LIQUID METER

• US 3,811,323 A
• Filed: 09/08/1971
• Issued: 05/21/1974
• Est. Priority Date: 09/08/1971
• Status: Expired due to Term

• Current Assignee: George H. Swenson
• Original Assignee: George H. Swenson
• Inventors: Swenson, George H.
• Primary Examiner(s): Ruehl, Charles A.
• Application Number:
  US05/178,678
• Time in Patent Office: 986 Days
• Field of Search: 73/231R
• US Class Current: 73/861.83
• CPC Class Codes: G01F 1/1155 with magnetic coupling only in a mechanical transmission path

Abstract

Liquid flow rate meter of the turbine type in which rotor thrust bearing unloading is achieved by downstream increase of effective flow rate area to produce a Bernoulli'"'"''"'"'s effect upstream force on the rotor.

Claims

1. A meter for measurement of liquid flow, comprising:

a housing with inlet and outlet ends, and a rotor mounted therebetween, said rotor being mounted for rotation on and with a shaft rotatably mounted relative to said housing, a downstream thrust bearing for said shaft, and an upstream thrust bearing for said shaft, the said thrust bearings being spaced apart a distance slightly greater than the length of said shaft, the effective net flow area being greater around the hub of said rotor than upstream of said rotor, whereby in consequence of Bernoulli'"'"''"'"'s equation there is diminished loading of said downstream thrust bearing as flow rate increases, in which the inlet end surfaces of vanes of said rotor slope from downstream vane faces to upstream vane faces, said slope being at an acute angle to a plane perpendicular to the axis of said shaft, providing reverse lift to enhance the unloading of said downstream thrust bearing and improving accuracy.

2. The meter of claim 1 in which outlet end surfaces of said vanes slope from downstream vane faces to upstream vane faces, said slope being at an acute angle to a plane perpendicular to the axis of said shaft to reduce, but not eliminate, cavitation-created drag on said rotor at high flow rates.

3. The meter of claim 1 in which the effective net flow area just downstream of said rotor is greater than that around the hub of said rotor, further enhancing the upstream force tendency in consequence of Bernoulli'"'"''"'"'s equation.

4. The meter of claim 1 wherein said thrust bearings are jewel thrust bearings, and said shaft is operatively coupled to an output member through a pair of magnets, one of said bearings being between said magnets, and the other of said bearings being adjustable toward and away from said one bearing.

5. The meter of claim 1 further comprising a pair of shafts one of which is operatively connected to an output member, said shafts respectively carrying a worm and a gear meshing with said worm, the other of said shaft being operatively coupled to said rotor through a magnetic coupling, at least one of said shafts being mounted with longitudinal play to reduce breakaway friction upon meter start-up.

6. The meter of claim 5 wherein said shaft carrying said worm is mounted between a pair of jewel thrust bearings, and said shaft carrying said gear is mounted with one end adjacent a jewel thrust bearing, both said shafts having said longitudinal play.