Impeller mounting structure of centrifugal fan, centrifugal fan and range hood

Abstract

The utility model relates to an impeller installation structure of centrifugal fan, centrifugal fan and range hood, including locking subassembly, the locking subassembly includes: knob piece, on which is defined a containing chamber that forms an opening on the side facing the wheel disc, the rotary knob piece is further provided with an installation hole channel formed in the axial direction of the output shaft of the motor from the bottom wall of the containing cavity. The cover plate is arranged in the containing cavity in the mode that the cover plate can move in the axial direction of the output shaft of the motor and abuts against the wheel disc in the axial direction of the output shaft of the motor. The first elastic piece acts between the cover plate and the knob piece and enables the knob piece to always have a trend of moving towards a direction far away from the wheel disc; the axial pre-tightening assembly is arranged in the containing cavity and abuts against the cover plate, and the axial pre-tightening assembly is provided with a pre-tightening rod which can penetrate through the bottom wall of the containing cavity of the rotary knob piece, stretch into the positioning sliding way and abut against a pin shaft of an output shaft of the motor in the axial direction. The reliable anti-loosening function is achieved while it is guaranteed that locking and unlocking are quicker and more labor-saving.

Description

Technical Field

[0001] The utility model relates to the technical field of centrifugal fans, in particular to an impeller mounting structure of a centrifugal fan, a centrifugal fan and a range hood. Background Art

[0002] Centrifugal fans are an important air supply device, commonly used in range hoods, air conditioners and other products. Among them, the fan system is the core component of the range hood, and the impeller is the key component of the fan system. When the impeller is contaminated by oil and the surface of the blades is oily, the oil will change the streamline of the blades and increase the weight of the impeller, thus causing the overall performance of the fan system to decline. When the accumulated oil reaches a certain amount, the overall performance of the range hood is seriously reduced, the noise increases, the air volume loss is serious, and smoke leakage occurs, which seriously affects the user experience. Therefore, after the range hood has been used for a period of time, the range hood, especially the impeller of its fan system, needs to be disassembled and cleaned.

[0003] In order to facilitate the disassembly and assembly of the impeller, a Chinese utility model patent application with application number CN01239583.8 discloses a fan impeller installation structure for a range hood, including an impeller and a motor output shaft, the impeller including a front ring and a rear ring arranged relatively to each other and a plurality of blades connected to the outer edges of the two, a wheel disk fixed at the central part of the rear ring, a central hole for the motor output shaft to pass through is opened on the wheel disk, a slot is opened on the central rear end face of the wheel disk, and a pin that can be embedded in the slot is passed through the motor output shaft at a corresponding position, and the front end face of the wheel disk is limited by a hand-tightening nut connected to the front end thread of the motor output shaft. However, the fixing method of the impeller is basically a left-handed tightening nut, and a certain pre-tightening force needs to be applied during installation to prevent loosening. During the long-term use of the fan, due to the vibration problem of the impeller, it is easy to loosen due to insufficient pre-tightening of the hand-tightening nut installation, that is, it does not have an anti-loosening effect, and therefore, there are certain safety hazards.

[0004] For this purpose, a Chinese utility model patent application with application number CN202320080046.3 (authorization announcement number: CN219220852U) discloses a mounting structure of a centrifugal fan impeller assembly, a centrifugal fan and a range hood, the mounting structure comprising: a motor having an output shaft; a locking position thereon, a locking assembly comprising a locking piece and a first spring, the locking piece having a mounting hole, a locking portion being provided on the inner wall of the mounting hole, a limiting structure allowing the locking piece to rotate between a locked position and an unlocked position with the output shaft of the motor as the rotation center is also constructed between the output shaft of the motor and the mounting hole of the locking piece, the first spring acts on the locking piece, and causes the locking piece to always have a tendency to move in a direction away from the wheel disc. When the locking member is in the locked position, the movement of the locking member can be limited in the axial direction and / or circumferential direction of the motor output shaft; when the locking member is in the unlocked position, the locking portion of the locking member is disengaged from the locking position on the motor output shaft to release the position limit between the two in the axial direction and circumferential direction along the motor output shaft. The installation structure of the impeller assembly can effectively avoid the loosening problem caused by insufficient installation pre-tightening.

[0005] However, the impeller installation structure in the above patent application still has certain shortcomings. Under normal circumstances, the spring of the locking assembly must be pressed by manual force and play an axial pre-tightening role after installation. However, as the operating speed of the range hood continues to increase, the acceleration of the startup is getting higher and higher, resulting in the axial component force becoming larger and larger during the impeller startup process. Therefore, when the motor is required to run at a high speed, the spring of the locking assembly cannot achieve axial pre-tightening while ensuring the installation feel, and therefore further optimization design is urgently needed. Utility Model Content

[0006] The first technical problem to be solved by the utility model is to provide an impeller installation structure of a centrifugal fan which is labor-saving to install and can realize firm locking in view of the current status of the prior art.

[0007] The second technical problem to be solved by the utility model is to provide a centrifugal fan using the above impeller installation structure in view of the current status of the prior art.

[0008] The third technical problem to be solved by the present invention is to provide a range hood using the centrifugal fan according to the current status of the prior art.

[0009] The technical solution adopted by the utility model to solve the first technical problem is: an impeller installation structure of a centrifugal fan, the centrifugal fan includes a motor and an impeller assembly, the motor has an output shaft, the outer peripheral wall of the output shaft has a pin extending radially outward, the impeller assembly includes an impeller and a wheel connected to the impeller, and the wheel is connected to the output shaft of the motor;

[0010] The impeller mounting structure includes a locking assembly, which is connected to the output shaft of the motor and is located on a side of the wheel disc away from the main body of the motor, and is used to limit the wheel disc in the axial direction of the output shaft. The locking assembly includes:

[0011] A knob member, the knob member defines a receiving chamber which is open on a side facing the wheel disc, the knob member also has a mounting hole which is opened from the bottom wall of the receiving chamber along the axial direction of the output shaft of the motor, the inner wall of the mounting hole is provided with a positioning slide extending along the mounting hole, and the pin shaft of the output shaft of the motor can be inserted into the mounting hole, rotated by a certain angle, and then circumferentially limited in the positioning slide;

[0012] A cover plate is disposed in the accommodating chamber in a manner that it can move along the axial direction of the output shaft of the motor, and abuts against the wheel disc in the axial direction of the output shaft of the motor;

[0013] A first elastic member acts between the cover plate and the knob member, and makes the knob member always have a tendency to move away from the wheel disc;

[0014] An axial preload assembly is disposed in the accommodating chamber and abuts against the cover plate. The axial preload assembly has a preload rod that can pass through the bottom wall of the accommodating chamber of the knob member and extend into the positioning slideway, and abuts against the pin shaft of the output shaft of the motor in the axial direction.

[0015] In order to realize the positioning of the output shaft and the pin shaft of the motor in the positioning slide by pressing and rotating, the inner circumferential wall of the mounting hole also has a guide slideway opened along the extension direction of the mounting hole, a transition slideway opened along the circumference of the mounting hole and a positioning slideway opened along the extension direction of the mounting hole; the bottom wall of the accommodating chamber has a mounting opening that is connected with the guide slideway for the pin shaft to slide into the guide slideway; the end of the guide slideway away from the wheel disc is connected to the first end of the transition slideway, the end of the positioning slideway away from the wheel disc is connected to the second end of the transition slideway, and the end of the positioning slideway adjacent to the wheel disc is a closed structure; the guide slideway, transition slideway and positioning slideway together constitute a locking slideway structure of the knob member, and the pin shaft on the output shaft of the motor can slide through the locking slideway structure and finally move into the positioning slideway.

[0016] As a preferred solution, the axial preload assembly includes:

[0017] A first axial limiting sleeve, wherein the end wall of the first axial limiting sleeve away from the wheel disc is provided with the preload rod;

[0018] A second elastic member is disposed between the cover plate and the first axial limiting sleeve, and enables the first axial limiting sleeve to always have a tendency to move away from the wheel disc;

[0019] The stiffness coefficient of the second elastic member is greater than the stiffness coefficient of the first elastic member.

[0020] In order to accommodate the second elastic member, the middle part of the cover plate has a first opening for the output shaft of the motor to pass through, and the outer peripheral edge of the first opening has an annular flange folded and extended toward the accommodating chamber, and the main body of the first axial limit sleeve has a limit stop portion extending radially outward, and the second elastic member is a second spring, one end of which is sleeved outside the annular flange of the cover plate, and the other end is sleeved outside the first axial limit sleeve and against the limit stop portion.

[0021] As another preferred scheme, the axial preload assembly includes a second axial limit sleeve, which has the preload rod on the end wall away from the wheel disc, and when the pin shaft of the output shaft of the motor moves into place in the positioning slide, the pin shaft and the end of the preload rod of the second axial limit sleeve are interference fit.

[0022] In order to facilitate the interference fit of the end of the preload rod of the second axial limit sleeve after rotation into place, it is provided with an inclined surface for forming an interference fit with the pin shaft during rotation with the output shaft of the motor, and the inclined surface protrudes a certain height relative to the front side wall of the transition slide.

[0023] In order to simplify the installation structure between the cover plate and the knob member, the cover plate is connected to the bottom wall of the accommodating chamber of the knob member through a plurality of connecting rods arranged sequentially in the circumferential direction, the first elastic member is a first spring, and the first axial limiting sleeve is arranged on the connecting rod and abuts against the cover plate and the bottom wall of the accommodating chamber of the knob member.

[0024] In order to ensure the reliability of locking the output shaft of the motor, the pin on the output shaft of the motor has two sections symmetrically arranged about the axis of the output shaft, the locking slide structure on the knob part also has two corresponding ones, and the preload rod of the axial preload assembly also has two corresponding ones.

[0025] In order to facilitate the user to apply force to operate the knob, the outer peripheral wall of the knob is also provided with anti-slip grooves which are sequentially arranged along the circumference and are all recessed inwards.

[0026] The technical solution adopted by the utility model to solve the second technical problem is: a centrifugal fan, including a volute, an impeller assembly and a motor, the main body of the motor is connected to the volute, the impeller assembly is arranged in the volute and connected to the output shaft of the motor, and the output shaft of the motor and the impeller assembly are connected using the above-mentioned impeller mounting structure of the centrifugal fan.

[0027] The technical solution adopted by the utility model to solve the third technical problem is: a range hood, including a fan system, characterized in that: the fan system adopts the above-mentioned centrifugal fan.

[0028] Compared with the prior art, the advantages of the utility model are as follows: after the output shaft of the motor is inserted into the mounting hole of the knob part and rotated a certain angle to be circumferentially limited in the positioning slide, the impeller mounting structure also limits the pin shaft of the output shaft of the motor in the axial direction through the preload rod of the axial preload assembly. Thus, while ensuring that locking and unlocking are faster and more labor-saving, a reliable anti-loosening function is achieved. Without external operation, loosening and falling off will not occur, and it is safer and more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a three-dimensional structural schematic diagram of the locking assembly of the impeller mounting structure of Example 1 of the utility model;

[0030] Figure 2 It is an axial cross-sectional view of the locking assembly of the impeller mounting structure of Example 1 of the utility model;

[0031] Figure 3 This is an exploded view of the locking assembly of the impeller mounting structure of Example 1 of the utility model;

[0032] Figure 4 A cross-sectional view of the locking assembly of the impeller mounting structure of Example 1 of the utility model and the output shaft of the motor being matched together;

[0033] Figure 5 This is a schematic diagram of the three-dimensional structure of the knob member of Example 1 of the utility model;

[0034] Figure 6 It is a sectional stereoscopic view of the knob member of Example 1 of the utility model;

[0035] Figure 7 This is a schematic diagram of the three-dimensional structure of the centrifugal fan of Example 1 of the utility model;

[0036] Figure 8 It is a cross-sectional view of the centrifugal fan of Example 1 of the utility model;

[0037] Fig. 9 It is an axial cross-sectional view of the locking assembly of the impeller mounting structure of Example 2 of the utility model;

[0038] Fig.10 This is a schematic diagram of the three-dimensional structure of the second axial limit sleeve of the impeller mounting structure of Example 2 of the utility model. DETAILED DESCRIPTION

[0039] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0040] In the specification and claims of the present invention, terms indicating directions, such as "front", "rear", "up", "down", "left", "right", "side", "top", "bottom", etc., are used to describe various exemplary structural parts and elements of the present invention, but these terms are used here only for the purpose of convenience of description and are determined based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in the present invention can be arranged in different directions, these terms indicating directions are only used as explanations and should not be regarded as limitations. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0041] Example 1

[0042] like Figure 1-Figure 8 A preferred embodiment of the present embodiment is shown, an impeller mounting structure of a centrifugal fan, which is used to mount the impeller assembly 2 of the centrifugal fan on the output shaft 11 of the motor 10, and to achieve axial and circumferential limitation of the impeller assembly 2 on the output shaft 11 of the motor 10.

[0043] The centrifugal fan of this embodiment includes a volute 70, a motor 10 and an impeller assembly 2. The main body of the motor 10 is connected to the volute 70, and the motor 10 has an output shaft 11. The outer peripheral wall of the end of the output shaft 11 has a pin 12 extending radially outward. The impeller assembly 2 is arranged in the volute 70, which includes an impeller and a wheel disc 21 connected to the middle disc 20 of the impeller, and the wheel disc 21 is connected to the output shaft 11 of the motor 10. The output shaft 11 of the motor 10 and the wheel disc 21 of the impeller assembly 2 are connected using the impeller mounting structure of this embodiment.

[0044] See also Figure 1-Figure 6 The impeller mounting structure includes a locking assembly, which is connected to the output shaft 11 of the motor 10 and is located on the side of the wheel disc 21 away from the main body of the motor 10, and is used to limit the wheel disc 21 in the axial direction of the output shaft 11. The locking assembly includes a knob member 3, a cover plate 4, a first elastic member 61 and an axial preload assembly.

[0045] The knob member 3 is a cap structure having an accommodation chamber 30 with an opening formed on the side facing the wheel disc 21. The knob member 3 also has a mounting hole 31 opened along the axial direction of the output shaft 11 of the motor 10 from the bottom wall of the accommodation chamber 30 (i.e., the side wall opposite to the opening). The inner peripheral wall of the mounting hole 31 also has a guide slideway 32 opened along the extension direction of the mounting hole 31, a transition slideway 33 opened along the circumference of the mounting hole 31, and a positioning slideway 34 opened along the extension direction of the mounting hole 31. The above-mentioned transition slideway 33 is an arc-shaped slideway, and its corresponding central angle is about 90°. The bottom wall of the accommodating chamber 30 has an installation opening 35 that is connected to the guide slideway 32 and allows the pin shaft 12 to slide into the guide slideway 32. The end of the guide slideway 32 away from the wheel disc 21 is connected to the first end of the transition slideway 33, and the end of the positioning slideway 34 away from the wheel disc 21 is connected to the second end of the transition slideway 33. The end of the positioning slideway 34 adjacent to the wheel disc 21 is a closed structure. The bottom wall of the accommodating chamber 30 also has a second opening 37 that axially penetrates to the second end of the positioning slideway 34.

[0046] The guide slide 32, transition slide 33 and positioning slide together constitute the locking slide structure of the knob member 3 of this embodiment. The pin 12 on the output shaft 11 of the motor 10 of this embodiment has two sections symmetrically arranged about the axis of the output shaft 11, and the locking slide structure on the knob member 3 also has two corresponding sections.

[0047] The cross section of the accommodating chamber 30 of the knob member 3 is circular, and correspondingly, the cover plate 4 is also a matching circular plate body, which is axially movably arranged in the accommodating chamber 30 of the knob member 3. Specifically, the cover plate 4 is connected to the bottom wall of the accommodating chamber 30 of the knob member 3 through a plurality of connecting rods 43 (such as step screws) arranged in sequence in the circumferential direction of the knob member 3. The first elastic member 61 adopts a first spring, and the first axial limit sleeve 51 is arranged on the connecting rod 43, and its two ends are respectively against the cover plate 4 and the bottom wall of the accommodating chamber 30 of the knob member 3. Under the elastic force of the first spring, the knob member 3 and the cover body have a tendency to move away from each other. Among them, the length dimension of the connecting rod 43 should be reasonably designed to ensure that the cover plate 4 does not fall out from the front opening of the knob member 3 in a natural state.

[0048] The axial preload assembly is also arranged in the accommodating chamber 30, specifically, between the cover plate 4 and the bottom of the accommodating chamber 30. The axial preload assembly includes a first axial limit sleeve 51 and a second elastic member 62. The middle part of the cover plate 4 has a first opening 41 through which the output shaft 11 and the pin shaft 12 of the power supply machine 10 pass, and the outer peripheral edge of the first opening 41 has an annular flange 42 that is folded and extended toward the accommodating chamber 30. The main body of the first axial limit sleeve 51 has a limit stop 511 extending radially outward. The second elastic member 62 of this embodiment is a second spring, one end of which is sleeved outside the annular flange 42 of the cover plate 4, and the other end is sleeved outside the first axial limit sleeve 51 and abuts against the limit stop 511. Under the elastic force of the above-mentioned second spring, the first axial limit sleeve 51 always has a tendency to move toward the side away from the wheel disc 21. The first axial limiting sleeve 51 has an axially extending preload rod 53 on its end wall away from the wheel disc 21. The preload rod 53 can pass through the second opening 37 on the bottom wall of the knob member 3 and extend into the positioning slideway 34, and axially abut against the pin 12 in the positioning slideway 34. In accordance with the number of locking slideway structures of the knob member 3, the axial preload assembly also has two corresponding preload rods 53.

[0049] In this embodiment, the stiffness coefficient of the second spring is greater than the stiffness coefficient of the first spring.

[0050] The combined length of the second spring and the first axial limit sleeve 51 of this embodiment is the distance between the inner end face of the cover plate 4 and the cylindrical surface of the pin shaft 12 of the output shaft 11 of the motor 10 after the knob 3 is installed in place. In order to ensure sufficient preload, the second spring should use a large stiffness spring, that is, the initial compression or a slight displacement can meet the axial preload requirement. Specifically, the combined length interference can be within 0.5mm to ensure the installation feel. During operation, the installation opening 35 on the bottom wall of the accommodating chamber 30 of the knob 3 is aligned with the pin shaft 12. When the outer end face of the cover plate 4 contacts the impeller 21 of the impeller, the first spring begins to compress. Since the first spring is not required to achieve axial preload in this embodiment, the first spring can ensure the reset of the knob 3 and the manual operation feel. During the process of the first spring being compressed and the pin shaft 12 moving along the guide slide 32 to the bottom of the mounting channel 31 of the knob member 3, due to the extrusion of the cover plate 4, the second spring pushes the first axial limit sleeve 51 to move downward. Since the first axial limit sleeve 51 has not yet contacted the main body of the knob member 3 (the bottom wall of the accommodating chamber 30), the second spring will not be compressed at this time and continues to press downward until the first axial limit sleeve 51 contacts the main body of the knob member 3. At this time, the second spring must ensure that it contacts the inner end surface of the cover plate 4. If it just contacts, the pin shaft 12 of the output shaft 11 of the motor 10 has already contacted the bottom of the guide slide 32 of the knob member 3, that is, it can rotate. If there is an interference, it is necessary to continue to move down an axial distance equivalent to the interference distance before it can rotate. If it moves down the interference distance, the second spring will be compressed. At this time, the interference distance is the compression distance of the second spring. Since the force compressing the second spring will be transmitted to the hand, the interference distance is designed to be as small as possible. When the downward pressure starts, the first spring is compressed. When the compression reaches the final stage, the second spring also begins to be compressed. However, since the interference distance is very small, there will be no obvious feeling of effort in this compression. The pin shaft 12 of the output shaft 11 of the motor 10 moves to the bottom of the guide slide 32 and rotates 90° to the left along the transition slide 33 to enter the position corresponding to the positioning slide 34. Then release the knob 3. At this time, the preload force is provided by the second spring and the first spring. Under the elastic force of the first spring, the knob 3 is pushed backward. At this time, the pin shaft 12 contacts the two preload rods 53 of the first axial limit sleeve 51. The axial preload force acts on the pin shaft 12 to complete the axial limit. Since the pin shaft 12 is stuck in the positioning slide 34, the circumferential limit is also achieved at the same time.

[0051] In order to further improve the hand feel, during the rotation process after the pin shaft 12 is compressed to the bottom of the guide slide 32 of the knob member 3, the front side wall surface of the transition slide 33 for the circumferential movement of the pin shaft 12 can be designed as a slope, and the interference displacement is borne by the pin shaft 12 rotating on the slope. Compared with pressing, the operating feel will be improved, that is, the pressing force is converted into rotational force.

[0052] After the output shaft 11 of the motor 10 is inserted into the mounting hole 31 of the knob 3 and rotated to a certain angle to be circumferentially limited in the positioning slide 34, the impeller mounting structure of this embodiment also limits the pin 12 of the output shaft 11 of the motor 10 in the axial direction through the preload rod 53 of the axial preload assembly. Thus, while ensuring that locking and unlocking are faster and more labor-saving, a reliable anti-loosening function is achieved. Without external operation, there will be no loosening and falling off, which is safer and more reliable. In addition, the impeller mounting structure also has a locking feel prompt, which is convenient for users to judge whether it is locked. This structure can be improved on the basis of the existing structure without modifying the original design, reducing costs and shortening the development cycle.

[0053] The present embodiment also relates to a range hood, comprising a fan system, wherein the fan system adopts the centrifugal fan mentioned above.

[0054] Example 2

[0055] See also Fig. 9 and Fig.10 , shows another preferred embodiment of the utility model, which differs from the embodiment 1 in that the structure of the axial preload assembly is different, the second spring is omitted, and a second axial limit sleeve 52 is used, and the axial length of the second axial limit sleeve 52 is also equivalent to the combined length of the second spring and the first axial limit sleeve 51 in the embodiment 1. The length of the second axial limit sleeve 52 is limited by interference to limit the axial displacement, and through reasonable size design, it is ensured that the minimum interference of the matching relationship is greater than 0, and the interference should not be too large, otherwise it cannot be assembled. When the second axial limit sleeve 52 contacts the knob member 3, the pin 12 is rotatable, and in this state, the end face of the guide column is not flush with the front side wall of the transition slide 33, but slightly exceeds a certain distance. The interference contact also starts from the rotation of the pin 12 to the guide column of the second axial limit sleeve 52. A small inclined surface 530 is designed at the end of the guide column. When the pin 12 contacts the inclined surface 530, an interference fit is gradually formed until the pin 12 can slide into the positioning slide 34. Under the elastic force of the first spring, the knob member 3 moves backward, so that the pin 12 contacts the bottom surface of the positioning slide 34, thereby completing the axial positioning.

Claims

1. An impeller mounting structure of a centrifugal fan, the centrifugal fan comprising a motor (10) and an impeller assembly (2), the motor (10) having an output shaft (11), the outer peripheral wall of the output shaft (11) having a pin shaft (12) extending radially outward, the impeller assembly (2) comprising an impeller and a wheel disc (21) connected to the impeller, the wheel disc (21) being connected to the output shaft (11) of the motor (10); The impeller mounting structure comprises a locking assembly, which is connected to the output shaft (11) of the motor (10) and is located on a side of the wheel disc (21) away from the main body of the motor (10), and is used to limit the wheel disc (21) in the axial direction of the output shaft (11), and the locking assembly comprises: A knob member (3), the knob member (3) defines a receiving chamber (30) which is open on a side facing the wheel disc (21), the knob member (3) also having a mounting hole (31) which is opened from the bottom wall of the receiving chamber (30) along the axial direction of the output shaft (11) of the motor (10), the inner wall of the mounting hole (31) is provided with a positioning slideway (34) which extends along the mounting hole (31), and the pin shaft (12) of the output shaft (11) of the motor (10) can be inserted into the mounting hole (31) and rotated by a certain angle to be circumferentially limited in the positioning slideway (34); A cover plate (4) is disposed in the accommodating chamber (30) in a manner that allows it to move along the axial direction of the output shaft (11) of the motor (10), and abuts against the wheel disc (21) in the axial direction of the output shaft (11) of the motor (10); A first elastic member (61) acts between the cover plate (4) and the knob member (3) and causes the knob member (3) to always have a tendency to move in a direction away from the wheel disc (21); An axial preload assembly is disposed in the accommodating chamber (30) and abuts against the cover plate (4). The axial preload assembly comprises a preload rod (53) which can pass through the bottom wall of the accommodating chamber (30) of the knob member (3) and extend into the positioning slideway (34), and abuts against the pin shaft (12) of the output shaft (11) of the motor (10) in the axial direction.

2. The impeller mounting structure of the centrifugal fan according to claim 1, characterized in that: The inner peripheral wall of the installation channel (31) is also provided with a guide slideway (32) opened along the extension direction of the installation channel (31), a transition slideway (33) opened along the circumference of the installation channel (31), and a positioning slideway (34) opened along the extension direction of the installation channel (31); the bottom wall of the accommodating chamber (30) is provided with an installation opening (35) which is in communication with the guide slideway (32) and allows the pin shaft (12) to slide into the guide slideway (32); the end of the guide slideway (32) away from the wheel disc (21) is in contact with the wheel disc (21); The first end of the transition slide (33) is connected, the end of the positioning slide (34) away from the wheel disc (21) is connected to the second end of the transition slide (33), and the end of the positioning slide (34) adjacent to the wheel disc (21) is a closed structure. The guide slide (32), the transition slide (33) and the positioning slide together constitute a locking slide structure of the knob member (3), and the pin shaft (12) on the output shaft (11) of the motor (10) can slide along the locking slide structure and finally move into the positioning slide (34).

3. The impeller mounting structure of the centrifugal fan according to claim 2, characterized in that: The axial preload assembly comprises: A first axial limiting sleeve (51), wherein the end wall of the first axial limiting sleeve (51) away from the wheel disc (21) is provided with the preload rod (53); A second elastic member (62) is disposed between the cover plate (4) and the first axial limiting sleeve (51), and enables the first axial limiting sleeve (51) to always have a tendency to move away from the wheel disc (21); The stiffness coefficient of the second elastic member (62) is greater than the stiffness coefficient of the first elastic member (61).

4. The impeller mounting structure of the centrifugal fan according to claim 3, characterized in that: The middle part of the cover plate (4) has a first opening (41) for the output shaft (11) of the motor (10) to pass through, and the outer peripheral edge of the first opening (41) has an annular flange (42) folded and extended toward the accommodating chamber (30), and the main body of the first axial limit sleeve (51) has a limit stop portion (511) extending radially outward, and the second elastic member (62) is a second spring, one end of which is sleeved outside the annular flange (42) of the cover plate (4), and the other end is sleeved outside the first axial limit sleeve (51) and abuts against the limit stop portion (511).

5. The impeller mounting structure of the centrifugal fan according to claim 2, characterized in that: The axial preload assembly comprises a second axial limit sleeve (52), and the second axial limit sleeve (52) has the preload rod (53) on its end wall away from the wheel disc (21). When the pin shaft (12) of the output shaft (11) of the motor (10) moves into position in the positioning slideway (34), the pin shaft (12) and the end of the preload rod (53) of the second axial limit sleeve (52) are interference fit.

6. The impeller mounting structure of the centrifugal fan according to claim 5, characterized in that: The end of the preload rod (53) of the second axial limit sleeve (52) has an inclined surface (530) for forming an interference fit with the pin shaft (12) during the rotation of the output shaft (11) of the motor (10), and the inclined surface (530) protrudes a certain height relative to the front side wall of the transition slideway (33).

7. The impeller mounting structure of a centrifugal fan according to claim 3 or 4, characterized in that: The cover plate (4) is connected to the bottom wall of the accommodating chamber (30) of the knob member (3) through a plurality of connecting rods (43) arranged in sequence in the circumferential direction; the first elastic member (61) is a first spring; the first axial limiting sleeve (51) is arranged on the connecting rod (43) and abuts against the bottom wall of the accommodating chamber (30) of the knob member (3).

8. The impeller mounting structure of a centrifugal fan according to any one of claims 1 to 6, characterized in that: The pin shaft (12) on the output shaft (11) of the motor (10) has two sections symmetrically arranged about the axis of the output shaft (11), the locking slide structure on the knob member (3) also has two corresponding sections, and the preload rods (53) of the axial preload assembly also have two corresponding sections.

9. The impeller mounting structure of a centrifugal fan according to any one of claims 1 to 6, characterized in that: The outer peripheral wall of the knob member (3) is also provided with anti-slip grooves which are sequentially arranged along its circumference and are all recessed inwards.

10. A centrifugal fan, comprising a volute (70), an impeller assembly (2) and a motor (10), wherein a main body of the motor (10) is connected to the volute (70), the impeller assembly (2) is arranged in the volute (70) and connected to an output shaft (11) of the motor (10), characterized in that: The output shaft (11) of the motor (10) and the impeller assembly (2) are connected using the impeller mounting structure of the centrifugal fan according to any one of claims 1 to 9.

11. A range hood, comprising a fan system, characterized in that: The fan system adopts the centrifugal fan as claimed in claim 10.

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