Flexible transmission shaft with bidirectional protection function and use method

Abstract

The flexible transmission shaft with the bidirectional protection function comprises an output shaft front section, a core shaft and an output shaft rear end, and is characterized in that a shear bearing section is arranged at the middle end of the output shaft front section, an inserting end is arranged at one end of the output shaft front section, a spiral buckling groove is formed in one side of the inserting end, and a clamping groove is formed in the other side of the inserting end; a starter connecting spline is arranged on the outer ring of the end, away from the spiral buckling groove, of the front section of the output shaft, an inner spline is arranged on one side of the inner wall of the front section of the output shaft, the mandrel comprises a shaft rod, a tail end is arranged at one end of the shaft rod, a first outer spline is arranged at the other end of the shaft rod, and a sealing ring groove is formed in the middle end of the rear end of the output shaft. A second outer spline is arranged on the surface of one end of the rear end of the output shaft, a connecting end is arranged at the other end of the rear end of the output shaft, a first pin hole is formed in one side of the connecting end, and a cylindrical pin is arranged in the first pin hole in a sliding mode. The two-way protection device is simple in structure, two-way protection of the air turbine starter and the aero-engine is achieved, and the use requirement is effectively met.

Description

Technical Field

[0001] The invention relates to the technical field of transmission mechanisms, and in particular to a flexible transmission shaft with a bidirectional protection function and a use method thereof. Background Art

[0002] Aircraft engines and air turbine starters are interrelated. Air turbine starters help aircraft engines start during the aircraft startup phase. During the aircraft startup process, the rotor of the aircraft engine needs to be accelerated to a sufficient speed to achieve autonomous operation. The air turbine starter drives a turbine by using the airflow generated by a high-pressure air source, and then accelerates the engine's rotor to the required speed by transmitting the power of the turbine.

[0003] An air turbine starter is a small-sized turbine starter that uses compressed air to work. It is connected to the splines inside an aircraft engine through a transmission shaft and is used to drive the gas generator rotor during ground and air starting of the aircraft engine. The present invention aims to design a flexible transmission shaft with a two-way protection function. By combining splines and pins, the hard connection between the transmission shaft and the splines inside the engine is replaced to protect the air turbine starter and the aircraft engine from damage to the other party when one of them fails. Summary of the invention

[0004] The object of the present invention is to provide a flexible transmission shaft with a bidirectional protection function and a use method thereof, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: comprising an output shaft front section, a core shaft and an output shaft rear end, characterized in that: a shear section is provided at the middle end of the output shaft front section, an insertion end is provided at one end of the output shaft front section, a spiral buckle groove is provided at one side of the insertion end, a starter connection spline is provided at the outer ring of one end of the output shaft front section away from the spiral buckle groove, and an inner spline is provided at one side of the inner wall of the output shaft front section;

[0006] The core shaft includes a shaft rod, one end of which is provided with a tail end, and the other end is provided with an external spline 1. A sealing ring groove is provided at the middle end of the rear end of the output shaft, and the surface of one end of the rear end of the output shaft is provided with external splines 2, and the other end is provided with a connecting end. A pin hole 1 is opened on one side of the connecting end, and a cylindrical pin is slidably arranged in the pin hole 1.

[0007] Preferably, a second pin hole is opened on one side of the tail end corresponding to the cylindrical pin.

[0008] Preferably, a retaining ring groove is provided at one end of the front section of the output shaft close to the starter connecting spline.

[0009] Preferably, one end of the insertion end extends into the connecting end, and one side of the spiral buckle groove is engaged with the cylindrical pin.

[0010] Preferably, one end of the core shaft is located in the front section of the output shaft, and the external spline 1 is meshed with the internal spline.

[0011] A method for using a flexible transmission shaft with a bidirectional protection function comprises the following steps:

[0012] Step 1, connect the front section of the output shaft to the output end of the turbine starter through the starter connecting spline, and control it by the clutch, connect the rear end of the output shaft to the accessory rotor of the aircraft engine through the external spline 2, and then insert the cylindrical pin into the pin hole 1 and penetrate the pin hole 2, so as to connect the tail end with the connecting end, insert the mandrel into the front section of the output shaft, and mesh the external spline 1 with the internal spline, and insert the installation end into the connecting end, and the spiral buckle groove and the cylindrical pin are clamped, so as to connect the turbine starter with the aircraft engine, wherein the rotation direction of the front section of the output shaft and the rear end of the output shaft is set counterclockwise;

[0013] Step 2: The clutch disengagement speed Mr / min is a constant value. When the starter is working, the turbine component performs work, and drives the aircraft engine accessory rotor to rotate through the front section and rear section of the output shaft. If there is a problem with the aircraft engine, the internal torque of the engine will increase, and the torque at the rear section of the output shaft is transmitted to the front section of the output shaft through the cylindrical pin. When the torque increases to the breaking torque H~KN·m, the insertion end of the front section of the output shaft will be disconnected, and the front section and rear section of the output shaft can no longer drive the aircraft engine accessory rotor to rotate, thereby avoiding damage to the aircraft engine.

[0014] Step 3, after the aircraft engine is started, the aircraft engine accessory rotor rotates with the starter output shaft through the front section and rear end of the output shaft. When the starter output shaft speed exceeds the M value, the starter clutch is disconnected, and the aircraft engine accessory rotor only drives the present application to rotate. If there is a problem with the clutch at this time and it cannot be disengaged, the aircraft engine accessory rotor drives the entire turbine component of the starter to rotate through the front section and rear end of the output shaft, and the torque value increases rapidly. At this time, the torque direction of the front section of the output shaft is the hypotenuse direction of the spiral buckle groove, which cannot withstand the torsional torque. Therefore, the torque at the rear end of the output shaft can only be transmitted to the core shaft through the cylindrical pin, and then transmitted to the front section of the output shaft through the connection of the outer spline and the inner spline. Since the shaft structure is designed as a slender shaft, it cannot withstand a large torsional torque, so the shaft will break under the action of large torque, and the rear end of the output shaft will be spirally rotated out along the spiral buckle groove through the cylindrical pin, and disengaged from the front section of the output shaft, protecting the starter and avoiding damage to the inside of the starter.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The present invention connects the front section of the output shaft and the rear section of the output shaft through the engagement between the spiral buckle groove and the cylindrical pin, and achieves a transmission effect. When the engine fails, the front section and the rear section of the output shaft can be effectively disengaged to avoid damage to the turbine starter.

[0017] 2. The present invention also connects the front section of the output shaft and the rear section of the output shaft through the core shaft, and has a transmission function. After the starter successfully drives the engine, when the starter clutch cannot be disengaged, the core shaft can break itself to protect the engine and avoid damage to the aircraft engine. It effectively plays a protective role and realizes two-way protection of the air turbine starter and the aircraft engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the overall structure of a flexible transmission shaft explosion with a bidirectional protection function according to the present invention;

[0019] Figure 2 This is a schematic diagram of a flexible transmission shaft connection structure with a bidirectional protection function according to the present invention;

[0020] Figure 3 This is a schematic diagram of the disassembled structure of a flexible transmission shaft with a bidirectional protection function according to the present invention;

[0021] Figure 4 The figure is a side structural schematic diagram of a front section of an output shaft in a flexible transmission shaft with a bidirectional protection function according to the present invention.

[0022] In the figure: 1. front section of output shaft; 11. shear section; 12. installation end; 13. spiral buckle groove; 14. starter connection spline; 15. internal spline; 2. mandrel; 21. shaft; 22. tail end; 23. external spline 1; 3. rear end of output shaft; 31. sealing ring groove; 32. external spline 2; 33. connection end; 34. pin hole 1; 4. cylindrical pin; 5. pin hole 2. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] See also Figure 1-4The present invention provides a technical solution: comprising an output shaft front section 1, a core shaft 2 and an output shaft rear end 3, characterized in that: a shear section 11 is provided at the middle end of the output shaft front section 1, an insertion end 12 is provided at one end of the output shaft front section 1, a spiral buckle groove 13 is provided at one side of the insertion end 12, a starter connecting spline 14 is provided at the outer ring of the end of the output shaft front section 1 away from the spiral buckle groove 13, and an inner spline 15 is provided at one side of the inner wall of the output shaft front section 1;

[0025] The core shaft 2 includes a shaft rod 21, one end of which is provided with a tail end 22, and the other end is provided with an external spline 23, a sealing ring groove 31 is provided at the middle end of the output shaft rear end 3, one end surface of the output shaft rear end 3 is provided with an external spline 2 32, and the other end is provided with a connecting end 33, a pin hole 34 is opened on one side of the connecting end 33, and a cylindrical pin 4 is slidably arranged in the pin hole 34, wherein the output shaft front section 1 and the output shaft rear end 3 are both made of low alloy ultra-high strength steel, and the core shaft 2 is made of alloy tool steel, which ensures the overall connection stability and self-strength, and the cylindrical pin 4 is made of alloy structural steel.

[0026] A second pin hole 5 is provided on one side of the tail end 22 corresponding to the cylindrical pin 4, wherein the cylindrical pin 4 and the first pin hole 34 and the second pin hole 5 are interference fit to ensure the connection and fixing effect.

[0027] A retaining ring groove is provided at one end of the output shaft front section 1 close to the starter connection spline 14, which facilitates installation when the output shaft front section 1 is connected to the turbine starter.

[0028] One end of the insertion end 12 extends into the connecting end 33, and one side of the spiral buckle groove 13 is engaged with the cylindrical pin 4. One side of 13 is set as a bevel, and the position engaged with the cylindrical pin 4 is set as a semicircular end, which is convenient for the detachment of the cylindrical pin 4 and at the same time ensures the limitation of the cylindrical pin 4.

[0029] One end of the core shaft 2 is located in the output shaft front section 1, and the external spline 23 is meshed with the internal spline 15, which can achieve an effective transmission effect and ensure the linkage between the output shaft front section 1 and the output shaft rear end 3.

[0030] A method for using a flexible transmission shaft with a bidirectional protection function comprises the following steps:

[0031] Step 1, connect the output shaft front section 1 to the output end of the turbine starter through the starter connecting spline 14, and control it by the clutch, connect the output shaft rear end 3 to the accessory rotor of the aircraft engine through the external spline 2 32, and then insert the cylindrical pin 4 into the pin hole 1 34 and penetrate the pin hole 2 5, so as to connect the tail end 22 with the connecting end 33, insert the mandrel 2 into the output shaft front section 1, and mesh the external spline 1 23 with the internal spline 15, and insert the installation end 12 into the connecting end 33, and at the same time, the spiral buckle groove 13 is clamped with the cylindrical pin 4, so as to connect the turbine starter with the aircraft engine, wherein the rotation direction of the output shaft front section 1 and the output shaft rear end 3 is set counterclockwise;

[0032] Step 2: The clutch disengagement speed Mr / min is a constant value. When the starter is working, the turbine component performs work, and drives the aircraft engine accessory rotor to rotate through the output shaft front section 1 and the output shaft rear end 3. If there is a problem with the aircraft engine, the internal torque of the engine will increase, and the torque of the output shaft rear end 3 is transmitted to the output shaft front section 1 through the cylindrical pin 4. When the torque increases to the breaking torque H~KN·m, the insertion end 12 of the output shaft front section 1 will be disconnected, and the output shaft front section 1 and the output shaft rear end 3 can no longer continue to drive the aircraft engine accessory rotor to rotate, thereby preventing the aircraft engine from being damaged.

[0033] Step three, after the aircraft engine is started, the aircraft engine accessory rotor drives the starter output shaft to rotate through the output shaft front section 1 and the output shaft rear end 3. When the starter output shaft speed exceeds the M value, the starter clutch is disconnected, and the aircraft engine accessory rotor only drives the application to rotate. If there is a problem with the clutch at this time and it cannot be disengaged, the aircraft engine accessory rotor drives the entire starter turbine component to rotate through the output shaft front section 1 and the output shaft rear end 3, and the torque value increases rapidly. At this time, the torque direction of the front section 1 of the output shaft is the hypotenuse direction of the spiral buckle groove 13, which cannot withstand the torsional moment. Therefore, the torque of the rear end 3 of the output shaft can only be transmitted to the core shaft 2 through the cylindrical pin 4, and then transmitted to the front section 1 of the output shaft through the connection between the external spline 23 and the internal spline 15. Since the shaft rod 21 is designed as a slender shaft and cannot withstand large torsional moment, the shaft rod 21 will break under the action of large torque, and the rear end 3 of the output shaft will be screwed out in a spiral surface along the spiral buckle groove 13 through the cylindrical pin 4, and disengaged from the front section 1 of the output shaft, so as to protect the starter and avoid damage to the inside of the starter.

[0034] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0035] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A flexible transmission shaft with a bidirectional protection function, comprising an output shaft front section (1), a core shaft (2) and an output shaft rear end (3), characterized in that: The middle end of the output shaft front section (1) is provided with a shear section (11), one end of the output shaft front section (1) is provided with an insertion end (12), one side of the insertion end (12) is provided with a spiral buckle groove (13), the outer ring of one end of the output shaft front section (1) away from the spiral buckle groove (13) is provided with a starter connection spline (14), and one side of the inner wall of the output shaft front section (1) is provided with an internal spline (15); The core shaft (2) comprises a shaft rod (21), one end of the shaft rod (21) is provided with a tail end (22), and the other end is provided with an external spline (23), the middle end of the rear end (3) of the output shaft is provided with a sealing ring groove (31), the surface of one end of the rear end (3) of the output shaft is provided with an external spline (32), and the other end is provided with a connecting end (33), one side of the connecting end (33) is provided with a pin hole (34), and a cylindrical pin (4) is slidably arranged in the pin hole (34).

2. The flexible transmission shaft with bidirectional protection function according to claim 1, characterized in that: A second pin hole (5) is provided on one side of the tail end (22) corresponding to the cylindrical pin (4).

3. The flexible transmission shaft with bidirectional protection function according to claim 1, characterized in that: A clamping ring groove is provided at one end of the output shaft front section (1) close to the starter connecting spline (14).

4. The flexible transmission shaft with bidirectional protection function and the method of using the same according to claim 1, characterized in that: One end of the insertion end (12) extends into the connecting end (33), and one side of the spiral buckle groove (13) is engaged with the cylindrical pin (4).

5. The flexible transmission shaft with bidirectional protection function and the method of using the same according to claim 1, characterized in that: One end of the core shaft (2) is located inside the front section (1) of the output shaft, and the first external spline (23) is meshed with the internal spline (15).

6. A method for using a flexible transmission shaft with a bidirectional protection function, characterized in that: The following steps are involved: Step 1: connect the output shaft front section (1) to the output end of the turbine starter through the starter connecting spline (14), and control it by the clutch; connect the output shaft rear end (3) to the accessory rotor of the aircraft engine through the external spline 2 (32); then insert the cylindrical pin (4) into the pin hole 1 (34) and pass through the pin hole 2 (5), so as to connect the tail end (22) with the connecting end (33); insert the mandrel (2) into the output shaft front section (1), and mesh the external spline 1 (23) with the internal spline (15); at the same time, insert the installation end (12) into the connecting end (33); at the same time, the spiral buckle groove (13) and the cylindrical pin (4) are engaged, so as to connect the turbine starter with the aircraft engine, wherein the rotation direction of the output shaft front section (1) and the output shaft rear end (3) is set to be counterclockwise; Step 2: The clutch disengagement speed M (r / min) is a constant value. When the starter is working, the turbine component performs work, and drives the aircraft engine accessory rotor to rotate through the output shaft front section (1) and the output shaft rear end (3). If a problem occurs in the aircraft engine, the internal torque of the engine will increase, and the torque of the output shaft rear end (3) will be transmitted to the output shaft front section (1) through the cylindrical pin (4). When the torque increases to a breaking torque H~K (N·m), the insertion end (12) of the output shaft front section (1) will be disconnected, and the output shaft front section (1) and the output shaft rear end (3) will no longer be able to drive the aircraft engine accessory rotor to rotate, thereby preventing the aircraft engine from being damaged. Step 3: After the aircraft engine is started, the aircraft engine accessory rotor drives the starter output shaft to rotate through the output shaft front section (1) and the output shaft rear end (3). When the starter output shaft speed exceeds the M value, the starter clutch is disconnected, and the aircraft engine accessory rotor only drives the starter to rotate. If the clutch has a problem and cannot be disengaged at this time, the aircraft engine accessory rotor drives the entire starter turbine component to rotate through the output shaft front section (1) and the output shaft rear end (3), and the torque value increases rapidly. At this time, the torque direction of the output shaft front section (1) is the hypotenuse direction of the spiral buckle groove (13), which cannot withstand the torsional moment. Therefore, the torque of the output shaft rear end (3) can only be transmitted to the core shaft (2) through the cylindrical pin (4), and then transmitted to the output shaft front section (1) through the connection between the external spline (23) and the internal spline (15). Since the shaft rod (21) is designed as a slender shaft and cannot withstand large torsional moment, the shaft rod (21) will break under the action of large torque, and the output shaft rear end (3) will be screwed out along the spiral buckle groove (13) through the cylindrical pin (4) in a spiral surface, and disengaged from the output shaft front section (1), thereby protecting the starter and avoiding damage to the inside of the starter.

Images