RU2729561C1 - High-pressure rotor support of gas turbine engine - Google Patents

Abstract

FIELD: machine building.SUBSTANCE: invention relates to gas turbine engines of aircraft and ground applications, in particular to rotors of compressors and turbines. High-pressure rotor support of gas turbine engine, comprising radial thrust bearing, comprising outer and inner rings with smooth running tracks, oil supply and discharge systems, wherein in each possible contact area of balls and races under axial load on the latter there is at least one radial oil-conducting groove.EFFECT: technical result of invention is higher reliability of high-pressure rotor support by reducing effect of oil wedge parameters on balls of its bearing and, as a result, reduced temperature gradient and reduced possibility of slippage.1 cl, 2 dwg

Description

The invention relates to gas turbine engines for aviation and ground use, in particular, supports for compressors and turbines rotors.

The closest analogue of the proposed technical solution is the well-known PS-90A high-pressure rotor support (A.A. Inozemtsev, M.A.Nikhamkin, V.L. Sandratsky, Gas turbine engines, Aviadvigatel OJSC, Perm, 2007, p. 197 - 199, Fig. 4.4.7.1_5). The ball bearing support is designed to transmit the radial and axial force from the high pressure rotor to the housing parts. The support includes an angular contact ball bearing with a split inner ring, an outer ring, and a cage. The oil is supplied through the nozzles.

However, during the operation of the known bearing in the contact areas of the balls with the raceways of the rings, oil wedges will appear and slippage of the balls during rolling will occur, which causes an increase in the operating temperature and noise during operation. In this case, the permissible temperature is only reached by the amount of cooling oil. This adversely affects the operation of the bearing and the high pressure rotor support as a whole.

The technical result of the proposed invention is to increase the reliability of the high-pressure rotor support by reducing the influence of the oil wedge parameters on the bearing balls and, as a consequence, reducing the temperature gradient and reducing the possibility of slipping.

The specified technical result is achieved by the fact that in the known support of the high-pressure rotor of a gas turbine engine, which includes an angular contact bearing containing an outer and an inner ring with smooth running tracks, an oil supply and discharge system, according to the proposal, in each possible contact area of balls and running tracks under the axial the load on the latter is made at least one radial oil-conducting groove.

The high pressure rotor mounts contain a bearing, oil supply and return system to provide lubrication and heat dissipation. As an energy exchange unit, the support operates under the influence of radial and axial loads, temperature and quantity of lubricant. For ball bearings, due to the action of axial forces, the rings are displaced relative to each other, which increases the contact area of the balls with the raceways of the rings, where the oil layer is compressed with the formation of oil “wedges” with high specific pressure. The resulting force acting on the balls from the side of the oil wedges tends to squeeze the balls off the rolling surface and turn them in the direction opposite to the working rotation. The ratio of forces is such that the force acting from the side of the outer ring is greater by the value of the centrifugal force of the balls. The resulting "sliding" of the balls causes wear of the bearing elements, an increase in operating temperature and noise.

The supply of all possible contact areas of the balls and raceways of the outer and inner rings with radial oil-conducting grooves allows the free flow of oil from the cavity in front of the balls to the cavity behind them, which contributes to the reduction or disappearance of oil wedges in front of the balls.

The number of radial oil-conducting grooves is selected based on the size of the contact area and the size of the bearing.

The profile of the radial oil-conducting grooves is selected based on the strength characteristics of the outer and inner rings. The area of the flow section of the groove is selected on the basis of ensuring the oil consumption in the amount of 5-10% of the volume of the oil wedge.

FIG. 1 shows a sectional view of the bearing of the high pressure rotor support in a static state.

FIG. 2 shows a section of the bearing of the high-pressure rotor support when it is subjected to an axial load.

1 - outer ring of the bearing;

2 - inner ring of the bearing;

3 - balls;

4 - radial oil-conducting groove;

5 - contact area.

The bearing of the high-pressure rotor support consists of an outer ring 1 and an inner ring 2 with smooth running tracks and balls enclosed inside rings 1, 2 3. Oil-conducting radial grooves are made on the running tracks of the outer ring 1 and the inner ring 2 4. Radial oil-conducting grooves 4 are located in possible contact areas 5 of the balls 3 and the raceways of the outer ring 1 and the inner ring 2 arising from the action of the axial force on the bearing.

In the process of bearing operation, under the action of an axial force, the outer ring 1 and the inner ring 2 are displaced relative to each other and the balls 3 come into contact with the raceways of the outer ring 1 and the inner ring 2 no longer at a point, as it happens in a static state, but in the oppositely located relative to the balls 3 contact areas 5. When the direction of application of the axial force on the bearing changes, the location of the contact areas 5 will be different, therefore, the radial oil-conducting grooves 4 are placed in all possible contact areas 5 formed under the axial load of the bearing. An oil wedge forms in the contact areas 5 in front of the rolling balls 3, which negatively affects rolling. Radial oil-conducting grooves 4, located in the contact areas 5, allow oil to flow from the area in front of the balls 3 to the area behind them, preventing a significant increase in pressure in the bearing.

Claims (1)

A support for a high-pressure rotor of a gas turbine engine, including an angular contact bearing, containing an outer and an inner ring with smooth raceways, an oil supply and discharge system, characterized in that in each possible contact area of balls and raceways under axial load on the latter, at least one radial oil channel.

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