Abstract:
An integrally geared compressor including a casing, which can be separated at a separating joint into a first partial casing and a second partial casing, wherein the casing encloses a casing interior, a first shaft, which supports a first gearwheel and is mounted along a first axis in at least one first bearing, and a second shaft, which supports a second gearwheel and is mounted along a second axis in at least one third bearing is provided.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims priority to PCT Application No. PCT/EP2013/067504, having a filing date of Aug. 23, 2013, based off of DE 102012217441.9 having a filing date of Sep. 26, 2012, the entire contents of which are hereby incorporated by reference. 
     
    
     FIELD OF TECHNOLOGY  
       [0002]    The following relates to an integrally geared compressor comprising a casing which can be split at a parting joint into a first casing part and a second casing part, which casing surrounds a casing internal space, and further comprising a first shaft which bears a first gearwheel and is mounted along a first axis in at least one first bearing, further comprising a second shaft which bears a second gearwheel and is mounted along a second axis in at least one third bearing. 
       BACKGROUND  
       [0003]    Integrally geared compressors within the context of embodiments of the invention are multistage turbocompressors in which individual stages are kinematically coupled to each other and to a drive via a transmission. In this context, the transmission is generally housed in a casing and the individual compressors or compressor stages are flange-mounted onto the transmission casing. In this context, the transmission provides drive shaft stubs which project out from the casing, for driving the rotor disks of the individual turbo compressor stages. A corresponding arrangement is already known from EP 1 691 081 B1. An essential feature of the integrally geared compressor presented therein is a horizontal parting joint which divides the casing of the integrally geared compressor into a lower half and an upper half. According to the embodiment presented therein, as many shafts of the transmission elements as possible are arranged with their axes of rotation in the plane of the parting joint, such that it is possible to assemble and disassemble the transmission casing upper part substantially without disassembling the kinematic components of the transmission—or with only minor disassembly thereof. 
         [0004]    One drawback of the arrangement according to EP 1 691 081 B1 is the loss of flexibility in the construction of the integrally geared compressor, as the separation between the shafts in the plane of the parting joint is strictly governed by the gear ratios in the transmission or by the diameters of the gearwheels. This provision can have the consequence that, especially for a configuration of various compressors and a drive, a transmission ratio is required which requires a particularly large transmission casing in order that the parting joint has enough space for the gearwheels to be housed in the transmission. In addition, the determined separations between the axes of the drive shafts of the individual compressors and the drive shaft of the drive can result in installation space conflicts between the individual subassemblies, which conflicts cannot be solved with the solution proposed in the European patent. 
         [0005]    An undivided casing for a compressor with axially introduced shafts is shown and/or described in U.S. Pat. No. 3,741,676 A. 
         [0006]    A transmission with a horizontal parting joint is shown and/or described in, respectively, from U.S. Pat. No. 5,156,576 A and DE 42 41 141 A1. 
         [0007]    A transmission with a stepped parting joint is shown and/or described in DE 10 2011 003 525 A1. 
         [0008]    Proceeding from the problem of the prior art, embodiments of the invention have addressed the problem of developing an integrally geared compressor of the type defined in the introduction such that the possibilities for the constructive configuration with respect to the axis separations for driving the individual compressor stages and for driving the integrally geared compressor can be configured more flexibly on the transmission without losing the advantage of simplified disassembly of the transmission casing. 
       SUMMARY  
       [0009]    An aspect relates to proposing an integrally geared compressor of the type defined in the introduction and having the additional features. In addition, an embodiment of the invention proposes a series of integrally geared compressors. 
         [0010]    The integrally geared compressor according to embodiments of the invention are preferably designed as a multistage turbocompressor with a casing of the integrally geared compressor in which the transmission is arranged. It is further preferred that compressors are attached to that casing in which the transmission is arranged. These are regularly flange-mounted onto the casing by means of a screw connection. These compressors comprise at least one compressor stage and a process fluid generally flows through them one after the other or in series or partially parallel to one another in a multistage compression process. In this context, the individual compressors are attached to various driving shafts which project out from the transmission casing, and are driven thereby. The compressors are distributed on the various driving shafts such that, preferably, mechanical loads from the compressors on the transmission at least partially cancel each other out. In this manner, axial forces from compressors on mutually opposing shaft ends of the transmission, which project on both sides out of the casing, can at least partially cancel each other out. Residual axial forces are taken up by thrust bearings and provisions on the teeth. 
         [0011]    A considerable advantage of the configuration according to embodiments of the invention of an integrally geared compressor is in particular that the need for an intermediate wheel in the transmission between a driven large wheel and a driving pinion on a compressor shaft implies no large additional construction space requirement. If for example it is necessary to reverse the direction of rotation of the driving pinion shaft, the intermediate wheel can be displaced, by means of the pillow block arranged in the first part of the casing, far enough toward the plane of the parting joint that the large wheel and the pinion have almost the same axis separation with respect to one another as would be the case in an arrangement without an intermediate wheel. Expediently, the pillow block can in this case also bear multiple bearings of the integrally geared compressor. The term “pillow block” designates in the context of embodiments of the invention a supporting receiving portion for the individual bearings—for at least one bearing—which, when the rotating shaft mounted in the bearing is stationary or is in operation, diverts mechanical forces into the first casing part. 
         [0012]    In the case of a horizontal parting joint, the first casing part is preferably the lower casing part and, under the same criteria, the second casing part is preferably the upper casing part. Thus, gravity aids the assembly of the overall arrangement. Fundamentally, it is advantageously possible for all the shafts of the turbocompressor to be mounted in such pillow blocks with a bearing, or even for all the shafts to be mounted in a single pillow block which extends, perpendicular to the shaft axes, substantially over more that 50% of the length of the casing internal space of the casing. One advantage of an embodiment of the invention is that the seal function of the parting joint of the casing is decoupled from the function of mounting the individual shafts of the integrally geared compressor. 
         [0013]    Preferably, at least one driven shaft is mounted without a pillow block according to embodiments of the invention and is supported with its bearing in a parting joint of the casing such that the planar sealing face of the parting joint is interrupted at this point by the passage of the driven shaft. An essential advantage of embodiments the invention results for the mounting of the shafts of the transmission which are not fed out through the casing and accordingly are termed intermediate shafts. According to embodiments of the invention, these intermediate shafts do not result in an interruption of the planar sealing face of the parting joint for mounting the intermediate shaft. Moreover, for improved sealing of the casing, the parting joint can continue uninterrupted and planar also in the region of the mounting of the intermediate shaft. 
         [0014]    Preferably, the second shaft is mounted in a third and a fourth bearing, wherein the fourth bearing is mounted in a second pillow block, wherein the second pillow block, just as the first pillow block, is arranged entirely within the casing and the second pillow block is attached only to the first casing part, just as the first pillow block. 
         [0015]    Preferably, the second shaft is not fed out from the casing. 
         [0016]    Preferably, the first shaft is fed out from the casing on at least one side at a shaft end. The first shaft is preferably the driven shaft. 
         [0017]    A third shaft meshes with a third gearwheel preferably with the second gearwheel of the second shaft. 
         [0018]    The third shaft is preferably fed out from the casing at least one shaft end side. 
         [0019]    The third shaft is preferably fed out from the casing at both shaft end sides. 
         [0020]    Preferably, the third shaft drives compressor stages by means of each of both shaft end sides. 
         [0021]    More preferably still, there is provided at least one fourth shaft which meshes in a driven manner with the first gearwheel by means of a fourth gearwheel, wherein the fourth shaft drives at least one compressor stage by means of a shaft end which is fed out through the casing. 
         [0022]    Particular preference is given to an embodiment in which the fourth shaft is fed out of the casing at both shaft ends and thereby drives compressor stages. One particularly preferred embodiment further provides that at least three shafts which are fed out from the casing, and which are in particular fed out from the casing on both sides, each have an axis of rotation, all of which axes lie in a common plane, wherein this common plane is preferably the plane of the parting joint of the casing. 
         [0023]    Expediently, the casing has one receiving shape for each pillow block. This can be additional molded material in the first casing part or material removed from the first casing part, such that in each case the pillow block with a shaped part can be fitted to this receiving shape and forces can be transmitted by means of a form fit. For example, a recess can be milled into the plane of the parting joint for this purpose such that a sealing plane of the plane of the parting joint is partially interrupted but nonetheless a part of the sealing face present at this circumferential position of the sealing plane remains. 
         [0024]    The series of integrally geared compressors according to the invention provides that second gearwheels have different diameters to each other, wherein the pillow blocks of this series are designed for a different position of the second axes of rotation. At the same time, the first casing part has a receiving shape for the third pillow block and preferably the fourth pillow block, in which the second shaft is mounted, which receiving shapes are identical for the entire series. Particularly preferably, the first casing part of the series is identical for all the integrally geared compressors. More preferably still, the second casing part of the series is identical for all the integrally geared compressors. 
       BRIEF DESCRIPTION  
       [0025]    Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein: 
         [0026]      FIG. 1  is a schematic perspective representation of a first casing part with a schematic representation of the shaft axes; 
         [0027]      FIG. 2  is a schematic representation of a section through a pillow block; and 
         [0028]      FIG. 3  is a schematic representation of a section through a pillow block, wherein the section runs perpendicular to the section of  FIG. 2 . 
     
    
     DETAILED DESCRIPTION  
       [0029]      FIG. 1   1  is a schematic perspective representation of a first casing part C 1  with a parting joint SP, wherein the parting joint SP is characterized by a sealing face SF. The first casing part C 1  is designed as the lower casing part CL, wherein an upper casing part—represented in FIG.  2 —is placed on top of the lower casing part CL. The upper casing part CU is shown in section in  FIG. 2   
         [0030]    The sealing face SF of the parting joint SP is interrupted at various points by shaft passages from the casing interior CI to the casing exterior AMB, because axes of rotation of the corresponding shafts lie in the plane of the parting joint SP. The shafts fed out are the shafts SH 1 , SH 4  and SH 3 , which rotate about the axes X 1 , X 3  and X 4  respectively. Shafts SH 4  and SH 3  are what are termed pinion shafts and are fed out of the casing interior CI on both shaft end sides. The first shaft SH 1 , which rotates about the first axis X 1 , is also termed the large wheel shaft and is fed out of the casing C only on one side. The large wheel shaft is a driven shaft, while the pinion shafts transmit the geared torque from the large wheel shaft to compressor stages (not shown) on the fed-out shaft ends. Compressor stages CO 1 , CO 2 , CO 3  and CO 4  arranged on the shaft ends are represented greatly simplified and are flange-mounted onto the casing C. 
         [0031]    The first shaft SH 1  is mounted in the first bearing B 1  and a second bearing B 2 . The second shaft SH 2  is mounted in a third bearing B 3  and a fourth bearing B 4 . The third shaft SH 3  is mounted in a fifth bearing B 5  and a sixth bearing B 6 . The fourth shaft SH 4  is mounted in a seventh bearing B 7  and an eighth bearing B 8 . The second bearing B 2 , fourth bearing B 4 , sixth bearing B 6  and the eighth bearing B 8  are respectively formed as fixed bearings—that is to say with an additional thrust bearing AL, as shown in  FIG. 2 . All the bearings each comprise a radial bearing BL. 
         [0032]    The axial mounting of the shafts SH 1 , SH 2 , SH 3  can in this context be of any configuration in order to take up the forces from the gas thrust of the compressors and any thrust from the teeth. An advantageous solution for supporting the axial thrust lies in using pressure pads on the gearwheels, such that a thrust can be transmitted to another shaft. 
         [0033]    The second shaft SH 2  is also termed intermediate shaft and is mounted in the third bearing B 3  and a fourth bearing B 4  at a distance from the plane of the parting joint by means of third and fourth pillow blocks LB 3 , LB 4  represented in  FIGS. 2 ,  3 . The separation is illustrated in  FIG. 1  by means of a separation vector from a fictitious axis X 2 ′ in the plane of the parting joint. The third pillow block LB 3  of the third bearing B 3  is also formed the same as the fourth pillow block LB 4 , wherein in such an embodiment the thrust bearing AL is located on a pillow block LB 3 , LB 4  for in each case one thrust direction. 
         [0034]      FIG. 2  shows the third and fourth pillow blocks LB 3 , LB 4  according to the section II shown in  FIG. 3  and  FIG. 3  shows the pillow block LB according to the section III shown in  FIG. 2 . 
         [0035]    As indicated in  FIG. 1  by the schematic bearing symbols, the thrust bearing AL can also be arranged entirely on one shaft end side of the second shaft SH for both thrust directions. The fourth bearing B 4  also comprises, in addition to the thrust bearing AL, a two-part radial bearing RL which has a bearing parting joint LSP for mounting the second shaft SH 2 . The radial bearing RL can in this context also be in one piece, such that the shaft is inserted axially. In this concrete exemplary embodiment, the second shaft SH 2  is placed from above into the radial bearing RL into a lower shell LH and an upper shell UH is then affixed.  FIGS. 1 and 2  in each case show the bearing separation LGA for the radial bearings RL of the second shaft SH 2 . The pillow block LB is fitted to a receiving shape FS of the first casing part C 1  by means of a shaped part FE. Horizontal adapters HPK and vertical adapters VPK (see  FIG. 3 ) are used as intermediate bearings for fitting. These adapters VPK, HPK make it possible for the shaped part FE to be received in a form-fitting manner in the receiving shape FS and for the second shaft SH 2  or the second axis X 2  to be oriented with precision. 
         [0036]    The adapters VPK, HPK are, in the terminology of embodiments of this invention, to be assigned to the third or the fourth pillow block LB 3 , LB 4  which according to embodiments of the invention is adapted instead of the first casing part C 1  for a displacement of the second shaft SH 2 . 
         [0037]    A further detail shown in  FIG. 2  is the conveying of the lubricating oil from the bearing B 3  or B 4  by means of a lubricating oil conduit LOC.  FIG. 1  also shows that the sealing face SF has, in the region of the pillow block LB for the second shaft SH 2  and in spite of the receiving shape FS milled into the first casing part C 1 , a remaining cross section which permits good sealing there. The pillow block LB is securely connected to the first casing part C 1  by means of the form-fitting connection between the receiving shape FS and the shaped part FE and by means of additional securing elements SC, and is preferably connected, secured and supported only there. Accordingly, the second casing part C 2  or the upper casing part CU can be removed from the first casing part CI without it being necessary to handle the mounting of the shaft SH 2 . 
         [0038]    As shown in  FIG. 3 , the pillow block LB 3 , LB 4  has a two-dimensional field F 2 D, illustrated with the coordinates X0, Y0 in  FIG. 3 , for the position of the second axis X 2  of the second shaft SH 2 . It is thus possible to produce a series of integrally geared compressors GV in which all casings C are identical and, for different transmission configurations of the transmission, a respective different position of the second shaft axis X 2  can be provided in the two-dimensional field F 2 D. Accordingly, in the case of the series of integrally geared compressors according to embodiments of the invention, it is only necessary to adapt the pillow block LB for the second shaft SH 2  which is to be displaced as desired. 
         [0039]    Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention. 
         [0040]    For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.