Double-air-inlet centrifugal fan

Abstract

The utility model relates to the technical field of fans, in particular to a double-air-inlet centrifugal fan, which overcomes the problems of low centering accuracy and poor stability of a stator shaft support bracket of the existing fan and the problem of inconvenience in processing of the bracket, and is provided with a volute, an outer rotor motor and a centrifugal impeller, the two ends, extending out of the outer rotor, of the stator shaft are fixed to the volute through supports at the positions of air inlets in the two sides of the volute respectively, the centrifugal impeller is fixed to the outer rotor, the supports are split type supports, and each split type support comprises three supporting arms which are distributed at equal intervals in the circumferential direction, are formed by steel plates and are the same in shape. The inner section of the supporting arm is a clamping section for supporting a stator shaft, the outer section of the supporting arm is a fixing section for fixing the support to the volute, the clamping section and the fixing section are connected through a connecting section, a flow guide arc part facilitating air flow entering is arranged at an air inlet of the volute, a positioning arc part is formed on the fixing section, and the positioning arc part of the supporting arm is pressed on the flow guide arc part of the volute. The radius of the inner arc of the positioning arc part is the same as that of the outer arc of the diversion arc part.

Description

Technical Field

[0001] This utility model relates to the field of fan technology, and in particular to a dual-inlet centrifugal fan. Background Technology

[0002] Centrifugal fans have relatively large air volume and air pressure, and long exhaust and supply distances. In a dual-inlet centrifugal fan, gas enters axially from both ends of the stator shaft into the centrifugal impeller driven by the outer rotor, and under the action of the centrifugal force of the impeller and the volute structure, the gas flows out radially. Both ends of the stator shaft are fixedly supported by brackets fixed to the air inlet of the volute.

[0003] The bracket at the air inlet is shaped like a Y-shaped three-pronged fork. The stator shaft is fixed to the core of the bracket, and the outer ends of the three forked arms of the bracket are fixed to the outer or inner wall of the volute. Existing brackets are either integral or separate. The structure of an integral bracket is shown in patent publication number CN119778288A for a dual-inlet centrifugal fan. This fan has two shortcomings in terms of the bracket: First, the centering accuracy and stability of the bracket are not good. The bracket is fixed by three fixing holes on the thin-walled volute, which is prone to installation errors. When the axis of the centrifugal impeller deviates from the axis of the volute, it will reduce the efficiency of the fan and increase the noise. Second, the bracket manufacturing process is complex. Different specifications of fans use brackets with different shapes and sizes, and the compatibility between the production tooling of different brackets is poor, which is not conducive to small-batch production. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a dual-inlet centrifugal fan that overcomes the problems of low centering accuracy and poor stability of the existing fan stator shaft support bracket, and also overcomes the problem of inconvenient bracket processing.

[0005] The technical solution adopted by this utility model to solve its technical problem is as follows: a dual-inlet centrifugal fan, comprising a volute and an outer rotor motor and a centrifugal impeller inside the volute. The two ends of the stator shaft extending from the outer rotor are fixed to the volute via brackets at the air inlets on both sides of the volute. The centrifugal impeller is fixed to the outer rotor. The bracket is a split bracket, which includes three identical support arms formed from steel plates and evenly distributed around the circumference. The inner section of the support arm is a clamping section that supports the stator shaft, and the outer section is a fixing section that fixes the bracket to the volute. The clamping section and the fixing section are connected by a connecting section. The air inlet of the volute has a guide arc portion that facilitates airflow. The fixing section has a positioning arc portion. The positioning arc portion of the support arm presses against the guide arc portion of the volute. The radius of the inner arc of the positioning arc portion is the same as the radius of the outer arc of the guide arc portion.

[0006] Specifically, the clamping section has a first connecting hole that is close to the fixed section and a second connecting hole that is far from the fixed section. In the clockwise direction, any support arm is fixed with a stud at the first connecting hole and the second connecting hole of the next support arm. The clamping sections of the three support arms are sequentially fixed to form a clamping space for the stator shaft.

[0007] Specifically, a transition piece is provided in the clamping space. The transition piece is circumferentially anti-rotation sleeved on the stator shaft. The three support arm clamping sections are sequentially fixed and then circumferentially anti-rotation sleeved on the transition piece.

[0008] Specifically, the support arm clamping section is formed with side wings to prevent axial movement of the transition piece.

[0009] Specifically, the stator shaft is provided with a positioning step that rests on the inner end face of the transition member.

[0010] Specifically, in order to reduce air intake resistance and improve the rigidity of the support, the connecting section of the steel plate forming support arm is a flat plate with reinforcing ribs, and the plane of the flat plate is parallel to the air intake direction.

[0011] The beneficial effects of this utility model are as follows: The dual-inlet centrifugal fan of this utility model has a positioning arc on the bracket, which fits against the air guide arc of the volute inlet, making the bracket axis, the inlet axis and the motor axis as consistent as possible, thus improving the fan accuracy. The fitting of the arc surface improves the stability of the bracket, and the positioning arc of the bracket also has the effect of guiding the air. For brackets of different specifications, the clamping section and the fixing section can be formed using the same mold, and only the connecting section can be formed with different molds to create reinforcing ribs. The bracket is easy to process and has low wind resistance. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is the front view of this utility model;

[0014] Figure 2 yes Figure 1 AA partial sectional view;

[0015] Figure 3 This is the left view of this utility model;

[0016] Figure 4 yes Figure 3 Enlarged view of point B;

[0017] Figure 5 This is an exploded view of the bracket and transition component in this utility model;

[0018] Figure 6 yes Figure 5 The C-direction view.

[0019] In the attached diagram: 1. Volute; 1-1. Guide arc;

[0020] 2. Centrifugal impeller;

[0021] 3. Stator shaft;

[0022] 4. Support arm; 4-1. Clamping section; 4-1-1. First connecting hole; 4-1-2. Second connecting hole; 4-1-3. Side wing; 4-2. Fixing section; 4-2-1. Positioning arc; 4-3. Connecting section; 4-3. Reinforcing rib.

[0023] 5. Transition components, 5-1. Bushing, 5-2. Vibration damping ring. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0025] As attached Figure 1 Main view and appendix Figure 3 The left view shows a dual-inlet centrifugal fan, comprising a volute 1 and an outer rotor motor and a centrifugal impeller 2 within the volute 1. The stator shaft 3 extends from the outer rotor at both ends and is fixed to the volute 1 via brackets at the air inlets on both sides. The centrifugal impeller 2 is fixed to the outer rotor. There are two brackets, each a split bracket, comprising three identical support arms 4 formed from steel plates, evenly distributed around the circumference. The shape of the support arms 4 is shown in the figure. Figure 5 and Figure 6 The inner section of the support arm 4 is a clamping section 4-1 that supports the stator shaft 3, and the outer section is a fixing section 4-2 that fixes the bracket to the volute 1. The clamping section 4-1 and the fixing section 4-2 are connected by a connecting section 4-3. The air inlet of the volute 1 has a guide arc section 1-1 that facilitates airflow. Figure 2As shown, the fixed section 4-2 is formed with a positioning arc 4-2-1. The positioning arc 4-2-1 of the support arm 4 presses on the flow guiding arc 1-1 of the volute 1. The radius of the inner arc of the positioning arc 4-2-1 is the same as the radius of the outer arc of the flow guiding arc 1-1.

[0026] like Figure 6 The clamping section 4-1 has a first connecting hole 4-1-1 that is close to the fixing section 4-2 and a second connecting hole 4-1-2 that is far from the fixing section 4-2, such as Figure 1 and Figure 5 In a clockwise direction, any one of the support arms 4 is fixed with a stud at the first connecting hole 4-1-1 and the second connecting hole 4-1-2 of the next support arm 4, and the clamping sections 4-1 of the three support arms 4 are sequentially fixed to form a clamping space for the stator shaft 3.

[0027] like Figure 5 and Figure 4 The clamping space includes a transition piece 5, which comprises a bushing 5-1 and a damping ring 5-2. The damping ring 5-2 is fitted onto the bushing 5-1. The outer rings of both the bushing 5-1 and the damping ring 5-2 are non-circular, which serves to prevent rotation. The inner ring of the damping ring 5-2 is identical to the outer ring of the bushing 5-1. The bushing 5-1 is circumferentially anti-rotating and fitted onto the stator shaft 3. The bushing 5-1 has fastening screws that press against the stator shaft 3. Three support arms 4 clamping sections 4-1 are sequentially fixed and fitted circumferentially anti-rotating onto the transition piece 5. The support arms 4 clamping sections 4-1 have side wings 4-1-3 to prevent axial movement of the transition piece 5. The damping ring 5-2 is wider at the side wings 4-1-3. During assembly, the damping ring 5-2 forms folded ears on both sides at the side wings 4-1-3. Figure 5 The upper damping ring 5-2 has a thinner wall but a wider width. The wide part in both directions can form the aforementioned folded lug. The folded lug plays a role in axial damping. In this way, the damping ring 5-2 provides both circumferential and radial damping as well as axial damping for the stator shaft 3.

[0028] In addition, the stator shaft 3 is provided with a positioning step that rests on the inner end face of the transition piece 5, and the connecting section 4-3 of the steel plate forming support arm 4 is a flat plate with reinforcing ribs 4-3-1 formed, and the plane direction of the flat plate is parallel to the airflow direction.

[0029] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A double-inlet centrifugal fan, comprising a volute (1) and an outer rotor motor and a centrifugal impeller (2) within the volute (1), wherein the stator shaft (3) extends from the outer rotor at both ends and is fixed to the volute (1) via supports at the air inlets on both sides of the volute (1), and the centrifugal impeller (2) is fixed to the outer rotor, characterized in that: The bracket is a split bracket, which includes three identical support arms (4) formed from steel plates and evenly distributed around the circumference. The inner section of the support arm (4) is a clamping section (4-1) that supports the stator shaft (3), and the outer section is a fixing section (4-2) that fixes the bracket to the volute (1). The clamping section (4-1) and the fixing section (4-2) are connected by a connecting section (4-3). The air inlet of the volute (1) has a guide arc (1-1) that facilitates airflow. The fixing section (4-2) is formed with a positioning arc (4-2-1). The positioning arc (4-2-1) of the support arm (4) presses on the guide arc (1-1) of the volute (1). The radius of the inner arc of the positioning arc (4-2-1) is the same as the radius of the outer arc of the guide arc (1-1).

2. The dual-inlet centrifugal fan according to claim 1, characterized in that: The clamping section (4-1) has a first connecting hole (4-1-1) close to the fixed section (4-2) and a second connecting hole (4-1-2) far from the fixed section (4-2). In the clockwise direction, any support arm (4) is studded at the first connecting hole (4-1-1) and the second connecting hole (4-1-2) of the next support arm (4). The clamping sections (4-1) of the three support arms (4) are sequentially fixed to form a clamping space for the stator shaft (3).

3. A dual-inlet centrifugal fan according to claim 2, characterized in that: The clamping space is provided with a transition piece (5), which is circumferentially anti-rotation sleeved on the stator shaft (3). The three support arms (4) clamping sections (4-1) are sequentially fixed and enclosed, and are circumferentially anti-rotation sleeved on the transition piece (5).

4. A dual-inlet centrifugal fan according to claim 3, characterized in that: The clamping section (4-1) of the support arm (4) is formed with side wings (4-1-3) to prevent the transition piece (5) from moving axially.

5. A dual-inlet centrifugal fan according to claim 3, characterized in that: The stator shaft (3) is provided with a positioning step that rests on the inner end face of the transition piece (5).

6. A dual-inlet centrifugal fan according to claim 1, characterized in that: The connecting section (4-3) of the steel plate forming support arm (4) is a flat plate with reinforcing ribs (4-3-1) formed, and the plane direction of the flat plate is parallel to the airflow direction.

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