EP3287643B1

EP3287643B1 - Pump having edge mounted o-ring seal

Info

Publication number: EP3287643B1
Application number: EP17186912.6A
Authority: EP
Inventors: Douglas D Colby
Original assignee: QED Environmental Systems Inc
Current assignee: QED Environmental Systems Inc
Priority date: 2016-08-24
Filing date: 2017-08-18
Publication date: 2019-12-11
Anticipated expiration: 2037-08-18
Also published as: ES2773696T3; CA2976706A1; CN207583676U; US20180058464A1; BR102017017965A2; EP3287643A1; AU2017218958A1

Description

FIELD

The present disclosure relates to fluid pumps, and more particularly to a fluid pump that includes an edge mounted O-ring seal that significantly improves the pressure that can be generated within the pump without leakage past the O-ring seal.

BACKGROUND

O-ring seals are frequently used in various types of pumps to provide a seal between two parallel surfaces, and more typically between two parallel metal surfaces. Typically, such O-rings are used on planar, facing metal surfaces. However, in certain applications where the internal pressures required to pump a fluid, such as a deep groundwater sampling well, are significant, such conventional O-ring implementations are fairly limited in the internal pressure that they can accommodate before allowing a leak to occur.
The ability to improve the internal pump pressure that a fluid pump, for example a fluid pump used in well bores of groundwater sampling wells, would extend the capability of existing pumps and allow existing pumps to accommodate even higher internal pressures than what is presently possible with conventionally mounted O-ring seals. In particular, the ability to accommodate greater internal pressures would be especially useful in regenerative fluid pumps, which are capable of generating significantly greater internal pressures, and which are used in especially deep well bore extending 100 meters or more below the ground surface.
EP 1327781 discloses a pump in which all the parts of the pump coming into contact with the material being pumped are made of a material which meets the appropriate requirements for sterility, or are coated with such a material. The induction cover and the flow channel housing, like all the other static components open to the functional cavities, are sealed off from each other.
EP 2366905 discloses a multi-stage pump comprising an external jacket with a suction port and a delivery port, provided at one end with a casing cover and at the opposite end with a lantern bracket supporting an electric motor associated with rotary pumping members. The casing cover and the lantern bracket are coupled to the ends of the external jacket through fixing means with the interposition of annular gaskets. Each gasket is housed in an annular seat defined by a shaped annular area present in the casing cover and the lantern bracket and by a counter-shaped annular area present in the corresponding end of the external jacket, opposing each other.
JP H06-229393 discloses a pump in which an impeller is arranged in an intake side casing, and an opening port communicated with a rotor chamber is provided on the end part of the intake side of a motor frame in a canned motor. An end plate for blocking the rotor chamber is provided on the end part of the discharging side of the motor frame. A cyclone separator main body part provided with a cylindrical part, a circular part extending from the cylindrical part, an intake port provided on the cylindrical part, and a discharging port provided on the end part of the circular part is provided integratedly on the outside of the end plate and in the discharging side casing. An opening port communicated with the rotor chamber is provided inward of radial direction of the end plate.

SUMMARY

In one aspect of the present invention, there is provided a fluid pump as defined in claim 1.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

Figure 1 is a partial side cross sectional view of a pump in accordance with one embodiment of the present disclosure;
Figure 2 is an enlarged view of a portion of the pump shown in Figure 1 showing in even greater detail an area where an O-ring of the present disclosure is mounted on an edge of one of the pump components; and
Figure 3 illustrate graphs of internal pump pressures achievable using a conventional O-ring and the new edge mounted O-ring construction of the present disclosure.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses, the scope of protection of the present invention being determined by the appended claims.
Referring to Figure 1, a pump 10 is shown in accordance with one embodiment of the present disclosure. The pump 10 is a regenerative pump constructed in large part in accordance with the description provided in co-pending U.S. Non-Provisional Application Serial No. 15/100,904, filed June 1, 2016 (16783-000123-US-NPB). The pump 10 of the present disclosure differs only from the pump shown in co-pending U.S. Application Serial No. 15/100,904 in the seal that is provided adjacent to a regenerative pump impeller, as will be described below in detail.
With continued reference to Figure 1, the pump 10 generally includes a tubular metal pump housing 12 having a housing end wall 14 with fluid inlet ports 15. Within the pump housing 12 is a motor 16, which may be a DC or AC powered motor, having an output shaft 18. The following discussion will reference a DC motor, but it will be appreciated that the pump 10 is equally well suited to use with AC or DC motors.
The output shaft 18 of the DC motor 16 drives an impeller 20 via a connection to an impeller retainer 22. The impeller 20 is disposed between the impeller retainer 22 and an impeller housing 24. An outlet end cap 26 is disposed at an opposite end of the pump housing 12 and includes a discharge bore 28 through which fluid which has entered the pump 10 is pumped out from the pump. A suitable hose (not shown) may be coupled to the discharge bore 28 through which the fluid may be pumped up a wellbore within which the pump 10 is positioned to a collection tank or reservoir. A conduit 30 forms a means for making an electrical connection with the DC motor 16 to power the DC motor. A circuit board 32 is also positioned within the pump housing 12 for assisting in controlling the DC motor 16 and controlling overall operation of the pump 10.
Referring to Figure 2, the circled area labelled 2 in Figure 1 is shown in highly enlarged form. The impeller retainer 22 includes a supply channel 34 formed therein, and the impeller 20 includes a channel 20a which communicates with the supply channel 34 and is used to pump fluid to a discharge channel (not visible in Figure 2) in the impeller housing 24. Disposed at a corner of the impeller retainer 22 and impeller housing 24 interface is an O-ring 36 which seals the interface area between these two components. The O-ring 36 is supported in a new edge mounted configuration that provides significantly improved pump performance by enabling a significantly increased internal pressure that can be accommodated by the pump 10.
The edge mounting of the O-ring 36 is accomplished by providing a radiused edge 38 on an upper peripheral corner of the impeller retainer 22. The O-ring 36 is only partially seated within the radiused edge 38. The radius of curvature of the radiused edge 38 is preferably about the same as, and more preferably exactly the same as, the radius of the O-ring 36. The housing end wall 14 includes an extending portion 14a having a flat surface 14b which makes contact with the O-ring 36 and helps to cause a controlled deformation of the O-ring 36. The O-ring 36 is also contacted by an upper flat surface 24a of a leg 24b of the impeller housing 24. The contact of the O-ring 36 with the flat surface 14b of the extending portion 14a, as well as the upper flat surface 24a of the impeller housing leg 24b and the radiused edge 38 all cooperate to cause the O-ring to be deformed in a controlled manner so as to bulge out along directional arrow 40. Directional arrow 40 extends generally at about a 45 degree angle relative to the pump housing 12. The 45 degree angle of the bulge provides a first vector component which pushes upwardly against the flat surface 14b of the extending portion 14a of the housing end wall 14, while simultaneously pushing outwardly along a horizontal vector against an inner wall surface 12a of the pump housing 12. This enables three sealing surfaces to be simultaneously created with the single O-ring 36: a first seal between the flat surface 14b and the impeller retainer 22; a second seal between the upper surface 24a of the impeller housing 24 and the inner wall surface 12a of the housing 12; and a third seal between the inner wall surface 12a and the right side of the O-ring 36.
The edge supported O-ring 36 shown in Figures 1 and 2 enables significantly higher internal pump pressures to be handled which would not be possible with a conventional O-ring mounting. Figure 3 illustrates the significantly increased pressures that the O-ring 36 enables relative to a conventional O-ring seal. In Figure 3 the graph 42 represents the pressures achievable using the O-ring 36, while graph 44 represents the pressures achievable by a conventional O-ring seal.
The edge-mounted O-ring 36 of the present pump 10 described herein does not require additional component parts to be included in the pump, nor does it require extensive modifications to the internal components of the pump. The edge mounted O-ring 36 construction also does not require significant modifications to the assembly procedure for assembling the pump 10, nor does it add appreciably to the overall cost or complexity of the pump 10. The significantly increased pressures that the pump 10 can accommodate enable the pump to be used to pump liquids at depths that would have heretofore been impossible to pump from with a conventional O-ring sealing construction.

Claims

A fluid pump (10) comprising:
a pump housing (12);

an inlet wall portion (14) positioned adjacent the pump housing and including an extending portion (14a) extending generally parallel to an inner wall surface (12a) of the pump housing;

a motor (16) housed within the pump housing;

an impeller (20) responsive to the motor;

an impeller retainer (22) disposed adjacent the impeller and including a radiused edge (38) on an upper peripheral corner of the impeller retainer (22); and

an O-ring (36) positioned at the radiused edge,

the O-ring exerting a force non-perpendicular to the inner wall surface (12a) of the pump housing to form a seal against the inner wall surface (12a) of the pump housing;

wherein the O-ring (36) exerts a force at about a 45 degree angle relative to the inner wall surface (12a) of the pump housing (12);

wherein only a minor portion of the O-ring (36) is seated in the radiused edge of the impeller retainer (22); and characterized in that

the O-ring also forms a seal against the extending portion of the inlet wall portion.
The fluid pump of claim 1, wherein the O-ring has a radius approximately the same as a radius of the radiused edge.
The fluid pump of claim 1 or claim 2, further including an impeller housing (24) positioned within the pump housing for housing the impeller, the impeller housing including a leg portion (24b) projecting therefrom.
The fluid pump of claim 3, the leg portion projecting parallel to and adjacent to the inner wall surface (12a) of the pump housing.
The fluid pump of claim 3 or claim 4, wherein the O-ring contacts a surface of the leg portion.
The fluid pump of any one of the preceding claims, wherein the O-ring bulges out to exert the force at approximately a 45 degree angle relative to the inner wall surface (12a) of the pump housing.
The fluid pump of any one of the preceding claims, wherein the radiused edge contacts a minor portion of the O-ring.
The fluid pump of any one of claims 3 to 7, wherein the O-ring simultaneously forms a three way seal including:
a first seal between the extending portion of the inlet wall portion and the impeller retainer;

a second seal between an upper surface of the leg portion of the impeller housing and the inner wall surface (12a) of the pump housing; and

a third seal between the inner wall surface (12a) of the pump housing and the radiused edge.
The fluid pump of any one of claims 3 to 8, wherein the O-ring simultaneously contacts:
the radiused edge of the impeller retainer;

a surface of the extending portion of the inlet wall portion;

an upper surface of the leg portion of the impeller housing; and

the inner wall surface (12a) of the pump housing.