US20080075616A1 - Orbiting Valve For A Reciprocating Pump - Google Patents
Orbiting Valve For A Reciprocating Pump Download PDFInfo
- Publication number
- US20080075616A1 US20080075616A1 US11/574,807 US57480705A US2008075616A1 US 20080075616 A1 US20080075616 A1 US 20080075616A1 US 57480705 A US57480705 A US 57480705A US 2008075616 A1 US2008075616 A1 US 2008075616A1
- Authority
- US
- United States
- Prior art keywords
- valve
- port
- cylinder
- orbit
- intake
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
- F01B13/00—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion
- F01B13/04—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion with more than one cylinder
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
- F01B3/00—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis
- F01B3/0002—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis having stationary cylinders
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
- F01B3/00—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis
- F01B3/02—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis with wobble-plate
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
- F01B3/00—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis
- F01B3/10—Control of working-fluid admission or discharge peculiar thereto
- F01B3/101—Control of working-fluid admission or discharge peculiar thereto for machines with stationary cylinders
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B27/00—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders
- F04B27/08—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis
- F04B27/10—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis having stationary cylinders
- F04B27/1009—Distribution members
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
- F04B39/10—Adaptations or arrangements of distribution members
Definitions
- the present invention comprises valves for the porting of intake and exhaust in reciprocating pumps, including vacuum pumps and compressors, and more particularly in multi-cylinder pumps such as swashplate or nutating or wobble-piston type pumps or pumps with axial pistons arranged about a central axis.
- Passive valves such as flapper, poppet or umbrella valves, are used for intake and exhaust porting for reciprocating piston pumps.
- a flapper valve is typically made of a thin, flat material.
- Stainless steel has been used for higher pressure flapper valve applications and elastomers have been used for small, low-pressure flapper valve applications.
- Poppet valves are typically made of a harder material that is biased against a valve plate using a spring.
- An umbrella valve is usually made of an elastomeric material and includes a built-in attachment method for retaining itself against the valve plate while covering several small holes. Each of these passive valve systems are activated by fluid pressure acting against the valve such that fluid is allowed to pass in one direction only.
- Passive valve systems are limited by the speed at which they can respond and tend to become more restrictive and much less effective at higher speeds.
- Direct-acting valve systems are known. Cardillo, U.S. Pat. No. 5,058,485, discloses a direct-acting orbiting ring valve for a hydraulic swashplate type pump. White, U.S. Pat. No. 4,877,383, discloses a direct-acting valve such as an orbiting valve for a gerotor device. U.S. Pat. No. 6,224,349 discloses a direct-acting orbiting valve for a swashplate type pump
- the present invention provides a direct-acting, orbiting valve system for reciprocating piston pumps, including compressors and vacuum pumps, that provides greater pumping efficiency at higher speed ranges than currently feasible with passive valving systems.
- the invention provides both intake and exhaust valve functions using a single orbiting valve member to alternately route the cylinder ports to separate intake and exhaust ports.
- a single orbiting valve member can be provided with port routing for separate pressure and vacuum cylinders connected to the same valve plate of a multi-cylinder machine.
- the invention reduces the ultimate torque required and the frictional losses associated with an orbiting valve member by allowing the member to rotate slightly under conditions of stiction creating a twisting motion that results in a mechanical advantage to more easily break away the stiction-adhered surfaces of the orbiting valve and the valve plate as compared to a rotary valve.
- routing of intake and exhaust is accomplished by using concentric grooves in the orbiting valve to interconnect cylinder ports in the valve plate with the intake and exhaust ports in the valve plate.
- the invention provides routing of intake and exhaust with discrete, non-concentric groove segments in the orbiting valve member. In this case the orbiting valve is constrained from rotating by a compliant member.
- 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. 5 a;
- 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. 5 a , 5 b;
- 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. 5 a 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. 5 a , 5 b ; 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 - 10 e 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. 5 a;
- 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. 12 a ; for convenience, the arms shown emanating from the orbiting valve in this perspective view were omitted from the plan view in FIG. 12 a;
- 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.
- 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 14 a , 14 b is fully shown. Each piston has a piston head 14 b and piston rod 14 a . Each piston rod 14 a is hollow and contains a socket halve 78 . Each wobble member's ball head 76 is coupled to a piston rod 14 a via the socket half 78 .
- each piston is associated with a respective cylinder 20 a , 20 b and 20 c .
- Each cylinder has associated with it a cylinder port 28 a , 28 b and 28 c .
- the cylinder ports 28 a , 28 b , 28 c each comprise elongated cylinder groove port portions 28 a ′′, 28 b ′′, 28 c ′′ and small centrally located oval cylinder through port portions 28 a ′, 28 b ′, 28 c ′.
- 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 18 a.
- 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 .
- eccentric 64 As the motor shaft 18 rotates, eccentric 64 , through bearing 62 , causes wobble member 60 to wobble and thereby drive rod 14 a 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 28 a , 28 b and 28 c to provide sequenced fluid communication with intake port 27 and exhaust port 26 . See FIG. 9 , 10 a - 10 e .
- Groove 22 can be described as a pressure or exhaust groove and groove 24 can be described as an intake groove.
- FIGS. 5 a , 5 b indicate fluid communication between exhaust port 26 shown in FIG. 9 and connector tube 46 shown in FIG. 5 a .
- 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. 5 a , 5 b show the fluid flow direction.
- FIG. 5 a and FIG. 5 b show piston rod 14 a in a top dead center position such that cylinder through port 28 a is no longer connected to exhaust groove 22 or intake groove 24 .
- FIGS. 10 a - 10 e the orbiting valve sequence can be further seen.
- the projection 16 c is not shown.
- Each of the other cylinders 20 b , 20 c are going through exactly the same sequence except the cylinders are 120° out of phase with each other.
- 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 30 a . The degrees of rotation can thus be correlated to the piston's position.
- FIGS. 10 a - 10 e depict the orbit valve's sequencing
- the orbiting valve being sequenced by eccentric 30 is phased to be 90° out of phase with the motion of the pistons.
- FIG. 10 a the piston is at the top dead center (TDC) position, see FIG. 5 a and 5 b .
- the cylinder port 28 a 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 28 a .
- FIG. 10 a the center 16 a 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. 10 a , would be “ ⁇ x”.
- the amount of displacement is determined by the offset 30 b ( FIG. 13 ) of the orbiting valve eccentric 30 from shaft centerline 18 a .
- the center 16 a of orbit valve 16 is not displaced along the y axis when rod 14 a is in the top dead center position.
- the orbit valve center 16 a is thus centered vertically with respect to shaft 18 .
- the orbiting valve center 16 a In the top dead center position, the orbiting valve center 16 a is located predominantly 90 degrees counterclockwise from the top cylinder 20 a shown in FIG. 10 a.
- FIG. 10 b the piston has traveled halfway down (away from valve plate 25 ) the cylinder 20 a . Cylinder through groove 28 a ′′ is in communication with intake groove 24 .
- FIG. 10 c the piston has traveled to bottom dead center (BDC), a maximum distance from valve plate 25 . Cylinder port 28 a is not in communication with either the intake 24 or pressure groove 22 .
- BDC bottom dead center
- Cylinder port 28 a is not in communication with either the intake 24 or pressure groove 22 .
- the cylinder through port 228 a ′ 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.
- FIG. 10 b the piston has traveled halfway down (away from valve plate 25 ) the cylinder 20 a . Cylinder through groove 28 a ′′ is in communication with intake groove 24 .
- FIG. 10 c the piston has traveled to bottom dead center (BDC), a maximum distance from valve plate 25 .
- the piston has traveled midway up the cylinder, i.e., at middle of upstroke and point of maximum compression.
- the piston is 45° before TDC.
- the cylinder port 28 a by way of cylinder groove portion 28 a ′′, is open to the exhaust or pressure groove 22 .
- the relative position of the other ports 28 b , 28 c , when the piston is 45° before TDC can be seen in FIG. 9 .
- 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.
- 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.
- a cylinder port with a grooved portion 28 a ′′ and a through portion 28 a ′ is believed to be advantageous over the use of a simple through port.
- having the inner groove 22 as the exhaust groove 22 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 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 .
- one or more axially extending springs could provide a biasing force between the orbiting valve 16 and eccentric 30 .
- a circumferential projection 16 c 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.
- a groove can be provided to receive an end coil of the spring.
- the spring 86 is not shown in its actual relative coiled and flexed state.
- FIGS. 12 a and 12 b 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 220 a is shown.
- the valve plate would have three cylinder ports, again for convenience only, port 228 a , comprising groove portion 228 a ′′ and through portion 228 a ′ is shown.
- the valve plate further has three exhaust ports; for convenience only one 226 a is shown.
- the orbiting valve 216 shown in FIGS. 12 b and 12 a has three intake segments 224 a , 224 b , 224 c ; each would be uniquely associated with one of the three cylinders.
- intake 224 a is associated with cylinder 220 a .
- 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. 12 a and 12 b would also have three grooved segmented exhaust ports; for convenience only exhaust port 222 a is shown. Each exhaust port segment is uniquely associated with a cylinder and a cylinder port. In the shown embodiment grooved exhaust segment 226 a is associated with cylinder port 228 a and cylinder 220 a . The exhaust segments do not pass through the orbit valve.
- the orbit valve would have a projection similar to the projection 16 c shown in FIGS. 5 a , 5 b . For convenience, the projection is not shown in FIGS. 12 a , 12 b.
- FIGS. 12 a and 12 b 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.
- 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.
- 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.
- four integral flexible compliant arms 216 d are four integral flexible compliant arms 216 d.
- a spring and projection similar to spring 86 and projection 16 c could also be used to form a resilient compliant.
- 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.
- 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.
- 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 .
- 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.
- 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 .
- 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. 12 a , 12 b .
- 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.
- coupling is used inclusively herein to cover both direct and indirect coupling.
- the shaft 18 is coupled to the wobble member 60 by way of an indirect coupling.
- the shaft is also coupled to the piston 14 a , 14 b by way of an indirect coupling.
Abstract
Description
- The present application claims priority from U.S.
provisional application 60/610,013 filed Sep. 15, 2004. - The present invention comprises valves for the porting of intake and exhaust in reciprocating pumps, including vacuum pumps and compressors, and more particularly in multi-cylinder pumps such as swashplate or nutating or wobble-piston type pumps or pumps with axial pistons arranged about a central axis.
- Passive valves, such as flapper, poppet or umbrella valves, are used for intake and exhaust porting for reciprocating piston pumps. A flapper valve is typically made of a thin, flat material. Stainless steel has been used for higher pressure flapper valve applications and elastomers have been used for small, low-pressure flapper valve applications. Poppet valves are typically made of a harder material that is biased against a valve plate using a spring. An umbrella valve is usually made of an elastomeric material and includes a built-in attachment method for retaining itself against the valve plate while covering several small holes. Each of these passive valve systems are activated by fluid pressure acting against the valve such that fluid is allowed to pass in one direction only.
- Passive valve systems are limited by the speed at which they can respond and tend to become more restrictive and much less effective at higher speeds.
- Direct-acting valve systems are known. Cardillo, U.S. Pat. No. 5,058,485, discloses a direct-acting orbiting ring valve for a hydraulic swashplate type pump. White, U.S. Pat. No. 4,877,383, discloses a direct-acting valve such as an orbiting valve for a gerotor device. U.S. Pat. No. 6,224,349 discloses a direct-acting orbiting valve for a swashplate type pump
- The present invention provides a direct-acting, orbiting valve system for reciprocating piston pumps, including compressors and vacuum pumps, that provides greater pumping efficiency at higher speed ranges than currently feasible with passive valving systems.
- The invention provides both intake and exhaust valve functions using a single orbiting valve member to alternately route the cylinder ports to separate intake and exhaust ports. In addition, a single orbiting valve member can be provided with port routing for separate pressure and vacuum cylinders connected to the same valve plate of a multi-cylinder machine.
- The invention reduces the ultimate torque required and the frictional losses associated with an orbiting valve member by allowing the member to rotate slightly under conditions of stiction creating a twisting motion that results in a mechanical advantage to more easily break away the stiction-adhered surfaces of the orbiting valve and the valve plate as compared to a rotary valve.
- In one embodiment of the invention, routing of intake and exhaust is accomplished by using concentric grooves in the orbiting valve to interconnect cylinder ports in the valve plate with the intake and exhaust ports in the valve plate. In an alternative embodiment the invention provides routing of intake and exhaust with discrete, non-concentric groove segments in the orbiting valve member. In this case the orbiting valve is constrained from rotating by a compliant member.
- The foregoing and other aspects of the invention, such as the inventions features, objects and advantages, are apparent in the brief description of the drawings, detailed description, attached drawings and attached claims.
-
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 inFIG. 1 ; -
FIG. 3 is a top view of the reciprocating pump shown inFIG. 1 ; -
FIG. 4 is a bottom view of the reciprocating pump shown inFIG. 1 ; -
FIG. 5 a is a sectional view taken along section line 5-5 ofFIG. 2 ; -
FIG. 5 b is a perspective of the cross section shown inFIG. 5 a; -
FIG. 6 a is a perspective view of the orbiting valve of the pump ofFIG. 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 inFIG. 6 ; -
FIG. 7 is a perspective view of the valve plate of the pump ofFIG. 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 inFIGS. 5 a, 5 b; -
FIG. 8 is a perspective view of the valve plate shown inFIG. 7 , looking into a face surface opposite the surface shown inFIG. 7 ; -
FIG. 9 is a face plan view of an assembly of components from the pump ofFIG. 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 inFIG. 5 a 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 inFIGS. 5 a, 5 b; 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-10 e are plan views generally the same as shown inFIG. 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 inFIG. 5 a; -
FIG. 12 a is a face plan view of an assembly of components from a pump of the type shown inFIG. 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 inFIG. 12 a; for convenience, the arms shown emanating from the orbiting valve in this perspective view were omitted from the plan view inFIG. 12 a; -
FIG. 13 is a top perspective view of the orbiting valve eccentric of the pump ofFIG. 1 ; -
FIG. 14 is an end perspective view of the shaft, orbiting valve eccentric and orbiting valve ofFIG. 1 assembled together. - Referring now to
FIGS. 1-5 b, nutating or wobble-piston type compressor orpump 100 has ahousing 102. Thehousing 102 encloses acrank case volume 104. The pump has certain main drive components in the housing. The main drive components in the housing includeshaft 18, eccentric 64,eccentric bearing 62,wobble member 60, and cross-typeuniversal joint 56.Universal joint 56 has two of its opposed arms journalled or coupled toconnector 59 and the other two of its opposed arms journalled or coupled to wobble oryoke member 60. - The
wobble member 60 has threearms 74 all of which are the same as each other. Only onearm 74 is shown. Each arm has, at its end, aball head 76. -
Pump 100 has three pistons, all of which are the same. Only onepiston piston head 14 b andpiston rod 14 a. Eachpiston rod 14 a is hollow and contains a socket halve 78. Each wobble member'sball head 76 is coupled to apiston rod 14 a via thesocket half 78. - As can be seen in
FIGS. 7 and 9 , each piston is associated with arespective cylinder cylinder port FIGS. 7 , 8 and 9. Thecylinder ports groove port portions 28 a″, 28 b″, 28 c″ and small centrally located oval cylinder throughport portions 28 a′, 28 b′, 28 c′. The small oval portions are the only portions of the cylinder ports that actually pass through the valve plate. The center ofUV joint 56 is aligned along the center theshaft axis 18 a. - During operation of
pump 100drive shaft 18 is rotated by themotor 58, the stator of which is affixed to theend cover 52, which is affixed, viawall 103, tohousing 102 to enclose orbitingvalve 16, orbiting valve eccentric 30, orbiting valveeccentric bearing 32 andcounter moment mass 54. - As the
motor shaft 18 rotates, eccentric 64, through bearing 62, causes wobblemember 60 to wobble and thereby driverod 14 a in a predominantly reciprocating motion. Orbiting valve eccentric 30, acting through orbiting valveeccentric bearing 32,causes orbiting valve 16 to orbit about theshaft centerline 18 as it slides relative to thevalve plate 25. Twoconcentric grooves valve 16, alternately slide over thecylinder ports intake port 27 andexhaust port 26. SeeFIG. 9 , 10 a-10 e.Groove 22 can be described as a pressure or exhaust groove and groove 24 can be described as an intake groove. The dashed line inFIGS. 5 a, 5 b indicates fluid communication betweenexhaust port 26 shown inFIG. 9 andconnector tube 46 shown inFIG. 5 a. Fluid intake is routed throughport 44 of theattenuation chamber 48 , throughports 42 into thecrankcase chamber 104 and then throughvalve intake port 27. The arrows inFIGS. 5 a, 5 b show the fluid flow direction. -
FIG. 5 a andFIG. 5 bshow piston rod 14 a in a top dead center position such that cylinder throughport 28 a is no longer connected to exhaustgroove 22 orintake groove 24. - Now referring more particularly to
FIGS. 10 a-10 e, the orbiting valve sequence can be further seen. In these Figures, for ease of reference, only onecylinder 20 a and its associatedcylinder port 28 a are shown. Also, for ease of reference, theprojection 16 c is not shown. Each of theother cylinders valve plate 16 from the cylinder side, the direction oforbit valve 16 is indicated byarrow 70 and is counterclockwise. The angular orientation of theshaft 18 relative to orbitvalve 16 during the sequence is marked bydarkened area 30 a. The degrees of rotation can thus be correlated to the piston's position. - In understanding the below description of how
FIGS. 10 a-10 e, 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. 10 a, the piston is at the top dead center (TDC) position, seeFIG. 5 a and 5 b. Thecylinder port 28 a is not in communication with either the exhaust orpressure groove 22 or theintake groove 24. Theintake groove 24 is ready to communicate with thecylinder port 28 a. InFIG. 10 a thecenter 16 a of orbitingvalve 16 is shown displaced to the left. The direction of displacement, if an “x, y” graph 17, oriented aboutshaft 18's center line, were superimposed overFIG. 10 a, would be “−x”. The amount of displacement is determined by the offset 30 b (FIG. 13 ) of the orbiting valve eccentric 30 from shaft centerline 18 a. Thecenter 16 a oforbit valve 16 is not displaced along the y axis whenrod 14 a is in the top dead center position. Theorbit valve center 16 a is thus centered vertically with respect toshaft 18. In the top dead center position, the orbitingvalve center 16 a is located predominantly 90 degrees counterclockwise from thetop cylinder 20 a shown inFIG. 10 a. - Moving on in the sequence,
FIG. 10 b, the piston has traveled halfway down (away from valve plate 25) thecylinder 20 a. Cylinder throughgroove 28 a″ is in communication withintake groove 24. Next,FIG. 10 c, the piston has traveled to bottom dead center (BDC), a maximum distance fromvalve plate 25.Cylinder port 28 a is not in communication with either theintake 24 orpressure groove 22. As the piston moves from BDC position, to a position approximately at the center of the upward stroke, the cylinder throughport 228 a′ 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. 10 d, the piston has traveled midway up the cylinder, i.e., at middle of upstroke and point of maximum compression. Finally, inFIG. 10 e, the piston is 45° before TDC. Thecylinder port 28 a, by way ofcylinder groove portion 28 a″, is open to the exhaust orpressure groove 22. The relative position of theother ports FIG. 9 . - In the above described sequence, the
orbit valve 16 is not restrained from rotation about its own axis, but since thegrooves orbit valve 16 against thevalve plate 25 would result in the motion being largely orbital with only little, if any, rotation. Further thegrooves - The use of a cylinder port with a
grooved portion 28 a″ and a throughportion 28 a′ is believed to be advantageous over the use of a simple through port. Also, having theinner groove 22 as theexhaust 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 theorbit valve 16 resulting from the fluid pressure. The orbitingvalve 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 orbitingvalve 16 and a stationary structure attached to the housing, such asend 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 orbitingvalve 16 contacting thevalve 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 thegrooves valve plate 25 ofhousing 102. Alternatively, one or more axially extending springs could provide a biasing force between the orbitingvalve 16 and eccentric 30. To improve biasing of the orbit valve, acircumferential projection 16 c 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 ofspring 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, thespring 86 is not shown in its actual relative coiled and flexed state. - Referring to
FIGS. 12 a and 12 b, an alternative embodiment having a segmented orbit valve with a combination of grooved segments and through segments is shown. The associatedvalve plate 225, would have 3 cylinders, for convenience only onecylinder 220 a is shown. The valve plate would have three cylinder ports, again for convenience only,port 228 a, comprisinggroove portion 228 a″ and throughportion 228 a′ is shown. The valve plate further has three exhaust ports; for convenience only one 226 a is shown. - The orbiting
valve 216 shown inFIGS. 12 b and 12 a has threeintake segments embodiment intake 224 a is associated withcylinder 220 a. 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. 12 a and 12 b would also have three grooved segmented exhaust ports; for convenience onlyexhaust port 222 a is shown. Each exhaust port segment is uniquely associated with a cylinder and a cylinder port. In the shown embodiment groovedexhaust segment 226 a is associated withcylinder port 228 a andcylinder 220 a. The exhaust segments do not pass through the orbit valve. The orbit valve would have a projection similar to theprojection 16 c shown inFIGS. 5 a,5 b. For convenience, the projection is not shown inFIGS. 12 a, 12 b. - Although the embodiment in
FIGS. 12 a and 12 b 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 asspring 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 12 b, are four integral flexiblecompliant arms 216 d. - A spring and projection similar to
spring 86 andprojection 16 c 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. 12 a, 12 b,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 theorbit valve 16. In this casecounter 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 toeccentric 64.Eccentric 64 imparts an orbiting motion to eccentric 330 by way ofeccentric bearings 332. Eccentric 330 imports an orbiting motion to orbitvalve 316 withcoupling 300. - Although the
orbit valve cavities grooves FIGS. 12 a, 12 b. 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 thewobble member 60 by way of an indirect coupling. The shaft is also coupled to thepiston - 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.
Claims (9)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/574,807 US20080075616A1 (en) | 2004-09-15 | 2005-09-15 | Orbiting Valve For A Reciprocating Pump |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US61001304P | 2004-09-15 | 2004-09-15 | |
PCT/US2005/032856 WO2006031935A1 (en) | 2004-09-15 | 2005-09-15 | Orbiting valve for a reciprocating pump |
US11/574,807 US20080075616A1 (en) | 2004-09-15 | 2005-09-15 | Orbiting Valve For A Reciprocating Pump |
Publications (1)
Publication Number | Publication Date |
---|---|
US20080075616A1 true US20080075616A1 (en) | 2008-03-27 |
Family
ID=36060376
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/574,807 Abandoned US20080075616A1 (en) | 2004-09-15 | 2005-09-15 | Orbiting Valve For A Reciprocating Pump |
Country Status (8)
Country | Link |
---|---|
US (1) | US20080075616A1 (en) |
EP (1) | EP1789678A1 (en) |
JP (1) | JP2008513649A (en) |
CN (1) | CN101018949A (en) |
AU (1) | AU2005284802A1 (en) |
CA (1) | CA2580022A1 (en) |
GB (1) | GB2432197A (en) |
WO (1) | WO2006031935A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20220033201A1 (en) * | 2019-01-11 | 2022-02-03 | Rorze Lifescience Inc. | Drive mechanism capable of dealing with gas sterilization |
US11408407B2 (en) | 2016-07-25 | 2022-08-09 | Caire Inc. | Wobble plate compressor and oxygen concentrator using the same |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AU2012340565B2 (en) * | 2011-11-22 | 2017-09-21 | Graco Minnesota Inc. | Box lubrication pump |
CN105332871B (en) * | 2015-11-20 | 2017-07-25 | 西安交通大学 | The cam-type axial piston pump of distributing cup-shaped cylinder body and roller bearings |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1774663A (en) * | 1929-07-24 | 1930-09-02 | Arthur S Parks | Pump |
US2142086A (en) * | 1933-09-09 | 1939-01-03 | Ex Cell O Corp | Fuel pump |
US2579879A (en) * | 1949-12-10 | 1951-12-25 | Sundstrand Machine Tool Co | Gyratory valve for hydraulic pumps or motors |
US2732808A (en) * | 1956-01-31 | Fluid pump and control | ||
US4877383A (en) * | 1987-08-03 | 1989-10-31 | White Hollis Newcomb Jun | Device having a sealed control opening and an orbiting valve |
US5058485A (en) * | 1986-11-04 | 1991-10-22 | Cardillo Joseph S | Ring valve pump |
US5733105A (en) * | 1995-03-20 | 1998-03-31 | Micropump, Inc. | Axial cam driven valve arrangement for an axial cam driven parallel piston pump system |
US6224349B1 (en) * | 1998-08-27 | 2001-05-01 | Denso Corporation | Reciprocating type compressor having orbiting valve plate |
US6572344B1 (en) * | 2001-11-26 | 2003-06-03 | Caterpillar Inc | Compact pump or motor with internal swash plate |
US6651794B2 (en) * | 2001-12-07 | 2003-11-25 | Caterpillar Inc | Hydro-mechanical combiner |
-
2005
- 2005-09-15 WO PCT/US2005/032856 patent/WO2006031935A1/en active Application Filing
- 2005-09-15 EP EP05796351A patent/EP1789678A1/en not_active Withdrawn
- 2005-09-15 AU AU2005284802A patent/AU2005284802A1/en not_active Abandoned
- 2005-09-15 JP JP2007531471A patent/JP2008513649A/en active Pending
- 2005-09-15 CA CA002580022A patent/CA2580022A1/en not_active Abandoned
- 2005-09-15 CN CNA2005800308863A patent/CN101018949A/en active Pending
- 2005-09-15 US US11/574,807 patent/US20080075616A1/en not_active Abandoned
-
2007
- 2007-03-09 GB GB0704521A patent/GB2432197A/en not_active Withdrawn
Patent Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2732808A (en) * | 1956-01-31 | Fluid pump and control | ||
US1774663A (en) * | 1929-07-24 | 1930-09-02 | Arthur S Parks | Pump |
US2142086A (en) * | 1933-09-09 | 1939-01-03 | Ex Cell O Corp | Fuel pump |
US2579879A (en) * | 1949-12-10 | 1951-12-25 | Sundstrand Machine Tool Co | Gyratory valve for hydraulic pumps or motors |
US5058485A (en) * | 1986-11-04 | 1991-10-22 | Cardillo Joseph S | Ring valve pump |
US4877383A (en) * | 1987-08-03 | 1989-10-31 | White Hollis Newcomb Jun | Device having a sealed control opening and an orbiting valve |
US5733105A (en) * | 1995-03-20 | 1998-03-31 | Micropump, Inc. | Axial cam driven valve arrangement for an axial cam driven parallel piston pump system |
US6224349B1 (en) * | 1998-08-27 | 2001-05-01 | Denso Corporation | Reciprocating type compressor having orbiting valve plate |
US6572344B1 (en) * | 2001-11-26 | 2003-06-03 | Caterpillar Inc | Compact pump or motor with internal swash plate |
US6651794B2 (en) * | 2001-12-07 | 2003-11-25 | Caterpillar Inc | Hydro-mechanical combiner |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11408407B2 (en) | 2016-07-25 | 2022-08-09 | Caire Inc. | Wobble plate compressor and oxygen concentrator using the same |
US20220033201A1 (en) * | 2019-01-11 | 2022-02-03 | Rorze Lifescience Inc. | Drive mechanism capable of dealing with gas sterilization |
Also Published As
Publication number | Publication date |
---|---|
JP2008513649A (en) | 2008-05-01 |
GB0704521D0 (en) | 2007-04-18 |
AU2005284802A1 (en) | 2006-03-23 |
EP1789678A1 (en) | 2007-05-30 |
CA2580022A1 (en) | 2006-03-23 |
GB2432197A (en) | 2007-05-16 |
CN101018949A (en) | 2007-08-15 |
WO2006031935B1 (en) | 2006-05-11 |
WO2006031935A1 (en) | 2006-03-23 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7451687B2 (en) | Hybrid nutating pump | |
US7635255B2 (en) | Long piston hydraulic machines | |
JPH0261627B2 (en) | ||
JPWO2012017820A1 (en) | Fluid rotating machine | |
JP6573605B2 (en) | Spin pump with planetary rotation mechanism | |
EP3812588A1 (en) | Piston pump and piston motor | |
US6450777B2 (en) | Fluid pumping apparatus | |
US20080075616A1 (en) | Orbiting Valve For A Reciprocating Pump | |
JPH01310181A (en) | Movable slant plate type compressor | |
US20110268596A1 (en) | Fluid device with flexible ring | |
JP3986764B2 (en) | Hydrostatic continuously variable transmission | |
JPH02169878A (en) | Variable positive-displacement | |
EP3438451B1 (en) | Hydraulic rotary machine | |
JP7044652B2 (en) | Hydraulic rotary machine | |
WO2008013162A1 (en) | Compressor | |
JP2007524026A (en) | Hybrid perturbation pump | |
JP3744861B2 (en) | Compressor | |
JP2007162534A (en) | Bidirectional reversible common mechanism for internal combustion engine and pump | |
JP2012026437A (en) | Micro compressor | |
JP2002061586A (en) | Spherical rotating piston pump and compressor | |
JP2874258B2 (en) | Multiple piston pump | |
US6733248B2 (en) | Fluid pumping apparatus | |
KR100715261B1 (en) | Variable displacement swash plate type compressor | |
JPH01138381A (en) | Pulsation reducing mechanism for compressor | |
JPH0518350A (en) | Capacity control device of variable capacity type axial piston machine |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: THOMAS INDUSTRIES, INC., WISCONSIN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:LYNN, HARRY;ROZEK, ROY;REEL/FRAME:018969/0084 Effective date: 20050914 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |
|
AS | Assignment |
Owner name: UBS AG, STAMFORD BRANCH. AS COLLATERAL AGENT, CONN Free format text: SECURITY AGREEMENT;ASSIGNORS:GARDNER DENVER THOMAS, INC.;GARDNER DENVER NASH, LLC;GARDNER DENVER, INC.;AND OTHERS;REEL/FRAME:030982/0767 Effective date: 20130805 |
|
AS | Assignment |
Owner name: CITIBANK, N.A., AS ADMINISTRATIVE AND COLLATERAL A Free format text: ASSIGNMENT OF PATENT SECURITY INTEREST;ASSIGNOR:UBS AG, STAMFORD BRANCH;REEL/FRAME:049738/0387 Effective date: 20190628 |