阅读说明：本技术 带有桨距调节结构的变速风机 (Variable speed fan with pitch adjusting structure ) 是由 卢思雨 于 2020-10-13 设计创作，主要内容包括：本发明公开了一种带有桨距调节结构的变速风机,包括主轴、主轮毂、副轮毂,主轮毂包括主壳和主叶片,主壳与主轴定速刚性传动连接,主壳外表以主轴为轴线圆周均布若干主叶片,副轮毂包括副壳和副叶片,副壳与主壳沿主轴方向插接连接,副叶片设置在副壳外表,副叶片沿主轴圆周方向布置,副壳根据通过风机的风量调节其与主壳的轴向相对位置,风量变大时,副叶片与主叶片沿主轴轴向相互远离。变速风机还包括配速组件,配速组件设置在主壳内,配速组件与副壳调速传动连接,副壳与主壳发生轴向移动时,副壳以低于主壳的转速转动,副叶片与主叶片轴向距离越远,则副壳与主壳转速差越大。(The invention discloses a variable speed fan with a pitch adjusting structure, which comprises a main shaft, a main hub and an auxiliary hub, wherein the main hub comprises a main shell and main blades, the main shell is in constant-speed rigid transmission connection with the main shaft, a plurality of main blades are uniformly distributed on the outer surface of the main shell by taking the main shaft as an axis circumference, the auxiliary hub comprises an auxiliary shell and auxiliary blades, the auxiliary shell is in plug-in connection with the main shell along the main shaft direction, the auxiliary blades are arranged on the outer surface of the auxiliary shell, the auxiliary blades are arranged along the circumferential direction of the main shaft, the axial relative position of the auxiliary shell and the main shell is adjusted according to the air volume passing through the fan, and when the air volume is increased, the auxiliary blades and the main blades are mutually far away along the main shaft axial direction. The variable speed fan further comprises a speed distribution assembly, the speed distribution assembly is arranged in the main shell and is in speed regulation transmission connection with the auxiliary shell, when the auxiliary shell and the main shell move axially, the auxiliary shell rotates at a rotating speed lower than that of the main shell, and the farther the axial distance between the auxiliary blade and the main blade is, the larger the difference between the rotating speeds of the auxiliary shell and the main shell is.)

1. The utility model provides a variable speed fan with pitch control structure which characterized in that: the fan comprises a main shaft (1), a main hub (2) and an auxiliary hub (3), wherein the main hub (2) comprises a main shell (21) and main blades (22), the main shell (21) is in constant-speed rigid transmission connection with the main shaft (1), a plurality of main blades (22) are uniformly distributed on the outer surface of the main shell (21) by taking the main shaft (1) as an axis circumference, the auxiliary hub (3) comprises auxiliary shells (31) and auxiliary blades (32), the auxiliary shells (31) are in plug connection with the main shell (21) along the direction of the main shaft (1), the auxiliary blades (32) are arranged on the outer surface of the auxiliary shells (31), the auxiliary blades (32) are arranged along the circumferential direction of the main shaft (1), the axial relative positions of the auxiliary shells (31) and the main shell (21) are adjusted according to the air volume passing through the fan, and when the air volume is increased, the auxiliary blades (32) and the main blades (22) are axially far away from each other along the main shaft (1);

the variable speed fan further comprises a speed distribution assembly (4), the speed distribution assembly (4) is arranged in the main shell (21), the speed distribution assembly (4) is in speed regulation transmission connection with the auxiliary shell (31), when the auxiliary shell (31) and the main shell (21) move axially, the auxiliary shell (31) rotates at a rotating speed lower than that of the main shell (21), and the farther the axial distance between the auxiliary blade (32) and the main blade (22) is, the larger the difference between the rotating speeds of the auxiliary shell (31) and the main shell (21) is;

the speed distribution assembly (4) comprises a pressure measuring assembly (42) extending to the outer surface of the main shell (21), a measuring point of the pressure measuring assembly (42) is positioned in front of the axial direction of the main blade (22), and when the pressure measuring assembly (42) measures that the pressure is low, the speed distribution assembly (4) is adjusted to drive the auxiliary shell (31) and the main shell (21) to generate an enlarged rotation speed difference;

the speed matching component (4) further comprises a middle tooth mounting rack (41), a middle gear (43), a driven gear (441), a driven seat (442), a resisting spring (45), a sliding ball (46) and a sliding cylinder (47), wherein the middle tooth mounting rack (41) is fixedly connected to the spindle (1), the middle tooth mounting rack (41) is bent in the axial direction after radially extending from the spindle (1) and is provided with a plurality of mounting shaft holes (411), the middle gear (43) is rotatably mounted in the mounting shaft holes (411) on the bent edge at the tail end of the middle tooth mounting rack (41), the axis of the middle gear (43) is perpendicular to and intersected with the axis of the spindle (1), the driven seat (442) is sleeved on the spindle (1), the driven gear (441) taking the spindle (1) as the axis is mounted on one end, facing the middle tooth mounting rack (41), of the driven seat (442), the other end of the driven seat (442) is flanged and the sliding ball (46) capable of radially sliding is arranged in the flange, the sliding cylinder (47) is sleeved outside the driven seat (442) and synchronously rotates with the driven seat (442), one end of the radial inner side of the sliding cylinder (47), adjacent to the sliding ball (46), is provided with a pressing plate conical surface (471), the pressing plate conical surface (471) presses the sliding ball (46) radially inwards, one end of the sliding cylinder (47), which is far away from the sliding ball (46), is tightly pressed by a pressing spring (45), the radial outer side of the sliding cylinder (47) is fixedly connected with the auxiliary shell (31),

the middle gear (43) and the driven gear (441) are both bevel gears and are meshed with each other, the tail end of the rotating shaft of the middle gear (43) is contacted with the pressure measuring component (42), and when the pressure measuring component (42) senses that the external pressure is reduced, the pressure measuring component (42) reduces the abutting force on the rotating shaft of the middle gear (43) so that the rotation resistance of the middle gear is reduced;

the load measuring component (42) comprises a sliding block (421), a first spring (422), a second spring (423) and a brake pad (424), the wall surface of the main shell (21) is provided with a wind pressure hole (211) and a slider groove (212) which are connected with each other, the wind pressure hole (211) is close to the outer surface of the main shell (21), the slider groove (212) is close to the inner surface of the main shell (21), the tail end of the rotating shaft of the intermediate gear (43) is provided with a brake groove (431), the slider (421) is positioned in the slider groove (212) and slides along the slider groove (212), one end of the first spring (422) is pressed against the surface of the sliding block (421), the other end is pressed against the stepped surfaces of the wind pressure hole (211) and the sliding block groove (212), one end of the second spring (423) is abutted against the surface of the sliding block (421), the other end of the second spring is connected with the brake pad (424), and the brake pad (424) is abutted against the brake groove (431).

Technical Field

The invention relates to the technical field of fans, in particular to a variable speed fan with a pitch adjusting structure. Background

The fan is a common work machine for industry and civil use, and accelerates or pressurizes wind for conveying.

In prior art's large-scale fan, its flow range is often great, and fan wheel goes up blade quantity and does not influence greatly to the wind pressure promotion, but can influence the air current flow condition of complete machine, specifically does: the area that the thickness sum of blade occupies on overflowing the cross-section is called and crowds the coefficient, and great crowds the coefficient influence inflow at the entrance, this point need focus on considering when designing large-traffic fan, and during the low discharge situation, and need more blade quantity to guarantee sufficient blade working face area, and in the prior art, when designing the fan of large-traffic scope, these two often compromise and confirm, influence the operating efficiency.

The vibration of a large fan is also a non-negligible factor, and besides the vibration caused by mechanical factors such as mechanical wear, bearing wear, machining tolerance, insufficient dynamic balance and the like, the vibration caused by airflow can also occur, the airflow periodically overflows blades, and vortices are generated behind the fan.

Disclosure of Invention

The present invention is directed to a variable speed wind turbine with a pitch adjustment structure to solve the problems set forth in the background art.

In order to solve the technical problems, the invention provides the following technical scheme:

the utility model provides a variable speed fan with pitch control structure, which comprises a main shaft, main wheel hub, vice wheel hub, main wheel hub includes main shell and main blade, the main shell is connected with main shaft constant speed rigid drive, a plurality of main blades of main shell outward appearance use the main shaft as axis circumference equipartition, vice wheel hub includes vice shell and vice blade, vice shell and main shell are connected along main shaft direction grafting, vice blade sets up at vice shell outward appearance, vice blade arranges along main shaft circumferencial direction, vice shell is according to the air regulation its and main shell's axial relative position through the fan, during the amount of wind grow, vice blade keeps away from each other along the main shaft axial with main blade. The displacement coefficient of the fan inlet determined by the number and the thickness of the blades is larger, when the flow is larger, the larger displacement coefficient influences the position of new air entering the blades, and under the condition of smaller flow, if the number of the blades is smaller, the total area of the working surface of the blades is too small, and the energy transfer between the blades and the air is influenced, so that when a large flow is generally designed, the inlet displacement coefficient of a fluid machine is selected to be smaller, and when the fluid machine used under the working condition of small flow is designed with more blades to ensure the working performance, the application ensures that partial blades move backwards axially through the design of the blades with axially adjustable distance under the condition of larger flow, improves the displacement condition of inlet air so as to introduce more air volume, changes the mode of the blades by respectively arranging installation positions for the blades, respectively installing the working blades on the auxiliary shell and the main shell, and when the main shaft runs at a high speed to improve the flow, the auxiliary shell moves backwards in the axial direction, and the blades are staggered.

Furthermore, the variable speed fan further comprises a speed distribution assembly, the speed distribution assembly is arranged in the main shell and is in speed regulation transmission connection with the auxiliary shell, when the auxiliary shell and the main shell move axially, the auxiliary shell rotates at a rotating speed lower than that of the main shell, and the farther the axial distance between the auxiliary blade and the main blade is, the larger the rotating speed difference between the auxiliary shell and the main shell is. When the auxiliary blade and the main blade have an axial distance, the acting of the auxiliary blade and the main blade is not parallel but series connection, the auxiliary blade boosts air for the second time, improves the air outlet pressure and the air speed while improving the flow, and certainly, the power transmitted from the main shaft is greatly increased. The secondary increase can not be avoided, if no constraint exists, the axial distance of the main blade and the auxiliary blade is adjusted at will, and the rotating speed is not changed, turbulence resonance is easy to occur at a certain distance, namely, a spiral air column sent by the main blade to the rear causes vibration on the auxiliary blade, if the rotating speed of the auxiliary blade is consistent with that of the main blade, resonance is generated, the whole structure of the fan is endangered, the use danger is caused, the rotating speed difference value of the auxiliary blade and the main blade is changed along with the change of the axial distance, air can be discharged out of the fan in a disorder turbulence mode, and the resonance is avoided although micro-vibration occurs.

Furthermore, the speed matching assembly comprises a pressure measuring assembly extending to the outer surface of the main shell, a measuring point of the pressure measuring assembly is located in the axial front of the main blade, and when the pressure measured by the pressure measuring assembly is lowered, the speed matching assembly is adjusted to drive the auxiliary shell and the main shell to generate a larger rotating speed difference. The flow change of the fan is identified through a pressure measuring mode, the Bernoulli equation of hydrodynamics can learn that the flow of the fan is increased under the condition that the pressure of an air inlet position at the front end of the fan is not changed, then the pressure of an inflow position of a blade is reduced.

Furthermore, the speed matching assembly also comprises a middle tooth mounting rack, an intermediate gear, a driven seat, a resisting spring, a sliding ball and a sliding cylinder, wherein the middle tooth mounting rack is fixedly connected to the main shaft, the middle tooth mounting rack is bent in the axial direction after radially extending from the main shaft and is provided with a plurality of mounting shaft holes, the intermediate gear is rotatably mounted in the mounting shaft holes on the bent edge at the tail end of the middle tooth mounting rack, the axis of the intermediate gear is perpendicular to and intersected with the axis of the main shaft, the driven seat is sleeved on the main shaft, the driven gear taking the main shaft as the axis is mounted at one end of the driven seat facing the middle tooth mounting rack, the other end of the driven seat is flanged and is internally provided with the sliding ball capable of radially sliding, the sliding cylinder is sleeved outside the driven seat and synchronously rotates with the driven seat, one end of the adjacent sliding ball on the radial inner side of the sliding cylinder is provided with a pressing plate conical surface, the pressing plate conical surface presses the sliding ball radially inwards, one end of the sliding cylinder, which deviates from the sliding ball, is pressed by the resisting spring, the radial outer side of the sliding cylinder is fixedly connected with the auxiliary shell,

furthermore, the intermediate gear and the driven gear are bevel gears and are meshed with each other, the tail end of a rotating shaft of the intermediate gear is in contact with the pressure measuring assembly, and when the pressure measuring assembly senses that the external pressure is reduced, the pressure measuring assembly reduces the abutting force on the rotating shaft of the intermediate gear, so that the autorotation resistance of the intermediate gear is reduced. This structure is a specific speed structure of joining in marriage, the pressure measurement subassembly perception external pressure reduces the operating mode that corresponds fan flow increase, at this moment, the power of supporting to the intermediate gear pivot end reduces, let its rotation resistance reduce, thereby cause the rotational speed difference of well tooth mounting bracket and driven gear, well tooth mounting bracket keeps the rotational speed unanimous because with main shaft fixed connection, driven gear is the transmission mode of relatively fixed to driven seat to sliding tube to subshell to the driven seat, see as whole when the analysis rotational speed, and the main shell is fixed with the main shaft, then can see out, when pressure measurement subassembly leads to intermediate gear rotation rotational speed to change, can make main shell and subshell produce the rotational speed difference, in addition, the reduction of driven seat rotational speed lets smooth ball centrifugal force reduce, self axial displacement when the smooth ball of awl clamp plate suppression, change subshell axial position.

Further, the pressure measuring component includes the slider, first spring, second spring and brake block, set up interconnect's wind pressure hole and slider groove on the main casing wall, the main casing surface is pressed close to in the wind pressure hole, the main casing internal surface is pressed close to in the slider groove, the end of intermediate gear pivot sets up the brake groove, the slider is located the slider inslot and slides along the slider groove, first spring one end is contradicted on the slider surface, the other end is contradicted on the ladder face in wind pressure hole and slider groove, second spring one end is contradicted on the slider surface, the brake block is connected to the other end, the brake block is contradicted on the brake groove. When external air flow flows through the wind pressure holes, the flow is increased, the pressure at the wind pressure holes is reduced, the sliding block is pushed outwards by the pressure in the main shell, the first spring is compressed, the second spring is released, the friction force of the brake block against the brake groove is reduced, the autorotation resistance of the intermediate gear is reduced, autorotation is smooth, the rotating speed proportion of the driven gear obtained from the intermediate gear mounting frame is reduced, and the main blade and the auxiliary blade generate a rotating speed difference.

Preferably, the speed matching assembly further comprises a thrust bearing arranged between the end part of the main shaft and the end part of the driven seat.

And optimally, spraying Teflon coatings on the outer surface of the sliding block and the inner surface of the sliding block groove. The Teflon coating has small friction, and the sliding block can move smoothly when doing piston motion along the sliding block groove.

Furthermore, elastic bulges are respectively arranged on the splicing surfaces of the auxiliary shell and the main shell. The sliding cylinder is axially limited with the contact end of the auxiliary shell and is connected with the overrunning clutch in the circumferential direction. The elastic bulge has a threshold value for allowing the axial sliding of the auxiliary shell and the main shell, and the sliding force of the auxiliary shell towards one end is not continuously changed, so that the axial sliding of the auxiliary shell can be realized only by allowing the elastic bulge on the auxiliary shell to pass the elastic bulge on the main shell. The sliding with the threshold value prevents the interference of the main blade and the auxiliary blade, the backward movement trend of the auxiliary shell must be accumulated to the extent that the auxiliary blade and the main blade are axially staggered, the auxiliary blade and the main blade collide when the abnormal speed is slightly generated without the structure, and the main blade pushes the auxiliary blade to rotate circumferentially after the collision. The sliding cylinder axially slides to generate thrust to the auxiliary shell, the original rotating speed is kept when the auxiliary blade on the auxiliary shell is not separated from the main blade, after separation, the auxiliary shell loses rotating power, and when the speed is reduced to the rotating speed of the sliding cylinder, the sliding cylinder continuously rotates at the rotating speed.

And optimally, the tail part of the auxiliary shell is provided with a flow guide cone. The air current is stably discharged to the water conservancy diversion awl.

Compared with the prior art, the invention has the following beneficial effects: the invention keeps more blades of the same stage to ensure working contact area through the form of double-layer blades when the air volume is small, reduces the number of blades of the first stage to improve the inlet suction condition when the flow is large, prevents the inflow from being influenced by larger displacement coefficient, rotates the auxiliary blades which are axially moved backwards at different rotating speeds which have different rotating speeds along with the length of axial movement, and effectively prevents the fan from generating periodic vortex to cause large-amplitude vibration and even resonance, which is particularly remarkable when the flow is large and is a factor endangering the safety of the fan.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic view of the vane arrangement of the present invention with no relative axial movement between the primary and secondary vanes;

FIG. 3 is a schematic view of the vane arrangement of the present invention with the primary and secondary vanes in axial relative motion;

FIG. 4 is a schematic view of the analysis of the deployment speed of the main and auxiliary vanes of the present invention on a cylindrical surface;

FIG. 5 is a first schematic view of the structure of the speed matching assembly of the present invention;

FIG. 6 is a schematic structural view of a second speed matching assembly of the present invention;

FIG. 7 is a schematic view of the load cell assembly and adjacent components of the present invention.

In the figure: 1-main shaft, 2-main wheel, 21-main shell, 211-wind pressure hole, 212-slide block groove, 22-main blade, 3-auxiliary wheel, 31-auxiliary shell, 311-guide cone, 32-auxiliary blade, 4-speed matching component, 41-middle tooth mounting rack, 411-mounting shaft hole, 42-pressure measuring component, 421-slide block, 422-first spring, 423-second spring, 424-brake block, 43-intermediate gear, 431-brake groove, 441-driven gear, 442-driven seat, 45-resisting spring, 46-sliding ball, 47-sliding cylinder, 471-pressing plate conical surface, 49-thrust bearing and 9-elastic bulge.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-7, the present invention provides the following technical solutions:

a variable speed fan with a pitch adjusting structure comprises a main shaft 1, a main hub 2 and an auxiliary hub 3, wherein the main hub 2 comprises a main shell 21 and main blades 22, the main shell 21 is in constant speed rigid transmission connection with the main shaft 1, for example, key transmission is adopted, a plurality of main blades 22 are uniformly distributed on the outer surface of the main shell 21 by taking the main shaft 1 as an axis circumference, the auxiliary hub 3 comprises an auxiliary shell 31 and auxiliary blades 32, the auxiliary shell 31 is in plug-in connection with the main shell 21 along the direction of the main shaft 1, the auxiliary blades 32 are arranged on the outer surface of the auxiliary shell 31, the auxiliary blades 32 are arranged along the circumferential direction of the main shaft 1, the axial relative position of the auxiliary shell 31 and the main shell 21 is adjusted according to the air volume passing through the fan, and when the air volume is increased, the auxiliary blades 32 and the main blades 22 are far away from each other along the axial direction of the main shaft 1. The displacement coefficient of the fan inlet determined by the number and thickness of the blades is larger, when the flow is larger, the larger displacement coefficient influences the position of new air entering the blades, and under the condition of smaller flow, if the number of the blades is smaller, the total area of the working surface of the blades is too small, and the energy transfer between the blades and the air is influenced, so that when a large flow is generally designed, the inlet displacement coefficient of a fluid machine is selected to be smaller, and when the fluid machine used under the working condition of small flow is designed to have more blades to ensure the work performance, the present application adopts the design of the blades with the axially adjustable distance, under the condition of larger flow, part of the blades are axially moved backwards, the displacement condition of inlet air is improved, so as to introduce more air volume, the mode of changing the blades is that the mounting positions are respectively arranged for the blades, as shown in figures 2 and 3, the working blades are respectively mounted on the auxiliary shell 31 and the main shell 21, when the main shaft 1 runs at a high speed to improve the flow, the sub-shell 31 is moved axially backward and the blades are staggered.

The variable speed fan further comprises a speed distribution assembly 4, the speed distribution assembly 4 is arranged in the main shell 21, the speed distribution assembly 4 is in speed regulation transmission connection with the auxiliary shell 31, when the auxiliary shell 31 and the main shell 21 axially move, the auxiliary shell 31 rotates at a lower rotating speed than the main shell 21, and the farther the axial distance between the auxiliary blade 32 and the main blade 22 is, the larger the difference between the rotating speeds of the auxiliary shell 31 and the main shell 21 is. When the auxiliary blades 32 are axially away from the main blade 22, the action of the auxiliary blades is not parallel but series connection, the auxiliary blades 32 boost the air for the second time, the flow rate is increased, the air outlet pressure and the air speed are also increased, and the power transmitted from the main shaft 1 is greatly increased. The secondary increase cannot be avoided, if no constraint exists, the axial distance of the main blade and the auxiliary blade is adjusted at will, and the rotating speed is not changed, turbulence resonance is easy to occur at a certain distance, namely, a spiral air column sent by the main blade 22 causes vibration on the auxiliary blade 32, if the rotating speed of the auxiliary blade 32 is consistent with that of the main blade 22, resonance is generated, the whole structure of the fan is endangered, the use danger is caused, and the rotating speed difference value of the auxiliary blade 32 and the main blade 22 is changed along with the change of the axial distance, air can be discharged out of the fan in a disorder turbulence mode, and the resonance is avoided although micro vibration occurs.

The speed matching assembly 4 comprises a load cell 42 extending to the outer surface of the main shell 21, the load cell 42 is located at the axial front of the main blade 22, when the pressure measured by the load cell 42 is low, the speed matching assembly 4 is adjusted to drive the sub-shell 31 and the main shell 21 to generate an increased rotation speed difference. The flow change of the fan is identified through a pressure measuring mode, the Bernoulli equation of hydrodynamics can know that the flow of the fan is increased under the condition that the pressure of an air inlet position at the front end of the fan is not changed, the pressure at the inflow position of the blade is reduced, the air pressure is measured by the pressure measuring component 42 arranged in the main shell 21 to know the air inlet flow, the pressure measured by the pressure measuring component 42 can be converted into mechanical force to drive the adjustment of a relevant structure in the speed distribution component 4, so that the auxiliary wheel 3 is adjusted relative to the main wheel 2, and the main blade and the auxiliary blade are adjusted relatively.

The speed matching component 4 further comprises a middle tooth mounting frame 41, a middle gear 43, a driven gear 441, a driven seat 442, a resisting spring 45, a sliding ball 46 and a sliding cylinder 47, wherein the middle tooth mounting frame 41 is fixedly connected to the spindle 1, the middle tooth mounting frame 41 is bent in the axial direction after radially extending from the spindle 1 and is provided with a plurality of mounting shaft holes 411, the middle gear 43 is rotatably mounted in the mounting shaft holes 411 on the bent edge at the tail end of the middle tooth mounting frame 41, the axis of the middle gear 43 is perpendicular to and intersected with the axis of the spindle 1, the driven seat 442 is sleeved on the spindle 1, the driven seat 442 facing one end of the middle tooth mounting frame 41 is provided with the driven gear 441 with the spindle 1 as the axis, the other end of the driven seat 442 is flanged and is provided with the sliding ball 46 capable of radially sliding, the sliding cylinder 47 is sleeved outside the driven seat 442 and synchronously rotates with the driven seat 442, one end of the sliding ball 46 adjacent to the radial inner side of the sliding cylinder 47 is provided with a pressing plate conical surface 471, the pressing plate conical surface presses the sliding ball 46 radially inwards, one end of the sliding cylinder 47, which is far away from the sliding ball 46, is tightly pressed by the abutting spring 45, the radial outer side of the sliding cylinder 47 is fixedly connected with the auxiliary shell 31,

the intermediate gear 43 and the driven gear 441 are both bevel gears and are meshed with each other, the tail end of the rotating shaft of the intermediate gear 43 is in contact with the load cell 42, and when the load cell 42 senses that the external pressure is reduced, the load cell 42 reduces the abutting force on the rotating shaft of the intermediate gear 43, so that the rotation resistance of the intermediate gear 43 is reduced. The structure is a specific speed matching structure, the pressure measuring assembly 42 senses the working condition that the external pressure is reduced and the flow of the fan is increased, at this time, the abutting force at the tail end of the rotating shaft of the intermediate gear 43 is reduced, the rotation resistance of the intermediate gear is reduced, so that the rotating speed difference between the intermediate gear mounting frame 41 and the driven gear 441 is caused, the rotating speed of the intermediate gear mounting frame 41 is kept consistent because the intermediate gear mounting frame is fixedly connected with the main shaft 1, as shown in fig. 5 and 6, the rotating speed of the main shaft is w1, when the rotating speed w3 of the intermediate gear 43 is changed from 0 to non-zero, the rotating speed w2 of the driven gear 441 is different from w1, w2 is less than w1, the rotating speed from the driven gear 441 to the driven seat 442 to the sliding cylinder 47 to the auxiliary shell 31 is in a relatively fixed transmission mode, the rotating speed is considered as a whole when being analyzed, and the main shell 21 is fixed with the main shaft 1, it can be seen that when the rotating speed measuring assembly 42 causes the rotating speed of the intermediate gear 43 to be changed, the main shell 21 and the auxiliary shell 31 can generate the rotating speed difference from w 1-2, further, the reduction in the rotation speed of the driven seat 442 reduces the centrifugal force of the sliding ball 46, and the conical pressing plate 471 moves axially while pressing the sliding ball 46, thereby changing the axial position of the sub-housing 31.

Pressure measuring component 42 includes slider 421, first spring 422, second spring 423 and brake block 424, set up interconnect's wind pressure hole 211 and slider groove 212 on the main casing 21 wall, wind pressure hole 211 presses close to main casing 21 surface, main casing 21 internal surface is pressed close to slider groove 212, the end of intermediate gear 43 pivot sets up brake groove 431, slider 421 is located slider groove 212 and slides along slider groove 212, first spring 422 one end is contradicted on slider 421 surfaces, the other end is contradicted on the ladder face of wind pressure hole 211 and slider groove 212, second spring 423 one end is contradicted on slider 421 surfaces, brake block 424 is connected to the other end, brake block 424 contradicts on brake groove 431. When the external air flow flows through the wind pressure hole 211, the flow rate is increased, the pressure at the wind pressure hole 211 is reduced, the sliding block 421 is pushed outwards by the pressure in the main shell 21, the first spring 422 is compressed, the second spring 423 is released, the friction force of the brake pad 424 against the brake groove 431 is reduced, the self-rotation resistance of the intermediate gear 43 is reduced, the self-rotation is smooth, the rotation speed proportion obtained by the driven gear 411 from the intermediate gear mounting frame 41 is reduced, and the main blade and the auxiliary blade generate the rotation speed difference.

The speed matching assembly 4 further comprises a thrust bearing 49 arranged between the end of the main shaft 1 and the end of the driven seat 442.

The outer surface of the sliding block 421 and the inner surface of the sliding block groove 212 are coated with Teflon coating. The teflon coating has low friction and keeps moving smoothly when the slider 421 makes a piston motion along the slider slot 212.

Elastic protrusions 9 are respectively arranged on the insertion surfaces of the auxiliary shell 31 and the main shell 21. The sliding cylinder 47 is axially limited with the contact end of the sub-housing 31 and is connected with an overrunning clutch in the circumferential direction. As shown in fig. 6, in order to make the axial sliding of the sub-housing 31 and the main housing 21 be threshold and not continuously variable, the sliding force of the sub-housing 31 toward one end must exceed the axial sliding that can be performed by the elastic protrusion 9 on the sub-housing 31 passing the elastic protrusion 9 on the main housing 21. The sliding with threshold value prevents the interference of the main and auxiliary blades, the backward movement tendency of the auxiliary shell 31 must be accumulated to the extent that the auxiliary blade 32 and the main blade 22 are axially staggered, when the structure is not provided, the auxiliary blade collides with the main blade when the abnormal speed is slightly generated, and the main blade 22 pushes the auxiliary blade 32 to rotate circularly after the collision. The sliding cylinder 47 slides axially to generate thrust to the sub-housing 31, and when the sub-blade 32 on the sub-housing 31 is not separated from the main blade 22, the original rotation speed is maintained, and after separation, the sub-housing 31 loses the rotation power, and when the speed is reduced to the rotation speed of the sliding cylinder 47, the sliding cylinder 47 continues to rotate at the rotation speed.

And a diversion cone 311 is arranged at the tail part of the auxiliary shell 31. The air current is stably discharged to the water conservancy diversion awl.

The working principle of the invention is as follows: the main shaft 1 drives the main wheel 2 and the auxiliary wheel 3 to rotate, the main and auxiliary blades start to blow air, when the rotating speed of the main shaft 1 is increased, the rotating speed of the main wheel 2 is increased, the flow of a fan is increased, the surface of the main shell 21 at an air inlet area recognizes that the air pressure is reduced, the sliding block 421 moves outwards under the action of centrifugal force, the resisting force of the brake block 424 in the brake groove 431 at the tail end of the intermediate gear 43 is reduced, the intermediate gear 43 starts to rotate, the revolution speed of the intermediate gear 43 can not be completely converted into the rotating speed of the driven gear 441, but the speed is lower than the original speed, when the rotating speed of the driven seat 442, the sliding cylinder 47 and the sliding ball 46 is reduced, the sliding cylinder 47 moves backwards, the thrust is moved backwards to the auxiliary shell 31, when the thrust is enough, the auxiliary blades 32 and the main blades 22 generate axial relative movement, the displacement coefficient of the inlet blades is reduced, and the flow can be further increased.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.