Electric machine for a motor vehicle, comprising a piezoelectric bearing module

An electric machine for a motor vehicle, said electric machine comprising a stator and a rotor mounted on said stator movably in rotation by means of a rotary shaft and a plurality of bearing modules, each bearing module comprising a fixed element mounted on the stator, a movable element mounted on the rotor, at least one rolling element mounted between the fixed element and the movable element and configured to allow the rotor to rotate relative to the stator, the electric machine being characterized in that:

• a fixed element of at least one bearing module comprises a “main” piezoelectric transceiver that is configured to transmit an ultrasonic power supply signal,
• the stator comprises a control stage configured to command said main piezoelectric transceiver to transmit,
• the electric machine comprises a sensor, mounted inside the rotor, comprising a “remote” piezoelectric transceiver, a measurement stage and a sensing element, said remote piezoelectric transceiver being configured to receive the ultrasonic power supply signal and to transmit it to the measurement stage, the measurement stage being configured to harvest and store the electrical energy contained in the received ultrasonic power supply signal and to electrically power the sensing element using the stored electrical energy, the sensing element being configured to measure a parameter inside the rotor, to generate a measurement signal including at least one value of the measured parameter and to transmit said generated measurement signal to the measurement stage, the measurement stage being configured to extract the at least one value of the measured parameter contained in the measurement signal, to generate an ultrasonic response signal including the at least one extracted value of the parameter, and to command the remote piezoelectric transceiver to transmit said generated ultrasonic response signal, the main piezoelectric transceiver being configured to receive said ultrasonic response signal and to transmit said received ultrasonic response signal to the control stage, said control stage being configured to extract the at least one value of the parameter contained in the transmitted ultrasonic response signal.