Compact pump with reduced vibration and reduced thermal degradation

Abstract

A positive displacement reciprocating multi-cylinder pump has a pair of cams and associated bearings and yokes that cooperatively and positively reciprocate the pistons. The fluid flow paths are configured through specially designed intake and outlet manifolds to provide intrinsic cooling of the bearings through specially configured fluid flow paths at distal ends of the pump. An intentional head geometry that is identical for each piston may be readily machined using exterior bores. Each head defines a cylinder, captures both inlet and outlet one-way valves, and provides essential fluid flow paths about the cylinders. All bearings are of the sealed type, and no additional oil baths or the like are required, permitting the pump to be stored, transported, and used in any orientation.

Claims

1. A pump body comprising: a fluid intake manifold having internal fluid inlet conduits; a first rotary drive shaft bearing affixed to said fluid intake manifold; a fluid outlet manifold having internal fluid outlet conduits; a second rotary drive shaft bearing affixed to said fluid outlet manifold; a plurality of heads, each individual one of said plurality of heads defining a piston cylinder and defining a fluid flow path coupling with a one of said internal fluid inlet conduits and a one of said internal fluid outlet conduits, each individual one of said plurality of heads affixed to the fluid intake and outlet manifolds; a rotary drive shaft passing entirely through a first one of said fluid intake manifold and said fluid outlet manifold; a first plurality of interconnected linear bores formed within and passing entirely through said first one of said fluid intake manifold and said fluid outlet manifold and defining a first one of said internal fluid inlet conduits and said internal fluid outlet conduits; a second plurality of interconnected linear bores formed within and passing entirely through a second one of said fluid intake manifold and said fluid outlet manifold and defining a second one of said internal fluid inlet conduits and said internal fluid outlet conduits; and a working fluid operatively flowing through each of said fluid inlet conduits, said fluid flow paths in each individual one of said plurality of heads, and said fluid outlet conduits and thereby cooling said first and second rotary drive shaft bearings; wherein said second plurality of interconnected linear bores comprise a pair of perpendicular bores, each one of said pair of perpendicular bores formed within and passing entirely through said second one of said fluid intake manifold and said fluid outlet manifold; and wherein said second one of said fluid intake manifold and said fluid outlet manifold further comprises a fluid port formed within said second one of said fluid intake manifold and said fluid outlet manifold and passing from an exterior of said second one of said fluid intake manifold and said fluid outlet manifold to an intersection between each one of said pair of perpendicular bores and extending longitudinally at an angle intermediate between each one of said pair of perpendicular bores, said fluid port adapted to be in fluid communication with an external fluid conduit.

2. The pump body of claim 1, wherein said first plurality of interconnected linear bores further comprise first and second parallel bores and a third bore perpendicular to said first and second parallel bores, each of said first, second, and third bores formed within and passing entirely through said first one of said fluid intake manifold and said fluid outlet manifold.

3. The pump body of claim 2, further comprising a fluid port formed within said first one of said fluid intake manifold and said fluid outlet manifold and passing from an exterior of said first one of said fluid intake manifold and said fluid outlet manifold to at least one of said first plurality of interconnected linear bores, said fluid port adapted to be in fluid communication with an external fluid conduit.

4. The pump body of claim 2, further comprising: a first one-way valve juxtaposed at a junction between said first and third bores and said first one of said fluid intake manifold and said fluid outlet manifold; a second one-way valve juxtaposed at a junction between said second and third bores and said first one of said fluid intake manifold and said fluid outlet manifold; a third one-way valve juxtaposed at the end of said first bore distal to the said junction between said first and third bores; and a fourth one-way valve juxtaposed at the end of said second bore distal to the said junction between said second and third bores.

5. The pump body of claim 1, wherein each individual one of said plurality of heads further comprises: a unitary billet; at least four linear bores open on a first end and closed internally within said unitary billet on a second end distal to the first end; a first bore of said at least four linear bores defining a radial fluid inlet bore; a second bore of said at least four linear bores defining a radial fluid outlet bore; a third bore of said at least four linear bores defining a piston cylinder; and a fourth bore of said at least four linear bores passing through each of said first, second, and third bores and defining both a longitudinal fluid inlet bore and a longitudinal fluid outlet bore.

6. The pump body of claim 5, wherein each individual one of said plurality of heads further comprises a cap closing an exterior end of said fourth bore.

7. The pump body of claim 1, further comprising: a rotary drive shaft eccentric cam configured to rotate in an eccentric manner with a rotary drive shaft about a rotary drive shaft axis of rotation; first and second pistons reciprocating along a first piston axis radial to said rotary drive shaft axis of rotation, each of said first and second pistons having a yoke contact surface rigidly affixed thereto; third and fourth pistons reciprocating along a second piston axis radial to said rotary drive shaft axis of rotation and angularly offset from said first piston axis, each of said third and fourth pistons having a yoke contact surface rigidly affixed thereto; said first and second rotary drive shaft bearings, each having an inside race circumscribing said rotary drive shaft eccentric cam and an outside race circumscribing said inside race and rotating freely relative thereto; a first yoke circumscribing and rigidly coupled to said first and second piston yoke contact surfaces; and a second yoke circumscribing and rigidly coupled to said third and fourth piston yoke contact surfaces; said first bearing outside race coupled to said first and second piston yoke contact surfaces and configured to cause said first and second pistons to reciprocate when said rotary drive shaft eccentric cam is rotated about said rotary drive shaft axis of rotation; and said second bearing outside race coupled to said third and fourth piston yoke contact surfaces and configured to cause said third and fourth pistons to reciprocate when said rotary drive shaft eccentric cam is rotated about said rotary drive shaft axis of rotation.

8. The pump body of claim 1, wherein each of said fluid intake manifold and said fluid outlet manifold further comprises a unitary body.

9. The pump body of claim 5, wherein each of said fluid intake manifold and said fluid outlet manifold further comprises a unitary body.

10. The pump body of claim 1, further comprising at least one one-way valve within each said fluid flow path in said each individual one of said plurality of heads.

11. The pump body of claim 10, further comprising: a first one-way valve juxtaposed at a junction between said fluid intake manifold and an individual one of said plurality of heads; and a second one-way valve juxtaposed at a junction between said individual one of said plurality of heads and said fluid outlet manifold.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The foregoing and other objects, advantages, and novel features of the present invention can be understood and appreciated by reference to the following detailed description of the invention, taken in conjunction with the accompanying drawings, in which:

(2) FIG. 1 illustrates a preferred embodiment compact pump with reduced vibration and reduced thermal degradation designed in accord with the teachings of the present invention from a front elevational view.

(3) FIG. 2 illustrates the preferred embodiment compact pump of FIG. 1 from rear view.

(4) FIG. 3 illustrates the preferred embodiment compact pump of FIG. 1 from right side view.

(5) FIG. 4 illustrates the preferred embodiment compact pump of FIG. 1 from left side view.

(6) FIG. 5 illustrates the preferred embodiment compact pump of FIG. 1 from sectional view taken along line 5′ of FIG. 1.

(7) FIG. 6 illustrates the preferred embodiment compact pump of FIG. 1 from sectional view taken along line 6′ of FIG. 2.

(8) FIG. 7 illustrates the preferred embodiment compact pump of FIG. 1 from sectional view taken along line 7′ of FIG. 1.

(9) FIG. 8 illustrates the preferred embodiment compact pump of FIG. 1 from sectional view taken along line 8′ of FIG. 1.

(10) FIG. 9 illustrates the preferred embodiment compact pump from sectional view taken along line 9′ of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT

(11) In a preferred embodiment of the invention illustrated in the Figures, a compact pump 10 having reduced vibration and reduced thermal degradation is comprised of a motor coupler 200 and pump body 300. Motor coupler 200 may, for exemplary and non-limiting purposes, include a coupling body that may provide a motor connection sleeve that might incorporate any suitable apparatus that will conveniently or appropriately couple to a motor shaft. Exemplary are paired geometries, such as but not limited to a slotted sleeve so as to receive a keyed shaft and associated key, or a shaft having one or more flats that engage with features in the surrounding sleeve.

(12) Within pump body 300, adjacent a first end there is provided an intake manifold 321 illustrated in FIG. 5 having an inlet port 320 and four inlet conduits 326 in fluid communication therewith. Inlet port 320 will also operatively be in fluid communication to any suitable source fluid which is to be pumped as is known in the art. For exemplary and non-limiting purposes, and while not illustrated, an inlet hose may be threaded into or otherwise coupled with inlet port 320.

(13) In preferred embodiment compact pump 10, intake manifold 321 is formed from a solid block of aluminum or aluminum alloy which is drilled from the exterior to form inlet port 320 and each of the four inlet conduits 326. The drilling or other boring process will leave visible lines in the cross-sectional view of FIG. 5 at the intersection of inlet port 320 and each of the four inlet conduits 326, but it will be understood that these all are connected together to allow the flow of fluid in a relatively unrestricted manner at the intersection. While aluminum and alloys thereof are most preferred for the composition of intake manifold 321, owing to the good heat conductivity, easy machinability, relatively low cost, and high strength to weight ratio of aluminum and aluminum alloys, other suitable materials may be substituted in alternative embodiments.

(14) Each of the four inlet conduits 326 are coupled distally to inlet port 320 with one-way inlet valves 324. In preferred embodiment compact pump 10, a slightly larger diameter bore may be provided adjacent to the surface of intake manifold 321 to partially receive valves 324. In addition, an even shallower and larger diameter bore may further be provided to receive o-ring seals 325.

(15) As also visible from FIG. 5, intake manifold 321 has a cross-sectional geometry with an octagonal outer perimeter. While the exact geometry is not critical to the invention, the provision of four major flat surfaces 327 is most preferred. A head 302 is attached to each of these flat surfaces 327 using suitable fasteners, for exemplary and non-limiting purpose socket-head bolts 304 illustrated.

(16) Each head 302 is most preferably fabricated from the same material and dimension as every other. As with intake manifold 321, in preferred embodiment compact pump 10 the four heads 302 will most preferably be fabricated from a solid block or billet of aluminum or aluminum alloy which is drilled from the exterior to form a set of four radial inlet bores 307 and a set of four radial outlet bores 309 therein. Radial inlet bores 307 are aligned with and in fluid communication with one-way inlet valves 324.

(17) O-ring seals 325 prevent leakage in the fluid path between intake manifold 321 and each of the four heads 302. These o-ring seals 325 may in one embodiment, just prior to installing the heads 302 and tightening socket-head bolts 304 at the time of installation, be conveniently wrapped around the associated inlet valve 324. The elasticity of the o-rings will hold them in place, simplifying installation. Other installation techniques and sequences may be used in other alternative embodiments. As may be apparent then, the installation of a head 302 onto intake manifold 321 will simultaneously capture and secure the associated one-way inlet valves 324 and o-ring seals 325, again reducing the number of installation steps and thereby simplifying installation.

(18) Fluid passes from inlet port 320 through each of the four inlet conduits 326, through the associated one-way inlet valve 324 into radial inlet bores 307. From there, the fluid passes into the associated cylinder 312, which has also been drilled from the exterior of each head 302 in a direction radial to rotary drive shaft 220. The fluid is prevented from escaping from cylinder 312 by a combination of the associated piston 345-348 and piston seal ring 349. In preferred embodiment compact pump 10, the cylinder wall is bored at two diameters, with the portion more adjacent to rotary drive shaft 220 having a slightly larger diameter to accommodate piston seal ring 349. Nevertheless, other methods of sealing the piston and cylinder wall are known in the prior art incorporated herein above by reference and in the industry, and these other methods will be suitably used in alternative embodiments.

(19) A single bore is drilled or otherwise formed in each of the four heads 302 that simultaneously defines both the longitudinal inlet bore 308 and the longitudinal outlet bore 310. Each of these longitudinal bores 308 and 310 are longitudinally parallel to the longitudinal axis of rotary drive shaft 220. Visible in FIGS. 3, 4, and 9 are threaded socket-head plugs 306 that are used to close off the otherwise exteriorly exposed open end of the bore that defines these longitudinal inlet bores 308 and longitudinal outlet bores 310.

(20) When fluid is expelled from a cylinder 312 by the associated piston 345-348, it will not be able to flow back into the radial inlet bore 307, owing to the one-way inlet valve 324 blocking flow in this direction. As a result, expelled fluid passes through longitudinal outlet bore 310 into radial outlet bore 309, and from there through one-way outlet valves 334 into outlet manifold 331 illustrated in FIG. 6. Each outlet valve 334 is sealed with an associated o-ring seal 335 in the same manner as the inlet valves 324 are sealed by o-ring seals 325.

(21) Each of the four outlet valves 334 pass into a common outlet conduit 336 formed within outlet manifold 331 that is generally “U” shaped, and which is in fluid communication with outlet port 330. Outlet conduit 336 is bored into outlet manifold 331 again entirely from the exterior thereto, and the openings that would remain are conveniently capped by a slightly larger diameter bore used to seat valves 334. As with inlet port 320, outlet port 330 will in nearly all cases operatively be coupled to an exterior hose, conduit, or the like through suitable fitting, for exemplary and non-limiting purpose such as a threaded coupler.

(22) Passing longitudinally through the center of pump body 300 is a rotary drive shaft 220, which is coupled with and driven by a suitable motor, the details of the motor which are not important to the present invention or illustrated herein. Generally centered relative to and affixed within each of intake manifold 321 and outlet manifold 331 are bearings 222, 232, respectively, visible in FIG. 9, that support rotary drive shaft 220. These bearings 222, 232 are in direct thermal communication with the inlet and outlet manifolds 321, 331, which in turn means that they are directly cooled by the liquid passing through the pump. As may be appreciated, this cooling helps to protect bearings 222, 232 from thermal overload and associated thermal degradation that can reduce the MTBF of a pump. In preferred embodiment compact pump 10, bearings 222, 232 are also preferably sealed bearings, which provides improved resistance to external contamination.

(23) Within pump body 300 and also rigidly affixed with rotary drive shaft 220 is an eccentric cam 370. Cam 370 will rotate with rotary drive shaft 220, and on an exterior surface is provided with a pair of adjacent roller bearings 352, 362, both visible in FIG. 9. In preferred embodiment compact pump 10, bearings 352, 362 are preferably sealed bearings, which provides improved resistance to external contamination.

(24) Each of these roller bearings 352, 362 drive one pair of the four pistons, through interaction with associated yoke contact surfaces 340-343. Opposed yoke contact surfaces 340 and 341 are in contact with a first bearing 352 of these two bearings, and form a part yoke 350 used to drive pistons 345 and 346. Opposed yoke contact surfaces 342 and 343 are in contact with a second bearing 362 of these two bearings, and form a second yoke 360 used to drive pistons 347 and 348. Each yoke 350, 360 visible in FIGS. 7 and 8 will be understood to have a name taken from the geometrically similar water and oxen yokes. Because the two yokes are angularly offset from each other by ninety degrees, at any given moment at least one of the four pistons is always pumping fluid. As a result, the preferred embodiment pump 10 is always pumping fluid and so is less susceptible to vibration and hammering than the prior art one and two piston pumps.

(25) The use of yokes 350, 360 allows rotary drive shaft 220 to pass entirely through between the pistons, enabling the single shaft to drive both piston pairs. This also permits shaft 220 to be anchored into bearings 222, 232 within each of inlet and outlet manifolds 321, 331, as already described herein above.

(26) As apparent from the Figures, each piston 345-348 has two associated one-way valves, an inlet valve 324 and an outlet valve 334, meaning the fluid will only flow from inlet to outlet, and not be circumvented by an adjacent piston.

(27) Preferred embodiment pump 10 offers a very compact geometry, while providing liquid cooling of critical components and substantially reduced vibration within a positive displacement pump. Pump 10 further requires a minimum of components that can easily be machined or produced and assembled in a low cost manner. Pump 10 will preferably use sealed bearings within an atmospheric chamber, thereby reducing the need for special lubricant sprays or immersion baths and allowing any leakage to be either released to atmosphere or if so desired, collected and removed without harming bearings or other internal components. This use of an atmospheric chamber and the lack of an oil bath permits pump 10 to be oriented in any direction, either during use, transport or storage without fear of leakage of the oil.

(28) While the foregoing details what is felt to be the preferred embodiment of the invention, no material limitations to the scope of the claimed invention are intended. Further, features and design alternatives that would be obvious to one of ordinary skill in the art are considered to be incorporated herein. The scope of the invention is set forth and particularly described in the claims herein below.