Abstract: A magnetic disc unit which can restrain occurrence of flutter so as to countermeasure such a problem that the larger the rotational speed of discs, the higher the flutter, causing heat positioning errors, in order that the high rotational speed and high positioning accuracy are consistent with each other. Discs are surrounded along their outer peripheries by a shroud (outer wall) while a gap between end faces of the discs and the shroud is decreased to a predetermined distance, thereby to eliminate air pressure differential between opposite surfaces of each of the discs in order to reduce flutter.

Abstract: A magnetic disc unit having a rotating disc type magnetic disc, a head for recording and reproducing data to and from the magnetic disc, and a shroud surrounding an end surface of an outer periphery of the magnetic disc, except a part where a carriage arm is inserted, wherein a gap between the outer peripheral end surface of the magnetic disc and the shroud is set in a range which is greater than 0.1 mm but not greater than 0.6 mm.

Abstract: Shock-absorbing material made from a mixture of solid particles and viscous elastic material is arranged at the periphery of an information storage and retrieval device. When an external shock is applied to the device, the shock-absorbing material is greatly deformed and dissipates the shock energy by inner friction sufficiently to prevent damage to the inner mechanism of the device. The deformed shock-absorbing material can be restored to the original shape so that it is repeatedly usable. Furthermore, by comparing the deformed shape and the quick reference table provided with the device, the amount shock acceleration can be roughly determined. The device conforms to one of a series of dimensional standards for information storage and retrieval devices.

Abstract: A spindle motor used in a magnetic disc apparatus having a hub to which a magnetic disc is mounted and a rotary shaft to which the hub is fixed. The rotary shaft is located in a bearing casing having one end opened and the other end closed by a hydrodynamic pressure radial bearing, the rotary shaft being supported by a hydrodynamic pressure thrust bearing and the hydrodynamic pressure radial bearing. An inner diameter D and a width L of the hydrodynamic pressure radial bearing having a relationship of L/D<1.

Abstract: 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.

Abstract: A magnetic head slider has a magnetic head mounting surface holding a magnetic head, to be kept closest to a magnetic disk when the magnetic head slider is in operation, a slider rail surface contiguous with a surface, on the side of an air inlet end, and opposite sides of a portion, near an air outlet end, of the magnetic head and extending near to the air outlet end, a step bearing surface formed at least on the side of the air inlet end of the slider rail surface, and a negative-pressure groove formed so as to surround the step bearing surface. The magnetic head mounting surface is typically formed on an alumina protective film protecting the magnetic head. The variation of the flying height of the magnetic head slider with respect to a rolling direction is reduced and a proximity ability to approach the magnetic disk is improved.

Abstract: 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.

Abstract: Shock-absorbing material made from a mixture of solid particles and viscous elastic material is arranged at the periphery of an information storage and retrieval device. When an external shock is applied to the device, the shock-absorbing material is greatly deformed and dissipates the shock energy by inner friction sufficiently to prevent damage to the inner mechanism of the device. The deformed shock-absorbing material can be restored to the original shape so that it is repeatedly usable. Furthermore, by comparing the deformed shape and the quick reference table provided with the device, the amount shock acceleration can be roughly determined. The device conforms to one of a series of dimensional standards for information storage and retrieval devices.

Abstract: 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.

Abstract: The present invention provides a thinner-type magnetic disc apparatus while maintaining the stiffness of the case. The magnetic disc apparatus includes a magnetic disk 100, a spindle motor 109 that rotationally actuates the magnetic disk, a magnetic head 110 that records and reproduces information on the magnetic disk, a carriage 209 with the magnetic head mounted at its tip, a voice coil motor (VCM) 101 that drives the carriage, electronic components 200 and 201 for processing signals from the magnetic head and a case 102 that encloses these structural element. Electrical wiring 108 interconnects the magnetic head and the electronic components or interconnects the electronic components, or both, and is plated onto the inner bottom surface of the case. An interface connecting part 300 is plated onto the outer bottom surface of the case and is connected to electrical wiring that is plated onto the inner bottom and side-wall surfaces of the case.

Abstract: Shock-absorbing material made from a mixture of solid particles and viscous elastic material is arranged at the periphery of an information storage and retrieval device. When an external shock is applied to the device, the shock-absorbing material is greatly deformed and dissipates the shock energy by inner friction sufficiently to prevent damage to the inner mechanism of the device. The deformed shock-absorbing material can be restored to the original shape so that it is repeatedly usable. Furthermore, by comparing the deformed shape and the quick reference table provided with the device, the amount shock acceleration can be roughly determined. The device conforms to one of a series of dimensional standards for information storage and retrieval devices.

Abstract: A magnetic disk drive having a disk for storing information, a spindle motor for rotating the disk, a head for recording information into the disk and reproducing information from said disk, a suspension supporting a slider provided with the head, a carriage supporting the suspension, a voice coil motor for exerting a rotational torque to the carriage so as to locate the head on the disk, a base and a cover, and a ramp serving as a guide for unloading the head from the disk. A part of the suspension slides over the ramp so as to effect the unloading operation and the position or the posture of the ramp is changed by sliding movement of the part of the suspension over and with respect to the ramp during the unloading operation.

Abstract: The present invention provides a thinner-type magnetic disc apparatus while maintaining the stiffness of the case. The magnetic disc apparatus comprises a magnetic disk 100, a spindle motor 109 that rotationally actuates the magnetic disk, a magnetic head 110 that records and reproduces information on the magnetic disk, a carriage 209 with the magnetic head mounted at its tip, a voice coil motor (VCM) 101 that drives the carriage, electronic components 200 and 201 for processing signals from the magnetic head, a case 102 that encloses these structural elements, electrical wiring 108 that interconnects the magnetic head and the electronic components or interconnects the electronic components, or both, and is plated onto the inner bottom surface of the case, and an interface connecting part 300 that is plated onto the outer bottom surface of the case and is connected to electrical wiring that is plated onto the inner bottom and side-wall surfaces of the case.

Abstract: A spindle motor used in a magnetic disc apparatus having a hub to which a magnetic disc is mounted and a rotary shaft to which the hub is fixed. The rotary shaft is located in a bearing casing having one end opened and the other end closed by a hydrodynamic pressure radial bearing and hydrodynamic pressure thrust bearing, an inner diameter D and a width L of the hydrodynamic pressure bearing having a relationship of L/D<1.

Abstract: A magnetic disc device includes a magnetic disc and a rotary shaft rotatably supporting the magnetic disc. The magnetic disk is laid in a bearing casing having one end opened, and having a bearing member at the other end. The rotary shaft is supported by a first hydrodynamic fluid bearing and a second hydrodynamic fluid bearing provided in the bearing member. The inner diameter D and the width L of the first hydrodynamic fluid bearing exhibits such a relationship as L/D>1.

Abstract: A magnetic head slider has a magnetic head mounting surface holding a magnetic head, to be kept closest to a magnetic disk when the magnetic head slider is in operation, a slider rail surface contiguous with a surface, on the side of an air inlet end, and opposite sides of a portion, near an air outlet end, of the magnetic head and extending near to the air outlet end, a step bearing surface formed at least on the side of the air inlet end of the slider rail surface, and a negative-pressure groove formed so as to surround the step bearing surface. The magnetic head mounting surface is typically formed on an alumina protective film protecting the magnetic head. The variation of the flying height of the magnetic head slider with respect to a rolling direction is reduced and a proximity ability to approach the magnetic disk is improved.

Abstract: 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.

Abstract: A rotary shaft is rotatably supported by a hydrodynamic fluid radial bearing and a hydrodynamic fluid thrust bearing which are excellent in shock resistance, an bearing arrangement in which vibration in a translation mode of the shaft, among vibration components caused by unbalance force exerted to the rotary shaft, is supported by the radial bearing, and vibration in conical mode is supported by the thrust bearing, magnetic fluid is used as lubrication oil, and a permanent magnet is located between the radial bearing and the thrust bearing so as to apply a magnetic attracting force between the rotary shaft and the thrust bearing so as to carry out axial positioning in order to use the magnetic disc device in an arbitrary attaching posture.

Abstract: In a magnetic disk apparatus including a plurality of magnetic disks 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 disks are larger than 0.1 mm and less than 0.6 mm. An open space is located, downstream of the arms, with respect to an air flow on surfaces of the magnetic disks, 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 disks and the shroud, and a bypass channel is provided which communicates between the opening and the open space.

Abstract: The hole that penetrates the axial direction in the hub, the force of the axial direction by fluid force that operates on the spindle motor is reduced during the rotation. Fluctuation of fluid power is reduced by this hole. The rotary precision of the axial direction improves. Against the oil leakage from the bearing equipment, magnetic fluid is used as a lubrication fluid of the bearing. Magnetic fluid is magnetized with the permanent magnet arranged in the bearing equipment, and oil leakage is prevented. Against scattering of the oil particle, the groove for dynamic pressure generation is in the opening of bearing equipment. The oil particle is kept inside the bearing equipment.