Wide-working-interval limited-angle motor and dynamic switching method thereof

Abstract

The invention aims to provide a wide-working-interval limited-angle motor and a dynamic switching method thereof, and belongs to the field of motors. Comprising a shell, a front connecting shaft, a rear connecting shaft and a permanent magnet installation shaft, a front end cover and a rear end cover are installed at the left end and the right end of the shell respectively, the front connecting shaft is installed in the front end cover through a first bearing, the rear connecting shaft is installed in the rear end cover through a second bearing, and the end of the front connecting shaft and the end of the rear connecting shaft are installed in the permanent magnet installation shaft respectively. The front connecting shaft and the rear connecting shaft are connected with the permanent magnet mounting shaft in a matched mode through shaft holes and are matched with key grooves through keys, the permanent magnet is mounted on the permanent magnet mounting shaft, the encoder frame is mounted on the rear end cover, the encoder circuit board is mounted on the encoder frame, and the encoder permanent magnet is mounted at the position, opposite to the encoder circuit board, of the rear connecting shaft. A magnet yoke is installed between the front end cover and the rear end cover. The problems that the permanent magnet synchronous motor is complex in reciprocating operation control and slow in response, and a limited-angle motor cannot rotate in a whole circle can be solved.

Description

Technical Field

[0001] The present invention relates to a motor and a control method thereof. Background Art

[0002] Electromagnetic actuators, devices that convert electrical energy into mechanical energy, are widely used in industrial manufacturing, transportation, robotics, aerospace, and the energy industry. Automated production, intelligent manufacturing, and human-machine collaboration are emerging trends in industrial development. As a core component of intelligent actuation, electromagnetic actuators, through interaction with sensors, control systems, and other equipment, can achieve automation, intelligence, and flexibility.

[0003] As the core component of the electromagnetic drive system, the motor's drive form determines the operating characteristics of the drive mechanism. Permanent magnet synchronous motors combined with position servo control methods can achieve movement at any angle, but they have the disadvantages of complex drive control, high cost, and difficult maintenance. Stepper motors can also achieve movement at any angle under open-loop control, but they have the disadvantages of low efficiency, slow response, low precision, and are prone to loss of steps under high-speed conditions. Rotary voice coil motors have the characteristics of high precision and high acceleration, but their torque density is low and they cannot be used in occasions with limited volume. Moreover, they can only achieve repeated yaw motion.

[0004] Limited-angle motors offer the advantages of simple structure, easy control, and high reliability. They are widely used in specialized technologies or complex control applications, such as imaging coverage drive systems, laser scanning drive systems, and joint drive systems for specialized industrial assembly robots. With increasing flexibility and control stability, their application areas are expanding, and they are becoming a hot topic of research and interest for scholars. However, limited-angle electromagnetic drive mechanisms can only achieve repetitive yaw motion and have a limited control angle. This makes them incapable of achieving full rotation for specialized drive requirements, such as panoramic imaging, 360-degree scanning ranging, and rotary joints. Summary of the Invention

[0005] The purpose of the present invention is to provide a wide working range limited angle motor and its dynamic switching method that can solve the problems of complex reciprocating operation control and slow response of existing permanent magnet synchronous motors and the inability of limited angle motors to rotate a full circle.

[0006] The object of the present invention is achieved like this:

[0007] The present invention provides a motor with a wide working range and limited rotation angle, which is characterized by comprising a housing, a front connecting shaft, a rear connecting shaft, and a permanent magnet mounting shaft, wherein a front end cover and a rear end cover are respectively installed at the left and right ends of the housing, the front connecting shaft is installed in the front end cover through a first bearing, and the rear connecting shaft is installed in the rear end cover through a second bearing, the end portions of the front connecting shaft and the rear end of the rear connecting shaft are respectively installed in the permanent magnet mounting shaft, the front connecting shaft and the rear connecting shaft are connected to the permanent magnet mounting shaft through shaft holes, and are matched with keys and keyways, the permanent magnet is installed on the permanent magnet mounting shaft, the rear end cover is installed with an encoder frame, an encoder circuit board is installed on the encoder frame, an encoder permanent magnet is installed at a position opposite to the encoder circuit board of the rear connecting shaft, and a yoke is installed between the front end cover and the rear end cover by screws.

[0008] The motor with a wide working range and limited rotation angle according to the present invention may further include:

[0009] 1. The permanent magnet includes a first permanent magnet and a second permanent magnet. The first permanent magnet and the second permanent magnet are arc-shaped and attached to the permanent magnet mounting axis. The first permanent magnet and the second permanent magnet have the same structure and opposite magnetization directions.

[0010] 2. The magnetic yoke is a split magnetic yoke, including a first magnetic yoke and a second magnetic yoke. The first magnetic yoke and the second magnetic yoke have the same structure and are connected by a convex semicircle and a concave semicircle at both ends.

[0011] 3. The main winding and the secondary winding are wound on the magnetic yoke. The main winding includes a first main winding and a second main winding. The first main winding and the second main winding have the same cross-sectional area, the same number of turns, and opposite current directions. The first main winding and the second main winding are connected in series; the secondary winding includes a first winding and a second winding. The first winding and the second winding have the same cross-sectional area, the same number of turns, and opposite current directions. The first winding and the second winding are connected in series.

[0012] 4. The mechanical angle occupied by the permanent magnet is smaller than the mechanical angle occupied by the main winding, but larger than the mechanical angle occupied by the secondary winding.

[0013] 5. The front end cover is provided with a front end flow distribution hole and a front end cover flow distribution groove, the rear end cover is provided with a rear end flow distribution hole and a rear end cover flow distribution groove, and a circular flow channel is provided in the outer shell. The front end flow distribution hole, the front end cover flow distribution groove, the circular flow channel, the rear end cover flow distribution groove, and the rear end flow distribution hole are connected in sequence.

[0014] 6. The distance between the encoder circuit board and the encoder permanent magnet should not exceed 1mm.

[0015] A dynamic switching method for a wide operating range, limited-angle motor according to the present invention is characterized by employing the wide operating range, limited-angle motor described above, and further comprising a drive circuit, a self-control circuit, and an inverter circuit. The inverter circuit comprises a DC power supply, first to eighth switching tubes, wherein the first to fourth switching tubes are connected to a primary winding, and the fifth to eighth switching tubes are connected to a secondary winding. All switching tubes include a gate, a source, and a drain. The drive circuit receives instructions from the self-control circuit and generates eight PWM signals corresponding to the first to eighth switching tubes, respectively. The gate receives the PWM signal. The sources of the first, second, fifth, and sixth switching tubes are connected to a high-voltage terminal of the DC power supply. The drains of the first, second, fifth, and sixth switching tubes are connected to the sources of the third, fourth, seventh, and eighth switching tubes, respectively. The drains of the third, fourth, seventh, and eighth switching tubes are connected to the negative electrode of the DC power supply. The first to fourth switching tubes form a first H-bridge circuit, and the fifth to eighth switching tubes form a second H-bridge circuit.

[0016] The method for dynamic switching of a motor with a wide working range and limited rotation angle according to the present invention may further include:

[0017] 1. Turn on the first and fourth switch tubes, turn off the remaining switch tubes, the main winding is energized in the forward direction, and the limited-angle motor rotates in the forward direction; turn on the second and third switch tubes, turn off the remaining switch tubes, the main winding is energized in the reverse direction, and the limited-angle motor rotates in the reverse direction, thereby achieving reciprocating rotation of the limited-angle motor.

[0018] 2. Turn on the first, fourth, fifth, and eighth switching tubes, and turn off the other switching tubes. The main winding and the secondary winding are energized in the forward direction, and the limited-angle motor rotates in the forward direction. Turn on the second, third, sixth, and seventh switching tubes, and turn off the other switching tubes. The main winding and the secondary winding are energized in the reverse direction, and the limited-angle motor rotates in the reverse direction. This enables the limited-angle motor to rotate continuously throughout a full cycle.

[0019] The advantages of the present invention are:

[0020] 1. The main winding of the present invention has a uniform excitation current in the reciprocating working mode and can reach the maximum current. Compared with the permanent magnet synchronous motor, the torque density is higher.

[0021] 2. The present invention only requires four switching tubes to achieve reciprocating operation in the reciprocating working mode. Compared with the permanent magnet synchronous motor, the drive and control are simpler.

[0022] 3. The present invention utilizes the coordinated work of the primary winding and the secondary winding to achieve full rotation of the slotless motor, and has a larger working range compared to a limited-angle motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is the AA section view;

[0024] Figure 2 This is a front view of a motor with a limited rotation angle and a wide working range without a front cover;

[0025] Figure 3 It is the front view of the motor with limited rotation angle without front cover and wide working range of winding;

[0026] Figure 4 It is the BB cross-sectional view;

[0027] Figure 5 The front and rear views of the motor;

[0028] Figure 6 This is the drive system diagram of the permanent magnet motor with a wide working range;

[0029] Figure 7 It is a structural diagram of the switch tube;

[0030] Figure 8 The motor torque characteristic diagrams of the two modes. DETAILED DESCRIPTION

[0031] The present invention will be described in more detail below with reference to the accompanying drawings:

[0032] Combine Figure 1-8The present invention discloses a wide working range limited angle motor comprising a rotor component, a stator component, and a feedback component; the rotor component comprises a permanent magnet mounting shaft 7, a permanent magnet 9, a front connecting shaft 6, and a rear connecting shaft 2; the stator component comprises a split yoke 11, a main winding 12, a secondary winding 4, a housing 10, a front cover 8, and a rear cover 1; and the feedback component comprises an encoder permanent magnet 14, an encoder circuit board 3, and an encoder frame 13. The front cover 8 is mounted in the left hole of the motor housing 10, and the rear cover 1 is mounted in the right hole of the housing 10. The front connecting shaft 6 is mounted in the front cover 8 via a bearing 5, and the rear connecting shaft 2 is mounted in the rear cover via a bearing 15. The front connecting shaft 6 is mounted in the left hole of the permanent magnet mounting shaft 7, and the rear connecting shaft 2 is mounted in the right hole of the permanent magnet mounting shaft 7. The front connecting shaft 6 and the rear connecting shaft 2 are connected to the permanent magnet mounting shaft 7 through shaft holes, and a key and keyway are used to prevent the parts from rotating relative to each other. The permanent magnet 9 is adhered to the permanent magnet mounting shaft 7 by means of structural adhesive. The permanent magnet 9 is arc-shaped, and its center coincides with the center of the permanent magnet mounting shaft. The front connecting shaft 6 is the power output shaft, which is connected to the load through this shaft. The rear connecting shaft 2 is the feedback sensing shaft, and an encoder permanent magnet 14 is installed at the end of this shaft. The encoder permanent magnet 14 is located at the axis center of the rear connecting shaft 2. The encoder frame 13 is installed on the rear end cover 1. The encoder frame 13 is used to install the encoder circuit board 3. The installation distance of the encoder circuit board 3 must ensure that the distance from the encoder permanent magnet 14 is no more than 1 mm. The chip on the encoder board 3 is facing the center of the encoder permanent magnet 14. The chip on the encoder board 3 can detect the change in the magnetic field, thereby obtaining the angle of the motor rotor. The split yoke 11 is formed by Figure 4 Screws 802, 804, 104, and 106 are shown securing the front cover 8 and rear cover 1. The primary winding 12 and secondary winding 4 are wound around a split yoke. The front cover 8, front connecting shaft 6, housing 10, permanent magnet mounting shaft 7, permanent magnet 9, split yoke 11, rear connecting shaft 2, rear cover 1, encoder seat 13, and encoder permanent magnet 14 are all coaxial. The permanent magnet mounting shaft 7, front connecting shaft 6, and rear connecting shaft 2 are all hollow structures to reduce inertial forces during movement. Housing 10 protects the winding coils and contains coolant channels.

[0033] like Figure 2As shown, the main winding 12 and secondary winding 4 of the wide operating range limited angle motor are independent of each other. The main winding 12 consists of a first main winding 121 and a second main winding 122. The first and second main windings 121 and 122 have the same cross-sectional area, the same number of turns, and opposite current directions. The first and second main windings 121 and 122 are connected in series. The secondary winding 4 consists of a first winding 41 and a second winding 42. The first and second windings 41 and 42 have the same cross-sectional area, the same number of turns, and opposite current directions. The first and second windings 41 and 42 are connected in series. The permanent magnet 9 consists of a first permanent magnet 91 and a second permanent magnet 92. The first and second permanent magnets 91 and 92 have the same structural dimensions and opposite magnetization directions. The mechanical angle occupied by the permanent magnet 9 is smaller than that occupied by the main winding 12, but larger than that occupied by the secondary winding 4.

[0034] like Figure 3 As shown, the split yoke 11 of the wide operating range slotless motor consists of a first yoke 111 and a second yoke 112. The first and second yokes 111 and 112 have identical structures. The split yoke design utilizes the convex and concave semicircular sides to simplify winding fabrication. The split yoke 11 is installed in the housing 10 and secured to the housing's side guide slots 102 via yoke side fins 113.

[0035] like Figure 4 As shown, the split yoke 11 in the stator assembly is fixed to the front cover 8 and the rear cover 1 by screws 802, 804, 104, and 106. The distance between the stator and the front cover 8 is determined by stator locating pins 803 to ensure that the split yoke 11 and the rotor assembly are not misaligned, ensuring the torque output capacity of the motor.

[0036] Motor coolant from Figure 5 As shown, the flow flows into the front cover distribution hole 805, is distributed to the circular flow channel 101 through the front cover distribution groove 801, flows into the rear cover distribution groove 103 through the circular flow channel 101, and finally flows out of the motor through the rear cover distribution hole 107. Figure 2 As shown, the circular flow channel 101 is a flow channel that is connected front to back and has a circular shape and is evenly distributed around the circumference. The seal between the end cover and the motor housing is achieved by an elastic sealing gasket installed in the sealing gasket groove 105.

[0037] like Figure 6As shown, the drive system for a wide-operating-range, limited-angle motor consists of a monitoring computer, acquisition and control circuits, a drive circuit, current sensing, a load, an encoder, and an inverter circuit. The monitoring computer displays the motor's operating status, including current, speed, angle, and switch status monitoring. The acquisition and control circuit receives current and angle information from the current sensing sensor and encoder, performing filtering and feedback calculations. The drive circuit receives instructions from the control circuit and generates eight PWM signals in a specific format. The current sensing circuit is connected in series with the primary winding 12 and the secondary winding 4 to detect the line currents in the primary and secondary windings. The encoder detects the rotor angle. The inverter circuit consists of a DC power supply, switches Q1-Q8, the primary winding 12, the secondary winding 4, and connecting wires. The primary and secondary windings 12 and 4 are wound on the split magnetic yoke 11 mounted on the motor. The switch tubes Q1-Q4 are connected to the primary winding 12, and the switch tubes Q5-Q8 are connected to the secondary winding 4. The primary winding 12 and the secondary winding 4 are independent of each other. Figure 7 As shown, it has a gate, source, and drain. The gate receives a PWM signal, turning on a high-level switch and off a low-level switch. The sources of switches Q1, Q2, Q5, and Q6 are connected to the high-voltage terminal of a DC power supply. The drains of switches Q1, Q2, Q5, and Q6 are connected to the sources of switches Q3, Q4, Q7, and Q8, respectively. The drains of switches Q3, Q4, Q7, and Q8 are connected to the negative terminal of the DC power supply. Switches Q1-Q4 form an H-bridge circuit, and switches Q5-Q8 form another H-bridge circuit. By adjusting the switching states of switches Q1-Q8, currents of specific magnitude and direction are given to the primary winding 12 and the secondary winding 4, generating a specific stator magnetic field. Under the combined action of the stator and rotor components, the motor operates in a specific manner.

[0038] When the switches Q1 and Q4 are turned on and the other switches are turned off, the main winding of the limited-angle motor is energized in the positive direction, and the motor rotates in the positive direction. The electromagnetic torque of the motor changes with the rotor angle. Figure 8 As shown in the "Mode 1 (Q1Q4-Open)" curve, the motor's operating range is Figure 8 In "Operating Range Mode 1," torque remains essentially constant within the operating range. Conversely, when switches Q2 and Q3 are on and the remaining switches are off, the limited-angle motor's main winding is energized in the reverse direction. The motor torque becomes negative within Operating Range Mode 1, and the motor rotates in the reverse direction. In this mode, combined with encoder feedback, closed-loop motor angle control is achieved, enabling the motor to reciprocate at a specific angle within Operating Range Mode 1.

[0039] When the switches Q1, Q4, Q5, and Q8 are turned on and the other switches are turned off, the primary and secondary windings of the limited-angle motor are energized in the forward direction, and the electromagnetic torque changes with the rotor angle. Figure 8 As shown in the "Mode 2 (Q1Q4, Q5Q8 - Q8 on)" curve, compared to the "Mode 1 (Q1Q4 - on)" curve, the electromagnetic torque in this case is non-zero at rotor angles of -90° and +90°, overcoming the electromagnetic torque dead point in Mode 1. This electromagnetic torque enables forward rotation of the motor. When switches Q2, Q3, Q6, and Q7 are on and the other switches are off, the primary and secondary windings of the limited-angle motor are energized in opposite directions, causing the motor to rotate in the reverse direction. Combined with the angle information fed by the encoder, continuous full-circle rotation of the motor in a specific direction and speed can be achieved.

Claims

1. A motor with a wide operating range and limited rotation angle, characterized by: It includes a shell, a front connecting shaft, a rear connecting shaft, and a permanent magnet mounting shaft. The front end cover and the rear end cover are respectively installed on the left and right ends of the shell. The front connecting shaft is installed in the front end cover through a first bearing, and the rear connecting shaft is installed in the rear end cover through a second bearing. The end portions of the front connecting shaft and the rear connecting shaft are respectively installed in the permanent magnet mounting shaft. The front connecting shaft and the rear connecting shaft are connected to the permanent magnet mounting shaft through shaft holes and are matched with keys and keyways. The permanent magnet is installed on the permanent magnet mounting shaft. The encoder frame is installed on the rear end cover, and the encoder circuit board is installed on the encoder frame. The encoder permanent magnet is installed at a position opposite to the encoder circuit board of the rear connecting shaft. The yoke is installed between the front end cover and the rear end cover by screws.

2. The wide operating range limited angle motor according to claim 1, characterized in that: The permanent magnet includes a first permanent magnet and a second permanent magnet. The first permanent magnet and the second permanent magnet are arc-shaped and attached to the permanent magnet installation axis. The first permanent magnet and the second permanent magnet have the same structure and opposite magnetization directions.

3. The wide operating range limited angle motor according to claim 1, characterized in that: The magnetic yoke is a split magnetic yoke, comprising a first magnetic yoke and a second magnetic yoke. The first magnetic yoke and the second magnetic yoke have the same structure and are connected by a convex semicircle and a concave semicircle at both ends.

4. The wide operating range limited angle motor according to claim 1, characterized in that: The main winding and the secondary winding are wound on the magnetic yoke. The main winding includes a first main winding and a second main winding. The first main winding and the second main winding have the same cross-sectional area, the same number of turns, and opposite current directions. The first main winding and the second main winding are connected in series; the secondary winding includes a first winding and a second winding. The first winding and the second winding have the same cross-sectional area, the same number of turns, and opposite current directions. The first winding and the second winding are connected in series.

5. The wide operating range limited angle motor according to claim 4, characterized in that: The mechanical angle occupied by the permanent magnet is smaller than the mechanical angle occupied by the primary winding and larger than the mechanical angle occupied by the secondary winding.

6. The motor with wide working range and limited rotation angle according to claim 1 is characterized in that: The cover is provided with a front flow distribution hole and a front cover flow distribution groove, the rear cover is provided with a rear flow distribution hole and a rear cover flow distribution groove, and a circular flow channel is provided in the outer shell. The front flow distribution hole, the front cover flow distribution groove, the circular flow channel, the rear cover flow distribution groove, and the rear flow distribution hole are connected in sequence.

7. The wide operating range limited angle motor according to claim 1, characterized in that: The distance between the encoder circuit board and the encoder permanent magnet should not exceed 1 mm.

8. A method for dynamic switching of a motor with a wide operating range and limited rotation angle, characterized by: The wide operating range limited angle motor according to claim 1 further includes a drive circuit, a self-control circuit, and an inverter circuit. The inverter circuit includes a DC power supply and first to eighth switching tubes. The first to fourth switching tubes are connected to the primary winding, and the fifth to eighth switching tubes are connected to the secondary winding. All switching tubes include gates, sources, and drains. The drive circuit receives instructions from the self-control circuit and generates eight PWM signals corresponding to the first to eighth switching tubes, respectively. The gates receive the PWM signals. The sources of the first, second, fifth, and sixth switching tubes are connected to the high voltage terminal of the DC power supply. The drains of the first, second, fifth, and sixth switching tubes are connected to the sources of the third, fourth, seventh, and eighth switching tubes, respectively. The drains of the third, fourth, seventh, and eighth switching tubes are connected to the negative electrode of the DC power supply. The first to fourth switching tubes form a first H-bridge circuit, and the fifth to eighth switching tubes form a second H-bridge circuit.

9. The method for dynamic switching of a motor with a wide operating range and limited rotation angle according to claim 8, characterized in that: Turn on the first and fourth switch tubes, turn off the remaining switch tubes, the main winding is energized in the forward direction, and the limited-angle motor rotates in the forward direction; turn on the second and third switch tubes, turn off the remaining switch tubes, the main winding is energized in the reverse direction, and the limited-angle motor rotates in the reverse direction, thereby achieving reciprocating rotation of the limited-angle motor.

10. The method for dynamic switching of a motor with a wide operating range and limited rotation angle according to claim 8, wherein: The first, fourth, fifth, and eighth switching tubes are turned on, and the other switching tubes are turned off. The primary winding and the secondary winding are energized in the forward direction, and the limited-angle motor rotates in the forward direction. The second, third, sixth, and seventh switching tubes are turned on, and the other switching tubes are turned off. The primary winding and the secondary winding are energized in the reverse direction, and the limited-angle motor rotates in the reverse direction. Thus, the limited-angle motor can rotate continuously throughout a full circle.

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