A dual-redundant direct-drive two-stage ball screw pair aviation electric servo

Abstract

The present invention provides a dual-redundant direct-drive, two-stage ball screw pair aircraft electric servo, belonging to the technical field of aircraft electric servos. The servo comprises a permanent magnet synchronous motor assembly, an electromagnetic brake assembly, a two-stage ball screw pair, a linear displacement sensor, a rotary transformer, an electrical connector, an output lug, and a structural support. The electric servo of the present invention utilizes dual permanent magnet synchronous motors connected coaxially in series to directly drive the two-stage ball screw pair for high-efficiency force and speed output. The servo also features a dual-redundant brake to ensure control surface stability in the event of a power outage, and a dual-redundant rotary transformer and linear displacement sensor to ensure operating position accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of aviation electric servos, and in particular to an aviation electric servo with a double-redundant direct-drive two-stage ball screw pair. Background Art

[0002] Electric servos are the actuators of flight control systems, outputting force and speed to move the corresponding control surfaces according to command. The performance of electric servos directly determines the performance of the flight control system, and thus the overall maneuverability of the aircraft, making their performance extremely important. With the development of high-performance aircraft technology, the performance requirements for electric servos are constantly increasing. Only electric servos with high reliability and high frequency response can enable control surfaces to move to the specified position more quickly and accurately. As a key actuator in aircraft flight control systems, electric servos often utilize redundant designs to ensure high reliability.

[0003] To ensure high reliability in flight control, most electric servos typically employ a dual-redundancy design. Currently, most dual-redundancy electric servos utilize either a dual-motor plus differential or a single-motor dual-winding configuration. Both dual-redundancy designs have their own shortcomings, hindering the development of high-reliability dual-redundancy electric servos. While the dual-motor plus differential approach significantly improves reliability, it results in a larger and heavier overall system, a longer transmission chain, a more complex transmission system, and slower system response. While the single-motor dual-winding approach seemingly avoids the increased system size and weight and increased transmission system complexity associated with dual-redundancy, it fails to address the issue of a short circuit in one winding, which could cause braking and potentially compromise the normal operation of the backup winding, leading to a persistent potential for failure.

[0004] In order to solve the inherent defects of the above two dual-redundancy designs, the prior art (CN104534041B) proposes a dual-redundancy direct-drive roller screw pair electric actuator, which is mainly composed of a brushless DC motor assembly, a clutch, a hollow screw, a displacement sensor and a housing. However, the actuator also has the following defects: First, since the actuator is not equipped with a brake, there is no static holding force after a power failure, causing abnormal disturbances in the moving parts. The stopped state after the failure is uncontrollable, causing the motion control system to lose control, resulting in unpredictable serious consequences; Second, only a first-stage roller screw is used. When the system has high thrust and speed requirements, the brushless DC motor is burdened with a large burden and generates serious heat. In order to ensure output performance and mechanical strength, the size of the brushless DC motor is increased and the reliability is reduced; Third, the heating problem leads to the processing of coolant channels inside its structural components for heat dissipation. This method not only increases the manufacturing difficulty, but also requires a separate cooling pump system, thereby introducing a new failure mode and reducing the overall reliability of the system; Fourth, the angle encoder as a position sensor has the disadvantages of weak shock resistance, a small operating temperature range, and poor overall resistance to harsh working environments. It is not enough to be competent for some systems with high environmental adaptability requirements. Summary of the Invention

[0005] In view of this, an embodiment of the present application provides a dual-redundant direct-drive two-stage ball screw pair aviation electric servo to achieve the purposes of improving the reliability of the servo system, ensuring the stability of the control surface in the event of a power outage, and ensuring efficient output performance and mechanical strength.

[0006] The present application provides the following technical solution: a dual-redundant direct-drive two-stage ball screw pair aviation electric servo, comprising:

[0007] A permanent magnet synchronous motor assembly, the permanent magnet synchronous motor assembly comprising an output end permanent magnet synchronous motor assembly and a fixed end permanent magnet synchronous motor assembly, the output end permanent magnet synchronous motor assembly and the fixed end permanent magnet synchronous motor assembly being coaxially connected in series;

[0008] An electromagnetic brake assembly, comprising an output-end electromagnetic brake assembly and a fixed-end electromagnetic brake assembly, wherein the output-end electromagnetic brake assembly is fixedly mounted on the side of the output-end permanent magnet synchronous motor assembly for braking the output-end permanent magnet synchronous motor; the fixed-end electromagnetic brake assembly is fixedly mounted on the side of the fixed-end permanent magnet synchronous motor assembly for braking the fixed-end permanent magnet synchronous motor;

[0009] A two-stage ball screw pair, comprising an output end nut, a fixed end nut, a first-stage ball screw and a second-stage ball screw, wherein the external thread of the output end of the first-stage ball screw is meshed with the internal thread of the output end nut, and the output end nut is interference-mounted in the rotor inner hole of the output end permanent magnet synchronous motor assembly, serving as the rotor of the output end permanent magnet synchronous motor assembly to directly output torque and speed; the external thread of the fixed end of the first-stage ball screw is meshed with the internal thread of the fixed end nut, and the fixed end nut is interference-mounted in the rotor inner hole of the fixed end permanent magnet synchronous motor assembly, serving as the rotor of the fixed end permanent magnet synchronous motor assembly to directly output torque and speed; the external thread of the second-stage ball screw is meshed with the internal thread of the first-stage ball screw;

[0010] A linear displacement sensor, wherein the mounting end of the linear displacement sensor is fixed within the fixed-end permanent magnet synchronous motor assembly, and the movable end of the linear displacement sensor is rigidly connected coaxially with the secondary ball screw, and moves linearly synchronously with the secondary ball screw, and is used to collect and feedback the output position information of the electric servo in real time;

[0011] A rotating transformer, wherein the rotating transformer includes an output-end rotating transformer and a fixed-end rotating transformer, the output-end rotating transformer includes an output-end rotating transformer stator and an output-end rotating transformer rotor arranged in the inner hole of the output-end rotating transformer stator, the output-end rotating transformer stator is fixedly mounted on the output-end electromagnetic brake assembly, the output-end rotating transformer rotor is fixedly mounted on the rotor of the output-end permanent magnet synchronous motor assembly, and is used to detect and record the rotor position and angle of the output-end permanent magnet synchronous motor assembly; the fixed-end rotating transformer includes a fixed-end rotating transformer stator and a fixed-end rotating transformer rotor arranged in the inner hole of the fixed-end rotating transformer stator, the fixed-end rotating transformer stator is fixedly mounted on the fixed-end electromagnetic brake assembly, the fixed-end rotating transformer rotor is fixedly mounted on the rotor of the fixed-end permanent magnet synchronous motor assembly, and is used to detect and record the rotor position and angle of the fixed-end permanent magnet synchronous motor assembly.

[0012] Furthermore, the output-end permanent magnet synchronous motor assembly includes an output-end main housing, an output-end stator assembly, and an output-end rotor assembly; the output-end stator assembly is interference-mounted in the inner hole of the output-end main housing, the output-end rotor assembly includes an output-end rotor yoke disposed within the output-end stator assembly, the output-end rotor magnet is adhered to the outer surface of the output-end rotor yoke, an output-end nut is interference-mounted in the inner hole of the output-end rotor yoke, and the output-end rotor hollow shaft is interference-mounted on the output-end nut;

[0013] The fixed-end permanent magnet synchronous motor assembly includes a fixed-end main housing, a fixed-end stator assembly and a fixed-end rotor assembly; the fixed-end main housing is fixedly connected to the output-end main housing, the fixed-end stator assembly is interference-mounted in the inner hole of the fixed-end main housing, the fixed-end rotor assembly includes a fixed-end rotor yoke arranged in the fixed-end stator assembly, the outer surface of the fixed-end rotor yoke is pasted with a fixed-end rotor magnet, a fixed-end nut is interference-mounted in the inner hole of the fixed-end rotor yoke, and a fixed-end rotor hollow shaft is interference-mounted on the fixed-end nut.

[0014] Furthermore, the side of the output end main housing is fixedly connected to the output end main end cover, a first bearing is installed in the bearing chamber of the output end main end cover, a second bearing is installed in the bearing chamber of the output end main housing, and the output end rotor assembly is supported by the first bearing and the second bearing;

[0015] The side of the fixed end main shell is fixedly connected to the fixed end main end cover, a third bearing is installed in the bearing chamber of the fixed end main end cover, a fourth bearing is installed in the bearing chamber of the fixed end main shell, and the fixed end rotor assembly is supported by the third bearing and the fourth bearing.

[0016] Furthermore, the output-end electromagnetic brake assembly includes an output-end brake housing fixedly mounted on a side of the output-end main housing, and also includes an output-end coil, an output-end armature, an output-end flywheel, and an output-end brake disc coaxially arranged in sequence on the output-end rotor hollow shaft, an inner hole of the output-end flywheel is provided with an inner spline that cooperates with the outer spline of the output-end rotor hollow shaft, and friction material is provided on both sides of the output-end flywheel for axially moving between the output-end armature and the output-end brake disc as the output-end rotor hollow shaft rotates, and rubbing against the output-end armature and the output-end brake disc simultaneously to generate a braking torque at the output end;

[0017] The fixed-end electromagnetic brake assembly includes a fixed-end brake housing fixedly mounted on the side of the fixed-end main housing, and also includes a fixed-end coil, a fixed-end armature, a fixed-end flywheel and a fixed-end brake disc coaxially arranged in sequence on the fixed-end rotor hollow shaft. The inner hole of the fixed-end flywheel is provided with an internal spline that cooperates with the external spline of the fixed-end rotor hollow shaft. Friction material is provided on both sides of the fixed-end flywheel for axial movement between the fixed-end armature and the fixed-end brake disc as the fixed-end rotor hollow shaft rotates, and rubs against the fixed-end armature and the fixed-end brake disc at the same time to generate a braking torque at the fixed end.

[0018] Furthermore, it also includes a guide bar, which is arranged on the outer ring of the secondary ball screw and is used to limit the rotational movement of the secondary ball screw so that the secondary ball screw only performs linear displacement movement.

[0019] Furthermore, the output-end rotating transformer stator of the output-end rotating transformer is fixedly mounted on the output-end brake disc, and the output-end rotating transformer rotor is interference mounted on the output-end rotor hollow shaft; the fixed-end rotating transformer stator of the fixed-end rotating transformer is fixedly mounted on the fixed-end brake disc, and the fixed-end rotating transformer rotor is interference mounted on the fixed-end rotor hollow shaft.

[0020] Furthermore, it also includes an electrical connector, which includes an output end signal electrical connector, an output end power electrical connector, a fixed end power electrical connector and a fixed end signal electrical connector, the output end signal electrical connector and the output end power electrical connector are arranged on the outer wall of the output end permanent magnet synchronous motor assembly, and the fixed end power electrical connector and the fixed end signal electrical connector are arranged on the outer wall of the fixed end permanent magnet synchronous motor assembly.

[0021] Furthermore, it also includes an output ear, which is fixed to the output end of the secondary ball screw. The output end joint bearing is installed on the output ear and is used to articulate the movable parts on the electric servo.

[0022] Furthermore, it also includes a connecting end cover, which is fixedly installed between the fixed end main housing and the output end main housing, and is used to fixedly connect the fixed end main housing and the output end main housing.

[0023] Furthermore, it also includes a small end cover at the fixed end and a small end cover at the output end, wherein the small end cover at the output end is fixedly mounted on the side of the output end brake housing, and the small end cover at the fixed end is fixedly mounted on the side of the fixed end brake housing, and the guide bar is fixed integrally with the small end cover at the output end.

[0024] Compared with the prior art, the beneficial effects achieved by at least one of the above-mentioned technical solutions adopted in the embodiments of this specification include at least the following: the electric servo in the embodiment of the present invention adopts dual permanent magnet synchronous motors connected coaxially in series to directly drive a two-stage ball screw pair to output force and speed with high efficiency; and has a dual redundant brake to ensure the stability of the control surface in the event of a power outage, and ensures the working position accuracy through a dual redundant rotary transformer and a linear displacement sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0026] Figure 11 is a cross-sectional view of a dual-redundant direct-drive two-stage ball screw pair aviation electric servo according to an embodiment of the present invention;

[0027] Figure 2 This is an axonometric view of a dual-redundant direct-drive two-stage ball screw pair aviation electric servo according to an embodiment of the present invention;

[0028] Among them, 1-output ear; 2-locking nut; 3-secondary ball screw; 4-guide bar; 5-small end cover of output end; 6-output end rotary transformer stator; 7-output end rotary transformer rotor; 8-output end flywheel; 9-output end brake housing; 10-first screw; 11-first anti-loosening washer; 12-output end main end cover; 13-output end signal electrical connector; 14-output end main housing; 15-output end power electrical connector; 16-second anti-loosening washer; 17-second screw; 18-connecting end cover; 19-fixed end power electrical connector; 20-linear displacement sensor movable end; 21-fixed end signal electrical connector; 22-fixed end main end cover; 23-third screw; 24-third anti-loosening washer; 25-fixed end armature; 26-fixed end brake disc; 27-fixed end rotary transformer stator; 28-fixed end rotary transformer rotor; 29-fourth screw; 30- Fixed end small end cover joint bearing; 31-fixed end small end cover; 32-linear displacement sensor mounting end; 33-fixed end rotor hollow shaft; 34-fixed end flywheel; 35-fixed end coil; 36-fixed end brake housing; 37-fixed end main housing; 38-third bearing; 39-fixed end stator assembly; 40-fixed end rotor magnet; 41-fixed end rotor yoke; 42-first ball; 43-fixed end nut; 44-fourth bearing; 45-second ball; 46-second bearing; 47-first stage ball screw; 48-third ball; 49-output end rotor magnet; 50-output end rotor yoke; 51-output end nut; 52-output end stator assembly; 53-first bearing; 54-fifth screw; 55-output end coil; 56-output end armature; 57-output end brake disc; 58-output end rotor hollow shaft; 59-locking washer; 60-output ear joint bearing. DETAILED DESCRIPTION

[0029] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0030] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments, and the technical solutions of the present invention will be clearly and completely described. Obviously, the embodiments described 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 making creative work are within the scope of protection of the present invention.

[0031] like Figure 1-Figure 2 As shown, an embodiment of the present invention provides a dual-redundant direct-drive two-stage ball screw pair aviation electric servo, including: a permanent magnet synchronous motor assembly, an electromagnetic brake assembly, a two-stage ball screw pair, a linear displacement sensor, a rotary transformer, an electrical connector, an output ear and a structural support.

[0032] The permanent magnet synchronous motor assembly comprises an output end permanent magnet synchronous motor assembly and a fixed end permanent magnet synchronous motor assembly, and the output end permanent magnet synchronous motor assembly and the fixed end permanent magnet synchronous motor assembly are coaxially connected in series;

[0033] The output-end permanent magnet synchronous motor assembly includes the output-end main end cover 12, the output-end stator assembly 52, the output-end rotor yoke 50, the output-end rotor magnets 49, the output-end rotor hollow shaft 58, and the output-end main housing 14. The fixed-end permanent magnet synchronous motor assembly includes the fixed-end main end cover 22, the fixed-end stator assembly 39, the fixed-end rotor yoke 41, the fixed-end rotor magnets 40, the fixed-end rotor hollow shaft 33, and the fixed-end main housing 37.

[0034] Specifically, the output-end stator assembly 52 of the output-end permanent magnet synchronous motor assembly is interference-fitted into the inner hole of the output-end main housing 14, and the output-end main end cover 12 is fixed to one side of the output-end main housing 14 by six first screws 10 and first anti-loosening washers 11 evenly distributed along the circumference. The fixed-end stator assembly 39 of the fixed-end permanent magnet synchronous motor assembly is interference-fitted into the inner hole of the fixed-end main housing 37, and the fixed-end main end cover 22 is fixed to one side of the fixed-end main housing 37 by six screws and anti-loosening washers evenly distributed along the circumference (the specific screws and anti-loosening washers are not shown in the figure). Figure 1 The principle behind this is the same as that of the output-end permanent magnet synchronous motor assembly. The output-end rotor magnet 49 is affixed to the outer surface of the output-end rotor yoke 50. The output-end nut 51 is interference-fitted into the inner hole of the output-end rotor yoke 50. The output-end rotor hollow shaft 58 is interference-fitted onto the output-end nut 51. The components, output-end rotor magnet 49, output-end rotor yoke 50, output-end nut 51, and output-end rotor hollow shaft 58, collectively comprise the output-end permanent magnet synchronous motor rotor assembly. Similarly, the components, fixed-end rotor magnet 40, fixed-end rotor yoke 41, fixed-end nut 43, and fixed-end rotor hollow shaft 33, collectively comprise the fixed-end permanent magnet synchronous motor rotor assembly.

[0035] The rotor assembly of the output-end permanent magnet synchronous motor assembly is supported by a first bearing 53 installed in the bearing chamber of the output-end main end cover 12 and a second bearing 46 installed in the bearing chamber of the output-end main housing 14. The rotor assembly of the fixed-end permanent magnet synchronous motor assembly is supported by a third bearing 38 installed in the bearing chamber of the fixed-end main end cover 22 and a fourth bearing 44 installed in the bearing chamber of the fixed-end main housing 37.

[0036] The electromagnetic brake assembly includes an output-end electromagnetic brake assembly and a fixed-end electromagnetic brake assembly. The output-end electromagnetic brake assembly is fixedly mounted on the side of the output-end permanent magnet synchronous motor assembly to brake the output-end permanent magnet synchronous motor; the fixed-end electromagnetic brake assembly is fixedly mounted on the side of the fixed-end permanent magnet synchronous motor assembly to brake the fixed-end permanent magnet synchronous motor;

[0037] The output-end electromagnetic brake assembly includes an output-end brake housing 9, an output-end coil 55, an output-end armature 56, an output-end flywheel 8, and an output-end brake disc 57. The fixed-end electromagnetic brake assembly includes a fixed-end brake housing 36, a fixed-end coil 35, a fixed-end armature 25, a fixed-end flywheel 34, and a fixed-end brake disc 26.

[0038] Specifically, the output brake housing 9 is mounted to the output main end cover 12 via six fifth screws 54 evenly spaced along the circumference. The output coil 55, output armature 56, output flywheel 8, and output brake disc 57 are coaxially arranged on the output rotor hollow shaft 58. The output armature 56 is made of a magnetically conductive material and cannot rotate, only moving axially. Friction material is machined on both sides of the output flywheel 8, rubbing against both the output armature 56 and the output brake disc 57, generating a braking torque. Its inner bore is machined with internal splines that mate with external splines on the output rotor hollow shaft 58. It rotates with the output rotor hollow shaft 58 and can also move axially between the output brake disc 57 and the output armature 56. The output brake disc 57 is fixed to the output brake housing 9 and is a non-moving component. Together, these components comprise the output electromagnetic brake assembly.

[0039] Because the output-end electromagnetic brake assembly and the fixed-end electromagnetic brake assembly are dual-redundant designs, their functions and principles are identical. Similarly, the fixed-end electromagnetic brake assembly consists of the fixed-end brake housing 36, the fixed-end coil 35, the fixed-end armature 25, the fixed-end flywheel 34, and the fixed-end brake disc 26.

[0040] The two-stage ball screw pair includes an output nut 51, a fixed nut 43, a primary ball screw 47, and a secondary ball screw 3. The external threads of the output end of the primary ball screw 47 and the internal threads of the output nut 51 simultaneously mesh with multiple third balls 48. The output nut 51 is interference-fitted into the inner bore of the output rotor yoke 50, directly outputting torque and speed as the rotor of the output permanent magnet synchronous motor assembly. Furthermore, the external threads of the fixed end of the primary ball screw 47 and the internal threads of the fixed nut 43 simultaneously mesh with multiple first balls 42. The external threads of the secondary ball screw 3 and the internal threads of the primary ball screw 47 simultaneously mesh with multiple second balls 45. Furthermore, the secondary ball screw 3 does not require machining of external threads with a long axial length. The fixed nut 43 is interference-fitted into the inner bore of the fixed rotor yoke 41, directly outputting torque and speed as the rotor of the fixed permanent magnet synchronous motor assembly.

[0041] The rotary transformer includes an output-end rotary transformer and a fixed-end rotary transformer, the output-end rotary transformer includes an output-end rotary transformer stator 6 and an output-end rotary transformer rotor 7 arranged in the inner hole of the output-end rotary transformer stator 6, the output-end rotary transformer stator 6 is fixedly installed with the output-end electromagnetic brake assembly, and the output-end rotary transformer rotor is fixedly installed with the rotor of the output-end permanent magnet synchronous motor assembly, and is used to detect and record the rotor position and angle of the output-end permanent magnet synchronous motor assembly; the fixed-end rotary transformer includes a fixed-end rotary transformer stator 27 and a fixed-end rotary transformer rotor 28 arranged in the inner hole of the fixed-end rotary transformer stator 27, the fixed-end rotary transformer stator 27 is fixedly installed with the fixed-end electromagnetic brake assembly, and the fixed-end rotary transformer rotor 28 is fixedly installed with the rotor of the fixed-end permanent magnet synchronous motor assembly, and is used to detect and record the rotor position and angle of the fixed-end permanent magnet synchronous motor assembly.

[0042] Specifically, the output-end resolver stator 6 is mounted on the output-end brake disc 57, and the output-end resolver rotor 7 is interference-fitted onto the output-end rotor hollow shaft 58. It rotates synchronously with the output-end rotor hollow shaft 58 and provides rotor position and angle information for the output-end permanent magnet synchronous motor assembly. The fixed-end resolver stator 27 is mounted on the fixed-end brake disc 26, and the fixed-end resolver rotor 28 is interference-fitted onto the fixed-end rotor hollow shaft 33. It rotates synchronously with the fixed-end rotor hollow shaft 33 and provides rotor position and angle information for the fixed-end permanent magnet synchronous motor assembly.

[0043] The linear displacement sensor mounting end 32 is fixed in the fixed end permanent magnet synchronous motor assembly, and the linear displacement sensor movable end 20 is coaxially and rigidly connected to the secondary ball screw 3, and performs synchronous linear motion with the secondary ball screw 3, so as to collect and feedback the output position information of the electric servo in real time.

[0044] The structural parts mainly include the output end main cover 12, the fixed end main cover 22, the output end small cover 5 and the fixed end small cover 31, and the connecting end cover 18. The output end small cover 5 is fixedly installed on the side of the output end main cover 12 (the relevant screws and anti-loosening washers are not in the Figure 1 (Indicated in the figure), its principle is the same as that of the fixed end. The fixed end small end cover 31 is fixedly installed on the side of the fixed end main end cover 22 by six third screws 23 and third anti-loosening washers 24 evenly distributed along the circumference. A guide bar 4 is processed on the output end small end cover 5 to constrain the rotational movement of the secondary ball screw 3 and ensure that the secondary ball screw 3 can only perform linear displacement movement. A fixed end small end cover joint bearing 30 is installed on the fixed end small end cover 31 to install and fix the electric servo. The linear displacement sensor mounting end 32 is fixed to the inner side of the fixed end small end cover 31 by the fourth screw 29. The connecting end cover 18 is fixedly installed between the fixed end main shell 37 and the output end main shell 14 by six second screws 17 and second anti-loosening washers 16 evenly distributed along the circumference on both sides ( Figure 1 The screws and anti-loosening washers connected to the fixed end main housing 37 are not shown) and are used to fix the fixed end main housing 37 to the output end main housing 14.

[0045] The output end of the secondary ball screw 3 is fixed to the output ear 1 by a locking nut 2 and a locking washer 59. The linear displacement sensor collects and feeds back the position of the output ear 1 in real time, and an output ear joint bearing 60 is installed on the output ear 1 to ensure the articulation between the electric servo and the movable parts.

[0046] The electric servo of this embodiment also includes an electrical connector, which includes an output end signal electrical connector 13, an output end power electrical connector 15, a fixed end power electrical connector 19 and a fixed end signal electrical connector 21. The output end signal electrical connector 13 and the output end power electrical connector 15 are arranged on the outer wall of the output end permanent magnet synchronous motor assembly, and the fixed end power electrical connector 19 and the fixed end signal electrical connector 21 are arranged on the outer wall of the fixed end permanent magnet synchronous motor assembly.

[0047] The dual-redundant direct-drive two-stage ball screw pair aviation electric servo of this embodiment adopts a one-master-one-backup working mode, that is, it is divided into a main channel and a backup channel. Its allocation method is relatively flexible. When the output end permanent magnet synchronous motor assembly, the output end electromagnetic brake assembly, and the output end rotary transformer serve as the main channel, the fixed end permanent magnet synchronous motor assembly, the fixed end electromagnetic brake assembly, and the fixed end rotary transformer serve as the backup channel; vice versa.

[0048] The working principle of the dual-redundant direct-drive two-stage ball screw pair aviation electric servo of this embodiment is as follows: under normal working conditions, after the main channel receives the upper-level action command, the controller immediately energizes the main channel electromagnetic brake to release the brake, and then immediately drives the main channel permanent magnet synchronous motor assembly to work. That is, the driver obtains the rotor position of the main channel permanent magnet synchronous motor through the main channel rotary transformer, injects a three-phase sinusoidal current into the main channel stator coil, and drives the rotor to rotate. At this time, the ball screw pair nut (fixed end nut 43 or output end nut 51) that is integrated with the motor rotor rotates and drives the primary ball screw 47 to perform both rotational motion and linear displacement motion. At the same time, the primary ball screw 47 drives the secondary ball screw 3 to perform linear displacement motion, and the movable end 20 of the linear displacement sensor performs synchronous linear displacement motion with the secondary ball screw 3, and the collected position signal is fed back to the controller to achieve system closed-loop control. At this point, the dual-redundant direct-drive two-stage ball screw pair aviation electric servo of the present invention outputs the force and speed required by the command through the output ear 1 and the output ear joint bearing 60 to meet the frequency response. When the main channel fails, the received superior action command is sent to the backup channel, and the backup channel takes action based on the same principle as the main channel. It should be noted that when either the main channel or the backup channel is operating, the electromagnetic brake of the other channel does not need to be powered on to release the brake, and can always remain in the power-off braking state or the power-on braking state.

[0049] In the extreme failure mode of the dual-redundant direct-drive two-stage ball screw pair aviation electric servo, that is, when both the main channel and the backup channel fail and cannot complete the action according to the command, the power-off braking feature of the electromagnetic brake of the main and backup channels can stably maintain the control surface in the current position, prevent the control surface from becoming unstable and uncontrollable, and avoid adverse consequences caused by failure of the flight control system.

[0050] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A dual-redundant direct-drive two-stage ball screw pair aviation electric servo, characterized in that: include: A permanent magnet synchronous motor assembly, the permanent magnet synchronous motor assembly comprising an output end permanent magnet synchronous motor assembly and a fixed end permanent magnet synchronous motor assembly, the output end permanent magnet synchronous motor assembly and the fixed end permanent magnet synchronous motor assembly being coaxially connected in series; An electromagnetic brake assembly, comprising an output-end electromagnetic brake assembly and a fixed-end electromagnetic brake assembly, wherein the output-end electromagnetic brake assembly is fixedly mounted on the side of the output-end permanent magnet synchronous motor assembly for braking the output-end permanent magnet synchronous motor; the fixed-end electromagnetic brake assembly is fixedly mounted on the side of the fixed-end permanent magnet synchronous motor assembly for braking the fixed-end permanent magnet synchronous motor; A two-stage ball screw pair, comprising an output end nut, a fixed end nut, a first-stage ball screw and a second-stage ball screw, wherein the external thread of the output end of the first-stage ball screw is meshed with the internal thread of the output end nut, and the output end nut is interference-mounted in the rotor inner hole of the output end permanent magnet synchronous motor assembly, serving as the rotor of the output end permanent magnet synchronous motor assembly to directly output torque and speed; the external thread of the fixed end of the first-stage ball screw is meshed with the internal thread of the fixed end nut, and the fixed end nut is interference-mounted in the rotor inner hole of the fixed end permanent magnet synchronous motor assembly, serving as the rotor of the fixed end permanent magnet synchronous motor assembly to directly output torque and speed; the external thread of the second-stage ball screw is meshed with the internal thread of the first-stage ball screw; A linear displacement sensor, wherein the mounting end of the linear displacement sensor is fixed within the fixed-end permanent magnet synchronous motor assembly, and the movable end of the linear displacement sensor is rigidly connected coaxially with the secondary ball screw, and moves linearly synchronously with the secondary ball screw, and is used to collect and feedback the output position information of the electric servo in real time; A rotating transformer, wherein the rotating transformer includes an output-end rotating transformer and a fixed-end rotating transformer, the output-end rotating transformer includes an output-end rotating transformer stator and an output-end rotating transformer rotor arranged in the inner hole of the output-end rotating transformer stator, the output-end rotating transformer stator is fixedly mounted on the output-end electromagnetic brake assembly, the output-end rotating transformer rotor is fixedly mounted on the rotor of the output-end permanent magnet synchronous motor assembly, and is used to detect and record the rotor position and angle of the output-end permanent magnet synchronous motor assembly; the fixed-end rotating transformer includes a fixed-end rotating transformer stator and a fixed-end rotating transformer rotor arranged in the inner hole of the fixed-end rotating transformer stator, the fixed-end rotating transformer stator is fixedly mounted on the fixed-end electromagnetic brake assembly, the fixed-end rotating transformer rotor is fixedly mounted on the rotor of the fixed-end permanent magnet synchronous motor assembly, and is used to detect and record the rotor position and angle of the fixed-end permanent magnet synchronous motor assembly.

2. The dual-redundant direct-drive two-stage ball screw pair aviation electric servo according to claim 1, characterized in that: The output-end permanent magnet synchronous motor assembly includes an output-end main housing, an output-end stator assembly, and an output-end rotor assembly; the output-end stator assembly is interference-mounted in the inner hole of the output-end main housing; the output-end rotor assembly includes an output-end rotor yoke disposed in the output-end stator assembly, an output-end rotor magnet is adhered to the outer surface of the output-end rotor yoke, an output-end nut is interference-mounted in the inner hole of the output-end rotor yoke, and an output-end rotor hollow shaft is interference-mounted on the output-end nut; The fixed-end permanent magnet synchronous motor assembly includes a fixed-end main housing, a fixed-end stator assembly and a fixed-end rotor assembly; the fixed-end main housing is fixedly connected to the output-end main housing, the fixed-end stator assembly is interference-mounted in the inner hole of the fixed-end main housing, the fixed-end rotor assembly includes a fixed-end rotor yoke arranged in the fixed-end stator assembly, the outer surface of the fixed-end rotor yoke is pasted with a fixed-end rotor magnet, a fixed-end nut is interference-mounted in the inner hole of the fixed-end rotor yoke, and a fixed-end rotor hollow shaft is interference-mounted on the fixed-end nut.

3. The dual-redundant direct-drive two-stage ball screw pair aviation electric servo according to claim 2, characterized in that: The side of the output end main housing is fixedly connected to the output end main end cover, a first bearing is installed in the bearing chamber of the output end main end cover, a second bearing is installed in the bearing chamber of the output end main housing, and the output end rotor assembly is supported by the first bearing and the second bearing; The side of the fixed end main shell is fixedly connected to the fixed end main end cover, a third bearing is installed in the bearing chamber of the fixed end main end cover, a fourth bearing is installed in the bearing chamber of the fixed end main shell, and the fixed end rotor assembly is supported by the third bearing and the fourth bearing.

4. The dual-redundant direct-drive two-stage ball screw pair aviation electric servo according to claim 2, characterized in that: The output-end electromagnetic brake assembly includes an output-end brake housing fixedly mounted on a side of the output-end main housing, and further includes an output-end coil, an output-end armature, an output-end flywheel, and an output-end brake disc coaxially arranged in sequence on the output-end rotor hollow shaft, an inner hole of the output-end flywheel is provided with an inner spline that cooperates with the outer spline of the output-end rotor hollow shaft, and friction materials are provided on both sides of the output-end flywheel for axial movement between the output-end armature and the output-end brake disc as the output-end rotor hollow shaft rotates, and rubs against the output-end armature and the output-end brake disc simultaneously to generate a braking torque at the output end; The fixed-end electromagnetic brake assembly includes a fixed-end brake housing fixedly mounted on the side of the fixed-end main housing, and also includes a fixed-end coil, a fixed-end armature, a fixed-end flywheel and a fixed-end brake disc coaxially arranged in sequence on the fixed-end rotor hollow shaft. The inner hole of the fixed-end flywheel is provided with an internal spline that cooperates with the external spline of the fixed-end rotor hollow shaft. Friction material is provided on both sides of the fixed-end flywheel for axial movement between the fixed-end armature and the fixed-end brake disc as the fixed-end rotor hollow shaft rotates, and rubs against the fixed-end armature and the fixed-end brake disc at the same time to generate a braking torque at the fixed end.

5. The dual-redundant direct-drive two-stage ball screw pair aviation electric servo according to claim 4, characterized in that: It also includes a guide bar, which is arranged on the outer ring of the secondary ball screw and is used to limit the rotational movement of the secondary ball screw so that the secondary ball screw only performs linear displacement movement.

6. The dual-redundant direct-drive two-stage ball screw pair aviation electric servo according to claim 4, characterized in that: The output-end rotary transformer stator of the output-end rotary transformer is fixedly mounted on the output-end brake disc, and the output-end rotary transformer rotor is interference mounted on the output-end rotor hollow shaft; the fixed-end rotary transformer stator of the fixed-end rotary transformer is fixedly mounted on the fixed-end brake disc, and the fixed-end rotary transformer rotor is interference mounted on the fixed-end rotor hollow shaft.

7. The dual-redundant direct-drive two-stage ball screw pair aviation electric servo according to claim 1, characterized in that: It also includes an electrical connector, which includes an output end signal electrical connector, an output end power electrical connector, a fixed end power electrical connector and a fixed end signal electrical connector. The output end signal electrical connector and the output end power electrical connector are arranged on the outer wall of the output end permanent magnet synchronous motor assembly, and the fixed end power electrical connector and the fixed end signal electrical connector are arranged on the outer wall of the fixed end permanent magnet synchronous motor assembly.

8. The dual-redundant direct-drive two-stage ball screw pair aviation electric servo according to claim 1, characterized in that: It also includes an output ear, which is fixed to the output end of the secondary ball screw. An output end joint bearing is installed on the output ear and is used to articulate the movable parts on the electric steering gear.

9. The dual-redundant direct-drive two-stage ball screw pair aviation electric servo according to claim 2, characterized in that: It also includes a connecting end cover, which is fixedly installed between the fixed end main housing and the output end main housing, and is used to fixedly connect the fixed end main housing and the output end main housing.

10. The dual-redundant direct-drive two-stage ball screw pair aviation electric servo according to claim 5, characterized in that: It also includes a small end cover at the fixed end and a small end cover at the output end. The small end cover at the output end is fixedly mounted on the side of the output end brake housing. The small end cover at the fixed end is fixedly mounted on the side of the fixed end brake housing. The guide bar is fixed integrally with the small end cover at the output end.

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