US2946908A - Commutator arrangements - Google Patents

Description

July 26, 1960 G. ULBRICH 2,946,908 COMMUTATOR ARRANGEMENTS Filed Sept. 4, 1956 INVf/VME; Gerhard Ulbrich United States Patent J COMMUTATOR ARRANGEMENTS Gerhard Ulbrich, Stuttgart, Germany, assignor to Robert Bosch, G.m.b.H., Stuttgart, Germany Filed Sept. 4, 1956, Ser. No. 607,707 Claims priority, application Germany Sept. 8, 1955 Claims. 01. s 234 The present invention relates to electric motors of the type used, for example, in automobiles and other engine driven vehicles.

More particularly, the present invention relates to the manner in which the armature wires of such a motor are connected to the several commutator bars of the motor.

One of the objects of the present invention is to provide a superior electrical contact between the armature wires and the several commutator wires.

Another object of the present invention is to connect the armature wires to the commutator bars in a manner capable of withstanding centrifugal forces resulting from high speed rotation of the armature.

A further object of the present invention is to provide a structure capable of accomplishing the above objects and at the same time composed of simple and ruggedly constructed elements which are very reliable in operation.

With the above objects in view the present invention mainly consists of an electric motor which includes a commutator ring having a plurality of. electrically conductive commutator bars parallel to and distributed about the axisof an armature which carries the commutator ring, these bars being spaced and insulated from each other. Each bar has an end directed toward the armature and formed with a pair of slots substantially parallel to each other and extending substantially radially from the axis of the. armature. A pair of armature wires are located over each bar at its end adjacent the armature with one of these wires located between the bar and the other of the wires. An electrically conductive elongated connector has a pair of legs respectively extending through said slots and embracing the wires for holding the latter together and in operative relationship with each bar.

The novel features which areconsidered as characteristic for the invention are set forth in. particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Fig. l is a fragmentary axial sectional elevational view of a commutator according to the present invention; and

Fig. 2 is an end view of the structure of Fig. 1 as seen from the left side thereof.

The commutator includes a ring 10 of pressed electrically non-conductive material in which the individual electrically conductive commutator bars 11 are anchored by the hook-shaped portions 12 of each bar which are embedded in the insulating material of the ring 10, the commutator bars being distributed about and parallel to the axis of the unillustrated armature which carries the commutator, and these bars being parallel to and insulated from each other. Portions 16 of the ring 10 are respectively located between the bars 11, and the end of the ring 10 adjacent the armature is formed with an annular cutout at the exterior of the ring 10. A plurality of partitions 14 are respectively jointed to the portions 16 of the ring 10 and are carried by the latter respectively in planes extending radially from the axis of the armature, these partitions 14 being made of electrical insulating material and extending across the annular cutout at the end of the ring 10 to divide the annular cutout into a plurality of spaces 13 separated from each other by the insulating partitions 14. The bars 11 respectively have free ends which respectively extend into the spaces 13, and the end face of each bar 11 is formed with a pair of slots 17 which are parallel to each other and which extend substantially radially from the axis of the armature. In other words, the pair of slots 17 of: each bar 11 do not extend radially from this axis but extend almost radially from this axis, and each pair of slots are parallel to each other.

A. connector 18 made in one piece from a strip of electrically conductive sheet metal or the like and having substantially the configuration of a ladys hair pin is associated with each bar 11 and has a pair of legs respectively located in the pair of slots 17 of each bar 11, the thickness of this strip being substantially equal to the width of the slots. As a result, each leg of each connector 18 is in electrical contact with the bar 11 to which itis connected at both side faces and one edge face of each portion of each leg which is located in a slot 17, so that a very large area of contact is provided. The outwardly extending portions of the legs of each connector 18 located outwardly beyond each bar 11 embraces a pair of wires 19 and 20 extending from the windings. of the unillustrated armature, these wires being in elec trical contact with each other and with the connector 18, and the wires 19 respectively engaging directly andbeing in electrical contact with the bars 11. Only the ends of the wires 19 and 20 are embraced by the connectors 18. The pairs of wire ends 19 and 20 are dipped in solder so as to provide a good electrical conduction between each pair of wires and the connector 18 as well as between the wires 19 and the bars 11, respectively. Moreover, the solder provides a superior mechanical connection between the parts. It will be noted that with the structure of the invention even when the armature rotates at high speed the parts will be able to reliably resist the action of the centrifugal forces.

It will be understood that each. of the elements described above, or two or more together, may also find a useful application in other types of commutators differing from the types described above.

While the invention has beenillustrated and described as. embodied in. commutator connections, it is not in.- tended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. In an electric motor, in combination, a commutator ring having a plurality of electrically conductive commutator bars parallel to and distributed about the axis of an armature which carries said ring and spaced and insulated from each other, each of said bars having an end face directed toward said armature and formed with Patented July 26, 1960 a pair of slots substantially parallel to each other and extending spaced from each other and the side faces of said bar substantially radially from the axis of the armature and substantially normal to said end face into each bar, said slots defining between themselves a central end portion in each bar; a pair of armature wires located over each bar at its end adjacent the armature with one of said wires directlyengaging the outer face of said bar and located between the latter and the other of said wires and engaging the latter; and an electrically conductive loop-shaped connector having a pair of legs respectively extending through said slots and embracing said central end portion and said Wires for holding the latter together and in operative relationship with each bar.

2. In an electric motor, in combination, a commutator ring having a plurality of electrically conductive commutator bars parallel to and distributed about the axis of an armature which carries said ring and spaced and insulated from each other, each of said bars having an end face directed toward said armature and formed with a pair of slots substantially parallel to each other and extending spaced from each other and the side faces of said bar substantially radially from the axis of the armature and substantially normal to said end face into each bar, said slots defining between themselves a central end portion in each bar; a pair of armature wires located over each bar at its end adjacent the armature with one of said wires located between said bar and the other of said wires; and an electrically conductive loop-shaped connector having a pair of legs respectively extending through said slots and embracing said central end portion and said wires for holding the latter together and in operative relationship with each bar.

3. In an electric motor, in combination, a commutator ring having a plurality of electrically conductive commutator bars parallel to and distributed about the axis of an armature which carries said ring and spaced and insulated from each other, each of said bars having an end face directed toward said armature and formed with a pair of slots substantially parallel to each other and extending spaced from each other and the side faces of said bar substantially radially from the axis of the armature and substantially normal to said end face into each bar, said Slots defining between themselves a central end portion in each bar; a pair of armature wires located over each bar at its end adjacent the armature with one of said wires located between said bar and the other of said wires; and a loop-shaped electrically conductive onepiece metallic connector having a pair of legs respectively extending through the slots of each bar and embracing said central end portion and said wires for holding the latter together and in operative relationship with said bar.

4. In an electnic motor, in combination, a commutator ring having a plurality of electrically conductive commutator bars parallel to and distributed about the axis of an armature which carries said ring and spaced and insulated from each other, each of said bars having an end face directed toward said armature and formed with a pair of slots substantially parallel to each other and extending spaced from each other and the side faces of said bar substantially radially from the axis of the armature and substantially normal to said end face into each bar, said slots defining between themselves a central end portion in each bar; a pair of armature wires located over each bar at its end adjacent the armature with one of said wires located between said bar and the other of said wires; and a loop-shaped electrically conductive one-piece metallic connector having a pair of legs respectively extending through the slots of each bar and embracing said central end portion and said wires for holding the latter together and in operative relationship with said bar, saidw-ires and said connector and commutator bar associated therewith being soldered to each other.

5. In an electric motor, in combination, a commutator ring composed of a tubular support of electrically nonconductive material having an end face directed toward an armature which carries said ring formed with an outer annular cutout and said ring including a plurality of commutator bars parallel to and distributed about the axis of the armature and carried by said tubular support in spaced parallel relationship to each other, each of said bars having a free end portion extending into said cutout and having at said free end portion an end face formed with a pair of slots substantially parallel to each other and extending spaced from each other and the side faces of said bar substantially radially from the axis of the armature, said slots defining between themselves a central end portion in each bar; a pair of armature wires located over each bar at its end adjacent the armature with one of said wires located between said bar and the other of said wires; and an electrically conductive elongated connector having a pair of legs respectively extending through said slots and having a connecting portion integral with said pair of legs and located in said cutout closely adjacent to said free end portion, said elongated connector embracing said free end portion and said wires for holding the latter together and in operative relationship with each bar.

References Cited in the file of this patent UNITED STATES PATENTS Germany Oct. 22,

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