Hitachi, Ltd.

Mitsubishi Hitachi Power Systems, Ltd.

Takanobu Mori

Yutaka Fukui

Masao Siga

Yoshimi Yanai

Tatsuro Ishizuka

Mitso Kuriyama

Tetsuo Kashimura

Takahiko Kato

Nobuyuki Iizuka

Hiroshi Satoh

Kiyoshi Yamaguchi

Yasuo Kondo

Yasuomi Yagi

Naoki Maki

Fumio Shibata

Kado Miyakawa

Shigeo Hattri

Disclosed is a low alloy steel material for generator rotor shafts, which has tensile strength of not less than 700 MPa at room temperature. Preferably the low alloy steel material consists of, by mass percent, 0.15 to 0.35% carbon, 0.01 to 0.10% Si, 0.10 to 0.50% Mn, 1.3 to 2.0% Ni, 2.1 to 3.0% Cr, 0.20 to 0.50% Mo, 0.15 to 0.35% Cu, 0.06 to 0.14% V, and the balance of Fe and unavoidable impurities.

Low alloy steel material for generator rotor shafts

A shape memory alloy pipe coupling in the present invention for joining two pipes, the pipe coupling comprising a tube of a shape memory alloy, and a cover of stainless steel having a sufficient thickness and having high corrosion resistance for covering the tube. The shape memory alloy is enclosed by the cover of high corrosion-resistant stainless steel, by which high-temperature water can be prevented from making the shape memory alloy brittle and from corroding and damaging the shape memory alloy particularly through galvanic corrosion even in the case where such high-temperature water exists in the inside or outside of the pipes.

Shape memory alloy pipe coupling and underwater pipes

New low-alloy steel compositions and rotor shafts for electric machines made from them are described. High nickel and chromium contents ensure high strength and toughness, while other components, notably silicon and other impurities, are kept low with the result that magnetic properties remain good. One aspect provides a steel with the following proportions by weight:

Steel rotor shafts of electric machines

The rotor for a dynamo electric machine serving as a synchronous generator as well as being designed operable as a variable speed motor for starting a prime mover for the synchronous generator, the rotor (1) comprising a rotor core (2), a plurality of slots (4) disposed around the circumference of the rotor core (2) and extending along the axial direction of the rotor core (2), rotor windings (3) being accommodated in the slots (4) and wedges (6) being accommodated in the slots (4) over the rotor windings (3) near at the surface of the rotor core (2) for preventing the rotor windings (3) from being pushed out due to a centrifugal force caused by rotation of the rotor (1), wherein wedges (6) where an eddy current flows are formed by Cu-0.05.about.4 wt % Zr-0.3.about.5 wt % Ni-0.2.about.1.5 wt % Si having a 0.2% proof stress equal to or more than about 20 Kg/mm.sup.2 and an electrical conductivity equal to or more than about 20% IACS (International Annealed Copper Standard), whereby damages of the rotor elements due to electrolytic corrosion are prevented.

Rotor for dynamo electric machine

Steel rotor shafts for electric machines

Steel for rotor shafts of electric machines and method and product

An electric rotary machine (for example, a dynamoelectric machine) having a superconducting rotor is disclosed in which an outer shielding member for protecting a superconducting field winding from the influence of the magnetic flux from the stator side and for interrupting heat radiated from the normal temperature side is made of a nickel alloy containing not more than 0.3% carbon, not more than 1% silicon, not more than 2% manganese, not more than 1.5% titanium, from 2 to 8% aluminum, from 8 to 40% copper, and not less than 55% nickel for the balance by weight. The nickel alloy has a structure that a .gamma.'-phase precipitation is formed by aging in an austenitic matrix, and is non-magnetic at 20.degree. C.

Electric rotary machine having superconducting rotor

A gas turbine combustor defines a combustion chamber for combustion of injected fuel and for introduction of the resultant hot combustion gas to nozzles of a gas turbine. The combustor has parts subjected to hot combustion gas during operation of the turbine, such as a cap connected to a fuel injection nozzle, a liner connected to the cap, and a transition piece connected to the liner. These parts subjected to the hot combustion gas are made from an alloy having a composition consisting essentially of 0.02 to 0.2 wt % of C, 15 to 30 wt % of Cr and 10 to 25 wt % of W.

Gas turbine combustor

A welded structure for use at very low temperatures having structural metallic members of austenitic stainless steel welded with a welding material of austenitic stainless steel. The oxygen content of the portion of the deposited metal where there is no dilution with the material of the structural metallic member is not greater than 0.06 wt %. The structural metallic members and the deposited metal have chemical compositions consisting essentially of 0.01 to 0.1 wt % of C, 0.05 to 1 wt % of Si, 1 to 10 wt % of Mn, 8 to 20 wt % of Ni, 16 to 22 wt % of Cr and the balance substantially Fe and have a fully austenite structure. The Ni equivalent of the deposited metal ranges between 17 and 22. The welded structure for use at very low temperatures can be used, for example, as the container for the magnet of a superconducting generator rotor.

Welded structure for use at very low temperatures

An electric rotary machine having a superconducting rotor, such as a dynamoelectric machine. A cylindrical shielding member is provided for protecting the superconducting winding from the influence of the magnetic flux of the stator, and for shielding the heat radiated from the normal-temperature side of the machine, thereby maintaining the superconducting winding at an extremely low temperature. An inner reinforcing body and an outer reinforcing body are fitted to the inner and the outer peripheral surfaces of the cylindrical shielding member so as to reinforce the latter. These reinforcing bodies are effective to reduce the stress in the rotor caused by the centrifugal force and electromagnetic force during a running of the electric rotary machine, thereby protecting the shielding member against breakage and/or deformation.

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Hitachi, Japan

Takanobu Mori