US20090226306A1

US20090226306A1 - Apparatus and method for adjusting a bearing array in a gas turbine aircraft engine

Info

Publication number: US20090226306A1
Application number: US11/816,618
Authority: US
Inventors: Alexander Boeck; Carsten Schoenhoff
Original assignee: Individual
Current assignee: MTU Aero Engines AG
Priority date: 2005-02-19
Filing date: 2006-02-08
Publication date: 2009-09-10
Also published as: WO2006086945A1; EP1848877A1; DE102005007776A1

Abstract

An apparatus and method for adjusting a bearing array, specifically for a gas turbine aircraft engine, is disclosed. The bearing array has a first stator-side, or fixed, bearing ring and a second rotor-side, or rotating, bearing ring, where rolling elements are located between the stator-side bearing ring and the rotor-side bearing ring. Transducers are assigned to the stator-side bearing ring to determine the position of the stator-side bearing ring and actuators govern the position of the stator-side bearing ring.

Description

This application claims the priority of International Application No. PCT/DE2006/000209, filed Feb. 8, 2006, and German Patent Document No. 10 2005 007 776.5, filed Feb. 19, 2005, the disclosures of which are expressly incorporated by reference herein.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a bearing array, specifically for a gas turbine aircraft engine.
In gas turbine engines rotors, rotating rotor blades for example, are carried rotatably opposite a stator, for example a fixed housing and similarly fixed guide vanes. Bearing arrays for carrying the rotor opposite the stator have a stator-side, or fixed, bearing ring and a rotor-side, or rotatable, bearing ring, where roller elements are positioned between the stator-side bearing ring and the rotor-side bearing ring. Hydraulic damping elements, known as squeeze-film dampers, are usually located on the stator-side bearing ring which damp the vibrations of the rotor. Such squeeze-film dampers allow a radial displacement of the bearings on the order of up to 0.2 mm.
To optimize the efficiency of gas turbine aircraft engines, gaps between the rotor and the stator must be minimized. The gaps in question are, for example, gaps between a hub of the rotor and radially inward lying ends of fixed guide vanes and gaps between radially outward lying ends of the rotor blades and a fixed housing. To maintain these gaps precisely and thus optimize the efficiency of the gas turbine aircraft engine, one of the necessary considerations is exact positioning of the rotor relative to the stator. When a gas turbine aircraft engine is operating, forces or moments affect the bearing arrays, for example as the result of maneuvering loads. As the result of maneuvering loads, operating forces or moments, primarily the housings are deformed, which results in worse gap characteristics. Maneuvering loads further cause undesirable bearing displacement in the case of bearings damped using squeeze-film dampers. This makes it more difficult to position the rotor precisely relative to the stator and to maintain an exact gap between the stator and the rotor.
With this as the starting point, the problem underlying the present invention is create a new type of bearing array.
In accordance with the invention, transducers are allocated to the stator-side bearing ring on the one hand to determine the position of the stator-side bearing ring, and actuators on the other hand to govern the position of the stator-side bearing ring.
In the meaning of the present invention, it is provided to allocate several transducers and several actuators to the stator-side, or fixed, bearing ring. With the aid of the transducers, the position of the fixed bearing ring can be determined, with the actuators it is possible to govern the position of the stator-side, or fixed, bearing ring. Undesirable displacement of the bearings using squeeze-film dampers which results during operation as the result of maneuvering loads, for example, can be equalized or compensated for.
Preferably at least three measuring and actuating elements are allocated to the stator-side bearing ring, distributed equidistant around the circumference of the stator-side bearing ring, where each of the measuring and actuating elements has a transducer for determining the position of the stator-side bearing ring and an actuator to govern the position of the stator-side bearing ring. The stator-side bearing ring can be adjusted with the help of the actuators of the measuring and actuating elements in two directions, each running perpendicular to a rotational axis of the rotor-side bearing ring.
The sensors and actuators also assume the task of damping the bearing, or compensating for a residual imbalance in the rotor by “tracking” the bearing about the axis of inertia of the rotor.
Preferred further developments of the invention emerge from the description following. One embodiment of the invention, without being restricted thereto, is explained more closely using the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a section from a gas turbine aircraft engine in the area of a bearing array in accordance with the invention; and

FIG. 2 shows a detail of the bearing array from FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

Hereinafter the invention is explained in greater detail with reference to FIGS. 1 and 2.
FIG. 1 shows a section from a gas turbine aircraft engine in the area of a bearing array 10 in accordance with the invention. The bearing array in accordance with the invention 10 comprises a stator-side, fixed bearing ring 11 and a rotor-side, rotating bearing ring 12. The stator-side, fixed bearing ring 11 is configured as an outer bearing ring and the rotor-side rotating bearing ring 12 is configured as an inner bearing ring. Several roller elements 13 are located between the outer bearing ring 11 and the inner bearing ring 12.
As can be seen from FIG. 1, the rotor-side, rotating inner bearing ring 12 is connected by a flange 14 to a rotor disk 15 of rotating rotor blades and a similarly rotating seal carrier 16. In accordance with FIG. 1, the connection between the rotor-side inner bearing ring 12 and the seal carrier 16 and the rotor disk 15 is made by a threaded connector 17. The stator-side, fixed outer bearing ring 11 is connected by way of what is known as a circumferential lock plate to a fixed part of the housing 19. The relative position of the bearing array in the circumferential direction is fixed through the circumferential lock plate 18.
In the meaning of the present invention, several measuring and actuating elements 20 are assigned to the stator-side, fixed outer bearing ring 11. At least three measuring and actuating elements 20 are assigned to the fixed outer bearing ring 11, which are distributed equidistant around the circumference of the fixed outer bearing ring 11. Each of the measuring and actuating elements 20 has a transducer, not shown, and an actuator 21. With the aid of the transducer, the position of the fixed outer bearing ring 11 can be determined relative to a set position. The transducers transmit corresponding actual values for the position of the outer bearing ring 11 to a control or feedback device, not shown, where the control or feedback device compares the actual values provided by the transducers for the relative position between the fixed outer bearing ring 11 and the set position with specified setpoints and, as a function thereof, generates positioning signals for the actuators 21. With the aid of the actuators 21, on the basis of the positioning signals generated by the control or feedback device, not shown, the position of the stator-side outer bearing ring 11, or the entire bearing array 10, can be adjusted, specifically in two directions which are both perpendicular to a rotational axis of the rotor, or rotor-side inner bearing ring 12. The actuators 21 act in consequence in a radial direction on the fixed bearing ring 11, where the circumferential lock plate 18 allows the bearing array 10 to be shifted in the radial direction.
As can be seen in particular from FIG. 2, the actuators 21 engage the measuring and actuating elements 20 in recesses 22 in the stator-side outer bearing ring 11. The actuators 21 in each case are in contact with the outer bearing ring 11 through a crowned contact surface 23.
The actuators are not a press fit in the housing 19 and the outer bearing ring 11, the connection is established rather by controlling the actuators 21. By comparing the signals from the transducers, or displacement sensors, and the control voltage of the particular actuator 21, the point can be determined at which contact still exists at the particular crowned contact surface 23 with the outer bearing ring 11. From a comparison of the actual values with the set values for the measuring and actuating elements 20, the crowned contact surfaces 23 are always kept in contact with the outer bearing ring 11 through the controls. It is also possible to determine and regulate the corresponding contact forces.
The actuators 21 are in the meaning of the present invention preferably configured as piezo-ceramic actuators. The bearings can be configured as oil bearings, air bearings or magnetic bearings. The measuring and actuating elements 20 are connected to the stator-side part of the housing 19 by threaded connectors.
Using the bearing array in accordance with the invention, it is possible in a particularly simple way to compensate for displacement of the bearing array using squeeze-film dampers during operation of the gas turbine aircraft engine by means of an active control. The bearing array can be adjusted by means of actuators in two directions which run perpendicular to the rotational axis of the rotor. In addition, maneuvering loads acting on the gas turbine aircraft engine in particular can be compensated for in order to maintain precise gaps between the rotor and the stator. Vibrations or tumbling motions of the bearing array arising during operation can be compensated for or damped using the bearing array 10, as the result of which loads acting on an engine suspension can be reduced.

Claims

1-10. (canceled)

11. A bearing array, specifically for a gas turbine aircraft engine, having a first stator-side, or fixed, bearing ring and a second rotor-side, or rotating, bearing ring, where rolling elements are located between the stator-side bearing ring and the rotor-side bearing ring, wherein transducers are assigned to the stator-side bearing ring to determine a position of the stator-side bearing ring and actuators are assigned to the stator-side bearing ring to govern the position of the stator-side bearing ring.

12. The bearing array according to claim 11, wherein a combined measurement and actuating element is assigned to the stator-side bearing ring, wherein the measurement and actuating element includes a transducer and an actuator.

13. The bearing array according to claim 12, wherein at least three combined measurement and actuating elements are assigned to the stator-side bearing ring which are arranged equidistant around a circumference of the stator-side bearing ring.

14. The bearing array according to claim 11, wherein the transducers determine the position of the stator-side bearing ring relative to a set position.

15. The bearing array according to claim 11, wherein the actuators govern the position of the stator-side bearing ring relative to a set position.

16. The bearing array according to claim 11, wherein, with aid of the actuators, the stator-side bearing ring is adjustable in two directions both running perpendicular to a rotational axis of the rotor-side bearing ring.

17. The bearing array according to claim 11, wherein the actuators are configured as piezo-ceramic actuators.

18. The bearing array according to claim 11, wherein an actual value determined by the transducers for the position of the stator-side bearing ring is compared with a set value in a control or feedback device, where the control or feedback device generates a control signal for the actuators as a function of the comparison between the set value and the actual value.

19. The bearing array according to claim 11, wherein the stator-side bearing ring is configured as an outer bearing ring and the rotor-side bearing is configured as an inner bearing ring.

20. The bearing array according to claim 11, wherein the actuators are in contact with the stator-side bearing ring through a crowned contact surface and wherein through the comparison of the actual value and the set value the crowned contact surface is kept in contact with the stator-side bearing ring.

21. A bearing array, comprising:

a fixed bearing ring including a transducer and an actuator; and

a rotating bearing ring disposed opposite the fixed bearing ring;

wherein the transducer determines a position of the fixed bearing ring and wherein the actuator governs the position of the fixed bearing ring.

22. The bearing array according to claim 21, wherein the transducer provides the position to a control device and wherein the control device compares the position to a desired position.

23. The bearing array according to claim 22, wherein the control device sends a positioning signal to the actuator based on the comparison of the position to the desired position.

24. The bearing array according to claim 23, wherein the actuator governs the position of the fixed bearing ring in response to the positioning signal received from the control device.

25. The bearing array according to claim 21, wherein the actuator includes a contact surface and wherein the actuator governs the position of the fixed bearing ring such that the contact surface remains in contact with the fixed bearing ring.

26. The bearing array according to claim 25, wherein the actuator includes a piezo-ceramic material.

27. The bearing array according to claim 21, wherein the actuator is radially moveable within the fixed bearing ring.

28. A method for adjusting a bearing array, wherein the bearing array includes:

a fixed bearing ring including a transducer and an actuator; and

a rotating bearing ring disposed opposite the fixed bearing ring;

and comprising the steps of:

determining a position of the fixed bearing ring by the transducer and governing the position of the fixed bearing ring by the actuator.

29. The method according to claim 28, further comprising the step of providing the position to a control device by the transducer and comparing the position to a desired position by the control device.

30. The method according to claim 29, further comprising the step of sending a positioning signal to the actuator by the control device based on the comparing step.