Reciprocating fluid pump assembly employing reversing polarity motor

A fuel injector for spraying fuel into a cylinder of an internal combustion engine, comprising:

• a drive section having:
• a housing;
• at least one permanent magnet fixedly supported within the housing;
• a coil bobbin slidable with respect to the at least one permanent magnet between a first position and a second position away from the at least one magnet;
• a coil wound on the bobbin, the coil having free ends for receiving energizing control signals;
• a plunger operatively connected to the coil bobbin such that movement of the coil bobbin in one direction causes movement of the plunger in the same direction;
• and
• a first biasing spring for biasing the plunger and the coil bobbin towards the first position;
• a pump section having a first end and a second end, the first end of the pump section being secured to the drive section, the pump section also having:
• a central aperture for receiving a portion of the plunger of the drive section;
• a pump chamber adjacent to the central aperture for receiving fuel;
• and
• a first fluid passage for introducing fuel into the pump chamber;
• and
• a nozzle assembly having:
• a nozzle body fitted to the second end of the pump section and having a central aperture;
• a poppet positioned in the central aperture of the nozzle body, the poppet being movable between an open position and a sealed position;
• and
• a second biasing spring for biasing the poppet towards the sealed position.

A fuel injector for spraying fuel into a cylinder of an internal combustion engine, comprising:

• a housing;
• at least one permanent magnet fixedly attached to a portion of the housing;
• a coil bobbin disposed about the at least one permanent magnet and being reciprocally movable relative thereto;
• a coil wound on the bobbin;
• a drive member secured to the coil bobbin;
• a plunger received within a central aperture, the plunger having a head region designed to contact the drive member so as to reciprocate with the coil bobbin;
• a first biasing spring for biasing the plunger, the drive member, and the coil bobbin towards the portion of the housing to which the at least one permanent magnet is attached;
• a pump chamber adjacent to the central aperture for receiving fuel;
• a valve member positioned in the pump chamber and being reciprocally movable therein by interacting with the plunger;
• a first passage for introducing fuel in the pump chamber;
• a second biasing spring for biasing the valve member towards the plunger;
• a second passage in fluid communication with the pump chamber;
• a poppet disposed in the second passage, the poppet being movable between an open position and a sealed position;
• and
• a third biasing spring for biasing the poppet towards the sealed position.

A fuel injector for spraying fuel into a cylinder of an internal combustion engine, comprising:

• a drive section having:
• a housing;
• at least one permanent magnet fixedly supported within the housing;
• a coil bobbin slidable with respect to the at least one permanent magnet between a first position and a second position away from the at least one magnet;
• a coil wound on the bobbin, the coil having free ends for receiving sequentially a first signal having a first polarity and a first amplitude to control movement of the coil bobbin towards the second position, and a second signal having a second polarity opposite to the first polarity and a second amplitude to control movement of the coil bobbin towards the first position, the first and second signal being generated by a controller and being independently alterable as a function of engine demand;
• a plunger operatively connected to the coil bobbin such that movement of the coil bobbin in one direction causes movement of the plunger in the same direction;
• and
• a first biasing spring for biasing the plunger and the coil bobbin towards the first position;
• a pump section having a first end, a second end, and a pump chamber therein for receiving fuel, the first end of the pump section being secured to the drive section;
• and
• a nozzle assembly having:
• a nozzle body fitted to the second end of the pump section and having a central aperture;
• and
• a poppet positioned in the central aperture of the nozzle body.