CN116014969A

CN116014969A - Centralized full-electric dual-redundancy emergency discharging electromechanical actuator

Info

Publication number: CN116014969A
Application number: CN202211670034.2A
Authority: CN
Inventors: 郭智; 匡克焕; 郭绍军; 张行星
Original assignee: SICHUAN LINGFENG AVIATION HYDRAULIC MACHINERY CO Ltd
Current assignee: SICHUAN LINGFENG AVIATION HYDRAULIC MACHINERY CO Ltd
Priority date: 2022-12-25
Filing date: 2022-12-25
Publication date: 2023-04-25

Abstract

The centralized full-electric dual-redundancy emergency electro-mechanical actuator provided by the invention is stable in operation, safe, reliable and smooth in speed regulation. The invention provides the following technical scheme: the main motor and the auxiliary motor can work simultaneously or any motor works, the other motor performs cold backup, the main motor and the auxiliary motor work simultaneously, the main screw rod cylinder drives the main screw rod nut and the auxiliary screw rod to extend, and the auxiliary screw rod drives the auxiliary screw rod nut and the sleeved piston cylinder to extend. If the main motor works and the auxiliary motor fails, the main motor drives the main screw rod cylinder to rotate through the main transmission gear, and drives the main screw rod nut to push the auxiliary screw rod nut and the sleeved piston cylinder to overcome the load and stretch out; if the main motor 1 fails or the transmission chain is blocked, the auxiliary motor works, the auxiliary motor drives the transmission shaft to rotate through the auxiliary transmission gear, and the transmission shaft drives the auxiliary screw rod which is in spline engagement with the transmission shaft to synchronously rotate, so that the auxiliary screw rod nut and the sleeved piston cylinder are driven to overcome the extension of the load. The invention effectively solves the problem of low reliability of the conventional dual-redundancy electromechanical actuator.

Description

Centralized full-electric dual-redundancy emergency discharging electromechanical actuator

Technical Field

The invention relates to a dual redundancy function emergency release structure applied to an all-motor electric actuator, in particular to an innovative structure which can improve the safety and task reliability of the all-motor electric actuator and enable another motor and a transmission part to complete the action of extending out of a piston cylinder under the working condition that one motor of the actuator fails or a transmission chain is blocked.

Background

The actuator is a transmission mechanism for the motion control device to perform motor action, and the mechanical transmission of the early actuating system to the later hydraulic transmission are all driven by adopting a centralized hydraulic source of the airplane. The recently developed full-electric transmission hydraulic servo system occupies a large weight of the system, and has the defects of complex structure, high failure rate, large power transmission loss, high heat load and the like, thereby being unfavorable for system integration and reducing reliability. With the proposal of the concept of a full-electrochemical transmission system, an electromechanical actuator is used as a linear motion actuating element and is an energy conversion device for realizing linear reciprocating motion or swinging motion less than 360 degrees of a working mechanism. The basic constitution of a typical electromechanical actuator is as follows: the device comprises a motor, a reduction gearbox, a transmission part, a ball screw pair, an outer cylinder assembly, a piston cylinder assembly, a self-locking assembly and the like. And the electromechanical actuator with the self-locking device can prevent the movement caused by external force when stopping movement at a limited position, and is usually locked by a mechanical lock sleeved with a spline of an actuator cylinder. The mechanical lock is usually a steel ball lock, which consists of steel balls, locking grooves, conical pistons, springs and the like.

In some applications where high safety and task reliability are required, for example, in electromechanical actuators for retraction of an aircraft landing gear, the safety margin for the landing gear must be provided. Thus, electromechanical actuators (EMA) are critical components of flight control systems, the reliability of which directly affects the flight safety of an aircraft. In improving reliability, EMA mainly uses redundancy technology, i.e. adopts redundant design for the system, and the main method for improving the power density of the system is to apply a high-power density motor to realize transmission. After the partial control channel of the electromechanical actuator with the redundancy structure fails, in an active/active working mode, the two channels work simultaneously to jointly push the serial hydraulic cylinders, and force disputes are generated between the two channels. The resolution method of force fighting is as follows 5 kinds: (1) the servo loop parameters, particularly the feedback gain tolerance, are strictly controlled, the machining precision of the parts is improved, errors among channels are reduced as much as possible, and the consistency among the channels is improved. Because errors of various types of systems are unavoidable, force disputes can only be relieved to a certain extent, and cost is increased. (2) Input signal differences are eliminated or reduced by voting the output single value command signals, but other errors are unavoidable. (3) By voting the displacement feedback signals, a waiting stepping mode is adopted, and the difference of output signals is eliminated or reduced. The presence of non-linearities in the manner of waiting for a step reduces the natural frequency of the actuation system. (4) The magnitude of force fighting is reduced by reducing the pressure gain and increasing the damping, but the stiffness and dynamic performance of the system are reduced. (5) By adopting the equalization technology, the output forces of all channels are forced to be consistent, so that the force fighting phenomenon is relieved or eliminated. The above 5 methods are best in a manner that reduces force fighting with equalization techniques. Among the 5 methods for reducing force disputes currently used, the other 4 methods can only reduce the force disputes to a certain extent, and can cause a certain negative influence on the system, and the existence of the force disputes can reduce the response speed of the system and also influence the position accuracy of the system.

How to improve the reliability of the other control channels of the system and increase the power density of the system, the operation mode of the other degree system comprises two modes of active parallel operation and standby conversion operation, the latter means that one or part of the systems work, the other subsystems are in a standby state, and when the working subsystems are in failure, the monitoring device detects the failure and converts the failure into the standby complete subsystems, so that the system continues to work. In order to avoid force fighting during simultaneous working, the redundant electromechanical actuator is generally designed as a motor for backing up one, and when the main motor fails, the standby motor works to realize emergency lowering of the piston cylinder, but single-point faults of the screw pair blocking plug cannot be solved, the task reliability is low, and the practicability is poor.

In the past, most of redundant electromechanical actuators adopt a differential mechanism or a fault-tolerant motor method. The disadvantage of using a differential is that the moment of inertia, moment of inertia and weight are increased, and therefore are mostly applied to small common electromechanical actuators. In order to solve the current fighting problem of the electromagnetic integrated system of the electromechanical actuator. The dual-redundancy electromechanical actuator takes a permanent magnet brushless direct current motor as a core, and adopts a balanced control method of dual-redundancy winding current of the brushless direct current motor, wherein the motor of the dual-redundancy electromechanical actuating system is a dual-redundancy torque magnetic coupling samarium cobalt permanent magnet brushless direct current motor, and two identical three-phase windings are arranged on a stator. The two sets of windings are 60 degrees apart in electrical angle. Two sets of photoelectric position sensors are arranged on the rotor to form a dual-redundancy dual-trigger sensor. The outputs of the power converters are magnetically coupled to apply a combined torque to the main shaft of the motor to drive the control surface of the aircraft. The dual redundancy controller is composed of two singlechips and peripheral circuits, and one is actively operated and the other is thermally backed up by adopting a backup rule. And according to the system control instruction and the state information, two paths of PWM wave signals are sent to control the two sets of power converters, and the balance of the currents of the two sets of windings of the motor can be ensured through balance adjustment. However, the equalization technique will mask the true failure of the system, so an appropriate failure threshold is set to prevent the system from being masked by the current equalization technique. Because the two channels of the dual redundancy system cannot be completely symmetrical and the influence of various factors, such as the difference of power supplies, load change, environmental temperature change and the like, the current imbalance of two sets of windings of the motor can be caused. Thus, there is a "current fighting" phenomenon in the operation of dual redundancy electromechanical actuator systems. Simulation of parallel operation of the system proves that when the voltage difference between two sets of power converter power supplies is large, serious unbalance of current can occur, even one set of windings is in an electric state, the other set of windings is in a power generation state, and the motor is seriously heated, so that the safety of the system is endangered. There are many reasons for the fact that the displacement of the two channel outputs is inconsistent. For example, manufacturing variations (processes), energy variations, variations in components such as sensors, controller variations (components), environmental changes (temperature), wear (long-term performance degradation), and changes in dynamic hydraulic stiffness of actuators, all result in variations in output displacement, speed, and the like.

Disclosure of Invention

In view of the above problems in the prior art, the invention aims to provide a scheme which has the advantages of simple structure, stable operation, safety, reliability, smooth speed regulation and capability of realizing emergency extension of the piston cylinder under the supply of electric power energy only. The problem that a single-point fault of a clamping plug of a screw pair cannot be solved by a conventional dual-redundancy electromechanical actuator is effectively solved, and full-electricity redundancy emergency is realized.

The technical scheme adopted for solving the technical problems is as follows: a centralized full-electric dual-redundancy emergency discharge electromechanical actuator, comprising: the main motor 1 and the auxiliary motor 11 which are assembled on the upper end side of the outer cylinder 3 and serve as main power sources and the lower end side of the outer cylinder 3 serve as auxiliary power sources, the main motor 1 and the auxiliary motor 11 serving as power output sources which are mutually backed up are respectively provided with a transmission gear pair which is meshed with the main screw cylinder 4 and the transmission shaft 13, and a main screw nut 6 which is sleeved on an outer spiral rollaway of the main screw cylinder 4, and the main screw nut is characterized in that: the main shaft of the main motor 1 is meshed with a main screw rod cylinder 4 gear in a transmission cavity through a main transmission gear 2, a main shaft gear of the auxiliary motor 11 is meshed with an outer end gear of a transmission shaft 13 in the transmission cavity through an auxiliary transmission gear 12, an outer spline at the right end of the transmission shaft 13 is sleeved with an auxiliary screw rod 8, a shaft end plunger round table spline extending out of a port of the main screw rod cylinder 4 is meshed with an inner cavity spline groove of the auxiliary screw rod 8 assembled with a bearing through a containing cavity of a main screw rod nut 6, the main screw rod cylinder 4 can be driven by the main motor 1, the auxiliary screw rod 8 can be driven by an auxiliary motor 11 and is integrated together by a piston cylinder 10 of an inner sleeve auxiliary screw rod nut 9 to form two relatively independent transmission chains, the main screw rod cylinder 4 and the transmission shaft 13 are meshed with the main motor gear and the auxiliary motor gear in a staggered and parallel mode to transmit loads, and when any motor fails or the corresponding transmission chain is blocked, the other motor independently completes a dual-redundancy emergency release control mechanism extending out of the piston cylinder.

Compared with the prior art, the invention has the following gain effects:

the invention adopts the main motor 1 which is assembled on the upper end side of the outer cylinder 3 and is used as a main power source, and the auxiliary motor 11 which is assembled on the lower end side of the outer cylinder 3 and is used as an emergency power source, the main motor 1 and the auxiliary motor 11 which are used as power output sources for mutual backup are respectively provided with a transmission gear pair which is meshed with the main screw cylinder 4 and the transmission shaft 13, and the main screw nut 6 which is sleeved on the outer spiral rollaway of the main screw cylinder 4.

According to the invention, a main shaft of the main motor 1 is meshed with a gear of the main screw rod barrel 4 in the transmission cavity through the main transmission gear 2, a main shaft gear of the auxiliary motor 11 is meshed with an outer end gear of the main screw rod barrel 4 spline sleeve-connected transmission shaft 13 in the transmission cavity through the auxiliary transmission gear 12, the outer spline teeth of the transmission shaft 13 are meshed with the spline grooves in the inner cavity of the auxiliary screw rod 8, when any motor fails or a corresponding transmission chain is blocked, the other motor can independently complete the task of extending out of the piston barrel, the safety and the task reliability of the electric actuator of the whole motor can be improved, and under the working condition that one motor fails or the transmission chain of the actuator is blocked, the other motor and a transmission part can complete the action of extending out of the piston barrel, so that the problem that the single-point failure problem of the screw rod auxiliary blocking is not solved by the conventional electromechanical actuator is solved.

According to the invention, the auxiliary screw rod 8 which can bear load and can be driven to freely rotate is axially assembled on the main screw rod nut 6, so that the main screw rod cylinder 4 can be driven by the main motor 1, the auxiliary screw rod 8 can be driven by the auxiliary motor 11, two relatively independent transmission chains are formed, and the two transmission chains are integrated together by the piston cylinder 10. When the main motor 1 and the auxiliary motor 11 work simultaneously, the extending speed of the piston cylinder is twice that of the single motor, the power of the actuator is increased, the response speed of the system is accelerated, the force fighting is greatly reduced, and the amplitude and duration of the force fighting can be reduced. Through simulation verification, the amplitude of force fighting can be greatly reduced, and the time for the force fighting to disappear is shortened. The staggered parallel double redundancy emergency release control mechanism is respectively meshed with the lead screw gears; when the main motor 1 and the auxiliary motor 11 can work simultaneously, the time for reaching the balance state is quickened, and the requirements of the aircraft landing gear system for rapidness, high power and redundancy can be met by shortening the time for reaching the balance state.

Drawings

FIG. 1 is a schematic diagram of a piston cylinder retraction state structure of a centralized full-electric dual redundancy function emergency release electromechanical actuator.

Fig. 2 is a schematic diagram of spline engagement of a transmission shaft of the centralized full-electric dual-redundancy functional emergency release electromechanical actuator and an auxiliary lead screw.

In the figure: the device comprises a main motor 1, a main transmission gear 2, an outer cylinder 3, a main screw cylinder 4, a thrust angular contact ball bearing 5, a main screw nut 6, a bidirectional thrust angular contact ball bearing 7, an auxiliary screw 8, an auxiliary nut 9, a piston cylinder 10, an auxiliary motor 11, an auxiliary transmission gear 12 and a transmission shaft 13.

The invention will be further described with reference to the drawings and examples, without thereby restricting the invention to the scope of the examples. All such concepts should be considered as being generic to the disclosure herein and to the scope of the invention.

Detailed Description

See fig. 1. In a preferred embodiment described below, a centralized all-electric dual-redundancy emergency-discharge electromechanical actuator, comprising: the main motor 1 and the auxiliary motor 11 which are assembled on the upper end side of the outer cylinder 3 and serve as main power sources and the lower end side of the outer cylinder 3 serve as auxiliary power sources, the main motor 1 and the auxiliary motor 11 serving as power output sources which are mutually backed up are respectively provided with a transmission gear pair which is meshed with the main screw cylinder 4 and the transmission shaft 13, and a main screw nut 6 which is sleeved on an outer spiral rollaway of the main screw cylinder 4, and the main screw nut is characterized in that: the main shaft of the main motor 1 is meshed with a main screw rod cylinder 4 gear in a transmission cavity through a main transmission gear 2, a main shaft gear of the auxiliary motor 11 is meshed with an outer end gear of a transmission shaft 13 in the transmission cavity through an auxiliary transmission gear 12, an outer spline at the right end of the transmission shaft 13 is sleeved with an auxiliary screw rod 8, a shaft end plunger round table spline extending out of a port of the main screw rod cylinder 4 is meshed with an inner cavity spline groove of the auxiliary screw rod 8 assembled with a bearing through a containing cavity of a main screw rod nut 6, the main screw rod cylinder 4 can be driven by the main motor 1, the auxiliary screw rod 8 can be driven by an auxiliary motor 11 and is integrated together by a piston cylinder 10 of an inner sleeve auxiliary screw rod nut 9 to form two relatively independent transmission chains, the main screw rod cylinder 4 and the transmission shaft 13 are meshed with the main motor gear and the auxiliary motor gear in a staggered and parallel mode to transmit loads, and when any motor fails or the corresponding transmission chain is blocked, the other motor independently completes a dual-redundancy emergency release control mechanism extending out of the piston cylinder.

The main motor 1 and the auxiliary motor 11 as power output sources for mutual backup can work simultaneously or any motor works, and the other motor is cold backed up.

The main motor 1 and the auxiliary motor 11 work simultaneously, the main screw cylinder 4 which is output as the rotation speed of the main motor 1 drives the main screw nut 6, the auxiliary motor 11 drives the auxiliary screw nut 9 on the outer spiral rollaway nest of the auxiliary screw 8, and the piston cylinder 10 which performs telescopic movement in the outer cylinder 3 drives to move together, the auxiliary screw nut 9 assembled in the hollow stepped hole of the piston cylinder 10 sequentially transmits the load of the piston cylinder to the auxiliary screw 8 and the main screw nut 6, and the load is transmitted to the main screw cylinder 4 through the thrust angular contact ball bearing 5, the main screw cylinder 4 drives the main screw nut 6 and the auxiliary screw 8 to extend, and the auxiliary screw 8 drives the auxiliary screw nut 9 and the sleeved piston cylinder 10 to extend; if the main motor 1 fails or the transmission chain is blocked, the auxiliary motor 11 works, the auxiliary motor 11 drives the transmission shaft 13 to rotate through the auxiliary transmission gear 12, the auxiliary screw rod 8 which is in spline engagement with the transmission shaft 13 is driven to synchronously rotate by the transmission shaft 13, and the auxiliary screw rod nut 9 and the sleeved piston cylinder 10 are driven to extend out against the load.

The main screw rod cylinder 4 is in threaded connection with the main screw rod nut 6 through a thrust angular contact ball bearing 5 on a bearing seat in a transmission cavity of the outer cylinder 3, and is driven to move together through a bidirectional thrust angular contact ball bearing 7 restrained by a double-arm bearing seat assembled in a hollow stepped hole in the main screw rod nut 6, an auxiliary screw rod nut 9 sleeved on an outer spiral raceway of the auxiliary screw rod 8 and a piston cylinder 10 which performs telescopic movement in the outer cylinder 3.

The thrust angular contact ball bearing 5 installed in the hollow stepped hole of the outer barrel 3 is axially limited on the stepped shaft at the upper end of the main screw barrel 4 in an inner ring manner, and bears the load of the main screw barrel 4; the inner ring of the bidirectional thrust angular contact ball bearing 7 arranged in the hollow stepped hole of the main screw nut 6 is axially limited on the stepped shaft at the upper end of the auxiliary screw 8, and the load of the auxiliary screw 8 is born;

during normal operation, the main motor 1 and the auxiliary motor 11 can work simultaneously or any motor works, the other motor is used for cold backup, the main motor 1 and the auxiliary motor 11 work simultaneously, the main screw rod cylinder 4 drives the main screw rod nut 6 and the auxiliary screw rod 8 to extend, and the auxiliary screw rod 8 drives the auxiliary screw rod nut 9 and the sleeved piston cylinder 10 to extend.

While embodiments of the present invention have been illustrated and described above, the embodiments of the present invention have been described in detail, and the description of the embodiments is only for aiding in the understanding of the present invention; also, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, and the scope of the invention is not to be construed as limited by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A centralized full-electric dual-redundancy emergency discharge electromechanical actuator, comprising: the main motor (1) and the auxiliary motor (11) which are assembled on the upper end side of the outer cylinder (3) and serve as main power sources, the auxiliary motor (11) and the main motor (1) serving as power output sources which are mutually backed up are respectively provided with a transmission gear pair which is meshed with the main screw cylinder (4) and the transmission shaft (13), and a main screw nut (6) which is sleeved on an outer spiral raceway of the main screw cylinder (4), and the emergency power source is characterized in that: the main shaft of the main motor (1) is meshed with a main screw cylinder (4) gear in a transmission cavity through a main transmission gear (2), the main shaft gear of the auxiliary motor (11) is meshed with an outer end gear of a transmission shaft (13) in the transmission cavity through an auxiliary transmission gear (12), an outer spline at the right end of the transmission shaft (13) is sleeved with an auxiliary screw (8), a shaft end plunger round table spline extending out of a port of the main screw cylinder (4) is meshed with an inner cavity spline groove of the auxiliary screw (8) assembled with a bearing through a main screw nut (6), the main screw cylinder (4) can be driven by the main motor (1), the auxiliary screw (8) can be driven by the auxiliary motor (11), and two relatively independent transmission chains integrated together by a piston cylinder (10) of an inner sleeve auxiliary screw nut (9) are formed, the main screw cylinder (4) and the transmission shaft (13) are respectively meshed with the main motor gear and the auxiliary motor gear in a staggered and parallel mode, and when any motor or the corresponding transmission chain is blocked, the other motor is used for independently completing a dual-redundancy emergency release control mechanism extending out of the piston cylinder task.

2. The centralized all-electric dual-redundancy emergency electro-mechanical actuator of claim 1, wherein: the main motor (1) and the auxiliary motor (11) which are power output sources for mutual backup can work simultaneously or any motor works, and the other motor performs cold backup.

3. The centralized all-electric dual-redundancy emergency electro-mechanical actuator of claim 1, wherein: the main motor (1) and the auxiliary motor (11) work simultaneously, the main screw cylinder (4) which is used for outputting the rotating speed of the main motor (1) drives the main screw nut (6), the auxiliary motor (11) drives the auxiliary screw nut (9) on the outer spiral rollaway nest of the auxiliary screw (8), the piston cylinder (10) which performs telescopic motion in the outer cylinder (3) drives to move together, the auxiliary screw nut (9) assembled in the hollow stepped hole of the piston cylinder (10) sequentially transmits the load of the piston cylinder to the auxiliary screw (8) and the main screw nut (6), the load is transmitted to the main screw cylinder (4) through the angular contact ball bearing (5), the main screw cylinder (4) drives the main screw nut (6) and the auxiliary screw (8) to stretch out, and the auxiliary screw (8) drives the auxiliary screw nut (9) and the sleeved piston cylinder (10) to stretch out.

4. The centralized all-electric dual-redundancy emergency electro-mechanical actuator of claim 3, wherein: if the main motor (1) fails or the transmission chain is blocked, the auxiliary motor (11) works, the auxiliary motor (11) drives the transmission shaft (13) to rotate through the auxiliary transmission gear (12), and the auxiliary screw (8) meshed with the transmission shaft (13) is driven to synchronously rotate by the transmission shaft (13), so that the auxiliary screw nut (9) and the sleeved piston cylinder (10) are driven to overcome the extension of a load.

5. The centralized all-electric dual-redundancy emergency electro-mechanical actuator of claim 1, wherein: the main screw rod cylinder (4) is in threaded connection with the main screw rod nut (6) through a thrust angular contact ball bearing (5) on a bearing seat in a transmission cavity of the outer cylinder (3), and is driven to move together through a bidirectional thrust angular contact ball bearing (7) restrained by a double-arm bearing seat assembled in a hollow step hole in the main screw rod nut (6), an auxiliary screw rod nut (9) sleeved on an outer spiral raceway of the auxiliary screw rod (8) and a piston cylinder (10) which performs telescopic movement in the outer cylinder (3).

6. The centralized all-electric dual-redundancy emergency electro-mechanical actuator of claim 1, wherein: the thrust angular contact ball bearing (5) installed in the hollow stepped hole of the outer barrel (3) is axially limited on the stepped shaft at the upper end of the main screw barrel (4) and bears the load of the main screw barrel (4).

7. The centralized all-electric dual-redundancy emergency electro-mechanical actuator of claim 1, wherein: the inner ring of the bidirectional thrust angular contact ball bearing (7) arranged in the hollow stepped hole of the main screw nut (6) is axially limited on the stepped shaft at the upper end of the auxiliary screw (8) to bear the load of the auxiliary screw (8).

8. The centralized all-electric dual-redundancy emergency electro-mechanical actuator of claim 1, wherein: during normal operation, the main motor (1) and the auxiliary motor (11) can work simultaneously or any motor works, the other motor is used for cold backup, the main motor (1) and the auxiliary motor (11) work simultaneously, the main screw rod cylinder (4) drives the main screw rod nut (6) and the auxiliary screw rod (8) to extend, and the auxiliary screw rod (8) drives the auxiliary screw rod nut (9) and the sleeved piston cylinder (10) to extend.