A direct-drive solar wing drive device

Abstract

The present invention relates to a direct-drive solar wing drive device, which relates to the field of spacecraft design technology, and includes: a stepper motor, a limit device and an output connecting shaft; the limit device and the output connecting shaft are respectively connected to the housing and the output shaft of the stepper motor by bolts; the stepper motor includes: a rotor output end flange, a housing end cover, a motor housing, a motor cable, a rotor hollow shaft, a stator coil, stator teeth, rotor teeth and a bearing; the limit device includes: a mounting seat, a limit block and a limit switch. The direct-drive solar wing drive device of the present invention simplifies the two components of the harmonic reducer and the conductive slip ring, and is only composed of a stepper motor and a limit switch; the stepper motor directly provides the torque, and the harmonic reducer's deceleration and torque increase link is omitted; the continuous rotation of the traditional SADA is converted into a reciprocating swing, and the conductive slip ring can be omitted. The direct-drive solar wing drive device of the present invention has a simple and reliable structure, is light in weight, has low cost and high reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of spacecraft design, and in particular to a direct-drive solar wing driving device. Background Art

[0002] The Solar Array Drive Assembly (SADA) drives the solar arrays to maintain continuous solar orientation, maximizing the efficiency of the satellite's solar arrays. It also serves as the energy and signal exchange channel between the satellite and the solar arrays. The SADA consists of two parts: the Solar Array Drive Mechanism (SADM) and the Solar Array Drive Electronics (SADE).

[0003] The SADM is a key component of the power subsystem of spacecraft such as satellites. It controls and drives the positioning and adjustment of solar panels, continuously transmitting the generated electricity to the satellite's power supply unit. Some missions also require the SADM to transmit control and sensor signals, such as panel deployment control signals, deployment status sensor signals, solar sensors, magnetic sensors, surveillance cameras, and temperature sensors. SADMs are typically installed outside the spacecraft, facing the harsh space environment, and require consideration of thermal control and motor operating temperature.

[0004] At present, SADM is usually composed of several parts such as stepper motor, harmonic reducer, bearings and conductive slip rings. It has many components and a relatively complex structure, resulting in high overall cost and poor reliability of SADA. Summary of the Invention

[0005] The present invention aims to solve the technical problems of high overall cost and poor reliability of solar wing drive devices in the prior art, and provides a direct-drive solar wing drive device.

[0006] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0007] A direct-drive solar wing drive device, comprising:

[0008] A stepper motor, a limit device and an output connecting shaft; the limit device and the output connecting shaft are respectively connected to the housing and the output shaft of the stepper motor through bolts;

[0009] The stepper motor includes: rotor output end flange, housing end cover, motor housing, motor cable, rotor hollow shaft, stator coil, stator teeth, rotor teeth and bearings;

[0010] The rotor output flange is connected to the output connecting shaft, the housing end cover is fixed to one side of the motor housing output end, the motor cable is led out from the other side, the stator coil and stator teeth are fixed inside the motor housing, and the rotor hollow shaft is connected to the housing end cover and the motor housing through bearings. The rotor teeth and stator teeth are axially corresponding, and the rotor teeth and stator teeth adopt an unequal tooth pitch design;

[0011] The limit device includes: a mounting seat, a limit block and a travel switch. The two limit blocks are respectively bonded to the mounting seat. The mounting seat and the shell end cover are connected by bolts. The travel switch is set on the limit block.

[0012] In the above technical solution, a relay and an anti-short-circuit resistor R are connected in series between the positive and negative poles of phase A and phase B of the stepper motor; the relay is a normally closed relay. When the stepper motor is working normally, the drive circuit controls the relay to be powered on and disconnected. When the drive circuit is powered off, the relay is connected, so that the coils of each phase of the stepper motor form a closed loop.

[0013] In the above technical solution, the output connecting shaft and the rotor output end flange are connected by bolts.

[0014] In the above technical solution, the rotor teeth and stator teeth are designed with unequal pitch: the number of teeth of the rotor teeth is , the pitch of the rotor teeth , then: the difference between the stator tooth pitch and the rotor tooth pitch is , the stator tooth pitch .

[0015] In the above technical solution, the rotor teeth and stator teeth are designed with unequal tooth pitches as follows:

[0016] If the number of rotor teeth is 50, the pitch of the rotor teeth is 7.2°, and the pitch of the stator teeth is 6.84° or 7.56°;

[0017] Or if the number of rotor teeth is 100, the pitch of the rotor teeth is 3.6°, and the pitch of the stator teeth is 3.42° or 3.78°;

[0018] Or if the number of rotor teeth is 150, the pitch of the rotor teeth is 2.4°, and the pitch of the stator teeth is 2.28° or 2.52°;

[0019] Or if the number of rotor teeth is 200, the pitch of the rotor teeth is 1.8°, and the pitch of the stator teeth is 1.71° or 1.89°.

[0020] The present invention has the following beneficial effects:

[0021] The direct-drive solar wing drive system of the present invention streamlines the harmonic reducer and conductive slip ring components, consisting solely of a stepper motor and a travel switch. The stepper motor directly provides torque, eliminating the need for the harmonic reducer's torque reduction and torque amplification step. By converting the conventional SADA's continuous rotation into a reciprocating oscillation, the conductive slip ring can be omitted. The direct-drive solar wing drive system of the present invention boasts a simple and reliable structure, light weight, low cost, and high reliability.

[0022] The direct-drive solar wing drive device of the present invention simplifies the harmonic reducer, optimizes the design of the stepper motor, and reduces the cogging torque of the stepper motor; the reduction of the step angle and the reduction of the cogging torque will improve the speed stability of the stepper motor during rotation, thereby reducing the impact of the direct-drive solar wing drive device on satellite attitude control.

[0023] The direct-drive solar wing drive device of the present invention connects a relay and an anti-short-circuit resistor in series between the positive and negative terminals of each phase of the stepper motor, thereby preventing the rotor from rotating by providing a resistance torque. The faster the speed, the greater the resistance, which can inhibit the relative rotation of the sailboard and the star body.

[0024] In the direct-drive solar wing drive device of the present invention, the stepper motor adopts a hollow shaft design. The solar wing cable passes through the center of the stepper motor and enters the satellite body, converting the cable swing into torsion, greatly reducing the cable resistance torque and improving the driving torque margin. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Figure 1 Schematic diagram of the structure of the direct-drive solar wing drive device of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of the limiting device and output connecting shaft of the direct-drive solar wing drive device of the present invention;

[0028] Figure 3 Schematic diagram of the external structure of the stepping motor of the direct-drive solar wing drive device of the present invention;

[0029] Figure 4 Schematic diagram of the internal structure of the stepping motor of the direct-drive solar wing drive device of the present invention;

[0030] Figure 5 The direct drive solar wing drive device of the present invention Figure 4 A partial enlarged schematic diagram of the stator teeth and rotor teeth at position A in the middle;

[0031] Figure 6 This is another schematic diagram of the internal structure of a stepper motor of a direct-drive solar wing drive device according to the present invention;

[0032] Figure 7 This is a schematic diagram of the driving circuit of the direct-drive solar wing driving device of the present invention.

[0033] The reference numerals in the figures indicate:

[0034] 1-stepper motor; 101-rotor output flange; 102-housing end cap; 103-motor housing; 104-motor cable; 105-rotor hollow shaft; 106-stator coil; 107-stator teeth; 108-rotor teeth; 109-bearing;

[0035] 2-limit device; 201-mounting seat; 202-limit block; 203-travel switch; 3-output connecting shaft. DETAILED DESCRIPTION

[0036] The inventive concept of the present invention is:

[0037] The direct-drive solar wing drive device of the present invention is a low-cost direct-drive solar wing drive device suitable for micro-nano satellites with requirements such as low cost, light weight, high reliability and mass production.

[0038] The direct-drive solar wing drive device of the present invention solves the problems of poor speed stability, small driving torque, and weak locking performance of the direct-drive configuration through the design of SADM and SADE. More specifically:

[0039] (1) Simplified structure: Traditional SADM is usually composed of several parts such as stepper motor, harmonic reducer, bearing and conductive slip ring, with many components and relatively complex structure. The SADM of the direct-drive solar wing drive device of the present invention simplifies the two components of harmonic reducer and conductive slip ring and only consists of stepper motor and limit switch. The stepper motor directly provides the torque, omitting the deceleration and torque increase link of the harmonic reducer. The present invention optimizes the SADA driving strategy and converts the continuous rotation of the traditional SADA into reciprocating swing, so that the conductive slip ring can be omitted. The SADA of the present invention has a simple and reliable structure, light weight, low cost and high reliability.

[0040] (2) Improve speed stability: The stepper motor of the traditional SADA drives the solar wing to rotate through the harmonic reducer. The deceleration ratio of the harmonic reducer is relatively large, usually reaching 100, which can compensate for the jitter characteristics of the stepper motor and greatly improve the speed stability of the SADA output shaft. The present invention simplifies the harmonic reducer, so that the jitter characteristics of the stepper motor cannot be suppressed, and the speed stability is poor. To solve this problem, the stepper motor is optimized: first, the step angle resolution of the stepper motor is improved by a small step angle design; then, the cogging torque of the stepper motor is reduced by adopting an unequal tooth pitch design for the stator and rotor; the reduction of the step angle and the reduction of the cogging torque will improve the speed stability of the stepper motor during rotation, thereby reducing the influence of SADA on satellite attitude control.

[0041] (3) Suppressing the relative rotation of the sailboard and the star: Due to the presence of the reducer, the power-off holding torque of the stepper motor in the traditional SADA is amplified, and it usually has better locking performance. The power-off holding torque of the direct-drive SADA mainly depends on the cogging torque of the stepper motor. Therefore, the present invention innovatively proposes the following solution: a relay and an anti-short-circuit resistor are connected in series between the positive and negative terminals of each phase of the stepper motor. When the SADE is powered on, the relay is disconnected and the SADE works normally; after the SADE is powered off, the relay is connected, so that each phase of the stepper motor forms a closed coil. When the permanent magnet rotor rotates, according to Faraday's law of electromagnetic induction, an induced electromotive force is generated in the coil. According to Lenz's law, the magnetic field generated by the induced current always hinders the change in the magnetic flux that causes it, so it will provide a resistance torque to prevent the rotor from rotating. The faster the speed, the greater the resistance, which can play a role in suppressing the relative rotation of the sailboard and the star.

[0042] (4) Increased torque margin: The direct-drive solar wing drive device of the present invention eliminates the harmonic reducer, significantly reducing the driving torque. To ensure sufficient torque margin, the resistance torque must be reduced accordingly. Therefore, the present invention proposes a hollow shaft design for the stepper motor. The solar wing cable passes through the center of the stepper motor and enters the satellite body, converting the cable swing into torsion, significantly reducing the cable resistance torque and improving the driving torque margin.

[0043] The direct-drive solar wing drive device provided by the present invention consists of two parts: a solar wing drive mechanism and a solar wing drive circuit. The solar wing drive mechanism includes a stepper motor, a limit device and an output connecting shaft. The stepper motor adopts a small step angle and unequal tooth pitch design of the stator and rotor to improve its speed stability. The limit device includes two limit blocks and two limit switches to calibrate the extreme position of the SADA. The angle between the two limit switches can be designed according to actual needs. The output connecting shaft is used to connect the output shaft of the stepper motor and the solar wing. The solar wing drive circuit short-circuits a relay and an anti-short-circuit resistor between the positive and negative terminals of each phase of the stepper motor, and uses Lenz's law to suppress the relative rotation of the sailboard and the star.

[0044] The present invention will be described in detail below with reference to the accompanying drawings.

[0045] like Figure 1 and 2 As shown, the direct-drive solar wing driving device of the present invention mainly includes: a stepper motor 1, a limiting device 2 and an output connecting shaft 3; the limiting device 2 and the output connecting shaft 3 are respectively connected to the housing and the output shaft of the stepper motor 1 through bolts.

[0046] like Figure 1-6 As shown, the stepper motor 1 includes: a rotor output end flange 101, a housing end cover 102, a motor housing 103, a motor cable 104, a rotor hollow shaft 105, a stator coil 106, stator teeth 107, rotor teeth 108, and bearings 109. The rotor output end flange 101 is connected to the output connecting shaft 3 by bolts, the housing end cover 102 is fixed to one side of the output end of the motor housing 103, and the motor cable 104 is led out from the other side. The stator coil 106 and stator teeth 107 are fixed inside the motor housing 103. The rotor hollow shaft 105 is connected to the housing end cover 102 and the motor housing 103 via bearings 109. The rotor teeth 108 and stator teeth 107 are axially aligned, and the rotor teeth 108 and stator teeth 107 adopt an unequal tooth pitch design.

[0047] The stepper motor 1 of the present invention adopts a small step angle design (0.9°), corresponding to a rotor tooth 108 having 100 teeth and a tooth pitch of 3.6°. Calculations of the cogging torque of the stepper motor 1 show that when the stator tooth 107 pitch is 3.6±0.18°, the lowest-order harmonic component in the total air gap permeance of the stepper motor 1 is eliminated, significantly reducing the cogging torque. Therefore, the pitches of the stator teeth 107 and rotor teeth 108 are set at 3.78° and 3.6°, respectively.

[0048] In the present invention, the principle of the stepper motor 1 adopting the design of small step angle and unequal pitch of stator and rotor is: the stepper motor 1 is a two-phase hybrid stepper motor, when the number of teeth of the rotor teeth 108 is , then the pitch of the rotor teeth 108 After calculating the cogging torque of the stepper motor 1, the difference between the pitch of the stator teeth 107 and the pitch of the rotor teeth 108 is When , the lowest-order harmonic component in the total air gap permeance of the stepper motor 1 is eliminated, and the cogging torque is greatly reduced.

[0049] In other specific embodiments, the rotor teeth 108 and the stator teeth 107 are designed with unequal tooth pitches to meet the following requirements: the number of teeth of the rotor teeth 108 is , the pitch of rotor teeth 108 , then: The difference between the pitch of the stator teeth 107 and the pitch of the rotor teeth 108 is , the pitch of stator teeth 107 .

[0050] For example:

[0051] If the number of teeth of the rotor teeth 108 is 50, the pitch of the rotor teeth 108 is 7.2°, and the pitch of the stator teeth 107 is 6.84° or 7.56°;

[0052] If the number of teeth of the rotor teeth 108 is 100, the pitch of the rotor teeth 108 is 3.6°, and the pitch of the stator teeth 107 is 3.42° or 3.78°;

[0053] If the number of teeth of the rotor teeth 108 is 150, the pitch of the rotor teeth 108 is 2.4°, and the pitch of the stator teeth 107 is 2.28° or 2.52°;

[0054] If the number of rotor teeth 108 is 200, the pitch of the rotor teeth 108 is 1.8°, and the pitch of the stator teeth 107 is 1.71° or 1.89°. See Table 1 below for details.

[0055] Table 1 Stepper motor parameters

[0056]

[0057] The parameter value ranges described in this embodiment are intended only as examples to illustrate the core mechanism of the unequal pitch design. Their specific values ​​do not constitute the sole limiting feature of the scope of protection of the claims. Any technical solution that achieves an equivalent technical effect by adjusting the process parameter values ​​while essentially following the technical principles and creative design ideas described in this invention shall fall within the scope of protection covered by the present invention's principle of determining equivalent infringement.

[0058] like Figure 7 As shown, a relay and an anti-short-circuit resistor R are connected in series between the positive and negative poles of phases A and B of the stepper motor 1. The relay is a normally closed relay. When the stepper motor 1 is operating normally, the drive circuit controls the relay to be powered on and disconnected. When the drive circuit is powered off, the relay is closed, forming a closed loop for the single-phase coil of the stepper motor 1.

[0059] like Figure 2 As shown, the limit device 2 includes: a mounting seat 201, a limit block 202 and a travel switch 203. The two limit blocks 202 are respectively bonded to the mounting seat 201 at specific angles. The mounting seat 201 and the shell end cover 102 are connected by bolts. The travel switch 203 is set on the limit block 202.

[0060] The control strategy of the direct-drive solar wing drive device of the present invention is to convert the continuous rotation of the traditional solar wing drive device (SADA) into reciprocating swing.

[0061] When driving the solar wing to orient itself towards the sun, traditional SADA usually needs to respond in real time and rotate continuously according to the signal from the sun sensor, and the maximum rotation angle is generally greater than 360°. In order to avoid cable entanglement or strangulation, conductive slip rings are required to transmit energy and signals, but this will introduce new sources of failure and reduce reliability. After analyzing the laws of satellite in-orbit motion, the SADA rotation angle range can be controlled to below 360°, and the use of a reciprocating swing drive method can also avoid cable entanglement or strangulation. Therefore, the direct-drive solar wing drive device of the present invention can omit the conductive slip ring component. The significant advantages of this control strategy are high reliability and low cost.

[0062] The direct-drive solar wing drive device of the present invention simplifies the harmonic reducer and optimizes the design of the stepper motor 1: first, the step angle resolution of the stepper motor 1 is improved by designing a small step angle; then, the stator and rotor are designed with unequal tooth pitches to reduce the cogging torque of the stepper motor 1; the reduction of the step angle and the reduction of the cogging torque will both improve the speed stability of the stepper motor 1 during rotation, thereby reducing the impact of the direct-drive solar wing drive device of the present invention on satellite attitude control.

[0063] The direct-drive solar wing drive device of the present invention features a relay and short-circuit protection resistor R connected in series between the positive and negative terminals of each phase of the stepper motor 1 (i.e., between the positive and negative terminals of phases A and B). When the SADE is powered on, the relay disconnects, allowing the SADE to operate normally. When the SADE is powered off, the relay connects, forming a closed coil for each phase of the stepper motor 1. When the permanent magnet rotor rotates, an induced electromotive force is generated in the coil according to Faraday's law of electromagnetic induction. According to Lenz's law, the magnetic field generated by the induced current always opposes the change in magnetic flux that causes it, thus providing a resistive torque that prevents rotor rotation. The faster the speed, the greater the resistance, thus inhibiting the relative rotation of the sailboard and the planet.

[0064] In the direct-drive solar wing drive device of the present invention, the stepper motor 1 adopts a hollow shaft design. The solar wing cable passes through the center of the stepper motor 1 and enters the satellite body, converting the cable swing into torsion, greatly reducing the cable resistance torque and improving the driving torque margin.

[0065] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A direct-drive solar wing drive device, characterized in that: include: A stepper motor (1), a limiting device (2) and an output connecting shaft (3); the limiting device (2) and the output connecting shaft (3) are respectively connected to the housing and the output shaft of the stepper motor (1) by bolts; The stepper motor (1) comprises: a rotor output end flange (101), a housing end cover (102), a motor housing (103), a motor cable (104), a rotor hollow shaft (105), a stator coil (106), stator teeth (107), rotor teeth (108) and a bearing (109); The rotor output end flange (101) is connected to the output connecting shaft (3), the housing end cover (102) is fixed to one side of the output end of the motor housing (103), the motor cable (104) is led out from the other side, the stator coil (106) and the stator teeth (107) are fixed inside the motor housing (103), the rotor hollow shaft (105) is connected to the housing end cover (102) and the motor housing (103) through the bearing (109), the rotor teeth (108) and the stator teeth (107) are axially corresponding, and the rotor teeth (108) and the stator teeth (107) are designed with unequal tooth pitch; The limiting device (2) comprises: a mounting seat (201), a limiting block (202) and a travel switch (203), wherein the two limiting blocks (202) are respectively bonded to the mounting seat (201), the mounting seat (201) and the housing end cover (102) are connected by bolts, and the travel switch (203) is arranged on the limiting block (202).

2. The direct-drive solar wing drive device according to claim 1, characterized in that: A relay and an anti-short-circuit resistor R are connected in series between the positive and negative poles of the A phase and the B phase of the stepper motor (1); the relay is a normally closed relay. When the stepper motor (1) is working normally, the drive circuit controls the relay to be powered on and disconnected. When the drive circuit is powered off, the relay is connected, so that the coils of each phase of the stepper motor (1) form a closed loop.

3. The direct-drive solar wing drive device according to claim 1, characterized in that: The output connecting shaft (3) and the rotor output end flange (101) are connected by bolts.

4. The direct-drive solar wing drive device according to claim 1, characterized in that: The rotor teeth (108) and the stator teeth (107) are designed with unequal tooth pitches, specifically: The number of teeth of the rotor teeth (108) is , the pitch of the rotor teeth (108) ,but: The difference between the pitch of the stator teeth (107) and the pitch of the rotor teeth (108) is , the pitch of the stator teeth (107) .

5. The direct-drive solar wing drive device according to claim 4, characterized in that: The rotor teeth (108) and the stator teeth (107) are designed with unequal tooth pitches, specifically: The number of teeth of the rotor teeth (108) is 50, the pitch of the rotor teeth (108) is 7.2°, and the pitch of the stator teeth (107) is 6.84° or 7.56°; Or if the number of the rotor teeth (108) is 100, the pitch of the rotor teeth (108) is 3.6°, and the pitch of the stator teeth (107) is 3.42° or 3.78°; Or if the number of the rotor teeth (108) is 150, the pitch of the rotor teeth (108) is 2.4°, and the pitch of the stator teeth (107) is 2.28° or 2.52°; Or if the number of the rotor teeth (108) is 200, the pitch of the rotor teeth (108) is 1.8°, and the pitch of the stator teeth (107) is 1.71° or 1.89°.

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