External rotor motor

Abstract

The invention relates to the field of motor supports with radiating fins for improving heat conduction, in particular to an external rotor motor. The external rotor motor comprises a stator support, an armature is installed on the stator support, a fixing part of a sensor is further installed on the stator support, and a heat insulation layer or a heat resistance layer is arranged between the stator support and the fixing part of the sensor. The heat insulation layer or the heat resistance layer is arranged between the stator bracket and the sensor fixing part, so that the heat transferred from the stator bracket to the sensor is effectively reduced, and the sensor is prevented from being damaged at a high temperature to influence the stable operation of the outer rotor motor.

Description

Technical Field

[0001] The invention relates to the field of a motor support with a heat sink for improving heat conduction, in particular to an outer rotor motor. Background Art

[0002] When the outer rotor motor is working, the stator armature inside the motor is energized in a specific power-on sequence to generate a rotating magnetic field. The rotor magnet located outside the electronic winding interacts with the rotating magnetic field to rotate the rotor. The sensor installed inside the motor is used to convert the rotational displacement of the internal shaft of the motor into a digital signal for precise control by the control system. When the stator armature is energized, heat is generated. Although the heat can be dissipated along the components outside the stator armature or the gaps between the components, the heat dissipation path is long and the heat is not easy to dissipate in time. Therefore, after the motor has been running for a period of time, the heat generated by the stator armature will continue to be transferred to other components inside the motor through the stator bracket. Because the heat resistance of the sensor inside the outer rotor motor is poor, when the heat is continuously transferred to the sensor, the sensor will be damaged because the temperature transferred exceeds its temperature tolerance value. The damage of the sensor will affect the stable operation of the entire outer rotor motor. Summary of the invention

[0003] The object of the present invention is to provide an outer rotor motor to solve the problem that the heat generated by the electronic armature inside the existing outer rotor motor is transferred to the sensor, causing the temperature of the sensor to exceed its temperature resistance value and be damaged, thereby affecting the operating stability of the outer rotor motor.

[0004] To achieve the above purpose, the outer rotor motor of the present invention adopts the following technical solutions: An outer rotor motor comprises a stator bracket, an armature is mounted on the stator bracket, a fixed part of a sensor is also mounted on the stator bracket, a heat insulating layer or a heat resisting layer is arranged between the stator bracket and the fixed part of the sensor, and the thermal conductivity of the heat resisting layer is smaller than the thermal conductivity of the stator bracket.

[0005] Furthermore, the stator bracket is a cylindrical structure, and the heat-resistant layer is a metal cylinder sleeved between the stator bracket and the fixed part of the sensor.

[0006] Furthermore, a heat dissipation structure or a heat storage structure is also provided on the stator bracket.

[0007] Furthermore, the armature is located outside the stator bracket, and the heat insulation layer or heat resistance layer and the heat dissipation structure or heat storage structure are all located inside the stator bracket.

[0008] Furthermore, the rotor of the outer rotor motor includes a core shaft located on the inner side of the stator bracket and a rotor cylinder connected to the end of the core shaft and sleeved on the outer side of the armature. The core shaft and the stator bracket are rotatably matched through a middle bearing, and the heat-resistant structure and the heat-dissipating structure are located on both sides of the middle bearing.

[0009] Furthermore, an end bearing is provided at the end of the stator bracket, the outer ring of the end bearing is connected to the rotor cylinder, and the inner ring is connected to the stator bracket.

[0010] Furthermore, the heat dissipation structure is a fin-type heat dissipation structure.

[0011] Furthermore, the fin-type heat dissipation structure includes a cylinder portion sleeved on the circumferential surface of the stator support and fins arranged on the cylinder portion.

[0012] Furthermore, the core shaft is a hollow core shaft, and the fin-type heat dissipation structure has a central through hole, which is coaxial with and communicated with the core shaft.

[0013] Furthermore, the sensor is an encoder, and the fixed part of the sensor is the fixed part of the encoder.

[0014] Beneficial effect: The outer rotor motor of the present invention is an improved invention. Specifically, a heat insulating layer or a heat-resistant layer is arranged between the stator bracket and the sensor fixing part, which effectively reduces the heat transferred from the stator bracket to the sensor, and avoids damage to the sensor under high temperature conditions and affects the stable operation of the outer rotor motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic structural diagram of an embodiment of an outer rotor motor of the present invention; Figure 2 for Figure 1 A schematic diagram of a fin-type heat dissipation structure from another perspective in an embodiment.

[0016] In the figure: 1. armature; 2. fin type heat dissipation structure; 21. cylinder; 22. fin; 3. stator bracket; 4. metal cylinder; 5. encoder; 6. rotor cylinder; 7. core shaft; 8. end bearing; 9. middle bearing. DETAILED DESCRIPTION

[0017] The outer rotor motor of the present invention is mainly a motor used in situations where short-term starting is required. A heat insulation layer or a heat resistance layer is arranged on the temperature transfer path between the stator bracket and the sensor inside the outer rotor motor. During the time period when the outer rotor motor is running, the heat insulation layer or the heat resistance layer prevents the heat at the stator bracket from being transferred to the sensor, so that the temperature at the sensor is kept below its temperature resistance value.

[0018] Based on the above concept, as a basic embodiment, the sensor takes an encoder as an example, such as Figure 1 As shown, the outer rotor motor of the present invention includes a stator bracket 3, an armature 1 is mounted on the stator bracket 3, and a fixed part of an encoder 5 is also mounted on the stator bracket 3. The stator bracket 3 is a cylindrical structure, and the armature 1 is located outside the stator bracket 3. The rotor of the outer rotor motor includes a core shaft 7 located inside the stator bracket and a rotor barrel 6 connected to the end of the core shaft 7 and sleeved on the outside of the armature 1. The core shaft 7 is an internal hollow structure, and is rotatably matched with the stator bracket 3 through the middle bearing 9. The rotating part of the encoder 5 is connected to the core shaft and rotates with the core shaft. An end bearing 8 is provided at the end of the stator bracket 3, and the outer ring of the end bearing 8 is connected to the rotor barrel 6, and the inner ring is connected to the stator bracket 3. In other embodiments, the sensor can also be other types of sensors such as a rotary transformer and a Hall sensor, but the fixed part of the sensor needs to be installed on the stator bracket.

[0019] In one embodiment, a heat-resisting layer is provided between the stator support 3 and the fixed part of the encoder 5, and the heat-resisting layer is located inside the stator support 3. The thermal conductivity of the heat-resisting layer is less than the thermal conductivity of the stator support, so the heat transfer efficiency of the heat-resisting layer is low. The heat-resisting layer is a metal cylinder 4 sleeved between the stator support 3 and the fixed part of the encoder 5, and the thermal conductivity of the metal cylinder 4 is less than the thermal conductivity of the stator support 3. When the heat generated by the armature 1 of the stator part is transferred to the encoder 5 through the stator support 3, since the thermal conductivity of the metal cylinder 4 is less than the thermal conductivity of the stator support 3, the heat transfer efficiency of the metal cylinder 4 is low, and the heat transferred to the inside of the encoder 5 within a certain period of time is small, which ensures that the temperature at the encoder 5 is below the temperature resistance value of the encoder 5 during the operation of the external rotor motor, and the metal cylinder 3 has a certain strength and toughness, which can ensure that the metal cylinder maintains its structural stability when subjected to high temperatures. The thickness of the heat-resistance layer is adjustable. By increasing the thickness of the heat-resistance layer, the heat transfer efficiency of the heat-resistance layer can be greatly reduced, thereby reducing the amount of heat transferred from the stator bracket 3 to the encoder 5 within a certain period of time.

[0020] In another embodiment, a heat insulation layer is provided between the stator bracket 3 and the fixed part of the encoder 5, and the heat insulation layer is located on the inner side of the stator bracket 3. The heat insulation layer is a heat insulation composite layer structure made of a heat insulation material, and the good heat insulation performance of the heat insulation material can effectively slow down the heat transfer from the stator bracket 3 to the encoder, so that the temperature at the encoder can be kept below the temperature resistance value of the encoder 5 during the operation of the outer rotor motor, thereby ensuring the stable operation of the outer rotor motor.

[0021] In order to further disperse the heat transferred from the armature 1 to the encoder 5, in one embodiment, a heat dissipation structure is provided on the stator bracket 3, and the heat dissipation structure is located on the inner side of the stator bracket 3. The heat dissipation structure is a fin-type heat dissipation structure 2, such as Figure 2As shown, the fin type heat dissipation structure 2 and the metal cylinder 4 are respectively located on both sides of the middle bearing 9, and the fin type heat dissipation structure 2 includes a cylinder part mounted on the circumferential surface of the stator bracket 3 and fins installed on the cylinder part. The central part of the cylinder has a central through hole formed by the fins, and the through hole is coaxial with and communicated with the core shaft 7. When the heat generated by the stator armature 1 is transferred to the inner side of the stator bracket 3 through the stator bracket 3, the heat is transferred to the air between the fins through the fins, and the heat in the air is dissipated upward along the inside of the core shaft 7 through the central through hole of the fin type heat dissipation structure 2 or from the bottom of the fin type heat dissipation structure. The fin type heat dissipation structure 2 effectively disperses the heat transferred by the armature 1, so that the heat transferred from the stator bracket 3 to the encoder 5 is reduced. In other embodiments, the heat dissipation structure can also be covered with a heat dissipation pipe structure on the inner cylinder wall of the stator bracket 3. The heat dissipation pipe structure can dissipate part of the heat transferred from the armature 1 to the stator bracket 3, thereby reducing the heat on the stator bracket 3 and reducing the heat transferred from the stator bracket 3 to the encoder 5.

[0022] In order to further disperse the heat transferred from the armature 1 to the encoder 5, in another embodiment, a heat storage structure is provided on the stator bracket 3, and the heat storage structure is located on the inner side of the stator bracket 3. The heat storage structure is a phase change heat storage block structure covering the inner wall of the stator bracket 3. When the heat generated by the armature 1 is transferred in through the stator bracket 3, the phase change heat storage block structure can absorb part of the heat transferred from the stator bracket 3, thereby reducing the heat on the stator bracket 3 and reducing the heat transferred from the stator bracket 3 to the encoder 5.

[0023] The heat dissipation structure or heat storage structure disperses the heat transferred from the armature 1 through the stator bracket 3, thereby reducing the heat on the stator bracket 3, thereby reducing the heat transferred from the stator bracket 3 to the encoder 5. The heat then further passes through the heat insulation layer or heat resistance layer between the stator bracket 3 and the encoder 5. The heat insulation layer or heat resistance layer blocks the heat, so that less heat is transferred to the encoder 5, so that the encoder 5 will not be damaged due to excessive temperature, thereby ensuring the normal and stable operation of the outer rotor motor.

[0024] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the contents of the description and drawings of the present invention should also be included in the protection scope of the present invention.

Claims

1. An outer rotor motor, comprising a stator support, an armature mounted on the stator support, and a fixed part of a sensor mounted on the stator support, characterized in that: A heat insulating layer or a heat resistant layer is provided between the stator support and the fixed part of the sensor, and the thermal conductivity of the heat resistant layer is smaller than the thermal conductivity of the stator support.

2. The outer rotor motor according to claim 1, characterized in that: The stator bracket is a cylindrical structure, and the heat-resistance layer is a metal cylinder sleeved between the stator bracket and the fixed part of the sensor.

3. The outer rotor motor according to claim 1, characterized in that: The stator bracket is also provided with a heat dissipation structure or a heat storage structure.

4. The outer rotor motor according to claim 3, characterized in that: The armature is located on the outside of the stator bracket, and the heat insulation layer or heat resistance layer and the heat dissipation structure or heat storage structure are all located on the inside of the stator bracket.

5. The outer rotor motor according to claim 4, characterized in that: The rotor of the outer rotor motor includes a core shaft located inside the stator bracket and a rotor cylinder connected to the end of the core shaft and sleeved on the outside of the armature. The core shaft and the stator bracket are rotatably matched through the middle bearing, and the heat resistance layer and the heat dissipation structure are located on both sides of the middle bearing.

6. The outer rotor motor according to claim 5, characterized in that: An end bearing is arranged at the end of the stator bracket, the outer ring of the end bearing is connected to the rotor cylinder, and the inner ring is connected to the stator bracket.

7. The outer rotor motor according to claim 5 or 6, characterized in that: The heat dissipation structure is a fin-type heat dissipation structure.

8. The outer rotor motor according to claim 7, characterized in that: The fin type heat dissipation structure comprises a cylinder part sleeved on the circumferential surface of the stator support and fins arranged on the cylinder part.

9. The outer rotor motor according to claim 8, characterized in that: The core shaft is a hollow core shaft, and the fin-type heat dissipation structure has a central through hole, which is coaxial with and communicated with the core shaft.

10. The outer rotor motor according to any one of claims 1 to 6, characterized in that: The sensor is an encoder, and the fixed part of the sensor is the fixed part of the encoder.

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