the direction of the thickness of the toroidal shape. Accordingly, magnetization of the permanent magnet becomes easier and the number of components can be reduced. In this manner, a compact and light-weight electromagnet can be mass-produced.

Plunger type electromagnet

A solenoid which is driven positively in both directions by reversal of coil current and held in place at either end by flux from a permanent magnet located at the center of the frame. The permanent magnet is formed of two opposed sections fitting tightly between the plunger tube and frame, and is located in a space between two coils. In one form the two magnet sections are formed of compressible material and are recessed to fit closely around the plunger tube.

Double acting permanent magnet latching solenoid

A self-sustaining solenoid which is adapted so that when applying an operating current to a coil, a moving iron core disposed in the coil is attracted into contact with a fixed receiver. A magnetic yoke is provided to extend between the fixed receiver and the end portion of the moving iron core projecting out of the coil, and a permanent magnet is disposed on the magnetic yoke at least at one end in the direction of movement of the moving iron core. When the moving iron core is held in contact with the fixed receiver, magnetic fluxes emanating from the permanent magnet mostly pass through the moving iron core, the fixed receiver and the magnetic yoke, and even if the operating current is cut off, the moving iron core is retained in contact with the fixed receiver. A magnetic gap is provided through which the magnetic fluxes of the permanent magnet mostly pass when the moving iron core is out of contact with the fixed receiver, and magnetic flux resulting from the application of the operating current pass through the magnetic gap.

Toru Yoshimura

Papers

Self-sustaining solenoid