A symmetrical linkage servo drive device

Abstract

A symmetrical linkage servo drive device, relating to the field of servo motor technology, includes a drive mechanism, a motor, a gear reduction mechanism, and a rudder shaft rocker arm mechanism. The output shaft of the motor is driven by the gear reduction mechanism, and the rudder shaft rocker arm mechanism is located on the side of the gear reduction mechanism opposite to the motor. The rudder shaft rocker arm mechanism includes a base, and a rudder shaft is rotatably connected to the inner cavity of the base. The rudder shaft has a crank. A self-locking mechanism capable of locking the rudder shaft is located at the bottom of the inner cavity of the base. A drive mechanism is located on one side of the motor, and the drive mechanism includes a housing. A lead screw is rotatably connected within the housing, and the lead screw is correspondingly driven by the output gear of the gear reduction mechanism. This invention has a simple structure, and the parallel arrangement of the motor and drive mechanism effectively reduces the overall volume, making the whole device compact and small. The self-locking mechanism at the bottom of the inner cavity of the base can lock the rudder shaft, preventing external force from being transmitted to the drive mechanism when the rudder shaft stops rotating.

Description

Technical Field

[0001] This invention relates to the field of servo motor technology, and in particular to a symmetrical linkage servo drive device. Background Technology

[0002] As is well known, servo drive mechanisms are used to drive the motion of the controlled object. When the controlled object is in linear motion, the servo drive mechanism needs to convert the rotational motion of the motor into the linear motion of the controlled object; when the controlled object is in rotational motion, the servo drive mechanism needs to convert the speed of the motor into the speed required by the controlled object. At present, the control accuracy of servo drive mechanisms at home and abroad is generally required to be no greater than 0.2°. However, with the increasing demand for small-volume, high-precision servo drive mechanisms for precise control of UAVs, etc., the need is becoming more and more urgent.

[0003] Chinese patent (publication number: CN207053315U) discloses a narrow and elongated servo motor structure. This patent includes a servo motor, with a first-stage reduction mechanism connected to the output shaft of the servo motor. Through two-stage conversion, the rotation output by the servo motor is converted into the oscillation of the final output shaft. In practical use, it was found that this patented structure is relatively large, and while maintaining output torque, it cannot be further reduced in size, making it unsuitable for smaller devices. Furthermore, it was discovered that the ball screw pair suffers from uneven load distribution, making it prone to accidental jamming during use. In addition, the servo shaft of this patented structure cannot achieve self-locking, while most existing servos with self-locking capabilities use worm gear mechanisms for drive transmission. However, worm gear mechanisms have low transmission efficiency and high frictional resistance during startup. These defects are problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention discloses a symmetrical linkage servo drive device.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0006] A symmetrical linkage servo drive device includes a drive mechanism, a motor, a gear reduction mechanism, and a rudder shaft rocker arm mechanism. The output shaft of the motor is driven by the gear reduction mechanism, and the rudder shaft rocker arm mechanism is located on the side of the gear reduction mechanism opposite to the motor. The rudder shaft rocker arm mechanism includes a base, and a rudder shaft is rotatably connected to the inner cavity of the base. The rudder shaft has a crank. A self-locking mechanism capable of locking the rudder shaft is provided at the bottom of the inner cavity of the base. A drive mechanism is located on one side of the motor. The drive mechanism includes a housing, and a lead screw is rotatably connected inside the housing. The lead screw is driven by the output gear of the gear reduction mechanism. A nut that slides in accordance with the housing is threaded onto the lead screw. Connecting rods are hinged to both sides of the nut, and the other ends of the two connecting rods are respectively hinged to the crank.

[0007] Preferably, the self-locking mechanism includes a locking disc coaxially and fastened to the rudder shaft, and a locking sleeve coaxially and movably sleeved to the rudder shaft. One end of the locking sleeve corresponding to the locking disc has a flared guide flange. The locking disc surface has multiple notches spaced circumferentially, with friction blocks hinged within each notch. A torsion spring is provided at the hinged position between the friction block and the locking disc to deflect the friction block and extend it out of the locking disc. Two adjacent friction blocks are arranged opposite each other. An electromagnet is fastened to the end of the locking sleeve facing away from the locking disc within the base, capable of driving the locking sleeve away from the locking disc along the rudder shaft. This electromagnet has a fixed sleeve that allows the locking sleeve to be movably inserted, and the outer wall of the locking sleeve and the inner wall of the fixed sleeve are slidably fitted by a spline. A return spring is provided between the locking sleeve and the electromagnet to reset the locking sleeve and lock the rudder shaft.

[0008] Preferably, the friction block disc surface is provided with an arc-shaped groove, and the locking disc is provided with a limiting pin at the position corresponding to the arc-shaped groove to limit the deflection angle of the friction block.

[0009] Preferably, the end of the rudder shaft corresponding to the notch on the locking disc is fitted with a pressure plate and threadedly connected with a locking nut for pressing the pressure plate.

[0010] Preferably, the end of the connecting rod that is hinged to the crank has a bent portion.

[0011] Preferably, the housing has an opening at the end opposite to the rudder shaft rocker arm mechanism, and an end cap is installed at the position corresponding to the opening.

[0012] Preferably, one end of the lead screw is rotatably connected to the end cover via an angular contact ball bearing, and the end cover is provided with a shim at the position corresponding to the angular contact ball bearing to eliminate the assembly clearance of the angular contact ball bearing.

[0013] Preferably, the housing is equipped with an angle encoder for detecting the rotation angle of the rudder shaft.

[0014] By employing the technical solution described above, the present invention has the following beneficial effects:

[0015] This invention discloses a symmetrical linkage servo drive device with a simple structure. A drive mechanism is located on one side of the motor, and the parallel arrangement of the motor and drive mechanism effectively reduces the overall volume, making the device compact and small. The symmetrical arrangement of the two linkages effectively prevents the nut from jamming or experiencing uneven wear due to force on one side, further improving the transmission smoothness of the screw-nut pair. The linkages and cranks cooperate to form a crank-connecting rod mechanism, which effectively increases the output torque and load-bearing capacity of the rudder shaft. A self-locking mechanism is provided at the bottom of the housing cavity to lock the rudder shaft, preventing external force from being transmitted to the drive mechanism when the rudder shaft stops rotating. Attached Figure Description

[0016] Figure 1This is a schematic diagram of the structure of the present invention;

[0017] Figure 2 This is a schematic diagram of the drive mechanism;

[0018] Figure 3 A schematic diagram of the rudder shaft rocker arm mechanism;

[0019] Figure 4 This is a schematic diagram of the self-locking mechanism;

[0020] Figure 5 This is a schematic diagram of the internal structure of the self-locking mechanism;

[0021] Figure 6 This is a top view of the locking disc.

[0022] In the diagram: 1. Drive mechanism; 1-1. Housing; 1-2. Lead screw; 1-3. Nut; 1-4. Connecting rod; 1-5. End cap; 1-6. Angular contact ball bearing; 2. Motor; 3. Gear reduction mechanism; 4. Rudder shaft rocker arm mechanism; 4-1. Base; 4-2. Rudder shaft; 4-3. Crank; 5. Self-locking mechanism; 5-1. Locking disc; 5-2. Locking sleeve; 5-3. Friction block; 5-4. Arc groove; 5-5. Limit pin; 5-6. Electromagnet; 5-7. Return spring; 5-8. Pressure plate; 5-9. Locking nut. Detailed Implementation

[0023] The present invention can be explained in detail through the following embodiments. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "front", "rear", "left", "right" indicating the orientation or positional relationship, they are only corresponding to the drawings of this application for the convenience of describing the present invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation.

[0024] Example 1, in conjunction with Appendix Figures 1-3 A symmetrical linkage servo drive device includes a drive mechanism 1, a motor 2, a gear reduction mechanism 3, and a rudder shaft rocker arm mechanism 4. The output shaft of the motor 2 is driven by the gear reduction mechanism 3. The rudder shaft rocker arm mechanism 4 is provided on the side of the gear reduction mechanism 3 away from the motor 2. The rudder shaft rocker arm mechanism 4 includes a base 4-1. The housing of the gear reduction mechanism 3 is correspondingly and fastened to the base 4-1. The housing of the motor 2 is correspondingly and fastened to the housing of the gear reduction mechanism 3, so that the motor 2 can output power. The rudder shaft 4-2 is rotatably connected to the inner cavity of the base 4-1. The shaft of the rudder shaft 4-2 is provided with a crank 4-3. The bottom of the inner cavity of the base 4-1 is provided with a self-locking mechanism 5 that can lock the rudder shaft 4-2. That is, when the rudder shaft 4-2 stops rotating, the rudder shaft 4-2 can be locked by the self-locking mechanism 5 to prevent external force from being transmitted to the drive mechanism 1 through the rudder shaft 4-2.

[0025] A drive mechanism 1 is provided on one side of the motor 2. The parallel arrangement of the motor 2 and the drive mechanism 1 effectively reduces the overall volume, making the whole compact and small. The drive mechanism 1 includes a housing 1-1, which is fastened to the base 4-1. A lead screw 1-2 is rotatably connected inside the housing 1-1. The lead screw 1-2 is correspondingly connected to the output gear of the gear reduction mechanism 3. The lead screw 1-2 is threaded with a nut 1-3 that slides with the housing 1-1. That is, the lead screw 1-2 and the nut 1-3 cooperate to form a lead screw. The screw nut assembly is preferably a ball screw assembly, which offers high transmission efficiency, smooth transmission, and high transmission precision. Connecting rods 1-4 are hinged to both sides of the nut 1-3, with the other ends of each connecting rod 1-4 correspondingly hinged to the crank 4-3. The symmetrical arrangement of the two connecting rods 1-4 effectively prevents jamming or uneven wear caused by force on one side of the nut 1-3, further improving the transmission smoothness of the screw nut assembly. The connecting rods 1-4 and crank 4-3 together form a crank-connecting rod mechanism, which effectively increases the output torque and load-bearing capacity of the rudder shaft 4-2.

[0026] In use, the motor 2 drives the gear reduction mechanism 3, which in turn outputs power to drive the lead screw 1-2. The lead screw 1-2 drives the nut 1-3, which in turn drives the connecting rod 1-4 to drive the crank 4-3. The crank 4-3 then drives the rudder shaft 4-2 to rotate.

[0027] Example 2, in conjunction with Appendix Figures 4-6 A symmetrical linkage servo drive device, which differs from Embodiment 1 in that, based on Embodiment 1, the self-locking mechanism 5 includes a locking disc 5-1 coaxially and fastened to the rudder shaft 4-2, and a locking sleeve 5-2 coaxially and movably sleeved to the rudder shaft 4-2. The locking sleeve 5-2 has a flared guide flange at one end corresponding to the locking disc 5-1. The surface of the locking disc 5-1 has multiple notches spaced around the circumference. Friction blocks 5-3 are hinged in the notches. At the position where the friction blocks 5-3 are hinged to the locking disc 5-1, a torsion spring is provided to deflect the friction blocks 5-3 and extend them out of the locking disc 5-1. Two adjacent friction blocks 5-3 are arranged opposite each other, that is, two adjacent friction blocks 5-3 are arranged in a figure-eight shape.

[0028] Working principle: When the locking sleeve 5-2 moves away from the locking disc 5-1 along the rudder shaft 4-2, the friction block 5-3 disengages from the locking sleeve 5-2, thus unlocking the rudder shaft 4-2. When the locking sleeve 5-2 moves in the opposite direction along the rudder shaft 4-2, the friction block 5-3 retracts inward under the action of the guide flange of the locking sleeve 5-2 until the friction block 5-3 comes into contact with the inner wall of the locking sleeve 5-2. At this time, it is in a locked state. Regardless of whether the rudder shaft 4-2 rotates forward or reverses, it will receive the corresponding frictional force between the friction block 5-3 and the locking sleeve 5-2.

[0029] An electromagnet 5-6 is fastened to the end of the locking sleeve 5-2 facing away from the locking disc 5-1 inside the base 4-1. This electromagnet 5-6 can drive the locking sleeve 5-2 away from the locking disc 5-1 along the rudder shaft 4-2. The electromagnet 5-6 is provided with a fixed sleeve that allows the locking sleeve 5-2 to be inserted movably. The outer wall of the locking sleeve 5-2 and the inner wall of the fixed sleeve are slidably fitted by a spline, which can effectively limit the axial rotation of the locking sleeve 5-2. The electromagnet 5-6 is existing technology, so its structure and working pressure will not be described in this embodiment. A return spring 5-7 is provided between the locking sleeve 5-2 and the electromagnet 5-6 to reset the locking sleeve 5-2 and lock the rudder shaft 4-2.

[0030] When the electromagnet 5-6 is energized, it generates a magnetic attraction force, which can attract the locking sleeve 5-2 to move along the rudder shaft 4-2 away from the locking disc 5-1, thereby unlocking the rudder shaft 4-2. When the electromagnet 5-6 loses its electromagnetic attraction force, the locking sleeve 5-2 moves along the rudder shaft 4-2 closer to the locking disc 5-1 under the action of the return spring 5-7, so that the friction block 5-3 and the inner wall of the locking sleeve 5-2 come into contact again, thereby automatically locking the rudder shaft 4-2.

[0031] The friction block 5-3 has an arc-shaped groove 5-4 on its surface. The locking disc 5-1 has a limiting pin 5-5 at the position corresponding to the arc-shaped groove 5-4 to limit the deflection angle of the friction block 5-3. That is, the limiting pin 5-5 can limit the deflection angle of the friction block 5-3 to prevent the friction block 5-3 from deflecting too much when it is in the unlocked state, which would cause the locking sleeve 5-2 to fail to reset and thus fail to achieve the locking action.

[0032] The rudder shaft 4-2 is fitted with a pressure plate 5-8 at one end of the locking disc 5-1 with a notch, and is threaded with a locking nut 5-9 for pressing the pressure plate 5-8. That is, the pressure plate 5-8 can effectively prevent the friction block 5-3 from accidentally disengaging from the locking disc 5-1.

[0033] Example 3, in conjunction with the appendix Figure 1 A symmetrical linkage servo drive device, based on embodiment 1 or 2, wherein the end of the linkage 1-4 that is hinged to the crank 4-3 is provided with a bent part, which can effectively prevent the crank 4-3 from deflecting excessively, causing the linkage 1-4 and the crank 4-3 to jam unexpectedly.

[0034] Example 4, in conjunction with Appendix Figure 1A symmetrical linkage servo drive device, based on any of the embodiments 1 to 3, has an opening at one end of the housing 1-1 away from the rudder shaft rocker arm mechanism 4, and an end cover 1-5 is installed at the corresponding opening position, allowing grease to be injected into the housing 1-1 through the end cover 1-5 to ensure the smooth and stable operation of the drive mechanism 1; one end of the lead screw 1-2 is rotatably connected to the end cover 1-5 through an angular contact ball bearing 1-6, and the end cover 1-5 is provided with a shim at the position corresponding to the angular contact ball bearing 1-6 to eliminate the assembly clearance of the angular contact ball bearing 1-6, which can effectively eliminate the axial backlash of the lead screw 1-2, effectively improve the transmission accuracy of the drive mechanism 1, and thus improve the rotational accuracy of the rudder shaft 4-2; furthermore, the base 4-1 is provided with an angle encoder for monitoring the rotational angle of the rudder shaft 4-2, which monitors the rotational angle of the rudder shaft 4-2 in real time and feeds it back to the control system, further improving the rotational accuracy of the rudder shaft 4-2.

[0035] The parts of this invention not described in detail are prior art. It will be apparent to those skilled in the art that this invention is not limited to the details of the above exemplary embodiments, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects, and are intended to encompass all changes falling within the meaning and scope of equivalents within this invention.

Claims

1. A symmetrical linkage servo drive device, characterized in that: It includes a drive mechanism (1), a motor (2), a gear reduction mechanism (3), and a rudder shaft rocker arm mechanism (4); the output shaft of the motor (2) is driven by the gear reduction mechanism (3), and the gear reduction mechanism (3) is provided with a rudder shaft rocker arm mechanism (4) on the side away from the motor (2). The rudder shaft rocker arm mechanism (4) includes a base (4-1), and the inner cavity of the base (4-1) is rotatably connected to the rudder shaft (4-2). The rudder shaft (4-2) is provided with a crank (4-3) on its shaft body; the bottom of the inner cavity of the base (4-1) is provided with a self-locking mechanism that can lock the rudder shaft (4-2). Locking mechanism (5); A driving mechanism (1) is provided on one side of the motor (2). The driving mechanism (1) includes a housing (1-1). A lead screw (1-2) is rotatably connected inside the housing (1-1). The lead screw (1-2) is connected to the output gear of the gear reduction mechanism (3) in a corresponding transmission connection. The lead screw (1-2) is threaded with a nut (1-3) that is in sliding fit with the housing (1-1). Both sides of the nut (1-3) are hinged with connecting rods (1-4). The other ends of the two connecting rods (1-4) are respectively hinged to the crank (4-3). The self-locking mechanism (5) includes a locking disc (5-1) coaxially and fastened to the rudder shaft (4-2), and a locking sleeve (5-2) coaxially and movably sleeved to the rudder shaft (4-2). The locking sleeve (5-2) has a flared guide flange at one end corresponding to the locking disc (5-1). The locking disc (5-1) has multiple notches spaced circumferentially on its surface, with friction blocks (5-3) hinged within each notch. A torsion spring is provided at the hinged position between the friction block (5-3) and the locking disc (5-1) to deflect the friction block (5-3) and extend it out of the locking disc (5-1). Adjacent friction blocks (5-1)... -3) Relative arrangement; The end of the locking sleeve (5-2) facing away from the locking disc (5-1) inside the base (4-1) is fastened with an electromagnet (5-6) that can drive the locking sleeve (5-2) away from the locking disc (5-1) along the rudder shaft (4-2). The electromagnet (5-6) is provided with a fixed sleeve that allows the locking sleeve (5-2) to be inserted movably, and the outer wall of the locking sleeve (5-2) and the inner wall of the fixed sleeve are slidably engaged by a spline; A return spring (5-7) is provided between the locking sleeve (5-2) and the electromagnet (5-6) for resetting the locking sleeve (5-2) and locking the rudder shaft (4-2).

2. The symmetrical linkage servo drive device as described in claim 1, characterized in that: The friction block (5-3) has an arc-shaped groove (5-4) on its surface, and the locking disc (5-1) has a limiting pin (5-5) at the position corresponding to the arc-shaped groove (5-4) to limit the deflection angle of the friction block (5-3).

3. The symmetrical linkage servo drive device as described in claim 1, characterized in that: The rudder shaft (4-2) has a notch at one end corresponding to the locking disc (5-1), and a pressure plate (5-8) is fitted on it, and a locking nut (5-9) for pressing the pressure plate (5-8) is threadedly connected to it.

4. The symmetrical linkage servo drive device as described in claim 1, characterized in that: The connecting rod (1-4) is provided with a bent part at one end that is hinged to the crank (4-3).

5. The symmetrical linkage servo drive device as described in claim 1, characterized in that: The housing (1-1) has an opening at one end away from the rudder shaft rocker arm mechanism (4), and an end cap (1-5) is installed at the position corresponding to the opening.

6. The symmetrical linkage servo drive device as described in claim 5, characterized in that: One end of the lead screw (1-2) is rotatably connected to the end cover (1-5) via an angular contact ball bearing (1-6). The end cover (1-5) is provided with a shim at the position corresponding to the angular contact ball bearing (1-6) to eliminate the assembly clearance of the angular contact ball bearing (1-6).

7. The symmetrical linkage servo drive device as described in claim 1, characterized in that: The base (4-1) is equipped with an angle encoder for monitoring the rotation angle of the rudder shaft (4-2).

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