Patent GB-189718548-A (GB)
Title: Improvements in the Construction of Electrical Motors and Generators.
Inventor: SHORT SIDNEY HOWE
Filed: 1897-08-10
Granted: 1898-03-19
Abstract: 18,548. Short, S. H. Aug. 10. Drawings to Specification. Dynamos and motors.-Comprises various detail improvements in the construction of generators and motors. Armatures.-An armature core is built up from a number of plates or laminµ, toothed at the edges to receive the inductors and their insulation. The plates are made to gauge, and are cut and trued according to size. The various layers are put together so as to break joint, the inner edges being dovetailed to fit into similar recesses in the supporting-spider. The plates may have bent tongues or raised stampings, so as to form ventilating or cooling spaces ; the external teeth may also be bent transversely. The laminated cores are secured to the spider by side cheeks and through bolts. The peripheries of the side cheeks are recessed and covered with insulation, so that, when the inductors are laid in the insulating-troughs, between the teeth of the core, binding-wires and protective coverings may be placed round the inductors without forming projecting ridges on the surface of the armature. Commutators.-Two forms of commutator bars are described, one in which the bars are grooved obliquely to receive the inductor connecting-strips, and the other in which projections are formed on the bars to engage with the inductor connections. In the first form, the bars are built up and separated by insulating-sheets provided with projecting portions to separate the inductor connections. The bars are supported on insulating-sleeves, and are recessed at the ends to receive insulating-rings which are clamped into position through end rings. The inductor connections consist of multiple flexible strips of copper, riveted together and to the bars, and at their outer ends embracing the inductors. In the second form, the commutator bars are dovetailed to receive moulded insulating-rings clamped into position by end rings. The commutator is trued in building by compression in a circular split ring surrounded by an outer ring provided with pressure screws. Field magnets.- The field-magnet cores are either formed of laminµ bunched and riveted together, or of solid portions provided with slots and grooves. The series of cores are arranged in position and the annular yoke is cast on to the butt ends, rigid connection being formed by the grooves and slots. The windings are prepared as flat coils, and are then curved by pressure so as to fit into the ring or yoke, the pole-pieces being afterwards secured in position. Brushes and brush-holders.-The brush-holders are mounted by means of insulating-sleeves in an adjustable ring carried by grooved projecting arms from the magnet yoke or frame. The adjustment is secured by means of a tangent-screw mounted on the frame and connected to the brush ring by a binge joint. The brush-holders are connected in two series by means of conducting-rings passing through their outer extremities. The brush-holder itself is preferably formed of a spring-mounted jaw, having an adjustable pressure spring and a clamping-plate provided with two screws for ensuring a parallel grip. In another form, a spring and lever are employed for holding the brush both to the holder and against the commutator. Casings.-A casing is provided which is formed in two parts secured together and has peep holes for showing the relative adjustment and position of the armature and field magnets. Frames.-The frames of the machines are arranged so that the field-magnet ring is supported on preferably grooved side supports provided with lateral and transverse adjusting-screws. These supports form the edge of a pit, in the centre of which is placed a jack-screw forming a central bearing for the magnet ring. The armature is carried by separate supports so as to allow adjustment between the parts.