Submersible multistage centrifugal pumps and method of making the impeller and guide vanes pump stage

摘要

1. The submersible multistage centrifugal pump comprising a housing, a shaft, stage consisting of an impeller and a guide vane formed by casting from cast-iron of the following composition, wt.%: Carbon 3,2-3,9kremny 0,2-1,0marganets 0 5-0,8hrom 0,1-0,5med 0,8-1,5alyuminy 1,7-4.0titan - 0,0-0,3fosfora not more 0,2sery 0,02zhelezo not more than the rest, and impeller surfaces and guiding apparatus comprise nitrided layer of low-temperature nitriding, impellers mounted on the shaft by means of hubs rotatably and contain lower ae -hand wheel support with the support surface of the blade, the hub, an upper axial bearing with a bearing surface and guide vanes mounted in the pump housing by a cylindrical cage comprise a support shoulder with the support surface of the guide apparatus, a cylindrical holder, the blade, a lower supporting surface, wherein that impellers nitrided layer of the support surface of the lower axial bearing contact with the bearing surface nitrided layer of the support collar of the guide apparatus, forming a pair treniya.2. Pump according to Claim. 1, characterized in that the supporting surface of the upper axial impeller support adapted to contact nitrided layer, forming a friction pair with the nitrided layer of the lower support surface of the guide apparata.3. The pump according to claim. 1 and 2, characterized in that the nitrided layer is formed by low-temperature nitriding thickness of 30 to 500 microns and bolee.4. A method of manufacturing the impeller and the guide vane stage of a multistage submersible centrifugal pump comprising alumina surface entry under disintegrations