US1293770A - Commutator-cylinder for dynamo-electric machines. - Google Patents

Description

R. E. HELLMUND.

COMMUTATOR CYLINDER FOR DYNAMO ELECTRIC MACHINES. APPLICATION FILED SEPT-27,1916.

1,293,770. Patented Feb. 11, 1919 UNITED STATES PATENT OFFICE.

RUDOLF E. HELLMUND, 0F SWISSVALE, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENN- SYLVANIA.

Specification of Letters Patent.

Patented Feb. 11, 1919.

Application filed September 27, 1916. Serial No. 122,374.

To all whom it may concern Be it known that I, RUDoLF E. HELLMUND, a subject of the Emperor of Germany, and a resident of Swissvale, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in commutator Cylinders for Dynamo Electric Machines, of which the following is a specification. v Y

My invention relates to the construction of commutator cylinders for dynamo-electric machines, and it has for its object to provide a commutator cylinder that is particularly adapted for use in connection with dynamo-electric machines of the high-voltage type.

In the construction of commutator cylinders for high voltage, it is essential that suficient insulation be provided in order to prevent electrical discharges between the conducting segments which are at machine potential and the V rings which are at ground potential. The obvious expedient is to increase the length of the creepage path which is usually defined as the shortest distance over the exposed surfaces of the insulating material between the live parts and the ground. The desired results have heretofore been obtained by merely extending the insulation beyond the conducting segments, but, owing to the space limitations existing in certain types of apparatus, such as railway motors, this has not always been found practicable.

According to the present invention, I provide a high-voltage commutator cylinder having a safe creepage path wherein the length of the commutator cylinder is actually decreased, as compared with existing types. Furthermore, my invention may be readily applied to commutator cylinders of the existing type by a slight modification in the form of one of the V-rings.

The single figure of the accompanying drawing is a view, partially in section and partially in side elevation, of a portion of a commutator cylinder embodying my invention.

A plurality of conducting and insulating segments 1 and 2, respectively, are alternately disposed upon V-rings 3 and 1 that are secured together by means of throughbolts 5 and serve to maintain the segments 1 and 2 in their proper relation. The V-ring 3 is shorter than the V-ring 4 and is provided with a flat annular surface 3 intermediate the ends of the commutator segments. The segments 1 and 2 thus project beyond the end of the V-ring 3, in the form of an annulus, the inner surface of which is of varying diameter. A layer 6 of insulation (preferably mica) is interposed between the segments 1 and 2 and the V-ring 3 and conforms to the inner surface of the segments 1 and 2. A ring 7, preferably com posed of a hard and durable insulating material, such as bakelite, and of varying diameter is secured to the face 3 of the V-ring 3 by means of bolts 8 which extend through openings 9 provided in the ring 7. The wedging action between the conical surfaces of the ring 7 and the mica insulation 6 insures a close fit therebetween. The openings 9 are formed with a countersunk portion 9 within which plugs 10 of insulating material are located. The insulating ring 7 is further provided with an inwardly extending annular flange 11 that is spaced from, and substantially parallel to, the surface 3 of the V-ring.

From the foregoing, it is apparent that the length of the creepage path provided by the insulating ring 7 and its flange 11 is several times L which represents the shortest distance from the end of the conducting segments 1 to the end of the V-ring. Furthermore, it is apparent that my invention may be embodied in existing types of commutator cylinders by merely shortening one V-ring and applying the insulating ring thereto.

While I have shown my invention in its simplest and preferred form, it is not so limited but is capable of various modifications within the scope of the appended claims.

I claim as my invention:

1. In a commutator cylinder, the combination with conducting and insulating segments, of a, supporting structure therefor, said segments projecting beyond the ends of said supporting structure, and an insulatin member located within the annulus forme by the projecting portions of said segments, said insulating member having an inwardly extending flange that is spaced from the remainder of the commutator structure and that provides a long creepage path between said segments and said supporting structure.

2. In a commutator cylinder, the combi-t nation with conducting and insulating segments and a supporting V-ring therefor, the said segments projecting beyond the end of said V-ring, of an insulating member located within the annulus formed by the pro jecting portions of said segments, sa d insulating member having an inwardly 'pro-' jecting flange to provide a comparatively long creepage path between said segments and said 'V-ring.

nation Withfconducting and insulating segments and 'asupporting 'V-rinfg therefor, the

' said segmentsproject'ing beyond the end of said V ring, of an insulating"member lo cated withln' the annulus formed by the projecting portions of sald segmentsand ha mg ani'nwardly projecting flange spaced 7 from said V ring. a

g 4. In "a con mutator cylinder, the combination with conducting and insulating'se'gcommutator cylinder, the combiments, of a cylindrical supporting structure therefor, said segments projecting beyond the end of said-supporting structure, and an insulating member located within the annulus formed by the projecting portions of said segments,"said insulating member having a tapering portion adapted to exert a we'd in force a must said se ents and also having aninwardly projecting flange that 1s spaced from theyrema-mder of the commutator-structure and that provides an extended cr'eepage path between said "segments and said supporting structure.

" in testimony whereof, I have hereunto subscribed myina-me this22nd day of Sept,

' RUn'oLF E; HELLMUND.

"Copies (if this patent ma be obtained for five 'cents 'aclij-by ajidressiifg tre-commissionermurmurs,

' washington, D. G.

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