Cooling air duct and motor thereof

Abstract

The utility model relates to a cooling air duct and a motor thereof, the top of a motor housing close to one side of a shaft extension end is provided with an air inlet, an end cover of a non-shaft extension end is provided with an air outlet, and a stator iron core and a rotor iron core are provided with ventilation holes along the axial direction; an air inlet cavity is formed between the shaft extension end cover and the stator core, an air outlet cavity is formed between the non-shaft extension end cover and the stator core, an air inlet in the top of the motor shell is communicated with the air inlet cavity, and an air outlet in the non-shaft extension end cover is communicated with the air outlet cavity. The ventilation holes in the stator iron core and the ventilation holes in the rotor iron core are communicated with the air inlet cavity and the air outlet cavity; a circulation path from the stator iron core ventilation hole to the air outlet cavity is a first air channel, a circulation path from an axial air gap between the stator iron core and the rotor iron core to the air outlet cavity is a second air channel, and a circulation path from the rotor iron core ventilation hole to the air outlet cavity is a third air channel. According to the scheme, the cooling effect is better than that of a design scheme in the prior art.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, in particular to a cooling air duct and a motor thereof. Background Art

[0002] For high-power industrial motors, better heat dissipation effect is required. In the prior art, fans are often used to cool the motors. The first design is to use the cold air blown by the fan to dissipate the heat on the outer surface of the motor casing. This heat dissipation method has extremely low cooling efficiency because the heat generated inside the motor casing can only be transferred to the casing by heat conduction, while the heat emitted by internal parts such as the stator and rotor core, magnetic steel and enameled wire inside the casing cannot be cooled. Another design is to open an air inlet and an air outlet on the motor casing, connect the fan to the air inlet of the casing through an air duct, and the cold air blown by the fan is poured into the casing, which can directly bring the heat generated inside the casing to the outside of the casing. Compared with the first method, the cooling effect is better. However, in the latter design, the fan and the motor are not directly connected, and the presence of the air duct will increase the wind resistance and reduce the cooling effect. This split installation structure also occupies a large space overall.

[0003] In order to further improve the cooling effect of the second design scheme mentioned above, some designers in the existing literature directly install the fan on the motor, eliminating the use of the air duct, achieving a more ideal cooling effect by reducing wind resistance, and reducing the overall space occupation. For example, the utility model patent with announcement number CN217956984U discloses "a frequency conversion integrated machine", which is to install the first fan for cooling the motor on the non-axial end cover of the motor, open an air inlet on the non-axial end cover of the motor, and open an air outlet on the axial end cover of the motor. The air outlet of the fan is directly connected to the air inlet of the non-axial end cover, and the cold air blown by the fan is poured into the interior of the casing, which can take out the heat inside the casing from the air outlet of the axial end cover. Although this scheme has a good cooling effect, the installation position of the fan will increase the overall size of the motor, which is not conducive to reducing the space occupation.

[0004] The invention patent with announcement number CN112311297B discloses a "frequency conversion integrated machine". This patent installs a fan on the top of the casing near the non-shaft end cover, opens an air inlet on the shaft end cover, and uses the suction force of the fan to suck the external cold air from the air inlet on the shaft end cover into the inside of the casing, and then discharges the heat from the air outlet of the fan to form an L-shaped cooling air flow path. Although this solution is conducive to reducing the overall size, the heat dissipation effect is not very ideal. First, this solution uses the suction force of the fan to drive the flow of cold air, which is slightly worse than the cooling effect of the fan directly blowing cold air into the casing; second, the inlet and outlet wiring inside the motor is mainly concentrated on the side close to the non-shaft end, making the space inside the casing close to the non-shaft end relatively small. The fan is installed on the top of the casing close to the non-shaft end. Even if the fan is used to blow cold air into the casing, its cooling effect is relatively poor.

[0005] In addition, in the above-mentioned prior art, ventilation holes are generally not provided on the stator core and the rotor core inside the motor housing. After the cold air blown out by the fan is poured into the motor housing, it mainly relies on the gap between the stator core and the housing, and the air gap between the stator core and the rotor core as a cooling air duct. This cooling air duct is mainly used for cooling the surface of the stator core and the surface of the rotor core, and there is still room for improvement in the cooling effect. Utility Model Content

[0006] In order to further improve the cooling effect of high-power industrial motors, the utility model first discloses a cooling air duct for an air-cooled motor, which is specifically implemented by the following technical solutions:

[0007] A cooling air duct, comprising:

[0008] The motor housing has an air inlet at the top of the motor housing near the shaft extension end;

[0009] An end cover at the non-shaft extension end; an air outlet is provided on the end cover at the non-shaft extension end;

[0010] A stator core; a ventilation hole is provided in the axial direction of the stator core;

[0011] A rotor core; a ventilation hole is provided in the axial direction of the rotor core;

[0012] The end cover at the shaft extension end; an air inlet cavity is formed between the end cover at the shaft extension end and the stator core, an air outlet cavity is formed between the end cover at the non-shaft extension end and the stator core, the air inlet at the top of the motor housing is connected to the air inlet cavity, the air outlet on the end cover at the non-shaft extension end is connected to the air outlet cavity, and the ventilation holes on the stator core and the ventilation holes on the rotor core are both connected to the air inlet cavity and the air outlet cavity;

[0013] The cold air poured into the air inlet cavity from the air inlet forms at least three air ducts inside the motor housing, wherein the flow path along the ventilation holes of the stator core to the air outlet cavity is the first air duct, the flow path along the axial air gap between the stator core and the rotor core to the air outlet cavity is the second air duct, and the flow path along the ventilation holes of the rotor core to the air outlet cavity is the third air duct.

[0014] Furthermore, magnetic isolation plates are respectively provided at both ends of the rotor core, ventilation holes are provided on the magnetic isolation plates, and the ventilation holes on the magnetic isolation plates are correspondingly connected with the ventilation holes on the rotor core.

[0015] Furthermore, an air guide plate is provided on the outer side of the non-axial extension end cover, and the air guide plate includes a main body, an air outlet is opened on the main body, and an air guide cover is provided at the air outlet on the main body to shield the upper part of the air outlet, and the air outlet on the air guide plate is connected with the air outlet on the non-axial extension end cover.

[0016] Furthermore, the ventilation holes of the stator core include outer ring ventilation holes close to the outer circumference and inner ring ventilation holes close to the inner circumference, and both the outer ring ventilation holes and the inner ring ventilation holes are provided with a plurality of circular holes spaced apart along the circumferential direction.

[0017] Furthermore, two adjacent ventilation holes in the outer ring ventilation holes are staggered along different radii.

[0018] Furthermore, each circular hole of the inner ring ventilation hole is opened directly opposite to each stator slot.

[0019] Furthermore, a plurality of ventilation holes are provided on the rotor core along a circumferential direction, and a cross-sectional area of ​​a single ventilation hole on the rotor core is larger than a cross-sectional area of ​​a single ventilation hole on the stator core.

[0020] Furthermore, a plurality of ventilation openings of the magnetic isolation plate are provided on the magnetic isolation plate along a circumferential direction, and each ventilation opening on the magnetic isolation plate corresponds to each ventilation hole on the rotor core.

[0021] Furthermore, a plurality of air outlets are provided on the non-axial extension end cover along the circumferential direction.

[0022] The utility model also discloses a motor with the above-mentioned cooling air duct. In addition to the above-mentioned cooling air duct, it also includes a fan. One end of the air outlet of the fan is fixedly connected to the air inlet on the top of the motor housing, so that the air outlet of the fan is connected to the air inlet of the motor housing.

[0023] The air-cooled motor designed by the utility model eliminates the need for an intermediate connecting air duct and directly installs the fan on the top of the motor housing near the shaft extension end. The cold air blown out by the fan is directly poured into the air inlet cavity with a larger space, and the internal parts of the motor, such as the bearings, stator and rotor cores, magnetic steel and enameled wires, are fully cooled and cooled by means of three-way air ducts. The utility model fully considers factors such as the reduction in the space occupied by the overall equipment and the best cooling effect for the selection of the fan installation position. The designed three-way air duct cooling path takes into account the surface and internal cooling effect of the stator and rotor cores, the cooling effect of the shaft surface, and the cooling effect of the motor bearings and the end faces of the wire package. After overall evaluation, for motors with the same power, the cooling effect of the scheme of the utility model is better than the design scheme in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the air-cooled motor in the embodiment;

[0025] Figure 2 It is a cross-sectional view of an air-cooled motor;

[0026] Figure 3 It is a schematic diagram of the structure of the stator punching sheet;

[0027] Figure 4 It is a schematic diagram of the structure of the rotor punching;

[0028] Figure 5 It is a structural schematic diagram of a magnetic isolation plate;

[0029] Figure 6 It is a structural schematic diagram of the non-shaft extension end cover;

[0030] Figure 7 It is a structural schematic diagram of the air guide plate.

[0031] Description of Figure Numbers:

[0032] 1. Motor housing; 2. Fan; 3. Non-shaft end cover; 31. Air outlet; 4. Fan motor; 5. Shock absorber plate; 6. Air guide plate; 61. Main body; 62. Air guide cover; 63. Air outlet; 7. Stator punching plate; 71. Outer ring ventilation holes; 72. Inner ring ventilation holes; 8. Rotor punching plate; 81. Ventilation holes; 9. Magnetic isolation plate; 91. Ventilation holes; 10. Stator core; 11. Rotor core; 12. Rotating shaft; 13. Shaft end bearing; 14. Non-shaft end bearing; 15. Wire package. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0034] This embodiment discloses a cooling air duct of an air-cooled motor, and also discloses an air-cooled motor having the cooling air duct, which is mainly designed for high-power industrial motors and is beneficial to increasing the power density of the motor by improving the cooling effect of the motor. Figure 1 and Figure 2 As shown, the strong air-cooled motor of this embodiment mainly includes a motor housing 1, and a rotating shaft 12, a stator core 10, a rotor core 11, and a stator core coil 15 are arranged inside the motor housing 1. End caps and bearings are respectively arranged at both ends of the motor housing 1. The end caps and bearings are distinguished according to the direction in which the rotating shaft 12 extends out. The end cap close to the end of the motor housing 1 extending out of the rotating shaft 12 is the shaft extension end cap, and the end cap 3 far from the end extending out of the rotating shaft 12 is the non-shaft extension end cap. Similarly, the shaft extension end bearing 13 is installed in the bearing chamber of the shaft extension end cap, and the non-shaft extension end bearing 14 is installed in the bearing chamber of the non-shaft extension end cap 3. The above structures are all common structures of motors in the prior art. The following focuses on the technical improvements made by the utility model to improve the cooling effect of the motor in conjunction with the accompanying drawings.

[0035] This embodiment uses a fan 2 to cool the inside of the motor. A fan mounting seat is set on the top of the motor housing 1 near the end cover of the shaft end, and an air inlet is opened. One end of the air outlet of the fan 2 is directly mounted on the fan mounting seat of the motor housing 1, so that the air outlet of the fan 2 is directly connected to the air inlet of the motor housing 1, and the fan 2 is fixedly connected to the motor housing 1 with bolts. The fan 2 is equipped with a dedicated fan motor 4 to drive the impeller to rotate. In order to reduce the vibration of the fan motor 4 during operation, a shock absorbing plate 5 is also fixedly installed on the fan motor 4. A junction box is set on the top of the motor housing 1 near the non-shaft end end cover 3 on the side of the fan 2, and the lead wires of the stator core 10 are led out from one end near the non-shaft end end cover 3 and connected to the copper busbar of the junction box. In order to form a good cooling air duct, such as Figure 6 In this embodiment, an air outlet 31 is provided on the end cover 3 at the non-axial extension end. Figure 3 As shown, ventilation holes are also provided on the stator punching sheets 7 constituting the stator core 10, such as Figure 4 As shown in FIG. 1 , ventilation holes 81 are also provided on the rotor punching 8 constituting the rotor core 11. Magnetic isolation plates 9 are provided at both ends of the rotor core 11. Figure 5 As shown, a ventilation hole 91 is provided on the magnetic isolation plate 9 , and the ventilation hole 91 corresponds to and is connected with the ventilation hole 81 .

[0036] To further illustrate, a plurality of stator punching sheets 7 are stacked and the ventilation holes correspond to each other, and axially penetrating ventilation holes are formed on the stator core 10. Figure 3As shown, the ventilation holes on a single stator punching sheet 7 can be divided into outer ring ventilation holes 71 close to the outer circumference and inner ring ventilation holes 72 close to the inner circumference. The outer ring ventilation holes 71 and the inner ring ventilation holes 72 are formed by multiple circular holes spaced apart in the circumferential direction. In order to improve the ventilation effect, the aperture of the outer ring ventilation hole 71 is larger than the aperture of the inner ring ventilation hole 72, and the two adjacent circular holes in the outer ring ventilation hole 71 are staggered along different radial positions. As for the opening position of each circular hole in the inner ring ventilation hole 72, in this embodiment, it is chosen to be opened opposite to each stator slot, which can achieve a better heat dissipation effect. Multiple rotor punching sheets 8 are stacked and the ventilation holes correspond to each other, and axially through ventilation holes are formed on the rotor core 11. As shown Figure 4 As shown, a single rotor punching 8 has a plurality of ventilation holes 81 arranged along the circumferential direction, and the shape of the ventilation holes 81 is triangular. In this embodiment, the cross-sectional area of ​​a single ventilation hole 81 is larger than the cross-sectional area of ​​a single ventilation hole on the stator punching 7. Figure 5 As shown, the magnetic isolation plate 9 has a plurality of ventilation openings 91 arranged along the circumferential direction, and the shape of the ventilation openings 91 is also triangular. Figure 6 As shown, a plurality of air outlets 31 are provided on the non-axial extension end cover 3 along the circumferential direction, and the shape of the air outlets 31 is a trapezoid.

[0037] In this embodiment, considering the need for rain protection when the motor is working outdoors, a circular air guide plate 6 is further installed on the outer side of the non-shaft extension end cover 3. Figure 7 As shown, the main body 61 of the air guide plate 6 is disc-shaped, and a plurality of air outlets 63 are provided on the main body 61. The air outlets 63 are interconnected with the air outlets 31 on the non-axial extension end cover 3. An air guide cover 62 is provided at each air outlet 63 on the main body 61 to shield the top of the air outlet 63 to prevent rainwater from pouring into the motor from the air outlet 63.

[0038] According to the above structure, the air duct inside the motor housing 1 is set, so that at least three cooling air flow paths are formed inside the motor housing 1, and the parts inside the motor housing 1 are fully cooled. In order to better show the three different air ducts, Figure 2 The arrows in the figure indicate the flow paths of the three different air ducts. Inside the motor housing 1, the stator and rotor cores are located in the middle area of ​​the motor housing 1. Figure 2The direction shown is for reference. The cavity between the end cover at the shaft extension end and the left end face of the stator and rotor core is used as the air inlet cavity, and the cavity between the end cover 3 at the non-shaft extension end and the right end face of the stator and rotor core is used as the air outlet cavity. The air inlet at the top of the motor housing 1 is connected to the air inlet cavity, the air outlet 31 on the end cover 3 at the non-shaft extension end is connected to the air outlet cavity, and the ventilation holes on the stator core 10 and the ventilation holes on the rotor core 11 are connected to the air inlet cavity and the air outlet cavity. The external cold air is poured into the air inlet cavity from the air inlet at the top of the motor housing 1 through the fan 2, and the cold air in the air inlet cavity is divided into three paths. Among them, the first path of cold air blows through the shaft extension end bearing 13 and the left end of the coil 15, and then passes through the ventilation holes on the stator core 10 and merges into the air outlet cavity, and is finally discharged from the air outlet 63 of the air guide plate 6. The second cold air flows from the air inlet cavity through the working air gap between the stator core 10 and the rotor core 11, then flows into the air outlet cavity, and finally is discharged from the air outlet 63 of the air guide plate 6. The third cold air flows from the air inlet cavity through the vent 91 of the left end magnetic isolation plate 9, the vent hole on the rotor core 11, and the vent 91 of the right end magnetic isolation plate 9, then flows into the air outlet cavity, and finally is discharged from the air outlet 63 of the air guide plate 6.

[0039] Since the heat generated by the motor is mainly concentrated in the stator and rotor magnetic steel, the coil 15 and the enameled wire, in order to achieve a better cooling effect on the above-mentioned heat sources, the present embodiment is specially provided with the above-mentioned three cooling air ducts. The first duct mainly cools the heat-generating bearings, the left end of the coil 15, the stator core 10 and the right end of the coil 15. Among them, the outer ring ventilation holes 71 on the stator core 10 are close to the outer surface of the stator core 10, and the inner ring ventilation holes 72 are close to the inner surface of the stator core 10, so that the first air duct can cool the inner and outer surfaces and the interior of the stator core 10 at the same time. The second duct mainly cools the enameled wire, the inner surface of the stator core 10, and the outer surface of the rotor core 11. The third duct mainly cools the shaft extension end bearing 13, the enameled wire and the interior of the rotor core 11, from Figure 4 It can be seen from the figure that the ventilation holes 81 on the rotor punching 8 are located relatively close to the inner ring of the rotor punching 8, and the cross-sectional area of ​​the ventilation holes 81 is relatively large. While cooling the inside of the rotor core 11, it also actually has a cooling effect on the inner surface of the rotor core 11 close to the shaft 12.

[0040] In summary, the utility model comprehensively improves the installation position of the fan 2 and the air duct path setting inside the motor housing 1, thereby improving the cooling effect of the motor as a whole, which is beneficial to increasing the power density of the motor.

[0041] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A cooling air duct, characterized in that: include: The motor housing has an air inlet at the top of the motor housing near the shaft extension end; End cover at non-shaft extension end; An air outlet is provided on the non-shaft extension end cover; A stator core; a ventilation hole is provided in the axial direction of the stator core; A rotor core; a ventilation hole is provided in the axial direction of the rotor core; The end cover at the shaft extension end; an air inlet cavity is formed between the end cover at the shaft extension end and the stator core, an air outlet cavity is formed between the end cover at the non-shaft extension end and the stator core, the air inlet at the top of the motor housing is connected to the air inlet cavity, the air outlet on the end cover at the non-shaft extension end is connected to the air outlet cavity, and the ventilation holes on the stator core and the ventilation holes on the rotor core are both connected to the air inlet cavity and the air outlet cavity; The cold air poured into the air inlet cavity from the air inlet forms at least three air ducts inside the motor housing, wherein the flow path along the ventilation holes of the stator core to the air outlet cavity is the first air duct, the flow path along the axial air gap between the stator core and the rotor core to the air outlet cavity is the second air duct, and the flow path along the ventilation holes of the rotor core to the air outlet cavity is the third air duct.

2. A cooling air duct according to claim 1, characterized in that: Magnetic isolation plates are respectively provided at both ends of the rotor core. Ventilation holes are provided on the magnetic isolation plates. The ventilation holes on the magnetic isolation plates are correspondingly connected with the ventilation holes on the rotor core.

3. A cooling air duct according to claim 1, characterized in that: An air guide plate is provided on the outside of the non-axial extension end cover, and the air guide plate includes a main body, an air outlet is provided on the main body, and an air guide cover is provided at the air outlet on the main body to shield the upper part of the air outlet. The air outlet on the air guide plate is connected with the air outlet on the non-axial extension end cover.

4. The cooling air duct according to claim 1, characterized in that: The ventilation holes of the stator core include outer ring ventilation holes close to the outer circumference and inner ring ventilation holes close to the inner circumference. The outer ring ventilation holes and the inner ring ventilation holes are both provided with a plurality of circular holes spaced apart along the circumferential direction.

5. A cooling air duct according to claim 4, characterized in that: Two adjacent ventilation holes in the outer ring ventilation holes are arranged alternately along different radii.

6. A cooling air duct according to claim 4, characterized in that: Each circular hole of the inner ring ventilation hole is arranged opposite to each stator slot.

7. The cooling air duct according to claim 1, characterized in that: The rotor core has a plurality of ventilation holes formed on the rotor core along a circumferential direction, and the cross-sectional area of ​​a single ventilation hole on the rotor core is greater than the cross-sectional area of ​​a single ventilation hole on the stator core.

8. The cooling air duct according to claim 2, characterized in that: The magnetic isolation plate has a plurality of ventilation openings formed on the magnetic isolation plate along a circumferential direction, and each ventilation opening on the magnetic isolation plate corresponds to each ventilation hole on the rotor core.

9. The cooling air duct according to claim 1, characterized in that: A plurality of air outlets are provided on the non-axial extension end cover along the circumferential direction.

10. A motor, characterized in that: It comprises a cooling air duct and a fan as described in any one of claims 1 to 9, wherein one end of the air outlet of the fan is fixedly docked with the air inlet at the top of the motor housing, so that the air outlet of the fan is connected with the air inlet of the motor housing.

Images