RU2303148C1 - Gas-turbine engine intershaft support unit - Google Patents

Abstract

FIELD: aircraft engineering; engines.

SUBSTANCE: proposed intershaft support unit of gas-turbine engine can be used in stressed intershaft supports. Unit contains shafts of high-pressure and low-pressure compressors, intermediate shaft adjusting member installed on shaft of low-pressure compressor, radial-thrust intershaft ball bearing whose outer race is installed on inner surface of shaft of high-pressure compressor and inner race, on outer surface of intermediate shaft and which is arranged in oil space limited by graphite contact seal, and radial-thrust ball bearing arranged on shaft of high-pressure compressor. Through radial slots are made in inner race of intershaft ball bearing, ring channel is formed between shafts of high-and low-pressure compressors, oil nozzle is installed on stator of high-pressure compressor, and longitudinal slots are made on outer surface of intermediate shaft from side of ring channel which are interconnected at outlets by ring groove arranged opposite to radial slots of inner race of intershaft bearing. Adjusting member is made in form of threaded bushing connected by thread with intermediate shaft and by splines, with outer surface of shaft of low-pressure compressor. Invention provides optimum delivery of lubricating oil and effective cooling of bearing and precludes oil leakage into engine flow path, thus increasing service life of support.

EFFECT: simplified assembling and disassembling of rotors of low-pressure compressors and low-pressure turbine.

6 cl, 1 dwg

Description

The invention relates to gas turbine engines (GTE) for aviation and ground applications, namely, to the construction of an inter-shaft support, and can be used in the most intense inter-shaft support of a GTE.

A well-known support for a double-circuit turbojet engine containing an inter-shaft angular contact ball bearing installed between the shafts of low and high pressure compressors, an intermediate shaft with an inner bearing ring mounted on it, an oil cavity for lubricating and cooling bearings (G.S. Skubachevsky "Aircraft gas turbine engines" Design and calculation of parts. M.: Mechanical Engineering, 1974, p. 71, Fig. 3.22).

The disadvantage of such a support is that the intermediate shaft with the inner ring of the bearing transmits torque from the turbine to the compressor through the splines and, when distorted in the spline connection, negatively affects the operation of the bearing, skewing the bearing rings relative to each other. A complex oil supply system for bearings degrades their performance. To adjust the mutual axial position of the turbine and compressor, there is an adjusting ring that is installed between the inner ring of the bearing and the shoulder on the countershaft.

To set the axial position of the compressor and turbine, you must have a set of such rings. When replacing it requires complex disassembly of the compressor.

The closest in technical essence to the claimed solution is a gas turbine engine containing high and low pressure compressor shafts, low pressure turbine shaft (LPH), an intermediate shaft mounted on the low pressure compressor shaft (KND), an adjusting element, an angular contact ball bearing, the outer ring of which is installed on the inner surface of the shaft of the high-pressure compressor (HPC), and the inner ring is on the outer surface of the intermediate shaft located in the oil cavity, ichennoy contact seal, and angular contact ball bearings disposed on the shaft HPC (AN Nikitin "assembly technology aircraft engines", Moscow, Mechanical Engineering, 1982, page 213 ... 216).

A disadvantage of the known device is the organization of the oil supply to the inter-shaft ball bearing through the holes in the HPC shaft. Thus, the oil is supplied to the bearing from its one side into the gap between the inner ring and the cage, which leads to uneven cooling of the bearing. In addition, the oil cavity is separated from the air cavities by split metal rings, which do not provide a long service life of the support due to their wear as the operating time increases, and through such seals, oil leaks into the engine flow part.

The objective of the invention is the organization of the optimal oil supply for lubrication and cooling of bearings of the inter-shaft support of the gas turbine engine.

This task is achieved by the fact that in the assembly of the gas-bearing support for the gas turbine engine, which contains the shafts of the high and low pressure compressors, the low-pressure turbine shaft, the intermediate shaft mounted on the low-pressure valve shaft, an adjusting element, the angular-contact ball bearing, the outer ring of which is mounted on the inner surface of the shaft KVD, and internal - on the outer surface of the intermediate shaft, located in the oil cavity bounded by the contact seal, and angular contact ball bearing located on the shaft of the KVD, according According to the invention, radial grooves are made in the inner ring of the inter-shaft bearing, an annular channel is formed between the shafts of the high and low pressure compressors, an oil nozzle is installed on the HPC stator opposite the entrance to this channel, and longitudinal grooves are made on the outer surface of the intermediate shaft from the side of the annular channel between themselves at their exits an annular groove located opposite the radial grooves of the inner ring of the inter-shaft bearing.

In addition, the following may occur in the device:

- contact seals that limit the oil cavity are made of graphite;

- the adjusting element is made in the form of a threaded sleeve connected by a thread with an intermediate shaft and splines - with the outer surface of the shaft of the low-pressure compressor;

- the outer surface of the shaft of the low pressure compressor and the inner surface of the shaft of the low pressure turbine are connected by splines;

- longitudinal channels are made on the outer surface of the shaft of the high-pressure compressor, interconnected at their outputs by an annular groove located opposite the radial grooves of the inner ring of the angular contact ball bearing;

- the inner surface of the intermediate shaft and the outer surface of the shaft of the low-pressure compressor are connected by splines.

This embodiment of the device allows the supply of oil for lubrication and cooling of the inter-shaft bearing by individual nozzles along the annular channel between the shafts of the HPC and KND and further along the axial channels in the intermediate shaft and along the radial grooves of the inner ring of the bearing, which contributes to its effective lubrication and uniform cooling. The separation of the oil cavity of the support from air contact graphite seals eliminates the leakage of oil into the flow part of the engine.

The drawing shows a longitudinal section of a node between the shaft support GTE.

The assembly comprises a low pressure valve shaft 1, a turbine shaft 2, a high pressure cylinder shaft 3, an intermediate shaft 4 mounted on the low pressure valve shaft 1, and an angular-contact angular contact ball bearing 5 fixed by a nut 6, the outer ring 7 of which is mounted on the inner surface of the high-pressure shaft 3, and the internal ring 8 - on the outer surface of the intermediate shaft 4. Ball bearing 5 is placed in the oil cavity 9, limited by a graphite contact seal 10, separating it from the air cavity 11. On the intermediate shaft 4 behind the graphite seal 10, a labyrinth seal 12 is installed, closed captured by a nut 13. Between the intermediate shaft 4 and the shaft 1 KND installed adjusting element 14, made in the form of a threaded sleeve connected by a thread 15 to the inner surface of the intermediate shaft 4 and the slots 16 - with the outer surface of the shaft 1 KND. On the axle 17 of the HPC shaft 3, an inner ring 18 of an angular contact ball bearing 19 is installed, fixed by a nut 20. The bearing 19 is placed in the oil cavity 21, limited by a graphite contact seal 22, separating it from the air cavity 23, limited by the labyrinth seal 24. Between the shafts 1 and 3 KND and KVD formed an annular channel 25, opposite the entrance to which there is an oil nozzle 26 mounted on the stator of the KVD (not shown). Through radial grooves 27 are made in the inner ring 8 of the inter-shaft ball bearing 5, and through radial grooves 28 are made in the inner ring 18 of the ball bearing 19. Longitudinal grooves 29 are made on the outer surface of the intermediate shaft 4 from the side of the annular channel 25, interconnected at their outputs by an annular groove 30, located opposite the radial grooves 27 of the inner ring 8 of the inter-shaft bearing 5. On the outer surface of the shaft 3 of the HPC, longitudinal grooves 31 are made, interconnected by an annular groove 32 located opposite the radial grooves 28 of the inner ring 18 of the bearing 19. On the outer surface of the low pressure valve shaft 1, slots 33 are made that are in contact with the slots made on the inner surfaces of the intermediate shaft 4 and the high pressure pump shaft 2.

Assembly of the node is as follows.

An inter-shaft graphite seal 10 and a labyrinth seal 12 are installed on the intermediate shaft 4 and tightened with a nut 13. Then an inter-shaft ball bearing 5 is installed and tightened with a nut 6. The resulting assembly is axially inserted into the pin 17 of the HPC shaft 3, a contact sleeve 34 is installed, combined with the cover 35 the labyrinth seal 12, and is fixed with a nut 36. The HPH shaft 2 is connected by splines 33 to the LPC shaft 1, pulled together by a spline sleeve 37 and locked by the 38 sleeve. The axial position of the LPC shaft 1 and the LPC shaft 2 is determined by the adjusting member 14, which abuts the LPT shaft 2.

When the engine is running, oil from the nozzle 26 is fed into the annular channel 25 and enters the annular cavities 39 and 40 of the nuts 20 and 6, then under the action of centrifugal forces passes through the longitudinal grooves 31 and 29 and enters the radial grooves 27 and 28 in the inner rings 8 and 18 bearings 5 and 19.

The invention allows to organize the optimal supply of oil for lubrication and efficient cooling of bearings of the GTE inter-shaft support, as well as to prevent oil leakage into the engine duct, which leads to an increase in the service life of the support and the engine as a whole. The introduction of the adjusting element in the form of a threaded sleeve can significantly simplify the Assembly and disassembly of the rotors KND and TND. At the same time, the intermediate shaft is fitted with an interference fit, which improves the operation of the shaft support.

Claims (6)

1. An inter-shaft support assembly for a gas turbine engine comprising high and low pressure compressor shafts, a low pressure turbine shaft, an intermediate shaft mounted on the low pressure compressor shaft, an adjusting element, an angular contact ball bearing, an outer ring of which is mounted on the inner surface of the high compressor shaft pressure, and internal - on the outer surface of the intermediate shaft, located in the oil cavity bounded by a contact seal, and an angular contact ball bearing a rosehip, located on the shaft of the high-pressure compressor, characterized in that through radial grooves are made in the inner ring of the inter-shaft ball bearing, an annular channel is formed between the shafts of the high and low pressure compressors, an oil nozzle is installed on the stator of the high-pressure compressor, and on the outer surface of the intermediate shaft with the sides of the annular channel are made longitudinal grooves interconnected at their outputs by an annular groove located opposite the radial grooves of the inner ring tsa mezhvalnogo bearing. 2. The site of the inter-shaft support of a gas turbine engine according to claim 1, characterized in that the contact seal is made of graphite. 3. The inter-shaft support assembly of a gas turbine engine according to claim 1, characterized in that the adjusting element is made in the form of a threaded sleeve connected by a thread to the intermediate shaft and splines with the outer surface of the low-pressure compressor shaft. 4. The inter-shaft support assembly of a gas turbine engine according to claim 1, characterized in that the outer surface of the low pressure compressor shaft and the inner surface of the low pressure turbine shaft are connected by splines. 5. The inter-shaft support assembly of a gas turbine engine according to claim 1, characterized in that longitudinal grooves are made on the outer surface of the high-pressure compressor shaft, interconnected at their outputs by an annular groove opposite the radial grooves of the inner ring of an angular contact ball bearing. 6. The inter-shaft support assembly of a gas turbine engine according to claim 1, characterized in that the inner surface of the intermediate shaft and the outer surface of the low-pressure compressor shaft are connected by splines.