Note: Descriptions are shown in the official language in which they were submitted.
CA 02581994 2007-03-08
ROTOR BLADE SYSTEM FOR ROTOR AND ROTOR CASE INSPECTION
FIELD OF INVENTION
The present invention relates to an inspection system. More specifically, the
invention
relates to a rotor blade system for inspecting the position of a compressor
rotor in
relation to a compressor rotor case thereof.
BACKGROUND OF THE INVENTION
The inspection of a compressor case is generally conducted by measuring a gap
between the tip of rotor blades and the compressor case.
The rotor blades and the blade path of the compressor case are an area of
critical
concern both in the assembly and the operation of turbine engine technology,
in
particular gas turbine engine technology used in the aerospace industry.
Incorrect
positioning of the compressor rotor within its respective compressor case will
result in
dubious performance parameters leading to blade clearance variations.
Accordingly,
blade clearance can vary over the operating points of a gas turbine engine
including
during ground idle, takeoff, cruise or deceleration as well as over the cycle
life of the
engine. These variations can be due to a number of factors including loads on
both
static and rotating parts and the wear of these parts. In certain situations
excessive
blade clearance between the rotor blades and surrounding case can result in
reduced
engine efficiency, as a result the performance of the gas turbine engine can
be
adversely affected. A number of systems have been developed in an attempt to
reduce
blade tip clearance problems found in gas turbine engines. More specifically,
off-centre
positioning of the compressor rotor will increase the clearance in one area
around a
circumference of the compressor case but at the same time inadvertently
increase the
risk of a tip rub situation in opposite areas of the compressor case
circumference.
United States Patents No's US 6,949,939; 5,497,101; 5,166,626; US 5,140,494;
and
US 4,071,820 disclose the use of probe members particularly adapted to be
inserted
and fixed in one or more positions within and around the compressor casing of
gas
-1-
CA 02581994 2007-03-08
turbine engines. Systems used for determining turbine blade clearance
incorporate
capacitance tip clearance systems to measure the capacitance between the fixed
probe and the blade tip. Some of those systems require the full working of the
turbine
engine to put into affect their system. In particular, methods applied to
position the
compressor rotor relative to the compressor case rely on shims used in each
quadrant
around the compressor case circumference between the blade tips and case.
However, in an attempt to optimize compressor rotor performance and
subsequently
reduce blade tip clearance problems, the accuracy of those systems and methods
appear to be compromised by the very nature of the systems and methods used
resulting in the aforementioned problems including but not limited to engine
lock-up.
In order to overcome the disadvantages of the prior art, the present invention
provides
a rotor blade system for inspecting and optimizing the performance parameters
of
rotors used for example, in turbine engines, in particular gas turbine engines
used in
the aerospace industry.
SUMMARY OF INVENTION
An object of the invention is to provide a method tools thereof for producing
information
to correctly align a compressor rotor within a compressor case to achieve the
benefits
of minimized tip clearance and enhanced performance of a rotor. More
specifically, the
present invention accurately determines performance parameters to optimally
align a
compressor rotor within a compressor case. In particular, the invention
relates to a
rotor blade system for inspecting a blade path on the circumference of a
compressor
rotor case for determining the position of the compressor rotor with respect
to the
compressor rotor case using wireless, wired or both communication link, a
laser probe,
capacitance probe or both to scan about a compressor rotor blade path of the
compressor rotor case. A rotor positioner having an encoder, transmitter,
receiver or
combinations thereof associated with the rotor positioner. The system uses
information
gathered about the position of the compressor rotor in relation to information
gathered
about the compressor rotor case to produce accurate and efficient operational
-2-
CA 02581994 2007-03-08
performance parameters for the safety and economical use of compressor rotors
used
within their respective surroundings.
In an aspect of the present invention there is provided a rotor blade system
for
inspecting a position of a compressor rotor within a compressor rotor case,
the system
comprises a probe holder dimensioned for releasable attachment to a rotor
blade of
said compressor rotor, a first fixture for immobilizing the rotor blade, a
second fixture
for operably moving said probe holder and a probe thereof about a rotor blade
path of
said compressor case.
In a further aspect the present invention provides a method for inspecting a
position of
a compressor rotor within a compressor rotor case, including the steps of a)
releasably
securing a first fixture to a compressor rotor blade for immobilizing said
rotor blade,
b) releasably securing a probe holder and probe thereof to the rotor blade for
scanning
a rotor case blade path and transmitting collected information thereof, c)
establishing
a zero-point between said probe and the rotor case, d) releasably attaching a
second
fixture to a central portion of said compressor rotor case; and e) actuating
the second
fixture for rotating the compressor rotor at least one revolution about the
rotor case
blade path.
In an even further aspect the present invention provides a probe holder
comprising a
body dimensioned for releasably securement to a rotor blade thereof, said body
further
dimensioned for retaining a signal transmitter, a scanning device or both.
A further aspect of the present invention provides a kit for applying
implements,
fixtures, probe holders and probe thereof with the means for interpretation of
the
gathered data for example with computer related software like for instance the
commercially available AccuScan@.
In a preferred embodiment of the present invention the probe holder includes a
scanning device in the form of a probe which is used for operably scanning the
blade
path for retrieving and transmitting information about the blade path. The
probe is a
laser probe, a capacitance probe or both. Preferably the scanning device is a
laser
-3-
CA 02581994 2007-03-08
probe having a signal transmitter for wireless, wired or both forms of
communication
to a computer.
In a further preferred embodiment the probe holder is made of a non-
scratchable
material for preventing damage to a surface of the rotor blade, that material
being
natural, manmade or both.
A further aspect of the present invention provides a first implement for
releasable
engagement of the probe holder having a hinged body with an operably actuated
proximal handle for effecting a toothed jaw of a distal portion of said body.
A further aspect of the present invention provides a first fixture for
immobilizing the
compressor rotor blade of the compressor rotor having a hex-bolt operably
connected
to a cam lock, said hex-bolt actuated with a turn of a hexagonally dimensioned
tool for
introducing in to a hexagonal receiving aperture of the hex-bolt for operably
immobilizing the rotor blade.
An even further aspect of the present invention provides a second fixture for
operably
moving the probe about a circumference of said rotor blade path having a body,
a
handle attached therefrom, an elongate member extending centrally from a
proximal
end of said body to a distal end thereof for complementary engagement with
said
compressor rotor, said body further comprising a receiver, encoder,
transmitter or
combinations thereof.
Another aspect of the present invention provides a second implement having a
tapered
body for setting a pre-determined distance between the probe and the rotor
case, said
body having distal and proximal ends, said proximal end held by the end user
said
distal end used for establishing said distance.
In a preferred embodiment of the present invention, the inspection kit is used
for
inspecting a position of a compressor rotor within a compressor rotor case
having a
probe holder for securing a probe, said holder being dimensioned for
releasable
attachment to the rotor blade with a first fixture used for immobilizing said
rotor blade.
-4-
CA 02581994 2007-03-08
In a further embodiment of the present invention, a first fixture has a hex-
bolt
connected to a cam lock, said hex-bolt being operably actuated with a turn of
a
hexagonally dimensioned tool for immobilizing the rotor blade, the tool being
operably
introduced in to a hexagonal receiving aperture of the hex-bolt.
In a further preferred embodiment, the present invention provides a second
fixture for
releasable attachment to the compressor rotor, compressor rotor case or both
for
operably moving said probe about said rotor blade path. The second fixture
having a
body, a handle attached therefrom, an elongate member extending centrally from
a
proximal end of the body to a distal end for complementary engagement with a
portion
of the compressor rotor, the second fixture also having an encoder,
transmitter,
receiver or a combination thereof that are releasably attached thereon or
therein or
both.
A further embodiment of the present invention provides a first implement of
the kit for
releasably engaging the probe holder, the first implement having a hinged body
with
an operably actuated proximal handle for effecting a toothed jaw of a distal
portion of
the body. A second implement of the kit of the present invention preferably
provides
for setting a pre-determined distance for establishing a zero-point between
the probe
and the rotor case, said second implement having an elongate, tapered body for
ease
of insertion and measurement.
In a preferred embodiment, the present invention provides the probe holder of
the
inspection kit with a body dimensioned for receiving and transmitting
information from
said probe holder, probe or both, the body is furtherdimensioned for receiving
the rotor
blade of the compressor rotor. In an even further embodiment of the present
invention
part of the body is made of a non-scratchable manmade or natural material for
preventing damage to a surface of the rotor blade, in particular the material
would be
nylon.
In an aspect of the present invention the inspection kit uses a wired, non-
wired or both
communication link for transmitting information from a laser probe, a
capacitance
probe or both. The capacitance probe would be a non-contact capacitance
-5-
CA 02581994 2007-03-08
probe.These and other features of the invention will become more apparent from
the
following description in which reference is made to the appended drawings
wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1. is a representational view of a rotor blade system;
Figure 2. is a perspective view of embodiments of the rotor blade system of
the
present invention;
Figure 3. is a side view of embodiments of the rotor blade system of the
present
invention;
Figure 4. is a top and side view of the probe holder and probe thereof of the
present
invention;
Figure 5. is a top and side view of the cam lock of the present invention;
Figure 6. is a side view of the first implement of the present invention; and
Figure 7, is a side view of the second implement of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Although other applications may be envisioned for inspection systems of
compressor
rotor cases and the rotor blade path thereof, the application of the present
invention
is particularly advantageous for accurately determining the position of a
compressor
rotor within its respective compressor case. Accordingly, without intending to
limit the
present invention to the embodiments described herein, the invention will be
described
below in further detail having regard to the system, a method and apparatus
applied
in the system and in particular the use of specialized equipment for the probe
inspection system including features used therein as shown in Figures 1 to 7.
Figure 1, shows an embodiment of the present invention providing a rotor blade
system. A probe holder 2 has a probe 1, the probe holder 2 is attached to a
rotor blade
4 of a compressor rotor 6 using means to secure the probe holder 2 to prevent
movement of the probe 1 about the rotor blade 4 when in scanning motion about
a
blade path (not shown) of a compressor case 7. A probe holder 2 in accordance
with
a preferred embodiment of the present invention is releasably attached to the
rotor
blade 4 to secure the probe 1 thereon or therein. The probe holder 2 has
apertures 2a
for releasable engagement with a fist implement 12 of the probe holder 2 and
probe
-6-
CA 02581994 2007-03-08
thereof to attach the probe holder 2 to the rotor blade 4, the first implement
12 being
operably engaged to releasably attach the probe holder 2 and probe 1 thereof
to the
rotor blade 4. There is provided a first fixture 3, 3a (Cam lock 3 with Hex-
bolt 3a) to
immobilize the rotor blade 4, and a second fixture 5 (rotor positioner with an
encoder
therein) for releasable attachment to a housing of a compressor module 11 for
operable movement of said probe 1 about said rotor blade path (not shown) and
for
determining the relative position of the rotor 6 in relation to the compressor
case 7. In
accordance with a preferred embodiment of the present invention the second
fixture
5 gathers information about the position of the compressor rotor 6 and encodes
that
information for transmission to the computer and monitor 10 thereof. The probe
holder
2, the probe 1 or both can establish in accordance with a preferred embodiment
of the
present invention a communication Iinkto transmit information from a signal
transmitter
1 a, the probe 1, the probe holder 2 or a combination thereof to the computer
10, the
second fixture 5 or both. In a preferred embodiment the signal transmitter 1a
may be
linked to or be part of the probe 1, probe holder 2 or both. The transfer of
information
(not shown) may be in the form of wireless, wired, optical, radio frequency or
a
combination thereof. The probe 1, according to a preferred embodiment of the
present
invention, is a laser, capacitance, contact, non-contact probe 1 or a
combination
thereof. In a preferred embodiment the probe 1 is a laser probe 1. More
preferably the
probe 1 is a wireless laser probe 1. Figure 1 further shows the second fixture
5 (rotor
positioner with encoder therein) according to an embodiment of the present
invention.
The second fixture has a handle 8 for operably moving the rotor 6, the first
fixture 3,3a,
the probe holder 2 and the probe 1 thereof about a circumference of a
compressor
case 7 of a compressor module 11. The encoder of the rotor positioner 5 has a
communication link therein which includes but is not limited to an encoder
cable 9 for
communicating with the AccuScan computer software and monitor 10 thereof. The
rotor positioner 6 receives, encodes and transmits information about the
relative
position of the compressor rotor in relation to the compressor rotor case. The
rotor
positioner 6, in a preferred embodiment of the present invention, includes
further
means for communicating with the computer 10. The rotor positioner 6 with
encoder
therein can communicate coded signals to the computer 10 by wireless, wired,
infra-
red, radio frequency or combinations thereof.
-7-
CA 02581994 2007-03-08
Prior to the attachment of the probe 1 or probe holder 2 and probe 1 therein
or
thereon, the rotor blade 4 is secured and immobilized in accordance with an
embodiment of the present invention with the attachment of a first fixture 3,
3a (as
shown in figure 5) to the rotor blade 4. The cam lock 3 is adjusted about the
hex-bolt
3a which is moveably attached therethrough. A hexagonal aperture of the hex-
bolt 3a
is actuated with a commonly known Allan wrench (not shown) to engage and
immobilize a rotor blade 4 to a further rotor blade 4 thereby increasing the
rigidity of
the rotor blade 4 with the probe 1 thereon and decreasing vibration of those
blades to
effect an effective and efficient scan of the blade path.
Figure 2 and 3 show the rotor positioner 5 with an encoder cable 9 according
to a
further embodiment of the present invention. Figure 3, shows the probe 1 in a
desired
position in relation to the compressor rotor case 7 of the compressor module
11.
Figure 4, shows the probe holder 2 with probe 1 therein according to an
embodiment
of the present invention. The probe holder 2 with probe 1 therein is initially
engaged
with the first implement 12 according to a preferred embodiment of the present
invention. The first implement 12 having teeth 15 extending from the distal
end 16. The
teeth 15 of the first implement 12 operably engage apertures 2a of the probe
holder
for correct positioning of probe holder 2.
Prior to the compressor rotor 6 being engaged, a gap between the compressor
rotor
case 7 and the probe 1 is set using a second implement 17 in accordance with
an
embodiment of the present invention. Figure 7 shows the tapered body 18 of the
second implement 17 having a proximal end 19 and a distal end 20. The tapered
body
18 is dimensioned for ease of use when pre-setting a zero-point between the
probe 1
and the compressor case 7 (may also referred to as the rotor housing).
Embodiments of the present invention provide an inspection system which can be
used in various engine types including but not limited to: T56/501, AE21 00,
AE3007,
CF34, PT6, PW100, Vericor's ASE models, LM1600, CFM56, TF33, J85; PW2000,
JT8D, F100, F110, F404. In particular, the probe inspection system of the
present
invention can be used for the Rolls Royce T-56, which operates in the C-130
Hercules
aircraft. More specifically, the inspection system of the present invention
uses the
-8-
CA 02581994 2007-03-08
the rotor positioner with encoder 5 as shown in figures 1, 2 and 3 for
generating
information to aid in aligning the compressor rotor 6 within its respective
compressor
case 7. For example, the system of the present invention can be applied to a
compressor module 11 as shown in figures 1 to 3.
INDUSTRIAL APPLICABILITY
The rotor blade system of the present invention provides an economical and
accurate
system for determining crucial parameters of rotor case dimensions of
compressor
rotors as found in gas turbine engines of a type used in the aerospace
industries and
elsewhere. Compared to other systems known to those skilled in the art, the
present
invention accurately determines performance parameters to optimally align a
compressor rotor within a compressor rotor case, in a sequential or
synchronized way
by reducing the number of probes used, by having at least one probe that can
include,
a contact or non-contact, capacitance probe, laser probe used alone or in the
case of
the laser probe with for example reflective devices and by applying the unique
implements/tools and fixtures of the present invention to effect an economical
and
accurate rotor blade system. The rotor blade system in kit form of the present
invention
can be used when applying the kit having the implements, fixtures, probe
holders and
probe thereof of the present invention accompanied with the means for
interpretation
of the acquired data, for example with computer related software like for
instance the
commercially available AccuScan'8~ In particular, the inspection kit is used
for
inspecting a position of a compressor rotor within a compressor rotor case
having a
probe holder for securing a probe, said holder dimensioned for releasable
attachment
to a rotor blade, a first fixture for immobilizing said rotor blade. The fist
fixture having
a hex-bolt connected to a cam lock, said hex-bolt being operably actuated with
a turn
of a hexagonally dimensioned tool for immobilizing the rotor blade, the tool
would be
operably introduced in to a hexagonal receiving aperture of the hex-bolt. The
inspection
kit would also have a second fixture for releasable attachment to the
compressor rotor,
compressor rotor case or both for operably moving said probe about said rotor
blade
path. The second fixture having a body, a handle attached therefrom, an
elongate
member extending centrally from a proximal end of the body to a distal end for
complementary engagement with a portion of the compressor rotor, the second
fixture
-9-
CA 02581994 2007-03-08
fixture also having an encoder, transmitter, receiver or a combination thereof
that are
releasably attached thereon or therein or both.
A first implement of the kit is used for releasably engaging the probe holder,
the first
implement having a hinged body with an operably actuated proximal handle for
effecting a toothed jaw of a distal portion of the body. An inspection kit
would also have
a second implement for setting a pre-determined distance for establishing a
zero-point
between the probe and the rotor case, said second implement having an
elongate,
tapered body for ease of insertion and measurement. The probe holder of the
inspection kit also has a body dimensioned for receiving and transmitting
information
from said probe holder, probe or both, the body is further dimensioned for
receiving the
rotor blade of the compressor rotor, part of the body is made of a non-
scratchable
manmade or natural material for preventing damage to a surface of the rotor
blade, in
particular the material would be nylon. The inspection kit would use a wired,
non-wired
or both communication link for transmitting information from a laser probe, a
capacitance probe or both. The capacitance probe would be a non-contact probe.
-10-
