摘要:
A double sleeve type dynamic bearing comprises a fixed shaft having at least one end fixedly mountable to an apparatus in which the bearing is utilized, a rotary sleeve arranged coaxially with the fixed shaft so that a first fine gap is formed therebetween, a fixed sleeve arranged coaxially with the rotary sleeve so that a second fine gap is formed therebetween, and a lubrication oil filled in the fine gaps. The first fine gap and the second fine gap each have an open end exposed to air outside the bearing and an opposite end that is not exposed to the air, the opposite ends being in communication with each other. A holding member holds the fixed shaft and the fixed sleeve and is disposed adjacent to a lower end surface of the rotary sleeve to form a third fine gap between the holding member and the lower end surface of the rotary sleeve. The third fine gap is formed with a thrust dynamic pressure producing groove, and opposite ends of the first and second fine gaps meet each other through the third fine gap. A peripheral surface of at least one of the fixed shaft, the rotary sleeve and the fixed sleeve forming at least one of the first and second fine gaps has a dynamic pressure producing groove formed therein.
摘要:
The present invention is a double sleeve type fluid dynamic pressure bearing, comprising a fixed shaft having respective ends to be fixed to a utilized apparatus; a rotary sleeve arranged to provide a first fine gap between an inner peripheral surface thereof and an outer peripheral surface of the fixed shaft, a fixed sleeve arranged to provide a second fine gap between an inner peripheral surface thereof and an outer peripheral surface of the rotary sleeve, a holder member arranged to cooperate with a lower end surface of the rotary sleeve to provide a third gap, and wherein the first fine gap and the second fine gap are formed with radial dynamic pressure producing grooves while the third fine gap is formed with a thrust dynamic pressure producing groove, the first, second and third fine gaps being filled with lubrication oil, the first fine gap and the second fine gap having one ends made as opening ends contacting with the air and the other ends made as closed ends communicated with each other through the third fine gap.
摘要:
A method for lubricating a part without leaving air bubbles includes the steps of assembling components so that an open end is formed for application of lubricating fluid and a fluid path is provided through which the lubricating fluid is to be circulated, introducing the lubricating fluid into the open end and applying a centrifugal force to the component by moving the component about a circular path so that the centrifugal force causes the lubricating fluid to be urged throughout the fluid path. The method is used in an embodiment to lubricate a dynamic pressure bearing having a gap between relatively moving parts. The gap has an open end into which the lubrication fluid is dripped and a closed end. During movement of the bearing about a circular path, the fluid is urged from the open end to the closed end.
摘要:
In order to alleviate mutual interference between axial dynamic pressure portions and a radial dynamic pressure portion in a ring-like hydraulic dynamic pressure bearing, in the case of a ring-like hydraulic dynamic pressure bearing 1 constituted by supporting a shaft portion 4 constituted by fixing a ring 3 to an end portion 2A of a shaft main body 2 by a bearing portion 5, ring-like spaces 8 and 9 for storing lubricant for generating dynamic pressure are provided along contiguous portions of the radial dynamic pressure bearing portion and the axial dynamic pressure bearing portions formed between the ring 3 and the bearing portion 5, and the ring-like spaces 8 and 9 are maintained at atmospheric pressure via paths formed at the bearing portion 5 to thereby prevent negative pressure from generating at boundary regions of the two dynamic pressure bearing portions.
摘要:
A hydraulic dynamic bearing has a rotational assembly and a bearing member for rotationally supporting the rotational assembly. The bearing member has a main body having a recess portion and a cover for covering an open end of the recess portion. The rotational assembly has a shaft main body having an end portion extending into the recess of the bearing main body for undergoing rotation relative thereto and a ring member disposed in the recess of the bearing main body. The ring member is connected to the end portion of the shaft main body for rotation therewith. Axial dynamic pressure generating grooves are formed in upper and lower surface portions of the ring member for generating axial dynamic pressure during rotation of the rotational assembly. Radial dynamic pressure generating grooves are formed in an outer peripheral surface portion of the ring member for generating radial dynamic pressure during rotation of the rotational assembly. Spaces are formed between the bearing member and the rotational assembly for storing a lubricant.
摘要:
In a method for assembling a spindle motor having a liquid dynamic pressure bearing having a flanged shaft member formed by press-fitting a dynamic pressure ring member on a cylindrical member, a hub is press-fit on the flanged shaft member without causing deviation in the press-fit position of the dynamic pressure ring member. A hub press-fitting apparatus press fits a mount hole of the hub on a cylindrical end portion of the cylindrical member. The hub press-fitting apparatus comprises a hub holding member, a rotation shaft member, a coupling member, and an anti-rotation member. During assembly, a temporary coupling between the hub press-fitting apparatus and the liquid dynamic pressure bearing is made by screwing a threaded tap in a tap hole provided in an end face of the cylindrical member.
摘要:
A spindle motor comprises a base, a stator coil connected to the base, and a sleeve-and-bearing unit connected to a central portion of the base. The sleeve-and-bearing unit has a sleeve and a bearing section mounted in the sleeve having a linear expansion coefficient greater than that of the sleeve. The sleeve has a groove disposed in an outer peripheral surface thereof for receiving an adhesive material for connecting the base to the outer peripheral surface of the sleeve. A rotor unit is connected to the sleeve-and-bearing unit for undergoing rotation relative to the sleeve-and-bearing unit. The rotor unit has a shaft section supported by the bearing section for undergoing rotation, a hub connected to the shaft section for rotation therewith, and a rotor magnet connected to the hub and disposed opposite to and spaced apart from the stator coil.
摘要:
A hydraulic dynamic pressure bearing motor has a rotational shaft mounted to undergo rotation about a rotational axis and having a shaft section and a flange section. A sleeve has a cavity for receiving the rotational shaft. A cover member is disposed over an open end of the sleeve cavity. A hydraulic dynamic pressure bearing includes minute radial and thrust clearances disposed between outer surface portions of the shaft and flange sections of the rotational shaft and inner surface portions of the sleeve and the cover member. A lubricating fluid is disposed in the minute radial and thrust clearances. The minute radial and thrust clearances are dimensioned so that during a non-rotational state of the rotational shaft, the flange section of the rotational shaft contacts preselected inner surface portions of the sleeve and the cover member while the shaft section of the rotational shaft does not contact any portion of the sleeve and an inner peripheral surface of the cover member.
摘要:
In a hydraulic bearing motor, by means of dynamic pressure generating grooves provided on a thrust shaft with a larger diameter not only on the end face thereof but also on the shaft surface thereof, pressures generated in oil when rotating a shaft body are made to be applied not only in the axial direction but also in the radial direction with high magnitude. This can provide the hydraulic bearing motor as being capable of satisfying features of exhibiting small NRRO, and vibration and shock resistance even with a thinned hydraulic bearing motor.
摘要:
A motor has a support member, a bearing member mounted in a hollow space of the support member for undergoing rotation, a rotor member having a shaft portion disposed in a hollow space of the bearing member for rotation therewith, at least one magnet connected to one of the support member and the rotor member, and electromagnets connected to the other of the support member and the rotor member and in confronting relation to the magnet for generating a rotational magnetic field that coacts with the magnet to rotate the rotor member. At least one of an inner peripheral surface of the bearing member and an outer peripheral surface of the shaft portion of the rotor member has contact portions disposed in contact with the other of the inner peripheral surface and the outer peripheral surface to form lubricating gaps each disposed between an adjacent pair of contact portions and between the inner and outer peripheral surfaces.