U.S. patent application number 15/965010 was filed with the patent office on 2018-11-01 for rotor arrangement with balancing element and method for mounting a balancing element.
The applicant listed for this patent is Rolls-Royce Deutschland Ltd & Co KG. Invention is credited to Steffen DREVS, David ROCKEL.
Application Number | 20180313367 15/965010 |
Document ID | / |
Family ID | 62046727 |
Filed Date | 2018-11-01 |
United States Patent
Application |
20180313367 |
Kind Code |
A1 |
DREVS; Steffen ; et
al. |
November 1, 2018 |
ROTOR ARRANGEMENT WITH BALANCING ELEMENT AND METHOD FOR MOUNTING A
BALANCING ELEMENT
Abstract
A rotor arrangement, with a rotor for an engine having a rotor
disc that extends along a circumferential direction about a central
axis, and at least one balancing element that is attached at the
rotor disc for balancing the rotor. At least one attachment section
projecting axially with respect to the central axis is embodied at
the rotor disc, and the at least one balancing element engages
around the axially projecting attachment section.
Inventors: |
DREVS; Steffen; (Berlin,
DE) ; ROCKEL; David; (Berlin, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rolls-Royce Deutschland Ltd & Co KG |
Blankenfelde-Mahlow |
|
DE |
|
|
Family ID: |
62046727 |
Appl. No.: |
15/965010 |
Filed: |
April 27, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D 29/662 20130101;
F16F 15/34 20130101; G01M 1/36 20130101; F01D 5/027 20130101; F01D
5/066 20130101; F01D 5/10 20130101; F05D 2260/15 20130101; F01D
25/04 20130101 |
International
Class: |
F04D 29/66 20060101
F04D029/66 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 28, 2017 |
DE |
10 2017 207 283.0 |
Claims
1. A rotor arrangement, with a rotor for an engine, having a rotor
disc extending along a circumferential direction about a central
axis, and at least one balancing element that is attached at the
rotor disc for balancing the rotor, wherein at least one attachment
section projecting axially with respect to the central axis is
embodied at the rotor disc, and the at least one balancing element
engages around the axially projecting attachment section.
2. The rotor arrangement according to claim 1, wherein the at least
one balancing element has a balancing element body with a
wrap-around section by means of which the balancing element engages
around the axially projecting attachment section.
3. The rotor arrangement according to claim 2, wherein the
wrap-around section has at least one--with respect to the central
axis--radially outer first leg section and at least one radially
inner second leg section, and wherein at least a part of the
axially projecting attachment section is received between the first
and the second leg sections.
4. The rotor arrangement according to claim 3, wherein at least one
of the first and second leg sections has a curvature that is convex
in the direction of the attachment section.
5. The rotor arrangement according to claim 1, wherein the at least
one balancing element comprises a balancing element body and a
fixation element that is adjustable relative to the balancing
element body.
6. The rotor arrangement according to claim 5, wherein the
balancing element engages around the axially projecting attachment
section by means of at least one section of the balancing element
body and at least one section of the fixation element.
7. The rotor arrangement according to claim 3, wherein the at least
one balancing element comprises a balancing element body and a
fixation element that is adjustable relative to the balancing
element body, and wherein, for fixating the balancing element at
the attachment section, the fixation element is configured and
adjustably mounted relative to the balancing element body in such a
manner that a radial distance of the first and second leg sections
can be modified by adjusting the fixation element.
8. The rotor arrangement according to claim 7, wherein the fixation
element extends with one section between the first and the second
leg sections radially with respect to the central axis.
9. The rotor arrangement according to claim 8, wherein the section
of the fixation element extending between the first and the second
leg sections extends not through the attachment section, but
instead past it.
10. The rotor arrangement according to claim 5, wherein, for
fixating the balancing element at the attachment section, the
fixation element is configured and adjustably mounted relative to
the balancing element body in such a manner that the fixation
element can be brought into contact with the attachment
section.
11. The rotor arrangement according to claim 5, wherein the
fixation element forms a contact surface via which the fixation
element acts on one of the first and second leg sections or the
axially projecting attachment section for fixating the balancing
element at the attachment section.
12. The rotor arrangement according to claim 1, wherein the
wrap-around section has a trapezoidal contour, as viewed in a side
view along the central axis.
13. The rotor arrangement according to claim 1, wherein the at
least one balancing element has a balancing element body with a
wrap-around section by means of which the balancing element engages
around the axially projecting attachment section, and wherein the
wrap-around section has at least one--with respect to the central
axis--radially outer first leg section and at least one radially
inner second leg section, and wherein at least a part of the
axially projecting attachment section is received between the first
and the second leg sections, and the wrap-around section has two
second radially inner [leg sections] that are located opposite a
first radially outer leg section.
14. A method for mounting a balancing element at a rotor that is
rotatable about a central axis and has a rotor disc with at least
one--with respect to the central axis--axially projecting
attachment section, wherein the method comprises at least the
following steps: providing a balancing element with mounting jaws,
and attaching the balancing element at the at least one attachment
section, so that the balancing element engages around the
attachment section and at least a part of the attachment section is
received inside the mounting jaws.
15. The method according to claim 14, wherein the balancing element
comprises (a) a balancing element body with a wrap-around section,
wherein the wrap-around section has at least two facing leg
sections that define the mounting jaws, or (b) a balancing element
body and a fixation element adjustably mounted thereat, wherein the
mounting jaws engaging around the attachment section is defined by
a section of the balancing element body and a section of the
fixation element.
16. The method according to claim 14, wherein the balancing element
attached at the attachment section is displaced into a balancing
position along a circumferential direction about the central axis,
and is subsequently fixated.
17. The method according to claim 14, wherein an adjustably mounted
fixation element of the balancing element is adjusted for fixating
the balancing element in a balancing position at the attachment
section.
18. The method according to claim 14, wherein a mounting tool at
which a balancing element body of the balancing element is held in
a form-fitting manner and by means of which the balancing element
body is further displaced into the balancing position is used for
attaching the balancing element body at the attachment section.
19. The method according to claim 17, wherein a mounting tool at
which a balancing element body of the balancing element is held in
a form-fitting manner and by means of which the balancing element
body is further displaced into the balancing position, is used for
attaching the balancing element body at the attachment section, and
wherein the mounting tool is embodied in at least two parts with a
holding part that holds the balancing element body in a
form-fitting manner and a part for the displacement of the fixation
element adjustably mounted at the holding part.
20. The method according to claim 19, wherein the adjustably
mounted part is mounted so as to be rotatable and displaceable at
the holding part, and is connected in a torque-proof manner to the
fixation element for the fixation of the balancing element, while
the balancing element body remains retained at the holding part.
Description
REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to German Patent
Application No. 10 2017 207 283.0 filed on Apr. 28, 2017, the
entirety of which is incorporated by reference herein.
BACKGROUND
[0002] The invention relates to a rotor arrangement as well as to a
method for mounting a balancing element at a rotor.
[0003] The balancing of a rotor for an engine, in particular of a
rotor for a gas turbine engine, is usually realized by attaching
balancing elements at different balancing positions. Here, the
attachment of individual balancing elements is the method of
choice, for instance when a selective arrangement of rotor blades
at a rotor disc of the motor is not possible and the rotor is made
in one piece with the rotor blades as a blisk, for example. While
in a rotor in which the rotor blades are manufactured separately
and are mounted at the rotor disc a displacement of the rotor
blades across the circumference of the rotor can be achieved in a
computer-aided manner based on measurements at the individual rotor
blades by means of which unbalanced masses are prevented, in a
blisk with rotor blades that are embodied in one piece with the
rotor disc, there is only the possibility of locally removing
material or locally attaching balancing elements in order to
compensate for unbalanced masses. At that, with a view to costs and
effort, the attachment of balancing elements is usually
favored.
[0004] What is known from the state of the art in this context are
differently designed balancing elements and attachment sections
adjusted to them at the rotors of an engine that make it possible
to attach the respective balancing elements at the rotor. For
instance, it is known from DE 10 2008 016 329 A1 to provide
radially inwards facing webs with receiving grooves for
respectively one balancing element at a rotor disc extending along
a circumferential direction about a central axis of the rotor (with
respect to this central axis). Here, the design of the attachment
sections for the balancing elements that are defined by the
radially inwards facing webs and receiving grooves is comparatively
complex. Further, in the rotor arrangement of DE 10 2008 016 329
A1, the balancing elements can only be mounted from the inside and
either cannot be removed at all or cannot be removed easily after
mounting. Thus, the balancing elements of DE 10 2008 016 329 A1 are
to be deformed after attachment for fixating at the respective
attachment section, and the attachment sections are not accessible
from a radially outer side.
SUMMARY
[0005] The invention is thus based on the objective to improve a
rotor arrangement with a rotor and at least one balancing element
attached thereat and an associated mounting method in particular
with respect to the mountability and the balancing of the
rotor.
[0006] This objective is achieved through a rotor arrangement with
features as described herein as well as through a mounting method
with features as described herein.
[0007] Here, the proposed rotor arrangement has at least one rotor
for an engine comprising a rotor disc that extends along a
circumferential direction about a central axis of the rotor.
Further, at least one balancing element is provided that is
attached at the rotor disc for balancing the rotor. Here, the at
least one balancing element is attached at least at one attachment
section of the rotor disc that protrudes axially with respect to
the central axis by the balancing element engaging around the
axially projecting attachment section.
[0008] Through the at least one axially projecting attachment
section in combination with a balancing element that engages around
this attachment section, it is not only possible to fixate the
balancing element at the rotor disc in a comparatively simple and
captive manner in order to balance the rotor. But the balancing
element can also remain easily accessible from a radially outer
side, for example to be able to alter the position of the at least
one balancing element at the rotor disc also after mounting of the
rotor in an engine or at least after the assembly of a rotor
assembly group comprising the rotor.
[0009] For the wrap-around engagement of the attachment section,
the at least one balancing element can have a balancing element
body with a wrap-around section. By means of this wrap-around
section, the balancing element then engages around the axially
projecting attachment section.
[0010] In an alternative embodiment variant, the wrap-around
engagement is realized by means of at least one section of a
balancing element body of the balancing element and at least one
section of a fixation element that is adjustably mounted at the
balancing element body. Here, the fixation element can for example
be radially adjustable with respect to the central axis in order to
apply a clamping force for fixating the balancing element at the
attachment section if the balancing element is present at a
desired/predefined balancing position.
[0011] At that, it can in particular be provided that the fixation
element does not extend through the attachment section. In an
exemplary embodiment based hereon, the balancing element engages
around the attachment section by the attachment section being
clamped between a (with respect to the central axis) radially
outwardly positioned section of the balancing element body and a
radially inwardly positioned section of the fixation element. The
radially inwardly positioned section of the fixation element can
for example be a clamping head. This clamping head can then be
displaced in the direction of the radially outwardly positioned
section of the balancing element body to bring the clamping head in
abutment with the attachment section and to fixate the balancing
element at the attachment section in a clamping manner.
[0012] In one embodiment variant, a wrap-around section of the
balancing element body has at least one--with respect to the
central axis--radially outer first leg section and at least one
radially inner second leg section, wherein then at least one part
of the axially projecting attachment section is received between
the first and the second leg sections. Thus, at least one part of
the axially projecting attachment section that is formed by the
rotor disc is received in a sandwiched manner between the first and
the second leg sections of the wrap-around section to hold the
balancing element at the rotor disc in a form-fitting manner. On
the one hand, such a wrap-around engagement of the at least one
attachment section of the rotor disc can ensure that the balancing
element can be easily attached at the rotor disc in a captive
manner, and on the other hand it makes it possible for the already
attached balancing element to remain adjustable relative to the
rotor disc along the circumferential direction until a fixation of
the balancing element at a predefined balancing position
occurs.
[0013] For a defined abutment of the balancing element body at the
at least one attachment section of the rotor disc as well as for an
additional axial securing of the balancing element once it is
attached at the attachment section, at least one of the first and
second leg sections can have a curvature that is convex in the
direction of the attachment section. By means of this convex
curvature, the balancing element that is mounted at least at one
attachment section of the rotor disc according to the intended use
can also engage around the attachment section in the axial
direction in a possible further development to avoid unintended
detachment of the balancing element that is mounted according to
the intended use at the rotor disc.
[0014] In an embodiment variant with a wrap-around section, the at
least one balancing element can also comprise a fixation element
that is adjustable relative to the balancing element body. Here,
the fixation element may also be radially adjustable with respect
to the central axis, for example. At that, the fixation element
serves for fixating the balancing element at the axially projecting
attachment section after the balancing element body has been
arranged thereat.
[0015] In this context, the fixation element for fixating the
balancing element at the attachment section can for example be
configured and adjustably mounted relative to the balancing element
body in such a manner that a radial distance of the first and
second leg sections can be changed by adjusting the fixation
element. Thus, in this variant, it is achieved by means of the
fixation element that the first and second facing leg sections can
be clamped against each other to enclose the enclosed part of the
axially projecting attachment section in between them in a
form-fitting and clamping manner, and in this way fixate the
balancing element at the rotor disc in a predefined balancing
position.
[0016] In this variant, the fixation element extends at the rotor
arrangement with one section between the first and the second leg
sections radially with respect to the central axis, for example to
be respectively directly connected to the first and the second leg
sections and be able to act on them directly.
[0017] In one embodiment variant, the section of the fixation
element extending between the first and the second leg sections
extends not through the attachment section, but instead past it.
The section of the fixation element extending between the first and
the second leg sections thus in particular extends not through a
bore in the attachment section, but rather axially offset with
respect to the attachment section.
[0018] In an alternative embodiment variant, the fixation element
for fixating the balancing element at the attachment section is
configured and adjustably mounted relative to the balancing element
body in such a manner that the fixation element can be brought into
contact with the attachment section. If, in the previously
explained variant, an abutment of the first and the second facing
leg sections is achieved on different sides of the axially
projecting attachment section through the fixation element, and the
balancing element is thus fixated at the attachment section,
variant the fixation element itself serves as a counter bearing and
with one section is brought into abutment with the attachment
section in this alternative embodiment. At that, the fixation
element that is supported at the first radially outer (external)
side of the attachment section can for example be adjusted, so that
the balancing element body is displaced radially outwards and in
this way the second radially inner leg section of the wrap-around
section is displaced in the direction of a second (internal) side
of the attachment section that is located opposite the first
(external) side of the attachment section for the fixation element.
Consequently, in this variant an area of the attachment section is
clamped not between the first and second leg sections engaged
around the attachment section, but rather between the fixation
element and only one of the first and second leg sections.
[0019] For applying a clamping force for fixating the balancing
element body in a predefined balancing position, the fixation
element can principally form a contact surface via which the
fixation element acts--depending on the embodiment variant--on one
of the first and second leg sections or the axially projecting
attachment section to fixate the balancing element at the
attachment section. This contact surface is for example embodied at
a (clamping) head of the fixation element. This clamping head then
engages behind one leg section, for example the second radially
inner leg section, or the attachment section, and/or is pressed
against the axially projecting attachment section due to the
displacement of the fixation element relative to the balancing
element body.
[0020] In one embodiment variant, the balancing element and the
fixation element respectively have a thread for adjustably fixating
the fixation element at the balancing element body. For instance,
the fixation element comprises an external thread and the balancing
element body comprises an internal thread. Correspondingly, the
fixation element can be screwed in with its external thread into an
opening or bore of the balancing element body that is provided with
the internal thread. If then the fixation element is screwed in
further, with the balancing element body being already attached at
the axially projecting attachment section (and at that is displaced
for example in the radial direction with respect to the central
axis), this causes (a) a distance of the first and second leg
sections of the wrap-around section or (b) a distance between the
fixation element and an opposing (second) leg section to be
reduced, so that the balancing element is finally fixated.
[0021] In one embodiment variant, the fixation element forms--with
respect to the central axis--a radially externally positioned tool
interface at which a mounting tool can be applied to adjust the
fixation element relative to the balancing element body. At that,
the tool interface can for example comprise an external or internal
hexagon. The fixation of the balancing element in a desired
balancing position can be realized comparatively easily through the
arrangement of the tool interface at a radially outwardly
positioned side of the balancing element. Likewise, a fixation of
the balancing element can be released again in a comparatively easy
manner. If the fixation is released, the balancing element body can
also be displaced into a different balancing position in the
circumferential direction about the central axis via the
wrap-around engagement at the axially projecting attachment
section. Here, the balancing element and a mounting tool for
fixating the balancing element can be embodied in such a manner
that, with the fixation released, a displacement of the balancing
element body in the circumferential direction is also possible by
means of the mounting tool, before the balancing element is then
fixated again in a new balancing position by adjusting the fixation
element by means of the mounting tool.
[0022] In an exemplary embodiment, the wrap-around section of the
balancing element body has a trapezoidal contour, as viewed in a
side view along the central axis. Here, the longer side of this
trapezoidal contour is located radially inside at the rotor
arrangement. In this manner, an improved stress development inside
the wrap-around section is achieved, in particular if the balancing
element is fixated by a fixation element that acts on the
attachment section radially outside and at least one radially inner
leg section that is displaced by adjustment of the fixation element
in the radially outward direction against the attachment section.
In particular, disadvantageous bending moments can be reduced in
this manner during the fixation of the balancing element.
[0023] In an exemplary embodiment, the wrap-around section has two
second radially inner leg sections that are positioned opposite a
(single) first radially outer leg section. The wrap-around section
thus has two separated radially inner leg sections to abut at the
axially projecting attachment section at two positions that are
spatially offset with respect to one another (in different
attachment areas of the attachment sections) via these second leg
sections if the balancing element is fixated according to the
intended use.
[0024] For instance, a recess extending in the circumferential
direction is embodied at the wrap-around section between the two
second radially inner leg sections. Through this recess, the two
second leg sections are spatially separated from each other to
achieve a defined force introduction at the leg sections during
fixation of the balancing element. In addition, as a result of the
material savings associated with the recess, it can be avoided that
a weight of the balancing element is significantly increased by the
two leg sections as compared to a variant with only one second
radially inner leg section.
[0025] In one embodiment variant, the attachment section at the
rotor disc at which one balancing element or multiple balancing
elements can be fixated is embodied in a ring-shaped or ring
segment-shaped manner. Here, the ring-shaped or ring segment-shaped
attachment section extends along a circle line about the central
axis at the rotor disc. During mounting of the balancing element,
the balancing element body can be attached at the ring-shaped or
ring segment-shaped attachment section, so that the balancing
element engages around a part of the attachment section, e.g. by
means of the wrap-around section of the balancing element body or
by means of the balancing element body and a fixation element.
Then, the balancing element body that is held in such a manner at
the attachment section can be displaced along the circumferential
direction at the ring-shaped or ring segment-shaped attachment
section until the balancing element body is in a predefined (other)
balancing position, in which an imbalance of the rotor is
compensated. Subsequently, the balancing element is fixated at the
occupied balancing position, for example by screwing in a fixation
element.
[0026] Alternatively or additionally, the attachment section has at
least two axially projecting attachment areas that are arranged at
a distance to one another in the circumferential direction. The
respectively axially projecting attachment areas, which may for
example be separated from each other by a gap in the
circumferential direction, can define different balancing positions
for respectively one balancing element, and/or a defined contact
point for a fixation element or one of the first and second leg
sections of the wrap-around section.
[0027] For instance, it is provided in a further development that
the attachment section has two outer, respectively axially
projecting (first) attachment areas as well as an also axially
projecting inner or middle (second) attachment area between the two
outer attachment areas. If a balancing element with a radially
outer leg section and two radially inner leg sections is used in
such an embodiment variant, a balancing position for a possibly to
be attached balancing element can be predefined comparatively
precisely through the different attachment areas of an attachment
sections. In this way, respectively one outer axially projecting
attachment area is received between the radially outer first leg
section and one of the two radially inner second leg sections,
while the inner attachment area serves only for supporting the
first leg section or the fixation element. In the latter case, the
fixation element itself thus acts on the (second) inner attachment
area located between the two outer attachment areas of the
attachment section to fixate the balancing element at the
attachment section.
[0028] To save material and thus weight, a gap can be respectively
embodied at the rotor disc between the axially projecting outer
attachment areas and the axially projecting inner attachment
area.
[0029] In principle, multiple preferably geometrically identically
embodied attachment sections and/or multiple balancing elements can
be provided at the rotor disc. When defined balancing positions
along the circumference are prescribed, at which a balancing
element according to the intended use can be fixated, the number of
these possible balancing positions may be limited. For instance, at
least 8, but no more than 24, e.g. 16 to 18, balancing positions at
the rotor disc of the rotor may be predefined, at which a balancing
element can be fixated according to the intended use.
[0030] In particular against this background, multiple attachment
sections succeeding each other along the circumferential direction
and respectively projecting axially are provided at the rotor disc
in one embodiment variant, with respectively one intermediate area
having an axial extension that is reduced as compared to the
attachment sections being provided in between them. Consequently,
here the attachment of a balancing element by axial wrap-around
engagement is not possible in the intermediate areas. The possible
attachment points for a balancing element at the rotor disc are
correspondingly limited. But on the other hand, as a result of the
intermediate areas with reduced axial extension, weight is saved in
particular with respect to a variant in which an attachment section
extends at the rotor disc in a ring-shaped manner. Preferably, an
attachment section is respectively embodied in one piece at the
rotor disc, thus being formed at the same.
[0031] A rotor of the rotor arrangement is for example provided for
a gas turbine engine. For instance, it may be a rotor for a
compressor stage of the gas turbine engine that is provided with
rotor blades, for example a rotor of a high-pressure compressor of
the gas turbine engine.
[0032] A further aspect of the proposed solution is an improved
method for mounting a balancing element at a rotor that is
rotatable about a central axis.
[0033] Also here, the rotor comprises a rotor disc with at least
one attachment section that is axially projecting with respect to
the central axis and at which a balancing element for balancing the
rotor can be attached. The proposed method comprises at least the
following steps:
[0034] providing a balancing element with mounting jaws, and
[0035] attaching the balancing element to the balancing element
body at the at least one attachment section, so that a balancing
element engages around the attachment section and at least a part
of the attachment sections is received inside the mounting
jaws.
[0036] Here, the mounting jaws can be defined by at least two
facing leg sections of a wrap-around section of the balancing
element body of the balancing element, as has already been
explained above. Alternatively, the mounting jaws provided for the
wrap-around engagement of the attachment section are defined by a
section of the balancing element body and a section of a fixation
element adjustable thereat, i.e. for example by a leg section of
the balancing element body and a clamping head of the fixation
element that is positioned opposite this leg section.
[0037] Here, the balancing element attached at the attachment
section can be displaced along a circumferential direction about
the central axis into a balancing position (optionally of multiple
possible and predefined balancing positions) and subsequently
fixated. As has already been explained above, the balancing element
is thus initially attached at the attachment section by means of
the balancing element body, and namely in such a manner that the
balancing element is held at the rotor disc so as to be still
displaceable, in particular shiftable. The balancing element can
thus be displaced along the circumferential direction about the
central axis of the rotor along an adjustment path predefined by
the attachment section, wherein it is ensured that the balancing
element body remains at the attachment section by means of the
form-fitting wrap-around engagement of the attachment section. If
the balancing element body and thus the balancing element take the
desired balancing position along the circumference, the balancing
element is fixated.
[0038] For fixating the balancing element, the fixation element
adjustably mounted at the balancing element body may for example be
adjusted.
[0039] As a part of an embodiment variant of a possible mounting
method, a mounting tool is used for attaching the balancing element
body at the attachment section, with the balancing element body
being held at the mounting tool in a form-fitting manner and being
further displaced into the balancing position at the rotor disc by
means of the mounting tool. The mounting tool is thus provided for
a form-fitting connection to the balancing element body to be able
to attach the balancing element body at the rotor by means of the
mounting tool in a simple and quick way, namely in such a manner
that the wrap-around section of the balancing element body or the
balancing element body and the fixation element engage(s) around
the attachment section. A displacement of the balancing element
body along the circumferential direction is then still facilitated
through the mounting tool, so that the balancing element body can
be displaced, in particular shifted, into the desired balancing
position. The form fit of the balancing element body and the
mounting tool is for example provided by a hook-shaped section of
the mounting tool. In one embodiment variant, the mounting tool has
a section that is embodied as a holding hook and that can be
inserted at a corresponding interface of the balancing element
body. In a further development, the balancing element body for
example has a middle part that is offset with respect to adjoining
sections of the balancing element body, and at which a thickness of
the balancing element body is reduced and the holding hook of the
mounting tool is plugged on to engage around the balancing element
body and place it at the rotor by means of the mounting tool.
[0040] The mounting tool may for example be embodied with at least
two parts, comprising a holding part that holds the balancing
element body in a form-fitting manner and a part for displacing of
a fixation element that is adjustably mounted at the holding part.
Thus, the balancing element body can be attached at the rotor disc
by means of the mounting tool, so that e.g. the wrap-around section
of the balancing element body engages around the at least one
attachment section. Subsequently, the fixation element of the
balancing element is adjusted relative to the balancing element
body and in this way finally fixated in the desired balancing
position my means of the balancing element by using the same
mounting tool--and without having to separate the balancing element
body from the holding part of the mounting tool, for example in the
form of holding hooks.
[0041] In one embodiment variant, the adjustably mounted part is
mounted at the holding part of the mounting tool in a rotatable and
displaceable manner. The part that is thus adjustably mounted can
be connected in a torque-proof manner to the fixation element for
fixating the balancing element, while the balancing element body
remains retained at the holding part. For example, in a further
development based thereon, the fixation element is mounted in a
rotatable manner at the balancing element body and provided with an
external thread. Via the external thread, the fixation element can
be screwed in at a threaded section of the balancing element body
provided with the internal thread to fixate the balancing element.
As has already been explained above, in one embodiment variant, the
fixation element can be brought into abutment with a first
(external) side of the attachment section, and a second radially
inner leg section of the wrap-around section can be clamped against
the opposite second (internal) side of the attachment section in
this manner. In an alternative embodiment variant, in which the
fixation element is fixated at the second radially inner leg
section in a form-fitting manner and the threaded section of the
balancing element body is connected in one piece to the first
radially outer leg section, the first and second leg sections are
moved closer to each other by screwing in the fixation element
(further). Likewise, in one embodiment variant, the fixation
element can be brought into abutment with a second (internal) side
of the attachment section, and a first radially outer leg section
of the balancing element body can be clamped against the opposite
first (external) side of the attachment section. Thus, by means of
the two-part mounting tool, the balancing element body is brought
into position in all cases, and the fixation element is
subsequently screwed in to fixate the balancing element with the
balancing element body and the fixation element in a desired
balancing position in a clamping manner. By forming a rotatable
fixation element that meshes with an internal thread of the
balancing element body, a fixation of the balancing element can
also be easily released by means of a correspondingly adjustable
and in particular rotatably mounted part of the mounting tool, and
the balancing element can be displaced.
[0042] In one variant, the adjustable fixation element is secured
at the balancing element body against removal from the balancing
element by means of a securing element. For instance, the
adjustable fixation element is secured against removal from the
balancing element in the radial direction with respect to the
central axis. For instance, the fixation element thus cannot be
easily twisted out of the balancing element body. By means of the
securing element, which may for example be embodied as a securing
ring, it can further be ensured also in the balancing element
embodied as a multi-part that the adjustable fixation element is
present at the balancing element body in a mounting position,
before the balancing element is attached at the axially projecting
attachment section of the rotor disc.
[0043] In principle, the fixation element can be embodied for
example in the manner of a screw with a threaded section, a shaft
and a (clamping) head, wherein the attachment section or one of the
leg sections is acted on to fixate the balancing element by means
of the (clamping) head.
[0044] The proposed mounting method can ultimately also be used in
a proposed rotor arrangement, so that advantages and features that
are explained above as well as in the following in connection with
exemplary embodiments of such a rotor arrangement also apply to
embodiment variants of a mounting method and vice versa.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] The attached Figures illustrate possible embodiment variants
of the proposed solution by way of example.
[0046] FIG. 1 shows, in sections and in sectioned view, an
embodiment variant of a rotor arrangement with a ring-shaped
axially projecting attachment section at the rotor disc of a
rotor.
[0047] FIG. 2 shows, in sectioned view and in a mounted state, the
rotor arrangement of FIG. 1 with a balancing element in a
high-pressure compressor of a gas turbine engine.
[0048] FIGS. 3A-3B show different views of the rotor arrangement of
FIG. 2.
[0049] FIGS. 4A-4B show the balancing element of FIGS. 2 and 3A to
3B in sectioned view with an adjustably mounted fixation element in
different positions.
[0050] FIGS. 5A-5C show the balancing element of FIGS. 4A and 4B in
a mounted state at an axially projecting attachment section of the
rotor of FIG. 1 in different phases during the fixation of the
balancing element.
[0051] FIGS. 6A-6B show a further embodiment variant of a balancing
element in different individual views.
[0052] FIGS. 7A-7B show a rotor arrangement with the balancing
element of FIGS. 6A and 6B.
[0053] FIGS. 8A-8B show the rotor arrangement of FIGS. 7A and 7B
with a balancing element in enlarged scale and in different
views.
[0054] FIGS. 9A-9F show different views of the rotor arrangement
with a mounting tool for attaching and fixating the balancing
element of FIGS. 7A to 8B;
[0055] FIG. 10 shows, in enlarged scale, the two-part mounting tool
with a view on a holding hook and an adjustably mounted rotating
part of the mounting tool.
[0056] FIGS. 11A-11B show different perspective views of a further
embodiment variant of a rotor arrangement with an alternatively
embodied balancing element for the attachment at a rotor, for
example according to FIG. 1.
[0057] FIG. 12 shows, in sections and in sectioned view, the rotor
arrangement of FIGS. 11A and 11B in the mounted state in a
high-pressure compressor of a gas turbine engine.
[0058] FIGS. 13A-13B show a further development of the embodiment
variant of FIGS. 11A to 12, also rendering a part of the attachment
section without (FIG. 13A) and with a balancing element (FIG. 13B),
in a sectioned view.
[0059] FIGS. 14A-14E show a further embodiment variant of a rotor
arrangement with a balancing element in which the balancing element
engages around the attachment section by means of a radially outer
leg section of a balancing element body and a section of a fixation
element that is adjustably mounted at the balancing element
body.
[0060] FIG. 15 shows, in a sectional view, a gas turbine engine in
which an embodiment variant of the proposed rotor arrangement is
used.
DETAILED DESCRIPTION
[0061] FIG. 15 shows, in a sectioned side view, a gas turbine
engine T which in the present case is embodied as a turbofan
engine. The individual components of the gas turbine engine T are
successively arranged along a central axis or rotational axis M.
Air is suctioned into the gas turbine engine T via a fan 12 of the
gas turbine engine T at an inlet or intake 11. Behind the fan 12,
the inflowing air is transported into two different channels, a
primary flow channel A of a core engine K and a secondary flow
channel or bypass channel B surrounding the core engine K. Inside
the core engine K, a medium-pressure compressor 13 and a
high-pressure compressor 14 are successively arranged along the
rotational axis M to compress the inflowing air in the primary flow
channel A. Subsequently, the air is transported into a combustion
chamber 15 of the core engine K. Due to the combustion taking place
in this combustion chamber 15 by means of the injected fuel, a
turbine with a high-pressure turbine 16, a medium-pressure turbine
17 and a low-pressure turbine 18 is driven. Behind the low-pressure
turbine 18, the exhaust gases created as a result of the combustion
are discharged into the environment via an outlet 19.
[0062] At that, the turbine with the high-pressure turbine 16,
medium-pressure turbine 17 and low-pressure turbine 18 in
particular drives the fan 12 to create the desired thrust through
the air that enters the bypass channel B.
[0063] Rotors with rotor blades that are mounted so as to be
rotatable about the rotational axis M are provided in the
medium-pressure and high-pressure compressors 13 and 14 as well as
in the high-pressure, medium-pressure and low-pressure turbines 16,
17 and 18. To ensure an even rotation in these high-speed rotors,
in particular in the area of the high-pressure compressor 14, the
individual rotors of a rotor blade row are balanced. However, due
to the installation space situation and the designs of the rotors
as they have been customary so far, the attachment of corresponding
balancing elements at predefined balancing positions at these
rotors can be performed only with difficulties. The proposed
solution is meant to remedy this problem.
[0064] FIG. 1 illustrates a first exemplary embodiment of a rotor
arrangement with a rotor 2 in sections. This rotor 2 is for example
provided for use in the high-pressure compressor 14 and is
configured as a blisk. Here, a rotor disc 21 that mounts the rotor
2 so as to be rotatable about a rotational axis M is embodied
integrally, i.e. in one part, with the rotor blades 20. The rotor
disc 21 extends along a circumferential direction U about the
centrally located middle axis M, which in the installed state of
the rotor 2 coincides with the rotational axis M of the gas turbine
engine T.
[0065] The rotor disc 21 forms a ring-shaped attachment section 22
at a downstream backside of the rotor disc 21, referring to the
installed state of the rotor 2. This ring-shaped attachment section
22 is embodied to be axially projecting with respect to the central
axis M, and extends along a circular path about the central axis M
along the circumferential direction U. The attachment section 22 of
the rotor 2 of FIG. 1 is further embodied to be slightly tilted
radially outwards to facilitate accessibility to a fixation element
5 of a balancing element 3 attached at this attachment section 22
if the rotor 2 has been mounted according to the intended use. This
is in particular illustrated in more detail in the sectional view
of FIG. 2.
[0066] For balancing the rotor 2, a balancing element 3 is fixated
at least at one balancing position along the circumference of the
attachment section 22. At that, corresponding to the rendering of
FIG. 2, the balancing element 3 has a balancing element body 4 with
a wrap-around section 41 that engages around a part of the
attachment section 22. The balancing element body 4 of the
balancing element 3 is thus held in a form-fitting manner at the
axially projecting attachment section 22, and can still be
displaced at the same along the circumferential direction U into
the desired balancing position along the attachment section 22.
[0067] The wrap-around section 41 of the balancing element body 4
forms a first radially outer leg section 41a as well as a second,
radially inner leg section 410 that is opposite in the radial
direction. If the balancing element 3 has been attached at the
attachment section 22 according to the intended use, a part of the
attachment section 22 of the rotor disc 21 is received between the
first and the second leg sections 41a and 410. The radially inner
leg section 410 thus faces a radially inwardly positioned internal
side 221 of the attachment section 22, while the other, radially
outer leg section 41a faces a radially outer external side 220 of
the attachment section 22.
[0068] In the present case, the balancing element 3 is embodied
with at least two parts and in addition to the balancing element
body 4 with the wrap-around section 41 has a fixation element in
the form of a screw 5. This screw 5 is screwed in at a
sleeve-shaped threaded section 40 of the balancing element body 4
in the area of the first radially outer leg section 41a. For this
purpose, the threaded section 40 forms a passage opening with an
internal thread 400 in which the screw 5 meshes with an external
thread. A clamping head 50 of the screw 5 protrudes at a radially
inner end of the passage opening that is provided with the internal
thread 400, and can be brought into abutment with the external side
220 of the attachment section 22.
[0069] At that, to adjust the screw 5 in the direction of the
attachment section 22 or away from the same, the screw 5 is mounted
at the threaded section 40 of the balancing element body 4 in a
rotatable manner. If the screw 5 is screwed in (further) into the
balancing element body 4, the clamping head 50 of the screw 5 is
pressed against the external side 220 of the attachment section 22
if the balancing element body 4 is plugged onto the attachment
section 22. The rotation of the screw 5 that abuts the attachment
section 22 via the clamping head 50 ultimately leads to the
balancing element body 4 being displaced radially outwards and thus
the radially inner leg section 410 being displaced against the
internal side 221 of the attachment section 22. Thus, by turning
the screw 5, a distance between the clamping head 50 of the screw 5
and the radially inner leg section 410 can be reduced, and the
balancing element 3 can be fixated at the axially projecting
attachment section 22 in this way.
[0070] For tightening and loosening the screw 5, it has a radially
externally positioned tool interface 51, for example with an
internal hexagon. At this tool interface 51, the screw 5 can be
connected to a mounting tool in order to adjust the screw 5
relative to the balancing element body 4 which can be fixated at
the attachment section 22. In the mounted state of the balancing
element 3, the tool interface 51 of the screw 5 is accessible from
the outside via a radially outwardly positioned installation gap
100 that is formed between the rotor 2 and an engine component TK
of the gas turbine engine T axially connecting thereto. The further
engine component TK can for example be a further rotatable rotor of
the high-pressure compressor 14.
[0071] In the present case, the balancing element 3 embodied as a
multi-part and the axially projecting attachment section 22 of the
rotor 2 are adjusted to installation space conditions in such a
manner that the tool interface 51 of the screw 5 remains accessible
from the outside via the installation gap 100 if the rotor 2 is
already connected to further engine components TK according to the
intended use. Thus, also in the assembled state of a rotor assembly
group comprising the rotor 2 with the at least one balancing
element 3, a mounting tool can be applied to the screw 5 to tighten
the screw 5 and thus fixate the balancing element 3 at the
attachment section 22. Likewise, the screw 5 can also be turned in
the rotor assembly group for detaching the fixation, and then the
balancing element body 4 can be displaced into a different
balancing position along the attachment section 22 in the
circumferential direction U.
[0072] A curvature 410a, which is convex in the direction of the
internal side 221, is embodied at the radially inner leg section
410 of the wrap-around section 41. This convex curvature 410a is
engaged behind the axially projecting attachment section 22, and a
physical guidance of the balancing element body 4 along the
attachment section 22 is provided if the screw 5 is not yet fully
tightened and does not yet abut the external side 220 of the
attachment section 22 in a clamping manner via its clamping head
50.
[0073] FIGS. 3A and 3B again illustrate, in different perspective
views, the form-fit wrap-around engagement of the balancing element
3 at the axially projecting ring-shaped attachment section 22 of
the rotor disc 21. The wrap-around section 41 of the balancing
element body 4 is C-shaped in side view, and has a radially
outwardly extending sleeve-shaped threaded section 40 at the outer
leg section 41a. The screw 5 that is screwed into the threaded
section 40 can be screwed in further into the threaded section 40
in the direction of the radially inner leg section 410, and thus
fixate the balancing element 3 at the attachment section 22.
[0074] As illustrated based on the sectional views of FIGS. 4A and
4B, the screw 5 forms a contact surface 500 at its clamping head
50, which can be brought into a planar contact with the external
side 220 of the axially projecting attachment section 22 for
fixating the balancing element 3. For this purpose, the screw 5 can
be adjusted through rotation about a screw axis along a rotational
direction D1 in a displacement direction V1 towards the second, and
in the mounted state radially inner, leg section 410. If, by
contrast, the screw 5 is turned into an opposite rotational
direction D2, the screw 5 is displaced into an opposite
displacement direction V2 away from the second leg section 410, and
thus a distance between the contact surface 500 of the clamping
head 5 and the second leg section 410 is enlarged.
[0075] For assembling the balancing element 3, the screw 5 is
initially screwed into the threaded section 40 so far that the
clamping head 50 protrudes at an inner end of the threaded section
40. Then, a securing element in the form of a securing ring 52 is
attached at the protruding end to axially secure the screw 5 at the
balancing element body 4 and to avoid it from being twisted out of
the threaded section 40. Thus, the securing ring 52 limits the
adjustability of the screw 5 (in the area of the clamping head 50)
in the direction of the displacement direction V2 relative to the
balancing element body 4. Thus, the securing ring 52 is stopped at
an end stop 401 inside the threaded section 40 and blocks any
further displacement of the screw 5 along the displacement
direction V2 beyond a predefined relative position between the
clamping head 50 and the second leg section 410. A mounting
position of the screw 5 at the balancing element body 4 is also
predefined by the securing ring 52 to be able to easily attach a
balancing element 3 at the attachment section 22 of the rotor 2, so
that the wrap-around section 41 of the balancing element body 4
engages around a part of the attachment section 22.
[0076] As illustrated based on FIG. 5A in sectional view, after the
balancing element 3 has been attached, the clamping head of the
screw 5 abuts in a planar manner at the attachment section 22 at
its external side 220 due to gravity. In contrast, the radially
internally positioned second leg section 410 of the wrap-around
section 41 is still arranged at least at a small distance from the
internal side 221 of the attachment section 22. A slot s is present
between the bottom side 221 and the convex curvature 410a of the
inner leg section 410. The balancing element body 4 is thus still
displaceable at the attachment section 22 in the circumferential
direction U, although the balancing element body 4 is already
plugged onto the axially projecting attachment section 22, so that
a part of the attachment section 22 is received inside mounting
jaws 30 of the wrap-around section 41 that is defined between the
two leg sections 41a and 410 (cf. also FIG. 4B).
[0077] If now the screw 5 is screwed in further and thus the
balancing element body 4 is displaced radially outwards via the
internal thread 400 of its threaded section 40 that combs with the
external thread of the screw 5, for one thing a distance between
the contact surface 500 of the clamping head 50 of the screw 5 and
the radially inner leg section 410 is reduced, and, for another,
the radially inner leg section 410 is pressed against the internal
side 221 of the attachment section 22. This phase during the
fixation of the balancing element 3 is illustrated based on FIG.
5B.
[0078] If the screw 5 is tightened strongly enough, as illustrated
in FIG. 5C, the balancing element 3 is held at the attachment
section 22 around which its balancing element body 4 is engaged not
only in a form-fitting manner, but is also fixated at it in a
clamping manner. The balancing element 3 is thus fixated immovably
in an occupied balancing position at the attachment section 22, and
can be displaced only when the fixation is released by turning the
screw 5 at the rotor 2.
[0079] FIGS. 6A to 8B show a further embodiment variant of a
balancing element 3 with a balancing element body 4 that is
geometrically modified as compared to the embodiment variant of
FIGS. 2 to 5C. In side view, the balancing element body 4 of the
embodiment variant of FIGS. 6A to 8B has a trapezoidal contour,
wherein in the mounted state of the balancing element body 4 the
longer side of the trapezoidal contour abuts an axially projecting
attachment section 22 of a rotor radially inside. In the present
case, two second leg sections 410 and 411 are embodied at this
radially inner side, being separated from each other by a recess
412. Here again, each of the leg sections 410 and 411 has a convex
curvature 410a or 411a for abutment at the attachment section 22 in
the fixated state of the balancing element 3. Via the two second
leg sections 410 and 411, the balancing element body 4 can be
brought into contact with an attachment section 22 at two locations
that are spatially separated from each other along the
circumferential direction U. Here, material is saved thanks to the
recess 412. At the sides, the recess 412 is bordered by two facing
cross webs 412a and 412b. These cross webs 412a, 412b extend
between the respective second leg section 410 or 411 and first leg
section 41a. In the mounted state of the balancing element 3, these
cross webs 412a, 412b thus extend substantially radially with
respect to the central axis M.
[0080] The trapezoidal contour of the balancing element body 4 and
in particular of the wrap-around section 41 reduces stresses
occurring inside the balancing element body 4 if the screw 5 is
tightened and the balancing element 3 is fixated at the rotor disc
21 in this manner. Against this background, there are also lateral,
obliquely extending force introduction sections 413 and 414
embodied at the wrap-around section 41, which respectively connect
one of the second leg sections 410 or 411 to the first leg sections
41a at which the threaded section 40 with the passage opening is
embodied with an internal thread 400 for the screw 5.
[0081] Further, a middle part 145 is embodied between these lateral
force introduction sections 413 and 414 of the wrap-around section
41, which is embodied so as to be deepened or set back as compared
to the adjoining force introduction sections 413 and 414. Due to
the associated local reduction of a wall thickness of the
wrap-around section 41 in a middle area between the two force
introduction sections 413 and 414, the weight of the balancing
element body 4 is even more reduced, and, despite the two second
leg sections 410 and 411, differs only minimally from the weight of
a balancing element body 4 with only one single second leg section
410. Further, an interface for a holding part 64 of a mounting tool
6, by means of which the balancing element body 4 of the balancing
element 3 can be attached at the rotor 2, is provided by the
backset middle part 415. This is illustrated in more detail in the
following based on the FIGS. 9A to 9F that will be explained in the
following.
[0082] For additional weight reduction at the rotor 2, one
embodiment variant of the rotor arrangement corresponding to FIGS.
7A to 8B further provides that multiple individual attachment
sections 22 arranged at a distance to one another are embodied at
the rotor disc 21 along the circumferential direction U. What is
accordingly provided is not an individual ring-shaped attachment
section 22, but rather a plurality of attachment sections 22 that
are distributed across the circumference of the rotor disc 21.
Thus, these attachment sections 22 define possible balancing
positions at which a balancing element 3 can be attached according
to the intended use. A recess 23 is provided between respectively
two neighboring attachment sections 22. This recess 23 respectively
represents an intermediate area with an axial extension that is
reduced as compared to the attachment section 22.
[0083] Three attachment areas 22a, 22b and 22c axially projecting
in a tongue-like or web-like manner are embodied at each attachment
section 22. Here, a middle attachment area 22c is present between
two outer attachment areas 22a and 22b. A gap 223ac or 223bc
extending in the circumferential direction is respectively provided
between an outer attachment area 22a or 22b and the middle
attachment areas 22c. One of the cross webs 412a, 412b of the
balancing element body 4 is received at least partially inside each
of these gaps 223ac, 223bc when the balancing element 3 is attached
according to the intended use.
[0084] Here, the respectively outer attachment areas 22a and 22b of
an attachment section 22 are provided for connection with
respectively one of the second, and in the mounted state radially
inner, leg sections 410 and 411 of the balancing element body 4.
The middle attachment area 22c located in between serves for
contact with the screw 5 provided for fixating. Consequently, if a
balancing element 3 is fixated according to the intended use at an
attachment section 22 of FIGS. 7A to 8B, respectively one leg
section 410 or 411 presses along a radially outwards pointing
direction against an internal side 221 of an outer attachment area
22a or 22c. Via the contact surface 500 at the clamping head 50,
the screw 5 in turn presses against the middle attachment area 22c
at an external side 220 along a radially inward pointing direction.
Thus, through the division of an attachment section 22 into
different attachment areas 22a to 22c, the position of a balancing
element 3 to be fixated thereat is largely predefined.
[0085] If, in one embodiment variant of a rotor arrangement
according to FIGS. 7A to 8B, a fixation of a balancing element 3 by
means of a screw 5 is released, the respective balancing element 3
can be shifted to another attachment section 22 along the
circumferential direction U. At that, respectively at least a small
axial projection may be present also in the area of the recesses 23
of the rotor disc 21, around which the wrap-around section 41 of
the balancing element body 4 can engage and along which the
balancing element 3 is thus held in a physically guided manner.
[0086] As shown in the view of FIG. 8A with a view onto the
radially internally located side of the attachment section 22, in
the newly taken balancing position, the balancing element body 4
with its wrap-around section 41 should again abut at the outer
attachment areas 22a and 22b with its two second radially inner leg
sections 410 and 411, so that the middle attachment area 22c,
against which the clamping head 50 of the screw 5 presses on the
radially outer side, is located inside the recess 412 between the
two second leg sections 22a and 22b.
[0087] To render mounting of a balancing element 3 easier, an
especially embodied mounting tool can be used, by means of which,
on the one hand, the balancing element body 4 is brought into
position and, on the other hand, the screw 5 can be tightened for
fixating the balancing element 3. FIGS. 9A to 9F and 10 illustrate
an exemplary embodiment of such a mounting tool 6.
[0088] The mounting tool 6 has a rod-shaped holding part 64 with a
sleeve portion 640 that a user can manipulate in order to position
a balancing element 3 and handle the mounting tool 3. Further, a
holding hook 641, at which the balancing element body 4 can be
retained in a form-fitting manner, is embodied at an end of the
holding part 64. For this purpose, the holding hook 641 engages
radially around the balancing element body 4 in the area of the
backset middle part 415. For the wrap-around engagement, a web 6410
embodied at the holding hook 641 extends obliquely to the middle
part 415 at an internal side of the middle part 415 in the
direction of the recess 412 of the balancing element body 4.
[0089] In the present case, the mounting tool 6 is embodied at
least in two parts, and in addition to the holding part 64 has a
rotating part 65. This rotating part 65 is embodied in a rod-shaped
manner and is mounted inside the sleeve portion 640 of the holding
part 64 so as to be rotatable and displaceable along a longitudinal
extension direction of the sleeve portion 640. At least in the area
of an end that can protrude from the sleeve portion 640 at an exit
opening 6400 of the sleeve portion 640 in the area of the holding
hook 641, the cross-sectional shape of the rotating part 65
corresponds to the inner contour of the tool interface 51 of the
screw 5 at the balancing element 3. In the present case, the
rotating part 65 is for example embodied with a hexagonal profile
to mesh with the tool interface 51 of the screw 5 in a form-fitting
manner.
[0090] If the balancing element 3 has been attached at the rotor
disc 21 by means of the mounting tool 6, so that the balancing
element body 4 of the balancing element body 4 held at the holding
hook 641 engages around an attachment section 22, a section of the
rotating part 65 is accessible, for example at a radially outer end
of the sleeve portion 640, so that a user can rotate the rotating
part 65 relative to the holding part 64. Through the rotation of
the rotating part 54, the screw 5 that is in mesh with the same is
then turned, and thus the balancing element 3 is fixated at the
attachment section 22, or such a fixation is released. Due to the
balancing element body 4 being held at the holding hook 641 of the
mounting tool 6 in a form-fitting manner, the mounting tool 6 can
also be used for displacing the balancing element 3 into another
balancing position at the rotor disc 21 if the fixation is
released.
[0091] To remove the mounting tool 6 from the balancing element 3
that is fixated according to the intended use, the rod-shaped
rotating part 65 is pulled radially outwards. Here, the end of the
rotating part 65 that is to be brought into mesh with the screw 5
is pulled into an exit opening 6400 of the sleeve portion 640
embodied at the radially inner end (cf. FIG. 10), so that the
rotating part 65 and the screw 5 of the balancing element 3 are no
longer in mesh. Subsequently, the holding part 64 is tilted so far
that the web 6410 of the holding hook 641 no longer engages around
the middle part 415 of the wrap-around section 41. Then, the
mounting tool 6 can be removed from the balancing element 3 through
the installation gap 100. Also in the mounted state of the rotor 2,
the mounting tool 6 can again be moved towards the balancing
element 3 through the installation gap 100, release the fixation,
and displace the balancing element 3 into another balancing
position.
[0092] In the embodiment variant of a rotor arrangement illustrated
by FIGS. 11A-11B and 12, an alternatively embodied multi-part
balancing element 3 is proposed. In this variant, it is not a
clamping head 50 and at least one leg section 410 or 411 that abut
the attachment section 22 for fixating the balancing element 3 at
an axially projecting attachment section 22 of the rotor disc 21.
Rather, here two facing leg sections 41a and 410 are provided for
clamping abutment at the attachment section 22. Here, a fixation
element in the form of a screw 5 for the clamping fixation of a
balancing element body 4 forming the two leg sections 41a and 410
at a wrap-around section 41 is provided for reducing the distance
between the first and the second leg sections 41a and 410.
[0093] The screw 5 extends through a passage opening at the second
leg section 410 that is located radially inside in the mounted
state, and engages behind this second leg section 410 with a
clamping head 50. Thus, the contact surface 500 formed at the
clamping head 50 of the screw 5 abuts a radially inner side of the
second leg section 410. If the screw 5 is tuned via its tool
interface 51, so that the screw 5 is displaced into a radially
outwards pointing direction, the clamping head 50 presses against
the second radially inner leg section 410 and presses it in the
direction of the other, first radially outer leg section 41a. The
part of the attachment section 22 around which the leg sections
41a, 410 of the wrap-around section 41 of the balancing element
body 4 are engaged is thus clamped in between the two leg sections
41a and 410.
[0094] In order to optionally allow for an elastic displacement of
the two leg sections 41a and 410 towards each other and away from
each other through the rotation of the screw 5, they are connected
to each other by means of a presently convexly curved connection
portion 416 that allows for a displacement of the one leg section
410 relative to the other leg section 41a.
[0095] In order to avoid having to provide bores for the screw 5 of
the balancing element 3 at the (blisk) rotor 2, a shaft 53 of the
screw 5 extending between the leg sections 41a and 410 extends in
an axially offset manner with respect to a front face of the
attachment section 22. Thus, the shaft 53 of the screw 5 extends
past the attachment section 22 and not through the same.
[0096] In a possible further development of the embodiment variant
of the FIGS. 11A-11B and 12, the balancing element body 4 can also
be embodied with two radially inner leg sections 410 and 411
analogously to the embodiment variant of FIGS. 6A-6B. In that case,
the leg sections could consequently be displaced in the direction
of a (single) radially outer leg section 41a by rotating the screw
5, and could thus be pressed against the attachment section 22 (in
particular against a divided attachment section corresponding to
FIGS. 7A to 8B) to fixate the balancing element 3 in a desired
balancing position at the rotor disc 21 of the rotor 1 in a
releasable manner.
[0097] In the embodiment variant of a rotor arrangement that is
illustrated in the different views of FIGS. 13A and 13B, what is
again provided, analogously to the embodiment variant of FIGS.
11A-11B and 12, is a balancing element 3 with facing leg sections
41a and 410 that can be moved closer to each other by means of a
screw 5 as the fixation element in order to fixate the balancing
element 3 at the attachment section 22. Here too, the clamping head
50 of the screw 5 engages behind the radially inner leg section 410
and thus presses the leg section 410 to the attachment section 22
when the screw 5 is turned. However, in contrast to the variant of
FIGS. 11A to 11B and 12, in this case the balancing element body 4
is provided with a connection portion 416 that is only barely
curved or not curved at all, and that connects the two leg sections
41a and 410 to each other. In this way, the balancing element body
4 is more slim and requires less installation space. A reduced wall
thickness is provided at the connection portion 416 for the
displaceability of the two leg sections 41a and 410 with respect to
each other, and thus as certain degree of flexibility is introduced
in a targeted manner.
[0098] In the embodiment variant of a rotor arrangement that is
shown in FIGS. 14A to 14E in different views, a balancing element 3
mounted according to the intended use engages around an axially
projecting attachment section 22, with a section of the balancing
element body 4 abutting the radially outwardly positioned external
side 220 of the attachment section 22, and a section of the
fixation element abutting the radially inwardly positioned internal
side 221 of the attachment section 22, here in the form of the
clamping head 50 of the screw 5. Hence, here the attachment section
22 is enclosed between the balancing element body 4 and a section
of the fixation element 5 and is clamped between then if the
balancing element 3 is fixated according to the intended use.
Accordingly, in this case the mounting jaws 30 of the balancing
element 3, inside of which the enclosed part of the attachment
section 22 is received, are formed by a section of the balancing
element body 4 and the clamping head 50 of the screw 5.
[0099] As shown in the combined view of FIGS. 14A to 14E, the
clamping head 50 of the screw 5 engages behind the attachment
section 22 and, in the fixated state of the balancing element 3
according to the intended use, directly abuts the internal side 221
of the attachment section 22 via its contact surface 500. At the
opposite external side 220, the balancing element body 4 abuts the
attachment section 22 via an abutment surface 4100. In the present
case, the clamping head 50 is embodied in a disc-shaped manner and
thus has a contact surface 500 that is provided for abutment at the
attachment section 22, extending in a tilted manner with respect to
the extension plane of the shaft 53 of the screw 5. The abutment
surface 4100 of the balancing element body 4 is likewise beveled.
In the case of the contact surface 500 of the clamping head 50 as
well as in the case of the abutment surface 4100 of the balancing
element body 4, the respective bevel corresponds to a
correspondingly tilted course of the internal side 221 or the
external side 220 of the attachment section 22, so that, when the
screw 5 is tightened, a spline connection is provided on both sides
of the attachment section 22 and the balancing element 3 is aligned
to the attachment section 22 in a self-acting manner. This is
illustrated in particular based on the sectioned views of FIGS. 14A
and 14B.
[0100] At that, FIG. 14A shows the balancing element 3 in a
position in which the screw 5 is not yet tightened. Consequently, a
slot remains between the contact surface 4100 of the balancing
element body 4 and the external side 220 of the attachment section
22, as well as between the contact surface 500 of the clamping head
50 and the internal side 221 of the attachment section 22. The
balancing element 3 is thus still held at the attachment section 22
in a displaceable manner. FIG. 14B illustrates the balancing
element 3 that is then fixated at the attachment section 22 in a
clamping manner by tightening the screw 5.
[0101] The abutment surface 4100 of the balancing element body 4 is
formed at an (outer) leg section 41a that is located opposite the
clamping head 50. Projecting from this leg section 41a radially
inward are two cross webs 412a, 412b that are separated from each
other by a recess 412. Thus, when the balancing element 3 is
mounted at the rotor disc 21 according to the intended use, these
cross webs 412a and 412b project radially inward from the leg
section 41a. Each of these cross webs 412a and 412b extends in the
direction of the radially inwardly positioned internal side 221 of
the attachment section 22 if the balancing element 3 has been
attached at the attachment section 22 according to the intended
use, but without engaging around the attachment section 22.
[0102] The pair of cross webs 412a and 412b lock the balancing
element 3 against any twisting when the latter has been attached at
the attachment section 22. Further, the two cross webs 412a and
412b ensure the physical guidance of the balancing element body 4
at the attachment section 22 along the circumferential direction U,
so that here too the balancing element body 4 can be displaced
along the ring-shaped protruding attachment section 22 into the
desired balancing position until the screw 5 is tightened.
[0103] In the present case, the cross webs 412a and 412b extend on
both sides of the shaft 53 of the screw 5. Thus, the end of the
shaft 53 that transitions into the clamping head 50 extends inside
the recess 412 of the balancing element body 4 that is bordered by
the facing cross webs 412a and 412b.
[0104] In the rotor arrangement of FIGS. 14A to 14E, in the
assembled state of the engine T according to the intended use, the
clamping head 50 is further received inside an annular gap 7 that
is formed, on the one hand, by the axially projecting attachment
section 22 of the rotor 2 and, on the other hand, by an axial
projection 8 of the further engine component TK. If the rotor 2 and
the engine component TK are mounted according to the intended use,
the projection 8 of the engine component TK, which preferably
protrudes in the direction of the rotor disc 21 in a ring-shaped
manner, extends over the clamping head 50. Thus, on the one side,
the clamping head 50 faces towards the internal side 221 of the
attachment section 22 in the radially outwards pointing direction,
and, on the other side (at an axial distance to the internal side
221 of the attachment section 22), faces towards a bottom side of
the projection 8.
[0105] During mounting of the engine T or of a rotor assembly group
comprising the rotor 2 and the further engine component TK, the
balancing element 3 is initially fixated at the attachment section
22 of the rotor disc 21, so that the balancing element body 4 and
the clamping head 50 of the screw 5 engage around the attachment
section 22, without finally fixating the balancing element 3 at the
attachment section 22. The balancing element 3 is thus held in a
captive manner at the attachment section 22, but is still
displaceable at the attachment section 22 along the circumference.
Subsequently, the rotor assembly group, in which the rotor 2 forms
one stage and the further engine components TK form a further stage
of the high-pressure compressor 14, is assembled. In this manner,
the annular gap 7 is formed, inside of which the clamping head 50
is subsequently completely received. The balancing element 3 can
still be displaced into a desired balancing position in the
circumferential direction U, and can subsequently be fixated at the
attachment section 22 of the rotor 2 in a clamping manner by
tightening the screw 5. As can be seen in FIGS. 14A to 14E, for
this purpose the tool interface 51 of the screw 5 still remains
accessible from radially outside, even after rotor 2 and the engine
component TK have been assembled.
PARTS LIST
[0106] 100 installation gap [0107] 11 inlet/intake [0108] 12 fan
[0109] 13 medium-pressure compressor [0110] 14 high-pressure
compressor [0111] 15 combustion chamber [0112] 16 high-pressure
turbine [0113] 17 medium-pressure turbine [0114] 18 low-pressure
turbine [0115] 19 outlet [0116] 2 rotor [0117] 20 rotor blade
[0118] 21 rotor disc [0119] 22 attachment section [0120] 220
external side [0121] 221 internal side [0122] 223ac, 223bc gap
[0123] 22a, 22b outer attachment area [0124] 22c middle attachment
area [0125] 23 recess (intermediate area with reduced axial
extension) [0126] 3 balancing element [0127] 30 mounting jaws
[0128] 4 balancing element body [0129] 40 threaded section [0130]
400 internal thread [0131] 401 ledge [0132] 401 wrap-around section
[0133] 41a outer leg section [0134] 410, 411 inner leg section
[0135] 410a, 411a curvature [0136] 4100 abutment surface [0137] 412
recess [0138] 412a, 412b cross web [0139] 413, 414 force
introduction section [0140] 415 middle part [0141] 416 connection
portion [0142] 5 screw (fixation element) [0143] 50 clamping head
[0144] 500 contact surface [0145] 51 tool interface [0146] 52
securing ring (securing element) [0147] 53 shaft [0148] 6 mounting
tool [0149] 64 holding part [0150] 640 sleeve portion [0151] 6400
exit opening [0152] 641 holding hook [0153] 6410 web [0154] 65
rotating part [0155] 7 annular gap [0156] 8 projection [0157] A
primary flow channel [0158] B secondary channel/bypass channel
[0159] D1, D2 rotational direction [0160] K core engine [0161] M
central/rotational axis [0162] s slot [0163] gas turbine engine
[0164] TK engine component [0165] U circumferential direction
[0166] V1, V2 displacement direction
* * * * *