| 摘要 |
PURPOSE:To prevent the temperature of a bearing from rising, by providing spacers of low thermal conductivity between a target and a rotor and between the rotor and a rotary shaft. CONSTITUTION:Spacers 8 made of alumina ceramic plates of 2mm. in thickness are provided between a target 1 and a rotor 3 and between the rotor and a rotary shaft 5 to reduce heat conduction from the target. Since the thermal conductivity of the alumina ceramic plates 8 is 0.01cal/cm.s. deg.C and that of the target 1 made of molybdenum is 0.3cal/cm.s. deg.C which is thirty times higher than that of the alumina ceramic plates, the thermal conduction from the target to a bearing 6 is diminished so that the temperature of the bearing is lowered to about 45 to 52 deg.C when that of the target is 1,100 deg.C. |
