Clamping and fixing device for cavity type fan blade

Abstract

The utility model relates to a fan blade of an industrial fan, in particular to a fixing device of a cavity type fan blade. A clamping and fixing device of a cavity type fan blade comprises an outer inserting piece, one end of the outer inserting piece is forked to clamp the root of the fan blade, the other end of the outer inserting piece is fixed to a fan rotating disc, the clamping and fixing device further comprises an inner inserting piece, the inner inserting piece is inserted into a cavity of the root of the fan blade, and the upper surface and the lower surface of the inner inserting piece are matched with the inner surface of the cavity of the fan blade in shape and size. And the surface contact and clearance fit are formed, and fixing bolts which penetrate through the upper part of the outer inserting piece from bottom to top and penetrate out of the upper part of the outer inserting piece are used for fixing. The contact surface between the clamping piece and the fan blade is increased, stress concentration is reduced, and the service life of the fan blade is prolonged.

Description

Technical Field

[0001] This utility model relates to fan blades for industrial fans, and more particularly to a fixing device for cavity fan blades. Background Technology

[0002] Industrial fans are large in size, resulting in significant weight. Their blades can be over three meters long. Therefore, it's crucial to reduce weight and inertia while maintaining sufficient strength for safety. To reduce weight, hollow blades are used, and appropriate materials are selected to ensure blade strength. However, industry analysis indicates that the connection between the blade and the fan rotor is a stress concentration area. Therefore, a forked connector is used, with the unforked end connecting to the fan rotor, and the blade root inserted into the forked end, secured vertically with bolts. This method addresses the issue to some extent. However, to ensure the fixing bolts have sufficient prestress, considerable force is applied during installation. This can damage the bolt holes on the blades, creating a weak point in the blade's working condition, making it prone to deformation and damage. Summary of the Invention

[0003] This invention aims to overcome the aforementioned deficiencies of the prior art by providing a clamping and fixing device for hollow fan blades. This invention increases the contact surface between the clamping component and the fan blade, reducing stress concentration and extending the lifespan of the fan blades.

[0004] This utility model discloses a clamping and fixing device for a hollow fan blade. It includes an external plug, one end of which is forked to clamp the root of the fan blade, and the other end is fixed to the fan turntable. It also includes an internal plug, which is inserted into the cavity at the root of the fan blade. Its upper and lower surfaces are designed to mimic the shape and size of the inner surface of the fan blade cavity, forming a surface contact and clearance fit. It is fixed by a fixing bolt that passes through the upper part of the external plug from bottom to top and through the upper part of the external plug.

[0005] The aforementioned clamping and fixing device for a hollow fan blade has three fixing bolts arranged in a row along the outward extension direction of the fan blade.

[0006] The aforementioned clamping and fixing device for a cavity fan blade includes two fixing bolts near the center of the fan that fix the outer insert, the cavity wall of the fan blade, and the inner insert together, and the outermost fixing bolt that fixes the cavity wall of the fan blade and the inner insert together.

[0007] The clamping and fixing device for a cavity fan blade further includes a fixing nut and a washer that pass through the fixing bolt.

[0008] The aforementioned clamping and fixing device for a hollow fan blade has reinforcing ribs on both sides of the inner insert inside the fan blade cavity, which serve as limiting baffles for the inner insert.

[0009] The aforementioned cavity-type fan blade clamping and fixing device has an external insert fork that matches the contact surface of the fan blade, which is a contour-following design.

[0010] This invention incorporates an internal insert. The contact surfaces of the internal insert and the fan blades are perfectly matched, with a clearance fit to form surface contact. Furthermore, the fixing bolts must penetrate the internal insert. When tightening the fixing bolts, the internal insert provides support to ensure the fan blades do not deform, thus extending their lifespan. Both the internal and external inserts and the fan blade contact surfaces employ a contour-following design for a tight fit, preventing relative displacement. Attached Figure Description

[0011] The present invention will be further described below with reference to the accompanying drawings:

[0012] Figure 1 This is an assembly diagram of the present invention;

[0013] Figure 2 This is an assembly drawing of the outer clamping member and the inner clamping member;

[0014] Figure 3 This is a cross-sectional view of the part where the fan blade is clamped.

[0015] Figure 4 This is a cross-sectional view of the assembled fan blades and clamping assembly (position of bolt 4). Detailed Implementation

[0016] Please see Figures 1-3 A clamping and fixing device for a cavity fan blade includes an outer plug 2, one end of which is forked to clamp the root of the fan blade 1, and the other end is fixed to the fan turntable (not shown in the figure). It also includes an inner plug 3, which is inserted into the cavity at the root of the fan blade. The shape and size of its upper and lower surfaces match the inner surface of the fan blade cavity to form a surface contact and clearance fit, and is fixed by a fixing bolt 5 that passes through the upper part of the outer plug from bottom to top and through the upper part of the outer plug.

[0017] The aforementioned clamping and fixing device for a hollow fan blade has three fixing bolts arranged in a row along the outward extension direction of the fan blade.

[0018] The aforementioned clamping and fixing device for a cavity fan blade includes two fixing bolts near the center of the fan that fix the outer insert, the cavity wall, and the inner insert of the fan blade together, and the outermost fixing bolt that fixes the cavity wall and the inner insert of the fan blade together.

[0019] The clamping and fixing device for a cavity fan blade, wherein the fixing bolt further includes a fixing nut 4 and a washer that pass through it.

[0020] The aforementioned clamping and fixing device for a hollow fan blade includes reinforcing ribs on both sides of the inner insert within the fan blade cavity, which serve as limiting baffles for the inner insert (see...). Figure 2 ).

[0021] like Figure 4 As shown, the forked outer insert matches the contact surface of the fan blade, which is a contour-following design. In this way, it works in conjunction with the inner insert to tightly clamp the fan blade, preventing deformation.

Claims

1. A clamping and fixing device for hollow fan blades, comprising an external insert, one end of which is forked to clamp the root of the fan blade, and the other end of which is fixed to a fan rotor, characterized in that, It also includes an inner insert that is inserted into the cavity at the root of the fan blade. Its upper and lower surfaces are designed to mimic the shape and size of the inner surface of the fan blade cavity, forming a surface contact and clearance fit. It is fixed by a fixing bolt that passes through the upper part of the outer insert from bottom to top and through the upper part of the outer insert.

2. The clamping and fixing device for a cavity fan blade according to claim 1, characterized in that, There are three fixing bolts, arranged in a row along the outward extension direction of the fan blade.

3. The clamping and fixing device for a cavity fan blade according to claim 2, characterized in that, The two fixing bolts near the center of the fan fix the outer insert, the cavity wall of the fan blade and the inner insert together, and the outermost fixing bolt fixes the cavity wall of the fan blade and the inner insert together.

4. A clamping and fixing device for a cavity-type fan blade according to claim 1, 2 or 3, characterized in that, The fixing bolt also includes a fixing nut and a washer that are inserted through it.

5. The clamping and fixing device for a cavity fan blade according to claim 1, characterized in that, The inner insert inside the fan blade cavity is provided with reinforcing ribs on both sides as limiting baffles for the inner insert.

6. The clamping and fixing device for a cavity fan blade according to claim 1, characterized in that, The external insert forks and the contact surface of the fan blades are matched, i.e., contouring design.

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