Repair and restoration of shafts, couplings, splined and keyed joints

Abstract

The article provides an overview of the methods of restoration and repair of various parts of the equipment: shafts, couplings, splined and keyed joints. Recommendations on the choice of methods, equipment and tools are given. In case of wear, the keyway is repaired by welding the face with subsequent milling. At the same time, the keyway size set by the standard is maintained. Such repairs are also possible: the keyway is expanded and deepened, completely eliminating the traces of wear, after which a stepped key is made to it. However, with such repairs, a high-quality connection is not provided and, therefore, it is used in exceptional cases (during inspections and ongoing repairs). When repairing keyed joints, the worn keyed joints are not repaired, but new ones are made, fitting them to achieve a firm contact with the side surfaces of the grooves of the connected parts. The exception is the taper keys: they are driven into the keyway with a hammer blow so that they are jammed in height. The taper key should also be hammered in such a way that, when loosened, it can be deposited. Between the head of the key and the end of the part, there must be a distance equal to the height of the key. The connection with the help of splines is used for fixing gears, gear wheels, and bushings on the shafts. It has a number of advantages over other types of connection. The component parts of this joint are more easily centered. This significantly reduces mechanical deformations at the bushing boundary. During operation, under the influence of various loads, the spline joint loses its properties. In this case, the splines or grooves in which they are placed are restored. Splines of small rollers are usually not repaired; the parts with worn splines are mostly replaced with new ones. Such work is carried out in specialized workshops. In some cases, the repair and restoration of such products is carried out in a small workshop, but equipped with the necessary machines.