RU2482303C1 - Front support of lp turbine rotor of two-shaft gas turbine engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: bearing is designed radial-thrust, splines and mating splines of one of splined joints are designed screw-type in the shape of multi-start thread, which threads are directed to the opposite side from direction of HP rotor rotation with possibility of axial displacement of a spring to create axial force on outer ring of the bearing during engine operation after the mode of its start. Also there is a fixing device restricting axial displacement of the spring in direction from the bearing.

EFFECT: eliminating defect of slipping motion during engine operation.

2 cl, 3 dwg

Description

The invention relates to gas turbine engines for aviation and ground applications, namely, to the placement of supports for turbomachines rotors rotating with a high speed of rotation, and can be used in the most stressed supports.

A known gas turbine engine containing a roller bearing, the inner ring of which is mounted on the shaft of the low pressure rotor, and the outer ring is installed in the node of the central bevel gear on the inner surface of the bevel gear (see Fig. 6.13, authors: Yu.S. Eliseev and others. "Technology operation, diagnostics and repair of gas turbine engines ”, Moscow,“ Higher School ”, 2002. Appendix No. 1 on 2 sheets attached).

The disadvantages of such a support include the location of the bearing rings on the rotating rotors, which leads to slipping of the rolling bodies and disruption of the bearing, with its subsequent destruction. Slippage defect occurs due to small radial loads coming to such supports.

The objective of the invention is to ensure the operability of the front support of the low-pressure rotor by replacing the radial roller bearing with an angular contact ball bearing and forcing it to be axially loaded.

The technical result achieved by using this solution is to eliminate the slip defect during engine operation.

The technical result is achieved in that the front bearing of the low-pressure turbine rotor of the twin-shaft gas turbine engine, comprising a bearing, the inner ring of which is mounted on the low-pressure rotor shaft, and the outer ring in the bevel gear assembly on the inner surface of the bevel gear in contact with the spring by means of a spline connection, wherein the spring is in contact with the axle of the high-pressure rotor by means of a spline connection, while the bearing is made angularly resistant, the splines and the reciprocal slots of one of the mentioned splined joints are screw-shaped in the form of a multi-thread, the turns of which are directed in the opposite direction from the direction of rotation of the high-pressure rotor with the possibility of axial displacement of the spring to create axial force on the outer ring of the bearing when the engine is running after it has been started, except Furthermore, it further comprises fixing means limiting the axial displacement of the spring in the direction from the bearing.

What is new is that the bearing is made angularly resistant, the slots and reciprocal slots of one of the mentioned spline connections are screw-shaped in the form of multiple threads, the turns of which are directed in the opposite direction from the direction of rotation of the high-pressure rotor with the possibility of axial displacement of the spring to create axial force on the outside the bearing ring when the engine is running after passing through its start-up mode, in addition, further comprises a locking means limiting the axial displacement of the spring in the direction from the bearing.

In this case, the fixing means is made in the form of a shoulder located on the spring from the side of the high-pressure rotor with the possibility of abutment in the end surface of its axle.

Replacing a radial roller bearing with an angular contact ball bearing and loading it with an axial load eliminates the radial displacement of the bearings to create additional radial load. This contributes to the interchangeability of engine elements, additional modularity appears.

To eliminate the slippage defect in the bearing, the outer ring is additionally loaded with axial force coming from the spring, which is displaced in the axial direction due to the spline connection, which is made in the form of a multi-thread. The condition for choosing the angle of the slots is determined based on the fact that the friction angle of the slots must be less than the angle of the slots, since the thread jams should not occur during axial movement of the spring relative to the pin, i.e. the spring must be screwed on with a trunnion. The axial force of the spring depends on the angle of inclination of the spline and on the moment of torsion resistance, which varies depending on the speed of the high pressure rotor. A positive effect of this solution is that the loading force increases with increasing rotor speed.

Figure 1 shows a longitudinal section of a support.

Figure 2 shows the angular arrangement of the cross section AA of the spline connection relative to the axis of rotation.

Figure 3 shows a cross section of a spline connection.

The front support of the rotor of the low pressure turbine of a twin-shaft gas turbine engine contains an angular contact bearing 1, the inner ring 2 of which is mounted on the shaft 3 of the low pressure rotor, and the outer ring 4 in the bevel gear assembly on the inner surface 5 of the bevel gear 6, which is in contact with the spring 7 by spline connection 8. In this case, the spring is in contact with the pin 9 of the high pressure rotor by means of spline connection 10. The spring contains fixing means, which is made in the form of a collar 11, with the possibility of its emphasis on the end surface 12 of the pin 9.

In the process of engine operation, the torque of the high-pressure rotor directed in the opposite direction relative to the turns of multi-thread, produces an axial displacement of the spring 7 relative to the axle 9 of the high-pressure shaft (i.e., the spring is unscrewed from the axle), and the greater the moment, the greater the axial force coming to the bearing. Therefore, the bearing 1 is always loaded with axial force. This eliminates slippage defects.

In the engine start mode, when using a spring 7, a high pressure rotor is unwound. The spring will be screwed into the slots, transmitting torque. Therefore, a spring 11 is provided on the spring, which in this mode abuts against the end face 12 of the pin. Also, this shoulder is necessary as a limiter when moving the engine in an idle state.

Claims (2)

1. The front support of the rotor of the low-pressure turbine of a twin-shaft gas turbine engine, comprising a bearing, the inner ring of which is mounted on the shaft of the low-pressure rotor, and the outer ring in the bevel gear assembly on the inner surface of the bevel gear in contact with the spring by means of a spline connection, while the spring is in contact with trunnion of the high-pressure rotor by means of a spline connection, characterized in that the bearing is angular contact, splines and reciprocal splines of one of the aforementioned the front connections are made in the form of multi-thread, the turns of which are directed in the opposite direction from the direction of rotation of the high-pressure rotor with the possibility of axial displacement of the spring to create axial force on the outer ring of the bearing when the engine is running after passing through its start-up mode, in addition, additionally contains fixing means , limiting the axial displacement of the spring in the direction from the bearing. 2. The front support according to claim 1, characterized in that the fixing means is made in the form of a shoulder located on the spring from the side of the high pressure rotor with the possibility of abutment in the end surface of its axle.

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