A locking structure for wind tunnel fan blades

Abstract

The present invention relates to a locking structure for a wind tunnel fan blade, comprising a blade (1), a blade handle, an eccentric sleeve I (3), a pad I (4), a bolt I (5), a hub outer ring (7), a bolt II (8), a pad II (10) and an eccentric sleeve II (11); the present invention realizes a slight adjustment of the blade angle, can meet the tolerance requirements of all blade installation angles, and ensures the overall balance requirements of the overall wind tunnel fan. At the same time, the locking structure limits the freedom of the blade in the three coordinate axes, improves the blade's shimmy stiffness, and shares part of the blade's centrifugal force, making the fan run safer and more reliable.

Description

Technical Field

[0001] The invention relates to the technical field of blade testing, and in particular to a locking structure for a wind tunnel fan blade. Background Art

[0002] The BHAW wind tunnel fan system project is a national key scientific research project. The main purpose of the fan system is to provide the necessary power for the wind tunnel airflow circulation. In the wind tunnel fan system, the impeller is an important component of the fan section rotor system, the power component of the wind tunnel operation, and also a key component of the wind tunnel.

[0003] In order to make each blade achieve a slight adjustment in angle within the specified installation angle range and ensure the tolerance requirements of the blade angle, a blade installation angle fine-tuning structure is designed. At the same time, in order to prevent the occurrence of resonance, strict requirements are imposed on the natural frequency of the blade, and the second-order frequency must be greater than 100Hz. The second-order frequency of the blade reflects its swing stiffness. In order to solve the problem of blade swing stiffness, a locking structure is designed to improve the blade swing stiffness. Summary of the invention

[0004] Purpose of the invention: The purpose of the invention is to enable the blade to achieve slight angle adjustment while improving the blade's swing stiffness.

[0005] In order to achieve the minor adjustment of the blade at the specified angle and improve the blade's vibration stiffness, the bottom of the blade and the outer ring of the hub are locked by two eccentric sleeve locking structures. This eccentric sleeve locking structure can achieve two purposes: ⑴. It enables the blade to achieve angle fine-tuning within the specified installation angle range to ensure the tolerance requirements of the blade angle installation. ⑵. This locking structure limits the three-axis degrees of freedom of the blade, improves the blade's vibration stiffness and shares part of the blade's centrifugal force.

[0006] Technical solution: A locking structure for a wind tunnel fan blade, comprising a blade (1), a blade handle, an eccentric sleeve I (3), a spacer I (4), a bolt I (5), a hub outer ring (7), a bolt II (8), a spacer II (10) and an eccentric sleeve II (11);

[0007] The petiole is embedded in the blade root of the blade, and the petiole forms a locking boss I (2) and a locking boss II (12), and the locking boss I (2) and the locking boss II both protrude from the blade root to the outside of the blade, and the locking boss I (2) and the locking boss II (12) are respectively located on both sides of the petiole;

[0008] The locking boss I (2) and the locking boss II (12) both have a central threaded hole;

[0009] The hub outer ring is provided with a first mounting hole and a second mounting hole, the eccentric sleeve I (3) is slidably mounted in the first mounting hole, and the eccentric sleeve II (11) is slidably mounted in the second mounting hole;

[0010] The locking boss I (2) is coaxially inserted into the eccentric hole of the eccentric sleeve I, and the locking boss II (12) is coaxially inserted into the eccentric hole of the eccentric sleeve II;

[0011] The hub outer ring is fixed with a pad I (4) and a pad II (10), the pad I (4) is provided with a through hole, the through hole diameter of the pad I is smaller than the eccentric hole diameter of the eccentric sleeve I, and larger than the center threaded hole diameter of the locking boss I, the through hole diameter of the pad II is smaller than the eccentric hole diameter of the eccentric sleeve II, and larger than the center threaded hole diameter of the locking boss II; the eccentric sleeve I is supported on the pad I, and the eccentric sleeve II is supported on the pad II;

[0012] The bolt I passes through the pad I and cooperates with the central threaded hole of the locking boss I, and the bolt II passes through the pad II and cooperates with the central threaded hole of the locking boss II; rotating bolt I and bolt II can press and fix the eccentric sleeve between the root of the blade and the hub to achieve locking, and rotating eccentric sleeve I and eccentric sleeve II can adjust the angle of the blade relative to the hub.

[0013] Furthermore, a spring washer I (6) is provided between the bolt I and the cushion block I, and a spring washer II (9) is provided between the bolt II and the cushion block II.

[0014] Furthermore, the eccentric sleeve I and the eccentric sleeve II are symmetrically arranged relative to the petiole axis.

[0015] Furthermore, the locking boss I and the locking boss II are symmetrically arranged relative to the petiole axis.

[0016] Furthermore, the eccentric sleeve I and the eccentric sleeve II are made of stainless steel or aluminum alloy.

[0017] Furthermore, the blades are made of foam core composite material.

[0018] Furthermore, the hub outer ring is made of high-strength steel.

[0019] Furthermore, bolts I and II are hexagon socket head bolts.

[0020] Installation method: Before installing the blade (1), first install the eccentric sleeve I (3) and the eccentric sleeve II (11) into the spacer I (4) and the spacer II (10) on the hub outer ring (7) respectively. When installing the blade (1), insert the blade locking boss I (2) and the blade locking boss II (12) into the eccentric sleeve I (3) and the eccentric sleeve II (11) respectively. Check the installation angle of the blade (1). If it does not meet the requirements, adjust the eccentric sleeve I (3) and the eccentric sleeve II (11) and adjust the angle of the blade (1) at the same time, so that the center of the eccentric hole of the eccentric sleeve and the center of the threaded hole of the blade boss are concentric, so as to achieve the purpose of fine-tuning the installation angle. After meeting the requirements, install the spring washer I (6) into the hexagon socket head screw I (5), and then insert it into the thread of the blade locking boss I (2) through the spacer I (4) and lock it. After the spring washer II (9) is installed into the hexagon socket head screw II (8), it is inserted into the thread of the blade locking boss II (12) through the spacer II (10) and locked.

[0021] Technical effect: The present invention realizes a small adjustment of the blade angle, can meet the tolerance requirements of all blade installation angles, and ensure the overall balance requirements of the wind tunnel fan. At the same time, this locking structure limits the freedom of the blade in the three coordinate axes, improves the blade's swing stiffness, and shares part of the blade's centrifugal force, making the fan operation safer and more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the present invention;

[0023] Figure 2 It is a partial enlarged schematic diagram of one side;

[0024] Figure 3 This is a partial enlarged schematic diagram of the other side;

[0025] Figure 4 sectional view of the eccentric sleeve;

[0026] Figure 5 This is a schematic diagram of the eccentric position of the eccentric sleeve;

[0027] Among them: 1-blade, 2-locking boss Ⅰ, 3-eccentric sleeve Ⅰ, 4-spacer Ⅰ, 5-bolt Ⅰ, 6-spring washer Ⅰ, 7-hub outer ring, 8-bolt Ⅱ, 9-spring washer Ⅱ, 10-spacer Ⅱ, 11-eccentric sleeve Ⅱ, 12-locking boss Ⅱ. DETAILED DESCRIPTION

[0028] In conjunction with the accompanying drawings, a locking structure for a wind tunnel fan blade is specifically provided, comprising a blade (1), a blade handle, an eccentric sleeve I (3), a spacer I (4), a bolt I (5), a hub outer ring (7), a bolt II (8), a spacer II (10) and an eccentric sleeve II (11);

[0029] The petiole is embedded in the blade root of the blade, and the petiole forms a locking boss I (2) and a locking boss II (12), and the locking boss I (2) and the locking boss II both protrude from the blade root to the outside of the blade, and the locking boss I (2) and the locking boss II (12) are respectively located on both sides of the petiole;

[0030] The locking boss I (2) and the locking boss II (12) both have a central threaded hole;

[0031] The hub outer ring is provided with a first mounting hole and a second mounting hole, the eccentric sleeve I (3) is slidably mounted in the first mounting hole, and the eccentric sleeve II (11) is slidably mounted in the second mounting hole;

[0032] The locking boss I (2) is coaxially inserted into the eccentric hole of the eccentric sleeve I, and the locking boss II (12) is coaxially inserted into the eccentric hole of the eccentric sleeve II;

[0033] The hub outer ring is fixed with a pad I (4) and a pad II (10), the pad I (4) is provided with a through hole, the through hole diameter of the pad I is smaller than the eccentric hole diameter of the eccentric sleeve I, and larger than the center threaded hole diameter of the locking boss I, the through hole diameter of the pad II is smaller than the eccentric hole diameter of the eccentric sleeve II, and larger than the center threaded hole diameter of the locking boss II; the eccentric sleeve I is supported on the pad I, and the eccentric sleeve II is supported on the pad II;

[0034] The bolt I passes through the pad I and cooperates with the central threaded hole of the locking boss I, and the bolt II passes through the pad II and cooperates with the central threaded hole of the locking boss II; rotating bolt I and bolt II can press and fix the eccentric sleeve between the root of the blade and the hub to achieve locking, and rotating eccentric sleeve I and eccentric sleeve II can adjust the angle of the blade relative to the hub.

[0035] A spring washer I (6) is arranged between the bolt I and the cushion block I, and a spring washer II (9) is arranged between the bolt II and the cushion block II.

[0036] The eccentric sleeve I and the eccentric sleeve II are symmetrically arranged relative to the petiole axis.

[0037] The locking boss I and the locking boss II are symmetrically arranged relative to the petiole axis.

[0038] Bolts Ⅰ and Ⅱ are hexagon socket head bolts.

Claims

1. A locking structure for a wind tunnel fan blade, Features: It comprises a blade (1), a blade handle, an eccentric sleeve I (3), a spacer I (4), a bolt I (5), a hub outer ring (7), a bolt II (8), a spacer II (10) and an eccentric sleeve II (11); The petiole is embedded in the blade root of the blade, and the petiole forms a locking boss I (2) and a locking boss II (12), and the locking boss I (2) and the locking boss II both protrude from the blade root to the outside of the blade, and the locking boss I (2) and the locking boss II (12) are respectively located on both sides of the petiole; The locking boss I (2) and the locking boss II (12) both have a central threaded hole; The hub outer ring is provided with a first mounting hole and a second mounting hole, the eccentric sleeve I (3) is slidably mounted in the first mounting hole, and the eccentric sleeve II (11) is slidably mounted in the second mounting hole; The locking boss I (2) is coaxially inserted into the eccentric hole of the eccentric sleeve I, and the locking boss II (12) is coaxially inserted into the eccentric hole of the eccentric sleeve II; The hub outer ring is fixed with a pad I (4) and a pad II (10), the pad I (4) is provided with a through hole, the through hole diameter of the pad I is smaller than the eccentric hole diameter of the eccentric sleeve I, and larger than the center threaded hole diameter of the locking boss I, the through hole diameter of the pad II is smaller than the eccentric hole diameter of the eccentric sleeve II, and larger than the center threaded hole diameter of the locking boss II; the eccentric sleeve I is supported on the pad I, and the eccentric sleeve II is supported on the pad II; The bolt I passes through the pad I and cooperates with the central threaded hole of the locking boss I, and the bolt II passes through the pad II and cooperates with the central threaded hole of the locking boss II; rotating the bolt I and the bolt II can make the root of the blade and the hub press and fix the eccentric sleeve to achieve locking, and rotating the eccentric sleeve I and the eccentric sleeve II can adjust the angle of the blade relative to the hub; A spring washer I (6) is arranged between the bolt I and the cushion block I, and a spring washer II (9) is arranged between the bolt II and the cushion block II; The eccentric sleeve I and the eccentric sleeve II are symmetrically arranged relative to the petiole axis; The locking boss I and the locking boss II are symmetrically arranged relative to the petiole axis; The materials of eccentric sleeve I and eccentric sleeve II are stainless steel or aluminum alloy; The blades are made of foam core composite material blades; The hub outer ring is made of high-strength steel; Bolts Ⅰ and Ⅱ are hexagon socket head bolts.

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