US2198395A

US2198395A - Collector ring

Info

Publication number: US2198395A
Application number: US219847A
Authority: US
Inventors: Harry B Spear
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-07-18
Filing date: 1938-07-18
Publication date: 1940-04-23
Anticipated expiration: 1957-04-23

Description

April 23, 1940. a SPEAR 2,198,395

COLLECTOR RING Filed July 18, 1958 Patented Apr. 23, 1940 UNITED STATES PATENT OFFICE 5 Claims.

My invention relates to new and useful improvements in collector rings for electrical machines; such as generators, motors, rotary converters, or other types of alternating current machines in which a rubbing contact is maintained between the brushes and the ring contacts mounted on a rotary element.

Heretofore, as rings have been ordinarily constructed, it was extremely diflicult to replace the old worn ring with a new one. The collector ring according to my invention is constructed with a removable wearing member so that when the wearing surface of the ring is worn, this member may be replaced easily and readily. I divide my collector ring into two parts which for convenience are termed respectively, the inner ring member and the outer or wearing ring member.

The primary object of my invention is to provide a form of collecting device, such that the parts thereof are easily constructed and readily assembled and such that the outer wearing member is firmly and effectively connected mechanically to the inner ring member by means of screwthreads and a screw set.

A further object of my invention is to substan- A tially increase the surfaces of the two members in contact so that there shall be the maximum electrical conductivity and no resistance developed between them. 1

Another object of my invention is to construct a simple and eflieient form of a collector ring which can be changed readily without removing the rotor of the dynamo-electric machine but which will not work loose under the stress of operating conditions.

With the foregoing and other objects in view which will appear as the description proceeds, my invention consists in the novel features hereinafter described in detail, illustrated in the accompanying drawing, and particularly pointed out in the appended claims. It will be understood that the invention is not limited to the details disclosed but includes all such variations and modifications as fall within the spirit of my invention and the scope of the appended claims.

In the drawing:

Fig. 1 is a side view partly in section showing the shaft, the inner and outer ring members, with the latter secured according to my invention;

Fig. 2 is a side elevation of the collector ring mounted on the rotor shaft, and

Fig. 3 is a transverse section along line 3--3 of Fig. 2.

As shown in detail in the drawing, the improved collector ring includes a rotor shaft 4, an

inner ring member 5 and an outer member 6. The inner member of the collector ring is insulated from shaft 4, the insulation being shown at 1. I provide a key 8 by which the inner ring member is keyed to the shaft.

The inner and outer ring members are firmly secured together by means of a screw thread 9, preferably relatively fine such as thirty-six threads per inch for a motor of average size. In

order to secure more firmly the two ring members, 7

I use a set screw Ill which may be of twelve gauge and twenty-four threads per inch for such a motor. I next provide two holes II in one side wall of the outer member for a spanner wrench in order to facilitate its assembly on the inner memher or its removal for replacement.

At the left of Fig. l, I have iullustrated the complete assembly partly in cross-section. The assembly is shown in side elevation in the center and at the right is shown the inner ring alone. The connections between the inner rings and the individual windings of the rotor or armature are of the usual construction and have been omitted for simplicity in illustration.

My arrangement permits permanent mounting of the inner rings on the shaft and their connection with the armature windings. The diameters of the several inner rings may be progressively diminished in the direction away from the armature windings to allow easy clearance in assembly and removal of the separate outer rings.

These outer rings are assembled on the respective inner rings by screw-threading. The fineness of the threads increases materially the contact surfaces between each outer wearing member and the inner member. Thus the electrical conductivity between each pair of rings is not materially affected by this mode of assembly. The screw-threading is facilitated by the use of a spanner wrench in the holes I I.

The final attachment between the inner and outer rings consists of the set-screw i0. This locks the rings against relative rotation. At the same time it permits slight thermal expansion of the outer ring relative to the inner ring. Such expansion does not lessen materially the electrical conduction between the rings since adequate contacting area is providedby the fineness of the screw-threads. When the wearing surface of the outer ring becomes Worn, pitted or uneven, the ring may be removed for repair or replacement in the manner above described.

This structural arrangement is a suitable means whereby the inner and outer ring members may be effectively secured and the invention may obviously be varied within the scope of the appended claims.

What I claim is:

1. A collector ring comprising an inner ring member and an outer ring member, the inner member having a threaded outer annular surface, and the outer member having a threaded inner annular surface directly engaged with said outer surface.

2. A collector ring comprising an inner ring member and an outer ring member, the outer member being secured to the inner member by threaded means and by a set screw in co-operation with said threaded means.

3. A current-collecting device for electrical machines, a supporting member, an inner ring member fixed to said supporting member, and an outer ring member secured to the inner ring member by means of screw threads.

4. A collector ring comprising an inner ring member screw-threaded on its outer surface, an outer ring member internally screw-threaded, and means for locking said members together against relative rotation.

5. In combination a collector ring comprising an armature shaft with a key-Way, an inner ring member screw-threaded on its outer surface, insulation between said shaft and ring, a key for fastening the ring on the shaft, an outer Wearing ring having internal screw-threads complementary to those on the inner ring, and means for locking the rings together.

HARRY B. SPEAR.