BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a reciprocating pump which embodies the features of one embodiment of the present invention;
FIG. 2 is a side view of the pump shown in FIG. 1;
FIG. 3 is a top view of the reciprocating pump shown in FIG. 1;
FIG. 4 is a bottom view of the reciprocating pump shown in FIG. 1;
FIG. 5
a is a sectional view taken along section line 5-5 of FIG. 2;
FIG. 5
b is a perspective of the cross section shown in FIG. 5a;
FIG. 6
a is a perspective view of the orbiting valve of the pump of FIG. 1, looking into a face surface of the valve having two concentric grooves therein;
FIG. 6
b is a plan view of the orbiting valve's grooved surface shown in FIG. 6;
FIG. 7 is a perspective view of the valve plate of the pump of FIG. 1, looking into a face surface of the valve plate having three cylinders emanating therefrom; for convenience of illustration the plate has been shown with a squarish shape as opposed to its actual round shape as indicated in FIGS. 5a, 5b;
FIG. 8 is a perspective view of the valve plate shown in FIG. 7, looking into a face surface opposite the surface shown in FIG. 7;
FIG. 9 is a face plan view of an assembly of components from the pump of FIG. 1, wherein the assembly has a valve plate having three cylinders, an orbiting valve, and an eccentric interfacing the valve plate with the orbit valve; for convenience, the orbit valve circumferential projection seen in FIG. 5a is not shown; also for convenience of illustration the valve plate has been shown with a squarish shape as opposed to its actual round shape as indicated in FIGS. 5a, 5b; wherein the view looks towards the pump's motor end, away from the pump end opposite the motor, and into the face surface of the valve plate having the cylinders emanating therefrom;
FIGS. 10
a-10e are plan views generally the same as shown in FIG. 9, except for further convenience, only one cylinder and its associated cylinder port are shown; the Figures show the orbiting valve's sequence relative to stated positions of the piston;
FIG. 11 is a partial cross sectional view taken along a longitudinal axis of a pump having an alternative embodiment of the invention, wherein the pump has its orbit valve eccentric on the opposite side of the valve plate as compared to the placement of the orbit valve in FIG. 5a;
FIG. 12
a is a face plan view of an assembly of components from a pump of the type shown in FIG. 1; the view shows an alternative embodiment of the invention, wherein the assembly has a multi cylinder valve plate, for convenience, only one cylinder is shown; an orbiting valve having multiple segmented intake through ports and multiple segmented exhaust grooves, again for convenience, only one exhaust segment is shown; and an eccentric interfacing the valve plate with the orbiting valve, wherein the view looks towards the pump's motor end, away from the pump end opposite the motor, and into the face surface of the valve plate having the cylinders emanating therefrom;
FIG. 12
b is a perspective view of the assembly shown in FIG. 12a; for convenience, the arms shown emanating from the orbiting valve in this perspective view were omitted from the plan view in FIG. 12a;
FIG. 13 is a top perspective view of the orbiting valve eccentric of the pump of FIG. 1;
FIG. 14 is an end perspective view of the shaft, orbiting valve eccentric and orbiting valve of FIG. 1 assembled together.
DETAILED DESCRIPTION
Referring now to FIGS. 1-5b, nutating or wobble-piston type compressor or pump 100 has a housing 102. The housing 102 encloses a crank case volume 104. The pump has certain main drive components in the housing. The main drive components in the housing include shaft 18, eccentric 64, eccentric bearing 62, wobble member 60, and cross-type universal joint 56. Universal joint 56 has two of its opposed arms journalled or coupled to connector 59 and the other two of its opposed arms journalled or coupled to wobble or yoke member 60.
The wobble member 60 has three arms 74 all of which are the same as each other. Only one arm 74 is shown. Each arm has, at its end, a ball head 76.
Pump 100 has three pistons, all of which are the same. Only one piston 14a, 14b is fully shown. Each piston has a piston head 14b and piston rod 14a. Each piston rod 14a is hollow and contains a socket halve 78. Each wobble member's ball head 76 is coupled to a piston rod 14a via the socket half 78.
As can be seen in FIGS. 7 and 9, each piston is associated with a respective cylinder 20a, 20b and 20c. Each cylinder has associated with it a cylinder port 28a, 28b and 28c. See FIGS. 7, 8 and 9. The cylinder ports 28a, 28b, 28c each comprise elongated cylinder groove port portions 28a″, 28b″, 28c″ and small centrally located oval cylinder through port portions 28a′, 28b′, 28c′. The small oval portions are the only portions of the cylinder ports that actually pass through the valve plate. The center of UV joint 56 is aligned along the center the shaft axis 18a.
During operation of pump 100 drive shaft 18 is rotated by the motor 58, the stator of which is affixed to the end cover 52, which is affixed, via wall 103, to housing 102 to enclose orbiting valve 16, orbiting valve eccentric 30, orbiting valve eccentric bearing 32 and counter moment mass 54.
As the motor shaft 18 rotates, eccentric 64, through bearing 62, causes wobble member 60 to wobble and thereby drive rod 14a in a predominantly reciprocating motion. Orbiting valve eccentric 30, acting through orbiting valve eccentric bearing 32, causes orbiting valve 16 to orbit about the shaft centerline 18 as it slides relative to the valve plate 25. Two concentric grooves 22 and 24, in the orbiting valve 16, alternately slide over the cylinder ports 28a, 28b and 28c to provide sequenced fluid communication with intake port 27 and exhaust port 26. See FIG. 9, 10a-10e. Groove 22 can be described as a pressure or exhaust groove and groove 24 can be described as an intake groove. The dashed line in FIGS. 5a, 5b indicates fluid communication between exhaust port 26 shown in FIG. 9 and connector tube 46 shown in FIG. 5a. Fluid intake is routed through port 44 of the attenuation chamber 48 , through ports 42 into the crankcase chamber 104 and then through valve intake port 27. The arrows in FIGS. 5a, 5b show the fluid flow direction.
FIG. 5
a and FIG. 5b show piston rod 14a in a top dead center position such that cylinder through port 28a is no longer connected to exhaust groove 22 or intake groove 24.
Now referring more particularly to FIGS. 10a-10e, the orbiting valve sequence can be further seen. In these Figures, for ease of reference, only one cylinder 20a and its associated cylinder port 28a are shown. Also, for ease of reference, the projection 16c is not shown. Each of the other cylinders 20b, 20c are going through exactly the same sequence except the cylinders are 120° out of phase with each other. Looking into the valve plate 16 from the cylinder side, the direction of orbit valve 16 is indicated by arrow 70 and is counterclockwise. The angular orientation of the shaft 18 relative to orbit valve 16 during the sequence is marked by darkened area 30a. The degrees of rotation can thus be correlated to the piston's position.
In understanding the below description of how FIGS. 10a-10e, depict the orbit valve's sequencing, it is important to note that the orbiting valve being sequenced by eccentric 30, relative to the piston, is phased to be 90° out of phase with the motion of the pistons. At the start of the sequence, FIG. 10a, the piston is at the top dead center (TDC) position, see FIG. 5a and 5b. The cylinder port 28a is not in communication with either the exhaust or pressure groove 22 or the intake groove 24. The intake groove 24 is ready to communicate with the cylinder port 28a. In FIG. 10a the center 16a of orbiting valve 16 is shown displaced to the left. The direction of displacement, if an “x, y” graph 17, oriented about shaft 18's center line, were superimposed over FIG. 10a, would be “−x”. The amount of displacement is determined by the offset 30b (FIG. 13) of the orbiting valve eccentric 30 from shaft centerline 18a. The center 16a of orbit valve 16 is not displaced along the y axis when rod 14a is in the top dead center position. The orbit valve center 16a is thus centered vertically with respect to shaft 18. In the top dead center position, the orbiting valve center 16a is located predominantly 90 degrees counterclockwise from the top cylinder 20a shown in FIG. 10a.
Moving on in the sequence, FIG. 10b, the piston has traveled halfway down (away from valve plate 25) the cylinder 20a. Cylinder through groove 28a″ is in communication with intake groove 24. Next, FIG. 10c, the piston has traveled to bottom dead center (BDC), a maximum distance from valve plate 25. Cylinder port 28a is not in communication with either the intake 24 or pressure groove 22. As the piston moves from BDC position, to a position approximately at the center of the upward stroke, the cylinder through port 228a′ is not in communication with either intake nor exhaust groove. This allows the pressure to build up within the cylinder to a level nearly equal to that pressure in the exhaust groove. Next, FIG. 10d, the piston has traveled midway up the cylinder, i.e., at middle of upstroke and point of maximum compression. Finally, in FIG. 10e, the piston is 45° before TDC. The cylinder port 28a, by way of cylinder groove portion 28a″, is open to the exhaust or pressure groove 22. The relative position of the other ports 28b, 28c, when the piston is 45° before TDC , can be seen in FIG. 9.
In the above described sequence, the orbit valve 16 is not restrained from rotation about its own axis, but since the grooves 22 and 24 are circular the orbit valve can rotate as well as orbit, although the rotation about its own axis does not affect its operation. In addition, the combination of bearing 32 and the friction of the orbit valve 16 against the valve plate 25 would result in the motion being largely orbital with only little, if any, rotation. Further the grooves 22 and 24 do not pass through the orbit valve to form a through space.
The use of a cylinder port with a grooved portion 28a″ and a through portion 28a′ is believed to be advantageous over the use of a simple through port. Also, having the inner groove 22 as the exhaust groove 22 , as opposed to the outer groove, is believed to be advantageous in that the surface area forming the inner groove is less than the outer groove. The smaller area reduces the forces on the orbit valve 16 resulting from the fluid pressure. The orbiting valve 16, however, could be configured with the outer groove as the exhaust groove.
A further feature that can be included in a pump embodying the invention is an axial spring bias force 86 that may be provided between the orbiting valve 16 and a stationary structure attached to the housing, such as end cover 52. The spring serves to overcome the net separation forces caused by the difference between (1) the fluid pressure acting on an area of the surface of the orbiting valve 16 contacting the valve plate 25 and (2) the fluid pressure acting on the surface of the orbit valve opposite the orbit valves sealing surface. The spring assures sealing between the land areas surrounding the grooves 22, 24 and the valve plate 25 of housing 102. Alternatively, one or more axially extending springs could provide a biasing force between the orbiting valve 16 and eccentric 30. To improve biasing of the orbit valve, a circumferential projection 16c is provided on the valve's end wall surface opposite the valve surface having the concentric grooves. The circumferential projection defines a space to receive an end coil of spring 86. The projection of course does not have to be continuous. As an alternative to a projection, a groove can be provided to receive an end coil of the spring. For convenience, the spring 86 is not shown in its actual relative coiled and flexed state.
Referring to FIGS. 12a and 12b, an alternative embodiment having a segmented orbit valve with a combination of grooved segments and through segments is shown. The associated valve plate 225, would have 3 cylinders, for convenience only one cylinder 220a is shown. The valve plate would have three cylinder ports, again for convenience only, port 228a, comprising groove portion 228a″ and through portion 228a′ is shown. The valve plate further has three exhaust ports; for convenience only one 226a is shown.
The orbiting valve 216 shown in FIGS. 12b and 12a has three intake segments 224a, 224b, 224c; each would be uniquely associated with one of the three cylinders. In the shown embodiment intake 224a is associated with cylinder 220a. The intake segments completely pass through the orbit valve. Having the intake segments as through apertures, allows for direct intake into the associated cylinder port, thus eliminating the need for any intake ports in the valve plate.
The orbiting valve of FIGS. 12a and 12b would also have three grooved segmented exhaust ports; for convenience only exhaust port 222a is shown. Each exhaust port segment is uniquely associated with a cylinder and a cylinder port. In the shown embodiment grooved exhaust segment 226a is associated with cylinder port 228a and cylinder 220a. The exhaust segments do not pass through the orbit valve. The orbit valve would have a projection similar to the projection 16c shown in FIGS. 5a,5b. For convenience, the projection is not shown in FIGS. 12a, 12b.
Although the embodiment in FIGS. 12a and 12b show their intake segment as passing through the orbit valve; they do not have to pass through the orbit valve. In this case, proper intake porting through the valve plate would have to be provided. Further, in this case, it would be possible to have the exhaust segments as pass through holes thereby eliminating the need for exhaust ports in the valve plate. In this case, the cavity in which the orbit valve is enclosed would have to be pressure sealed. The pressure allowed to build up in the cavity could be made sufficient to overcome the net separation forces between the valve plate and orbit valve so as to eliminate the need for an external biasing force member such as spring 86. The amount of pressure allowed to act as the biasing force should not be so great as to create undue friction forces between the orbit valve and valve plate. The pressure could be regulated by a pressure regulation port in the cavity or some or some other pressure regulator.
The orbit valve 216 must be prevented from rotating relative to the housing by use of any of several possible methods including but not limited to an Oldham coupling, one or more idler crank mechanisms, one or more torsional springs, one or more leaf springs, or other compliant mechanisms either separately attached between the disk and the stationary housing or integrated as a monolithic member with the disk itself. For convenience, shown only in the perspective view 12b, are four integral flexible compliant arms 216d.
A spring and projection similar to spring 86 and projection 16c could also be used to form a resilient compliant. In this case, the projection used to receive an end coil of the spring would be sized so that the circumferential projection forms a cavity which permits the end coil to snap-fit into the cavity. The snap-fit would serve to couple the spring to the orbit valve with a sufficient frictional fit to resist the torsion forces imparted to the orbit valve by the eccentric. If a groove were used to receive the spring, the groove could have a cavity therein to receive a spring end and thereby limit the orbit valves rotation.
Referring to FIGS. 12a, 12b, orbit valve 216 could be used with a pump having compression and vacuum cylinders. The cylinders would be a combination of compression and vacuum cylinders. Each cylinder would be associated with a combination of orbit valve intake/exhaust cavities, which could be combinations of grooves, or through ports. The valve plate and orbit valve would be configured to interconnect the pressure and vacuum cylinders provided within the same pump to the appropriate intake or exhaust ports in the valve plate to sequence and to provide both vacuum and pressure pumping capability with separate fluid circuits; or to provide a combination of pumping and motoring using either a pressure or vacuum fluid source and/or an electric motor in any combination.
Referring to FIG. 13 the eccentric 30 could include a portion (not shown) that acts as a counter weight to dynamically balance the primary radial dynamic forces created by the orbiting motion of the orbit valve 16. In this case counter moment mass 54 would contain a counter moment mass to dynamically balance both the primary drive mechanism unbalance moment of the pump or motor and the unbalance moment created by the orbit valve and its eccentric counter mass being located in two different axial planes.
In still another aspect of the invention, the orbit valve eccentric 330 may be on the same side of valve plate 325 as the eccentric 64. See FIG. 11. In this case, the eccentric 330 is coupled directly to eccentric 64. Eccentric 64 imparts an orbiting motion to eccentric 330 by way of eccentric bearings 332. Eccentric 330 imports an orbiting motion to orbit valve 316 with coupling 300.
Although the orbit valve cavities 22, 24 have been described as grooves 22, 24, they can also be passages, channels or ducts. Additionally, although both 22 and 24 are described as grooves, they could comprise a combination of grooves and pass through apertures. In this case the porting of the valve plate would follow the principles described with regards to FIGS. 12a, 12b. The orbit valve can have a variety of shapes beyond those shown or described. The valve plate and housing can also have a variety of shapes beyond those disclosed.
It should be noted that the term coupling is used inclusively herein to cover both direct and indirect coupling. For instance the shaft 18 is coupled to the wobble member 60 by way of an indirect coupling. The shaft is also coupled to the piston 14a, 14b by way of an indirect coupling.
Varying embodiments of the invention have been described in considerable detail. Many modifications and variations to the embodiments described will be apparent to a person of ordinary skill in the art. Therefore, the invention should not be limited to the embodiments described.
Patent Application
20080075616
