Airex Corporation

Other

David J Carroll

Richard D Sedgewick

James Sedgewick

Michael Drew

John Salwen

The present invention provides a linear, rotary spherical motor with an integrated magnetic bearing. The motor can be a toothless permanent magnet, BLDC design composed of a permanent magnet rotor and a Zigzag stator winding containing at least two-phase windings, where each phase is constructed of at least two circuits. Other exemplary embodiments include a trapezoidal winding configuration. The individual circuits of a phase are displaced away from each other along a line that is at right angles to the direction of the alternating polarity magnet array. The circuits forming a phase share the same 'slot', and each circuit resembles a complete phase winding, however each circuit contains a proportion of the total number of turns of the phase. Controllable axial bearing force is developed through the differential balance of the currents in the circuits, while required motor torque is generated by the sum of the individual currents in a given phase. The relative motion in the rotor can produce back EMF which can provide positional information; A) in the direction parallel to the magnet array via the sum of the voltages in a phase; B) in the direction normal to the magnet array via the difference in circuit voltages.

Magnetic bearing using displacement winding techniques

The present invention provides a rotational magnetic gimbal with an integral magnetic bearing. Brushless DC motor technology provides electromagnetic suspension, using a single electromagnetic actuator to perform both the radial bearing and rotary torque (motoring) functions. An integrated motor and magnetic bearing consistent with the invention comprises a rotor comprising a plurality of permanent magnets and a stator comprising a plurality of independently controlled coil segments magnetically coupled to the permanent magnets. Embodiments may further comprise first and second radial position sensors, the first radial position sensor disposed in or adjacent to a clearance gap between the rotor and the stator for sensing the position of the rotor with respect to the stator along a first axis, and a second radial position sensor disposed in or adjacent to the clearance gap between the rotor and the stator for sensing the position of the rotor with respect to the stator along a second axis. In method form, a method for providing integral electromagnetic motor and bearing functions comprises sensing a first radial position of a rotor, the rotor comprising a plurality of permanent magnets, with respect to a stator along a first axis, the stator comprising a plurality of independently controlled coil segments magnetically coupled to the permanent magnets; and sensing a second radial position of the rotor with respect to the stator along a second axis; and delivering current to at least one coil segment, the amount of current based on at least one sensed position.

Integrated magnetic bearing

A coil winding system and process is provided that includes a coil winding fixture and a coil press fixture. The coil winding fixture includes a pair of winding arms each having a set of in-line winding pins. The sets of in-line pins are arranged parallel to one another in one axis, and form an angle to another axis. Magnetic wire is machine wound into the slots between the pins to form coil phases, and, advantageously the individual coils can be wound together to minimize spatial tolerance build-up between phases. Likewise the slots are arranged parallel and adjacent one another to ensure that each winding is parallel to the next to maximize efficiency of the coils. The press fixture includes a forming press and a saddle to form the wound coils into a predetermined shape using heat and pressure applied to the press fixture.

Method and apparatus for winding and forming motor coil assemblies

The present invention provides a linear motor assembly that uses keying technique to provide a uniform mechanical interface for linear motor coils to the mount or mounting bracket. This permits a molded coil assembly to be built as a subassembly, so that later insertion into brackets of varying configurations is possible. The keying technique locks the coil to the mount or mounting bracket, and accommodates many different bracket configurations without modification to the coil assembly. The coil is keyed to the bracket and may be attached with an adhesive such as an epoxy bond or thermal grease to improve the thermal dissipation from the motor to the mounting surface. This subassembly can be pre-manufactured and transformed to an application-specific assembly with relative ease in a short period of time. Bracket or mounting options may include various cooling features such as water or air-cooling. The subassembly can also be integrated directly to a linear system comprised, for example, of bearings or encoders. This eliminates the need for a separate mounting bracket, and improves heat dissipation.

Linear motor with keyed mounting arrangement

A linear motor comprising a DC magnetic field of alternating polarity arranged in a longitudinal axis, a coil assembly located substantially in a plane parallel to and immersed in the alternating magnetic field, said coil assembly containing individual coil loops of essentially rectangular shape and having end turn areas arranged parallel to said longitudinal axis of the magnet field and coil side areas being perpendicular to said longitudinal axis of the magnetic field with each coil side having a coil side width (CSW) and each coil loop having a coil outside width (COW) and coil inside width (CIW) such that COW=CIW+(2.times.CSW) wherein the coils have a coil outside length (COL), forming a coil assembly area (CAA) approximately equal to COW.times.COL and said coil assembly has a coil assembly thickness (CAT) in a direction creating acoil assembly volume (CAV) approximately equal to the coil assembly area (CAA) times the coil assembly thickness (CAT) pursuant to the following equation: CAV.apprxeq.CAT.times.COW.times.COL. wherein said assembly is formed with a plurality of phases each formed in the manner of the first phase, each phase uniformly and sequentially offset from adjacent phases and means for switching current successively between the phases thereby alternating the magnetic fields within the coil assembly sequentially, said plurality of offset phases substantially filling the coil inside width (CIW) of the first phase, such that CIW=CSW.times.(#.phi.-1). The above coil assembly optimally includes a longitudinal opening along the end turn areas within the coil assembly volume allowing non-magnetic metallic members for heat dissipation and structural strength, including a mounting bracket on one end turn area, and a heat sink cap enclosing the opposite end turn area.

Linear motor with improved coil design and heat removal

A linear motor comprising a DC magnetic field of alternating polarity arranged in a longitudinal axis, a coil assembly located substantially in a plane parallel to and immersed in the alternating magnetic field, said coil assembly containing individual coil loops of essentially rectangular shape and having end turn areas arranged parallel to said longitudinal axis of the magnet field and coil side areas being perpendicular to said longitudinal axis of the magnetic field with each coil side having a coil side width CSW) and each coil loop having a coil outside width (COW) and coil inside width (CIW) such that COW=CIW+(2.times.CSW) wherein the coils have a coil outside length (COL), forming a coil assembly area (CAA) approximately equal to COW.times.COL and said coil assembly has a coil assembly thickness (CAT) in a direction creating a coil assembly volume (CAV) approximately equal to the coil assembly area (CAA) times the coil assembly thickness (CAT) pursuant to the following equation: CAV.apprxeq.CAT.times.COW.times.COL, wherein said assembly is formed with a plurality of phases each formed in the manner of the first phase, each phase uniformly and sequentially offset from adjacent phases and means for switching current successively between the phases thereby alternating the magnetic fields within the coil assembly sequentially, said plurality of offset phases substantially filling the coil inside width (CIW) of the first phase, such that CIW=CSW.times.(#.phi.-1). The above coil assembly optimally includes a longitudinal opening along the end turn areas within the coil assembly volume allowing non-magnetic metallic members for heat dissipation and structural strength, including a mounting bracket on one end turn area, and a heat sink cap enclosing the opposite end turn area.

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Strafford, NH, United States of America

David J Carroll