High-reliability servo actuating device

Abstract

The invention provides a high-reliability servo actuating device which comprises an actuator body, the outer end of a piston rod of the actuator body penetrates out of a connecting part at a port of the actuator body, a locking plate and a limiting thread sleeve are arranged on the outer side of the connecting part, and the locking plate can move in the length direction of the connecting part. A first limiting nut is further connected to the connecting position of the outer end of the piston rod and the connecting base in a screwed mode, an emergency centering groove is formed in the position, corresponding to the piston cavity, of the inner wall of a shell of the actuator body, an emergency centering opening is formed in the surface of the shell, and the emergency centering groove is communicated with the emergency centering opening through a centering channel arranged in the side wall of the shell. The device has the beneficial effects that the stroke is adjustable through the limiting screw sleeve and the locking plate; high-pressure oil can be led out of the shell through the emergency centering groove, and the requirement for the opening degree of a vector nozzle of an engine can be met.

Description

Technical Field

[0001] The invention belongs to the technical field of servo actuators, and in particular relates to a high-reliability servo actuator. Background Art

[0002] With the rapid changes in the modern air combat environment, combat aircraft have put forward higher maneuverability requirements, requiring them to be better in post-stall maneuverability. Therefore, the demand for aircraft engines to be equipped with vector nozzles has gradually increased, in order to achieve precise control of the thrust output direction of the aircraft engine by changing the direction of the nozzle, provide engine thrust in the off-axis direction, and then maintain the lift of the aircraft under high angle of attack conditions, and improve the post-stall maneuverability of combat aircraft. Usually, aircraft engines achieve this function by adding a nozzle control loop to the fuel control system, that is, adding a servo actuator at the nozzle to control the nozzle direction. This type of nozzle is called a vector nozzle.

[0003] Compared with the servo actuators widely used in the adjustable inlet guide vanes of aircraft engine fans and compressors, multiple sets of actuators are usually set at the vector nozzle and their displacement output is controlled separately. The nozzle angle is deflected by the displacement difference, and the actuator stroke corresponding to the neutral position of the nozzle is in the middle position. The traditional servo actuator will return to one end when the engine loses power, but such emergency settings at the nozzle cannot meet the requirements of the engine vector nozzle opening, so the emergency return function is an important requirement of the nozzle vector actuator.

[0004] Since the nozzle vector actuator usually has a synchronous mechanism design, its mechanical structure is usually more complicated. Therefore, the traditional nozzle vector actuator usually adopts a fixed stroke design to simplify its structure. However, the fixed stroke actuator cannot fully meet the needs of adjusting the initial nozzle area during assembly during actual installation, and is not conducive to the development of such product series. Therefore, in view of the demand for improved assembly processability of the nozzle vector actuator and the rapidly increasing demand for product types, it is very important for it to have an adjustable stroke function.

[0005] At the same time, the vector nozzle is located at the part with the highest energy in the aircraft engine. Changing the shape and direction of the nozzle requires overcoming huge aerodynamic forces. Usually, the load of the actuator will reach ten or even dozens of times that of similar devices in the fan, compressor and other parts. This makes the eccentric load that the actuator bears when working is also much greater than that of similar devices. If no measures are taken, the piston rod of the actuator will suffer more serious wear and tear on the cylinder due to the lateral force, which may eventually evolve into a piston rod damage failure, resulting in oil leakage or movement jamming, affecting flight safety. Therefore, the design of lateral force resistance under high load conditions is an important requirement for this type of servo actuator.

[0006] Based on the above analysis, a high-reliability servo actuator that has emergency return to center function, adjustable stroke function and can withstand lateral force under large load conditions is of great significance. Summary of the invention

[0007] In view of this, the present invention aims to overcome the above-mentioned deficiencies in the prior art and propose a high-reliability servo actuator.

[0008] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0009] A high-reliability servo actuator comprises an actuator body, wherein the outer end of a piston rod of the actuator body passes through a connecting portion arranged at a port of the actuator body, a locking plate and a limiting screw sleeve are arranged on the outer side of the connecting portion, and the locking plate can move along the length direction of the connecting portion, and the adjusting distance of the limiting screw sleeve is limited by the locking plate, and a first limiting nut is also threadedly connected at the connection between the outer end of the piston rod and the connecting seat, and the stroke of the actuator body is controlled by the distance between the first limiting nut and the limiting screw sleeve when the piston rod is moved, an emergency return groove is opened on the inner wall of the shell of the actuator body at a position corresponding to the piston cavity, and an emergency return opening is opened on the surface of the shell, and the emergency return groove is connected to the emergency return opening through a return channel arranged in the side wall of the shell.

[0010] Furthermore, the outer end of the limiting screw sleeve is aligned with the outer end of the connecting portion or extends out of the outer end of the connecting portion.

[0011] Furthermore, there are two first limiting nuts, which are tightly pressed against each other.

[0012] Furthermore, a second limiting nut is threadedly connected to the connection portion at the rear side of the locking plate, and the locking plate is tightened by the second limiting nut.

[0013] Furthermore, a guide groove is opened on the surface of the connecting part along the length direction, the locking plate is an annular structure sleeved on the outside of the connecting part, an integrally formed limit block is provided on the side of the locking plate facing the limit screw sleeve, and the inner end of the limit block is inserted in the guide groove, and a plurality of radially arranged grooves are evenly arranged on the end of the limit screw sleeve facing the locking plate, and the limit block is clamped together with one of the grooves.

[0014] Furthermore, an annular groove is provided along the inner wall at the port of the connection portion, and a bushing is installed in the annular groove.

[0015] Furthermore, a mounting hole is opened on the outer side of the connecting portion corresponding to the bushing, and a pin is installed in the mounting hole, and the bushing is fixed in the annular groove through the pin.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] (1) The high-reliability servo actuator described in the present invention adds a stroke-adjustable mechanism on the basis of the original actuator product, that is, the stroke is adjustable through a limit screw sleeve and a locking plate, thereby improving the assembly processability of such products during engine assembly; the added stroke-adjustable mechanism has a simple structure and does not interfere with more complex functional structures such as hydraulic cylinders, sensors and return oil circuits, and can be improved on existing nozzle vector actuator products, and a series of products with different stroke ranges can be designed for different engines; at the same time, the locking plate can more accurately control the stroke adjustment amount of the limit screw sleeve, and according to the installation conditions of the same batch of products, the stroke can be pre-adjusted before the vector nozzle actuator is assembled, thereby simplifying the assembly adjustment process; the high-pressure oil inside the shell can be led out of the shell through the emergency return groove, which can meet the requirements of the emergency state opening of the engine vector nozzle;

[0018] (2) The high-reliability servo actuator described in the present invention can maintain the integrity of the piston rod coating under the high lateral force generated by a large load by arranging a soft bushing at the connection part, thereby improving the reliability of the piston rod operation and enabling it to operate reliably for a long time under the high load conditions of the nozzle vector servo system; at the same time, the design mainly changes the structure of the piston rod opening of the actuator body, that is, the structure at the connection part, which can be improved on the existing products; different kinds of soft materials can also be selected to contact the piston rod to form a series design suitable for piston rods of various materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0020] Figure 1 A schematic diagram of the structure of a high-reliability servo actuator according to an embodiment of the present invention;

[0021] Figure 2 A cross-sectional view of the connecting portion structure according to an embodiment of the present invention;

[0022] Figure 3 It is an exploded view of the connection structure of the locking plate and the limiting screw sleeve on the connection part according to an embodiment of the present invention.

[0023] Description of reference numerals:

[0024] 1. Actuator body; 11. Connecting part; 12. Annular groove; 13. Guide groove; 14. Emergency return groove; 15. Emergency return port; 2. Piston rod; 3. Limiting screw sleeve; 31. Slot; 4. Locking plate; 41. Limiting block; 5. Second limiting nut; 6. Connecting seat; 7. First limiting nut; 8. Bushing; 9. Pin; 10. Emergency return pipe joint. DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0026] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0028] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0029] As shown in the figure, a high-reliability servo actuator comprises an actuator body 1, wherein the outer end of a piston rod 2 of the actuator body 1 passes through a connecting portion 11 at a port of the actuator body 1, a locking plate 4 and a limiting screw sleeve 3 are arranged on the outer side of the connecting portion 11, and the locking plate 4 can move along the length direction of the connecting portion 11, and the limiting screw sleeve 3 is limited by the locking plate 4 to adjust the distance, and a first limiting nut 7 is also threadedly connected at the connection between the outer end of the piston rod 2 and the connecting seat 6, and the stroke of the actuator body 1 is controlled by the distance between the first limiting nut 7 and the limiting screw sleeve 3 when the piston rod 2 is moved, an emergency return groove 14 is opened on the inner wall of the shell of the actuator body 1 at a position corresponding to the piston cavity, and an emergency return port 15 is opened on the surface of the shell, and the emergency return groove 14 is connected to the emergency return port 15 through a return channel arranged in the side wall of the shell. In this embodiment, an emergency return pipe joint 10 is installed at the emergency return port 15. When in use, the emergency return pipe joint 10 is connected to the oil pipe, and the oil is led out of the actuator body 1 through the oil pipe. During processing, in order to facilitate processing, the emergency return groove 14 is directly set as a hole body that penetrates the surface of the actuator body 1, and then blocked by a sealing plug on the outer end side of the hole body, so that the emergency return groove 14 forms a blocked state at the opening of the shell surface. In this embodiment, by improving the existing connection part 11 on the actuator body 1, the adjustment position of the limit screw sleeve 3 is constrained by the locking plate 4 and positioned by the locking plate 4 after adjustment, the adjustment of the spacing between the limit screw sleeve 3 and the first limit nut 7 is achieved, that is, the stroke adjustment of the actuator body 1 is achieved.

[0030] The outer end of the limiting screw sleeve 3 is aligned with the outer end of the connecting portion 11 or extends out of the outer end of the connecting portion 11 to ensure that the first limiting nut 7 abuts against the limiting screw sleeve 3 during the movement of the piston rod 2 to control the stroke of the actuator body 1.

[0031] There are two first limiting nuts 7 , which are pressed against each other to form a locking state to prevent slippage between the connecting seat 6 and the piston rod 2 .

[0032] A second limiting nut 5 is threadedly connected to the connection portion 11 at the rear side of the locking plate 4 , and the locking plate 4 is pressed against by the second limiting nut 5 .

[0033] A guide groove 13 is provided on the surface of the connection part 11 along the length direction. The locking piece 4 is an annular structure sleeved on the outside of the connection part 11. An integrally formed limit block 41 is provided on the side of the locking piece 4 facing the limit screw sleeve 3, and the inner end of the limit block 41 is inserted into the guide groove 13. A plurality of radially arranged slots 31 are evenly provided at one end of the limit screw sleeve 3 facing the locking piece 4, and the limit block 41 is engaged with one of the slots 31. In this embodiment, when adjusting the stroke, the second limit nut 5 is loosened and moved to the rear side of the connection part 11, and then the locking piece 4 is moved backward to be separated from the limit screw sleeve 3, and the stroke is adjusted by screwing in and out of the limit screw sleeve 3. When adjusting, the limit block 41 of the locking piece 4 cooperates with the slot 31 on the limit screw sleeve 3, so that the limit screw sleeve 3 must be adjusted to a certain distance each time it is adjusted before it can be locked. Finally, the second limit nut 5 is tightened to fix it, thereby realizing the precise adjustment of the stroke of the actuator, and the actuator can work according to the adjusted stroke. For example, there are 10 slots 31 evenly distributed. Then, by adjusting the limit screw sleeve 3 by 1 / 10 of the pitch, the next slot 31 can be aligned with the guide groove 13, ensuring that the limit block 41 of the locking plate 4 is inserted into the slot 31, positioning the limit screw sleeve 3, and finally tightening the two second limit nuts 5 to press against the locking plate 4.

[0034] An annular groove 12 is provided along the inner wall at the end of the connecting portion 11, and a bushing 8 is installed in the annular groove 12. In the present embodiment, the bushing 8 is made of a soft material. Under the action of lateral force, the piston rod 2 will first contact the soft bushing 8. The soft bushing 8 will be slightly deformed under the action of contact stress, and at the same time, will be slightly worn due to friction with the hard surface of the piston rod 2. This process ensures that under high load and high lateral force working conditions, the surface of the piston rod 2 can remain intact without the occurrence of surface eccentric wear damage, thereby increasing its reliability.

[0035] A mounting hole is provided on the outer side of the connecting portion 11 corresponding to the bushing 8 , and a pin 9 is installed in the mounting hole. The bushing 8 is fixed in the annular groove 12 through the pin 9 .

[0036] In this embodiment, aluminum bronze alloy QAl10-4-4 is used to make bushing 8 with interference size, and stainless steel pin 9 is used to fix bushing 8 in annular groove 12. The average hardness of aluminum bronze alloy QAl10-4-4 is 206HBS, which is lower than the hardness of titanium alloy TA15 used for piston rod 2, and it has good wear resistance. When working with piston rod 2, it will not scratch its surface. By selecting the above material, the function of anti-eccentric wear mechanism under large load condition of actuator is realized.

[0037] In this embodiment, when in use, the emergency return pipe joint 10 is connected to an oil pipe, which is connected to the emergency return oil path of the engine through the oil pipe to form an emergency return oil path for draining oil, and a valve is provided on the oil pipe. The piston chamber inside the actuator body 1 is divided into two parts by the piston, namely, a rod chamber and a rodless chamber, that is, a chamber on the piston rod 2 side and a chamber on the non-piston rod 2 side. When the fuel control system works normally, the emergency return oil circuit is closed, and the product works normally. When the product moves to the specified position, the forces in the two chambers are balanced, and the piston rod 2 stops moving; when the fuel control system fails, the emergency return groove 14 is connected to the emergency return oil circuit, which is a pressure-free oil circuit. When it is connected to any of the rod chamber and the rodless chamber of the actuator body 1, the oil in the chamber will flow out from the emergency return oil circuit and the pressure in the chamber will be reduced. Since the pressure in the other chamber remains unchanged, the piston moves in the opposite direction, that is, the emergency return position, under the action of the pressure in the other chamber; when the emergency return groove 14 is in the rod chamber, the emergency return oil circuit is connected to the rod chamber, and the rod chamber is a low-pressure chamber. Under the action of the high-pressure oil in the rodless chamber, the piston moves toward the emergency return groove 14 and the rod chamber. When the emergency return groove 14 is moved to the position, the piston will cover the emergency return groove 14, the pressure of the two chambers will return to a balanced state again, and the piston rod 2 will stop at the emergency return position; when the emergency return groove 14 is in the rodless chamber, the emergency return oil circuit is connected to the rodless chamber, and the rodless chamber is a low-pressure chamber. Under the action of the high-pressure oil in the rod chamber, the piston moves toward the emergency return groove 14 and the rod chamber. When the emergency return groove 14 is moved to the position, the piston will cover the emergency return groove 14, the pressure of the two chambers will return to a balanced state again, and the piston rod 2 will stop at the emergency return position. Emergency return is a dynamic balancing process, which can ensure that when the engine fuel and control system fail, the actuator in any position quickly exits the vector control state and enters the pre-designed non-vector control state. The product can determine the return speed by the area of ​​the emergency return groove 14, and the return position and accuracy by the position of the emergency return groove 14.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high reliability servo actuator, characterized in that: It includes an actuator body, the outer end of the piston rod of the actuator body passes through the connecting part at the port of the actuator body, a locking plate and a limit screw sleeve are arranged on the outside of the connecting part, and the locking plate can move along the length direction of the connecting part, and the adjustment distance of the limit screw sleeve is limited by the locking plate, and a first limit nut is also threaded at the connection between the outer end of the piston rod and the connecting seat, and when the piston rod is moved, the stroke of the actuator body is controlled by the distance between the first limit nut and the limit screw sleeve, an emergency return groove is opened on the inner wall of the shell of the actuator body corresponding to the piston cavity, and an emergency return opening is opened on the surface of the shell, and the emergency return groove is connected with the emergency return opening through a return channel arranged in the side wall of the shell.

2. A high reliability servo actuator according to claim 1, characterized in that: The outer end of the limiting screw sleeve is aligned with the outer end of the connecting part or extends out of the outer end of the connecting part.

3. The high reliability servo actuator according to claim 1, characterized in that: There are two first limiting nuts, which are tightly pressed against each other.

4. The high reliability servo actuator according to claim 1, characterized in that: A second limiting nut is threadedly connected on the connection portion at the rear side of the locking plate, and the locking plate is tightened by the second limiting nut.

5. A high reliability servo actuator according to claim 4, characterized in that: A guide groove is opened on the surface of the connecting part along the length direction. The locking plate is an annular structure sleeved on the outside of the connecting part. An integrally formed limit block is provided on the side of the locking plate facing the limit screw sleeve, and the inner end of the limit block is inserted in the guide groove. A plurality of radially arranged grooves are evenly arranged on the end of the limit screw sleeve facing the locking plate, and the limit block is clamped together with one of the grooves.

6. The high reliability servo actuator according to claim 1, characterized in that: An annular groove is arranged along the inner wall at the port of the connection part, and a bushing is installed in the annular groove.

7. The high reliability servo actuator according to claim 6, characterized in that: A mounting hole is provided on the outer side of the connection portion corresponding to the bushing, and a pin is installed in the mounting hole, and the bushing is fixed in the annular groove through the pin.

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