Abstract: When a group III nitride crystal is grown in a pressurized atmosphere of a nitrogen-containing gas from a melt 50 including at least a group III element, nitrogen and an alkali metal or an alkali earth metal, a melt-holding vessel 160 that holds the above-described melt 50 is swung about two axes different in direction from each other such as an X-axis and a Y-axis.

Abstract: When a group III nitride crystal is grown in a pressurized atmosphere of a nitrogen-containing gas from a melt 50 including at least a group III element, nitrogen and an alkali metal or an alkali earth metal, a melt-holding vessel 160 that holds the above-described melt 50 is swung about two axes different in direction from each other such as an x-axis and a Y-axis.

Abstract: A hydrodynamic bearing device capable of inhibiting leakage of a working fluid to an outside of a bearing and preventing reduction in radial bearing rigidity, and capable of keeping a gap between a thrust bearing and a radial bearing favorable and rotating stably. The hydrodynamic bearing device includes a shaft relatively rotatably inserted into a bearing hole of a sleeve, a radial bearing surface having dynamic pressure generating grooves formed on at least one of an outer peripheral surface of the shaft and an inner peripheral surface of the sleeve, and a gap filled with a working fluid between the shaft and the sleeve. The shaft is made of high manganese chrome steel or stainless steel, and the sleeve is entirely made of sintered metal of metal particles including at least 60% by weight of iron or copper. Resin, metal or water glass is impregnated in pores on a surface of the sintered metal and cured.

Abstract: A hydrodynamic bearing device capable of inhibiting leakage of a working fluid to an outside of a bearing and preventing reduction in radial bearing rigidity, and capable of keeping a gap between a thrust bearing and a radial bearing favorable and rotating stably. The hydrodynamic bearing device includes a shaft relatively rotatably inserted into a bearing hole of a sleeve, a radial bearing surface having dynamic pressure generating grooves formed on at least one of an outer peripheral surface of the shaft and an inner peripheral surface of the sleeve, and a gap filled with a working fluid between the shaft and the sleeve. The shaft is made of high manganese chrome steel or stainless steel, and the sleeve is entirely made of sintered metal of metal particles including at least 60% by weight of iron or copper. Resin, metal or water glass is impregnated in pores on a surface of the sintered metal and cured.

Abstract: A manufacturing method is provided for forming a hollow cylinder with a bottom which may be employed in rotary head drums of magnetic recording and reproduction systems such as video tape recorders and digital audio tape recorders.The manufacturing method includes pressing a single circular plate to form the hollow cylinder, thrusting an end of a side wall of the hollow cylinder in a direction substantially parallel to the side wall in a press die so as to adjust the thickness of the side wall to be uniform, and machining an outer surface of the side wall of the hollow cylinder so as to have a given surface roughness and a given roundness.