Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Keigo Kusaka

Takafumi Asada

Hiroaki Saito

Daisuke Itou

Takao Yoshitsugu

Hiroyuki Kiriyama

Daisuke Ito

Hisaaki Yano

Teruo Maruyama

Yasuhiro Asaida

Masafumi Kumoi

Miyuki Furuya

Kazuichi Yamashita

Koji Hirata

Yoshihito Watanabe

Koichi Fujimoto

With a hydrodynamic bearing device, a first gap Gis formed between a shaftand a sleeve. A second gap Gis formed between a sleeve capand the sleeve, and holds a lubricant. A thrust bearing memberis disposed near the inner peripheral surface of a center holeof the sleeve cap. A third gap Gis formed between the thrust bearing memberand the sleeve cap, and is open to the atmosphere. A fourth gap Gis formed between the thrust bearing memberand the sleeve. The lubricantcirculates along a circulation passage that includes a communicating path, the first gap Gand the second gap G

Hydrodynamic bearing device, and spindle motor and information apparatus equipped with same

A hydrodynamic bearing rotary device which can reduce rotation friction, and recording and reproducing apparatus including the same is provided. In the hydrodynamic bearing rotary device, such as hard disc devices, a rotary shaft having a hub on one end is provided in a bearing of a sleeve so as to be rotatable. Thrust hydrodynamic grooves are provided on the other end surface of the rotary shaft, to form a thrust bearing with the thrust plate. A communication path is provided in the sleeve. The second gap between the hub and the sleeve end surface is used as a flow channel and is connected to the communication path. In this way, the rotation friction torque of the thrust bearing can be made sufficiently small, and internal pressure in bonded portions of the rotary shaft or the bottom plate can be suppressed. Thus, the oil can be prevented from oozing out from a small space of the bonded surfaces. Furthermore, the hydrodynamic bearing can be made thin. These effects can be combined to realize an optimal hydrodynamic bearing rotary device.

Hydrodynamic bearing rotary device and information apparatus

A hydrodynamic bearing, a motor including the same, and a recording and reproducing apparatus which can improve vibration resistance property and suppress noises even in a situation where vibration is expected are provided. Radial hydrodynamic grooves formed on an inner peripheral surface of a sleeve have a shape which satisfy the relational expression L&#x3c;L/2. Lrefers to a length of a hydrodynamic causing portion of a radial bearing portion in an axial direction; and Lrefers to a length in the axial direction from a benchmark point where an end portion of the radial bearing portion on an outward side in the axial direction and center of a predetermined radial hydrodynamic groove cross each other, to a relative rotational direction backward side end portion of a radial hydrodynamic groove adjacent to the predetermined radial hydrodynamic groove on the forward side in a relative rotational direction.

Hydrodynamic bearing, motor including the same, and recording and reproducing apparatus

In a hydrodynamic bearing device in which a radial bearing face having a dynamic pressure generating groove on a shaft or an inner periphery of a sleeve is provided and a clearance between the shaft and the sleeve is filled with lubricant, an annular depression is provided on one end face of the sleeve adjacent to a rotor hub and a cover plate for covering the depression is attached to the sleeve so as to define a reservoir for the lubricant or air for the purpose of preventing such a risk that absence of an oil film occurs in clearances of a bearing of the hydrodynamic bearing device due to outflow of oil upon forcing of the oil by air received into the bearing. A step portion is provided on the other end face of the sleeve such that the step portion and the reservoir are communicated with each other by a communication hole. During operation of the hydrodynamic bearing device, air in the hydrodynamic bearing device reaches the reservoir via the communication hole so as to be discharged from the reservoir.

Hydrodynamic bearing device and disk rotation apparatus

Hydrodynamic bearing device and disk rotating apparatus

A high-accuracy, long-life hydrodynamic bearing that does not cause oil film breakage in bearing clearances and a disc rotation apparatus using the bearing is disclosed. Oil film breakage is avoided as negative pressure is prevented from generating between the shaft and sleeve of the hydrodynamic bearing. Herringbone shaped dynamic pressure generating grooves, located on the thrust bearing section and the radial bearing section of the hydrodynamic bearing, are oil filled and have optimum shapes. The optimum shapes prevent the generation negative pressure and thus prevents the coagulation of air bubbles that can cause oil film breakage. The disc rotation apparatus, that holds a reproduction/recording disc, is concentrically secured to the hydrodynamic bearing and rotated. The disc is put into contact with magnetic or optical heads while rotating in the disc rotation apparatus. Both the hydrodynamic bearing and the disc rotation apparatus experience high reliability.

Hydrodynamic bearing and disc rotation apparatus using the same

A hydrodynamic bearing device includes a sleeve having a bearing bore substantially at a center portion, a shaft inserted in the bearing bore in a rotatable manner, a thrust plate for supporting an end of the shaft in the thrust direction and an upper retaining portion that has an opening portion through which the shaft passes and covers the upper surface of the sleeve. A radial hydrodynamic bearing is formed between the bearing bore of the sleeve and the shaft, while a thrust hydrodynamic bearing is formed between the thrust plate and an end of the shaft. A first space is formed between the upper surface of the sleeve and the upper retaining portion. A second space is formed between the upper retaining portion and a step portion.

Hydrodynamic bearing device, spindle motor and hard disk driving apparatus having the hydrodynamic bearing device

Radial dynamic pressure grooves are provided in a first regionA and a second regionB on the side of a fixed shaft. A ventD is provided inside the top endA of the fixed shaft. The ventD connects spaces over and under a flangeto each other. The flangein an annular shape is fixed at the top endA of the fixed shaft. Thrust dynamic pressure groovesA andB are provided on the surfaces of the flange. A circulation holeC is provided in the flange, and connects spaces over and under the flangeto each other. A sleeverevolves around the fixed shaft. A thrust platein an annular shape is fixed at the top of the sleeveand opposed to the flange. The first regionA, the second regionB, the thrust dynamic pressure groovesA andB, and the circulation holeC of the flangeare filled with a lubricant. At the revolution of the sleeve, the lubricantis concentrated in each central part of the first regionA, the second regionB, and the thrust dynamic pressure groovesA andB and their vicinities, then raising the pressure. The sleevekeeps its stable high-speed revolution, avoiding contact with the fixed shaft. The lubricantcirculates on surfaces of the flangethrough the circulation holeC.

Hydrodynamic bearing and disk recording/reproducing apparatus having a vent inside a fixed shaft

A reduced pressure or pressurizing pump is provided which can be used in a wide variety of fields of foods, pharmaceuticals, medical treatment, agriculture, healthcare equipment, room air conditioning, combustion, biotechnology, and so on. By the application of the pump of the present invention, there can be materialized, for example, an oxygen enriching apparatus or a nitrogen enriching apparatus, which have the features of an oil-free structure, a small size, compactness, low vibration, low noise, long operating life, and so on. A transport groove of a viscosity pump, which exerts a force feed action on the fluid, is formed at a relative displacement interface between a rotor and a housing, and the rotor supported by a bearing capable of coping with a high-speed rotation is rotated at a high speed.

Fluid transport system and method therefor

A sleeveis fixed on a base. Radial dynamic-pressure generating groovesA andB are provided on an inner surface of the sleeve. A thrust platehermetically seals a lower opening end of the sleeve. A shaftis inserted inside the sleeve, being allowed to revolve. A flangeis fixed at the bottom end of the shaft, and its lower surface is placed close to an upper surface of the thrust plate. Thrust dynamic-pressure generating groovesA andB are provided on the surfaces of the flange. Gaps A&#x2013;H among the sleeve, the shaft, the flange, and the thrust plateare filled with a lubricant. HollowsC&#x2013;F are provided on the inner surface of the sleeve. The gaps A and C over the thrust dynamic-pressure generating groovesA andB and their vicinities are narrower than the surrounding gaps B and D (A&#x3c;B, A&#x3c;D, C&#x3c;B, and C&#x3c;D), and the surrounding gaps B and D are narrower than the gap H in the upper opening end of the sleeveand its vicinity (B&#x3c;H and D&#x3c;H). The gaps E and G over the radial dynamic-pressure generating grooves and their vicinities are narrower than the surrounding gaps D and F (E&#x3c;D, E&#x3c;F, G&#x3c;D, and G&#x3c;F), and the surrounding gaps D and F are narrower than the gap H in the upper opening end of the sleeveand its vicinity (D&#x3c;H and F&#x3c;H).

Hydrodynamic bearing and disk recording/reproducing apparatus

A fluid dynamic bearing device including a shaft having an interior pressure regulating hole by which a center portion of a thrust surface confronting a thrust plate and a lubricant pool portion of an inner circumferential surface of a sleeve are communicated with each other. Thus, the device is capable of obtaining stable thrust floating characteristics and preventing leaks of the lubricant as well as exhaustion of the lubricant.

Fluid dynamic bearing device and motor including the device

A rotatable hub in which a supporting shaft having hydrodynamic pressure generating grooves is inserted comprises an annular thrust bearing plate in its lower portion and annular permanent magnets in its upper portion. The thrust bearing plate is inserted between the lower end face of the supporting shaft and a thrust flange fixed to the supporting shaft, maintaining the respective clearances D and E. The permanent magnets on the hub are confronting in such a manner that an upward and downward repulsive forces are generated between permanent magnets mounted on the supporting shaft, respectively maintaining the clearances B and C. Since the clearances B and C are greater than the clearances D and E, the permanent magnets will not mutually contact even when the hub is caused to move upward or downward by an external force during rotation and the thrust bearing plate contacts with the lower end face of the supporting shaft or the thrust flange.

Hydrodynamic gas bearing

A hydro dynamic gas bearing having a sleeve with one end closed and connected to a front end of a shaft supported at its proximal end relative to a base on a fixed side, a plurality of hydro dynamic pressure generating grooves on at least one of an outer peripheral surface of the shaft and an inner peripheral surface of the sleeve opposite the outer peripheral surface, and a through hole communicating with the outside of the base extending from the front end to the proximal end of the shaft, the through hole having an air vent for adjusting pressure between the shaft and the sleeve for adjustment of discharge air so that the sleeve rotates in a contactless fashion relative to the shaft.

Growing community of inventors

Ozu, Japan

Keigo Kusaka