Abstract: In a vortex chamber flow meter, a bearingless annular rotor rotates about an axis in a cylindrical operating chamber. The chamber is enclosed in a jet ring within a meter housing. Liquid enters the housing and flows to a plurality of circumferentially spaced ports in the jet ring, directing flow through conduits into the vortex operating chamber tangentially. Liquid flow exits the vortex chamber axially through a central aperture. Optical sensing means respond to markings on the surface of a rotor moving past a selected position. The meter is constructed to effectively offset the entry of the liquid into the vortex chamber. The centerlines of the ports define a plane which is positioned to be off center from a plane bisecting the vortex chamber in the axial degree of freedom. The offset is in an axial direction away from the exit.

Abstract: Improved dynamic balance of the ring-shaped rotor used in conjunction with a vortex chamber in the bearingless type of flowmeter is obtained by symmetrically spacing at least nine jets circumferentially around the vortex chamber. Additional stabilization is provided for the rotor by employing a plurality of exhaust ports for the vortex chamber radially displaced from the chamber center and disposed equidistant from the center and one another.