RU2256810C1 - Gas-turbine rotor oil support venting system - Google Patents

Abstract

FIELD: aircraft engines, mechanical engineering and other industries.

SUBSTANCE: invention relates to lubrication of supports of gas-turbine engines. Proposed gas-turbine engine rotor oil support venting system including oil pump and venting main line communicating with oil support space and connected with breather is furnished, according to invention, with pump to out air-oil mixture. Inlet of pump is placed in communication with oil space of support, and outlet communicates with venting main line with ejection of air-oil mixture from support oil space. Said pump have common drive.

EFFECT: improved reliability of venting system in operation.

4 cl, 3 dwg

Description

The invention relates to the lubrication of supports of gas turbine engines, in particular to systems of venting oil supports of the rotor of a gas turbine engine, and can be used in aircraft engine manufacturing, mechanical engineering and other technical fields.

A known system of venting the oil support of the rotor of a gas turbine engine, comprising a pumping oil pump located in the oil cavity of the support of the rotor of the gas turbine engine, a breather and a vent line connected to the latter, and a double-acting shut-off device with valves opening the vent gate at reaching the vent cavity a certain excess pressure, for example, 0.05-0.01 kgf / cm ² , and valves that open the vent line when reaching in n it a certain vacuum pressure, for example, 0.4-0.1 kgf / cm ² (see RF patent No. 2148177, class F 02 C 7/06, publ. 04/27/2000).

The disadvantages of the known system are as follows. The presence of additional valves in the system complicates the design of the system, since additional space is required for the location of the valves and their careful adjustment (calibration and integration into a single control and flow system). The system is insufficiently reliable in operation, since when one of the valves fails, the entire engine oil system fails. When the air-oil mixture moves from the high temperature zone (cavity of the engine mounts) with a low speed, coke deposits are formed in the venting lines and engine mounts, which limit the throughput of the mixture, which reduces the reliability of the oil system as a whole.

The objective of the invention is to increase the reliability of the venting system.

This task is achieved by the fact that in the system of venting the oil support of the rotor of a gas turbine engine with an oil pump, comprising a vent line connected to the cavity of the oil support, connected to the prompter, according to the invention, a pump is pumped out of the air-oil mixture, the input of which is connected to the oil cavity the bearings, and the outlet is connected to the venting line with ejection of the air-oil mixture from the oil cavity of the support, while the pumps have a common drive.

For better layout, reduction in size and weight, the pumps can be located in the oil cavity of the support and enclosed in a common housing.

For ease of replacement, diagnosis and control, the pump out pump can be located outside the cavity of the oil support.

To reduce the dimensions and weight, one of the pumps can be made centrifugal-gear.

The device is illustrated by the following drawings.

Figure 1 shows a diagram of a venting system;

figure 2 is a view a of figure 1;

figure 3 is a variant of the location of the pumps.

The gas turbine engine support venting system includes a venting line 1 connected to the centrifugal breather 2 and to the oil cavity of the support 3, and an oil tank 4 in communication with the centrifugal breather 2 via line 5. The oil pump 6 is connected to the oil tank 4 by means of a pumping line 7. The evacuation pump 8 communicated by the input with the oil cavity of the support 3, and the output with the vent line 1 according to the ejector scheme, namely: the additional vent line 9 is connected to the pump 8 and with the vent line 1 and expansion wife at an acute angle line 1 venting. Oil from the breather 2 is returned to the oil tank 4 via line 10, and air is vented to the atmosphere through the pipe 11. The pump 8 is made with intakes 12 located in the upper part of the oil cavity of the support 3, the oil pump 6 with intakes 13 located in the lower part of the oil cavities of the support 3. The line 1 venting is enclosed in the racks 14 of the engine, and the additional line 9 is in the racks 15 of the engine. The rack 7 is enclosed in the rack 16. The pumps 6, 8 have a common drive, are located in the cavity of the support 3, and are enclosed in a common housing.

The venting system works as follows. When the engine is operating at operating modes from minimum to maximum gas, in line 1 (in the area after connecting the lines 1, 9), the mixture (combination) of flows of the air-oil mixture (i.e. a mixture with an air content greater than oil) is mixed namely, the flow received in the venting line 1 from the oil cavity of the support 3 by a passive (inertial) method, and the flow received in the venting line 1 from the venting line 1 from the venting line 9 in an active (forced) way using pump 8, the mixture moving speed on line 9 is greater than the speed of the mixture, moved inertia. The kinetic energy of the combined flow of the mixture in comparison with the flow of the mixture, moving inertially along the line 1, increases, respectively, increases its speed of movement, thereby increasing the flow rate of the mixture into the prompter 2 and contributing to its more rapid removal due to ejection from the cavity of the support 3 The combined flow of the air-oil mixture through the venting line 1 enters the centrifugal breather 2, from where, after separation, air is discharged through the pipe 11 into the atmosphere, and the oil enters slobak 4 on line 10. From the oil tank 4, oil (in a known manner) is supplied to each rotor bearing (not shown in the drawing), ensuring their operability, and the air entering the oil tank on line 5 is discharged to the centrifugal breather 2 through the venting line 1.

At the same time, the pump 6 through the intakes 13 pumps the oil from the cavity of the support 3 and feeds it through the hollow rack 16 along the line 7 to the oil tank 4.

Thus, the use of the so-called “active, forced exhaust” will increase the speed of the mixed (combined) flow of the air-oil mixture in the highway 1 in the section after the mixture flows are connected, which will reduce coke formation in this section and will provide an opportunity to pump out the air faster the oil mixture from the oil cavity of the support, thereby preventing overheating of the engine mounts.

At engine idle operation, for example, when the hot engine is stopped, started and the engine is turned off, the air-oil mixture is discharged from the oil cavity of the support 3 to the breather 2 in a larger volume along the vent line 1, since the speed of the pump 8 decreases due to reducing the engine speed, which does not allow to fully pump the air-oil mixture into line 1 through line 9, as a result of which only the inertia system continues to work.

Thus, the inertial retraction duplicates the active retraction, thus preventing the possibility of an emergency.

The operation of the venting system is considered on the example of one of the oil supports of the rotor, when the pumps are made centrifugally gear, when they are located in the cavity of the support in a single housing. Obviously, for other supports, another arrangement of pumps and their structural design, the operation of the venting system is similar.

It should be noted that the considered ejector scheme is one example of the constructive implementation of the ejector. With other ejector designs, the venting system operates in a similar manner.

Claims (4)

1. The system of venting oil support of the rotor of a gas turbine engine with an oil pump, comprising a venting line connected to the cavity of the oil support connected to a breather, characterized in that a pump is introduced into the system, pumping the flow of the air-oil mixture, the input of which is in communication with the oil cavity of the support, and the outlet is connected to a vent line with ejection of the air-oil mixture from the oil cavity of the support, while the pumps have a common drive. 2. The venting system according to claim 1, characterized in that the pumps are located in the oil cavity of the support and are enclosed in a common housing. 3. The venting system according to claim 1, characterized in that the evacuation pump is located outside the cavity of the oil support. 4. The venting system according to any one of claims 1 to 3, characterized in that one of the pumps is made of centrifugal gear.

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