Patent Application
20120237339
This application claims priority to German patent application 10 2011 005 556.8 filed on Mar. 15, 2011, which is hereby incorporated by reference in its entirety.
The disclosure relates to an adjusting ring for a variable turbine and/or compressor geometry. The disclosure additionally relates to a variable turbine and/or compressor geometry with such an adjusting ring. Furthermore, the disclosure relates to a charging device, in particular an exhaust gas turbocharger, having a variable turbine and/or compressor geometry of the mentioned type.
The variable turbine and/or compressor geometry is an established technique for the power control of a charging device, in particular of an exhaust gas turbocharger, with different gas throughputs. Therefore, an adjusting ring with recesses is provided, which substantially show two parallel lateral flanks, wherein the recesses receive blade lever heads of blade levers. In the process, the blade lever heads are moved through a contact with the flanks of the recesses of the adjusting ring, which results in a rotation of guide blades arranged on a blade bearing ring, which are connected to the blade levers in a rotationally fixed manner via a blade mounting pin. Here, the cross section opened by the guide blades is reduced upon high power demand through the charging device and/or low propulsion gas throughput. Accordingly, the cross section that is available through the guide blades is increased upon low power demand through the charging device and/or high drive gas throughput. Disadvantageous in this case is that a gap between the blade lever heads and the corresponding flank can develop, which results in a sluggishness of the variable turbine and/or compressor geometry. Furthermore, an incorrect transmission of an adjusting force via the flanks to the corresponding blade lever heads for the development of a friction takes place, which likewise contributes to the sluggishness of the variable turbine and/or compressor geometry. The sluggishness, in particular with load changes or changes of the power demand by the charging device, leads to a delayed reaction time or a hysteresis and thus a power reduction of the charging device.
Generic adjusting rings are known for example from DE 10 2007 022 356 A1 and DE 10 2004 023 209 A1.
The present disclosure therefore deals with the problem of stating an improved embodiment for an adjusting ring of the generic type, which in particular contributes to an elimination or at least reduction of the hysteresis behaviour of the variable turbine and/or compressor geometry.
According to the disclosure, this problem is solved through the features of the independent claims. Advantageous embodiments are the subject of the dependent claims.
The present disclosure is based on the general idea of configuring the flanks of at least one recess with an adjusting ring of a variable turbine and/or compressor geometry of a charging device, wherein the adjusting ring comprises recesses directed to the inside for mounting blade lever heads of blade levers and each mount comprises two flanks, in such a manner that the blade lever heads and at least one of the flanks of the associated recesses have a contact for any positions of the associated guide blade and thus of the blade lever heads. In addition or alternatively, the flanks are designed in such a manner that a transmission of an adjusting force via the flanks to the corresponding blade lever heads is optimised. The disclosure thereby utilises the realisation that a gap between a blade lever head and the flank of the associated clearance of the adjusting ring is caused through the parallel arrangement of the flanks of a recess with certain positions of the adjusting ring and thus of the blade lever heads. A friction caused through an unfavourable transmission of the adjusting force between blade lever head and flank is in particular caused through the parallel arrangement of the flanks as well, which make possible an optimal transmission of the adjusting force only with certain adjusting positions of the adjusting ring and thus with certain positions of the blade lever head. Corresponding to the general inventive idea, at least one flank of at least one recess has a curved shape, in particular a parabolic shape, or both flanks of a recess have a predefined deviation from a parallel arrangement. The curvature angle of the for example curved flanks can in particular have a dependency on a nominal diameter of the blade lever head. The curved shape of the flank in this case serves in particular for the purpose of guaranteeing a contact between blade lever head and said flank for any positions of the guide blades and thus of the blade lever head. In addition or alternatively, these embodiments of the flank serve for the purpose of optimising an adjusting force transmitted by the flank onto the blade lever head in such a manner that the friction between flank and blade lever head is at least reduced.
With an alternative embodiment, the flanks of a recess are designed in such a manner that they have a predefined deviation from a parallel arrangement. Accordingly, the flanks are configured in such a manner that they are for example arranged obliquely to one another. Such an arrangement, too, serves in particular for the purpose of guaranteeing a contact between blade lever head and the corresponding flank/flanks for any positions of the guide blades and thus of the blade lever head. In addition or alternatively, this embodiment of the flanks serves for the purpose of optimising an adjusting force transmitted to the blade lever head through the flank in such a manner that the friction between flank and blade lever head is at least minimised.
With a further embodiment of the solution according to the disclosure, the flanks of a recess, which have a deviation from a parallel arrangement, are designed in such a manner that at least one of the flanks runs in a radial plane of the adjusting ring. Alternatively, both flanks of a recess can also lie in a radial plane. This arrangement of the flanks now leads in particular to the contact between blade lever head and flank/flanks for any positions of the guide blades and thus of the blade lever head being guaranteed. Here, too, the force transmission can be improved, the hysteresis effect and the friction reduced.
A further advantageous embodiment comprises flanks of at least one recess, which are arranged in mirror image to one another. As an example, reference is made here to flanks which are mirrored to one another with respect to a radial plane of the adjusting ring running in their middle. The flanks are thus designed in particular with curved shape of the respective flanks in such a manner that the make available the same, however mirrored, mount on both sides of the associated recess.
With a further embodiment, a base of the recess additionally to the already mentioned embodiments has a curved shape. Here, the base can be for example rounded off in order to prevent in particular a friction of the blade lever head with the base of the associated recess.
According to an advantageous further development, the adjusting ring is integrated in a variable turbine and/or compressor geometry. Here, the blade levers are connected by blade lever pins to a blade bearing ring, wherein guide blades are coupled to the blade lever pins in a rotationally fixed manner. This further development now serves in particular for the purpose of at least reducing a friction force between the flanks of the recesses of the adjusting ring and the associated recesses, independently of the position of the blade bearing ring and thus of the associated guide blades.
According to an advantageous embodiment of the variable turbine and/or compressor geometry according to the disclosure, the flanks of the adjusting ring are designed in such a manner that the associated blade lever heads are supported substantially orthogonally on the associated flank independently of the position of the adjusting ring and thus of the guide blades. This orthogonal support in this case serves in particular for the purpose of achieving an optimal transmission of the adjusting force to the blade lever heads and thus to the guide blades through the adjusting ring.
It is pointed out that the rotation of the adjusting ring in a variable turbine and/or compressor geometry merely runs over a few angular degrees. Accordingly, the respective flanks according to the disclosure can be designed in such a manner that they merely ensure an optimised transmission of the adjusting force between adjusting ring and blade lever head and/or a contact between blade lever head and the associated flank merely in the relevant angular range.
Further important features and advantages of the disclosure are obtained from the subclaims, from the drawings and from the associated Figure description by means of the drawings.
It is to be understood that the features mentioned above and still to be explained in the following cannot only be used in the respective combination stated but also in other combinations or by themselves without leaving the scope of the present disclosure.
Preferred exemplary embodiments of the disclosure are shown in the drawings and are explained in more detail in the following description, wherein same reference numbers refer to same or similar of functionally same components.
It shows, in each case schematically:
As is shown in
In the embodiment of the adjusting ring 1 according to the disclosure shown in
With a corresponding design of the flanks 3, 3′ according to
In the embodiment of the recess 2 of an adjusting ring 1 shown in
These embodiments in particular serve for the purpose of improving a transmission of an adjusting force via the flanks 3, 3′ to the associated blade lever heads through the shape of the flanks 3, 3′. This is effected in particular in that the flanks 3, 3′ are designed such that their shape and arrangement ensure a substantially orthogonal support of the associated blade lever head, independently of the position of the corresponding guide blades and thus of the blade lever head. The force introduction between the lever head and the adjusting ring 1 merely takes place in circumferential direction (tangentially) of the adjusting ring 1.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102011005556.8 | Mar 2011 | DE | national |
