Abstract: A cold rolling mill rolling condition calculation method includes: an estimation step of estimating a rolling constraint condition with respect to a target steady rolling condition of a roll target material, by inputting second multi-dimensional data to a prediction model, the prediction model having been trained with explanatory variable and response variable, the explanatory variable being first multi-dimensional data generated based on non-steady rolling performance data, among past rolling performance in rolling a roll material by a cold rolling mill, and the response variable being steady rolling performance data and rolling constraint condition data during steady rolling, and the second multi-dimensional data having been generated based on non-steady rolling performance data of the roll target material; and a change step of changing the target steady rolling condition so that the estimated rolling constraint condition satisfies a predetermined condition.

Abstract: A turbocharger includes a rolling bearing including at least one rolling element for rotatably supporting a rotational shaft, a bearing support cylinder located on a radially outer side relative to the rolling bearing, for supporting the rolling bearing, and a housing located on the radially outer side relative to the bearing support cylinder, for covering a circumference of the bearing support cylinder. Between an outer circumferential surface of the bearing support cylinder and an inner circumferential surface of the housing, a gap for forming an oil film by inflow of lubricant oil is provided. At least one of the outer circumferential surface of the bearing support cylinder and the inner circumferential surface of the housing includes an oil film holding portion for suppressing outflow of the lubricant oil from the gap.

Abstract: A bearing device according to an embodiment is a bearing device for rotatably supporting a rotational shaft, the device including at least one rolling bearing which includes an inner race fixed to the rotational shaft, a rolling element, and an outer race for rotatably holding the rolling element with the inner race, and a casing for housing the rolling bearing, the casing including a plurality of first oil supply holes formed at intervals in a circumferential direction for supplying lubricant oil to a first gap between the rolling bearing and an inner circumferential surface of the casing. Each of the plurality of first oil supply holes satisfies: ?·d1·?1<?·d12/4,??(a) where d1 is a diameter of an outlet opening of the first oil supply hole, and ?1 is a space of the first gap.

Abstract: A forced induction device (100) includes: a rotor (1) which includes a turbine side shaft portion (11), a compressor side shaft portion (12), and a connection shaft portion (13) connecting these to each other; a turbine side bearing (5) which supports the turbine side shaft portion (11); and a compressor side bearing (6) which supports the compressor side shaft portion (12). A rigidity of the connection shaft portion (13) is lower than that of the turbine side shaft portion (11) and the compressor side shaft portion (12) so that a node in a mode shape at each critical speed involving with an operating rotational speed region of the rotor (1) is located between the turbine side bearing (5) and the compressor side bearing (6).

Abstract: A compressor according to an embodiment includes: a rotational shaft provided with a compressor impeller on one end side; a rolling bearing device for rotatably supporting the rotational shaft; and a housing for housing the rolling bearing device. The rolling bearing device includes: an inner ring mounted on the rotational shaft; an outer ring supported by the housing with application of a load from the housing in an axial direction of the rotational shaft; a rolling element disposed between the inner ring and the outer ring; an elastic member disposed on an outer circumferential side of the outer ring so as to come into contact with the housing; and a sliding portion disposed on one end side of the outer ring in the axial direction so as to come into contact with the housing.

Abstract: A turbocharger is provided with: a rotational shaft; a rolling bearing rotatably supporting the rotational shaft; an oil film damper disposed radially outward of an outer ring of the rolling bearing; and a housing having a first axial retaining portion and a second axial retaining portion, disposed adjacent to both ends of the oil film damper in the axial direction, respectively, for restricting movement of the outer ring in the axial direction. An axial end surface of the outer ring, or a facing surface of the first axial retaining portion or the second axial retaining portion facing the axial end surface of the outer ring has: a coefficient of static friction smaller than that of a portion of the housing excluding the first axial retaining portion and the second axial retaining portion; or has a recess where oil of the oil film damper can enter.

Abstract: A bearing device according to an embodiment is a bearing device for rotatably supporting a rotational shaft, the device including at least one rolling bearing which includes an inner race fixed to the rotational shaft, a rolling element, and an outer race for rotatably holding the rolling element with the inner race, and a casing for housing the rolling bearing, the casing including a plurality of first oil supply holes formed at intervals in a circumferential direction for supplying lubricant oil to a first gap between the rolling bearing and an inner circumferential surface of the casing. Each of the plurality of first oil supply holes satisfies: ?·d1·?1<?·d12/4 ??(a) , where d1 is a diameter of an outlet opening of the first oil supply hole, and ?1 is a space of the first gap.

Abstract: A turbocharger includes a rolling bearing including at least one rolling element for rotatably supporting a rotational shaft, a bearing support cylinder located on a radially outer side relative to the rolling bearing, for supporting the rolling bearing, and a housing located on the radially outer side relative to the bearing support cylinder, for covering a circumference of the bearing support cylinder. Between an outer circumferential surface of the bearing support cylinder and an inner circumferential surface of the housing, a gap for forming an oil film by inflow of lubricant oil is provided. At least one of the outer circumferential surface of the bearing support cylinder and the inner circumferential surface of the housing includes an oil film holding portion for suppressing outflow of the lubricant oil from the gap.

Abstract: An unbalance detection device for detecting unbalance of a rotor of a turbo-cartridge which includes the rotor including a turbine wheel and a compressor wheel coupled via a rotational shaft and a bearing housing accommodating a bearing which supports the rotor rotatably, includes: a sound pressure sensor capable of detecting vibration upon rotation of the rotor by contactlessly measuring a sound pressure generated from vibration upon rotation of the rotor.

Abstract: A forced induction device (100) includes: a rotor (1) which includes a turbine side shaft portion (11), a compressor side shaft portion (12), and a connection shaft portion (13) connecting these to each other; a turbine side bearing (5) which supports the turbine side shaft portion (11); and a compressor side bearing (6) which supports the compressor side shaft portion (12). A rigidity of the connection shaft portion (13) is lower than that of the turbine side shaft portion (11) and the compressor side shaft portion (12) so that a node in a mode shape at each critical speed involving with an operating rotational speed region of the rotor (1) is located between the turbine side bearing (5) and the compressor side bearing (6).

Abstract: An unbalance detection device for detecting unbalance of a rotor of a turbo-cartridge which includes the rotor including a turbine wheel and a compressor wheel coupled via a rotational shaft and a bearing housing accommodating a bearing which supports the rotor rotatably, includes: a sound pressure sensor capable of detecting vibration upon rotation of the rotor by contactlessly measuring a sound pressure generated from vibration upon rotation of the rotor.

Abstract: The invention relates to a casting core composition including refractory mullite grains and 1.0-2.2 wt % of a phenolic resin for binding the mullite grains. The mullite grains are substantially spherical in shape and have a special grain size distribution. That is, the mullite grains contain first to eighth fractions. These fractions respectively have first to eighth diameters which are respectively within ranges of larger than 420 .mu.m, 297-420 .mu.m 210-297 .mu.m, 149-210 .mu.m, 105-149 .mu.m, 74-105 .mu.m, 53-74 .mu.m, and smaller than 53 .mu.m.