Insulated pole and coil assembly and method of making same

摘要

A dynamoelectric machine pole and coil assembly having a magnetic pole member around which a preformed coil of insulated magnet wire is mounted. The assembly is characterized by including a plurality of preformed, extended corner sheets of insulating material that are positioned to extend around and beyond each of the corners of the magnetic pole member into overlapping relationship with adjacent extended corner sheets. The extended corner sheets are bonded to the pole member and to one another at their overlapped ends. Projecting tip portions on the magnetic pole member have their upper surfaces completely shielded from the energizing coil by lip parts of the extended corner insulating sheets. A felt piece impregnated with thermosetting resin is used to make a readily conformable corner section of the lip part. The cured piece is free of voids, so reinforces the insulation of the ground barrier of the assembly at the critical corner areas. A castable dielectric material forms a rigid body between the sheets of insulating maerial and the energizing coil to provide good thermal conduction for dissipating heat from the coil to the pole member. One aspect of the invention is a method for making a pole assembly with preformed sheets of insulating material so that each such sheet is provided with a relatively uniform, smooth lip surface including a corner section for each lip part of the insulating sheets so that they can be smoothly adhered to the surface of the magnetic pole member to which they conform closely in surface configuration, thereby to avoid the formation of air spaces between it and the associated coil when those components are assembled in operating position.