RU2507405C1 - Gas turbine engine resilient damping bearing support - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: proposed support comprises ball bearing with resilient element with cutouts and roller bearing. The latter incorporates zigzag-like resilient element with cutouts. Length of cutouts made at said zigzag-like resilient element is 1.5-5 times smaller than that of cutouts made on ball bearing resilient element.

EFFECT: higher reliability of gas turbine engine bearing support.

4 dwg

Description

The invention relates to elastic damper supports of gas turbine engines for aviation and ground applications.

Known is the elastic damper support for engines of the CF34 - 10E family, in which the outer ring of the roller bearing is fixed without an elastic element at the rear, and the outer ring of the ball bearing is fixed in the elastic element at the front ("Foreign Aircraft Engines", issue 14, Moscow, TsIAM, 2005, p. 75- 79).

A disadvantage of the known design is the lack of elastic and oil damping of the roller bearing.

Closest to the claimed is the elastic damper support of gas turbine engines of the GP 7200 family, which contains located inside the housing a ball bearing with an elastic element having slots, and a roller bearing. In this case, the outer ring of the roller bearing is fixed with oil damping without an elastic element in front, and the outer ring of the ball bearing is integral with the elastic element and fixed at the back ("Foreign Aircraft Engines", issue 14, Moscow, TsIAM, 2005, pp. 176-192) .

A disadvantage of the known design adopted as a prototype is the lack of an elastic element in the roller bearing in the presence of oil damping, as well as the uneven circumference of the oil damper due to poor centering in the elastic element.

The technical result of the claimed invention is to increase the reliability of the support of the gas turbine engine due to the elastic damping in the roller bearing and uniform radial clearance in the oil damper.

The technical result is achieved in that the elastic damper support of the gas turbine engine comprises a ball bearing located inside the housing with an elastic element having slots, and a roller bearing that is provided with a zigzag elastic element with slots, while the length of the slots made on the zigzag elastic element of the roller bearing is less than 1.5 ... 5 times the length of the slots made on the elastic element of the ball bearing.

In this case, the zigzag elastic element can be made integral with the outer cage of the roller bearing.

The elastic element is made integral with the outer cage of the ball bearing.

The presence of a zigzag elastic element with slots in the roller bearing provides additional damping of the rotor and centering to ensure a uniform oil film. In addition, the radial movement of the rotor is reduced during acceleration and reset modes, which reduces the working radial clearances along the blades of the turbocharger.

The execution of the length L of the slots on the zigzag elastic element of the roller bearing is less than 1.5 ... 5 times the length L1 of the slots on the elastic element of the ball bearing provides excess stiffness of the zigzag elastic element of the roller bearing with respect to the stiffness of the elastic element of the ball bearing, which increases the reliability of the support of the gas turbine engine.

The implementation of a zigzag elastic element integral with the outer race of the roller bearing and the execution of the elastic element integral with the outer race of the ball bearing also increases the reliability of the support due to the absence of nuts.

Figure 1 shows a longitudinal section of an elastic damper support of a gas turbine engine.

Figure 2 shows a cross section of an elastic damper support along a zigzag elastic element of a roller bearing.

Figure 3 shows a cross-section of an elastic damper support along the elastic element of a ball bearing.

Figure 4 shows the implementation of the outer cage of the ball bearing and roller bearing at the same time, respectively, with an elastic element and a zigzag elastic element.

The elastic damper support of the gas turbine engine consists of a housing 1 in which elastic elements 2 and 3 are installed, while the elastic element 2 is made in a zigzag shape. The elastic elements 2 and 3 by means of nuts 4 and 5 are fixed, respectively, with the outer race 6 of the roller bearing 7 and the outer race 8 of the ball bearing 9. The roller bearing 7 is made with rollers 10, and the ball bearing 9 with balls 11. The elastic elements 2 and 3 are installed, respectively , above the roller bearing 7 and ball bearing 9. Between the housing 1 and the zigzag elastic element 2 of the roller bearing 7, an annular oil cavity 12 is made, into which oil flows through the holes 13, which serves to damp the vibrations of the rotor 14. Seals the ring rings 15 on the outer surface of the zigzag elastic element 2 limit and seal the oil cavity 12. The zigzag element 2 of the roller bearing 7 is made with slots 16, and the elastic element 3 of the ball bearing 9 is made with slots 17. The length L of the slots 16 on the zigzag elastic element 2 of the roller bearing 7 is made 1.5-5 times less than the length L1 of the slots 17 on the elastic element 2 of the ball bearing 9.

The choice of the specified ratio of the lengths L of the slots 16 and L1 of the slots 17 is due to the fact that only this ratio provides an excess of stiffness of the zigzag elastic element 2 of the roller bearing 7 with respect to the stiffness of the elastic element 3 of the ball bearing 9. The fulfillment of the ratio of lengths L and L1 less than 1.5 does not allow excess of the stiffness of the elastic element 2 over the elastic element 3 to transfer most of the radial force from the rotor through the support of the roller bearing 7, and the fulfillment of the ratio of lengths L and L1 more than 5 increases the stiffness bearings of the roller bearing 7 to a value when the oil damper stops working.

To increase the reliability of the support, the zigzag elastic element 2 can be made integral with the outer race 6 of the roller bearing 7, and the elastic element 3 can be integral with the outer race 8 of the ball bearing 9. This embodiment eliminates the use of nuts 4 and 5 in the construction of the support.

Elastic damper gas turbine engine operates as follows.

When the engine is running and when the shaft vibrates, the rotor 14, which is located in the support of the roller bearing 7, is guaranteed to be centered using an elastic element 2 having great rigidity, transmitting mainly radial force, and an oil film of the annular cavity 12, in which uniform clearance is ensured. Ball bearing 8 mainly accepts axial load. When damping, the vibrational energy of the rotor 14 is spent on pumping oil around the circumference. In addition to the oil damping of the vibrations of the rotor 14 in the support of the roller bearing 7, additional damping takes place in the elastic elements 2 and 3, respectively, of the roller bearing 7 and the ball bearing 9, which also reduces the production of blades and labyrinths.

Claims (2)

1. An elastic damper support for a gas turbine engine comprising a ball bearing located inside the housing with an elastic element having slots, and a roller bearing, characterized in that the roller bearing is provided with a zigzag elastic element with slots, while the length of the slots made on the zigzag elastic element of the roller bearing is less than 1 5 ... 5 times the length of the slots made on the elastic element of the ball bearing. 2. The elastic damper support according to claim 1, characterized in that the zigzag elastic element is integral with the outer race of the roller bearing.

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