A brushless direct current motor

Abstract

The application discloses a brushless direct current motor and relates to the technical field of brushless direct current motors.The brushless direct current motor comprises a rotating shaft, a steel sleeve is rotationally connected to the shaft wall of the rotating shaft through two bearings, the outer wall of the steel sleeve is fixedly connected with a framework, the surface of the framework is fixedly connected with an upper partition plate and a lower partition plate, and the brushless direct current motor further comprises a judging unit, the judging unit comprises a data acquisition module, a data processing module, a temperature evaluation module and a cooling execution module, the operation state of the motor is evaluated through the temperature evaluation module, and the operation state is divided into a normal operation state, a general operation state and a dangerous operation state; the brushless direct current motor is cooperated with the above structure, a winding temperature model is constructed through electric parameters, environmental parameters and heat dissipation characteristics, the heating state of the motor is directly reflected, a risk index is calculated based on real-time temperature, a temperature rising rate and an environmental temperature difference, a dynamic early warning function is realized, the motor is subjected to targeted cooling treatment based on actual conditions, and the overheat protection reliability of the brushless direct current motor is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of brushless DC motor technology, specifically to a brushless DC motor. Background Technology

[0002] Brushless DC motors are a new type of motor that replaces the traditional mechanical commutation structure with electronic commutation technology. Compared with brushed DC motors, they have significant advantages such as high efficiency, long life and low maintenance cost. Their core working principle is to use an electronic commutation controller to sequentially energize the stator windings to generate a rotating magnetic field to drive the rotor permanent magnet to rotate, thereby effectively eliminating the inherent defects of brushed motors such as wear, electrical sparks and operating noise caused by mechanical commutation.

[0003] However, when a brushless DC motor operates under high power density conditions, the copper loss of the stator winding, the iron loss of the iron core, and the eddy current loss of the permanent magnet will generate a lot of heat, which will cause the internal temperature of the motor to rise. If the temperature exceeds the design threshold, it will cause the motor output efficiency to decrease and the service life to be shortened. In extreme cases, it may even cause safety hazards such as short circuits and fires.

[0004] In existing technologies, heat dissipation solutions for brushless DC motors are mainly divided into two categories. The first is passive air cooling, which involves coaxially connecting a drive impeller to the motor output shaft and using the rotation of the shaft end to drive airflow for forced convection cooling. This method has a simple structure but limited heat dissipation efficiency. Moreover, since the impeller rotates with the shaft, once the motor stops, the heat will not decrease rapidly, and the impeller has stopped operating, resulting in limited cooling efficiency. The second is liquid cooling, which improves heat dissipation efficiency to some extent by setting flow channels in the motor housing and introducing coolant. However, this method lacks real-time monitoring of the motor's operating status, making it impossible to dynamically adjust the heat dissipation intensity according to the actual heat generation power. This can easily lead to problems of "overcooling" or "undercooling." Therefore, existing brushless DC motors have insufficient dynamic adaptability in terms of heat dissipation direction, making it difficult to monitor the motor's operating status in real time and intelligently adjust heat dissipation measures. Overall, their practicality still needs to be improved. Summary of the Invention

[0005] The purpose of this invention is to provide a brushless DC motor that solves the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a brushless DC motor, comprising a rotating shaft, a steel sleeve rotatably connected to the shaft wall via two bearings, a frame fixedly connected to the outer wall of the steel sleeve, an upper partition and a lower partition fixedly connected to the surface of the frame, a stator core assembly provided on the side of the frame, a housing fixedly connected to the shaft wall of the rotating shaft, a magnetic rotor assembly provided on the inner wall of the housing, a separator ring fixedly connected to the outer wall of the upper partition, two cooling coils fixedly connected below the separator ring, a cooling coil assembly provided above the upper partition, cooling fan blades provided on the rotating shaft, and a judgment unit;

[0007] The judgment unit includes a data acquisition module, a data processing module, a temperature assessment module, and a cooling execution module. The temperature assessment module assesses the operating status of the motor and classifies it into normal operating status, general operating status, and dangerous operating status.

[0008] The cooling execution module includes a primary cooling component, two sets of advanced cooling components, and two sets of braking cooling components. The primary cooling component cools the motor under normal operating conditions through the cooperation of the cooling fan blades and the cooling coils. The advanced cooling component opens the cooling coils and actively dampens the shaft when the temperature assessment module determines that the motor is in a normal operating state. The braking cooling component stops the rotation drive of the shaft and changes the cooperation mode between the shaft and the cooling fan blades when the motor is assessed as being in a dangerous operating state.

[0009] Optionally, the primary cooling component includes two retaining shafts, a top plate is fixedly connected to the surface of the frame, both retaining shafts are slidably connected to the inner wall of the rotating shaft, the cooling fan blades are rotatably connected to the surface of the rotating shaft, two retaining plates are fixedly connected to the top surface of the cooling fan blades, the partition ring is rotatably connected to the inner wall of the outer shell, two sets of cooling devices are provided on the top surface of the partition ring, the two sets of cooling devices are respectively connected to the two cooling coils and the cooling pipe group, and a sliding plate is slidably connected to the inner wall of the rotating shaft.

[0010] Optionally, the advanced cooling component includes an electromagnetic lifting rod, which is fixedly connected to the inner wall of the frame. A drive plate is fixedly connected to the output end of the electromagnetic lifting rod. A slider is slidably connected to the inner wall of the drive plate. A connecting shaft is fixedly connected to the inner wall of the slider. Two displacement grooves are formed on the inner wall of the frame, including an oblique groove and a vertical groove. The two ends of the connecting shaft are slidably connected to the inner walls of the two displacement grooves respectively. A lifting rod is fixedly connected to the top surface of the slider. An adjusting rod is sleeved on the surface of the lifting rod. The adjusting rod is slidably connected to the inner wall of the frame. The adjusting rod extends into the cooling pipe assembly. Multiple blocking blocks are fixedly connected to the arm of the adjusting rod. Through holes are formed on the surface of the blocking blocks, and the airflow in the cooling pipe assembly is blocked through the side wall of the blocking blocks.

[0011] The inner wall of the frame is slidably connected to a wedge block, the surface of the wedge block is connected to the inner wall of the frame through a connecting spring, a pressure ball is fixedly connected to the surface of the wedge block, and an expansion ring connected to the pressure ball is fixedly connected to the surface of the frame.

[0012] Optionally, the braking and cooling component includes: a transmission rod fixedly connected to the bottom surface of the slide plate, the transmission rod slidably connected to the inner wall of the rotating shaft, a groove formed on the surface of the locking shaft, the end of the transmission rod extending into the groove, a compression spring fixedly connected to the end of the locking shaft, the end of the compression spring being connected to the inner wall of the rotating shaft, a distance sensor for monitoring the position of the locking shaft being provided inside the rotating shaft, and a locking device for limiting the locking shaft being provided on the frame.

[0013] Optionally, the data acquisition module includes a temperature sensor mounted on the frame, a current sensor for monitoring the current on the stator core assembly, and an encoder for monitoring the rotational speed of the shaft.

[0014] Optionally, while the motor is operating, the motor's heating status is measured via a data processing module. The specific measurement process is as follows:

[0015] ;

[0016] Let t be the temperature of the motor windings.

[0017] Ambient temperature;

[0018] This refers to the copper loss power of the winding;

[0019] This refers to the iron loss power of the iron core;

[0020] The total thermal resistance from the motor to the environment;

[0021] ;

[0022] This refers to the real-time operating current.

[0023] For winding resistance;

[0024] ;

[0025] This is the iron loss coefficient;

[0026] This refers to the real-time rotational speed.

[0027] A winding temperature model is constructed using current, speed, temperature, and thermal resistance parameters to directly reflect the motor's heating state. After obtaining the motor winding temperature at time t, the calculated value is then input into the temperature evaluation module.

[0028] Optionally, the actual state of the motor can be evaluated using the temperature evaluation module. The specific evaluation process is as follows:

[0029] ;

[0030] Temperature risk warning index;

[0031] This is the weighting coefficient for the rate of temperature change;

[0032] This represents the winding temperature at the previous moment.

[0033] The sampling time interval;

[0034] This is the temperature rise weighting coefficient;

[0035] Based on the motor's rated parameters, warning intervals A and B are set. When... When A < A, it is determined to be in normal operating condition, and the cooling execution module is in the state of primary cooling component operation. When A ≤ When B < B, it is determined to be in normal operating state, causing the cooling execution module to drive the two sets of advanced cooling components to operate; when B ≤ B < ... When the system is deemed to be in a dangerous operating state, it triggers the operation of two sets of braking and cooling components. Based on the real-time temperature, heating rate and ambient temperature difference, the risk index is calculated, and the cooling execution module is controlled as needed to achieve dynamic early warning function.

[0036] Optionally, a tire is fitted onto the surface of the housing, and a connector is provided on the stator core assembly.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] I. This invention constructs a winding temperature model based on electrical parameters, environmental parameters, and heat dissipation characteristics to directly reflect the motor's heating state. It also calculates a risk index based on real-time temperature, heating rate, and ambient temperature difference to achieve dynamic early warning. Based on the actual situation, it performs targeted cooling treatment on the motor, effectively improving the reliability of overheat protection for brushless DC motors.

[0039] Second, when the motor is in normal operation, the invention creates a low-temperature partition space, which makes it less likely for the heat generated by the internal components of the motor to affect the tire, while the synchronously rotating cooling fan blades can normally drive the air to dissipate heat from the internal components of the motor.

[0040] Third, when the motor is in normal operating condition, a certain amount of heat has been generated inside the motor, and the speed is relatively high. At this time, more cooling energy is delivered to the places where it is needed. By cooling the motor through the flow of air, the cooling efficiency of the heat inside the motor is improved. At the same time, the expansion ring will also expand and deform. When it contacts the shaft, it will eliminate the resonance phenomenon caused by the high speed of the shaft in a damping manner, thereby reducing noise and improving the practicality of the motor.

[0041] Fourth, when the motor is assessed to be in a dangerous operating state, the clamping shaft retracts into the rotating shaft, and the rotation drive of the rotating shaft stops. Since the clamping plate loses the clamping shaft's restraint, the clamping plate and the cooling fan blades continue to rotate under the action of inertia. Through the continued rotation process, the internal cooling process of the motor continues, thereby extending the processing time of the cooling measures. Attached Figure Description

[0042] Figure 1 This is an isometric view of the present invention;

[0043] Figure 2 This is a cross-sectional axonometric view of the present invention from a frontal viewing angle;

[0044] Figure 3 This is a cross-sectional axonometric view of the present invention from a right-view perspective;

[0045] Figure 4 This is an exploded view of the internal structure of the present invention.

[0046] Figure 5 For the present invention Figure 4 Enlarged view of the structure at point A in the middle;

[0047] Figure 6This is a cross-sectional schematic diagram of the connection between the cooling fan blade and the rotating shaft of the present invention;

[0048] Figure 7 This is a cross-sectional view of the part where the rotating shaft and the frame mate in this invention;

[0049] Figure 8 For the present invention Figure 7 Enlarged view of the structure at point B;

[0050] Figure 9 This is a schematic diagram of the transmission principle from the slide plate to the locking shaft of the present invention;

[0051] Figure 10 This is a schematic diagram of the state control principle of the cooling pipe assembly of the present invention;

[0052] Figure 11 This is a schematic diagram of the judgment unit of the present invention.

[0053] In the diagram: 1. Shaft; 2. Bearing; 3. Steel sleeve; 4. Frame; 5. Upper partition; 6. Lower partition; 7. Stator core assembly; 8. Outer shell; 9. Magnetic rotor assembly; 10. Separator ring; 11. Cooling winding tube; 12. Cooling tube assembly; 13. Cooling fan blade; 14. Shaft clamp; 15. Top plate; 16. Clamping plate; 17. Refrigeration device; 18. Slide plate; 19. Electromagnetic lifting rod; 20. Drive plate; 21. Slider; 22. Connecting shaft; 23. Displacement groove; 24. Lifting rod; 25. Adjusting rod; 26. Blocking block; 27. Wedge block; 28. Connecting spring; 29. ​​Pressure ball; 30. Expansion ring; 31. Transmission rod; 32. Compression spring. Detailed Implementation

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] Example 1, please refer to Figures 1 to 11 This invention provides a brushless DC motor, including a rotating shaft 1. The shaft wall of the rotating shaft 1 is rotatably connected to a steel sleeve 3 via two bearings 2. A frame 4 is fixedly connected to the outer wall of the steel sleeve 3. An upper partition 5 and a lower partition 6 are fixedly connected to the surface of the frame 4. A stator core assembly 7 is provided on the side of the frame 4. A housing 8 is fixedly connected to the shaft wall of the rotating shaft 1. A magnetic rotor assembly 9 is provided on the inner wall of the housing 8. A separator ring 10 is fixedly connected to the outer wall of the upper partition 5. Two cooling coils 11 are fixedly connected below the separator ring 10. A cooling coil assembly 12 is provided above the upper partition 5. A cooling fan blade 13 is provided on the rotating shaft 1. The motor also includes a judgment unit.

[0056] The judgment unit includes a data acquisition module, a data processing module, a temperature assessment module, and a cooling execution module. The temperature assessment module evaluates the operating status of the motor and classifies it into normal operating status, general operating status, and dangerous operating status.

[0057] The cooling execution module includes a primary cooling component, two sets of advanced cooling components, and two sets of braking cooling components. The primary cooling component is used to cool the motor under normal operating conditions through the cooperation of the cooling fan blade 13 and the cooling coil 11. The two sets of advanced cooling components are set to open the cooling tube group 12 and actively perform vibration damping treatment on the rotating shaft 1 when the temperature assessment module assesses the motor as being in a normal operating state. The two sets of braking cooling components are used to stop the rotation drive of the rotating shaft 1 and change the cooperation mode between the rotating shaft 1 and the cooling fan blade 13 when the motor is assessed as being in a dangerous operating state. The data acquisition module includes a temperature sensor set on the frame 4, a current sensor for monitoring the current on the stator core group 7, and an encoder for monitoring the rotation speed of the rotating shaft 1.

[0058] The motor's heating status is measured through a data processing module while the motor is operating. The specific measurement process is as follows:

[0059] ;

[0060] in The temperature of the motor windings at time t directly reflects the heating state of the motor core.

[0061] The ambient temperature is measured directly using a temperature sensor.

[0062] The calculation method for winding copper loss power is as follows:

[0063] ;

[0064] The real-time operating current is collected by a current sensor;

[0065] The winding resistance varies with temperature and can be measured at room temperature.

[0066] The calculation method for the iron core loss power is as follows:

[0067] ;

[0068] The total thermal resistance from the motor to the environment;

[0069] This is the iron loss coefficient, which is related to the material and structure of the motor core and is determined experimentally.

[0070] The rotational speed is obtained in real time via an encoder;

[0071] More specifically, in this embodiment: a winding temperature model is constructed using current, speed, temperature, and thermal resistance parameters to directly reflect the motor's heating state. After obtaining the motor winding temperature at time t, the calculated value is input into the temperature evaluation module. The temperature evaluation module then evaluates the actual state of the motor. The specific evaluation process is as follows:

[0072] ;

[0073] The temperature risk warning index comprehensively reflects the risk value of current temperature, rate of warming, and relative temperature rise, and is used for comparison with the warning range.

[0074] The weighting coefficient for the rate of temperature change is set to 1.2.

[0075] This represents the winding temperature at the previous moment.

[0076] The sampling time interval;

[0077] The temperature rise weighting factor is set to 0.3.

[0078] Based on the motor's rated parameters, warning intervals A and B are set. When... When A < A, it is determined to be in normal operating condition, and the cooling execution module is in the state of primary cooling component operation. When A ≤ When B < B, it is determined to be in normal operating state, causing the cooling execution module to drive the two sets of advanced cooling components to operate; when B ≤ B < ... When the operation is deemed to be in a dangerous state, two sets of braking and cooling components are triggered to operate. Based on the real-time temperature, heating rate and ambient temperature difference, the risk index is calculated, and the cooling execution module is controlled as needed to achieve dynamic early warning function, effectively improving the reliability of overheat protection for brushless DC motors.

[0079] Example 2, based on the above examples:

[0080] Please see Figures 1 to 10The primary cooling component includes: two retaining shafts 14, a top plate 15 fixedly connected to the surface of the frame 4, both retaining shafts 14 being slidably connected to the inner wall of the rotating shaft 1, a cooling fan blade 13 being rotatably connected to the surface of the rotating shaft 1, two retaining plates 16 being fixedly connected to the top surface of the cooling fan blade 13, a partition ring 10 being rotatably connected to the inner wall of the outer shell 8, two sets of cooling devices 17 being provided on the top surface of the partition ring 10, the two sets of cooling devices 17 being respectively connected to two cooling coils 11 and a cooling pipe group 12, a sliding plate 18 being slidably connected to the inner wall of the rotating shaft 1, a tire being fitted on the surface of the outer shell 8, and a connector being provided on the stator core group 7.

[0081] More specifically, in this embodiment: the stator core assembly 7 is energized through the connector, thereby driving the rotating shaft 1 to rotate through its cooperation with the magnetic rotor assembly 9. This process is the common driving principle of brushless DC motors, and will not be described in detail here. When the motor is in normal operation, the rotation of the rotating shaft 1 will drive the two retaining shafts 14 to rotate synchronously. The retaining shafts 14 push the cooling fan blades 13, so that the cooling fan blades 13 and the retaining shafts 14 maintain a synchronous rotation state. At the same time, the cooling device 17 delivers cool air to the cooling coil 11, so that the cooling coil 11 maintains a low temperature. In this way, a low-temperature space is formed between the tire, the magnetic rotor assembly 9, and the stator core assembly 7.

[0082] The low-temperature partition space ensures that the heat generated by the internal components of the motor does not easily affect the tires during normal operation, while the synchronously rotating cooling fan blades 13 normally drive the air to dissipate heat from the internal components of the motor.

[0083] Example 3, based on the above examples:

[0084] Please see Figures 4 to 10 The advanced cooling components include: an electromagnetic lifting rod 19, which is fixedly connected to the inner wall of the frame 4. The output end of the electromagnetic lifting rod 19 is fixedly connected to a drive plate 20. A slider 21 is slidably connected to the inner wall of the drive plate 20. A connecting shaft 22 is fixedly connected to the inner wall of the slider 21. Two displacement grooves 23 are opened on the inner wall of the frame 4. The displacement grooves 23 include oblique grooves and vertical grooves. The two ends of the connecting shaft 22 are slidably connected to the inner walls of the two displacement grooves 23 respectively. A lifting rod 24 is fixedly connected to the top surface of the slider 21. An adjusting rod 25 is sleeved on the surface of the lifting rod 24. The adjusting rod 25 is slidably connected to the inner wall of the frame 4. The adjusting rod 25 extends into the cooling pipe assembly 12. Multiple blocking blocks 26 are fixedly connected to the arm of the adjusting rod 25. Through holes are opened on the surface of the blocking blocks 26. The airflow in the cooling pipe assembly 12 is blocked through the side wall of the blocking blocks 26.

[0085] A wedge 27 is slidably connected to the inner wall of the frame 4. The surface of the wedge 27 is connected to the inner wall of the frame 4 through a connecting spring 28. A pressure ball 29 is fixedly connected to the surface of the wedge 27. An expansion ring 30 connected to the pressure ball 29 is fixedly connected to the surface of the frame 4.

[0086] More specifically, in this embodiment: when the temperature assessment module assesses the motor as being in normal operating condition, the electromagnetic lifting rod 19 is activated, causing the drive plate 20 to move upward a certain distance. This causes the slider 21 to move synchronously, allowing the connecting shaft 22 to slide along the inclined groove on the displacement groove 23. Simultaneously, the slider 21 moves upward and approaches the rotating shaft 1. Through the transmission of the lifting rod 24, the regulating rod 25 moves synchronously towards the rotating shaft 1 until the connecting shaft 22 reaches the vertical groove on the displacement groove 23, completing this part of the driving process. During the movement of the regulating rod 25, multiple blocking blocks 26 move synchronously, so that the sidewalls of the blocking blocks 26 no longer block the airflow openings within the cooling pipe assembly 12. At this point, the cool air generated by the cooling device 17 will no longer be solely delivered to the cooling coil 11, but rather half will be delivered to the cooling pipe assembly 12. This will lower the temperature of the partitioned space, causing the airflow to be driven by the cooling fan blades 13 from... Figure 2 As the air flows from top to bottom in the direction shown, the temperature of the airflow is reduced by the cooling pipe assembly 12, thereby cooling the inside of the motor through the generated cold air. In this way, more cooling energy is delivered to the places where it is needed under normal operating conditions, and the cooling efficiency of the heat inside the motor is improved by cooling the airflow.

[0087] Considering that under normal operating conditions, as the temperature rises compared to normal operating conditions, the rotational speed of shaft 1 will also increase. When its rotational speed is high, resonance will occur between it and bearing 2. This phenomenon is one of the sources of noise when the motor is working for a long time. Therefore, during the upward movement of drive plate 20, wedge block 27 will be squeezed, causing wedge block 27 to squeeze connecting spring 28. At the same time, wedge block 27 squeezes pressure ball 29, causing pressure ball 29 to deform, thereby driving expansion ring 30 to expand. When it contacts shaft 1, it will eliminate the resonance phenomenon generated by shaft 1 in a damping manner, thereby reducing noise and improving the practicality of the motor.

[0088] Example 4, based on the above examples:

[0089] Please see Figures 6 to 9The braking and cooling component includes: a transmission rod 31, which is fixedly connected to the bottom surface of the slide plate 18 and slidably connected to the inner wall of the rotating shaft 1; a groove is provided on the surface of the clamping shaft 14, and the end of the transmission rod 31 extends into the groove; a compression spring 32 is fixedly connected to the end of the clamping shaft 14, and the end of the compression spring 32 is connected to the inner wall of the rotating shaft 1; a distance sensor for monitoring the position of the clamping shaft 14 is provided inside the rotating shaft 1; and a locking device for limiting the clamping shaft 14 is also provided on the frame 4.

[0090] More specifically, in this embodiment: when the motor is assessed as being in a dangerous operating state, the electromagnetic lifting rod 19 continues to be driven, causing the slider 21 to continue moving upward. During this process, the connecting shaft 22 slides along the vertical groove on the displacement groove 23, while the wedge block 27 remains in a compressed state. During this process, the lifting rod 24 slides upward along the inner wall of the control rod 25, pushing the slide plate 18 upward. Although the slide plate 18 is rotating during this process, it does not affect the upward pushing process. During the upward movement of the slide plate 18 relative to the rotating shaft 1, through the transmission of the transmission rod 31, its lower end can be disengaged from the groove on the retaining shaft 14. At this time, under the elastic reset action of the compression spring 32, the retaining shaft 14 will retract. Inside the rotating shaft 1, when the distance sensor detects that the retaining shaft 14 has retracted completely, it sends a command signal to cut off the power to the connector, thereby stopping the rotation drive of the rotating shaft 1. The locking device immediately stops the rotation of the rotating shaft 1 to avoid damage to the components. The specific working principle of the locking device is the same as that of the vehicle brake assembly, which is a common method in the prior art. Therefore, the corresponding structure and process are not described in detail in this embodiment. At this time, since the retaining plate 16 loses the restriction of the retaining shaft 14, the retaining plate 16 and the cooling fan blade 13 continue to rotate under the action of inertia. By continuing to rotate, the internal cooling process of the motor continues, thereby extending the processing time of the cooling measures.

[0091] Working principle: When the brushless DC motor is in use, the stator core assembly 7 is energized through the connector. This, in conjunction with the magnetic rotor assembly 9, drives the rotating shaft 1 to rotate, thus completing the rotation drive process of the motor. When the motor is in normal operation, the rotation of the rotating shaft 1 will drive the two retaining shafts 14 to rotate synchronously. The retaining shafts 14 push the cooling fan blades 13, so that the cooling fan blades 13 and retaining shafts 14 rotate synchronously. At the same time, the cooling device 17 delivers cool air to the cooling coil 11, so that the cooling coil 11 maintains a low temperature. In this way, a low-temperature space is formed between the tire and the magnetic rotor assembly 9 and the stator core assembly 7. Through the formation of a low-temperature separation space, the heat generated by the internal components of the motor is not likely to affect the tire under normal operation. Meanwhile, the synchronously rotating cooling fan blades 13 normally drive the air to dissipate heat from the internal components of the motor.

[0092] When the temperature assessment module assesses the motor as being in normal operating condition, the electromagnetic lifting rod 19 is activated, causing the drive plate 20 to move upward. At this point, the cool air generated by the cooling device 17 is no longer solely delivered to the cooling coil 11, but is instead partially delivered to the cooling pipe assembly 12. Driven by the cooling fan blades 13, the temperature of the flowing air is lowered by the cooling pipe assembly 12, thus cooling the motor's interior through the generated cold air. In this way, more cool air energy is delivered to where it is needed during normal operation, improving the cooling efficiency of the motor's internal heat by cooling the flowing air. Considering that the rotation speed is also relatively high in this state, the drive plate 20 also compresses the wedge block 27 during its upward movement, causing the expansion ring 30 to expand. This increases damping and eliminates the resonance phenomenon generated by the rotating shaft 1, thereby reducing noise and improving the motor's practicality.

[0093] When the motor is assessed as being in a dangerous operating state, the electromagnetic lifting rod 19 is continued to be driven, causing the slider 21 to continue to move upward, thereby causing the retaining shaft 14 to retract into the rotating shaft 1. At this time, since the retaining plate 16 loses the restriction of the retaining shaft 14, the retaining plate 16 and the cooling fan blade 13 continue to rotate under the action of inertia. Through the continued rotation process, the internal cooling of the motor continues, thereby extending the processing time of the cooling measures. When the temperature drops to the standard, the locking device is unlocked, and the electromagnetic lifting rod 19 is driven to reset.

[0094] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A brushless DC motor, comprising a rotating shaft (1), characterized in that: The shaft wall of the rotating shaft (1) is rotatably connected to a steel sleeve (3) via two bearings (2). A frame (4) is fixedly connected to the outer wall of the steel sleeve (3). An upper partition (5) and a lower partition (6) are fixedly connected to the surface of the frame (4). A stator core assembly (7) is provided on the side of the frame (4). An outer shell (8) is fixedly connected to the shaft wall of the rotating shaft (1). A magnetic rotor assembly (9) is provided on the inner wall of the outer shell (8). A separator ring (10) is fixedly connected to the outer wall of the upper partition (5). Two cooling coils (11) are fixedly connected below the separator ring (10). A cooling tube assembly (12) is provided above the upper partition (5). A cooling fan blade (13) is provided on the rotating shaft (1). A judgment unit is also included. The judgment unit includes a data acquisition module, a data processing module, a temperature assessment module, and a cooling execution module. The temperature assessment module assesses the operating status of the motor and classifies it into normal operating status, general operating status, and dangerous operating status. The cooling execution module includes: The primary cooling component is used to cool the motor in normal operation through the cooperation of the cooling fan blade (13) and the cooling coil (11). It includes two retaining shafts (14), a top plate (15) is fixedly connected to the surface of the frame (4), the two retaining shafts (14) are slidably connected to the inner wall of the rotating shaft (1), the cooling fan blade (13) is rotatably connected to the surface of the rotating shaft (1), two retaining plates (16) are fixedly connected to the top surface of the cooling fan blade (13), the partition ring (10) is rotatably connected to the inner wall of the outer shell (8), the top surface of the partition ring (10) is provided with two sets of cooling devices (17), the two sets of cooling devices (17) are respectively connected to the two cooling coils (11) and the cooling pipe group (12), and a sliding plate (18) is slidably connected to the inner wall of the rotating shaft (1). Two sets of advanced cooling components are provided to open the cooling pipe group (12) and actively dampen the shaft (1) when the temperature assessment module assesses the motor as being in normal operating condition. The components include an electromagnetic lifting rod (19), which is fixedly connected to the inner wall of the frame (4). The output end of the electromagnetic lifting rod (19) is fixedly connected to a drive plate (20). A slider (21) is slidably connected to the inner wall of the drive plate (20). A connecting shaft (22) is fixedly connected to the inner wall of the slider (21). Two displacement grooves (23) are provided on the inner wall of the frame (4). The displacement grooves (23) include an oblique groove and a vertical groove. The two ends of the connecting shaft (22) are slidably connected to the inner walls of the two displacement grooves (23), the top surface of the slider (21) is fixedly connected to the lifting rod (24), the surface of the lifting rod (24) is fitted with the adjusting rod (25), the adjusting rod (25) is slidably connected to the inner wall of the skeleton (4), the adjusting rod (25) extends into the cooling pipe group (12), the arm of the adjusting rod (25) is fixedly connected to multiple blocking blocks (26), the surface of the blocking block (26) is provided with through holes, and the air passage in the cooling pipe group (12) is blocked through the side wall of the blocking block (26); The inner wall of the skeleton (4) is slidably connected to a wedge (27). The surface of the wedge (27) is connected to the inner wall of the skeleton (4) through a connecting spring (28). A pressure ball (29) is fixedly connected to the surface of the wedge (27). An expansion ring (30) connected to the pressure ball (29) is fixedly connected to the surface of the skeleton (4). Two sets of braking and cooling components are provided to stop the rotation drive of the rotating shaft (1) and change the cooperation mode between the rotating shaft (1) and the cooling fan blade (13) when the motor is assessed to be in a dangerous operating state. The components include a transmission rod (31), which is fixedly connected to the bottom surface of the slide plate (18). The transmission rod (31) is slidably connected to the inner wall of the rotating shaft (1). The surface of the retaining shaft (14) is provided with a groove. The end of the transmission rod (31) extends into the groove. The end of the retaining shaft (14) is fixedly connected to a compression spring (32). The end of the compression spring (32) is connected to the inner wall of the rotating shaft (1). A distance sensor is provided inside the rotating shaft (1) to monitor the position of the retaining shaft (14). A locking device that can limit the position of the retaining shaft (14) is also provided on the frame (4).

2. The brushless DC motor according to claim 1, characterized in that: The data acquisition module includes a temperature sensor mounted on the frame (4), a current sensor for monitoring the current on the stator core assembly (7), and an encoder for monitoring the rotational speed of the shaft (1).

3. The brushless DC motor according to claim 2, characterized in that: When the motor is operating, the heating status of the motor is measured through the data processing module. The specific measurement process is as follows: ; Let t be the temperature of the motor windings. Ambient temperature; This refers to the copper loss power of the winding; This refers to the iron loss power of the iron core; The total thermal resistance from the motor to the environment; ; This refers to the real-time operating current. For winding resistance; ; This is the iron loss coefficient; This refers to the real-time rotational speed. A winding temperature model is constructed using current, speed, temperature, and thermal resistance parameters to directly reflect the motor's heating state. After obtaining the motor winding temperature at time t, the calculated value is then input into the temperature evaluation module.

4. The brushless DC motor according to claim 3, characterized in that: The actual condition of the motor is evaluated using the temperature evaluation module. The specific evaluation process is as follows: ; Temperature risk warning index; This is the weighting coefficient for the rate of temperature change; This represents the winding temperature at the previous moment. The sampling time interval; This is the temperature rise weighting coefficient; Based on the motor's rated parameters, warning intervals A and B are set. When... When A < A, it is determined to be in normal operating condition, and the cooling execution module is in the state of primary cooling component operation. When A ≤ When B < B, it is determined to be in normal operating state, causing the cooling execution module to drive the two sets of advanced cooling components to operate; when B ≤ B < ... When the system is deemed to be in a dangerous operating state, it triggers the operation of two sets of braking and cooling components. Based on the real-time temperature, heating rate and ambient temperature difference, the risk index is calculated, and the cooling execution module is controlled as needed to achieve dynamic early warning function.

5. The brushless DC motor according to any one of claims 2-4, characterized in that: The outer shell (8) is fitted with a tire, and the stator core assembly (7) is equipped with a connector.

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