Ntn Corporation

Other

Yoshio Fujikawa

Shoji Fujii

Tomoya Kawai

Takayuki Itoh

Shizuka Yamazaki

Toru Takahashi

Takashi Koike

Yoshitaka Nagano

Kenichi Iwamoto

Junichi Hirata

Kiyotaka Kusunoki

Kazuyuki Aono

Ryu Inoue

Hidehiko Nishijima

A hydroelectric power generation apparatus includes a hydroelectric power generation module, a beam as a supporting part, and a fixing part. The hydroelectric power generation module includes a rotary blade and a power generator that generates power by rotation of the rotary blade. The supporting part supports the hydroelectric power generation module. The fixing part fixes the supporting part to a water channel. The fixing part includes a bolt to press a surface of a wall portion of the water channel to fix the supporting part to the water channel. The hydroelectric power generation apparatus can dispense with a work performed around the water channel to install the apparatus and also be relocated easily and inexpensively.

Hydroelectric power generation apparatus

A hydroelectric power generation apparatus includes a hydroelectric power generation module, a supporting part, and a bar. The hydroelectric power generation module includes a rotary blade and a power generator that generates power by rotation of the rotary blade. The supporting part supports the hydroelectric power generation module. The supporting part can be installed at a water channel. The bar is connected to the supporting part to protrude from the supporting part. With one end of the bar closer to the supporting part or a portion of the supporting part serving as a center, the other end of the bar opposite to one end of the bar can be pivoted to switch a first state to a second state and vice versa.

A hydrostatic gas bearing capable of easily adjusting a clearance between a rotor and a radial bearing pad is provided. This hydrostatic gas bearing comprises a radial bearing pad radially supporting a rotor, a linear motion guide moving the radial bearing pad and a ball stud swingably coupling the radial bearing pad to the linear motion guide. The linear motion guide moves the radial bearing pad in a direction intersecting with a direction connecting the center of rotation of the rotor and the ball stud with each other. The quantity of adjustment in movement of the radial bearing pad caused by the linear motion guide is larger than the quantity of change in the clearance between the outer peripheral surface of the rotor and the radial bearing pad, whereby a small quantity of the bearing clearance can be precisely adjusted.

Hydrostatic gas bearing, rotator and CT scanner

An externally pressurized gas bearing comprising a main shaft, and journal bearing sections having a plurality of axial gas feed rows each having a plurality of circumferentially equispaced gas feed holes, the gas feed holes in the gas feed rows being adapted to spout compressed gas to thereby rotatably radially support the main shaft in a non-contact state, the externally pressurized gas bearing being arranged so that the gas feed holes in the gas feed row are disposed so as to be positioned circumferentially intermediate between gas feed holes in the adjoining gas feed row.

Externally pressurized gas bearing and spindle equipment using this

To provide a compact bearing assembly equipped with a rotation sensor capable of detecting not only pulse signals for detecting the number of revolution, but also a home position signal, the bearing assembly equipped with the rotation sensor includes a rotatable member () and a non-rotatable member () with rolling elements () interposed between the rotatable and non-rotatable members () and () to permit the rotatable member () to be rotatable relative to the non-rotatable member (). The rotatable member () is provided with a magnetic encoder () and the non-rotatable member () is provided with magnetic sensors (A) to (C). The magnetic encoder () includes first and second to-be-detected elements (A) and (B) each having a plurality of equally spaced, opposite magnetic poles defined therein so as to alternate with each other in a direction circumferentially thereof. The first to-be-detected element also has a magnetic characteristic disturbing element () provided at a predetermined site on a circumference of the magnetic encoder () for agitating a periodicity of the opposite magnetic poles. The two magnetic sensors (A) and (B) for detecting the first to-be-detected element (A) are spaced in a circumferential direction a distance greater than a circumferentially extending width of the disturbing element (), and are so positioned as to be held in substantially phase-matched relation with a cycle of repetition of the opposite magnetic poles.

Bearing assembly equipped with rotation sensor to determine rotation and position of rotating element

A foil bearing is provided, which is simple in structure, has a large load capacity and a large damping capability and can therefore allow a rotary shaft having a large unbalance as compared with the conventional bearing to be driven stably at a high speed. A spindle device utilizing such foil bearing is also provided, which is designed to increase the permissible amount of unbalance and also to have a light-weight feature. Each of the foil bearingsandincludes an elastic memberprepared from a wire net formed by braiding wires, and a thin bearing foilsupported by the elastic memberand defining an elastic bearing surface S. The respective foil bearingandis used at least as a radial bearingin the spindle device including a rotary shafthaving a head mounton which an atomizer head is mounted, and the radial and thrust bearingsandfor rotatably supporting the rotary shaft

Foil bearing and spindle device using the same

A spindle for an electrostatic painting machine has a main spindle and a rotor coupled to the rear end of the main spindle. The main spindle and the rotor are rotatably supported through bearing gaps of externally pressurized gas bearing portions, and a paint spray head is mounted to one end of the main spindle. A current-carrying member having conductivity with the housing is brought into contact with the main spindle and floated off it via a small gap due to dynamic pressure produced by the rotation of the main spindle. With this arrangement, it is ensured that discharge occurs at gaps of externally pressurized gas bearing portions, sputtering is suppressed, and the life of the spindle is prolonged.

Externally pressurized gas bearing spindle

A compact externally pressurized gas bearing spindle assembly can increase the degree of vacuum in a vacuum chamber. In a spindle assembly wherein a rotary shaft is provided in a housing through a bearing gap, and compressed gas is introduced into the bearing gap to support the rotary shaft in a non-contact manner relative to the housing, an exhaust gas suction device for sucking gas discharged from the bearing gap is provided inside the housing or the rotary shaft. The bearing gap near the outside of the housing is smaller than the other bearing gap. Near the bearing gap near the outside of the housing, a non-contact seal gap is formed to prevent leakage of compressed gas into the vacuum chamber in a non-contact manner.

Externally pressurized gas bearing spindle assembly

An externally pressurized gas bearing assembly including a bearing sleeve fixed in contact with an inner peripheral surface of a housing provided with a gas supply passage communicated with fine feed ports of thrust bearings and opening at an outer peripheral surface of the bearing sleeve through an interior of the bearing sleeve. The bearing sleeve supports a main shaft in an axial direction through an externally pressurized gas by a thrust bearing surface having a plurality of fine feed ports of the thrust bearing.

Externally pressurized gas bearing assembly

An externally pressurized air bearing spindle comprises: a first cylindrical bearing portion having a journal bearing surface opposing an outer circumferential surface of a main shaft with a small journal bearing clearance therebetween, a thrust bearing surface opposing one end surface of a thrust plate disposed on the main shaft with a small thrust bearing clearance therebetween, and plural bearing nozzles formed in the journal bearing surface and the thrust bearing surface and arranged in planes perpendicular to an axis thereof; and a second cylindrical bearing portion having a thrust bearing surface opposing the other end surface of the thrust plate with a small thrust bearing clearance therebetween and plural bearing nozzles formed in the thrust bearing surface and arranged in a plane perpendicular to an axis thereof; the arrangement being such that the main shaft is supported on the bearing surfaces without contact by the action of compressed air fed through the bearing nozzles into the bearing clearances, and that an annular groove is formed between an outer wall of at least one of the first and second bearing portions and an inner wall of an outer case for that one bearing portion so that the bearing nozzles are fed with compressed air from a bearing air feed port formed in the outer case through the annular groove.

Externally pressurized bearing spindle

A spindle assembly having a spindle used as a rotary shaft or a machine tool or the like, at least one bearing sleeve for supporting the spindle as an externally pressurized gas bearing without touching it, a plurality of journal bearing clearances formed between the spindle and the bearing sleeve, and a housing accommodating the bearing sleeve. The bearing sleeve is formed with an annular groove for guiding compressed gas in a circumferential direction, at least three axially-extending gas supply grooves for directing the compressed gas through gas supply restrictor holes into the journal bearing clearances, and at least one axially-extending exhaust groove for discharging the compressed gas from said journal bearing clearances. The axial gas supply grooves and the exhaust groove have a plurality of gas supply restrictor holes and discharge holes, respectively.

Growing community of inventors

Iwata, Japan

Yoshio Fujikawa