Patent ID: 6487919
Filing Date: 2002-12-03
Classification: G01F

Abstract:
A flow meter comprising:a plastic housing defining a substantially straight flow passageway between an inlet pipe section and an outlet pipe section, the plastic housing further having portions defining a central volume which is part of the flow passageway, the central volume being between the inlet pipe section and the outlet pipe section, the plastic housing having a first portion and a second portion joined together by a spin weld, the joint being defined by a flash catching structure; a plastic turbine body defining an axis of rotation and having a plurality of blades which are more parallel than not to the axis, the plastic turbine body mounted for rotation about the axis within the central volume, the plastic turbine body having an upstream end which is mounted to portions of the plastic housing to form an upstream bearing, the turbine body having a downstream end, mounted to portions of the plastic housing to form a downstream bearing, the rotation axis lying substantially parallel to the straight flow passageway between the inlet pipe section and the outlet pipe section; at least one magnet mounted to the plastic turbine body to rotate with the plastic turbine body; wherein the plastic housing has portions defining a sensor cavity which is separated from the flow passageway by portions of the plastic housing, so that fluid cannot move between the flow passageway and the sensor cavity; and a magnetic field sensor positioned within the sensor cavity to detect rotation of the at least one magnet mounted on the plastic turbine body.