Gas turbine rotor positioning device

Abstract

A device for positioning the rotor of a gas turbine by linearly actuating a piston rod that actuates on its end a ratched wheel that moves the rotor of the gas turbine. The device includes an eccentric wheel and a synchronous motor. The piston rod is moved through the eccentric wheel, which is connected to the synchronous motor. The device also includes an incremental counter controlling the angular position of the synchronous motor. The device can permit accurate positioning of the rotor for boroscopic inspection.

Claims

1. A device for positioning a rotor of a gas turbine, the device comprising: a linearly movable rod that is moveable to actuate a ratched wheel coupled to the rotor of the gas turbine, the ratched wheel coupled to the rotor such that the rotor is rotatable via motion of the ratched wheel; an eccentric wheel connected to the rod such that rotation of the eccentric wheel drives linear motion of the rod; a motor connected to the eccentric wheel to rotate the eccentric wheel to drive linear motion of the rod; a motion controller connected to the motor such that said motor is controlled by the motion controller, the motion controller configured to calculate a trigonometric trajectory conversion from rotary movement of the motor to linear movement of the rod, the motion controller also configured to calculate torque needed for linear force required for the linear movement of the rod to be driven via rotation of the eccentric wheel to be driven by the motor.

2. The device according to claim 1, wherein the motion controller comprises a frequency converter, which varies rotation speed of the motor to define a speed and stroke of the rod.

3. The device according to claim 2, wherein the frequency converter varies the output torque of the motor.

4. The device according to claim 1, wherein the motor is a synchronous motor.

5. The device according to claim 4, also comprising: an incremental counter controlling an angular position of the synchronous motor.

6. The device according to claim 1, wherein an end of the rod is connected to the ratched wheel.

7. A gas turbine comprising a device according to claim 1.

8. The device according to claim 1, comprising: a frequency converter connected to the motor to vary rotational speed of the motor; an incremental counter connected to the motor, the incremental counter configured to facilitate control of an angular position of the motor.

9. The device according to claim 8, wherein the motor is a synchronous motor.

10. The device according to claim 8, wherein the ratched wheel encircles the rotor of the gas turbine.

11. A method of performing a boroscpic inspection of a gas turbine having a rotor, comprising: providing the device of claim 1; actuating the motor to rotate the rotor; and performing boroscopic inspection of the rotor.

12. The method of claim 11, wherein the rotor is rotated without rotation of the rotor being driven by a hydraulic cylinder.

13. The method of claim 11, wherein the device is an electromechanical device.

14. The method of claim 11, comprising: adjusting a circumferential position of the rotor via the actuating of the motor to rotate the rotor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The foregoing objects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description when taken in conjunction with the accompanying drawings, wherein.

(2) FIG. 1 shows a schematic view of the configuration of the electromechanical device for positioning the rotor of a gas turbine, according to the present invention within the gas turbine configuration.

DETAILED DESCRIPTION

(3) The present invention relates to a device for positioning the rotor 2 of a gas turbine in an accurate way. The device comprises a piston rod 11 that linearly moves a ratched wheel 1 of which is moving the rotor 2 of the gas turbine. The drive mechanism 10 comprises an eccentric wheel 12 and a drive means, preferably a synchronous motor 14. The piston rod 11 is moved through the eccentric wheel 12, connected to the synchronous motor 14.

(4) The synchronous motor 14 of the drive mechanism 10 allows a precise control of its angular position via the incremental counter 22.

(5) The frequency converter 21 can vary the rotation speed of the synchronous motor 14 which determines the speed and position of the piston rod 11 as well as the output torque of the synchronous motor which allows a definition of the exerted linear force.

(6) The trigonometric trajectory conversion from the rotary movement of the synchronous motor 14 to the linear movement of the piston rod 11 is calculated by a motion controller 20. The motion controller 20 also calculates the torque which is needed for the defined linear force.

(7) Thanks to the positioning device according to this invention, the rotor 2 can be precisely adjusted in its circumferential position.

(8) Some of the main advantages provided by the device of the invention are the following: a more accurate positioning of the rotor 2 is obtained; for proceeding boroscopic inspections, only one person is needed; the risks of injuries are highly minimized as nobody needs to act on the rotor 2 or turn it manually; hot boroscopic inspection could be done; the rotor 2 of the gas turbine can be turned in a more variable way.

(9) Although the present invention has been fully described in connection with preferred embodiments, it is evident that modifications may be introduced within the scope thereof, not considering this as limited by these embodiments, but by the contents of the following claims.