A torque buffer device for shaft-driven fans in aviation

Abstract

This invention relates to a torque buffer device for shaft-driven fans in aircraft, comprising an input shaft, a housing, a friction disc, a clamping spring, an adjusting disc, a cam disc assembly, bearings, and an output shaft. The rollers press against the wavy surface of the cam disc. When the cam disc rotates, the peaks of the wavy surface push the adjusting disc axially to clamp the friction spring, causing the annular shoulder of the input shaft to press against the housing. When the cam disc rotates, the troughs of the wavy surface cause the adjusting disc to axially displace, releasing the clamping force of the friction spring and depressing the annular shoulder of the input shaft from the housing. This invention, employing its torque buffer device, allows for smooth changes in force on the fan drive shaft during start-up or shutdown, preventing fan shaft breakage due to excessive torque during acceleration and deceleration, and improving aircraft reliability.

Description

Technical Field

[0001] This invention relates to the field of aircraft fan structure design, specifically an aircraft shaft-driven fan torque buffer device. Background Technology

[0002] An aerospace-grade shaft-driven fan torque buffer device is employed. This device is mounted on the fan's power receiving shaft and consists of a power shaft connection mechanism, an over-torque shearing mechanism, a friction transmission mechanism, and an angular acceleration detection and actuation mechanism. Under normal operating conditions, the fan driving force is ensured by the friction transmission mechanism. During acceleration, the torque increases and may momentarily exceed the design value. At this time, the angular acceleration detection and actuation mechanism generates axial displacement, reducing the clamping force of the friction transmission mechanism and causing short-term slippage. The fan accelerates at a lower acceleration. After the speed approaches the drive shaft, the angular acceleration detection and actuation mechanism retracts, the friction transmission mechanism restores its normal clamping force, and the fan operates normally. When the fan malfunctions and jams, the over-torque shearing mechanism is destroyed, protecting the drive shaft on the aircraft.

[0003] By using this aviation shaft drive fan torque buffer device, the fan shaft can be prevented from breaking due to excessive torque during acceleration and deceleration, thus improving the aircraft's availability. Summary of the Invention

[0004] The purpose of this invention is to solve the problem of shaft breakage caused by power fluctuations in the airborne shaft-driven fan exceeding the shear shaft protection torque, and to ensure smooth force changes in the transmission shaft during acceleration and deceleration, thereby improving the reliability of the rotating shaft and the aircraft's completeness.

[0005] The technical solution of this invention is:

[0006] A torque buffer device for an aerospace shaft-driven fan is provided, comprising an input shaft 1, a housing 2, a friction disc 3, a compression spring 4, an adjusting disc 5, a cam disc assembly 6, a bearing, and an output shaft 7;

[0007] The front end of the input shaft 1 and the rear end of the output shaft are coaxially arranged inside the housing 2, and the friction disc 3, the compression spring 4, the adjusting disc assembly 5 and the cam disc assembly 6 are sequentially sleeved on the front end of the input shaft 1;

[0008] The input shaft has an annular shoulder at its front end, and the annular shoulder has an axial friction mating surface with the housing. The annular shoulder is located axially between the friction disc 3 and the housing. The clamping spring is disposed between the friction disc and the adjusting disc 5. The spring applies an axial preload to the friction disc. The adjusting disc is splined with the housing, and the adjusting disc has an axially extending lug with a roller.

[0009] The cam disk assembly 6 includes a cam disk, a buffer spring, and a mass block. The surface of the cam disk is wavy and cooperates with the roller. The cam disk and the mass block are in a circumferential sliding fit. The mass block is splinedly connected to the housing. The buffer spring is provided between the mass block and the cam disk, forming a circumferential buffer between the mass block and the cam disk. The bearing is provided between the cam disk and the output shaft, and the output shaft is fixed to the housing. Under the action of the friction spring, the roller presses on the wavy surface of the cam disk. When the cam disk rotates, the peaks of the wavy surface push the adjusting disk to axially displace and press the friction spring, so that the annular shoulder of the input shaft is pressed into the housing. When the cam disk rotates, the troughs of the wavy surface cause the adjusting disk to axially displace and release the pressure of the friction spring, so that the annular shoulder of the input shaft is released from the housing.

[0010] Furthermore, the bearing is a ball bearing.

[0011] Furthermore, there are multiple mass blocks, which are evenly distributed in a circumferential direction.

[0012] Furthermore, there are multiple buffer springs, which are evenly distributed in a circumferential direction.

[0013] Furthermore, the cam disk is a double-layered disk, and the spring and mass block are located between the double-layered disk.

[0014] Furthermore, there are multiple rollers, which are evenly distributed in a circumferential direction.

[0015] Furthermore, the friction spring is a disc spring.

[0016] Furthermore, the bearing is a thrust bearing.

[0017] Furthermore, the friction area of ​​the shell or the annular shoulder is provided with multiple cooling holes, which are evenly distributed circumferentially. Preferably, multiple rings of cooling holes are provided. The flow area of ​​the cooling holes in the shell is not completely blocked by the annular shoulder, so that an airflow passage is formed inside and outside the shell.

[0018] The invented torque buffer device for shaft-driven fans in aviation is installed on the aircraft as a drive shaft, with one end connected to the onboard drive shaft. When the shaft-driven fan starts, the onboard drive shaft accelerates rapidly. Due to rotational inertia and low lubrication system temperature, the torque on the drive shaft is greater than the torque during stable operation, and the fan rotor begins to accelerate along with the buffer device. Under the action of angular acceleration, the cam disk in the buffer device overcomes the force of the return spring and twists at a certain angle. The highest point of the cam is offset from the contact point of the adjusting disk assembly, causing the adjusting disk assembly to move closer to the cam disk assembly under the force of the compression spring. The compression spring's clamping force decreases, and the friction disk slips briefly, ensuring that the rotor accelerates under lower driving force and improving its working conditions.

[0019] As the acceleration process nears completion, the angular acceleration experienced by the buffer device decreases. Under the force of the return spring, the cam disc returns to its initial position, restoring the contact point between the highest point of the cam and the adjusting disc assembly. The adjusting disc moves away from the cam disc, restoring the initial deformation of the compression spring. The friction disc clamping force returns to its normal operating value, and the fan enters a stable operating state. When the fan speed decreases before stopping, the buffer device similarly prevents the drive shaft from stopping too quickly and avoids the instantaneous high torque caused by the fan rotor's rotational inertia, protecting the rotor from slowing down. In the event of a fan jamming fault, the friction disc can continuously slip to prevent damage to the drive shaft. If the friction transmission part jams due to overheating or other reasons, the shear shaft will shear off due to over-torque, protecting the drive shaft from damage.

[0020] The advantages of this invention are: the torque buffer device of this invention can make the force on the fan drive shaft change smoothly during the start-up or stop of the shaft-driven fan, avoid the fan shaft breakage caused by excessive torque during acceleration and deceleration, and improve the aircraft's availability. Attached Figure Description

[0021] Figure 1 A cross-sectional view of the torque buffer device for an aviation shaft-driven fan of the invention.

[0022] Figure 2 Assembly diagram for torque buffer device of shaft-driven fan for aircraft;

[0023] Figure 3 A 3D view of the adjustment disc assembly;

[0024] Figure 4 A 3D view of the cam disc assembly;

[0025] Figure 5 A 3D view of the circumferential limiting block;

[0026] Figure 6 This is a schematic diagram of the internal assembly relationship of the cam disk assembly;

[0027] Figure 7A three-dimensional view of the shell;

[0028] Figure 8 This is a perspective view of the shear axis in Example 1;

[0029] Figure 9 A 3D view of a torque buffer device for shaft-driven fans used in aviation.

[0030] In the figure: 1 - Input shaft, 2 - Housing, 3 - Friction disc, 4 - Compression spring, 5 - Adjustment disc, 6 - Cam disc assembly, 7 - Output shaft, 8 - Bearing, 9 - Annular shoulder, 10 - Wave-shaped disc surface, 11 - Ear plate, 12 - Roller, 13 - Buffer spring, 14 - Mass block. Detailed Implementation

[0031] The disclosed examples will be described more fully with reference to the accompanying drawings, in which some (but not all) of the disclosed examples are shown. In fact, many different examples may be described, and these examples should not be construed as limited to those set forth herein. Rather, these examples are described so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0032] Descriptions of various advantageous arrangements have been shown for illustrative and descriptive purposes, but such descriptions are not intended to be exclusive or limited to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. Furthermore, different advantageous examples may describe different advantages compared to other advantageous examples. One or more examples have been selected and described in order to best illustrate the principles and practical application of the examples, and to enable those skilled in the art to understand that this disclosure contains various examples with various modifications suitable for the particular intended use.

[0033] The example is shown in the appendix. Figure 1 -9. A torque buffer device for an aviation shaft-driven fan, comprising an input shaft 1, a housing 2, a friction disc 3, a compression spring 4, an adjusting disc 5, a cam disc assembly 6, a bearing, and an output shaft 7;

[0034] The front end of the input shaft 1 and the rear end of the output shaft are coaxially arranged inside the housing 2, and the friction disc 3, the compression spring 4, the adjusting disc assembly 5 and the cam disc assembly 6 are sequentially sleeved on the front end of the input shaft 1;

[0035] The input shaft has an annular shoulder at its front end, and the annular shoulder has an axial friction mating surface with the housing. The annular shoulder is located axially between the friction disc 3 and the housing. The clamping spring is disposed between the friction disc and the adjusting disc 5. The spring applies an axial preload to the friction disc. The adjusting disc is splined with the housing, and the adjusting disc has an axially extending lug with a roller.

[0036] The cam disk assembly 6 includes a cam disk, a buffer spring, and a mass block. The surface of the cam disk is wavy and cooperates with the roller. The cam disk and the mass block are in a circumferential sliding fit. The mass block is splinedly connected to the housing. The buffer spring is provided between the mass block and the cam disk, forming a circumferential buffer between the mass block and the cam disk. The bearing is provided between the cam disk and the output shaft, and the output shaft is fixed to the housing. Under the action of the friction spring, the roller presses on the wavy surface of the cam disk. When the cam disk rotates, the peaks of the wavy surface push the adjusting disk to axially displace and press the friction spring, so that the annular shoulder of the input shaft is pressed into the housing. When the cam disk rotates, the troughs of the wavy surface cause the adjusting disk to axially displace and release the pressure of the friction spring, so that the annular shoulder of the input shaft is released from the housing.

[0037] The bearing is a ball bearing.

[0038] The mass blocks are multiple and evenly distributed in a circumferential direction.

[0039] The buffer springs are multiple and evenly distributed in a circumferential direction.

[0040] The cam disk is a double-layer disk, and the spring and the mass block are located between the double-layer disk.

[0041] There are multiple rollers, which are evenly distributed in a circumferential direction.

[0042] The friction spring is a disc spring.

[0043] The bearing is a thrust bearing.

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

Claims

1. A torque buffer device for an aircraft shaft-driven fan, characterized in that... Includes input shaft, housing, friction disc, pressure spring, adjusting disc, cam disc assembly, bearing, and output shaft; The front end of the input shaft and the rear end of the output shaft are coaxially arranged inside the housing, and the friction disc, the clamping spring, the adjusting disc assembly and the cam disc assembly are sequentially sleeved on the front end of the input shaft; The input shaft has an annular shoulder at its front end, and the annular shoulder has an axial friction mating surface with the housing. The annular shoulder is located axially between the friction disc and the housing. The clamping spring is disposed between the friction disc and the adjusting disc. The spring applies an axial preload to the friction disc. The adjusting disc is splined with the housing, and the adjusting disc has an axially extending lug with a roller. The cam disk assembly includes a cam disk, a buffer spring, and a mass block. The surface of the cam disk is wavy and cooperates with the roller. The cam disk and the mass block are in a circumferential sliding fit. The mass block is splinedly connected to the housing. The buffer spring is disposed between the mass block and the cam disk, forming a circumferential buffer between the mass block and the cam disk. The bearing is disposed between the cam disk and the output shaft, and the output shaft is fixed to the housing. Under the action of the compression spring, the roller presses on the wavy surface of the cam disk. When the cam disk rotates, the peaks of the wavy surface push the adjusting disk to axially displace and compress the compression spring, so that the annular shoulder of the input shaft is pressed into the housing. When the cam disk rotates, the troughs of the wavy surface cause the adjusting disk to axially displace and release the compression spring, so that the annular shoulder of the input shaft is released from the housing.

2. The torque buffer device for an aircraft shaft-driven fan according to claim 1, characterized in that... The bearing in question is a ball bearing.

3. The torque buffer device for an aircraft shaft-driven fan according to claim 1, characterized in that... The mass blocks are multiple and evenly distributed in a circumferential direction.

4. The torque buffer device for an aircraft shaft-driven fan according to claim 1, characterized in that... The buffer springs are multiple and evenly distributed in a circumferential direction.

5. The torque buffer device for an aircraft shaft-driven fan according to claim 1, characterized in that... The cam disk is a double-layer disk, and the spring and the mass block are located between the double-layer disk.

6. The torque buffer device for an aircraft shaft-driven fan according to claim 1, characterized in that... The rollers are multiple and evenly distributed in a circumferential direction.

7. The torque buffer device for an aircraft shaft-driven fan according to claim 1, characterized in that... The compression spring is a disc spring.

8. The torque buffer device for an aircraft shaft-driven fan according to claim 1, characterized in that... The bearing in question is a thrust bearing.

9. A torque buffer device for an aircraft shaft-driven fan according to claim 1, characterized in that... The friction area of ​​the shell or annular shoulder is provided with multiple cooling holes, which are evenly distributed circumferentially.

10. A torque buffer device for an aircraft shaft-driven fan according to claim 9, characterized in that... The cooling holes are arranged in multiple rings; the flow area of ​​the cooling holes in the shell is not completely blocked by the annular shoulder, so that an airflow passage is formed inside and outside the shell.

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