| 主权项 |
1. A linear motor, comprising:
a. a housing having an exterior wall to form an interior chamber, the housing having an open proximal end and a closed distal end, a movable bobbin at least partially within the chamber and movable in a back and forth axial direction from the distal end of the housing to and through the open proximal end of the housing; b. a distal axially magnetized permanent magnet located within and adjacent the distal end of the housing, the distal permanent magnet having a first magnetic pole and a second magnetic pole, the distal permanent magnet coaxially connected at a location of its second magnetic pole to a first side of a distal pole piece made of ferromagnetic material; c. a middle non-magnetic spacer located within the housing and aligned with the distal permanent magnet, the middle non-magnetic spacer coaxially affixed at a location of its first side to a second side of the distal pole piece and affixed at a location of its second side to a first side of a middle pole piece made of ferromagnetic material; d. a proximal axially magnetized permanent magnet located within the housing and aligned with the middle non-magnetic spacer, the proximal permanent magnet having a third magnetic pole and a fourth magnetic pole, the proximal permanent magnet affixed at a location of its third magnetic pole to a second side of the middle pole piece and affixed at a location of its fourth magnetic pole to a first side of a proximal pole piece made of ferromagnetic material; e. the first and second poles of the distal permanent magnet determine the direction of magnetization of the distal permanent magnet, the third and fourth magnetic poles of the proximal permanent magnet determine the direction of magnetization of the proximal permanent magnet, and the distal and proximal permanent magnets have a same direction of magnetization; f. the distal permanent magnet affixed at a location of its first magnetic pole to an interior surface of the distal end of the housing and a second side of the proximal pole piece is aligned with the open proximal end of the housing, a circumferential air gap of a given radial width formed between an interior circumferential wall of the housing and an aligned magnet assembly of the distal permanent magnet, non-magnetic spacer and proximal permanent magnet and distal, middle and proximal pole pieces; g. the bobbin having a cylindrical wall with an exterior surface and an interior surface surrounding a hollow interior chamber, three spaced apart barriers formed on and extending radially above the exterior surface including a proximal barrier with a longitudinal groove, a middle barrier with an aligned longitudinal groove and a distal barrier, a first winding area formed on the cylindrical wall of the bobbin between the proximal barrier and the middle barrier and a second winding area formed on the cylindrical wall of the bobbin between the middle bather and the distal barrier; h. a single electrical wire wound on the bobbin, the single electrical wire having a first end retained by the proximal barrier and extending through the longitudinal groove of the proximal barrier and wound around the first winding area of the bobbin cylindrical wall until it reaches the middle barrier, the electrical wire passing through the longitudinal groove in the middle barrier and wound around the second winding area of the cylindrical wall of the bobbin until the electrical wire reaches the distal barrier to complete a first winding layer, a second winding layer in the second winding area formed by winding the electrical wire in the same direction and going from the distal barrier to the middle barrier, passing through the groove in the middle barrier and wound in the same direction in the first winding area until it reaches the proximal barrier to complete the second winding layer, so that at least a second end of the electrical wire extends through the groove in the proximal barrier to rest adjacent the first end of the electrical wire; i. the bobbin movably retained in the housing so that the hollow interior chamber of the bobbin surrounds the magnet assembly and barriers of the bobbin reside within the air gap in the housing between the magnet assembly and the interior circumferential wall of the housing, the middle barrier of the bobbin being of sufficient width so that when windings on the bobbin are entirely within the housing, the electrical wire wound on the first winding area and the electrical wire wound on the second winding area do not encircle the middle non-magnetic spacer and when the bobbin is in its fully extended condition that is partially out of the housing, the electrical wire wound on the first winding area and the electrical wire wound on the second winding area do not encircle the proximal permanent magnet; and j. a source of electrical current connected to the electrical wire interacts with the magnetic field created by the distal and proximal permanent magnets, thereby moving the bobbin axially relative to the housing so that the electrical wire of first and second winding areas are entirely within the housing in a first condition and the electrical wire of the first winding area is out of the housing while the electrical wire of the second winding area is in the housing in a second condition, the use of the single electrical wire reducing the radial width of the air gap between the bobbin and the interior circumferential wall of the housing so that an increased force is generated by the relative movement of the bobbin and the housing.
|
