U.S. patent application number 14/523071 was filed with the patent office on 2015-04-30 for centrifugal pump with self-cleaning wear plate.
The applicant listed for this patent is Michael Stoffer, Bryce Thiel. Invention is credited to Michael Stoffer, Bryce Thiel.
Application Number | 20150118024 14/523071 |
Document ID | / |
Family ID | 52995678 |
Filed Date | 2015-04-30 |
United States Patent
Application |
20150118024 |
Kind Code |
A1 |
Thiel; Bryce ; et
al. |
April 30, 2015 |
CENTRIFUGAL PUMP WITH SELF-CLEANING WEAR PLATE
Abstract
A centrifugal pump having an impeller assembly within a pump
housing and a wear plate positioned in confronting relationship
with the impeller assembly. The wear plate includes an annular wear
plate portion defining an impeller side that confronts the impeller
and further defines an annular portion defining an eye formed
generally centrally and has a center point that is substantially
aligned with a rotational axis of the impeller. The eye includes a
plurality of peripheral notches separated by tooth-like spacer
gaps. At least one protrusion extends from the eye towards the
impeller at a predetermined angle. Inner and outer radial grooves
are formed in the wear plate surface that confronts the
impeller.
Inventors: |
Thiel; Bryce; (Lexington,
OH) ; Stoffer; Michael; (Ashland, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Thiel; Bryce
Stoffer; Michael |
Lexington
Ashland |
OH
OH |
US
US |
|
|
Family ID: |
52995678 |
Appl. No.: |
14/523071 |
Filed: |
October 24, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61895131 |
Oct 24, 2013 |
|
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|
Current U.S.
Class: |
415/121.1 |
Current CPC
Class: |
F04D 9/02 20130101; F04D
7/04 20130101; F04D 13/08 20130101; F05D 2250/294 20130101 |
Class at
Publication: |
415/121.1 |
International
Class: |
F04D 7/04 20060101
F04D007/04; F04D 9/02 20060101 F04D009/02; F04D 1/00 20060101
F04D001/00 |
Claims
1. A centrifugal pump, comprising a) a pump housing; b) an impeller
assembly mounted to said pump housing; c) a wear plate mounted
within said housing in a confronting relationship with an impeller
forming part of said impeller assembly, said wear plate comprising:
i) an annular wear plate portion defining an impeller side that
confronts said impeller when said wear plate is mounted within said
pump housing; ii) said annular portion defining an eye formed
generally centrally in said portion and is substantially aligned
with a rotational axis of said impeller; and iii) at least one
protrusion extending from said eye toward said impeller.
2. The pump of claim 1 wherein said notches are wider in dimension
than said tooth-like gaps.
3. The centrifugal pump of said claim 1 wherein said protrusion
includes a prong extending at an angle from a mounting segment
formed on said wear plate portion.
4. The centrifugal pump of claim 3 wherein said prong extends at an
angle of substantially 45.degree. with respect to a plane defined
by said wear plate portion.
5. The centrifugal pump of claim 3 wherein said prong is welded to
said mounting segment.
6. The centrifugal pump of claim 3 wherein said prong and mounting
segment are integrally formed with said wear plate portion.
7. The centrifugal pump of claim 1 wherein said wear plate is
attached to a wear plate cover which forms an assembly that is
removably attached to said pump housing.
8. The centrifugal pump of claim 1 wherein said wear plate portion
includes at least one radial groove.
9. The centrifugal pump of claim 8 wherein said wear plate portion
includes a second radial groove, said one radial groove extending
inwardly from an outer diameter of said wear plate and said second
groove extends outwardly from said eye.
10. The centrifugal pump of claim 9 wherein said grooves have a
predetermined depth but do not extend through said wear plate
portion.
11. The centrifugal pump of claim 9 wherein said grooves extend
through said wear plate portion.
12. The centrifugal pump of claim 1 wherein said protrusion
includes an aperture to facilitate bending of said protrusion
during its manufacturing process.
13. The centrifugal pump of claim 7 wherein said wear plate
includes at least one stand-off by which said wear plate is
attached to said wear plate cover.
14. The centrifugal pump of claim 1 wherein said annular wear plate
portion defines a substantially planar wear plate surface
confronting said impeller.
15. The centrifugal pump of claim 9 wherein said one radial groove
has an inner end that is in a radial, overlapping relationship with
an outer end of said second radial groove.
16. A wear plate for a centrifugal pump having a rotatable impeller
located in a confronting relationship with said wear plate, said
wear plate comprising: a) an annular portion defining a wear plate
surface that is in a confronting relationship with respect to said
impeller when said wear plate is mounted within said centrifugal
pump; b) said annular portion defining an aperture that is axially
aligned with an axis of rotation of said impeller when said wear
plate is operatively positioned in said centrifugal pump; and c) at
least one protrusion extending toward said impeller from said
annular portion, said protrusion extending at a predetermined angle
with respect to a plane defined by said annular portion.
17. The wear plate of claim 6 wherein said notches are
substantially wider in dimension than said tooth-like gaps.
18. The wear plate of claim 16 wherein said protrusion includes a
prong that extends at a predetermined angle from said annular wear
plate portion.
19. The wear plate of claim 18 wherein said angle is substantially
45.degree. with respect to a plane defined by said wear plate
portion.
20. The wear plate of claim 16 wherein said annular wear plate
portion includes at least one groove that interrupts said wear
plate surface.
21. The wear plate of claim 20 wherein said wear plate portion
includes a second groove that interrupts said wear plate surface,
said one groove extending inwardly from an outer diameter of said
wear plate and said second groove extending outwardly from said
aperture.
22. The wear plate of claim 21 wherein said grooves define recesses
that are below said wear plate surface but do not extend through
said wear plate.
23. The wear plate of claim 21 wherein said grooves extend through
said annular wear plate portion.
24. The wear plate of claim 23 wherein said wear plate forms part
of a wear plate assembly that can be removable mounted to said
centrifugal pump.
25. The wear plate of claim 21 wherein said grooves extend in
substantially the radial direction.
26. The wear plate of claim 16 wherein a periphery of said aperture
is defined by at least one outwardly extending notch.
27. The wear plate of claim 16 wherein said periphery of said
aperture is defined by a plurality of outwardly extending notches
separated by tooth-like spacer gaps.
28. The centrifugal pump of claim 1 wherein said wear plate eye
includes at least one peripheral notch.
29. The centrifugal pump of claim 1 wherein said wear plate eye
includes a plurality of peripheral notches separate by tooth-like
gaps.
30. The centrifugal pump of claim 1 wherein said centrifugal pump
is of the self-priming variety.
31. The centrifugal pump of claim wherein said centrifugal pump is
of the submersible variety.
Description
RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Patent Application Ser. No. 61/895,131, filed on Oct. 24, 2013, the
disclosure of which is entirely incorporated herein by
reference.
TECHNICAL FIELD
[0002] The present invention relates generally to pumps and, in
particular, to a centrifugal type pump that has enhanced solid
handling properties.
BACKGROUND ART
[0003] Centrifugal pumps are typically used to pump sewage and
wastewater. Sewage, in particular, often includes solids that must
pass through the impeller chamber of the centrifugal pump. In the
past, impeller/impeller chambers were designed to allow solids up
to a predetermined size to pass through the pump without clogging.
More recently, it has been found that sewage effluent in addition
to solids, also carries stringy and fibrous materials which can
clog or compromise the operation of conventional centrifugal
pumps.
SUMMARY OF THE INVENTION
[0004] The present invention provides a new and improved
centrifugal pump, including a self-cleaning wear plate. The
disclosed wear plate significantly improves a pump's ability to
resist clogging due to stringy or fibrous materials without
sacrificing the ability of the pump to handle spherical waste
material.
[0005] According to one preferred embodiment, a centrifugal pump is
disclosed which includes a pump housing and an impeller assembly
mounted to the pump housing. A wear plate constructed in accordance
with the invention is mounted within the housing in a confronting
relationship with an impeller that forms part of the impeller
assembly. According to one embodiment, the wear plate includes an
annular wear plate portion that defines an impeller side that
confronts the impeller when the wear plate is mounted within the
pump housing. The annular portion also defines an eye formed
generally centrally in the annular portion and includes a center
point that is substantially aligned with a rotational axis of the
impeller. According to this embodiment, the wear plate includes at
least one protrusion that extends towards the impeller. The
protrusion includes a prong that extends at an angle from a
mounting segment formed on the wear plate. In a more preferred
embodiment, the prong extends at an angle of substantially
45.degree. with respect to a plane defined by the wear plate
portion. In this embodiment, the prong and mounting segment are
integrally formed with the wear plate portion and in another
disclosed embodiment, the prong is welded to the mounting
segment.
[0006] According to the preferred embodiment, the eye includes at
least one peripheral notch. In the illustrated embodiment, the eye
includes a plurality of peripheral notches separated by tooth-like
gaps or spacing members and one protrusion extends from the eye
toward the impeller. In the illustrated embodiment, the notches are
substantially wider in dimension than the tooth-like gaps or
spacers
[0007] According to a feature of the invention, the wear plate
portion includes at least one substantial radial groove and, in a
more preferred embodiment, includes a second radial groove with the
one radial groove extending inwardly from an outer diameter of the
wear plate portion and the second groove extending outwardly from
the eye. In one illustrated embodiment the grooves extend below a
wear plate surface but do not extend through the wear plate. In
another illustrated embodiment, the grooves extend through or cut
through the wear plate portion.
[0008] In the illustrated embodiment, the wear plate is attached to
a wear plate cover, preferably by stand-offs forming part of the
wear plate. In a more preferred embodiment, an aperture is formed
in the protrusion to facilitate bending of the prong when the
protrusion is integrally formed with the annular wear plate
portion. In the illustrated embodiment, one radial groove has an
inner end that is in a radial, overlapping relationship with
respect to the outer end of the other radial groove. The disclosed
construction of the wear plate includes a single prong and a single
and a single outer radial groove. It should be noted that the
present invention contemplates multiple protrusions that would
extend towards the impeller for some applications. In addition, the
depths of the radial grooves can be uniform or can vary and more
than two radial grooves (both inner and outer) can be used to
improve performance for some applications. In addition, in the
illustrated construction, the notches formed on the periphery of
the eye or center aperture of the wear plate are substantially
wider than the tooth-like gaps or fingers. The present invention
contemplates notches that can be smaller than those shown, as well
as a pattern of notches in which the width of the notches varies
along the periphery of the wear plate eye.
[0009] The disclosed wear plate improves the performance of a
centrifugal pump because it is better able to handle fibrous and
stringy materials without comprising its ability to handle larger
spherical waste material which centrifugal pumps of this type were
originally intended to handle.
[0010] Additional features of the invention will become apparent
and a fuller understanding obtained by reading the following
description made in connection with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 is an exploded view of a centrifugal pump, including
assemblies constructed in accordance with a preferred embodiment of
the invention;
[0012] FIG. 2 is isometric view of a wear plate constructed in
accordance with a preferred embodiment of the invention;
[0013] FIG. 3 is another isometric view of the wear plate shown in
FIG. 2 that illustrates another side of the wear plate shown in
FIG. 2;
[0014] FIG. 4 is an isometric view of a wear plate constructed in
accordance with another preferred embodiment of the invention;
[0015] FIG. 5 is an enlarged fragmentary view of a portion of the
wear plate indicated by the phantom circle shown in FIG. 4 and
constructed in accordance with one embodiment of the invention;
[0016] FIG. 6 is another enlarged fragmentary view of a portion of
the wear plate indicated by the phantom circle in FIG. 4, but
constructed in accordance with another embodiment of the
invention;
[0017] FIG. 7 is isometric view of a back cover or wear plate
access cover constructed in accordance with a preferred embodiment
of the invention;
[0018] FIG. 8 is another isometric view of the wear plate access
cover shown in FIG. 7, but rotated 180.degree.;
[0019] FIG. 9 is a plan view of a wear plate blank prior to a
bending operation; and
[0020] FIG. 10 is an isometric view of a wear plate constructed in
accordance with another preferred embodiment of the invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0021] FIG. 1 illustrates the overall construction of a centrifugal
pump 10 constructed in accordance with a preferred embodiment of
the invention. The pump includes a pump housing 10a which, as is
known, defines an inlet and an outlet for receiving and discharging
effluent and an internal chamber for receiving an impeller assembly
10b and a wear plate assembly 10c. The illustrated wear plate
assembly 10c is constructed in accordance with a preferred
embodiment of the invention. The illustrated centrifugal pump is of
the self-priming variety. Additional details regarding the pump
body and impeller assembly can be found in U.S. Pat. Nos. 3,898,014
and 8,414,257, which are hereby incorporated by reference.
[0022] FIGS. 2 and 3 illustrate a wear plate 20 constructed in
accordance with one preferred embodiment of the invention. As seen
in FIG. 2, the wear plate 20 includes two studs 22 by which the
wear plate is attached to a back or wear plate access cover 24 (see
also FIGS. 7 and 8). It should be noted here that the cover 24 best
illustrated in FIGS. 7 and 8 includes adjustment hardware for
adjusting the distance between the wear plate 20 and an associated
impeller 32 (see FIG. 1). The details of this wear plate adjustment
feature can be found in U.S. Pat. No. 6,887,034 which is hereby
incorporated by reference.
[0023] As seen in FIGS. 2 and 3, the wear plate 20 is generally
circular in construction and includes an annular portion that
includes an eye 34 which forms at least part of the inlet to the
impeller chamber which is defined within the pump body 10a when the
impeller assembly 10b and the wear plate assembly 10c are mounted
to the pump body 10. The eye 34 is a generally circular opening
located at or near the center of the wear plate 20. A center 38 of
the eye 34 is preferably located in line with the rotational axis
of the impeller 32.
[0024] According to the invention, the outer periphery of the eye
34 is characterized by at least one notch, but preferably a
plurality of notches 46 that are separated by gaps or spacer teeth
48. In the illustrated embodiment, the spacer teeth extend radially
inwardly from the periphery of the eye or aperture 34. The notches
46 can be of a different number, width or depth from that shown. It
is also believed that a wider notch 46 provides better performance
than a narrower notch.
[0025] For purposes of reference, a side of the wear plate 20,
which includes the mounting studs and faces the wear plate cover
24, shall be indicated by the reference character 20a. A side of
the wear plate includes a surface that confronts the impeller 32 as
shown in FIG. 3 shall be indicated by the reference character 20b.
The illustrated wear plate confronting surface 20b is generally
planar. The present invention contemplates a tapered confronting
surface which would be used with a tapered impeller.
[0026] In the illustrated embodiment shown in FIG. 3, the wear
plate side 20b of the wear plate 20 includes inner and outer
grooves 50, 52 which extend generally radially. As seen in FIG. 3,
the inner groove 50 opens into the impeller eye, whereas the outer
groove opens at the periphery or outer diameter of the wear plate.
In the embodiment illustrated in FIG. 3, the grooves are cut
partially into the wear plate but do not extend from the side 20a
to the side 20b of the wear plate. The inner and outer grooves 50,
52 can be of a varying number, position, angle and depth.
[0027] According to the invention, the wear plate also includes at
least one protrusion 60 which extends from the plane of the wear
plate 20, towards the impeller 32 and through the eye 34. Referring
also to FIGS. 1 and 7, the extension of the protrusion 60 towards
the impeller can be seen. Referring also to FIGS. 4-6, the
protrusion includes a mounting segment 62 which extends radially
from the wear plate 20 and a tooth or prong 64 which extends
towards the impeller 32. The tooth or prong 64, which in the
illustrated embodiment is generally triangular in shape and
includes an apex or point 64a, is joined to the mount 62 by an
interconnecting portion 66. FIG. 5 is an enlargement of a portion
of FIG. 4 which shows a configuration of the protrusion 60 when it
is integrally formed with the wear plate 20. FIG. 6 shows an
alternate construction in which a tooth segment 64' is welded to a
lug or mount segment 62'.
[0028] FIG. 4 also illustrates an alternate embodiment of the wear
plate 20' in which inner and outer notches 50', 52' are cut through
the wear plate and, in particular, extend from the cover side 20a'
to the wear plate side 20b' of the wear plate 20'. In FIG. 4, the
protrusion 60 is bent or formed integrally with the wear plate.
[0029] FIG. 7 illustrates the wear plate 20 mounted to the back or
wear plate cover 24 of the pump 10. The back cover 24 includes an
integral inspection feature. U.S. Pat. No. 8,500,393 discloses a
cover with the inspection feature and is hereby incorporated by
reference, The disclosed wear plate can be incorporated into back
covers of different configurations, including those not having
inspection features. In addition, the wear plate 20 can be formed
as an integral part of the back cover, i.e., not separately mounted
via the studs 22.
[0030] FIG. 9 illustrates a general fiat layout of a wear plate
constructed in accordance with one or more embodiments of the
present invention. The wear plate 20 can be stamped or cut from
flat stock. Depending on the application, the length L1 of the
protrusion 60 can be selected in accordance with the pump
application and impeller design. The angle .theta., it is believed,
is best kept at or below 45.degree. (the angle at which the
protrusion is bent towards the impeller). L2 is the dimension for
the gap or tooth 48 between notches 46 and L3 is the width of the
notches 46. L4 is the width selected for the grooves 50, 52, again
dependent on application. It should be noted that the inner and
outer grooves 50, 52 may have different widths.
[0031] The invention has been described in connection with a
self-priming centrifugal pump. It should be noted that the
invention contemplates use of the invention on any number of
different types of centrifugal pumps, including but not limited to,
self-priming, submersible, chopper and end suction solids handling
pumps.
[0032] It is believed that the notches 46 and protrusion 60 shown
in the figures inhibit stringy and fibrous materials from clinging
to or wrapping around the wear plate and/or the impeller, thus
reducing the chance of pump clogging by the material. With the
disclosed configurations, the centrifugal pump can handle stringy
or fibrous material without compromising the pump's ability to
handle more conventional, large sized solids.
[0033] In addition, the present invention contemplates wear plates
in which the outer groove 52 may be eliminated for some
applications and also that there may be different numbers of inner
and outer grooves and there may not be a need in some applications
for a one-to-one correspondence between inner and outer grooves 50,
52. In addition, in the illustrated embodiment, the inner end 52a
of the outermost groove is the same distance as measured radially
as the outermost end of the inner groove. This relationship is
shown in FIG. 9, where it can be seen that the innermost end
segment 52a of the outer groove 52 and outermost end segment 50a of
the inner groove 50 lie on a common annulus, indicated by the
reference character 70. In other words, the groove ends 50a, 52a
are in an overlapping relationship, The invention contemplates
configurations where the respective ends of the grooves do not lie
on a common circle or annulus and contemplates the forming of
intermediate grooves on the wear plates for some applications. The
invention also contemplates inner and outer grooves that do not
have uniform depths across their radially extent. Finally, the
invention contemplates a wear plate construction having multiple
protrusions extending from the wear plate.
[0034] FIG. 10 illustrates a wear plate 20'' that is substantially
similar to the wear plate 20 configuration shown in FIG. 4.
However, in the configuration shown in FIG. 10, a hole or aperture
74 is formed in the protrusion 60''. This hole 74 is provided to
facilitate bending of the protrusion 60'' when the wear plate is
constructed of a relatively hard material which, if not for the
aperture, would cause fracturing or other unwanted conditions to be
created in the protrusion 60'' during the bending process.
[0035] Although the invention has been described with a certain
degree of particularity, it should be understood that those skilled
in the art can make various changes to it without departing from
the spirit or scope of the invention as hereinafter claimed.
* * * * *