COMPRESSOR
A compressor includes a cylinder assembly in a V4 configuration. A crankshaft of the compressor has a main shaft and first and second eccentric bodies. The two eccentric bodies drive four pistons.
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The present application is based on and claims priority to Application Ser. No. 61/234,330 filed Aug. 17, 2010, the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTIONThe present application relates to the field of gas compressors.
BACKGROUNDOxygen has many important medical uses including, for example, assisting patients that have congestive heart failure or other diseases. Supplemental oxygen allows patients to receive more oxygen than is present in the ambient atmosphere. Systems and methods for delivering such oxygen typically include a compressor as a component. U.S. Pat. No. 5,988,165, for example, discloses the use of an inline compressor for this purpose, U.S. Pat. No. 6,923,180 discloses the use of a radial compressor for this purpose, and U.S. Patent Application Publication Pub. No. 2007/0065301 discloses an in-line compressor for this purpose. U.S. Pat. Nos. 5,988,165 and 6,923,180 and U.S. Patent Application Pub. No. 2007/0065301 are incorporated herein by reference in their entirety.
SUMMARY OF THE INVENTIONThe present application discloses embodiments of a gas compressor. For example, compressors that are suitable for compressing oxygen. In one exemplary embodiment, a compressor for compressing gas comprises first, second, third and fourth cylinders. The central axis of the first cylinder is generally parallel with a central axis of the second cylinder and a central axis of the third cylinder is generally parallel with the central axis of the fourth cylinder. The axes of the first and second cylinders are oriented at an angle with respect to the axes of the third and fourth cylinders to form a V4 cylinder configuration. First, second third and fourth pistons are disposed in the first, second, third and fourth cylinders. A crankshaft has a main shaft and only two eccentric driving bodies that drive the first, second, third, and fourth pistons.
In one exemplary embodiment, a compressor includes a crankshaft having a main shaft that includes a crank axis about which the crankshaft rotates. The crankshaft includes first and second circular driving bodies that extend radially outward from and are eccentric to the crank axis. The first circular connecting rod driving body abuts the second circular connecting rod driving body. Two drive or connecting rods are rotatably connected to each of the first and second circular connecting rod driving bodies, such that rotation of the first and second circular connecting rod bodies about the crank axis reciprocates the four drive or connecting rods.
Further features and advantages of the present invention will become apparent to those of ordinary skill in the art to which the invention pertains from a reading of the following description together with the accompanying drawings, in which:
As described herein, when one or more components are described as being connected, joined, affixed, coupled, attached, or otherwise interconnected, such interconnection may be direct as between the components or may be in direct such as through the use of one or more intermediary components. Also as described herein, reference to a “member,” “component,” or “portion” shall not be limited to a single structural member, component, or element but can include an assembly of components, members or elements.
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The cylinders 36A-36D and corresponding pistons 40A-40D are of varying diameters and as a result, the stroke of each piston 40A-40D in its respective cylinder results in a different displacement of gas during the stroke of each piston. The concept of pistons 40A-40D having different strokes from one another may optionally be implemented in the compressor 10. If the strokes of the pistons are different from one another, one or more of the pistons may have the same diameter as one or more other pistons. In the illustrated embodiment, the first cylinder 36A is the largest in diameter, the second cylinder 36B is smaller than the first cylinder, the third cylinder 36C is smaller yet, and the fourth cylinder 36D is the smallest. In other embodiments, the compressor may have more than four cylinders or fewer than four cylinders.
As indicated above, the upper sleeves 30A-30D are in engagement with lower sleeves 20A-20D. The openings 26A-26D in the lower guide sleeves align with the cylinders 36A-36D in the upper cylinder sleeves. The compressor 10 may include one or more guides that are slideably disposed in the openings 26A-26D. Referring to
In the illustrated embodiment, no guide is disposed in the opening 26A. The first piston 40A is fixed for movement with the drive or connecting rod 52A. This arrangement is referred to as a “wobble piston,” because fixing the piston 40A to the connecting rod 52A causes some amount of canting or wobbling as the piston 40A moves in the cylinder 36A. Alternatively, the first piston 40A could be pivotally connected to the connecting rod 52A in a conventional manner. In this embodiment, the first piston 40A will slide in the cylinder 36A without significant canting or wobbling. The illustrated connecting or drive rod 52A includes a ring portion 53A for rotatable connection to a crankshaft 50.
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The crankshaft 50 includes a main shaft 70 having a generally cylindrical configuration defined by a cylindrical outer surface centered on a crank axis X of the compressor 10. The crankshaft 50 rotates about the crank axis X during operation of the compressor 10. In the illustrated embodiments, the main shaft 70 has externally threaded opposite end portions 78 and 80. Referring to
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The connecting rod drive bodies 84A, 84B may take a wide variety of different forms. In the embodiments illustrated by
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The first eccentric connecting rod driving body 84A drives both the first and third pistons 40A, 40C. Referring to
Rotation of the main shaft 70 about the crank axis X results in reciprocating movement of pistons 40A-40D in the cylinders 36A-36D. A drive pulley (not shown) may be located on one of the end portions 78 of the main shaft 70 to facilitate the application of a drive torque to the main shaft 70, to reciprocate the pistons 40A-40D.
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A plurality of components are located in the component chamber 114 of the cylinder heads 110A, 110B. The components direct fluid flow between the inlet 118 of the first head 110A, the cylinders 36A-36D and the outlet 120 of the second head 110B. The components include a plurality of check valves 130A-130F for controlling flow of air into and out of the various cylinders 36A-36D, and a plurality of components or structures for positioning the check valves in the chamber 114 and inhibiting gas flow around the check valves (i.e. leakage around the check valves). In one exemplary embodiment, the components for positioning the check valves are spacers and are configured to direct air to flow between the check valves. The check valves may also be spaced apart in a variety of ways, other than using spacers. For example, one or more of the check valves may thread into the component chamber 114, the component chamber may include a stop surface, etc. Any manner of positioning the check valves may be used. In the drawings, arrangements for setting the position of the check valves with respect to the inlets 118 and outlets 120 of the cylinder heads 110A, 110B are not shown. However, it is understood that spacers or another positioning arrangement would be used to position the illustrated check valves and spacers as shown. For example, U.S. Patent Application Publication, Pub. No. 2007/0065301 shows that inlet and outlet connectors 180, 196 may engage spacers that fix the position of the valves. The components located in the component chamber may also include a plurality of seals that prevent leakage around the check valves.
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Spacers 150A-150D are positioned in the chamber 114 and space the check valves 130A-130F apart.
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A small diameter central opening 170 extends for the length of the short spacer between the upstream end portion 164 and the downstream end portion 166. The spacer 150A also has an internal passage 172 that extends radially outward from the central passage 170 and terminates in a groove 174 on the outer surface of the spacer 150A. As a result, fluid communication is established between the upstream and downstream end portions 164 and 166 of the spacer 150A, and the external groove 174.
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An inlet check valve 130E is positioned in the component chamber 114 in the first cylinder head 110A. The inlet opening 138 of the inlet check valve 130E is in communication with the inlet 118 of compressor 10. In an exemplary embodiment, a seal may be provided between the check valve and the component chamber 114.
The spacer 150A is positioned in the component chamber 114 in the cylinder head 110 such that an upstream end of the spacer 154A engages the downstream end of the inlet check valve 130E. The external groove 174 on the spacer 162 aligns with the first charging port 122A in the cylinder head 110A. As a result, fluid communication can be established between the component chamber 114 and the first cylinder 36A. (See
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A spacer 150C is positioned in the component chamber 114 in the cylinder head 110B. The upstream end of the spacer 150C engages the downstream end of the check valve 130C. The central opening 155 of the spacer 150C aligns with the central opening of the check valve 130C. The external groove 160 of the spacer 150C aligns with the charging port 122C in the cylinder head 110B. As a result, fluid communication can be established between the component chamber 114 and the third cylinder 36C (See
A fifth check valve, or third cylinder check valve, 130D is positioned in the component chamber 114 in the cylinder head 110B. The upstream end of the check valve 130D engages the downstream end of the spacer 150C. The opening 138 of the check valve 130D aligns with the passage 155 in the spacer 150C. A seal may be provided between spacer 150C and the check valve 130D.
A spacer 150D is positioned in the component chamber 114 in the cylinder head 110B. The upstream end of the spacer 150D engages the downstream end of the third cylinder check valve 130D. The central opening 156 of the spacer 150D aligns with the central chamber of the check valve 130D. The external groove 160 at the downstream end of the fourth spacer 150D aligns with the fourth charging port 122D in the cylinder head 110. As a result, fluid communication can be established between the component chamber 114 and the fourth cylinder 36D.
A sixth check valve, or fourth cylinder check valve 130F is positioned in the component chamber 114 in the cylinder head 110B. The upstream end of the fourth cylinder check valve 130F engages the downstream end of the spacer 150D. The opening 138 of the check valve aligns with the central passage 155 in the spacer 150D. An optional seal is provided between the spacer 150D and the check valve 130D.
An outlet connector 196 is fixed to the downstream end of the cylinder head 110B. The outlet connector 196 has a fluid outlet passage 198 that is in fluid communication with the component chamber 114 of the cylinder head 110B. In the illustrated embodiments, all the check valves 130A-F of the compressor 10 are located in the cylinder heads 110A, 110B.
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When the compressor 10 is at the portion of its cycle in which the first cylinder 36A is on the intake phase, the pressure in the first cylinder is lower than the intake pressure. As a result, intake gas flows through the inlet check valve 130E and into the spacer 150A.
The gas flows from the central passage 170 (See
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When the first piston 40A thereafter is compressing the air in the first cylinder 36A, the pressure in the first cylinder becomes higher than the intake pressure. As a result, intake air can not flow upstream through the inlet check valve 130E into the spacer 150A. Therefore, all the air flowing out of the first cylinder is directed through the first charging port 122A, the spacer 150A, and through the second check valve 130A.
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The timing of the first and second cylinders 36A and 36B is selected so that when the first cylinder 36A is on its exhaust phase, the second cylinder 36B is on its intake phase. This is achieved by the 180 degree offset β between the first and second eccentric bodies 84A, 84B. The air that is compressed in the first cylinder 36A and forced into the second spacer 150B is able to flow into the second cylinder 36B, to be further compressed, because the second cylinder is smaller in diameter than the first cylinder but has the same stroke in the illustrated exemplary embodiment.
During the time the second cylinder 36A is being charged by the first cylinder 36B, the air flowing through the second spacer 150B does not flow through the third check valve 130B, even through the second spacer is open to the third check valve. This is because the pressure downstream of the third check valve 130B, (i.e., the pressure in the third cylinder 36C), is higher than the pressure at the third check valve. Therefore, the third check valve 130B stays closed and the air flows into the second cylinder 36B.
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Gas not directed to the patient is carried via line 222 to two-way valve 224. A very small portion of the gas in the flow line 220 is directed through line 226 and restrictor 228 into an oxygen sensor 230 which detects whether or not the concentration of the oxygen is of a predetermined value, for example, at least 84 percent as directed to the patient and at least 93±3% as directed to the compressor.
When the oxygen sensor 230 detects a concentration at or above the predetermined level, the two-way valve 224 is kept open to permit the oxygen-enriched gas to flow through the valve 224 and line 232 into a buffer tank 234 wherein the pressure is essentially the same as the pressure in the product tank 214. However, should the oxygen sensor 230 not detect a suitable oxygen concentration, two-way valve 224 is closed so that the oxygen concentrator 212 can build up a sufficient oxygen concentration. This arrangement prioritizes the flow of oxygen-enriched gas so that the patient is assured of receiving a gas having a sufficient oxygen concentration therein.
Buffer tank 234 can have a regulator 236 thereon generally set at 12 psi to admit the oxygen-enriched gas to the compressor 10 when needed. The output of the compressor 10 is used to fill a cylinder or portable tank 238 for ambulatory use by the patient. Alternatively, the pressure regulator 236 can be set at anywhere from about 13 to about 21 psi. A restrictor 240 controls the flow rate of gas from the buffer tank 234 to the compressor 10. Should the operation of the compressor 10 cause the pressure in the buffer tank 234 to drop below a predetermined value, a pressure sensor (not shown) automatically cuts off the flow of gas at a pressure above the pressure of the gas being fed to the patient. This prioritization assures that the patient receives priority with regard to oxygen-enriched gas.
The foregoing description relates to a four-cylinder compressor. However, the features described in this application are applicable to compressors that have different numbers of cylinders. In addition, disclosed features may be used in compressors having cylinder heads with different check valve and spacer designs.
While the present invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Still further, while cylindrical components have been shown and described herein, other geometries can be used including elliptical, polygonal (e.g., square, rectangular, triangular, hexagonal, etc.) and other shapes can also be used. Therefore, the invention, in its broader aspects, is not limited to the specific details, the representative apparatus, and illustrative examples shown and described. Accordingly, departures can be made from such details without departing from the spirit or scope of the applicant's general inventive concept.
Claims
1. A compressor for compressing gas, comprising:
- first, second, third and fourth cylinders, wherein a central axis of the first cylinder is parallel with a central axis of the second cylinder and a central axis of the third cylinder is parallel with the central axis of the fourth cylinder, wherein axes of the first and second cylinders are oriented at an angle with respect to the axes of the third and fourth cylinders to form a V4 cylinder configuration;
- first, second, third and fourth pistons disposed in the first, second, third and fourth cylinders;
- a crankshaft having a main shaft and only two eccentric driving bodies that drive the first, second, third, and fourth pistons.
2. The compressor of claim 1 wherein an angle formed between the axes of the first and second cylinders and the axes of the third and fourth cylinders is ninety degrees.
3. The compressor of claim 1 further comprising a head assembly that routes gas compressed in the first cylinder to the second cylinder, gas compressed in the second cylinder to the third cylinder, and gas compressed in the third cylinder to the fourth cylinder.
4. The compressor of claim 1 wherein the first cylinder has a first diameter, the second cylinder has a second diameter, the third cylinder has a third diameter, and the fourth cylinder has a fourth diameter, wherein the first diameter is larger than the second diameter, the second diameter is larger than the third diameter, and the third diameter is larger than the fourth diameter.
5. A compressor for compressing a gas, comprising:
- a cylinder assembly having a first cylinder having a first diameter, a second cylinder having a second diameter, a third cylinder having a third diameter, and a fourth cylinder having a fourth diameter, wherein the first diameter is larger than the second diameter, the second diameter is larger than the third diameter, and the third diameter is larger than the fourth diameter, wherein the first cylinder is in-line with the second cylinder, wherein third cylinder is in-line with the fourth cylinder, wherein the first and second cylinders form and angle of approximately ninety degrees with respect to the third and fourth cylinders such that the cylinder assembly is a V4 configuration;
- first, second, third and fourth pistons received in the first, second, third, and fourth cylinders respectively;
- first, second, third, and fourth drive rods arranged to move the first, second, third, and fourth pistons in the first, second, third, and fourth cylinders;
- a crankshaft having a main shaft that includes a crank axis about which the crankshaft rotates, wherein the crankshaft includes first and second circular connecting rod driving bodies that extend radially outward from and are eccentric to the crank axis, wherein the first and third drive rods are rotatably connected to the first circular connecting rod driving body such that rotation of the first circular connecting rod body about the crank axis reciprocates the first and third drive rods and wherein the second and fourth drive rods are rotatably connected to the second circular connecting rod driving body such that rotation of the second circular connecting rod body about the crank axis reciprocates the second and fourth drive rods;
- a gas inlet for providing a source of gas to the first cylinder, a first gas flow passage for providing the gas from the first cylinder to the second cylinder, a second gas flow passage for providing the gas from the second cylinder to the third cylinder, a third gas flow passage for providing the gas from the third cylinder to the fourth cylinder, and a gas outlet for providing the gas out of the compressor in a compressed state.
6. The compressor of claim 5 wherein the first and second circular connecting rod driving bodies are the only connecting rod driving bodies of the crankshaft.
7. The compressor of claim 5 wherein the connecting rod driving bodies each consist of a single continuous cylinder.
8. The compressor of claim 5 wherein the connecting rod driving bodies each consist of a single continuous cylinder integrally formed with the main shaft.
9. The compressor of claim 5 wherein the first connecting rod driving body abuts the second connecting rod driving body.
10. The compressor of claim 7 wherein the first connecting rod driving body abuts the second connecting rod driving body.
11. The compressor of claim 8 wherein the first connecting rod driving body abuts the second connecting rod driving body.
12. The compressor of claim 5 wherein the first connecting rod driving body is connected to the second connecting rod driving body only at an area of overlap between the first connecting rod driving body and the second connecting rod driving body.
13. The compressor of claim 5 wherein the first connecting rod driving body is connected to the second connecting rod driving body by a circular disk disposed between the first connecting rod driving body and the second connecting rod driving body.
14. The compressor of claim 13 wherein the circular disk is centered on the crank axis.
15. The compressor of claim 14 wherein an outer circumference of the circular disk extends outward of the outer circumference of both of the first and second connecting rod driving bodies.
16. The compressor of claim 8 wherein the first connecting rod driving body is connected to the second connecting rod driving body by a circular disk that is integrally formed with and disposed between the first connecting rod driving body and the second connecting rod driving body.
17. The compressor of claim 5 wherein the first piston comprises a wobble piston.
18. The compressor of claim 5 wherein the second piston comprises a guide member pivotably connected to the second drive rod and a compression member that is separate from the guide member disposed in the second cylinder.
19. The compressor of claim 5 wherein the guide member engages the compression member to force the compression member toward a head end of the second cylinder during a compression stroke of the second drive rod.
20. The compressor of claim 19 wherein pressurized gas forced into the second cylinder by the first piston forces the compression member toward a crank end of the second cylinder during a charging stroke of the second drive rod.
21. The compressor of claim 5 wherein a first bearing support portion of the crankshaft has a diameter that is less than a diameter of the first circular connecting rod driving body.
22. A compressor for compressing a gas, comprising:
- a cylinder assembly having a first cylinder having a first diameter, a second cylinder having a second diameter, a third cylinder having a third diameter, and a fourth cylinder having a fourth diameter, wherein the first diameter is larger than the second diameter, the second diameter is larger than the third diameter, and the third diameter is larger than the fourth diameter, wherein the first cylinder is in-line with the second cylinder, wherein third cylinder is in-line with the fourth cylinder;
- first, second, third and fourth pistons received in the first, second, third, and fourth cylinders respectively;
- first, second, third, and fourth drive rods arranged to move the first, second, third, and fourth pistons in the first, second, third, and fourth cylinders;
- a crankshaft having a main shaft that includes a crank axis about which the crankshaft rotates, wherein the crankshaft includes first and second circular connecting rod driving bodies that extend radially outward from and are eccentric to the crank axis, wherein the first circular connecting rod driving body abuts the second circular connecting rod driving body, wherein the first and third drive rods are rotatably connected to the first circular connecting rod driving body such that rotation of the first circular connecting rod body about the crank axis reciprocates the first and third drive rods and wherein the second and fourth drive rods are rotatably connected to the second circular connecting rod driving body such that rotation of the second circular connecting rod body about the crank axis reciprocates the second and fourth drive rods;
- a gas inlet for providing a source of gas to the first cylinder, a first gas flow passage for providing the gas from the first cylinder to the second cylinder, a second gas flow passage for providing the gas from the second cylinder to the third cylinder, a third gas flow passage for providing the gas from the third cylinder to the fourth cylinder, and a gas outlet for providing the gas out of the compressor in a compressed state.
23. The compressor of claim 22 wherein the first and second circular connecting rod driving bodies are the only connecting rod driving bodies of the crankshaft.
24. The compressor of claim 22 wherein the connecting rod driving bodies each consist of a single continuous cylinder.
25. The compressor of claim 22 wherein the connecting rod driving bodies each consist of a single continuous cylinder integrally formed with the main shaft.
26. The compressor of claim 22 wherein the first connecting rod driving body is connected to the second connecting rod driving body only at an area of overlap between the first connecting rod driving body and the second connecting rod driving body.
27. The compressor of claim 22 wherein the first piston comprises a wobble piston.
28. The compressor of claim 22 wherein the second piston comprises a guide member pivotably connected to the second drive rod and a compression member that is separate from the guide member disposed in the second cylinder.
29. The compressor of claim 22 wherein the guide member engages the compression member to force the compression member toward a head end of the second cylinder during a compression stroke of the second drive rod.
30. The compressor of claim 29 wherein pressurized gas forced into the second cylinder by the first piston forces the compression member toward a crank end of the second cylinder during a charging stroke of the second drive rod.
Type: Application
Filed: Aug 17, 2010
Publication Date: Feb 17, 2011
Applicant: Invacare Corporation (Elyria, OH)
Inventors: Gerold Goertzen (Homerville, OH), Michael R. Nemcek (Avon, OH), Bradley A. Kushner (Elyria, OH), William A. Null, JR. (Sullivan, OH)
Application Number: 12/857,844