| 摘要 |
Revolution speeds n<SUB>ca</SUB>, n<SUB>ib </SUB>of rolling elements 9 a , 9 b are sensed by a pair of revolution speed sensors 21 a , 21 b. Also, a rotational speed n<SUB>i </SUB>of a hub 2 is sensed by a rotational speed sensor 15 b. A sum "n<SUB>ca</SUB>+n<SUB>cb</SUB>" or a difference "n<SUB>ca</SUB>-n<SUB>i</SUB>b" the revolution speeds of rolling elements 9 a , 9 b in double rows is calculated based on sensed signals of the revolution speed sensors 21 a , 21 b, and then a ratio "n<SUB>ca</SUB>+n<SUB>i</SUB>b/ni" or "n<SUB>ca</SUB>-n<SUB>cb</SUB>/n<SUB>i</SUB>" of this sum or difference to the rotational speed n<SUB>i </SUB>is calculated. Then, the radial load or the an axial load is calculated based on the ratio "n<SUB>ca</SUB>+n<SUB>c</SUB>b/ni" or "<SUB>ca</SUB>-n<SUB>ib</SUB>/ni". |
