TURBINE BUSHING Russian patent published in 2002 - IPC

FIELD: mechanical engineering; liquid handling pumps. SUBSTANCE: part of working surface of bushing is made with opposite and parallel rectangular slots formed by cuts of flats with plane-to- plane distance to slot or slots width ratio being 22: 5. Axial length of shoulder of end face zone and total length of turbine bushing ratio is 3: 44.9. Inner surface of bushing hole is machined with negative tolerance whose minimum is (-33μm). With turbine wheel mounted, seat working surface of inner hole has minimum tolerance equal to (-11μm). Change of said tolerance does not relate to 40% of axial distance in inner hole of bushing free from contact with seat surface designed for mating with driven shaft. End face of bushing engaging with graphite ring. Hardness 49 HRc, is made multi- profile provided with conical surfaces with angles of generating lines equal to 11 and 15 degrees relative to surface of central hole. No perpendicularity of surfaces of working end face and axis of bushing does not exceed 50μm, and said end face is hardened by high-frequency currents to depth of 1,5...2,5μm to ≥ 42 HRc.. EFFECT: increased service life and reliability in operation. 3 dwg