Shell rotor direct current generator

#This invention is concerned with dynamoelectric machines and more particularly with commutator type generators for supplying speed responsive direct current. Specifically, the invention relates to a direct current generator having a shell rotor displaced relative to permanent magnet pole pairs. More particularly, the invention is concerned with a direct current generator including a cylindrically shaped shell rotor having a multiplicity of longitudinally aligned copper segments in which said segments current is induced when the segments are displaced relative to permanent magnet pole pairs.

#Direct current generators have conventionally embodied a rotor comprised of coil windings in which currents are induced by a relative displacement of the windings with respect to a magnetic field. These coils are conventionally wound around a thin cylindrical nonmagnetic member to form a rotor as is typically shown in Hayes, U.S. Pat. No. 2,860,267. Alternately, direct current generator rotors have been constructed of a tubular nonmagnetic material supporting a plurality of windings of the printed circuit type which are deposited on the tublar nonmagnetic material.

#Both of these prior art rotor constructions present several obvious problems. In the case of the coil-wound rotor, the cross sectional area is limited by two factors. The first factor is that for a given pole pair gap, the size of the coil conductor cross-sectional area is limited by the necessity of having a nonconducting supporting material. The second factor reducing cross sectional area is the configuration of the coils. That is, coils having a circular cross section do not yield the most efficient utilization of space within the magnet pole pair gap. In the case of the printed circuit type of windings, the cross-sectional area of the conductors is limited not only by the necessity of having a non-conducting supporting material, but also by the inherent thinness of the printed circuit type of windings.

#FIG. 1 is a full sectional view of the preferred embodiment taken on the line 1--1 of FIG. 2 and showing in detail the construction thereof.

#FIG. 2 is an end view of the preferred embodiment shown in FIG. 1 looking in the direction indicated by the arrows 2--2 of FIG. 1 with portions broken away to illustrate the details of construction.

#FIG. 3 is a partial pictorial view of the shell rotor with the magnetic members shown schematically to more fully illustrate the principles of operation of the invention.

#Referring to FIG. 1, there is shown a DC generator generally designated as 10. The DC generator 10 is comprised of a frame structure 11 having parallel plate members 8 and 19 with suitable openings for shaft 12. The shaft 12 is journalled in bearings 13 and 14 to allow for the free rotation of the shaft 12. The frame structure 11 may be mounted by affixing either the plate members 8 and 19 or the housing 7 to a stationary member which is not shown.

#Fixedly attached to the shaft 12 is inner pole assembly 16 which consists of a permanent magnet member having, in the preferred embodiment, eight integrally formed longitudinally disposed radially outward facing poles, said poles having alternating polarity. The details of construction of the inner pole assembly 16 are more clearly shown in FIG. 2.

#Attached to the inner pole assembly 16 by means of an insulating member 17 is outer pole assembly 18. The insulating member 17 has a circular slot 9 therein. Disposed within the slot 9 is common conducting band 49 of shell rotor 23. Outer pole assembly 18 is comprised of a permanent magnet having, in the preferred embodiment, eight integrally formed longitudinally disposed radially inward facing poles, said poles having alternating polarity.