Nozzle device for cleaning range hood and range hood

Abstract

The utility model relates to a nozzle device for cleaning a range hood and the range hood, and the nozzle device comprises a nozzle piece which is used for being communicated with a cleaning medium supply device in a fluid manner so as to spray a cleaning medium to an impeller of the range hood; the power output end of the first movement device is connected with the nozzle piece, so that the nozzle piece is driven to move back and forth along a set trajectory; the first mounting plate is fixed relative to the range hood, the first moving device is movably arranged on the first mounting plate in the first linear direction, and the first linear direction is perpendicular to the axis direction of the impeller; the power output end of the second movement device acts on the first movement device, and therefore the first movement device and the nozzle piece arranged on the first movement device can be driven to move in the first linear direction. The nozzle device for cleaning the range hood has the advantages that the jet flow can cover more effective cleaning areas of the impeller, so that the overall cleaning rate is effectively improved.

Description

Technical Field

[0001] This utility model relates to the field of range hood technology, and in particular to a nozzle device for cleaning a range hood and a range hood. Background Technology

[0002] A range hood is a kitchen appliance used to purify the kitchen environment. With the continuous advancement of self-cleaning technology, steam cleaning or water cleaning has been widely used in the field of range hood self-cleaning. The basic principle is that a steam generator produces steam or a water pump pumps water to deliver steam or water to the nozzles at the end of the spray pipe. The steam or water is then quickly sprayed out from the nozzles to clean the impeller and volute.

[0003] Currently, most self-cleaning systems for range hoods use stationary nozzles, while a small number use moving nozzles. The purpose of using moving nozzles is mainly to expand the cleaning range or area, thereby further improving the cleaning efficiency and ensuring the effectiveness of the cleaning.

[0004] For stationary nozzle devices, single or multiple nozzles are often used. The nozzles are installed inside the impeller, with the nozzles facing the pressure surface of the impeller blades. However, static nozzles have a limited cleaning area and can only clean a limited area. The nozzles cannot cover the entire width direction of the blades (impeller axis), so only local areas can be cleaned, resulting in poor cleaning efficiency. At the same time, uneven oil accumulation between cleaned and uncleaned areas can increase impeller vibration and affect the life of the fan.

[0005] For dynamic nozzles, they are essentially single dynamic nozzles, meaning the movement direction of the dynamic nozzle is unidirectional, that is, the axial direction of the covering blades, thereby cleaning the covered surface. For example, the invention patent application with application number CN201711480573.9 (application publication number CN109990332A) discloses a cleaning device for a range hood fan system, located outside the range hood fan. The fan includes a volute with an air outlet and an impeller disposed within the volute. The cleaning device includes a nozzle, and an elongated clearance hole extending along the fan axial direction is opened on the annular wall of the volute. The nozzle outlet faces the opening and moves along the length direction of the opening under the drive of the drive mechanism. Although a single dynamic nozzle solves the problem of incomplete coverage, it places high demands on the moving nozzle. The jet must be coaxial with the nozzle, and the nozzle cannot deviate too much; otherwise, the effective cleaning area of ​​the blades may not be cleaned. Specifically, considering that the nozzle's cleaning target is the pressure surface of the blades, the jet is directed from the back towards the pressure surface through the gap between the blades. However, to ensure performance, the gap between impeller blades is often relatively small. Therefore, the nozzle's jet can only pass through a very small area to clean the pressure surface, as shown in the attached diagram. Figure 1As shown, assuming the target of the cleaning is blade a2, the jet is injected from the upper edge of blade a2 and flushes downward under the guidance of the pressure surface s, cleaning the entire blade a2. However, due to manufacturing errors, installation errors, and jet stability, the nozzle may be biased upward, causing the jet to flush blade a1. At this time, since the flushing point of blade a1 is lower, the lower half of the blade can be cleaned, but the upper edge of blade a1 (the area marked by the elliptical dashed line in the figure) has very poor cleaning efficiency. Therefore, while cleaning is being done while the impeller is rotating, the upper edges of all blades have very low cleaning efficiency, resulting in low overall cleaning efficiency. Alternatively, the jet may be tilted, which may directly cause the nozzle to fail to clean the pressure surface of the blade.

[0006] Therefore, the nozzle devices of existing range hoods still need further improvement. Utility Model Content

[0007] The first technical problem to be solved by this utility model is to provide a nozzle device for cleaning range hoods that enables the jet stream to cover more effective cleaning areas of the impeller, thereby effectively improving the overall cleanliness rate, in light of the current state of the technology.

[0008] The second technical problem to be solved by this utility model is to provide a range hood that uses the above-mentioned nozzle device, in view of the current state of the prior art.

[0009] The technical solution adopted by this utility model to solve the first technical problem is: a nozzle device for cleaning range hoods, comprising:

[0010] The nozzle is used to be in fluid communication with the cleaning medium supply device, so as to spray the cleaning medium onto the impeller of the range hood;

[0011] The first motion device has its power output end connected to the nozzle component, thereby driving the nozzle component to reciprocate along a set trajectory line;

[0012] Also includes:

[0013] The first mounting plate is fixed relative to the range hood, and the aforementioned first moving device is movably mounted on the first mounting plate along a first straight line direction, which is perpendicular to the axis direction of the impeller.

[0014] The second motion device has its power output end acting on the first motion device, thereby driving the first motion device and the nozzle component provided on the first motion device to move along a first linear direction.

[0015] The trajectory line mentioned above can be a straight line, a curved line, or a combination of a curve and a straight line.

[0016] While the nozzle is driven by the first motion device to move along the set trajectory line, it can move a certain amount in the first straight direction, increasing the cleaning coverage of the impeller in the first straight direction (that is, the direction perpendicular to the axis of the impeller). This can effectively cover the effective cleaning area of ​​the blades. During the cleaning process, as the impeller rotates, it can cover more effective cleaning areas, improve the overall cleanliness, reduce manufacturing requirements, and has a certain degree of fault tolerance, which can ensure the final cleaning effect.

[0017] The first motion device can be a linear motion mechanism (in which the nozzle moves in a straight line, and the straight trajectory is the aforementioned set trajectory line), a rotary motion mechanism, or a motion device combining linear and rotary motion mechanisms. However, considering that the stroke of the linear motion mechanism is relatively large, this easily leads to a larger overall size of the first motion device, occupying more space. Therefore, to simplify the structure of the first motion device and make it more compact, the first motion device includes a first drive motor. The nozzle is connected to the output shaft of the first drive motor. The trajectory line formed by the rotation of the nozzle driven by the output shaft of the first drive motor is the aforementioned set trajectory line. On the other hand, the cleaning path formed by the linear motion of the traditional nozzle is simple and difficult to effectively remove oil stains from the complex curved surface of the impeller. The first drive motor (the device that provides rotational power) drives the nozzle to rotate and form a set trajectory line (such as a circular or spiral path). By dynamically rotating and spraying the cleaning medium, the cleaning efficiency of the impeller's curved surface and crevices is improved.

[0018] As an improvement, an auxiliary connecting arm is connected to the output shaft of the first drive motor, and the nozzle component is detachably mounted on the auxiliary connecting arm. The auxiliary connecting arm (a transition component connecting the motor output shaft and the nozzle) enables a detachable nozzle design, facilitating quick replacement or cleaning of the nozzle and reducing maintenance costs.

[0019] To address the issues of unstable nozzle installation and easy detachment, as well as the difficulty in securing the nozzle component, the nozzle component is a long, narrow tube. The auxiliary connecting arm has a mounting groove for housing the nozzle component and a cover plate for closing the mounting groove to secure the nozzle component. The combined design of the mounting groove and cover plate (the groove accommodates the nozzle, and the cover plate is secured by bolts or clips) ensures a stable installation of the long, narrow nozzle while also accommodating nozzles of different sizes.

[0020] To address the issue of bulky structure and large space occupation caused by mounting the drive motor and nozzle on the same side, a first clearance opening is provided on the first mounting plate. The output shaft of the first drive motor passes through the first clearance opening and connects to the nozzle component. The first drive motor and the nozzle component are located on opposite sides of the plane containing the first clearance opening on the first mounting plate. The first clearance opening (a through hole on the mounting plate) separates the drive motor and nozzle on opposite sides of the mounting plate, optimizing the spatial layout and facilitating equipment installation in confined spaces.

[0021] To prevent the first moving device from easily deviating from the predetermined direction during movement and affecting the cleaning accuracy, a second mounting plate is also included for mounting the first moving device. The first mounting plate is provided with guide posts, the extension direction of which is the first straight line direction. The second mounting plate has guide holes for the guide posts to pass through. The guide posts (cylindrical guide rails fixed on the mounting plate) cooperate with the guide holes to constrain the second mounting plate (the plate that carries the first moving device) to move accurately along the first straight line direction, preventing deviation.

[0022] To simplify the structure of the second motion device, the first linear direction includes a first direction and a second direction with opposite directions. The second motion device includes:

[0023] The second driving member acts on the first moving device and causes the first moving device and the nozzle member provided on the first moving device to move along the first direction;

[0024] An elastic element acts on the first moving device and causes the first moving device and the nozzle element disposed on the first moving device to always have a tendency to move along the second direction.

[0025] The first motion device is moved along the first direction by a second driving element (such as a motor or cylinder), and an elastic element (such as a spring) provides a reverse restoring force, which simplifies bidirectional motion control and improves the reliability of the mechanism.

[0026] The aforementioned elastic element can employ various existing technologies, including compression springs, torsion springs, leaf springs, and other elastic components. However, to better cooperate with the guide post, the elastic element is a spring, which is sleeved on the guide post and abuts against the first moving device. The spring's sleeve on the guide post and its abutment against the first moving device ensures stable transmission of the elastic restoring force and prevents spring displacement.

[0027] As an improvement, there are at least three guide posts and at least three springs, with each spring sleeved on a corresponding guide post. The at least three guide posts and springs are symmetrically distributed (e.g., in a triangular layout) to enhance the balance of the motion device and prevent tilting or jamming.

[0028] The second driving component can employ a conventional linear motion mechanism, such as an electric actuator, a structure combining a drive motor and a lead screw-slider assembly, a structure combining a drive motor and a connecting rod assembly, or a structure combining a drive motor and a cam. To simplify the structure of the second driving component and to accommodate the resetting action of the elastic element, the second driving component includes a second drive motor and an eccentric cam connected to the output shaft of the second drive motor. This eccentric cam can be driven to rotate by the second drive motor and act eccentrically on the first motion device. The eccentric cam (a disk whose center is offset from the axis of rotation) converts the rotational motion of the second drive motor into reciprocating linear motion, resulting in a simple structure and precise control.

[0029] The technical solution adopted by this utility model to solve the second technical problem is as follows: a range hood, including a centrifugal fan and a nozzle device, wherein the centrifugal fan includes a volute and an impeller rotatably disposed within the volute, the impeller including blades arranged sequentially along the circumference, the nozzle device adopts the above-mentioned range hood cleaning nozzle device, the nozzle device is arranged on the outside of the volute, and the volute has a second clearance opening for at least the spray nozzle portion to pass through and enter the volute.

[0030] Compared with the prior art, the advantages of this utility model are: while the nozzle is driven by the first motion device to move along the set trajectory line, it can move a certain amount in the first straight direction, increasing the cleaning coverage of the impeller in the first straight direction (that is, the direction perpendicular to the axis of the impeller). This can effectively cover the effective cleaning area of ​​the blade. During the cleaning process, as the impeller rotates, it can cover more effective cleaning areas, improve the overall cleanliness, reduce manufacturing requirements, have a certain fault tolerance, and ensure the final cleaning effect. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the blade cleaning process of an impeller in the prior art;

[0032] Figure 2 This is a three-dimensional structural diagram of the centrifugal fan according to an embodiment of the present utility model;

[0033] Figure 3 This is a sectional perspective view of the centrifugal fan according to an embodiment of the present utility model;

[0034] Figure 4 for Figure 3 Enlarged view of point M in the image;

[0035] Figure 5 This is a three-dimensional structural diagram of the nozzle device according to an embodiment of the present utility model;

[0036] Figure 6This is a three-dimensional structural diagram of the nozzle device according to another embodiment of the present utility model;

[0037] Figure 7 This is a three-dimensional structural diagram of the nozzle component and the auxiliary connecting arm in the connection state according to an embodiment of the present utility model;

[0038] Figure 8 This is an exploded view of the nozzle component and auxiliary connecting arm according to an embodiment of the present utility model;

[0039] Figure 9 This is a schematic diagram of the blade cleaning process of the impeller in an embodiment of the present invention. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0041] In the specification and claims of this utility model, terms indicating direction, such as "front," "rear," "upper," "lower," "left," "right," "side," "top," and "bottom," are used to describe various exemplary structural parts and elements of this utility model. However, the use of these terms is merely for the purpose of explanation and is based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this utility model can be arranged in different orientations, these terms indicating direction are for illustrative purposes only and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0042] Figures 1-9 A preferred embodiment of a range hood cleaning nozzle device and a range hood is shown. The range hood includes a housing and a centrifugal fan disposed within the housing. The housing generally includes a fan frame and a smoke collection hood disposed at the bottom of the fan frame, with the inner cavity of the fan frame communicating with the inner cavity of the smoke collection hood. An air inlet is provided on the front side wall of the smoke collection hood, through which external fumes can enter the smoke collection hood. The centrifugal fan is disposed within the fan frame; when the centrifugal fan operates, it generates negative pressure, drawing external fumes into the smoke collection hood through the air inlet. An oil filter is also provided at the air inlet of the smoke collection hood for filtering fumes. An oil cup, which is an elongated strip extending laterally, is provided at the bottom of the smoke collection hood to collect oil stains flowing down from the smoke collection hood.

[0043] The range hood also includes a cleaning system, which can be automatically activated based on actual usage (i.e., a self-cleaning system) or manually activated by the user. Since the blades 120 of the centrifugal fan impeller 12 are the main components contaminated with grease, the cleaning system primarily targets the impeller 12 for cleaning. The cleaning system generally includes a nozzle device connected to a cleaning medium supply device via piping, which sprays the cleaning medium onto the impeller 12 of the range hood. The cleaning medium supply device is generally located on the range hood casing (e.g., inside or attached to the outside), but can also be separate from the range hood. The cleaning medium supply device typically includes a pump for delivering the cleaning medium, which can be liquid or steam. When the cleaning medium is liquid, a cleaning agent for removing grease is usually added as well.

[0044] See Figures 5-8 The nozzle device in this embodiment includes a nozzle component 20, a first motion device 30, a first mounting plate 51, and a second motion device 40. The nozzle component 20 is a long, narrow tube with a curved structure. One end is connected to an external water pump via a flexible hose, and the other end has one or more spray holes for spraying cleaning water onto the impeller 12 of the range hood. The first motion device 30 includes a first drive motor 31, whose output shaft is connected to an auxiliary connecting arm 32. The nozzle component 20 is detachably installed in a mounting groove 320 at the end of the auxiliary connecting arm 32 and fixed by a cover plate 321. The auxiliary connecting arm 32 and the output shaft of the first drive motor 31 are connected by a non-circular limiting structure, such as a non-circular hole on the main body of the auxiliary connecting arm 32, and the end of the output shaft of the first drive motor 31 is also designed with a corresponding non-circular profile. After the first drive motor 31 starts, it drives the auxiliary connecting arm 32 and the nozzle component 20 to rotate around the output shaft axis, causing the nozzle component 20 to reciprocate along a circular trajectory, expanding the cleaning coverage area.

[0045] See Figure 7 and Figure 8 The connection structure between the main body of the auxiliary connecting arm 32 and the cover plate 321 can be fixed by screws 323 or by a snap-fit ​​assembly 322, or a combination of screws 323 and snap-fit ​​322. For example... Figure 8 As shown, the main body of the auxiliary connecting arm 32 is provided with two buckles 322, and the cover is provided with two corresponding slots 3210 for the buckles 322 to be inserted into. After the main body of the auxiliary connecting arm 32 and the cover plate 321 are assembled by limiting the buckles 322, they are then fixed by screws 323.

[0046] The first mounting plate 51 can be made of metal and is fixed to the outside of the range hood housing 10 by bolts, specifically arranged on the outside of the annular wall 11 of the housing 10. The first drive motor 31 is mounted on one side of the first mounting plate 51, and its output shaft passes through the first clearance opening 510 on the first mounting plate 51 and connects to the auxiliary connecting arm 32 located on the other side. The first mounting plate 51 is also provided with four guide posts 511, which extend in a direction perpendicular to the axis of the impeller 12. The second mounting plate 52 is sleeved on the guide posts 511 through guide holes thereon, and the first drive motor 31 is fixed on the second mounting plate 52.

[0047] The second motion device 40 includes a second drive motor 41 and an eccentric cam 42. A U-shaped third mounting plate 53 is mounted on the first mounting plate 51. The second drive motor 41 is fixed on the third mounting plate 53, and its output shaft is connected to the eccentric cam 42. The eccentric cam 42 contacts the first drive motor 31 (or the second mounting plate 52). When the second drive motor 41 rotates, the eccentric cam 42 pushes the first drive motor 31 to move along the guide post 511 in the first direction A1, compressing the spring sleeved on the guide post 511. When the cam rotates to the reset position, the elastic force of the spring pushes the second mounting plate 52 back to its original position along the second direction A2. Thus, the nozzle 20 reciprocates along the direction perpendicular to the axis of the impeller 12 while rotating, further expanding the cleaning coverage area.

[0048] The range hood's volute 10 has a second clearance opening 110 on its annular wall 11. A nozzle assembly is positioned at this opening, and the nozzle 20's spray nozzle passes through it into the volute 10, rinsing the pressure surface of the impeller 12 blades. When the impeller 12 rotates, the first drive motor 31 and the second drive motor 41 operate. The combined motion of the nozzle 20 (rotational + linear reciprocating) covers the entire axial and transverse (parallel to radial) areas of the impeller 12, effectively removing accumulated oil and avoiding blind spots in cleaning.

[0049] See Figure 9 This embodiment mainly uses coupled motion to allow the nozzle component 20 to have a certain displacement in the first linear direction A, thereby increasing the longitudinal coverage area and ensuring that the nozzle component 20 can cover the effective cleaning area of ​​the blade. Coupled with the rotational motion of the impeller 12, it can cover even more effective cleaning areas, improving the overall cleanliness rate. At the same time, it reduces manufacturing requirements, has a certain degree of error tolerance, and can guarantee the final cleaning effect. Figure 9As shown, if the nozzle 20 deviates from the cleaning point of the previous blade, the cleaning efficiency will decrease (see the background art for details). However, by increasing the vertical movement A (i.e., the first straight line direction A), the nozzle can move up and down. The cleaning point will not remain at the cleaning point of blade a1 as shown in the figure, but will move within the effective area of ​​the upper edge of blade a1 and the upper edge of blade a2. Therefore, the cleaning area is expanded, that is, the effective cleaning area increases, and the cleanliness rate is improved. At the same time, the pressure surface exposed between the two blades is cleaned by direct jet impact, resulting in greater cleaning force and a significant improvement in cleanliness. Moreover, oil stains are concentrated at the outer edge of the blades, so the cleanliness rate can be effectively improved. In addition, because of the vertical movement displacement, there is no need to worry about minor manufacturing or installation errors, reducing manufacturing requirements. Combined with the rotational speed of the impeller 12, the coverage rate and cleanliness rate can be further improved.

[0050] In this embodiment, the "pressure surface" of the blade refers to the side of the blade that directly propels the air (or fumes) during rotation and bears higher fluid pressure. The cross-section of the impeller blade is usually curved, with the pressure surface located on the concave side of the blade (i.e., the inner side of the blade facing the center of rotation), while the suction surface is located on the convex side (outer side).

[0051] The term "fluid connectivity" as used in this utility model refers to the spatial relationship between two components or parts (hereinafter referred to as the first part and the second part, respectively), that is, a fluid (gas, liquid, or a mixture of both) can flow from the first part along a flow path and / or be transported to the second part. This can be a direct connection between the first part and the second part, or an indirect connection between the first part and the second part through at least one third party. The third party can be a fluid channel such as a pipe, channel, conduit, guide, hole, or groove, or a chamber or combination thereof that allows fluid to flow through.

[0052] Based on the above embodiments, other embodiments can be obtained by replacing and improving the relevant technical features. For example, the first motion device 30 can be a linear motor, whose power output end is directly connected to the nozzle 20, driving the nozzle 20 to reciprocate along a linear trajectory. The stroke range of the linear motor covers the axial length of the impeller 12, ensuring that the cleaning medium can cover the width direction of the blades. As another example, the second motion device 40 can be an electric push rod, the telescopic end of which is connected to the base of the first motion device 30. When the electric push rod extends, it pushes the first motion device 30 and the nozzle 20 to move along the first linear direction A; when the electric push rod retracts, the nozzle 20 returns to its initial position through the tension of the return spring.

Claims

1. A nozzle device for cleaning a range hood, comprising: a nozzle member (20) for being in fluid communication with a cleaning medium supply device so as to spray a cleaning medium to an impeller (12) of the range hood; a first moving device (30) having a power output end connected to the nozzle member (20) so as to drive the nozzle member (20) to move along a set trajectory line; characterized in that further comprising: a first mounting plate (51) fixed relative to the range hood, the first moving device (30) being movably arranged on the first mounting plate (51) along a first linear direction (A) which is perpendicular to an axial direction of the impeller (12); and a second moving device (40) having a power output end acting on the first moving device (30) so as to drive the first moving device (30) and the nozzle member (20) arranged on the first moving device (30) to move along the first linear direction (A). The first moving device (30) comprises a first driving motor (31), and the nozzle member (20) is connected to an output shaft of the first driving motor (31), and the trajectory line formed by the rotation of the nozzle member (20) driven by the output shaft of the first driving motor (31) is the set trajectory line. The output shaft of the first driving motor (31) is connected with an auxiliary connecting arm (32), and the nozzle member (20) is detachably arranged on the auxiliary connecting arm (32). The nozzle member (20) is a long strip-shaped tube body, and the auxiliary connecting arm (32) has a mounting groove (320) for accommodating the nozzle member (20) and a cover plate (321) for covering the mounting groove (320) to fix the nozzle member (20). The first mounting plate (51) is provided with a first displacement opening (510), the output shaft of the first driving motor (31) passes through the first displacement opening (510) and is connected to the nozzle member (20), and the first driving motor (31) and the nozzle member (20) are respectively located on opposite sides of a plane where the first displacement opening (510) of the first mounting plate (51) is located. Further comprising a second mounting plate (52) for accommodating the first moving device (30), the first mounting plate (51) is provided with a guide column (511) whose extension direction is the first linear direction (A), and the second mounting plate (52) has a guide hole for passing the guide column (511) therethrough.

2. The range hood cleaning nozzle device according to claim 1, characterized in that: The first linear direction (A) comprises a first direction (A1) and a second direction (A2) which are opposite to each other, and the second moving device (40) comprises: a second driving member acting on the first moving device (30) and driving the first moving device (30) and the nozzle member (20) arranged on the first moving device (30) to move along the first direction (A1); and a second driving motor (41) connected to the second driving member.

3. The range hood cleaning nozzle device according to claim 2, characterized in that: ​ 4. The range hood cleaning nozzle device according to claim 3, characterized in that: ​ 5. The range hood cleaning nozzle device according to claim 2, characterized in that: ​ 6. The extractor hood cleaning nozzle device according to any one of claims 1 to 5, characterized in that: ​ 7. The range hood cleaning nozzle device according to claim 6, characterized in that: ​ ​ An elastic member (43) acts on the first moving device (30) and makes the first moving device (30) and the nozzle member (20) arranged on the first moving device (30) always have a tendency to move in the second direction (A2).

8. The range hood cleaning nozzle device according to claim 7, characterized in that: The elastic member (43) is a spring which is sleeved on the guide column (511) and abuts against the first moving device (30).

9. The range hood cleaning nozzle device according to claim 8, characterized in that: The guide column (511) has at least three, and the spring also has at least three, each of the springs being sleeved on a corresponding guide column (511).

10. The range hood cleaning nozzle device according to claim 7, characterized in that: The second driving member comprises a second driving motor (41) and an eccentric cam (42) connected with an output shaft of the second driving motor (41), the eccentric cam (42) being capable of being driven by the second driving motor (41) to rotate and eccentrically act on the first moving device (30).

11. An extractor hood comprising a centrifugal fan comprising a volute (10) and an impeller (12) rotatably arranged in the volute (10), the impeller (12) comprising blades arranged in succession in the circumferential direction, characterized in that: The nozzle device adopts the nozzle device for cleaning the range hood according to any one of claims 1-10, the nozzle device is arranged outside the volute (10), and a second accommodating opening (110) is formed in the volute (10) to allow at least a part of the nozzle member (20) to pass through and enter the volute (10).

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