A connecting rod driven single swing mirror scanning mechanism

Abstract

The present invention provides a connecting rod driven single pendulum mirror scanning mechanism, which belongs to the field of space laser communication, and is functionally divided into a pitch axis and an azimuth axis, including a base, a permanent magnet synchronous motor, a hollow azimuth axis shaft body with a central through hole, a hollow azimuth axis rotating bracket, a steering gear, a pitch driving assembly, a pitch swing bracket and a single pendulum mirror; a stator of a permanent magnet synchronous motor is installed below the base, a rotor of the permanent magnet synchronous motor is directly connected to the hollow azimuth axis shaft body to drive it to rotate, a hollow azimuth axis rotating bracket is installed above the azimuth axis shaft body, a steering gear and a pitch driving assembly are installed above the hollow azimuth axis rotating bracket, a pitch driving assembly composed of a joint bearing and a connecting rod is driven by the steering gear, a pitch swing bracket is installed at the end of the pitch driving assembly, and a single pendulum mirror is bonded above the pitch swing bracket, so that the steering gear drives the single pendulum mirror to achieve a small range of swing. The present invention achieves simplification and lightweight miniaturization.

Description

Technical Field

[0001] The invention relates to the technical field of space laser communication, and in particular to a connecting rod driven single swing mirror scanning mechanism. Background Art

[0002] Space laser communication is a communication method that uses laser beams with high collimation characteristics as information carriers to transmit data in space. In space laser communication, there are problems such as long transmission distance, small laser signal beam divergence and limited reception time, which poses a major challenge to maintaining good coaxiality between the two communication terminals to ensure smooth data transmission. In order to maintain precise alignment of the two terminals and maintain a smooth link, the Acquisition, Tracking, Pointing (PAT system) is introduced, which is called the tracking system.

[0003] The classic space laser communication tracking and aiming system consists of five units: auxiliary capture unit, beacon transmission unit, advance unit, coarse tracking unit and fine tracking unit.

[0004] The coarse tracking unit is mainly responsible for capturing and tracking the communication beam, and is the basis of the entire tracking and aiming system. As satellite platforms equipped with laser communication terminal systems have developed towards low orbits and lightweight miniaturization in recent years, the space environment faced by the tracking and aiming system has become more complex, and the satellite payload is limited, so the space and weight reserved for the tracking and aiming system have also become limited. Therefore, how to achieve lightweight miniaturization of the tracking and aiming system while ensuring high-precision tracking is a difficult problem that urgently needs to be solved in the field of space laser communications. The scanning mechanism, as the core component of the coarse tracking system, accounts for the vast majority of the volume and weight of the entire system, and plays a vital role in achieving lightweight miniaturization of the tracking and aiming system. Therefore, there is an urgent need for a lightweight scanning mechanism. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a connecting rod driven single pendulum mirror scanning mechanism. Compared with the method of using a DC motor part and a gear set meshing and arranged inside and outside the base of the mechanism, the transmission mechanism is directly omitted by horizontally arranging the stator and rotor of the permanent magnet synchronous motor at the bottom of the base, which can greatly reduce the size and weight of the scanning mechanism. At the same time, the present invention uses a servo to drive a plane crank rocker mechanism, and the pitch swing bracket participates in the movement of the crank connecting rod mechanism as a load and a connecting rod at the same time. The movement of the pitch swing bracket is a rigid body movement, that is, it rotates around an axis while moving horizontally, so as to realize the swing of the single pendulum mirror carried on the pitch swing bracket within a certain range. Compared with the method of using a DC motor part and a pitch shaft system part to drive the load, the size and weight of the mechanism can be effectively reduced. Another advantage of doing so is that compared with rotating around a fixed axis and the single pendulum mirror and the mounting bracket being too large in size, the single pendulum mirror and the bracket can be prevented from interfering with the mechanism below.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A connecting rod driven single-swing mirror scanning mechanism is composed of an azimuth axis system and a pitch axis system, and comprises a base, a permanent magnet synchronous motor, a hollow azimuth axis shaft body, a hollow azimuth axis rotating bracket, a steering gear, a pitch driving assembly, a pitch swing bracket and a single-swing mirror; a stator of the permanent magnet synchronous motor is installed below the base, a rotor of the permanent magnet synchronous motor is directly connected to the hollow azimuth axis shaft body to drive it to rotate, a hollow azimuth axis rotating bracket is installed above the hollow azimuth axis shaft body, a steering gear and a pitch driving assembly are installed above the hollow azimuth axis rotating bracket, a pitch driving assembly composed of a joint bearing and a connecting rod is driven by the steering gear, a pitch swing bracket is installed at the end of the pitch driving assembly, and a single-swing mirror is bonded above the pitch swing bracket, so that the steering gear drives the single-swing mirror to achieve a small range of swing.

[0008] Furthermore, the base is composed of two parts of cylinders with different diameters, the upper and lower parts are open, and an annular edge is protruded on the inner side. The upper part of the annular edge is used to support the outer ring of the bearing of the azimuth axis system. The lower half of the base is provided with a circular groove, and the circular groove is used to install the stator part of the permanent magnet synchronous motor; a square boss is provided on the outer side of the circumference of the lower half of the base for installing the reading head of the angle encoder.

[0009] Furthermore, the hollow azimuth shaft body is capable of rotating relative to the base, the center is through, and a plurality of height difference portions are formed on the outer side of the cylindrical surface from top to bottom. The lower end face of the hollow azimuth shaft body is provided with an annular flange to provide positioning for the rotor part installed on the end face; a pair of bearings are arranged on the outer side face of the hollow azimuth shaft body to support the rotation of the hollow azimuth shaft body relative to the base.

[0010] Furthermore, it also includes inner and outer pressure rings of the bearing of the azimuth shaft system, which are used to position and provide preload for a pair of bearings of the azimuth shaft system. The outer pressure ring of the bearing is installed on the upper end surface of the base, and the inner pressure ring of the bearing is installed on a height difference portion of the hollow azimuth shaft body.

[0011] Furthermore, a frame structure is provided at the upper end of the hollow azimuth axis rotation bracket for installing a servo, and an annular flange is provided at the lower end of the hollow azimuth axis rotation bracket for winding around the code disk part of the encoder to cooperate with the encoder reading head installed on the base to measure the azimuth axis rotation angle in real time.

[0012] Furthermore, the pitch drive assembly includes a servo arm, a joint bearing, a connecting rod, a hinge seat, and a hinge pin with a shoulder buckle ring, wherein the servo arm is used to constitute the driving side prime mover crank of the crank-rocker mechanism, and the joint bearing and the connecting rod constitute the driving side rocker, the crank and rocker on the driven side; the hinge seat and the hinge pin with a shoulder buckle ring are used to position the crank and rocker, so as to install them at a fixed position on the upper end surface of the hollow azimuth axis rotation bracket.

[0013] Furthermore, the pitch and swing bracket is installed as a connecting rod between the crank and the rocker on the driving side and the driven side.

[0014] Furthermore, the single pendulum mirror is elliptical and is fixed on the pitch and swing bracket by gluing.

[0015] Beneficial effects:

[0016] The present invention directly drives the moving parts by horizontally arranging a permanent magnet synchronous motor at the bottom of the base, thereby forming a compact structure. As a result, the size and weight of the scanning mechanism are effectively reduced. In addition, the present invention uses a servo to drive a planar crank rocker mechanism to drive the load to achieve pitch axis swing. Compared with the method of using a DC servo motor and its mounting shaft system, the structure is simplified and the weight of the system is reduced. Another advantage of this is that compared with rotating around a fixed axis and the size of the single pendulum mirror and the mounting bracket being too large, the single pendulum mirror and the bracket can avoid interference with the mechanism below. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the base of the present invention;

[0018] Figure 2 It is a structural schematic diagram of the hollow azimuth axis body of the present invention;

[0019] Figure 3 It is a schematic structural diagram of the hollow azimuth axis rotating bracket of the present invention;

[0020] Figure 4 It is a three-dimensional structural schematic diagram of a connecting rod driven single swing mirror scanning mechanism of the present invention;

[0021] Figure 5 It is a cross-sectional view of a connecting rod driven single swing mirror scanning mechanism of the present invention along the azimuth axis perpendicular to the pitch axis;

[0022] Figure 6 It is a schematic diagram of the connection relationship between the first connecting rod and the second connecting rod of the present invention.

[0023] Wherein: base 1, annular edge 1a, circular groove 1b, square boss 1c, hollow azimuth axis rotating bracket 2, frame structure 2a, annular flange 2b, hollow azimuth axis body 3, first height difference portion 3a, second height difference portion 3b, third height difference portion 3c, first hinge seat 4a, second hinge seat 4b, third hinge seat 4c, first shoulder buckle ring hinge pin 5a, second shoulder buckle ring hinge pin 5b, third shoulder buckle ring hinge pin 5c, fourth shoulder buckle ring hinge pin 5d, fifth shoulder buckle ring hinge pin 5e, sixth shoulder buckle ring hinge pin 5f, seventh shoulder buckle hinge 5g, double-headed joint bearing 6, first connecting rod 7a, second connecting rod 7b, first joint bearing 8a, second joint bearing 8b, third joint bearing 8c, fourth joint bearing 8d, first connecting rod 9a, second connecting rod 9b, pitch swing bracket 10, single swing mirror 11, servo 12, servo arm 13, encoder reading head 14, azimuth axis encoder reading bracket 15, encoder code disk 16, stator 17, rotor 18, first bearing 19, second bearing 20, bearing outer pressure ring 21, bearing inner pressure ring 22. DETAILED DESCRIPTION

[0024] like Figure 1-Figure 5 The figure shows an embodiment of the present invention, which discloses a connecting rod driven single swing mirror scanning mechanism, which can be divided into a pitch axis and an azimuth axis according to its function.

[0025] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown, the azimuth axis is mainly composed of a base 1 and a hollow azimuth axis body 3. The circular groove 1b in the lower part of the base 1 is used to install the stator 17 of the permanent magnet synchronous motor. The rotor 18 of the permanent magnet synchronous motor is installed on the hollow azimuth axis body 3, and an air gap is left between the stator 17 and the rotor 18 is driven to rotate by the rotating magnetic field generated by the stator 17. The hollow azimuth axis body 3 is arranged inside the base 1; the hollow azimuth axis rotating bracket 2 is installed above the base 1 and fixedly connected to the hollow azimuth axis body 3.

[0026] The base 1 is composed of two cylinders of different diameters, the center part is through, and an annular edge 1a is protruded on the inner side of the upper half, close to the lower half, and a circular groove 1b is formed on the inner side of the lower half. At the same time, a square boss 1c is provided in the cross-sectional direction of the outer circumference of the lower half.

[0027] The hollow azimuth axis body 3 is as follows Figure 2 As shown, it is a hollow shape, and a first height difference portion 3a, a second height difference portion 3b, and a third height difference portion 3c are sequentially arranged on the outside.

[0028] The hollow azimuth axis rotating bracket 2 is as follows Figure 3 As shown, a frame structure 2a is arranged on its upper end surface, and an annular flange 2b is arranged on its lower end surface.

[0029] At the same time, a first bearing 19 and a second bearing 20 are arranged on the inner side above the annular edge 1a of the upper half of the base 1, corresponding to the upper side of the third height difference portion 3c of the hollow azimuth shaft body 3, for supporting the hollow azimuth shaft body 3 and the rotor 18 of the permanent magnet synchronous motor installed thereon for rotation.

[0030] Furthermore, a bearing outer pressure ring 21 is installed on the upper end surface of the base 1, and a bearing inner pressure ring 22 is installed above the second height difference portion 3b of the hollow azimuth shaft body 3. Their functions are to fix and preload the first bearing 19 and the second bearing 20.

[0031] An azimuth axis encoder reading bracket 15 is mounted on the square boss 1 c in the lower half of the base 1 , and an encoder reading head 14 is mounted on the azimuth axis encoder reading bracket 15 .

[0032] In addition, the lower end of the hollow azimuth axis rotating bracket 2 is installed on the first height difference portion 3a of the hollow azimuth axis shaft body 3, and an encoder code disk 16 is bonded to the annular flange 2b of the hollow azimuth axis rotating bracket 2, which cooperates with the encoder reading head 14 on the base 1 to complete the measurement of the azimuth axis angle.

[0033] like Figure 4 , Figure 5 As shown, for the pitch axis, the bottom shaft hole of the pitch swing bracket 10 close to the driving side of the servo 12 is connected to the end of the servo arm 13 through the seventh shoulder buckle ring hinge pin 5g, and the servo arm 13 is connected to the output shaft of the servo 12, and the servo 12 is installed in the frame structure 2a on the above-mentioned hollow azimuth axis rotation bracket 2; at the same time, the middle shaft hole of the pitch swing bracket 10 close to the driving side of the servo 12 is connected to one end of the second connecting rod 7b through the sixth shoulder buckle ring hinge pin 5f, and the other end of the second connecting rod 7b is installed on the second hinge seat 4b through the fourth shoulder buckle ring hinge pin 5d and then installed on the hollow azimuth axis rotation bracket 2.

[0034] Furthermore, the bottom axial hole of the pitch swing bracket 10 on the driven side away from the servo 12 is connected to one end of the double-headed joint bearing 6 through the second shoulder buckle ring hinge pin 5b, and the other end thereof is connected to the first hinge seat 4a through the first shoulder buckle ring hinge pin 5a and then installed on the hollow azimuth axis rotation bracket 2; at the same time, the middle axial hole of the pitch swing bracket 10 on the driven side away from the servo 12 is connected to one end of the first connecting rod 7a through the third shoulder buckle ring hinge pin 5c, and the other end of the first connecting rod 7a is connected to the third hinge seat 4c through the fifth shoulder buckle ring hinge pin 5e and then installed on the hollow azimuth axis rotation bracket 2.

[0035] A single pendulum mirror 11 is installed by bonding on one side of the pitch swing bracket 10 close to the hollow azimuth axis rotation bracket 2 to drive it to swing in a small amplitude.

[0036] like Figure 6 As shown, the first connecting rod 7a is connected by the first joint bearing 8a, the first connecting rod 9a, and the second joint bearing 8b. Specifically, the internal threaded hole at one end of the first joint bearing 8a is connected to the stud with external threads at one end of the first connecting rod 9a in a threaded engagement manner, and the stud with external threads at the other end of the first connecting rod 9a is connected to the internal threaded hole at one end of the second joint bearing 8b in a threaded engagement manner. The second connecting rod 7b is connected by the third joint bearing 8c, the second connecting rod 9b, and the fourth joint bearing 8d. Specifically, the internal threaded hole at one end of the third joint bearing 8c is connected to the stud with external threads at one end of the second connecting rod 9b in a threaded engagement manner, and the stud with external threads at the other end of the second connecting rod 9b is connected to the internal threaded hole at one end of the fourth joint bearing 8d in a threaded engagement manner.

[0037] The working mode of a connecting rod driven single swing mirror scanning mechanism of the present invention is as follows:

[0038] First, the connecting rod driven single swing mirror scanning mechanism is installed and fastened through the mounting flange hole on the outer periphery of the base. As the stator 17 of the permanent magnet synchronous motor in the circular groove 1b of the lower half of the base 1 generates a rotating magnetic field, the rotor 18 is driven to drive the hollow azimuth axis body 3 installed thereon to rotate. At the same time, since the hollow azimuth axis rotating bracket 2 is installed above the hollow azimuth axis body 3, the hollow azimuth axis rotating bracket 2 will rotate accordingly, thereby forming a rotary motion of the azimuth axis. At the same time, the servo 12, the pitch swing bracket 10 and the pitch drive assembly are all installed above the hollow azimuth axis rotating bracket 2, and the entire pitch axis can move with the rotation of the hollow azimuth axis rotating bracket 2.

[0039] In addition, the servo 12 drives the servo arm 13 to swing. Since the servo arm 13, the pitch swing bracket 10, the second connecting rod 7b and the hollow azimuth axis rotation bracket 2 constitute a plane crank rocker mechanism, at this time, as the servo arm 13 moves, the second connecting rod 7b moves accordingly, and at this time the pitch swing bracket 10 participates in the movement of the mechanism as a connecting rod, and a rigid body motion occurs, that is, a rotational motion about an axis is generated while a translational motion is realized, thereby realizing the swinging motion of the carried single pendulum mirror 11.

Claims

1. A connecting rod driven single swing mirror scanning mechanism, characterized in that: It is composed of an azimuth axis system and a pitch axis system, including a base, a permanent magnet synchronous motor, a hollow azimuth axis body, a hollow azimuth axis rotating bracket, a steering gear, a pitch driving assembly, a pitch swing bracket and a pendulum mirror; the stator of the permanent magnet synchronous motor is installed below the base, the rotor of the permanent magnet synchronous motor is directly connected to the hollow azimuth axis body to drive it to rotate, the hollow azimuth axis body is installed above the hollow azimuth axis rotating bracket, the steering gear and the pitch driving assembly are installed above the hollow azimuth axis rotating bracket, the pitch driving assembly composed of a joint bearing and a connecting rod is driven by the steering gear, the pitch swing bracket is installed at the end of the pitch driving assembly, and the pendulum mirror is bonded above the pitch swing bracket, so that the steering gear drives the pendulum mirror to achieve a small range of swing; The base is composed of two cylinders with different diameters, the upper and lower parts are open, and an annular edge is protruded on the inner side. The upper part of the annular edge is used to support the outer ring of the bearing of the azimuth axis system. The lower part of the base is provided with a circular groove, and the circular groove is used to install the stator part of the permanent magnet synchronous motor; a square boss is provided on the outer side of the circumference of the lower half of the base for installing the reading head of the angle encoder; The hollow azimuth shaft body can rotate relative to the base, the center is through, and a plurality of height difference parts are formed on the outer side of the cylindrical surface from top to bottom. The lower end face of the hollow azimuth shaft body is provided with an annular flange to provide positioning for the rotor part installed on the end face; a pair of bearings are arranged on the outer side face of the hollow azimuth shaft body to support the rotation of the hollow azimuth shaft body relative to the base.

2. The connecting rod driven single swing mirror scanning mechanism according to claim 1, characterized in that: It also includes inner and outer pressure rings of the bearing of the azimuth shaft system, which are used to position and provide preload for a pair of bearings of the azimuth shaft system. The outer pressure ring of the bearing is installed on the upper end surface of the base, and the inner pressure ring of the bearing is installed on a height difference portion of the hollow azimuth shaft body.

3. The connecting rod driven single swing mirror scanning mechanism according to claim 2, characterized in that: The upper end of the hollow azimuth axis rotation bracket is provided with a frame structure for installing a servo, and the lower end of the hollow azimuth axis rotation bracket is provided with an annular flange for winding around the code disk part of the encoder and cooperating with the encoder reading head installed on the base to measure the azimuth axis rotation angle in real time.

4. The connecting rod driven single swing mirror scanning mechanism according to claim 3, characterized in that: The pitch drive assembly includes a servo arm, a joint bearing, a connecting rod, a hinge seat, and a hinge pin with a shoulder buckle ring, wherein the servo arm is used to constitute the driving side prime mover crank of the crank-rocker mechanism, the joint bearing and the connecting rod constitute the driving side rocker, the crank and rocker on the driven side; the hinge seat and the hinge pin with a shoulder buckle ring are used to position the crank and rocker, so as to install them at a fixed position on the upper end surface of the hollow azimuth axis rotation bracket.

5. The connecting rod driven single swing mirror scanning mechanism according to claim 4, characterized in that: The pitching and swinging bracket is installed as a connecting rod between the crank and the rocker on the driving side and the driven side.

6. The connecting rod driven single swing mirror scanning mechanism according to claim 1, characterized in that: The single pendulum mirror is elliptical and is fixed on the pitch and swing bracket by gluing.

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