Self shielding linear motor

Claim 2

A linear motor as set forth in claim 1, wherein at least one end of said shell is open.

Claim 3

A linear motion motor of the moving coil type comprising: a. a hollow cylindrical magnet having opposite poles on the interior and exterior surfaces of the cylinder and having a cylindrical axis; b. means for concentrating the lines of flux on one of the surfaces of the cylinder; c. a pole piece spaced from said cylinder surface having the concentrating means, to define a working air gap; d. a magnetic return circuit connecting the pole piece to the other surface of the cylinder including a low reluctance shell enclosing the magnet and the air gap; e. a conductor disposed in said air gap for axial movement and constructed to flow a current in a plane transverse to the cylinder axis; f. and means extending through said magnetic return circuit to mechanically transmit the motion of said conductor as it moves axially within said magnet.

Claim 4

A motor as defined in claim 4 wherein the means for concentrating the lines of flux is located on the interior surface of the magnet and the pole piece is generally circular and spaced from the inside surface of said cylindrical magnet.

Claim 5

A motor as defined in claim 4 wherein the means for concentrating the flux is disposed on the exterior surface of the magnet and the pole piece is ring shaped and spaced from the exterior surface of the magnet.

Claim 6

A motor as defined in claim 4 wherein the pole piece is a ring and the magnetic return circuit includes an axial low reluctance member passing through that part of the magnet and pole piece combination located on the axis of the cylinder.

Claim 7

A motor as set forth in claim 7 wherein the low reluctance axial member is hollow and a rod reciprocates in the hollow and is connected to the coil for transmitting movement of the coil.

Claim 8

A motor as defined in claim 4 wherein the means for concentrating the lines of flux is a soft iron sleeve in intimate contact with one surface of the magnet.

Claim 9

A motor as defined in claim 4 wherein the conductor is in the form of a helix.

Claim 10

A motor as defined in claim 4 wherein the pole piece is located substantially within the middle one half of the axial extent of the magnet.

Claim 11

A linear motion motor of the moving coil type comprising: a. a tubular magnet of uniform cross section along an axis and having a magnetic polarity transverse to the axis wherein the exterior surface is of one polarity and the interior surface of the magnet is of an opposite polarity; b. a pole piece having a low magnetic reluctance and high saturation density, spaced from one magnet surface to form a working air gap; c. a magnetic return circuit structure connecting the pole piece to the other surface of the magnet and including a shell of low reluctance material surrounding the pole piece, air gap and magnet; d. a conductor disposed in said air gap and constructed to pass current in a plane transverse to said magnet axis; e. and means extending to the exterior of said magnet return circuit structure and mechanically connected to the conductor to transmit movement of said conductor.

Claim 12

A motor as set forth in claim 12 wherein there is a central bore parallel to the magnet axis, a rod is mounted therein for reciprocation, and means mechanically connect the rod and conductor whereby movement of the conductor in response to conductor current interacting with the air gap flux is transmitted by the rod.

Claim 13

A motor as set forth in claim 12 wherein the pole piece is located inside the magnet, the magnet return circuit structure inside the magnet has a bore parallel to the magnet axis, a rod reciprocates within the bore, and means mechanically connect the conductor and the rod, whereby movement of the conductor in response to conductor current interacting with air gap flux is transmitted by the rod, and whereby the bore walls of the magnetic return circuit shield said bore from any stray flux and prevent flux leakage from the motor.

Claim 14

A linear motor as set forth in claim 1, wherein the exterior surface of the magnet is in contact with the tubular shell and an air gap is formed between the inner surface of the tubular magnet and center core.

Claim 15

A linear electric motor comprising: a. a tubular shell of magnetic material having a tubular axis; b. an end plate of magnetic material closing off one end of the tube, the other end being open; c. a center core of magnetic material supported by said end plate in cantilever fashion and spaced from the shell; d. a radially polarized tubular permanent magnet disposed within the cylindrical shell for magnetic contact with the surface of one of said shell or center core and spaced from the surface of other to form a working air gap; e. an armature winding disposed in the air gap; f. and means for supporting the armature for axial movement within the motor.

Claim 16

A linear motor as set forth in claim 1, wherein the thickness of the tubular shell varies over the axial extent of the magnet and the radial dimension of the shell is greater toward said low reluctance magnetic path connecting the shell to the core, whereby a minimum amount of material is used in the shell and the flux density in the shell is substantially uniform.

Claim 17

A motor as set forth in claim 1, wherein at least one end of the tubular magnet is spaced from the low reluctance magnetic path connecting the shell and center core by a dimension at least as great as the approximate radial dimension of the magnet.

Claim 18

A linear motor as set forth in claim 1, wherein the means for transmitting the motion of the armature coil includes a longitudinal bore in center core, at least one slot in the core extending from the bore to the exterior of the core, and a rod is disposed in the bore for reciprocation therein, and at least one support interconnects the rod and armature coil and is disposed in said slot.

Claim 19

A linear motor as set forth in claim 1, wherein the means for transmitting the motion of the armature coil includes at least one longitudinal slot in the tubular shell, and at least one support is disposed therein and is connected to the armature coil.

Claim 20

A motor as set forth in claim 1, wherein the one end of the tubular shell is closed by an end plate, the armature coil is generally tubular, and the means for transmitting the motion of the armature coil to the exterior of the motor includes tubular longitudinal support sections extending from one end of the coil and include slots in the end plate through which these extensions pass to the exterior of the plate.

Claim 21

A linear motor as set forth in claim 3, wherein the means for transmitting motion of the armature coil includes a support tube connected to one end of the armature coil and extending out of the open end of the shell, and an armature coil guide means is connected to the other end of the support tube.

Claim 22

A linear motor comprising: a. a tubular shell of magnetic material having a tubular axis; b. a center core of magnetic material spaced from the shell; c. a tubular magnet disposed inside of the shell and having a radial polarization and defining an air gap between at least one of said shell and said center core; d. a movable armature coil disposed in said air gap and having conductors generally in a plane transverse to the tubular axis of the shell; e. means for supplying electric current to the armature coil. f. and means connected to the armature coil and extending to the exterior of the motor for transmitting the motion of the armature coil.