Drive device for pivoting adjustable blades of a turbomachine

Abstract

A drive device for pivoting adjustable blades of a turbomachine is provided. The drive device includes an annular flow channel section surrounded by a blade carrier, the section extending along the center line of the blade carrier and blades being provided in the section in a ray-like manner, forming a ring, wherein each of the blades can be pivoted about the longitudinal axis thereof and each has a pin which extends at least into the blade carrier and is coupled to at least one adjustment ring which encloses the blade carrier and may be driven by means of at least one motor. In order to provide a particularly low-wear and reliable drive, the drive shaft of the motor or motors is coupled to the adjustment ring or adjustment rings by means of a pinion gear.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is the US National Stage of International Application No. PCT / EP2011 / 052188, filed Feb. 15, 2011 and claims the benefit thereof. The International Application claims the benefits of European Patent Office application No. 10001722.7 EP filed Feb. 19, 2010. All of the applications are incorporated by reference herein in their entirety.FIELD OF INVENTION[0002]The invention refers to a drive device for the pivoting of adjustable vanes of a turbomachine, with an annular flow passage section which is encompassed by a vane carrier, extends along the center axis of the vane carrier, and in which vanes are provided in a radial manner, forming a ring, wherein the vanes are pivotable in each case around their longitudinal axis and have in each case a pivot pin which extends at least into the vane carrier and is coupled to an adjustment ring which is rotatable in the circumferential direction.BACKGROUND OF INVENTION[0003]A device of ...

AI Technical Summary

Benefits of technology

[0022]An especially simple and reliable supporting of the adjustment ring can be achieved if this—with regard to the center axis of the vane carrier—is guided radially on the outside by the cover of the circumferential groove and radially on the inside by the groove base of the circumferential groove. The cover then also serves as a guide for the adjustment ring since this bears in a slidable, but clearance-free, manner both on the cover and on the groove base. This avoids the use of additional construction elements such as support rollers for the central supporting of the adjustment ring in relation to the machine axis. This embodiment also enables a comparatively thin adjustment ring since its natural rigidity can now be lower than previously.

[0023]A further advantage of the cover is the guiding of the adjustment ring along the entire circumference since this is assembled from at least two segments. The segments of the adjustment ring, on account of the proposed external guiding by means of the cover, can be interconnected or screwed together in a comparatively simple manner. Avoiding the basically linkage-like adjustment ring is not possible as a result of the full circumferential guiding.

[0024]In order to prevent gaping of the toothing, the adjustment ring is axially guided by a sid

Problems solved by technology

In this case, the drives which are known from U.S. Pat. No. 5,549,448 and EP 1 524 413 A2 are costly in construction since a large number of components are necessary and are to be designed.

The large number of components lead to a time-consuming assembly during manufacture, which, on account of the required accuracy of the position of the rotation angle of the individual vanes, is additionally time-intensive, moreover.

These temperature differences can lead to unequally set incidence angles of the vanes of the vane ring so that care is always to be taken that the adjustment ring and the vane carrier are mounted coaxially or concentrically to a common center axis.

In addition, the tangential force application via push rods can also bring about a similarly disadvantageous decentering of the adjustment ring.

Also, the bearing arrangement of the known adjustment rings can be susceptible to contaminants and malfunctions,

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