Turbine-type flowmeter

Claim 1

A turbine-type flowmeter comprising: a flowmeter outer casing having therewithin a flowpath for flow therethrough of a fluid whose flowrate is to be measured; a turbine rotor rotatably supported within said casing and supporting a plurality of turbine blades of magnetic material rotated by said fluid flowing through said flowpath at a rotational speed in accordance with the flowrate of the fluid; a yoke structure mounted on and partly within the wall of the casing and having an outer end part, a shank body, and a plurality of inner end parts positioned to confront the radially outer ends of the blades as the blades rotate, at least more than one of said inner end parts bEing so arranged as to lie within a space interval corresponding to the space interval between two adjacent blades of said plurality of turbine blades; a single permanent magnet disposed in contact with the outer end part of said yoke structure, said permanent magnet producing magnetic flux passing through the yoke structure and inner end parts thereof; and coil means wound around a part of the yoke structure for generating output signals induced by the magnetic flux produced within the yoke structure and changing in accordance with changes of the magnetic flux each time one of the turbine blades passes through said position to successively confront each of the inner end parts of the yoke structure as the blades thus rotate.