阅读说明：本技术 一种大流量低速风机的风叶 (Fan blade of large-flow low-speed fan ) 是由 梁连国 桂幸民 吴光明 王佳算 姜春芳 梁惠娟 于 2020-08-18 设计创作，主要内容包括：一种大流量低速风机的风叶,包括轮毂套、风叶、固定杆和固定螺栓；风叶通过前端面板、后端面板和若干固定螺丝与固定杆刚性连接；风叶使用U形箍将固定杆连接在轮毂套上；风叶外形平直,各截面的叶型几何相同,分为三个区域：前缘导流区、中部增压区和尾缘整流区；前缘导流区约占10％弦长,能够适应不同线速度下来流的相对气流方向；中部增压区是继前缘导流区之后的50％弦长,通过叶型几何外形差异产生足够的风压上升,并具有不小于15％的相对厚度,以使其内部能够安装固定杆；尾缘整流区为叶型后部约40％弦长,采用小楔形角、小曲率几何外形以使静压差减小,减缓排气损失。所述三个区域的叶型表面几何坐标由多个多项式函数生成。(A fan blade of a large-flow low-speed fan comprises a hub sleeve, a fan blade, a fixed rod and a fixed bolt; the fan blades are rigidly connected with the fixed rods through the front end panel, the rear end panel and a plurality of fixed screws; the fan blade uses a U-shaped hoop to connect the fixed rod on the hub sleeve; the fan blade is straight in appearance, and the blade profile geometry of each cross section is the same, divide into three regions: the device comprises a front edge flow guide area, a middle pressurizing area and a tail edge flow rectifying area; the leading edge guide zone accounts for about 10 percent of chord length and can adapt to the relative airflow direction of the incoming flow under different linear speeds; the middle supercharging area is 50% chord length behind the leading edge flow guiding area, generates enough wind pressure rise through the geometric shape difference of the blade profile, and has the relative thickness not less than 15% so as to enable the fixing rod to be installed inside the middle supercharging area; the trailing edge rectifying area is about 40 percent of chord length at the rear part of the blade profile, and the geometric shape with small wedge angle and small curvature is adopted to reduce the static pressure difference and slow down the exhaust loss. The geometric coordinates of the blade profile surfaces of the three regions are generated by a plurality of polynomial functions.)

1. The utility model provides a fan blade of large-traffic low-speed fan, includes wheel hub cover, fan blade, and a plurality of fan blades are the even array of radial form through fixed knot structure and sheathe in at wheel hub, and the wheel hub cover is fixed on the fan pivot, and fan blade quantity is 2-8, and the fan blade casing is hollow, and the centre has strengthening rib, its characterized in that: the fan blade is straight and straight in appearance, and the cross sections at all positions are the same in size; the fan blade is rigidly connected with the fixed rod through a front end panel, a rear end panel and a plurality of screw components, the fan blade fixing structure is a plurality of U-shaped hoops, and the fixed rod is connected on the hub sleeve by the U-shaped hoops;

the fan blade is straight in appearance, the blade profile geometry of each section is completely the same, and the fan blade can be divided into three areas: the device comprises a front edge flow guide area, a middle pressurizing area and a tail edge flow rectifying area; the leading edge guide area accounts for about 10 percent of chord length and can adapt to the relative airflow direction of the incoming flow under different linear speeds; the middle supercharging area is 50% of chord length behind the leading edge flow guiding area, generates enough wind pressure rise through the geometric shape difference of the blade profile, and has the relative thickness not less than 15% so as to enable the fixing rod to be installed inside the middle supercharging area; the trailing edge rectifying area is about 40 percent of chord length at the rear part of the blade profile, and the static pressure difference is reduced by adopting a small wedge angle and a small curvature geometric shape, so that the exhaust loss is reduced;

the geometric coordinates of the blade profile surfaces of the three regions are generated by a plurality of polynomial functions, the camber line geometry which is suitable for the pneumatic effect is determined by the camber line bevel angle, a fourth-order polynomial fitting curve is generated according to the designed camber line bevel angle, and the design formula is as follows: 30.782c⁴-93.764c³+141.39c²-131.79c +33.3706, wherein c is the percent chord length and α is the mean camber angle;

secondly, calculating the coordinates of the mean camber line according to the bevel angle of the mean camber line to form a sextic polynomial curve, wherein the design formula is as follows:

y＝-3.8117×10^-13c⁶+3.6398×10^-10c⁵-1.4459×10^-7c⁴+3.4525×10^-5c³-6.7509×10^{- 3}c²+6.7714×10^-1c-3.19373

wherein c is the percentage chord length, and y is the relative deflection of the mean camber line;

finally, the geometric coordinates of the blade profile surface are generated by the thickness distribution which is suitable for the aerodynamic rules of leading edge flow guiding, middle pressurizing, trailing edge rectifying and the like, and the design formula of the thickness distribution is as follows:

t＝-0.56403m⁶+2.1175m⁵-3.3814m⁴+3.2549m³-2.0297m²+0.58494m+0.021270

wherein m is the relative length of the mean camber line, and t is the relative half thickness.

2. The fan blade of the large-flow low-speed fan according to claim 1, characterized in that: the two ends of the fan blade shell are provided with a front end panel and a rear end panel, and the peripheral contour lines of the front end panel and the rear end panel are matched with the peripheral contour line of the fan blade shell; the front panel is provided with a through hole for accommodating the fixed shaft to pass through.

3. The fan blade of the large-flow low-speed fan according to claim 1, characterized in that: the fan blade fixing structure comprises a plurality of U-shaped hoops and fixing rods; and a plurality of annular grooves are formed in one side of the fixed shaft close to the hub sleeve, and the diameters of the annular grooves are matched with those of the U-shaped hoops.

4. The fan blade of the large-flow low-speed fan according to claim 1, characterized in that: the hub sleeve is provided with a plurality of semicircular grooves, and the radius of the semicircular grooves is matched with the fixed shaft of the fan blade.

5. The fan blade of the large-flow low-speed fan according to claim 1, characterized in that: the hub sleeve is also provided with a plurality of through holes; a key groove is arranged in the central rotating shaft hole.

6. The fan blade of the large-flow low-speed fan according to claim 1, characterized in that: the fan blades are made of aluminum alloy or glass fiber reinforced plastic.

[ technical field ] A method for producing a semiconductor device

The invention belongs to the field of fan application, and particularly relates to a fan blade of a high-flow low-speed fan, which is suitable for an axial flow type ventilation machine with the wind pressure lower than 300 Pa.

[ background of the invention ]

The failure patent 201020161228 hollow blade of fan discloses a fan blade, which is characterized in that the hollow blade is adopted, and the connection strength between the blade and the rotating shaft is enhanced.

For the fan blade, in addition to the above technology, the shape and structure of the aerodynamic performance of the blade are more important to determine, and are key design factors of the fan performance and energy efficiency. There are also enterprises that take reverse design to change their aerodynamic shape to circumvent the western patent, but are not aware of the same, so the resulting changes often severely degrade performance and do not provide an effective, self-designed product according to the needs of the user.

Traditionally, the high-flow low-speed fan adopts fan blades with equal-thickness blade profiles, the fan blades are twisted from a hub to a casing to adapt to the relative incoming flow direction, the fan is various, and various fans present unique personality due to different use objects and cannot form standard blade profiles to expand the application range. At present, fan blades with variable thickness blade profiles are widely applied to the field of axial flow type ventilation machinery, and the invention is a standard blade profile suitable for wind pressure lower than 300Pa formed through repeated design optimization and practical tests on the basis of long-term basic research.

The company has accumulated abundant manufacturing experience when engaged in fan design and manufacture for more than twenty years, is in close cooperation with universities and colleges, and makes great improvement and breakthrough on the fan blades of the high-flow low-speed fan. The scheme accordingly occurs.

[ summary of the invention ]

In order to improve the aerodynamic performance of the fan and overcome the defects of poor applicability, complex manufacturing and high cost of a large-flow low-speed fan in the current market, the invention provides the fan blade of the large-flow low-speed fan.

In order to achieve the purpose, the invention adopts the technical scheme that:

a fan blade of a large-flow low-speed fan comprises: the fan comprises a hub sleeve, fan blades, a fixed rod and a fixed bolt; the fan blades are uniformly arrayed on the hub sleeve in a radial shape through the fixing structure, the hub sleeve is rigidly fixed on a rotating shaft of the fan, the number of the fan blades can be 2-8 according to the requirements of air volume and air pressure, the fan blades are of a hollow structure, reinforcing ribs are arranged in the fan blades, and the fan blades are rigidly connected with the fixing rod through a front end panel, a rear end panel and a plurality of fixing screws; the fan blade fixing structure is a plurality of U-shaped hoops, and the fixing rod is connected to the hub sleeve by using the U-shaped hoops;

the fan blade is straight in appearance, the blade profile geometry of each section is completely the same, and the fan blade can be divided into three areas: the device comprises a front edge flow guide area, a middle pressurizing area and a tail edge flow rectifying area; the leading edge guide area accounts for about 10 percent of chord length and can adapt to the relative airflow direction of the incoming flow under different linear speeds; the middle supercharging area is 50% of chord length behind the leading edge flow guiding area, generates enough wind pressure rise through the geometric shape difference of the blade profile, and has the relative thickness not less than 15% so as to enable the fixing rod to be installed inside the middle supercharging area; the trailing edge rectifying area is about 40 percent of chord length at the rear part of the blade profile, and the geometric shape with small wedge angle and small curvature is adopted to reduce static pressure difference and slow down exhaust loss.

The geometric coordinates of the blade profile surfaces of the three regions are generated by a plurality of polynomial functions:

firstly, determining the geometry of the camber line which is suitable for the pneumatic effect by using the camber line bevel angle, generating a fourth-order polynomial fitting curve according to the designed camber line bevel angle, wherein the design formula is as follows:

α＝30.782c⁴-93.764c³+141.39c²-131.79c+33.3706

wherein c is the percentage chord length, and alpha is the camber line bevel angle;

secondly, calculating the coordinates of the mean camber line according to the bevel angle of the mean camber line to form a sextic polynomial curve, wherein the design formula is as follows:

y＝-3.8117×10^-13c⁶+3.6398×10^-10c⁵-1.4459×10^-7c⁴+3.4525×10^-5c³-6.7509×10^-3c²+6.7714×10^-1c-3.19373

wherein c is the percentage chord length, and y is the relative deflection of the mean camber line;

finally, the geometric coordinates of the blade profile surface are generated by the thickness distribution which is suitable for the aerodynamic rules of leading edge flow guiding, middle pressurizing, trailing edge rectifying and the like, and the design formula of the thickness distribution is as follows:

t＝-0.56403m⁶+2.1175m⁵-3.3814m⁴+3.2549m³-2.0297m²+0.58494m+0.021270

wherein m is the relative length of the mean camber line, and t is the relative half thickness.

As an optimization scheme, a front end panel and a rear end panel are arranged at two ends of the fan blade shell, and the peripheral contour lines of the front end panel and the rear end panel are matched with the peripheral contour line of the fan blade shell; the front panel is provided with a through hole for accommodating the fixed rod to pass through.

As an optimized scheme, the fan blade fixing structure comprises a plurality of U-shaped hoops and fixing rods; a plurality of annular grooves are formed in one side of the fixed rod, close to the hub sleeve, and the diameters of the annular grooves are matched with those of the U-shaped hoops; the fixed rod is fixed inside the fan blade shell by screws.

As an optimized scheme, the hub sleeve is provided with a plurality of semicircular grooves, and the radius of each semicircular groove is matched with the fixed rod of the fan blade; the number of the installed fan blades can be conveniently determined according to the using process.

As an optimized scheme, the hub sleeve is also provided with a plurality of through holes, so that the U-shaped hoop can conveniently penetrate through the through holes to tightly press the fixing rod on the hub sleeve; the key slot is arranged in the rotating shaft hole in the center of the hub sleeve, so that the hub sleeve can be conveniently fixed on a rotating shaft (not shown) of the fan.

As an optimized scheme, the fan blade is made of aluminum alloy or glass fiber reinforced plastic.

The invention has the following beneficial effects:

1. the blade profile which can adapt to a large attack angle range is adopted, the geometric shape of the blade is greatly simplified, the blade has more advanced pneumatic performance characteristics, and the formed standard blade is beneficial to high efficiency, low power consumption, low noise, corrosion resistance and high fatigue strength, and the manufacturing cost is reduced.

2. The hub is sleeved with a plurality of specifications, has different sizes and has different numbers of semicircular grooves; the fan blades rigidly arranged on the hub sleeve are replaceable and have various sizes and shapes; various combinations of the hub sleeve and the fan blades enable multi-specification standardization serialization of the fan to be implemented, various fan flow requirements are provided through changing of the diameter, the height difference and the number of the blades and scaling of the geometric shapes of the blades, and a user can freely select the optimal fan diameter according to the application.

3. The connection between the fan blade and the hub sleeve allows the angle of the fan blade to be partially adjusted, which is beneficial to simply and conveniently adjusting dynamic balance.

4. The fan blades have fixed geometric shapes and cannot be twisted under ultra-strong wind pressure.

[ description of the drawings ]

FIG. 1 is a schematic view of the general assembly of a fan blade according to the present invention;

fig. 2 is a schematic view of the back of the general assembly of the fan blade;

FIG. 3 is a schematic view of a fan blade component;

FIG. 4 is an exploded view of a fan blade structure;

fig. 5 is a schematic sectional view of a new blade profile (H is the maximum thickness and C is the chord length).

FIG. 6 is a cross-sectional view of an old fan blade in the prior art;

FIG. 7 is a comparison of blade profiles of the new and old blades of the present invention;

FIG. 8 is the calculation results of the full pressure characteristic curve of example 2;

FIG. 9 is a static pressure rise characteristic curve calculation result of example 2;

FIG. 10 shows the calculation results of the efficiency characteristics of example 2;

FIG. 11 shows the calculation results of the power characteristics of example 2;

FIG. 12 is the calculation results of the full pressure characteristic curve of example 3;

FIG. 13 is a static pressure rise characteristic curve calculation result of example 3;

FIG. 14 shows the calculation results of the efficiency characteristics of example 3;

FIG. 15 shows the calculation results of the power characteristics of example 3;

FIG. 16 is a full pressure characteristic curve of example 3 with different steps;

FIG. 17 is an efficiency characteristic curve in different steps of example 3.

Reference numerals:

1. a hub sleeve; 1.1 semicircular groove and 1.2 rotating shaft holes.

2. A fan blade; 2.1 fan blade casing, 2.1.1 strengthening rib, 2.2 wheel hub end panel, 2.2.1 dead lever through-hole, 2.3 blade top end panel, 2.3.1 front edge, 2.3.2 front edge diversion district, 2.3.3 middle part pressure boost area, 2.3.4 suction surface, 2.3.5 dead lever position, 2.3.6 trailing edge, 2.3.7 pressure face, 2.3.8 trailing edge rectification district.

3. Fixed rod, 3.1 ring groove.

A U-shaped hoop.

5. And a screw component.

6. A new fan blade.

7. Old fan blades.

[ detailed description ] embodiments

The technical solution of the present invention will be further described in detail with reference to the accompanying drawings and examples.

A blade of a high-flow low-speed fan mainly comprises a standard blade type fan blade and a fan assembly. Because a certain blade profile geometry is required to adapt to the convection fields of the wind turbines with different blade heights, different flow rates and different wind pressures, the blade must adapt to a large attack angle range, and meanwhile, in order to ensure that a pull rod for tensioning and fixing the blade has enough strength, the blade profile geometry of the blade adopts a pneumatic design different from the traditional geometric shape. The design characteristics include: leading edge flow guiding region 2.3.2, middle booster region 2.3.3 and trailing edge fairing 2.3.8 are generated from three polynomial function curves. The leading edge guide area 2.3.2 not only adapts to the direction of the incoming flow by using the leading edge 2.3.1, but also adapts to the change of the attack angle in a large range by using the leading edge guide area with about 10 percent of chord length, so that the low-loss attack angle range is increased, and the adaptability to the direction of the incoming flow is expanded; the gentle pressure surface 2.3.7 makes the air current entering the blower slow down, make its surface static pressure rise consistently, and the suction surface 2.3.4 accelerates sharply at the front, make the surface static pressure reach the maximum in the area of maximum thickness H, thus has formed the huge pressure difference of the pressure surface 2.3.7 and suction surface 2.3.4, form the middle pressurized area with front loading characteristic, the energy input static pressure potential energy of the impeller is mainly finished in this area, produce the sufficient wind pressure through the geometric shape difference of the blade profile to rise; about 40% of the chord length at the trailing edge of the airfoil is the trailing edge fairing 2.3.8 which acts to slow the static pressure rise at the pressure face 2.3.7, while the static pressure at the suction face 2.3.4 is still linearly increasing, providing a balanced static pressure at the flow to the trailing edge 2.3.6 to reduce the trailing edge at the exit of the airfoil. Because the aerodynamic structure characteristics of small wedge angle and small curvature of the trailing edge rectifying region 2.3.8 are effectively utilized, the trailing edge 2.3.6 can be in a square or triangular geometric shape and the like, and the requirement on the manufacturing precision of the trailing edge is effectively reduced; since the pressure surface 2.3.7 has a relatively low flow velocity, its friction losses are not decisive for the efficiency and the manufacturing accuracy can be reduced.