CN219795730U

CN219795730U - Emergency multilevel electromechanical actuator with lock and anti-jamming function

Info

Publication number: CN219795730U
Application number: CN202223464079.2U
Authority: CN
Inventors: 匡克焕; 汪驰; 孟嘉
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: 2023-10-03
Anticipated expiration: 2032-12-25

Abstract

The locking anti-jamming emergency multi-stage electromechanical actuator provided by the utility model has the advantages of emergency unlocking, extension and reliable locking. The method is realized by the following technical scheme: the primary piston head restrains the primary locking spring in the primary upper lock bushing sealed with the inner step Kong Bihuan in the sleeve ring groove of the primary screw nut, the anti-jamming bushing sealed with the hollow blind hole ring of the primary screw nut restrains the anti-jamming spring at the bottom end of the blind hole, restrains the upper edge locking steel ball and the lower edge locking steel ball on the outer ring surface of the chamfer end of the anti-jamming bushing, forms a high-pressure medium which can be entered from an emergency air port, realizes the anti-jamming locking of the screw pair and the bearing sleeve, and unlocks the anti-jamming mechanism of the primary high-pressure medium.

Description

Emergency multilevel electromechanical actuator with lock and anti-jamming function

Technical Field

The utility model belongs to the technical field of electromechanical servo, and particularly relates to a safe emergency unlocking, extending and locking structure of dissimilar energy emergency mechanical equipment, which is applied to double-end locking and long-stroke retraction of an electromechanical actuator, and more particularly relates to an innovative structure for greatly reducing the structural length of the electromechanical actuator with a locking function under a specified stroke.

Background

The electromechanical actuator is used as a core component of an electromechanical servo system and is an energy conversion device for realizing linear reciprocating motion or swinging motion smaller than 360 degrees of a working mechanism. The main function is to convert the electric energy into mechanical energy after receiving the control instruction, overcome the external load moment and reach the preset speed and position. 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. The bearing part is mainly a ball screw pair or a planetary roller screw pair, the multi-point contact working principle of the thread teeth of the planetary roller screw pair is adopted, the bearing capacity is relatively larger, the transmission precision is higher, and the planetary roller screw pair is a part which is preferred at present. The mechanical lock is generally composed of a steel ball, a locking groove, a conical piston, a spring and the like, is usually locked by the mechanical lock in the actuating cylinder, can prevent the external force from acting to play when the movement is stopped at a limited position, but has the phenomena of blocking, jamming and jamming in a transmission part in the occasions with high reliability and high safety, is greatly limited in application, and is difficult to achieve higher reliability requirements in the field of flight control. In some application occasions with limited installation space or longer working stroke requirements, such as retraction and extension of an undercarriage, retraction of a cabin door and the like, a common single-stage electromechanical actuator is relatively complex in system due to the fact that the overall dead structure length is longer, and the output response speed and the output response precision of a motor are relatively poor. The adopted speed reducing mechanism is matched with the ball screw or the roller screw, the rotary motion of the motor is converted into the linear motion of the actuating mechanism, the structure has high requirements on the performance of the motor under the condition that the actuating cylinder moves at a high speed, particularly reciprocates at a high speed, the system cost is high, and the ball screw or the roller screw is easy to generate fatigue pitting corrosion which affects the transmission precision of the system under the action of dynamic load, so that the reliability is poor, and the requirement of limited installation space cannot be met. In addition, the existing electromechanical actuators are controlled by a single motor, the movement range of the actuating cylinder is fixed, and the redundancy of a single motor control system is poor. Although the large working stroke retraction can be realized through the multi-stage electromechanical actuator, the conventional multi-stage electromechanical actuator still adopts a mode of locking a motor shaft by a brake to realize mechanical locking, and has poor reliability and lower bearing capacity than a mechanical lock, so that the practicability is poor. In order to solve the problem of single-point faults of a transmission part of an electromechanical actuator, the conventional multistage electromechanical actuator in the prior art adopts a transmission mechanism redundancy design scheme, still faces the problem of single-point faults such as a screw pair blocking plug, and can greatly limit the application range of the multistage electromechanical actuator if the multistage electromechanical actuator can not be guaranteed to isolate faults under an emergency state and realize emergency actuation.

Disclosure of Invention

The utility model aims to solve the problems in the prior art, and provides a scheme which has the advantages of simple structure, normal working mode, higher safety and reliability, larger working stroke, emergency unlocking, extension and reliable locking of a piston cylinder, small installation space and capability of relieving jamming, clamping stagnation and jamming faults, and is beneficial to popularization and application to more fields. The problem that the locking capacity of a conventional multistage electromechanical actuator is poor and the problem of single-point fault of a clamping plug of a screw pair cannot be solved is solved.

The technical scheme adopted for solving the technical problems is as follows: the utility model provides an emergent multistage electromechanical actuator of locking jam-proof, includes the radial bilateral symmetry main motor 1 of urceolus 3, vice motor 27 rotary motion is converted into the drive unit of reduction gear linkage lead screw pair and lead screw nut mechanical energy in the transmission cavity to and ring seal piston head is at least two-stage piston section of thick bamboo and the emergent jam-proof mechanism of telescoping motion in urceolus 3 cylinder body, its characterized in that: the outer cylinder 3 with the emergency air port 5 is provided with a primary piston head with a hollow inner step hole in a ring sealing manner, a primary locking spring 8 is restrained in a ring groove of a primary lead screw nut sleeve 11 with the inner step Kong Bihuan in the ring sealing manner, a blocking preventing bush 25 with a hollow blind hole in the primary lead screw nut 12 is restrained at the bottom end of the hollow blind hole, an upper edge locking steel ball 13 and a lower edge locking steel ball 24 which are locked in a steel ball guide hole along the opening direction of the primary lead screw nut 12 are restrained on an outer ring surface of a chamfer end of the blocking preventing bush 25, a high-pressure medium which can enter from the emergency air port 5 is formed through the end surface limit of the primary lead screw nut 12, so that a lead screw pair is blocked, blocked and locked by a bearing sleeve 15, and unlocked, and an unlocked primary high-pressure medium is unlocked, and a blocking preventing mechanism is mechanically locked on the upper edge locking steel ball 6 and the lower edge locking steel ball 10 in the opening direction of the primary lead screw nut 12, a primary steel ball 10 is mechanically locked on the front and back of the steel ball, the primary steel ball is selectively locked with the secondary piston head, the primary high-pressure medium is engaged with the secondary piston head is driven by the piston head and the secondary piston head 14 in the front and the secondary piston head is locked by the two-stage piston head position and the two-stage piston head is driven by the piston head and the piston head is locked by the piston head and the piston head is selectively locked by the two-stage and the piston head is locked by the piston head and the piston head 14.

Compared with the prior art, the utility model has the following gain effects:

according to the utility model, the electromechanical actuator is taken as an independent unit, the screw pair is taken as an actuating mechanism, and the screw nut is driven by taking the nut as a driving part through the motion conversion relation of two sets of screws and the nut, so that the motion conversion is realized, and the problem of small stroke of a single electromechanical actuator is solved. Meanwhile, a primary upper steel ball 6 mechanical lock and a primary lower steel ball 10 mechanical lock which can be unlocked and locked are designed between the outer cylinder 3 and the primary piston cylinder 14, and the primary motor 1 can drive the primary piston cylinder 14 to be locked at the upper end and the lower end of the outer cylinder 3 and reliably unlocked; compared with the traditional electromechanical actuator structure layout and function form, the device has higher safety and reliability, and can relieve jamming, clamping stagnation and jamming faults.

According to the utility model, a mechanical lock of a second-level upper steel ball 17 and a mechanical lock of a second-level lower steel ball 21 which can be unlocked and locked are designed between a first-level piston cylinder 14 and a second-level piston cylinder 23, and an auxiliary motor 27 can drive the second-level piston cylinder 23 to be locked at the upper end and the lower end of the first-level piston cylinder 14 and reliably unlocked, so that the piston cylinder is locked at an extending position and a retracting position in a mechanical lock mode, and the problem that a motor shaft cannot bear a large load due to locking of a brake by a conventional multi-level electromechanical actuator is solved;

according to the utility model, an anti-jamming mechanism which can be unlocked by a high-pressure medium is designed among the main screw nut sleeve 11, the main screw nut 12 and the bearing sleeve 15, and under the condition that transmission mechanisms such as a screw pair are jammed, after the high-pressure medium unlocks the anti-jamming mechanism and the mechanical locks of the primary upper steel ball 6 and the secondary upper steel ball 17, the primary piston cylinder 14 and the secondary piston cylinder 23 are respectively driven to overcome load emergency extension, so that the problem that a single point of extending the piston cylinder cannot be completed due to jamming of the screw pair of a conventional multi-stage electromechanical actuator is solved, and the safety and reliability of a flight control system are improved.

Drawings

FIG. 1 is a schematic diagram of the piston cylinder retraction state structure of the locking anti-jamming emergency multi-stage electromechanical actuator of the present utility model.

Fig. 2 is a schematic view of a spline of the spline housing drive shaft meshing pair lead screw of fig. 1.

Fig. 3 is a schematic view of the piston cartridge of fig. 1 in a contracted and extended state.

In the figure: the novel high-speed hydraulic transmission device comprises a main motor 1, a main transmission gear 2, an outer cylinder 3, a main screw 4, an emergency air port 5, a primary upper steel ball 6, a primary upper lock bushing 7, a primary locking spring 8, a primary lower lock bushing 9, a primary lower steel ball 10, a main screw nut sleeve 11, a main screw nut 12, a primary upper edge locking steel ball 13, a primary piston cylinder 14, a bearing sleeve 15, a secondary screw 16, a secondary upper steel ball 17, a secondary piston cylinder 18, a secondary locking spring 19, a secondary lower lock bushing 20, a secondary lower steel ball 21, a secondary screw nut 22, a secondary piston cylinder 23, a secondary lower edge locking steel ball 24, a blocking prevention bushing 25, a blocking prevention spring 26, a secondary motor 27, a secondary transmission gear 28 and a spline sleeve transmission shaft 29.

The utility model will be further described with reference to the drawings and examples and other innovative features will be appreciated. But are not intended to limit the utility model to the embodiments so described. All such concepts should be considered as being generic to the disclosure herein and to the scope of the utility model.

Detailed Description

See fig. 1. In the preferred embodiments described below, one embodiment of the present utility model provides a locked anti-jam emergency multi-stage electromechanical actuator comprising: the driving unit converts the rotary motion of the main motor 1 and the auxiliary motor 27 which are symmetrical on two radial sides of the outer cylinder 3 into mechanical energy of a speed reducer linkage screw pair and a screw nut in a transmission cavity, and the at least two-stage piston cylinder and the emergency jam preventing mechanism enable the ring sealing piston head to do telescopic motion in the cylinder body of the outer cylinder 3. : the outer cylinder 3 with the emergency air port 5 is sealed with a primary piston head with a hollow inner step hole, a primary locking spring 8 is restrained in a ring groove of a sealed main screw nut sleeve 11 and is sealed with an inner step Kong Bihuan, a primary high-pressure medium unlocking anti-jamming mechanism for unlocking and unlocking is realized, under the condition that a screw auxiliary transmission mechanism is jammed, jammed and jammed, a high-pressure medium unlocking anti-jamming mechanism is locked at the bottom end of a hollow blind hole, an upper edge locking steel ball 13 and a lower edge locking steel ball 24 which are locked in a steel ball guide hole along the opening direction of the main screw nut 12 are restrained on the outer ring surface of the chamfer end of the anti-jamming sleeve 25, the end face of the main screw nut 12 is limited, high-pressure medium which can be entered from the emergency air port 5 is formed, and a primary high-pressure medium unlocking anti-jamming mechanism for unlocking and unlocking is realized, under the condition that the screw auxiliary transmission mechanism is jammed, jammed and jammed, the high-pressure medium unlocking is mechanically locked with the primary high-pressure steel ball 6 and the primary steel ball 10 in the front and rear direction of the primary bus, the primary piston head is mechanically locked with the primary piston head, the primary high-pressure medium unlocking mechanism is selectively locked with the secondary piston head, the primary piston head is in the front and the secondary piston head is in the front and rear direction, and the secondary piston head is in the front position and the secondary piston cylinder is in the front of the position and the secondary piston cylinder is in the two-stage position and the front of the piston cylinder is in the position and the opposite to the piston cylinder is in the opposite to the position and the primary cylinder is in the front and the position and is in the position and the front to the piston and is in the position and the piston is in the opposite to the front and the piston and the stage and is opposite to the stage and the piston is opposite to the piston.

The drive unit includes: the output shaft gear of the main motor 1 is meshed with the main transmission gear to drive the main screw 4 to rotate, and the output shaft gear of the auxiliary motor 27 is meshed with the end-facing gear transmission system of the spline housing transmission shaft 29 through the auxiliary transmission gear 28. The drive train has a plurality of gears coupled to each other for transmission to a plurality of interconnected gear outputs.

The thrust angular contact ball bearing inner ring installed in the hollow step hole at the tail part of the outer barrel 3 is axially limited between the step shaft annular groove of the main screw 4 and the inner annular groove of the outer barrel, and bears the load of the main screw 4.

The bearing sleeve 15 coupled and connected with the main screw nut 12 is used for bearing the load of the auxiliary screw 16 on the step shaft at the upper end of the axial limiting auxiliary screw 16 through the inner ring of the bidirectional thrust angular contact ball bearing in the hollow step hole.

The primary upper lock bushing 7 and the primary lower lock bushing 9 which are sealed by the primary piston head hollow step Kong Bihuan are oppositely and symmetrically restrained with the primary lock spring 8, and the primary lock spring 8 which keeps the locking force is restrained on the inner end surface step of the outer ring groove of the main screw nut sleeve 11.

The primary piston cylinder 14 is hollow and faces the bottom end of the cavity of the outer cylinder 3, an upper steel ball guide hole for assembling the primary upper steel ball 6 is formed in the front-back direction of a primary piston head bus, a lower steel ball guide hole for assembling the primary lower steel ball 10 is formed in the inner cavity wall of the outer cylinder 3, and a primary upper ring locking groove and a primary lower ring locking groove which correspond to the primary upper steel ball 6 and the primary lower steel ball 10 in positions opposite to the upper steel ball guide hole are formed in the inner cavity wall of the outer cylinder 3.

The front and back directions of a bus bar of the secondary piston head in the cylinder body of the inner wall of the stepped cylinder in the extending direction of the primary piston cylinder 14 are provided with an upper steel ball guide hole and a secondary upper steel ball 17 and a secondary lower steel ball 21 assembled by the lower steel ball guide hole, the inner cavity wall of the primary piston cylinder 14 is provided with a secondary upper ring locking groove and a secondary lower ring locking groove corresponding to the secondary upper steel ball 17, the wall of the stepped hole in the secondary piston head is provided with a secondary upper locking bushing 18 and a secondary lower locking bushing 20 which are symmetrical in opposite directions in a sealing manner, the secondary locking spring 19 is restrained on the annular disc end surfaces at the two ends of the annular groove of the secondary lead screw nut 22, and the secondary upper steel ball 17 and the secondary lower steel ball 21 which are locked in the secondary upper locking bushing 18 and the secondary lower locking bushing 20 are restrained on the outer annular surface of the chamfer end of the secondary upper locking bushing 18, so as to form a mechanical locking mechanism for locking, locking and unlocking the secondary piston cylinder 23 extending outwards at the bottom of the cavity of the primary piston cylinder 14.

In an alternative embodiment, in a normal working mode, an output shaft gear of the main motor 1 is meshed with an end gear of the main screw 4 through the main transmission gear 2, the main screw 4 is restrained in a ball bearing in a cylinder body of the outer cylinder 3 through a necking groove at the end part, the main screw 4 is driven to rotate in a transmission cavity of the primary piston cylinder 14, the main screw nut 12 is used as a driving piece to drive a primary upper lock bushing 7 with a hollow stepped hole formed at the tail part of the primary piston cylinder 14 to move rightwards, a primary upper steel ball 6 in the front-rear direction of a locking bus is separated from a locking ring groove on the inner wall of the outer cylinder, unlocking of the mechanical lock is achieved, and meanwhile, the primary piston cylinder 14 in a retracted state is driven to extend out of the outer cylinder 3 to overcome external load moment, so that rated thrust output is completed.

The gear of the output shaft of the auxiliary motor 27 is meshed with the gear of the shaft end of the rotating shaft 29 through the auxiliary transmission gear 28, the spline sleeve transmission shaft 29 in the hollow cylinder body of the main screw 4 is driven to rotate, the auxiliary screw 16 sleeved on the external spline teeth of the spline sleeve transmission shaft 29 is driven to rotate together through the bearing sleeve 15, the auxiliary screw nut 22 is used as a driven piece to drive the secondary upper locking bushing 18 with a hollow stepped hole at the tail part of the secondary piston cylinder 23 which performs telescopic motion in the primary piston cylinder 14 to move rightwards, the secondary upper steel ball 17 locked on the upper steel ball guide hole in the front-rear direction of the bus is separated from the locking ring groove on the inner wall of the primary piston cylinder 14, the unlocking of the mechanical lock is realized, and meanwhile, the secondary piston cylinder 23 in a retracted state is driven to extend out of the port of the primary piston cylinder 14, the external load moment is overcome, and rated thrust output is completed.

When the mechanical lock is in operation, the main motor 1 drives the main screw 4 and the main screw nut 12 to rotate, the upper edge step of the screw nut 12 pushes the main screw nut sleeve 11 to move right, the upper edge step of the main screw nut sleeve 11 pushes the primary upper lock bushing 7 to move right, the primary upper steel ball 6 is driven to be separated from the annular wall lock ring groove in the outer cylinder 3, the mechanical lock is unlocked, and the right end face of the main screw nut sleeve 11 pushes the primary piston cylinder 14 and the auxiliary screw 16 to extend.

The primary piston cylinder 14 moves to the limit locking cavity position of the outer cylinder 3, the primary lower steel ball 10 is opposite to the primary lower locking groove of the outer cylinder 3, under the action of the elasticity of the primary locking spring 8, the primary lower steel ball 10 is pushed to the primary lower locking groove by the chamfer inclined surface of the primary lower locking bushing 9, the primary lower steel ball 10 is limited to move, and the primary lower steel ball 10 is mechanically locked, so that the primary piston cylinder 14 is locked. The output shaft gear of the auxiliary motor 27 drives the spline housing transmission shaft 29 shaft end gear through the auxiliary transmission gear 28 to drive the auxiliary screw rod 16 to rotate, and then drives the auxiliary screw rod nut 22 to push the secondary locking bushing 18 to move right, and drives the secondary upper steel ball 17 on the outer annular surface of the secondary piston head to be separated from the chamfer inclined surface of the secondary locking bushing 18, so that unlocking of the mechanical lock is realized, and the right end surface of the auxiliary screw rod nut 22 pushes the secondary piston cylinder 23 to extend out of the primary piston cylinder 14.

The secondary piston cylinder 23 moves to the limit position of the primary piston cylinder 14, the secondary lower steel ball 21 is opposite to the secondary lower locking groove of the primary piston cylinder 14, the secondary lower locking bushing 20 pushes the secondary lower steel ball 21 to the secondary lower locking groove under the action of the elasticity of the secondary locking spring 19, and the secondary lower locking bushing 20 is clamped into the lower end chamfer inclined surface of the secondary lower steel ball 21 to limit the movement of the secondary lower steel ball 21 and realize the mechanical locking of the secondary lower steel ball 21, so that the secondary piston cylinder 23 is locked.

If the motor fails or any transmission mechanism is blocked, dissimilar energy sources different from electric energy, such as high-pressure medium enters the inner cavity of the outer cylinder 3 of the actuator from the emergency air port 5 of the outer cylinder 3, the high-pressure medium pushes the anti-jamming bushing 25 sealed in the opening cylinder of the main screw nut 12, the high-pressure medium moves left against the elasticity of the anti-jamming spring 26, the upper edge locking steel ball 13 and the lower edge locking steel ball 24 are separated from the locking groove of the main screw nut sleeve 11, and unlocking of the anti-jamming mechanism is realized, namely, the main screw nut sleeve 11, the main screw nut 12 and the bearing sleeve 15 are separated.

The high-pressure medium pushes the primary upper lock bushing 7 to pull out the primary upper steel ball 6 from the chamfer inclined surface of the primary upper lock bushing 7, the primary upper steel ball 6 is mechanically locked and unlocked, meanwhile, the high-pressure medium pushes the secondary upper lock bushing, the secondary upper steel ball 17 is pulled out from the chamfer inclined surface of the secondary upper lock bushing, the secondary upper steel ball 17 is mechanically locked and unlocked, and the high-pressure medium respectively drives the primary piston cylinder 9 and the secondary piston cylinder 12 sealed by the rings to extend against the load, so that the emergency extending piston cylinder action is completed.

While the utility model has been described in connection with certain preferred embodiments, the utility model is not limited to those embodiments. On the contrary, the utility model is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the utility model as defined by the appended claims.

Claims

1. An emergency multilevel electromechanical actuator with a lock and a jam-proof function, comprising: the device is characterized by comprising a driving unit for converting rotary motion of a main motor (1) and an auxiliary motor (27) which are symmetrical on two radial sides of an outer cylinder (3) into mechanical energy of a speed reducer linkage screw pair and a screw nut in a transmission cavity, and at least two-stage piston cylinders and an emergency anti-jamming mechanism for enabling a ring sealing piston head to do telescopic motion in a cylinder body of the outer cylinder (3), wherein the driving unit is characterized in that: the outer cylinder (3) with an emergency air port (5) is provided with a first-stage piston head with a hollow inner step hole in a ring sealing manner, a first-stage locking spring (8) is restrained on a first-stage upper locking bushing (7) sealed with the inner step Kong Bihuan in a ring groove of a main screw nut sleeve (11) with a ring seal, an anti-jamming bushing (25) with a hollow blind hole in the main screw nut (12) is sealed in a ring seal manner, an anti-jamming spring (26) is restrained at the bottom end of the hollow blind hole, an upper edge locking steel ball (13) and a lower edge locking steel ball (24) which fall into a steel ball guide hole along the opening direction of the main screw nut (12) are restrained on the outer ring surface of the chamfer end of the anti-jamming bushing (25) and are limited through the end surface of the main screw nut (12), the high-pressure medium which can be entered from the emergency air port (5) is formed to realize the one-level high-pressure medium unlocking anti-jamming mechanism for locking, unlocking and unlocking the screw rod pair, under the condition that the screw rod pair transmission mechanism is locked, jammed and jammed, the high-pressure medium unlocking anti-jamming mechanism is mechanically locked through the one-level upper steel ball (6) and the one-level lower steel ball (10) in the front-back direction of the one-level piston head bus, can be selectively jointed with the outer cylinder (3) between the locking position and the unlocking position, and is mechanically locked through the two-level upper steel ball (17) and the two-level lower steel ball (21) in the front-back direction of the two-level piston head bus, is selectively engaged with the primary piston cylinder (14) between a locking position and an unlocking position, and respectively drives the primary piston cylinder (14) and the secondary piston cylinder (23) to extend out in an emergency way against the variable stroke of the external load.

2. The locked anti-jamming emergency multi-stage electromechanical actuator of claim 1, wherein: the drive unit includes: the output shaft gear of the main motor (1) is meshed with the main transmission gear to drive the end direction gear transmission system of the main screw rod (4) to rotate, and the output shaft gear of the auxiliary motor (27) is meshed with the end direction gear transmission system of the spline housing transmission shaft (29) through the auxiliary transmission gear (28).

3. The locked anti-jamming emergency multi-stage electromechanical actuator of claim 1, wherein: the thrust angular contact ball bearing inner ring installed in the hollow step hole at the tail part of the outer barrel (3) is axially limited between the step shaft annular groove of the main screw rod (4) and the inner annular groove of the outer barrel body, and bears the load of the main screw rod (4).

4. The locked anti-jamming emergency multi-stage electromechanical actuator of claim 1, wherein: the bearing sleeve (15) is coupled with the main screw nut (12), and the load of the auxiliary screw (16) is born on the step shaft at the upper end of the axial limiting auxiliary screw (16) through the bidirectional thrust angular contact ball bearing inner ring in the hollow step hole.

5. The locked anti-jamming emergency multi-stage electromechanical actuator of claim 1, wherein: the primary upper locking bushing (7) and the primary lower locking bushing (9) which are sealed by the hollow step Kong Bihuan of the primary piston head are oppositely and symmetrically restrained with the primary locking spring (8), and the primary locking spring (8) which keeps the locking force is restrained on the step of the inner end surface of the outer ring groove of the main screw nut sleeve (11).

6. The locked anti-jamming emergency multi-stage electromechanical actuator of claim 1, wherein: the primary piston cylinder (14) is hollow and faces the bottom end of the cavity of the outer cylinder (3), an upper steel ball guide hole for assembling a primary upper steel ball (6) is formed in the front-back direction of a primary piston head bus, a lower steel ball guide hole for assembling a primary lower steel ball (10) is formed in the inner cavity wall of the outer cylinder (3), and a primary upper ring locking groove and a primary lower ring locking groove corresponding to the upper steel ball guide hole, the primary upper steel ball (6) and the primary lower steel ball (10) are formed in the inner cavity wall of the outer cylinder (3).

7. The locked anti-jamming emergency multi-stage electromechanical actuator of claim 1, wherein: an upper steel ball guide hole, a lower steel ball guide hole and a second upper steel ball (17) and a second lower steel ball (21) are arranged in the front-back direction of a second piston head bus in a cylinder body of the inner wall of the stepped cylinder in the extending direction of the first piston cylinder (14), and a second upper ring locking groove and a second lower ring locking groove which correspond to the second upper steel ball (17) are formed in the inner cavity wall of the first piston cylinder (14); the secondary upper lock bushing (18) and the secondary lower lock bushing (20) which are symmetrical in opposite sealing manner are arranged in the stepped hole wall ring in the secondary piston head, the secondary lock spring (19) is restrained on the annular disc end surfaces at two ends of the annular groove of the auxiliary screw nut (22), the secondary upper steel ball (17) and the secondary lower steel ball (21) which are locked in the steel ball guide hole of the secondary piston head are restrained on the outer annular surfaces of the chamfer ends of the secondary upper lock bushing (18) and the secondary lower lock bushing (20), and a mechanical lock mechanism for locking, locking and unlocking the secondary piston head at the bottom end of the cavity of the primary piston cylinder (14) outwards extends out of the secondary piston cylinder (23) is formed.

8. The locked anti-jamming emergency multi-stage electromechanical actuator of claim 1, wherein: the output shaft gear of the main motor (1) is meshed with the end gear of the main screw rod (4) through the main transmission gear (2), the main screw rod (4) is restrained in a ball bearing in a cylinder body of the outer cylinder (3) through a necking groove at the end part, the main screw rod (4) is driven to rotate in a transmission cavity of the primary piston cylinder (14), the main screw rod nut (12) is used as a driving piece to drive a primary upper locking bushing (7) with a hollow stepped hole at the tail part of the primary piston cylinder (14) to move rightwards, a primary upper steel ball (6) in the front and rear directions of the locking bus is separated from the locking groove at the inner wall of the outer cylinder, unlocking of the mechanical lock is realized, and meanwhile, the primary piston cylinder (14) in a retraction state is driven to extend out of the outer cylinder (3) to overcome external load moment, and rated thrust output is completed.

9. The locked anti-jamming emergency multi-stage electromechanical actuator of claim 1, wherein: the output shaft gear of the auxiliary motor (27) is meshed with the shaft end gear of the spline housing transmission shaft (29) through the auxiliary transmission gear (28), the spline housing transmission shaft (29) in the hollow cylinder body of the main screw rod (4) is driven to rotate, the auxiliary screw rod (16) sleeved on the external spline teeth of the spline housing transmission shaft (29) is driven to rotate together through the bearing housing (15), the auxiliary screw rod nut (22) is used as a driven piece to drive the second-stage upper locking bush (18) with a hollow stepped hole at the tail part of the second-stage piston cylinder (23) which performs telescopic motion in the first-stage piston cylinder (14) to move rightwards, the second-stage upper steel ball (17) locked on the upper steel ball guide hole in the front-rear direction of the bus is separated from the locking ring groove on the inner wall of the first-stage piston cylinder (14), so as to realize mechanical lock unlocking, and simultaneously drive the second-stage piston cylinder (23) in a retracted state to extend out of the port of the first-stage piston cylinder (14), and rated thrust output is completed.

10. The locked anti-jamming emergency multi-stage electromechanical actuator of claim 1, wherein: the high-pressure medium pushes the primary upper lock bushing (7) to separate from the chamfer inclined plane of the primary upper lock bushing (7), the primary upper steel ball (6) is mechanically locked and unlocked, meanwhile, the high-pressure medium pushes the secondary upper lock bushing, the secondary upper steel ball (17) is separated from the chamfer inclined plane of the secondary upper lock bushing, the secondary upper steel ball (17) is mechanically locked and unlocked, and the high-pressure medium drives the ring-sealed primary piston cylinder (14) and the secondary piston cylinder (23) to overcome the load and stretch out respectively, so that the emergency stretching piston cylinder action is completed.