Abstract: A method and apparatus are described for non-contact measurement of torque applied to a torque-bearing member such as a shaft. The method involves the use of a piezoelectric transducer mechanically coupled to the shaft for rotation therewith, and having electrical characteristics responsive to applied torque. Electrical signal characteristics are changed by the torque-dependent transducer characteristics. The electrical signals are coupled to the outside (non-rotating) world by at least one capacitive coupler. In one embodiment, an fixed-frequency oscillator produces signal, and the transmission of the signal is affected by the torque-dependent resonant frequency of the transducer. In another embodiment, the transducer is coupled in the feedback loop of a circuit to form an oscillator, in which the frequency is responsive to the torque. A transducer may be placed and distributed in a protective holder. The holder may be pierced in particular locations in order to increase or decrease its sensitivity.

Abstract: A method and apparatus are described for non-contact measurement of torque applied to a torque-bearing member such as a shaft. The method involves the use of a piezoelectric transducer mechanically coupled to the shaft for rotation therewith, and having electrical characteristics responsive to applied torque. Electrical signal characteristics are changed by the torque-dependent transducer characteristics. The electrical signals are coupled to the outside (non-rotating) world by at least one capacitive coupler. In one embodiment, an fixed-frequency oscillator produces signal, and the transmission of the signal is affected by the torque-dependent resonant frequency of the transducer. In another embodiment, the transducer is coupled in the feedback loop of a circuit to form an oscillator, in which the frequency is responsive to the torque. A transducer may be placed and distributed in a protective holder. The holder may be pierced in particular locations in order to increase or decrease its sensitivity.

Abstract: A method and apparatus are described for noncontact measurement of torque applied to a torque-bearing member such as a shaft. The method involves the use of a piezoelectric transducer mechanically coupled to the shaft for rotation therewith, and having electrical characteristics responsive to applied torque. Electrical signal characteristics are changed by the torque-dependent transducer characteristics. The electrical signals are coupled to the outside (non-rotating) world by at least one capacitive coupler. In one embodiment, an fixed-frequency oscillator produces signal, and the transmission of the signal is affected by the torque-dependent resonant frequency of the transducer. In another embodiment, the transducer is coupled in the feedback loop of a circuit to form an oscillator, in which the frequency is responsive to the torque. A transducer may be placed and distributed in a protective holder. The holder may be pierced in particular locations in order to increase or decrease its sensitivity.

Abstract: A method and apparatus are described for non-contact measurement of torque applied to a torque-bearing member such as a shaft. The method involves the use of a piezoelectric transducer mechanically coupled to the shaft for rotation therewith, and having electrical characteristics responsive to applied torque. Electrical signal characteristics are changed by the torque-dependent transducer characteristics. The electrical signals are coupled to the outside (non-rotating) world by at least one capacitive coupler. In one embodiment, an fixed-frequency oscillator produces signal, and the transmission of the signal is affected by the torque-dependent resonant frequency of the transducer. In another embodiment, the transducer is coupled in the feedback loop of a circuit to form an oscillator, in which the frequency is responsive to the torque. A transducer may be placed and distributed in a protective holder. The holder may be pierced in particular locations in order to increase or decrease its sensitivity.