US543383A - Dynamo-electric machine - Google Patents

Description

(No Model.)

' T. H. HICKS.

DYNAMO ELECTRIC MACHINE. No. 543,383. Patented July 23, 1895.

IVHWESSES 4 lm Em'm V z m4 By $9 242207722] I UNITED STATES PATENT OFFICE.

THOMAS H. HICKS, OF DETROIT, MICHIGAN.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 543,383, dated July 23, 1 895.

Application filed January 13, 1894:- Serial No. 496,756. (No model.)

.To aZZ whom it may concern:

Be it known that I, THOMAS H. HIcKs, a subject of the Queen of Great Britain, residing at Detroit, county of Wayne, State of Michigan, have invented a certain new and useful Improvement in a Radial Consequent- Pole Electric Machine; and I declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

This invention relates to certain new and useful improvements in radial consequentpole dynamoelectric machines. Said improvements refer specifically to the construction and arrangement of the field-magnets and the construction of the commutator used in connection therewith.

The two parts of my invention-via, the field-magnets and the commutator-I have illustrated separately, Figures 1, 2, and 3 referring to the field-magnets,'and Figs. 4, 5, and 6 to the commutator.

In the drawings, Fig. 1 is an end elevation showing all parts of my invention which refer to the field-magnets. Fig. 2 is a view in perspective of the magnet-cores upon which the field-coils are to be wound. Fig. 3 is a longitudinal section of the commutator. Fig. 4 is an end view of the commutator, serving to represent either end through the lines a: so of Fig. 3. Fig. 5 is a side elevation showing the external parts of a complete commutator except the cement R, which is omitted so as to expose the wire band L.

The field-magnet portion of my invention I describe as follows: The field-magnet consists of two radial cores or limbs B and B, joined to a triangular pole-piece O. The two magnet-limbs are secured to yokes F F. The limbs B and B are each wound with ordinary bobbins of wire D D, which are joined together in any well-known manner, so that when a current of electricity flows through the two bobbins or helices D D like polarities of one magnetic sign will be set up in the triangular pole-piece O and the opposite poles of the other polarity set up in the yokes F F. Each magnet-limb is wound with a helix or bobbin of wire, the helix of one limb being marked D and the helix of the other limb being marked D. T is a space which separates the ends of the yokes.

The dotted lines P P in Fig. l indicate the axes of the two magnet-limbs B B, and the dotted line P indicates the magnetic axis between the two field-poles of opposite polarities, one of said poles being marked with dashes (thus, and the other by crosses (thus,

My chief object in constructing the fieldmagnet of two radial limbs and forming one polein the yokes is to shorten the return magnetic circuit through the yokes. If a magnet having only one limb were used instead of the one I have described, its length would require to equal the total length of the two limbs I show. In such a case the outerend of the one-limb magnet would be located at W, Fig. 1,the magnetic circuit being thereby increased the extra distance, which I indicate by the dotted lines which start from the point W and terminate in the outer ends of the dotted lines P P, representing the axes of the two limbs B B. A biradial magnet of itself is not new; but a biradial magnet having one of the polepieces located in the yokes and the space T, which prevents magnetic leakage from the pole-piece C to the outer ends of the magnets, forms a new combination.

G2 in Figs. 1, 2, 3, 4, and 5 indicates a shaft. The commutator is constructed as follows: I take a sleeve G, Figs. 3 and 4:, which may be of iron, and I cover this sleeve with an insulating-band H, upon which the commutatorsegments J are arranged and pressed firmly around the insulation by a powerful annular clamp, which is only used during construction, and hence is not shown in the drawings. The segments of the commutator thus held together are then turned off in a lathe, forming sunken portions of the segments at the end peripheries, and also in a portion of the segments corresponding to portions of the commutator coming between each pair of brushes used. The sunken portions of the ends referred to are marked K, and the portion between the brushes is marked K Figs. 6 and 8. These sunken portions, which form annular grooves, are next insulated at the bottom and sides, and each one is then wound with a band of strong wire. The convolutions of said wire are then soldered together, and the end bands are then turned off in the lathe. The bands of wire are marked L. A metal ring M is next turned off in the lathe, so that its inner surface will just pass over the wire bands L when strong force is applied. The central band or bands do not require an outer ring M. hVhen the commutator is thus far constructed, the annular clamp above referred to is next removed and the commutator can then be turned off on the periphery surface and ends. I next put insulating-disks of asbestos at the ends of the commutator over the sleeve and then screw a nut at each end of the sleeve against the asbestos. The nuts are marked N and the asbestos O. The nuts are only used for protection to the ends of the segments and for appearance. They do not assist in holding the commutator together, the rings M and the bands L being alone used for that purpose.

My objectin using a spongy substance, such as asbestos O, is to allow still further com pression thereof when the segments of the commutator expand in length by heat during rotation. In this way expansion of the segments does not affect the integrity of the commutator. The band L is to prevent the segments from rising in their center during expansion and rotation, which is sure to occur when long segments are used and when only held together from their ends alone. After the wire band L is wound in the annular groove K, I then fill each groove on the top of the band with a suitable cement, such as plaster-of-paris. \Vhen the cement, is turned off even with the segments of the commutator it maybe shellacked. The cement is marked R and is shown in section in Fig. 6. When verylarge commutators are to be made, I then prefer to widen the base of the groove K, so as to form a slight dovetail. This I do to more securely prevent the plaster-of-paris from coming out of the groove; but it is very diffioult to get it out of the grooves even when its sides are parallel to each other. The cement prevents all metallic dust from short-circuiting the commutator-segments and adds to the appearance also.

When carbon brushes are used it becomes necessary that the comutator should preserve its external shape while hot and during rotation. Otherwise, heat and sparking at the brushes would occur to a detrimental extent. A commutator constructed in a manner such as I have described prevents the segments from either sinking or rising, the sleeve above described preventing them from sinking and the wire bands and metal rings preventing them from rising.

My object in using a wire band L under the metal ringM'is to prevent the ring from either wrinkling, tearing, or moving the insulation which is under the band. It would be impossible to obtain sufficient pressure by the ring alone if pressed over the insulation without the wire bands. Instead of pressing the rings over the wire bands the former may be screwed on, using the wire as a thread and then threading the ring to match the wire; but such a method would be more trouble to carry into practice. \Vhen only one pair of brushes is used the groove K and its wire band L may be omitted, this band only becoming necessary when the com inutator-segments are beyond a length required for one pair of brushes.

\Vhat I claim as my invention is- 1. In an electric machine, a field magnet consisting of two radial limbs B and B, a polepiece 0 of one magnetic polarity joining said limbs together at one end, separate yokes F and F joining the other ends of said limbs, the ends of the yokes, joined to the magnetliinbs, being separated by a space T; the magnetic polarities of the outer ends of the magnet-limbs, established in the yokes, having an opposite polarity to the pole-piece O, substantially as described.

2. In an electric machine, the combination with yokes, F and F, of a field magnet having only two radial limbs, B and B: said yokes having located therein one of the field poles, substantially as described.

3. In an electric machine, the combination with yokes F and F, separated from each other at one end by the space T, of a field magnet having radial limbs B and B, and having one of the magnetic field-poles located in said yokes, substantially as described.

4.. In an electric machine, the combination with yokes F and F, of a field magnet having only two radial limbs 13 and B; said yokes being separated at one end by the space T; magnetic poles of one polarity being located in said yokes, substantially as described.

5. In an electric machine, the combination of yokes F and F, with field magnets each consisting of radial limbs B and B, and a pole-piece O; the yokes each being bolted to one of the outer ends of the radial limbs; each pair of yokes and radial limbs beingseparated at their ends by an open space T, substantially as described.

6. In an electric machine, the combination of two field magnets each having two radial limbs 13 and B, and a pole-piece C; of the yokes F and F uniting said field -magnets, only one of said yokes being secured to the base of the machine; the ends of the yokes being separated from each other by an open space between each pair of radial limbs B and B substantially as described.

'7. In an electric machine provided with field magnets, an armature, armature shaft, and a commutator, the commutator constructed with a sleeve, G, mounted on the armature shaft, commutator segments insulated from the sleeve, said segments of said commutator constructed with annular grooves located at the peripheral ends of the segments; wire bands, L, located in said grooves and insulated from the segments, and rings located upon said wire bands, substantially as described.

8. In an electric machine provided with field magnets, an armature, armature shaft, and a commutator, the commutator con structed with a sleeve, G, mounted on the armature shaft, segments insulated from the sleeve, the segments of said commutator constructed with annular grooves located at the peripheral ends of the segments; an annular groove intermediate the ends of said commutator, wire bands located in each of said grooves, the intermediate wire band preventing the commutator segments from rising in the center during the rotation of the armature, substantially as described.

9. In an electric machine, a commutator constructed with an annular groove, K, and a wire band located in said groove to prevent the commutator segments from rising during the rotation of said commutator, substantially as described.

10. In an electric machine, a commutator constructed with an annular groove, K, a wire band located in said groove to prevent the commutator segments from rising during the rotation of said commutator, and a covering cement located upon said wireband, substantially as set forth.

11. In an electric machine, a commutator constructed with annular grooves, K, toward the extremities of the commutator, wire bands located in said grooves and insulated from the commutator segments, substantially as described.

12. In an electric machine, a commutator constructed with annular grooves, K, toward the extremities of the commutator, wire bands located in said grooves and insulated from the commutator segments, and rings located THOMAS H. HICKS. Witnesses:

N. S. WRIGHT,

OTTO B. BARNZIGER.

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