阅读说明：本技术 一种使用被动轴承的磁悬浮鼓风机 (Magnetic suspension air blower using passive bearing ) 是由 袁军 钟仁志 于 2021-10-13 设计创作，主要内容包括：本发明涉及磁悬浮鼓风机领域,尤其涉及一种使用被动轴承的磁悬浮鼓风机。该鼓风机包括电机筒、前轴承座、后轴承座、电机轴和轴承固定块；转子轴承孔内壁固定设置有径向转子磁钢,轴承固定块上固定设置有径向定子磁钢,径向定子磁钢与径向转子磁钢的位置相对应并且两者相对表面的磁极相反；电机轴在前后轴向两侧分别固定设置有前转子磁钢和后转子磁钢,前轴承座和后轴承座分别固定设置有前定子磁钢和后定子磁钢；前定子磁钢和前转子磁钢的位置相对应并且两者相对表面的磁极相反,后定子磁钢和后转子磁钢的位置相对应并且两者相对表面的磁极相反。该鼓风机降低了磁轴承的价格,简化了鼓风机的结构,增加了系统稳定性。(The utility model relates to the field of magnetic suspension blowers, in particular to a magnetic suspension blower using a passive bearing. The blower comprises a motor barrel, a front bearing seat, a rear bearing seat, a motor shaft and a bearing fixing block; the inner wall of the rotor bearing hole is fixedly provided with radial rotor magnetic steel, the bearing fixing block is fixedly provided with radial stator magnetic steel, the radial stator magnetic steel corresponds to the radial rotor magnetic steel in position, and the magnetic poles of the opposite surfaces of the radial stator magnetic steel and the radial rotor magnetic steel are opposite; the front rotor magnetic steel and the rear rotor magnetic steel are respectively and fixedly arranged on the front axial side and the rear axial side of the motor shaft, and the front stator magnetic steel and the rear stator magnetic steel are respectively and fixedly arranged on the front bearing seat and the rear bearing seat; the front stator magnetic steel and the front rotor magnetic steel are corresponding in position and opposite in magnetic pole on the opposite surfaces, and the rear stator magnetic steel and the rear rotor magnetic steel are corresponding in position and opposite in magnetic pole on the opposite surfaces. The blower reduces the price of the magnetic bearing, simplifies the structure of the blower and increases the stability of the system.)

1. A magnetic suspension blower using a passive bearing is characterized by comprising a motor barrel (1), a front bearing seat (2), a rear bearing seat (3), a motor shaft (4), an impeller (5), a volute (6) and a bearing fixing block (7); the front bearing seat (2) and the rear bearing seat (3) are respectively fixed at two ends of the motor barrel (1); a motor stator (11) is fixedly embedded in the inner wall of the motor barrel (1), a motor rotor (41) is fixedly arranged on the radial outer side of the motor shaft (4), and the motor stator (11) corresponds to the motor rotor (41); the motor shaft (4) is provided with a rotor bearing hole (42) along the axial direction, and the bearing fixing block (7) is fixed on the rear bearing block (3) and is positioned in the rotor bearing hole (42); the inner wall of the rotor bearing hole (42) is fixedly provided with radial rotor magnetic steel (43), the bearing fixing block (7) is fixedly provided with radial stator magnetic steel (71), the radial stator magnetic steel (71) corresponds to the radial rotor magnetic steel (43) in position and the magnetic poles of the opposite surfaces of the radial stator magnetic steel and the radial rotor magnetic steel (43) are opposite; a front rotor magnetic steel (44) and a rear rotor magnetic steel (45) are respectively fixedly arranged on the front axial direction and the rear axial direction of the motor shaft (4), and a front stator magnetic steel (21) and a rear stator magnetic steel (31) are respectively fixedly arranged on the front bearing seat (2) and the rear bearing seat (3); the front stator magnetic steel (21) and the front rotor magnetic steel (44) are corresponding in position and opposite in magnetic pole on the opposite surfaces, and the rear stator magnetic steel (31) and the rear rotor magnetic steel (45) are corresponding in position and opposite in magnetic pole on the opposite surfaces.

2. The magnetic suspension blower using the passive bearing is characterized in that a front stator magnetic steel seat (22) is fixedly arranged on the inner side surface of the front bearing seat (2), a front magnetic steel groove (23) is arranged on the inner side of the front stator magnetic steel seat (22), and the front stator magnetic steel (21) is fixedly embedded in the front magnetic steel groove (23); a rear stator magnetic steel seat (32) is fixedly arranged on the inner side surface of the rear bearing seat (3), a rear magnetic steel groove (33) is arranged on the inner side of the rear stator magnetic steel seat (32), and the rear stator magnetic steel (31) is fixedly embedded in the rear magnetic steel groove (33).

3. The magnetic suspension blower using the passive bearing is characterized in that the outer side surfaces of the front stator magnetic steel seat (22) and the rear stator magnetic steel seat (32) are provided with threaded holes (24), and the front bearing seat (2) and the rear bearing seat (3) are provided with screw holes (34) which axially penetrate through; the magnetic suspension air blower is also provided with locking screws and locking nuts, and the locking screws respectively penetrate through screw holes (34) of the front bearing seat (2) and the rear bearing seat (3) and are respectively screwed into screw holes (24) of the front stator magnetic steel seat (22) and the rear stator magnetic steel seat (32); the plurality of locking nuts are screwed with the locking screws respectively, and the inner surfaces of the plurality of locking nuts are attached to the outer side surfaces of the front bearing seat (2) and the rear bearing seat (3) respectively.

4. The magnetic suspension blower using the passive bearing is characterized in that the motor rotor (41) comprises a silicon steel sheet (46), a magnetic steel (47), a front rotor magnetic steel seat (48) and a rear rotor magnetic steel seat (49); the plurality of silicon steel sheets (46) are fixedly sleeved on the outer wall of the motor shaft (4) and are axially aligned and stacked, and the front rotor magnetic steel seat (48) and the rear rotor magnetic steel seat (49) are fixedly sleeved on the outer wall of the motor shaft (4) and are respectively positioned at the two axial ends of the stacked silicon steel sheets (46); the silicon steel sheet (46) is provided with a magnetic steel hole, and a plurality of magnetic steels (47) are fixedly embedded in the magnetic steel hole.

5. The magnetic suspension blower using the passive bearing is characterized in that the outer wall of the motor cylinder (1) is provided with heat dissipation ribs (12), and the heat dissipation ribs (12) are used for dissipating heat of the motor cylinder (1).

6. The maglev blower using passive bearings according to claim 1, characterized in that the inlet end of the impeller (5) is provided with a fairing (51), and the fairing (51) is used for rectifying the gas at the inlet end of the volute (6) to improve the inlet efficiency.

7. The magnetic suspension blower using the passive bearing is characterized in that the back of the impeller (5) is provided with a convex reinforcing rib (52), and the front bearing seat (2) is provided with a labyrinth seal (25); the radial outer surface of the reinforcing rib (52) and the labyrinth seal (25) form a labyrinth structure for reducing gas discharge at the gas outlet end of the impeller (5).

8. A magnetic levitation blower using a passive bearing as claimed in claim 4 characterised in that the rear bearing block (3) is provided with a plurality of first channels (81) running through axially, the rear rotor magnet steel block (49) is provided with a second channel (82) and a third channel (83); the motor shaft (4) is provided with a fourth channel (84) which axially penetrates through, and the front rotor magnetic steel seat (48) is provided with a fifth channel (85); the silicon steel sheet (46) is provided with a plurality of axially-through sixth channels (86), and the motor barrel (1) is provided with a plurality of radially-through seventh channels (87); the first channel (81), the second channel (82), the fourth channel (84), the fifth channel (85), the sixth channel (86), the inner gap of the motor cylinder (1) and the seventh channel (87) are communicated in sequence to form a heat dissipation channel.

9. A magnetic levitation blower using a passive bearing as claimed in claim 8, characterised in that the motor shaft (4) is further provided with a rotor channel (40), the front bearing block (2) is provided with a radially through bearing block channel (26); the first channel (81), the rotor bearing hole (42), the rotor channel (40) and the bearing seat channel (26) are communicated in sequence to form a second heat dissipation channel.

10. The maglev blower using passive bearings according to claim 8, characterised in that the rear rotor steel magnet holder (49) is further provided with an eighth channel (88); the first channel (81), the eighth channel (88), the sixth channel (86) and the seventh channel (87) are communicated in sequence to form a third heat dissipation channel.

Technical Field

The utility model relates to the field of magnetic suspension blowers, in particular to a magnetic suspension blower using a passive bearing.

Background

The magnetic suspension blower is one kind of turbine equipment with magnetic suspension bearing. The main structure is that the blower impeller is directly installed on the extension end of the firing shaft, and the rotor is vertically suspended on the active magnetic bearing, so as to realize the single-machine high-speed centrifugal blower which is directly driven by the high-speed motor and is regulated by the frequency converter. The fan adopts an integrated design, has the technical characteristics of energy conservation, high efficiency, high cooling efficiency, low noise and the like, and is widely applied to factories at present.

The Chinese utility model patent application (publication No. CN209398592U, published: 20140604) discloses a magnetic suspension blower, which comprises a motor, a cooling system and a load pipeline; the cooling system is arranged on a motor of the blower, the load pipeline is arranged at the outlet of the blower and is communicated with the air outlet of the cooling system; the magnetic suspension blower provided by the utility model has the advantages that the structure of the magnetic suspension blower is optimized, the energy is fully utilized, the gas generated by the cooling system is introduced into the load pipeline and is integrated with the air flow discharged by the blower, and the gas is completely converted into the compressed gas required by the load and utilized, so that the utilization rate of energy consumption is improved, and the energy conservation optimization is effectively carried out.

The prior art has the following defects: the traditional centrifugal blower generally adopts an active magnetic suspension bearing such as a ceramic ball bearing or a tilting pad sliding bearing; the ceramic ball bearing is generally imported from abroad, has high price, limited rotating speed, axial load and radial load and needs to be maintained regularly; the tilting pad sliding bearing has a complex structure and a large space, adopts oil cooling, and needs to replace lubricating oil regularly; in addition, for the active magnetic suspension bearing, the volume is large, a sensor is required to acquire signals, and an external magnetic bearing controller is adopted to realize the control of the magnetic suspension bearing, so that the structure of the whole blower is complex.

Disclosure of Invention

The purpose of the utility model is: aiming at the problems, the front rotor magnetic steel and the rear rotor magnetic steel are respectively controlled by the front stator magnetic steel and the rear stator magnetic steel in the axial direction, and the radial rotor magnetic steel is controlled by the radial stator magnetic steel in the radial direction; the motor shaft is directly controlled by magnetic force without adopting lubricating oil for lubrication, so that the maintenance steps are reduced; meanwhile, the passive magnetic suspension bearing does not need to adopt a sensor, so that the price of a magnetic bearing is reduced, the structure of the air blower is simplified, and the system stability is improved.

In order to achieve the purpose, the utility model adopts the following technical scheme:

a magnetic suspension blower using a passive bearing comprises a motor barrel, a front bearing seat, a rear bearing seat, a motor shaft, an impeller, a volute and a bearing fixing block; the front bearing seat and the rear bearing seat are respectively fixed at two ends of the motor cylinder; a motor stator is fixedly embedded in the inner wall of the motor barrel, a motor rotor is fixedly arranged on the radially outer side of the motor shaft, and the motor stator corresponds to the motor rotor in position; the motor shaft is provided with a rotor bearing hole along the axial direction, and the bearing fixing block is fixed on the rear bearing seat and is positioned in the rotor bearing hole; the inner wall of the rotor bearing hole is fixedly provided with radial rotor magnetic steel, the bearing fixing block is fixedly provided with radial stator magnetic steel, the radial stator magnetic steel corresponds to the radial rotor magnetic steel in position, and the magnetic poles of the opposite surfaces of the radial stator magnetic steel and the radial rotor magnetic steel are opposite; the front rotor magnetic steel and the rear rotor magnetic steel are respectively and fixedly arranged on the front axial side and the rear axial side of the motor shaft, and the front stator magnetic steel and the rear stator magnetic steel are respectively and fixedly arranged on the front bearing seat and the rear bearing seat; the front stator magnetic steel and the front rotor magnetic steel are corresponding in position and opposite in magnetic pole on the opposite surfaces, and the rear stator magnetic steel and the rear rotor magnetic steel are corresponding in position and opposite in magnetic pole on the opposite surfaces.

Preferably, a front stator magnetic steel seat is fixedly arranged on the inner side surface of the front bearing seat, a front magnetic steel groove is formed in the inner side of the front stator magnetic steel seat, and the front stator magnetic steel is fixedly embedded in the front magnetic steel groove; the inner side surface of the rear bearing seat is fixedly provided with a rear stator magnetic steel seat, the inner side of the rear stator magnetic steel seat is provided with a rear magnetic steel groove, and the rear stator magnetic steel is fixedly embedded in the rear magnetic steel groove.

Preferably, the outer side surfaces of the front stator magnetic steel seat and the rear stator magnetic steel seat are provided with threaded holes, and the front bearing seat and the rear bearing seat are provided with screw holes which axially penetrate through the front bearing seat and the rear bearing seat; the magnetic suspension air blower is also provided with locking screws and locking nuts, and the locking screws respectively penetrate through the screw holes of the front bearing seat and the rear bearing seat and are respectively screwed into the screw holes of the front stator magnetic steel seat and the rear stator magnetic steel seat; the plurality of locking nuts are screwed with the locking screws respectively, and the inner surfaces of the plurality of locking nuts are attached to the outer side surfaces of the front bearing seat and the rear bearing seat respectively.

Preferably, the motor rotor comprises a silicon steel sheet, magnetic steel, a front rotor magnetic steel seat and a rear rotor magnetic steel seat; the front rotor magnetic steel seat and the rear rotor magnetic steel seat are fixedly sleeved on the outer wall of the motor shaft and are respectively positioned at the two axial ends of the stacked silicon steel sheets; the silicon steel sheet is provided with a magnetic steel hole, and a plurality of magnetic steels are fixedly embedded in the magnetic steel hole.

Preferably, the outer wall of the motor cylinder is provided with a heat dissipation rib, and the heat dissipation rib is used for dissipating heat of the motor cylinder.

Preferably, the air inlet end of the impeller is provided with a fairing, and the fairing is used for rectifying the gas at the air inlet end of the volute so as to improve the air inlet efficiency.

Preferably, the back of the impeller is provided with a convex reinforcing rib, and the front bearing seat is provided with a labyrinth seal; the radial outer surface of the reinforcing rib and the labyrinth seal form a labyrinth structure for reducing gas discharge at the gas outlet end of the impeller.

Preferably, the rear bearing seat is provided with a plurality of first channels which axially penetrate through the rear bearing seat, and the rear rotor magnetic steel seat is provided with a second channel and a third channel; the motor shaft is provided with a fourth channel which axially penetrates through the motor shaft, and the front rotor magnetic steel seat is provided with a fifth channel; the silicon steel sheet is provided with a plurality of axially-through sixth channels, and the motor cylinder is provided with a plurality of radially-through seventh channels; the first channel, the second channel, the fourth channel, the fifth channel, the sixth channel, the motor cylinder inner gap and the seventh channel are communicated in sequence to form a heat dissipation channel.

Preferably, the motor shaft is also provided with a rotor channel, and the front bearing seat is provided with a bearing seat channel which penetrates through the front bearing seat in the radial direction; the first channel, the rotor bearing hole, the rotor channel and the bearing seat channel are communicated in sequence to form a second heat dissipation channel.

Preferably, the rear rotor magnetic steel seat is also provided with an eighth channel; the first channel, the eighth channel, the sixth channel and the seventh channel are communicated in sequence to form a third heat dissipation channel.

The magnetic suspension blower using the passive bearing adopting the technical scheme has the advantages that:

when the motor works, the motor stator is electrified to drive the motor rotor to rotate so as to drive the motor shaft to rotate; the front stator magnetic steel and the rear stator magnetic steel respectively control the positions of the front rotor magnetic steel and the rear rotor magnetic steel through magnetic force so as to control the axial position of the motor shaft, and the radial stator magnetic steel controls the position of the radial rotor magnetic steel so as to control the radial position of the motor shaft; meanwhile, the motor shaft rotates to drive the impeller to rotate so as to compress the external air to complete the working process of the magnetic suspension blower. In this way, the passive magnetic bearing is divided into three pairs of six circular ring magnetic steels, wherein the action surfaces of the two magnetic steels of each group of bearings are all homopolar, and repulsion is generated to restrain the displacement of the rotor with six degrees of freedom. The supporting surface between the radial stator magnetic steel and the radial rotor magnetic steel almost supports the inside of the whole rotor shaft system, so that great supporting force is provided, and the rigidity of the bearing is greatly superior to that of other types of bearings. In addition, the mode adopts the form of a passive magnetic suspension bearing in the axial direction and the radial direction, the motor shaft is directly controlled by the magnetic force of the magnetic steel, lubricating oil lubrication is not needed, and the maintenance steps are reduced; meanwhile, the passive magnetic suspension bearing does not need a sensor, so that the price of a magnetic bearing is reduced, the structure of the air blower is simplified, and the stability of the system is improved.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic structural view of the front bearing seat.

Fig. 3 is a schematic structural view of the rear bearing seat.

Fig. 4 is a schematic structural view of a blower rotor system.

Fig. 5 and 6 are schematic structural diagrams of the motor rotor.

Fig. 7 and 8 are schematic structural views of the motor cartridge.

Fig. 9 is a schematic structural view of the impeller.

Fig. 10 and 11 are schematic structural views of a motor shaft.

Fig. 12 is a schematic structural diagram of a radial rotor magnetic steel field.

Fig. 13-15 are schematic structural views of the front rotor magnetic steel seat.

Fig. 16-18 are schematic structural views of the rear rotor magnetic steel seat.

Fig. 19 is a schematic structural view of a bearing fixing block.

Fig. 20 is a schematic diagram of the structure of a radial stator magnetic steel field.

Fig. 21 is a schematic structural view of a heat dissipation channel.

Detailed Description

The following describes in detail embodiments of the present invention with reference to the drawings.

Example 1

A magnetic levitation blower using a passive bearing as shown in fig. 1, the blower includes a motor barrel 1, a front bearing block 2, a rear bearing block 3, a motor shaft 4, an impeller 5, a volute 6 and a bearing fixing block 7; the front bearing seat 2 and the rear bearing seat 3 are respectively fixed at two ends of the motor barrel 1; a motor stator 11 is fixedly embedded in the inner wall of the motor barrel 1, a motor rotor 41 is fixedly arranged on the radial outer side of the motor shaft 4, and the motor stator 11 corresponds to the motor rotor 41 in position; the motor shaft 4 is provided with a rotor bearing hole 42 along the axial direction, and the bearing fixing block 7 is fixed on the rear bearing block 3 and is positioned in the rotor bearing hole 42; the inner wall of the rotor bearing hole 42 is fixedly provided with radial rotor magnetic steel 43, the bearing fixing block 7 is fixedly provided with radial stator magnetic steel 71, the radial stator magnetic steel 71 corresponds to the radial rotor magnetic steel 43 in position, and the magnetic poles of the opposite surfaces of the radial stator magnetic steel 71 and the radial rotor magnetic steel 43 are opposite; the front rotor magnetic steel 44 and the rear rotor magnetic steel 45 are respectively and fixedly arranged on the two sides of the motor shaft 4 in the front-rear axial direction, and the front stator magnetic steel 21 and the rear stator magnetic steel 31 are respectively and fixedly arranged on the front bearing seat 2 and the rear bearing seat 3; the front stator magnetic steel 21 and the front rotor magnetic steel 44 are corresponding in position and opposite in magnetic pole on the opposite surfaces, and the rear stator magnetic steel 31 and the rear rotor magnetic steel 45 are corresponding in position and opposite in magnetic pole on the opposite surfaces. When the motor works, the motor stator 11 is electrified to drive the motor rotor 41 to rotate so as to drive the motor shaft 4 to rotate; the front stator magnetic steel 21 and the rear stator magnetic steel 31 respectively control the positions of the front rotor magnetic steel 44 and the rear rotor magnetic steel 45 through magnetic force so as to control the axial position of the motor shaft 4, and the radial stator magnetic steel 71 controls the position of the radial rotor magnetic steel 43 so as to control the radial position of the motor shaft 4; meanwhile, the motor shaft 4 rotates to drive the impeller 5 to rotate, so that external air is compressed, and the working process of the magnetic suspension blower is completed. In this way, the passive magnetic bearing is divided into three pairs of six circular ring magnetic steels, wherein the action surfaces of the two magnetic steels of each group of bearings are all homopolar, and repulsion is generated to restrain the displacement of the rotor with six degrees of freedom. The supporting surface between the radial stator magnetic steel 71 and the radial rotor magnetic steel 43 almost supports the inside of the whole rotor shaft system, so that great supporting force is provided, and the rigidity of the bearing is greatly superior to that of other types of bearings. In addition, the mode adopts the form of a passive magnetic suspension bearing in the axial direction and the radial direction, the motor shaft is directly controlled by the magnetic force of the magnetic steel, lubricating oil lubrication is not needed, and the maintenance steps are reduced; meanwhile, the passive magnetic suspension bearing does not need a sensor, so that the price of a magnetic bearing is reduced, the structure of the air blower is simplified, and the stability of the system is improved.

As shown in fig. 2 and 3, a front stator magnetic steel seat 22 is fixedly arranged on the inner side surface of the front bearing seat 2, a front magnetic steel groove 23 is arranged on the inner side of the front stator magnetic steel seat 22, and the front stator magnetic steel 21 is fixedly embedded in the front magnetic steel groove 23; the inner side surface of the rear bearing seat 3 is fixedly provided with a rear stator magnetic steel seat 32, the inner side of the rear stator magnetic steel seat 32 is provided with a rear magnetic steel groove 33, and the rear stator magnetic steel 31 is fixedly embedded in the rear magnetic steel groove 33.

The outer side surfaces of the front stator magnetic steel seat 22 and the rear stator magnetic steel seat 32 are provided with threaded holes 24, and the front bearing seat 2 and the rear bearing seat 3 are provided with screw holes 34 which axially penetrate through; the magnetic suspension air blower is also provided with locking screws and locking nuts, and the locking screws respectively penetrate through screw holes 34 of the front bearing seat 2 and the rear bearing seat 3 and are respectively screwed into threaded holes 24 of the front stator magnetic steel seat 22 and the rear stator magnetic steel seat 32; the plurality of locking nuts are screwed with the locking screws respectively, and the inner surfaces of the plurality of locking nuts are attached to the outer side surfaces of the front bearing seat 2 and the rear bearing seat 3 respectively. When the actual load of the motor shaft 4 changes, the axial position of the locking screw is adjusted to respectively drive the front stator magnetic steel seat 22 and the rear stator magnetic steel seat 32 to axially move to the corresponding positions, and then the locking screw is locked by using a locking nut; thereby adjusting the distance between the front stator magnetic steel 21 and the front rotor magnetic steel 44 and the distance between the rear stator magnetic steel 31 and the rear rotor magnetic steel 45 to change the magnitude of the repulsive force between the two; so that the repulsive force between the front stator magnetic steel 21 and the front rotor magnetic steel 44 and between the rear stator magnetic steel 31 and the rear rotor magnetic steel 45 satisfies the actual load of the motor shaft 4.

As shown in fig. 4-6, the motor rotor 41 includes a silicon steel sheet 46, a magnetic steel 47, a front rotor magnetic steel seat 48 and a rear rotor magnetic steel seat 49; the plurality of silicon steel sheets 46 are fixedly sleeved on the outer wall of the motor shaft 4 and are axially aligned and stacked, and the front rotor magnetic steel seat 48 and the rear rotor magnetic steel seat 49 are fixedly sleeved on the outer wall of the motor shaft 4 and are respectively positioned at the two axial ends of the stacked silicon steel sheets 46; the silicon steel sheet 46 is provided with magnetic steel holes, and a plurality of magnetic steels 47 are fixedly embedded in the magnetic steel holes.

As shown in fig. 7 and 8, the outer wall of the motor cartridge 1 is provided with heat dissipation ribs 12, and the heat dissipation ribs 12 are used for dissipating heat from the motor cartridge 1.

As shown in fig. 1, a fairing 51 is provided at the air inlet end of the impeller 5, and the fairing 51 is used for rectifying the air at the air inlet end of the volute 6, so as to improve the air inlet efficiency.

As shown in fig. 1 and 9, the back of the impeller 5 is provided with a convex reinforcing rib 52, and the front bearing seat 2 is provided with a labyrinth seal 25; the radially outer surface of the rib 52 forms a labyrinth structure with the labyrinth seal 25 for reducing gas discharge at the gas outlet end of the impeller 5.

As shown in fig. 21, the rear bearing block 3 is provided with a plurality of first passages 81 that axially penetrate, and the rear rotor magnetic steel block 49 is provided with a second passage 82 and a third passage 83; the motor shaft 4 is provided with a fourth channel 84 which axially penetrates through, and the front rotor magnetic steel seat 48 is provided with a fifth channel 85; the silicon steel sheets 46 are provided with a plurality of sixth passages 86 which axially penetrate through, and the motor cylinder 1 is provided with a plurality of seventh passages 87 which radially penetrate through; the first channel 81, the second channel 82, the fourth channel 84, the fifth channel 85, the sixth channel 86, the inner gap of the motor cylinder 1 and the seventh channel 87 are communicated in sequence to form a heat dissipation channel. When the cooling device works, the motor stator 11 is electrified to drive the motor rotor 41 to rotate so as to drive the motor shaft 4 to rotate, and external cooling air enters the blower along the heat dissipation channel to cool the blower and then is discharged along the seventh channel 87 to finish the cooling process of the blower; in this way, the fourth passage 84 and the sixth passage 86 are axially distributed cooling passages, and are communicated with each other through the fifth passage 85; in the cooling mode, the multi-layer bent cooling channels are adopted for cooling in the radial direction, so that the length of the cooling channels is increased; and when the rotor part is bigger in radial thickness, the multilayer cooling channel can cool the rotor part with bigger radial thickness into the part with smaller radial thickness of the multilayer, thereby further improving the cooling effect on the rotor part.

The motor shaft 4 is also provided with a rotor channel 40, and the front bearing seat 2 is provided with a bearing seat channel 26 which penetrates through the front bearing seat in the radial direction; the first channel 81, the rotor bearing hole 42, the rotor channel 40 and the bearing seat channel 26 are sequentially communicated to form a second heat dissipation channel.

The rear rotor magnetic steel seat 49 is also provided with an eighth channel 88; the first channel 81, the eighth channel 88, the sixth channel 86 and the seventh channel 87 are communicated in sequence to form a third heat dissipation channel.