Cantilever slide for mounting and dismounting a rotor block

Description

Technical area

[0001] The invention relates to the field of rotating machines. It concerns a lifting device and a method for displacing a rotor block in a housing along the rotational axis of the rotor contained in the rotor block.

[0002] Such lifting devices are used as assembly / disassembly tools for exhaust gas turbochargers of supercharged internal combustion engines or similar rotating machines, where the rotor block can weigh from over a hundred kilograms to several tons. State of the art

[0003] Exhaust gas turbochargers are used to supercharge large internal combustion engines. These engines power ocean-going vessels or large emergency power generators, for example.

[0004] To service the exhaust turbocharger every few thousand hours, the rotating parts must be removed from the housing. For this purpose, the multi-part housings of conventional exhaust turbochargers are removed, and the rotor is then lifted axially out of the housing using a crane. Specifically, to disassemble an exhaust turbocharger, the compressor housing is usually removed so that a crane boom can access the rotor block above the center of gravity.

[0005] The rotor block of an exhaust gas turbocharger includes not only the rotating parts of the shaft and the turbine and compressor wheels connected to the shaft, but also the bearing components, i.e., axial and radial bearings, and inner bearing housing components. This rotor block is also referred to as a cartridge. During servicing, it is possible to completely replace a cartridge of an exhaust gas turbocharger. This reduces the downtime of the exhaust gas turbocharger and thus of the internal combustion engine turbocharged by the exhaust gas turbocharger. The effort required to remove and reinsert the cartridge can be further reduced if as few housing components as possible need to be removed. For example, it would be desirable not to have to remove the outer compressor housing, which with its large air outlet is firmly integrated into the piping of the internal combustion engine, nor the entire turbine housing during maintenance work.Thus, only the inner compressor housing on the air inlet side would have to be removed in order to be able to pull the rotor block out of the compressor housing and the bearing housing and gas outlet housing behind it through the axial opening thus created.

[0006] Various devices and methods for pulling and / or inserting rotors, rotor blocks or bearing components from a housing are described in the prior art.

[0007] JP10-220399, for example, discloses a device for dismantling a rotor of a pump, in which extension pieces are placed on the shaft attachments, which are slidably mounted on a support and with the aid of which the rotor can be pushed out of the housing so that it can then be lifted by a crane.

[0008] US2011 / 0052426A1 discloses a device for disassembling a rotor of a large compressor, which device comprises support for the rotor on both sides, with extension elements provided on the rear side of the rotor to ensure support during the removal of the rotor from the housing. The device further comprises rail elements along which the rotor to be removed can be slid. In particular, US2011 / 0052426A1 relates to an insertion / removal system for a compressor housing and a compressor bundle. The system comprises a frame extending from a first axial end of the compressor housing and configured to support the compressor bundle during insertion.The system further comprises a service end roller assembly coupled to the compressor bundle proximal to an axial end of the compressor bundle, the service end roller assembly configured to provide movable support for the compressor bundle on the gantry. Brief description of the invention

[0009] The object of the present invention is to provide a tool and a method which enables the removal of a rotor block from a housing comprising the rotor block along the axis of rotation of the rotor contained in the rotor block.

[0010] One aspect of the invention relates to a lifting device according to independent claim 1. A lifting device comprises a cantilever beam which is fastened to a vertical stop, i.e. to an axial end face, of the housing, and on which a structure which is displaceable along the cantilever beam is arranged, which structure is also fastened to a vertical stop, i.e. to an axial end face of the rotor block.

[0011] The linear movement of the structure on the cantilever beam is carried out by linear guides (rails) and is optionally equipped with ball bearings.

[0012] The structure of the lifting device is arranged on a carriage, whereby the support of the structure is in two parts and comprises a tilting rod and a vertical fastening, whereby the structure can be tilted with respect to the position of the cantilever beam.

[0013] Optionally, a trapezoidal thread spindle can be provided to drive the displacement along the cantilever beam, which can be moved either by hand or with a cordless screwdriver.

[0014] Optionally, the height and inclination of the rotor block can be adjusted using threaded screws.

[0015] The lifting device according to the invention requires no additional supports and only requires the installation space of the filter silencer. In particular, the installation space above the exhaust turbocharger housing is not used during the removal and reinstallation of the rotor block, thus ensuring that insulation, piping, etc., are not compromised.

[0016] Further advantages arise from the dependent claims.

[0017] A further aspect of the invention relates to a method according to independent claim 9. Short description of the drawings

[0018] Following are embodiments of the lifting device according to the invention explained with reference to the drawings. Fig. 1 a schematic representation of a section along the shaft axis (A) through an exhaust gas turbocharger, wherein the exhaust gas turbocharger comprises a rotor block that can be pulled out of the housing in the axial direction towards the compressor side, Fig. 2 an isometric view of an exhaust gas turbocharger according to Fig. 1 with the lifting device according to the invention in a first embodiment and the rotor block partially pulled out of the housing, Fig. 3 a schematic representation of a section along the shaft axis through the exhaust gas turbocharger including the lifting device according to Fig. 2 , Fig. 4 a schematic representation of an enlarged section through the lifting device according to Fig. 2 and 3 , Fig. 5 a side view of an exhaust gas turbocharger according to Fig. 1with the lifting device according to the invention in a second embodiment and the rotor block partially pulled out of the housing, Fig. 6 an oblique view of the arrangement according to Fig. 5 , Fig. 7 is an isometric view of the structure of the lifting device, and Fig. 8 is an isometric view of the cantilever beam of the lifting device and the mounting bracket for attaching the cantilever beam to the housing of an exhaust gas turbocharger. Way of implementing the invention

[0019] Fig. 1 and Fig. 2 show an exhaust gas turbocharger typically used for turbocharging large internal combustion engines. It comprises an axial-flow exhaust turbine and a radial compressor.

[0020] The housing of the exhaust turbocharger essentially consists of five housing parts. The outer bearing housing 13 is located axially in the center. The bearing housing is usually mounted on a bracket attached to the internal combustion engine.

[0021] On the turbine side, the gas outlet casing 12 is attached to the bearing housing, and the gas inlet casing 11 is attached to it. The gas inlet casing 11 directs the hot exhaust gas flow from the gas inlet to the rotor blades of the turbine wheel 21. The flow channel is deflected by the gas inlet casing from the circular tube shape at the gas inlet to an annular tube shape in the flow area of ​​the turbine blades. The gas outlet casing 12 has a large, spiral-shaped collecting chamber and opens into the gas outlet, from where the exhaust gases are directed, for example, to the exhaust system or a downstream, second turbine stage.

[0022] On the compressor side, the outer compressor housing 14 connects to the outer bearing housing 13. The outer compressor housing essentially comprises a spiral-shaped collecting chamber which opens into the air outlet. The compressor's air outlet, like the gas inlet and outlet on the turbine side, is permanently connected to the internal combustion engine's piping system, and the respective flange fastenings should normally not need to be removed. The fifth housing section, the inner compressor housing, is located in the Fig. 1 and 2 Not shown. The inner compressor housing is secured to the outer compressor housing 14 by means of fastening bolts 142, and also forms the connection to the air inlet.

[0023] The air intake can be achieved either through a mounted filter silencer or through a tubular intake manifold. This connection is the only one that must be regularly disconnected during servicing. On the one hand, the filter silencer itself requires regular maintenance; on the other hand, the opening exposed by removing the inner compressor housing forms the maintenance hatch through which the turbocharger rotor block can be pulled out of the housing.

[0024] As the illustration suggests, the center of gravity of the rotor block 2, which includes the actual rotor with turbine wheel 21, shaft, and compressor wheel 22 as well as the inner bearing area 23, is located axially somewhere in the area of ​​the bearing housing. In order to lift the rotor out of the housing opening using a crane directly attached to the rotor block, the outer compressor housing 14 would also have to be removed from the outer bearing housing 13. This additional effort can be eliminated with the assembly and disassembly tool according to the invention described below.

[0025] Fig. 2 , Fig. 3 and Fig. 4 show a first embodiment of the lifting device 4 according to the invention in use. Fig. 5 and Fig. 6 show a second embodiment of the lifting device 4 according to the invention in use. The individual components of the second embodiment of the lifting device 4 are shown in Fig. 7 and Fig. 8presented in detail.

[0026] In both embodiments, the lifting device 4 comprises two main components, a cantilever 5 and a structure 6 which can be moved thereon. A cantilever (also known as cantilever beam or cantilever known) is generally a cantilevered, horizontal beam which carries a load. The cantilever beam has a single support. The cantilever beam can generally be subjected to shear, bending and torsion, whereby the support fixes all six degrees of freedom (forces and moments). In the present case of the cantilever beam 5 of the lifting device 4 according to the invention, the horizontal beam is a support frame 51 and a mounting plate 56 at one end of the support frame serves as a support on the outer compressor housing 14. The compressor housing has fastening holes 141 distributed along the circumference for receiving the Fig. 1shown fastening bolts 142. The fastening holes are recessed into a vertical surface of the outer compressor housing, so that a vertical stop is formed, which serves to fasten the inner compressor housing and, in the case of assembly / disassembly, the cantilever beam 5 of the lifting device 4 according to the invention.

[0027] To simplify the installation of the cantilever beam on the outer compressor housing 14, and especially to ensure the portability of the cantilever beam for exhaust gas turbochargers of different sizes, a mounting bracket 7 can be provided between the mounting plate 56 of the cantilever beam and the vertical stop of the compressor housing. Optionally, the cantilever beam could also be screwed directly onto the outer compressor housing. The mounting bracket 7 is screwed onto the vertical stop of the outer compressor housing using fasteners 72, advantageously using the aforementioned fastening holes 141. Optionally, specially provided holes for fastening the mounting bracket 7 could also be used. Mounting holes 71 for receiving fastening means 561 of the mounting plate 56 of the cantilever beam 5 are recessed into the mounting bracket 7.Optionally, the cantilever beam mounting plate could also be connected to the mounting bracket in another way, for example by means of a positive plug connection.

[0028] The structure 6, the second component of the lifting device, comprises a construction 61 made of profiled bars, which serves to absorb and transmit forces to the cantilever beam. The basic task of the structure of the lifting device according to the invention is to grip the rotor block in order to move it along the extension of the support frame of the cantilever beam and relative to the housing. For this purpose, the structure 6 is mounted on a carriage 53, which in turn can be moved on rails 52 along the support frame 51. Optionally, the carriage 53 can be guided along the rails 52 of the cantilever beam by means of a trapezoidal thread spindle, which is moved either by hand via a spindle wheel 54 with a crank 541 or by cordless screwdriver. This allows for continuous, slow movement of the structure and the rotor block attached to it.

[0029] In a simple form, the structure itself could be guided directly along a rail on the cantilever beam, as long as the transmission of forces and moments is ensured. However, this does not provide any options for correcting the height and angular position of the rotor relative to the housing. To address precisely this point, the structure according to the invention includes, in addition to the attachment points on the rotor block and the support on the carriage, means for tilting the structure and aligning it relative to the rotor block 2.

[0030] The illustrated construction made of profile bars 61 comprises, in the simplest, first embodiment, an L-shaped basic frame formed from the two profile bars 611 and 613, which is supplemented by the threaded rod 631 of the fastening point 63 to form a C-shaped base support. This base support is fastened to two designated locations on the rotor block, wherein the two fastening points are advantageously vertically spaced from one another. In the present case, the two fastening points 63 and 66 are located above and below the compressor wheel at approximately the same radial height. In the area of ​​the lower fastening point, a mounting plate is arranged at the free end of the profile bar 611, which can be fastened directly to the vertical stop 26 of the rotor block by means of fastening means 661. In the area of ​​the upper fastening point, the threaded rod 631 is screwed directly into a corresponding bore 32 in the rotor block.On the rotor block, the fastening points can be arranged either directly on the inner bearing housing 23 itself, or via a cover plate that covers any unevenness, such as an existing guide device in the diffuser area. The openings for the fastening screws 31, with which the rotor block is fixed to the outer bearing housing 13, are used to accommodate the threaded rod 631 of the upper fastening point. The aforementioned C-shaped base frame is equipped with a tilting rod 62 in the intersection area of ​​the two profile rods 611 and 613, which is rotatably mounted in a receiving device 532 on the carriage 53 of the cantilever beam 5. The inserted tilting rod 62 is secured against falling out in the receiving device 532 by a locking bolt during operation of the lifting device. The tilting rod allows a tilting movement of the construction consisting of profile rods 61 and the rotor block attached to it.In order to be able to adjust the extent of the tilting movement to a specific angular position, a vertical fastening 64 of the structure 6 on the carriage is provided at a distance from the tilting rod. The vertical fastening 64 essentially comprises, as adjustment means, a threaded rod 642 with a nut 643, a horizontal stop 644 with a hole for receiving the threaded rod, and a connecting pin 641 attached to the threaded rod, which is arranged in a receiving device 531 provided for this purpose on the carriage 53 and is also secured against falling out during operation. The hole for receiving the threaded rod in the horizontal stop 644 is arranged at a distance from the vertically extending profile rod 613 of the base frame. In the first embodiment, the horizontal stop is directly connected to the base frame, and in the second embodiment, for improved force transmission with heavier rotor blocks, it is firmly connected via several profile rods 612, 614, 615, and 616.The horizontal stop 644, spaced apart from the vertically extending profile bar 613 of the base frame, can be positioned more or less far from the anchorage on the carriage connecting pin 641 by turning the nut 643, thereby allowing a corresponding adjustment of the extent of the tilting movement as well as a specific angular position of the structure comprising profile bars 62 and the rotor block attached thereto relative to the cantilever beam. The multiple profile bars 612, 614, 615, and 616 according to the second embodiment ensure increased stability of the structure 6, which can be advantageous, for example, with larger, heavier rotor blocks.

[0031] In the area of ​​the upper attachment point, the structure includes a second option for adjusting the angular position of the rotor block attached to the structure. In addition to the lock nut 633 for screwing the threaded rod 631 into the rotor block 2, the threaded rod 631 has a further nut 632 for adjusting the alignment of the structure with respect to the rotor block. This nut rests on a vertical stop 634. By turning the nut 632 on the threaded rod 631, the axial distance between the vertical stop 634 and the rotor block can be adjusted. If this distance changes, this influences the angular position of the rotor block with respect to the structure made of profile rods. If the two adjustment options are superimposed, it is possible to raise the height of the rotor block, in addition to the possibility of adjusting the angular position.Tilting the structure of profile rods 61 around the axis of tilt rod 62 results in a changed angular position of the rotor block attached to the structure. By changing the distance between the vertical stop 634 and the rotor block, the changed angular position can be corrected, resulting in a height adjustment.

[0032] This allows the rotor block to be adjusted in height and angular position when removed from the housing by turning the two nuts 632 and 643. Due to the rotor's heavy weight, this is a significant advantage, especially during installation, as otherwise there would be a risk of the rotor at least partially resting on the housing, which could cause damage.

[0033] In the event of disassembly, the rotor block is pressed out of the centering seat in the outer bearing housing using press-off screws 635. For this purpose, the specially provided press-off screws 635 are screwed through the bore 32 until the seat length is in the range of two - in Fig. 3 indicated by way of example - coordinated seats 132 on the outer bearing housing 13 and 231 on the inner bearing housing 23.

[0034] In order for this axial displacement to take place when the lifting device is already mounted, the seat length mentioned above must be adjusted as shown in Fig. 4Shown in detail is a freewheel between a spindle nut 57 mounted on the threaded rod 55 and the carriage 53. The spindle nut 57 is moved along the threaded rod by turning the threaded rod. The spindle nut has a groove-shaped freewheel area 571 in which a projection 533 of the carriage is freely movable between two axial stops. To dampen the free movement of the carriage relative to the spindle nut 57, which is possible within the axial stops, a spring 535 is mounted axially on the threaded rod between the spindle nut and an axial stop 534 of the carriage. As soon as the spring 535 of the freewheel is fully compressed, the threaded rod 55 can be rotated by turning the spindle wheel, and the movable carriage 53 is driven along. List of reference symbols

[0035] 11Gas inlet casing of the exhaust turbine 12Gas outlet casing of the exhaust turbine 13Outer bearing housing 132Centering seat on the outer bearing housing 14Outer compressor housing 141Mounting holes 142Mounting bolts 2Rotor block 21Turbine wheel 22Compressor wheel 23Inner bearing housing 231Centering seat on the inner bearing housing 25Compressor wheel cover 26Vertical stop with holes for fastening devices 31Fasteners for attaching the rotor block to the bearing housing 32Bore in the rotor block 4Lifting device (comprising 5 and 6) 5 Cantilever beam of the lifting device, comprising: 51Supporting frame 52Rail 53Slide 531Holder for vertical fastening of the superstructure 532Holder for the tilting rod of the superstructure 533Protrusion on the slide for guidance in the freewheel area of ​​the spindle nut 57 534Axial stop on the slide 535Spring 54Spindle wheel 541Crank 55Threaded rod (spindle) 56Mounting plate of the cantilever beam for fastening to the mounting bracket 561Fasteners 57Spindle nut 571Groove-shaped freewheel area 6 Structure of the lifting device, comprising: 61Construction made of profile bars (611, 612, 613, 614, 615, 616) 62Tilt rod of the superstructure 63Fastening point (horizontal fastening of the superstructure) 631Threaded rod 632Nut for adjusting the alignment of the rotor block with respect to the construction made of profile bars 633Lock nut for screwing the threaded rod into the rotor block 634Vertical stop 635Press-off screw 64Vertical fastening of the superstructure 641Connecting pin for vertical fastening of the superstructure to the cantilever beam 642Threaded rod 644Horizontal stop 643Nut for adjusting the alignment of the construction made of profile bars with respect to the cantilever beam 66Fastening point (mounting plate of the superstructure for fastening to the rotor block) 661Fasteners 7Mounting bracket 71Holes in the mounting bracket for holding fasteners 72Fasteners

Claims

1. Lifting device (4) for moving a rotor block (2) arranged in a housing of an exhaust turbocharger along the axis of rotation (A) of the rotor contained in the rotor block (2), comprising a cantilever (5) which is provided for fastening to a vertical stop of a housing surrounding the rotor block (2), wherein the cantilever (5) comprises a support frame (51) with rails (52) arranged thereon and a carriage (53) guided on the rails (52), and a superstructure (6) which is arranged on the carriage (53), wherein the superstructure (6) comprises at least two vertically spaced fastening points (63, 66) for fastening the superstructure (6) to the rotor block (2) to be moved in the housing along the axial direction by means of the lifting device (4), and wherein the at least two fastening points (63, 66) are connected to the carriage (53) via a C-shaped base support, wherein a support of the superstructure (6) is two-part and comprises a rocker arm (62) and a vertical fastening (64), wherein an axis of the rocker arm (62) is oriented perpendicularly with respect to a longitudinal axis of the cantilever and horizontally, and wherein the vertical fastening (64) comprises means for adjusting the orientation of the superstructure (6) with respect to the cantilever (5), with the result that the angular position of the superstructure (6) is adjustable around the axis of the rocker arm (62), wherein receiving devices (531, 532) for fastening the superstructure (6) on the carriage (53), which can be fastened to a vertical stop (26) of the rotor block (2), are arranged on the carriage (53), with the result that the superstructure (6) can be moved by means of the carriage (53) along the rails (52) arranged on the support frame (51) of the cantilever (5), wherein the at least two vertically spaced fastening points (63, 66) are connected via the C-shaped base support with the rocker arm (62) and the vertical fastening (64), each of which is arranged horizontally spaced at different distances from the at least two vertically spaced fastening points (63, 66), wherein the superstructure (6) is fastened by means of the rocker arm (62) and the vertical fastening (64) to the likewise horizontally spaced receiving devices (531, 532) of the carriage (53), and wherein an adjusting means of the vertical fastening (64) is directly or indirectly connected fixedly to the C-shaped base support.

2. Lifting device (4) according to Claim 1, further comprising a threaded rod (55), wherein the carriage (53) is connected to a spindle nut (57) which is arranged on the threaded rod (55), with the result that, by turning the threaded rod (55), the spindle nut (57) and thus the carriage (53) can be moved along the threaded rod (55), wherein a spindle wheel (54) is preferably provided for turning the threaded rod (55).

3. Lifting device (4) according to Claim 2, wherein a connection with play in the direction of the threaded rod (55) is provided between the spindle nut (57) and the carriage (53), with the result that the carriage (53) can be moved within the context of the play relative to the spindle nut (57) along the threaded rod (55), even if the threaded rod (55) is not turned.

4. Lifting device (4) according to one of Claims 1 to 3, wherein the at least two fastening points (63, 66) are connected to the carriage (53) via profile rods (611, ..., 616) of the C-shaped base support.

5. Lifting device (4) according to Claim 4, wherein the at least two vertically spaced fastening points (63, 66) are connected via the profile rods (611, ..., 616) to the rocker arm (62) and the vertical fastening (64).

6. Lifting device (4) according to either of Claims 4 or 5, wherein at least one of the at least two vertically spaced fastening points (63, 66) comprises means for adjusting the orientation of the superstructure (6) with respect to a rotor block (2) attached to the superstructure (6), wherein these means preferably comprise a threaded rod (631) and a nut (632).

7. Lifting device (4) according to one of Claims 4 to 6, wherein the means for adjusting the angular position of the superstructure (6) comprise a threaded rod (642) and a nut (643), and the angular position of the superstructure(6) can be adjusted around the axis of the rocker arm (62) by means of the nut (643) and the threaded rod (642).

8. Lifting device (4) according to one of Claims 1 to 7, wherein a mounting bracket (7) is provided for fastening the cantilever (5) to a vertical stop of the housing.

9. Method for moving a rotor block (2) arranged in a housing of an exhaust turbocharger along the axis of rotation (A) of the rotor contained in the rotor block (2) in precisely this housing by means of a lifting device (4) according to one of Claims 1 to 8, comprising the following steps: - fastening the cantilever (5) of the lifting device (4) to a vertical stop of the housing, - fastening the superstructure (6) of the lifting device (4) to the rotor block (2), - moving the superstructure (6) along the cantilever (5).