Abstract: For improving characteristic uprising at the right-hand side of head-flow rate characteristic of a turbo machine, as well as for suppressing increase of vibration and/or noises thereof, a plurality of first grooves 24 in direction of gradient in pressure of fluid are formed on an inner flow surface of a casing, for connecting an inlet side of blades of an impeller and an area on the inner flow surface of the casing where the impeller blades reside in, over an inner circumference of the casing. Also, second grooves 25 in a circumferential direction are formed in an area on the inner flow surface of the casing where the impeller blades reside in, for communicating the first grooves in the circumferential direction of the casing.

Abstract: For improving characteristic uprising at the right-hand side of head-flow rate characteristic of a turbo machine, as well as for suppressing increase of vibration and/or noises thereof, a plurality of first grooves 24 in direction of gradient in pressure of fluid are formed on an inner flow surface of a casing, for connecting an inlet side of blades of an impeller and an area on the inner flow surface of the casing where the impeller blades reside in, over an inner circumference of the casing. Also, second grooves 25 in a circumferential direction are formed in an area on the inner flow surface of the casing where the impeller blades reside in, for communicating the first grooves in the circumferential direction of the casing.

Abstract: A turbo machine comprising: an impeller having a plurality of blades therewith; a casing having a flow surface defined therein and being positioned with the impeller therein; and a plurality of grooves being formed in the flow surface of the casing, for connecting between an inlet side of said impeller and an area on the flow surface of the casing in which the blades of said impeller reside. Each groove has a length of at least part of which is oriented in an axial direction of the casing, a width measured in a circumferential direction, and a depth. The width of each groove is equal to or greater than the depth thereof.

Abstract: For improving characteristic uprising at the right-hand side of head-flow rate characteristic of a turbo machine, as well as for suppressing increase of vibration and/or noises thereof, a plurality of first grooves 24 in direction of gradient in pressure of fluid are formed on an inner flow surface of a casing, for connecting an inlet side of blades of an impeller and an area on the inner flow surface of the casing where the impeller blades reside in, over an inner circumference of the casing. Also, second grooves 25 in a circumferential direction are formed in an area on the inner flow surface of the casing where the impeller blades reside in, for communicating the first grooves in the circumferential direction of the casing.

Abstract: A turbo machine comprising: an impeller having a plurality of blades therewith; a casing having a flow surface defined therein and being positioned with the impeller therein; and a plurality of grooves being formed in the flow surface of the casing, for connecting between an inlet side of said impeller and an area on the flow surface of the casing in which the blades of said impeller reside, on a periphery thereof, wherein an index of determining a form of the grooves is obtained by a following equation: JE No.

Abstract: For improving characteristic uprising at the right-hand side of head-flow rate characteristic of a turbo machine, as well as for suppressing increase of vibration and/or noises thereof, a plurality of first grooves 24 in direction of gradient in pressure of fluid are formed on an inner flow surface of a casing, for connecting an inlet side of blades of an impeller and an area on the inner flow surface of the casing where the impeller blades reside in, over an inner circumference of the casing. Also, second grooves 25 in a circumferential direction are formed in an area on the inner flow surface of the casing where the impeller blades reside in, for communicating the first grooves in the circumferential direction of the casing.

Abstract: Hard particles are provided containing 20 to 70% of Mo, 0.5 to 3% of C, 5 to 40% of Ni, 1 to 20% of Mn, a balance in Fe, and impurities, where % represents percentage by mass, and may further contain at least one of 40% or less of Co, 0.1 to 10% of Cr, and 4% or less of Si. A wear resistant iron-based sintered alloy contains 4 to 30% of Mo, 0.2 to 3% of C, 1 to 20% of Ni, 0.5 to 12% of Mn, a balance in Fe, and impurities, with respect to the total mass of the iron-based sintered alloy as represented by 100%. In the sintered alloy, the base contains 0.2 to 5% of C, 0.1 to 12% of Mn, a balance in Fe, and impurities, with respect to the total mass of the base, and the hard particles contain 20 to 70% of Mo, 0.5 to 3% of C, 5 to 40% of Ni, 1 to 20% of Mn, a balance in Fe, and impurities, with respect to the total mass of the hard particles. The hard particles are dispersed in the base with an area ratio of 10 to 60%. A method to produce a wear resistant sintered alloy of the above composition is also provided.

Abstract: An overlaying alloy containing no Cr or a reduced amount of Cr, in which an effective amount of Mo oxide is formed even in a weak oxidizing atmosphere such as a combustion atmosphere of diesel engines and engines using CNG, LPG or other gases as a fuel to provide an improved non-damaging property and wear resistance. An overlaying alloy comprising 20-70 wt % Mo, 0.5-3 wt % C, 5-40 wt % Ni, and the balance being Fe and unavoidable impurities, which contains no Cr to facilitate formation of Mo oxide and is advantageously applied to the parts on which an oxide coating is not easily formed such as the engine parts subject to a lower temperature combustion atmosphere. An overlaying alloy comprising 20-60 wt % Mo, 0.2-3 wt % C, 5-40 wt % Ni, 0.1-10 wt % Cr, and the balance of Fe and unavoidable impurities, which contains a small amount of Cr to control formation of Mo oxide and is advantageously applied to the parts on which an oxide coating is relatively easily formed.

Abstract: A process for producing a sliding member employs a base material having a covering surface and pores, and a layer material comprising a constitutive component for reacting with a constitutive component of the base material. Initially, the layer material comes into contact with at least part of the covering surface of the base material. Next, the both are heated to the sintering temperature of the base material. Thus, a molten liquid occurs at the boundary between the base material and the layer material. Since the solidus temperature of the molten liquid increases with the reaction proceeding, the molten liquid can solidify early to seal the pores at the covering surface of the base material early. Therefore, the layer material remains on the covering surface of the base material, the remaining layer material comes to constitute a sliding surface.

Abstract: In a drainage pump station, a driving machine has a capacity greater than a shaft power necessary for no-discharge operation of a pump, and during severe flooding the pump is operated at an overload exceeding its design capacity. During maintenance operation water is fed from a river on the delivery side of the pump station into the station. When an inflow of rainwater into the pump station is great the pump is operated at the necessary capacity, when it becomes small the water level is kept above a rated value, and when the inflow rate is zero the pump discharge is increased to a capacity at which sediment can be discharged. A suction blower is disposed at the top of a suction sump and interstage valves are disposed in entrances of vertical shafts to effect efficient ventilation of the underground waterway. A feed channel is operated as a pressure channel and the pump is of variable capacity and the water level in the underground waterway is controlled to be constant.

Abstract: Disclosed are an Fe-based alloy powder adapted for sintering, an Fe-based sintered alloy, and a process for producing the Fe-based sintered alloy. The Fe-based alloy powder or the matrix of the Fe-based sintered alloy consists, percent by weight, essentially of 2.0 to 15% Co, 2.0 to 10% Mo, and the balance of Fe and inevitable impurities. The Fe-based alloy powder exhibits superb compressibility and corrosion resistance, and accordingly the Fe-based sintered alloy made therefrom exhibits excellent wear resistance, corrosion resistance and oxidation resistance. The Fe-based sintered alloy is further improved in the excellent properties by dispersing novel Ni-based alloy hard particles in the matrix.

Abstract: Disclosed are an Fe-based alloy powder adapted for sintering, an Fe-based sintered alloy, and a process for producing the Fe-based sintered alloy. The Fe-based alloy powder or the matrix of the Fe-based sintered alloy consists, percent by weight, essentially of 2.0 to 15% Co, 2.0 to 10% Mo, and the balance of Fe and inevitable impurities. The Fe-based alloy powder exhibits superb compressibility and corrosion resistance, and accordingly the Fe-based sintered alloy made therefrom exhibits excellent wear resistance, corrosion resistance and oxidation resistance. The Fe-based sintered alloy is further improved in the excellent properties by dispersing novel Ni-based alloy hard particles in the matrix.

Abstract: Disclosed are an Fe-based alloy powder adapted for sintering, an Fe-based sintered alloy, and a process for producing the Fe-based sintered alloy. The Fe-based alloy powder or the matrix of the Fe-based sintered alloy consists, percent by weight, essentially of 2.0 to 15% Co, 2.0 to 10% Mo, and the balance of Fe and inevitable impurities. The Fe-based alloy powder exhibits superb compressibility and corrosion resistance, and accordingly the Fe-based sintered alloy made therefrom exhibits excellent wear resistance, corrosion resistance and oxidation resistance. The Fe-based sintered alloy is further improved in the excellent properties by dispersing novel Ni-based alloy hard particles in the matrix.

Abstract: In a roller guide apparatus for guiding a steel material to be rolled into a rolling mill machine, a ratio (K/M) of an elastic constant (K [N/mm]) of the roller guide portion of a roller guide apparatus to a gradient (M [N/mm]) in a plasticity characteristic curve obtained when pressing the steel material nipped between the guide rollers in rolling is determined to be 0.5 or more, to thereby prevent the steel material from tilting between the guide rollers. As a result, dimensional accuracy in sectional shape and size of an end product can be improved, and miss-rolling can be prevented, thus producing high-quality rolled steel products without surface defects with remarkably high yield rate and productivity.

Abstract: In a drainage system wherein drain water is collected from a drainage path including a small river, guided to a plurality of drainage pump facilities, and drained into a destination river, a drainage distribution amount is determined for each of the plurality of drainage pump facilities in accordance with an actual precipitation or estimated precipitation, a river water level at a drainage point of each of the plurality of drainage pump facilities is estimated in accordance with the drainage distribution amount and a change in a detected water level at an upstream of the destination river, and the drainage distribution amount for each of the plurality of drainage pump facilities is corrected so as to make the estimated river water level have a value equal to or smaller than an upper limit of the river water level at the drainage point.

Abstract: Provided herein is a solder for sintered metal parts which is composed of Fe and/or Cr 5.about.40%, Si and/or B 1.about.5%, Cu 20.about.65%, Mn 5.about.30%, and Ni 20% and up, and optional flux 1.about.6% (by weight). The solder may lack either or both of Cu and Mn. Provided also herein is a process for soldering sintered metal parts with the solder. The solder joins parts very well with a minimum of infiltration into and corrosion to the sintered metal parts.

Abstract: A valve-seat insert for internal combustion engines comprises a double-layered, sintered alloy composed of a valve-seat layer on which a valve is seated, and a base layer integrated with the valve-seat layer and adapted to be seated in a cylinder head of an engine. The valve-seat layer is composed of a sintered alloy of a high heat resistance and a high wear resistance having a composition comprising, by weight, 4 to 8% Co, 0.6 to 1.5% Cr, 4 to 8% Mo, 1 to 3% Ni, 0.3 to 1.5% C, 0.2 to 0.6% Ca, and the balance of Fe and inevitable impurities, the additives, Co, Cr and Mo being present mainly in a form of a Co-Cr-Mo hard alloy and a hard Fe-Mo alloy dispersed in the Fe matrix. The base layer is composed of a sintered alloy of a higher heat resistance and a higher creep resistance than those of the valve-seat layer and having a composition comprising, by weight, 11 to 15% Cr, 0.4 to 2.0% Mo, 0.05 to 0.3% C, and the balance of Fe and inevitable impurities.

Abstract: A valve-seat insert for internal combustion engines comprises a double-layered, sintered alloy composed of a valve-seat layer on which a valve is seated, and a base layer integrated with the valve-seat layer and adapted to be seated in a cylinder head of an engine. The valve-seat layer is composed of a sintered alloy of a high heat resistance and a high wear resistance having a composition comprising, by weight, 4 to 8% Co, 0.6 to 1.6% Cr, 4 to 8% Mo, 1 to 3% Ni, 0.3 to 1.5% C, 0.2 to 0.6% Ca, and the balance of Fe and inevitable impurities, the additives, Co, Cr and Mo being present mainly in a form of a Co-Cr-Mo hard alloy and a hard Fe-Mo alloy dispersed in the Fe matrix. The base layer is composed of a sintered alloy of a higher heat resistance and a higher creep resistance than those of the valve-seat layer and having a composition comprising, by weight, 11 to 15% Cr, 0.4 to 2.0% Mo, 0.05 to 0.3% C, and the balance of Fe and inevitable impurities.

Abstract: An improved device for measuring an inclination angle of the tapered surface of a plaster die duplicated from the prepared tooth in the field of restorative dentistry is disclosed. The device is used also for scraping operation for the was pattern. It includes a turnable tool holding plate which is turnably held in a slot formed on the lower part of a core so as to turn about a support shaft. A rotary ring with its lower end face cut to a predetermined inclination angle, for instance, 7 degrees is rotatably fitted onto the core in such a manner that the lower inclined face comes in contact with the upper faces of wing-shaped lateral projections of the tool holding plate with a transversely extending shaft disposed therebetween. The transversely extending shaft is inserted through the tool holding plate at the same inclination angle as that of the lower inclined end face of the rotary ring so that its axis intersects with the axis of the support shaft.