US3778192A - Method and apparatus for unloading a rotary compressor - Google Patents
Method and apparatus for unloading a rotary compressor Download PDFInfo
- Publication number
- US3778192A US3778192A US00242166A US3778192DA US3778192A US 3778192 A US3778192 A US 3778192A US 00242166 A US00242166 A US 00242166A US 3778192D A US3778192D A US 3778192DA US 3778192 A US3778192 A US 3778192A
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- United States
- Prior art keywords
- compressor
- outlet
- air
- pressure
- arrangement according
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- Expired - Lifetime
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
- F04C29/12—Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet
- F04C29/124—Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet with inlet and outlet valves specially adapted for rotary or oscillating piston pumps
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
- F04C28/06—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids specially adapted for stopping, starting, idling or no-load operation
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
- F04C28/24—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
- F04C29/02—Lubrication; Lubricant separation
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C2270/00—Control; Monitoring or safety arrangements
- F04C2270/56—Number of pump/machine units in operation
Definitions
- Tilberry [57] ABSTRACT A method and apparatus are disclosed for relieving the fluid pressure at the outlet of an air compressor when the latter pressure exceeds the pressure of air in a compression cell of the compressor arriving at the outlet.
- the air pressure at the outlet is relieved by blocking backfiow of air under pressure at a point downstream from the outlet and transferring air under pressure at the outlet to a point downstream of the point of backflow blocking. Blocking is achieved by means of a fluid pressure responsive check valve in a flow path between the outlet and a point of use for the compressed air, and transfer of air under pressure from between the outlet and the check valve is achieved by an auxiliary compressor, having a smaller input capacity than the output of the main compressor.
- the auxiliary compressor and check valve cooperate to deliver the compressor output toward the point of use.
- the present invention relates ,to fluid compressors, such as air compressors, which are driven directly or indirectly by a suitable motor or internal combustion engine to compress a fluid and deliver the compressed fluid to a point of use such as might be defined, for example, by pneumatic tools such as jackhammers. While the invention will be described in conjunction with a particular type of air compressor, it will be understood that the principles of the invention are applicable to other types of compressors and to the compressing of fluids other than air.
- Compressors of the above character include a housing having a chamber therein and a driven component or components in the chamber which are driven by the drive motor.
- the driven member or members and chamber cooperate to define one or more compression cells adapted to receive air through a variable inlet leading to the chamber and to compress the air to a cell pressure for discharge through an outlet from the chamber, wherebytair at a discharge pressure is available for delivery to a point of use.
- Such compressors have a rated intake capacity, compression ratio and discharge pressure.
- the speed of the compressor drive motor and the sizeof the air inlet opening are generally controlled in accordance with discharge pressure so that compressor operation is achieved in accordance with the demand for compressed air at the point of use and so as to prevent the compressor output pressure from exceeding the rated magnitude. Accordingly, if the discharge pressure is at the rated magnitude and there is less than full demand for air delivery, the speed of the compressordrive is below the maximum therefor and the air inlet opening is throttled.
- Another object of the present invention is to provide for reducing the discharge pressure at the outlet of a compressor by blocking backflow through the compressor outlet and transferring fluid from between the compressor outlet and the point of backflow blocking.
- Yet another object of the present invention is to provide for decreasing the discharge pressure at the outlet of a compressor in a manner whereby backflow of fluid at discharge pressure into the compressor is reduced to advantageously decrease the load otherwiseimposed on the compressor drive.
- Still another object of the present invention is to reduce the discharge pressure at the outlet of a compressor by providing a second compressor of smaller capacity in series with the outlet of the compressor and in parallel with backflow preventing means for the second compressor to transfer fluid between the outlet and backflow preventing means to a point downstream of the backflow preventing means.
- Yet a further object of the present invention is the provision of a method to reduce the load imposed on the drive means of a fluid compressor during periodsof compressor operation in which a fluid back pressure is exerted on the compressor through the discharge outlet thereof.
- a compressor 10 which includes a housing 12 having a cylindrical chamber 14 therein and in which a rotary, bladed type compressing member 16 is disposed.
- Rotor 16 is suitably mounted on shaft 18 having one end thereof extending outwardly of one end of housing 12 for connection with compressor drive means 20 such as might be defined, for example, by an internal combustion engine having a drive shaft directly or indirectly. coupled to shaft 18 to impart rotation thereto.
- compressor drive means 20 such as might be defined, for example, by an internal combustion engine having a drive shaft directly or indirectly. coupled to shaft 18 to impart rotation thereto.
- the drive means can be defined by motor means other than an internal combustion engine.
- Rotor 16 is provided with a plurality of radially slidable blades 22, and rotor 16 and shaft 18 are eccentrically mounted in chamber 14 relative to the chamber axis by suitable bearing means at opposite ends of the rotor.
- the space between circumferentially adjacent blades 22, the outer surface 24 of the rotor therebetween and the inner surface of chamber 14 defines a compression cell for fluid to be compressed.
- Chamber 14 is provided with an inlet 26 and an outlet 28 at circumferentially spaced locations and, in a manner well known, fluid to be compressed enters a compression cell through inlet 26 and is carried by the cell and compressed therein during rotation of the rotor toward outlet 28.
- the compressed fluid flows through the outlet thus to provide fluid at the outlet at a discharge pressure. Fluid under pressure leaving the outlet is of course adapted to be delivered to a point of use, as described more fully hereinafter.
- control means 30 which is operable to vary the amount of air entering the compression cells.
- control means 30 is a fluid actuated variable valve assembly including a housing 31 having a fluid intake opening 32 and a fluid discharge opening 34 leading to inlet opening 26.
- a reciprocable valve element 36 is supported within housing 31 and is actuated by diaphragm component 38 to vary the quantity of air flowing through intake opening 32 toward outlet opening 34.
- Diaphragm 38 is biased by spring 40 in a direction to increase the size of the opening of intake 32 and is displaced by fluid under pressure entering chamber 42 therebehind to move valve element 36 in the direction to close opening 32.
- fluid under pressure for actuating diaphragm 38 is air delivered to chamber 42 through line 44 which leads to chamber 42 from the discharge side of the compressor.
- Means such as a suitable pressure responsive valve in line 44, is provided to prevent delivering of air to chamber 42 until the discharge air pressure reaches a predetermined magnitude such as, for example, the rated discharge pressure. It will be appreciated therefore that when air is discharged at or above the rated pressure valve element 36 is moved in a direction to close intake opening 32. Similarly, a reduction in discharge pressure from the rated magnitude results in movement of valve element 36 in the opposite direction by spring 40 to increase the airinlet opening.
- Air at outlet or discharge pressure from the compressor is delivered to drive motor 20 through a line 46 leading thereto from the discharge side of the compressor.
- Air flowing through line 46 is operable in conjunction with suitable control means associated with the motor to control the speed of the drive motor in accordance with compressor outlet pressure.
- suitable control means associated with the motor to control the speed of the drive motor in accordance with compressor outlet pressure.
- an increase in discharge pressure is operable to reduce engine speed and a reduction in discharge pressure is operable to increase the speed of the drive means.
- the speed control for the drive means and the air intake control are operable together to provide for a more uniform compressor operation in response to varying demands for compressed air during compressor operation.
- an oil separator unit 48 is employed in conjunction with the compressor and includes an oil reservoir section 50 from which oil 52 is delivered through line 54 to an oil filter assembly 56 having an outlet passage 58 through which oil is delivered to chamber 14.
- Suitable oil cooler means 59 is provided, and the oil delivered from reservoir 52 is circulated through the oil cooler before delivery to chamber 14 if the oil is above a predetermined temperature.
- compressed air discharged from the compressor is delivered through separator 48 to a point of use, and the separator operates to remove oil entrained in the compressed air.
- the separator includes filtering means 60 through which the compressed air passes for flow through separator outlet 62 leading to the point of use.
- Filter means 60 has an oil collecting pan or the like 64 associated therewith and in which oil separated from the compressed air collects.
- An aspirator line 66 has one end thereof disposed in the oil in pan 64 and the other end thereof is connected to fluid inlet housing 28, whereby oil is drawn from pan 64 and delivered to the fluid inlet housing by inlet air flow and thence through discharge opening 34 and chamber opening 26 of a compressor.
- the compressed air discharged from compressor 10 is adapted to be delivered to a point of use through separator 48 upon demand for compressed air at the point of use.
- the point of use is illustrated schematically at 68.
- the manner in which the compressed air is used at this point is not important to the present invention.
- an operator controlled pneumatic tool is located at the point of use and is connected to the outlet of separator 48 by suitable conduit means illustrated schematically and which may be defined, for example, by a flexible hose.
- suitable conduit means illustrated schematically and which may be defined, for example, by a flexible hose.
- the output of compressor is directed toward the point of use 68 along a flow path which includes separator 48 and line 70.
- the flow path further includes a flow path portion 72 between compressor outlet 28 and separator 48.
- Flow path portion 72 includes a secondcompressor 74 of smaller input capacitythan the output of compressor 10, and a fluid flow control valve 76.
- the second compressor and valve are connected in fluid flow parallel relationship and have the inlet sides thereof in flow communication with compressor outlet 28and the outlet sides thereof in flow communication with separator 48. More particularly, a flow line 78 extends from compressor outlet 28 to separator 48and valve 76 is interposed in line 78 downstream from outlet 28.
- Compressor 74 has an inlet 80 connected to line 78 by means of line 82 and has an outlet 84 connected to separator 48 through line 86.
- Compressor 74 is disposed in a housing 88 defining a chamber 90 in which a rotor 92 is disposed.
- Rotor 92 is similar to rotor 16 and in this respect includes a plurality of radially slidable blade components 94 cooperable with the rotor and chamber to define compression cells.
- Rotor 92 is mounted on a shaft 96 supported in housing 88 for rotation about an axis eccentric to the axis of chamber90.
- Compressor 74 may be supported relative to compressor 10 in any suitable manner and in the embodiment illustrated is mounted on one end of compressor 10 forshaft 96 to be axially aligned with shaft 18 of compressor 10.
- compressor 74 is adapted to bedriven by drive motor of compressor 10 and, accordingly, the adjacent ends of shafts 18 and 96 are suitably interconnected by coupling means 98.
- Any suitable coupling means may be employed and may, for example, rigidly interconnect shafts 18 and 96 for the shafts to be rotatable at the samespeed at all times.
- the coupling means may, however, advantageously be in the form of a clutch operable in response to suitable control means 100 to provide for selectively disengaging compressor 74 from compressor 19.
- the drive of compressor 74 by drive motor 20 could otherwise be achieved such as through suitable belt, chain or gear train assemblies, and that compressor 74 can be operated at a different speed from that of compressor 19, as pointed out more fully hereinafter.
- an integral common shaft could be employed for compressor rotors 16 and 92 rather than coupled shaft elements.
- Fluid flow control valve 76 in the embodiment illustrated, includes a ball valve element 102 biased by a coil spring 104 toward engagement with a valve seat 106 provided in valve housing 108.
- the valve permits fluid flow in the direction from outlet 28 of compressor 10 toward separator 48 and prevents backflow in the opposite direction by engagement of ball valve 102 with seat 106.
- the bias of spring 104 need only be of a magnitude sufficient to seat ball 102 because valve 76 is not intended to be responsive to a particular magnitude of fluid pressure exerted against the upstream side thereof in order to open. Accordingly, it will be appreciated that valve 76 could be vertically disposed and that ball 102 could be biased into engagement with seat 106 by its own weight only.
- Line 86 from compressor 74 opens into valve housing 108 downstream of ball valve 102, but it will be appreciated that line 86 could open into line 78 downstream of valve 76 or could extend to and open directly into separator 48.
- second or auxiliary compressor 74 has an input capacity less than the output of compressor 10.
- the'second compressor is not operable to reduce the outlet pressure thereof.
- Auxiliary compressor 74 can be of any" size smaller thanthat-compressor l0, and an auxiliary compressor havingan intake capacity V4 the output of compressor 10 has been found to work quite satisfactorily.
- a main compressor having a 100 cfm input capacity, an 8:1 compression ratio and a rated pressure of 100 psi will have an output, fully loaded, of 12.5 cfm at rated pressure.
- auxiliary compressor 74 having an input capacity of about 3.1 cfm would be desirable.
- the primary purpose of auxiliary compressor 74 is to deliver or transfer the air under pressure between outlet 28 and valve 76 downstream of the valve to prevent backflow into compressor 10 as described hereinabove. Accordingly, it is advantageous to reduce or eliminate any unnecessary work in connection with operation of the auxiliary compressor during normal operation of main compressor 10 when there is no backflow problem. This can be achieved as mentioned above by providing for the auxiliary compressor to be decoupled from drive motor 10 or otherwise rendered inoperable during normal operation of compressor 10.
- Another approach particularly suitable when the auxiliary compressor is directly coupled to drive motor 20 or is otherwise operated to be driven conti uously with compressor 10, is to provide for the auxiliary compressor to have a very low compression ratio of from about 1:1 to 2:] and preferably from about 1:1 to 15:1. Any work or loading of the drive motor 20 or a separate drive means for the auxiliary compressor resulting from driving the auxiliary compressor or during periods of normal operation of compressor 10 is superfluous and is advantageously reduced when the auxiliary compressor is continuously operated by providing for the auxiliary compressor to have a low compression ratio.
- auxiliary compressor 74 is operated independently of compressor l and only during those periods when scavanging of compressed air at discharge pressure from the outlet of compressor, 10 is desired, then it becomes advantageous to provide for the auxiliary compressor to have a higher compression ratio than 2:1 to further decrease the load on the drive motor 20 by providing less exposed compressor blade area at the discharge port of the auxiliary compressor against which back pressure exerts a force to load the drive.
- compressor 74 and valve 76 to reduce the discharge pressure of compressor 10 will be described assuming compressor 74 to have a compressed air input capacity A the output of compressor 10 and to be coupled therewith for rotors l6 and 92 to be driven simultaneously at the same rotational speed.
- compressor 74 Upon start-up of compressor 10 by drive motor 20, rotors l6 and 92 are driven simultaneously and the compressed air output of compressor 10 is delivered to separator 48 by compressor 74 until the output of compressor 10 reaches the input capacity of compressor 74 as measured, for example, in cubic feet per minute.
- the output pressure of compressor 10 opens valve 76 and the remainder of the output of compressor 10 flows to separator 48 through valve 76.
- compressor 10 when compressor 10 is operating to deliver its rated capacity, 25 percent of the output thereof is transferred from one side of valve 76 to the other by compressor 74 which, accordingly, merely operates to transfer'compressed air across the valve and does not operate to reduce the discharge pressure at the outlet of compressor 10.
- compressor 10' is operating at its rated capacity and air intake valve 36 moves in the direction to close inlet 32 in response,for example, to a decrease in demand for compressed air at point of use 68, less air is drawn into compressor 10 resulting in a lower pressure being established in the compression cells thereof when the cells move into communication with outlet 28. Since the pressure of air in the cells arriving at outlet 28 is less than the discharge pressure existing at the outlet, air under pressure at the outlet tends to flow back therethrough and into the compression cells. Such backflow is blocked by ball valve 102 which closes against seat 106 because the downstream pressure on the ball valve now exceeds the upstream pressure thereon.
- compressor 74 operates to scavange air under pressure between outlet 28 and valve 76. It will be noted that as the two compressors continue to operate under these conditions a back pressure load similar to that removed from compressor 10 exists at the discharge of compressor 74 and that this load is imposed as a work load on drive motor 20 since the drive motor is common to both compressors. The work load thus imposed on the motor by compressor 74, however, is much less than that which would be imposed thereon by compressor 10 if the discharge pressure of compressor 10 was not reduced.
- the work load on motor 20 in response to unloaded operation of compressor 10 would be 60 to percent of the work load on the motor when the compressor is operated fully loaded. If the input of compressor 74 is /4 the output of compressor 10 and compressor 74 has a compression ratio of 1:1, only about 25 percent of the power otherwise required to drive compressor 10 unloaded is required when the auxiliary compressor is employed. Thus, the work load imposed on drive motor 20 during unloaded operation of compressor 10 is, in the embodiment described, only 25 percent of the 60 to 70 percent of full work load heretofore imposed on drive motor 20.
- the work load imposed on drive motor 20 during unloaded operation of compressor 10 in the present embodiment is only 15 to 17.5 percent of the full work load requirement imposed on drive motor 20 in operating compressor 19 at its rated capacity. It will be appreciated, therefore, that the present arrangement provides for a substantial decrease in the requirements of power from drive motor 20 during operation of compressor 10 in an unloaded condition. Further, the 15 to 17.5 percent work load can be advantageously reduced by employing an auxiliary compressor having a compression ratio greater than 1:1 so that less blade area is exposed at the outlet thereof. Accordingly, if the auxiliary compressor is operated only when pressure unloading is desired and does not have to be driven continuously by the drive motor it becomes advantageous to use an auxiliary compressor having a higher compression ratio.
- the work load imposed on drive motor 20 during operation of compressor 10 from a fully loaded toward an unloaded condition will, of course, vary upwardly from the minimum percent work load imposed when compressor 10 is operating fully unloaded but, in any event, will be less than the work load which would be imposed on the drive motor in the absence of the discharge pressure reducing arrangement of the present invention. It will be further appreciated, that the percent work load achieved as described above will vary in accordance with the ratio of size between compressor 10 and second compressor 74.
- compressor 74 were of a size or capacity one-half the output of compressor 10 and had a compression ratio of 1:1, the power requirements of drive motor 20 during fully unloaded operation of compressor 10 would be 30 to 35 percent of the power required to drive compresv sor 10 fully unloaded without the discharge pressure reduction arrangement of the present invention. As mentioned above, this percentage would be reduced by use of an auxiliary compressor having a compression ratio greater than lzl.
- the second compressor In order for the discharge pressure reduction arrangement of the present invention to be operable, it is only necessary that the second compressor have a smaller input capacity than the output of the first compressor.
- the ratio of capacities of compressors l0 and 74 therefore, may be any desired ratio.
- the four-to-one ratio described hereinabove is merely one ratio which has been found to be highly satisfactory in providing the desired results.
- control means 100 can be actuated to cause declutching or uncoupling of the second compressor from the drive means during other periods of main compressor operation. If such decoupling is employed, the total compressed air output of compressor 10 would then be delivered to the point of use through valve 76.
- the clutch or coupling means could be controlled so as to cause compressor 74 to be actuated in response to the existence of the condition to be avoided, namely the existence of a discharge pressure at outlet 28 exceeding the pressure existing in the compression cells upon communication thereof with outlet 28.
- control means 100 could, for example, be a pressure responsive control operable in response to a sensed pressure delivered thereto from a suitable point in the compressor system.
- the two compressors are radially sliding vane type compressors
- the present invention is readily applicable to other types of compressors.
- the two compressors could be screw-type compressors.
- the two compressors need not be of the same type.
- one of the compressors could be a screw type compressor and the other a radially sliding vane type compressor.
- the two compressors could be physically separated and the drive shafts thereof interconnected with one another or separately interconnected with the drive means.
- the two compressors may have different rotational speed requirements foroperation at the rated capacity output thereof, whereby the shafts thereof would be suitably interconnected with one another or with drive means in a manner whereby each would be operable atits own rated speed.
- the two compressors could be independently driven by corresponding drive means. In the latter arrangement, a smaller drive unit would be required to drive the second compressor and, while the latter drive would be loaded during operation of the main compressor fully unloaded, the load on the larger drive means required for the main compressor would still advantageously be reduced during operation of the main compressor fully unloaded.
- An air compressor arrangement including housing means having inlet and outlet openings, driven rotor means in said housing and cooperable therewith to provide compression cell means for receiving air through said inlet compressing the air and delivering the compressed air to said outlet, means for controlling the volume of air entering said cell means through said inlet and thus the pressure of air delivered to said outlet by said-cell means, said control means including means responsive to the pressure of air discharged through said outlet to reduce the volume of air entering said cell means when said discharge pressure exceeds a predetermined magnitude, whereby said cell means then delivers compressed air to said outlet at a pressure below said predetermined magnitude, flow path means for compressed air discharged through said outlet, and means in said flow path to reduce the discharge pressure at said compressor outlet when said discharge pressure exceeds said predetermined magnitude and said control means reduces the volume of air entering said cell means, said pressure reducing means including means to block backflow of air under pressure toward said outlet and means to transfer air under pressure from between said outlet and blocking means to a point in said flow path downstream from said blocking means.
- said blocking means is tluid flow responsive valve means operable to permit air flow along said path in the direction leading from said outlet.
- said transferring means is a second compressor having second driven rotor means, and means interconnecting said driven rotor means of said compressor and said second driven rotor means of said second compressor.
- said blocking means is fluid pressure responsive valve means operable to permit air flow along said path in the direction leading from said compressor outlet.
Abstract
Description
Claims (12)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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US24216672A | 1972-04-07 | 1972-04-07 |
Publications (1)
Publication Number | Publication Date |
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US3778192A true US3778192A (en) | 1973-12-11 |
Family
ID=22913712
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US00242166A Expired - Lifetime US3778192A (en) | 1972-04-07 | 1972-04-07 | Method and apparatus for unloading a rotary compressor |
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US (1) | US3778192A (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2515382A1 (en) * | 1981-10-27 | 1983-04-29 | Maco Meudon Sa | REGULATOR DEVICE FOR A COMPRESSOR, AND IN PARTICULAR A SCREW COMPRESSOR |
US4497618A (en) * | 1983-09-12 | 1985-02-05 | General Motors Corporation | Combined vacuum pump and power steering pump assembly |
US5531571A (en) * | 1993-06-16 | 1996-07-02 | Atlas Copco Airpower, Naamloze Vennootschap | Regulating device with starting and stopping device for screw-type compressors, and starting and stopping device used hereby |
US5967761A (en) * | 1997-07-15 | 1999-10-19 | Ingersoll-Rand Company | Method for modulation lag compressor in multiple compressor system |
WO2002012692A1 (en) * | 2000-08-10 | 2002-02-14 | Conocophillips Company | Compressor starting torque converter |
US9145877B2 (en) | 2011-11-22 | 2015-09-29 | Thermo King Corporation | Compressor unloading device |
US20190277282A1 (en) * | 2018-03-06 | 2019-09-12 | Schwäbische Hüttenwerke Automotive GmbH | Vacuum pump sealing element |
US20230122823A1 (en) * | 2020-03-10 | 2023-04-20 | Atlas Copco Airpower N.V. | A lubricant recovery system |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1049894A (en) * | 1909-04-17 | 1913-01-07 | Gen Electric | Pumping system. |
CH114967A (en) * | 1924-05-05 | 1926-05-17 | Bbc Brown Boveri & Cie | Method for controlling centrifugal compressors. |
US1753280A (en) * | 1925-04-06 | 1930-04-08 | Bbc Brown Boveri & Cie | Compressor apparatus |
US1814857A (en) * | 1927-11-28 | 1931-07-14 | Voith Gmbh J M | Controlling apparatus for conduits |
US2218565A (en) * | 1937-05-01 | 1940-10-22 | Vickers Inc | Compound positive displacement pump circuit |
US2599701A (en) * | 1945-10-25 | 1952-06-10 | Eaton Mfg Co | Pumping system |
US2761387A (en) * | 1950-09-25 | 1956-09-04 | Gen Motors Corp | Fuel system |
US3168236A (en) * | 1963-09-05 | 1965-02-02 | Jaeger Machine Co | Oil scavenging system for a rotary compressor |
-
1972
- 1972-04-07 US US00242166A patent/US3778192A/en not_active Expired - Lifetime
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1049894A (en) * | 1909-04-17 | 1913-01-07 | Gen Electric | Pumping system. |
CH114967A (en) * | 1924-05-05 | 1926-05-17 | Bbc Brown Boveri & Cie | Method for controlling centrifugal compressors. |
US1753280A (en) * | 1925-04-06 | 1930-04-08 | Bbc Brown Boveri & Cie | Compressor apparatus |
US1814857A (en) * | 1927-11-28 | 1931-07-14 | Voith Gmbh J M | Controlling apparatus for conduits |
US2218565A (en) * | 1937-05-01 | 1940-10-22 | Vickers Inc | Compound positive displacement pump circuit |
US2599701A (en) * | 1945-10-25 | 1952-06-10 | Eaton Mfg Co | Pumping system |
US2761387A (en) * | 1950-09-25 | 1956-09-04 | Gen Motors Corp | Fuel system |
US3168236A (en) * | 1963-09-05 | 1965-02-02 | Jaeger Machine Co | Oil scavenging system for a rotary compressor |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2515382A1 (en) * | 1981-10-27 | 1983-04-29 | Maco Meudon Sa | REGULATOR DEVICE FOR A COMPRESSOR, AND IN PARTICULAR A SCREW COMPRESSOR |
US4497618A (en) * | 1983-09-12 | 1985-02-05 | General Motors Corporation | Combined vacuum pump and power steering pump assembly |
US5531571A (en) * | 1993-06-16 | 1996-07-02 | Atlas Copco Airpower, Naamloze Vennootschap | Regulating device with starting and stopping device for screw-type compressors, and starting and stopping device used hereby |
US5967761A (en) * | 1997-07-15 | 1999-10-19 | Ingersoll-Rand Company | Method for modulation lag compressor in multiple compressor system |
WO2002012692A1 (en) * | 2000-08-10 | 2002-02-14 | Conocophillips Company | Compressor starting torque converter |
US6463740B1 (en) * | 2000-08-10 | 2002-10-15 | Phillips Petroleum Company | Compressor starting torque converter |
JP2004506116A (en) * | 2000-08-10 | 2004-02-26 | コノコフィリップス カンパニー | Compressor starting torque converter |
EP1309778A4 (en) * | 2000-08-10 | 2005-07-06 | Conocophillips Co | Compressor starting torque converter |
EP2267289A1 (en) * | 2000-08-10 | 2010-12-29 | ConocoPhillips Company | Compressor starting torque converter |
JP4729240B2 (en) * | 2000-08-10 | 2011-07-20 | コノコフィリップス カンパニー | Compressor starting torque converter |
US9145877B2 (en) | 2011-11-22 | 2015-09-29 | Thermo King Corporation | Compressor unloading device |
US20190277282A1 (en) * | 2018-03-06 | 2019-09-12 | Schwäbische Hüttenwerke Automotive GmbH | Vacuum pump sealing element |
US11286929B2 (en) * | 2018-03-06 | 2022-03-29 | Schwäbische Hüttenwerke Automotive GmbH | Vacuum pump sealing element |
US20230122823A1 (en) * | 2020-03-10 | 2023-04-20 | Atlas Copco Airpower N.V. | A lubricant recovery system |
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Owner name: WELLS FARGO BUSINESS CREDIT, XEROX BUILDING, SUITE Free format text: SECURITY INTEREST;ASSIGNORS:DAVEY COMPRESSOR COMPANY, A CORP. OF OH.;AERO-DRI CORPORATION, A CORP. OF OH.;REEL/FRAME:004487/0367 Effective date: 19850614 Owner name: DAVEY COMPRESSOR COMPANY, AN OHIO CORP. Free format text: LICENSE;ASSIGNOR:WELLS FARGO BUSINESS CREDIT;REEL/FRAME:004487/0379 Effective date: 19850614 Owner name: AERO-DRI CORPORATION, A CORP. OF OH. Free format text: LICENSE;ASSIGNOR:WELLS FARGO BUSINESS CREDIT;REEL/FRAME:004487/0379 Effective date: 19850614 |
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Owner name: INDIANA NATIONAL BANK, THE, 11311 CORNELL PARK DRI Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:DAVEY COMPRESSOR COMPANY;AERO-DRI CORPORATION;REEL/FRAME:004663/0466 Effective date: 19861222 Owner name: AERO-DRI CORPORATION, A OHIO CORP. Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:WELLS FARGO BUSINESS CREDIT, A CA. CORP.;REEL/FRAME:004678/0446 Effective date: 19861222 |
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Owner name: FIRST NATIONAL BANK OF CINCINNATI, THE, 425 WALNUT Free format text: LICENSE;ASSIGNOR:DAVEY COMPRESSOR COMPANY;REEL/FRAME:004812/0207 Effective date: 19871006 |
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Owner name: AERO-DRI CORPORATION,OHIO Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:INDIANA NATIONAL BANK;REEL/FRAME:004849/0371 Effective date: 19871006 Owner name: DAVEY COMPRESSOR COMPANY,OHIO Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:INDIANA NATIONAL BANK;REEL/FRAME:004849/0371 Effective date: 19871006 Owner name: AERO-DRI CORPORATION, 11060 KENWOOD ROAD, CINCINNA Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:INDIANA NATIONAL BANK;REEL/FRAME:004849/0371 Effective date: 19871006 Owner name: DAVEY COMPRESSOR COMPANY, 11060 KENWOOD ROAD, CINC Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:INDIANA NATIONAL BANK;REEL/FRAME:004849/0371 Effective date: 19871006 |
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Owner name: DAVEY COMPRESSOR COMPANY, OHIO Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:STAR BANK, NATIONAL ASSOCIATION, CINCINNATI;REEL/FRAME:005597/0238 Effective date: 19901203 |
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