Abstract: A railroad wheel revolving around an XX' axle perpendicular to a median plane P, of the type that includes a rim with a rolling surface and a flange, a hub, a plate a connecting area of the plate with the rim, a connecting area of the plate with the hub and with the plate section constructed along a meridian line AB extending between a point A located at the junction of the plate and the connecting area of the plate with the rim and a point B located at the junction of the plate and the connecting area of the plate with the hub, and characterized by the fact that the two points A and B are located on either side of the median plane P and are symmetrical to one another in relation to the intersection point I of the meridian line AB and the plane P, with point I an inflection point for the curve AB.

Abstract: A railroad wheel revolving around an XX' axle perpendicular to a median plane P, of the type that includes a rim with a rolling surface and a flange, a hub, a plate a connecting area of the plate with the rim, a connecting area of the plate with the hub and with the plate section constructed along a meridian line AB extending between a point A located at the junction of the plate and the connecting area of the plate with the rim and a point B located at the junction of the plate and the connecting area of the plate with the hub, and characterized by the fact that the two points A and B are located on either side of the median plane P and are symmetrical to one another in relation to the intersection point I of the meridian line AB and the plane P, with point I an inflection point for the curve AB.

Abstract: In order to obtain, in service, a reduced acoustic emission, the position of the true point of contact (P) of the wheel with the rail is determined, the distribution of the masses of the section of the rim and of the wheel center of the wheel is adjusted so that the point of contact (P), the center of inertia (G1) of the section of the rim and the center of inertia (G2) of the section of the wheel center are located on one and the same straight line (XX') perpendicular to the axis (YY') and the outline of the section of the wheel is adjusted so that the point (P) is a vibration node for the axial vibration modes of the rim. The invention applies particularly to wheels for high-speed trains.

Abstract: The device includes a stand, a rail for supporting the wheel fixed to a horizontal part of the stand, longitudinal guide members fixed to a vertical part of the stand and extending in a direction parallel to the rail, slideways fixed to the horizontal part of the stand and extending in a direction parallel to the rail, and a carriage movable along the slideways. The carriage carries a grinding device and a hardness measuring device. Means permit applying a force on the hardness measuring device. An ultrasonic inspection device carried by the carriage may also be provided.

Abstract: The wheel rests upon a rail. A chassis mounted on a lifting and supporting mechanism carries slides arranged on either side of the rail and parallel to the rail. Two carriages are mounted to move translationally on the slides. Grinding devices, an ultrasound checking device and two position detectors are mounted on the carriages to move translationally in a direction perpendicular to the slides. The propagation time for the ultrasound in the rim is measured in two perpendicular directions and the width of the rim is measured. The propagation speeds of the ultrasound are calculated and compared so as to determine the stressed state of the rim.