US 4,787,823 AGranted

Electromagnetic linear motor and pump apparatus

OwnerBarry W. Hultmaninventor

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Abstract

An electromagnetic linear motor having a variable length stroke and providing a substantially large force in both its power stroke and return stroke includes concentric inner and outer magnetic circuits arranged coaxially for movement relative to one another in a rectilinear path with reciprocating motion in response to the interaction of magnetic fields produced by the inner and outer magnetic circuits, respectively. The length of the stroke and the rate of reciprocation are directly proportional to the magnitude of the voltage used to excite primary and secondary coils which generate the respective magnetic fields and the rate at which the polarity of the voltage applied to the secondary coil is changed between negative and positive polarities. The invention further resides in a central core pump having a pumping tube connected for movement with the outer magnetic circuit and in coaxially alignment with inlet and discharge tubes and each of the three tubes having a check valve to form variable volume chambers between the pumping and inlet and pumping and outlet tubes respectively so that one or more successive volumes of fluid are drawn into one and discharged from the other when the outer circuit moves in one direction and discharged from one and drawn into the other when the outer circuit moves in the opposite direction. The invention further resides in the electromagnetic linear motor being arranged with a central core pump to provide fuel injection to an internal combustion engine.

Claims10

Dependent claims

An electromagnetic linear motor having a controllable variable length stroke, said motor comprising:

(a) a magnetic structure including an inner magnetic circuit means and an outer magnetic circuit means,
(b) said inner magnetic circuit means including,
i. an axially elongated cylindrical core of magnetic material supported at one end by a bottom plate and having a diametrically enlarged portion at the end opposite the supported end, said core having a conductor wound around it between said supported end and said enlarged portion to form a first electric coil means,
said inner magnetic circuit means including a first-applied electric signal having a controllable magnitude,
said first electric coil means producing in response to said first applied electric signal, a first magnetic field having a variable intensity, and
ii. an outer concentric shell supported by said bottom plate and made of a magnetic material for forming an air gap between said enlarged end portion and said concentric shell to support said first field thereacross,
(c) said outer magnetic circuit means including shuttle means coaxially arranged between said core and said outer concentric shell and extending through said air gap in an axial direction along said elongated cylindrical core, said shuttle means including a bobbin having a conductor would thereon to form a second electric coil means,
said outer magnetic circuit means including a second-applied electric signal having a controllable magnitude,
said second electric coil means producing in response to said second applied electric signal, a second magnetic field having a variable intensity
(d) means for continuously controlling said controllable magnitude of said first-applied electric signal and and controllable magnitude of said second-applied electric signal,
said shuttle means traveling between two predetermined spaced apart positions for a desired displacement along a rectilinear path in one and an opposite direction through the air gap, respectively in response to said second magnetic field interacting with said first magnetic field, said displacement by said shuttle means being directly proportional to and controllable by the magnitude of the intensity of said magnetic field whereby the stroke length of said shuttle means is controlled by said means for continuously controlling said controllable magnitudes of said first and second-applied electric signals to produce the desired displacement.

8 more elements

In combination with a reciprocating fluid pump having inlet and outlet means, a fluid chamber and a pumping piston in the chamber connected to a piston rod with an electromagnetic linear motor having a variable stroke connected thereto, said electromagnetic motor comprising:

(a) a magnetic structure including an inner magnetic circuit means and an outer magnetic circuit means,
(b) said inner magnetic circuit including,
i. an axially elongated cylindrical core of magnetic material supported at one end by a bottom plate and having a diametrically enlarged portion at the end opposite the supported end, said core having a conductor wound around it between said supported end and said enlarged portion to form a first electric coil means,
said inner magnetic circuit means including a first applied electric signal having a controllable magnitude,
said first electric coil means producing in response to said first applied electric signal, a first magnetic field having a variable intensity, and
ii. an outer concentric shell supported by said bottom plate and made of a magnetic material for forming an air gap between said enlarged end portion and said concentric shell to support said first magnetic field thereacross,
(c) said outer magnetic circuit including shuttle means connected with said piston rod and coaxially arranged between said core and said outer concentric shell and extending through said air gap in a axial direction along said elongated cylindrical core, said shuttle means including a bobbin having a conductor wound threon to form a second electrical coil means,
said outer magnetic circuit means including a second-applied electric signal having a controllable magnitude,
said second electric coil means producing in response to said second applied electric signal, a second magnetic field having a variable intensity,
(d) means for continuously controlling said controllable magnitude of said first-applied electric signal and said controllable magnitude of said second-applied electric signal,
said shuttle means having means for coupling said shuttle means to said piston rod to drive said pump with a reciprocating motion as said shuttle means moves in a rectilinear path in one and an opposite direction through the air gap, respectively in response to said magnetic field interacting with said first magnetic field, whereby said means for continuously controlling said controllable magnitude of said first-applied electric signal and said controllable magnitude of said second-applied electric signal variably and resultingly controls the magnetic field interaction between said first and second magnetic fields to vary the stroke of the pumping piston.

8 more elements

Dependencies are inferred from the claim text.