Brushless motor and detection system thereof

Abstract

The invention provides a brushless motor and a detection system thereof. The heat conduction layer is arranged on the stator, and the heat conduction rod is led out from the inner wall of the stator to the convection cavity between the stator and the casing, so that on one hand, heat in the motor is led out through the heat conduction layer and the heat conduction rod, and on the other hand, the heat can be effectively replaced to the outside of the motor through the circulating cooling medium in the casing; and the effective cooling of the inner core part of the motor is realized. The stator is sealed by using the casing cover of the motor, so that the influence on the power output of the motor when the temperature of the motor cannot be reduced in the existing immersion method can be effectively avoided. According to the motor, heat of the motor body can be conducted to the surface of the motor shell body through the multiple heat conduction rods, the heat dissipation area is enlarged, the heat dissipation effect is enhanced, through the heat conduction and condensation medium heat exchange principle, the temperature rise of the motor shell body is reduced, and the temperature of the motor shell body and the temperature of the motor body are controlled.

Description

Technical Field

[0001] The present application relates to the field of brushless motor equipment, and in particular to a brushless motor and a detection system thereof. Background Art

[0002] The motor generates heat during operation due to resistance loss, core hysteresis, eddy current loss and mechanical friction. In particular, for brushless motors with large torque output or high speed, if the heat generated during the operation of the motor is not intervened, it is easy to cause the motor to overheat, affecting the output efficiency and life of the motor, and in extreme cases, it may even cause damage to the motor.

[0003] Existing motor cooling technologies usually use air cooling or condensing media. Air cooling technology will introduce additional wind resistance when the motor speed is high, resulting in a waste of motor output power. The condensing medium has a slow flow rate, which will affect the power output of the motor when the immersion method is used. When the condensing medium is used to cool the outside of the motor, it is easy for the water vapor in the air to form condensed water on the inner wall of the motor housing or the inner wall of the junction box, thereby corroding the insulation layer and metal parts of the motor and accelerating the aging of the motor.

[0004] In addition, the existing cooling method cannot make real-time adjustments according to the temperature of the motor, especially it cannot dynamically keep the motor in the optimal temperature range according to the changes in environmental conditions, thus affecting the working efficiency of the motor. For example, when liquid cooling or wind power is overused, the motor temperature will be too low, affecting its transmission output performance, and excessive use of air cooling and liquid cooling will also lead to huge waste of resources. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present application provides a brushless motor and a detection system thereof. The present application sets the motor stator to a surface material with high thermal conductivity and directly leads the heat-conducting rod from the inner layer of the stator to the outer layer, so as to use the cooling medium of the outer layer to cool the motor. The present application specifically adopts the following technical solutions.

[0006] Firstly, to achieve the above-mentioned purpose, a brushless motor and its detection system are proposed, comprising a stator and a rotor enclosed in a motor housing, wherein at least a heat-conducting layer is provided on the inner wall of the stator, and a heat-conducting rod led out from the inner wall is also provided in the stator; the end of the stator is sealed in a housing cover, and a temperature detection device and a medium pipe are provided on the housing cover, the temperature detection device abuts against the end of the stator, and the medium pipe is connected to a cavity between the motor housing and the stator, and a cooling medium is circulated in the cavity according to the temperature detected by the detection device.

[0007] Optionally, a brushless motor and its detection system as described in any of the above, wherein the stator includes a plurality of installation cavities for installing stator components, the side walls of the installation cavities are led outward to the cavity between the motor housing and the stator to form the heat-conducting rod, and a positioning support plate is also provided on the outer wall of the stator, and the positioning support plate extends outward and is fixed to the inner wall of the motor housing to fix the motor.

[0008] Optionally, in a brushless motor and detection system thereof as described in any of the above, the surfaces of the heat-conducting layer and the heat-conducting rod are respectively coated with an aluminum nitride layer; a temperature sensing device is also embedded in the housing cover at the end of the stator at the position of the heat-conducting layer; the temperature sensing device detects the temperature of the heat-conducting layer in real time and triggers the adjustment of the flow rate and / or temperature of the cooling medium in the medium pipe according to the temperature.

[0009] Optionally, a brushless motor and its detection system as described in any of the above, wherein the front end of the positioning support plate abuts against the casing cover, the outer side of the positioning support plate abuts against the positioning groove on the inner wall of the motor casing, and a spacing distance is left between the rear end of the positioning support plate and the bottom of the motor casing; the positioning support plate divides the space between the motor casing and the stator into: two circumferential convection chambers and a spoiler chamber located at the rear of the stator; one side of the casing cover is provided with an input pipe for inputting cooling medium into one of the convection chambers, and the other side of the casing cover is provided with a receiving The output pipe of the cooling medium output by the other convection cavity; one end of the stator is closed by the casing cover, and the stator is also set as a double-layer closed structure on the side away from the casing cover, and the spoiler cavity is located between the bottom of the motor casing and the closed structure of the stator; the ends of at least some of the heat-conducting rods in the stator protrude from the closed structure surface of the stator and extend toward the spoiler cavity; the cooling medium flows from the input pipe through the convection cavity into the spoiler cavity, and then flows out from the output pipe of the convection cavity on the other side, and each heat-conducting rod and the support plate are cooled by the convection of the cooling medium.

[0010] Optionally, in any of the above brushless motors and detection systems thereof, the step of adjusting the flow rate of the cooling medium in the medium pipe according to the temperature trigger specifically comprises: collecting the temperatures of the cooling medium input pipe and the output pipe respectively, and adjusting the flow rate of the cooling medium according to the temperature difference Δt between the two pipes when the temperature difference Δt between the two pipes increases. The flow rate is increased in proportion until the temperature difference between the cooling medium inlet pipe and the outlet pipe is stable, where ξ represents the thermal circumference of the channel between the motor housing and the stator, in m; L represents the length of the channel through which the cooling medium passes, in m; W is the temperature at the bottom of the stator heat conduction rod, w is the temperature of the cooling medium in the turbulent cavity, and T is the original temperature of the cooling medium inlet pipe.

[0011] Optionally, in any of the above brushless motors and detection systems thereof, the step of adjusting the temperature of the cooling medium in the medium pipe according to the temperature trigger specifically comprises: collecting the temperatures of the cooling medium input pipe and the cooling medium output pipe respectively, and adjusting the temperature of the cooling medium input pipe and the cooling medium output pipe according to the temperature difference Δt between the two pipes when the temperature difference Δt increases. The temperature of the cooling medium is reduced until the temperature of the cooling medium outlet pipe reaches the same temperature as the stator outer wall surface temperature or the difference is less than the preset value; wherein, K p , K i , K d are constants obtained in advance, and τ represents the interval between the two temperature differences Δt1 and Δt2.

[0012] Optionally, a brushless motor and a detection system thereof as described in any of the above, wherein the heat-conducting rods and the positioning support plates are symmetrically arranged along the circumference of the stator, wherein the positioning support plates are arranged on the outer wall of the stator opposite to each other, and there are at least two pairs of them; and the heat-conducting rods are arranged at equal intervals between each positioning support plate.

[0013] Optionally, a brushless motor and its detection system as described in any of the above, wherein the stator is configured as a double-layer structure, a heat-conducting medium is provided between the inner and outer layers, and the heat-conducting rod of the inner layer at least extends its end to the surface of the outer layer; the double-layer structure, the heat-conducting rod and the support plate are respectively provided with an aluminum nitride layer formed according to the following steps: sandblasting to remove the oxide layer on the upper surface of the inner and outer layer structures of the stator alone, spraying aluminum nitride and aluminum powder particles, sintering at 400-700°C in a nitrogen atmosphere, and then annealing in a straight-chain or branched aliphatic hydrocarbon having a carbon number of 5-15.

[0014] Optionally, in any of the brushless motors and detection systems described above, the annealing temperature is controlled between 200 and 300°C.

[0015] Beneficial Effects

[0016] The brushless motor and its detection system provided by the present application are provided with a heat-conducting layer on the stator, and the heat-conducting rod is led out from the inner wall of the stator to the convection cavity between the stator and the casing, so that, on the one hand, the heat inside the motor is led out through the heat-conducting layer and the heat-conducting rod, and on the other hand, the heat can be effectively replaced to the outside of the motor by the cooling medium circulating in the casing, so as to achieve effective cooling of the inner core part of the motor. The present application uses the casing cover of the motor to seal the stator, so as to effectively avoid the influence of the existing immersion method on the power output of the motor when reducing the temperature of the motor. The motor of the present application can conduct the heat of the motor body to the surface of the motor housing body through multiple heat-conducting rods, expand the heat dissipation area and enhance the heat dissipation effect, and reduce the temperature rise of the motor housing body through the principle of heat conduction and heat exchange of the condensing medium, and control the temperature of the motor housing body and the motor body.

[0017] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent from the description, or may be understood by practicing the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings:

[0019] Figure 1 is a schematic diagram of the cross-sectional structure of the brushless motor of the present application;

[0020] Figure 2 is a schematic diagram of the longitudinal cross-sectional structure of the brushless motor of the present application;

[0021] In the figure, 1 represents the motor housing; 2 represents the stator; 20 represents the inner wall of the stator; 21 represents the heat conducting rod; 22 represents the positioning support sheet; 3 represents the rotor; and 31 represents the output shaft. DETAILED DESCRIPTION

[0022] In order to make the purpose and technical solution of the embodiment of the present application clearer, the technical solution of the embodiment of the present application will be clearly and completely described in conjunction with the drawings of the embodiment of the present application. Obviously, the described embodiment is a part of the embodiment of the present application, not all of the embodiments. Based on the described embodiment of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0023] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0024] Figure 1 A brushless motor and its detection system according to the present application include a stator 2 and a rotor 3 enclosed in a motor housing 1, a detection device arranged on the motor housing, and a pipeline and a medium temperature control system for feeding a cooling medium into the stator external circulation. In the present application, at least a heat-conducting layer is arranged on the inner wall of the stator, and a heat-conducting rod 21 is also arranged in the stator extending from the inner wall 20;

[0025] The end of the stator is sealed in the casing cover, and the casing cover is also connected to a medium pipe, which is connected to the cavity between the motor casing and the stator, and provides cooling medium for circulation in the cavity. The heat inside the motor is transferred to the cooling medium outside the stator through the heat conductive layer and the heat conductive rod. The motor is cooled by the circulation of the cooling medium, thereby improving the operating efficiency of the motor.

[0026] Specific reference Figure 2 As shown, the stator of the present application can be set as a polygonal prism structure according to the driving needs, or it can be directly set as a cylindrical shape. It includes two layers of inner and outer side walls, and a heat-conducting rod 21 and a positioning support sheet 22 are arranged between the inner and outer side walls to separate a number of installation cavities, and each installation cavity is used to install the stator original corresponding to different rotation angles of the motor. The side wall of the installation cavity can lead the heat-conducting rod 21 and the positioning support sheet 22 radially outward to the cavity between the motor housing and the stator to form a heat dissipation structure. In some implementations, the positioning support sheet 22 can be separately arranged on the outer side wall of the stator to improve the coherence of the internal installation cavity of the stator and facilitate the layout of the internal circuit components. The positioning support sheet 22 extends outward and abuts and is fixed on the inner wall of the motor housing to fix the motor. As a result, the heat-conducting rod 21 can transfer the heat received by the inner wall of the stator to the cavity between the outer wall of the stator and the motor housing, and the cooling medium circulating in the cavity is used to cool and control the temperature of the motor.

[0027] In order to improve the heat transfer efficiency of the motor stator, the present application preferably coats the heat-conducting layer on the inner wall of the motor stator and the surface of the heat-conducting rod 21 with aluminum nitride material. Aluminum nitride material has sufficient surface strength and has the characteristics of insulation and non-magnetic conductivity, and will not cause any interference to the internal electromagnetic field state of the motor.

[0028] The present application preferably sets the temperature sensing device in the detection system in the casing cover at the end of the stator. The outer periphery of the casing cover is sealed with the motor housing, and the inside of the casing cover is provided with a circular groove structure that matches the end face of the stator. The circular groove structure is embedded with a temperature sensing device that is connected to the heat-conducting layer to realize the actual detection of the internal temperature of the motor and provide sealing for the stator mounting cavity of the motor. The rotor of the motor is driven to rotate by an alternating electromagnetic field in the stator cavity, driving the output shaft 31 connected to the casing cover and held in rotation by a sealed bearing to operate, thereby realizing torque output. The temperature sensing device detects the temperature of the heat-conducting layer in real time and triggers the flow rate and / or temperature of the cooling medium in the regulating medium pipe according to the temperature.

[0029] In order to improve the heat exchange effect of the cooling medium, the present application preferably adopts the front end of the positioning support plate 22 Figure 2 Left way, so that it faces Figure 2 The left side abuts against the elastic sealing pad layer provided on the inner wall of the housing cover, and the outer side of the positioning support sheet 22 corresponds to Figure 2 The upper and lower ends of the stator can be abutted against the positioning grooves on the inner wall of the motor housing, and the stator is suspended and supported inside the motor housing. The rear end of the positioning support sheet 22 can be spaced apart from the bottom of the motor housing to form a cavity structure that provides turbulence for the cooling medium. Thus, the two positioning support sheets 22 arranged opposite to each other on the outer periphery of the stator can divide the U-shaped space between the motor housing and the stator into: two convection cavities arranged opposite to each other along the outer diameter of the stator in the circumferential direction and a turbulence cavity located at the rear of the stator;

[0030] An input pipe for inputting a cooling medium into one of the convection cavities is disposed on one side of the casing cover, and an output pipe for receiving the cooling medium outputted by another convection cavity is disposed on the other side of the casing cover. The input pipe and the output pipe are respectively connected to the inlet and outlet of the compressor outside the system. The cooling medium is cooled by the compressor outside the motor to remove the heat of the motor, and a cooling medium with a lower temperature is provided to the motor to realize real-time regulation of the operating temperature of the motor.

[0031] One end of the stator is closed by the housing cover, and the bottom of the stator is also set as a double-layer closed barrel structure on the side away from the housing cover, and the spoiler cavity corresponds to the space between the bottom of the motor housing and the bottom plate of the closed barrel structure of the stator. In a more preferred implementation, the positioning support sheet 22 is arranged vertically inside the housing, and the space between the housing and the stator is divided into two left and right convection chambers, wherein an input pipe is set at the bottom of one convection chamber. An output pipe is set in the convection chamber on the other side. One side of the space realizes the supply of cooling medium through the convection chamber with the input pipe located at the bottom, and the other side discharges the cooling medium through another convection chamber with the output pipe located at the top. The cooling medium enters the turbulent cavity from the bottom of the motor. On the one hand, the newly input cooling medium gradually fills the above three cavities from bottom to top, and squeezes the medium originally injected into the cavity and has absorbed heat to form a higher temperature to the top of the cavity and is discharged through the output pipe; on the other hand, since the output and the output are respectively passed through two convection cavities arranged opposite to each other in the longitudinal direction, and their ends are respectively connected to the left and right sides of the turbulent cavity, a lateral turbulence can be formed in the turbulent cavity, so that the newly input medium can form a lateral circulating turbulence between the three cavities while raising its exchange liquid level in the longitudinal direction, so as to keep the temperature of the motor stator in all directions uniform, and avoid the temperature control imbalance caused by the better cooling effect of unidirectional convection at the inlet position and the poorer cooling effect at the outlet position.

[0032] In addition, the ends of at least some of the heat-conducting rods 21 in the stator can also extend backward so that they protrude from the closed structure surface of the stator and extend toward the spoiler cavity to block the flow direction of the newly input medium in the spoiler cavity. The cooling medium flows from the input pipe through the convection cavity into the spoiler cavity, and then flows out from the output pipe of the convection cavity on the other side. In this process, each heat-conducting rod 21 and the support sheet cause the cooling medium to form a tiny turbulence in the spoiler cavity, prolonging its residence time, thereby prolonging the flow path of the medium during its heat exchange process, increasing the circulation path of the medium, and prolonging its heat exchange process, so that the convection of the cooling medium allows the medium to extend the contact time and contact area with the outer wall of the stator and the heat-conducting rod through turbulence, thereby improving its heat exchange effect.

[0033] The detection system of the present application triggers the flow rate of the cooling medium in the medium pipe to be adjusted according to the following steps after receiving the stator temperature detected by the temperature sensor device on the motor cover:

[0034] Collect the temperature of the cooling medium input pipe and output pipe respectively, and when the temperature difference Δt between the two increases, The flow rate is increased in proportion to the temperature sensor data at the preset interval Y1 until the temperature difference between the cooling medium input pipe and the output pipe is stable. Wherein, ξ represents the thermal circumference of the channel between the motor housing and the stator, in m; L represents the length of the channel through which the cooling medium passes, in m; W is the temperature at the bottom of the stator heat-conducting rod 21, w is the temperature of the cooling medium in the turbulent cavity, and T is the original temperature of the cooling medium input pipe. Such a flow rate adjustment ratio can dynamically adjust the contact time between the medium and the heat source introduced by the stator during the heat exchange process according to the heat exchange efficiency of the cooling medium and the temperature difference before and after the heat exchange, so that the exchange medium absorbs the heat energy of the motor as much as possible and discharges the heat from the motor.

[0035] At the same time, the system of the present application further triggers the adjustment of the temperature of the cooling medium in the medium pipe according to the temperature: when the temperature sensing device in the pipeline or externally arranged on the outer wall of the input and output pipelines respectively collects the temperatures of the cooling medium input pipe and the output pipe, the temperature of the input pipe before the interval time τ and the temperature of the output pipe after the interval time τ are obtained according to the preset interval time τ, and the temperature difference Δt is calculated. When the temperature difference Δt increases within a period of time, the temperature difference Δt is adjusted according to the temperature difference Δt. The temperature of the cooling medium is reduced until the temperature of the cooling medium outlet pipe reaches the same temperature as the stator outer wall surface temperature or the difference is less than the preset value; wherein, K p , K i , K dare constants obtained in advance training, τ represents the interval between the two temperature difference collection moments Δt1 and Δt2, and Δt1 and Δt2 represent the temperature difference between the input pipe and the output pipe collected at the two temperature difference collection moments. In this way, the present application can obtain the medium temperature that matches the current cooling medium heat exchange efficiency and maximizes its heat exchange efficiency through the change of the temperature difference of the pipeline, thereby improving the cooling efficiency of the motor as a whole and reducing the energy consumption of the external compressor cooling process.

[0036] The present application arranges the heat-conducting rod 21 and the positioning support sheet 22 symmetrically along the circumference of the stator so that they are arranged horizontally at different heights along the stator. On the one hand, the positioning and installation of the internal drive component of the motor can be realized by at least two pairs of the positioning support sheets 22 arranged opposite to each other on the outer wall of the stator. On the other hand, the horizontal circulation of the cooling medium can be formed in the interconnected cavity space inside the motor to increase the contact area between the medium and the motor stator, thereby promoting the absorption of the heat of the stator. The heat-conducting rod 21 is arranged between each positioning support sheet 22 at equal intervals, and can also provide drainage and guidance for the cooling medium in the motor, so that it can evenly obtain the heat on the surface of the stator. On the other hand, it can also reduce the resonance frequency of the motor mechanical structure through its contact with the cooling medium during the rotation of the motor, and use the extrusion of the cooling medium during the vibration of the heat-conducting rod driven by the motor operation to counteract the vibration inside the motor, so that the motor mechanical structure is more stable.

[0037] When constructing the motor of the present application, it is generally preferred to set the stator as a double-layer barrel structure, and the corresponding solid or liquid heat-conducting medium can be filled between the inner and outer layers between the electrical components of the stator and the installation cavity to promote the discharge of heat inside the motor. The heat-conducting medium can be an insulating polymer heat-conducting material, and the inner layer of the heat-conducting rod 21 at least extends its end to the outer surface to contact the cooling medium outside the stator to increase the heat dissipation area. The double-layer structure of the stator, the heat-conducting rod 21 and the support plate 22 are respectively provided with aluminum nitride layers formed according to the following steps:

[0038] After obtaining a stator structure with double inner and outer layers of barrels and attached with a heat-conducting rod 21 and a supporting plate 22 through a die-casting or welding process, the oxide layer on the upper surface of the inner and outer layers of the stator is first removed by sandblasting, and then aluminum nitride and aluminum powder particles are sprayed on the surface. The stator is sintered at 400 to 700°C using a nitrogen atmosphere to isolate the oxidation reaction. The sintered stator can be immersed in a straight-chain or branched aliphatic hydrocarbon with a carbon number of 5 to 15 for annealing. The annealing temperature is controlled between 200 and 300°C to effectively increase the toughness of the surface heat-conducting layer, so that it can effectively absorb the vibration caused by the rotation of the motor, improve the stability of the motor operation, and at the same time ensure that the heat-conducting layer stably feeds the motor heat into the cooling medium during the vibration to achieve heat exchange and reduce the operating temperature of the motor.

[0039] The above is only an implementation method of the present application, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present application. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present application, which all belong to the protection scope of the present application.

Claims

1. A brushless motor and a detection system thereof, comprising a stator and a rotor enclosed in a motor housing, characterized in that: A heat-conducting layer is provided at least on the inner wall of the stator, and a heat-conducting rod (21) extending from the inner wall (20) is also provided in the stator; The end of the stator is sealed in the casing cover, and a temperature detection device and a medium pipe are provided on the casing cover. The temperature detection device abuts against the end of the stator, and the medium pipe is connected to the cavity between the motor casing and the stator. Cooling medium is circulated in the cavity according to the temperature detected by the detection device.

2. The brushless motor and detection system thereof according to claim 1, characterized in that: The stator comprises a plurality of installation cavities for installing stator components, the side walls of the installation cavities are led outwards to a cavity between a motor housing and the stator to form the heat conducting rod (21), and a positioning support sheet (22) is also provided on the outer wall of the stator, the positioning support sheet (22) extends outwards and is fixedly abutted against the inner wall of the motor housing to fix the motor.

3. The brushless motor and detection system thereof according to claim 1, characterized in that: The surfaces of the heat-conducting layer and the heat-conducting rod (21) are respectively coated with an aluminum nitride layer; a temperature sensing device is also embedded in the housing cover at the end of the stator at the position of the heat-conducting layer; the temperature sensing device detects the temperature of the heat-conducting layer in real time and triggers the adjustment of the flow rate and / or temperature of the cooling medium in the medium pipe according to the temperature.

4. The brushless motor and detection system thereof as claimed in claim 3, characterized in that: The front end of the positioning support piece (22) abuts against the housing cover, the outer side of the positioning support piece (22) abuts against the positioning groove on the inner side wall of the motor housing, and a spacing distance is left between the rear end of the positioning support piece (22) and the bottom of the motor housing; The positioning support sheet (22) divides the space between the motor housing and the stator into two circumferential convection chambers and a spoiler chamber located at the rear of the stator; An input pipe for inputting a cooling medium into one of the convection cavities is disposed on one side of the housing cover, and an output pipe for receiving the cooling medium outputted by another convection cavity is disposed on the other side of the housing cover; One end of the stator is closed by the housing cover, and the stator is also provided with a double-layer closed structure on a side away from the housing cover, and the spoiler cavity is located between the bottom of the motor housing and the closed structure of the stator; The ends of at least some of the heat-conducting rods (21) in the stator protrude outward from the closed structure surface of the stator and extend toward the spoiler cavity; The cooling medium flows from the input pipe through the convection cavity into the turbulent cavity, and then flows out from the output pipe of the convection cavity on the other side. Each heat-conducting rod (21) and the supporting sheet are cooled by the convection of the cooling medium.

5. The brushless motor and detection system thereof as claimed in claim 4, characterized in that The step of adjusting the flow rate of the cooling medium in the medium pipe according to the temperature trigger specifically includes: The temperature of the cooling medium input pipe and output pipe is collected separately, and the temperature difference between the two is Increase according to The flow rate is increased in proportion to the temperature difference between the cooling medium input pipe and the output pipe until the temperature difference between the cooling medium input pipe and the output pipe is stable, wherein ξ represents the thermal circumference of the channel between the motor housing and the stator, in m; L represents the length of the channel through which the cooling medium passes, in m; W is the temperature of the bottom of the stator heat conducting rod (21), w is the temperature of the cooling medium in the turbulent cavity, and T is the original temperature of the cooling medium input pipe.

6. The brushless motor and detection system thereof according to claim 4, characterized in that: The step of adjusting the temperature of the cooling medium in the medium pipe according to the temperature trigger specifically includes: collecting the temperatures of the cooling medium input pipe and the output pipe respectively, and calculating the temperature difference between the two. Increase according to + The temperature of the cooling medium is reduced until the temperature of the cooling medium output pipe reaches the same temperature as the surface temperature of the stator outer wall or the difference is less than a preset value; wherein, , , are the constants obtained in pre-training, Indicates the temperature difference between the two The interval time between.

7. The brushless motor and detection system thereof as claimed in claims 1 to 5, characterized in that: The heat conducting rods (21) and the positioning support sheets (22) are symmetrically arranged along the circumference of the stator, wherein the positioning support sheets (22) are arranged opposite to each other on the outer wall of the stator, and there are at least two pairs of them; the heat conducting rods (21) are arranged at equal intervals between the positioning support sheets (22).

8. The brushless motor and detection system thereof according to claim 6, characterized in that: The stator is configured as a double-layer structure, wherein a heat-conducting medium is disposed between the inner and outer layers, and the heat-conducting rod (21) of the inner layer at least extends its end to the surface of the outer layer; the double-layer structure, the heat-conducting rod (21) and the support sheet (22) are respectively provided with an aluminum nitride layer formed according to the following steps: The oxide layer on the upper surface of the stator's separate inner and outer layer structures is removed by sandblasting, aluminum nitride and aluminum powder particles are sprayed, sintering is performed at 400-700°C in a nitrogen atmosphere, and then annealing is performed in a straight-chain or branched aliphatic hydrocarbon with a carbon number of 5-15.

9. The brushless motor and detection system thereof as claimed in claim 9, characterized in that: The annealing temperature is controlled between 200 and 300°C.

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