Abstract:
In the method proposed a peripheral wall with at least one axial section of high shaping and fitting accuracy is made by forming an initial blank. This accuracy is achieved, in that before the peripheral wall is formed, sheet material which has been put into a plastic state is swaged in places round the periphery, then the swaged locations are sized, and/or in that during or after the formation of the peripheral wall, the wall is shaped by stamping in a plurality of places along its periphery, whereby the said zone providing shaping and fitting accuracy is formed from fitting areas at at least one side of the peripheral wall in the region of the swaged and/or stamped locations. An apparatus for carrying out such a method is generally in the form of a drawing machine, wherein the holder and/or the bottom die contain radial apertures, which open into the inner edge of the holder and/or into the shaping cavity of the die, and which are arranged at intervals round the periphery. The wall surfaces of the upper die and/or of the shaping cavity act as sizing surfaces to form fitting areas in swaged locations on the peripheral wall of the shaped part, the swaged locations being formed by said apertures.
Abstract:
A multistage in-line rotary pump which comprises a closed pump body, a base element provided with suction and delivery connectors, and a head element. The pump body is surrounded by a cylindrical jacket or casing spaced from the pump body to form an annular return space, which casing is clamped between the base and head elements by means of stay bolts. Flat joints are provided between the base and head elements and the respective axial ends of the casing. To prevent high areal compression stresses in the area of the flat joints, the two extremities of the casing are plastically deformed to obtain a wall thickness which is greater than the wall thickness of the rest of the casing tube.