摘要:
A polyarylene sulfide resin composition having an excellent fluidability and a good moldability is disclosed. The resin composition is useful as a material for an optical pick-up part which has a high reliability and a high tenacity and does not generate deviation of an optical axis with changes in environmental conditions such as temperature and humidity. The polyarylene sulfide resin composition comprises, as main components, a polyarylene sulfide resin, a fibrous filler and a particulate filler, and, optionally, a silane coupling agent and an alicyclic hydrocarbon.
摘要:
A dynamic-pressure fluid bearing comprises bearing parts formed by a pair of dynamic-pressure surfaces. One of the dynamic-pressure surfaces of the bearing parts is a polyamideimide coating thicker than 3 .mu.m and the other surface is metal. The bearing is particularly applicable to driving motors for polygon mirrors. In addition, a so-called particle removing function is added to one or more of the surfaces of the bearing parts or a position nearby that causes easier removal of dust and other particles accumulated on the parts.
摘要:
A fluid sealing device for use in a motor having a fluid bearing for mounting a frame to a shaft. The fluid sealing device includes a bearing fluid reservoir, a sealing plate, and a bearing fluid absorbing pad. The bearing fluid reservoir is positioned at one axial end of the fluid bearing. The sealing plate is mounted on the frame and positioned axially outward of the bearing fluid reservoir. The sealing plate has an inner edge extending radially toward the shaft to provide a sealing space between the shaft and the sealing plate. A bearing fluid absorbing pad is mounted axially inward from the sealing plate. A capture space is provided between the bearing fluid absorbing pad, sealing plate and reservoir such that the bearing fluid absorbing pad is exposed to the reservoir.
摘要:
A fluid bearing unit includes a shaft; a bearing; bearing fluid arranged between a shaft and a bearing which are rotatably engaged with each other so that they can be relatively rotated so as to generate dynamic pressure in the bearing fluid, wherein at least one of the bearing and the member for fixing the bearing unit is made of iron alloy having the volumetric magnetostriction of which acts to cancel the thermal expansion so as to become the coefficient of linear expansion thereof lower than that of the shaft.
摘要:
To provide a photosensitive resin which realizes formation of a pattern having a good shape, without involving a problem in terms of poor compatibility between an acid generator and a photoresist primary-component polymer having an acid dissociable group, and a photosensitive composition containing the photosensitive resin.The photosensitive resin includes a repeating unit represented by formula (1): (wherein R1 represents a C2-C9 linear or branched divalent hydrocarbon group; each of R2 to R5 represents a hydrogen atom or a C1-C3 linear or branched hydrocarbon group; each of R6 and R7 represents an organic group, wherein R6 and R7 may together form a divalent organic group; and X− represents an anion); at least one of a repeating unit represented by formula (2): (wherein R8 represents a C2-C9 linear or branched hydrocarbon group) and a repeating unit represented by formula (3): a repeating unit represented by formula (4): optionally, a repeating unit represented by formula (5).
摘要:
A dynamic pressure bearing apparatus comprises a rotary shaft, a sintered oil retaining bearing rotatably supporting the rotary shaft, the sintered oil retaining bearing having an interior surface defining an internal surface configuration for generating dynamic pressure to thereby form a dynamic pressure bearing between the rotary shaft and the sintered oil retaining bearing. The internal surface of the sintered oil retaining bearing comprises in a peripheral direction thereof, a minimum-gap section, a large-gap section and a separation groove section. The minimum-gap section has the minimum gap between the rotary shaft and the internal surface of the sintered oil retaining bearing. The large-gap section is continuous to the minimum-gap section, and has a larger gap between the rotary shaft and the sintered oil retaining bearing than that at the minimum-gap section to thereby increase pressure of lubrication oil that is present between the rotary shaft and the sintered oil retaining bearing toward the minimum-gap section. The separation groove section is provided between the large-gap section and the minimum-gap section. The separation groove section has a gap greater than that of the large-gap section. The minimum-gap section and the large-gap section define a dynamic pressure bearing surface section. The minimum-gap section is located at a predetermined angular position with respect to the separation groove section in a manner that a ratio between an arc angle defined by the dynamic pressure bearing surface section and the predetermined angular position of the minimum-gap section is 1:0 through 0.2. Furthermore, a maximum gap in the large-gap section with respect to the rotary shaft is two times or less greater than a minimum gap at the minimum-gap section with respect to the rotary shaft.
摘要:
A hydrodynamic bearing apparatus comprises two hydrodynamic bearing sections which have a shaft member, a bearing member fit to the shaft member with a predetermined space therein, lubricants filling the space between the shaft member and the bearing member, and which are separately placed in the axial direction of the shaft member. The lubricants of the two hydrodynamic bearing sections are separated from each other by an air layer. The lubricants are pressured by hydrodynamic generating grooves formed on the hydrodynamic bearing sections such that the shaft member and the bearing member are rotatably supported in relation to each other. The hydrodynamic generating grooves separately formed on the two hydrodynamic bearing sections are formed into an unbalanced shape such that the lubricants are moved in a predetermined direction to correct the slope of the shaft member and the bearing member when rotation is suspended. Capillary sealing sections are formed in continuation to end sections of each of the two hydrodynamic bearing sections to sustain the lubricants by capillarity. The maximum amount of the lubricant in one of the capillary sealing sections, which is located downstream in the moving direction of the lubricants, is established to be larger than the moving amount of the lubricants.
摘要:
A sealing device for use in a motor. The motor, which maintains a shaft: and a frame that are interconnected by a bearing, includes a magnetic-fluid-seating device and a collecting device. The magnetic-fluid-sealing device seals the bearing with a magnetic fluid to prevent particles and fluids from escaping the bearing, whereas, the collecting device collects any particles and fluids which may escape the magnetic-fluid-sealing device.
摘要:
A gas dynamic pressure bearing apparatus comprises a fixed shaft, a bearing member which is positioned opposite from the fixed shaft and at least a radial gas dynamic pressure bearing portion and a thrust gas dynamic pressure bearing portion which are positioned in a space between the fixed shaft and the bearing member. Dynamic pressure generating means are included for pressurizing gas in the radial gas dynamic pressure bearing portion and the thrust gas dynamic pressure bearing portion such that dynamic pressure action is generated. The bearing member is rotatably supported in relation to the fixed shaft by means of the pressurizing action such that rotational driving is performed by a predetermined motor. The radial gas dynamic pressure bearing portion and the thrust gas dynamic pressure bearing portion are structured such that gas is sealed from the space around the motor by a space sealing means and that gas flows from one side to other. The flowing gas is circulated between the radial gas dynamic pressure bearing portion and the thrust gas dynamic pressure bearing portion through a gas circulation path. A gas passage is formed on the fixed shaft such that the gas circulation path is connected to the outer end of the fixed shaft. Dust collecting means is formed in one of the gas circulation and the gas passage.
摘要:
A hydrodynamic bearing apparatus for use in a spindle motor. The bearing includes at least two hydrodynamic bearing sections for supporting a rotary member with respect to a fixed member, a hydrodynamic pressure generating mechanism, a space between the two hydrodynamic bearing sections, a lubricant, two capillary sealing sections, and a lubricant reservoir. In the hydrodynamic bearing apparatus, the hydrodynamic pressure generating mechanism is positioned at the hydrodynamic bearing sections, and the capillary sealing section of the two capillary sealing sections has a space capacity which allows for an increased amount of lubricant. The lubricant is moved by a predetermined amount in one direction by a differential pressure generated at the hydrodynamic bearing sections when the rotary member rotates.