Abstract:
An air compressor system having a cast separator tank for use with an oil-flooded air compressor. The cast separator tank including an integrally cast airend inlet opening which is mountable in face-to-face engagement with an airend discharge opening of the compressor; an integrally cast first channel which extends between the airend inlet opening and a separation chamber; an integrally cast second channel which communicates with a lower portion of the separation chamber and which extends along an outer portion of the cast separator tank; and an integrally cast lip which extends around an inner wall of the separation chamber. The compressor system further having a motor, such that the compressor, the motor and the cast separator tank are attached to form a single unit for ease of handling. The compressor system also has a plurality of mounting feet for attachment to an appropriate subbase.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to an air compressor system and more particularly to an air/oil separator tank for use with an oil-flooded air compressor.  
         BACKGROUND OF THE INVENTION  
         [0002]    In conventional air compressor systems which utilize an oil-flooded compressor, air is compressed in a compression chamber or airend by a set of rotary screws, and a lubricant, such as oil, is injected into the compression chamber and mixes with the compressed air. The oil is generally injected into the compression chamber for a number of reasons including cooling the air compressor system, lubricating bearings, balancing axial forces and sealing the rotary screws. Although using oil is essential for operating these types of air compressor systems, the oil must be removed from the stream of compressed air before the compressed air may be used downstream for pneumatic equipment and/or other tools.  
           [0003]    Thus, in such conventional air compressor systems, the compressed air and oil mixture discharged from the airend of the compressor flows with a high velocity into a separator tank where the air and oil of the air/oil mixture are caused to separate. The separator tank is usually cylindrical and the air/oil mixture is directed around an inner wall of a separation chamber. The combination of the centrifugal forces acting on the air/oil mixture and contact between the air/oil mixture and the inner wall of the separation chamber causes much of the oil to separate from the air/oil mixture, thereby allowing gravity to draw the oil downwardly into a lower portion of the separation chamber and also allowing the air to separate from the oil and flow upwardly in the separation chamber. This type of separation effect is known in the art as primary separation.  
           [0004]    As generally known, an air/oil separator tank for an oil-flooded air compressor system generally provides two functions. The separator tank provides a means to separate oil from the air/oil mixture introduced into the separation chamber as described above and it also functions as an oil sump for the compressor system.  
         SUMMARY OF THE INVENTION  
         [0005]    Conventional air compressor systems as described above include multiple hoses, tubes, pipes or the like and associated fittings connecting a compressor to a separator tank. Hoses and associated fittings provide potential leak paths which, if developed, could adversely affect the overall operation of the compressor system. Using hoses and associated fittings also requires additional assembly time. Thus, there is a need for an air compressor system which eliminates or at least reduces the number of hoses and associated fittings used to connect a compressor to a separator tank.  
           [0006]    As commonly understood, conventional air compressor systems as described above include a motor or drivetrain to operate the compressor. Since conventional air compressor systems use a hose, typically a flexible hose, to connect the compressor to a separator tank, the drivetrain, the compressor and the separator tank are not securely attached as a single unit, thereby making it virtually impossible to maneuver the entire compressor system as one. In addition, since the compressor and the separator tank are individual units, each is provided with its own isolation or supporting mounts, thereby adding undesirable cost to the overall compressor system. Thus, there is a need for an air compressor system which is easier to handle and which is assembled together in such a way that the entire compressor system can be handled or moved as a single unit, and which is also mountable to an associated subbase, so as to provide a more cost effective compressor system.  
           [0007]    Conventional air compressor systems as described above may include a baffle element strategically placed within a separation chamber of a separation tank to inhibit the migration of oil separated from the air/oil mixture introduced into the separation chamber from undesirably migrating upwardly into an upper portion of the separation chamber. However, such a baffle element adds to the overall cost of the compressor system and increases the assembly time associated with the compressor system. Thus, there is a need for an air compressor system which does not require the use of a baffle element and which still inhibits the migration of oil separated from the air/oil mixture introduced into the separation chamber from undesirably migrating upwardly into the upper portion of the separation chamber.  
           [0008]    The present invention provides in one aspect thereof, a cast separator tank having an airend inlet opening which is directly mountable to an airend discharge opening of a compressor. The construction of the invention eliminates any need for a hose and associated fittings to connect the airend discharge opening of the compressor to the airend inlet opening of the separator tank.  
           [0009]    The present invention provides in another aspect thereof, a cast separator tank having an integrally cast channel extending between an airend inlet opening and a separation chamber. An air/oil mixture discharged from a compressor enters the airend inlet opening and flows through the channel into the separation chamber. The integrally cast channel further eliminates the need for associated hoses and fittings between the compressor and the separator tank.  
           [0010]    In one embodiment, a cast separator tank includes an integrally cast member which surrounds the airend inlet opening and which is positioned beneath the airend discharge opening of the compressor, so as to support the end of the compressor which houses the airend discharge opening of the compressor. In one aspect of the present invention, a drivetrain for operating the compressor is provided with a mounting foot and the separator tank is provided with an integrally cast mounting foot. The integrally cast member of the separator tank that supports the end of the compressor which houses the airend discharge opening of the compressor provides a third mounting foot. Because the compressor and the separator tank are directly attached to one another and the motor is directly secured to the compressor, the entire compressor system can be moved as a single unit. The mounting feet are conveniently attached to a support base in a chosen location.  
           [0011]    The present invention provides in another aspect thereof, a cast separator tank having an integrally cast channel which is in fluid flow communication with a lower portion of a separation chamber and which extends along an outer surface of the separator tank. Oil separated from an air/oil mixture introduced into the separation chamber collects in the lower portion of the separation chamber. Pressure within the separation chamber causes the oil to flow into the channel and out of the separation chamber. Because the channel is integrally cast with the separator tank, there is no need for a hose and fitting device to enable the oil to flow out of the lower portion of the separation chamber.  
           [0012]    In another embodiment, a cast separator tank includes an integrally cast lip which extends circumferentially around an inner wall of a separation chamber between an upper and a lower portion of the separator chamber. The integrally cast lip inhibits oil in an air/oil mixture introduced into the separation chamber from migrating up into the upper portion of the separation chamber when the air/oil mixture is directed around an inner wall of the separation chamber and subjected to centrifugal forces. Because the lip is integrally cast with the tank, the use of a baffle element is not required.  
           [0013]    Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is a perspective view of an air compressor system embodying the present invention.  
         [0015]    [0015]FIG. 2 is a partial exploded perspective view of the compressor system of FIG. 1.  
         [0016]    [0016]FIG. 3 is a side perspective view of the cast separator tank of FIG. 1.  
         [0017]    [0017]FIG. 4 is another side perspective view of the cast separator tank of FIG. 1.  
         [0018]    [0018]FIG. 5 is a cross-sectional view taken along line V-V of FIG. 4.  
         [0019]    [0019]FIG. 6 is a partial cut-away view of the cast separator tank of FIG. 1.  
         [0020]    [0020]FIG. 7 is cross-sectional view taken along line VII-VII of FIG. 6. 
     
    
       [0021]    Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0022]    Illustrated in FIG. 1 is an air compressor system  10  embodying the present invention. It should be understood that the present invention is capable of use in other compressor systems and the air compressor system  10  is merely shown and described as an example of one such system.  
         [0023]    The air compressor system  10  illustrated in FIG. 1 includes a compressor  14 , a motor or drivetrain  18 , and a separator tank  22 . A feature of the present invention is that the separator tank  22  is a cast separator tank, rather than a fabricated steel tank as is the case for many conventional separator tanks. The compressor  14  is an oil-flooded, rotary screw air compressor. Air enters the compressor  14  and is compressed by rotary screws (not shown) found within housing  26 . Oil is injected into the compressor  14  to lubricate the rotary screws and a gearbox (not shown) which drives the rotary screws. The oil further serves as a sealing means for the compressor  14 . The compressed air and some of the oil travel out of the rotary screws through an airend discharge opening  30  and into an airend inlet opening  34  in the cast separator tank  22 . The cast separator tank  22  serves to separate oil from the compressed air and also serves as an oil sump for the oil used to lubricate the rotary screws, the gearbox and other components. The compressed air and oil enter the cast separator tank  22  and are caused to undergo a cyclonic motion within the cast separator tank  22 . As the compressed air and oil are flung around an inner surface the cast separator tank  22 , the oil will slide down the inner wall and collect at the bottom of the cast separator tank  22  which acts as the oil sump for the compressor system  10 , and the air will move up and out of the cast separator tank  22  for further filtering, cooling and ultimate use.  
         [0024]    As representatively shown in FIG. 1, the air compressor system  10  is mounted on a support frame or subbase  38 . With reference to FIG. 2, the motor  18  is secured to the compressor  14 . The motor  18  includes a mounting foot  42 . The cast separator tank  22  includes an integrally cast mounting foot  46 . The cast separator tank  22  further includes another integrally cast mounting foot  50 . As will be further explained below, the integrally cast mounting foot  46  is also configured to support the end  54  (i.e., the airend) of the compressor  14  that houses the airend discharge opening  30  of the compressor  14 , such that the compressor  14  and the cast separator tank  22  are securely attached to one another. As assembled in FIG. 2, the entire air compressor system  10  can be conveniently handled as a single unit. The air compressor system  10  is secured to the support frame  38  via mounting feet  42 ,  46  and  50  and associated hardware. Preferably, the mounting feet  42 ,  46  and  50  are arranged to provide a triangular support base.  
         [0025]    FIGS.  3 - 7  illustrate in greater detail the cast separator tank  22 . The cast separator tank  22  includes a side wall  58  and defines a separation chamber  62 . The cast separator tank  22  further includes an airend inlet opening  34  (FIGS. 4, 6 and  7 ) which is positionable in direct or abutting relationship with the airend discharge opening  30  of the compressor  14  (see FIGS. 1 and 2). The compressed air and oil flowing out of the airend discharge opening  30  of the compressor  14  flows directly into the airend inlet opening  34  of the cast separator tank  22 . Preferably, the cast separator tank  22  includes an integrally cast member  66  (FIGS. 4, 6 and  7 ) which extends outwardly from the side wall  58  of the cast separator tank  22 . The integrally cast member  66  includes a mounting pad  70  which surrounds the airend inlet opening  34  of the cast separator tank  22 . The airend inlet opening  34  of the cast separator tank  22  is positioned beneath the airend discharge opening  30  of the compressor  14  (see FIGS.  1 - 2 ). The mounting pad  70  is secured in face-to-face relationship with an associated pad  74  (see FIGS.  1 - 2 ) surrounding the airend discharge opening  30  of the compressor  14 . Preferably, the integrally cast member  66  includes the integrally cast mounting foot  46  (see FIG. 2). Thus, the integrally cast member  66  supports the airend  54  of the compressor  14 .  
         [0026]    The cast separator tank  22  further includes an integrally cast channel  78  (FIGS.  3 - 4 , and  6 - 7 ) extending between the airend inlet opening  34  and the separation chamber  62 . The integrally cast channel  78  extends around a portion of the cast separator tank  22 . Arrow  82  (FIGS. 6 and 7) best illustrates the flow path for the compressed air and oil from the airend inlet opening  34  through the channel  78  and into the separation chamber  62 . The outlet  86  (FIG. 7) of the channel  78  that opens into the separation chamber  62  is arranged to tangentially introduce the air/oil mixture against an inner wall  90  of the separation chamber  62 . Moreover, to enhance the separation process of the air/oil mixture, the outlet  86  of the channel  78  is also arranged to provide cyclonic motion to the air/oil mixture when the air/oil mixture enters and flows around the separation chamber  62 .  
         [0027]    The cast separator tank  22  also includes an integrally cast channel  94  (FIGS.  4 - 5 ) extending along an outer portion of the side wall  58  of the cast separator tank  22 . The channel  94  is in fluid flow communication with a lower portion  98  (FIG. 5) of the separation chamber  62 , so that as oil separates from the air/oil mixture introduced into the separation chamber  62  and collects in the lower portion  98 , pressure within the separation chamber  62  will force the oil to flow into and up the channel  94  and out of an exit port  102  (FIGS.  4 - 5 ) provided in the channel  94 . A thermal valve  106  (see FIG. 1 and partially shown in FIG. 5) is received by the exit port  102 . The thermal valve  106  monitors the temperature of the oil. If the oil is too hot, at least a portion of the oil will flow through hose  110  (see FIG. 1) to a cooler (not shown) and back to the thermal valve  106  via hose  114  (see FIG. 1). Downstream of the thermal valve  106  is an oil filter device  118  (see FIG. 1) which filters the oil prior to it being fed to the compressor  14  to lubricate the rotary screws, the gearbox and other components.  
         [0028]    The channel  94  preferably includes a first portion  122  (FIG. 5) which opens into the lower portion  98  of the separation chamber  62  and a second portion  126  (FIG. 5) which communicates with the first portion  122 . The second portion  126  is preferably substantially parallel with the side wall  58  of the cast separator tank  22 . The channel  94  also includes an oil fill port  130  (FIG. 5) for pouring oil into the separation chamber  62  and an oil drain port  134  (FIG. 5) for draining oil from the separation chamber  62 . Each port  130 ,  134  is preferably threaded to receive a respective complementary plug  138 ,  142  (FIG. 5) when it is desired to close the ports  130 ,  134 . Oil is introduced through the oil fill port  130  to provide an initial charge of lubricant for the air compressor system  10  and to top off or replenish any oil which is used or burned off during operation of the air compressor system  10 .  
         [0029]    The cast separator tank  22  includes an integrally cast lip  146  (FIG. 5) which extends circumferentially around the inner wall  90  of the separation chamber  62  between an upper portion  150  and the lower portion  98  of the separation chamber  62 . The integrally cast lip  146  inhibits the oil in the air/oil mixture from migrating up into the upper portion  150  along the inner wall  90  when the air/oil mixture is directed around the inner wall  90  and subjected to centrifugal forces. As shown in FIG. 5, the air/oil mixture will flow into the separation chamber  62  via channel  78  below the lip  146 . Although not clearly shown, because of the very nature of a cast piece, the inner wall  90  of the separation chamber  62  is provided with a non-smooth surface to further enhance separation of the oil from the air/oil mixture. Although not shown, the lip  146  may also be a support structure for various separating devices which may be utilized within the upper portion  150  of the separation chamber  62 .  
         [0030]    It should be noted that the hole  154  shown in FIG. 3 in the side wall  58  of the cast separator tank  22  does not communicate with the channel  78 . The hole  154  is provided to allow for the casting of the separator tank  22  and is plugged (see FIG. 1) upon final assembly of the air compressor system  10 . It should also be noted that the plug  158  (see FIG. 1) extending through the side wall  58  of the cast separator tank  22  is an oil sight glass for the separation chamber  62 .  
         [0031]    Variations and modifications of the foregoing are within the scope of the present invention. It is understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art.  
         [0032]    Various features of the invention are set forth in the following claims.