Hitachi, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Masayuki Kaiho

Shigeo Nakamura

Kenichi Hattori

Shigenori Togashi

Kazuo Sakai

Hideaki Mori

Ryoichi Shiobara

Masao Iwakura

Hayato Shimizu

Toshiaki Kobari

Shigekazu Kieda

Mikio Tokuyama

Shozo Saegusa

Yuzo Yamaguchi

Masahiko Sega

Toshihisa Okazaki

Satomitsu Imai

Akiyoshi Komura

Masao Fukunaga

Tadashi Sonobe

Masahiro Ikegawa

Ikuo Uematsu

Yoshiki Abe

Akitomi Senba

A magnetic disk apparatus includes a plurality of magnetic disks driven to rotate by a spindle motor, arms supporting magnetic heads on the magnetic disks, an actuator for moving the arms on the magnetic disks by a voice coil motor, and a housing which surrounds the magnetic disks, the arms and the actuator. A shroud which arcuately surrounds the magnetic disks along the outer periphery thereof has an opened portion for inserting the arms is formed in a part of the housing. The shroud on an upstream side of the arms relative to airflow generated by the magnetic disks when rotating is provided with an opening having a greater width than that of a gap defined between the shroud and the outer periphery of the magnetic disks. An empty bypass channel is provided which communicates from the opening through a rear side of the voice coil motor to the downstream side of the arms.

Magnetic disk apparatus with shroud and having open space downstream of moveable arms in communication with bypass channel

A magnetic disk apparatus includes magnetic disks stacked on a rotating shaft, arms supporting magnetic heads, a rotary actuator for moving the arms, and a housing forming at least a part of an arcuate-shaped shroud which substantially surrounds a portion of side surfaces of the magnetic disks so as to define a gap between the shroud and the portion of the side surfaces of the magnetic disks. The arcuate-shaped shroud has portions delimiting an open space adjacent to another portion of the side surfaces of the magnetic disks which is located on a downstream side of the arms relative to an air flow which moves on surfaces of the magnetic disks. A bypass channel provides air flow to the disks in a region of the open space at a reduced pressure on the downstream side of the arms with respect to pressure at an upstream side of the arms.

Magnetic disk apparatus with air flow bypass channel

A turbine electric power generator is provided with winding slots and sub-slots of a rotor; rotor windings having conductors and insulation materials laminated alternately thereon; wedges; and radial ventilation flow passages communicating the sub-slots with through holes of the wedges. In this turbine electric power generator, a projection is provided on an inner face of the radial ventilation flow passages, and the projection height is changed at a rotational axial position. In this manner, there can be provided a gas cooling type rotary electric power generator for turbine with its high cooling performance and high reliability at a low cost.

Rotary electric power generator

In a magnetic disc apparatus including a plurality of magnetic discs mounted on a spindle, arms supporting magnetic heads, a rotary actuator for the arms, and a housing having an arcuate-shaped shroud, the improvement wherein gaps between the shroud and the sides of outer peripheries of the magnetic discs are larger than 0.1 mm and less than 0.6 mm. An open space is located, downstream of the arms with respect to the air flow on surfaces of the magnetic discs, the open space being devoid of the shroud. An opening is provided in the shroud, upstream of the arms with respect to the air flow and having a greater width than a width of the gaps defined between the magnetic discs and the shroud, and a bypass channel is provided which communicates between the opening and open space.

Magnetic-disc unit with gap between disc and shroud

A magnetic disk apparatus arranged in a housing having a plurality of magnetic disks stacked on a rotating shaft, arms supporting thereon magnetic heads and adapted to be inserted between said magnetic disks, a rotary actuator for moving the arms, a housing forming at least a part of an arcuate-shaped shroud which substantially surrounds a portion of side surfaces of the magnetic disks so as to permit movement of the arms and which is concentric with the magnetic disks so as to define a gap between the shroud and the portion of the side surfaces of said magnetic disks. The gap defined between the outer peripheral end surfaces of the magnetic disks and the shroud is in a range of 0.1 mm to 0.6 mm.

Magnetic disk apparatus

To suppress pressure fluctuation caused by insertion of arms between disks, which arms support thereon magnetic heads, to reduce disk flutter to thereby reduce disk driving power in a magnetic disk apparatus, there are provided an open space not covered by a shroud, which constitutes a part of a housing structure to cover a side surface of a disk stack, and provided on a downstream side of the arms relative to an airflow moving along surfaces of the disks as the disks rotate, and a channel, which connects a space on an upstream side of the arms and the open space not restricted by the shroud on the downstream side of the arms, the channel being provided with a linear section, which has a rectifying effect on the airflow.

Magnetic disk apparatus with shroud having opening downstream of moveable arm

There is provided an electric rotary machine having, in particular, a large capacity, in which a volume of cooling air is ensured for the axially center part thereof so as to make the temperature distribution uniform in the axial direction of the rotor and the stator. Each of gas coolers in the electric rotary machine is divided into not less than two of passage parts in which streams run in two directions in opposite to each other are created, and a stator-cooling connection passage is formed so as to connect not less than two passage parts located in the radially outward part of the stator and axially defined by partition walls with the passage parts in the gas coolers in the electric rotary machine. With this arrangement, cold gas can be led into the axially center part of the stator without increasing the total ventilation resistance, and accordingly, it is possible to prevent occurrence of temperature rise in the axially center parts of the stator and the rotor, which would be caused in the electric rotary machine having, in particular, a large capacity.

Rotary electric machine

Efficient ventilation and cooling for a rotor is realized at a low cost by reducing the pressure loss at inlet flow passages, which lead to axial flow passages through which cooling gas flows to the rotor. Inlet flow passages leading to axial flow passages for cooling an interior of the rotor are composed of convex portions, which are formed axially on surfaces of a rotor spindle between and below coil ends of the rotor, and concave grooves formed between the convex portions. Also, the convex portions are designed to have a height increasing toward a downstream side, and assuming that L designates an length of the convex portions, L is greater than a radial difference between the positions of a maximum radius and a minimum radius of the convex portions.

Electric rotating machine

An apparatus in which a magnetic field is generated by an excitation coil provided in the outside of a conduit and electromotive force generated in electrodes attached on the conduit is detected to thereby measure a flow rate of a fluid flowing in the conduit, in which the conduit is made thinner in a manner so that a ratio of the axial length of the conduit to the inside diameter of the conduit is set to a value within a range of from 0.2 to 1.0, and in which correction data previously analyzed in accordance with magnetic permeability and inside surface conductivity of a mate piping to which the conduit is to be connected are stored so that a detection signal from the electrodes is corrected on the basis of the correction data to thereby measure the flow rate of the fluid flowing in the conduit.

Growing community of inventors

Chiyoda, Japan

Masayuki Kaiho