A locking blade stop device for an aeroengine fan rotor and a method of assembly

Abstract

The application discloses an aero-engine fan rotor locking blade stop device and an assembling method. The stop device comprises a base, a cushion block, a screw rod, a pin, a nut and a knurled high head screw. The base comprises an axial support arm parallel to the axial direction of the aero-engine fan rotor and a radial support arm parallel to the radial direction of the aero-engine fan rotor, wherein a slot is formed in the axial support arm to divide the axial support arm into an upper support arm and a lower support arm. The nut and the screw rod are assembled on the axial support arm, and the cushion block is detachably connected to the base. When assembling the stop pin, the base is first placed between two adjacent stages of the disc, then the cushion block is placed, so that the two are respectively tightly pressed against the opposite end faces of the two stages of the disc, then the nut is screwed, the stop pin is lifted through the lower support arm, and then the flaring operation is performed. The application realizes single-person assembling, improves the one-time assembling qualified rate of the stop pin, and shortens the processing time.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine manufacturing, and specifically relates to a special device and method for fixing and locking the stop pin after assembling the blades of the fan rotor balance assembly, a core rotating component of an aero-engine. Background Technology

[0002] like Figure 1 and Figure 2 As shown, the fan rotor balancing assembly is implemented in the following manner when assembling the blades: first, the blades are installed into the wheel disc tenon grooves, then the retaining rings are installed circumferentially into the grooves at the bottom of the blades to fix the blades, and finally the retaining rings are tightened at both ends with stop pins. It is necessary to use a punch to open the stop pins and then lock the retaining rings to lock the blades and prevent the blades from axially moving.

[0003] The current method for locking the fan rotor blade retaining pin is as follows: a shim is placed under the retaining pin, one operator uses a pry bar on the shim to lift the retaining pin, and another person uses a 30°, 60°, and 90° punch to pry open the retaining pin until the retaining pin is flush with the inner surface of the pin hole on the rotor disc (e.g., Figure 2 Clearly, the current locking mechanism requires two people to operate simultaneously; a worker cannot complete the task independently. Furthermore, controlling the force applied when using a pry bar to lift the lock pin is difficult. Excessive force can damage the pin head, rendering the part unusable; insufficient force fails to meet the locking requirements during punching. In addition, current technology typically takes over 0.6 hours to lock a single fan rotor, which is not only time-consuming but also incurs significant labor costs.

[0004] Based on the above, in order to achieve high-efficiency, high-quality and low-cost assembly of the fan rotor balancing assembly, a core rotating component of aero-engines, it is urgent to propose a special device and assembly method for fixing and locking the stop pin after assembling the blades of the fan rotor balancing assembly, a core rotating component of aero-engines. Summary of the Invention

[0005] The present invention aims to provide a locking blade stop device and assembly method for aero-engine fan rotors, enabling assembly personnel to independently complete the assembly process, effectively improving the first-time assembly pass rate of the stop pin, reducing manpower consumption, shortening processing time, and accelerating the flow efficiency within the fan rotor assembly unit.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A fan rotor locking blade stop device for an aircraft engine includes:

[0008] The base is L-shaped and includes an axial support arm parallel to the axis of the aero-engine fan rotor and a radial support arm parallel to the radial direction of the aero-engine fan rotor. The axial support arm has a slot that divides it into an upper support arm and a lower support arm. The end of the lower support arm forms the position of a support stop pin. The axial support arm also has a through hole that passes through the upper support arm, the slot, and the lower support arm. The thickness of the upper support arm along the axis of the through hole is greater than the thickness of the lower support arm along the axis of the through hole.

[0009] The screw includes a head and a shank. The outer diameter of the head is larger than the inner diameter of the upper hole of the lower support arm corresponding to the through hole. At least a portion of the surface of the shank has external threads. The screw is inserted into the through hole and its head is located on the side of the lower support arm away from the upper support arm.

[0010] The nut is connected to the external thread of the screw rod via a through hole on one side of the upper support arm.

[0011] Furthermore, the aircraft engine fan rotor locking blade stop device also includes a pad, which is detachably connected to one side of the radial support arm on the base via a connector and fits against the surface of the radial support arm.

[0012] Furthermore, the aircraft engine fan rotor locking blade stop device also includes:

[0013] A notch is provided at the head of the screw;

[0014] A pin, which is mounted on the lower support arm and a portion of the pin is inserted into a notch.

[0015] Alternatively, the groove cross-sectional shape of the axial support arm is a combination of rectangular and circular, wherein the circular cross-section is located at one end of the rectangular cross-section along its length.

[0016] Alternatively, the upper arm end also includes a clearance groove, below which is the end of the lower arm support stop pin.

[0017] A method for assembling locking blades of an aero-engine fan rotor, employing the aforementioned stop device without pads, and comprising the following steps:

[0018] Step 1: Place the base between the two adjacent stage discs, ensuring that the two end faces of the axial support arm are firmly pressed against the two opposite surfaces of the two stage discs;

[0019] Step 2: Rotating the nut causes the screw to move, making the lower support arm move closer to the upper support arm, while the end of the lower support arm lifts up the stop pin;

[0020] Step 3: Use punches of different sizes to flare the stop pins. After flaring, use a file to flatten the part of the stop pin that protrudes above the wheel surface.

[0021] A method for assembling locking blades of an aero-engine fan rotor, employing the aforementioned stop device with pads, and comprising the following steps:

[0022] Step 1: First, place the base between two adjacent wheel discs, ensuring that one end face of the axial support arm is pressed against one of the two opposing surfaces on the two wheel discs. Then, insert the pad between the base and the surface of the other wheel disc, ensuring that the pad is pressed against the surface of that wheel disc. Finally, connect the pad to the base.

[0023] Step 2: Rotating the nut causes the screw to move, making the lower support arm move closer to the upper support arm, while the end of the lower support arm lifts up the stop pin;

[0024] Step 3: Use punches of different sizes to flare the stop pins. After flaring, use a file to flatten the part of the stop pin that protrudes above the wheel surface.

[0025] The above two methods for assembling the locking blades of the aero-engine fan rotor also include step four: disassembling the stop device, placing the stop device between two other adjacent two-stage discs, and repeating steps one to three until all stop pins are assembled.

[0026] The existing method for assembling locking pins requires two people to work together. One person places a pry bar on a pad to lift the locking pin, while the other person uses a punch to widen the locking opening of the locking pin. Furthermore, it is difficult to control the force with which the pry bar lifts the locking pin each time. If the force is too small, the opening will not be widened properly and the locking requirements will not be met. If the force is too large, the locking pin may be damaged. As a result, the current assembly method is time-consuming, labor-intensive, inefficient, and prone to damaging parts.

[0027] Compared with existing assembly methods, the stop assembly device of the present invention not only solves the problem that the current assembly of stop pins cannot be operated independently by a single person, but also ensures that the force of lifting the stop pin each time is the same (this force depends on the material of the base and the size of the slot), preventing damage to the parts, effectively improving the assembly efficiency of stop pins and the first-time assembly pass rate, and realizing the high-efficiency, high-quality and low-cost assembly of the fan rotor balance assembly, a core rotating component of aero-engines. Attached Figure Description

[0028] Figure 1 This is a partial schematic diagram of the assembly of the locking blade stop pin of the aero-engine fan rotor in this invention;

[0029] Figure 2 This is a schematic diagram illustrating the assembly principle of the locking blade stop pin for the aero-engine fan rotor in this invention.

[0030] Figure 3 This is a schematic diagram of the aero-engine fan rotor locking blade stop device in this invention;

[0031] Figure 4 This is a schematic diagram of the base in the locking blade stop device for the aero-engine fan rotor of the present invention;

[0032] In the diagram: 1-base; 2-pad; 3-screw; 4-pin; 5-nut; 6-knurled head screw. Detailed Implementation

[0033] The present invention will be further described below with reference to specific embodiments, but it should not be construed as limiting the scope of the subject matter of the present invention to the following embodiments. All modifications, substitutions and alterations made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0034] In this embodiment, the assembly problem of the stop pin is solved in the following way:

[0035] First, the design of the stopping device.

[0036] First, such as Figure 3 and Figure 4 As shown, the stopping device mainly consists of a base 1, a pad 2, a screw 3, a pin 4, a nut 5, and knurled head screws 6. The base 1 is L-shaped. Its axial support arm, parallel to the axis of the aero-engine fan rotor, allows it to engage with the pad 2 and press firmly between the axial end faces of the two-stage discs. Its radial support arm, parallel to the radial direction of the aero-engine fan rotor, corresponds to the assembly position of the stopping pin. Due to the limited space between the two-stage discs after fan assembly, interference structures prevent the entire base 1 from being placed in one go. Therefore, a split design is adopted, where a portion of the base 1 is divided into pad 2. The interference structure is avoided by placing the base 1 and pad 2 sequentially. The base 1 and pad 2 are connected and fixed using knurled head screws 6. Figure 3 As shown, a groove is machined between the upper and lower support arms of the base 1. Through holes are machined near the right ends of both the upper and lower support arms. The inner diameter of the through hole in the upper support arm is larger than the outer diameter of the nut 5, allowing for a clearance for the nut 5 to rotate. The right end of the lower support arm contacts the head (horizontal part) of the stop pin. When the nut 5 is rotated, because the thickness of the upper support arm along the axis of the through hole is greater than that of the lower support arm along the axis of the through hole (making the rigidity of the lower support arm less than that of the upper support arm, causing it to deform before the upper support arm or with a greater deformation amount under external force), the lower support arm deforms and moves closer to the upper support arm. The groove between the upper and lower support arms gradually narrows, thus using the end of the lower support arm to lift the stop pin.

[0037] In the above scheme, the height of the groove can be 1.5mm to 2.5mm.

[0038] In the above scheme, in order to prevent the screw 3 from rotating, a notch is made at the head of the screw 3, and a pin 4 is installed on the lower support arm. The pin 4 is inserted into the notch, so that the screw 3 only moves in a straight line under the drive of the nut 5 and does not rotate.

[0039] In the above scheme, such as Figure 4 As shown, for the "T"-shaped stop pin, the upper arm of the base 1 has a circular clearance groove at the right end to avoid the vertical part (rod) of the stop pin, and below the clearance groove is the end of the lower arm to support the horizontal part (head) of the stop pin.

[0040] Second, the assembly method for locking blades on the aero-engine fan rotor:

[0041] Step 1: For adjacent primary and secondary disks, first place base 1 against the top end face of the secondary disk;

[0042] Step 2: Place the pad 2 into the gap between the base 1 and the first-stage disk, and press it against the bottom end face of the first-stage disk. Use knurled head screws 6 to connect and fix the pad 2 and the base 1. At this time, the lower support arm of the base 1 is in contact with the head (horizontal part) of the "T"-shaped stop pin.

[0043] Step 3: Tighten nut 5 to drive screw 3 upwards, thereby moving the lower support arm closer to the upper support arm. This causes the end of the lower support arm to push the stop pin upwards. Tighten nut 5 until the stop pin can no longer move upwards. At this point, the assembler uses punches with angles α1, α2, α3, α4, and α5 in sequence to flare the stop pin. After flaring, use a file to smooth the portion of the stop pin that protrudes above the fan wheel disc surface until the final state required by the design is achieved. Figure 2 As shown.

[0044] In the above scheme, angles α1, α2, α3, α4 and α5 are 30°, 45°, 60°, 75° and 90° respectively.

[0045] Step four: Similarly, the locking and assembly method of the stop pins for the third and fourth level disks is the same as that for the second level disk. Finally, the stop pins are fixed and locked after the blades of the fan rotor balance assembly, the core rotating component of the aero-engine, are assembled.

[0046] Contents not described in detail in this specification are prior art known to those skilled in the art. Although illustrative specific embodiments of the invention have been described above to facilitate understanding by those skilled in the art, it should be understood that the invention is not limited to the scope of the specific embodiments. Various modifications are readily apparent to those skilled in the art as long as they fall within the spirit and scope of the invention as defined and determined by the appended claims, and all inventions utilizing the concept of this invention are protected.

Claims

1. A device for locking blades of an aero-engine fan rotor, characterized in that, include: The base (1) is L-shaped and includes an axial support arm parallel to the axial direction of the aero-engine fan rotor and a radial support arm parallel to the radial direction of the aero-engine fan rotor. The axial support arm has a slot that divides it into an upper support arm and a lower support arm. The end of the lower support arm forms the position of a support stop pin. The axial support arm also has a through hole that penetrates the upper support arm, the slot and the lower support arm. The thickness of the upper support arm along the axis of the through hole is greater than the thickness of the lower support arm along the axis of the through hole. The screw (3) includes a head and a rod. The outer diameter of the head is larger than the inner diameter of the upper hole of the lower support arm corresponding to the through hole. At least a part of the surface of the rod has external threads. The screw (3) is inserted into the through hole and its head is located on the side of the lower support arm away from the upper support arm. Nut (5), the nut (5) is connected to the external thread of the rod (3) through the through hole on the side corresponding to the upper support arm; A notch is provided at the head of the screw (3); Pin (4), said pin (4) is mounted on the lower support arm, and a portion of the pin (4) is inserted into the notch; The groove cross-sectional shape of the axial support arm is a combination of rectangle and circle, wherein the circular cross-section is located at one end of the rectangular cross-section along its length. The upper arm also includes a clearance groove at its end, below which is the end of the lower arm support stop pin.

2. The aero-engine fan rotor locking blade stop device according to claim 1, characterized in that, It also includes a pad (2), which is detachably connected to one side of the radial support arm on the base (1) by a connector and fits against the surface of the radial support arm.

3. A method for assembling locking blades on an aero-engine fan rotor, characterized in that, The stop device according to claim 1 is used, and includes the following steps: Step 1: Place the base (1) between the two adjacent wheel discs, ensuring that the two end faces of the axial support arm are pressed against the two opposite surfaces of the two wheel discs respectively; Step 2: Rotate the nut (5) to drive the screw (3) to move so that the lower support arm moves closer to the upper support arm, and at the same time the end of the lower support arm lifts up the stop pin; Step 3: Use punches of different sizes to flare the stop pins. After flaring, use a file to flatten the part of the stop pin that protrudes above the wheel surface.

4. A method for assembling locking blades on an aero-engine fan rotor, characterized in that, The stop device according to claim 2 is used, and includes the following steps: Step 1: First, place the base (1) between two adjacent wheel discs, ensuring that one end face of the axial support arm is pressed against one of the two opposing surfaces on the two wheel discs. Then, insert the pad (2) between the base (1) and the surface of the other wheel disc, ensuring that the pad (2) is pressed against the surface of the wheel disc. Then, connect the pad (2) to the base (1). Step 2: Rotate the nut (5) to drive the screw (3) to move so that the lower support arm moves closer to the upper support arm, and at the same time the end of the lower support arm lifts up the stop pin; Step 3: Use punches of different sizes to flare the stop pins. After flaring, use a file to flatten the part of the stop pin that protrudes above the wheel surface.

5. A method for assembling locking blades of an aero-engine fan rotor according to claim 3 or 4, characterized in that: The process also includes step four, disassembling the stop device, placing the stop device between two other adjacent two-stage discs, and repeating steps one through three until all stop pins are assembled.

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