Patent Publication Number: US-6220825-B1

Title: Rotary-screw air compressor having a separator and a cooler fan assembly

Description:
The present application is a continuation of application Ser. No. 08/843,515 filed Apr. 16, 1997 now U.S. Pat. No. 5,947,711; and is a continuation-in-part of application Ser. No. 08/935,668 filed Sep. 23, 1997 issued as U.S. Pat. No. 6,022,200 of Feb. 8, 2000. 
    
    
     FIELD OF INVENTION 
     This invention is directed to a rotary-screw air-compressor and more particularly to a rotary-screw air-compressor having an air end, a separator, and a mounting apparatus for the separator and air end. 
     BACKGROUND 
     Rotary-screw air-compressors are used to drive air-powered machines and tools. Rotary-screw air-compressors are known for their reliability, durability and ease of maintenance. The reliability, durability and ease of maintenance in large part come from the simplicity of the air end. The air end is the portion of the compressor which compresses the air, and generally utilizes a less complex assemblage of parts than reciprocating compressors. 
     U.S. Pat. No. 5,199,858, Tsuboi, improves upon an oil-injected rotary-screw air-compressor by providing an oil tank having an L-shaped vertical section and a base portion. The L-shaped vertical section contains an oil separating element. A compressor body is mounted on the base portion of the oil tank. An air reservoir tank is formed unitarily with and below the oil tank. 
     The present invention seeks to improve upon previous rotary-screw air-compressors. The present invention seeks to reduce the floor space taken up by a rotary-screw air-compressor. The invention reduces floor space use by vertically stacking parts of the rotary-screw air-compressor. 
     The invention further desires to reduce the noise level and improve durability over previous rotary-screw air-compressors. The invention reduces noise level and improves durability by reducing the vibrational impact and the load the motor and air end have on various components of the compressor such as the separator. 
     The invention further reduces noise level by providing a cooler fan assembly which creates less operating noise than previous cooler fan assemblies. 
     The invention further desires to reduce the overall number of parts utilized in the rotary-screw air-compressor. The invention reduces the overall number of parts by providing a separator which eliminates the need for previously used moisture separating units. 
     The invention further improves the efficiency of the cooler fan assembly. 
     SUMMARY 
     Accordingly, in one embodiment of the invention, a water-injected rotary-screw air-compressor is provided with a first platform. A separator having a separator body is connected to the first platform. A second platform has a second platform support. The support is disposed vertically above the separator. An air end and a means to power said air end are disposed over the second platform support and connected to the second platform support. A means prevents the second platform support from producing a load on the separator body. The second platform is connected to the first platform. 
     In another embodiment of my water-injected rotary-screw air compressor, the first platform includes a first elevated surface and a second elevated surface. A chasm separates the first and second elevated surfaces. A portion of the separator body is disposed in the chasm. The separator body remains free of contact with the first platform. 
     In still a further embodiment of my invention, a water-injected rotary-screw air-compressor separator is provided with a separator body. An internal surface of the separator body defines a hollow. A partition divides the hollow into a first and a second chamber. A first baffle is disposed in the first chamber and a second baffle is disposed in the second chamber. A discharge inlet opens into the first chamber. The discharge inlet permits an amount of compressed air and an amount of coolant discharged from an air end to enter into the first chamber. A coolant outlet opens out of the first chamber. The coolant outlet permits the coolant to exit the first chamber. A compressed air outlet opens out of the first chamber. The compressed air outlet permits compressed air to leave the first chamber. 
     A compressed air inlet opens into the second chamber. The compressed air inlet permits compressed air from the first chamber to enter the second chamber. A compressed air discharge outlet opens out of the second chamber. A moisture outlet opens out of the second chamber. 
     In still another embodiment of my invention, a water-injected rotary-screw air-compressor cooler fan assembly is provided with a shroud. The shroud has a first end and an opposite second end. The shroud defines an air passage. The air passage has a constriction. A coolant cooling heat exchanger is connected to the shroud. A compressed air cooling heat exchanger (aftercooler) is connected to the shroud. The coolant cooling heat exchanger and aftercooler are opposite each other. A pair of cooler fans are disposed completely within the shroud and between the aftercooler and coolant cooling heat exchanger. 
    
    
     Other desires, results and novel features of the present invention will become more apparent from the following drawings, detailed description and the accompanying claims. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic of the water-injected rotary-screw air-compressor; 
     FIG. 2 is a top view looking down into the water-injected rotary-screw air-compressor; 
     FIG. 3 is a first end view of the water-injected rotary-screw air-compressor showing the air end connected to the separator body; 
     FIG. 4 is a side view of the water-injected rotary-screw air-compressor showing the pair of cooler fans; 
     FIG. 5 is a second end view of the water-injected rotary-screw air-compressor opposite the first end view and looks into the compressor motor; 
     FIG. 6 is a top side perspective view of the water-injected rotary-screw air-compressor having a portion of the compressor&#39;s acoustic housing removed. 
     FIG. 7 is a top side perspective view of the water-injected rotary-screw air-compressor enclosed in an acoustic housing; 
     FIG. 8 is an exploded view of the mounting apparatus used in conjunction with the separator, motor and air end; 
     FIG. 9 is an exploded view of the cooler fan assembly; 
     FIG. 10 is a top view of the separator; 
     FIG. 10 a  is a sectional view of the separator taken along view line  10 A; 
     FIG. 11 is a side view of the separator looking into the compressed air outlet; 
     FIG. 11 a  is a sectional view of the separator taken along view line  11 A of FIG. 11; 
     FIG. 12 is an end view of the separator looking into the second end of the separator body; 
     FIG. 13 is a side top perspective view of the second platform of the mounting apparatus; 
    
    
     DETAILED DESCRIPTION 
     Referring to FIGS. 8 and 9, my water-injected rotary-screw air-compressor includes a separator  21  mounted between a first platform  22  and a second platform  23 ; a motor  24  and air end  25  are mounted on top the second platform and connected thereto. A cooler fan assembly  26  is mounted vertically over the motor and air end. 
     In more detail, the separator  21  is connected to an elevated surface  27   a ,  27   b  of the first platform. The elevated surface forms a first elevated surface  27   a  and a second elevated surface  27   b.    
     Now referring to FIGS. 10,  10   a ,  11 ,  11   a  and  12 , the separator has a separator body  28 . The separator body has an internal surface  30   a ,  30   b ,  30   c  which defines a hollow  32   a ,  32   b . The hollow is divided into a first chamber  32   a  and a second chamber  32   b . A discharge inlet  34  is connected to the first chamber. The inlet receives compressed air and coolant discharged from the air end. A compressed air outlet  36  is connected to the first chamber and a coolant outlet  38  is also connected to the first chamber. 
     A compressed air inlet  40  is connected to the second chamber and a compressed air discharge outlet  42  is connected to the second chamber. 
     Again referring to FIGS. 6,  8 , and  9 , the second platform  23  has a second platform support  43   a ,  43   b . The second platform support  43   a ,  43   b  is disposed vertically above the separator body and spaced apart therefrom. The air end and motor are disposed over the second platform support  43   a ,  43   b  and connected thereto. The second platform  23  is connected to the first platform. 
     The cooler fan assembly  26  is disposed vertically above the air end  25  and motor  24  and spaced apart therefrom. The cooler fan assembly includes a shroud  48 , a first heat exchanger  50  and a second heat exchanger  52 . The heat exchangers are disposed at axially opposite ends of the shroud. A pair of cooler fans  54   a ,  54   b  are disposed within the shroud and are axially between the first and second heat exchangers (see FIG.  4 ). Each cooler fan has a fan motor  55   a  and a fan blade  55   b . The first exchanger  50  is vertically above the second heat exchanger  52 . 
     Now also referring to FIG. 1, a duct  56  connects the first heat exchanger to the coolant outlet  38 . A duct  56  a also connects the first heat exchanger to the air end  25 . 
     A duct  60  connects the second heat exchanger to the compressed air outlet  36 . A duct  62  also connects the second heat exchanger to the compressed air inlet  40 . 
     During operation, coolant and compressed air are discharged from the air end  25 . The discharged coolant and compressed air pass through the discharge inlet  34  and into the first chamber  32   a  of the separator. While in the first chamber, the coolant and the compressed air are separated. 
     The coolant outlet  38  allows the coolant to exit the first chamber. The duct  56  directs the coolant from the coolant outlet to the first heat exchanger. The first heat exchanger  50  reduces the coolant&#39;s temperature. The duct  56   a  then directs the coolant from the first heat exchanger back into the air end. The coolant is recirculated by being discharged back into the separator through a duct  63 . 
     The compressed air outlet  36  permits the compressed air to leave the first chamber of the separator. The duct  60  directs the compressed air from the compressed air outlet to the second heat exchanger  52 . The second heat exchanger reduces the temperature of the compressed air. 
     The duct  62  directs the compressed air from the second heat exchanger to the compressed air inlet  40 . The compressed air passes through the compressed air inlet  40  and into the second chamber  32   b  of the separator. In the second chamber, moisture is removed from the compressed air. Cool, dry compressed air is then discharged from the second chamber through the compressed air discharge outlet  42 . 
     In the shown embodiment, the coolant is water. The first heat exchanger  50  is a coolant cooling heat exchanger, and more particularly a water cooler, and the second heat exchanger  52  is an aftercooler. 
     Referring to FIGS. 10,  10   a ,  11 ,  11   a  and  12  in still more detail, the separator body has two conical ends. The first conical end  64  is at one end of the separator body&#39;s longitudinal length; the second conical end  65  is at the opposite end of the separator body&#39;s longitudinal length. The hollow  32   a ,  32   b  has a longitudinal length  67  of about 42 inches. 
     The internal surface  30   a ,  30   b ,  30   c  includes a plurality of internal concave surfaces. A first internal concave surface  30   a  forms the internal surface of the first conical end, and a second internal concave surface  30   b  forms the internal surface of the second conical end. The portion of the internal surface connecting the concave surfaces is annular. The internal annular surface  30   c  forms a cylinder having an internal diameter  75  of about 0.28 times the longitudinal length  67  of the hollow. 
     A partition  77  divides the hollow  32   a ,  32   b  into the first chamber  32   a  and the second chamber  32   b . The first chamber is adjacent to the first conical end and the second chamber is adjacent to the second conical end. The partition separates the two chambers and is constructed to prevent compressed air from one chamber entering into the other chamber. The partition isolates and seals off the environments of the first and second chambers from one another. 
     The partition  77  is a bulkhead that is preferably perpendicular to a longitudinal axis  79  of the hollow. The bulkhead lies in a cross-sectional plane transverse to the longitudinal length of the hollow. The bulkhead has a longitudinal distance of about 28 inches from the focal point  81  of the first internal concave surface. 
     The separator body  28  has a first longitudinal section  83   a  and a second longitudinal section  83   b  (see FIG.  11 ). The first and second sections are on opposite sides of a cross-sectional plane taken along the longitudinal axis  79  of the hollow. The coolant  85  collects on a portion of the internal surface in the second longitudinal section and in the first chamber. The moisture  87  from the cooled air collects on a portion of the internal surface in the second longitudinal section  83   b  and in the second chamber  32   b.    
     Baffle  89   a  is disposed in the first chamber, and baffle  89   b  is disposed in the second chamber; each baffle extends axially away from the internal annular surface of the first longitudinal section and towards the internal annular surface of the second longitudinal section. 
     Each baffle lies in a cross-sectional plane transverse to the longitudinal length of the hollow. Each baffle is at a right angle to the longitudinal axis  79  of the hollow. 
     Each baffle has a linear edge  90   a ,  90   b  and a curved edge  91   a ,  91   b  (see FIG.  8 ). The curved edge is opposite the linear edge. The linear edge has ends which form the ends of the curved edge. The linear edge has a length about equal to 0.9 of the internal diameter of the cylinder. The arc of the curved edge is the same as the arc of the internal annular surface  30   c . The curved edge is integral with the internal annular surface  30   c . Each baffle forms a sort of half-moon shape. 
     The baffle disposed in the first chamber is first baffle  89   a  and has a longitudinal distance  92  from the focal point  81  of the first internal concave surface of about 7 inches. The baffle in the second chamber is second baffle  89   b . The second baffle  89   b  has a longitudinal distance of about 7 inches to the bulkhead. 
     The discharge inlet  34  includes an exit  93 . The exit is disposed in the first chamber and is disposed in the first longitudinal section. The exit opens towards the first internal concave surface  30   a . The exit is between the first baffle and the first internal concave surface  30   a . The exit has a distance  95  of about 3 inches to the first internal concave surface  69 . 
     The discharge inlet  34  has an entrance  97  opening into the first longitudinal section and the first chamber. The entrance opens through the internal annular surface. 
     The discharge inlet directs the coolant and compressed air discharge in a flow direction in the first chamber. A tube  101  connects the exit and the entrance to define the flow direction. The tube passes through the first baffle. 
     The flow direction includes a first  99   a  and second  99   b  flow direction. The first flow direction  99   a  flows from the internal annular surface of the first longitudinal section towards the second longitudinal section. 
     The second flow direction  99   b  is along the longitudinal length of the hollow and flows away from the second conical end and towards the first conical end. 
     The coolant outlet  38  opens out of the first chamber and through the internal annular surface of the second longitudinal section. The coolant outlet is connected to the water cooler  50 . 
     The compressed air outlet  36  has an entrance  103  disposed in the first longitudinal section and the first chamber. The entrance opens towards the annular surface of the first longitudinal section. The entrance has a distance  105  to the internal annular surface of about 1 inch. The entrance has a distance  107  of about 3 inches to the bulkhead and a distance to the first baffle of about 18 inches. The entrance is between the first baffle and the bulkhead. 
     The compressed air outlet has an exit  109 . The exit opens out of the first chamber and through the internal annular surface. 
     The compressed air outlet directs the compressed air in a flow direction in the first chamber. A tube  113  connects the entrance and exit to define the flow direction. The flow direction includes a first  111   a  and second  111   b  flow direction. The first flow direction  111   a  is transverse to the longitudinal length of the hollow and flows in a direction away from the first longitudinal section and towards the second longitudinal section. The second flow direction  111   b  is transverse to the longitudinal length of the hollow. It flows from the interior of the hollow towards the interior annular surface. 
     The compressed air inlet has an exit  116  and an entrance  117 . The entrance  117  opens into the second chamber and through the internal annular surface. The exit  116  of the compressed air inlet is disposed in the second chamber. The exit  116  is disposed in the first longitudinal section  83   a . The exit opens towards the internal annular surface. The exit has a distance of about 1 inch to this internal annular surface. It has a distance of about 4 inches to the second baffle. It is disposed between the second baffle  89   b  and the bulkhead  77 . 
     The compressed air inlet directs the compressed air in a flow direction in the second chamber. A tube  119  connects the exit and entrance to define the flow direction. The flow direction includes a first and second flow direction. The first flow direction  118   a  is transverse to the longitudinal length of the hollow and flows away from the annular internal surface and towards the interior of the hollow. The second flow direction  118   b  is transverse to the longitudinal length of the hollow and flows away from the second longitudinal section and towards the first longitudinal section. 
     The compressed air discharge outlet  42  opens out of the second chamber. The compressed air discharge outlet opens through the second internal concave surface. 
     A moisture outlet  120  opens out of the second longitudinal section and the second chamber. The outlet opens through the internal annular surface. 
     A vent  121  opens through the second chamber. Vent  121  vents the moisture trap  122  (see FIG.  1 ). 
     A separator level switch  123  is disposed in the first chamber. The switch extends from the first longitudinal section towards the second longitudinal section. The level switch detects when a low level of coolant is circulating through the rotary-screw compressor. 
     A support  125   a ,  125   b  is connected to the separator body. The support is a pair of metal straps. A metal strap  125   a  is towards the first conical end. A metal strap  125   b  is towards the second conical end. The central portion of each metal strap wraps around the second longitudinal section  83   b  of the separator body. The ends of each metal strap form flanges. Metal strap  125   a  has a first flange  126   a  and a second flange  126   b . The first flange  126   a  is disposed on a side of the separator opposite to the disposition of the second flange  126   b.    
     A third  126   c  and fourth  126   d  flange form the ends of metal strap  125   b  in the same manner as the first and second flanges form the ends of metal strap  125   a , excepting the third and fourth flanges are towards the second conical end  65 . The first, second, third and fourth flanges are disposed in the same plane. 
     Each flange has a first side  127   a  and an opposite second side  127   b.    
     The elevated surface  27   a ,  27   b  of the first platform is vertically spaced from and in a different horizontal plane than a lower surface  131  of the first platform. The first  27   a  and second  27   b  elevated surfaces are horizontally spaced apart from each other. A chasm  133  separates the first and second elevated surfaces. 
     The chasm  133  has a horizontal width to accommodate the transverse length of the separator body. The chasm accommodates at least a portion of the second longitudinal section of the separator body. 
     The second platform support  43   a ,  43   b  has a first level  43   a  and a second level  43   b . The second platform has four legs  136   a ,  136   b ,  136   c ,  136   d.    
     A back  138  forms part of the second platform. The back has a first opening  139  and a second opening  140 . The first opening is laterally spaced from the second opening. 
     A plate  141  is disposed over and connected to the second platform support. 
     Referring to FIG. 8, the flanges connect the separator body  28  to the first  27   a  and second  27   b  elevated surfaces of the first platform  22 . The second side  127   b  of each flange faces towards the first  27   a  and second  27   b  elevated surfaces of the first platform. An isolator  143  is disposed between the second side  127   b  of each flange and the elevated surfaces  27   a ,  27   b  of the first platform. The second longitudinal section  83   b  of the separator body is disposed in the chasm (see FIG.  3 ). The separator body is suspended in the chasm  133  via the metal straps  125   a ,  125   b  and remains free from contact with the first platform. 
     The second platform is connected to the first platform. The four legs  136   a-d  axially space apart the second platform support  43   a ,  43   b  and the separator body so that the second platform support is vertically above, and free of contact with, the separator body. Each of the four legs is disposed over a corresponding flange and connected to a corresponding flange. The four legs remain free from contact with the separator body. The legs prevent said second platform support  43   a ,  43   b  from producing a load on said separator body. 
     The air end  25  is disposed over the second level  43   b  of the second platform support and connected thereto. The air end has a shaft  147 . The shaft is transverse to the back  138 . The shaft is transverse to the longitudinal length of the hollow. The shaft extends through the first opening  139  of the back. 
     The motor  24  is disposed over the first level  43   a  of the second platform support and connected thereto. A shaft  148  of the motor extends through the second opening  140  of the back. The shaft  148  is transverse to the back. 
     The plate  141  is connected to the second platform support and is disposed between the motor and the second platform support. 
     A guard  149  is connected to the back. The guard covers the first and second openings of the back. The guard covers a coupling  151  (FIG. 4) which operatively connects the motor to the air end. 
     Referring to FIGS. 4,  6 , and  9 , the cooler fan assembly  26  is vertically above and spatially separated from the air end and motor. The fan blades and fan motor are disposed completely within the shroud. A coupling  153  connects the fan motor to the shroud. The first heat exchanger  50  is disposed vertically above and opposite the second heat exchanger  52 . 
     The shroud defines an air passageway. The passageway has a constriction  155 . The fan blades and fan motor are disposed in the air passageway. The fan sucks air through the aftercooler  52  and blows it through the water cooler  50 . The cooler fan assembly is connected to the separator. 
     An acoustic covering  157  (FIGS. 6,  7 ) forms a housing of the rotary-screw air-compressor. The housing has a plurality of air vents  159 . 
     FIG. 1 shows a schematic illustration of the preferred manner in which the various compressor parts are joined together which have been described in some detail above. A parts list is hereinafter set forth to provide guidance. 
     
       
         
           
               
               
               
             
               
                   
                   
               
             
            
               
                   
                 24 
                 Motor 
               
               
                   
                 25 
                 Air End 
               
               
                   
                 28 
                 Separator Body 
               
               
                   
                 50 
                 First Heat Exchanger 
               
               
                   
                 52 
                 Second Heat Exchanger 
               
               
                   
                 54a, 54b 
                 Pair of Cooler Fans 
               
               
                   
                 121 
                 Vent to Moisture Trap 
               
               
                   
                 122 
                 Moisture Trap 
               
               
                   
                 160 
                 Oil Reservoir Fill 
               
               
                   
                 161 
                 Oil Level Sight Glass 
               
               
                   
                 163 
                 Oil Reservoir Drain 
               
               
                   
                 164 
                 Inlet Bearing Grease Fitting (2 places) 
               
               
                   
                 165 
                 Air Inlet Valve 
               
               
                   
                 166 
                 Air Filter 
               
               
                   
                 167 
                 System Water Filter 
               
               
                   
                 168 
                 Make-up Water Filter 
               
               
                   
                 170 
                 Magnetic Unloaded Solenoid Valve 
               
               
                   
                 171 
                 Control Check Valve 
               
               
                   
                 172 
                 Muffler 
               
               
                   
                 173 
                 Blowdown Solenoid Valve 
               
               
                   
                 174 
                 Pressure Regulator 
               
               
                   
                 175 
                 Air Line Filter 
               
               
                   
                 176 
                 Shuttle Valve 
               
               
                   
                 177 
                 System Pressure Transducer 
               
               
                   
                 178 
                 Reservoir Pressure Transducer 
               
               
                   
                 179 
                 Injection Water Transducer 
               
               
                   
                 180 
                 Air Filter Vacuum Switch 
               
               
                   
                 181 
                 Water Injection Manifold 
               
               
                   
                 182 
                 Pressure Relief Valve 
               
               
                   
                 183 
                 Separator Level Switch 
               
               
                   
                 184 
                 Discharge Check Valve 
               
               
                   
                 186 
                 Water Inlet Solenoid Valve 
               
               
                   
                 187 
                 Globe Valve 
               
               
                   
                 188 
                 Auto Drain Solenoid Valve 
               
               
                   
                 189 
                 Manual Drain Globe Valve 
               
               
                   
                 190 
                 Check Valve 
               
               
                   
                 191 
                 Check Valve 
               
               
                   
                 192 
                 Purge Valve 
               
               
                   
                 193 
                 Water Treatment Housing and Cartridge 
               
               
                   
                   
               
            
           
         
       
     
     Applicant&#39;s separator and mounting apparatus have several advantages. Previous compressors required an individual moisture separating unit and an individual separator. The moisture separating units used complex baffling structures or cyclone structures within their housings. These moisture separators provided a negligible amount of air reservoir space. 
     Applicant&#39;s separator eliminates the need for the previously used moisture separating units. Applicant&#39;s separator performs the moisture separating function. The single separator can be manufactured more cheaply than having to manufacture both a previous coolant separating unit and a previous moisture separating unit. 
     The separator performs moisture separation without reducing the overall reservoir capacity from previous coolant separating units. 
     The separator mounting apparatus helps to reduce the surface area taken up by the compressor. The mounting apparatus vertically elevates the motor and the air end over the separator. The vertical stacking reduces the horizontal surface area taken up by a rotary-screw air-compressor. 
     The apparatus reduces the load and vibrational impact the motor and air end place on the separator body. The separator body is suspended in the chasm of the first platform. The motor and air end are disposed over and connected to the second platform support. 
     The second platform supports the air end and motor vertically above and apart from the separator body. The apparatus thus helps to isolate the separator body from vibrations caused by the motor and air end. In addition, the apparatus ensures that the motor and air end do not create a load on the separator. 
     Reducing the load and vibrational impact on the separator allows the separator to be made more cost effectively. The separator does not require previously used structural supports. 
     It is important to note that the present invention has been described with reference to an example of an embodiment of the invention. It would be apparent to those skilled in the art that a person understanding this invention may conceive of changes or other embodiments or variations which utilize the principles of the invention without departing from the broader spirit and scope of the invention as set forth in the appended claims. All are considered within the spirit and scope of the invention. The specifications and drawings are therefore to be regarded in an illustrative rather than a restrictive sense. Accordingly, it is not intended that the invention be limited except as may be necessary in view of the appended claims.