CN108240357B - Noise-reducing volute tongue of fan - Google Patents
Noise-reducing volute tongue of fan Download PDFInfo
- Publication number
- CN108240357B CN108240357B CN201711449597.8A CN201711449597A CN108240357B CN 108240357 B CN108240357 B CN 108240357B CN 201711449597 A CN201711449597 A CN 201711449597A CN 108240357 B CN108240357 B CN 108240357B
- Authority
- CN
- China
- Prior art keywords
- noise reduction
- volute tongue
- side face
- tongue body
- cavities
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000009467 reduction Effects 0.000 claims abstract description 118
- 230000007423 decrease Effects 0.000 claims description 6
- 230000007704 transition Effects 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 4
- 230000008030 elimination Effects 0.000 abstract description 4
- 238000003379 elimination reaction Methods 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 230000030279 gene silencing Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
- F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
- F04D29/663—Sound attenuation
- F04D29/665—Sound attenuation by means of resonance chambers or interference
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/40—Casings; Connections of working fluid
- F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
- F04D29/4206—Casings; Connections of working fluid for radial or helico-centrifugal pumps especially adapted for elastic fluid pumps
- F04D29/422—Discharge tongues
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/40—Casings; Connections of working fluid
- F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
- F04D29/4206—Casings; Connections of working fluid for radial or helico-centrifugal pumps especially adapted for elastic fluid pumps
- F04D29/4226—Fan casings
- F04D29/4233—Fan casings with volutes extending mainly in axial or radially inward direction
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
The invention discloses a fan noise reduction volute tongue, which comprises a volute tongue body and is characterized in that: noise reduction cavities are formed on the upper side face and the lower side face of the volute tongue body, an outer cover matched with the volute tongue body is arranged outside the volute tongue body, and noise reduction holes corresponding to the noise reduction cavities one by one are formed in the outer cover. Compared with the prior art, the invention has the advantages that: according to the fan noise reduction volute tongue, the noise reduction cavities are formed in the upper side face and the lower side face of the volute tongue body, the noise reduction holes corresponding to the noise reduction cavities one to one are formed in the outer cover outside the volute tongue body, and each noise reduction cavity and the noise reduction holes are matched to form an independent noise reduction cavity, so that the volute tongue can reduce noise by utilizing the Helmholtz resonance noise elimination principle, and the fan noise reduction volute tongue is simple in structure and good in noise reduction and noise elimination effect.
Description
Technical Field
The invention relates to a range hood, in particular to a fan noise reduction volute tongue.
Background
The main function of the fan volute tongue for the range hood is to intercept (prevent the impeller from driving air flow to rotate and not go out), generally, the volute tongue can be divided into a sharp tongue, a deep tongue, a short tongue and a flat tongue, and for the traditional straight volute tongue, the deeper the volute tongue, the smaller the clearance between the volute tongue and the impeller is, the efficiency is improved, but the noise is increased. The flow velocity of the air flow in the volute is basically in secondary curve distribution with large middle flow velocity and small flow velocity at two ends along the axial direction, and the result of fluid simulation analysis shows that the secondary flow which flows from the middle to the left and right sides obviously forms a large vortex due to the large middle velocity and the small velocity at the two ends near the air outlet of the fan, which is common in the traditional straight volute tongue fan.
In order to reduce noise and eliminate vortex of the fan, the structure of the volute tongue is improved, such as a ' range hood fan ' and a range hood provided with the fan ' disclosed in Chinese patent application publication No. 20110427490. X (application publication No. CN 102518603A), wherein a concave part concave towards the outer side of the volute casing is formed on the volute tongue of the volute casing, so that the concave part is arc-shaped in the direction of the air outlet, and although the concave part is arranged to rectify the air flow at the position, the noise generated at the volute tongue during the operation of the range hood is reduced, the lower end surface of the volute tongue has the same size as the gap of the impeller, and therefore, vortex is easily generated on the front side and the rear side of the volute tongue during the operation of the fan. As disclosed in chinese patent application No. 201210890. X (application publication No. 103512064 a), the volute includes a concave surface, which is a smooth curved surface, so that the airflow at the volute is smoother, which is beneficial to noise reduction. The volute tongue structure disclosed by the above is mainly used for reducing noise by changing the profile structure of the air inlet side of the volute tongue, and has a good noise reduction effect, but the volute tongue is difficult to process, so that the manufacturing cost of the volute tongue is increased.
Disclosure of Invention
The invention aims to solve the technical problem of providing the fan noise reduction volute tongue with simple structure and good noise reduction effect.
The technical scheme adopted for solving the technical problems is as follows: the fan noise reduction volute tongue comprises a volute tongue body and is characterized in that: noise reduction cavities are formed on the upper side face and the lower side face of the volute tongue body, an outer cover matched with the volute tongue body is arranged outside the volute tongue body, and noise reduction holes corresponding to the noise reduction cavities one by one are formed in the outer cover.
Preferably, the noise reduction cavity on the upper side of the volute tongue body forms a diversion noise reduction cavity, the noise reduction cavity on the lower side of the volute tongue body forms a backflow noise reduction cavity, correspondingly, the upper side of the outer cover is a diversion surface, the lower side of the outer cover is a return surface, and the diversion surface and the return surface are provided with noise reduction holes.
Further preferably, the diversion surface and the backflow surface of the outer cover are mutually connected through a smooth transition diversion surface.
In order to adapt the noise reduction structure of the volute tongue to the airflow speed at the front end and the rear end of the volute tongue, the ratio S/V of the noise reduction hole area S to the corresponding noise reduction cavity volume V meets the following conditions: the S/V value is the largest at the position corresponding to the impeller middle disc, and gradually decreases from the position corresponding to the impeller middle disc to the front side and the rear side of the volute tongue.
As a preferable scheme, the sizes of the noise reduction hole areas S on the same side face of the outer cover are equal, the volumes V of the noise reduction cavities on the upper side face and the lower side face of the volute tongue body at the positions corresponding to the middle disc of the impeller are minimum, and the volumes V of the noise reduction cavities on the same side face of the volute tongue body gradually become larger from the positions corresponding to the middle disc of the impeller to the front side and the rear side of the volute tongue.
Preferably, the noise reduction cavities on the same side face of the volute tongue body have the same depth, and the sectional areas of the noise reduction cavities on the same side face gradually become larger from the positions corresponding to the middle disc of the impeller to the front side and the rear side of the volute tongue.
Preferably, the cross-sectional areas of the noise reduction cavities on the same side are equal in size, and the depths of the noise reduction cavities on the same side of the volute tongue body gradually increase from the positions corresponding to the middle disc of the impeller to the front side and the rear side of the volute tongue.
Further preferably, all noise reduction hole areas S on the outer cover are equal in size.
As another preferable scheme, the volumes of the noise reduction cavities on the same side face of the volute tongue body are equal, and the area S of the noise reduction holes on the same side face of the outer cover is gradually reduced from the position corresponding to the middle disc of the impeller to the front side and the rear side of the volute tongue.
Preferably, the volute tongue body is of an integrally formed structure.
Compared with the prior art, the invention has the advantages that: according to the fan noise reduction volute tongue, the noise reduction cavities are formed in the upper side face and the lower side face of the volute tongue body, the noise reduction holes corresponding to the noise reduction cavities one to one are formed in the outer cover outside the volute tongue body, and each noise reduction cavity and the noise reduction holes are matched to form an independent noise reduction cavity, so that the volute tongue can reduce noise by utilizing the Helmholtz resonance noise elimination principle, and the fan noise reduction volute tongue is simple in structure and good in noise reduction and noise elimination effect.
Drawings
FIG. 1 is a schematic diagram of a first embodiment of the present invention;
FIG. 2 is an exploded view of a first embodiment of the present invention;
FIG. 3 is an exploded view of an alternative embodiment of the present invention;
FIG. 4 is a schematic diagram illustrating an internal structure of a first embodiment of the present invention;
FIG. 5 is a schematic view illustrating a variation in cross-sectional area of a noise reduction cavity of a volute tongue body according to a first embodiment of the present invention;
FIG. 6 is a schematic view of a fan with a volute tongue according to one embodiment of the invention;
FIG. 7 is a schematic view of variation of noise reduction holes in a volute tongue housing according to a second embodiment of the present invention;
Fig. 8 is a schematic diagram of a noise reduction cavity depth variation of a volute tongue body according to a third embodiment of the present invention.
Detailed Description
The invention is described in further detail below with reference to the embodiments of the drawings.
Embodiment one:
As shown in fig. 1 to 6, the fan noise reduction volute tongue in the present embodiment includes a volute tongue body 1 and an outer cover 2 covering the volute tongue body, the volute tongue body 1 is an integrally formed structure, and the shape of the outer cover 2 is adapted to the volute tongue body 1. The upper side surface and the lower side surface of the volute tongue body 1 are respectively provided with a noise reduction cavity 11, the noise reduction cavities 11 on the upper side surface form a diversion noise reduction cavity, and the noise reduction cavities 11 on the lower side surface form a backflow noise reduction cavity; correspondingly, a diversion surface 22 is formed on the upper side surface of the outer cover 2, a return surface 23 is formed on the lower side surface of the outer cover 2, noise reduction holes 21 corresponding to the diversion noise reduction cavities one by one are formed on the diversion surface 22, and noise reduction holes 21 corresponding to the return noise reduction cavities one by one are formed on the return surface 23. Furthermore, the flow guiding surface 22 and the return surface 23 of the housing 2 are joined to each other by a smooth transition flow dividing surface 24.
According to the Helmholtz resonance principle, each independent noise reduction cavity 11 has a resonance frequency ofC is sound velocity, S is the area of the corresponding noise reduction hole 21, V is the volume of the noise reduction cavity, and L is the effective neck length of the noise reduction hole 21. As can be seen from this, the volume of the noise reduction chamber 11 increases and the resonance frequency f decreases, whereas the volume of the noise reduction chamber 11 decreases and the resonance frequency f increases, with other parameters unchanged. By utilizing the Helmholtz resonance silencing principle, an elastic resonance system is formed by the air column in the noise reduction hole 21 and the air in the noise reduction cavity 11, and when the partial noise frequency of the range hood is the same as the natural frequency of the resonance system, the air column in the noise reduction hole 21 resonates and rubs with the hole wall severely, and the acoustic energy is converted into heat energy by friction, so that the purpose of silencing is achieved.
According to the flow velocity distribution at the outlet of the fan, the air velocity at the middle disk 3 of the corresponding impeller is the largest, the air velocity at the front and rear disks of the impeller is the smallest, and the ratio S/V of the area S of the noise reduction hole 21 to the volume V of the corresponding noise reduction cavity 11 is required to satisfy the following conditions by combining the Helmholtz resonance principle: the S/V value is the largest at the position corresponding to the impeller middle disc 3, and gradually decreases from the position corresponding to the impeller middle disc 3 to the front side and the rear side of the volute tongue.
In this embodiment, the areas S of the noise reduction holes 21 on the same side of the housing 2 are equal, but it is needless to say that the areas S of all the noise reduction holes 21 on the housing 2 may be equal. The volume V of the noise reduction cavity 11 on the upper side surface and the lower side surface of the volute tongue body 1 at the position corresponding to the impeller middle disc 3 is minimum, and the volume V of the noise reduction cavity 11 on the same side surface of the volute tongue body 1 gradually increases from the position corresponding to the impeller middle disc 3 to the front side and the rear side of the volute tongue.
The trend of the change in the volume V of the noise reduction chamber 11 is specifically as follows: the depth D of the noise reduction cavity 11 on the same side of the volute tongue body 1 is the same, and the cross-sectional area of the noise reduction cavity 11 on the same side gradually increases from the position corresponding to the impeller middle plate 3 to the front and back sides of the volute tongue, that is, the cross-sectional area of the noise reduction cavity 11 near the position C1 is the smallest, and gradually increases along the direction indicated by the arrow A1.
Embodiment two:
As shown in fig. 7, the trend of the change in the volume V of the noise reduction cavity 11 of the noise reduction volute tongue of the present embodiment is specifically as follows: the cross-sectional areas of the noise reduction cavities 11 on the same side are equal in size, and the depth of the noise reduction cavities 11 on the same side of the volute tongue body 1 gradually increases from the position corresponding to the middle disc of the impeller to the front side and the rear side of the volute tongue, namely, the depth of the noise reduction cavity 11 near the C2 is minimum, and gradually increases along the direction indicated by an arrow A2. The remaining structure is the same as that of the first embodiment and will not be described here.
Embodiment III:
As shown in fig. 8, the volume of the noise reduction cavities 11 of the noise reduction volute tongue of the present embodiment on the same side of the volute tongue body 1 is equal, and the area S of the noise reduction holes 21 on the same side of the housing 2 gradually decreases from the position corresponding to the impeller middle disk to the front and rear sides of the volute tongue. I.e. the area S of the noise reduction aperture near C3 is greatest and becomes progressively smaller in the direction indicated by arrow A3.
Claims (8)
1. The utility model provides a fan noise reduction volute tongue, includes volute tongue body (1), its characterized in that: the volute tongue body (1) is characterized in that a noise reduction cavity (11) is formed in the upper side face and the lower side face of the volute tongue body (1), an outer cover (2) matched with the volute tongue body is arranged outside the volute tongue body (1), noise reduction holes (21) in one-to-one correspondence with the noise reduction cavities (11) are formed in the outer cover (2), and the ratio S/V of the area S of the noise reduction holes (21) to the volume V of the corresponding noise reduction cavity (11) meets the following conditions: the S/V value at the position corresponding to the impeller middle disc is maximum, the S/V value gradually decreases from the position corresponding to the impeller middle disc to the front side and the rear side of the volute tongue, and the volute tongue body (1) is of an integrated structure.
2. The fan noise reduction volute tongue of claim 1, wherein: the noise reduction cavity (11) of the upper side face of the volute tongue body (1) forms a diversion noise reduction cavity, the noise reduction cavity (11) of the lower side face of the volute tongue body (1) forms a backflow noise reduction cavity, correspondingly, the upper side face of the outer cover (2) is a diversion face (22), the lower side face of the outer cover (2) is a backflow face (23), and noise reduction holes (21) are formed in the diversion face (22) and the backflow face (23).
3. The fan noise reduction volute tongue of claim 2, wherein: the diversion surface (22) and the backflow surface (23) of the outer cover (2) are mutually connected through a smooth transition diversion surface (24).
4. The fan noise reduction volute tongue of claim 1, wherein: the areas S of the noise reduction holes (21) on the same side face of the outer cover (2) are equal in size, the volumes V of the noise reduction cavities (11) on the upper side face and the lower side face of the volute tongue body (1) at positions corresponding to the middle disc of the impeller are minimum, and the volumes V of the noise reduction cavities (11) on the same side face of the volute tongue body (1) gradually increase from the positions corresponding to the middle disc of the impeller to the front side and the rear side of the volute tongue.
5. The fan noise reduction volute tongue of claim 4, wherein: the depth of the noise reduction cavities (11) on the same side face of the volute tongue body (1) is the same, and the sectional area of the noise reduction cavities (11) on the same side face gradually increases from the position corresponding to the middle disc of the impeller to the front side and the rear side of the volute tongue.
6. The fan noise reduction volute tongue of claim 4, wherein: the cross sections of the noise reduction cavities (11) on the same side are equal in size, and the depth of the noise reduction cavities (11) on the same side of the volute tongue body (1) gradually increases from the position corresponding to the middle disc of the impeller to the front side and the rear side of the volute tongue.
7. The fan noise reduction volute tongue of any one of claims 4-6, wherein: the areas S of all the noise reduction holes (21) on the outer cover (2) are equal in size.
8. The fan noise reduction volute tongue of claim 1, wherein: the volumes of the noise reduction cavities (11) on the same side face of the volute tongue body (1) are equal, and the areas S of the noise reduction holes (21) on the same side face of the outer cover (2) are gradually reduced from the positions corresponding to the middle disc of the impeller to the front side and the rear side of the volute tongue.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711449597.8A CN108240357B (en) | 2017-12-27 | 2017-12-27 | Noise-reducing volute tongue of fan |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711449597.8A CN108240357B (en) | 2017-12-27 | 2017-12-27 | Noise-reducing volute tongue of fan |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108240357A CN108240357A (en) | 2018-07-03 |
| CN108240357B true CN108240357B (en) | 2024-05-14 |
Family
ID=62700225
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711449597.8A Active CN108240357B (en) | 2017-12-27 | 2017-12-27 | Noise-reducing volute tongue of fan |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108240357B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110439860A (en) * | 2018-05-04 | 2019-11-12 | 宁波方太厨具有限公司 | A kind of volute structure of centrifugal blower |
| CN110873077A (en) | 2018-08-29 | 2020-03-10 | 联想（新加坡）私人有限公司 | Fan device and electronic apparatus |
| CN111096711B (en) * | 2018-10-25 | 2022-03-22 | 广东美的白色家电技术创新中心有限公司 | Motor cover assembly and dust collector with same |
| CN111096708B (en) * | 2018-10-25 | 2022-03-01 | 广东美的白色家电技术创新中心有限公司 | Air outlet cover assembly of dust collector and dust collector with same |
| CN111102247B (en) * | 2018-10-25 | 2022-05-17 | 广东美的白色家电技术创新中心有限公司 | Amortization subassembly, centrifugal fan's spiral case subassembly, centrifugal fan and lampblack absorber |
| CN111255746A (en) * | 2018-11-30 | 2020-06-09 | 无锡小天鹅电器有限公司 | Volute air duct, fan assembly and clothes dryer |
| CN109458736A (en) * | 2018-12-24 | 2019-03-12 | 广东美的白色家电技术创新中心有限公司 | Gas water-heater housing and gas heater |
| CN110925240A (en) * | 2019-09-13 | 2020-03-27 | 浙江理工大学上虞工业技术研究院有限公司 | Frequency-adjustable noise-reducing centrifugal ventilator and volute thereof |
| CN112460071B (en) * | 2021-01-26 | 2021-07-13 | 佛山市顺德区美的洗涤电器制造有限公司 | Noise-reduction volute tongue, volute, fan and range hood |
| WO2023272928A1 (en) * | 2021-06-29 | 2023-01-05 | 广东美的制冷设备有限公司 | Centrifugal fan and air conditioner |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2226666Y (en) * | 1995-09-29 | 1996-05-08 | 中国科学院工程热物理研究所 | Perforated plate volute tongue silencer of centrifugal fan |
| CN1465868A (en) * | 2002-07-02 | 2004-01-07 | ÷˹���ɷݹ�˾ | Stabilizer for noise-proof and vortex-proof |
| CN103835999A (en) * | 2014-02-13 | 2014-06-04 | 珠海格力电器股份有限公司 | Centrifugal volute and air-conditioner indoor unit with the centrifugal volute |
| CN105526193A (en) * | 2016-02-29 | 2016-04-27 | 宁波方太厨具有限公司 | Blower volute for extractor hoods |
| CN106678083A (en) * | 2016-12-28 | 2017-05-17 | 中联重科股份有限公司 | Resonant cavity noise elimination device, noise-eliminating volute, centrifugal fan and road cleaning device |
| CN107289605A (en) * | 2017-07-31 | 2017-10-24 | 广东美的制冷设备有限公司 | Snail tongue, spiral case, cross flow fan and indoor apparatus of air conditioner |
| CN207634402U (en) * | 2017-12-27 | 2018-07-20 | 宁波方太厨具有限公司 | A kind of wind turbine noise reduction spiral tougue |
-
2017
- 2017-12-27 CN CN201711449597.8A patent/CN108240357B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2226666Y (en) * | 1995-09-29 | 1996-05-08 | 中国科学院工程热物理研究所 | Perforated plate volute tongue silencer of centrifugal fan |
| CN1465868A (en) * | 2002-07-02 | 2004-01-07 | ÷˹���ɷݹ�˾ | Stabilizer for noise-proof and vortex-proof |
| CN103835999A (en) * | 2014-02-13 | 2014-06-04 | 珠海格力电器股份有限公司 | Centrifugal volute and air-conditioner indoor unit with the centrifugal volute |
| CN105526193A (en) * | 2016-02-29 | 2016-04-27 | 宁波方太厨具有限公司 | Blower volute for extractor hoods |
| CN106678083A (en) * | 2016-12-28 | 2017-05-17 | 中联重科股份有限公司 | Resonant cavity noise elimination device, noise-eliminating volute, centrifugal fan and road cleaning device |
| CN107289605A (en) * | 2017-07-31 | 2017-10-24 | 广东美的制冷设备有限公司 | Snail tongue, spiral case, cross flow fan and indoor apparatus of air conditioner |
| CN207634402U (en) * | 2017-12-27 | 2018-07-20 | 宁波方太厨具有限公司 | A kind of wind turbine noise reduction spiral tougue |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108240357A (en) | 2018-07-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108240357B (en) | Noise-reducing volute tongue of fan | |
| CN108240353B (en) | Noise-reducing volute tongue of fan | |
| CN207634387U (en) | A kind of centrifugal blower volute for range hood | |
| CN102536892A (en) | Multi-blade centrifugal fan with reinforced air inlet function | |
| CN109424586B (en) | Volute tongue structure for radial flow fan | |
| CN105756981A (en) | Noise reduction fan wall for shell-free centrifugal fan | |
| TWI276743B (en) | Fan and fan housing with air-guiding static blades | |
| CN109973432A (en) | A kind of centrifugal blower volute for range hood | |
| CN109780596B (en) | Noise reduction flow guiding device and range hood using same | |
| CN213901431U (en) | Air duct assembly and household appliance | |
| CN202360458U (en) | Multi-wing centrifugal fan with reinforced air inlet function | |
| CN212376959U (en) | Volute of centrifugal fan | |
| CN205639022U (en) | A fan wall of making an uproar falls for having shell centrifugal fan | |
| CN109595651B (en) | Air outlet cover structure and range hood applying same | |
| CN207634402U (en) | A kind of wind turbine noise reduction spiral tougue | |
| TWI328080B (en) | Fan and impeller thereof | |
| CN203297148U (en) | Through-flow fan for air conditioner capable of effectively improving fan performance | |
| CN219795686U (en) | Noise reduction structure, spiral case, air outlet cover, fan and integrated kitchen | |
| CN213450997U (en) | Volute tongue and centrifugal fan provided with same | |
| CN207187950U (en) | A kind of special muffler of micronizer | |
| CN114109908B (en) | Volute, centrifugal fan and range hood | |
| JP2011202560A (en) | Electric blower and electric vacuum cleaner using the same | |
| CN114109909B (en) | Volute, centrifugal fan, range hood and volute generation method | |
| CN217440379U (en) | Centrifugal fan and range hood with function of making an uproar is fallen | |
| CN215409425U (en) | Duplex centrifugal air duct volute tongue structure |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |