Miniaturized rotary electromechanical actuator

Abstract

A miniaturized rotary electromechanical actuator relates to the field of spaceflight servo and comprises a permanent magnet synchronous motor, a gear reducer and an output rudder shaft, the permanent magnet synchronous motor is connected to the gear reducer, an output shaft of the permanent magnet synchronous motor extends into the gear reducer, the output rudder shaft is connected with a steering engine output main shaft, and the steering engine output main shaft is rotatably connected to the gear reducer. The gear reduction box comprises a box body and a reduction gear shaft system, the reduction gear shaft system comprises a first-stage spiral bevel gear and a plurality of straight gears which are rotationally connected to the box body, the axes of the first-stage spiral bevel gear and the multiple straight gears are parallel to the axis of the steering engine output main shaft, and the steering engine output main shaft is coaxially connected with a sixth-stage straight gear; an output shaft of the permanent magnet synchronous motor is coaxially connected with an output bevel gear, the first-stage spiral bevel gear comprises a bevel tooth part and a first pinion which are distributed in the axis direction of the first-stage spiral bevel gear and synchronously rotate, the bevel tooth part is meshed with the output bevel gear, and the first pinion is meshed with the sixth-stage straight gear through a plurality of straight gears. And the transmission efficiency of the rotary steering engine is improved.

Description

Technical Field

[0001] The present application belongs to the field of aerospace servo, in particular to the field of electromechanical actuators for aircraft air rudder swing angle position control servo systems, and relates to a miniaturized rotary electromechanical actuator. Background Art

[0002] Electromechanical actuators are the actuators of the aerodynamic control system. They amplify power according to the swing angle input command of the control system, and accurately, quickly and stably control the swing angle of the air control surface to reach the predetermined position, complete aerodynamic control, and make the aircraft fly stably according to the required attitude. Electromechanical actuators can be divided into two categories according to the output form: linear actuators and rotary actuators.

[0003] Beijing University of Aeronautics and Astronautics patent CN1562704A discloses an aircraft wing rotation or folding actuator, which includes an actuator cylinder, a piston rod, an adapter joint, a locking mechanism, etc., which can keep the aircraft wing stable in flight and rotate or fold on the ground or parked, so as to reduce the floor space and improve the airport utilization efficiency and aircraft storage capacity.

[0004] Patent CN109693782A of Zhuhai Longhua Helicopter Technology Co., Ltd. discloses a helicopter rotary servo and a helicopter, including a power source and a reduction output assembly. The product has a compact structure, a small size, and is easy to install and disassemble.

[0005] Traditional rotary electromechanical actuators mostly use servo motors to output power, and the transmission mechanism uses a ball screw pair combined with a fork structure to complete the angular displacement output of the output shaft. The above solution has the disadvantage that the servo mechanism is large in size. At the same time, under high-speed motion conditions, the rolling friction between the roller and the fork turns into sliding friction, resulting in low transmission efficiency. Summary of the invention

[0006] The technical problem solved by the present application is: to overcome the deficiencies of the prior art, to provide a miniaturized rotary electromechanical actuator, to adopt a combined transmission of a permanent magnet synchronous motor and a gear transmission shaft system, to improve the transmission efficiency of the rotary servo, and to overcome the drawback of sliding friction under high-speed motion conditions of the fork mechanism. The first stage of the transmission gearbox adopts a spiral bevel gear transmission, and the second to sixth stages adopt a spur gear transmission. At the same time, in order to improve the positioning accuracy of the rotary electromechanical actuator, a rotary transformer is configured on the output shaft side of the servo to detect the real-time position of the rotor.

[0007] The technical solutions provided by this application are as follows:

[0008] A miniaturized rotary electromechanical actuator comprises a permanent magnet synchronous motor, a gear reduction box and an output rudder shaft, wherein the permanent magnet synchronous motor is fixedly connected to the gear reduction box, the output shaft of the permanent magnet synchronous motor extends into the gear reduction box, the output shaft of the permanent magnet synchronous motor transmits torque to the output rudder shaft through a reduction gear shaft system, the output rudder shaft is used to connect a steering gear output main shaft, the steering gear output main shaft is rotatably connected to the gear reduction box, the axis of the steering gear output main shaft is perpendicular to the axis of the output shaft of the permanent magnet synchronous motor; the gear reduction box comprises a housing and a reduction gear shaft system, the reduction gear shaft system comprises a first-stage spiral bevel gear rotatably connected to the housing and a plurality of spur gears, the axes of the first-stage spiral bevel gear and the plurality of spur gears are parallel to the axis of the steering gear output main shaft, the steering gear output main shaft is coaxially connected with a sixth-stage spur gear, the output shaft of the permanent magnet synchronous motor is coaxially connected with the output bevel gear, the first-stage spiral bevel gear comprises a bevel gear portion and a first pinion distributed along its own axis and rotating synchronously, the bevel gear portion is meshed with the output bevel gear, and the first pinion is meshed with the sixth-stage spur gear through a plurality of spur gears.

[0009] The multiple spur gears include a second-stage spur gear, a third-stage spur gear, a fourth-stage spur gear and a fifth-stage spur gear. The second-stage spur gear includes a second large gear and a second small gear distributed along its own axial direction and rotating synchronously. The third-stage spur gear includes a third large gear and a third small gear distributed along its own axial direction and rotating synchronously. The fourth-stage spur gear includes a fourth large gear and a fourth small gear distributed along its own axial direction and rotating synchronously. The fifth-stage spur gear includes a fifth large gear and a fifth small gear distributed along its own axial direction and rotating synchronously. The second large gear is meshed with the first small gear, the second small gear is located on the side of the second large gear facing the bevel gear portion, the third large gear is meshed with the second small gear, the third small gear is located on the side of the third large gear away from the second large gear, the fourth large gear is meshed with the third small gear, the fourth small gear is located on the side of the fourth large gear facing the third large gear, the fifth large gear is meshed with the fourth small gear, the fifth small gear is located on the side of the fifth large gear facing the fourth large gear, and the sixth-stage spur gear is meshed with the fifth small gear.

[0010] The axes of the first-stage spiral bevel gear and the multi-stage spur gear are sequentially distributed in the circumferential direction of the outer side of the steering gear output main shaft to form an enveloping distribution.

[0011] The box is also connected to an angular displacement sensor, the steering gear output main shaft is connected to a fan gear, the angular displacement sensor output shaft of the angular displacement sensor is connected to a meshing gear, the fan gear is meshed with the meshing gear, and the swing angle of the steering gear output main shaft is transmitted to the angular displacement sensor output shaft through the fan gear and the meshing gear.

[0012] The box is also connected to a rotary transformer, and the output shaft of the angular displacement sensor is fastened to the rotor shaft of the rotary transformer.

[0013] The sector gear is located on the side of the sixth-stage spur gear facing the fifth large gear.

[0014] A rotary electromechanical actuator for aerodynamic control comprises a permanent magnet synchronous motor, a transmission gear shaft assembly arranged in a gear box housing, a rotary transformer, and an output shaft preload disc spring; the transmission gear shaft assembly comprises a first-stage spiral bevel gear transmission, a second-stage spur gear transmission, a third-stage spur gear transmission, a fourth-stage spur gear transmission, a fifth-stage spur gear transmission, a sixth-stage spur gear transmission and a rotary transformer transmission shaft assembly.

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

[0016] (1) The present invention adopts a transmission scheme of permanent magnet synchronous motor + gear box, which transmits the rotational motion of the servo motor rotor to the steering gear output spindle after deceleration and distance increase, and drives the air control surface to rotate. The steering gear output spindle and the motor output shaft are installed in a normal direction. The transmission efficiency of the rotary electromechanical actuator reaches 81%.

[0017] (2) The swing angle of the electromechanical actuator of the present invention can reach ±32 degrees. The overall size of the mechanism is 152mm×133mm×70mm, the total volume is small, the total weight is only 2.5kg, and it can withstand a load torque of 200N·m, which is lightweight and small while having high load-bearing capacity.

[0018] (3) The electromechanical actuator of the present invention uses a rotary transformer installed coaxially with the fan gear at the output spindle end of the servo gear to collect the angular displacement of the air rudder main shaft, and eliminates the transmission gap between the output end of the servo motor and the air rudder main shaft transmission gear through position closed-loop control, thereby achieving high-precision control of the rudder shaft swing angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of a rotary electromechanical actuator in an embodiment of the present invention;

[0020] Figure 2 A schematic diagram of a transmission mechanism of a rotary electromechanical actuator in an embodiment of the present invention;

[0021] Figure 3 A schematic diagram of the rudder shaft angle measurement scheme of the rotary electromechanical actuator of the present invention;

[0022] Figure 4 Schematic diagram of the reduction gear shaft system. DETAILED DESCRIPTION

[0023] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0024] like Figures 1 to 3As shown, the embodiment of the present application discloses a miniaturized rotary electromechanical actuator, including a permanent magnet synchronous motor 1, a gear reduction box 2, a rotary transformer 3, a rotary transformer socket 4, and an output rudder shaft 5. The gear reduction box 2 is composed of a box body and a reduction gear shaft system. The box body includes a gear box upper shell 13 and a gear box lower shell 11, and the reduction gear shaft system is composed of a first-stage spiral bevel gear 6, a second-stage spur gear 7, a third-stage spur gear 8, a fourth-stage spur gear 9, a fifth-stage spur gear 10, and a sixth-stage spur gear 161.

[0025] The permanent magnet synchronous motor 1 is fixedly connected to the gear reduction box 2, and the output shaft of the permanent magnet synchronous motor 1 extends into the gear reduction box 2. The output shaft of the permanent magnet synchronous motor 1 transmits the torque to the output rudder shaft 5 through the reduction gear shaft system. The output rudder shaft 5 is used to connect the output spindle of the steering gear. The output rudder shaft 5 is rotatably connected to the gear reduction box 2, and the axis of the output spindle of the steering gear is perpendicular to the axis of the output shaft of the permanent magnet synchronous motor 1. The rotary transformer 3 is used to measure the actual swing angle of the output spindle of the steering gear. The rotary transformer socket 4 is connected to the gear reduction box 2. The rotary transformer socket 4 is used to connect the control cable and output the rotary transformer signal of the rotary transformer 3 to the control driver.

[0026] like Figure 2 and Figure 4 As shown, the output shaft of the permanent magnet synchronous motor 1 is coaxially connected with the output bevel gear, the first-stage spiral bevel gear 6, the second-stage spur gear 7, the third-stage spur gear 8, the fourth-stage spur gear 9 and the fifth-stage spur gear 10 are all rotatably connected to the box body and the axis is parallel to the axis of the steering gear output main shaft, the first-stage spiral bevel gear 6 includes a bevel gear portion and a first pinion distributed along the axis direction of its own axis and rotating synchronously, the second-stage spur gear 7 includes a second large gear and a second small gear distributed along the axis direction of its own axis and rotating synchronously, the third-stage spur gear 8 includes a third large gear and a third small gear distributed along the axis direction of its own axis and rotating synchronously, the fourth-stage spur gear 9 includes a fourth large gear and a fourth small gear distributed along the axis direction of its own axis and rotating synchronously. The fifth stage spur gear 10 includes a fifth large gear and a fifth small gear distributed along its own axis and rotating synchronously; the bevel gear part is meshed with the output bevel gear, the second large gear is meshed with the first small gear, the second small gear is located on the side of the second large gear facing the bevel gear part, the third large gear is meshed with the second small gear, the third small gear is located on the side of the third large gear away from the second large gear, the fourth large gear is meshed with the third small gear, the fourth small gear is located on the side of the fourth large gear facing the third large gear, the fifth large gear is meshed with the fourth small gear, and the fifth small gear is located on the side of the fifth large gear facing the fourth large gear; the sixth stage spur gear 161 is coaxially connected with the output rudder shaft 5, and the sixth stage spur gear 161 is meshed with the fifth small gear. The axes of the first stage spiral bevel gear 6, the second stage spur gear 7, the third stage spur gear 8, the fourth stage spur gear 9, and the fifth stage spur gear 10 are sequentially distributed in the circumferential direction of the outer side of the steering gear output main shaft to form an enveloping distribution.

[0027] like Figure 2 As shown, the permanent magnet synchronous motor 1 rotates according to the control system command, and the motor rotor rotation motion is transmitted to the gear shaft of the first-stage spiral bevel gear 6 through the spiral bevel gear, and the gear shaft axis of the first-stage spiral bevel gear 6 is perpendicular to the normal direction of the motor rotor axis. The second-stage spur gear 7, the third-stage spur gear 8, the fourth-stage spur gear 9, the fifth-stage spur gear 10 and the sixth-stage spur gear 161 are all in the form of spur gears. The gear shaft of the sixth-stage spur gear 161 is integrated with the output main shaft of the steering gear.

[0028] like Figure 3 As shown, a sector gear 14 is arranged on the servo output main shaft 16, and the sector gear 14 is located on the side of the sixth-stage spur gear 161 facing the fifth large gear. The angular displacement sensor output shaft 17 is connected with the meshing gear 15, and the sector gear 14 meshes with the meshing gear 15. The swing angle of the servo output main shaft 16 is transmitted to the angular displacement sensor output shaft 17 through the sector gear 14 and the meshing gear 15. The angular displacement sensor output shaft 17 is fastened to the rotor shaft of the rotary transformer 3, and the actual angle of the servo output main shaft 16 is measured in real time.

[0029] according to Figures 1 to 3 The rotary electromechanical actuator has an outer dimension envelope of 152 mm×133 mm×70 mm, a load swing angle of ±32 degrees, a gearbox reduction ratio of 152, and a total weight of 2.5 kg.

[0030] The miniaturized rotary electromechanical actuator provided by the present invention adopts a transmission scheme of a permanent magnet synchronous motor + a gearbox, and adopts a design concept of integrating a steering gear output spindle with a gearbox output shaft, thereby reducing power transmission links and improving system specific power.

[0031] The main innovations of this application are as follows:

[0032] (1) The permanent magnet synchronous motor of the power element is arranged vertically with the load rudder shaft, and the motor output shaft and the load rudder shaft are transmitted through a six-stage gear system, in which the first stage gear adopts a spiral bevel gear transmission scheme, and the second to sixth stages adopt a straight parallel shaft transmission scheme. All six-stage transmission gear systems are arranged in a wrap-around manner along the load rudder shaft, which reduces the size of the electromechanical actuator and realizes a lightweight, miniaturized, and high-rigidity design.

[0033] (2) The actuator adopts a flexible gear system layout design. At the same time, the servo output main shaft is integrated with the transmission sector gear (sixth-stage spur gear 161) and the measuring sector gear (sector gear 14), which reduces the axial height of the main transmission shaft and the load bending moment of the aerodynamic load acting on the rudder shaft supporting tapered roller bearing, thereby reducing the bearing design load and creating convenient conditions for optimizing the aerodynamic shape design of the aircraft.

[0034] (3) A measuring sector gear is arranged on the output main shaft of the actuator, and a measuring shaft system is meshed with the measuring sector gear. A rotary transformer is coaxially arranged on the measuring shaft system for accurately measuring the angular displacement signal of the output rudder shaft. The dual rotary transformer control scheme of the measuring rotary transformer and the motor rotary transformer reduces the influence of the transmission clearance of the six-stage main transmission gear system on the swing angle of the output rudder shaft, thereby improving the angular displacement control accuracy of the actuator.

[0035] Specifically, the rotary transformer 3 is located on the measuring shaft system, and the actual swing angle can be obtained; the permanent magnet synchronous motor 1 has a motor rotary transformer, and the theoretical swing angle can be obtained by calculation. Due to the existence of transmission clearance, there will be a certain difference between the actual swing angle and the theoretical swing angle. By comparing the two through closed-loop control, the error can be further eliminated.

[0036] (4) The servo motor adopts a high-temperature design, the electrical connector adopts a micro-rectangular high-temperature connector, the actuator housing adopts a high-temperature alloy 4169, and the bearing adopts a high-temperature resistant bearing. The actuator can adapt to the working environment of high temperature resistance and long flight time.

[0037] The contents not described in detail in this application specification belong to the common knowledge of those skilled in the art.

[0038] The present application is described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, a variety of equivalent replacements, modifications or improvements can be made to the technical solution of the present application and its implementation methods, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached claims.

Claims

1. A miniaturized rotary electromechanical actuator, characterized in that: The invention comprises a permanent magnet synchronous motor (1), a gear reduction box (2) and an output rudder shaft (5), wherein the permanent magnet synchronous motor (1) is fixedly connected to the gear reduction box (2), the output shaft of the permanent magnet synchronous motor (1) extends into the gear reduction box (2), the output shaft of the permanent magnet synchronous motor (1) transmits torque to the output rudder shaft (5) through a reduction gear shaft system, the output rudder shaft (5) is used to connect to a steering gear output main shaft (16), the steering gear output main shaft is rotatably connected to the gear reduction box (2), and the axis of the steering gear output main shaft is perpendicular to the axis of the output shaft of the permanent magnet synchronous motor (1); the gear reduction box (2) comprises a housing and a reduction gear. The gear shaft system comprises a first-stage spiral bevel gear (6) and a plurality of spur gears rotatably connected to a housing, the axes of the first-stage spiral bevel gear (6) and the plurality of spur gears are parallel to the axis of a steering gear output main shaft, the steering gear output main shaft is coaxially connected to a sixth-stage spur gear (161), the output shaft of the permanent magnet synchronous motor (1) is coaxially connected to the output bevel gear, the first-stage spiral bevel gear (6) comprises a bevel gear portion and a first pinion gear distributed along its own axis and rotating synchronously, the bevel gear portion is meshed with the output bevel gear, and the first pinion gear is meshed with the sixth-stage spur gear (161) via the plurality of spur gears.

2. A miniaturized rotary electromechanical actuator according to claim 1, characterized in that: The plurality of spur gears include a second-stage spur gear (7), a third-stage spur gear (8), a fourth-stage spur gear (9) and a fifth-stage spur gear (10). The second-stage spur gear (7) includes a second large gear and a second small gear distributed along its own axis and rotating synchronously. The third-stage spur gear (8) includes a third large gear and a third small gear distributed along its own axis and rotating synchronously. The fourth-stage spur gear (9) includes a fourth large gear and a fourth small gear distributed along its own axis and rotating synchronously. The fifth-stage spur gear (10) includes a The fifth large gear and the fifth small gear are distributed and rotate synchronously, the second large gear is meshed with the first small gear, the second small gear is located on the side of the second large gear facing the bevel gear portion, the third large gear is meshed with the second small gear, the third small gear is located on the side of the third large gear away from the second large gear, the fourth large gear is meshed with the third small gear, the fourth small gear is located on the side of the fourth large gear facing the third large gear, the fifth large gear is meshed with the fourth small gear, the fifth small gear is located on the side of the fifth large gear facing the fourth large gear, and the sixth-stage spur gear (161) is meshed with the fifth small gear.

3. A miniaturized rotary electromechanical actuator according to claim 1, characterized in that: The axes of the first-stage spiral bevel gear (6) and the multi-stage spur gear are sequentially distributed in the circumferential direction of the outer side of the steering gear output main shaft to form an enveloping distribution.

4. A miniaturized rotary electromechanical actuator according to claim 1 or 2, characterized in that: The box is also connected to an angular displacement sensor, the steering gear output main shaft is connected to a sector gear (14), the angular displacement sensor output shaft (17) of the angular displacement sensor is connected to a meshing gear (15), the sector gear (14) meshes with the meshing gear (15), and the swing angle of the steering gear output main shaft (16) is transmitted to the angular displacement sensor output shaft (17) through the sector gear (14) and the meshing gear (15).

5. A miniaturized rotary electromechanical actuator according to claim 4, characterized in that: The box is also connected to a rotary transformer (3), and the angular displacement sensor output shaft (17) is fastened to the rotor shaft of the rotary transformer (3).

6. A miniaturized rotary electromechanical actuator according to claim 4, characterized in that: The sector gear (14) is located on the side of the sixth-stage spur gear (161) facing the fifth large gear.

7. A miniaturized rotary electromechanical actuator according to claim 1, characterized in that: The load swing angle of the output rudder shaft (5) is ±32 degrees.

8. A miniaturized rotary electromechanical actuator according to claim 1, characterized in that: The electric actuator has an overall dimension envelope of 152mm×133mm×70mm, a gearbox reduction ratio of 152, and a total weight of 2.5kg.

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