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Tham khảo tài liệu 'machining and monitoring strategies part 9', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Machining and Monitoring Strategies 511 static bearings58 offer the indirect benefits of improved hard-part machined surface texture greater component accuracy and precision coupled with increased tool life. While due to the fact that hydraulic fuild is virtually incompressible if an interrupted cut occurs for any reason the tool can later pick-up exactly where the interruption occurred thereby eliminating the ostensibly termed witness marks on the machined surface. Great demands for increased spindle power are not necessary as typical DOc s are 0.75 mm coupled to small feedrates. With for example the cutting data for a Ộ12 mm hard-turned part might be by utilising a spindle speed of 4 500 rev min-1 which equates to a surface speed of 170 m min-1. This is well within the capabilities of some turning centres today that have spindle speeds of 10 000 rev min-1. As one can gather from this discussion hard-part turning and threading Fig. 251a is principally concerned with saving money by removing additional and now superfluous operations from the overall product s cycle time. It has been reported by industrial-users that by utilising a hard-part turning strategy then the total time to complete the component has been reduced by up to 75 when compared to the traditional approach of roughturning then heat-treating and finally cylindrically grinding. This latter process of cylindrical grinding can still be valid where extremely tight tolerances are to be held coupled to when high-quality surface texture demands are to be met. Often both for large-batches or if continuous production runs are necessary for either hard-part finished turning or when cylindrical grinding they require critical dimensional tolerances to be held across certain diameters or indeed for their lengths. In this metrological situation a receiver gaug 58 Hydro-static bearing performance is characterised by three factors these are its load-carrying capacity oil flow-rate and pumping power. The magnitudes .
