Abstract: A state monitoring device for a plate spring mounted on a railcar bogie is configured to monitor a state of the plate spring, the plate spring including fiber-reinforced resin containing electrically conductive reinforced fibers containing reinforced fibers extending in a longitudinal direction of the plate spring. The state monitoring device includes: an electrode pair provided at both width direction side end surfaces of the plate spring and sandwiching the plate spring, a width direction of the plate spring being perpendicular to the longitudinal direction of the plate spring and a thickness direction of the plate spring; and a measuring unit electrically connected to the electrode pair and configured to measure an electrical characteristic of the plate spring.

Abstract: A field rotor of a superconducting rotating machine including: a rotation shaft; a supply shaft that supplies a refrigerant to the rotation shaft at one end of the rotation shaft; an input/output shaft provided at the other end of the rotation shaft so as to integrally rotate with the rotation shaft; and a superconducting coil held on a circumferential surface of the rotation shaft to be cooled by the refrigerant, wherein the supply shaft and the input/output shaft are fixed to each other so as to rotate integrally with each other, and the rotation shaft and the supply shaft are at least partly brought in contact with each other in order to allow the rotation shaft to be supported by the supply shaft and in order to be slidably fitted to each other in a circumferential direction of the rotation shaft and in an axial direction of the rotation shaft.

Abstract: A railroad vehicle where an air conditioner can be installed in an upper part of a roof thereof includes a roof structure having an opening, and a low roof main body having a recessed part provided in the opening, and recessed in a cross section, the air conditioner being able to be placed on the recessed part, and an edge part of the low roof main body which is continuously formed from the low roof main body and joined to the roof structure. The low roof main body and the edge part of the low roof main body are made of plastic.

Abstract: A method of producing plate springs for a railcar bogie, the plate springs each extending in a car longitudinal direction and elastically supporting a cross beam while being supported by an axle box in the railcar bogie, the axle box accommodating a bearing for an axle, the method includes: a molding step of molding a mother plate made of fiber-reinforced resin, the mother plate including a layer made of continuous fibers oriented in a first direction when viewed from a normal direction of a main surface of the mother plate; a cut position determining step of determining positions of a plurality of parallel cut lines for cutting the mother plate along the first direction; and a cutting step of cutting the mother plate along the plurality of cut lines to take out the plate springs made of the fiber-reinforced resin.

Abstract: A field rotor of a superconducting rotating machine including: a rotation shaft; a supply shaft that supplies a refrigerant to the rotation shaft at one end of the rotation shaft; an input/output shaft provided at the other end of the rotation shaft so as to integrally rotate with the rotation shaft; and a superconducting coil held on a circumferential surface of the rotation shaft to be cooled by the refrigerant, wherein the supply shaft and the input/output shaft are fixed to each other so as to rotate integrally with each other, and the rotation shaft and the supply shaft are at least partly brought in contact with each other in order to allow the rotation shaft to be supported by the supply shaft and in order to be slidably fitted to each other in a circumferential direction of the rotation shaft and in an axial direction of the rotation shaft.

Abstract: A railroad vehicle where an air conditioner can be installed in an upper part of a roof thereof includes a roof structure having an opening, and a low roof main body having a recessed part provided in the opening, and recessed in a cross section, the air conditioner being able to be placed on the recessed part, and an edge part of the low roof main body which is continuously formed from the low roof main body and joined to the roof structure. The low roof main body and the edge part of the low roof main body are made of plastic.