Patent attributes
There are provided a device for detecting a rotation rate that prevents an eddy current from being generated in a housing member around a rotation rate sensor, and a device for detecting a rotation rate that prevents a decrease in the compressing efficiency of a fluid compressed by a rotor. A slit-shaped concave portion for preventing a generation of an eddy current is formed on the housing on both side of the rotation sensor. The rotation rate sensor generates a magnetic field by being supplied with a high-frequency alternating excitation current. The concave portion prevents an eddy current from being generated in the housing around the rotation rate sensor based on the magnetic field generated by the coil. The concave portion has a small capacity, and is formed along the flow of intake air. As a result, a decrease in the compression efficiency of the blades of the suction-side turbine can be prevented.