JP2016532805A - Turbo engine having a torsion coupling integrated into at least one drive shaft or driven shaft - Google Patents

Abstract

The turbo engine includes a drive shaft (3) and a driven shaft (8) that is operated by the drive shaft and is connected to the drive shaft using a torsion coupling. The torsional coupling comprises a region (11; 17) and is at least integrated with one of a driven shaft and a drive shaft which is flexible to rotate so as to constitute the torsional coupling. [Selection] Figure 1

Description

  The present invention relates to a turbo engine, for example, an integrated electric compressor. However, it should be understood that it does not fall outside the scope of the present invention simply because it relates to another type of turbo engine, namely a turbo alternator.

  The integrated electric compressor group is a compression preventive housing provided with an engine, for example, an electric motor, and a compressor group, for example, a driven shaft composed of a rotor of a motor or operated by a motor. A multi-stage unit comprising one or more wheels having a working blade.

  One method of connecting the drive shaft and the driven shaft is to connect the driven shaft and the drive shaft using a rigid coupling, and the bearing is provided to support the end of the axis of the electric compressor group in the same way as the central portion. It has been.

  This method has several examples of manufacturing problems and problems related to rotor power.

  Therefore, in order to avoid problems related to alignment, it has been proposed to connect the drive shaft and the driven shaft using a flexible coupling. In this respect, reference can be made to the document WO 2004/083644 which describes such a layout.

  Generally, the membrane type flexible coupling currently used increases the axial dimension of the electric compressor group usually by about 35 to 40 cm as compared with the flange type rigid coupling. In addition, they can only be subjected to, for example, an axially limited tensile or compressive force, thus indicating a fragile region.

  However, during the function of the layout described in the document WO 2004/083644, the gas supplying the compressor is completely or partially extracted after the compression process to cool the motor used. The flow of cooling gas in the motor occurs in the direction of the compressor.

  The electric compressor has one abutment on the compressor rotor on the opposite side of the coupling. Because of this fact, axial thrust is generated by the motor and absorbed by the coupling before being carried to the axial abutment.

  Therefore, in order to alleviate these disadvantages, it has been proposed to use a torsion coupling that is arranged on the hollow shaft of the compressor. Such a layout is described in the document FR 2 969 722. While this is effective to alleviate the disadvantages associated with using a flexible coupling between the drive shaft and the driven shaft, such a layout complicates the structure of the shaft assembly.

French Patent No. 2969722

  In view of the above problems, the object of the present invention is to alleviate the problems associated with the layout according to the prior art, and in particular to support the axial force generated during the function of the compression surface with a simple layout. Is to make it possible.

  Accordingly, an object of the present invention is a turbo engine comprising a drive shaft and a driven shaft operated by the drive shaft and connected to the drive shaft using a torsion coupling.

  Further, the torsion coupling is at least integrated with one of the driven shaft and the drive shaft having a torsionally flexible region so as to form the torsion coupling.

  This can be, for example, an electric compressor group that includes a motor that drives the compressor and a set of wheels that have compression blades attached to the driven shaft.

  The set is mounted in a common housing that is impermeable to gas produced by the electric compressor group.

  Since the torsional coupling is integrated with the drive shaft and / or the driven shaft, the torsional coupling assembled to the drive shaft or the driven shaft as described in the above-cited French Patent No. 2,969,722. Problems with existing assemblies, i.e. problems in terms of design and manufacturing, are solved.

  The shaft with which the torsional coupling is integrated preferably further comprises an outer peripheral region which constitutes support means for the function performed by the rotor.

  This torsional region present at least on one of the drive shaft and the driven shaft is formed, for example, by a cylindrical part having a smaller diameter than the rest of the shaft with which the torsion coupling is integrated.

  It advantageously has a length selected for the diameter so as to impart torsional capability to the coupling. Due to this diameter reduction, the shaft assembly comprises an internal shaft having a reduced dimension through which the drive shaft and driven shaft are coupled, allowing local deformation of the shaft assembly by torsion.

  In other embodiments, the torsional cylindrical portion can be attached to either the driven shaft or the drive shaft, or both the drive shaft and the driven shaft.

  The torsional cylindrical part may protrude completely from the shaft with which the coupling is integrated, or it may be partly or entirely inside the hollow part in the form of a hollow shaft, so that it is hollow Allows the shaft to support one or more functions performed by the rotor. If the torsional cylindrical part is located inside the hollow shaft, this will therefore be a cantilever around the torsion. This method can ultimately be realized using a throat or by reducing the diameter of the assembly.

  The realization of the torsion partly or completely inside the hollow part allows the length of the shaft assembly to be limited, thus limiting the size, weight and cost of the turbo engine.

  This can also have a beneficial effect on the power of the rotor.

  It should be noted that the cylindrical portion can be obtained using various techniques.

  One embodiment comprises an axial cylindrical throat that delimits one internal shaft and the other external shaft connected to the other drive shaft or driven shaft within the shaft. For example, the axial cylindrical throat is formed by electrolytic corrosion.

  Alternatively, this torsional coupling is obtained by reducing (eg by forging and machining) the diameter of the driven shaft and / or drive shaft during the manufacturing stage.

  In this case, at least one of the driven shaft and the drive shaft comprises in its torsional coupling region a single axial cylindrical throat delimited by an internal shaft and a single external shaft assembled around the internal shaft. .

  In one embodiment, the external shaft extends to the connection area of the drive shaft and the driven shaft.

  According to another embodiment, the free end of the shaft in which the torsional coupling is integrated with a diameter larger than the diameter of its central part forms a connection region between the inner shaft and the other drive or driven shaft To do.

  Alternatively, it can also be ensured that the free end of the shaft with which the torsional coupling is integrated has a smaller diameter than the diameter of the connecting region corresponding to the other drive shaft or driven shaft to which one is connected. It is possible to form a flange that ensures the connection of the drive shaft or the driven shaft.

  Other objects, features and advantages of the present invention are provided by way of example only, without limitation, and will become apparent upon reading the following description with reference to the accompanying drawings.

It is the schematic which shows the whole structure of the electric compressor group which concerns on this invention. It is a figure which shows 1st Embodiment of the electric compressor group which concerns on FIG. It is a figure which shows another embodiment of the electric compressor group which concerns on this invention. It is a figure which shows another example of the compressor group which concerns on this invention. It is a figure which shows another mounting aspect of a twist area | region.

  Referring first to FIG. 1, an electric compressor according to the present invention, generally designated G, has a high rotational speed of a motor 1, for example 6,000 to 16,000 rev / min, and is driven by a frequency converter. For example, an electric motor having a stator 2 and a rotor, which is supplied with electric power and forms a drive shaft 3 of an electric compressor group, and blades 5, 6 and 7 (here, three) attached to the driven shaft 8 are included. A compressor group 4 having a set of wheels is mainly provided. As can be seen in the figure, the driven shaft 8 is supported by a radial bearing 9.

  This configuration is attached to a base (not shown) and is located in a common casing 10 that is impermeable to gas produced by the electric compressor group. The casing 10 has an input “INPUT” through which the generated gas is drawn into the compressor by suction and an output “OUTPUT” through which the compressed gas is delivered as it leaves the compressor group 4. Prepare.

  In the embodiment shown, the compressor group 4 comprises three wheels with blades attached to the driven shaft 8. As can be seen, the compressor group 4 can comprise any number of wheels with blades or wheels with blades of different layouts.

  In the embodiment shown in FIGS. 1 and 2, the driven shaft 8 is provided with a shoulder E on the surface of its end region, so that this shaft is bolted to one end with respect to the drive shaft 3 of the motor 1. ing.

  In any case, the connection between the driven shaft and the drive shaft consists of a torsion coupling.

  The torsional coupling can be obtained by mounting it on at least one of the driven shaft and the drive shaft in the torsional region that is flexible to rotation.

  In the embodiment shown in FIGS. 1 to 4, this torsional coupling is obtained by machining the axial cylindrical throat 11 in the driven shaft 8, whereby the driven shaft 8 is connected to the drive shaft 3 via it. The driven shaft 8 is formed with an inner shaft 12 and an outer shaft 13 through which the driven shaft 8 is guided by the radial bearing 9. The length of the throat is selected with respect to the diameter of the shaft to which it is attached so as to impart torsional properties to the coupling.

  In this way, by attaching the cylindrical throat to the driven shaft 8, the useful diameter of the shaft 8 transmitting the actuation force is locally reduced, while the resistance to torsion and radial deformation can be reduced. Thus, important radial stiffness is maintained. The driven shaft, in particular the inner shaft 12, remains able to withstand the axial forces generated during the operation of the wheel having, among other things, the compression blades 5, 6 and 7.

  The presence of the torsion can cause the driven shaft 8 to be deformed by bending and elastic torsion due to local shrinkage of the effective part of the shaft assembly, so that during installation of the electric compressor or during its operation In addition, it is possible to provide a characteristic that an angular alignment defect on the one hand and a lateral defect on the other hand can be compensated between the driven shaft and the drive shaft.

  This flexibility also allows for filtering of flexural vibrations between the drive shaft and the driven shaft.

  Furthermore, the torsional region can gradually change the force transmitted during a sudden change in torque transmitted by the resistance torque generated by the motor or compressor.

  In addition, the installation is very simple because the shaft assembly consists only of two parts of the shaft, namely the drive shaft and the driven shaft.

  It should be noted that in the embodiment shown in FIGS. 1 and 2, the torsion is attached to the driven shaft 8. Further, the driven shaft 8 includes an external shaft 13 whose end is behind the free end of the internal shaft 12, whereby the shaft 12 is fixed to the drive shaft 3. In other respects, in this embodiment, the inner shaft 12 has a diameter that is smaller than the diameter of the end formed by the shoulder E.

  Furthermore, the torsional coupling, as can be seen in FIGS. 1 and 2, forms the end region of the driven shaft with a reduced diameter in the manufacturing stage, for example by forging and machining the driven shaft 8 to obtain a local reduction. And then a cylindrical throat is realized to form the outer shaft 13.

  The torsional coupling obtained in the embodiment shown in FIGS. 1 and 2 by placing the throat on the drive shaft is, of course, by placing the throat on the drive shaft or on the drive shaft and the driven shaft. Can be formed.

  In another embodiment, seen in FIG. 3, the outer shaft 13 extends over the majority of the inner shaft 12 which here does not have an end shoulder. Therefore, the inner shaft 12 is attached to the end of the drive shaft 3 by using a flange 14 that is bolted to the free end of the drive shaft 3 and fixed by being rotationally connected to the inner shaft 12. The axial throat can be provided, for example, on the inner peripheral surface of the flange 14 that will engage the corresponding rib attached to the free end of the inner shaft 12.

  In this regard, flanges having a general conical shape or provided with an end shoulder as seen in FIG. 3 can be used.

  This embodiment is effective as long as the distance between the end portions of the shaft can be shortened, that is, the distance between the free end portion of the external shaft 13 and the free end portion with respect to the drive shaft 3 can be shortened. The distance is fixed by the length of the flange 14.

  According to the third embodiment shown in FIG. 4, both the drive shaft 3 and the driven shaft 8 have axial cylindrical throats 11 and 11a. The throat 11 is the same as the throat used in the embodiment of FIG.

  Similar to the embodiment described above, with respect to the driven shaft, the axial cylindrical throat 11 forms an internal shaft 12 and an external shaft 13 that extends along most of the internal shaft 12, and the internal shaft 12 is a flange. 15 extends from the outer shaft 13 along a length sufficient for attachment.

  With respect to the drive shaft 3, the axial cylindrical throat 11 a forms an internal shaft 16 and an external shaft 17 extending along most of the internal shaft 16 in the shaft 3, and the internal shaft 16 is connected to the flange 15. It extends beyond the free end of the outer shaft 17 along a length sufficient for attachment.

  Therefore, in this embodiment, the torsional region of the shaft assembly is formed in the drive shaft 3 and the driven shaft 8.

  In other respects, the shaft assembly includes a torsional region of increased length relative to the previously described embodiments.

  It is noted that the embodiment shown in FIGS. 3 and 4 where the attachment of the driven shaft and drive shaft is performed using a mating flange allows the formation of a torsional area at the manufacturing stage, ie by forging and subsequent machining. I want.

  The mounting of the torsional region is in particular the inner shaft in the driven shaft 8 through which the driven shaft 8 is connected to the drive shaft 3 and then assembled to the driven shaft 8 between the inner shaft and the outer shaft. It consists of the realization of an external shaft 13 through which the driven shaft 8 is guided by a radial bearing 9 so as to form a cylindrical throat. In other respects, and as indicated by the dotted lines in the figure, the outer shaft is assembled around a region of the shaft having a reduced diameter.

  Such an assembly can be obtained by various means. The hollow portion can be assembled, for example, on the rotor proximate the torsional region, for example by bolting and / or via the diameter of the abutment and / or by hearth teeth and / or using many other assembly modes .

  The embodiment shown in FIGS. 3 and 4 where the driven shaft comprises an inner shaft 12 and an outer shaft 13 is also advantageous because the outer shaft can then be used to implement the function performed by the rotor.

  In particular, one or more wheel supports with bearing supports and / or blades can be realized (FIG. 3).

  As is apparent, the present invention is not limited to the above-described embodiment. Also, in one variant, axial cylindrical throats are arranged on the drive shaft and the driven shaft so that the distance between the ends of the shaft, ie the ends of the two external shafts 13 and 17, with respect to both the drive shaft and the driven shaft. Ensure that the distance between the parts is equal to half the torsional length, or otherwise, both the drive shaft and the driven shaft, as in the embodiment described with reference to FIG. With respect to, it is possible to ensure that the length of the inner shaft extending outside the outer shaft is equal to the length of the outer shaft.

  Thus, in the embodiment shown in FIG. 5, the torsional region can be formed by the realization of the region 18 having a reduced diameter to impart torsional properties to the coupling during the manufacture of the driven shaft. As in the embodiment described above, the connection with the drive shaft can be realized both by providing a shoulder E at the end as shown, or by using a fitting flange.

  A reduced diameter region can also be realized independently of the rest of the driven shaft and can be assembled to the driven shaft as already shown with reference to FIGS.

  As will be apparent, the reduced diameter region can alternatively be formed on the drive shaft or two of the driven shaft and the drive shaft as already shown. Note that, similar to the embodiment shown in FIGS. 1-4, the length of the reduced diameter region is selected for the diameter of this region to impart torsional properties to the shaft.

  For example, for a shaft diameter of about 50 mm, the torsional region can be realized with a length of 600 mm to 700 mm.

  Finally, the axial cylindrical throat formed in the driven shaft and / or the drive shaft in different embodiments can be formed by electrical erosion or EDM (“Electrical Discharge Machining”), which is an electrical discharge. It should be noted that this is a processing procedure in which material is integrally removed using.

DESCRIPTION OF SYMBOLS 1 Motor 2 Stator 3 Drive shaft 4 Compressor group 5 Blade 6 Blade 7 Blade 8 Drive shaft 9 Radial bearing 10 Casing 11 Axial cylindrical throat, cylindrical part 11a Axial cylindrical throat 12 Internal shaft 13 External shaft 14 Flange 15 Flange 16 Internal shaft 17 External shaft 18 Area

Claims (15)

  A drive shaft (3) and a driven shaft (8) operated by the drive shaft (3) and connected to the drive shaft (3) using a torsion coupling, the torsion coupling comprising: A turbo engine that is integrated with at least one of the driven shaft (8) and the drive shaft (3) having a rotationally flexible region (11; 17) so as to constitute a torsion coupling. .   The turbo engine according to claim 1, wherein the shaft (3, 8) with which the torsional coupling is integrated further comprises an outer peripheral region that constitutes support means for the function performed by the rotor.   The flexible region comprises a cylindrical part (11) having a smaller diameter than the rest of the shaft (3, 8) with which the torsional coupling is integrated. Turbo engine.   The turbo engine according to claim 3, wherein the length of the cylindrical part (11) is selected with respect to the diameter so as to impart torsional properties to the coupling.   The turbo engine according to any one of claims 3 and 4, wherein the cylindrical portion (11) is attached to the driven shaft (8) or the drive shaft (3).   The turbo engine according to any one of claims 2 and 4, wherein the cylindrical portion (11) is attached to the driven shaft (8) and the drive shaft (3).   The turbo engine according to any one of claims 3 to 6, wherein the twisted cylindrical portion (11) protrudes completely from the shaft (3, 8) with which the coupling is integrated.   The turbo engine according to any one of claims 3 to 6, wherein the twisted cylindrical portion (11) is located partially or completely inside the hollow portion.   At least one of the driven shaft (8) and the drive shaft (3) is connected to the torsional coupling region of the driven shaft (8) and the drive shaft (8) in the shaft (3, 8). The turbo engine according to any one of claims 1 to 8, comprising an axial cylindrical throat (11, 11a) separating the inner shaft (12) and the outer shaft (13).   The turbo engine according to claim 9, wherein the axial cylindrical throat (11, 11a) is formed by electrolytic corrosion.   At least one of the driven shaft (8) and the drive shaft (3) is in its torsional coupling region by an internal shaft (12) and an external shaft (13) assembled around the internal shaft (12). A turbo engine according to any one of the preceding claims, comprising a delimited axial cylindrical throat (11, 11a).   A turbo engine according to any one of claims 9, 10 and 11, according to claim 2, wherein the external shaft (13) constitutes the support means of the function performed by the rotor.   The turbo engine according to any one of claims 9, 10 and 11, wherein the external shaft (13) extends to a connection region of the drive shaft (3) and the driven shaft (8).   The free end of the shaft (12) with which the torsional coupling is integrated has a diameter larger than the diameter of its central portion, and the internal shaft (12) and the other drive shaft (3) or driven The turbo engine according to any one of claims 1 to 13, which forms a coupling region with the shaft (8).   The free end of the shaft (12) with which the torsional coupling is integrated is smaller than the diameter of the connecting region corresponding to the other drive shaft (3) or driven shaft (8) to which one is connected. 14. A turbo engine according to any one of the preceding claims, having a diameter and a flange (14) ensuring the connection of the shafts (3, 8).