CN-121744554-B - Cantilever turbine rotor and design method thereof

CN121744554BCN 121744554 BCN121744554 BCN 121744554BCN-121744554-B

Abstract

The invention discloses a cantilever turbine rotor and a design method thereof, wherein a turbine shaft is set to be a hollow shaft, a rigidity adjusting structure is arranged on a non-torque transmission part of the turbine shaft, so that the rigidity of the turbine shaft is reduced through the rigidity adjusting structure, the elastic deformation of the turbine shaft is increased, the maximum range of a given initial pretightening force is increased, main parameters of the rigidity of the turbine shaft are influenced by the rigidity adjusting structure, torque transmission cannot be influenced even when the rigidity adjusting structure is arranged on the non-torque transmission part, and the rigidity of the turbine shaft is adjusted by designing corresponding rigidity adjusting structures aiming at different cantilever turbine rotors, so that a compression nut can give a proper initial pretightening force when the cantilever turbine rotor is assembled, and the axial joint surface of the cantilever turbine rotor is in a non-loosening or non-overload state in the cold state, hot state or cold-hot state conversion process, so that the cantilever turbine rotor has strong practicability and is suitable for wide popularization and application.

Inventors

FENG LEI
LI XIN
ZENG FEI
YU SUOYUAN
XING FENGTAO
DUAN BINGBING

Assignees

中国航发湖南动力机械研究所

Dates

Publication Date: 20260512
Application Date: 20260228

Claims (6)

1. A design method of a cantilever turbine rotor for designing the cantilever turbine rotor, the cantilever turbine rotor comprising a turbine shaft, the design method comprising the steps of: s1, setting a turbine shaft as a hollow shaft, and arranging a rigidity adjusting structure on a non-torque transmission part of the turbine shaft, wherein the rigidity adjusting structure comprises n adjusting holes which are circumferentially arranged on the turbine shaft at intervals, the adjusting holes are communicated with an inner cavity of the turbine shaft, the circumferential occupation angle of each adjusting hole relative to the axis of the turbine shaft is theta, and n is an integer larger than 1; S2, constructing a first relation type association cantilever turbine rotor initial pretightening force, a cantilever turbine rotor maximum relaxation force and a tightness reserve coefficient; S3, constructing a second relation to correlate the initial pretightening force of the cantilever turbine rotor, the maximum compacting force of the cantilever turbine rotor, the yield tension of the turbine shaft and the yield safety coefficient of the turbine shaft; S4, constructing a third relation to correlate the yield tension of the turbine shaft, the yield strength of the turbine shaft material and the minimum cross-sectional area of the turbine shaft; S5, constructing a fourth relation to associate the minimum cross-sectional area of the turbine shaft, the circumferential occupied angle of the rigidity adjusting structure relative to the axis of the turbine shaft, the inner diameter of the turbine shaft and the outer diameter of the turbine shaft; S6, deriving a fifth relation through the first relation, the second relation, the third relation and the fourth relation to determine the circumferential occupation angle of the rigidity-adjusting structure relative to the axis of the turbine shaft through the fifth relation, so as to determine the number n of the adjusting holes and the circumferential occupation angle theta of the adjusting holes relative to the axis of the turbine shaft; the first relation is: ; In the formula, For the initial pre-tightening force of the cantilever turbine rotor, A is the tightness reserve coefficient, Maximum relaxation force for the cantilevered turbine rotor; The second relation is: ; In the formula, For the maximum compression force of the cantilevered turbine rotor, For the yield tension of the turbine shaft, B is the yield safety coefficient of the turbine shaft; the third relation is: ; In the formula, For the yield strength of the turbine shaft material, Is the minimum cross-sectional area of the turbine shaft; the fourth relation is: ; In the formula, Is the inner diameter of the turbine shaft, Is the outer diameter of the turbine shaft.
2. The method of designing a cantilevered turbine rotor according to claim 1 further comprising the step of, after step S6: A sixth relationship is constructed to evaluate whether the initial preload is applied in place during the assembly process, the sixth relationship being as follows: ; Wherein DeltaL is the elastic elongation of the turbine shaft, In order to adjust the axial length of the hole, E is the elastic modulus of the turbine shaft, Is the minimum cross-sectional area of the turbine shaft.
3. The method of designing a cantilevered turbine rotor according to claim 1 further comprising the steps of: a seventh relation is constructed to determine that the turbine shaft yield safety coefficient B meets design requirements, the seventh relation being as follows: ; In the formula, , For the yield strength of the turbine shaft material, Is the maximum equivalent stress of the turbine shaft.
4. A cantilevered turbine rotor, characterized in that a method of designing a cantilevered turbine rotor according to any one of claims 1-3 is employed.
5. The cantilevered turbine rotor of claim 4, further comprising a compression nut (20), a primary turbine rotor (30) and a secondary turbine rotor (40) axially sleeved in sequence outside the turbine shaft (10), the compression nut (20) being configured to apply a pre-load force axially to compress the primary turbine rotor (30) and the secondary turbine rotor (40) in sequence, the stiffness structure being axially positioned intermediate the primary turbine rotor (30) and the secondary turbine rotor (40) for guiding airflow.
6. The cantilever turbine rotor according to claim 5, wherein the turbine shaft (10) comprises a first hollow section (11), a solid section (12) and a second hollow section (13) in sequence along the axial direction, the compression nut (20), the primary turbine rotor (30) and the secondary turbine rotor (40) are sleeved on the first hollow section (11), a first torque transmission spline (14) for being in spline fit with the secondary turbine rotor (40) is arranged on the first hollow section (11), the solid section (12) is used for being in axial abutment with the secondary turbine rotor (40), and a second torque transmission spline (15) is arranged on the second hollow section (13).

Description

Cantilever turbine rotor and design method thereof Technical Field The invention relates to the technical field of turbine rotor structure design, in particular to a design method of a cantilever turbine rotor. The invention further relates to a cantilevered turbine rotor. Background The cantilever turbine rotor meets the core requirements of the turbine shaft engine on the compactness and the maintenance convenience, so that the cantilever turbine rotor is widely applied to the turbine shaft engine. The cantilever turbine rotor is not only a heavy-duty component in the turboshaft engine, but also the safety and reliability of the operation of the cantilever turbine rotor directly affect the stable operation of the turboshaft engine and even the flight safety of an aircraft. Because the pre-tightening forces required by the cantilever turbine rotors in turbine shaft engines of different types are different, at present, the pre-tightening force of the cantilever turbine rotor is set mainly by a compression nut arranged at the end part of the turbine shaft, the axial elastic deformation of the end part of the turbine shaft can be caused when the pre-tightening force is set by the compression nut, but the axial elastic deformation of the existing turbine shaft is relatively small, so that the condition that the compression nut cannot be given with proper initial pre-tightening force when assembled easily occurs, the cantilever turbine rotor is in a cold state stage when assembled, is in a hot state stage in the working process, and is in a hot state stage in the working process of converting from the cold state stage to the hot state stage, if the initial pre-tightening force is too small, the axial joint surface of the rotor is separated due to non-compression, so that the working fault of the turbine shaft engine is caused, and if the initial pre-tightening force is too large, the axial joint surface of the rotor is damaged due to too large load, and the working fault of the turbine shaft engine is also caused. Disclosure of Invention The invention provides a cantilever turbine rotor and a design method thereof, which are used for solving the technical problem that the axial joint surface of the cantilever turbine rotor is loosened or overloaded when the cantilever turbine rotor works due to the fact that the proper initial pretightening force cannot be given easily. According to one aspect of the invention, a design method of a cantilever turbine rotor is provided, the design method is used for designing the cantilever turbine rotor, the cantilever turbine rotor comprises a turbine shaft, the design method comprises the following steps of S1, setting the turbine shaft as a hollow shaft, opening a rigidity adjusting structure at a non-torque transmission part of the turbine shaft, wherein the rigidity adjusting structure comprises n adjusting holes which are arranged on the turbine shaft at intervals along the circumferential direction, the adjusting holes are communicated with an inner cavity of the turbine shaft, the circumferential occupation angle of each adjusting hole relative to the axis of the turbine shaft is theta, n is an integer larger than 1, S2, constructing a first relation to associate the initial pretightening force of the cantilever turbine rotor, the maximum relaxation force and the tightness reserve coefficient of the cantilever turbine rotor, S3, constructing a second relation to associate the initial pretightening force of the cantilever turbine rotor, the maximum compression force of the cantilever turbine rotor, the yield tensile force of the turbine shaft and the yield safety coefficient of the turbine shaft, S4, constructing a third relation to associate the yield tensile force of the turbine shaft, the yield strength of the turbine shaft material and the minimum cross-section area of the turbine shaft, S5, constructing a fourth relation to associate the minimum cross-section area of the turbine shaft, determining the rigidity adjusting structure relative to the axis of the fourth relation to the circumferential direction, determining the occupation angle of the fourth relation to the axis, and the fifth relation to the circumferential rigidity adjusting structure through the first relation, and the first relation to the circumferential angle of the fourth relation, and the fifth relation to the circumferential rigidity adjusting structure. As a further improvement of the above technical scheme: Further, the first relation is: ; In the formula, For the initial pre-tightening force of the cantilever turbine rotor, A is the tightness reserve coefficient,Is the maximum relaxation force of the cantilevered turbine rotor. Further, the second relation is: ; In the formula, For the maximum compression force of the cantilevered turbine rotor,And B is the yield safety coefficient of the turbine shaft. Further, the third relation is: ; In the formula, For the yield strength of the turbine sha