Kabushiki Kaisha Toshiba

Tadashi Tanuma

Kenji Kamimura

Satoru Asai

Masataka Kikuchi

Taro Sakamoto

Satoru Yanaka

Ryusuke Tsuboi

Masashi Takahashi

Masahiro Saito

Kenichi Imai

Akio Sayano

Sakae Kawasaki

Junichi Tominaga

Kazuyoshi Nakajima

A steam turbineincludes: a turbine rotor; a rotor bladeimplanted to the turbine rotor; a stator bladeprovided at an upstream side of the rotor blade; and a turbine casingsupporting the stator bladeand including the turbine rotor, the rotor bladeand the stator blade, and have a constitution in which a stageis formed by a pair of the rotor bladeand the stator blade, and a steam passageis formed by arranging plural stagesin an axial direction of the turbine rotor. A surface treatment to suppress an increase of a surface roughness caused by oxidation is performed for at least a part of a surface of the stator bladeand a surface of the rotor blade

Steam turbine and steam turbine blade

The present invention comprises a turntable which holds a turbine part at a predetermined position, the turn table being rotatably supported by a support member, and rotated and driven by a driving motor, an abrasive feeding unit which feeds an abrasive particle having an elastic material as a core to a predetermined position as an abrasive, and a polishing head including an impeller which is rotated and driven by an impeller driving motor at high speed and applies rotary energy to the abrasive particle to be supplied from the abrasive feeding unit, the polishing head injecting the abrasive particle flying from the tangential direction of the impeller at a predetermined speed toward a surface to be polished of the turbine part held on the turntable, and an abrasive recovery unit which recovers the abrasive particle provided for polishing of the turbine part from the polishing head, and feeding into the abrasive feeding unit.

Large part polishing apparatus and polishing method

A surface to be polished of a large part is polished by projecting and colliding an abrasive comprising abrasive grains and an elastic petrochemical high polymer material having the specific gravity of 0.5 to 1.8 g/cmand elasticity of 10 to 200 ckg/cmor an elastic natural material, to the surface to be polished of the large part at a speed of 600 m to 3800 m per minute and by a volume of 5 to 300 cc/cm&#xb7;sec per unit area, and sliding the abrasive.

Method of polishing a large part and abrasive for use in the method

In the axial turbine according to the present invention, a nozzle bladeand/or a movable bladehas a profile in which a throat-pitch ratio 's/t' is maximized at a blade-central portion in height, wherein 's' being a shortest distance between a rear edge of a nozzle blade (movable blade) and a back side of another nozzle blade that is adjacent to the nozzle blade, and &#x201c;t&#x201d; being a pitch of the nozzle blades disposed in the row, minimized in a position between the blade-central portion in height and a blade-root portion and increased from a minimized value to the blade-root portion. This structure enables to provide the axial turbine, which permits to control flow distribution of the working fluid in the height direction of the blade in the passage between the blades of a turbine nozzle unit and a turbine movable nozzle and reduce the blade profile loss and the secondary flow loss at the blade-root portion, thus making a further improvement in the turbine stage efficiency.

Axial flow turbine

A steam turbine that passes more turbine driving steam by off-setting the turbine moving blade throat&bull;pitch ratio before operation and, when a blade untwist is generated during operation, causing more turbine driving steam to flow by maintaining an appropriate value, and, at the same time causing the turbine moving blade throat&bull;pitch ratio to swell by giving the blade untwisting angle to the blade cross-sections in regions where the aerodynamic loss is small. The steam turbine is one in which the throat&bull;pitch ratio (S/T) distribution of a turbine moving blade is offset by forming a curve providing at least one minimal value and maximal value by giving blade twist angle to the blade cross-sections in the blade height direction from blade root to blade tip and, at the same time, the distribution of throat&bull;pitch ratio (S/T) taking into consideration blade untwist generated during operation.

High efficiency blade configuration for steam turbine

A steam turbine that passes more turbine driving steam by off-setting the turbine moving blade throat-pitch ratio before operation and, when a blade untwist is generated during operation, causing more turbine driving steam to flow by maintaining an appropriate value, and, at the same time causing the turbine moving blade throat-pitch ratio to swell by giving the blade untwisting angle to the blade cross-sections in regions where the aerodynamic loss is small. The steam turbine is one in which the throat-pitch ratio (S/T) distribution of a turbine moving blade is offset by forming a curve providing at least one minimal value and maximal value by giving blade twist angle to the blade cross-sections in the blade height direction from blade root to blade tip and, at the same time, the distribution of throat-pitch ratio (S/T) taking into consideration blade untwist generated during operation.

Growing community of inventors

Yokohama, Japan

Tadashi Tanuma