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Claims  |
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I claim:
1. A valveless, double acting, positive displacement fluid transfer device,
comprising:
a rotary shaft having a first end and an opposite second end, with said
second end having a radial arm affixed thereto and extending therefrom;
said radial arm having a distal end including a spherical bearing shell
having a spherical bearing therein;
a single plunger adapted to rotate and reciprocate simultaneously within a
corresponding single cylinder, with said plunger having a plunger rod end
with a concentric plunger rod extending therefrom, an opposite distal end,
and a lateral surface closely and sealingly fitting within said cylinder;
said plunger further having an internal first fluid passage extending from
said plunger rod end through a first opening in said lateral surface, and
a separate second fluid passage extending from said distal end through a
second opening in said lateral surface, with said first opening and said
second opening being diametrically opposite one another;
said cylinder having a lateral cylinder wall including a first port and a
second port therethrough, with said first port and said second port being
in coaxial alignment;
said plunger, said plunger rod, and said cylinder being angularly offset
from said rotary shaft, and;
said plunger rod including a distal end having a bearing pin affixed
thereto and extending radially therefrom, with said bearing pin having a
distal end to which said spherical bearing is secured, whereby;
said plunger rotates with said rotary shaft as said rotary shaft revolves,
and simultaneously reciprocates by means of said angular offset between
said plunger and said rotary shaft, with said first opening and said
second opening of said plunger alternatingly communicating with said first
port and said second port of said cylinder with each reciprocating stroke
of said plunger within said cylinder, to provide a double action of said
fluid transfer device and positive displacement by means of said sealingly
fitted plunger within said cylinder and said separate first and second
internal fluid passages within said plunger.
2. The fluid transfer device according to claim 1, wherein:
said fluid transfer device comprises a motor, with motor operation provided
by means of differential fluid pressure between said first port and said
second port of said cylinder.
3. The fluid transfer device according to claim 1, including:
a rotational speed differential device connected to said first end of said
rotary shaft.
4. The fluid transfer device according to claim 1, including:
a single dynamic seal disposed about said plunger rod and captured within a
cylinder base plate through which said plunger rod passes, and a single
static seal disposed between said cylinder and said cylinder base plate.
5. The fluid transfer device according to claim 1, wherein:
at least said cylinder and said plunger are formed of plastic material.
6. The fluid transfer device according to claim 1, wherein:
said fluid transfer device comprises a pump, with said rotary shaft being
driven by a motor connected to said first end thereof.
7. The fluid transfer device according to claim 6, wherein:
said motor comprises a direct current electric motor, and reverse rotation
of said pump is precluded by means of a diode installed in series with
said motor.
8. A valveless, double acting, positive displacement fluid transfer device,
comprising:
a rotary shaft having a first end and an opposite second end, with said
second end having a radial arm affixed thereto and extending therefrom;
said radial arm having a distal end including a spherical bearing shell
having a spherical bearing therein;
said bearing shell comprising a first and a separate second portion, with
each said bearing shell portion being substantially equal and symmetrical
to one another;
a single plunger adapted to rotate and reciprocate simultaneously within a
corresponding single cylinder, with said plunger having a plunger rod end
with a concentric plunger rod extending therefrom, an opposite distal end,
and a lateral surface closely and sealingly fitting within said cylinder;
said plunger further having at least two fluid passages incorporated
integrally therewith;
said cylinder having a lateral cylinder wall including a first port and a
separate second port therethrough;
said plunger, said plunger rod, and said cylinder being angularly offset
from said rotary shaft, and;
said plunger rod including a distal end having a bearing pin affixed
thereto and extending radially therefrom, with said bearing pin having a
distal end to which said spherical bearing is secured within said first
and said second bearing shell portion, whereby;
said plunger rotates with said rotary shaft as said rotary shaft revolves,
and simultaneously reciprocates by means of said angular offset between
said plunger and said rotary shaft, with said at least two fluid passages
of said plunger alternatingly directly communicating with said first port
and said second port of said cylinder with each reciprocating stroke of
said plunger within said cylinder, to provide a double action of said
fluid transfer device and positive displacement by means of said sealingly
fitted plunger within said cylinder and said at least two fluid passages
within said plunger, with each said bearing shell component providing for
ease of manufacture, assembly, and disassembly of said device as required.
9. The fluid transfer device according to claim 8, wherein:
said spherical bearing shell is diametrically split to form said first and
said second portion thereof.
10. The fluid transfer device according to claim 8, wherein:
said spherical bearing shell is axially split to form said first and said
second portion thereof.
11. The fluid transfer device according to claim 8, wherein:
said fluid transfer device comprises a pump, with said rotary shaft being
driven by a motor connected to said first end thereof.
12. The fluid transfer device according to claim 8, wherein:
said fluid transfer device comprises a motor, with motor operation provided
by means of differential fluid pressure between said first port and said
second port of said cylinder.
13. The fluid transfer device according to claim 8, including:
a single dynamic seal disposed about said plunger rod and captured within a
cylinder base plate through which said plunger rod passes, and a single
static seal disposed between said cylinder and said cylinder base plate.
14. The fluid transfer device according to claim 8, wherein:
at least said cylinder and said plunger are formed of plastic material.
15. The fluid transfer device according to claim 8, including:
a bearing enclosure disposed about said spherical bearing and said bearing
shell, with said enclosure providing a lubrication pocket for said bearing
and said bearing shell.
16. The fluid transfer device according to claim 15, including:
a lubrication supply fitting disposed through said bearing enclosure and
communicating with said lubrication pocket, with said fitting providing
for the replenishment of lubrication means within said pocket as required.
17. A valveless, double acting, positive displacement fluid transfer
device, comprising:
a rotary shaft having a first end and an opposite second end, with said
second end having a radial arm affixed thereto and extending therefrom;
said radial arm having a distal end including a spherical bearing shell
having a spherical bearing therein;
a single plunger adapted to rotate and reciprocate simultaneously within a
corresponding single cylinder, with said plunger having a plunger rod end
with a concentric plunger rod extending therefrom, an opposite distal end,
and a lateral surface closely and sealingly fitting within said cylinder;
a cylinder base plate to which said cylinder is affixed, with said cylinder
base plate including a plunger rod passage therethrough;
said plunger rod passage of said cylinder base plate including a dynamic
seal captured therein by means of a negative draft seal retainer formed
integrally with said cylinder base plate, wherein said seal retainer
includes a seal groove and a seal retaining lip, with said seal groove
having a larger diameter than said seal retaining lip;
said plunger further having at least two fluid passages incorporated
integrally therewith;
said cylinder having a lateral cylinder wall including a first port and a
separate second port therethrough;
said plunger, said plunger rod, and said cylinder being angularly offset
from said rotary shaft, and;
said plunger rod including a distal end having a bearing pin affixed
thereto and extending radially therefrom, with said bearing pin having a
distal end to which said spherical bearing is secured, whereby;
said plunger rotates with said rotary shaft as said rotary shaft revolves,
and simultaneously reciprocates by means of said angular offset between
said plunger and said rotary shaft, with said at least two fluid passages
of said plunger alternatingly directly communicating with said first port
and said second port of said cylinder with each reciprocating stroke of
said plunger within said cylinder, to provide a double action of said
fluid transfer device and positive displacement by means of said sealingly
fitted plunger within said cylinder and said at least two fluid passages
within said plunger, with said plunger rod being sealed within said
plunger rod passage of said cylinder base plate by means of said negative
draft seal retainer and said seal captured therein.
18. The fluid transfer device according to claim 17, wherein:
said fluid transfer device comprises a pump, with said rotary shaft being
driven by a motor connected to said first end thereof.
19. The fluid transfer device according to claim 17, wherein:
said fluid transfer device comprises a motor, with motor operation provided
by means of differential fluid pressure between said first port and said
second port of said cylinder.
20. The fluid transfer device according to claim 17, wherein:
at least said cylinder, said plunger, and said cylinder base plate are
formed of plastic material. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to pumps, motors, and the like
using hydraulic or other fluid as a medium, and more specifically to
various improvements in such a device having an angularly offset axis
providing for simultaneous rotation and reciprocation of a positive
displacement plunger. The improvements comprise various means providing
for economy of manufacture, such as a split race for the spherical bearing
incorporated therein and a negative draft casting for the seals thereof,
as well as means providing for greater durability, such as a lubrication
reservoir for the spherical bearing incorporated.
2. Description of the Prior Art
Positive displacement hydraulic pumps and motors using the principle of an
angularly offset rotary axis to cause a piston or plunger to rotate and
reciprocate simultaneously, have been known for some time. While
development of such devices has continued, they nevertheless have various
limitations relating to durability, reliability, cost, and ease of
manufacture, particularly in such devices primarily adapted for smaller
jobs and portability.
Generally in the past, the response to any such limitations has been to
attack the problem from one end or the other, i. e., either the durability
aspect or the cost aspect. Increases in durability have been achieved by
using materials and components which are more difficult to machine and
manufacture (e.g., stainless steels as opposed to softer metals and
plastics), thus driving up costs, or to provide relatively inexpensive
materials and manufacturing methods, thus reducing costs, but resulting in
a decrease in durability and reliability. However, these two aspects are
not necessarily completely mutually exclusive, as shown by the present
fluid transfer device. A discussion of the limitations of the prior art,
particularly in comparison with the present invention, is presented
immediately below.
U.S. Pat. No. 1,147,116 issued to Budd G. Nice on Jul. 20, 1915 describes a
Ball Bearing incorporating a diametrically split race. The race is not
adaptable for use with a single spherical bearing, as it is not
symmetrical, and even if machined for a spherical bearing, the wider
portion could not be installed over the major diameter of the spherical
bearing. The present invention provides for this with two symmetrical
diametric spherical bearing race halves, which sandwich the single
spherical bearing therein. A ball bearing configuration could not be
applied to the device, as ball bearings require accurate axial alignment
between rotating and fixed components at all times, whereas the angularly
offset axis of the present device requires a spherical bearing to allow
for the variation in alignment during each revolution.
U.S. Pat. No. 1,300,450 issued to Fred S. Morton on Apr. 15, 1919 describes
a Ball Bearing having a diametrically and symmetrically split outer race,
with a sleeve surrounding the two race halves to secure them together.
However, Morton provides only a conical surface for his bearing race
halves, as no use with other than plural ball bearings is anticipated. A
plurality of smaller spherical ball bearings contained within an outer
bearing race having conical surfaces, would provide only two contact
points in the outer race for each ball. The present split bearing race or
housing comprises a spherical concavity, closely fitting the corresponding
single spherical bearing therein, and thus reducing the contact pressure
at any given point. Further, the Morton bearing cannot tolerate
misalignment, as provided by the present spherical bearing.
U.S. Pat. No. 1,312,962 issued to George J. Dourte on Aug. 12, 1919
describes a Valveless Pump providing double action, but the mechanism
involves a crankshaft and bevel gear arrangement, in which an upper
connecting rod is reciprocated by the crankshaft and rotated by the bevel
gears. As the angle between the plunger rod and the connecting rod is
continually changing, an additional pivotable connection must be provided
between the two, as opposed to the fixed angular offset of the present
fluid transfer device which allows the offset arm to be rigidly affixed to
the plunger rod, thus providing a more durable mechanism. Moreover, Dourte
does not provide additional volume in each end of his plunger, as provided
by the present invention, for greater capacity.
U.S. Pat. No. 1,340,310 issued to George Wolff on May 18, 1920 describes an
Antifriction Bearing comprising an axially split ball bearing race and
cage, adapted for installation about a monolithic cylindrical crankshaft
journal or the like. The spherical bearing housing of the present
invention may be either axially split or diametrically split, but in
either case, is adapted to fit closely about a single spherical bearing
end to allow for the substantial axial misalignment between the shaft of
the spherical bearing and the housing, as the alignment changes with each
revolution of the angularly offset axis of the device. The axially split
ball bearing race and cage of the Wolf patent cannot provide for any
significant misalignment between the relatively stationary bearing block
and rotating journal.
U.S. Pat. No. 1,927,466 issued to David B. Menton on Sep. 19, 1933
describes a Ball Bearing having a diametrically split outer race and a
single piece inner race. While such construction provides complete
enclosure for the plurality of bearing balls enclosed in the toroidal race
therein, the single piece inner race cannot be separated for installation
about a journal, as provided by other devices discussed above. In any
case, the Menton bearing assembly is more closely related to those other
devices with their plural bearing balls or spheres than to the present
single spherical bearing, and cannot be adapted for use with the single
spherical bearing of the present invention, or to allow for the cyclic
axial alignment variation which occurs as a result of operation of the
present device.
U.S. Pat. No. 1,967,821 issued to Donald P. Hess on Jul. 24, 1934 describes
a Process Of Making Raceway Members for cylindrical or conically tapered
roller bearings. The raceway members are formed by making rings of flat
stock, and welding the ends of each ring together to make a closed
raceway. The resulting closed cylindrical form is then processed and
machined conventionally to form a conventional, closed bearing race. While
various alternative configurations are disclosed for the blanks, they are
all welded closed in the manufacturing process. Hess does not disclose any
finished bearing races which are split in any way, as provided by one of
the features of the present invention.
U.S. Pat. No. 3,168,872 issued to Harry E. Pinkerton on Feb. 9, 1965
describes a Positive Displacement Piston Pump in which at least one
embodiment, functions similarly to the present fluid transfer device.
However, numerous differences are noted. The piston or plunger of the
Pinkerton pump is externally slotted, rather than having internal passages
as in the present invention. While double action is provided, such is only
possible using a double cylinder with the plunger having two working ends.
Also, the spherical connector between the pump drive motor and the
angularly offset plunger rod is installed through the wall of a cup-like
component; no sealing of any lubricant around the spherical bearing is
provided, nor is any means for lubricating the fitting disclosed. Further,
any fluid leakage past the end of the cylinder is free to flow to the
external environment, and no sealing means between plunger or rod and
cylinder bore is disclosed.
U.S. Pat. No. 3,266,432 issued to Stewart W. Wortley on Aug. 16, 1966
describes a Pump having a single cylinder with a piston centrally located
therein. A valve is positioned on each side of the piston, with each valve
alternatingly covering and uncovering an intake and a discharge port.
Reciprocation of the piston is accomplished by an angularly adjustable
swash plate, rather than an angularly offset arm, as in the present
invention. The device is equivalent to a two cylinder pump, with the
single piston alternatingly reciprocating through the central bore of the
single cylinder in each direction. While the Wortley pump is double
acting, it requires the equivalent action of two cylinders in order to
function in such a manner, and the complexity of separate valves which
rotate and reciprocate with the piston and rod.
U.S. Pat. No. 3,447,468 issued to Walter E. Kinne on Jun. 3, 1969 describes
a Metering Pump which functions somewhat along the lines of the device of
the patent to Wortley discussed immediately above. Kinne, however,
provides an elongated and slotted piston or plunger which also acts as a
valve means as well as separating the two ends of the cylinder. A
pressurized fluid is applied to one end of the cylinder through radially
disposed ports, which provides reciprocation of the piston as it rotates,
thereby causing a pumping action of fluid through the opposite end of the
cylinder. Rather than using fluid means to reciprocate the plunger, the
present invention utilizes mechanical means with an angularly offset arm.
U.S. Pat. No. 3,597,819 issued to Hudson B. Scheifele on Aug. 10, 1971
describes a Method Of Making A Composite Tapered Roller Bearing Race. The
method is similar to that disclosed in the patent to Hess, discussed
further above, in that two pieces of straight bar stock are rolled to form
two semicircles and the ends welded together and smoothly finished to form
a cylindrical bearing race. Scheifele provides only completely circular
races, and does not disclose the use of split races (either diametrically
or axially) in a completed bearing. In any case, the stock used by
Scheifele would require further machining, in order to be compatible with
a single spherical bearing as used in the present invention.
U.S. Pat. No. 4,008,003 issued to Harry E. Pinkerton on Feb. 15, 1977
describes a Valveless Positive Displacement Pump similar to that disclosed
in his earlier '872 patent. However, Pinkerton recognizes the desirability
of providing equal volumes at each end of the cylinder for any given
respective positioning of the piston or plunger therein, and provides an
idler rod which extends through the opposite end of the cylinder from the
drive rod in order to displace a volume equal to that of the drive rod.
This results in further complexity, in that additional sealing around the
idler rod is required. While the volumes at each end of the double acting
plunger of the present invention may not be precisely equal due to the
single rod extending from one end of the plunger, the sealing of the
present apparatus is considerably more reliable than the multiple seals
required of the Pinkerton device.
U.S. Pat. No. 4,067,668 issued to Erik A. Nimell on Jan. 10, 1978 describes
a Valveless Rotary-Oscillating Double-Acting Piston Pump. The pump
comprises a cylinder with opposite closed ends having oblique internal
surfaces, and a plunger installed therein with complementary oblique end
surfaces and opposite passages communicating with opposed side ports in
the cylinder. As the plunger is rotated, the ends ride against the oblique
internal ends of the cylinder to force the plunger to reciprocate
simultaneously, thereby alternatingly changing the volume at each end and
producing a double acting pumping action. While the device is exceedingly
simple, it nevertheless relies upon an internal axially sliding coupling
between the motor shaft and the plunger, as well as the sliding of the
plunger within the cylinder bore. The relatively small diameter rod seal
and spherical bearing of the present device appear to provide lower
friction and better sealing.
U.S. Pat. No. 4,941,809 issued to Harry E. Pinkerton on Jul. 17, 1990
describes a Valveless Positive Displacement Metering Pump. the device is
similar to those disclosed in the same patentee's earlier '872 and '003
patents, but includes an angularly adjustable table to adjust the angular
offset between the drive motor and the pump cylinder and plunger.
Reversibility is provided by swinging the cylinder and plunger axis from
one offset side to the other, thereby reversing the intake and outlet
ports of the cylinder when the plunger is respectively in compression and
expansion strokes. In any case, the same distinctions between this device
and the present invention apply, as discussed further above.
U.S. Pat. No. 5,074,767 issued to C. Richard Gerlach et al. on Dec. 24,
1991 describes a Positive Displacement Pump With Rotating Reciprocating
Piston And Improved Lubrication Feature. The single plunger has a single,
central bore which communicates with a single lateral passage in the
plunger. An inlet and an opposite outlet port are disclosed, but due to
the single passage and central bore, the Gerlach et al. device is only
single acting, and has no double action. Thus, when fluid is being
expelled from the outlet port, no fluid is flowing into the inlet port,
and vice versa. The present device provides for simultaneous inlet and
outlet flow, due to the separate inlet and outlet passages and sides of
the single plunger. Also, while Gerlach et al. disclose a lubrication
pocket for the bearing, no means is provided to add grease to the pocket,
without disassembly of the pump.
U.S. Pat. No. 5,246,354 issued to Guillermo P. Pardinas on Sep. 21, 1993
describes a Valveless Metering Pump With Reciprocating, Rotating Piston.
The cylinder includes a single inlet port and two outlet ports, with the
three ports being radially spaced apart about the cylinder. The single
plunger includes a single relief on one side, which alternatingly
communicates with the ports. The advantage of the Pardinas device is that
the timing between the relief and the ports may be adjusted to provide
accurate metering of fluid from the pump. However, the single relief of
the plunger provides only a single acting pump, with the inlet function
being idle when fluid is passing through the outlet port(s), and vice
versa.
Finally, U.S. Pat. No. 5,287,623 issued to Thomas M. Francis et al. on Feb.
22, 1994 describes a Bearing Split Outer Ring And Method Of Assembly. The
disclosure is directed to an axially split housing or race for use with
plural individual bearing units (balls, rollers, etc.) and cannot be
adapted to a single spherical bearing, as the outer race or housing is
specifically divided axially into two unequal parts. The larger of the two
components subtends an arc of greater than 180 degrees, and thus cannot be
fit around a single spherical bearing. The problem is similar to that of
the '116 patent to Nice discussed initially, in that asymmetrical bearing
shells are disclosed in both patents. Nice, however, uses a diametrically
split shell, whereas Francis et al. uses an axially split shell. Neither
is adaptable for use with a single spherical bearing, as noted above.
None of the above inventions and patents, taken either singly or in
combination, is seen to describe the instant invention as claimed.
SUMMARY OF THE INVENTION
Accordingly, it is a principal object of the invention to provide an
improved valveless, double acting, positive displacement fluid transfer
device which may be driven by power means to serve as a pump, or which may
alternatively be driven by hydraulic or other liquid or fluid to serve as
a fluid driven motor.
It is another object of the invention to provide an improved fluid transfer
device which utilizes a single plunger, working in a single cylinder, to
provide an inlet pulse and an outlet pulse with every plunger expansion
and compression stroke to provide for double action of the device.
It is a further object of the invention to provide an improved fluid
transfer device which plunger includes two separate internal passages
therethrough for inlet and discharge functions.
An additional object of the invention is to provide an improved fluid
transfer device which utilizes a spherical bearing between the radial arm
of the motor or pump assembly and the angularly offset radial arm of the
plunger assembly, and which may utilize a split bearing housing and/or
lubrication pocket for the bearing, respectively for greater economy of
manufacture and durability.
Still another object of the invention is to provide an improved fluid
transfer device which plunger shaft seal retaining means may be formed
using a negative draft process for greater economy of manufacture.
It is an object of the invention to provide improved elements and
arrangements thereof in an apparatus for the purposes described which is
inexpensive, dependable and fully effective in accomplishing its intended
purposes.
These and other objects of the present invention will become readily
apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view in section of the present valveless, double
acting, positive displacement fluid transfer device, showing the internal
arrangement of components and their structural details.
FIG. 2 is an elevation view in section of one plunger embodiment of the
present fluid transfer device, showing the arrangement of the separate
internal fluid passages therein.
FIG. 3A is an elevation view of an alternative embodiment plunger adaptable
for use with the present fluid transfer device.
FIG. 3B is a bottom plan view of the plunger of FIG. 3A.
FIG. 4A is an elevation view of another alternative embodiment plunger
adaptable for use with the present fluid transfer device.
FIG. 4B is a bottom plan view of the plunger of FIG. 4A.
FIG. 5 is an exploded perspective view of a spherical bearing embodiment
and retaining means of the present invention, using a diametrically split
bearing shell and threaded retainer.
FIG. 6 is an exploded perspective view of a spherical bearing embodiment
and retaining means of the present invention, using an axially split
bearing shell and snap ring retainer.
FIG. 7 is an electrical schematic of one means which may be incorporated to
prevent reverse operation of the present device when used as a pump and
driven by a dc electric motor.
Similar reference characters denote corresponding features consistently
throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now particularly to FIG. 1 of the drawings, the present invention
will be seen to relate to a valveless, double acting, positive
displacement fluid transfer device 10 which may be used as a pump to
transfer fluid when driven by a prime mover (i. e., combustion engine,
pneumatic or other fluid motor, electric motor, etc.), or which may
alternatively be used as a motor itself when supplied with fluid under
differential pressure between an inlet and an outlet port. T | | |
