A bidirectional output motor mechanism with synchronous and differential function conversion

Abstract

The application provides a bidirectional output electric mechanism with synchronous and differential function conversion, and belongs to the technical field of electric mechanism design. The bidirectional output electric mechanism comprises an angular velocity sensor, an output gear shaft, a planetary gear reduction assembly, a torque limiter, a brushless DC motor, an over gear and a bevel gear differential assembly. The bevel gear differential assembly can perform bilateral linear displacement output, and can perform synchronous output when the load difference between the left side and the right side is small, and can perform differential output when the load difference between the left side and the right side is large. The differential value can be adjusted. The mechanical structure ensures the synchronization, and the synchronization performance is good. One electric mechanism can realize the function, and the structure is compact and reliable.

Description

Technical Field

[0001] This application belongs to the field of electric mechanism design technology, and in particular relates to a bidirectional output electric mechanism with synchronous and differential function switching. Background Technology

[0002] Electric actuators are widely used in the aerospace field, primarily for outputting linear or rotary displacement to control the position of certain mechanisms. However, simple electric actuators are insufficient for the following complex operating conditions: 1) Linear displacement is required on both sides, with inconsistent loads on both sides. 2) The initial displacement positions are consistent, and the actuators on both sides extend synchronously, but the stopping positions are inconsistent and random. When one side reaches its position, the other side needs to continue moving, requiring differential operation between the two actuators. Operation stops when both actuators have fully extended. 3) The actuators need to retract synchronously. Due to the inconsistent extension strokes of the two actuators, one side reaches its position first during retraction, requiring differential operation between the two actuators. Operation stops when both actuators have fully retracted. Based on these requirements, two electric actuators are typically used. The speed of the motors in both electric actuators is adjusted through controller software or hardware, and closed-loop control is achieved by real-time monitoring of the output linear displacement speed and position signals.

[0003] However, the above solution has the following drawbacks: due to the inconsistent loads on both sides, the motor is prone to jamming under closed-loop control, resulting in poor synchronization; it is also heavy and occupies a large space. Summary of the Invention

[0004] To address the problems of inconsistent loads on both sides in related technologies, which can lead to motor jamming and poor synchronization under closed-loop control, as well as significant weight and space requirements, this invention provides a bidirectional output electric mechanism capable of switching between synchronous and differential functions. The technical solution is as follows:

[0005] A bidirectional output electric mechanism capable of switching between synchronous and differential functions includes: an end cover, an angular velocity sensor, an output gear shaft, a housing, a planetary gear reduction assembly, a torque limiter, a brushless DC motor, an earpiece connector, a support sleeve, two lead screws and nuts, two Hall effect switches, an angular contact ball bearing, and a differential assembly of transition gears and bevel gears.

[0006] A brushless DC motor is mounted on the housing, and its motor shaft is connected to the input of a torque limiter. The input of the output gear shaft is connected to the output of the torque limiter, and the torque and speed of the brushless DC motor are transmitted to the output gear shaft through the torque limiter. An angular velocity sensor for detecting the output gear shaft speed is installed at the rear end of the output gear shaft. The gear on the output gear shaft meshes with the outer ring gear of the planetary gear reduction assembly to transmit speed and torque to the planetary gear reduction assembly. A transition gear is mounted on the output shaft of the planetary carrier of the planetary gear reduction assembly. The transition gear meshes with the differential gear on the bevel gear differential assembly to transmit speed and torque. The bevel gear differential assembly is connected to the first bevel gears on both sides of the bevel gear differential assembly, which are respectively connected to the lead screws on both sides to transmit the speed and torque to the lead screws on both sides; the lead screws and lead screw nuts cooperate to convert the rotational motion into the linear motion of the lead screw nuts; the output gear shaft, planetary gear reduction assembly, and bevel gear differential assembly are installed between the housing and the end cover through the bevel gear differential assembly; the lead screws on both sides are installed on the housing and the end cover respectively through two pairs of angular contact ball bearings, and are supported by support sleeves on the outside; two Hall switches are installed on the support sleeves on both sides to provide feedback on the lead screw retraction signal; the lug connector is connected to the lead screw.

[0007] The Hall switch has a switch cover on its outer side.

[0008] The brushless DC motor is electrically connected to the controller, and the controller drives the brushless DC motor to work.

[0009] The brushless DC motor has a brake at the rear end of the shaft to enable power-off braking and self-locking of the motor.

[0010] In the planetary gear reduction assembly, the sun gear is fixed, the planetary gear ring serves as the input end, and the planet carrier serves as the output end for speed reduction.

[0011] In this case, the motor shaft of the brushless DC motor is connected to the input end of the torque limiter via a spline;

[0012] In the bevel gear differential assembly, the first bevel gears on both sides are connected to the lead screws on both sides via splines.

[0013] The input end of the output gear shaft is connected to the output end of the torque limiter via a flat key;

[0014] The transition gear is mounted on the planet carrier output shaft of the planetary gear reduction assembly via a flat key.

[0015] The bevel gear differential assembly includes: a differential gear, friction plates, a first bevel gear, a support base, a second bevel gear, a fixed shaft, adjusting shims, opposing wave springs, a deep groove ball bearing, and a differential housing.

[0016] The differential gears are connected to the differential housing. Supported by deep groove ball bearings, the differential housing rotates with the differential gears to transmit speed and torque. Two second bevel gears are mounted on the differential housing via a fixed shaft, and friction plates are installed between the two second bevel gears and the differential housing. A counter-spring and two support seats are installed in the middle of the fixed shaft to provide pressure to the second bevel gears on both sides. Adjusting shims are installed between the counter-spring and the support seats. The first and second bevel gears on the left and right sides mesh with each other and are supported on the differential housing by deep groove ball bearings, outputting speed and torque to the left and right sides.

[0017] A thrust plane bearing is installed between the support base and the second bevel gear.

[0018] The output gear shaft, planetary gear reduction assembly, and bevel gear differential assembly are mounted between the housing and the end cover via deep groove ball bearings.

[0019] The present invention has at least the following advantages:

[0020] 1. It can achieve synchronous and differential functions of bidirectional output using a single electric mechanism, with a compact structure and light weight.

[0021] 2. The difference in load torque between the two sides during differential output can be adjusted by changing the thickness of the adjusting shims.

[0022] 3. The position control is reliable. All actuators use mechanical hard limit switches, and the transmission chain slips after the position is reached, maintaining the output load of the actuator and preventing damage to the mechanical structure.

[0023] This invention utilizes an electric mechanism to achieve bidirectional actuator output. When the load difference between the two sides is small, the actuator outputs synchronously, and when the load is large, the actuator outputs differentially. It can be self-locked upon power-off at the designated position. The load torque difference during bidirectional differential output can be adjusted according to different working conditions. The form of the actuator can be changed according to different working conditions, such as by eliminating the lead screw and nut, the electric mechanism can output rotational motion, and it can be promoted for different working conditions. Attached Figure Description

[0024] Figure 1 A schematic diagram of a bidirectional output electric mechanism capable of switching between synchronous and differential functions is provided for an embodiment of this application;

[0025] Figure 2 This is a schematic diagram of the bevel gear differential assembly structure provided in the embodiments of this application;

[0026] Figure 3 A schematic diagram illustrating the working principle of the bidirectional output electric mechanism provided in this application embodiment.

[0027] The components are as follows: 1-End cap; 2-Angular velocity sensor; 3-Output gear shaft; 4-Housing; 5-Planetary gear reduction assembly; 6-Torque limiter; 7-Brushless DC motor; 8-Earring connector; 9-Support sleeve; 10-Lead screw nut; 11-Lead screw; 12-Hall switch; 13-Angular contact ball bearing; 14-Switch cover; 15-Transition gear; 16-Bevel gear differential assembly; 17-Differential gear; 18-Friction plate; 19-First bevel gear; 20-Support base; 21-Second bevel gear; 22-Screw; 23-Fixed shaft; 24-Thrust plane bearing; 25-Adjusting shim; 26-Top wave spring; 27-Deep groove ball bearing; 28-Differential housing. Detailed Implementation

[0028] The present application will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0029] This invention provides a bidirectional output electric mechanism capable of switching between synchronous and differential functions. The design incorporates a bevel gear differential assembly for bidirectional linear displacement output. When the load difference between the left and right sides is small, the output is synchronous; when the load difference is large, the output is differential. This differential value is adjustable. Synchronization is ensured through a mechanical structure, resulting in good synchronization performance. This function can be achieved using a single electric mechanism, exhibiting a compact structure and high reliability.

[0030] This invention provides a bidirectional output electric mechanism capable of switching between synchronous and differential functions. Please refer to [link to relevant documentation]. Figure 1 It includes: end cap 1, angular velocity sensor 2, output gear shaft 3, housing 4, planetary gear reduction assembly 5, torque limiter 6, brushless DC motor 7, ear ring connector 8, support sleeve 9, two lead screws 11 and lead screw nuts 10, two Hall switches 12, angular contact ball bearing 13, switch cover 14, transition gear 15 and bevel gear differential assembly 16.

[0031] The brushless DC motor 7 is mounted on the housing 4 with screws, and the motor shaft of the brushless DC motor 7 is connected to the input end of the torque limiter 6 via a spline.

[0032] The input end of the output gear shaft 3 is connected to the output end of the torque limiter 6 via a key. The torque and speed of the brushless DC motor 7 are transmitted to the output gear shaft 3 through the torque limiter 6. The torque limiter 6 has a structure similar to a coupling. When the torque difference between the input shaft and the output shaft is less than the rated value, the input shaft and the output shaft rotate synchronously. When the torque difference between the input shaft and the output shaft is greater than the rated value, the output shaft is disengaged, and the input end rotates freely.

[0033] An angular velocity sensor 2 is installed at the rear end of the output gear shaft 3 to detect the rotational speed of the output gear shaft 3.

[0034] For brushless DC motors, driven by a controller, the rear end of the motor shaft has a brake that can achieve power-off braking to make the motor self-locking when the power is off. The motor has an angular velocity sensor 2 that can feed back the motor speed to the control box.

[0035] The gear on the output gear shaft 3 meshes with the outer ring gear of the planetary gear reducer assembly 5, which is used to transmit speed and torque to the planetary gear reducer assembly 5. The sun gear in the planetary gear reducer assembly 5 is fixed, the planetary gear ring gear serves as the input end, and the planet carrier serves as the output end for speed reduction.

[0036] The transition gear 15 is mounted on the planet carrier output shaft of the planetary gear reduction assembly 5 via a flat key.

[0037] The transition gear 15 meshes with the differential gear on the bevel gear differential assembly 16 to transmit speed and torque to the bevel gear differential assembly 16.

[0038] The first bevel gears 19 on both sides of the bevel gear differential assembly 16 are connected to the lead screws 11 on both sides via splines, and are used to transmit speed and torque to the lead screws on both sides.

[0039] The lead screw 11 and the lead screw nut 10 work together to convert the rotational motion into the linear motion of the lead screw nut 10.

[0040] The output gear shaft 3, planetary gear reduction assembly 5, and bevel gear differential assembly 16 are mounted between the housing 4 and the end cover 1 via the deep groove ball bearing 27 of the bevel gear differential assembly 16.

[0041] The lead screws 11 on both sides are mounted on the housing 4 and the end cover 1 respectively via two pairs of diagonal contact ball bearings 13, and are supported on the outside by support sleeves 9. Two Hall switches 12 are mounted on the support sleeves 9 on both sides respectively, and are used to provide feedback signals that the lead screws 11 have retracted to the correct position. The switch cover 14 is set outside the Hall switch 12 to protect it.

[0042] The earring connector 8 is connected to the lead screw 11 via threads, serving as the mounting interface for the actuator (i.e., the lead screw nut 10).

[0043] Specifically, please see Figure 2 The bevel gear differential assembly 16 includes: a differential gear 17, a friction plate 18, a first bevel gear 19, a support base 20, a second bevel gear 21, a screw 22, a fixed shaft 23, a thrust plane bearing 24, an adjusting shim 25, a counter-rotating wave spring 26, a deep groove ball bearing 27, and a differential housing 28.

[0044] The differential gear 17 is connected to the differential housing 28 via screws 22. Supported by a deep groove ball bearing 27, the differential housing 28 rotates with the differential gear 17 to transmit speed and torque. Two second bevel gears 21 are mounted on the differential housing 28 via a fixed shaft 23. Friction plates 18 are installed between the two second bevel gears 21 and the differential housing 28 to provide end-face friction. A counter-spring 26 and two support seats 20 are installed in the middle of the fixed shaft 23 to provide pressure to the two second bevel gears 21. A thrust plane bearing 24 is installed between the support seats 20 and the second bevel gears 21 to reduce the friction between the support seats 20 and the second bevel gears 21. An adjusting shim 25 is installed between the counter-spring 26 and the support seats 20. Changing the thickness of the adjusting shim 25 changes the pressure provided by the counter-spring 26 to the two second bevel gears. The first bevel gear 19 on the left and right sides meshes with the second bevel gear 21, and is supported on the differential housing 28 by deep groove ball bearings 27, outputting speed and torque to the left and right sides.

[0045] In this invention, the spring force of the top wave spring presses the second bevel gear against the friction plate, and the other side of the friction plate contacts the differential housing. The spring force of the top wave spring is converted into end-face friction force of the second bevel gear. Due to the presence of this friction force, the second bevel gear cannot rotate. The differential gear of this bevel gear differential assembly serves as the input end, transmitting torque and speed to the second bevel gear through the differential housing and fixed shaft. Through the bevel gear transmission principle, the torque and speed are then transmitted to the first bevel gears on the left and right sides after changing direction. When the load torque difference between the two first bevel gears is small, the second bevel gear does not rotate, and the rotation speeds of the two first bevel gears are the same. When the load torque difference between the two first bevel gears is large, the load torque applied by the two first bevel gears to the two second bevel gears is greater than the end-face friction force between the friction plate and the second bevel gear, causing the second bevel gear to rotate, resulting in a speed difference between the two first bevel gears and differential output.

[0046] To reduce the impact of the second bevel gear's rotation on the opposing wave spring and improve transmission efficiency, a thrust plane bearing and support seat are added between the second bevel gear and the opposing wave spring. By changing the thickness of the adjusting shim, the initial pressure of the opposing wave spring can be adjusted, thereby adjusting the load torque difference index on both sides when differential operation occurs.

[0047] The working principle diagram of this invention is as follows: Figure 3 As shown. The transmission chain of this invention uses the output speed and torque of a brushless DC motor, which is reduced and increased in torque via an output gear shaft, a planetary gear reducer assembly, and a bevel gear differential assembly. The first bevel gear then connects to a lead screw (including a lead screw nut and a lead screw rod), converting the rotary motion into linear motion. The lead screw nut acts as an actuator (push rod) extending / retracting. The specific working process is as follows:

[0048] When the electric actuator extends: Under the control of the controller, the motor brake unlocks, and the motor operates normally. The motor shaft is connected to the torque limiter, which transmits the motor's output speed and torque to the output gear shaft. The output gear shaft meshes with the ring gear of the planetary gear reduction assembly, transmitting the speed and torque through the planetary gears to the planet carrier (the sun gear is fixed), and then to the intermediate gear. The intermediate gear, as the input end of the bevel gear differential transmission, meshes with the differential gear, transmitting the speed and torque to the bevel gear differential assembly. When the load force at both ends of the actuator screw nut is small (less than the friction force generated by the opposing wave spring), the second bevel gear does not rotate. Through the fixed shaft and the second bevel gear, the torque is transmitted to the first bevel gear meshing with it. The first bevel gears on both sides serve as input ends, transmitting the torque to the screw, driving the screw to rotate, and the screw nuts of both actuators extend synchronously. When the lead screw nut of one actuator is in position, the load on that side increases, creating a load force difference with the lead screw nut of the other actuator. This load difference is transmitted to the bevel gear differential assembly via the lead screw. The load difference on the first bevel gears on both sides of the bevel gear differential assembly increases (greater than the frictional force generated by the opposing wave spring), and the bevel gear differential assembly begins differential operation. The actuators on both sides extend differentially (the end in position stops extending, while the end not in position continues to extend). When both actuators are fully extended, the load in the transmission chain increases, and the load difference between the two ends of the torque limiter increases, causing the motor to slip and disengage. The controller compares the output signals of the angular velocity sensor at the motor end with those of the angular velocity sensor installed at the output gear shaft end. When a difference appears between the two speeds, it is determined that the actuator has fully extended, and the motor brake is de-energized and self-locked. After the push rod is in position, it has a self-locking function because the lead screw thread helix angle is no greater than 4°30′.

[0049] When the actuators on both sides retract, the motor brake is unlocked under the control of the controller, and the motor operates normally.

[0050] The motor's output speed and torque are transmitted to the lead screw of the screw drive via a torque limiter, output gear shaft, planetary differential transmission, and bevel gear differential transmission, driving the lead screw nut to retract synchronously. When the lead screw nut of one actuator reaches its position first, it triggers the Hall switch on that side. The Hall switch sends a Hall position signal to the controller. Simultaneously, the mechanical limit on the lead screw increases the load on that side, transmitting torque to the bevel gear differential assembly. The load difference between the first bevel gears on both sides increases (greater than the frictional force generated by the opposing wave spring), causing the actuators on both sides to retract differentially (the retraction stops at the position where the actuator is in position, and continues at the position where the actuator is not in position). When the other actuator retracts to its position and triggers the Hall switch, sending a Hall position signal to the controller, the controller cuts off the power to the motor for braking.

[0051] The above description merely illustrates the embodiments of this application, and while the description is relatively specific and detailed, it should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Furthermore, any parts of this invention not described in detail are conventional techniques.

Claims

1. A bidirectional output electric mechanism capable of switching between synchronous and differential functions, characterized in that, Comprise: End cover (1), angular velocity sensor (2), output gear shaft (3), shell (4), planetary gear reducer assembly (5), torque limiter (6), brushless DC motor (7), ear joint (8), support sleeve (9), two screw rod (11) and screw nut (10), two Hall switches (12), angular contact ball bearing (13), transition gear (15) and bevel differential assembly (16), Brushless DC motor (7) is installed on the shell (4), the motor shaft of brushless DC motor (7) is connected with the input end of torque limiter (6); the input end of output gear shaft (3) is connected with the output end of torque limiter (6), and the torque and rotational speed of brushless DC motor (7) are transmitted to the output gear shaft (3) through torque limiter (6); the rear end of output gear shaft (3) is provided with angular velocity sensor (2) for detecting the rotational speed of output gear shaft (3); the gear on output gear shaft (3) is engaged with the outer gear ring of planetary gear reducer assembly (5), for transmitting the rotational speed and torque to planetary gear reducer assembly (5); transition gear (15) is installed on the planetary carrier output shaft of planetary gear reducer assembly (5); transition gear (15) is engaged with the differential gear of bevel differential assembly (16), for transmitting the rotational speed and torque to bevel differential assembly (16); the first bevel gears (19) on both sides of bevel differential assembly (16) are connected with two screw rods (11) respectively, for transmitting the rotational speed and torque to the two screw rods; screw rod (11) cooperates with screw nut (10) to convert the rotary motion into the linear motion of screw nut (10); output gear shaft (3), planetary gear reducer assembly (5) and bevel differential assembly (16) are installed between shell (4) and end cover (1) through the deep groove ball bearing of bevel differential assembly; the two screw rods (11) are installed on shell (4) and end cover (1) through two pairs of angular contact ball bearings (13) respectively, and the outer side is supported by support sleeve (9); two Hall switches (12) are installed on two support sleeves (9) respectively, for feeding back the signal of screw rod (11) returning to position; ear joint (8) is connected with screw rod (11); Bevel differential assembly (16) comprises: differential gear (17), friction plate (18), first bevel gear (19), support seat (20), second bevel gear (21), fixed shaft (23), adjusting gasket (25), top wave spring (26), deep groove ball bearing (27) and differential housing (28), The differential gear (17) is connected with the differential housing (28), the differential housing (28) rotates with the differential gear (17) to transmit the rotating speed and torque under the support of the deep groove ball bearing (27); the two second bevel gears (21) are installed on the differential housing (28) through the fixed shaft (23), and the friction plate (18) is installed between the two second bevel gears (21) and the differential housing (28); the butt wave spring (26) and the two support seats (20) are installed at the middle position of the fixed shaft (23) to provide pressure for the two second bevel gears (21); the adjusting washer (25) is installed between the butt wave spring (26) and the support seat (20), the thickness of the adjusting washer is changed to change the pressure provided by the butt wave spring for the two second bevel gears; the left and right first bevel gears (19) are engaged with the second bevel gears (21) and are supported on the differential housing (28) through the deep groove ball bearing (27) to output the rotating speed and torque to the left and right sides; The thrust plane bearing (24) is installed between the support seat (20) and the second bevel gear (21).

2. The bidirectional output electric motor mechanism according to claim 1, characterized by, The outer side of the Hall switch (12) is provided with a switch outer cover (14).

3. The bidirectional output electric motor according to claim 1, wherein The brushless DC motor (7) is electrically connected with the controller, and the controller drives the brushless DC motor (7) to work. The brake is arranged at the rear end of the shaft of the brushless DC motor (7) to realize power-off braking and self-locking of the motor.

4. The bidirectional output electric motor mechanism according to claim 1, wherein The sun gear in the planetary gear reduction assembly (5) is fixed, the planetary gear ring is used as an input end, and the planetary carrier is used as an output end for speed reduction.

5. The bidirectional output motor mechanism according to claim 1, wherein, The motor shaft of the brushless DC motor (7) is connected with the input end of the torque limiter (6) through a spline. The first bevel gears (19) on the two sides of the bevel gear differential assembly (16) are connected with the two screw rods (11) on the two sides through splines respectively.

6. The bidirectional output motor mechanism according to claim 1, wherein, The input end of the output gear shaft (3) is connected with the output end of the torque limiter (6) through a key. The transition gear (15) is installed on the planetary carrier output shaft of the planetary gear reduction assembly (5) through a key.

7. The bidirectional output electric motor mechanism according to claim 1, wherein The output gear shaft (3), the planetary gear reduction assembly (5) and the bevel gear differential assembly (16) are installed between the housing (4) and the end cover (1) through the deep groove ball bearing (27).

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