CN111946667A

CN111946667A - Fan with bent blades

Info

Publication number: CN111946667A
Application number: CN202010740229.4A
Authority: CN
Inventors: 夏哲浩; 江扬帆; 李东平; 权妮; 彭斯
Original assignee: Dongfeng Male Thermal System Co ltd
Current assignee: Dongfeng Male Thermal System Co ltd
Priority date: 2020-07-28
Filing date: 2020-07-28
Publication date: 2020-11-17

Abstract

The invention relates to a blade bending fan which comprises a fan blade and an insert, wherein the fan blade comprises a hub and a blade, the insert is embedded into the hub, a plurality of blades are uniformly arranged on the hub, and the roots of the blades are all arranged on the hub; the tail end of each blade is bent towards the windward side of the fan in an equal diameter mode to form a bent part and an original blade part, and the length A of the bent part along the radial direction of the fan and the diameter of the fan

The relation between B and B is that (B-2A)/B is more than or equal to 0.8, the bending radius R of the bending part is the diameter of the fan

8 to 12 percent of B. The blade is bent at the position close to the tail end, so that the blade is effectively improvedThe aerodynamic performance of the edge reduces the phenomena of airflow disturbance and leading edge stall at the edge of the blade, reduces the loss of air quantity, improves the efficiency of the fan blade and reduces the power consumption; meanwhile, noise is reduced due to the fact that airflow disturbance at the edge of the fan blade is reduced.

Description

Fan with bent blades

Technical Field

The invention relates to the technical field of cooling of automobile engines, in particular to a blade bending fan.

Background

Heat dissipation of an engine thermal system of a current commercial vehicle is completed through a silicone oil fan, and the working principle is as follows: the torque of the engine is transmitted through the viscous force of the silicone oil, and the fan blades are driven to rotate so as to radiate heat of an engine radiator and an air conditioner condenser, and the fan is divided into an electric/temperature control silicone oil fan according to a working mode. The power of the silicone oil fan of the commercial vehicle comes from an engine, accounts for 5-10% of the oil consumption of the whole vehicle, and how to reduce the power consumption of the silicone oil fan becomes an important subject to be faced by silicone oil fan manufacturers.

The structural design of the silicone oil fan blade can directly influence the power consumption and the air volume of the silicone oil fan blade, the foreign blade design and the blade hydromechanics research are earlier, the domestic design and development start is later, most of the used blade shapes are designed by the foreign existing design, and the domestic silicone oil fan blade is designed by the foreign blade shapes which are mostly linear (straight along the diameter direction of the blade) with single shapes (as shown in figure 1).

Through the CFD flow field analysis of the existing linear type blades, the air flow disturbance exists at the edges of the blades, and the phenomenon of the air flow disturbance is caused by the high-pressure air flow near the edges of the blades, so that the blades lose a lot of effective air quantity during operation, the useless work of the blades is increased, and the noise of the whole fan is increased by the disturbed flow.

Disclosure of Invention

In order to solve the problems, the invention provides the blade bending fan which is large in air volume, high in efficiency and low in noise.

The technical scheme adopted by the invention is as follows: the blade bending fan includes fan blades and insertsCharacterized in that: the fan blades comprise hubs and blades, the inserts are embedded into the hubs, a plurality of blades are uniformly arranged on the hubs, and the roots of the blades are arranged on the hubs; every blade tail end is all to fan windward side equal diameter bending, forms bending portion and former blade portion, radial length A and the fan diameter of fan are followed to bending portion

The relation between B and B is that (B-2A)/B is more than or equal to 0.8, and the bending radius R of the bending part is the diameter of the fan

8 to 12 percent of B.

Preferably, the end of the bending part widens towards two sides.

Preferably, the length a of the bent portion in the radial direction of the fan and the diameter of the fan

The relationship between B is (B-2A)/B ═ 0.8.

Preferably, the bending angle of the bent portion is 60 ° to 90 °.

Preferably, the bending part is tangent to the original blade part, and the bending transition line of the bending part and the original blade part is an arc line.

Preferably, each blade is close to all to be equipped with preceding stator blade in the windward side, preceding stator blade sets up in former blade portion.

Preferably, the front guide vane is connected with the blades through an arc-shaped transition chamfer, and the height of the front guide vane is gradually increased from the air inlet side to the rear side.

The beneficial effects obtained by the invention are as follows: the bending design is carried out at the position of the blade close to the tail end, so that the aerodynamic performance of the edge of the blade is effectively improved, the phenomena of airflow disturbance and front edge stall at the edge of the blade are reduced, the loss of air volume is reduced, the efficiency of the blade is improved, and the power consumption is reduced; meanwhile, noise is reduced due to the fact that airflow disturbance at the edge of the fan blade is reduced.

Drawings

FIG. 1 is a schematic structural view of a conventional linear blade fan;

FIGS. 2-4 are schematic structural views of the present invention;

FIG. 5 is a graph comparing pressure and flow rate of the original model and the optimized model;

FIG. 6 is a comparison of power consumption of the original model and the optimized model;

reference numerals: 1. an insert; 2. a blade; 21. a bending part; 22. a raw blade part; 23. bending a transition line; 24. a front guide vane.

Detailed Description

The invention will be further described with reference to the following drawings and specific embodiments.

As shown in fig. 2 to 4, the blade bending fan of the present invention includes a blade and an insert 1, wherein the blade is a plastic part, and the insert 1 is a high strength metal part. The fan blade is a rotating part and is used for radiating heat of an engine system, the clutch assembly is connected with the insert 1 through screws, and the flange shaft is connected with the engine and is used for transmitting the input torque of the engine.

The flabellum includes wheel hub and blade 2, evenly is equipped with multi-disc blade 2 on the wheel hub, and the root of multi-disc blade 2 all sets up on wheel hub. The tail end of each blade 2 is bent towards the windward side of the fan at the bending transition line 23 in an equal diameter mode, and the blade 2 is divided into two parts at the bending transition line 23, namely a bending part 21 at the tail end and an original blade part 22 connected with the hub (the original blade part is a straight line in the diameter direction of the blade). The tail ends of the blades 2 are bent, so that airflow disturbance at the edges of the blades 2 when the fan rotates is effectively reduced, unnecessary work is reduced, power consumption is reduced, no loss is caused to air volume, and efficiency is improved (fan blade efficiency is air volume static pressure/power consumption); the bending part 21 adopts equal-diameter bending to ensure stable airflow of the bending part when the blade 2 rotates.

In this embodiment, the bending radius R is the diameter of the fan

8% -12% of B, the bending radius is too small, the manufacturing difficulty is increased, the bending range is too small, and the airflow stability of the blade is not improvedActing; the bending angle is 60-90 degrees; the length A of the bent portion 21 along the radial direction of the fan and the diameter of the fan

The relationship between B is (B-2A)/B is not less than 0.8.

In this embodiment, the end of the bending portion 21 is widened to both sides (i.e., the width of the end of the blade is widened), so that the working area of the blade 2 can be effectively increased, and the air volume can be increased.

In this embodiment, the bent portion 21 is tangent to the original blade portion 22, and the bending transition line 23 between the bent portion 21 and the original blade portion 22 is an arc line. The air flow of the blade 2 is smoother, and the phenomenon of air flow disorder is not generated. The edge of the bent blade 2 is in smooth transition, before the blade 2 is bent, the edge of the blade 2 is generally sharp, a hand is easy to cut during assembly, and the sharp point is easy to cause airflow separation and generate noise; therefore, fillet transition is added after the edge of the blade 2 is bent, so that the assembly is easier and the noise caused by airflow separation is reduced.

In this embodiment, the windward side of each blade 2 is provided with a front guide vane 24, the front guide vane 24 is arranged in the region of the original blade part 22, the front guide vane 24 is connected with the blade 2 through an arc transition chamfer, and the height of the front guide vane 24 is gradually increased from the air inlet side to the rear side.

And (3) CFD flow field analysis verification is adopted: setting a boundary condition: the clearance between the fan and the wind protection cover is 10 mm; the distance of extending into the wind shield is 40 mm; air physical properties of dry air at ambient temperature 25 ℃: density 1.18kg/m³And dynamic viscosity of 18.4X 10E-4 Pa.s. The verification results are as follows:

from the above table, it can be seen that: the first optimized scheme is 9% lower than the original scheme (linear blades), the efficiency is improved by 6.8%, the air volume is reduced more than the original scheme, the influence on the use of customers is large, and continuous optimization is needed. In order to increase the working area, the bending area is continuously increased (the value of (B-2A)/B is reduced) based on the optimization scheme.

The data of the second optimization scheme shows that the air volume is reduced by 6% compared with the original model, the efficiency is improved by 4.6%, the air volume is improved by some compared with the first optimization scheme, the efficiency is reduced by some, and the increase of the acting area is verified to improve the air volume to a certain extent, so that the forward sweeping of the fan blades is increased on the basis of the second optimization scheme, and the bending area is increased again.

The simulation air volume and the efficiency data of the third optimization scheme show that the third optimization scheme is 1% higher than that of the original model, the efficiency is 4.4% higher than that of the original model, the air volume is not reduced compared with that of the original scheme, and the efficiency is improved more. And (2) continuing to increase the working area ((B-2A)/B is 0.75, (B-2A)/B is 0.7, and (B-2A)/B is 0.65), compared with the scheme III, the air volume is not obviously increased, and the efficiency is not obviously increased, so the optimized scheme III ((B-2A)/B is 0.8) is taken as a final selection scheme.

As shown in fig. 5, the test results show that, at the general working condition point of the whole vehicle, the air volume of the third optimized scheme is increased by 1.5% compared with the original scheme (linear blades); meanwhile, compared with the actually measured fan efficiency, the optimized model has the efficiency greatly improved by 4.2 percent compared with the original model (as shown in figure 6).

The foregoing shows and describes the general principles and principal structural features of the present invention. The present invention is not limited to the above examples, and various changes and modifications may be made without departing from the spirit and scope of the invention, which fall within the scope of the claimed invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. The utility model provides a blade fan of bending, includes flabellum and inserts, its characterized in that: the fan blades comprise hubs and blades, the inserts are embedded into the hubs, a plurality of blades are uniformly arranged on the hubs, and the roots of the blades are arranged on the hubs; every blade tail end is all to fan windward side equal diameter bending, forms bending portion and former blade portion, radial length A and the fan diameter of fan are followed to bending portion

Is close toIs (B-2A)/B is more than or equal to 0.8, and the bending radius R of the bending part is the diameter of the fan

8 to 12 percent of the total weight of the composition.

2. The blade bending fan according to claim 1, wherein: the tail end of the bending part is widened towards two sides.

3. The blade bending fan according to claim 1, wherein: the length A of the bent part along the radial direction of the fan and the diameter of the fan

The relationship (B-2A)/B is 0.8.

4. The blade bending fan according to claim 1, wherein: the bending angle of the bending part is 60-90 degrees.

5. The blade bending fan according to claim 1, wherein: the bending part is tangent to the original blade part, and the bending transition line of the bending part and the original blade part is an arc line.

6. The blade bending fan according to claim 1, wherein: every the blade windward side leans on and all is equipped with preceding stator, preceding stator sets up in former blade portion.

7. The blade bending fan according to claim, wherein: preceding stator is connected through circular arc formula transition chamfer with the blade, preceding stator height increases from the air inlet side to the rear side gradually.