Linear brushless D.C. motor with stationary armature and field and with integralable magnetic suspension

• US 20060113848A1
• Filed: 11/04/2005
• Published: 06/01/2006
• Est. Priority Date: 11/15/2004
• Status: Active Grant

• Current Assignee: Sandor Wayne Shapery
• Original Assignee: Sandor Wayne Shapery
• Inventors: Studer, Philip Albert
• Granted Patent: US 7,617,779 B2
• Time in Patent Office: Days
• US Class Current: 310/12.250
• CPC Class Codes: H02K 41/03 Synchronous motors; Motors moving step by step; Reluctance motors H02K41/035 takes precedence
• CPC Class Codes: H02K 7/09 with magnetic bearings

Abstract

This disclosure describes an electronically commutated linear d.c. motor with an armature and field source fixed relative to each other and a third element on which motor action takes place, consisting of a salient pole structure into which magnetic flux is impressed with no physical contact and little or no reluctance change with axial motion. This machine retains all the virtues of conventional d.c. motors as efficient bilateral mechanical to electrical force transducers, with conventional or ironless armatures and permanent and electromagnet fields. It has a completely passive salient pole element which may be either the stationary or moving part of the motor. This disclosure also illustrates how the newly invented form of linear d.c. motor can be designed in such a way that the magnetic circuit is part of a suspension system. This dual functional use of the magnet and permeable iron minimizes weight and cost. The moving (relative to armature) element (part of the motor'"'"'s field) is totally passive yet, acting like a multipole array of alternating polarity magnets is inexpensive for many applications. And, it provides a way of using a steel rails of any length as a track for vehicular levitation and propulsion. The efficiency and controllability of a D.C. traction motor can be superior to both types of A.C. motors currently being tested and marketed worldwide. The geometry of the magnetic circuit in the region of the suspension airgap is new and of special interest. The airgaps separating the parts in relative motion are magnetically in series but are so arranged that motion in the direction of suspension opens one as the other closes, reducing a source of control non-linearity.

Claims

1. ) I claim to be the original inventor of a device that separates the functional elements of an electronically commutated linear direct current motor into three parts, yielding unique characteristics.

2. ) 1 also claim the motor of claim 1 in which the field assembly consists of two distinct parts, one of which, containing the source of magnetic flux, is fixed to the armature, the other free to move linearly with respect to the armature.

3. ) I also claim the motor of claim 2 in which the other part of the field assembly receives flux across an airgap, divides it to multiple poles, themselves interdigitated with another of opposite polarity, both facing the armature.

5. ) 1 also claim the motor of claim 1 having an armature composed solely of insulated conductors with no ferrous material (ironless construction), in which case the moving element may reach around the other side to shorten the flux path.

6. ) 1 also claim the linear motor of claim 1 in which the field magnet is a permanent magnet or an electromagnet, or combination of both.

7. ) 1 also claim the device of claim 1 in which virtually all of the heat generated by the device and its commutation and control electronics can be directly conducted to the structure on which it is mounted and not the moving element.

9. ) I also claim the devices of claims (1&

4) in which the moveable element is magnetically supported and/or controlled by control of the magnetic flux between these elements as a motor or separate bearing fluxes.

4. ) 1 also claim a motor of claim I with a variable field enabling the motor characteristic to be varied dynamically to suit the load condition.

8. ) I also claim the motor of claim 4 extends the attributes of variable field d.c. motor technology to linear motion devices to extend their operational capacity and improve heat rejection.

10. ) I claim to be the sole and independent inventor of a non-contacting device containing both magnetic suspension and linear d.c. motor drive capability.

11. ) I also claim the device of claim 10 which employs common magnetic structure and flux source to produce suspension capability and linear d.c. motor field flux.

12. ) I also claim the device of claim 10 with an electromagnetic structure capable of load bearing in at least one axis, maintaining alignment stabilizing lateral position, and producing bidirectional forces along the desired straight line.

13. ) I also claim the device of claim 12 which is capable of electromagnetic control over suspension, propulsion, and alignment when connected to a d.c. power source controlled or commutated by intelligent electronics with respect to multi-axis displacement sensors.

15. ) I also claim the device of claim 11 having electromagnetic coils so located as to provide control over vertical, lateral, and rotational motion and, when used redundantly a distance apart, can control all degrees of freedom while allowing unrestricted axial motion when desired.

14. ) I claim a magnetic bearing structure which has small total reluctance change due to displacement in the direction of suspension.