Abstract: A detection signal representing changes of an object observed can be easily transmitted to any desirable site, without performing complex adjustment to use the signal. An AE sensor is provided on an appropriate part of the circumferential surface of a rotating-side chuck which holds a workpiece. A signal-transmitting unit is provided in a space made in the rotating-side chuck. A signal-receiving unit is mounted on an appropriate part of a main section on which the rotating-side chuck is provided. The signal-transmitting unit transmits by radio a detection signal generated by the AE sensor. The signal-receiving unit receives and demodulates the detection signal, generating a signal that will be processed in signal processing.

Abstract: It is possible to stably supply an electric signal to an ultrasonic generation element without causing friction or damage on parts or without requiring periodical parts exchange. A reception coil (11) connected to a vibrator (6) is wound on the outer circumference of a housing (1) constituting a shaft (30) of a machining spindle (101). The reception coil (11) is surrounded coaxially by a transmission coil (12) at an appropriate interval. A predetermined electric signal outputted from an ultrasonic drive device (21) for driving the vibrator (6) is applied to the transmission coil (12). The predetermined electric signal may be applied to the vibrator (6) via the reception coil (11) by electromagnetic induction between the transmission coil (12) and the reception coil (11).

Abstract: To enable detection and transmission of an ultrasonic signal with a high S/N ratio without any need for a component requiring high machining precision or high precision in mounting a component. In a dresser head 41, an ultrasonic sensor 21 detecting an ultrasonic wave is provided, and further provided are: a signal converting/transmitting circuit 23 converting a detected signal of the ultrasonic sensor 21 to a digital signal and subjecting the digital signal to radio modulation; and a signal transmission antenna 26 to which the signal resulting from the radio modulation by the signal converting/transmitting circuit 23 is applied. Further, near the dresser head 41, a signal reception antenna 34 receiving a signal emitted by the signal transmission antenna 26 and a signal reception head 35 demodulating the reception signal obtained by the signal reception antenna 26 are provided, and the demodulated signal is output as a digital signal or an analog signal in a predetermined signal format via a control part 31.

Abstract: A detection signal representing changes of an object observed can be easily transmitted to any desirable site, without performing complex adjustment to use the signal. An AE sensor 21 is provided on an appropriate part of the circumferential surface of a rotating-side chuck 4 which holds a workpiece 5. A signal-transmitting unit 101 is provided in a space made in the rotating-side chuck 4. A signal-receiving unit 102 is mounted on an appropriate part of a main section 3 on which the rotating-side chuck 4 is provided. The signal-transmitting unit 101 transmits by radio a detection signal generated by the AE sensor 21. The signal-receiving unit 102 receives and demodulates the detection signal, generating a signal that will be processed in signal processing.