CA2947306C - Oil-free compressor crankcase cooling arrangement - Google Patents
Oil-free compressor crankcase cooling arrangement Download PDFInfo
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- CA2947306C CA2947306C CA2947306A CA2947306A CA2947306C CA 2947306 C CA2947306 C CA 2947306C CA 2947306 A CA2947306 A CA 2947306A CA 2947306 A CA2947306 A CA 2947306A CA 2947306 C CA2947306 C CA 2947306C
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- crankcase
- compressor
- compressor crankcase
- air
- inlet valve
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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
- 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
- F04B39/06—Cooling; Heating; Prevention of freezing
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- 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
- F04B37/00—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00
-
- 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
- F04B39/0005—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 adaptations of pistons
- F04B39/0022—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 adaptations of pistons piston rods
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- 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
- F04B39/0094—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 crankshaft
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- 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
- F04B39/06—Cooling; Heating; Prevention of freezing
- F04B39/066—Cooling by ventilation
-
- 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
- F04B39/08—Actuation of distribution members
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- 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
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- 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
- F04B39/12—Casings; Cylinders; Cylinder heads; Fluid connections
- F04B39/128—Crankcases
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- 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
- F04B39/16—Filtration; Moisture separation
Abstract
An oil-free compressor crankcase cooling arrangement includes a compressor crankcase, at least one piston cylinder supported in the compressor crankcase, a crankshaft assembly supported by the compressor crankcase and linked to a piston of the at least one piston cylinder by a connecting rod, at least one inlet valve supported on and in fluid communication with the compressor crankcase, and at least one outlet valve supported on and in fluid communication with the compressor crankcase. A cooling cross-flow of air is established between the at least one inlet valve and the at least one outlet valve to cool the compressor crankcase. The at least one inlet valve and the at least one outlet valve include check valves. A first nozzle is positioned on the at least one inlet valve, and a second nozzle is positioned on the at least one outlet valve.
Description
OIL-FREE COMPRESSOR CRANKCASE COOLING ARRANGEMENT
[0001]
BACKGROUND OF THE INVENTION
Fief dofittte Invention
[0001]
BACKGROUND OF THE INVENTION
Fief dofittte Invention
[0002] The present disclosure relates to the field of air compressors adapted for use on rail vehicles for supplying compressed air to pneumatic units associated with the rail vehicle and, in particular, to an oil-free compressor crankcase cooling arrangement for maintaining a safe operating temperature within the crankcase.
Description of Related Art
Description of Related Art
[0003] By design, an oil-free compresSOr utiliks specially designed bearings and composite sealing materials to allow the air compressor to operate without lubrication. An example lone such oil-free air compressor for a rail vehicle is disclosed in U.S. Patent Application No. 14/030,588 to Kapadia et al. filed on September 18, 2013, which may be referred to. While the specialized components and materials allow the bearing surfaces to survive the internal loading within the air compressor without lubrications, they do not benefit from the cooling effects that are provided by a large sump of oil included in an oil-flooded air compressor. Therefore, internal cooling must be provided by alternative means.
[0004] There are two common preexisting methods for achieving improved cooling within the crankcase of an oil-free air compressor. The first method is to not seal the crankcase and allow air to naturally move into and out of the crankcase. The second method is to draw the compressor inlet air through the crankcase prior to being introduced into the low pressure cylinders for compression.
[0005] There are several deficiencies to using the first method of allowing air to naturally move into and out of the crankcase. By leaving the crankcase open to atmosphere, contamination and debris from the surrounding environment is easily pulled into the crankcase and increases the wear of the bearing surfaces, especially the piston ring and cylinder surf ace that are more prone to contamination. Further, the open crankcase does not create a cooling flow through the crankcase but, instead, creates a wafting-like effect where Date Recue/Date Received 2021-09-14 WO 201 Sri 72145 PCT/US2015/030154 the same air is pulled in and pushed out of the crankcase. This fails to cool the internal components of the air compressor as efficiently as possible since the hot air pushed out of the air compressor is not moved away from the crankcase.
[0006] There are also several deficiencies in using the second method of drawing compressor inlet air through the crankcase prior to being introduced into the low pressure cylinders for compression. By pulling all of the inlet air through the crankcase before entering the first stage of compression, the second method does create a positive flow of fresh air through the crankcase that can be directed from a single inlet point to a single discharge point. However, when the air is routed through the crankcase prior to entering the first stage cylinder, the temperature of the air entering the compressor is higher than it would be if pulled directly into the cylinder. This has at least two effects on the air compressor. Firstly, any or the heat taken out of the crankcase is put back into the compressor within the primary compressing flow path resulting in a higher first stage component temperature.
This will = ultimately lead to a reduced life span for the inner air compressor components. Further, the increased temperature at the compressor inlet will result in a lower compressor efficiency as the inlet air temperature is inversely proportional to compressor efficiency.
Secondly, another deficiency becomes apparent if the air compressor utilizes head unluaders that are a conunon means to operate an air compressor in an idle mode (not compressing air). In this cycle, the head unloaders typically act to mechanically hold the inlet valves open. 13y holding the inlet valves open, the air compressor continues to rotate but will not compress air, as the atmospheric air pulled in during the intake stroke is pushed back to atmosphere through the inlet valves during what is normally the compression stroke. As the same air is cycled in and out of the cylinder, the temperature of the air increases during the unloaded cycle. If the cylinder inlet air is routed through the crankcase prior to the atmospheric connection, then the air in the crankcase will be pulled into the Hist stage cylinder then pushed back into the case during the unloaded cycle. Therefore. the air temperature within the case will increase in temperature during the unloaded cycle similar to the air at the cylinder inlet that increases during the unloaded cycle in any common reciprocating air compressor with head unionders.
Lastly. pulling the inlet air through the crankcase poor to introducing the air into the first stage cylinder may result in contamination from the crankcase being spread into the first stage cylinder. This includes wear debris from the piston rings and excess grease released from the scaled bearings that are both typical occurrences in an oil-free compressor. This contamination will wear on the valves of the air compressor and reduce the life span of the valves.
This will = ultimately lead to a reduced life span for the inner air compressor components. Further, the increased temperature at the compressor inlet will result in a lower compressor efficiency as the inlet air temperature is inversely proportional to compressor efficiency.
Secondly, another deficiency becomes apparent if the air compressor utilizes head unluaders that are a conunon means to operate an air compressor in an idle mode (not compressing air). In this cycle, the head unloaders typically act to mechanically hold the inlet valves open. 13y holding the inlet valves open, the air compressor continues to rotate but will not compress air, as the atmospheric air pulled in during the intake stroke is pushed back to atmosphere through the inlet valves during what is normally the compression stroke. As the same air is cycled in and out of the cylinder, the temperature of the air increases during the unloaded cycle. If the cylinder inlet air is routed through the crankcase prior to the atmospheric connection, then the air in the crankcase will be pulled into the Hist stage cylinder then pushed back into the case during the unloaded cycle. Therefore. the air temperature within the case will increase in temperature during the unloaded cycle similar to the air at the cylinder inlet that increases during the unloaded cycle in any common reciprocating air compressor with head unionders.
Lastly. pulling the inlet air through the crankcase poor to introducing the air into the first stage cylinder may result in contamination from the crankcase being spread into the first stage cylinder. This includes wear debris from the piston rings and excess grease released from the scaled bearings that are both typical occurrences in an oil-free compressor. This contamination will wear on the valves of the air compressor and reduce the life span of the valves.
[0007] There is a current need for an oil-free air compressor crankcase cooling arrangement that increases the cooling of the crankcase without increasing the contamination = of the internal components of the crankcase. There is also a current need for an oil-free air compressor crankcase cooling arrangement that maximizes the life of the internal dynamic components while maintaining the crankcase at a safe operating temperature.
SUMMARY OF THE INVENTION
SUMMARY OF THE INVENTION
[0008] In one embodiment, an oil-free compressor crankcase cooling arrangement for a rail vehicle includes a compressor crankcase, at least one piston cylinder supported in the compressor crankcase, a crankshaft assembly supported by the compressor crankcase and linked to a piston of the at least one piston cylinder by a connecting rod, at least one inlet, valve supported on and in fluid communication with the compressor crankcase, and at least one outlet valve supported on and in fluid communication with the compressor crankcase. A
cooling cross-flow of air is established between the at least one inlet valve and the at least one outlet valve to cool the compressor crankcase.
cooling cross-flow of air is established between the at least one inlet valve and the at least one outlet valve to cool the compressor crankcase.
[0009] The at least one inlet valve and the at least one outlet valve may include cheek valves. A first nozzle may be positioned on the at least one inlet valve, and a second nozzle may be positioned on he at least one outlet valve. An inlet air filter may be positioned on the at least one inlet valve. The inlet air filter may protect the compressor crankcase from contamination and debris. An inlet air filter may be positioned on the first nozzle of the at least one inlet valve. The inlet air filter may protect the compressor crankcase from contamination and debris. The compressor crankcase may define a cavity for housing the crankshaft assembly. The cooling cross-flow of air may be directed through the cavity of the compressor crankcase from a first side of the compressor crankcase to an opposing, second side of the compressor crankcase. The at least one inlet valve may be supported on a first side of the compressor crankcase and the at least one outlet valve may be supported on an opposing, second side of the compressor crankcase. The at least one inlet valve may be opened as air is pulled into the compressor crankcase during an upstroke of the at least one piston cylinder. The at least one outlet valve may he opened as air is pushed out of the compressor crankcase during a downstroke of the at least one piston cylinder.
An unloader valve assembly may be positioned on the at least one piston cylinder and may be configured to exhaust pressurized fluid from the al least one piston cylinder.
[00101 In another embodiment, a method of cooling an oil-free compressor crankcase of a = rail vehicle includes the steps of providing an oil-tree compressor including a compressor WO 2015/1721.15 PCT/US20151030154 crankcase, at least one piston cylinder supported in the compressor crankcase, a crankshaft assembly supported by the compressor crankcase and linked to a piston of the at least one piston cylinder by a connecting rod, at least one inlet valve supported on and in fluid communication with the compressor crankcase, and at least one outlet valve supported on and in fluid communication with the compressor crankcase; pulling air into the compressor crankcase via the at least one inlet valve: directing the air through the compressor crankcase;
and pushing the air out of the compressor crankcase via the at least one outlet valve.
[00111 A further step of the method may include opening the at least one inlet valve during an upstroke of the at least one piston cylinder. Air may be pulled into the compressor crankcase through the open inlet valve: A further step of the method may include opening the at least one outlet valve during a downstroke of the at least one piston cylinder. Air may be pushed out of the compressor crankcase through the open outlet valve. A
further step of the method may include establishing a cooling cross-flow of air that is directed from a first side of the compressor crankcase, over the crankshaft assembly, and out of an opposing, second side of the compressor crankcase. The at least one inlet valve may be supported on the first side of the compressor crankcase. The at least one outlet valve may be supported on the opposing, second side of the compressor crankcase. A first nozzle may be positioned on the at least one inlet valve and a second nozzle may be positioned on the at least one outlet valve.
Still further steps of the method may include providing an inlet air filter on the at least one inlet valve; and filtering the air that is pulled into the compressor crankcase via the at least one inlet valve using the inlet air filter. Further steps of the method may include providing an inlet air filler on the first nozzle of the at least one inlet valve; and filtering the air that is pulled lino the compressor crankcase via the at least one inlet valve using the inlet air filter.
The at least one inlet valve and the at least one outlet valve may include check valves. 'Me at least one inlet valve may be supported on the compressor crankcase on a first side of the at least one piston cylinder. 'file at least one outlet valve may be supported on the compressor crankcase on an opposing second side of the at least one piston cylinder. A
further step of the method may include providing an unloadcr valve assembly on the at least one piston cylinder.
Still a further step of the method may include exhausting Fluid from the at least one piston cylinder via the unloader valve assembly.
[0012] Further details and advantages will be understood from the following detailed description read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] FIG. I is a front perspective view of an oil-lice air compressor including a crankcase cooling arrangement in accordance with this disclosure.
[00141 FIG. 2 is a rear perspective view of the oil-free air compressor of FIG. 1.
[0015] FIG. 3 is a cross-sectional view of an oil-frec air compressor including a crankcase cooling arrangement in accordance with another embodiment of this disclosure.
[0016] FIG. 4 is another cross-sectional view of the oil-free air compressor of FIG. 3 in which a piston cylinder is on a downstroke.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] For purposes of the description hereinafter, spatial orientation terms, as used, shall relate to the referenced embodiment as it is oriented in the accompanying drawings. figures, or otherwise described in the following detailed description. However, it is to be understood that the embodiments described hereinafter may assume many alternative variations and configurations. It is also to be understood that the specific components, devices, features, and operational sequences illustrated in the accompanying drawings, figures, or otherwise described herein are simply exemplary and should not be considered as limiting.
[0018] The present disclosure is directed to, in general, an oil-free compressor crankcase cooling arrangement and, in particular, to an oil-free compressor crankcase cooling arrangement including at least two valves used to create a cross-flow of cooling air through the compressor crankcase. Certain preferred and non-limiting embodiments of the components of the cooling arrangement are illustrated in FIGS. 1-4.
[0019] Referring to FIGS. 1-4, an air compressor 10 according to one embodiment of the = disclosure is shown. As shown, the air compressor 10 is a multi-cylinder air compressor 10 including a first piston cylinder 20, a second piston cylinder 30, a third piston cylinder 40, and a fourth piston cylinder 50. In ond embodiment, the air compressor 10 is an oil-free air compressor for a rail vehicle (not shown). The first piston cylinder 20, the second piston cylinder 30, the third piston cylinder 40, and the fourth piston cylinder 50 are supported by a compressor housing or crankcase 12 and each are driven by a crankshaft assembly 60 disposed within the compressor crankcase 12 and rotationally supported by the compressor crankcase 12. The compressor crankcase 12 may define a cavity 14 therein for housing the crankshaft assembly 60. The foregoing components of the air compressor 10 are described in detail herein. A inctimd of cooling the compressor crankcase 12 is described in further detail hereinbclow. The air compressor 10 may have a pentagonal-shaped cross-section.
A support member 13 may be fastened to a bottom surface of the air compressor 10. The support member 13 may he used to mount the air compressor 10 on a locomotive or rail vehicle (not shown).
[0020] The first piston cylinder 20, the second piston cylinder 30, the third piston cylinder 40, and the fourth piston cylinder 50 may be of substantially similar construction with the first piston cylinder 20 operating as the first cylinder, the second piston cylinder 30 operating as the second cylinder, the third piston cylinder 40 operating as the third cylinder, and the fourth piston cylinder 50 operating as the fourth cylinder in the multi-cylinder air compressor
An unloader valve assembly may be positioned on the at least one piston cylinder and may be configured to exhaust pressurized fluid from the al least one piston cylinder.
[00101 In another embodiment, a method of cooling an oil-free compressor crankcase of a = rail vehicle includes the steps of providing an oil-tree compressor including a compressor WO 2015/1721.15 PCT/US20151030154 crankcase, at least one piston cylinder supported in the compressor crankcase, a crankshaft assembly supported by the compressor crankcase and linked to a piston of the at least one piston cylinder by a connecting rod, at least one inlet valve supported on and in fluid communication with the compressor crankcase, and at least one outlet valve supported on and in fluid communication with the compressor crankcase; pulling air into the compressor crankcase via the at least one inlet valve: directing the air through the compressor crankcase;
and pushing the air out of the compressor crankcase via the at least one outlet valve.
[00111 A further step of the method may include opening the at least one inlet valve during an upstroke of the at least one piston cylinder. Air may be pulled into the compressor crankcase through the open inlet valve: A further step of the method may include opening the at least one outlet valve during a downstroke of the at least one piston cylinder. Air may be pushed out of the compressor crankcase through the open outlet valve. A
further step of the method may include establishing a cooling cross-flow of air that is directed from a first side of the compressor crankcase, over the crankshaft assembly, and out of an opposing, second side of the compressor crankcase. The at least one inlet valve may be supported on the first side of the compressor crankcase. The at least one outlet valve may be supported on the opposing, second side of the compressor crankcase. A first nozzle may be positioned on the at least one inlet valve and a second nozzle may be positioned on the at least one outlet valve.
Still further steps of the method may include providing an inlet air filter on the at least one inlet valve; and filtering the air that is pulled into the compressor crankcase via the at least one inlet valve using the inlet air filter. Further steps of the method may include providing an inlet air filler on the first nozzle of the at least one inlet valve; and filtering the air that is pulled lino the compressor crankcase via the at least one inlet valve using the inlet air filter.
The at least one inlet valve and the at least one outlet valve may include check valves. 'Me at least one inlet valve may be supported on the compressor crankcase on a first side of the at least one piston cylinder. 'file at least one outlet valve may be supported on the compressor crankcase on an opposing second side of the at least one piston cylinder. A
further step of the method may include providing an unloadcr valve assembly on the at least one piston cylinder.
Still a further step of the method may include exhausting Fluid from the at least one piston cylinder via the unloader valve assembly.
[0012] Further details and advantages will be understood from the following detailed description read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] FIG. I is a front perspective view of an oil-lice air compressor including a crankcase cooling arrangement in accordance with this disclosure.
[00141 FIG. 2 is a rear perspective view of the oil-free air compressor of FIG. 1.
[0015] FIG. 3 is a cross-sectional view of an oil-frec air compressor including a crankcase cooling arrangement in accordance with another embodiment of this disclosure.
[0016] FIG. 4 is another cross-sectional view of the oil-free air compressor of FIG. 3 in which a piston cylinder is on a downstroke.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] For purposes of the description hereinafter, spatial orientation terms, as used, shall relate to the referenced embodiment as it is oriented in the accompanying drawings. figures, or otherwise described in the following detailed description. However, it is to be understood that the embodiments described hereinafter may assume many alternative variations and configurations. It is also to be understood that the specific components, devices, features, and operational sequences illustrated in the accompanying drawings, figures, or otherwise described herein are simply exemplary and should not be considered as limiting.
[0018] The present disclosure is directed to, in general, an oil-free compressor crankcase cooling arrangement and, in particular, to an oil-free compressor crankcase cooling arrangement including at least two valves used to create a cross-flow of cooling air through the compressor crankcase. Certain preferred and non-limiting embodiments of the components of the cooling arrangement are illustrated in FIGS. 1-4.
[0019] Referring to FIGS. 1-4, an air compressor 10 according to one embodiment of the = disclosure is shown. As shown, the air compressor 10 is a multi-cylinder air compressor 10 including a first piston cylinder 20, a second piston cylinder 30, a third piston cylinder 40, and a fourth piston cylinder 50. In ond embodiment, the air compressor 10 is an oil-free air compressor for a rail vehicle (not shown). The first piston cylinder 20, the second piston cylinder 30, the third piston cylinder 40, and the fourth piston cylinder 50 are supported by a compressor housing or crankcase 12 and each are driven by a crankshaft assembly 60 disposed within the compressor crankcase 12 and rotationally supported by the compressor crankcase 12. The compressor crankcase 12 may define a cavity 14 therein for housing the crankshaft assembly 60. The foregoing components of the air compressor 10 are described in detail herein. A inctimd of cooling the compressor crankcase 12 is described in further detail hereinbclow. The air compressor 10 may have a pentagonal-shaped cross-section.
A support member 13 may be fastened to a bottom surface of the air compressor 10. The support member 13 may he used to mount the air compressor 10 on a locomotive or rail vehicle (not shown).
[0020] The first piston cylinder 20, the second piston cylinder 30, the third piston cylinder 40, and the fourth piston cylinder 50 may be of substantially similar construction with the first piston cylinder 20 operating as the first cylinder, the second piston cylinder 30 operating as the second cylinder, the third piston cylinder 40 operating as the third cylinder, and the fourth piston cylinder 50 operating as the fourth cylinder in the multi-cylinder air compressor
10. In one embodiment, the first piston cylinder 20, the second piston cylinder 30, the third piston cylinder 40, and the fourth piston cylinder 50 may be radially con figured about a longitudinal axis of the air compressor 10. The piston cylinders 20, 30, 40, 50 may interface with an outer circumference of the air compressor 10.
[00211 As shown in FIGS. 3 and 4, the first piston cylinder 20 includes a cylindrical housing 21 that has a first end 22a adapted to be inserted into a corresponding -opening, as described herein, in the compressor crankcase 12 and a second end 22h. The cylindrical housing 21 is formed with a liana: 23 located proximal the first end 22a for interfacing with the exterior of the compressor crankcase 12. Heat-dissipating fins 24 may be provided about the cylindrical housing 21, and the cylindrical housing 21 may he formed of any suitable material providing sufficient strength and heat-dissipating characteristics such as aluminum.
[0022] A cylinder head 25 is secured to the second end 22b of the cylindrical housing 21.
The cylinder head 25 generally comprises an air connecting unit 26 and an unloadcr cap 29 mechanically fastened to a top surface of the air connecting unit 26. The air connecting unit 26 includes a first air channel 27 and a 'second air channel 28. The air connecting unit 26 may be formed of any suitable material providing sufficient strength and heat transfer characteristics such as aluminum. The unloader cap 29 houses art anloader piston (not shown) that mechanically holds the inlet side of the valve assembly (not shown) open when pneumatic signal is piloted to the valve assembly. It is also to be understood that an electric signal may be used to pilot the valve assembly. When activated, the air compressor 10 will continue to operate without compressing air, thereby cooling the cavity 14 of the air compressor 10.
[0023] The first piston cylinder 20 may further include a first piston 70 that is reciprocally operable within the cylindrical housing 21. The piston 70 includes a first end 72a and a second end 720. and is made of any suitable material providing sufficient strength and heat transfer characteristics such as aluminum. The piston 70 is operatively connected to the crankshaft assembly 60 via a connecting rod 74. A cavity 76 may be defined in the cylindrical housing 21 to hold the piston 70. In operation, die piston 70 operates in a reciprocating movement which is generated via rotation of the crankshaft assembly 60. Air is drawn into the cavity 76 of the cylindrical housing 21 of the first piston cylinder 20 via one of the air channels 27, 28 as a result of the downward movement of the piston 70.
A valve assembly (not shown) may be associated with the cylinder head 25 and includes a portion that is opened during the downward movement of the piston 70, drawing air into the cylindrical housing 21, and closes during the upward movement. Further, the valve assembly may include another portion that closes during the downward movement of the piston 70 and opens during the upward movement of the piston 70. whereby air in the cylindrical housing 21 is compressed and is guided out of the cylindrical housing 21.
100241 As noted previously, the second piston cylinder 30, the third piston cylinder 40, and the fourth piston cylinder 50 have ir substantially similar construction to the first piston cylinder 20.
[0025] Referring to FIGS. 1 and 2, a first inlet valve 80 and a second inlet valve 82 are supported on a first side of the compressor crankcase 12. A first outlet valve 90 and a second outlet valve 92 may be supported on an opposing, second side of the compressor crankcase 12. The first inlet valve 80, the second inlet valve Si the first OW let valve 90. and the second outlet valve 92 may be in fluid communication with the compressor crankcase 12. In one embodiment, the first inlet valve 80, the second inlet valve 82, the first outlet valve 90, and the second outlet valve 92 may be check valves. In one embodiment, the first inlet valve 80, the second inlet valve 82, the first outlet valve 90, and the second outlet valve 92 may he ball-type check valves. In another embodiment, the first inlet valve 80, the second inlet valve 82, the first outlet valve 90, and the second outlet valve 92 may include an elastomer valve element (not shown) positioned between a seat (not shown) and guide member (not shown).
This type of cheek valve is commonly known as a "flapper" style check valve.
It is to be understood, however, that the use of alternative typii.s of check valves arc contemplated, such as a diaphragm check valve, a swine check valve, and a lift check valve, among others. In one embodiment, the first inlet valve 80, the second inlet valve 82, the first outlet valve 90, and the second outlet valve 92 may be used to establish a cooling cross-flow of air 16 between one another to cool the compressor crankcase 12. Although only two inlet valves and two outlet valves are shown in the drawings, it is contemplated that fewer or additional inlet valves and outlet valves !nay be supported on the compressor crankcase 12 to provide a reduced or greater amount of air for the cooling cross-flow 16 through the compressor crankcase 12. As shown in FIGS. .1 and 2, the first inlet valve 80 and the second inlet valve 82 may he positioned parallel to one. another, and the first outlet valve 90 and the second outlet valve 90 may be positioned parallel to one another. It is also to be understood, however, that die first inlet valve 80 and the second inlet valve 82 may he positioned in series with one another, and the first outlet valve 90 and the second outlet valve 92 may be positioned in series with one another. The configuration of the valves may be used according to the capacity needed in the air compressor 10 and to provide redundancy.
100261 In one embodiment, the first inlet valve 80 and the second inlet valve 82 may he supported on a lower portion of the compressor crankcase 12. The first outlet valve 90 and the second outlet valve 92 may be supported on an opposing, lower portion of the compressor crankcase 12. In one embodiment, the first inlet valve 80 and the second inlet valve 82 may be supported on the compressor crankcase 12 adjacent the first piston cylinder 20. The first outlet valve 90 and the second outlet valve 92 may be supported on the compressor crankcase 12 adjacent the fourth piston cylinder 50. Using this arrangement of the first inlet valve 80, the second inlet valve 82, the first outlet valve 90, and the second outlet valve 92, the cooling cross-flow of air 16 may be directed through the cavity 14 of the compressor crankcase 12 from the first side of the compressor crankcase 12 to the opposing, second side of the compressor crankcase 12. The cooling cross-flow of air 16 is directed over the crankshaft assembly 60 to provide cooling for the components of the crankshaft assembly 60 and the compressor crankcase 12. To establish this cooling cross-flow of air 16 in the compressor crankcase 11 air is pulled into the compressor crankcase 12 via the first inlet valve 80 and the second inlet valve 82. During an upstroke of the piston 70 in the cylindrical housing 21 of the first piston cylinder 20, the first inlet valve 80 and the second inlet valve 82 are opened by the air that is pulled into the compressor crankcase 12. The first inlet valve 80 and the second inlet valve 82 may be selected and/or adjusted according to the desired amount at air pressure that is necessary to open the first inlet valve 80 and the second inlet valve 82. During the upstroke or the piston 70 in the cylindrical housing 21 of the first piston cylinder 20, the First outlet valve 90 and the second outlet valve 92 are kept closed. In one embodiment, the cooling cross-flow of air 16 is then directed diagonally through the cavity 14 of the crankcase assembly 12 towards the first outlet valve 90 and the second outlet valve 92.
During a downstroke of the piston 70 in the cylindrical housing 21 of the first piston cylinder 20, the cooling cross-flow of air .16 is pushed out of the first outlet valve 90 and the second outlet valve 92 to atmosphere. During the downstroke of the piston 70 in the cylindrical housing 21 of the first piston cylinder 20, the first inlet valve 80 and the second inlet valve 82 are kept WO 2015/1721.15 PCT/US2015/030154 closed. The first outlet valve 90 and the second outlet valve 92 may be selected and/or adjusted according to the desired amount of air pressure that is necessary to open the first outlet valve 90 and the second outlet valve 92. The total change of volume in the air compressor 10 is a summation of all of the piston movement within the air compressor JO.
Therefore, it is the total volume changed by reciprocating movement of the first piston cylinder 20, the second piston cylinder 30, the third piston cylinder 40, and the fourth piston cylinder 50, combined. 'Ibis configuration and operation of the air compressor 10 ensures that the maximum amount of crankcase volume change is achieved without sacrificing other air compressor 10 characteristics. By combining the change in volume of all of the piston cylinders 20, 30, 40, 50, during rotation of the crankshaft assembly 60, a maximum volume of air inay be used to coot the air compressor 10.
= [0027] While FIGS. 1 and 2 depict the use of two inlet valves 80. 82 and two outlet valves 90. 92, it is also to he understood that only one inlet valve 80 and one outlet valve 90 may he used, as shown in FIGS. 3 and 4.
[0028] Referring now to FIGS. 3 and 4, a first nozzle 100 may be positioned on the first inlet valve 80 and/or the second inlet valve 82. The first nozzle 100 may be used to direct the flow of air into the first inlet valve 80 and/or the second inlet valve 82 during the upstroke of the piston 70 in the cylindrical housing 21 of the first piston cylinder 20. A
second nozzle 110 may be positioned on the first outlet valve 90 and/or the second outlet valve 92. The second nozzle 110 may be used to direct the flow away from the compressor crankcase 12 to avoid directing the exhausted hot air back, towards the compressor crankcase 12. It is to be understood that different types of nozzles may be used in place of the first nozzle 100 and the second nozzle 110, such as nozzles with a wider or narrower inlet or nozzles with a different cross-sectional shape. I murther, although FIGS. 3 and 4 only depict the use of the first inlet valve 80 and the first outlet valve 90, it is to be understood that the second inlet valve 82 and the second outlet valve 92 may be used as well. Nozzles may also be positioned on these valves as well.
[0029] With continued reference to FIGS. 3 and 4, an inlet air filter 120 may be operatively connected to the first inlet valve 80 and/or the second inlet valve 82. The inlet air filter 120 may be any standard inlet air filter commercially available that provides a screening function to remove contamination and debris front the air that is pulled into the compressor crankcase 12 through the first inlet valve 80 and/or the second inlet valve 82. The inlet air filter 120 provides filtering capabilities to the air compressor 10 by removing debris and other contamination that may create wear on the crankshaft assembly 60 and components of the piston cylinders 20, 30, 40. 50. In one embodiment, the inlet air filter 120 may he positioned on an end of the first nozzle 100. During use of the air compressor 10, air is pulled into the cavity 14 of the compressor crankcase 12 first through the inlet air filter 120, then through the =
first nozzle 100, and finally through the first inlet valve 80 and/or the second inlet valve 82.
1.00301 Although a description of the first inlet valve SO and the first outlet valve 90 being operatively positioned with the first piston cylinder 20 is provided, one of skill in the art will recognin that the first inlet valve 80 and the first outlet valve 90 may also be operatively positioned at different positions on the compressor crankcase 12, The first inlet valve 80 and = the first outlet valve 90 may he operatively positioned with another piston cylinder 30, 40, 50.
Further, the first inlet valve 80 and the first outlet valve 90 may be positioned adjacent the first piston cylinder 20 and the fourth piston cylinder 50, respectively. The arrangement of the inlet valve 80 and the outlet valve 90 would be substantially similar to the arrangement described above in connection with the first piston cylinder 20.
[003]] A method of cooling the compressor crankcase 12 is also described herein with reference to FIGS. 3 and 4. In one embodiment, this method includes the step of providing an air compressor 10 as described hereinabove, During use of the cooling method, air front at it is pulled into the cavity 14 of the compressor crankcase 12 via the first inlet valve 80. The air is used as a cooling cross-flow of air 16 that is directed front the first inlet valve -80 to the first outlet valve 90. The cooling cross-flow of air 16 is directed through the cavity 14 of the compressor crankcase 12, thereby flowing over the components of the crankshaft assembly 60 and the piston cylinders 20, 30. 40, 50. Alter the cooling cross-flow of air 16 is directed through the cavity 14 of the compressor crankcase 12, the air is pushed out of the compressor crankcase 12 via the first outlet valve 90. As the air is directed over the crankshaft assembly 60 and the components of the piston cylinders 20, 30, 40, 50. the components are cooled by the air. The heat generated by the components is transferred to the cooling cross-flow of air 16 and carried out of the compressor crankcase 12.
In one embodiment, the first inlet valve 80 and the first outlet valve 90 may be check valves, as described hereinabove. The first inlet valve 80 may be supported on a first side of the compressor crankcase 12. The first outlet valve 90 may he supported on an opposing, second side of the compressor crankcase 12.
[00321 As the pistons 20, 30, 40, 50 of the air compressor 10 move in and out of their respective piston cylinders, the total volume within the compressor crankcase 12 changes through a single rotation of the crankshaft assembly 60 provided the cylinders 20, 30, 40, 50 are not perfectly out of phase and of the same diameter. In one embodiment, the first inlet = µVO 2015/172145 PC:T/11:32015/030154 valve 80 is opened during an upstroke of the piston 70 in the cylindrical housing 21 of the first piston cylinder 20. The pressnre exerteci by the air (hat is pulled into the compressor crankcase 12 pushes open the first inlet valve 80. In one embodiment, air may be pulled into the compressor crankcase 12 via the first inlet valve 80 until a alaXillaall volume of the compressor crankcase 12 is filled. In one einhcaiiment, the first outlet valve 90 may be opened during a downstroke of the piston 70 in the cylindrical housing 21 of the first piston cylinder 20. The pressure exerted by he air that is pushed throne!' and out of the cavity 14 of =
the compressor crankcase 12 pusties open the first outlet valve 90. thereby allowing the air to vent to atmosphere. In one embodiment. air is pushed out of the compressor crankcase 12 via (he first outlet valve 90 until a minimum volume of the compressor crankcare 12 remains.
Using the described method, the cooling cross-flow of air 16 may be directed from a first side of the compressor crankcase 12, over the crankshaft assembly 60. and out of an o)posing.
= second side of the compressor crankcase 12. In this embodiment. the first inlet valve 80 is supported on the first side of the compressor crankcase 12 and the first outlet valve 90 is supported on the. opposing. second Side of the compressor crankcase 12.
Although the operation of the cooling method of the air compressor 10 is described in relation to the first piston cylinder 20. it is to he understood drat Ore cording method is a cumulative effect of the reciprocating movement of all of the piston cyllttders 20, 30, 40, 50 that creates the cooling crosa-flow of air 16. The second piston eylindt:r 59, the third piston cylinder 40, and the fourth piston cylinder 50 operating in a similar manner co the first piston cylinder 20 to create the cross-flow of air It,. it is also to he unds!..stood that the first inlet valve 80 and the first outlet valve 90 may be positioned near one of the second piston cylinder 30.
ihe third piston cylinder 40, or the fourth piston cylinder 50 to provide the same cooling effect in the air compressor 10.
[0033] In one embodiment of the method, the first nonle 100 may be posit icmed on the first inlet valve 80 snd the second nozzle 110 nury he positioned on the first outlet valve 90.
The first nozzle 100 may he configured to direct the air rrola atmosphere into the first inlet valve 80. The second nozzle .110 may he configured to direct the air from the first outlet valve 90 to atmosphere. The second trozzle 110 (lirocts the air, whose temperature has risen duc to the heat transferred from the compressor crt.ttc:tse !2 components, away front the compressor crunitcas.: :2 to rtinosphere.
10034'1 In another embodiment oi lite method, the inlet air fiiter 120 nary be operatively connected to the first inlet valve The nir that is pulled ion-, the first inlet valve 80 may he filtered by the inlet air filter 120 to rµantwe any contamination or deltris from the air, se as not LI
WO 2015/172145 = PCT/US2015/030154 to contaminate or wear the inner components of the air compressor 10. The inlet air filter 120 may also be positioned on an end of the first nozzle 100 connected to the first inlet valve 80.
[00351 As explained hereinabove, although a description of a method of using the first inlet valve 80 and the first outlet valve 90 with the first piston cylinder 20 to cool the inner components of the compressor crankcase 12 is provided, one of skill in the art will recognize that the method may also be performed at different positions on the compressor crankcase 11 The first inlet valve 80 and the first outlet valve 90 may be operatively positioned with another piston cylinder 30, 40, 50. Alternatively, the first inlet valve 80 and the first outlet valve 90 may be positioned adjacent to the first piston cylinder 20 and the fourth piston cylinder 50, respectively. It is also to be understood that the second inlet valve 82 and the second outlet valve 92 may be used to create a larger cooling cross-flow of air 16 through the compressor crankcase 12. The arrangement and operation of the inlet valve 80 and the outlet valve 90 would be substantially similar to the arrangement described above in connection with the first piston cylinder 20.
[0036] By using the method described hereinabove, there is no effect on the inlet air temperatures that are provided. Therelbre, the first inlet valve 80 and the first outlet valve 90 are able to provide a directed positive flow through the compressor crankcase 12 without reducing the overall efficiency of the air compressor 10, unlike if the inlet air was first routed through the compressor crankcase 12. Further, the air at the first inlet valve 80 will not be pre-heated upon entering the compressor crankcase 12, resulting in lower first stage temperatures. The air compressor 10 described hereinabove includes a multi-cylinder arrangement that maximizes the total change in the compressor crankcase 12 volume per revolution of the crankshaft assembly 60, without sacrificing the dynamic balance of the air compressor 10. In addition, the total crankshaft assembly 60 torque pulse per each revolution is reduced, while still maintaining a small overall size envelope for the air compressor 10.
100371 While an embodiment of an oil-free compressor crankcase cooling arrangement is shown in the accompanying Figures and described hereinabove in detail, other embodiments will be apparent to, and readily made by, those skilled in the art without departing from the scope and spirit of the invention. Accordingly, the foregoing description is intended to he illustrative rather than restrictive. The invention described hereinabove is defined by the appended claims and all changes to the invention that fall within the meaning and the range of the equivalency of the claims are to be embraced within their scope.
[00211 As shown in FIGS. 3 and 4, the first piston cylinder 20 includes a cylindrical housing 21 that has a first end 22a adapted to be inserted into a corresponding -opening, as described herein, in the compressor crankcase 12 and a second end 22h. The cylindrical housing 21 is formed with a liana: 23 located proximal the first end 22a for interfacing with the exterior of the compressor crankcase 12. Heat-dissipating fins 24 may be provided about the cylindrical housing 21, and the cylindrical housing 21 may he formed of any suitable material providing sufficient strength and heat-dissipating characteristics such as aluminum.
[0022] A cylinder head 25 is secured to the second end 22b of the cylindrical housing 21.
The cylinder head 25 generally comprises an air connecting unit 26 and an unloadcr cap 29 mechanically fastened to a top surface of the air connecting unit 26. The air connecting unit 26 includes a first air channel 27 and a 'second air channel 28. The air connecting unit 26 may be formed of any suitable material providing sufficient strength and heat transfer characteristics such as aluminum. The unloader cap 29 houses art anloader piston (not shown) that mechanically holds the inlet side of the valve assembly (not shown) open when pneumatic signal is piloted to the valve assembly. It is also to be understood that an electric signal may be used to pilot the valve assembly. When activated, the air compressor 10 will continue to operate without compressing air, thereby cooling the cavity 14 of the air compressor 10.
[0023] The first piston cylinder 20 may further include a first piston 70 that is reciprocally operable within the cylindrical housing 21. The piston 70 includes a first end 72a and a second end 720. and is made of any suitable material providing sufficient strength and heat transfer characteristics such as aluminum. The piston 70 is operatively connected to the crankshaft assembly 60 via a connecting rod 74. A cavity 76 may be defined in the cylindrical housing 21 to hold the piston 70. In operation, die piston 70 operates in a reciprocating movement which is generated via rotation of the crankshaft assembly 60. Air is drawn into the cavity 76 of the cylindrical housing 21 of the first piston cylinder 20 via one of the air channels 27, 28 as a result of the downward movement of the piston 70.
A valve assembly (not shown) may be associated with the cylinder head 25 and includes a portion that is opened during the downward movement of the piston 70, drawing air into the cylindrical housing 21, and closes during the upward movement. Further, the valve assembly may include another portion that closes during the downward movement of the piston 70 and opens during the upward movement of the piston 70. whereby air in the cylindrical housing 21 is compressed and is guided out of the cylindrical housing 21.
100241 As noted previously, the second piston cylinder 30, the third piston cylinder 40, and the fourth piston cylinder 50 have ir substantially similar construction to the first piston cylinder 20.
[0025] Referring to FIGS. 1 and 2, a first inlet valve 80 and a second inlet valve 82 are supported on a first side of the compressor crankcase 12. A first outlet valve 90 and a second outlet valve 92 may be supported on an opposing, second side of the compressor crankcase 12. The first inlet valve 80, the second inlet valve Si the first OW let valve 90. and the second outlet valve 92 may be in fluid communication with the compressor crankcase 12. In one embodiment, the first inlet valve 80, the second inlet valve 82, the first outlet valve 90, and the second outlet valve 92 may be check valves. In one embodiment, the first inlet valve 80, the second inlet valve 82, the first outlet valve 90, and the second outlet valve 92 may he ball-type check valves. In another embodiment, the first inlet valve 80, the second inlet valve 82, the first outlet valve 90, and the second outlet valve 92 may include an elastomer valve element (not shown) positioned between a seat (not shown) and guide member (not shown).
This type of cheek valve is commonly known as a "flapper" style check valve.
It is to be understood, however, that the use of alternative typii.s of check valves arc contemplated, such as a diaphragm check valve, a swine check valve, and a lift check valve, among others. In one embodiment, the first inlet valve 80, the second inlet valve 82, the first outlet valve 90, and the second outlet valve 92 may be used to establish a cooling cross-flow of air 16 between one another to cool the compressor crankcase 12. Although only two inlet valves and two outlet valves are shown in the drawings, it is contemplated that fewer or additional inlet valves and outlet valves !nay be supported on the compressor crankcase 12 to provide a reduced or greater amount of air for the cooling cross-flow 16 through the compressor crankcase 12. As shown in FIGS. .1 and 2, the first inlet valve 80 and the second inlet valve 82 may he positioned parallel to one. another, and the first outlet valve 90 and the second outlet valve 90 may be positioned parallel to one another. It is also to be understood, however, that die first inlet valve 80 and the second inlet valve 82 may he positioned in series with one another, and the first outlet valve 90 and the second outlet valve 92 may be positioned in series with one another. The configuration of the valves may be used according to the capacity needed in the air compressor 10 and to provide redundancy.
100261 In one embodiment, the first inlet valve 80 and the second inlet valve 82 may he supported on a lower portion of the compressor crankcase 12. The first outlet valve 90 and the second outlet valve 92 may be supported on an opposing, lower portion of the compressor crankcase 12. In one embodiment, the first inlet valve 80 and the second inlet valve 82 may be supported on the compressor crankcase 12 adjacent the first piston cylinder 20. The first outlet valve 90 and the second outlet valve 92 may be supported on the compressor crankcase 12 adjacent the fourth piston cylinder 50. Using this arrangement of the first inlet valve 80, the second inlet valve 82, the first outlet valve 90, and the second outlet valve 92, the cooling cross-flow of air 16 may be directed through the cavity 14 of the compressor crankcase 12 from the first side of the compressor crankcase 12 to the opposing, second side of the compressor crankcase 12. The cooling cross-flow of air 16 is directed over the crankshaft assembly 60 to provide cooling for the components of the crankshaft assembly 60 and the compressor crankcase 12. To establish this cooling cross-flow of air 16 in the compressor crankcase 11 air is pulled into the compressor crankcase 12 via the first inlet valve 80 and the second inlet valve 82. During an upstroke of the piston 70 in the cylindrical housing 21 of the first piston cylinder 20, the first inlet valve 80 and the second inlet valve 82 are opened by the air that is pulled into the compressor crankcase 12. The first inlet valve 80 and the second inlet valve 82 may be selected and/or adjusted according to the desired amount at air pressure that is necessary to open the first inlet valve 80 and the second inlet valve 82. During the upstroke or the piston 70 in the cylindrical housing 21 of the first piston cylinder 20, the First outlet valve 90 and the second outlet valve 92 are kept closed. In one embodiment, the cooling cross-flow of air 16 is then directed diagonally through the cavity 14 of the crankcase assembly 12 towards the first outlet valve 90 and the second outlet valve 92.
During a downstroke of the piston 70 in the cylindrical housing 21 of the first piston cylinder 20, the cooling cross-flow of air .16 is pushed out of the first outlet valve 90 and the second outlet valve 92 to atmosphere. During the downstroke of the piston 70 in the cylindrical housing 21 of the first piston cylinder 20, the first inlet valve 80 and the second inlet valve 82 are kept WO 2015/1721.15 PCT/US2015/030154 closed. The first outlet valve 90 and the second outlet valve 92 may be selected and/or adjusted according to the desired amount of air pressure that is necessary to open the first outlet valve 90 and the second outlet valve 92. The total change of volume in the air compressor 10 is a summation of all of the piston movement within the air compressor JO.
Therefore, it is the total volume changed by reciprocating movement of the first piston cylinder 20, the second piston cylinder 30, the third piston cylinder 40, and the fourth piston cylinder 50, combined. 'Ibis configuration and operation of the air compressor 10 ensures that the maximum amount of crankcase volume change is achieved without sacrificing other air compressor 10 characteristics. By combining the change in volume of all of the piston cylinders 20, 30, 40, 50, during rotation of the crankshaft assembly 60, a maximum volume of air inay be used to coot the air compressor 10.
= [0027] While FIGS. 1 and 2 depict the use of two inlet valves 80. 82 and two outlet valves 90. 92, it is also to he understood that only one inlet valve 80 and one outlet valve 90 may he used, as shown in FIGS. 3 and 4.
[0028] Referring now to FIGS. 3 and 4, a first nozzle 100 may be positioned on the first inlet valve 80 and/or the second inlet valve 82. The first nozzle 100 may be used to direct the flow of air into the first inlet valve 80 and/or the second inlet valve 82 during the upstroke of the piston 70 in the cylindrical housing 21 of the first piston cylinder 20. A
second nozzle 110 may be positioned on the first outlet valve 90 and/or the second outlet valve 92. The second nozzle 110 may be used to direct the flow away from the compressor crankcase 12 to avoid directing the exhausted hot air back, towards the compressor crankcase 12. It is to be understood that different types of nozzles may be used in place of the first nozzle 100 and the second nozzle 110, such as nozzles with a wider or narrower inlet or nozzles with a different cross-sectional shape. I murther, although FIGS. 3 and 4 only depict the use of the first inlet valve 80 and the first outlet valve 90, it is to be understood that the second inlet valve 82 and the second outlet valve 92 may be used as well. Nozzles may also be positioned on these valves as well.
[0029] With continued reference to FIGS. 3 and 4, an inlet air filter 120 may be operatively connected to the first inlet valve 80 and/or the second inlet valve 82. The inlet air filter 120 may be any standard inlet air filter commercially available that provides a screening function to remove contamination and debris front the air that is pulled into the compressor crankcase 12 through the first inlet valve 80 and/or the second inlet valve 82. The inlet air filter 120 provides filtering capabilities to the air compressor 10 by removing debris and other contamination that may create wear on the crankshaft assembly 60 and components of the piston cylinders 20, 30, 40. 50. In one embodiment, the inlet air filter 120 may he positioned on an end of the first nozzle 100. During use of the air compressor 10, air is pulled into the cavity 14 of the compressor crankcase 12 first through the inlet air filter 120, then through the =
first nozzle 100, and finally through the first inlet valve 80 and/or the second inlet valve 82.
1.00301 Although a description of the first inlet valve SO and the first outlet valve 90 being operatively positioned with the first piston cylinder 20 is provided, one of skill in the art will recognin that the first inlet valve 80 and the first outlet valve 90 may also be operatively positioned at different positions on the compressor crankcase 12, The first inlet valve 80 and = the first outlet valve 90 may he operatively positioned with another piston cylinder 30, 40, 50.
Further, the first inlet valve 80 and the first outlet valve 90 may be positioned adjacent the first piston cylinder 20 and the fourth piston cylinder 50, respectively. The arrangement of the inlet valve 80 and the outlet valve 90 would be substantially similar to the arrangement described above in connection with the first piston cylinder 20.
[003]] A method of cooling the compressor crankcase 12 is also described herein with reference to FIGS. 3 and 4. In one embodiment, this method includes the step of providing an air compressor 10 as described hereinabove, During use of the cooling method, air front at it is pulled into the cavity 14 of the compressor crankcase 12 via the first inlet valve 80. The air is used as a cooling cross-flow of air 16 that is directed front the first inlet valve -80 to the first outlet valve 90. The cooling cross-flow of air 16 is directed through the cavity 14 of the compressor crankcase 12, thereby flowing over the components of the crankshaft assembly 60 and the piston cylinders 20, 30. 40, 50. Alter the cooling cross-flow of air 16 is directed through the cavity 14 of the compressor crankcase 12, the air is pushed out of the compressor crankcase 12 via the first outlet valve 90. As the air is directed over the crankshaft assembly 60 and the components of the piston cylinders 20, 30, 40, 50. the components are cooled by the air. The heat generated by the components is transferred to the cooling cross-flow of air 16 and carried out of the compressor crankcase 12.
In one embodiment, the first inlet valve 80 and the first outlet valve 90 may be check valves, as described hereinabove. The first inlet valve 80 may be supported on a first side of the compressor crankcase 12. The first outlet valve 90 may he supported on an opposing, second side of the compressor crankcase 12.
[00321 As the pistons 20, 30, 40, 50 of the air compressor 10 move in and out of their respective piston cylinders, the total volume within the compressor crankcase 12 changes through a single rotation of the crankshaft assembly 60 provided the cylinders 20, 30, 40, 50 are not perfectly out of phase and of the same diameter. In one embodiment, the first inlet = µVO 2015/172145 PC:T/11:32015/030154 valve 80 is opened during an upstroke of the piston 70 in the cylindrical housing 21 of the first piston cylinder 20. The pressnre exerteci by the air (hat is pulled into the compressor crankcase 12 pushes open the first inlet valve 80. In one embodiment, air may be pulled into the compressor crankcase 12 via the first inlet valve 80 until a alaXillaall volume of the compressor crankcase 12 is filled. In one einhcaiiment, the first outlet valve 90 may be opened during a downstroke of the piston 70 in the cylindrical housing 21 of the first piston cylinder 20. The pressure exerted by he air that is pushed throne!' and out of the cavity 14 of =
the compressor crankcase 12 pusties open the first outlet valve 90. thereby allowing the air to vent to atmosphere. In one embodiment. air is pushed out of the compressor crankcase 12 via (he first outlet valve 90 until a minimum volume of the compressor crankcare 12 remains.
Using the described method, the cooling cross-flow of air 16 may be directed from a first side of the compressor crankcase 12, over the crankshaft assembly 60. and out of an o)posing.
= second side of the compressor crankcase 12. In this embodiment. the first inlet valve 80 is supported on the first side of the compressor crankcase 12 and the first outlet valve 90 is supported on the. opposing. second Side of the compressor crankcase 12.
Although the operation of the cooling method of the air compressor 10 is described in relation to the first piston cylinder 20. it is to he understood drat Ore cording method is a cumulative effect of the reciprocating movement of all of the piston cyllttders 20, 30, 40, 50 that creates the cooling crosa-flow of air 16. The second piston eylindt:r 59, the third piston cylinder 40, and the fourth piston cylinder 50 operating in a similar manner co the first piston cylinder 20 to create the cross-flow of air It,. it is also to he unds!..stood that the first inlet valve 80 and the first outlet valve 90 may be positioned near one of the second piston cylinder 30.
ihe third piston cylinder 40, or the fourth piston cylinder 50 to provide the same cooling effect in the air compressor 10.
[0033] In one embodiment of the method, the first nonle 100 may be posit icmed on the first inlet valve 80 snd the second nozzle 110 nury he positioned on the first outlet valve 90.
The first nozzle 100 may he configured to direct the air rrola atmosphere into the first inlet valve 80. The second nozzle .110 may he configured to direct the air from the first outlet valve 90 to atmosphere. The second trozzle 110 (lirocts the air, whose temperature has risen duc to the heat transferred from the compressor crt.ttc:tse !2 components, away front the compressor crunitcas.: :2 to rtinosphere.
10034'1 In another embodiment oi lite method, the inlet air fiiter 120 nary be operatively connected to the first inlet valve The nir that is pulled ion-, the first inlet valve 80 may he filtered by the inlet air filter 120 to rµantwe any contamination or deltris from the air, se as not LI
WO 2015/172145 = PCT/US2015/030154 to contaminate or wear the inner components of the air compressor 10. The inlet air filter 120 may also be positioned on an end of the first nozzle 100 connected to the first inlet valve 80.
[00351 As explained hereinabove, although a description of a method of using the first inlet valve 80 and the first outlet valve 90 with the first piston cylinder 20 to cool the inner components of the compressor crankcase 12 is provided, one of skill in the art will recognize that the method may also be performed at different positions on the compressor crankcase 11 The first inlet valve 80 and the first outlet valve 90 may be operatively positioned with another piston cylinder 30, 40, 50. Alternatively, the first inlet valve 80 and the first outlet valve 90 may be positioned adjacent to the first piston cylinder 20 and the fourth piston cylinder 50, respectively. It is also to be understood that the second inlet valve 82 and the second outlet valve 92 may be used to create a larger cooling cross-flow of air 16 through the compressor crankcase 12. The arrangement and operation of the inlet valve 80 and the outlet valve 90 would be substantially similar to the arrangement described above in connection with the first piston cylinder 20.
[0036] By using the method described hereinabove, there is no effect on the inlet air temperatures that are provided. Therelbre, the first inlet valve 80 and the first outlet valve 90 are able to provide a directed positive flow through the compressor crankcase 12 without reducing the overall efficiency of the air compressor 10, unlike if the inlet air was first routed through the compressor crankcase 12. Further, the air at the first inlet valve 80 will not be pre-heated upon entering the compressor crankcase 12, resulting in lower first stage temperatures. The air compressor 10 described hereinabove includes a multi-cylinder arrangement that maximizes the total change in the compressor crankcase 12 volume per revolution of the crankshaft assembly 60, without sacrificing the dynamic balance of the air compressor 10. In addition, the total crankshaft assembly 60 torque pulse per each revolution is reduced, while still maintaining a small overall size envelope for the air compressor 10.
100371 While an embodiment of an oil-free compressor crankcase cooling arrangement is shown in the accompanying Figures and described hereinabove in detail, other embodiments will be apparent to, and readily made by, those skilled in the art without departing from the scope and spirit of the invention. Accordingly, the foregoing description is intended to he illustrative rather than restrictive. The invention described hereinabove is defined by the appended claims and all changes to the invention that fall within the meaning and the range of the equivalency of the claims are to be embraced within their scope.
Claims (18)
1. An oil-free compressor crankcase cooling arrangement for a rail vehicle, comprising:
a compressor crankcase;
at least one piston cylinder supported in the compressor crankcase;
a crankshaft assembly supported by the compressor crankcase and linked to a piston of the at least one piston cylinder by a connecting rod;
at least one inlet valve supported on a first side of the compressor crankcase at a location entirely below the crankshaft assembly, the at least one inlet valve in direct fluid communication with an interior of the crankcase; and at least one outlet valve supported on an opposing second side of the compressor crankcase at a location entirely above the crankshaft assembly, the at least one outlet valve in direct fluid communication with the interior of the crankcase, wherein the compressor crankcase defines a cavity for housing the crankshaft assembly, wherein a cooling cross flow of air is established and directed diagonally through the cavity of the compressor crankcase and diagonally across the crankshaft assembly between the at least one inlet valve to cool the compressor crankcase.
a compressor crankcase;
at least one piston cylinder supported in the compressor crankcase;
a crankshaft assembly supported by the compressor crankcase and linked to a piston of the at least one piston cylinder by a connecting rod;
at least one inlet valve supported on a first side of the compressor crankcase at a location entirely below the crankshaft assembly, the at least one inlet valve in direct fluid communication with an interior of the crankcase; and at least one outlet valve supported on an opposing second side of the compressor crankcase at a location entirely above the crankshaft assembly, the at least one outlet valve in direct fluid communication with the interior of the crankcase, wherein the compressor crankcase defines a cavity for housing the crankshaft assembly, wherein a cooling cross flow of air is established and directed diagonally through the cavity of the compressor crankcase and diagonally across the crankshaft assembly between the at least one inlet valve to cool the compressor crankcase.
2. The crankcase cooling arrangement as claimed in claim 1, wherein the at least one inlet valve and the at least one outlet valve comprise check valves.
3. The crankcase cooling arrangement as claimed in claim 1 or claim 2, further comprising a first nozzle positioned on the at least one inlet valve, and a second nozzle positioned on the at least one outlet valve.
4. The crankcase cooling arrangement as claimed in any one of claims 1-3, further comprising an inlet air filter operatively connected to the at least one inlet valve, wherein the inlet air filter protects the compressor crankcase from contamination and debris.
5. The crankcase cooling arrangement as claimed in claim 3, further comprising an inlet air filter positioned on the first nozzle of the at least one inlet valve, wherein the inlet air filter protects the compressor crankcase from contamination and debris.
6. The crankcase cooling arrangement as claimed in any one of claims 1-5, wherein the at least one inlet valve is opened as air is pulled into the compressor crankcase during an upstroke of the at least one piston cylinder.
7. The crankcase cooling arrangement as claimed in any one of claims 1-6, wherein the at least one outlet valve is opened as air is pushed out of the compressor crankcase during a downstroke of the at least one piston cylinder.
8. The crankcase cooling arrangement as claimed in any one of claims 1-7, further comprising an unloader valve assembly positioned on the at least one piston cylinder configured to exhaust pressurized fluid from the at least one piston cylinder.
9. A method of cooling an oil-free compressor crankcase of a rail vehicle, comprising the steps of:
a) providing an oil-free compressor, comprising:
a compressor crankcase;
at least one piston cylinder supported in the compressor crankcase;
a crankshaft assembly supported by the compressor crankcase and linked to a piston of the at least one piston cylinder by a connecting rod;
at least one inlet valve supported on a first side of the compressor crankcase at a location entirely below the crankshaft assembly, the at least one inlet valve in direct fluid communication with an interior of the crankcase; and at least one outlet valve supported on an opposing second side of the compressor crankcase at a location entirely above the crankshaft assembly, the at least one outlet valve in direct fluid communication with the interior of the crankcase, wherein the compressor crankcase defines a cavity for housing the crankshaft assembly;
b) pulling air into the compressor crankcase via the at least one inlet valve;
c) directing the air diagonally through the cavity of the compressor crankcase and diagonally across the crankshaft assembly; and d) pushing the air out of the compressor crankcase via the at least one outlet valve.
a) providing an oil-free compressor, comprising:
a compressor crankcase;
at least one piston cylinder supported in the compressor crankcase;
a crankshaft assembly supported by the compressor crankcase and linked to a piston of the at least one piston cylinder by a connecting rod;
at least one inlet valve supported on a first side of the compressor crankcase at a location entirely below the crankshaft assembly, the at least one inlet valve in direct fluid communication with an interior of the crankcase; and at least one outlet valve supported on an opposing second side of the compressor crankcase at a location entirely above the crankshaft assembly, the at least one outlet valve in direct fluid communication with the interior of the crankcase, wherein the compressor crankcase defines a cavity for housing the crankshaft assembly;
b) pulling air into the compressor crankcase via the at least one inlet valve;
c) directing the air diagonally through the cavity of the compressor crankcase and diagonally across the crankshaft assembly; and d) pushing the air out of the compressor crankcase via the at least one outlet valve.
10. The method of cooling a compressor crankcase as claimed in claim 9, further comprising the step of opening the at least one inlet valve during an upstroke of the at least one piston cylinder, wherein air is pulled into the compressor crankcase through the open inlet valve.
11. The method of cooling a compressor crankcase as claimed in claim 9 or claim 10, further comprising the step of opening the at least one outlet valve during a downstroke of the at least one piston cylinder, wherein air is pushed out of the compressor crankcase through the open outlet valve.
12. The method of cooling a compressor crankcase as claimed in any one of claims 9-11, further comprising the step of establishing a cooling cross-flow of air that is directed from a first side of the compressor crankcase, over the crankshaft assembly, and out of an opposing second side of the compressor crankcase, wherein the at least one inlet valve is supported on the first side of the compressor crankcase, and wherein the at least one outlet valve is supported on the opposing, second side of the compressor crankcase.
13. The method of cooling a compressor crankcase as claimed in any one of claims 9-12, the oil-free compressor further comprising a first nozzle positioned on the at least one inlet valve and a second nozzle positioned on the at least one outlet valve.
14. The method of cooling a compressor crankcase as claimed in any one of claims 9-13, further comprising the steps of:
providing an inlet air filter operatively connected to the at least one inlet valve;
and filtering the air that is pulled into the compressor crankcase via the at least one inlet valve using the inlet air filter.
providing an inlet air filter operatively connected to the at least one inlet valve;
and filtering the air that is pulled into the compressor crankcase via the at least one inlet valve using the inlet air filter.
15. The method of cooling a compressor crankcase as claimed in claim 13, further comprising the steps of:
providing an inlet air filter on the first nozzle of the at least one inlet valve; and filtering the air that is pulled into the compressor crankcase via the at least one inlet valve using the inlet air filter.
providing an inlet air filter on the first nozzle of the at least one inlet valve; and filtering the air that is pulled into the compressor crankcase via the at least one inlet valve using the inlet air filter.
16. The method of cooling a compressor crankcase as claimed in any one of claims 9-15, wherein the at least one inlet valve and the at least one outlet valve comprise check valves.
17. The method of cooling a compressor crankcase as claimed in any one of claims 9-16, wherein the at least one inlet valve is supported on the compressor crankcase on a first side of the at least one piston cylinder, and wherein the at least one outlet valve is supported on the compressor crankcase on an opposing second side of the at least one piston cylinder.
18. The method of cooling a compressor crankcase as claimed in any one of claims 9-17, further comprising the steps of:
providing an unloader valve assembly on the at least one piston cylinder, and exhausting fluid from the at least one piston cylinder via the unloader valve assembly.
providing an unloader valve assembly on the at least one piston cylinder, and exhausting fluid from the at least one piston cylinder via the unloader valve assembly.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US201461990934P | 2014-05-09 | 2014-05-09 | |
| US61/990,934 | 2014-05-09 | ||
| US14/705,319 US20150322937A1 (en) | 2014-05-09 | 2015-05-06 | Oil-free compressor crankcase cooling arrangement |
| US14/705,319 | 2015-05-06 | ||
| PCT/US2015/030154 WO2015172145A1 (en) | 2014-05-09 | 2015-05-11 | Oil-free compressor crankcase cooling arrangement |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2947306A1 CA2947306A1 (en) | 2015-11-12 |
| CA2947306C true CA2947306C (en) | 2023-01-17 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2947306A Active CA2947306C (en) | 2014-05-09 | 2015-05-11 | Oil-free compressor crankcase cooling arrangement |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US20150322937A1 (en) |
| JP (1) | JP2017516014A (en) |
| AU (2) | AU2015255673A1 (en) |
| BR (1) | BR112016025935B8 (en) |
| CA (1) | CA2947306C (en) |
| MX (1) | MX2016013961A (en) |
| WO (1) | WO2015172145A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10724510B2 (en) * | 2016-04-29 | 2020-07-28 | Scott Daniel Fleischman | Apparatus and method for gas compression |
| US11333140B2 (en) * | 2019-06-11 | 2022-05-17 | Caterpillar Inc. | Cooling block for multi-cylinder air compressor |
| US11396868B2 (en) * | 2020-03-09 | 2022-07-26 | Schaeffler Technologies AG & Co. KG | Linear actuator pumping system |
| GB2610423A (en) * | 2021-09-06 | 2023-03-08 | Gardner Denver Ltd | An improved reciprocating compressor |
Family Cites Families (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1109154A (en) * | 1913-04-11 | 1914-09-01 | Thomas Motive Power Company | Air-compressor. |
| US1445073A (en) * | 1919-10-25 | 1923-02-13 | Corpl Domenico | Portable compressor |
| US1891083A (en) * | 1928-10-18 | 1932-12-13 | Adiel Y Dodge | Air compressor |
| US2831625A (en) * | 1956-06-29 | 1958-04-22 | Worthington Corp | Unloader for compressor |
| FR1463769A (en) * | 1963-05-29 | 1966-07-22 | Piston compressor and its cooling method and device and its mounting devices | |
| US4190402A (en) * | 1975-05-06 | 1980-02-26 | International Telephone And Telegraph Corporation | Integrated high capacity compressor |
| JPS56169484U (en) * | 1980-05-20 | 1981-12-15 | ||
| JPS58142382U (en) * | 1982-03-20 | 1983-09-26 | トキコ株式会社 | Oil-free compressor |
| JPS623975U (en) * | 1985-06-21 | 1987-01-10 | ||
| CH684020A5 (en) * | 1990-04-18 | 1994-06-30 | Bauer Kompressoren | Dry Running reciprocating compressor. |
| JPH0763167A (en) * | 1993-08-20 | 1995-03-07 | Tokico Ltd | Multiple stage compressor |
| US5591011A (en) * | 1995-09-18 | 1997-01-07 | Carrier Corporation | Multi-refrigerant compressor |
| DE10138070C2 (en) * | 2001-08-03 | 2003-05-22 | Knorr Bremse Systeme | Piston compressor with a flow of cooling air |
| JP4115796B2 (en) * | 2002-09-30 | 2008-07-09 | 株式会社日立製作所 | air compressor |
| DE10360920B3 (en) * | 2003-12-23 | 2005-09-22 | Meta Motoren- Und Energie-Technik Gmbh | reciprocating |
| DE102004042944B4 (en) * | 2004-09-02 | 2009-09-10 | Knorr-Bremse Systeme für Schienenfahrzeuge GmbH | Piston compressor with an internal cooling air flow in the crankcase |
| NO322287B1 (en) * | 2004-09-24 | 2006-09-11 | Sperre Mek Verksted As | Cooling device for piston machinery |
| JP2007182820A (en) * | 2006-01-10 | 2007-07-19 | Anest Iwata Corp | Booster type gas compressor |
| DE102006012174A1 (en) * | 2006-03-16 | 2007-09-20 | Pari GmbH Spezialisten für effektive Inhalation | Inhalation therapy devices compressor |
| DE102007042318B4 (en) * | 2007-09-06 | 2017-11-30 | Knorr-Bremse Systeme für Nutzfahrzeuge GmbH | Compact dry running piston compressor |
| CN201546926U (en) * | 2010-01-08 | 2010-08-11 | 浙江鸿友压缩机制造有限公司 | Low noise structure oilless air compressor |
| CN105645059B (en) * | 2016-03-07 | 2018-03-13 | 广州明珞汽车装备有限公司 | A kind of frictional conveying system |
-
2015
- 2015-05-06 US US14/705,319 patent/US20150322937A1/en not_active Abandoned
- 2015-05-11 WO PCT/US2015/030154 patent/WO2015172145A1/en active Application Filing
- 2015-05-11 JP JP2016567178A patent/JP2017516014A/en active Pending
- 2015-05-11 CA CA2947306A patent/CA2947306C/en active Active
- 2015-05-11 MX MX2016013961A patent/MX2016013961A/en unknown
- 2015-05-11 AU AU2015255673A patent/AU2015255673A1/en not_active Abandoned
- 2015-05-11 BR BR112016025935A patent/BR112016025935B8/en active IP Right Grant
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2019
- 2019-01-08 AU AU2019200087A patent/AU2019200087B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| WO2015172145A1 (en) | 2015-11-12 |
| BR112016025935A2 (en) | 2017-08-15 |
| JP2017516014A (en) | 2017-06-15 |
| AU2015255673A1 (en) | 2016-12-15 |
| AU2019200087A1 (en) | 2019-01-31 |
| BR112016025935B1 (en) | 2022-10-04 |
| CA2947306A1 (en) | 2015-11-12 |
| BR112016025935B8 (en) | 2022-11-29 |
| US20150322937A1 (en) | 2015-11-12 |
| AU2019200087B2 (en) | 2020-04-23 |
| MX2016013961A (en) | 2017-01-09 |
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