Two-phase brushless direct current motor, driving device thereof and cleaning robot
By using a combination of bridge switching circuit and single-phase brushless DC motor chip in a two-phase brushless DC motor drive device, the problems of complexity and low integration of the existing drive device are solved, and the high integration of the drive device is achieved and miniaturize.
Patent Information
- Application Number
- CN202420139169.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-19
- Publication Date
- 2025-02-07
- Estimated Expiration
- 2034-01-19
AI Technical Summary
The circuit structure of the existing two-phase brushless DC motor drive device is complex and has low integration, which leads to a large space size of the drive device, affecting miniaturization.
It adopts a bridge switching circuit composed of 4 switching tubes, and connects the stator coil of the two-phase brushless DC motor in parallel with the switching tube in the bridge switching circuit, and combines the bridge switching circuit of the single-phase brushless DC motor chip. Implement the function of driving a two-phase brushless DC motor.
The integration of the drive device is improved, the circuit structure is simplified, the space occupation is reduced, and the drive device is miniaturized, and the drive device can be packaged in a two-phase brushless DC motor to form an integrated design.
Smart Images
Figure CN222441576U_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of motor drive circuits, and in particular to a two-phase brushless DC motor and a drive device thereof, and a cleaning robot. Background Art
[0002] A brushless DC motor is a motor without brushes and commutator (or collector ring), also known as a commutatorless motor. It is mainly composed of a rotor made of permanent magnetic material, a stator with coil windings, and a position sensor. The drive current flowing through the stator coil is provided by the drive device. When the drive device outputs the drive current, the stator coil is excited, thereby driving the rotor to rotate.
[0003] The structure of a two-phase brushless motor is similar to that of a three-phase brushless motor, both consisting of a rotor and a stator, but a two-phase brushless motor has only two-phase stator coils. When the two-phase stator coils are excited in sequence, the rotor is driven to rotate. The control of a two-phase brushless motor is relatively simple and has low power. It is usually used in low-power, low-speed application scenarios such as household appliances, toys, and small robots.
[0004] See also Figure 1 As shown, Figure 1 FIG. 1 is a schematic diagram of an existing driving device for driving a two-phase brushless motor. The two stator coils are connected in series between two MOS switch tubes and a driving power supply. Figure 1 In the embodiment, stator coil 1 is connected in series between the driving power supply and the switch tube Q7, and stator coil 2 is connected in series between the driving power supply and the switch tube Q8. Clamping diodes are connected in parallel at both ends of the stator coils to prevent instantaneous reverse electromotive force from being applied to the stator coils. The position signal from the position sensor controls the alternating conduction of the two switch tubes Q7 and Q8, that is, when Q7 is turned on, Q8 is turned off, and when Q7 is turned off, Q8 is turned on. In order to realize the alternating conduction of the two switch tubes Q7 and Q8, two opposite switch control signals are usually applied to the gates of the two switch tubes, such as Figure 1 The switch control circuit 1 is used to output the switch control signal 1 of the switch tube Q7, and the switch control circuit 2 is used to output the switch control signal 2 of the switch tube Q8, wherein the input end of the switch control circuit 1 is electrically connected to the output end of the position sensor, and the input end of the switch control circuit 2 is electrically connected to the drain of the switch tube Q7. The switch control circuit usually includes a three-stage tube and its peripheral resistors, and is electrically connected to the switch control power supply. The switch control power supply can be provided by an independent power supply chip.
[0005] The existing driving device has a complex circuit structure and low circuit integration, which results in a relatively large space size of the driving device, seriously affecting miniaturization. Summary of the invention
[0006] The utility model provides a two-phase brushless DC motor and a driving device thereof, and a cleaning robot, which are beneficial to improving the integration of the driving device.
[0007] The first aspect of the utility model provides a two-phase brushless DC motor driving device, the device comprising:
[0008] A bridge switch circuit composed of four switch tubes, wherein one end of the first switch tube is connected in series with one end of the second switch tube, one end of the third switch tube is connected in series with one end of the fourth switch tube, the other end of the first switch tube is connected in parallel with the other end of the third switch tube, the other end of the second switch tube is connected in parallel with the other end of the fourth switch tube, the node where the first switch tube and the third switch tube are connected in parallel is electrically connected to one end of a driving power supply, and the node where the second switch tube and the fourth switch tube are connected in parallel is electrically connected to the other end of the driving power supply,
[0009] When the first switch tube and the fourth switch tube are turned on, the third switch tube and the fourth switch tube are turned off.
[0010] When the first switch tube and the fourth switch tube are turned off, the third switch tube and the fourth switch tube are turned on.
[0011] Each switch tube is switched on and off alternately.
[0012] The first stator coil of the two-phase brushless DC motor is connected in parallel with the two ends of the first switch tube, and the second stator coil is connected in parallel with the two ends of the third switch tube; or, the first stator coil of the two-phase brushless DC motor is connected in parallel with the two ends of the second switch tube, and the second stator coil is connected in parallel with the two ends of the fourth switch tube.
[0013] Preferably, the switch tube is an N-channel field effect tube.
[0014] Preferably, the source of the first switch tube is electrically connected to the drain of the second switch tube, and the source of the third switch tube is electrically connected to the drain of the fourth switch tube.
[0015] The drain of the first switch tube is electrically connected to the drain of the third switch tube, and is electrically connected to the high potential end of the driving power supply. The source of the second switch tube is electrically connected to the source of the fourth switch tube, and is electrically connected to the low potential end of the driving power supply.
[0016] Two ends of the first stator coil are electrically connected to the drain of the first switch tube and the source of the first switch tube respectively.
[0017] The two ends of the second stator coil are electrically connected to the drain of the first switch tube and the source of the second switch tube respectively.
[0018] The gate of each switch tube is electrically connected to the output end of the switch control circuit, and the input end of the switch control circuit is electrically connected to the output end of the position sensor.
[0019] Preferably, the switch tube and the switch control circuit are integrated into a driving chip.
[0020] Preferably, the driving chip is a single-phase brushless DC motor chip for driving a single-phase brushless DC motor, and the chip at least has: an external power pin for an external power supply, a first coil pin and a second coil pin for connecting a stator coil, a sensor power pin for providing a working power supply to a position sensor, and a position signal input pin for inputting a position signal from the position sensor.
[0021] The first stator coil is electrically connected between the external power supply pin and the first coil pin.
[0022] The second stator coil is electrically connected between the external power supply pin and the second coil pin.
[0023] The output end of the position sensor is electrically connected to the input pin.
[0024] The power supply terminal of the position sensor is electrically connected to the sensor power supply pin.
[0025] Preferably, the position signal input pin includes a first position signal input pin and a second position signal input pin.
[0026] The differential signal output by the position sensor is input to the first position signal input pin and the second position signal input pin respectively.
[0027] Preferably, the single-phase brushless DC motor chip further comprises: at least one of a feedback pin for performing speed feedback and a speed control signal input pin for inputting a given speed signal.
[0028] The speed control signal input pin is electrically connected to the given speed signal output pin of the microprocessor.
[0029] The feedback pin is electrically connected to a feedback input pin of the microprocessor.
[0030] Preferably, the position sensor is a Hall sensor.
[0031] Preferably, the driving device is packaged in the two-phase brushless DC motor.
[0032] A second aspect of the utility model provides a two-phase brushless DC motor, comprising the two-phase brushless DC motor driving device.
[0033] The utility model provides a cleaning robot, comprising a liquid discharge pump for discharging liquid, wherein the liquid discharge pump is driven by a two-phase brushless DC motor, and the two-phase brushless DC motor is any one of the two-phase brushless DC motor driving devices.
[0034] The two-phase brushless DC motor driving device provided in the embodiment of the present application is achieved by connecting the first stator coil of the two-phase brushless DC motor in parallel with the two ends of the first switch tube in the bridge switch circuit, and connecting the second stator coil in parallel with the two ends of the third switch tube in the bridge switch circuit; or, the first stator coil of the two-phase brushless DC motor is connected in parallel with the two ends of the second switch tube in the bridge switch circuit, and the second stator coil is connected in parallel with the two ends of the fourth switch tube in the bridge switch circuit, so that the bridge switch circuit can be used to drive the two-phase brushless DC motor, which is beneficial to improving the integration of the driving device. Furthermore, by electrically connecting the first stator coil between the external power pin and the first coil pin of the single-phase brushless DC motor chip, and electrically connecting the second stator coil between the external power pin and the second coil pin of the single-phase brushless DC motor chip, the integration of the driving device is further improved, the circuit structure of the driving device is simplified, and the miniaturization of the driving device is improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Figure 1 A schematic diagram of an existing driving device for driving a two-phase brushless motor.
[0036] Figure 2 This is a schematic diagram of a bridge switch circuit composed of four switch tubes according to an embodiment of the present application.
[0037] Figure 3 This is a schematic diagram of a bridge switch circuit composed of four N-MOS tubes according to an embodiment of the present application.
[0038] Figure 4 It is a timing diagram of the working state of the switch tube and the voltage across the stator coil.
[0039] Figure 5 The figure is a schematic diagram of the internal circuit of a single-phase brushless DC motor chip and a single-phase brushless DC motor drive.
[0040] Figure 6 A schematic diagram of the operation of the H-bridge circuit in the internal circuit of a single-phase brushless DC motor chip.
[0041] Figure 7 The embodiment of the present application adopts a single-phase brushless DC motor chip for driving a single-phase brushless DC motor as a schematic diagram of a two-phase brushless DC motor drive circuit. DETAILED DESCRIPTION
[0042] In order to make the objectives, technical means and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings.
[0043] The applicant has found that two-phase brushless DC motors are rarely used in the industry, and there are relatively few corresponding drive devices that are easy to integrate or have high integration. They are generally built with discrete resistors, capacitors, transistors, and MOS tubes, which have complex circuits, high costs, small space, and low integration.
[0044] In view of this, the utility model provides a two-phase brushless DC motor drive device, see Figure 2 As shown, Figure 2 This is a schematic diagram of a bridge switch circuit composed of four switch tubes in an embodiment of the present application. Among them, one end of the first switch tube is connected in series with one end of the second switch tube, one end of the third switch tube is connected in series with one end of the fourth switch tube, the other end of the first switch tube is connected in parallel with the other end of the third switch tube, the other end of the second switch tube is connected in parallel with the other end of the fourth switch tube, the node where the first switch tube and the third switch tube are connected in parallel is electrically connected to one end of the driving power supply, and the node where the second switch tube and the fourth switch tube are connected in parallel is electrically connected to the other end of the driving power supply.
[0045] When the first switch tube and the fourth switch tube are turned on, the third switch tube and the fourth switch tube are turned off.
[0046] When the first switch tube and the fourth switch tube are turned off, the third switch tube and the fourth switch tube are turned on.
[0047] Each switch tube is switched on and off alternately.
[0048] The first stator coil of the two-phase brushless DC motor is connected in parallel with the two ends of the first switch tube, and the second stator coil is connected in parallel with the two ends of the third switch tube, for example, the switch tube is an N-MOS tube; or, the first stator coil of the two-phase brushless DC motor is connected in parallel with the two ends of the second switch tube, and the second stator coil is connected in parallel with the two ends of the fourth switch tube, for example, the switch tube is a P-MOS tube.
[0049] See also Figure 3 As shown, Figure 3 This is a schematic diagram of a bridge switch circuit composed of four N-MOS tubes in an embodiment of the present application. The source of the first switch tube is electrically connected to the drain of the second switch tube, the source of the third switch tube is electrically connected to the drain of the fourth switch tube,
[0050] The drain of the first switch tube is electrically connected to the drain of the third switch tube, and is electrically connected to the high potential end of the driving power supply. The source of the second switch tube is electrically connected to the source of the fourth switch tube, and is electrically connected to the low potential end of the driving power supply.
[0051] Two ends of the first stator coil are electrically connected to the drain of the first switch tube and the source of the first switch tube respectively.
[0052] The two ends of the second stator coil are electrically connected to the drain of the first switch tube and the source of the second switch tube respectively.
[0053] The gate of each switch tube is electrically connected to the output end of the switch control circuit, and the input end of the switch control circuit is electrically connected to the output end of the position sensor.
[0054] See also Figure 4 As shown, Figure 4 It is a timing diagram of the working state of the switch tube and the voltage at both ends of the stator coil. When the first switch tube and the fourth switch tube are turned on, and the second switch tube and the third switch tube are turned off, the two ends of the first stator coil are equipotential points, and no driving current flows through the first stator coil. The two ends of the second stator coil are applied with driving power, and the driving current flows through the second stator coil.
[0055] When the second switch tube and the third switch tube are turned on and the first switch tube and the fourth switch tube are turned off, the two ends of the second stator coil are equipotential points, no driving current flows through the second stator coil, and a driving power supply is applied to the two ends of the first stator coil, and a driving current flows through the first stator coil.
[0056] As an example, each switch tube may have its own switch control circuit. To reduce the complexity of the circuit, the switch tubes working synchronously may share the same switch circuit. For example, the first switch tube and the fourth switch tube share one switch circuit, and the second switch tube and the third switch tube share another switch circuit. Alternatively, one switch control circuit may be used to control all the switch tubes.
[0057] In this embodiment, since the bridge switch circuit composed of the switch tubes has good symmetry, it is convenient for integration. As an example, the switch control circuit and the bridge switch circuit can be integrated into a driver chip.
[0058] See also Figure 5 As shown, Figure 5 The present invention is a schematic diagram of the internal circuit of a single-phase brushless DC motor chip and a single-phase brushless DC motor drive. The position signal from the Hall sensor used to characterize the rotor position is input into the single-phase brushless DC motor chip, and the single-phase brushless DC motor chip generates a control signal through its internal control engine to control the on and off of its internal bridge switch circuit; the first coil pin, such as the MOTV pin, and the second coil pin, such as the MOTU pin, of the single-phase brushless DC motor driver chip are respectively connected to the stator coil of the single-phase brushless DC motor, so that the stator coil and the bridge switch circuit inside the single-phase brushless DC motor driver chip form an H-bridge circuit, and when working, the diagonal switches of the H bridge are turned on at the same time.
[0059] See also Figure 6 As shown, Figure 6This is a schematic diagram of the operation of an H-bridge circuit. For example, Q1 and Q4, Q2 and Q3 are turned on alternately in pairs. When Q1 and Q4 are turned on and Q2 and Q3 are turned off, the driving current is from the power supply through the drain, source, stator coil of Q1, drain and source of Q4 to the ground terminal. When Q1 and Q4 are turned off and Q2 and Q3 are turned on, the driving current is from the power supply through the drain, source, stator coil of Q2, drain and source of Q3 to the ground terminal. The directions of the driving currents flowing through the stator coil twice are opposite. In this way, the single-phase brushless DC motor will obtain different magnetic poles to achieve the purpose of repelling the same poles and attracting the opposite poles.
[0060] Since the single-phase brushless DC motor chip has a bridge switch circuit inside, and the diagonal switch tubes can be turned on and off at the same time according to the control signal, the single-phase brushless DC motor chip can be used to drive the two-phase brushless DC motor. Figure 7 As shown, Figure 7 A schematic diagram of a two-phase brushless DC motor drive circuit using a single-phase brushless DC motor chip for driving a single-phase brushless DC motor is provided in the embodiment of the present application. The single-phase brushless DC motor chip has: an external power supply pin such as a VCC pin for an external power supply, a first coil pin such as a MOTV pin for connecting a stator coil, and a second coil pin such as a MOTU pin, a sensor power supply pin such as an HB pin for providing a working power supply to a position sensor, and a position signal input pin such as an H_INP and a H_INN pin for inputting a position signal from a sensor, wherein the external power supply pin is used for both an external power supply to provide a working power supply for the single-phase brushless DC motor chip and a driving power supply for the two-phase brushless DC motor.
[0061] The first stator coil is electrically connected between the external power supply pin and the first coil pin,
[0062] The second stator coil is electrically connected between the external power supply pin and the second coil pin.
[0063] The output end of the position sensor is electrically connected to the position signal input pin. As an example, the position signal input pin includes a first position signal input pin and a second position signal input pin. The differential signal output by the position sensor is input to the first position signal input pin and the second position signal input pin, respectively.
[0064] The power supply terminal of the position sensor is electrically connected to the sensor power supply pin to provide working power for the position sensor, for example, to provide working power for the Hall sensor.
[0065] As an example, the single-phase brushless DC motor chip further includes: at least one of a feedback pin for speed feedback, such as an FG pin, and a speed control signal input pin for inputting a given speed signal, such as a PWM pin, wherein the given speed signal is a pulse width modulation signal.
[0066] The speed control signal input pin is electrically connected to the given speed signal output pin of the microprocessor, so that the microprocessor outputs the given speed signal to the single-phase brushless DC motor chip, thereby controlling the motor speed.
[0067] The feedback pin is electrically connected to the feedback input pin of the microprocessor so that the single-phase brushless DC motor chip feeds back a speed signal for characterizing the speed of the motor to the microprocessor.
[0068] Combined with the internal bridge switching circuit of the single-phase brushless DC motor chip, when Q1 and Q4 are turned on and Q2 and Q3 are turned off, the two ends of the first stator coil are equipotential points, and no driving current flows through the first stator coil. A driving power supply is applied to both ends of the second stator coil, and a driving current flows through the second stator coil. When Q1 and Q4 are turned on and Q2 and Q3 are turned off, the two ends of the second stator coil are equipotential points, and no driving current flows through the second stator coil. A driving power supply is applied to both ends of the first stator coil, and a driving current flows through the first stator coil. In this way, the two stator coils of the two-phase brushless DC motor are excited at one time, thereby driving the rotor to rotate.
[0069] Figure 7 In the circuit, the VSS pin is the ground terminal of the control signal, and the F-GND pin is the power ground terminal, which can be connected to the low potential terminal of the external power supply.
[0070] This embodiment uses a single-phase brushless DC motor chip to drive a two-phase brushless DC motor, and there is no need to modify the inside of the chip, so that various single-phase brushless DC motor chips can be applicable to the drive of the two-phase brushless DC motor, which improves the selectivity of the two-phase brushless DC motor drive device and greatly reduces the peripheral circuit structure, improves the integration of the drive device, reduces the space occupied by the drive device, and is conducive to the miniaturization of the drive device. It is also conducive to encapsulating the drive device in the two-phase brushless DC motor to form an integrated whole, which is conducive to the miniaturization of the two-phase brushless DC motor.
[0071] The two-phase brushless DC motor driving device provided by the utility model can be packaged in the two-phase brushless DC motor, thereby becoming one with the two-phase brushless DC motor.
[0072] As an application example, the two-phase brushless DC motor driving device of the embodiment of the present application can be applied to a drainage pump of a cleaning robot. A cleaning robot usually includes a drainage pump for draining sewage, and the drainage pump includes a two-phase brushless DC motor, and the driving device of the embodiment of the present application is encapsulated in the two-phase brushless DC motor, which is conducive to the miniaturization of the cleaning robot.
[0073] In this article, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.
[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A two-phase brushless DC motor drive device, characterized in that: The device includes: A bridge switch circuit composed of four switch tubes, wherein one end of the first switch tube is connected in series with one end of the second switch tube, one end of the third switch tube is connected in series with one end of the fourth switch tube, the other end of the first switch tube is connected in parallel with the other end of the third switch tube, the other end of the second switch tube is connected in parallel with the other end of the fourth switch tube, the node where the first switch tube and the third switch tube are connected in parallel is electrically connected to one end of a driving power supply, and the node where the second switch tube and the fourth switch tube are connected in parallel is electrically connected to the other end of the driving power supply, When the first switch tube and the fourth switch tube are turned on, the third switch tube and the fourth switch tube are turned off. When the first switch tube and the fourth switch tube are turned off, the third switch tube and the fourth switch tube are turned on. Each switch tube is switched on and off alternately. The first stator coil of the two-phase brushless DC motor is connected in parallel with the two ends of the first switch tube, and the second stator coil is connected in parallel with the two ends of the third switch tube; or, the first stator coil of the two-phase brushless DC motor is connected in parallel with the two ends of the second switch tube, and the second stator coil is connected in parallel with the two ends of the fourth switch tube.
2. The two-phase brushless DC motor driving device according to claim 1, characterized in that: The switch tube is an N-channel field effect tube. The source of the first switch tube is electrically connected to the drain of the second switch tube, the source of the third switch tube is electrically connected to the drain of the fourth switch tube, The drain of the first switch tube is electrically connected to the drain of the third switch tube, and is electrically connected to the high potential end of the driving power supply. The source of the second switch tube is electrically connected to the source of the fourth switch tube, and is electrically connected to the low potential end of the driving power supply. Two ends of the first stator coil are electrically connected to the drain of the first switch tube and the source of the first switch tube respectively. The two ends of the second stator coil are electrically connected to the drain of the first switch tube and the source of the second switch tube respectively. The gate of each switch tube is electrically connected to the output end of the switch control circuit, and the input end of the switch control circuit is electrically connected to the output end of the position sensor.
3. The two-phase brushless DC motor driving device according to claim 2, characterized in that: The switch tube and the switch control circuit are integrated in a driving chip.
4. The two-phase brushless DC motor driving device according to claim 3, characterized in that: The driving chip is a single-phase brushless DC motor chip for driving a single-phase brushless DC motor, and the chip at least has: an external power pin for an external power supply, a first coil pin and a second coil pin for connecting a stator coil, a sensor power pin for providing a working power supply to a position sensor, and a position signal input pin for inputting a position signal from the position sensor. The first stator coil is electrically connected between the external power supply pin and the first coil pin. The second stator coil is electrically connected between the external power supply pin and the second coil pin. The output end of the position sensor is electrically connected to the input pin. The power supply terminal of the position sensor is electrically connected to the sensor power supply pin.
5. The two-phase brushless DC motor driving device according to claim 4, characterized in that: The position signal input pin includes a first position signal input pin and a second position signal input pin, The differential signal output by the position sensor is input to the first position signal input pin and the second position signal input pin respectively.
6. The two-phase brushless DC motor driving device according to claim 4, characterized in that: The single-phase brushless DC motor chip further includes: at least one of a feedback pin for performing speed feedback and a speed control signal input pin for inputting a given speed signal. The speed control signal input pin is electrically connected to the given speed signal output pin of the microprocessor. The feedback pin is electrically connected to a feedback input pin of the microprocessor.
7. The two-phase brushless DC motor driving device according to claim 4, characterized in that: The position sensor is a Hall sensor.
8. The two-phase brushless DC motor driving device according to claim 4, characterized in that: The driving device is packaged in the two-phase brushless DC motor.
9. A two-phase brushless DC motor, characterized in that: It comprises a two-phase brushless DC motor driving device as claimed in any one of claims 1 to 8.
10. A cleaning robot, comprising a liquid discharge pump for discharging liquid, characterized in that: The displacement pump is driven by a two-phase brushless DC motor, and the two-phase brushless DC motor includes the two-phase brushless DC motor driving device according to any one of claims 1 to 8.