Abstract: A bearing apparatus supports a rotating body with a bearing including an inner ring, an outer ring, and a rolling element. The bearing apparatus includes a power generator including a Peltier element variable in amount of power generation depending on a temperature difference between the inner ring and the outer ring caused in the bearing and an abnormality sensing apparatus that senses abnormality of the bearing based on the amount of power generation by the power generator. Preferably, the abnormality sensing apparatus senses abnormality of the bearing based on any of the amount of power generation by the power generator, a time derivative value of the amount of power generation, and following relation between the amount of power generation and another parameter. The bearing apparatus and a spacer in which abnormality of the bearing can accurately be sensed early are thus provided.

Abstract: A bearing apparatus includes a housing where a main spindle is accommodated, a bearing including an inner ring and an outer ring, the bearing supporting the main spindle rotatably with respect to the housing, a retaining lid fitted to an inside surface of the housing while the retaining lid is in contact with an axial end surface of the housing and an axial end surface of the outer ring, and a communication module arranged in a region opposed to the retaining lid with the bearing being interposed, the communication module wirelessly communicating over electromagnetic waves. In a portion of the retaining lid in contact with the housing, a non-metallic layer composed of ceramic which is a non-metallic material is provided.

Abstract: A bearing apparatus includes a bearing that rotatably supports a main spindle around a rotation axis, a spacer including an inner-ring spacer adjacent to an inner ring of the bearing and an outer-ring spacer adjacent to an outer ring, and a heat flux sensor provided in an inside surface of the outer-ring spacer. A distance in a direction along the rotation axis from a center of the bearing to a center of the heat flux sensor is longer than 0.5 time and shorter than one time of a dimension of the bearing in the direction along the rotation axis.

Abstract: A bearing apparatus includes two bearings that rotatably support a main spindle, a spacer arranged between the two bearings, and a communication module arranged in the spacer. The bearing includes an inner ring and an outer ring made of a metal and a plurality of rolling elements arranged between the inner ring and the outer ring. The communication module contains a plurality of sensors and a communication apparatus that wirelessly transmits a result of detection by the sensors. An outer dimension of the inner ring of the bearing is set to be smaller than an inner dimension of the outer ring of the bearing. The rolling element is made of silicon nitride through which electromagnetic waves can pass.

Abstract: A bearing apparatus supports a rotating body with a bearing including an inner ring, an outer ring, and a rolling element. The bearing apparatus includes a power generator including a Peltier element variable in amount of power generation depending on a temperature difference between the inner ring and the outer ring caused in the bearing and an abnormality sensing apparatus that senses abnormality of the bearing based on the amount of power generation by the power generator. Preferably, the abnormality sensing apparatus senses abnormality of the bearing based on any of the amount of power generation by the power generator, a time derivative value of the amount of power generation, and following relation between the amount of power generation and another parameter. The bearing apparatus and a spacer in which abnormality of the bearing can accurately be sensed early are thus provided.

Abstract: A data collection apparatus includes an input portion to which a result of detection (heat flux) by a heat flux sensor provided in a beating is provided and a controller configured to collect the result of detection by the sensor provided to the input portion in prescribed sampling cycles for storage. When magnitude of the heat flux is smaller than a switching threshold value, the controller sets the sampling cycle to a first cycle, and when magnitude of the heat flux is larger than the switching threshold value, the controller switches the sampling cycle to a second cycle shorter than the first cycle and determines whether or not there is a sign of abnormality of the bearing based on a rate of change in heat flux collected in the second cycles.