CN204942078U - A kind of mechanical device of automatic adjusting axle axial flow fan blade pitch - Google Patents

Abstract

The utility model relates to a kind of mechanical device of automatic adjusting axle axial flow fan blade pitch.The device that object is to provide should be able to make axial-flow blower noise reduction to greatest extent under different operating mode.Technological scheme is: a kind of mechanical device of automatic adjusting axle axial flow fan blade pitch, comprises being arranged on wheel hub coaxially arranged with casing in fan casing, being distributed in the some blades on wheel hub outer peripheral surface and being furnished with the PLC of wireless launcher; It is characterized in that several described blades are fixed on corresponding circular arc slide plate respectively one by one, all circular arc slide plates are sequentially arranged on all slidably and are positioned on wheel hub outer peripheral surface and around the chute of circumferential directions, separately there is the controlling mechanism one_to_one corresponding of respective amount to drive respectively and control circular arc slide plate and slide in chute, thus the pitch of adjusting vane.

Description

A kind of mechanical device of automatic adjusting axle axial flow fan blade pitch

Technical field

The utility model belongs to axial-flow blower noise reduction field, particularly relates to a kind of mechanical device of automatic adjusting axle axial flow fan blade pitch.

Background technique

The purposes of axial-flow blower is very wide, is no matter the radiation fan of personal computer, or the air compressor of jumble jet, is all the application of axial-flow blower in different field.These blower fans, while making air flow, also can cause the disturbance of air and produce aerodynamic noise.When axial-flow blower high speed rotating, because rotation blade periodically hits air particle, cause air periodic pressure pulsation and the crest frequency noise ratio eddy current of the series of discrete produced and eddy current divide the continuous print wideband noise excited more preponderates and larger to the harm of human body.Therefore, the emphasis that discrete crest frequency noise is axial-flow blower noise reduction is reduced.

Research shows, irregular pitch Leaf positional distribution, owing to decreasing periodic excitation, has modulating action to blower fan by frequency and harmonic wave thereof.By making the angle between two adjacent blades all unequal, the airborne noise peak value produced during rotation can be distributed to other frequencies, avoids the peak value of some wavelength coverages, thus reduces total noise rank.In addition, the relative change rate of irregular pitch and equal pitch can't produce large impact to aerodynamic performance in a big way, therefore, can select the best distribution mode of vanepiston neatly.

According to research, obtain the method calculating vanepiston best distribution, the distribution mode that the method is tried to achieve, not only can reduce discrete peaks frequency noise to greatest extent, and the barycenter of impeller entirety can also be made still to be positioned at the center of running shaft and eccentric rotary vibration does not occur.

But along with the change of rotation speed of fan, the vanepiston best distribution mode that said method obtains also can change.In real work, the rotating speed of axial-flow blower needs to change as requested, but the pitch of axial-flow fan blade is fixed adding man-hour, and this vanepiston best distribution mode of trying to achieve under just making rated speed may not be optimal solution under other operating mode.Therefore, the axial-flow blower that vanepiston is fixed cannot meet under various operating mode can the requirement of noise reduction to greatest extent.

Model utility content

The purpose of this utility model is the deficiency overcoming above-mentioned background technology, provides a kind of mechanical device of automatic adjusting axle axial flow fan blade pitch.This device should be able to make axial-flow blower noise reduction to greatest extent under different operating mode.

The technological scheme that the utility model provides is: a kind of mechanical device of automatic adjusting axle axial flow fan blade pitch, comprises being arranged on wheel hub coaxially arranged with casing in fan casing, being distributed in the some blades on wheel hub outer peripheral surface and being furnished with the PLC of wireless launcher; It is characterized in that several described blades are fixed on corresponding circular arc slide plate respectively one by one, all circular arc slide plates are sequentially arranged on all slidably and are positioned on wheel hub outer peripheral surface and around the chute of circumferential directions, separately there is the controlling mechanism one_to_one corresponding of respective amount to drive respectively and control circular arc slide plate and slide in chute, thus the pitch of adjusting vane;

Described controlling mechanism comprises the adjustment motor of internal gear section, the terminal teeth wheels of driving internal gear section, the train of reduction gears driving terminal teeth wheels and the driving train of reduction gears be fixed on below circular arc slide plate; The PLC instruction works that described adjustment motor sends according to wireless launcher.

Described train of reduction gears comprises several retarding stages be connected in series; Each retarding stage is by connecting shaft, the path external gear being coaxially connected to connecting shaft two ends respectively and large footpath internal gear composition; Large footpath internal gear wherein in chopped-off head retarding stage is driven by the small gear regulated on motor output shaft, and the path external gear in all the other retarding stages is all for driving the large footpath internal gear in next retarding stage adjacent.

Described terminal teeth wheels are by coupling shaft and be coaxially connected to the external gear at coupling shaft two ends and internal gear forms.

Connecting shaft in described each retarding stage and the coupling shaft in terminal teeth wheels all can be distributed on wheel hub inner peripheral surface rotatably about the axis by several connecting shaft supports; The axis of connecting shaft at different levels is all positioned on the same circumferential surface coaxial with hub axis; Ensure that the barycenter of every grade of several connecting shaft supports is in hub axis, prevent the rotary vibration problem that overall bias causes.

Described several regulate motor to be circumferentially evenly arranged on the dividing plate in wheel hub in direction; The train of reduction gears of described respective amount is circumferentially evenly distributed on the connecting shaft support in wheel hub in direction.

Working principle of the present utility model is as follows:

Switch on power, rotor electric machine drives hub rotation; According to the change of operating mode, the best distribution method of each blade is gone out by the program computation in PLC, and combine the adjustment rotating speed of motor and the velocity ratio of driving mechanism, the signal wireless of sense of rotation and rotational time is passed to and regulates motor accordingly, thus start the pinion rotation regulating motor to make on its output shaft; Then through the multi-stage speed-reducing of train of reduction gears and terminal teeth wheels, by transmission of power to the internal gear section be fixed on by linkage section below circular arc slide plate, order about in the chute of circular arc slide plate on wheel hub outer peripheral surface and slide, namely the pitch of the blade be fixed on circular arc slide plate is regulated.When the position that blade movement requires to program, regulate motor stalls accordingly.Thus realize automatic adjusting axle axial flow fan blade pitch, the object of noise reduction to greatest extent.

The beneficial effects of the utility model are: due to can according to different operating modes automatic adjusting vane pitch, thus be reduced in prevailing discrete peaks frequency noise in aerodynamic noise, make the means of noise reduction more flexible; In addition, whole adjustment process controls by pre-set programs, does not need manual operation completely, not only regulates laborsaving convenience, can also guarantee degree of regulation, meets the needs of users.

Accompanying drawing explanation

Fig. 1 is the schematic perspective view (fan casing office sectional view) of the utility model mounting structure.

Fig. 2 is the schematic diagram (ladder is cut the circular hole on connecting shaft support open and removed the driving mechanism of a blade) of the utility model wheel hub internal gear transmission.

Fig. 3 is the schematic diagram (ladder cuts the circular hole on connecting shaft support open) of the utility model wheel hub structure.

Fig. 4 is the structural representation of the utility model blade-section.

Fig. 5 is the structural representation of the utility model terminal teeth wheels.

Fig. 6 is the structural representation of arbitrary retarding stage in the utility model train of reduction gears.

Fig. 7 is the schematic flow sheet of the utility model regulable control.

Embodiment

Below in conjunction with accompanying drawing, described embodiment is further illustrated.

As Figure 1-Figure 2, a kind of mechanical device (using 5 blade axial-flow blower fans as example) of automatic adjusting axle axial flow fan blade pitch, comprises fan casing 1, rotor electric machine 2, electric machine support 3, wheel hub 4, blade 5, circular arc slide plate 6, dividing plate 7, regulates motor 8, small gear 9, train of reduction gears 10, bearing 11, connecting shaft support 12, terminal teeth wheels 13, linkage section 14, internal gear section 15.

As shown in Figure 1, rotor electric machine 2 is fixed on the inner chamber of fan casing 1 by electric machine support 3; One end of wheel hub 4 is fixed on the output shaft of rotor electric machine 2 and (ensures that wheel hub 4 is coaxial with blower fan runner), and is driven by rotor electric machine; Several blades 5 are distributed on wheel hub 4 outer peripheral surface, and rotor electric machine controls the rotation of wheel hub 4.It is more than the structure of conventional axial-flow blower.

Improvement of the present utility model is: several blades 5 described are separately fixed on corresponding circular arc slide plate 6, circular arc slide plate 6 is arranged in the chute 4-2 on wheel hub 4 outer peripheral surface (chute 4-2 arranges around outer peripheral surface) movably, separately there is a controlling mechanism to drive and control circular arc slide plate 6 and slide in chute 4-2 (circumferencial direction slip), thus the pitch of adjusting vane 5.

As shown in Fig. 4, Fig. 2: internal gear section 15 is fixed on below circular arc slide plate 6 by linkage section 14; Terminal teeth wheels 13 engage and drive internal gear section, and train of reduction gears 10 drives terminal teeth wheels, regulate motor 8 to drive train of reduction gears by small gear 9 fixing on its output shaft again.

As shown in Figure 3, Figure 4: uniform the circumferentially opening 4-1 in direction on the outer peripheral surface of wheel hub 4; Linkage section 14 is positioned at upstream position immediately below circular arc slide plate 6, and after the opening 4-1 through wheel hub 4 surface, upper and lower two ends respectively connected circular arc slide plate 6 and internal gear section 15.

As shown in Figure 5: the two ends gear of terminal teeth wheels 13 connects with coupling shaft 13-3, one end is external gear 13-1, engages with internal gear section 15, and the other end is internal gear 13-2, engages with the path external gear 10-1 in final reduction level.

As shown in Figure 6: the structure of each retarding stage of train of reduction gears 10 is all identical, the structure adopting and connected two ends gear (path external gear 10-1 and large footpath internal gear 10-2) by connecting shaft 10-3 is; Wherein, the path external gear 10-1 of one end of final reduction level engages with the internal gear 13-2 of terminal teeth wheels 13, and the large footpath internal gear 10-2 of the other end engages with the path external gear 10-1 of upper level retarding stage; In chopped-off head retarding stage, path external gear 10-1 engages with the large footpath internal gear 10-2 of next stage retarding stage, and large footpath internal gear 10-2 engages with regulating small gear 9 fixing on motor 8 output shaft.Thus velocity ratio is increased to greatest extent in limited space, improve the degree of regulation regulating motor 8.The progression slowed down is determined as required, and the utility model embodiment adopts 4 grades of decelerations.

As shown in Fig. 5-Fig. 6: two ends fix connecting shaft 10-3 and the coupling shaft 13-3 of two kinds of gears respectively, be arranged on respectively by bearing 11 (bearing 11 outer ring is fixed in the circular hole on connecting shaft support 12, and the intermediate portion of bearing 11 inner ring and connecting shaft 10-3 or coupling shaft 13-3 is fixed) in the circular hole on connecting shaft support 12.

As shown in Fig. 2-Fig. 3, several connecting shaft supports 12 in each train of reduction gears are arranged on wheel hub 4 inner peripheral surface, the axis (the axis hole axis namely on connecting shaft support 12 at different levels) of connecting shaft at different levels is all positioned on the same circumferential surface coaxial with hub axis, and entirety is around the same equal angles that rotates in a circumferential direction, ensure that the barycenter of several connecting shaft supports 12 is in hub axis, prevent the rotary vibration problem that overall bias causes; Dividing plate 7 is positioned at wheel hub 4 lumen downstream (right side of Fig. 1), be used for fixing and regulate motor 8, after regulating the hole of the output shaft of motor 8 through circumference uniform distribution on dividing plate, small gear 9 to be fixed on this output shaft again and to engage with the large footpath internal gear 10-2 in chopped-off head retarding stage.

In a word, 5 blades in the present embodiment are driven respectively one by one by 5 controlling mechanisms, and these controlling mechanisms are distributed on hub inner lumen and keep the barycenter after synthesizing to be positioned in hub axis, to keep moving equilibrium.

Regulate the angle of swing of motor 8 by program control.This program goes out the best distribution method (result calculated the barycenter of impeller entirety can be made still to be positioned at the center of running shaft and eccentric rotary vibration does not occur) of current working lower blade pitch according to rotation speed of fan tentative calculation, rotating speed in conjunction with the velocity ratio slowed down and adjustment motor 8 regulates motor 8 to send rotation signal to each, is controlled the adjustment of blade 5 pitch by the Movement transmit of described controlling mechanism.

As shown in Figure 7, described automatic control program is programmed in PLC, and concrete steps comprise

1) the blade 5 number B of input shaft flow fan and the rotating speed n of rotor electric machine 2;

2) with the central point of axial-flow blower wheel hub 4 for true origin sets up system of coordinates, preset the angle θ of B-2 blade 5 present position in a coordinate system _i, wherein, described θ _ithe angle of axial-flow blower i-th blade present position in a coordinate system, default θ _iat [θ _{i, min}, θ _{i, min}+ Δ θ, θ _{i, min}+ 2 Δ θ ...., θ _{i, max}] middle value, wherein, described θ _{i, min}and θ _{i, max}minimum angles and the maximum angle that axial-flow blower i-th blade modulated mechanism regulation range limits present position in a coordinate system respectively, Δ θ is the tentative calculation step-length of the angle of blade present position in described system of coordinates, by the angle θ of combination B-2 blade 5 present position in a coordinate system _i, obtain the location mode [θ of one group of B-2 blade 5 ₁, θ ₂...., θ _b-2];

3) basis ${\mathrm{cos\θ}}_B+{\mathrm{cos\θ}}_{B-1}+\underset{i=1}{\overset{B-2}{\Σ}}{\mathrm{cos\θ}}_i=0$ With ${\mathrm{sin\θ}}_B+{\mathrm{sin\θ}}_{B-1}+\underset{i=1}{\overset{B-2}{\Σ}}{\mathrm{sin\θ}}_i=0,$ Calculate the angle θ of remaining two blade present positions in described system of coordinates _b-1and θ _b, such Leaf positional distribution makes the barycenter of irregular pitch vane fan impeller entirety still be positioned in hub axis, there will not be eccentric vibrating during rotation;

4) θ is judged _b-1and θ _bwhether meet θ respectively _{b-1, min}≤ θ _b-1≤ θ _{b-1, max}and θ _{b, min}≤ θ _b≤ θ _{b, max}, if so, then continue next step, if not, repeat step 2);

5) the angle θ of each blade 5 present position of axial-flow blower is utilized _i, calculate the amplitude A of k subharmonic sound pressure signal when axial-flow blower rotates _k, wherein, described k is relevant to the rotating speed n of axial-flow blower, $A_k=\frac{1}{\mathrm{\π}}\left|\underset{i=1}{\overset{B}{\Σ}}{e}^{-{\mathrm{ik\θ}}_i}\right|=\frac{1}{\mathrm{\π}}\sqrt{{\[\underset{i=1}{\overset{B}{\Σ}}\cos \left({\mathrm{k\θ}}_i\right)\]}^2+{\[\underset{i=1}{\overset{B}{\Σ}}\sin \left({\mathrm{k\θ}}_i\right)\]}^2};$

6) the difference DELTA SPL of the rotational noise sound pressure level of irregular pitch axial-flow blower and equal pitch axial-flow blower is calculated, wherein, $\mathrm{\Δ}SPL=20\lg \frac{B}{\mathrm{\π}}-20{\mathrm{lgA}}_k;$

7) angle [θ of each blade 5 present position of axial-flow blower of Δ SPL and correspondence is stored ₁, θ ₂...., θ _b];

8) determining step 2) in the angle θ of B-2 blade present position in a coordinate system _iall combination [θ ₁, θ ₂...., θ _b-2] whether tentative calculation is complete, if so, then continues next step, if not, repeats step 2);

9) more all storages Δ SPL and export Δ SPL maximum time each blade present position in a coordinate system angle [θ ₁, θ ₂...., θ _b];

10) combine the adjustment rotating speed n* of the motor 8 and velocity ratio I of driving mechanism, regulate motor 8 to send the wireless signal of sense of rotation and rotational time to each respectively.

The above is a case study on implementation of the present utility model, and unrestricted the scope of the claims of the present utility model.Therefore, every according to technical spirit of the present utility model, simple modification and various similar change are done to the utility model, includes within scope of patent protection of the present utility model.

Claims (5)

1. a mechanical device for automatic adjusting axle axial flow fan blade pitch, comprises and is arranged on wheel hub (4) coaxially arranged with casing in fan casing (1), is distributed in the some blades (5) on wheel hub outer peripheral surface and is furnished with the PLC of wireless launcher; It is characterized in that several described blades are fixed on corresponding circular arc slide plate (6) respectively one by one, all circular arc slide plates are sequentially arranged on all slidably and are positioned on wheel hub outer peripheral surface and around the chute (4-2) of circumferential directions, separately there is the controlling mechanism one_to_one corresponding of respective amount to drive respectively and control circular arc slide plate and slide in chute, thus the pitch of adjusting vane;

Described controlling mechanism comprises the adjustment motor (8) of internal gear section (15), the terminal teeth wheels (13) of driving internal gear section, the train of reduction gears (10) driving terminal teeth wheels and the driving train of reduction gears be fixed on below circular arc slide plate; The PLC instruction works that described adjustment motor sends according to wireless launcher.

2. the mechanical device of automatic adjusting axle axial flow fan blade pitch according to claim 1, is characterized in that: described train of reduction gears comprises several retarding stages be connected in series; Each retarding stage is by connecting shaft (10-3), the path external gear (10-1) being coaxially connected to connecting shaft two ends respectively and large footpath internal gear (10-2) composition; Large footpath internal gear wherein in chopped-off head retarding stage is driven by the small gear regulated on motor output shaft, and the path external gear in all the other retarding stages is all for driving the large footpath internal gear in next retarding stage adjacent.

3. the mechanical device of automatic adjusting axle axial flow fan blade pitch according to claim 2, is characterized in that: described terminal teeth wheels are by coupling shaft (13-3) and be coaxially connected to the external gear (13-1) at coupling shaft two ends and internal gear (13-2) forms.

4. the mechanical device of automatic adjusting axle axial flow fan blade pitch according to claim 3, is characterized in that: the connecting shaft in described each retarding stage and the coupling shaft in terminal teeth wheels all can be distributed on wheel hub inner peripheral surface rotatably about the axis by several connecting shaft supports; The axis of connecting shaft at different levels is all positioned on the same circumferential surface coaxial with hub axis.

5. the mechanical device of automatic adjusting axle axial flow fan blade pitch according to claim 4, is characterized in that: described several regulate motor to be circumferentially evenly arranged on the dividing plate (7) in wheel hub in direction; The train of reduction gears of described respective amount is circumferentially evenly distributed on the connecting shaft support (12) in wheel hub in direction.