Dual-redundancy linear displacement actuator

Abstract

The invention provides a dual-redundancy linear displacement actuator, and relates to the technical field of mechanical transmission structures, and the actuator comprises a power source assembly which is used for providing power for the actuator; the power transmission chain assembly is connected with the power source assembly and used for amplifying and transmitting power provided by the power source; the power output shaft assembly is connected with the power transmission chain assembly and used for outputting power; the position feedback transmission chain assembly is connected with the power output shaft assembly and used for indirectly measuring the position of an output shaft in the power output shaft assembly and transmitting the position to a control system, and the power source assembly comprises two brakes matched with direct-current brushless motors. The actuator is high in working precision and high in safety and reliability and has a power-off self-locking function.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical transmission structures, and in particular provides a double-redundant linear displacement actuator. Background Art

[0002] At present, all dual-redundancy electric actuators adopt electrical dual-redundancy form, which can generally only be used as master-slave but not master-master. When the working stroke is large, the position feedback cannot meet the requirements of the effective electrical stroke, and the output shaft is still a single output shaft mechanism. Under working conditions with high load and support stiffness requirements, the actuator output shaft is prone to jamming when moving to the limit stroke, etc., which can no longer meet the current functional and performance requirements of electric actuators. Summary of the invention

[0003] The purpose of this application is to solve the problem that existing dual-redundancy electric actuators are difficult to meet the functional and performance requirements of current electric actuators, and to provide an actuator that uses two separate motors to drive the power transmission chain and synthesizes speeds through a planetary differential synthesis structure to avoid force disputes, while also having both main-main and main-standby operations.

[0004] In order to achieve the above object, the present invention adopts the following technical solution: a dual-redundant linear displacement actuator, the actuator comprising:

[0005] A power source assembly, used to provide power to the actuator;

[0006] A power transmission chain assembly connected to the power source assembly and used to amplify and transmit the power provided by the power source;

[0007] A power output shaft assembly, connected to the power transmission chain assembly, for outputting power; and

[0008] A position feedback transmission chain assembly is connected to the power output shaft assembly and is used to indirectly measure the position of the output shaft in the power output shaft assembly and transmit it to the control system.

[0009] The power source assembly includes two brakes matched with the DC brushless motors.

[0010] The dual-redundant linear displacement actuator provided by the present invention also has the following technical feature: the brake is a power-off brake.

[0011] The dual-redundant linear displacement actuator provided by the present invention also has such a technical feature that the power transmission chain assembly includes a planetary differential synthesis structure connected to the output end of the power source assembly and a transmission structure connected to the planetary differential synthesis structure for outputting the power processed by the planetary differential synthesis structure,

[0012] The planetary differential synthesis structure is used for speed synthesis.

[0013] The dual-redundant linear displacement actuator provided by the present invention also has the following technical features: when both DC brushless motors are working, the planetary differential synthesis structure synthesizes the output speeds of the two DC brushless motors and doubles them;

[0014] When only one brushless DC motor is working and the other is disconnected, the output speed of the brushless DC motor directly output by the planetary differential synthesis structure is halved.

[0015] The dual-redundancy linear displacement actuator provided by the present invention also has the following technical features: the power output shaft assembly includes a lead screw connected to the power transmission chain assembly, a first lead screw nut connected to the lead screw, a second lead screw nut sleeved on the first lead screw nut, a first mechanical limit structure and a second limit structure for limiting the second lead screw nut, a support slip ring group for supporting the second lead screw nut, two limit switch with reeds for preventing the second lead screw nut from overtravel, a double-ear hinge shaft connected to the second lead screw nut as the output shaft of the actuator, an end thrust ball bearing group for axial bearing of the lead screw, and a deep groove ball bearing group for radial support of the lead screw.

[0016] The first lead screw nut is connected to the second lead screw nut via a first hollow shear pin, and the second lead screw nut is connected to the first lead screw nut via a second hollow shear pin.

[0017] The supporting slip ring assembly comprises two supporting slip rings,

[0018] The second lead screw nut is provided with a lever for cooperating with the limit switch.

[0019] The lead screw is provided with a gear connected with the power transmission chain assembly and the position feedback transmission chain assembly.

[0020] The dual-redundant linear displacement actuator provided by the present invention also has the following technical features: the position feedback transmission chain assembly includes a double anti-backlash gear structure connected to the power transmission chain assembly, a harmonic reducer connected to the double anti-backlash gear structure, and a dual-redundant RVDT connected to the output shaft of the harmonic reducer.

[0021] The double-redundant linear displacement actuator provided by the present invention also has the following technical features: the power output transmission chain includes a dry friction torque limiter, which includes a gear shaft, an end face gear, a disc spring, and a locking nut; the gear shaft gear is meshed with the output gear of the planetary differential composite structure; the end face gear is a hollow structure and is sleeved on the gear shaft; a friction plate is provided on the mating surface of the end face gear and the gear shaft; the disc spring is sleeved on the gear shaft, and the disc spring is located on the outer side of the end face gear; the locking nut applies axial positive pressure to the disc spring to lock the disc spring on the gear shaft.

[0022] The double-redundant linear displacement actuator provided by the present invention also has the following technical features: the supporting slip ring assembly is made of aluminum bronze or lead bronze material, which has a small friction coefficient and plays a role of dry grinding self-lubrication.

[0023] The dual-redundant linear displacement actuator provided by the present invention also has the following technical feature: the first hollow shear pin and the second hollow shear pin are drawn aluminum bars.

[0024] Beneficial Effects

[0025] The dual-redundancy linear displacement actuator proposed by the present invention adopts two separate motors to drive the power output transmission chain, and performs speed synthesis through the planetary differential synthesis structure, thereby avoiding the problem of force disputes and having the working modes of main-main operation and main-backup operation. A dry friction torque limiter is set in the motor power output transmission chain, and the friction plate slips when overloaded to effectively protect the motor. The power output shaft assembly includes two sets of screw-screw pair transmission devices, one set of screw-screw pair transmission devices operates in the main working mode and drives the other set of screw-screw pair transmission devices to work at the same time; the other set of screw-screw pair transmission devices operates in the backup working mode, that is, when the first set of screw-screw pair transmission devices is stuck or stuck, the shear pin is sheared by strong operation, and the backup screw-screw pair transmission device starts to work, so that the linear displacement actuator can continue to work, effectively avoiding the single-point failure of the screw-screw pair when subjected to large loads and lateral force loads, ensuring that it can continue to work; it can meet the requirements of high-reliability screw-screw pair transmission. The actuator has high working precision, high safety and reliability, and has a power-off self-locking function. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1This is a principle block diagram of the dual-redundant linear displacement actuator provided by the present invention;

[0028] Figure 2 is a structural diagram of a dry friction torque limiter assembly in an embodiment of the present invention;

[0029] Figure 3 is a structural diagram of a power output shaft assembly in an embodiment of the present invention,

[0030] Among them: 1: housing; 2: first electromagnetic brake; 3: power source assembly; 4: first brushless DC motor; 5: double-redundant RVDT; 6: position feedback transmission chain assembly; 7: harmonic reducer; 8: double-link anti-backlash gear structure; 9: limit switch assembly; 10: double-ear hinge shaft; 11: power output shaft assembly; 11-1: first deep groove ball bearing; 11-2: first end thrust bearing; 11-3: gear; 11-4: second end thrust bearing; 11-5: second deep groove ball bearing; 11-6: first circumferential limit block; 11-7: first hollow shear pin; 11-8: lead screw; 11-9: lever; 11-10: first lead screw nut; 11-11 : The second lead screw nut; 11-12: The first supporting slip ring; 11-13: The second supporting slip ring; 11-14: The limit block; 11-15: The second hollow shear pin; 12: The dry friction torque limiter structure; 12-1: The third deep groove ball bearing; 12-2: The gear shaft; 12-3: The friction plate; 12-4: The first disc spring; 12-5: The second disc spring; 12-6: The locking nut; 12-7: The fourth deep groove ball bearing; 12-8: The third disc spring; 12-9: The fourth disc spring; 12-10: The end gear; 13: The power output transmission chain; 14: The planetary differential synthesis structure; 15: The second DC brushless motor; 16: The second electromagnetic brake. DETAILED DESCRIPTION

[0031] The present application is further described in detail below in conjunction with the accompanying drawings and examples, but it should be noted that these implementation methods are not limitations of the present application, and equivalent changes or substitutions in functions, methods, or structures made by ordinary technicians in the field based on these implementation methods are all within the scope of protection of the present application.

[0032] In the description of the embodiments of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the creation of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the creation of the present application.

[0033] In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0034] The terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention of this application can be understood by specific circumstances.

[0035] like Figure 1-3 As shown, an embodiment of the present application provides a dual-redundant linear displacement actuator, the actuator comprising:

[0036] A power source assembly 3, used to provide power to the actuator;

[0037] A power transmission chain assembly connected to the power source assembly and used to amplify and transmit the power provided by the power source;

[0038] A power output shaft assembly 11, connected to the power transmission chain assembly, for outputting power; and

[0039] The limit switch assembly 9 is used to prevent the actuator output shaft from overtravel.

[0040] The position feedback transmission chain assembly 6 is connected to the power output shaft assembly 11 and is used to indirectly measure the output shaft position in the power output shaft assembly 11 and transmit it to the control system.

[0041] The power source assembly includes a brake matched with two DC brushless motors. The two DC brushless motors include a first DC brushless motor 4 and a second DC brushless motor 15 .

[0042] In some embodiments, the actuator further includes a housing 1 , and the power source assembly 3 , the power output transmission chain 13 , the power output shaft assembly 11 , the limit switch assembly 9 , and the position feedback transmission chain assembly 6 are all arranged inside the housing 1 .

[0043] In some embodiments, the brake is a power-off brake. The brake includes a first electromagnetic brake 2 connected to the first brushless DC motor and a second electromagnetic brake 16 connected to the second brushless DC motor 15 .

[0044] In some embodiments, the power transmission chain assembly includes a planetary differential synthesis structure 14 connected to the output end of the power source assembly and a transmission structure connected to the planetary differential synthesis structure 14 for outputting the power processed by the planetary differential synthesis structure 14.

[0045] The planetary differential synthesis structure is used for speed synthesis.

[0046] In some embodiments, when both DC brushless motors are working, the planetary differential synthesis structure synthesizes the output speeds of the two DC brushless motors and doubles them;

[0047] When only one brushless DC motor is working and the other is disconnected, the output speed of the brushless DC motor directly output by the planetary differential synthesis structure is halved.

[0048] In some embodiments, the power output shaft assembly 11 includes a lead screw 11-8 connected to the power transmission chain assembly, a first lead screw nut 11-10 connected to the lead screw 11-8, a second lead screw nut 11-11 sleeved on the first lead screw nut 11-10, a first mechanical limiting structure and a second limiting structure 11-14 for limiting the second lead screw nut 11-11 are provided on the lead screw 11-8, a supporting slip ring group for supporting the second lead screw nut 11-11, two limit switch with reeds for preventing the second lead screw nut 11-11 from overtravel, a double-ear hinge shaft 10 connected to the second lead screw nut 11-11 as the output shaft of the actuator, and a first mechanical limiting structure and a second limiting structure 11-14 for limiting the second lead screw nut 11-11 are provided on the lead screw 11-8, and a support slip ring group for supporting the second lead screw nut 11-11, two limit switch with reeds for preventing the second lead screw nut 11-11 from overtravel, and a double-ear hinge shaft 10 connected to the second lead screw nut 11-11 as the output shaft of the actuator. -8 axially loaded end face thrust ball bearing group and deep groove ball bearing group for radial support of lead screw 11-8, the first lead screw nut 11-10 is connected to the second lead screw nut 11-11 through the first hollow shear pin 11-7, the second lead screw nut 11-11 is connected to the first lead screw nut 11-10 through the second hollow shear pin 11-15, the support slip ring group includes two support slip rings, the two support slip rings are respectively the first support slip ring 11-12 and the second support slip ring 11-13, the second lead screw nut 11-11 is installed with a lever 11-9 for cooperating with the limit switch, the lead screw 11-8 is provided with a gear 11-3 connected with the power transmission chain assembly and the position feedback transmission chain assembly 6. The deep groove ball bearing group includes the first deep groove ball bearing 11-1 and the second deep groove ball bearing 11-5, and the thrust ball bearing group includes the first end face thrust bearing 11-2 and the second end face thrust bearing 11-4. The first mechanical limiting structure is the first circumferential limiting block 11 - 6 , and the second limiting structure is the limiting stopper 11 - 14 .

[0049] The screw pair of the power output shaft assembly 11 provided in the above embodiment adopts a double-push double-branch structure, which improves the transmission support stability of the screw pair, and can also make the output shaft gapless and the damping very small. A limit switch is also provided. When the linear displacement actuator exceeds the working stroke, the limit switch outputs a "ground" logic signal, and the actuator is powered off to avoid over-travel operation, thereby improving the safety and reliability of the entire machine.

[0050] In some embodiments, the position feedback transmission chain assembly 6 includes a double anti-backlash gear structure 8 connected to the power transmission chain assembly, a harmonic reducer 7 connected to the double anti-backlash gear structure 8, and a double-redundant RVDT 5 connected to the output shaft of the harmonic reducer 7.

[0051] In some embodiments, the power output transmission chain 13 includes a dry friction torque limiter 12, which includes a gear shaft 12-2, an end gear 12-10, a disc spring, and a locking nut 12-6. The gear of the gear shaft 12-2 is meshed with the output gear of the planetary differential synthesis structure 14. The end gear 12-10 is a hollow structure and is sleeved on the gear shaft 12-2. A friction plate 12-3 is provided on the contact surface between the end gear 12-10 and the gear shaft 12-2. The disc spring is sleeved on the gear shaft 12-2, and the disc spring is located on the outer side of the end gear 12-10. The locking nut 12-6 applies axial positive pressure to the disc spring to lock the disc spring on the gear shaft 12-2. The disc spring includes a first disc spring 12-4, a second disc spring 12-5, a third disc spring 12-8, and a fourth disc spring 12-9.

[0052] In some embodiments, the support slip ring assembly is made of aluminum bronze or lead bronze, which has a small friction coefficient and plays a role of dry grinding self-lubrication. The support slip ring assembly includes a first support slip ring 11-12 and a second support slip ring 11-13.

[0053] In some embodiments, the first hollow shear pin 11 - 7 and the second hollow shear pin 11 - 15 are drawn aluminum bars AU4GT4.

[0054] The working process of the actuator provided in any of the above embodiments is as follows:

[0055] During normal operation, the dual-redundant linear displacement actuator is powered, and the two motors work simultaneously, driving the speed synthesis mechanism, the reducer, and the screw pair screw to rotate, driving the first nut of the screw pair to make a linear motion, and the first nut of the screw pair drives the second nut of the screw pair; at the same time, the RVDT position signal is converted into a voltage signal through the position feedback transmission chain component 6 and sent to the dual-redundant linear displacement actuator controller, and the stroke position closed-loop control is performed.

[0056] When the second nut of the lever screw pair moves beyond the travel, the limit switch converts the current position into a logic level signal and sends it to the dual-redundant linear displacement actuator controller. The controller starts to respond to the power-off operation, and the electromagnetic brake locks the output shaft at the current position, also avoiding over-travel operation.

[0057] If one motor fails, it is locked by the brake and the other motor works normally. At this time, due to the action of the speed synthesis mechanism, the operating speed of the actuator output shaft is half of the normal speed and the output force remains unchanged.

[0058] The above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A double-redundant linear displacement actuator, characterized in that: The actuator comprises: A power source assembly, used to provide power to the actuator; A power transmission chain assembly connected to the power source assembly and used to amplify and transmit the power provided by the power source; A power output shaft assembly, connected to the power transmission chain assembly, for outputting power; and A position feedback transmission chain assembly is connected to the power output shaft assembly and is used to indirectly measure the position of the output shaft in the power output shaft assembly and transmit it to the control system. The power source assembly includes two brakes matched with the DC brushless motors.

2. The dual-redundant linear displacement actuator according to claim 1, characterized in that: The brake is a power-off brake.

3. The dual-redundant linear displacement actuator according to claim 1, characterized in that: The power transmission chain assembly includes a planetary differential synthesis structure connected to the output end of the power source assembly and a transmission structure connected to the planetary differential synthesis structure for outputting the power processed by the planetary differential synthesis structure. The planetary differential synthesis structure is used for speed synthesis.

4. The dual-redundant linear displacement actuator according to claim 3, characterized in that: When both DC brushless motors are working, the planetary differential synthesis structure synthesizes the output speeds of the two DC brushless motors and doubles them; When only one brushless DC motor is working and the other is disconnected, the output speed of the brushless DC motor directly output by the planetary differential synthesis structure is halved.

5. The dual-redundant linear displacement actuator according to claim 1, characterized in that: The power output shaft assembly includes a lead screw connected to the power transmission chain assembly, a first lead screw nut connected to the lead screw, a second lead screw nut sleeved on the first lead screw nut, a first mechanical limit structure and a second limit structure for limiting the second lead screw nut, a support slip ring group for supporting the second lead screw nut, two limit switch with reeds for preventing the second lead screw nut from overtravel, a double-ear hinge shaft connected to the second lead screw nut as the output shaft of the actuator, an end thrust ball bearing group for axial bearing of the lead screw, and a deep groove ball bearing group for radial support of the lead screw. The first lead screw nut is connected to the second lead screw nut via a first hollow shear pin, and the second lead screw nut is connected to the first lead screw nut via a second hollow shear pin. The supporting slip ring assembly comprises two supporting slip rings, The second lead screw nut is provided with a lever for cooperating with the limit switch. The lead screw is provided with a gear connected with the power transmission chain assembly and the position feedback transmission chain assembly.

6. The dual-redundant linear displacement actuator according to claim 1, characterized in that: The position feedback transmission chain assembly includes a double anti-backlash gear structure connected to the power transmission chain assembly, a harmonic reducer connected to the double anti-backlash gear structure, and a double-redundant RVDT connected to the output shaft of the harmonic reducer.

7. The dual-redundant linear displacement actuator according to claim 1, characterized in that: The power output transmission chain includes a dry friction torque limiter, which includes a gear shaft, an end face gear, a disc spring, and a locking nut. The gear shaft gear is meshed with the output gear of the planetary differential synthesis structure. The end face gear is a hollow structure and is sleeved on the gear shaft. A friction plate is provided on the fitting surface of the end face gear and the gear shaft. The disc spring is sleeved on the gear shaft, and the disc spring is located on the outer side of the end face gear. The locking nut applies axial positive pressure to the disc spring to lock the disc spring on the gear shaft.

8. The dual-redundant linear displacement actuator according to claim 5, characterized in that: The supporting slip ring assembly is made of aluminum bronze or lead bronze material, which has a small friction coefficient and plays a role of dry grinding self-lubrication.

9. The dual-redundant linear displacement actuator according to claim 5, characterized in that: The first hollow shear pin and the second hollow shear pin are drawn aluminum bars.

Images