A blade angle synchronously adjustable impeller disc for small and medium-sized wind tunnels

Abstract

The application discloses a small and medium-sized wind tunnel blade angle synchronous adjustable impeller disc. The impeller disc is installed in a wind tunnel power section and comprises a fan blade (1), a connecting rod (2), a push rod (3), an adjusting disc (4), a front impeller disc (5) and a rear impeller disc (6). The impeller disc provided by the application has simple structure and is convenient to operate. The angle of all the fan blades on the impeller disc is simultaneously adjusted through a linkage device. The simultaneous angle adjustment of the fan blades is favorable to improving the debugging efficiency of the wind tunnel. Meanwhile, the internal space of the impeller disc is effectively utilized, the overall volume and mass of the impeller disc are not obviously increased while the attack angle adjustable function of the fan blades is increased, the internal adjusting mechanism is periodically distributed in a circle, the influence on dynamic balance is small, and the external structure is kept flat and does not have an adverse influence on the flow field.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of small and medium-sized wind tunnel impeller disc blade angle synchronous adjustable design, and particularly relates to a small and medium-sized wind tunnel impeller disc blade angle synchronous adjustable impeller disc. BACKGROUND

[0002] When the wind tunnel structure is processed and assembled, due to various design defects or installation errors, the initial installation attack angle of the impeller disc fan blade cannot meet the requirements of specific working conditions, and secondly, the initial installation attack angle of the fan blade cannot maximize the energy utilization rate of the wind tunnel power section, causing abnormal aerodynamic noise and the like. When the above situations occur, the installed fan blade often needs to be adjusted. For small and medium-sized wind tunnels, the upper limit of the total power is not high, and most of them operate at a low wind speed (<40 m / s), but for some wind tunnels whose upper limit of wind speed can reach more than 0.3 Mach, it is crucial to improve the operation quality of the power section, which will directly affect the operation efficiency of the wind tunnel, and the installation attack angle of the fan blade in the power section is a key link. In order to achieve the optimal operation efficiency and energy utilization rate under a certain experimental working condition, the best way is to adjust the attack angle of the fan blade, and the space of the small and medium-sized wind tunnel power section is limited, so adjusting the fan blade one by one will multiply the workload and is not conducive to controlling the dynamic balance of the impeller disc. How to realize the overall adjustment of the fan blade attack angle has become a difficult problem. SUMMARY

[0003] The purpose of the present application is to provide a small and medium-sized wind tunnel blade angle synchronous adjustable impeller disc, which has a simple structure and is easy to operate. The angle of all blades on the impeller disc is adjusted simultaneously by setting a linkage device. The present application can adjust the fan blade angle simultaneously without significantly increasing the volume and mass of the impeller disc, and can avoid affecting the dynamic balance of the impeller disc.

[0004] In order to achieve the above purpose, the present application adopts the following technical solutions:

[0005] A small and medium-sized wind tunnel blade angle synchronous adjustable impeller disc is installed in the wind tunnel power section, comprising a fan blade (1), a connecting rod (2), a push rod (3), an adjusting disc (4), a front impeller disc (5), and a rear impeller disc (6).

[0006] The front impeller disk (5) and the rear impeller disk (6) are clamped together to form an impeller disk. The multiple fan blades (1) are distributed circumferentially along the impeller disk. Several fan blades (1) are installed in several columnar cavities formed by the front impeller disk (5) and the rear impeller disk (6). The fan blades (1) can rotate in the cavities. The shoulder on the handle of the fan blade (1) restricts its radial position on the impeller disk. The inside of the handle is machined into a columnar cavity, and the side wall is machined with a horizontally penetrating spiral groove. A push rod (3) can be horizontally inserted into the groove. The adjusting plate (4) is sleeved on the rear impeller disk (6) and can rotate freely relative to the impeller disk. Multiple connecting rods (2) are hinged in the circumferential direction. The other end of the connecting rod (2) is hinged to a push rod (3). The push rod (3) has a "T" shaped structure. Each push rod (3) is inserted into the cylindrical cavity of the fan blade (1). The crossbar at the upper end of the push rod is inserted into the groove in the handle of the fan blade (1). Multiple circumferentially distributed guide grooves are machined on the inner end face of the rear impeller disk (6). The axis of the guide groove coincides with the radial direction of the impeller disk. The push rod (3) is installed in the groove. The guide groove plays the role of restricting the movement direction of the push rod (3). The spline groove for installing the main shaft is machined in the center of the rear impeller disk (6).

[0007] Rotating the adjustment disc (4) counterclockwise causes all the connecting rods (2) to rotate in tandem and push the push rod (3) to move radially outward from the impeller disc. The push rod (3) moves in translation, forcing the fan blade (1) to rotate. Reversing the adjustment disc (4) can reverse the fan blade (1).

[0008] When the angle of attack of the fan blade (1) is at its minimum, there is a significant angle α between the connecting rod (2) and the push rod (3). As the fan blade is rotated counterclockwise by rotating the adjustment disc (4), the angle α gradually decreases and the angle of attack of the fan blade gradually increases.

[0009] The connections between the connecting rod (2), push rod (3), and adjusting plate (4) can all rotate freely.

[0010] The flange at the end of the adjusting disc (4) is machined with mounting holes. After the fan blade angle is adjusted, the adjusting disc (4) is fastened to the rear impeller disc (6) through the mounting holes.

[0011] The front impeller disk (5) and the rear impeller disk (6) are connected by bolts, and the threaded holes are evenly distributed along the circumference of the impeller disk.

[0012] The beneficial effects of this invention are:

[0013] 1. The blades on the impeller disk can be adjusted in angle simultaneously, which helps improve the commissioning efficiency of the wind tunnel;

[0014] 2. The internal space of the impeller disk is effectively utilized, and the overall volume and mass are not significantly increased while increasing the adjustable angle of attack of the fan blades; the internal adjustment mechanism is arranged in a circumferential periodic distribution, which has little impact on the dynamic balance; the external structure remains flat and does not have an adverse effect on the flow field. Attached Figure Description

[0015] Figure 1 This is the front view of the present invention;

[0016] Figure 2 This is a rear view of the present invention;

[0017] Figure 3 This is an exploded isometric view of the present invention;

[0018] In the diagram: fan blade (1), connecting rod (2), push rod (3), adjusting plate (4), front impeller (5), rear impeller (6). Detailed Implementation

[0019] A small-to-medium-sized wind tunnel blade angle synchronously adjustable impeller disk is installed in the power section of the wind tunnel, including fan blades, connecting rods, push rods, adjustment disks, front impeller disks, and rear impeller disks. The diameter and thickness of the impeller disks are 510mm and 65mm, respectively, and the material is 7075 aluminum alloy.

[0020] The aforementioned multiple fan blades are distributed circumferentially along the impeller disk. Each fan blade is installed within a cylindrical cavity formed by the front and rear impeller disks, with a clearance fit between the two parts. The fan blade can rotate within the cavity. A shoulder on the fan blade handle restricts its radial position on the impeller disk. The interior of the handle is machined into a cylindrical cavity, and the sidewalls are machined with horizontally penetrating spiral grooves. The lines intersecting the grooves and the perpendicular sections of the handle's axis are parallel. Viewed from the end of the fan blade handle towards the end of the fan blade, the grooves spiral upwards, but the shortest distance between the two walls of the grooves remains relatively constant. The helix angle of the spiral surface of the grooves is greater than 60°; in this embodiment, the helix angle is 62°. °, a rod can be horizontally inserted into the slide groove, the adjusting plate is sleeved on the rear impeller disk, the two parts are clearance fit, it can rotate freely relative to the impeller disk, the adjusting plate is circumferentially hinged to multiple connecting rods, the other end of the connecting rod is hinged to a push rod, the push rod has a "T" shaped structure, each push rod is inserted into the columnar cavity of the fan blade, and the crossbar at the upper end of the push rod is inserted into the slide groove in the fan blade handle, multiple circumferentially distributed guide grooves are machined on the inner end face of the rear impeller disk, each guide groove extends outward along the radial direction of the impeller disk, the push rod is installed in the groove, the guide groove plays the role of restricting the direction of movement of the push rod, and the spline groove for installing the main shaft is machined in the center of the rear impeller disk;

[0021] Rotating the adjustment disc counterclockwise causes all connecting rods to rotate in tandem and push the push rod to move radially outward from the impeller disk. When the push rod is pushed up, the spiral groove on the blade handle decomposes the radial outward thrust along the impeller disk into the circumference of the axis where the blade handle is located, thereby forcing the blade to rotate. The push rod is translated to force the blade to rotate. Reversing the adjustment disc can reverse the blade. When the angle of attack of the blade is at its minimum, there is a significant angle α = 50° between the connecting rod and the push rod. During the process of rotating the adjustment disc counterclockwise to rotate the blade, the angle α gradually decreases and the angle of attack of the blade gradually increases. For the blade in this embodiment, the range of angle changes between the connecting rod and the push rod is 0° < α < 50°, while the corresponding range of angle changes between the blade and the angle of attack is 4° < θ < 59°. The connections between the connecting rod, the push rod, and the adjustment disc can all rotate freely. During the adjustment of the blade's angle of attack, the angle does not exceed the above-mentioned specified range.

[0022] The flange at the end of the adjusting disc is machined with mounting holes. After the fan blade angle is adjusted, the adjusting disc is fastened to the rear impeller disc through the mounting holes. The aforementioned front impeller disc and rear impeller disc are connected by bolts, and the threaded holes are evenly distributed along the circumference of the impeller disc.

Claims

1. A small to medium-sized wind tunnel blade angle synchronously adjustable impeller disk is installed in the power section of the wind tunnel, characterized in that: It includes multiple fan blades (1), connecting rod (2), push rod (3), adjustment plate (4), front impeller (5), and rear impeller (6); The front impeller disk (5) and the rear impeller disk (6) are clamped together to form an impeller disk. The multiple fan blades (1) are distributed circumferentially along the impeller disk. Several fan blades (1) are installed in several columnar cavities formed by the front impeller disk (5) and the rear impeller disk (6). The fan blades (1) can rotate in the cavities. The shoulder on the handle of the fan blade (1) restricts its radial position on the impeller disk. The inside of the handle is machined into columnar cavities, and the sidewall is machined with a horizontally penetrating spiral groove. The push rod (3) can be horizontally inserted into the groove. The adjusting plate (4) is sleeved on the rear impeller disk (6) and can rotate relative to the impeller disk. By rotating, the adjusting disc (4) is circumferentially hinged to multiple connecting rods (2), and the other end of the connecting rod (2) is hinged to a push rod (3). The push rod (3) has a "T" shaped structure. Each push rod (3) is inserted into the cylindrical cavity of the fan blade (1), and the crossbar at its upper end is inserted into the groove in the handle of the fan blade (1). Multiple circumferentially distributed guide grooves are machined on the inner end face of the rear impeller disc (6). The axis of the guide groove coincides with the radial direction of the impeller disc. The push rod (3) is installed in the groove. The guide groove plays the role of restricting the movement direction of the push rod (3). The spline groove of the main shaft is machined in the center of the rear impeller disc (6). Rotating the adjustment disc (4) counterclockwise causes all connecting rods (2) to rotate in tandem and push the push rod (3) to move radially outward from the impeller disc. The push rod (3) moves in translation, forcing the fan blade (1) to rotate. Reversing the adjustment disc (4) can reverse the fan blade (1). When the angle of attack of the fan blade (1) is at its minimum, there is a significant angle between the connecting rod (2) and the push rod (3). During the process of rotating the fan blades by rotating the adjustment disc counterclockwise (4), the included angle As the angle of attack of the fan blades gradually decreases, the angle of attack of the fan blades gradually increases. The connections between the connecting rod (2), the push rod (3), and the adjusting plate (4) can all rotate freely; The flange at the end of the adjusting disc (4) is machined with mounting holes. After the fan blade angle is adjusted, the adjusting disc (4) is fastened to the rear impeller disc (6) through the mounting holes. The front impeller disk (5) and the rear impeller disk (6) are connected by bolts, and the threaded holes are evenly distributed along the circumference of the impeller disk.

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