RU2214536C2 - Compressor of gas-turbine engine - Google Patents

Abstract

FIELD: mechanical engineering; gas-turbine engines of aircraft and ground applications. SUBSTANCE: according to invention, in compressor of gas- turbine engine with radial-thrust antifriction bearing, sealing of oil space in form of labyrinth seal with oil-deflecting lip is made double-tier, with ratio of outer diameter of oil-deflecting lip and mean diameter of bearing being 1.01-1.2, and ratio of value of axial clearance between stator flange of labyrinth upper tier and oil-deflecting lip to value of axial clearance between stator flange of lower tier and plate of outer labyrinth being 1.01-1.5. Invention is aimed at prevention of getting of seal wear products into bearing and damaging of oil-deflecting lip in process of compressor demounting. EFFECT: improved reliability of compressor of gas-turbine engine. 3 dwg

Description

 The invention relates to gas turbine engines for aviation and ground applications.

 A known compressor of a gas turbine engine, bearing seals of bearings of which are made without oil scallops [1].

 The disadvantage of this design is its low reliability due to the possibility of oil getting into the gas-air path at reduced engine operating conditions at low air pressure cooling the bearing support.

 Closest to the claimed technical essence is a compressor of a gas turbine engine, the bearings of the bearings of the support of which are made with an oil scallop [2].

 The disadvantage of this design is its low reliability due to the likelihood that the wear products of the seal get into the bearing, as well as damage to the scallop during the dismantling of the bearing during disassembly of the compressor of the gas turbine engine.

 The technical problem that the invention solves is to increase the reliability of the compressor of a gas turbine engine by eliminating the products of seal wear getting into its bearing, as well as preventing damage to the oil scallop during compressor dismantling.

 The essence of the invention lies in the fact that in a compressor of a gas turbine engine with an angular contact rolling bearing, the oil cavity seal of which is made in the form of a labyrinth seal with an oil scallop, according to the invention the seal is made in two layers, the ratio of the outer diameter of the oil scallop and the average diameter of the bearing is 1.01 ... 1,2, and the ratio of the axial clearance between the stator flange of the upper tier of the labyrinth and the oil scallop to the value of the axial clearance about the gap between the stator flange of the lower tier and the canvas of the external labyrinth is 1.01 ... 1.5.

When the engine is running, the wear products of these seals cannot get on the treadmill (working surface) of the bearing and cause this bearing to fail, i.e. the flinger is made with an outer diameter D greater than the average diameter D _{cp of the} bearing. The execution of the outer diameter D of the valve stem equal to 1.01 ... 1.1 D _{cp of the} ball bearing protects the working surfaces of this bearing from the ingress of seal wear, and during transient conditions protects the labyrinth seal and the gas-air duct of the engine from oil.

When D / D _{cp is} less than 1.01, it is possible that the products of the labyrinth seal run-in may fall on the treadmill of the bearing, its chipping and bearing failure. With D / D _cp greater than 1.2, it is difficult to disassemble the bearing of the compressor due to the impact of the oil scallop on the outer ring of the bearing.

 When disassembling the compressor, dismantling from the shaft of the inner ring of the bearing mounted on the shaft with an interference fit is carried out due to the stop of the internal stator flange in the labyrinth canvas made in one piece with the oil scallop, for which the axial clearance Δ is made smaller than the clearance δ. In the case when δ / Δ = 1.01-1.5, the load on the labyrinth sheet during the dismantling of the bearing is minimal, otherwise deformation of the oil scallop is possible.

 With δ / Δ <1.01, a breakdown of the scallop during the dismantling of the bearing is possible.

 At δ / Δ> 1.5, the axial overall oil cavities increase due to the increase in the axial length of the labyrinth seals.

 The invention is illustrated by the following figures.

 Figure 1 shows a longitudinal section of a compressor of a gas turbine engine.

 Figure 2 presents the element I in figure 1 in an enlarged view.

 In FIG. 3 shows an element I in FIG. 1 in an enlarged view when dismantling a bearing.

 The compressor 1 of the gas turbine engine consists of a stator 2 and a rotor 3, which in turn consists of a shaft 4 with disks 5 mounted on it with rotor blades 6.

At the outlet of the compressor 1, on the stator 2, a support 7 of an angular contact ball bearing 8 is installed to seal the oil cavity 9 which, from the compressor discharge cavity 10, uses a two-tier labyrinth seal 11, consisting of a two-tier stator flange 12 and a two-tier labyrinth 13, made with an oil reflector comb 14 outer diameter D, large D _cp ball bearing 8.

 The two-tier stator flange of the labyrinth 2 on the inner surfaces 15 and 16 is made with a soft coating that allows the scallops 17 of the labyrinth 13 to be inserted by cutting to reduce the radial clearance in the labyrinth seal and, accordingly, to reduce the leakage of hot air from the compressor cavity 10 into the oil cavity 9.

 The axial clearance Δ between the inner flange 18 and the web 19 of the labyrinth 13 is made smaller than the axial clearance δ between the outer flange 20 of the labyrinth 13 and the oil scallop 14.

 The front 21 and rear 22 inner rings of the bearing 8 are mounted on the shaft 4 of the compressor 1 with an interference fit in the radial direction and axially fixed with a nut 23 through the intermediate shaft 24.

 To drain the used oil in the support 7 of the ball bearing 8, many axial channels 25 are made, connected at the outlet to the oil cavity 26 of the casing 27.

 The claimed device operates as follows.

 When the engine is running due to the embedding of the scallops 17 of the labyrinth 13 into the soft coating on the surface 15 and 16, the latter wears out, the products of wear due to the difference in air pressure enter the front surface of the oil scallop 14, from where they are discarded to the periphery of the oil cavity 9 by the action of centrifugal forces axial channels polluting particles are discharged into the oil cavity 26 of the shaft casing 27 and then to pumping (not shown). Contaminant particles entering the oil cavity 9 together with air from the discharge cavity 10 are separated in the same way.

 When disassembling the compressor 1, the nut 23 and the intermediate shaft 24 are removed, and the shaft 4 is pressed out of the rings 21, 22 of the bearing 8 by moving the shaft 4 with the disks 5 forward. In this case, the flange 18 abuts against the web 19 of the labyrinth 13, which eliminates damage to the ring 21 of the angular contact ball bearing 8 and the oil scallop 14.

Sources of information
1. S. A. Vyunov. Design and engineering of aircraft gas turbine engines. M .: Engineering, 1981, p.66, Fig. 3.10.

 2. S. A. Vyunov. Design and engineering of aircraft gas turbine engines. M .: Engineering, 1981, p. 228, Fig. 4.69.

Claims (1)

 A compressor of a gas turbine engine with an angular contact rolling bearing, the oil cavity seal of which is made in the form of a labyrinth seal with an oil scallop, characterized in that the seal is two-tier, the ratio of the outer diameter of the oil scallop and the average diameter of the bearing is 1.01 ... 1.2 and the ratio of the axial clearance between the stator flange of the upper tier of the labyrinth and the oil scallop to the value of the axial clearance between the stator flange of the lower tier and the canvas of the external labyrinth is 1.01 ... 1.5.

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