The purpose of this study was clarified optimum shapes and dimension of pole-piece at linear magnetic gear to be obtained the maximum transmission load. The linear magnetic gear composed by two plate magnets unit and ferromagnetic pole piece based on magnetic gear design. Gear ratio of the linear magnetic gear designed at 1/2, 1/3 and 1/6, the gear ratio. The shape of pole piece was designed six various types such as symmetry Box type, I type, Drum type, asymmetry S type, Z type and SZ type, and the width of pole piece was 8mm and 12mm. By the transmission test result, the optimum shape of pole-piece was Drum type, the maximum driven load of Drum-type pole-piece in width 8mm (D8) was 57N, minimum driven load of ZS type in width 8mm (ZS8) was 36N at gear ratio 1/3. When the gear ratio was larger, the driven magnet hardly affected by magnetic flux of pole pieces that change magnetic pole, because the distance between two pole-pieces which change magnetic pole was larger. For the same reason, the optimum width of pole-piece was 8 mm rather than 12mm.

This paper presents an experimental study on the high-speed milling of stainless steel (SUS13Cr) and titanium alloy (Ti-6Al-4V) for high-efficiency machining of steam turbine blades. As experimental conditions, the cutting speed was used as a parameter, and the width of flank wear of the outer edge of the end mill, the surface hardness of the machined surface, and the observation results of the end mill surface using energy dispersive X-ray analysis (hereinafter abbreviated as EDX) were used as evaluation criteria. The results show that the width of flank wear becomes larger at higher cutting speeds for both materials and that the surface hardness of the machined surface became harder at higher cutting speeds for stainless steel. It can be presumed that this is because the coating on the end mill is peeled off and the coefficient of friction at the cutting point is increased, which increases the strain on the surface of the crop, resulting in work hardening. As a result of using two types of coated endmills with different heat resistance temperatures on titanium alloy, a sudden increase in the width of the flank wear of the outer edge of the end mill occurred at an inflection point under a certain cutting speed. By using EDX, it was confirmed that the coating peels off and disappear. As a result of estimating the processing point temperature using AdvantEdge FEM, the processing-point temperature was higher than the heatresistance temperature of the coating, and this is considered to be the main cause. Based on these results, when highspeed milling is performed with the aim of high-efficiency machining, the surface hardness of stainless steel is improved (work hardening). In the case of titanium alloys, it is important that the processing-point temperature is not higher than the heat-resistant temperature of the coating and that the hardness of the processed surface is not reduced.