Apparatus for Soldering the Coil of an Electric Machine to Its Collector

This invention relates to an apparatus for soldering the wires of an armature coil to the collector or commutator of an electric machine.

An installation for soldering the coil to the collector of an electric machine is known; this consists of a device for creating a flow of molten solder connected with a device for supporting and fixing the rotor in space, and a device for rotating the rotor around its axis. The soldering of the collector is accomplished by dipping the collector elements in the flow of molten solder, while at the same time rotating it steadily around its axis.

Disadvantages of this installation are its complex construction and the complex system for melting, heating and controlling the temperature of the solder, the great length of the molten metal flow, and the consequent increased electrical energy consumption.

Another installation for soldering the coil to the collector of an electric machine is known; this consists of a device for creating a flow of molten solder, in the form of a monophase magnet-hydrodynamic pump consisting of a coil and a cylindrical magnetic core, such device being connected to a pan, a charger with two nozzles, means for rotating the armature with its collector around its axis, and a device for clamping, shifting and fixing the armature with the collector in respect to the charger and the nozzles.

This installation is designed mainly for soldering the coil to a front type collector. Its operation requires the rotation of the rotor of the electric machine, a longer working cycle, and a greater electrical energy consumption.

The object of the present invention is to provide an apparatus for soldering the coil to the collector of an electrical machine, such apparatus having a simpler construction, a higher productivity, and a reduced energy consumption.

This object is achieved by an apparatus in accordance with the invention for soldering the coil to the collector of an electric machine, such apparatus consisting of a device for clamping, shifting and fixing the armature with respect to the collector, a monophase magnet-hydrodynamic pump, a charger, and a pan containing molten solder. The magnetic core of the monophase magnet-hydrodynamic pump is shaped as a hollow cylinder which is chamfered at its upper end. Around the core, coaxially thereof, there is placed the charger, the lower end of the charger being disposed above the bottom of the pan. The upper, chamfered end of the core is disposed at the same level as the upper end of the charger. Between the upper end of the charger and the chamfered end of the core is provided an annular channel which leads liquid solder at a predetermined angle toward the axis of the collector. In a preferred embodiment of the invention an adjustable, armature-supporting and centering element is disposed within the hollow core.

The advantages of the apparatus of the invention, in comparison with other known apparatus, are its high productivity as a result of the simultaneous soldering of all of the collector elements; the design and servicing of the apparatus are also simpler. The apparatus is of small dimensions, and works with a relatively small electrical energy consumption.

The invention will be explained in more detail with the aid of the accompanying drawings, wherein:

FIG. 1 is a view in vertical section through a first embodiment of the apparatus shown in its working mold; and

FIG. 2 is a view in vertical section of a second embodiment of the apparatus of the invention, such apparatus being provided with an adjustable armature supporting and centering element.

Turning first to FIG. 1, under a pan 1 containing molten solder 2 there is disposed a monophase magnet-hydrodynamic pump 3, which has magnetic core in the shape of a hollow cylinder or sleeve which is externally shamfered on its upper end. Around the core 4 coaxially thereof there is disposed an annular charger 5, the lower end of which is disposed above the bottom of the pan 1, while the upper, smaller diameter end thereof is at the same level as the chamfered end of the core 4. The upper end of the charger 5 is of upwardly converging, frusto-conical shape parallel to the chamfer on the upper end of the core 4 so as to provide an annular channel 6 between the chamfered end of the core and the charger 5. The thus formed channel 6 is directed upwardly at a predetermined angle and has its upper, discharged end directed toward a segmented annular shoulder 8 having the segments thereof aligned with and forming parts of the segments of the collector 7 of the armature 10. The named, lower part of the collector is sealed from the molten solder supplied to the segments of the shoulder 8, to which wires (not shown) of the armature are to be soldered by an annular, heat resistant gasket 9 which may be made, for example, of asbestos. The weight of the armature 10 is born by the chamfered upper end of the core 4 acting through the gasket 9. The gasket thus effects a secure seal between the upper, chamfered end of the core 4 and the lower transverse edge of the segmented shoulder 8.

The apparatus of FIG. 1 functions as follows: the pan 1 is supplied with molten solder 2 which is maintained at the predetermined temperature by the heat produced by the functioning of the monophase magnet-hydrodynamic pump 3 and from electric resistance heaters (not shown) disposed around the cylindrical outer surface of pan 1. In armature 10 has a gasket 9 applied thereto as shown in FIG. 1, and the thus equipped armature is then mounted in the apparatus as shown. The monophase magnet-hydrodynamic pump 3 is then started. Pressure is created in the annular channel 6, under the action of which molten solder 2 flows upwardly pouring over the parts of the shoulder 8 and the wires to be connected thereto. The molten solder heats and enters the channels in the shoulder 8 and the ends of the wires, while the excess solder returns to the bath thereof in pan 1. After the soldering process has been completed, the pump 3 is switched off and remains so until the next armature 10 is mounted in the apparatus. As a result of the compression of the gasket 9, above referred to, molten solder cannot flow into the central opening in the core 4.

The second embodiment of the apparatus of the invention is shown in FIG. 2. Parts which are the same in FIG. 2 as those in FIG. 1 are designated by the same reference characters. The apparatus of FIG. 2 differs from that of FIG. 1 by having an adjustable centering and supporting means 11 for the armature 10 situated within the passage in the core 4. In this case, although the gasket 9 continues to seal the interior of the core 4 and the main, lower part of the collector 7 from the molten solder, it leaves the segmented shoulder 8, and the ends of the wires to be connected thereto, exposed to molten solder flowing upwardly to them through the channel 6.

The apparatus of the two functions in a manner quite similar to that of FIG. 1. Before placing the armature 10 in the apparatus, the gasket 9 is mounted thereupon in the position shown. Before mounting the armature 10 in the apparatus, the centering and supporting device 11 is appropriately adjusted by screwing the central, slotted screw thereof upwardly or downwardly, as the case may be. Means 11 carries most of the weight of the armature, but the gasket 9 sustains at least a small part of such weight so that it is compressed between the chamfered upper end of the core 4 and the shoulder 8. As before, the gasket 9 prevents the leakage of molten solder downwardly within the passage in core 4. The remainder of the soldering process is the same as that above described in connection with FIG. 1.

Although the invention has been illustrated and described with reference to preferred embodiments thereof, it is expressly understood that it is in no way limited to the disclosures of such preferred embodiments but is capable of numerous modifications within the scope of the appended claims.