Abstract: A first spacer, a second tubular member, and a second spacer are externally fitted and fixed to an outer peripheral surface of a nut. The second tubular member is formed by stacking a plurality of silicon steel plates without any gap, and is arranged between the first spacer and the second spacer axially. The outer diameter of an outer peripheral surface of the second tubular member is made larger than the outer diameter of an outer peripheral surface of the first spacer and the outer diameter of an outer peripheral surface of the second spacer. A detection surface of a first displacement detector is made to radially face a contact portion between the second spacer and the second tubular member, while a detection surface of a second displacement detector is made to radially face a contact portion between the first spacer and the second tubular member.

Abstract: A rolling bearing device with a sensor includes a rotational component estimator that extracts a rotational synchronization component included in the rotation of an inner shaft relative to an outer ring from each of a signal output by a first displacement detector and a signal output by a second displacement detector. The rotational component estimator performs rotational operation and integration operation.

Abstract: A rolling bearing device with a sensor includes a rotational component estimator that extracts a rotational synchronization component included in the rotation of an inner shaft relative to an outer ring from each of a signal output by a first displacement detector and a signal output by a second displacement detector. The rotational component estimator performs rotational operation and integration operation.

Abstract: A first spacer, a second tubular member, and a second spacer are externally fitted and fixed to an outer peripheral surface of a nut. The second tubular member is formed by stacking a plurality of silicon steel plates without any gap, and is arranged between the first spacer and the second spacer axially. The outer diameter of an outer peripheral surface of the second tubular member is made larger than the outer diameter of an outer peripheral surface of the first spacer and the outer diameter of an outer peripheral surface of the second spacer. A detection surface of a first displacement detector is made to radially face a contact portion between the second spacer and the second tubular member, while a detection surface of a second displacement detector is made to radially face a contact portion between the first spacer and the second tubular member.

Abstract: A bearing device supporting a rotation shaft of a fuel cell compressor includes a pair of radial foil bearings and mounted in concentric relation to the rotation shaft and supporting the rotation shaft in a radial direction, and an axial magnetic bearing opposed to the rotation shaft in an axial direction and supporting the rotation shaft in the axial direction. A control device includes bearing life diagnostic unit for accumulating times during which a rotational speed of the rotation shaft has been below a predetermined value, so as to obtain a cumulative contact time, thereby judging a bearing lifetime.