GB2581334A - Fan blade walker system - Google Patents

Abstract

A fan blade walker system 200, which connects to a fan of a turbine engine during maintenance, comprises a housing 201 having a clamp 202, which engages with the fan, a drive mechanism 204, a battery (302, fig 3), and a computer (308, fig 3) provided with pre-programmed command signals. The computer is instructed to perform a pre-set program by a user, the signals for this are applied to a motor controller (306, fig 3) which provides a current to a motor, which is applied to the drive mechanism, which causes the walker to rotate the fan according to the instructions of the pre-set program. A method of rotating a fan blade comprises mounting the fan blade walker system to the fan of a turbine engine using the clamp, such that the drive mechanism contacts an internal surface of a turbine engine casing. The controller is initialised, the motor is set up and gyroscopes are initialised. A communication link is established between the controller and a user input device. The computer is instructed to perform one of its programmed instructions by an input command through the communication link, and the computer is used to monitor for further input instructions.

Description

FAN BLADE WALKER SYSTEM

Field of the Disclosure

The invention relates to a system for controlling the rotation of a fan blade of a 5 gas turbine engine during maintenance.

Background of the Disclosure

Borescoping is a process in which an optical device is inserted into an object to allow for visual inspection of objects that are inaccessible by other means.

During the borescoping inspection of a gas turbine engine the maintenance engineer needs to be able to insert a flexible camera into the engine through purpose designed ports. Once the camera is in position the fan is then rotated to drive the low pressure compressor and turbine causing rotation of the blades for inspection. Currently, when this is performed two operators are employed, one operator works the camera system and is positioned at the camera inspection area, the second operator is responsible for rotating the fan blade to the desired position or at a desired speed. Communication between the two operators is carried out through verbal instruction, wherein the person in charge of the camera gives instructions to the person turning the blade to rotate it to a given set of instructions. Such a system therefore, ties up two engineers and is also not as safe, as would be desired, in a noisy environment. The instructions of the operators may not be heard, which could result in potential injury to the operators and/or damage to the inspection equipment and/or the engine.

With the advent of geared gas turbine engines and the development of engines which have shorter intakes this process is also becoming more physically onerous on the operators whilst safety levels are reduced. This is because the operator has to apply a greater force to rotate the blades, whilst the smaller intake provides less room for stabilisation. This system is also limited by the accuracy of the movement, because a human operator will find it difficult to perform the operation to a repeatable set of conditions, such that identical tests can be carried out across a number of engines. Furthermore, it is desirable to reduce the number of skilled engineers who are employed in performing these inspections. This would act to free engineers to work on other engines and thereby increase the efficiency of the maintenance, repairs and overhaul functions operations. As such it is desirable to achieve a safer means of rotating the blades for the inspection of the low pressure turbines and compressors.

Summary of the Disclosure

According to a first aspect there is provided a fan blade walker system for connecting to a fan blade of a turbine engine comprising; a housing having a clamp and a drive mechanism; the housing includes a battery, a motor controller, an electronic motor, and a computer which is provided with a store of preprogrammed command signals to be used to send commands to the motor controller; the drive mechanism comprises a converter for converting the output from the electronic motor into movement of the fan blade walker; the clamp engages with a turbine fan blade to maintain the fan blade walker system in a fixed position relative to the blade; the fan blade walker system being arranged to be operated by the computer, which is instructed to perform a pre-set program by a user, the signals for this are applied to the motor controller which in turn provides a current to the motor, which is in turn applied to the drive mechanism, which is capable of causing the walker to rotate the fan blade within its housing according to the instructions of the pre-set computer program.

The drive mechanism may comprise drive wheels or a tracked drive system.

Bias may be applied to the drive mechanism to force the drive mechanism away from the housing.

The motor may be a stepper motor.

The stepper motor may be a geared stepper motor.

The controller may be remotely operated, so as to perform movement commands based upon the input signals from an external device.

The external device and the controller may be linked via a BluetoothTM connection.

A counter balance may be used on a turbine blade opposite to the walker.

A second fan blade walker device may be used on another fan blade of the gas 5 turbine engine.

According to a second aspect there is provided a method of rotating a fan blade of a turbine engine comprising mounting a fan blade walker system as previously disclosed to the fan blade of the turbine engine, the method comprising: connecting the fan blade walker system to a fan blade of a turbine engine using the clamp, such that the drive mechanism contacts with an internal surface of a turbine engine casing; initialising the controller of the fan blade walker system, such that the motor is setup, the gyroscopes are initialised; establishing a communication link between the controller and an input device from the user; providing the computer with an input command through the communication link providing, such that the computer is instructed to perform one of its programmed instructions; and monitoring using the computer for any further input instructions.

The user input may cause the turbine to rotate a predetermined number of degrees.

The user input may cause the fan blade to rotate at a set pre-determined speed. 20 The input is provided remotely from an external device.

The external device may couple with the electronic controller via a BluetoothTM connection.

The computer may be configured to store within its memory information relating to the rotation of the walker system.

The information stored may relate to force applied to the drive mechanism to perform the pre-programmed instruction and any information provided by the gyroscope in the operation of the program.

A gas turbine engine that includes a gas turbine walker system as previously discussed.

The skilled person will appreciate that except where mutually exclusive, a feature described in relation to any one of the above aspects may be applied mutatis mutandis to any other aspect. Furthermore except where mutually exclusive any feature described herein may be applied to any aspect and/or combined with any other feature described herein.

Brief Description of the Drawings

Embodiments will now be described by way of example only, with reference to the Figures, in which: Figure 1 is a sectional side view of a gas turbine engine; Figure 2 is an illustration of a fan blade walker system of the present disclosure; Figure 3 is a schematic of an example of electronic circuitry that could be used 15 within the fan blade walker system of figure 2; Figure 4 is a schematic of the software architecture used in the fan blade walker system of figure 2; Figure 5 is a flow chart of the operation of the fan blade walker system of figure 2.

Detailed Description

With reference to Figure 1, a gas turbine engine is generally indicated at 10, having a principal and rotational axis 11. The engine 10 comprises, in axial flow series, an air intake 12, a propulsive fan 13, an intermediate pressure compressor 14, a high-pressure compressor 15, combustion equipment 16, a high-pressure turbine 17, an intermediate pressure turbine 18, a low-pressure turbine 19 and an exhaust nozzle 20. A nacelle 21 generally surrounds the engine 10 and defines both the intake 12 and the exhaust nozzle 20.

The gas turbine engine 10 works in the conventional manner so that air entering the intake 12 is accelerated by the fan 13 to produce two air flows: a first air flow into the intermediate pressure compressor 14 and a second air flow which passes through a bypass duct 22 to provide propulsive thrust. The intermediate pressure compressor 14 compresses the air flow directed into it before delivering that air to the high pressure compressor 15 where further compression takes place.

The compressed air exhausted from the high-pressure compressor 15 is directed into the combustion equipment 16 where it is mixed with fuel and the mixture combusted. The resultant hot combustion products then expand through, and thereby drive the high, intermediate and low-pressure turbines 17, 18, 19 before being exhausted through the nozzle 20 to provide additional propulsive thrust. The high 17, intermediate 18 and low 19 pressure turbines drive respectively the high pressure compressor 15, intermediate pressure compressor 14 and fan 13, each by suitable interconnecting shaft.

Other gas turbine engines to which the present disclosure may be applied may have alternative configurations. By way of example such engines may have an alternative number of interconnecting shafts (e.g. two) and/or an alternative number of compressors and/or turbines. Further the engine may comprise a gearbox provided in the drive train from a turbine to a compressor and/or fan.

The fan blade walker system 200 as shown in Figure 2 comprises a housing 201, with external clamps 202 for connecting the device to a fan blade. Inside of the housing is an electronics housing 203 which contains the control circuitry for the fan blade walker system. At the lower end of the electronic housing there is an electronic motor which powers the drive wheels 204. The motor housing and the wheels may be contained within their own separate enclosure, which is resistively pushed by a force generator 205. This could consist of compression springs which push the wheels outwards onto the fan casing. This biasing resulting from the force generators forces the drive wheels onto the surface of the fan casing to increase the traction of the drive wheels, and thus reduces the chances of slippage of the wheels. Alternatively, the springs may instead force the axle/driveshaft of the device downwards with a suitable force and configuration. The configuration of the hardware as presented in Figure 2 is only an example of the possible configurations of the device that would be apparent to the person skilled in the art.

The clamps can be any suitable clamps for connecting the device to the blade.

This can be a mechanical vice clamp which may be tightened via a screw or ratchet drive; it could also be a hydraulic or pneumatic vice for controlled application of pressure to the blades. Vacuum, suction or magnetic clamping could also be used to maintain the fan blade walker system in position. The clamping surface may also be angled to accommodate connection to different blade surfaces or profiles. The clamp face may also feature a pre-shaped surface to provide a greater contact surface when gripping the blade. Alternatively a strap mechanism can be used with either a ratchet clamp or another suitable mechanism. Figure 2 shows the presence of two clamps, in this the two clamps may be of different types, or could both be the same.

Alternatively, there could be a single clamp used or more than two clamps. Similarly, the fan blade walker system can be positioned between two pairs of blades with the clamps being connected to the ends of two arms extending from the body of the fan blade walker system and which are able to engage with adjacent blades, so that the force applied to the blades in opposite directions maintains the fan blade walker system in position. This force could be applied using any suitable method. Alternatively, the fan blade walker system may be clamped to both of the blades in a way as described above in relation to clamping a single blade or through the use of grippers connected to the ends of arms. Alternatively, the fan blade walker system can be connected to the spinner via an elongate arm, wherein the elongate arm has a suitable means of gripping the spinner or applying enough force between the spinner and the housing to maintain the fan blade walker system in position. This could be through the use of a pneumatic or hydraulic piston to apply the force or through the use of a telescopic arm which has locking features to maintain its length. Other suitable mechanisms may also be used. The connector to the spinner can be of any suitable configuration.

The housing/chassis can be manufactured from metal, such as sheets of aluminium, steel or from suitable plastics. These can be mounted on an internal frame, or the sides can be suitably connected together. The design can be of any suitable configuration depending upon the clamping mechanism. For example if, as shown, there are two clamping positions on a single blade then an elongate housing can be used to distribute the load along the blade. In a system which is coupled to the spinner or between the blades or with a single clamping point then the housing may be smaller. This will keep the centre of gravity closer to the blade housing. Similarly, the positioning of the hardware inside the housing may be configured to redistribute the centre of mass or gravity in the device to a suitable position. This may be to keep this in the centre of the housing with the centre of mass located directly between the drive wheels. Rather than the configuration presented in Figure 2 the electronic housing and the motor housing may be positioned together for ease of connection, or to reduce the size of the housing.

The system in Figure 2 is shown as having two wheels; however, there are configurations in which a single wheel or three or four wheels may be desirable. The wheels themselves may be solid and may be formed of a plastic or rubber material. Alternatively, they could be manufactured from a rubber or suitable compound surrounding a rigid rim/hub made from plastic or metal. A pneumatic tyre could alternatively be provided to the outside of this rim or hub. In other configurations the drive may be applied via a tracked or belt drive mechanism. A force generation system may be employed to push the drive wheels onto the housing of the fan blade. This could also be done using pre-tensioned springs, pneumatic, hydraulics or electromechanical actuators. The amount of force applied by the spring or actuators may vary depending upon the drive mechanism used, as well as the mass of the blade, the coefficient of friction of the housing among other things. Once the force required has been determined, the springs or actuators can be selected based upon these values and the drive requirements of the system. This force application system may be interchangeable, such that the device can be configured to work on other engines in a fleet of aircraft. Also, this interchangeable system may be desirable as the system can then work on either the front acoustic panel of the engine nacelle as well as the fan track liner, which may have different coefficients of friction.

The electronics module may be contained within its own housing as shown in Figure 2. This can be constructed out of any suitable material such as plastic or metal. Additionally, it may be constructed using any well-known fabrication process. This could be through attaching panels to a frame. Alternatively it could be fabricated by creating a 3D printed box. This box may contain the controller and associated circuitry for the motor, as well as the communication electronics. The battery may also be located within the housing. The reason a housing is desirable is that there is a need to maintain the control circuitry in a fixed orientation, so that the location of the fan blade walker system can be accurately determined. As such, it may be desirable that the housing is mounted to a structural component within the fan blade walker frame. Alternatively, the electronics and the motor may be contained within the general housing. The components in the electronics module could be separated by suitable partitioning. Alternatively they could be clipped or fastened to the inside of the housing.

As shown in Figure 3 the control circuit of the demonstrator module comprises a power supply 302 connected to a computer control unit 308 and to the motor driver 306. The computer control unit and the motor driver are also connected via ground and fixed voltage connection as well as through a pair of outputs one for the direction and one for the step. The motor driver is further connected to the stepper motor 310 via a number of paired connections. A ground line is also provided between the battery and the computer control unit as well as between the power supply and the motor driver. Fuses 304 may be positioned in the output lines between the power supply and the motor driver and the controller respectively. Other alternative circuits could also be used to control the circuit.

The motor in the fan blade walker system must be powerful enough to rotate the fan blade and the associated compressors and turbines on its own without any additional force applied. In some configurations, it may be beneficial for the fan blade may be moved by two fan blade walker systems of a similar configuration to that described above. The use of multiple devices can be beneficial as it increases the mechanical torque in the system. It can also be advantageous as such a configuration provides a means of balancing the blades. Alternatively, a counter balance of equal mass can be placed on the blade directly opposite - 180° -to the location of the fan blade walker system. This counter balance may be connected using any suitable means. The use of this will minimise any destabilising effects caused by the mass of the fan blade walker system being connected to one of the blades.

A computer control unit, preferably a single board computer is used to control the device. This computer control unit can support network connectivity from both Bluetooth-rm and Wi-Fi, and possibly other communication protocols such that the fan blade walker system can be controlled by any suitable device remotely. The computer control unit could be a commercially available device such as a BeagleBone BIueTM device or Raspberry PiTM or Arduino-rm microcontrollers or similar devices. Alternatively, a custom built computer could be used. Any such device would require an appropriate processor, memory, and input hardware, such as USB ports and wireless communication capability through Wi-Fi, Bluetooth-rm or Bluetooth low energy-rm (BLE) as well as their associated operating programs. The system can be programmed with any appropriate operating software, for example LinuxTM or AndroidTM. The purpose of the computer is to take the signals form the user and convert them into output commands based upon the pre-programmed user program on the computer control unit to the motor driver. The control circuitry may be provided with additional functionality, such as gyroscopes to determine the angle of the board. Accelerometers, and magnetometers, barometers and thermometers may also be provided. The information provided from these pieces of additional functionality may be stored on the computer, or transmitted to the user.

The motor driver requires signals to be provided. For example in the case of a stepper motor these two signals to be provided are -step and direction -form the computer board. A controller may be used to communicate these signals as it allows for a smoother motion of the motor and allows for greater power to be applied to the motor than can be transferred directly from the computer board. The current limiting circuit in the motor controller can be tuned to supply the maximum current at all times. The driver needs to be adapted to be able to deliver the maximum amount of current to the motor, in order to produce the maximum torque for the stepper motor. A stepper motor can be selected to meet the torque requirements of the system. As such the stepper motor may be geared to facilitate lower speed drive with higher torque. However, other configurations and suitable motors may be employed for the purpose of driving the fan blade, as would be apparent to the person skilled in the art.

In the fan blade walker system any suitable battery may be used to provide 5 power to the controller and the stepper motor drive and ultimately to the drive motor itself. One of the requirements is to have a battery with a compact size and high power density. An example of a battery that meets these requirements is a Lithium Polymer battery. These have the advantage that they are readily available and are lightweight with high power densities. Fuses may also be used 10 in the control circuit to increase the safety of the system and to limit the current within the electronic circuitry.

A schematic of the computer operation is shown in Figure 4. In this it shows the relationship between the central computer program and the input and library functions as well as with the output function. The main computer program 402 takes the user input 404 from the operators input device; this can be for example to rotate the fan blade walker system at a set speed. In doing this, the computer program also links to the input signal control library 408; this could be a BluetoothlM library, which is used in order to read the input signals. The input signals provided by the operators input device can be provided by any suitable means. The computer program also receives information from the stepper library 406 and the gyroscope library 410 to determine information about the status of the fan blade walker system before initiating the output signal. With all of this information the program is then able to determine output needs to be provided to the stepper motor controller 412, in order to move or to stop the fan blade walker system depending upon what was required by the user.

As outlined above the functioning of the main computer program is used in controlling the apparatus of the computer and then outputting commands to the motor controller in order to move the fan blade walker system. The computer may be programmed with any appropriate software and using any well-known programming language. Control can be provided via a BluetoothTM link, or through other appropriate wired or wireless connection links such as Wi-Fi. The computer is installed with a main control program which has three custom input libraries, from which it is able to control the fan blade walker system.

Provided is a basic installation and function library. This library is there to simplify the installation of the microprocessor outputs. For example if a desired output is required from a certain outlet port then the library provides the desired function for this to occur. This library is crucial to the operation computer, as it configures the computer to be able to convert the input commands from the control program on the user's device and turns these into an output command for the motor controller. For example, a command can be provided to the motor controller from the program for it to apply power to the motor and move the fan blade walker system at a constant speed in a constant direction. In this, there may be a number of options for the program to be able to perform this at different speeds as desired by the operator. Another option is upon receiving the input command the computer can control the rotation of the device to a specified position, in order to do so the program accesses the gyroscope on the computer to determine the current angle of the device it then moves the device to a target location based upon a target angle of the gyroscope and other functions. Once the fan blade walker system reaches the desired angle a command may be issued to stop the motor in that position. As such this gives the fan blade walker system the functionality to be rotated at a constant speed and the ability to rotate to a certain position such that the turbine and compressor blades can move to the operator's requirements. The output of the motor can be controlled so that the fan blade walker system is able to operate forwards or backwards, such that the blades could be rotated either clockwise or anticlockwise as desired by the operator. Also, the speed of the rotation can be controlled so that the fan blade walker systems moves at any suitable value. For example this could be a value between 1-12 revolutions per minute. Higher or lower values could be obtained if desired.

The second control library is an input control library this can be set up to couple the controller to the input communication systems on the board. For example this can be a BluetoothTM connection, in which case the library utilises the BluetoothlM adaptor on the processor board. This allows the board to receive commands at the standard BluetoothlM frequency, which can then be used by the main program to command the device. Other suitable communication protocols can be used such as Wi-Fi or any other wireless or wired communication methods to provide the control signals to an appropriate computer with the appropriate hardware installed. In the example of a BluetoothlM connection a setup command function is used, this sets up the boards BluetoothTM communication port on the computer and waits for a known device to connect. In this case, for safety reasons, the controlling device needs to be trusted and registered. Input device registration can be performed manually on the computer board, using an appropriate input command control tool. The second purpose of the second control library is to read the commands from the client/user from the input device program. This can be in the form of a single character or a command string. Alternatively, it could be a pre-prepared command associated with selecting a certain desired output on a control app installed on the input device. Once this input is read the main program will run this continuously until another command is entered or for as long as is required by a pre-set program. When the user first connects the controller or mobile device to the controller the system remains in a paused state. The fan blade walker system may also be able to link with the control system program so as to be self-aware; i.e. this is in terms of location such that it could provide an exact blade detail. It could also be able to determine the location of the appropriate blade in either the turbine or compressor system and be able to rotate the input fan to the degree required to be able to observe this blade more closely with the camera. This would ensure that all blades in the system can be accurately inspected and that the inspection of all of them is equivalent.

The control input program may be created or installed on any suitable device. This could be an application to run on a computer, or a hand held device such as a tablet or a phone or other such suitable device. The only requirement being that the device must be capable of communicating with the input processor circuit board. In other instances the program could carry the instructions for an entire borescoping process. Also, the program, which could be an app, may be configured to receive data from the computer so that recorded parameters from the operation of the fan blade walker system may be stored. This stored data could provide a comparison on the values recorded at every service for the engine. Analysis of this data may be able to provide information on the state of the engine, for example by recording the acceleration data, it may be able to determine if the friction in the system has increased and if so may be able to provide a warning to the operator, to investigate. Alternatively, it could record vibration, which may be able to determine issues with the fan casing or highlight alignment issues. The information stored could relate to the force applied to the drive mechanism to perform the pre-programmed instruction and any information provided by the gyroscope in the operation of the program. The information for this could be stored and used by the engineer or by a central system to track conditions of different engines in a fleet or used to build up an overall evaluation of issues within the range of engines. Alternatively, the data could be sent to a central location, such that a trained operator can look at it without having to be on site, and a technician is used to connect the fan blade walker system to the blade at the inspection site.

A function is also provided to set up the gyroscope on the control board, such that the fan blade walker system can be programmed to move to certain positions or angles as desired. The function initially runs a setup of the gyroscope and the other associated hardware, such as the accelerometer and magnetometers -if present. This set up allows the gyroscopic function of the board to work effectively. A void command then determines the various different Tait-Bryan angles of the device, by forming a composite of the readings from the gyroscope, accelerometer, and magnetometer in order to be able to determine the angle of the fan blade walker system accurately. Once this has been established, the device can then track these values as the fan blade walker system is moved to constantly monitor the position. The main control program is then able to run the main logic that uses the gyroscope and input commands from the operator to be able to control the device by providing appropriate commands to the motor about when and how to move, such that the blades rotate as desired.

Consequently, the control of the program is provided as shown in Figure 5. This is shown as a five-step process, but steps could be added or removed as appropriate. Step 1 is an initialization stage, which can run the bootup of the software used on the computer board and then sets the main code running after the computer board has undergone bootup. Step 2 runs the controller to set up the motor drive outputs on the computer board and is carried out through the motor output controller via the initialization library. Additionally, there may be the setup of the gyroscope and the associated hardware. This allows the controller to determine the position of the fan blade walker system. The input controller can be initiated, such that the hardware can be paired with the processor when the input is started. Furthermore, it starts the input controller so that it pairs with the input device. Once this is completed, Step 3 can be initiated in this the processor can start reading any of the inputs from the controller device and subsequently updates the commands delivered to the motor as appropriate. This input to the motor is dependent upon the signal entered into the program, for example it can set the motion to be continuous or a rotation of the device to a desired point. In Step 4 the computer program instructs the infrastructure to keep checking the user input, in order to determine if there have been any new commands issued to the device. In Step 5 the program instructs the hardware to react if there has been a command as listed in any of the preceding steps.

The commands to the program issued from the user input device can be in any suitable format. For example, there could be separate instructions to pause the fan blade walker system, and to operate it at 2, 4, 6, 8, 10, and 12 revolutions per minute in the clockwise direction. Alternatively sequential numbers could be used, or speeds in odd number values. The rotation direction could be either clockwise or anticlockwise. A command may be available for the device to check its position, which provides a real time read out from the device for the user, and can display all the relevant parameters on the user input device. Also there can be a separate capability for the device to be moved to a desired position. Finally a shutdown command can be used to instruct the instrument to shut down its electronic functionality, such that it is in a safe state and can be removed from the blades, or if the battery needs to be swapped or charged. The system is also configured to shut down if connection is lost with the user input terminal; this is to keep the operator and the system safe in such a case. Reset functionality can also be added to the system, such that if there is an issue with the device or communication with the operator lost a reset can be performed to initialise the system again.

An example device was constructed in an aluminium chassis, with two wheels protruding from the chassis. The wheels being connected to axles that are directly couple to the motor output. The motor was a geared stepper motor with a gearing ratio of 19:1. Depending upon the power output requirements different gearing ratios could be applied. The motor and wheels are contained within a separate motor housing which fits within the chassis, but which is able to move relative to it. The motor housing and the wheels were resistively biased using 4 springs each providing an outward force of 50 N; however, any suitable values could be used. For example, values of 5-100 N could be used depending upon the design requirements of the system. These springs are connected at their other end to a plate mounted on the chassis. Also contained within the chassis is the electronics housing containing the battery and control computer and the motor driver. The battery was selected as an 18.5 V Lithium Polymer battery, the computer was chosen as a Beaglebone BIueTM featuring Bluetoothml connectivity. This is a LinuxTM based controller specially designed for robotic devices. Also provided was a motor drive board to control the output power to the stepper motor, in this case a Pololu A4988 stepper motor driver was used, however, other suitable drivers may also be used instead. The output of the battery was controlled by the use of two 1 A fuses, to limit the current in the lines. The example used an upper mechanical vice like clamp, and a lower ratchet strap clamping mechanism. However, as discussed above, there are a number of other suitable clamping configurations that could be used.

It will be understood that the invention is not limited to the embodiments above-described and various modifications and improvements can be made without departing from the concepts described herein. Except where mutually exclusive, any of the features may be employed separately or in combination with any other features and the disclosure extends to and includes all combinations and sub-combinations of one or more features described herein.

Claims (16)

1. CLAIMS1. A fan blade walker system for connecting to a fan of a turbine engine comprising; a housing having a clamp and a drive mechanism; the housing includes a battery, a motor controller, an electronic motor, and a computer which is provided with a store of preprogrammed command signals to be used to send commands to the motor controller; the drive mechanism comprises a converter for converting the output from the electronic motor into movement of the fan blade walker; the clamp engages with a turbine fan to maintain the fan blade walker system in a fixed position relative to the blade; the fan blade walker system being arranged to be operated by the computer, which is instructed to perform a pre-set program by a user, the signals for this are applied to the motor controller which in turn provides a current to the motor, which is in turn applied to the drive mechanism, which is capable of causing the walker to rotate the fan about its housing according to the instructions of the pre-set computer program.
2. The fan blade walker system as claimed in claim 1 wherein the drive mechanism comprises drive wheels or a tracked drive system.
3. 3. The fan blade walker system as claimed in any preceding claim wherein a bias is applied to the drive mechanism to force the drive mechanism away from the housing.
4. The fan blade walker system as claimed in any preceding claim wherein the motor is a stepper motor.
5. 5. The fan blade walker system as claimed in claim 4 wherein the stepper motor is a geared stepper motor.
6. 6. The fan blade walker system as claimed in any preceding claim wherein the motor controller is remotely operated.
7. The fan blade walker system as claimed in claim 6 wherein the external device and the controller are linked via a BluetoothTM connection.
8. 8. The fan blade walker system as claimed in any preceding claim wherein a counter balance is used on a turbine blade opposite to the walker.
9. The fan blade walker system as claimed in any one of claims 1-7 wherein a second fan blade walker system is used on a turbine blade opposite to the walker.
10. 10. A method of rotating a fan blade of a turbine engine comprising mounting a fan blade walker system of any one of the preceding claims to the fan of the turbine engine, the method comprising: connecting the fan blade walker system to a fan blade of a turbine engine using the clamp, such that the drive mechanism contacts with a internal surface of a turbine engine casing, initialising the controller of the fan blade walker system, such that the motor is setup, the gyroscopes are initialised; establishing a communication link between the controller and an input device from the user; providing the computer with an input command through the communication link providing, such that the computer is instructed to perform one of its programmed instructions; and monitoring using the computer for any further input instructions.
11. 11. The method as claimed in claim 10 wherein the fan blade is rotated a predetermined number of degrees in response to a user input.
12. 12. The method as claimed in claim 11 wherein the user input causes the fan blade to rotate at a set pre-determined speed.
13. 13. The method as claimed in any one of claims 10-12 wherein the user input is provided remotely from an external device.
14. 14. The method as claimed in any one of claims 10-13, wherein the computer stores within its memory information from an operation of the walker system.
15. 15. The method as claimed in claim 14 wherein the information stored relates to force applied to the drive mechanism to perform the preprogrammed instruction and any information provided by the gyroscope in the operation of the program.
16. 16. A gas turbine engine that includes a gas turbine walker system of any one of claims 1 to 8.