A brushless DC motor

Abstract

The present invention relates to the technical field of motor devices, specifically to a brushless DC motor, comprising a base, a rotor rotatably mounted on the upper end of the base, and an output shaft for transmitting mechanical power fixedly connected to the upper end of the rotor, an inner support plate fixedly mounted on the upper end of the base, a center tube fixedly clamped on the upper end of the inner support plate, a plurality of support shells fixedly mounted on the outer surface of the center tube, the plurality of support shells are divided into three groups, a coil is wound on the outer surface of each group of support shells, a cooling device for cooling the coil is provided at the inner end of the support shell, cooling oil circulates inside the support shell, directly absorbs heat generated by the coil, and quickly transfers the heat to the outside through the cooling pipe and the heat dissipation fins, significantly reducing the overall temperature of the coil and the motor, and at the same time, during the circulation of the cooling oil, the heat dissipation fan inside the rotor works in coordination, achieving efficient heat transfer through liquid cooling, and enhancing the heat dissipation effect through air flow, thereby ensuring stable operation of the motor in a high-temperature environment.

Description

Technical Field

[0001] The present invention relates to the technical field of motor devices, and in particular to a brushless DC motor. Background Art

[0002] A brushless DC motor (BLDC) is a motor that uses electronic commutation instead of traditional mechanical commutation. Compared with brushed DC motors, brushless motors have higher efficiency, longer life, and lower maintenance costs. Its working principle is to sequentially energize the stator windings through an electronic controller (usually a three-phase inverter), thereby generating a rotating magnetic field that drives the permanent magnets on the rotor to rotate.

[0003] Traditional brushed DC motors use brushes and a commutator to switch the direction of current. However, the mechanical contact between the brushes and the commutator causes wear, sparks, and noise, limiting the life and performance of the motor. Brushless motors eliminate these problems through electronic commutation, and therefore have gradually replaced brushed motors in many application scenarios.

[0004] After searching, it was found that the prior art publication number is CN 115912747 A, which discloses a brushless DC motor, including a motor body, a top plate fixedly mounted on the surface of the motor body, an output shaft provided inside the motor body, an air intake pipe fixedly mounted on the inner wall of the top plate, a group of thin tubes fixedly mounted on one end of the air intake pipe that passes through and is inserted into the motor body, a diffusion tube fixedly mounted on the end of the thin tube away from the air intake pipe, a group of spray holes opened on the surface of the diffusion tube, an air outlet cavity opened on the inner wall of the motor body, and the dry air entering the nozzle is finally sprayed out from the spray holes. This solution absorbs heat from the inside of the motor body and then leaves the motor body along the air outlet cavity and enters the protective elastic block. The protective elastic block then expands to wrap the motor body to prevent external force from colliding and knocking on the motor body and causing deformation of the shell, thereby achieving the effect of protecting the motor body while dissipating heat.

[0005] Therefore, based on the above search and combined with existing technologies, the motor cooling system of the existing technology usually relies on single air cooling or simple liquid cooling, which has low heat dissipation efficiency and is difficult to effectively meet the heat dissipation needs under high load and high temperature conditions. In addition, the existing cooling system is often complex in structure, occupies a large space, and is difficult to integrate into the motor, resulting in an increase in the overall volume of the motor and unsatisfactory heat dissipation effect, resulting in insufficient heat dissipation under high load conditions or energy waste under low load conditions. For this reason, we propose a DC brushless motor. Summary of the Invention

[0006] The object of the present invention is to provide a brushless DC motor to solve the problems raised in the above background technology.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a brushless DC motor, comprising a base, a rotor rotatably mounted on the upper end of the base, and an output shaft for transmitting mechanical power fixedly connected to the upper end of the rotor, an inner support plate fixedly mounted on the upper end of the base, a center tube fixedly clamped on the upper end of the inner support plate, a plurality of support shells fixedly mounted on the outer surface of the center tube, and the support shells are arranged in a ring shape, a stator fixedly mounted on one end of the support shell away from the center tube, the plurality of support shells are divided into three groups, a coil is wound on the outer surface of each group of support shells, a cooling device for cooling the coil is provided inside the support shell, the interior of the center tube is filled with cooling oil, and a movable sleeve is provided inside, a high-temperature power-off device is provided between the center tube and the inner support plate, when the temperature of the rotor is too high, the high-temperature power-off device can cut off the internal power supply to avoid damage to the device caused by high-temperature overload.

[0008] As a further solution of the present invention, the cooling device is composed of multiple cooling tubes and auxiliary tubes, the cooling tubes and auxiliary tubes are distributed in a ring shape and arranged in an interlaced manner, the cooling tubes and auxiliary tubes are both passed through the interior of the supporting shell, and multiple heat dissipation fins are fixedly installed inside the supporting shell, and the cooling tubes and auxiliary tubes are tightly fitted with the interior of the heat dissipation fins, and two adjacent cooling tubes are connected by a conducting tube, the cooling tubes and auxiliary tubes are distributed in a ring shape and arranged in an interlaced manner, which increases the contact area between the coolant and the heat dissipation fins and significantly improves the heat dissipation efficiency. The cooling tubes are tightly fitted with the heat dissipation fins to ensure that heat can be quickly transferred to the coolant, further enhancing the heat dissipation effect.

[0009] As a further solution of the present invention, a movable rod is passed through the inner end of the cooling tube, and the movable rod is a permanent magnet. When the coil on the outer surface of the support shell is energized, a magnetic field is generated inside the support shell. According to the direction of the magnetic field, the movable rod is subjected to attraction or repulsion, and moves left and right inside the cooling tube. The cooling tube is connected to the interior of the central tube, and the movable rod and the movable sleeve are rotatably connected by an auxiliary rod. A movable plug is provided on the outer surface of the movable rod, and a plurality of conducting grooves are opened on the outer surface of the movable rod, and the movable plug corresponds to the conducting grooves. The movable rod is a permanent magnet and can move left and right in the cooling tube according to the change of the magnetic field inside the support shell (attraction or repulsion), thereby automatically adjusting the flow direction and flow rate of the coolant to realize dynamic cooling control.

[0010] As a further solution of the present invention, an evaporator tube is provided at the inner end of the supporting shell, and the evaporator tube is located between two adjacent cooling tubes, and the input end of the evaporator tube is fixedly connected to the output end of the conducting tube, and the inner end of the evaporator tube is fixedly connected to an evaporator sleeve, and the center diameter of the circle at the center of the evaporator sleeve is smaller than the center diameter of the circle of the evaporator tube, and a plurality of balloons are fixedly installed at the inner end of the central tube, and the balloons correspond to the auxiliary tube and are fixedly connected thereto, and the output end of the evaporator tube is fixedly connected to a water outlet pipe, and the water outlet pipe is fixedly connected to the balloon, and the cooling oil output by the evaporator tube flows from the water outlet pipe into the interior of the balloon, and the evaporator tube is connected with the cooling tube, the conducting tube and the balloon to form a complete cooling oil circulation system, ensuring that the cooling oil can flow efficiently and absorb heat, thereby improving the overall heat dissipation efficiency.

[0011] As a further solution of the present invention, the high-temperature power-off device includes an isolation sleeve, which is inserted into the inside of the movable sleeve. Two movable tubes are respectively provided at the upper and lower ends of the isolation sleeve. The two adjacent movable tubes are connected by a matching tube. The movable tube close to the isolation sleeve is fixedly connected to the isolation sleeve. The design of the isolation sleeve and the movable tube can trigger the power-off mechanism when the motor temperature is too high, cut off the power supply in time, avoid damage to the motor due to overheating, and significantly improve the safety and reliability of the motor.

[0012] As a further solution of the present invention, the upper and lower ends of the inner side of the movable sleeve are fixedly connected with a sealing cover, and the sealing cover is fixedly connected to the outer surface of the movable tube away from the isolation sleeve. The inner end of the isolation sleeve is provided with a magnetic block, and the magnetic block is triangular in shape. The upper and lower ends of the magnetic block are rotatably connected with matching rods. The interiors of the two movable tubes are penetrated by memory metal strips, and the sealing cover is fixedly connected to the outer surface of the movable tube, ensuring the sealing of the interior of the movable sleeve, preventing leakage of cooling oil, and improving the reliability and safety of the system.

[0013] As a further solution of the present invention, the memory metal strips are respectively located on the upper and lower sides of the magnetic block, and a sealing plug is passed through the inner end of the movable tube. The sealing plug is located below the magnetic block, and the upper end of the sealing plug is fixedly connected to the bottom end of the memory metal strip. The bottom end of the sealing plug is fixedly connected to a passive rod. The memory metal strips are located on the upper and lower sides of the magnetic block, can be deformed in a high temperature environment, and transmit actions through the sealing plug and the passive rod, accurately responding to temperature changes, and ensuring the reliability of the high temperature power-off device.

[0014] As a further solution of the present invention, the bottom end of the inner support plate is fixedly connected to an unlocking shell, a trigger rod is rotatably installed on the inner left end of the unlocking shell, and two trigger protrusions are fixedly installed on the bottom end of the passive rod, and the end of the trigger rod away from the unlocking shell is located between the two trigger protrusions.

[0015] As a further solution of the present invention, an unlocking rod is provided at the inner end of the unlocking shell, the unlocking rod is connected to the unlocking shell by a reset spring, and the unlocking rod and the trigger rod correspond to each other. A power supply head is fixedly installed at the right end of the unlocking rod, and the power supply head is in contact with the coil connector contact. The corresponding design of the unlocking rod and the trigger rod can quickly trigger the power-off mechanism under high temperature or other abnormal conditions, cut off the power supply, and avoid damage to the motor due to overload or overheating, thereby significantly improving the safety and reliability of the motor.

[0016] As a further solution of the present invention, a cooling fan is fixedly installed at the bottom end of the output shaft, and the cooling fan is located inside the rotor. A cooling coil is fixedly installed at the bottom end of the inner support plate through a clamp, and the cooling coil is connected to the center tube through multiple connecting pipes.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. When the present invention is working, the cooling oil circulates inside the support shell, directly absorbing the heat generated by the coil and quickly transferring the heat to the outside through the cooling tube and heat dissipation fins, significantly reducing the overall temperature of the coil and the motor. At the same time, during the cooling oil circulation process, the heat dissipation fan inside the rotor works in coordination, achieving efficient heat transfer through liquid cooling and enhancing the heat dissipation effect through air flow, ensuring stable operation of the motor in a high-temperature environment.

[0019] 2. When the present invention is working, when the motor is operating under high load and high temperature conditions, the high-temperature power-off device can quickly respond to temperature changes through the synergistic effect of the memory metal strip and the magnetic block, ensuring that the power-off operation is immediately executed when the temperature reaches the dangerous threshold to prevent the motor from further overheating. At the same time, the automatic triggering mechanism of the high-temperature power-off device does not require human intervention and can automatically cut off the power supply when the motor temperature is too high, ensuring the safety of the motor and peripheral equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural diagram of a brushless DC motor;

[0021] Figure 2 This is a disassembly diagram of a brushless DC motor;

[0022] Figure 3 It is a structural diagram of the stator part;

[0023] Figure 4 Schematic diagram of the structure of the stator and the supporting shell;

[0024] Figure 5 Schematic diagram of the structure inside the central tube;

[0025] Figure 6 Figure 1 is a diagram showing the relationship between the balloon and the support shell;

[0026] Figure 7 It is a structural diagram of the cooling tube and the evaporation tube;

[0027] Figure 8 Schematic diagram of the internal structure of the cooling tube and evaporation tube;

[0028] Figure 9 It is a structural diagram of the connection between the auxiliary pipe and the return pipe;

[0029] Figure 10 Schematic diagram of the internal structure of the movable sleeve;

[0030] Figure 11 Schematic diagram of the internal structure of the isolation sleeve;

[0031] Figure 12 Schematic diagram of the internal structure of the unlocking shell.

[0032] In the figure: 1, base; 2, rotor; 3, output shaft; 101, stator; 102, inner support plate; 103, heat dissipation coil; 104, heat dissipation fan; 105, center tube; 106, connecting pipe; 107, coil connector;

[0033] 201, unlocking shell; 202, power supply head; 203, return spring; 204, unlocking lever; 205, trigger lever;

[0034] 301, support shell; 302, auxiliary rod; 303, water outlet pipe; 304, balloon; 305, auxiliary pipe; 306, movable rod; 307, evaporation pipe; 308, cooling pipe; 309, heat dissipation fin; 310, conduction pipe; 311, movable plug; 312, conduction groove; 313, evaporation sleeve; 314, one-way valve; 315, return pipe;

[0035] 401. Movable sleeve; 402. Extrusion strip; 403. Coordinating tube; 404. Movable tube; 405. Isolation sleeve; 406. Magnetic block; 407. Coordinating rod; 408. Memory metal strip; 409. Sealing plug; 410. Passive rod; 411. Triggering bump; 412. Sealant cover. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] Example 1: Please refer to Figure 1 - Figure 4A brushless DC motor comprises a base 1, a rotor 2 being rotatably mounted on the upper end of the base 1, and an output shaft 3 for transmitting mechanical power being fixedly welded to the upper end of the rotor 2, a plurality of permanent magnets being fixedly connected to the inner end of the rotor 2 and arranged in a ring shape, an inner support plate 102 being fixedly welded to the upper end of the base 1, a center tube 105 being fixedly clamped to the upper end of the inner support plate 102, a plurality of support shells 301 being fixedly mounted on the outer surface of the center tube 105, and the support shells 301 being arranged in a ring shape, a stator 101 being fixedly mounted on one end of the support shell 301 away from the center tube 105, both the stator 101 and the support shell 301 being made of metal, the plurality of support shells 301 being divided into three groups, the outer surface of each group of support shells 301 being wound with coils in different directions;

[0038] Specifically, a coil connector 107 is provided above the inner support plate 102, and the input ends of the three sets of coils are fixedly connected to the coil connector 107. The coil connector 107 adopts a three-phase (U, V, W) structure, and the three-phase windings are energized in sequence (for example: U→V→W→U...), and the cycle repeats. Each time the power is applied, the magnetic field generated by the coil attracts the permanent magnets on the rotor 2, causing the rotor 2 to rotate. As the power-on sequence changes, the direction of the magnetic force of the winding also changes, driving the rotor 2 to continue rotating, and in turn, the output shaft 3 to rotate.

[0039] A cooling device for cooling the coil is provided inside the support shell 301. The interior of the central tube 105 is filled with cooling oil, usually synthetic oil, and a movable sleeve 401 is provided inside. A high-temperature power-off device is provided between the central tube 105 and the inner support plate 102. When the temperature of the rotor 2 is too high, the high-temperature power-off device can cut off the internal power supply to avoid damage to the device caused by high-temperature overload.

[0040] See also Figure 3 、 Figure 5 - Figure 8 The cooling device is composed of a plurality of cooling tubes 308 and auxiliary tubes 305. The cooling tubes 308 and the auxiliary tubes 305 are distributed in a ring shape and arranged in an interlaced manner. The cooling tubes 308 and the auxiliary tubes 305 are both made of metal. The cooling tubes 308 and the auxiliary tubes 305 are both arranged inside the support shell 301. A plurality of heat dissipation fins 309 are fixedly installed inside the support shell 301. The heat dissipation fins 309 are made of metal. The cooling tubes 308 and the auxiliary tubes 305 are tightly fitted with the inside of the heat dissipation fins 309. Two adjacent cooling tubes 308 are connected by a conducting tube 310.

[0041] A movable rod 306 is provided at the inner end of the cooling tube 308. The movable rod 306 is a permanent magnet having fixed magnetic poles (N and S poles) and interacts with the magnetic field generated by the coil. When the coil on the outer surface of the support shell 301 is energized, a magnetic field is generated inside the support shell 301. Depending on the direction of the magnetic field, the movable rod 306 is subjected to an attractive or repulsive force and moves left and right inside the cooling tube 308. The cooling tube 308 is connected to the interior of the central tube 105, so that the cooling oil inside the central tube 105 can flow into the interior of the cooling tube 308. The movable rod 306 is rotatably connected to the movable sleeve 401 via the auxiliary rod 302 (as shown in FIG. Figure 5 As shown), the outer surface of the movable rod 306 is provided with a movable plug 311, and the outer surface of the movable plug 311 is provided with a sealing rubber ring, and is tightly fitted with the inner wall of the cooling tube 308 to increase the sealing performance. The outer surface of the movable rod 306 is provided with a plurality of conducting grooves 312, which are arranged in a ring shape, and the movable plug 311 corresponds to the conducting grooves 312. Specifically, a limit ring is fixedly installed on the outer surface of the movable rod 306, and the limit ring is located on the left side of the movable plug 311, and a limit block is fixedly welded at the junction of each conducting groove 312, and the limit block is located on the right side of the movable plug 311;

[0042] More specifically, when the movable plug 311 moves to the left and contacts the limiting ring, the conducting groove 312 is completely exposed on the right side of the movable plug 311. When the movable plug 311 moves to the right and contacts the limiting block, the conducting groove 312 connects the left and right chambers of the movable plug 311. Therefore, when the movable rod 306 moves to the left, the cooling oil enters the interior of the cooling tube 308. When the movable rod 306 moves to the right, the movable plug 311, under the action of the limiting ring, squeezes the cooling oil in the cavity of the cooling tube 308 and flows it into the interior of the conducting tube 310.

[0043] like Figure 7 、 Figure 8 As shown, an evaporation tube 307 is provided at the inner end of the support shell 301. The evaporation tube 307 is located between two adjacent cooling tubes 308, and the input end of the evaporation tube 307 is fixedly connected to the output end of the conducting tube 310. An evaporation sleeve 313 is fixedly welded to the inner end of the evaporation tube 307. Specifically, the evaporation sleeve 313 is hourglass-shaped, and the left and right ends of the evaporation sleeve 313 are fixedly welded to the inner wall of the evaporation tube 307. The center diameter of the evaporation sleeve 313 is smaller than the center diameter of the evaporation tube 307. When the cooling oil flows from the right side to the left side of the evaporation sleeve 313, the center of the evaporation sleeve 313 is smaller, so that the cooling oil will be atomized after flowing to the left side. At this time, according to Newton's law of cooling (the law followed when an object with a temperature higher than the surrounding environment transfers heat to the surrounding medium and gradually cools down), the temperature will drop rapidly.

[0044] like Figure 2 、 Figure 5 - Figure 9 As shown, a plurality of balloons 304 are fixedly mounted on the inner end of the central tube 105. The balloons 304 correspond to the auxiliary tubes 305 and are fixedly connected thereto. The output end of the evaporation tube 307 is fixedly connected to the water outlet pipe 303, and the water outlet pipe 303 is fixedly connected to the balloon 304. The cooling oil output by the evaporation tube 307 flows from the water outlet pipe 303 into the interior of the balloon 304. The input end of the auxiliary tube 305 is fixedly connected to a one-way valve 314. When the balloon 304 is squeezed, the liquid inside the balloon 304 enters the interior of the auxiliary tube 305 through the one-way valve 314, while the liquid inside the auxiliary tube 305 cannot flow back into the interior of the balloon 304. The auxiliary tubes 305 are connected to each other through the reflux pipe 315. A plurality of extrusion strips 402 are fixedly mounted on the outer surface of the movable sleeve 401. The extrusion strips 402 correspond to the balloon 304.

[0045] When the movable rod 306 moves rightward under the magnetic force of the coil, the movable sleeve 401 is driven to move in the same direction as the movable rod 306 through the auxiliary rod 302. At this time, the extrusion strip 402 on the outer surface of the movable sleeve 401 squeezes the balloon 304 to deform it.

[0046] Example 2: Please refer to Figure 5 、 Figure 10 - Figure 12 A brushless DC motor, based on Example 1, wherein the high-temperature power-off device includes an isolation sleeve 405, which is inserted into the interior of a movable sleeve 401. Two movable tubes 404 are provided at the upper and lower ends of the isolation sleeve 405, respectively. The two adjacent movable tubes 404 are connected by a matching tube 403. The movable tube 404 close to the isolation sleeve 405 is fixedly connected to the isolation sleeve 405. The matching tube 403 is made of soft silicone, while the movable tube 404 and the isolation sleeve 405 are both made of hard silicone. A plurality of through-holes are formed on the outer surface of the movable tube 404 away from the isolation sleeve 405 and the outer surface of the movable sleeve 401, so that cooling oil can penetrate into the interior of the isolation sleeve 405 through the through-holes.

[0047] The movable tube 404 located at the inner upper end of the movable sleeve 401 is rotatably connected to the inner upper end of the rotor 2 to provide a stable fulcrum, and the movable tube 404 located at the inner bottom end of the movable sleeve 401 is fixedly connected to the central tube 105.

[0048] The upper and lower ends of the inner side of the movable sleeve 401 are fixedly connected with a sealing rubber cover 412, and the sealing rubber cover 412 is fixedly connected to the outer surface of the movable tube 404 away from the isolation sleeve 405. Specifically, the sealing rubber cover 412 is made of soft silicone and has elasticity to ensure that the movable sleeve 401 does not affect the isolation sleeve 405 when being pulled by the movable rod 306. The inner end of the isolation sleeve 405 is provided with a magnetic block 406. The magnetic block 406 is triangular and the edges and corners are rounded to avoid scratching the inner wall of the isolation sleeve 405 during rotation. The upper and lower ends of the magnetic block 406 are rotatably connected to the matching rod 407 through the rotating shaft. The inner surfaces of the two movable tubes 404 are connected to the inner surfaces of the movable tubes 404. Memory metal strips 408 are pierced through the movable tube 404, and the memory metal strips 408 are respectively located on the upper and lower sides of the magnetic block 406. Specifically, the memory metal strips 408 are deformed in a high temperature environment and return to their initial state after the ambient temperature drops. A sealing plug 409 is pierced through the inner end of the movable tube 404. The sealing plug 409 is located below the magnetic block 406. The outer surface of the sealing plug 409 is covered with a sealing rubber ring and fits tightly with the inner wall of the movable tube 404 to increase the sealing performance. More specifically, a limit ring is fixedly installed on the inner end of the movable tube 404. The limit ring is located above the sealing plug 409 to limit the sealing plug 409 from moving too far upward.

[0049] like Figure 3 、 Figure 11 、 Figure 12 As shown, the upper end of the sealing plug 409 is fixedly welded to the bottom end of the memory metal strip 408, the memory metal strip 408 located above the magnetic block 406 is fixedly welded to the inner upper end of the movable tube 404, the bottom end of the sealing plug 409 is fixedly connected to the passive rod 410 by bolts, the bottom end of the inner support plate 102 is fixedly connected to the unlocking shell 201 by bolts, the trigger rod 205 is rotatably mounted on the inner left end of the unlocking shell 201, the bottom end of the passive rod 410 is fixedly mounted with two triggering protrusions 411, and the end of the triggering rod 205 away from the unlocking shell 201 is located between the two triggering protrusions 411;

[0050] Specifically, the two trigger protrusions 411 are connected in an arc shape, and the trigger rod 205 located between the two trigger protrusions 411 is arc-shaped. When the trigger protrusion 411 moves upward or downward, it squeezes the trigger rod 205 to cause it to deflect, and the trigger rod 205 is clamped to the unlocking shell 201 via a reset torsion spring.

[0051] The inner end of the unlocking shell 201 is provided with an unlocking rod 204, and the unlocking rod 204 is connected to the unlocking shell 201 by a return spring 203, and the unlocking rod 204 corresponds to the trigger rod 205. Specifically, the right end of the trigger rod 205 and the left end of the unlocking rod 204 are fixedly installed with triangular blocks, and the two triangular blocks are engaged with each other. The right end of the unlocking rod 204 is fixedly installed with a power supply head 202, and the power supply head 202 contacts the coil connector 107. When the trigger rod 205 is deflected, the two engaged triangular blocks are disengaged from each other. At this time, under the action of the elastic force of the return spring 203, the unlocking rod 204 drives the power supply head 202 to move, and is no longer connected to the coil connector 107, and stops supplying power to the coil.

[0052] like Figure 2 、 Figure 3 、 Figure 9 As shown, a cooling fan 104 is fixedly installed at the bottom end of the output shaft 3. The cooling fan 104 is located inside the rotor 2. Ventilation holes are provided at the upper end of the rotor 2, the inner support plate 102 and the outer surface of the base 1. When the output shaft 3 rotates, the cooling fan 104 rotates to allow internal air to flow, thereby increasing the heat dissipation efficiency. A cooling coil 103 is fixedly installed at the bottom end of the inner support plate 102 through a clamp. The cooling coil 103 is made of metal, which makes the heat transfer efficiency higher. The cooling coil 103 is connected to the central tube 105 through a plurality of connecting pipes 106, wherein the return pipe 315 inside the support shell 301 is connected to some of the connecting pipes 106.

[0053] The working principle of the present invention is:

[0054] During operation, current circulates through the windings on the outer surface of the support shell 301, magnetizing the support shell 301 and the stator 101. The magnetic field generated by the coils attracts the permanent magnets on the rotor 2, causing the rotor 2 to rotate. As the power-on sequence changes, the direction of the magnetic force in the windings also changes, pushing the rotor 2 to continue rotating. This in turn drives the output shaft 3 to rotate, causing the cooling fan 104 to also start rotating, and accelerating the air flow inside the rotor 2.

[0055] At the same time, the internal movable rod 306 is attracted by the magnetic force of the coil. When the movable rod 306 moves to the right, the movable plug 311 squeezes the cooling oil in the cavity of the cooling tube 308 under the action of the limiting ring to flow into the inside of the guide tube 310. At the same time, the movable sleeve 401 is driven to move in the same direction as the movable rod 306 through the auxiliary rod 302. At this time, the extrusion strip 402 on the outer surface of the movable sleeve 401 squeezes the balloon 304 to deform it. The movable rod 306 moves to the right due to the movable sleeve 401 and is pulled to the right by the auxiliary rod 302. Conversely, when the currently pulled movable rod 306 moves to the right, the movable plug 311 moves to the left and contacts the limiting ring. The guide groove 312 is completely exposed to the right side of the movable plug 311, allowing the cooling oil to enter the interior of the cooling tube 308.

[0056] The deformed balloon 304 squeezes the cooling oil inside into the auxiliary pipe 305, and eventually flows into the heat dissipation coil 103 along the return pipe 315. The air on the outer surface of the heat dissipation coil 103 is constantly flowing, thus achieving a certain heat dissipation effect.

[0057] As the magnetic fields of the multiple support shells 301 are constantly changing, the magnetic block 406 inside the isolation sleeve 405 rotates with the change of the magnetic field. If the motor is overloaded, the temperature inside the rotor 2 continues to rise, causing the cooling oil temperature inside the central cylinder 105 to become higher and higher, causing the memory metal strip 408 to deform due to the heat. At this time, the magnetic block 406 that rotates steadily will vibrate. When the memory metal strip 408 deforms, it pulls the sealing plug 409 upward. Since the magnetic block 406 is vibrating at this time, the passive rod 410 is moved upward or When the motor is powered on, the trigger rod 205 is displaced by the trigger protrusion 411, and the two interlocking triangular blocks are separated from each other. At this time, the unlocking rod 204 drives the power supply head 202 to move under the elastic force of the return spring 203, and is no longer connected to the coil connector 107, and stops supplying power to the coil, thereby realizing emergency disconnection of the power supply to the motor to prevent the heat generated by long-term overload from burning the motor. If the power supply is restored, the power supply head 202 is pushed with the help of a repair tool so that the trigger rod 205 is restored to the unlocking rod 204.

[0058] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A brushless DC motor, comprising a base, characterized in that: The upper end of the base is rotatably mounted with a rotor, and the upper end of the rotor is fixedly connected to an output shaft for transmitting mechanical power, the upper end of the base is fixedly mounted with an inner support plate, the upper end of the inner support plate is fixedly clamped with a center tube, a plurality of support shells are fixedly mounted on the outer surface of the center tube, and the support shells are arranged in a ring shape, a stator is fixedly mounted on one end of the support shell away from the center tube, the plurality of support shells are divided into three groups, and coils in different directions are wound on the outer surface of each group of support shells, a cooling device for cooling the coils is provided inside the support shell, the interior of the center tube is filled with cooling oil, and a movable sleeve is provided inside, a high-temperature power-off device is provided between the center tube and the inner support plate, when the temperature of the rotor is too high, the high-temperature power-off device can cut off the internal power supply to avoid damage to the device caused by high-temperature overload.

2. A brushless DC motor according to claim 1, characterized in that: The cooling device is composed of multiple cooling tubes and auxiliary tubes, which are distributed in a ring shape and arranged in an interlaced manner. The cooling tubes and auxiliary tubes are both installed inside the supporting shell. Multiple heat dissipation fins are fixedly installed inside the supporting shell, and the cooling tubes and auxiliary tubes are tightly fitted with the inside of the heat dissipation fins. Two adjacent cooling tubes are connected by a conducting tube.

3. A brushless DC motor according to claim 2, characterized in that: A movable rod is passed through the inner end of the cooling tube, and the movable rod is a permanent magnet. When the coil on the outer surface of the support shell is energized, a magnetic field is generated inside the support shell. According to the direction of the magnetic field, the movable rod is subjected to attractive or repulsive force and moves left and right inside the cooling tube. The cooling tube is connected to the interior of the central tube, and the movable rod and the movable sleeve are rotatably connected by an auxiliary rod. A movable plug is provided on the outer surface of the movable rod, and a plurality of conducting grooves are opened on the outer surface of the movable rod, and the movable plug corresponds to the conducting grooves.

4. A brushless DC motor according to claim 3, characterized in that: An evaporation tube is passed through the inner end of the support shell. The evaporation tube is located between two adjacent cooling tubes, and the input end of the evaporation tube is fixedly connected to the output end of the conducting tube. An evaporation sleeve is fixedly connected to the inner end of the evaporation tube, and the center diameter of the evaporation sleeve is smaller than the center diameter of the evaporation tube.

5. The brushless DC motor according to claim 1, wherein: The high-temperature power-off device includes an isolation sleeve, which is inserted into the inside of the movable sleeve. Two movable tubes are respectively provided at the upper and lower ends of the isolation sleeve. The two adjacent movable tubes are connected by a matching tube, and the movable tube close to the isolation sleeve is fixedly connected to the isolation sleeve.

6. A brushless DC motor according to claim 5, characterized in that: The upper and lower ends of the inner side of the movable sleeve are fixedly connected with a sealing rubber cover, and the sealing rubber cover is fixedly connected to the outer surface of the movable tube away from the isolation sleeve. The inner end of the isolation sleeve is provided with a magnetic block, which is triangular in shape. The upper and lower ends of the magnetic block are rotatably connected with matching rods, and the interior of the two movable tubes is penetrated by a memory metal strip.

7. A brushless DC motor according to claim 6, characterized in that: The memory metal strips are respectively located on the upper and lower sides of the magnetic block, and a sealing plug is passed through the inner end of the movable tube. The sealing plug is located below the magnetic block, the upper end of the sealing plug is fixedly connected to the bottom end of the memory metal strip, and the bottom end of the sealing plug is fixedly connected to a passive rod.

8. A brushless DC motor according to claim 7, characterized in that: The bottom end of the inner support plate is fixedly connected to an unlocking shell, the inner left end of the unlocking shell is rotatably mounted with a trigger rod, the bottom end of the passive rod is fixedly mounted with two trigger protrusions, and the end of the trigger rod away from the unlocking shell is located between the two trigger protrusions.

9. A brushless DC motor according to claim 8, characterized in that: An unlocking rod is provided at the inner end of the unlocking shell, and the unlocking rod is connected to the unlocking shell by a reset spring, and the unlocking rod corresponds to the trigger rod. A power supply head is fixedly installed at the right end of the unlocking rod, and the power supply head is in contact with the coil connector contact.

10. The brushless DC motor according to claim 1, characterized in that: A heat dissipation fan is fixedly installed on the bottom end of the output shaft, and the heat dissipation fan is located inside the rotor. A heat dissipation coil is fixedly installed on the bottom end of the inner support plate through a clamp, and the heat dissipation coil is connected to the central tube through multiple connecting pipes.

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