U.S. patent number 3,711,218 [Application Number 05/105,156] was granted by the patent office on 1973-01-16 for centrifugal pump with open type impeller.
This patent grant is currently assigned to Dorr-Oliver Incorporated. Invention is credited to George Wm. Kennel, Gerald Ornstein.
United States Patent |
3,711,218 |
Kennel , et al. |
January 16, 1973 |
CENTRIFUGAL PUMP WITH OPEN TYPE IMPELLER
Abstract
A centrifugal pump having an open type bladed impeller,
featuring an impeller shaft assembly which as such comprises a
hollow impeller shaft, a tie rod within the impeller shaft, and an
impeller with open blades connected to the tie rod so as to be
axially adjustable relative to the shaft and thus relative to the
pump housing through manipulation of the tie rod at the free end of
the shaft.
Inventors: |
Kennel; George Wm. (Flushing,
NY), Ornstein; Gerald (Riverdale, NY) |
Assignee: |
Dorr-Oliver Incorporated
(Stamford, CT)
|
Family
ID: |
22304342 |
Appl.
No.: |
05/105,156 |
Filed: |
January 11, 1971 |
Current U.S.
Class: |
415/131;
415/216.1; 415/214.1; 415/229 |
Current CPC
Class: |
F04D
29/049 (20130101); F04D 7/04 (20130101); F04D
29/20 (20130101); F04D 29/0462 (20130101); F04D
29/622 (20130101); F04D 15/0033 (20130101) |
Current International
Class: |
F04D
29/04 (20060101); F04D 7/04 (20060101); F04D
29/18 (20060101); F04D 29/20 (20060101); F04D
7/00 (20060101); F04D 15/00 (20060101); F01d
005/02 (); F04d 029/02 () |
Field of
Search: |
;415/129,130,131,134,139,197,200,213 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Raduazo; Henry F.
Claims
We claim:
1. A centrifugal pump which comprises
a hollow impeller shaft,
an open type impeller mounted on the forward end portion of the
shaft having torque transmitting means effective between, said
shaft and said impeller while allowing for axial movement of the
impeller on said shaft
a tie rod having a forward threaded end portion threaded into said
impeller shaft coaxial therewith, said threaded forward end portion
being formed with a rearwardly facing annular shoulder adjacent to
the end face of the impeller shaft, the rearward end portion of
said tie rod being formed with a thread projecting rearwardly from
said shaft, said tie rod being turnable relative to the impeller
shaft for thereby effecting axial adjustment of the impeller
relative to said shaft, as well as relative to the cover plate of a
housing section surrounding the impeller,
a lock nut provided upon said rearward end portion of the tie rod
for securing the axial adjustment of the impeller due to said
annular shoulder being tightened against said adjacent end face of
the forward end of the impeller shaft, when said lock nut is
tightened against the adjacent impeller shaft,
a housing section surrounding the impeller, having a body portion
provided with sealing means for the impeller shaft extending
therethrough, and having a cover portion connected to said body
portion, and formed with an inlet neck and with a outlet neck,
a bearing section rigidly connected to the housing section, and
having a pair of horizontally spaced bearings supporting the
impeller shaft,
and means for securing the impeller shaft against axial
displacement relative to said bearing section.
2. A centrifugal pump which comprises
a hollow impeller shaft formed interiorly with a forwardly facing
annular shoulder,
an open type impeller mounted on the forward end portion of the
shaft having torque transmitting means effective between, said
shaft and said impeller while allowing for axial movement of the
impeller on said shaft,
a tie rod having a forward end portion threaded into said impeller,
and extending rearwardly through the impeller shaft coaxial
therewith, and having a rearwardly facing annular shoulder adjacent
to said forwardly facing shoulder of the impeller shaft, and also
formed with a thread projecting rearwardly from said shaft, said
tie rod being turnable relative to the impeller shaft for thereby
axially adjusting the impeller relative to said shaft, as well as
relative to the cover plate of a housing section surrounding the
impeller,
a lock nut provided upon said rearward end portion of the tie rod
for securing the axial adjustment of the impeller due to said
rearwardly facing shoulder of the shaft being tightened against
said adjacent internal shoulder of the shaft, when said lock nut is
tightened against the impeller shaft,
a housing section surrounding the impeller, having a body portion
provided with sealing means for the impeller shaft extending
therethrough, and having a cover portion connected to said body
portion, and formed with an inlet neck and with an outlet neck,
a bearing section rigidly connected to the housing section, and
having a pair of horizontally spaced bearings supporting the
impeller shaft,
and means for securing the impeller shaft against axial
displacement relative to said bearing section.
3. A centrifugal pump which comprises
a hollow impeller shaft,
an open type impeller mounted on the forward end portion of the
shaft having torque transmitting means effective between, said
shaft and said impeller while allowing for axial movement of the
impeller on said shaft,
a tie rod having a forward end portion fixed to said impeller, and
extending rearwardly through the impeller shaft concentric
therewith, and formed with an annular groove adjacent to its
rearward end,
an externally threaded nipple surrounding the rearward end portion
of the tie rod, and threaded into the associated rearward end
portion of the impeller shaft, said nipple having an inwardly
directed radial projection extending into said annular groove, so
that rotating said nipple in the thread will axially adjust the tie
rod bodily together with the impeller relative to the impeller
shaft,
locking means for securing the nipple relative to the impeller
shaft and thereby securing the axially adjusted position of the
impeller,
a housing section surrounding the impeller, having a body portion
provided with sealing means for the impeller shaft extending
therethrough, and having a cover portion connected to said body
portion, and formed with an inlet neck and with an outlet neck,
a bearing section fixedly connected to the housing section,
supporting the impeller shaft,
and means for securing the impeller shaft against axial
displacement relative to said bearing section.
4. The centrifugal pump according to claim 3, wherein said locking
means comprise a lock nut engaging the external thread of said
nipple, and effective to secure said axial adjustment of the
impeller when said lock nut is tightened against the adjoining end
face of the impeller shaft.
5. In a centrifugal pump of the open impeller type, a rotor
assembly which comprises
a hollow impeller shaft,
an open type impeller mounted on the forward end portion of the
shaft having torque transmitting means effective between, said
shaft and said impeller while allowing for axial movement of the
impeller on said shaft,
a tie rod having a forward threaded end portion threaded into said
impeller, and extending rearwardly through the impeller shaft
coaxial therewith, the threaded forward end portion being formed
with a rearwardly facing shoulder adjacent to the end face of the
impeller shaft, the rearward end portion of the tie rod being
formed with a thread projecting rearwardly from said shaft, said
tie rod being turnable relative to the impeller shaft for thereby
axially adjusting the impeller relative to said shaft,
and a lock nut provided upon said rearward end portion of the tie
rod for securing the axial adjustment of the impeller due to said
annular shoulder being tightened against said adjacent end face of
the forward end of the impeller shaft, when said lock nut is
tightened against the impeller shaft.
6. In a centrifugal pump of the open impeller type, a rotor
assembly which comprises
a hollow impeller shaft formed interiorly with a forwardly facing
annular shoulder,
an open type impeller mounted on the forward end portion of the
shaft having torque transmitting means effective between, said
shaft and said impeller while allowing for axial movement of the
impeller on said shaft,
a tie rod having a forward threaded end portion threaded into said
impeller, and extending rearwardly through the impeller shaft
coaxial therewith and formed with a rearwardly facing annular
shoulder adjacent to said forwardly facing interior shoulder of the
shaft, and also formed with a thread projecting rearwardly from the
shaft, said tie rod being turnable relative to the impeller shaft
for thereby axially adjusting the impeller relative to said
shaft,
and a lock nut provided upon said rearward end portion of the tie
rod for securing the axial adjustment of the impeller due to said
rearwardly facing shoulder of the tie rod being tightened against
said adjacent internal shoulder of the shaft, when said lock nut is
tightened against the impeller shaft.
7. In a centrifugal pump, a rotor assembly which comprises
a hollow impeller shaft,
an open type impeller mounted on the forward end portion of the
shaft having torque transmitting means effective between, said
shaft and said impeller while allowing for axial movement of the
impeller on said shaft,
a tie rod having a forward end portion fixed to said impeller, and
extending rearwardly through the impeller shaft, and formed with an
annular groove adjacent to its rearward end,
an externally threaded nipple surrounding the rearward end portion
of the tie rod, and threaded into the associated rearward end of
the impeller shaft, said nipple having an inwardly directed radial
projection extending into said annular groove, so that rotating
said nipple in the thread will axially adjust the tie rod bodily
together with the impeller relative to the shaft,
and locking means for securing the nipple relative to the impeller
shaft and thereby securing the axially adjusted position of the
impeller.
8. The centrifugal pump according to claim 7, wherein said locking
means comprise a lock nut engaging the external thread of said
nipple, and effective to secure said axially adjusted position of
the impeller when said lock nut is tightened against the adjoining
end face of the impeller shaft.
9. A centrifugal pump which comprises
a hollow impeller shaft
an open type impeller mounted on the forward end portion of the
shaft having torque transmitting means effective between, said
shaft and said impeller while allowing for axial movement of the
impeller on said shaft,
a tie rod having a forward threaded end portion threaded into said
impeller, and extending rearwardly through the impeller shaft
coaxial therewith, said rod being turnable relative to the impeller
shaft for thereby effecting axial adjustment of the impeller
relative to said shaft, while secured against rearward axial
displacement relative to said shaft,
locking means for securing said axial adjustment by fixing said tie
rod relative to said shaft,
a housing section surrounding the impeller, having a body portion
provided with sealing means for the impeller shaft extending
therethrough, and having a cover portion connected to said body
portion, and formed with an inlet neck and with an outlet neck,
a bearing section rigidly connected to the housing section, and
having a pair of horizontally spaced bearings supporting the
impeller shaft,
and means for securing the impeller shaft against axial
displacement relative to said bearing section.
10. In a centrifugal pump of the open impeller type, a rotor
assembly which comprises
a hollow impeller shaft,
an open type impeller mounted on the forward end portion of the
shaft having torque transmitting means effective between, said
shaft and said impeller while allowing for axial movement of the
impeller on said shaft,
a tie rod having a forward end portion threaded to said impeller,
and extending rearwardly through the impeller shaft concentric
therewith, said rod being turnable relative to the impeller shaft
for thereby effecting axial adjustment of the impeller relative to
said shaft, while secured against rearward axial displacement
relative to said shaft,
and locking means for securing said axial adjustment by fixing said
tie rod relative to said shaft.
11. A centrifugal pump of the open impeller type, which
comprises
a hollow impeller shaft,
an open type impeller mounted on the forward end portion of the
shaft having torque transmitting means effective between, said
shaft and said impeller while allowing for axial movement of the
impeller on said shaft,
a tie rod having a forward end portion fixed to said impeller, and
extending rearwardly through the impeller shaft concentric
therewith, and formed with an annular groove adjacent to its
rearward end,
a threaded nipple surrounding the rearward end portion of the tie
rod, in threaded engagement with the associated rearward end
portion of the impeller shaft, said nipple having an inwardly
directed radial projection extending into said annular groove, so
that rotating said nipple relative to the shaft will axially adjust
the tie rod bodily together with the impeller relative to the
shaft,
locking means for securing the nipple relative to the impeller
shaft and thereby securing the axially adjusted position of the
impeller,
a housing section surrounding the impeller, having a body portion
provided with sealing means for the impeller shaft extending
therethrough, and having a cover portion connected to said body
portion, and formed with an inlet neck and an outlet neck,
a bearing section fixedly connected to the housing section,
supporting the impeller shaft,
and means for securing the impeller shaft against axial
displacement relative to said bearing section.
12. In a centrifugal pump, a rotor assembly which comprises
a hollow impeller shaft,
an open type impeller mounted on the forward end portion of the
shaft having torque transmitting means effective between, said
shaft and said impeller while allowing for axial movement of the
impeller on said shaft,
a tie rod having a forward end portion fixed to said impeller, and
extending rearwardly through the impeller shaft concentric
therewith, and formed with an annular groove adjacent to its
rearward end,
a threaded nipple surrounding the rearward end portion of the tie
rod, in threaded engagement with the associated rearward end
portion of the impeller shaft, said nipple having an inwardly
directed radial projection extending into said annular groove, so
that rotating said nipple relative to the shaft will axially adjust
the tie rod bodily together with the impeller relative to the
shaft,
and locking means for securing the nipple relative to the impeller
shaft and thereby securing the axially adjusted position of the
impeller.
13. A centrifugal pump which comprises
a hollow impeller shaft,
an open type impeller mounted on the forward end portion of the
shaft having torque transmitting means effective between, said
shaft and said impeller while allowing for axial movement of the
impeller on said shaft,
a tie rod extending concentrically within said impeller shaft, and
having a forward end portion connected to said impeller,
adjusting means effective between said tie rod and said impeller
shaft, constructed and arranged so as to be operable for adjustably
shifting said tie rod together with said impeller axially relative
to said impeller shaft,
locking means for securing the axially adjusted position of the tie
rod relative to the impeller shaft,
a housing section surrounding the impeller, having a body portion
provided with sealing means for the impeller shaft extending
therethrough, and having a cover portion connected to said body
portion, and formed with an inlet neck and an outlet neck,
a bearing section fixedly connected to the housing section,
supporting the impeller shaft,
and means for securing the impeller shaft against axial
displacement relative to said bearing section.
14. In a centrifugal pump, a rotor assembly which comprises
a hollow impeller shaft,
an open type impeller mounted on the forward end portion of the
shaft having torque transmitting means effective between, said
shaft and said impeller while allowing for axial movement of the
impeller on said shaft,
a tie rod extending concentrically within said impeller shaft, and
having a forward end portion fixedly connected to said
impeller,
adjusting means effective between said tie rod and said impeller
shaft, constructed and arranged so as to be operable for adjustably
shifting said tie rod together with said impeller axially relative
to said impeller shaft,
and locking means for securing the axially adjusted position of the
tie rod relative to the impeller shaft.
Description
This invention relates to centrifugal pumps, and more particularly
to the type having an open impeller designed for handling viscous
liquids or liquids carrying solids that would tend to clog pumps of
the closed impeller type.
In an open type impeller pump such as herein contemplated, the
impeller comprises an impeller disc upon one side of which are
formed the conventional impeller blades, while the impeller shaft
extend in the opposite direction from the disc.
A housing section of the pump unit surrounds the impeller
comprising a body portion or member through which extends the
impeller shaft in sealed relationship therewith, and a cover
portion or member connected to a pump inlet duct and a pump outlet
duct.
The impeller shaft protruding from the housing section is supported
by a pair of horizontally spaced bearings mounted in the bearing
section of the pump which in turn is bolted to the housing section
of the pump.
More in particular, this invention is concerned with devices
provided in this type of pump, whereby the critical clearance
between the impeller blades of the open type impeller and the pump
cover member is adjustable. This impeller clearance is to be
maintained at a practical minimum, in order to maintain optimum
pumping efficiency. Hence, periodical check up and/or readjustment
is required of the impeller clearance because of wear and tear
affecting the outer free edges of the pumping blades of the pump
handling the aforementioned suspensions or pulps.
Therefore, it is one object of this invention to provide improved
adjusting devices of great simplicity, whereby the impeller
clearance is adjustable conveniently and accurately to its optimum,
while avoiding structural and manipulitive complications inherent
in the adjusting means of prior art.
In a more specific sense, the object is to provide means for
impeller clearance adjustment, wherein a threaded member is
turnable concentric with and relative to the impeller shaft, to
impart corresponding axial movement to the impeller relative to the
impeller shaft, with the shaft itself secured against axial
displacement relative to the pump housing.
This object is attainable in one embodiment of the invention,
wherein a tie rod extends concentrically through the hollow
impeller shaft. The tie rod has a forward threaded end portion
screwed into the impeller which is slidably fitted upon the
associated end portion of the impeller shaft, but secured against
rotation relative to that shaft. Thus, because of the threaded
connection, rotating the tie rod from the rear-ward end thereof,
will impart corresponding axial movement to the impeller relative
to the shaft which in turn is secured against axial displacement in
the housing. Suitable locking means are provided, operable to fix
the tie rod and the impeller in the adjusted position relative to
the impeller shaft.
In another embodiment, the impeller and the tie rod are rigidly
interconnected, and axially adjustable as a unit relative to the
impeller shaft. The impeller clearance adjustment is effected by
means of a nipple surrounding the rearward end of the tie rod, and
threaded into the associated end portion of the impeller shaft. The
nipple has an inward radial projection extending into a circular
groove formed around the rearward end of the tie rod. Thus, turning
the nipple in the thread while holding the impeller shaft against
rotation, will through the rod impart axial adjustment to the
impeller relative to the impeller shaft, and thus relative to the
cover plate of the impeller housing.
Specific features of the invention lie in various ways of effecting
the impeller clearance adjustment, and in the manner of securing
the adjustment.
Other features and advantages will hereinafter appear.
As this invention may be embodied in several forms without
departing from the spirit or essential characteristics thereof, the
present embodiments are illustrative and not restrictive. The scope
of the invention is defined by the appended claims rather than by
the description preceding them, and all embodiments which fall
within the meaning and range of equivalency of the claims are
therefore intended to be embraced by those claims.
FIG. 1 is a longitudinal sectional view of the pump embodying one
form of the invention, wherein a tie rod is threaded into the
impeller, and one form of locking device secures the
adjustment.
FIG. 2 is fragmentary view of the pump of FIG. 1, illustrating an
intermediate phase of the procedure of the impeller adjustment.
FIG. 2a is an end view of FIG. 2 taken on the line 2a--2a.
FIG. 3 is a fragmentary view similar to the FIG. 2, illustrating
the final phase of the impeller adjustment.
FIG. 3a is an end view of FIG. 3 taken on the line 3a--3a.
FIG. 4 is a fragmentary view similar to FIGS. 2 and 3, illustrating
another form of the locking device.
FIG. 5 is a longitudinal sectional view of the pump, illustrating
another embodiment of the invention, featuring a threaded nipple as
a means for making the clearance adjustment.
FIG. 6 is an enlarged fragmentary view of the pump shown in FIG. 5,
more clearly showing the adjustment means.
In the embodiment of the pump illustrated in FIGS. 1, 2, 3, the
rotor assembly comprises a hollow impeller shaft 10 and an open
type impeller 11 mounted for bodily axial movement upon the forward
end portion of the shaft, although secured against rotation
relative to the shaft as by means of a key connection 12. Axial
adjustment of the impeller on the shaft is attainable by way of a
tie rod 13 extending from the impeller concentrically through the
impeller shaft.
This tie rod has an enlarged head portion 14 at the forward end in
threaded connection with the impeller, and formed with a rearwardly
facing annular shoulder 15 engaging the adjacent end face 16 of the
impeller shaft. The opposite or rearward portion 17 of tie rod 13
has threaded connection with a lock nut 18 which when tightened
against the end face of the shaft will tighten the shoulder 15
against the face 16 of the shaft, thereby securing the axially
adjusted position of the impeller relative to the impeller shaft,
as will be furthermore described below.
The impeller is surrounded by a housing section 19 of the pump,
having a body portion 20 which in turn comprises a sealing device
or stuffing box 20a through which extends rearwardly the impeller
shaft. A complementary front cover member 21 connected to the body
portion, is formed with a conventional pump inlet neck 22 and a
conventional pump outlet neck 23.
Rigidly connected to the housing section is a bearing section 24
containing a pair of horizontally spaced ball bearings 25 and 26
wherein the impeller shaft is supported for rotation. In order to
secure this shaft against axial displacement relative to the
bearing section, the main bearing 25 is closely confined between a
pair of snap rings 27 and 28 sprung into respective grooves formed
internally in the bearing section.
The pump body member 20 is confined between the front cover member
21 and the bearing section 24, with a gasket 29 providing a seal
between the two parts of the housing section. A set of bolts 30
connect the cover plate 21 with the bearing section, a pair of
locating pins 31 and 32 being provided between the body member 20
and the bearing section. A sealing 33 closes the rear end of the
bearing section.
For the purpose of inspecting the interior of the pump, it is only
necessary to loosen the bolts 30 and to horizontally withdraw the
bearing section 24 together with the body member 20 and with the
rotary impeller assembly, while leaving the front cover member 21
connected to an inlet duct 34 and to an outlet duct 35.
The manner of making the impeller clearance adjustment will now be
described in connection with the embodiments in FIGS. 1 to 3 as
follows:
With the impeller shaft 10 together with impeller itself secured
against rotation, and lock nut 18 loosened and backed off (see FIG.
2), the tie rod 13 may be turned as by means of a screw driver S
until the impeller is advanced from the old position P- 1 shown in
dot-and-dash (see FIG. 2) to an end position wherein the impeller
blades will have attained contact with the front cover member 21.
Thus, if the front end of the tie rod has a right hand thread,
turning the tie rod to the left or counterclockwise will advance
the impeller towards the cover plate a distance d-4 which is equal
to the distance that the threaded portion of the rod is retracted
in the thread of the impeller. This axially induced movement of the
impeller relative to the shaft takes place, since the impeller
shaft itself is secured against axial displacement, and with the
shoulder 15 of the tie rod remaining in contact with, or bracing
itself against the forward end face 16 of the shaft 10.
Once this forward end position of the impeller has been reached,
the tie rod may be turned in the opposite right hand or clockwise
direction a predetermined distance (see FIG. 3) as measured by the
pitch of the thread 14, thereby retracting the impeller a distance
representing the desired impeller clearance d-5. Lock 18 will then
be tightened to secure the adjustment. Accurate impeller clearance
adjustment is thus attainable without the need of disconnecting the
pump from the inlet and the outlet ducts.
The embodiment in FIG. 4, differs from FIG. 1 only in regard to the
manner in which the adjustment of the impeller clearance is
secured. Accordingly, a tie rod 36 has a forward threaded end
portion 37 of a diameter that need be no greater than the diameter
d-6 of the tie rod itself. This tie rod has a reduced threaded rear
end portion of the diameter d--7, thus presenting a rearwardly
facing shoulder 38 tightly engaging an inwardly facing shoulder 39
formed interiorly by the impeller shaft when a lock nut 41 is
tightened against the end face 42 of the impeller shaft. After
loosening the lock nut, an impeller clearance adjustment may be
made substantially in the manner described above in connection with
FIGS. 1 to 3.
The embodiment in FIGS. 5 and 6 differs from those in FIGS. 1 to 4
in that the impeller 43 has a fixed connection with a tie rod 44,
as indicated by a weld connection 45. Again, the impeller is
slidably fitted over the front end portion of a hollow impeller
shaft 46, with a key connection 47 securing it against rotation
relative to the shaft. An externally threaded nipple 48 in threaded
engagement with the internally rear end portion of the shaft, has a
radial inwardly directed projection 49 engaging an annular groove
50 formed in the rear end of the rod 44. Thus, when the impeller
shaft 46 is held against rotation, turning of the nipple in the
thread will, through tie rod 44 effect axial adjustment of impeller
43 relative to the shaft 46 as well as relative to front cover
member 50, as indicated by clearance d-6 (see FIG. 6). Such axial
adjustment then may be secured by tightening a previously loosened
lock nut 51 against the rear end face 52 of the impeller shaft.
* * * * *