Abstract: An acoustic signal unit comprises a signal generation unit to generate a first electrical signal, a first transducer to generate an acoustic signal in response to the first electrical signal, and a second transducer to generate a second electrical signal in response to the received acoustic signal. A calculation unit is provided to compare the first and second electrical signals to determine the time of flight of the acoustic signal, wherein the time of flight corresponds to the stress in the rolling element bearing. The stress may be calculated according to a formula or by multiplying an acoustic time constant for the rolling element bearing by the distance traveled by the acoustic signal across the rolling element bearing, and by the time of flight determined by said comparison unit.

Abstract: A system senses real-time rolling element loads in a rolling element bearing having a plurality of rolling elements disposed between an inner race and an outer race. A plurality of sensors are disposed about one of the inner race and the outer race of the bearing to output sensor data corresponding to detected loads. A control unit predicts bearing life from the sensor data and determines a load zone of the bearing in real time from the sensor data. Before operation of the system in real-time, the sensors are calibrated to model a relationship of roller load and measured strain. The bearing is then rotated and sensor data is output from each the sensors. The sensor data is cyclical, and peaks and valleys are extracted from the sensor data to determine rolling element loads and measured bearing speed. Load components from a plurality of bearings are then summed to obtain total applied system load in real time.

Abstract: A bearing is mounted within a housing having an acoustic-electric transducer mounted on its outside. A stationary annular outer race has at least one sensor, an electric-acoustic transducer, and an electronic system interconnecting the sensor and the electric-acoustic transducer. The electric-acoustic transducer is mounted in an opening extending radially through the stationary race. The electric-acoustic transducer has an elastic cap pressed into the inside of the housing by a spring. An alternative configuration, having at least one sensor mounted on a rotatable inner race, without a hard-wired connection through the bearing housing, is also disclosed.

Abstract: A temperature sensor is mounted on the inside surface of a stationary race around which a rotatable race rotates. Electric signals from the temperature sensor are converted into acoustic signals. Without the use of any hard wires, the acoustic signals are received by an acoustic-electric transducer mounted on the outside surface of the bearing housing. These electric signals from the acoustic-electric transducer are frequency demodulated and converted into signals which indicate on a display panel the temperatures within the bearing.

Abstract: A bearing is mounted within a housing having an acoustic-electric transducer mounted on its outside. A stationary annular outer race has at least one sensor, an electric-acoustic transducer, and an electronic system interconnecting the sensor and the electric-acoustic transducer. The electric-acoustic transducer is mounted in an opening extending radially through the stationary race. The electric-acoustic transducer has an elastic cap pressed into the inside of the housing by a spring.

Abstract: One or more sensors are mounted on the inside surface of a stationary race/sensor mount assembly in the bearing housing. A parameter sensed by the sensor is electronically fed to the outside surface of the stationary race/sensor mount assembly and detected by a transmitter mounted in the housing. The detected information is electrically fed from the transmitter to an electronic system located outside the housing.