Turbine flow monitoring device

• US 6,487,919 B1
• Filed: 11/06/2001
• Issued: 12/03/2002
• Est. Priority Date: 11/06/2001
• Status: Expired due to Fees

• Current Assignee: Key Safety Systems, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Breed Automotive Technology, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Edwards, Paul K.
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): THOMPSON, JEWEL VERGIE
• Application Number:
  US09/992,638
• Time in Patent Office: 392 Days
• Field of Search: 738/617.7, 731/87, 734/55, 738/618.7, 738/617.9
• US Class Current: 73/861.77
• CPC Class Codes: G01F 1/115 with magnetic or electromagnetic coupling to the indicating device
• CPC Class Codes: G01F 1/12 Adjusting, correcting, or compensating means therefor
• CPC Class Codes: G01F 15/006 characterised by the use of a particular material, e.g. anti-corrosive material G01F15/14 takes precedence

Abstract

A turbine type flow meter has a four-vaned plastic torpedo-shaped turbine mounted by portions of the plastic turbine within a housing between first and second bearings. The turbine supports a pair of magnets of the Neodymium-Iron-Boron type which rotate with the turbine. An upstream portion of the housing incorporates a sensor cavity, which is sealed from a flow cavity containing the turbine. A connector and an attached printed circuit board with a Hall effect sensor is mounted within the sensor cavity closely spaced from the rotating magnets. The sensor housing is constructed from two parts. Each part of the housing incorporates mating structures that are designed for joining by spin welding.

Claims

1. 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.

2. The flow meter of claim 1 wherein there are two Neodymium-Iron-Boron magnets mounted to the plastic turbine body.

3. The flow meter of claim 1 wherein the plastic housing is constructed of a material chosen from the group consisting of Modified Polyethylene Oxide and Polyphenylene Ether.

4. The flow meter of claim 1 wherein magnet the turbine body is constructed of POM (polyacetal engineering polymers) with added Polytetrafluoroethylene (PTFE) to reduce friction.

5. A flow meter comprising:

a plastic housing defining a substantially straight flow passageway between an inlet pipe section and an outlet pipe section, wherein the plastic housing further has 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 rotation axis lying substantially parallel to the straight flow passageway between the inlet pipe section and the outlet pipe section;

at least one Neodymium-Iron-Boron 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 Hall effect sensor positioned within the sensor cavity to detect rotation of the at least one magnet mounted on the plastic turbine body.

6. The flow meter of claim 5 wherein there are two Neodymium-Iron-Boron magnets mounted to the plastic turbine body.

7. The flow meter of claim 5 wherein the plastic housing is constructed of a material chosen from the group consisting of Modified Polyethylene Oxide and Polyphenylene Ether.

8. The flow meter of claim 5 magnet the turbine body is constructed of POM (polyacetal engineering polymers) with added Polytetrafluoroethylene (PTFE) to reduce friction.

9. 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 having the following portions which are axially symmetric about an axis of rotation;

an upstream trunnion, a forward conical portion, a central cylindrical section, a rearward conical portion, and a downstream trunnion, the upstream trunnion and the downstream trunnion mounted to portions of the plastic housing to form bearings which support the turbine body in rotation;

a plurality of blades extending from the central cylindrical section of the turbine body;

at least two magnets mounted to the forward conical portion of the plastic turbine body by portions of the plastic turbine body which form radially extending magnet-receiving openings to hold the magnets for rotation with the plastic turbine body;

wherein the plastic housing has portions defining a sensor cavity positioned radially outwardly of the forward conical portion of the plastic turbine body, the sensor cavity being separated from the flow passageway by portions of the plastic housing, so that fluid cannot move between the flow passageway and the sensor cavity;

a magnetic field sensor positioned within the sensor cavity to detect rotation of the at least two magnets mounted on the plastic turbine body.

10. The flow sensor of claim 9 wherein the portions of the plastic turbine body which form radially extending magnet-receiving openings have teardrop-shaped, upstream portions to reduce drag.

11. The flow meter of claim 9 wherein the two magnets are of the Neodymium-Iron-Boron type.

12. The flow meter of claim 9 wherein the plastic housing is constructed of a material chosen from the group consisting of Modified Polyethylene Oxide and Polyphenylene Ether.

13. The flow meter of claim 9 wherein the turbine body is constructed of POM (polyacetal engineering polymers) with added Polytetrafluoroethylene (PTFE) to reduce friction.