Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Panasonic Intellectual Property Management Co., Ltd.

Hideaki Ohno

Takafumi Asada

Takanori Shiraishi

Katsushi Hirata

Tsutomu Hamada

Hiroaki Saito

Minoru Koda

Hideo Matsumoto

Takaki Fukami

Yasunori Tokunou

Takao Yoshitugu

Chuuryoh Yoshida

Churyo Yoshida

A component mounter is provided with a nozzle shaft holder which includes a through-hole into which a nozzle shaft, a component suction nozzle being installed on the bottom end thereof, is inserted, and bearings which are disposed in two locations separated vertically on an inner circumferential surface of the through-hole and which guide the nozzle shaft in the vertical direction. In the bearings, two ring-shaped guide portions which surround an outer circumferential surface of the nozzle shaft are formed separated in a vertical direction, a grease holder, which has a larger inner diameter than the ring-shaped guide portions, is formed between the two ring-shaped guide portions, and a space surrounded by the outer circumferential surface of the nozzle shaft, the two ring-shaped guide portions, and the grease holder is filled with grease.

Component mounter

A hydrodynamic bearing device being low in torque, low in power consumption, high in reliability and best suited for miniaturization and a spindle motor using the same. The hydrodynamic bearing device in accordance with the present invention, dynamic pressure generation grooves being provided on at least one of a shaft or a sleeve, and a lubricant being present in a clearance where the above-mentioned shaft and the above-mentioned sleeve are opposed to each other, is characterized in that the above-mentioned lubricant contains diesters obtained from a divalent alcohol having 4 to 8 carbon atoms and having no alkyl side chain at the &#x3b2; position and one or more kinds of saturated monovalent fatty acids having 9 to 13 carbon atoms.

Hydrodynamic bearing device and spindle motor using the same

Lubricant for fluid dynamic bearing, spindle motor equipped therewith and magnetic disk unit

The invention provides a hydrodynamic bearing device including at least one of a shaft structure and a sleeve having a dynamic pressure-generating mechanism, and a lubricant present in a gap between the shaft structure and the sleeve. The lubricant contains a diester with a total carbon number of 20-28 obtainable by a divalent alcohol that has at least one ether bond, and one or more types of C6 to C10 saturated monovalent fatty acid.

Hydrodynamic bearing device, and spindle motor and information device using the same

A hydrodynamic bearing device comprises at least one of a rotating component and a fixed component having a dynamic pressure-generating mechanism, and a lubricant present in a gap between the rotating component and the fixed component; wherein the lubricant contains at least one compound selected from the group consisting of aliphatic ethers having one or more ether bonds and a total carbon number of 24 to 39.

A hydrodynamic bearing device is provided for use with a spindle motor. The hydrodynamic bearing device has a sleeve made of a sintered metal that is obtained by sintering a sintering material that is iron, an iron alloy, copper, a copper alloy or a mixture thereof. This sintered metal has independent pores, which do not communicate with each other, by selecting conditions for forming a desired sintered body within a predetermined range. The conditions includes a grain size of powdered metal of a material for the sintered metal, a molding pressure when the molded body is formed, sintering temperature and sintering period in the sintering step.

Hydrodynamic bearing device

A hydrodynamic bearing device has high reliability and is suitable for miniaturization through superior heat resistance and by utilizing a dynamic pressure-generating liquid with little loss due to evaporation. The hydrodynamic bearing device has at least one of a shaft structure and a sleeve having a dynamic pressure-generating mechanism. The dynamic pressure-generating liquid present in a gap between the shaft structure and the sleeve has a main component that is ionic liquid.

A hydrodynamic bearing device capable of inhibiting leakage of a working fluid to an outside of a bearing and preventing reduction in radial bearing rigidity, and capable of keeping a gap between a thrust bearing and a radial bearing favorable and rotating stably. The hydrodynamic bearing device includes a shaft relatively rotatably inserted into a bearing hole of a sleeve, a radial bearing surface having dynamic pressure generating grooves formed on at least one of an outer peripheral surface of the shaft and an inner peripheral surface of the sleeve, and a gap filled with a working fluid between the shaft and the sleeve. The shaft is made of high manganese chrome steel or stainless steel, and the sleeve is entirely made of sintered metal of metal particles including at least 60% by weight of iron or copper. Resin, metal or water glass is impregnated in pores on a surface of the sintered metal and cured. Thereby, leakage of the working fluid to the outside of the bearing from the sleeve can be inhibited, and reduction in the pressure inside the bearing can be prevented.

In the present invention, in order to provide a fluid dynamic bearing, having heat resistance, wherein the electrical charging on a rotation portion is prevented and the torque loss caused by a lubricant is made lower, an ionic liquid or the like is added to the lubricant filled in the clearance between the opposed faces of a shaft and a sleeve unit as an electrical conductivity imparting agent.

Fluid dynamic bearing and magnetic disk apparatus

In a hydrodynamic bearing according to the present invention a fixed shaft has different diameter sizes by positions so that overflow or splashing of lubricant out of the apparatus is prevented due to a centrifugal force during high-speed rotation, and lubricant reservoirs are provided in narrower clearances and in wider clearances so that the lubricant is induced to move toward lubricant reservoirs in narrower clearances due to surface tension while the hydrodynamic bearing is in stop, therefore overflow of the lubricant is prevented at the time of starting up.

Hydrodynamic bearing and disk apparatus

A fluid-bearing apparatus comprising a shaft, a sleeve, dynamic pressure-generating grooves that are provided on either the shaft or on the bearing surface of the sleeve that faces the shaft, wherein a single-component composition is used as the base oil of a lubricant, and accordingly segregation of the lubricant components does not occur, thereby preventing both the development of cavitation arising from decreases in the local vapor pressure and the washing away of the lubricant to the outside of the region of the bearing resulting from the enhancement of the gradient of surface tension of the lubricant.

Fluid-bearing apparatus

A fluid bearing device including a shaft, a sleeve rotatably supported by the shaft, a thrust bearing plate supported by the sleeve, a radial groove formed on one of an outer periphery of the shaft and an inner periphery of the sleeve, and a spiral groove formed on one of one end face of the shaft and one face of the thrust bearing plate such that the radial groove retains oil, while the spiral groove retains grease containing thickener and base oil identical, in compositions and viscosity, with the oil of the radial groove.

Growing community of inventors

Sennan, Japan

Hideaki Ohno