Abstract: A system monitoring statuses such as presence and absence of abnormality and lifetime of a machine component such as, for example, a bearing having rolling elements, includes: a plurality of determining units respectively connected with a plurality of sensors, and a control unit connected with the determining units. Each sensor is disposed on the machine component of the associated rolling bearing to detect an influence signal resulting from passage of the rolling element induced in the machine component. Each determining unit determines, according a process set-up condition, the presence and absence of an abnormality and lifetime of the machine component associated with the sensor in reference to an output signal from the sensors. The control unit collects a result of determination performed by each determining unit. In this way, with a simplified structure, monitoring can be achieved at a low cost, precisely and efficiently.

Abstract: A system for monitoring statuses such as presence or absence of abnormality and lifetime of a machine component such as, for example, a bearing having rolling elements includes a plurality of determining units 4 each connected with a plurality of sensors 3, and a control means 5 connected with the determining units 4. Each sensor is disposed on the machine component 1 of the associated rolling bearing for detecting an influence signal resulting from passage of the rolling element induced in the machine component 1. Each determining unit 4 determines according a process set-up condition the presence or absence of an abnormality, lifetime and others of the machine component 1 associated with the sensor 3 in reference to an output signal from such sensor 3. The control means 5 collects a result of determination performed by each determining unit 4. In this way, with a simplified structure, monitoring can be achieved at a low cost, precisely and efficiently.

Abstract: A resistor welding machine control method for calculating a temperature distribution at a portion to be welded by using changes in welding current and voltage across two welding electrodes during welding and information on sheet combination sequence at a spot-welding position, and for controlling at least the welding current or pressure applied to the electrodes by using the calculated temperature distribution. The present invention can thus provide a resistor welding machine control method capable of controlling welding quality accurately. Spot-welding position information, wear comparison information and the like are available as other information.