U.S. patent number 3,697,190 [Application Number 05/086,429] was granted by the patent office on 1972-10-10 for truncated conical drag pump.
Invention is credited to Walter D. Haentjens.
United States Patent |
3,697,190 |
Haentjens |
October 10, 1972 |
TRUNCATED CONICAL DRAG PUMP
Abstract
High pressure low volume rate drag pump having a frusto-conical
rotor cooperating with a frusto-conical stator wall and having
close clearance with the stator wall. The rotor has a helical
channel extending therealong, in which the base or root of the
channel is formed along a different angle than the cone angle of
the rotor. The high pressure is attained by the maximum drag
surface along the relatively small passageways together with the
centrifugal force of the fluid due to increasing linear velocity of
the rotor from its inlet to its discharge end. The rotor is axially
adjustable to maintain a close clearance and a high pressure
capability of the pump.
Inventors: |
Haentjens; Walter D.
(Sugarloaf, PA) |
Family
ID: |
22198515 |
Appl.
No.: |
05/086,429 |
Filed: |
November 3, 1970 |
Current U.S.
Class: |
415/73; 415/72;
415/131; 415/219.1 |
Current CPC
Class: |
F04D
3/02 (20130101); F05B 2250/232 (20130101) |
Current International
Class: |
F04D
3/00 (20060101); F04D 3/02 (20060101); F01d
005/00 () |
Field of
Search: |
;415/71,72,73,215 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
849,002 |
|
Aug 1939 |
|
FR |
|
448,066 |
|
Apr 1948 |
|
CA |
|
68,594 |
|
Mar 1892 |
|
DD |
|
Primary Examiner: Husar; C. J.
Claims
I claim as my invention:
1. A drag pump comprising:
a housing having an interior frusto-conical wall portion,
an inlet into said housing opening to the small diameter end of
said frusto-conical wall portion,
an outlet leading from said housing and having communication with
the large diameter end of the frusto-conical wall portion
thereof,
a rotor rotatably journalled within said housing and having a
conical wall portion extending at the same angle as the interior
conical wall portion of said housing,
a shaft for said rotor,
bearings for said shaft at opposite ends of said housing,
journalling said shaft and rotor for rotation about an axis
extending longitudinally of said housing,
means mounting said shaft on said bearings for axial adjustable
movement therealong, accommodating adjustment of said shaft and
rotor relative to said interior frusto-conical wall, to maintain a
predetermined radial clearance between said rotor and internal
frusto-conical wall for the length of the frusto-conical wall of
said rotor,
said rotor having at least one constant width helical channel
extending along the conical wall portion thereof from the inlet to
the outlet end thereof, the base of said channel extending along a
uniform thread angle at a different angle than the angle of said
conical wall portion and converging toward said conical wall
portion at the large diameter end of said rotor, and thereby
varying in cross section from the inlet to the outlet end of said
rotor according to the radius of said rotor, to maintain a constant
fluid drag as the fluid progresses from the inlet to the outlet of
said rotor.
2. The drag pump of claim 1, wherein the means mounting said shaft
on said bearings comprise sleeves secured to said bearings and held
from axial movement thereby,
a keyed connection between said shaft and one of said sleeves for
rotating said sleeve with said shaft, and
an adjustable connection between the opposite end of said shaft and
its associated sleeve accommodating axial adjustment of said shaft
relative to said sleeve to take up clearance between said stator
and said interior frusto-conical wall.
3. The drag pump of claim 2,
wherein the adjustable connection between one sleeve on said shaft
comprises a threaded connection, and
wherein means are provided for locking said shaft in adjusted
relation relative to said sleeve.
4. The drag pump of claim 1,
wherein two continuous helical channels spaced 180.degree. apart
extend along said rotor from the inlet to the outlet end thereof to
effect a balance of the changes in pressure as fluid progresses
along said channels, and
wherein the channels are of a constant width and decreasing depth
as they progress to the outlet end of said rotor.
Description
THE FIELD OF THE INVENTION
This invention relates generally to low capacity high pressure
rotary pumps.
BACKGROUND, SUMMARY AND OBJECTS OF INVENTION
The pump of the present invention operates on the principles of a
dynamic shaft seal in which a shaft is provided with square threads
on its end to be sealed, which threaded end rotates within a closed
chamber. The effectiveness of the seal is directly dependent upon
the radial clearance and the pressure delivered is inversely
proportional to the square of the radial clearance. While such
seals generate high pressure and are in effect a pump operating
against a shut-off condition, it has not been possible to provide a
means for compensating for wear or for reducing the clearance
between the rotor and stator to maintain the efficiency required by
a high pressure pump. As is evident from the above relationship, an
increase in radial clearance, as would occur with wear, rapidly
reduces the pressure available.
The present invention utilizes but improves upon the features of
the dynamic seal, in that it places the channels or threads at an
angle, which matches a corresponding stator angle. The rotor may
thus be a cone or the frustum of a cone. Axial adjustment means are
provided to axially adjust the rotor relative to the conical wall
of the stator, to enable the clearance between the rotor and stator
to be controlled. The rotor may thus be operated with very close
clearances between the rotor and stator wall and the centrifugal
force created by the increasing diameter of the rotor from its
inlet to its outlet adds a pressure component to the pressure
attained by the drag of the fluid along the walls of the
channel.
The pump, therefore, operates on the principle of maintaining a
constant slip velocity between channel walls of the rotor and the
fluid, in which the channel depth varies, so that the velocity of
the fluid changes in accordance with the peripheral velocity of the
channel walls of the rotor.
A principal object of the present invention is to provide a more
efficient and practical high pressure low capacity pump by the use
of a conical channeled rotor having close clearance with the
conical wall of a stator.
A further object of the invention is to provide a novel and
improved form of low volume high pressure rotary pump of the
truncated conical type, in which the pressure available is a
combination of that produced by the hydraulic drag and the
centrifugal action on the fluid resulting from the increase in
peripheral speed of the rotor due to the change in radius of the
truncated conical rotor of the pump.
A further object of the invention is to provide a simplified form
of pump having a conical rotor cooperating with a frusto-conical
stator with helical channels extending along the rotor, in which
the bases or roots of the channels are formed along a different
angle than the angle of the rotor, to provide a constant volume of
fluid in the passageways from the inlet to the discharge end of the
pump with a substantially constant hydraulic drag as the fluid
progresses from the inlet to the outlet end of the rotor.
A still further object of the invention is to utilize a conical
drag pump in place of the conventional positive displacement
reciprocating pump for attaining a high pressure, by providing a
frusto-conical rotor having at least one helical channel extending
therealong from the inlet to the outlet end of the rotor, in which
the efficiency of the pump is maintained by the reduction in
clearance between the rotor and stator wall, and the clearance may
be controlled within fine limits by axially adjusting the rotor
relative to the stator wall.
A further improvement is the use of two or more helical channels,
arranged so that radial hydraulic balance exists, thus permitting
an extremely close operating clearance between the rotor and
stator.
Other objects, features and advantages of the invention will be
readily apparent from the following description of a preferred
embodiment thereof, taken in conjunction with the accompanying
drawings, although variations and modifications may be effected
without departing from the spirit and scope of the novel concepts
of the disclosure.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view taken through a pump
constructed in accordance with the principles of the present
invention, with the rotor shown in solid;
FIG. 2 is a sectional view taken substantially along line II--II of
FIG. 1;
FIG. 3 is a sectional view taken substantially along line III--III
of FIG. 1; and
FIG. 4 is a diagrammatic view illustrating the difference between
the cone angle and thread angle at the base of the channels,
compensating for increased drag velocity and increased diameters
and peripheral speed from the inlet to the outlet end of the
rotor.
DESCRIPTION OF A PREFERRED EMBODIMENT OF INVENTION
In the embodiment of the invention illustrated in the drawings, I
have shown in FIG. 1, a conical drag pump 10 including a housing 11
having a frusto-conical interior wall portion 12 forming a pumping
chamber and cooperating with a frusto-conical rotor 13 to produce a
high pressure of the fluid as discharged through the outlet of the
pump. An inlet chamber 14 is provided at the small diameter end of
the frusto-conical wall portion 12 and is shown as having an inlet
pipe 15 leading therein. An outlet chamber 16 is provided at the
large diameter end of the frusto-conical wall portion 12 and is
shown as having an outlet pipe 17 leading therefrom. The housing 11
is supported on feet 19, which may be bolted or otherwise secured
to a conventional foundation or base (not shown).
The outlet chamber 16 is closed by a detachable end cap 20,
suitably sealed thereto and removable to afford access to the
frusto-conical wall 12, to accommodate machining thereof and
assembly of the rotor 13 and a rotor shaft 21 within said housing
with the wall of said rotor in close clearance with the internal
frusto-conical wall 12.
The end cap 20 has a wall portion 22, closing the outlet end of the
housing, and having a cup-like boss 23 extending outwardly
therefrom. The cup-like boss 23 contains packing 24, contained to
said cup-like boss as by an adjustable gland nut 25 threaded in
said boss. The end cap 20 also has a pair of bracket arms 27
extending axially outwardly therefrom. The bracket arms 27 may be
formed integrally with the end cap 20 and are spaced apart to
afford access to the gland nut 25, to take up on the packing 24.
The bracket members 27 form a support at their outer ends for a
bearing boss 29 for an anti-friction bearing 30. The bearing 30 is
shown as retained against a shouldered portion of said bearing boss
as by a snap ring 31.
The bearing 30 may be a conventional form of ball bearing and has
an inner race 32 mounted on a sleeve 33 and retained against a
shouldered portion 34 of said sleeve as by a retainer nut 35
threaded on the outer end of said sleeve and suitably locked
thereto. The shaft 21 has a reduced diameter outer end portion 36
extending through the sleeve 33, with a close sliding fit extending
outwardly therefrom. The sleeve 33 may be feather keyed on the
reduced diameter end of the shaft 36 and sufficient clearance may
be provided between said shaft and the sleeve 33 to accommodate
axial movement of said shaft relative to said sleeve when taking up
on clearance between the frusto-conical wall 12 and frusto-conical
face of the rotor 13. The reduced diameter end portion 36 of the
shaft 21 is shown as having a coupling 37 mounted thereon, coupling
said shaft to a suitable motor (not shown) for driving said shaft
and the rotor 13. The coupling 37 may be of a conventional form, of
a type which will permit some axial movement of the shaft 21
relative to the motor shaft upon adjustment of clearance between
the rotor and the frusto-conical wall 12, and which will also
compensate for temperature changes. It should be understood that
the coupling 37 may be at either end of the shaft, although the
present location of said coupling is preferred to facilitate axial
adjustment of said shaft and the rotor 13 relative to the
frusto-conical wall 12.
The opposite end of the shaft 21 from the coupling 37 extends
through the inlet chamber 14 and is sealed by packing 39 contained
within a cup-like retainer 40 extending outwardly of the inlet end
wall portion of the housing 11. The packing 39 may be taken up by a
gland nut 41 threaded within the interior wall portion of said
cup-like retainer 40.
A bearing boss 43 is spaced outwardly of the packing nut 41 and is
supported by integrally formed bracket arms 44, extending axially
outwardly of the inlet end of the housing 11 and shown as being
formed integrally with said housing. The spaced bracket arms 44,
like the bracket arms 27, afford access to the gland nut 41, to
accommodate adjustment of the packing 39.
The end of the shaft 21 extending outwardly of the gland nut 41 has
a reduced diameter portion 45 having sliding fit with a bearing
sleeve 46, for a bearing 47 mounted in the bearing boss 43. The
bearing 47 may be a suitable form of anti-friction bearing, such as
a ball bearing and is shown as retained against an inner shouldered
position of the bearing boss 43, as by a snap ring 48.
The sleeve 46 has an inner flanged portion 49 forming a shoulder
abutted by an inner race 50 of the bearing 47. A nut 51 threaded on
said sleeve is provided to lock said inner race to said sleeve and
against the shoulder formed by the flange 49.
The outer end portion of the sleeve 46 is internally threaded, and
is threaded on a reduced diameter outer end portion 53 of the shaft
21. A lock nut 55 locks said sleeve to said shaft to effect
rotation of said sleeve upon rotation of said shaft. The threaded
end portion 53 of the shaft 21 may have opposite flat faces, one of
which is indicated by reference numeral 56, to accommodate axial
adjustment of said shaft relative to the sleeve 46 by loosening the
lock nut 55 and holding the shaft from rotation by a wrench
engaging the flat portions 56 thereof, and then turning the sleeve
46 along said shaft, to achieve the desired radial clearance
between the face of the rotor 13 and the interior cylindrical wall
12.
The rotor 13 may be keyed or otherwise secured to the shaft 21 and
is held on said shaft by a split or snap ring 57 snapped on said
shaft and engaging the small diameter end of the rotor 13, and by a
washer 59 abutting the large diameter end of said rotor, and held
thereto as by a nut 60 threaded on said shaft and suitably locked
thereto.
The rotor 13 has at least one helical channel 61 cut or otherwise
formed therein and leading from the inlet to the outlet end of said
rotor. As shown in FIGS. 1 and 3, two diametrically opposed
channels are shown as being in the form of double square threads,
each of which threads or channels have a root or base 63 and
parallel side walls 64. The channels, however, need not necessarily
be formed like square threads but may have rounded bases or may be
of various other forms.
While I have shown two helical channels herein, it should be
understood that the pump is not restricted to one or two helical
channels but that the rotor may have three or more helical
channels, provided they are spaced equal distances apart to effect
a balance of the changes in pressure as fluid progresses along the
channels to the discharge end of the pump.
In order to compensate for the increasing diameter of the rotor
from the inlet to the outlet thereof, the channels 61 are cut at a
different angle from that of the rotor. As for example, in FIG. 4,
this angle is diagrammatically illustrated by reference character A
and the angle of the frusto-conical face of the rotor is designated
by reference character B. The difference in cone angle from the
thread angle thus adjusts the geometry of the threads according to
the radius of the cone and the channels or threads 61 are of the
same width throughout the length of the cone. The depth, however,
decreases as the radius increases, to maintain a substantially
constant slip velocity between the passage walls of the rotor and
the fluid.
As previously mentioned, the pressure obtainable by the pump is
basically due to the drag of the fluid along the walls of the
channel, and the decreasing depth of the channel as it approaches
its discharge end adjusts the geometry according to the radius to
provide a constant hydraulic drag, as the fluid progresses from the
inlet to the outlet end of the rotor.
The pressure generated from the present truncated conical drag
pump, therefore, is a combination of that produced by a dynamic
seal and the centrifugal force resulting from the increase in
peripheral speed due to the increasing radius of the truncated
conical rotor from its inlet to its discharge end.
The pressure produced by the unit is, therefore, controllable by
the rotative speed of the rotor, the thread diameter and the thread
length and the pressure obtainable is exponentially dependent upon
close radial clearance between the periphery of the rotor and
internal frusto-conical wall of the stator, which can be adjusted
and maintained by holding the shaft 21 stationary and turning the
sleeve 46 along the threaded end portion of the shaft and then
locking the sleeve to the shaft by the lock nut 55.
It should be understood that while I herein show the channels cut
at a different angle from that of the face of the cone, and show
what are in effect square threads, that the channel may be cut in
the same angle as the cone angle and the desired thread geometry
may be attained by varying the width or shape of the channels from
the inlet to the outlet end of the rotor.
* * * * *