Abstract: Coal is extracted with heated and pressurized water, and an extract is collected as microspheres without use of an organic solvent or a surfactant. By this, microspheres containing a hollow spherical particle are produced. Biomass is extracted with heated and pressurized water, and an extract is collected as microspheres without use of an organic solvent or a surfactant.

Abstract: A disk drive device includes a base, a hub on which a recording disk is to be mounted, and a fluid dynamic bearing unit that supports the hub in a freely rotatable manner relative to the base. The hub includes a hub protrusion to be engaged with the center hole of the recording disk, and amount portion on which the recording disk is to be mounted. A manufacturing method of this disk drive device applies electromechanical machining to the hub protrusion to form an electromechanical machined surface.

Abstract: A disk drive unit includes a base, a hub rotatably supported on the base and including a setting part on which a recording disk is to be set, and a bearing unit having one end fixed to the base and another end holding the hub. The hub includes a cut surface formed by cutting a nonferrous metal or a steel material, and the cut surface includes a surface treatment layer formed thereon and preventing peeling of micro residue adhered on the cut surface.

Abstract: A hydrodynamic bearing having a high performance and a long life and a manufacturing method for the same are provided by forming hydrodynamic grooves to have a sufficient depth with a high accuracy, and sealing remaining pores on a bearing surface. A shaft is inserted into a bearing hole of a sleeve so as to be relatively rotatable. The bearing hole has a bearing surface having hydrodynamic grooves.

Abstract: The present invention provides an electromagnetic wave absorbing material which comprises an electromagnetic wave absorbing layer comprising a hydraulic inorganic binder and a fibrous conductor. The present invention also provides an electromagnetic wave absorbing material which comprises an electromagnetic wave absorbing layer comprising a hydraulic inorganic binder, a magnetic powder and a fibrous conductor.

Abstract: A housing for electronic apparatus which is effectively protected against electromagnetic wave leakage, the housing being equipped or lined, in an area of the conductive layer-carrying inside surface of the housing, the area adjoining, or is in the vicinity of, an opening of the housing, with a sheet molded, to a thickness of 70 to 300 .mu.m, from a magnetic material-containing resin composition comprising 7 to 60% by weight of a binder resin (a) and 40 to 93% by weight of a finely divided magnetic material (b) having a magnetic loss term, and a method of damping unwanted radiation of electromagnetic waves.

Abstract: A sleeve bore machining apparatus has a plurality of reamers with different diameters, wherein a ball etc. is pressed in and passed through the sleeve bore after a machining with the reamer inserted in the sleeve, measures the push-in load involved in the pass-through operation to select a diameter of the reamer to be used for the next machining process in response to a magnitude of the measured load, or carries out a machining process while a reamer having an edged taper portion or taper stepped portions in a grinding portion is kept inserted in the bore of the sleeve, and controls an extent of insertion of the reamer for the next machining process in response to a magnitude of the measured load, so that the dimensional accuracy of the bore as well as the cylindricity can be successfully machined.

Abstract: A sleeve bore machining apparatus has a plurality of reamers with different diameters, wherein a ball etc. is pressed in and passed through the sleeve bore after a machining with the reamer inserted in the sleeve, measures the push-in load involved in the pass-through operation to select a diameter of the reamer to be used for the next machining process in response to a magnitude of the measured load, or carries out a machining process while a reamer having an edged taper portion or taper stepped portions in a grinding portion is kept inserted in the bore of the sleeve, and controls an extent of insertion of the reamer for the next machining process in response to a magnitude of the measured load, so that the dimensional accuracy of the bore as well as the cylindricity can be successfully machined.

Abstract: A plurality of processing balls with different outer diameters are prepared at a slidable or rotatable upper stage. One ball, selected from the plurality of prepared balls in correspondence with the inner diameter of a bore of a workpiece, is inserted through the bore while being pressed by a pin.

Abstract: A bore processing device for processing an inner surface of a bore of an object to be processed, includes: a taper member having a taper section; a roller arranged to contact and rotate around an outer surface of the taper member; a roller guide member having a guide groove for accommodating the roller and arranged to rotate around the outer surface of the taper member; a first motor for moving the roller guide member to insert the roller into the bore of the object; a second motor for rotating one of the object and the roller guide member; and a third motor for axially moving one of the roller guide member and the taper member so that one of the roller guide member and the taper member relatively moves to the other thereof. The device further includes a detecting device for detecting an axial load applied to the object by the roller when the roller is inserted into the bore of the object.

Abstract: A dynamic pressure type fluid bearing device includes: a shaft; a sleeve into which the shaft is fitted to be rotatable relative to the shaft; two dynamic pressure generating grooves provided on either peripheral surface of the shaft or the inner peripheral surface of the sleeve; and a lubricant held between the shaft and the sleeve. The device has a void, enclosing air, interposed between the two dynamic pressure generating grooves, wherein each of the dynamic pressure generating grooves is not less than four microns in depth and makes an acute angle of less than 20.degree. with a rotational direction of the shaft or the sleeve.

Abstract: A disk driving apparatus has, a chassis, a fixed shaft having one end attached to the chassis, a hub rotatably mounted around an outer circumferential surface of the fixed shaft and at least one disk mounted on an outer circumferential surface of the hub, the other end of the fixed shaft having a stopper thereon for engaging the hub for retaining the hub on the fixed shaft, a disk fixing plate positioned over the other end of the fixed shaft and fixing the one disk to the hub and having a surface opposed to the other end of the fixed shaft, a thrust bearing element movably mounted between the disk fixing plate surface and one of the other end of the fixed shaft and the stopper, and a hydrodynamic pressure generating groove formed in one of a herringbone pattern and a helical pattern and being on one of an outer circumferential surface of the fixed shaft and an inner circumferential surface of the hub.

Abstract: A reduction gear equipped with a wave generator nearly elliptical in shape, two circular splines with differing numbers of internal teeth, a flex spline which partially meshes with the internal teeth of each of the circular splines and which is deformable in the radial direction and a bearing deformable in the radial direction, which, placed between the wave generator and the flex spline, renders both members relatively slidable, with notches which permit partial deformation of the bearing (6) or the flex spline provided in the wave generator or circular splines at positions corresponding to the balls of the aforementioned bearing, whereby backlash is eliminated and its positive operation is assured.

Abstract: In a rotary head assembly for magnetic recording and reproducing apparatus such as VTR sets, of the type comprising a stationary shaft having its one end securely joined to a stationary member, a rotor fitted over the stationary shaft for rotation, a drive means for driving or spinning the rotor and heads mounted on the rotor, the position N of a thrust support for supporting the rotor is so selected as to coincide with the center of gravity G of the rotor or as to be located between the center of gravity G and the center of gravity G.sub.1 of the rotor except an aggregate of component parts of said drive means mounted on the rotor, the center of gravity G being depending upon the center of gravity G.sub.1 and the center of gravity G.sub.2 of the aggregate of component parts mounted on the rotor, whereby the adverse effects of the precession of the rotor on the precision rotation or spinning thereof can be avoided.

Abstract: In a rotary head assembly for a magnetic recording and reproducing device of the type in which rotary head member is engaged through a hydraulic bearing with a shaft whose one end is securely fixed to a base and the other end is free, the position of a thrust supporting member formed at the free end of the shaft is suitably selected so as to minimize the adverse effects caused by the thermal expansions of the component parts whereby the variation in relative position between the head and tape due to the temperature variation can be minimized and the high radial rigidity can be attained.