An aeroengine rotor elastic support structure

Abstract

This application belongs to the field of rotor structure design and is a flexible support structure for an aero-engine rotor, including a mounting edge, cage bars, and a sleeve. The mounting edge and the sleeve are coaxially arranged, and the cage bars are located between the mounting edge and the sleeve. There are multiple sets of cage bars, which are evenly spaced along the circumference of the sleeve. The cage bars are X-shaped, and the two ends of the X-shaped structure are connected to the mounting edge and the sleeve, respectively. A triangular cavity is formed between the cage bars, the mounting edge, and the sleeve, and a rhomboid cavity is formed between adjacent cage bars. The X-shaped structure of the cage bars makes the cross-sectional area of ​​the cage bars gradually increase from the middle to the two ends, and the moment of inertia is small and also gradually increases from the middle to the two ends, thereby reducing the stress level and avoiding large stress concentration caused by high stress and sudden stiffness changes at the connection between the two ends of the cage bars and the main body of the sleeve. Since there is no large stress concentration, the low stiffness requirement is maintained.

Description

Technical Field

[0001] This application belongs to the field of rotor structure design, and specifically relates to an elastic support structure for an aero-engine rotor. Background Technology

[0002] Elastic structures are commonly used in the rotor support structure of aero-engines to adjust the support stiffness and critical speed of the rotor. Among these, the "squirrel cage" elastic support structure is relatively common, such as... Figure 1 As shown, it is a cantilever structure consisting of a mounting edge and a sleeve with rectangular perforations. The mounting edge is fixed to the bearing housing of the casing by bolts, and the bearing is installed in the sleeve that extends out at the other end to support the rotor. The sleeve has rectangular milled slots evenly distributed around its circumference, which alternate to form several cage bars with equal cross-sections. The cage bars have rounded corners and smoothly transition to the main body of the sleeve.

[0003] This type of elastic support structure often encounters problems such as high stress and stress concentration at both ends of the cage bars, leading to fatigue cracks and, in severe cases, even cage bar fracture, endangering the operational safety of the rotor system and even the entire machine. While increasing the cross-sectional size of the cage bars or using fillets can help reduce stress, this conflicts with the low stiffness design requirements of elastic supports, making it difficult to form a feasible structural solution.

[0004] Therefore, how to simultaneously satisfy the requirements of excessive stress concentration and low stiffness in elastic support structures is a problem that needs to be solved. Summary of the Invention

[0005] The purpose of this application is to provide an elastic support structure for aero-engine rotors to solve the problem that existing elastic support structures cannot simultaneously meet the requirements of stress reduction and low stiffness.

[0006] The technical solution of this application is: an elastic support structure for an aero-engine rotor, including a mounting edge, cage bars and a sleeve. The mounting edge and the sleeve are coaxially arranged. The cage bars are disposed between the mounting edge and the sleeve. There are multiple sets of cage bars, which are evenly spaced along the circumference of the sleeve. The cage bars are X-shaped, and the two ends of the X-shaped structure are respectively connected to the mounting edge and the sleeve. A triangular cavity is formed between the cage bars, the mounting edge and the sleeve. A rhomboid cavity is formed between adjacent cage bars.

[0007] Preferably, the two straight edges of the cage bars have the same width and are symmetrically distributed along the sleeve axis. The straight edges and obtuse angle sides of the cage bars are provided with transition fillets between the mounting edge and the sleeve.

[0008] Preferably, the angle between the straight edge of the cage bar and the axis of the sleeve is 15 to 30°.

[0009] This application discloses an elastic support structure for an aero-engine rotor, comprising a mounting edge, cage bars, and a sleeve. The mounting edge and the sleeve are coaxially arranged, and the cage bars are located between the mounting edge and the sleeve. Multiple sets of cage bars are evenly spaced along the circumference of the sleeve. The cage bars are X-shaped, with both ends of the X-shaped structure connected to the mounting edge and the sleeve, respectively. A triangular cavity is formed between the cage bars, the mounting edge, and the sleeve, and a rhomboid cavity is formed between adjacent cage bars. The X-shaped structure of the cage bars causes the cross-sectional area of ​​the cage bars to gradually increase from the middle to both ends, and the moment of inertia is small and also gradually increases from the middle to both ends, thereby reducing the stress level and avoiding large stress concentrations caused by high stress and sudden stiffness changes at the connection points between the cage bars and the sleeve body. Since large stress concentrations do not occur, the low stiffness requirement is maintained. Attached Figure Description

[0010] To more clearly illustrate the technical solutions provided in this application, the accompanying drawings will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application.

[0011] Figure 1 This is a schematic diagram of an elastic support structure in the background technology;

[0012] Figure 2 This is a schematic diagram of the flexible support structure of this application;

[0013] Figure 3 This is a partial structural diagram of the X-shaped cage bar in the circumferential direction of this application.

[0014] 1. Installation edge; 2. Sleeve; 3. Cage bar; 4. Triangular cavity; 5. Rhomboid cavity. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] An elastic support structure for an aero-engine rotor is an integral cantilever structure, such as... Figure 2 As shown, it includes a mounting edge 1, cage bars 3, and sleeve 2. The mounting edge 1 and sleeve 2 are coaxially arranged. The cage bars 3 are located between the mounting edge 1 and sleeve 2. The diameter of the mounting edge 1 is larger than the diameter of the sleeve 2. The mounting edge 1 is provided with multiple mounting holes. The mounting edge 1 is fixed to the casing bearing seat by bolts. The sleeve 2 is a cantilever structure and a bearing is installed inside the sleeve 2 to support the rotor.

[0017] The cage bars 3 are in multiple sets and are evenly spaced along the circumference of the sleeve 2. The cage bars 3 are X-shaped and the two ends of the X-shaped structure are connected to the mounting edge 1 and the sleeve 2 respectively. The cage bars 3, the mounting edge 1 and the sleeve 2 form a triangular cavity 4, and the adjacent cage bars 3 form a rhomboid cavity 5.

[0018] The X-shaped structure of the cage bar 3 causes the cross-sectional area of ​​the cage bar 3 to gradually increase from the middle to both ends, and the moment of inertia is small and also gradually increases from the middle to both ends. This reduces the stress level and avoids large stress concentration caused by high stress and sudden stiffness changes at the connection points of the cage bar 3 and the main body of the sleeve 2. Since there is no large stress concentration, the cross-section and stiffness of the cage bar 3 to the main body of the sleeve 2 change slowly, the overall stress level of the cage bar 3 is low, and the low stiffness requirement is maintained.

[0019] The triangular cavity 4 creates a relatively stable support structure between the cage bars 3, the mounting edge 1, and the sleeve 2, resulting in strong resistance to deformation. Meanwhile, the rhomboid cavity 5 allows for greater deformation capacity between adjacent cage bars 3, ensuring their elasticity. Therefore, the X-shaped cage bar design distributes the strength and elasticity of the cage bars 3 in different locations without mutual interference. Simultaneously, it alters the stress distribution, reducing stress concentration in high-stress areas of the structural component, thereby decreasing the component's sensitivity to surface finish and the rate of crack initiation / propagation.

[0020] Preferably, the two straight edges of the cage bar 3 have the same width and are symmetrically distributed along the axis of the sleeve 2. The symmetrical distribution design ensures the stability of the structure. The inclined design of the straight edges makes the high stress area of ​​the X-shaped cage bar 3 located on the obtuse angle side of the intersection of the cage bar 3. Therefore, a larger transition radius can be set between the straight edge and the obtuse angle side of the cage bar 3 and the mounting edge 1 and the sleeve 2 to further reduce the stress concentration. This is beneficial to reducing the sensitivity of the structural components to the surface finish and the crack formation / propagation rate.

[0021] Preferably, the angle between the straight edge of the cage bar 3 and the axial direction of the sleeve 2 is 15° to 30°. Figure 3 As shown, the larger the included angle, the lower the structural stability. The stability of the structure can be ensured by setting a smaller included angle for the straight side.

[0022] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change.

[0023] Secondly: The accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other.

[0024] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An elastic support structure for a rotor of an aeroengine, characterized in that: It includes an installation edge (1), cage bars (3) and a sleeve (2). The installation edge (1) and the sleeve (2) are coaxially arranged. The cage bars (3) are located between the installation edge (1) and the sleeve (2). There are multiple sets of cage bars (3) and they are evenly spaced along the circumference of the sleeve (2). The cage bars (3) are X-shaped and the two ends of the X-shaped structure are connected to the installation edge (1) and the sleeve (2) respectively. A triangular cavity (4) is formed between the cage bars (3), the installation edge (1) and the sleeve (2). A rhomboid cavity (5) is formed between adjacent cage bars (3). The two straight sides of the cage bar (3) have the same width and the two straight sides of the cage bar (3) are symmetrically distributed through the axis of the sleeve (2). The straight sides and obtuse angle sides of the cage bar (3) are provided with transition rounded corners between the mounting edge (1) and the sleeve (2). The angle between the straight edge of the cage bar (3) and the axis of the sleeve (2) is 15~30°.

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