Centrifugal fan driven by permanent magnet motor

Abstract

The invention discloses a centrifugal fan driven by a permanent magnet motor, and relates to the technical field of centrifugal fans, the centrifugal fan comprises a shell and an impeller body, the impeller body is rotatably arranged in the shell through an impeller shaft, the shell is provided with a motor body, the motor body comprises a motor shaft and a sleeve, and the motor shaft is connected with the sleeve. The motor body is connected with a motor shaft, an inner hole is formed in the motor shaft, a transmission shaft is arranged in the inner hole through a first elastic piece, and the motor further comprises a sleeve used for being connected with the impeller shaft. A first meshing part is arranged at the end part of the transmission shaft, and a second meshing part is arranged on the inner wall of the sleeve; the transmission shaft is provided with a first position and a second position in the axial direction, and at the first position, the transmission shaft drives the sleeve to rotate synchronously through meshing of the first meshing part and the second meshing part; and at the second position, the impeller shaft is limited, and the transmission shaft idles relative to the sleeve.

Description

Technical Field

[0001] The invention relates to the technical field of centrifugal fans, in particular to a centrifugal fan driven by a permanent magnet motor. Background Art

[0002] As is known, a centrifugal fan is a machine that relies on input mechanical energy to increase gas pressure and discharge gas. It is a driven fluid machine. Centrifugal fans are widely used in ventilation, dust removal and cooling of factories, mines, tunnels, cooling towers, vehicles, ships and buildings. The structure of a centrifugal fan includes an impeller, a casing, a coupling, an impeller shaft and a motor. The impeller is the main component for generating wind pressure and transmitting energy; the casing is used to introduce and discharge gas, and at the same time convert part of the kinetic energy of the gas into pressure energy; the coupling is used to connect the motor and the fan to transmit torque; the impeller shaft is installed and fixed with the impeller, and the impeller shaft is connected to the motor through the coupling. The motor is a device that converts electrical energy into mechanical energy. The motor provides rotational power for the impeller. The working principle of the centrifugal fan is as follows: the impeller is driven to rotate by the motor, and the gas enters the blade space from the fan axis. As the impeller rotates, the gas is subjected to the centrifugal force to obtain kinetic energy and is discharged from the periphery of the impeller. These gases are guided by the casing and flow toward the fan outlet. At the same time, negative pressure is formed in the center of the impeller, attracting external air flow to continuously flow in and replenish it, so that the fan can continuously discharge gas.

[0003] For example, the patent with publication number CN217783822U, publication date November 11, 2022, and titled "A Centrifugal Fan Driven by a Permanent Magnet Motor", discloses a centrifugal fan driven by a permanent magnet motor, including a permanent magnet motor, an electric control device, a volute, a wind wheel, and a sealing layer; one end of the permanent magnet motor is connected to the electric control device, and the other end of the permanent magnet motor is connected to one end of the volute; the other end of the volute away from the permanent magnet motor is provided with a first opening; the outer wall of the volute is provided with a second opening; the wind wheel is installed inside the volute; the sealing layer is provided at the connection position of the permanent magnet motor and the electric control device; the volute includes a first shell and a second shell, and the first shell and the second shell are detachably installed. The fan of this patent is provided with a sealing layer at the connection position of the permanent magnet motor and the electric control device for sealing, so as to achieve dustproof and waterproof effects at the connection position; and the volute is detachably installed by the first shell and the second shell, which is more convenient than the traditional integrated volute.

[0004] The deficiency in the prior art is that, since the output end of the motor (that is, the motor shaft) is connected to the impeller shaft to drive the impeller to rotate, the impeller on the centrifugal fan is prone to increase friction between the impeller and the casing after long-term use due to vibration, aging, deformation, dust adhesion to the impeller, etc., causing the impeller to get stuck when rotating. If the impeller shaft and the motor shaft are not properly lubricated, the impeller may also be deformed. The deformation of the impeller causes the impeller to shake when rotating, making it more prone to getting stuck. When the impeller is stuck, the motor is in normal working condition, making the motor prone to overload or even burn out. Summary of the invention

[0005] The object of the present invention is to provide a centrifugal fan driven by a permanent magnet motor to solve the above-mentioned problems in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: A centrifugal fan driven by a permanent magnet motor, comprising a housing and an impeller body, wherein the impeller body is rotatably arranged in the housing through an impeller shaft, and a motor body is arranged on the housing, characterized in that the motor body comprises a motor shaft and a sleeve, the motor body is connected to the motor shaft, an inner hole is arranged on the motor shaft, a transmission shaft is arranged in the inner hole through a first elastic member, and further comprising a sleeve for connecting with the impeller shaft; The end of the transmission shaft is provided with a first meshing portion, and the inner wall of the sleeve is provided with a second meshing portion; The transmission shaft has a first position and a second position in the axial direction. In the first position, the transmission shaft drives the sleeve to rotate synchronously through the engagement of the first engagement portion and the second engagement portion. In the second position, the impeller shaft is limited, and the transmission shaft idles relative to the sleeve.

[0007] As mentioned above, the second engaging portion arranged on the inner wall of the sleeve is a convex second protrusion, and the first protrusion and the second protrusion are arranged to engage with each other.

[0008] As mentioned above, the sleeve is mounted on the end of the motor shaft in a rotationally fitted manner.

[0009] As mentioned above, a plurality of straight grooves are evenly arranged on the inner wall of the inner hole along its circumferential direction, and the linear direction of each straight groove is the same as the axial direction of the transmission shaft, and a plurality of straight blocks are evenly installed on the outer wall of the transmission shaft along its circumferential direction, and each straight block is installed in each straight groove one by one in a sliding fit manner.

[0010] As mentioned above, the part of the transmission shaft located inside the sleeve is installed with a transmission ring, and the transmission ring is installed in the sleeve in a sliding fit manner, and multiple first protrusions are evenly arranged along the circumferential direction of the transmission ring, and the second protrusions are evenly arranged along the circumferential direction of the sleeve.

[0011] As mentioned above, a driven ring is mounted on the side wall of the sleeve away from the second protrusion in a rotationally matched manner, and the side wall of the transmission ring away from the second protrusion and the driven ring are connected via a second elastic member.

[0012] As mentioned above, a plurality of first arc surface grooves are evenly provided on the inner wall of the inner hole along its circumferential direction, and each of the first arc surface grooves is connected to each of the straight grooves in a one-to-one correspondence, and each of the first arc surface grooves and each of the straight blocks are slidably matched in a one-to-one correspondence.

[0013] As mentioned above, a portion on the inner wall of the inner hole located between the end of the motor shaft and the straight groove is evenly provided with a plurality of second arc grooves along its circumferential direction, and a plurality of clamping grooves are evenly provided on the outer wall of the transmission shaft along its circumferential direction, and a movable plate is respectively installed in each of the clamping grooves in a rotationally fitted manner, and each of the movable plates is installed in the second arc groove in a slidingly fitted manner.

[0014] As mentioned above, the movable plate and the inner wall of the second arc groove are connected via a third elastic member.

[0015] As mentioned above, the end portion of the first elastic member connected to the inner hole is mounted on the inner wall of the inner hole in a rotationally fitted manner.

[0016] The beneficial effect of the present invention is that when the centrifugal fan needs to transport gas, the motor shaft is driven by the motor body to drive the transmission shaft to rotate, and the transmission shaft drives the sleeve to rotate through the engagement between the first protrusion and the second protrusion, and the sleeve drives the impeller shaft and the impeller body to rotate. When the impeller shaft is limited, the motor shaft will drive the transmission shaft to idle in the sleeve to prevent the impeller shaft from being limited and damaging the motor body. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 A schematic diagram of a partial three-dimensional structure of an embodiment provided by the present invention; Figure 3 For the present invention Figure 2 A top view of Figure 4 For the present invention Figure 3 Schematic diagram of the cross-sectional structure at AA; Figure 5 For the present invention Figure 3 Schematic diagram of the cross-sectional structure at BB; Figure 6 For the present invention Figure 3 Schematic diagram of the cross-sectional structure at CC; Figure 7 For the present invention Figure 3 Schematic diagram of the cross-sectional structure at DD; Figure 8 It is a schematic diagram of the three-dimensional structure of the first protrusion and the second protrusion of the present invention; Fig. 9 is a schematic cross-sectional structural diagram of another embodiment of the present invention; Fig.10 It is a schematic diagram of the cross-sectional structure of the arc surface rack of the present invention; Fig.11 It is a schematic diagram of the three-dimensional structure of the lifting member and the propulsion member of the present invention.

[0019] Description of reference numerals: Motor body; 111, housing; 2, motor shaft; 3, sleeve; 4, inner hole; 5, first elastic member; 6, transmission shaft; 7, first protrusion; 8, second protrusion; 9, straight groove; 10, straight block; 11, transmission ring; 12, driven ring; 13, second elastic member; 14, first arc groove; 15, second arc groove; 16, slot; 17, movable plate; 18, third elastic member; 19, latching tooth; 20, fourth elastic member; 21, arc rack; 22, lifting member; 23, propulsion member. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0021] like Figures 1 to 11 As shown, an embodiment provided by the present invention relates to a centrifugal fan driven by a permanent magnet motor, comprising a housing 111 and an impeller body, wherein the impeller body is rotatably arranged in the housing through an impeller shaft, and a motor body 1 is arranged on the housing, characterized in that the motor body 1 comprises a motor shaft 2 and a sleeve 3, the motor body 1 is connected to the motor shaft 2, an inner hole 4 is arranged on the motor shaft 2, a transmission shaft 6 is arranged in the inner hole 4 through a first elastic member 5, and further comprises a sleeve 3 for connecting with the impeller shaft; The end of the transmission shaft 6 is provided with a first meshing portion, and the inner wall of the sleeve 3 is provided with a second meshing portion; The transmission shaft 6 has a first position and a second position in the axial direction. In the first position, the transmission shaft 6 drives the sleeve 3 to rotate synchronously through the engagement of the first engagement portion and the second engagement portion. In the second position, the impeller shaft is limited, and the transmission shaft 6 idles relative to the sleeve 3 .

[0022] Specifically, the centrifugal fan is a device for gas delivery. The housing 111 is the outer shell of the centrifugal fan. There is a wind cavity in the housing 111. The impeller body is installed in the wind cavity through the rotation of the impeller shaft. The impeller shaft is connected to the sleeve. When the centrifugal fan is delivering gas, the motor body 1 is started to drive the motor shaft 2 to rotate, and the motor shaft 2 drives the transmission shaft 6 to rotate. Since the first meshing part and the second meshing part are staggered and meshed with each other (that is, one of the first meshing parts is located between the two second meshing parts adjacent to it, that is, a first meshing part is arranged between the two second meshing parts, and when the transmission shaft 6 rotates, the first meshing part is driven to rotate, and the first meshing part is engaged with the first meshing part by the first meshing part The second meshing parts mesh with each other, so that the first meshing part squeezes the side wall of the second meshing part, so that the first meshing part drives the second meshing part to rotate, and the second meshing part drives the sleeve to rotate), and under the tight action of the first elastic member 5 (the first elastic member 5 is a telescopic member that can be stretched and contracted, preferably a spring rod) on the transmission shaft 6, the first meshing part and the second meshing part are tightly meshed with each other, so that the transmission shaft 6 can drive the sleeve 3 to rotate, and the sleeve 3 is directly connected to the impeller shaft through a coupling or the sleeve 3 to drive the impeller shaft to rotate, so that the motor body 1 can drive the impeller shaft to rotate stably through the motor shaft 2 and the transmission shaft 6. This is the first position. That is, under the premise that there is no strong external force (that is, the impeller shaft is limited), the motor shaft 2 and the transmission shaft 6 transmit power in sequence through the first meshing portion, the second meshing portion, the sleeve 3 and the impeller shaft, thereby driving the impeller shaft. The impeller shaft drives the impeller body to rotate. When the impeller body rotates in the wind cavity of the shell 111, the gas enters the wind cavity from the air inlet of the shell 111. As the impeller body rotates, the gas is subjected to the centrifugal force to obtain kinetic energy and is discharged from the periphery of the impeller body. These gases are guided by the shell 111 and flow to the outlet of the shell 111. At the same time, negative pressure is formed in the center of the impeller body, attracting external airflow to continuously flow in to supplement , so that the fan can continuously discharge gas. The gas transportation of the centrifugal fan is common knowledge in this field and will not be elaborated. When the impeller shaft is limited (such as the impeller shaft is rusted, the bearing ring is out of round, the impeller is deformed, and the impeller is stuck, the impeller shaft will be limited), the first meshing portion on the transmission shaft 6 and the second meshing portion in the sleeve 3 rub against each other and rotate idly. At this time, it is the second position. Since the first elastic member 5 has a certain elasticity, when the first meshing portion and the second meshing portion rub against each other and rotate idly, the transmission shaft 6 moves axially in the inner hole 4 of the motor shaft 2, so that the motor shaft 2 rotates idly in the inner hole 4, thereby not causing damage to the motor body 1.

[0023] The deficiency in the prior art is that, since the output end of the motor (i.e., the motor shaft 2) is connected to the impeller shaft to drive the impeller to rotate, dust is easily adhered to the impeller on the centrifugal fan after long-term use, resulting in increased friction between the impeller and the casing, causing the impeller to get stuck when rotating, and due to inadequate lubrication of the impeller shaft and the motor shaft, the impeller may be deformed. After the impeller is deformed, it causes the impeller to shake when rotating, making it more prone to getting stuck. When the impeller is stuck, the motor is in normal working condition, making the motor prone to overload or even burn out.

[0024] The beneficial effects of this embodiment are as follows: when the centrifugal fan needs to transport gas, the motor shaft 2 is driven by the motor body 1 to drive the transmission shaft 6 to rotate. The transmission shaft 6 drives the sleeve 3 to rotate through the engagement between the first protrusion and the second protrusion. The sleeve 3 drives the impeller shaft and the impeller body to rotate. When the impeller shaft is limited, the motor shaft will drive the transmission shaft 6 to idle in the sleeve 3 to prevent the impeller shaft from being limited and damaging the motor body 1.

[0025] Furthermore, the first meshing portion arranged at the end of the transmission shaft 6 is a convex first protrusion 7, and the second meshing portion arranged on the inner wall of the sleeve 3 is a convex second protrusion 8, and the first protrusion 7 and the second protrusion 8 are arranged to mesh with each other. Specifically, the number of the first protrusion 7 and the second protrusion 8 is the same and not less than 6. When the transmission shaft 6 rotates, the first protrusion 7 is driven to rotate. The first protrusion 7 is engaged with the second protrusion 8, so that the first protrusion 7 squeezes the side wall of the second protrusion 8, so that the first protrusion 7 drives the second protrusion 8 to rotate, and the second protrusion 8 drives the sleeve 3 to rotate.

[0026] Furthermore, the sleeve 3 is installed at the end of the motor shaft 2 in a rotationally fitted manner. Specifically, the sleeve 3 is installed at the end of the motor shaft 2 in a rotationally fitted manner. When the impeller shaft is limited (that is, when the sleeve 3 is limited), the motor shaft 2 drives the transmission shaft 6 to idle in the sleeve 3, and the sleeve 3 and the motor shaft 2 will not slide axially, thereby improving the stability of the installation of the sleeve 3.

[0027] Furthermore, a plurality of straight grooves 9 are evenly provided on the inner wall of the inner hole 4 along its circumferential direction, and the linear direction of each straight groove 9 is the same as the axial direction of the transmission shaft 6, and a plurality of straight blocks 10 are evenly installed on the outer wall of the transmission shaft 6 along its circumferential direction, and each straight block 10 is installed in each straight groove 9 in a sliding fit manner. Specifically, when the motor body 1 drives the motor shaft 2 to rotate, each straight groove 9 on the inner hole 4 of the motor shaft 2 drives the corresponding straight block 10 to rotate, and the straight block 10 drives the transmission shaft 6 to rotate, so that axial transmission can be performed between the motor shaft 2 and the transmission shaft 6, and idling between the motor shaft 2 and the transmission shaft 6 will not occur, thereby improving the stability of the motor shaft 2 driving the transmission shaft 6 to rotate.

[0028] Furthermore, a transmission ring 11 is installed on the portion of the transmission shaft 6 located inside the sleeve 3, and the transmission ring 11 is installed in the sleeve 3 in a sliding fit manner. The first protrusions 7 are evenly arranged along the circumferential direction of the transmission ring 11, and the second protrusions 8 are evenly arranged along the circumferential direction of the sleeve 3, and the first protrusions 7 and the second protrusions 8 abut against each other and engage with each other. Specifically, when the motor body 1 drives the motor shaft 2 to drive the transmission shaft 6 to rotate, the transmission shaft 6 drives the sleeve 3 to rotate through the mutual abutment and staggered engagement between the first protrusion 7 and the second protrusion 8. The sleeve 3 is directly connected to the impeller shaft through a coupling or the sleeve 3 to drive the impeller shaft to rotate, so that the motor body 1 can drive the impeller shaft to rotate stably through the motor shaft 2 and the transmission shaft 6.

[0029] Furthermore, a driven ring 12 is installed on the side wall of the sleeve 3 away from the second protrusion 8 in a rotationally matched manner, and the side wall of the transmission ring 11 away from the second protrusion 8 and the driven ring 12 are connected by a second elastic member 13. Specifically, when the impeller shaft is in a limited position, the motor shaft 2 drives the transmission shaft 6 to idle in the sleeve 3, and the first protrusion 7 on the transmission shaft 6 and the second protrusion 8 in the sleeve 3 are in frictional idle rotation. Due to the mutual tightness between the end of the first protrusion 7 and the end of the second protrusion 8, the first protrusion 7 drives the transmission ring 11 to slide axially in the axial direction of the motor shaft 2 toward one end close to the motor body 1, and the transmission ring 11 drives the transmission shaft 6 to slide axially toward one end close to the motor body 1, so that The first elastic member 5 and the second elastic member 13 (the second elastic member 13 is a telescopic member capable of stretching and contracting, preferably a spring rod) are in a compressed state (that is, the first protrusion 7 and the second protrusion 8 are in the second position), and when the end of the first protrusion 7 is inserted into the space between the two second protrusions 8, under the rebound action of the first elastic member 5 and the second elastic member 13, the transmission ring 11 drives the transmission shaft 6 to slide axially toward the end away from the motor body 1, so that the first protrusion 7 and the second protrusion 8 are in a position of mutually staggered abutment and engagement (that is, the initial position of the first protrusion 7 and the second protrusion 8, that is, the first protrusion 7 and the second protrusion 8 are in the first position), so as to realize that the motor shaft 2 drives the transmission shaft 6 to rotate idly in the sleeve 3.

[0030] Further, a plurality of first arc surface grooves 14 are uniformly provided on the inner wall of the inner hole 4 along its circumferential direction, and each of the first arc surface grooves 14 is connected to each of the straight grooves 9 in a one-to-one correspondence, and each of the first arc surface grooves 14 and each of the straight blocks 10 are slidably matched in a one-to-one correspondence, and a plurality of second arc surface grooves 15 are uniformly provided on the inner wall of the inner hole 4 between the end of the motor shaft 2 and the straight groove 9 in its circumferential direction, and a plurality of card grooves 16 are uniformly provided on the outer wall of the transmission shaft 6 along its circumferential direction, and a movable plate 17 is respectively installed in each of the card grooves 16 in a rotationally matched manner, and each of the movable plates 17 is installed in the second arc surface groove 15 in a slidingly matched manner, and the movable plate 17 is between the inner wall of the second arc surface groove 15 The third elastic member 18 is connected to the movable plate 17 by a third elastic member 18. Specifically, in the initial position, the movable plate 17 is installed in the card slot 16 in a sliding manner and is located in the second arc groove 15. The third elastic member 18 between the second arc groove 15 and the movable plate 17 (the third elastic member 18 is a telescopic member capable of stretching and contracting, preferably a spring) is in a stretched state. Since the straight block 10 is installed in the straight groove 9 in a sliding manner, even when the third elastic member 18 is in a stretched state, the straight groove 9 limits the straight block 10, so that the third elastic member 18 has only a pulling tendency on the movable plate 17, and will not drive the transmission shaft 6 to rotate. When the impeller shaft is in a limited state, when the motor shaft 2 drives the transmission shaft 6 to idle in the sleeve 3, the first convex portion on the transmission shaft 6 When the protruding portion 7 and the second protruding portion 8 in the sleeve 3 are in frictional idling, due to the mutual abutment between the end of the first protruding portion 7 and the end of the second protruding portion 8, the first protruding portion 7 drives the transmission ring 11 to slide axially toward one end of the motor body 1 in the axial direction of the motor shaft 2, and the transmission ring 11 drives the transmission shaft 6 to slide axially toward one end of the motor body 1, so that the first elastic member 5 and the second elastic member 13 are in a compressed state (that is, the first protruding portion 7 and the second protruding portion 8 are in the second position). During the axial sliding of the transmission shaft 6, the transmission shaft 6 drives the straight block 10 to slide axially in the straight groove 9 toward one end of the motor body 1, so that the straight block 10 slides into the first arc surface groove 14. At this time, the straight groove 9 has no circumferential force on the straight block 10. The rotation (that is, the circumferential direction of the motor shaft 2) is limited (that is, after the straight block 10 slides into the first arc surface groove 14, the straight block 10 slides out of the straight groove 9, so that the transmission shaft 6 can rotate circumferentially), and at this time, the movable plate 17 is limited by the second arc surface groove 15, so that the movable plate 17 slides in the clamping groove 16, and since the third elastic member 18 is in a stretched state, the third elastic member 18 has a tendency to pull the movable plate 17 to rotate circumferentially, and the straight groove 9 does not limit the circumferential rotation of the transmission shaft 6 through the straight block 10, so that the third elastic member 18 pulls the movable plate 17 to rotate into the second arc surface groove 15, and at the same time, the movable plate 17 drives the transmission shaft 6 to rotate, and the transmission shaft 6 drives the straight block 10 to rotate in the first arc surface groove 14,Since the first elastic member 5 and the second elastic member 13 are in a compressed state at this time, after the straight block 10 rotates into the first arc surface groove 14, the straight block 10 is stuck in the first arc surface groove 14 under the pushing action of the first elastic member 5 and the second elastic member 13, so that the first protrusion 7 and the second protrusion 8 on the transmission shaft 6 are separated, and when the motor shaft 2 drives the transmission shaft 6 to rotate, the first protrusion 7 and the second protrusion 8 will not have friction collision, thereby reducing the damage caused by the friction collision between the motor shaft 2 and the transmission shaft 6 at the first protrusion 7 and the second protrusion 8; when the staff finds that the motor body 1 drives the motor shaft 2 and the transmission shaft 6 to idle, they turn off the power of the motor body 1, repair the limit problem of the impeller shaft, and rotate the transmission shaft 6 to make the straight block 10 slide out of the first arc surface groove 14, and under the rebound action of the first elastic member 5 and the second elastic member 13, the straight block 10 slides back into the straight groove 9, and at this time the third elastic member 18 is still in a stretched state.

[0031] Furthermore, the end portion of the first elastic member 5 connected to the inner hole 4 is mounted on the inner wall of the inner hole 4 in a rotationally matched manner. Specifically, when the impeller shaft is in a limited position, and the movable plate 17 drives the straight block 10 to rotate in the first arc surface groove 14 through the transmission shaft 6, since the first elastic member 5 and the inner hole 4 are mounted in a rotationally matched manner, and the second elastic member 13 is mounted in the sleeve 3 in a rotationally matched manner through the driven ring 12, the first elastic member 5 and the second elastic member 13 rotate in the process of the circumferential rotation of the transmission shaft 6. 5 and the second elastic member 13 will rotate accordingly without becoming an obstacle to the circumferential rotation of the transmission shaft 6 (when the first elastic member 5 and the second elastic member 13 are both fixedly installed, during the circumferential rotation of the transmission shaft 6, due to the presence of a certain torsional force in the first elastic member 5 and the second elastic member 13, the circumferential rotation of the transmission shaft 6 may be hindered, and even if the transmission shaft 6 drives the straight block 10 to slide into the first arc groove 14 and is limited, it is possible that the transmission shaft 6 rotates to the initial position under the rebound effect of the first elastic member 5 and the second elastic member 13).

[0032] Preferably, the arrangement direction of the first arc surface groove 14 and the second arc surface groove 15 in the inner hole 4 is opposite to the circumferential direction in which the motor body 1 drives the motor shaft 2 to rotate, that is, when the motor body 1 drives the motor shaft 2 and the transmission shaft 6 to rotate clockwise, the arrangement direction of the first arc surface groove 14 and the second arc surface groove 15 in the inner hole 4 is counterclockwise; when the motor body 1 drives the motor shaft 2 and the transmission shaft 6 to rotate counterclockwise, the arrangement direction of the first arc surface groove 14 and the second arc surface groove 15 in the inner hole 4 is clockwise. Specifically, when the impeller shaft is in a limited position, since the third elastic member 18 is in a pulling position, The third elastic member 18 drives the transmission shaft 6 to rotate circumferentially through the movable plate 17 when the transmission shaft 6 slides axially. At this time, when the motor shaft 2 drives the transmission shaft 6 to rotate clockwise, the first arc surface groove 14 and the second arc surface groove 15 are set in the counterclockwise direction in the inner hole 4. The third elastic member 18 drives the transmission shaft 6 to rotate counterclockwise through the movable plate 17. At this time, the rotation directions of the motor shaft 2 and the transmission shaft 6 are opposite, so that the straight block 10 can easily slide into the first arc surface groove 14, so that the straight block 10 can stably limit the axial position of the transmission shaft 6, and vice versa.

[0033] In another embodiment provided by the present invention, the first meshing portion is a latch tooth 19, and the second meshing portion is a cambered rack 21. The end of the transmission shaft 6 is located in the sleeve 3, and a plurality of latch teeth 19 are evenly arranged in the circumferential direction of the end of the transmission shaft 6, that is, the latch teeth 19 on the end of the transmission shaft 6 form an incomplete gear. A plurality of fourth elastic members 20 are evenly arranged on the inner wall of the sleeve 3 along its circumferential direction, and each of the fourth elastic members 20 is provided with a cambered rack 21, and the cambered rack 21 and the latch teeth 19 are meshed with each other. A plurality of lifting members 22 are evenly arranged between the fourth elastic member 20 and the arc-surface rack 21. A plurality of pushers 23 are evenly installed along the circumferential direction of the side wall of the transmission ring 11 close to the latching tooth 19 and between the arc-surface rack 21 and the transmission ring 11. The pushers 23 and the lifting members 22 cooperate with each other. The pushers 23 and the lifting members 22 are arc-shaped as a whole. The end faces opposite to the pushers 23 and the lifting members 22 are curved wedge-shaped surfaces (that is, the end faces of the pushers 23 close to the lifting members 22 and the lifting members 22 are curved wedge-shaped surfaces). 22 The end surface of the side close to the propulsion member 23 is an inclined curved surface). Specifically, when the motor body 1 drives the motor shaft 2 to drive the transmission shaft 6 to rotate, the latch teeth 19 and the arc-surface rack 21 cooperate with each other, so that the transmission shaft 6 drives the arc-surface rack 21 to rotate through the latch teeth 19, and the arc-surface rack 21 drives the sleeve 3 to rotate through the fourth elastic member 20 (the fourth elastic member 20 is a telescopic member that can be stretched and contracted, preferably a spring rod). This is the first position; when the impeller shaft is limited, the motor body 1 drives the motor shaft 2 to drive the transmission shaft 6 to rotate, and the transmission The latching teeth 19 on the shaft 6 rotate in the arc-surface rack 21. Under the rebound effect of the fourth elastic member 20, the latching teeth 19 on the transmission shaft 6 idle in the sleeve 3. At the same time, the transmission shaft 6 drives the transmission ring 11 to idle in the sleeve 3. When the propulsion member 23 on the transmission ring 11 rotates to abut against the lifting member 22 on the inner wall of the sleeve 3 (because in the initial position, the propulsion member 23 on the transmission ring 11 and the lifting member 22 on the inner wall of the sleeve 3 are installed in a staggered manner, that is, the propulsion member 23 is located between two adjacent lifting members 22 (see Fig.10), at this time, the transmission shaft 6 can also be driven by the wedge friction between the pusher 23 and the lifting member 22, which improves the stability of the transmission shaft 6 driving the sleeve 3 to rotate). Since the pusher 23 and the lifting member 22 are abutted by a wedge-shaped curved surface, and the sleeve 3 is installed at the end of the motor shaft 2 in a rotating fit, when the pusher 23 and the lifting member 22 abut against each other, the pusher 23 drives the transmission shaft 6 to slide axially toward one end of the motor body 1 through the transmission ring 11. At the same time, the transmission shaft 6 drives The movable straight block 10 slides axially in the straight groove 9 toward one end of the motor body 1, so that the straight block 10 slides into the first arc surface groove 14. At this time, the straight groove 9 has no circumferential rotation (that is, the circumferential direction of the motor shaft 2) limit for the straight block 10 (that is, after the straight block 10 slides into the first arc surface groove 14, the straight block 10 slides out of the straight groove 9, so that the transmission shaft 6 can rotate circumferentially). At this time, the movable plate 17 slides in the slot 16 due to the limit of the second arc surface groove 15. The elastic member 18 is in a stretched state, and the third elastic member 18 has a tendency to pull the movable plate 17 to rotate the transmission shaft 6 in a circumferential direction, while the straight groove 9 does not limit the circumferential rotation of the transmission shaft 6 through the straight block 10, so that the third elastic member 18 pulls the movable plate 17 to rotate into the second arc surface groove 15. At the same time, the movable plate 17 drives the transmission shaft 6 to rotate, and the transmission shaft 6 drives the straight block 10 to rotate in the first arc surface groove 14. Since the first elastic member 5 and the second elastic member 13 are in a compressed state at this time, after the straight block 10 rotates into the first arc surface groove 14, under the pushing action of the first elastic member 5 and the second elastic member 13, the straight block 10 is stuck in the arc surface groove, and the transmission shaft 6 does not rotate in a circumferential direction, so that the first protrusion 7 and the second protrusion 8 on the transmission shaft 6 are separated, and when the motor shaft 2 drives the transmission shaft 6 to rotate, the first protrusion 7 and the second protrusion 8 will not rub and collide, thereby reducing the damage caused by the friction and collision between the motor shaft 2 and the transmission shaft 6 at the first protrusion 7 and the second protrusion 8.

[0034] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A centrifugal fan driven by a permanent magnet motor, comprising a housing and an impeller body, wherein the impeller body is rotatably arranged in the housing through an impeller shaft, and a motor body is arranged on the housing, characterized in that: The motor body comprises a motor shaft and a sleeve, the motor body is connected to the motor shaft, the motor shaft is provided with an inner hole, a transmission shaft is provided in the inner hole through a first elastic member, and also comprises a sleeve for connecting with the impeller shaft; The end of the transmission shaft is provided with a first meshing portion, and the inner wall of the sleeve is provided with a second meshing portion; The transmission shaft has a first position and a second position in the axial direction. In the first position, the transmission shaft drives the sleeve to rotate synchronously through the engagement of the first engagement portion and the second engagement portion. In the second position, the impeller shaft is limited, and the transmission shaft idles relative to the sleeve.

2. A centrifugal fan driven by a permanent magnet motor according to claim 1, characterized in that: The first meshing portion arranged at the end of the transmission shaft is a convex first convex portion, the second meshing portion arranged on the inner wall of the sleeve is a convex second convex portion, and the first convex portion and the second convex portion are meshed with each other.

3. A centrifugal fan driven by a permanent magnet motor according to claim 1, characterized in that: The sleeve is mounted on the end of the motor shaft in a rotationally fitted manner.

4. A centrifugal fan driven by a permanent magnet motor according to claim 2, characterized in that: A plurality of straight grooves are evenly arranged on the inner wall of the inner hole along its circumferential direction, and the linear direction of each straight groove is the same as the axial direction of the transmission shaft. A plurality of straight blocks are evenly installed on the outer wall of the transmission shaft along its circumferential direction, and each straight block is installed in each straight groove one by one in a sliding fit manner.

5. The centrifugal fan driven by a permanent magnet motor according to claim 2, characterized in that: The portion of the transmission shaft located inside the sleeve is installed with a transmission ring, and the transmission ring is installed in the sleeve in a sliding fit manner. The plurality of first protrusions are evenly arranged along the circumferential direction of the transmission ring, and the second protrusions are evenly arranged along the circumferential direction of the sleeve.

6. A centrifugal fan driven by a permanent magnet motor according to claim 5, characterized in that: A driven ring is mounted on the side wall of the sleeve away from the second protrusion in a rotationally matched manner, and the side wall of the transmission ring away from the second protrusion and the driven ring are connected via a second elastic member.

7. A centrifugal fan driven by a permanent magnet motor according to claim 4, characterized in that: A plurality of first arc surface grooves are evenly formed on the inner wall of the inner hole along the circumferential direction thereof, and each of the first arc surface grooves is connected to each of the straight grooves in a one-to-one correspondence, and each of the first arc surface grooves is slidably matched with each of the straight blocks in a one-to-one correspondence.

8. A centrifugal fan driven by a permanent magnet motor according to claim 7, characterized in that: A portion of the inner wall of the inner hole between the end of the motor shaft and the straight groove is evenly provided with a plurality of second arc grooves along its circumferential direction, and a plurality of clamping grooves are evenly provided on the outer wall of the transmission shaft along its circumferential direction, and a movable plate is respectively installed in each of the clamping grooves in a rotationally fitted manner, and each of the movable plates is installed in the second arc groove in a slidingly fitted manner.

9. A centrifugal fan driven by a permanent magnet motor according to claim 8, characterized in that: The movable plate and the inner wall of the second arc groove are connected via a third elastic member.

10. A centrifugal fan driven by a permanent magnet motor according to claim 1, characterized in that: The end portion of the first elastic member connected to the inner hole is mounted on the inner wall of the inner hole in a rotationally fitted manner.

Images