摘要:
A rotary body bearing apparatus has a bearing supporting member, a radial bearing member, a bearing chamber formed in the bearing supporting member for holding the radial bearing member, a rotative shaft supported rotatively by the radial bearing member, and lubricating oil filling a bearing clearance between the rotative shaft and the radial bearing member. An air bubble restraint means restrains the occurrence of air bubbles generated in the lubricating oil by the rotation of the rotative shaft. Even when the rotative shaft rotates at the high speed of rotation, by the provision of the air bubble occurrence restraint means, the occurrence of air bubbles generated in the lubricating oil can be restrained, high accuracy rotation can be maintained and a rotation number fluctuation of the rotary body can be reduced.
摘要:
A motor has a stator with a base part and a hollow projection as well as a rotor with a shaft which extends into the hollow projection. A radial bearing is mounted between the shaft and the hollow projection. There may be a further radial bearing in the base part of the stator. The radial bearing, lubricated by magnetic fluid, is sealed between the shaft and the projection by a magnetic seal at the end of the hollow projection remote from the base part. The rotor has an annular part extending around the hollow projection, which supports permanent magnets forming an armature. Those permanent magnets interact with drive coils on the stator to cause rotation of the rotor about the axis of the shaft. There is also a magnetic thrust bearing between the annular part of the rotor and the projection of the stator. This magnetic thrust bearing is axially displaced relative to the magnetic seal towards the base part of the stator, to counteract the effect of the magnetic thrust bearing on the magnetic seal.
摘要:
A motor has a rotor mounted on a stator to rotate about a rotation axis. The rotor is driven due to the interaction of a drive coil on the stator and a permanent magnet on the rotor. A magnetic thrust bearing, having permanent magnets on the stator and rotor, applies a radial thrust force. The radially outer surface of the permanent magnet on the rotor abuts a part of the rotor, so as to resist forces on the permanent magnet at high speed rotation or due to thermal deformation. The permanent magnets on the stator and the rotor may be axially offset by an offset of not more than 1/4 the axial length of the permanent magnets, or the axial length of the longer of the permanent magnets if they have different axial lengths. This generates an axial thrust at the thrust bearing, which counteracts the attractive force between the permanent magnet and the drive coil, and also the weight of the rotor.
摘要:
A motor provided with a magnetic fluid bearing device for suppressing vibration and irregular rotation as well as preventing the magnetic fluid from being scattered from a bearing portion and the inside of the motor. The motor includes a rotor having a polygon mirror mounted thereon, a stator unit having driving coils, a rotor position detector and a rotor revolution detector attached thereto, a magnetic fluid bearing unit having a magnetic seal and a dynamic pressure seal attached thereto and a magnetic bearing. A triple seal structure for magnetic fluid which includes a first fluid seal constituted by the seals of the bearing unit, a second fluid seal constituted by a magnet of the rotor and a third fluid seal constituted by a magnet of the seal magnet is provided in the motor.
摘要:
A motor with a magnetic fluid bearing for suppressing vibration and irregular rotation as well as preventing the magnetic fluid from being scattered from a bearing portion in the inside of the motor. The motor includes a rotor having a polygon mirror mounted thereon, a stator unit having driving coils, a rotor position detector and a rotor revolution detector attached thereto, a magnetic fluid bearing unit having a magnetic seal and a dynamic pressure seal attached thereto and a magnetic bearing. A triple seal structure for magnetic fluid which includes a first fluid seal constituted by the seals of the bearing unit, a second fluid seal constituted by a magnet of the rotor and a third fluid seal constituted by a seal of the magnetic magnet is provided in the motor.
摘要:
A sintered fluid dynamic pressure bearing completely seals or decreases the sizes of gaps formed in pores by shrinkage when a resin impregnated therein shrinks. The fluid dynamic pressure bearings can be reliably and easily produced using fewer processes while superior quality is maintained. A production method for a fluid dynamic pressure bearing includes a resin sealing process including a resin impregnating step in which a monomer of an anaerobic resin composed primarily of acrylate or methacrylate is impregnated in pores of a porous sintered compact, an excess resin washing off step in which excess resin adhering to the surface of the porous sintered compact is washed off, and a resin curing step in which the monomer of the anaerobic resin impregnated in the pores is cured by heating the porous sintered compact to at least the curing temperature of the resin after washing off the excess resin; the resin sealing process is repeatedly carried out, and a monomer of an anaerobic resin containing an organic peroxide at 0.1 to 1.0 mass % is used in at least the resin impregnating step of the last resin sealing process.
摘要:
A fluid dynamic pressure bearing composed of a cylindrical sintered compact includes: a thrust region which is formed on an end surface of the bearing and receives at least a thrust load; a roughed portion having small peaks and valleys formed on the thrust region; and thrust recesses for generating thrust fluid dynamic pressure, which are formed on the thrust region.
摘要:
A disk drive unit includes a rotary member, which has a spindle, and has an information-recording disk fixedly mounted thereon, and a bearing unit rotatably supporting the spindle. The bearing unit includes a radial bearing device, provided in opposed relation to an outer peripheral surface of the spindle, and a thrust bearing device provided in opposed relation to a distal end surface of the spindle. The radial bearing device has a concentric arc-shaped bearing surface, which is concentric with the circular outer periphery of the spindle, and a non-concentric arc-shaped bearing surface which is non-concentric with the circular outer periphery of the spindle. The disk drive unit further includes a motor for imparting a rotational force to the spindle, and a lubricating fluid filled in the bearing unit.
摘要:
A bearing apparatus comprises a housing formed of a non-magnetizable material and having a bottom portion, a fluid lubricating type radial bearing device provided coaxial with the housing and having a magnetic fluid sealing section and a radial bearing section, a thrust bearing device provided at the bottom portion of the housing, and a rotating shaft of a permeable material rotatably supported by the radial bearing device and thr thrust bearing device to extend through the radial bearing device. The magnetic fluid sealing section is disposed on the opening side of the housing with a predetermined spacing away from the radial bearing section whereby a space is provided between the magnetic fluid sealing section and a liquid surface of fluid lubricant filled in the radial bearing section.
摘要:
A rotary shaft of a hydraulic machine has a collar projecting radially outwardly therefrom. The rotary shaft and the collar are encased by a casing which carries a seal ring to be pressed against an axial end surface of the collar to form a fluid-tight seal therebetween. The axial end surface of the collar slidingly contacting with the seal ring is provided with a plurality of radial grooves extending from the central portion of the collar to the outer peripheral edge thereof. As the rotary shaft rotates at a high speed, a centrifugal force is generated to separate sand and soil particles from the water within the radial grooves.