Abstract:
Provided is a compression system including: at least one impeller; a gear train configured to the at least one impeller; a main drive shaft configured to drive the gear train; and a housing comprising an impeller container configured to house the at least one impeller and a gear train container configured to house the gear train.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
       [0001]    This application claims priority from Korean Patent Application No. 10-2013-0012940 filed on Feb. 5, 2013, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    Apparatuses and methods consistent with exemplary embodiments relate to a compression system. 
         [0004]    2. Description of the Related Art 
         [0005]    Compressors for compressing fluids such as air, gases, and steam are used in various fields and there are many kinds thereof. 
         [0006]    In the related art, compressors are classified into a volumetric type and a turbo type, and in more detail, reciprocating compressors, rotary screw compressors, turbo compressors, diaphragm compressors, and rotary sliding vane compressors. 
         [0007]    Such compressors may be used independently, but according to needs of a designer, several compressors may be combined to form a multi-stage system, which is capable of providing a greater compression ratio. 
         [0008]    On the other hand, Korean Patent Publication No. 1997-0021766 discloses a turbo compressor in which a gearbox and scrolls are separately manufactured, and the gearbox houses a train of gears and the scrolls houses impellers. 
       SUMMARY 
       [0009]    One or more exemplary embodiments provide a compression system having an inner configuration whose layout is simple. 
         [0010]    According to an aspect of an exemplary embodiment, there is provided a compression system including: at least one impeller; a gear train configured to drive the at least one impeller; a main drive shaft configured to drive the gear train; and a housing comprising an impeller container configured to house the at least one impeller and a gear train container configured to house the gear train. 
         [0011]    The at least one impeller may include at least two in number, and the at least two impellers may be arranged in series. 
         [0012]    The gear train may include: a bull gear connected to the main drive shaft; and at least one pinion gear engaged with the bull gear. 
         [0013]    The at least one pinion gear may be connected to an impeller shaft configured to rotate the at least two impellers. 
         [0014]    The housing may comprise: an upper housing; and a lower housing coupled with the upper housing. 
         [0015]    Each of the upper housing and the lower housing may be a one-piece casting housing. 
         [0016]    The at least one impeller includes a plurality of impellers, and the housing may also include a flow path configured to transfer a fluid between the plurality of impellers in the housing. 
         [0017]    The housing including the impeller container, the gear train container and the flow path may be a one-piece housing. 
         [0018]    The housing including the impeller container and the gear train container may be a one-piece housing. 
         [0019]    The at least one impeller comprises a plurality of impellers, wherein the compression system may further include at least two compression units, and wherein each of the compression units may include at least two impellers of the plurality of impellers. 
         [0020]    The housing may further include at least one connecting pipe configured to connect the at least two compression units. 
         [0021]    According to an aspect of another exemplary embodiment, there is provided a method of manufacturing a compression system, the method including: preparing an upper housing and a lower housing, each of the upper and lower housings including an impeller container and a gear train container; installing an impeller in the impeller container of the lower housing and installing a gear train in the gear train container of the lower housing; and coupling the upper housing with the lower housing. 
         [0022]    The upper housing and the lower housing may be formed by using a casting method. 
         [0023]    The preparing the upper housing and lower housing may include casting each of the upper and lower housings having the impeller container and the gear train container as a one-piece casting. 
         [0024]    The impeller may include a plurality of impellers, and the each of the upper and lower housings further comprises a flow path configured to transfer a fluid between the plurality of impellers. 
         [0025]    The preparing the upper housing and lower housing may include casting each of the upper and lower housings having the impeller container, the gear train container and the flow path as a one-piece casting. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    The above and/or other aspects will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: 
           [0027]      FIG. 1  is an external perspective view illustrating a compression system according to an exemplary embodiment; 
           [0028]      FIG. 2  is a schematic perspective view illustrating the compression system from which an upper housing is removed to show an inner configuration thereof; 
           [0029]      FIG. 3  is a schematic top view illustrating the inside of the compression system of  FIG. 2 ; 
           [0030]      FIG. 4  is a top view illustrating the inside of the upper housing of the compression system of  FIG. 1 ; and 
           [0031]      FIG. 5  is a schematic enlarged view illustrating a third compressing unit of the compression system of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    Hereinafter, one or more embodiments will be described in detail with reference to accompanying drawings. Also, in drawings, same reference numerals denote same elements to avoid repetition. 
         [0033]      FIG. 1  is an external perspective view illustrating a compression system  100  according to an exemplary embodiment,  FIG. 2  is a schematic perspective view illustrating the compression system  100  from which an upper housing  141  is removed to show an inner configuration thereof,  FIG. 3  is a schematic top view illustrating the inside of the compression system  100  of  FIG. 2 ,  FIG. 4  is a top view illustrating the inside of the upper housing  141  of the compression system  100 , and  FIG. 5  is a schematic enlarged view illustrating a third compression unit S3 of the compression system  100 . 
         [0034]    As shown in  FIGS. 1 through 5 , the compression system  100  includes an impeller part  110 , a gear train  120 , a main drive shaft  130 , a housing  140 , and a support  150 . 
         [0035]    The impeller part  110  includes a first impeller  111 , a second impeller  112 , a third impeller  113 , a fourth impeller  114 , a fifth impeller  115 , a sixth impeller  116 , a seventh impeller  117 , and an eighth impeller  118  arranged in the housing  140 , and performs multi-stage compression. 
         [0036]    The first impeller  111  and the second impeller  112  are arranged in series and form a first compression unit S1, the third impeller  113  and the fourth impeller  114  are arranged in series and form a second compression unit S2, the fifth impeller  115  and the sixth impeller  116  are in series and form the third compression unit S3, and the seventh impeller  117  and the eighth impeller  118  are in series and form a fourth compression unit S4. 
         [0037]    Compression pressure of the first compression unit S1, the second compression unit S2, the third compression unit S3, and the fourth compression unit S4 sequentially increases. That is, the first compression unit S1 is a compressor unit which produces the lowest pressure ratio and the fourth compression unit S4 is a compressor unit which produces the highest pressure ratio. In other words, a compressed gas discharged from the first compression unit S1 is transferred to the second compression unit S2, a compressed gas discharged from the second compression unit S2 is transferred to the third compression unit S3, and a compressed gas discharged from the third compression unit S3 is transferred to the fourth compression unit S4, thereby performing multi-stage compression in an increasing manner. For this, a first connecting pipe ( 171 ) is installed outside the housing  140  to connect an outlet of the first compression unit S1 to an inlet of the second compression unit S2, a second connecting pipe ( 172 ) is installed outside the housing  140  to connect an outlet of the second compression unit S2 to an inlet of the third compression unit S3, and a third connecting pipe ( 173 ) is installed outside the housing  140  to connect an outlet of the third compression unit S3 to an inlet of the fourth compression unit S4 as shown in  FIG. 4 . 
         [0038]    In the present exemplary embodiment, the impeller part  110  includes eight impellers, which are the first impeller  111 , the second impeller  112 , the third impeller  113 , the fourth impeller  114 , the fifth impeller  115 , the sixth impeller  116 , the seventh impeller  117 , and the eighth impeller  118 , and the eight impellers in pairs form the first compression unit S1, the second compression unit S2, the third compression unit S3, and the fourth compression unit S4. However, the exemplary embodiment is not limited thereto. In other words, there are no particular limitations to the numbers of impellers and compression units installed in the compression system  100 . For example, the number of impellers installed in the compression system  100  may be twelve and the twelve impellers may be coupled together in threes and thus form four compression units. 
         [0039]    As a type of the impeller part  110 , there is a type that uses centrifugal impellers. As shown in  FIG. 5 , each impeller of the impeller part  110  includes a base plate  110   a,  a plurality of blades  110   b  installed on the base plate  110   a,  and a shaft  110   c  connected to the base plate  110   a.    
         [0040]    The shaft  110   c  is connected to a pinion gear  122  and receives power therefrom, the shaft  110   c  being supported by using a first bearing  161 . In the present exemplary embodiment, there are two shafts  110   c,  as shown in  FIG. 3 , the left shaft  110   c  is installed in the first impeller  111 , the second impeller  112 , the third impeller  113 , and the fourth impeller  114  and the right shaft  110   c  is installed in the fifth impeller  115 , the sixth impeller  116 , the seventh impeller  117 , and the eighth impeller  118 . 
         [0041]    In the present exemplary embodiment, centrifugal impellers are used but the exemplary embodiments are not limited thereto. That is, the kind of the impellers used in the current exemplary embodiment is not limited to centrifugal impellers, but various kinds of impellers such as an axial flow type and mixed-flow type may also be used. 
         [0042]    On the other hand, the gear train  120  includes a bull gear  121  and two pinion gears  122  engaged with the bull gear  121 . 
         [0043]    The bull gear  121  receives power from the main drive shaft  130  and transmits the power to the pinion gears  122 . 
         [0044]    The pinion gears  122  receive the power from the bull gear  121  and transmit the power to the respective shafts  110   c  driving the impeller part  110 . 
         [0045]    In the present exemplary embodiment, the gear train  120  includes the one bull gear  121  and the two pinion gears  122  but the exemplary embodiment is not limited thereto. That is, a configuration of the gear train  120  may vary. For example, a gear train according to another exemplary embodiment may include two bull gears and four pinion gears. 
         [0046]    The main drive shaft  130  drives the gear train  120 , being connected to a shaft of a motor (not shown) generating power or connected to a shaft of a reducer (not shown) to transmit external power to the bull gear  121 . 
         [0047]    The main drive shaft  130  is inserted into an installation hole located in the center of the bull gear  121  and connected thereto, and the main drive shaft  130  is supported by using a second bearing  162 . 
         [0048]    The housing  140  includes the upper housing  141  and a lower housing  142 . 
         [0049]    As shown in  FIG. 4 , the upper housing  141  includes an impeller container  141   a , a gear train container  141   b , and a flow path  141   c  formed in a single body and the lower housing  142  also includes an impeller container  142   a,  a gear train container  142   b,  and a flow path  142   c  formed in a single body as shown in  FIG. 5 . 
         [0050]    The impeller containers  141   a  and  142   a  face each other to form a space for containing the impeller part  110 , and the gear train containers  141   b  and  142   b  face each other to form a space for containing the gear train  120 . 
         [0051]    Also, the flow paths  141   c  and  142   c  face each other to form a space for transferring a fluid around inside the impeller part  110 . That is, a path formed by the flow paths  141   c  and  142   c  includes a path for transferring the fluid from the first impeller  111  to the second impeller  112 , a path for transferring the fluid from the third impeller  113  to the fourth impeller  114 , a path for transferring the fluid from the fifth impeller  115  to the sixth impeller  116 , and a path for transferring the fluid from the seventh impeller  117  to the eighth impeller  118 . 
         [0052]    Each of the upper housing  141  including the impeller container  141   a , the gear train container  141   b,  and the flow path  141   c  and the lower housing  142  including the impeller container  142   a,  the gear train container  142   b,  and the flow path  142   c  is formed as a one-piece casting, respectively. That is, the upper housing  141  and the lower housing  142  are manufactured by using casting method. 
         [0053]    In a process of manufacturing the upper housing  141 , while forming the upper housing  141  in the one-piece casting, the impeller container  141   a,  the gear train container  141   b,  and the flow path  141   c  are formed in as a single body. The lower housing  142  is formed using the same method as the upper housing  141 , in which shapes of the impeller container  142   a,  the gear train container  142   b,  and the flow path  142   c  of the lower housing  142  are formed to be symmetrical to those of the impeller container  141   a,  the gear train container  141   b,  and the flow path  141   c  of the upper housing  141 , respectively. 
         [0054]    In detail, in the process of manufacturing the upper housing  141 , the impeller container  141   a,  the gear train container  141   b,  and the flow path  141   c  are formed as a single body all together using a single mold for casting the upper housing  141 . In a process of manufacturing the lower housing  142 , the impeller container  142   a,  the gear train container  142   b,  and the flow path  142   c  are formed in a single body all together using another single mold for casting the lower housing  142 . 
         [0055]    According to the present exemplary embodiment, the impeller container  141   a,  the gear train container  141   b,  and the flow path  141   c  are formed all together using the single mold for the upper housing  141  in the process of manufacturing the upper housing  141  and the impeller container  142   a,  the gear train container  142   b,  and the flow path  142   c  are formed all together using the single mold for the lower housing  142  in the process of manufacturing the lower housing  142 , but the exemplary embodiment is not limited thereto. That is, at least one of the impeller containers  141   a  and  142   a,  the gear train containers  141   b  and  142   b,  and the flow paths  141   c  and  142   c  may be formed by an additional cutting process after a casting process is performed. 
         [0056]    Since the impeller containers  141   a  and  142   a,  the gear train containers  141   b  and  142   b,  and the flow paths  141   c  and  142   c  of the housing  140  are formed in a single body by the casting process, there is no need to include a separate casing member, a shroud member, and a gearbox, which are used in compressor systems of the related art. Also, since the housing  140  includes the flow paths  141   c  and  142   c , it is possible to greatly reduce the number of flow path pipes installed outside the housing  140 . 
         [0057]    The support  150  is installed on a bottom of the lower housing  142  and supports the lower housing  142 . The support  150  is manufactured separately from the lower housing  142  and fastened to the lower housing  142  by using a method such as welding. 
         [0058]    According to the present exemplary embodiment, the support  150  is manufactured separately from the lower housing  142  and fastened to the lower housing  142  by using a method such as welding, but the exemplary embodiment is not limited thereto. That is, the support  150  may be manufactured together with the lower housing  142  in a single casting while manufacturing the lower housing  142 . In this case, a mold for the lower housing  142  includes a mold for the support  150 . 
         [0059]    Hereinafter, there will be described a method of manufacturing the compression system  100 . 
         [0060]    A manufacturer manufactures the upper housing  141  and the lower housing  142  in which the impeller containers  141   a  and  142   a,  the gear train containers  141   b  and  142   b,  and the flow paths  141   c  and  142   c  are also formed, respectively, by using a casting process. In addition, the manufacturer prepares elements of the impeller part  110  and the gear train  120  to be installed in the compression system  100 . 
         [0061]    The manufacturer arranges the prepared impeller part  110  in the impeller container  142   a  of the lower housing  142  and arranges the gear train  120  in the gear train container  142   b,  which have the shape as shown in  FIG. 2 . 
         [0062]    The manufacturer couples the upper housing  141  with the lower housing  142  and fastens the upper and lower housings. In this case, a sealing means such as a sealing ring (not shown) is disposed between the upper housing  141  and the lower housing  142  to perform sealing. In this case, as a fastening means of the upper housing  141  and the lower housing  142 , a screw-coupling method using bolts or a welding method may be used. 
         [0063]    Hereinafter, operation of the compression system  100  will be described. 
         [0064]    When a user starts driving the compression system  100 , the main drive shaft  130  rotates. When the main drive shaft  130  rotates, the bull gear  121  rotates and the pinion gears  122  engaged with the bull gear  121  rotates. 
         [0065]    When the pinion gears  122  rotate, the left and right shafts  110   c  rotate and the impeller part  110  rotates, thereby performing compression. 
         [0066]    A fluid flowing into an inlet (not shown) of the compression system  100  is compressed sequentially as it passes through the first compression unit S1, the second compression unit S2, the third compression unit S3, and the fourth compression unit S4 of the multi-stage system and is discharged via an outlet (not shown) of the compression system  100 . 
         [0067]    As described above, according to the present exemplary embodiment, in the upper housing  141  and the lower housing  142  of the compression system  100 , since the impeller containers  141   a  and  142   a,  the gear train containers  141   b  and  142   b,  and the flow paths  141   c  and  142   c  are formed as a single body, there is no need to include a separate casing member, a shroud member, or a gearbox member. Accordingly, a layout of an inner space of the compression system  100  is simplified in such a way that the number of manufacturing processes and the number of components may be reduced, thereby reducing manufacturing costs. Also, when designing the compression system  100 , it is possible to efficiently arrange the inner space thereof to reduce a volume of the compression system  100  and to improve efficiency of an assembly process or servicing for maintenance. Additionally, since the compression system  100  may optimize flow paths therein and reduce a transfer distance, compression efficiency may be improved. 
         [0068]    Particularly, in the case of the compression system  100 , a plurality of impellers are arranged in tandem with one another. When there are a large number of impellers and an arrangement thereof is in tandem, it is important to simplify the layout of the inner space of the compression system to reduce manufacturing processes and manufacturing costs. 
         [0069]    The compression system according to the present exemplary embodiment may have an inner configuration space whose layout is simple. 
         [0070]    While exemplary embodiments have been particularly shown and described above, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present inventive concept as defined by the following claims.