A transmission shaft with multi-point power output and an aircraft engine

Abstract

The present invention discloses a multi-point power output drive shaft for an aircraft engine. The drive shaft is provided with three sections of splines: front, middle, and rear, for transmitting power through the multi-point splines. The front section splines cooperate with the internal splines of a reducer component for transmission, with the spline pair having a clearance of 0.29 to 0.41. The middle section splines cooperate with the internal splines of the oblique transmission device drive shaft for transmission, with a clearance of 0.14 to 0.25. The front end of the rear section of the splines cooperates with the internal splines of the accessory drive gear for transmission; the rear end of the rear section of the internal splines cooperates with the internal splines of the compressor first-stage impeller for transmission, with the spline pair having a clearance of 0.14 to 0.25. The front splines are provided with an oil collecting pan for lubrication and an oil drain pan for draining lubricating oil. The three splines are designed in a reasonable position, with the spline spacing matching the power transmission level. The multi-point power transmission is stable, achieving stable transmission at each power output point on the drive shaft and achieving a spline load distribution effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of aero-engines, and in particular relates to a transmission shaft of an aero-engine; the present invention also relates to an aero-engine. Background Art

[0002] The drive shaft with multi-point power transmission is a key structural component of a certain type of turboprop aircraft engine. The shaft's power transmission uses an involute spline connection, with power transmission splines located at the front, middle, and rear of the shaft. The rear section of the rear spline is connected to the spline inside the first-stage compressor wheel as the power input. The front section of the rear spline, the middle spline, and the front spline transmit power to the engine accessories, the oblique transmission device, and the reducer components, respectively. The structural design of the drive shaft with multi-point power output must ensure that the drive shaft can smoothly transmit power from multiple positions, have an automatic self-aligning function to achieve load balancing, and play a role in reducing vibration. At the same time, the drive shaft rotates at high speed and is heavily loaded during operation, so lubrication and cooling issues must be considered for unlubricated splines.

[0003] Patent publication number CN114412933 discloses a splined shaft and a system for an aero-engine. This technical solution discloses a transmission shaft with external splines located at both ends of the shaft, one end for connecting to a transmission gear, and the other end for connecting to a drive gear. In this invention, the spline teeth are polished into a parabolic structure with a high center and low ends, and the ends of the spline teeth are reshaped to address the uneven distribution of working loads on the spline tooth surface. This makes the contact stress of the internal and external splines more uniform, reduces the stress on the tooth surface, improves fatigue resistance, and increases service life. However, this invention does not address the issue of multi-point power output, nor does it address the problem of achieving smooth transmission during multi-point power output. Summary of the Invention

[0004] The present invention aims to solve the problems in the prior art of multi-point output transmission shafts, such as the inability to achieve balanced power transmission and the inability to perform lubrication, and invents a multi-point power output transmission shaft to solve the above problems.

[0005] The technical solution adopted in the present invention is:

[0006] A multi-point power output drive shaft transmits power via splines. The drive shaft is equipped with front, middle, and rear splines, respectively used to transmit power to a reducer, an oblique transmission device, accessories, and a compressor. The front spline cooperates with the internal splines of the reducer components for transmission, with the spline pair having a clearance of 0.29 to 0.41. The ratio of the length l4 of the front spline to the pitch circle diameter d4 is l4 / d4 = 0.3 to 0.5. The ratio of the distance L2 from the front spline to the rear end of the rear spline to the length l4 of the front spline is designed to be L2 / l4 = 20 to 22. The middle section spline cooperates with the internal spline of the oblique transmission device drive shaft for transmission, with the clearance of the spline pair being 0.14 to 0.25. The ratio of the length l3 of the middle section spline to the pitch circle diameter d3 is designed to be l3 / d3 = 0.5 to 0.8. The ratio of the distance L1 from the middle section spline to the rear section of the rear spline to the length l3 of the middle section spline is designed to be L1 / l3 = 5 to 8. The front end of the rear section of the spline cooperates with the internal spline of the accessory drive gear; the rear end of the rear section of the internal spline cooperates with the internal spline of the first stage impeller of the compressor for transmission, with the side clearance of the spline pair being 0.14 to 0.25. The ratio of the length l1 of the rear section of the rear spline of the drive shaft to the pitch circle diameter d1 is designed to be l1 / d1 = 0.8 to 1, and the ratio of the length l2 of the front section of the rear spline of the drive shaft to the pitch circle diameter d1 is designed to be l2 / d1 = 0.4 to 0.6. An oil collecting pan for lubrication and an oil drain pan for draining the lubricating oil are provided at the front end spline.

[0007] Furthermore, the oil collecting pan is a disc-shaped part with a conical spoke, which is arranged on one side of the inner spline of the sun gear of the reducer component. An arc groove for positioning is opened on the outer circle of the oil collecting pan, and an oil storage groove is opened on the end face close to the inner spline of the sun gear of the reducer component.

[0008] Furthermore, the oil drain pan is a disc-shaped part, and an arc groove for positioning is provided on the outer circle of the oil drain pan, which is arranged on the other side of the spline inside the sun gear of the reducer component, and an oil drain groove is provided on the end face close to the spline inside the sun gear of the reducer component, and the oil drain groove is provided with an oil drain hole and an oil drain arc groove.

[0009] Furthermore, a locating pin hole is provided on each side of the inner spline of the sun gear of the reducer component for installing a locating pin, and the outer circle of the locating pin cooperates with the arc grooves on the oil collecting pan and the oil drain pan respectively; two clamping ring grooves for installing a clamping ring are also provided at both ends of the inner hole where the inner spline of the sun gear of the reducer component is located.

[0010] Furthermore, the transmission shaft is a thin-walled hollow tube part.

[0011] Furthermore, the wall thickness difference of the shaft sections of the transmission shaft is no more than 0.1 mm.

[0012] Furthermore, the ratio of the length l4 of the front section spline to the pitch circle diameter d4 is l4 / d4=0.3; the ratio of the distance L2 from the front section spline to the rear end of the rear section spline to the length l4 of the front section spline is designed to be L2 / l4=20.5; the ratio of the length l3 of the middle section spline to the pitch circle diameter d3 is designed to be l3 / d3=0.5, and the ratio of the distance L1 from the middle section spline to the rear section of the rear end spline to the length l3 of the middle section spline is designed to be L1 / l3=5; the ratio of the length l1 of the rear section of the rear end spline of the transmission shaft to the pitch circle diameter d1 is designed to be l1 / d1=0.8, and the ratio of the length l2 of the front section of the rear end spline of the transmission shaft to the pitch circle diameter d1 is designed to be l2 / d1=0.4.

[0013] Furthermore, the spline pair composed of the spline on the transmission shaft and the object part adopts a movable spline, which relies on the tooth side for centering during operation, and there is a certain tooth side clearance between the spline pairs.

[0014] Furthermore, the splines are all nitrided and shot peened, and the surface of the splines is silver plated.

[0015] Furthermore, the present invention also provides a turboprop aircraft engine that adopts any of the above-mentioned multi-point power output transmission shafts.

[0016] Compared with the prior art, the technical effects of the present invention are:

[0017] The designed positions of the three splines are relatively reasonable, the spline spacing matches the power transmission size, the power transmitted at multiple points is stable, and stable transmission of each power output point on the drive shaft is achieved.

[0018] The drive shaft acts as a gear coupling connecting the power input end of the first-stage impeller of the compressor and the sun gear of the reducer component. At this time, the front-end spline pair and the rear-end spline pair of the drive shaft adopt a larger tooth gap, which can compensate for a certain radial displacement and skew between the connected axes (i.e., the drive shaft axis), so that the sun gear of the reducer component can achieve automatic centering and parallel floating. During the floating process of high-speed rotation, the load distribution along the tooth width direction of the gear meshing tooth surface of the sun gear of the reducer component and the spline pair meshing tooth surface of its internal spline and the front-end spline of the drive shaft is improved, thereby realizing the load-balanced characteristics of the gears of the sun gear of the reducer component and the splines of the drive shaft, realizing the reduction of the gear vibration of the reducer component and the buffering of the load impact of the first-stage impeller of the compressor, and playing a two-way protection role for the reducer component and the compressor rotor, thereby ensuring the stable operation of the entire engine.

[0019] At the same time, an oil collecting pan, an oil drain pan and a clamping ring are designed at the front spline of the transmission shaft to ensure the lubrication and cooling effect of the front spline of the transmission shaft and the spline inside the sun gear of the reducer component, so that the transmission shaft can work normally under high speed and heavy load conditions and meet the engine use requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The diagram is a structural diagram of the transmission shaft (the upper left sub-diagram is the tooth profile diagram of spline 5, and the upper right sub-diagram is the tooth profile diagram of splines 2, 3, and 4);

[0021] Figure 2 This is the assembly structure diagram of the drive shaft;

[0022] Figure 3 This is a partial enlarged view of the transmission shaft;

[0023] Figure 4 This is the structure diagram of the sun gear of the reducer component (the lower right figure is the spline tooth profile diagram);

[0024] Figure 5 This is the three-dimensional structure diagram of the sun gear of the reducer component;

[0025] Figure 6 This is the oil tray structure diagram;

[0026] Figure 7 This is a three-dimensional structural diagram of the oil tray;

[0027] Figure 8 This is the oil drain pan structure diagram;

[0028] Figure 9 This is a three-dimensional structural diagram of the oil drain pan;

[0029] Figure 10 This is the structural diagram of the clamp ring and locating pin.

[0030] 1. Power shaft; 2. Rear section of rear spline; 3. Front section of rear spline; 4. Middle section spline; 5. Front spline; 6. Front shaft section; 7. Rear shaft section; 8. Tail section; 9. Spoke plate; 10. Compressor first stage impeller; 11. Accessory transmission driving gear; 12. Diagonal transmission device drive shaft; 13. Reducer component sun gear; 14. Locating pin; 15. Oil collecting pan; 16. Oil drain pan; 17. Retaining ring; 18. Engine internal fuel injector; 18. Retaining ring groove; 19. Locating pin hole; 20. Oil storage tank; 21. Arc groove 1; 22. Oil drain tank; 23. Oil drain hole; 24. Oil unloading arc groove; 25. Arc groove 2. d1, d3. Pitch arc diameters of the rear end spline and the middle section spline; d4. Pitch arc diameter of the front end spline; R. Adapter arc; l1. Length of the rear section of the rear end spline; l2. Length of the front section of the rear end spline; l3. Length of the middle section spline; l4. Length of the front end spline; L1. Distance from the middle section spline 4 to the rear section 2 of the rear end spline; L2. Distance from the front end spline 4 to the rear section 2 of the rear end spline. DETAILED DESCRIPTION

[0031] To make the technical problems, technical solutions, and beneficial effects of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly or indirectly located on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. Terms such as "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer" indicate directions or positions based on those shown in the accompanying drawings and are provided solely for ease of description and should not be construed as limiting the present invention. The terms "first" and "second" are used solely for descriptive purposes and should not be construed to indicate or imply relative importance or to implicitly specify the number of technical features. "Multiple" means two or more, unless otherwise specifically defined.

[0032] The present invention is further described below in conjunction with specific embodiments. The accompanying drawings are for illustrative purposes only and are schematic diagrams rather than actual drawings, and should not be understood as limiting this patent. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the drawings.

[0033] Example 1

[0034] like Figure 1-2 As shown, a transmission shaft with multi-point power output, the transmission shaft 1 is a thin-walled hollow tube type part, designed with front end splines 5, middle end splines 4 and rear end splines. The rear end splines are composed of front section 3 and rear section 2. The splines are used to transmit power.

[0035] The rear section external spline 2 of the rear end spline cooperates with the internal spline 10 of the first stage impeller of the compressor for transmission, and the rear section external spline 3 of the rear end spline cooperates with the internal spline 11 of the accessory drive gear for transmission. The side clearance of the above spline pair is designed to be 0.25. Since the power transmitted by the rear section of the rear end spline is only 4% of the power transmitted by the front section, a concentrated spline is designed to serve as both the power input end and the partial power output end. This will not affect the meshing performance of the power transmission spline, and can also simplify the structural design, facilitate processing and reduce manufacturing costs. Spline length that is too long will increase the difficulty of manufacturing and increase costs. In addition, due to the error of the spline tooth guide, the uneven distribution of load along the tooth length direction will increase. Therefore, in order to meet the power transmission requirements, the ratio of the length l1 of the rear section 2 of the rear end spline of the transmission shaft to the pitch circle diameter d1 is designed to be l1 / d1=0.8, and the ratio of the length l2 of the front section 3 of the rear end spline of the transmission shaft to the pitch circle diameter d1 is designed to be l2 / d1=0.4.

[0036] The external spline 4 of the middle section spline cooperates with the internal spline 12 of the transmission shaft of the oblique transmission device. The parameters of this section of spline are the same as those of the rear end spline to facilitate spline processing. The fitting clearance of the spline pair is also designed to be a large fitting tooth side clearance of 0.25. The power transmitted by the middle section spline 4 accounts for 2% of the power transmitted by the rear end spline rear section 2 (i.e. the total output power). The ratio of the length l3 of the middle section spline 4 to the pitch circle diameter d3 is designed to be l 3 / d3 = 0.5. To improve the uneven distribution of spline tooth load along the tooth length caused by torsional deformation of the transmission shaft during power transmission, the ratio of the distance L1 from the middle spline 4 to the rear end spline rear section 2 of the transmission shaft to the length l3 of the middle spline 4 is designed to be L1 / l3 = 5.

[0037] The external spline 5 of the front section spline cooperates with the internal spline of the sun gear 13 of the reducer component for transmission, and the fitting clearance of the spline pair is designed to be 0.41; the ratio of the length l4 of the front section spline 5 to the pitch circle diameter d4 is designed to be l4 / d4=0.3; the ratio of the distance L2 from the front section spline 5 to the rear section 2 of the rear section spline to the length l4 of the front section spline 5 is designed to be L2 / l4=20.5.

[0038] It can be seen from the above-mentioned transmission shaft structural design that the ratio of the tooth side clearance and the axial dimension L to the tooth length l of the front end spline of the transmission shaft is larger than that of other splines. This is because the power transmitted by the transmission shaft 1 is output from the rear end to the front end, and the power transmitted by the front end spline 5 accounts for 96% of the power transmitted by the rear end spline rear section 2 (that is, the total output power), which is much larger than the power transmitted by the middle section spline 4 and the front end spline 3. The torsional deformation of the designed transmission shaft front shaft section 6 is greater than the torsional deformation of the rear shaft section 7. Therefore, the front end spline is designed with a larger fitting clearance and a longer axial dimension. On the one hand, it can compensate for the influence of the torsional deformation caused by the transmission shaft when transmitting power on the meshing of the front end spline, thereby realizing the uniform load of the spline; on the other hand, the turboprop engine deceleration The reducer component sun gear 13 is a floating structure, and the transmission shaft acts as a gear coupling connecting the power input end 10 of the first-stage impeller of the compressor and the reducer component sun gear 13. At this time, the front-end spline pair and the rear-end spline pair of the transmission shaft adopt a larger tooth gap, which can compensate for a certain radial displacement and skew between the connected axes (i.e., the transmission shaft axis), so that the reducer component sun gear 13 can achieve automatic centering and parallel floating. During the high-speed rotation floating process, the load distribution along the tooth width direction of the gear meshing tooth surface of the reducer component sun gear 13 and the spline pair meshing tooth surface of its internal spline and the front-end spline 5 of the transmission shaft is improved, thereby achieving the load-balanced characteristics of the gears of the reducer component sun gear 13 and the splines of the transmission shaft 1.

[0039] like Figure 3-4 As shown, an oil collecting pan 15 and an oil drain pan 16 are respectively installed on both sides of the inner spline of the reducer component sun gear 13. The oil collecting pan 15 is used to lubricate the front end spline 5 of the transmission shaft and the inner spline of the reducer component sun gear 13. The oil drain pan 16 is convenient for timely draining the lubricating oil after lubricating the front end spline 5 of the transmission shaft and the inner spline of the reducer component sun gear 13, so as to maintain the fluidity of the lubricating oil and take away the heat generated when the splines are engaged.

[0040] Because the power shaft transmits a large amount of power, its spline tooth roots adopt round tooth roots; in addition, the spline pair consisting of the spline on the power shaft and the object part adopts a movable spline, which relies on the tooth side for centering during operation. There is a certain tooth side clearance between the spline pairs to adapt to the influence of the misalignment of the input and output axis.

[0041] Because the transmission shaft 1 has high speed and heavy load characteristics, the splines on it are all nitrided and shot peened to improve the wear resistance and fatigue strength of the splines; at the same time, the spline surface is silver-plated to reduce friction between the spline pairs and prevent adhesion.

[0042] To ensure that the drive shaft 1 effectively dampens vibration and impact, the wall thickness difference between the drive shaft segments must be strictly controlled. The wall thickness difference between the front and rear segments 6 and 7 of the drive shaft is designed to be on the order of 0.1 mm. At the same time, the drive shaft 1 must undergo a dynamic balancing check, and the designed imbalance is designed to be G2.5. The tail segment 8, located behind the rear spline of the drive shaft, is longer than the transition R between the rear spline and the tail segment, and features evenly spaced grooves on the end face. This serves as a transition zone for shot peening and silver plating of the spline, and also as a material removal area for dynamic balancing (i.e., material is removed from the notches to ensure a qualified dynamic balancing test). Furthermore, the front end of the front segment 6 is longer than the transition fillet within the spoke 9, also serving as a material removal area for dynamic balancing.

[0043] The front spline 5 of the drive shaft is connected to the front shaft section 6 via a spoke 9. Because the spoke must withstand the torque generated by the drive shaft's power transmission, to prevent stress concentration, the inner and outer walls of the spoke 9, connecting the front spline 5 and the front shaft section 6, use a large arc R transition. The inner and outer walls of the spoke are polished. In addition, all other spline-to-segment connections use a large arc R transition.

[0044] Example 2

[0045] A multi-point power output drive shaft is designed with front splines 5, mid-end splines 4, and rear splines. The rear splines consist of a front section 3 and a rear section 2. Each spline is used to transmit power, achieving multi-point power transmission. The external splines 5 of the front splines mate with the internal splines of the sun gear 13 of the reducer component.

[0046] like Figure 4-10 As shown, the reducer component sun gear 13 has two locating pin holes on either side of its internal spline for mounting two locating pins 14. The outer diameters of these locating pins mate with circular grooves in the oil collecting pan 15 and the oil drain pan 16 to define their positions and circumferential displacement. Two retaining ring grooves are also located at either end of the internal spline bore of the reducer component sun gear 13 for mounting two retaining rings 17, which limit the axial displacement of the oil collecting pan 15 and the oil drain pan 16. To improve the wear resistance and fatigue strength of the internal spline of the reducer component sun gear 13, the spline is carburized and shot peened. The spline surface is also copper-plated to prevent sticking. Furthermore, to reduce vibration caused by gear imbalance, the reducer component sun gear 13 is statically balanced using the spline as a reference. The imbalance is rated at G2.5, and material removal from the end faces of the component is permitted to meet the static balance requirements.

[0047] The oil collecting pan 15 is a disc-shaped part with a tapered spoke. An arc groove 21 is provided on the outer circle to cooperate with the positioning pin. An oil storage groove 20 is provided on the end face close to the spline inside the sun gear 13 of the reducer component. The tapered spoke and the oil storage groove 20 help to collect the lubricating oil sprayed by the fuel injector 18 inside the engine and lubricate the spline 5 at the front end of the drive shaft and the spline inside the sun gear 13 of the reducer component.

[0048] The oil drain pan 16 is a disc-shaped part with an arc groove 25 on its outer circle that cooperates with the locating pin. An oil drain groove is provided on the end face close to the spline inside the sun gear 13 of the reducer component. An oil drain hole 23 and an oil drain arc groove 24 are provided on the oil drain groove 22 to facilitate timely drainage of the lubricating oil behind the spline 5 at the front end of the lubricating drive shaft and the spline inside the sun gear 13 of the reducer component, thereby maintaining the fluidity of the lubricating oil and taking away the heat generated when the splines are engaged.

[0049] The clamping ring 17 is tightened in the clamping ring groove 18 of the sun gear 13 of the reducer component by elastic force, and a small hole is opened at the opening to facilitate installation and disassembly.

[0050] The above-mentioned positioning pin 14, oil collecting pan 15, oil drain pan 16 and retaining ring 17 not only ensure that the spline 2 at the front end of the transmission shaft and the spline inside the sun gear 13 of the reducer component are fully lubricated during operation, but also ensure the engagement length of the spline pair, thereby improving the working reliability of the transmission shaft 1 and the sun gear of the reducer component.

[0051] Example 3

[0052] This embodiment differs from Embodiment 1 in that the external splines 2 of the rear section of the rear spline engage with the internal splines 10 of the compressor first-stage impeller, and the external splines 3 of the rear section of the rear spline engage with the internal splines 11 of the accessory drive gear. The side clearance of these spline pairs is designed to be 0.14. The ratio of the length l1 of the rear section of the propeller shaft rear spline to the pitch circle diameter d1 is designed to be l1 / d1 = 1, and the ratio of the length l2 of the front section of the propeller shaft rear spline to the pitch circle diameter d1 is designed to be l2 / d1 = 0.6.

[0053] The external splines 4 of the middle spline section mate with the internal splines 12 of the drive shaft of the oblique transmission device. The parameters of this spline section are identical to those of the rear spline section to facilitate spline machining. The spline pair is also designed with a relatively large side clearance of 0.14. The ratio of the length l3 of the middle spline section to the pitch circle diameter d3 is designed to be l3 / d3 = 0.8. The ratio of the distance L1 from the middle spline section to the rear section of the rear spline section to the length l3 of the middle spline section is designed to be L1 / l3 = 8.

[0054] The external splines 5 of the front spline mate with the internal splines of the reducer sun gear 13, with a clearance of 0.29. The ratio of the front spline length l4 to the pitch circle diameter d4 is l4 / d4 = 0.5. The ratio of the distance L2 from the front spline to the rear end of the rear spline to the length l4 of the front spline is designed to be L2 / l4 = 22.

[0055] By designing the fitting clearance of the spline pair to the above-mentioned size, the requirements of the transmission shaft of the present invention for stable output power and uniform load can also be achieved.

[0056] Example 4

[0057] This embodiment discloses a turboprop aircraft engine, which uses any of the multi-point power output transmission shafts described in Examples 1-3.

[0058] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of the present invention.

Claims

1. A transmission shaft with multi-point power output, wherein the transmission shaft transmits power through splines, characterized in that: The transmission shaft is provided with three sections of splines, front, middle and rear, for transmitting power to the reducer, oblique transmission device, accessories and compressor respectively; The front spline cooperates with the internal spline of the reducer component for transmission, and the fitting clearance of the spline pair is 0.29 to 0.41; the ratio of the length l4 of the front spline to the pitch circle diameter d4 of the front spline is l4 / d4=0.3 to 0.5; the ratio of the distance L2 from the front spline to the rear end of the rear spline to the length l4 of the front spline is designed to be L2 / l4=20 to 22; The middle section spline cooperates with the spline inside the transmission shaft of the oblique transmission device for transmission. The clearance of the spline pair is 0.14-0.

25. The ratio of the length l3 of the middle section spline to the pitch circle diameter d3 of the middle section spline is designed to be l3 / d3=0.5-0.

8. The ratio of the distance L1 from the middle section spline to the rear end of the rear section spline to the length l3 of the middle section spline is designed to be L1 / l3=5-8. The front end of the rear spline cooperates with the internal spline of the accessory drive gear; the rear end of the rear spline cooperates with the internal spline of the compressor first-stage impeller, and the side clearance of the spline pair is 0.14 to 0.

25. The ratio of the rear end length l1 of the rear spline of the transmission shaft to the pitch circle diameter d1 of the rear spline is designed to be l1 / d1=0.8 to 1, and the ratio of the front end length l2 of the rear spline of the transmission shaft to the pitch circle diameter d1 of the rear spline is designed to be l2 / d1=0.4 to 0.

6. The front section spline is provided with an oil collecting pan for lubrication and an oil drain pan for draining the lubricating oil.

2. The transmission shaft with multi-point power output according to claim 1, characterized in that: The oil collecting pan is a disc-shaped part with a tapered spoke, which is arranged on one side of the inner spline of the sun gear of the reducer component. An arc groove for positioning is opened on the outer circle of the oil collecting pan, and an oil storage groove is opened on the end face close to the inner spline of the sun gear of the reducer component.

3. The transmission shaft with multi-point power output according to claim 2, characterized in that: The oil drain pan is a disc-shaped part. An arc groove for positioning is provided on the outer circle of the oil drain pan. It is located on the other side of the spline inside the sun gear of the reducer component. An oil drain groove is provided on the end face close to the spline inside the sun gear of the reducer component. The oil drain groove is provided with an oil drain hole and an oil drain arc groove.

4. A transmission shaft with multi-point power output according to claim 2 or 3, characterized in that: A locating pin hole is provided on each side of the inner spline of the reducer component sun gear for installing a locating pin, and the outer circle of the locating pin cooperates with the arc grooves on the oil collecting pan and the oil drain pan respectively; two clamping ring grooves for installing a clamping ring are also provided at both ends of the inner hole where the inner spline of the reducer component sun gear is located.

5. The transmission shaft with multi-point power output according to claim 1, characterized in that: The transmission shaft is a thin-walled hollow tube part.

6. The transmission shaft with multi-point power output according to claim 5, characterized in that: The wall thickness difference of the shaft sections of the transmission shaft is no more than 0.1 mm.

7. The transmission shaft with multi-point power output according to claim 1, characterized in that: The ratio of the length l4 of the front spline to the pitch circle diameter d4 of the front spline is l4 / d4=0.3; the ratio of the distance L2 from the front spline to the rear end of the rear spline to the length l4 of the front spline is designed to be L2 / l4=20.5; the ratio of the length l3 of the middle spline to the pitch circle diameter d3 of the middle spline is designed to be l3 / d3=0.5, and the ratio of the distance L1 from the middle spline to the rear end of the rear spline to the length l3 of the middle spline is designed to be L1 / l3=5; the ratio of the length l1 of the rear end of the rear spline of the transmission shaft to the pitch circle diameter d1 of the rear spline is designed to be l1 / d1=0.8, and the ratio of the length l2 of the front end of the rear spline of the transmission shaft to the pitch circle diameter d1 of the rear spline is designed to be l2 / d1=0.

4.

8. The transmission shaft with multi-point power output according to claim 1, characterized in that: The spline pair composed of the spline on the transmission shaft and the object part adopts a movable spline, which relies on the tooth side for centering during operation, and there is a certain tooth side clearance between the spline pairs.

9. The transmission shaft with multi-point power output according to any one of claims 7 or 8, characterized in that: The splines are all subjected to nitriding and shot peening treatments, and the surfaces of the splines are silver-plated.

10. An aircraft engine, characterized in that: A transmission shaft with multi-point power output according to any one of claims 1 to 9 is used.

Images