Вестник Дагестанского государственного технического университета: Технические науки (Mar 2017)
INCREASE IN THE WORKING LIFE OF SCREWS OF IMMERSION PUMPS BY VIBRATORY FINISHING OF THEIR SURFACES
Abstract
Objectives. To investigate the increased performance possibilities of screws on submersible pumps by vibratory finishing of their surfaces. Method. The vibratory finishing method is based on two principles: rejection of light plastic deformation polishing as well as the complication of kinematics associated with known cold working processes. Results. A schematic diagram of vibratory finishing; the compiled graphs show pressure, occurring in the surface layer of steel 30KhGSA when lathe turning and vibratory finishing; the microhardness dependence on the work hardening distribution depth at rolling and vibratory finishing is determined. It is established that since vibratory finishing is a method of hardening, kinematic and dynamic characteristics of the process are connected, as in other types of finishing, with characteristic indicators of machined surfaces. The task of developing methods for determining the vibratory finishing regime is complicated, firstly by the number of parameters that determine the process conditions being considerably greater than tumbling and other processing methods with relatively simple kinematics; secondly, due to the fact that all the mode parameters affect all surface quality characteristics in one way or another. Conclusion. When vibratory finishing the surface layer of a screw submerged in a vibratory machine, using steel shots for burnishing, an extension of the surface layer's elastic-plastic deformation to a certain depth is achieved. The temperature at the time of vibratory finishing, according to conventional standards, does not exceed 150-300OC; moreover, it decreases sharply with increasing depth and at room temperature is already at the depth of 0.1-0.3 mm from the surface of the screw. Microrelief optimisation of the bearing surfaces is the most effective way to improve conformability, reduce the run-in and normal wear and improve anti-seize properties.The efficiency and potential for the use of vibratory finishing in virtually all areas of the metal industry is proven.
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