JP2812633B2 - Variable blade axial flow fan - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable blade axial flow fan, and more particularly to a variable blade axial flow fan in which a variable blade rotating device of the variable blade axial flow fan is improved.

[0002]

2. Description of the Related Art Conventionally, in a variable blade mechanism of a variable blade axial flow fan, for example, a variable blade rotating device as shown in FIG. 6 is employed.

That is, the variable wing blade turning device 101
To support the blade 103 (partially omitted)
The locking portion 107 is integrally formed on the hub body 105 side by being cut out. A blade bracket 109 is fitted to the locking portion 107, and the blade 103 is fixed to the blade bracket 109 by a plurality of tightening bolts 111. The blade bracket 109
A bearing 113 is provided between the hub and the hub body 105, and the blade 103 is rotatably supported.

A counterbalance member 115 is provided on a base 117 of the blade 103, and a counterbalance 123 is fixed to a counterbalance member 119 by bolts 121. Reference numeral 125 denotes a cam floor, which is the base 1 of the blade 103.
17 and is actuated by an unillustrated operating mechanism.
5, the blade 103 is rotated.

[0005]

The conventional variable blade rotating device 101 of the variable blade axial flow fan has a locking portion 1 on the hub body 105 side for supporting the blade 103.
07 is integrally machined, which requires the most difficult and high-precision machine tools and complicated machining requiring skill and is expensive.

Further, the blade 103 is fixed to the blade bracket 109 by a plurality of tightening bolts 111, but the stress of the blade seating surface 127 of the bolt fastening portion is high, and the blade 103 is cut by a mounting hole, a counterbore process or the like. Due to the chipping effect, there is a limitation in design strength, and there is a problem in strength. Further, it is difficult to prevent the fastening bolt 111 from loosening,
There is a cost increase, a question of reliability, an obstacle at the time of disassembly and inspection, etc., and there are restrictions on the shape of the blade root portion 129 due to processing and strength problems of mounting the fastening bolt 111, and the aerodynamic best shape is limited. There was also a problem.

[0007] Regarding the counter balance member 115,
It takes time to disassemble, and it is easy to loosen, and it is easy to fine-tune the counter balance angle at any angle,
There was a problem that it could not be performed reliably.

[0008] An object of the present invention is to solve the above-mentioned problem by mounting a complicated hub-side shape necessary for assembling the blade of the variable wing blade turning device into the hub body as a separate part,
We abolished fastening bolt which had problem with strength, locking,
It is an object of the present invention to provide a variable blade axial flow fan which is fastened with a large diameter screw to achieve a large strength and reliability and to reduce the cost by simplifying the structure.

[0009]

In order to achieve the above object, a variable blade axial flow fan according to the present invention has a plurality of blades (5) mounted at appropriate intervals around the circumference of a hub body (7). A variable blade axial flow fan provided with a turning device for turning each of the blades (5), wherein the hub body (7) is made of a light alloy and has a flange portion (17F) at a lower portion. A hollow cylindrical bracket retainer (17) is detachably provided, and a flange (9F) formed at a lower portion of the blade (5) is provided at a lower portion of a base portion (9) having a smaller diameter than the flange portion (9F). A large-diameter screw (11) is formed and the screw (11) is formed.
Then, the inner peripheral surface of a hollow cylindrical blade bracket (13) having a flange portion (13F) at the bottom is screwed together,
The outer peripheral surface of the blade bracket (13) is mounted on the inner peripheral surface of the bracket retainer (17) and the flange portion (17F) of the bracket retainer (17).
Between the lower surface of the blade bracket (13) and the upper surface of the flange portion (13F) of the blade bracket (13) via a bearing (15).
The base (9) protruding inward from the lower surface in 3F)
The cam floor member (21) is locked to the lowermost end (9A) of the above.

[0010]

By using the variable blade axial flow fan of the present invention, a hollow cylindrical bracket retainer (17) made of a light alloy for the hub body (7) and provided with a flange portion (17F) at the bottom can be attached and detached. Provided. A large-diameter screw (11) is formed on the outer periphery of the base (9) having a smaller diameter than the flange (9F) below the upper flange (9F) formed below the blade (5). The inner peripheral surface of the hollow cylindrical blade bracket (13) having the flange portion (13F) was screwed together.

As a result, since the base (9) of the blade (5) is firmly connected to the blade bracket (13), loosening is prevented and strength is improved.

Since the bearing (15) is rotatably provided between the lower surface of the flange portion (17F) of the bracket retainer (17) and the upper surface of the flange portion (13F) of the blade bracket (13), the hub body. The impact force generated in (7) is transmitted from the light alloy to the bearing (15) via the bracket retainer (17). Therefore, a force such as an impact is absorbed by the soft material of the light alloy, which is the bracket retainer (17), and the bearing (15) is protected.
5) Used for a long time. Further, the hub body (7) does not require complicated processing.

Thus, the cost and the strength can be greatly improved, the reliability can be improved, and the cost can be reduced by simplifying the structure.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

To facilitate understanding, the overall configuration of the variable blade axial flow fan will first be schematically described.

Referring to FIGS. 3 to 5, the variable blade axial flow fan 1 includes a blade 5 provided with a variable pitch, that is, a variable blade rotating device 3 capable of changing the pitch, which is radially arranged on the outer periphery of a hub body 7. The hub body 7 is connected to an electric motor or the like, although not shown.

The blade 5 provided with the variable wing blade rotating device 3 has a screw 11 provided on a base 9 of the blade 5 and a blade bracket 13 screwed to the screw 11. The blade bracket 13 is provided with a bracket retainer 17 mounted on the hub body 7 via a thrust bearing 15.
Is engaged.

According to the above configuration, since the blade 5 is provided rotatably with respect to the hub body 7 via the thrust bearing 15, the blade pitch can be adjusted during the operation of the hub body 7.

As an adjusting mechanism of the blade 5, as shown in FIG.
A counterbalance member 19 and a cam floor member 21 are locked to the lowermost end 9A (downward in FIG. 3), which is the tip of the base 9 of the blade 5 protruding inward from the lower surface of the third flange 13F.

That is, the counter balance member 19 is
Counter weights 25 are fixed to the left and right ends of the counter balance member 23, and are fixed by a fixing screw 31 screwed to a taper ring 29 which is a wedge member 27 mounted between the base 9 of the blade 5 and the blade bracket 13. The balance member 19 is fixed to the blade 5.

The cam floor member 21 is provided outside the counter balance member 19 and has a cam floor 33.
Is mounted on the base 9 of the blade 5.

With the above configuration, the blade 5 is rotatable via the cam floor 33 by the actuator 37 described later.

The actuator 37 is provided inside the hub body 7, and the cam disk 45 is moved in the front-rear direction (by an actuator ring 39 locked to the hub body 7 and a slide shaft bearing 43 integrally provided on the hub cap 41). 3 (in the left-right direction in FIG. 3). On the outer periphery of the tip side (right side in FIG. 3) of the cam disc 45,
The cam floor 33 is fitted and inserted, and a rotary seal 49 is attached to the tip of a slide shaft 47 integrally provided on the rear end side of the cam disk 45.

A passage 51 communicating with the air inlet hole of the rotary seal 49 is formed in the shaft of the cam disk 45, and an air chamber 53 is formed inside the cam disk 45. A coil spring 55 is mounted between the cam disc 45 and the hub cap 41, and constantly urges the cam disc 45 toward the actuator ring 39.

With the above configuration, compressed air supplied from a compressed air source (not shown) is supplied from the rotary seal 49 to the flow path 51.
And flows into the air chamber 53. The cam disc 45 is moved leftward in FIG. 3 against the urging force of the coil spring 55 by the pressing force of the compressed air flowing into the air chamber 53. The movement of the cam disk 45 causes the cam disk 4
5, the cam floor 33 is rotated, and the cam lever 35 is rotated.
The blade 5 can be rotated through the shaft to freely change the pitch of the blade 5 during operation.

In this embodiment, compressed air is used as the operating source. However, it is also possible to use hydraulic pressure to mechanically operate with an electric motor or the like.

The variable blade mounting structure of the variable blade rotating device 3 will be described in more detail.

Referring to FIGS. 1 and 2, the hub body 7
Is formed with a mounting hole 7H.
H, a hollow cylindrical bracket retainer 17 having a flange portion 17F at a lower portion is mounted from below,
The upper surface of the flange portion 17F is the inner peripheral surface 7A of the hub body 7.
Is fixed in a detachable manner with a plurality of fastening bolts 57 in a state of contact with the
A hollow cylindrical blade bracket 13 provided with a flange portion 13F at a lower portion thereof is screwed into a screw 11 provided on the outer peripheral portion of the base portion 9 having a diameter smaller than that of the flange portion 9F at a lower portion of the flange portion F. A thrust bearing 15 is mounted between the upper surface of the bracket retainer 17 and the lower surface of the flange portion 17F of the bracket retainer 17. A complicated stepped locking portion 59 is formed on the surface of the bracket retainer 17 in contact with the blade bracket 13.

With the above configuration, the blade 5 is rotatable with respect to the hub body 7 via the thrust bearing 15. Then, the bracket retainer 17 is locked as a separate component to the hub body 7, and unlike the conventional case where the locking portion 107 is formed by cutting from the hub body 7, the bracket retainer 17 and the blade bracket 13 are separated. If it is assembled accurately, the mounting of the bracket retainer 17 to the hub body 7 may be simply fixed with the fastening bolt 57. For this reason, the processing of the mounting hole 7H of the hub main body 7 is simple and requires no cylindrical hole processing, and the division increases the number of parts, but can be manufactured at low cost.

The connection between the blade bracket 13 and the blade base 9 is made by a large-diameter screw 11, which has the effect of improving strength and preventing loosening, and can greatly improve the reliability. . Further, since there is no fastening bolt in the blade root portion 61 as compared with the related art, there is no reduction in strength due to the notch, and there is no restriction on the shape of the blade root portion 61, so that performance can be improved.

The flange portion 17F provided at the lower portion of the bracket retainer 17 has a mounting hole 7H formed in the hub body 7.
It has a larger diameter and the blade bracket 13
The flange portion 13F provided at the lower part of the hole has a larger diameter than the mounting hole 7H.

A wedge member 27 is provided to prevent the blade bracket 13 screwed to the base 9 of the blade 5 from loosening. That is, the wedge member 2 is attached to the base 9 of the blade 5.
7 is engaged, and this taper ring 29 is screwed together with a plurality of fixing screws 31 penetrating the counterbalance member 23 of the counterbalance member 19. Further, counter weights 25 are fixed to both ends of the counter balance member 23.

With the above configuration, when the fixing screw 31 is tightened, the taper ring 29 moves and exerts a wedge effect by the tapered surface 63, so that the blade bracket 13 is fixed to the blade 5 via the counter balance member 23. it can. When the fixing screw 31 is loosened, a gap is formed in the tapered surface 63 between the tapered ring 29 and the blade bracket 13, and the fastening state can be released.

For this reason, the reliability is high with a simple structure, fine adjustment of the counterbalance angle can be easily performed at an arbitrary angle, and it is possible to flexibly cope with a change in the control method at the installation site. .

A cam floor member 21 is mounted below the counter balance member 19 (the lower side in FIG. 1). That is, the cam lever 35 that rotatably supports the cam floor 33 is fastened by bolts or the like to the lowermost end 9A, which is the tip of the base 9 of the blade 5 that protrudes inward from the lower surface of the flange portion 13F of the blade bracket 13. . As a result, the position of the cam floor 33 with respect to the angle of the blade 5 can be arbitrarily finely adjusted easily and easily.

With the above configuration, the cam floor member 21 is moved by the operation of the actuator 37 described above.
3, the blade 5 can be rotated via the cam lever 35, and the blade angle can be freely changed during operation.

As described above, since conventional bracketing is stopped and the bracket retainer 17 provided with the flange portion 17F is provided at the lower portion, the number of parts increases, but the machine tool is the most difficult and high-precision machine tool. In addition, the processing of the hub body, which requires skill, is simple and does not require precision, so that inexpensive and efficient manufacturing is possible. Further, the bracket retainer 17 as a separate component can be machined at a low price with a general-purpose automatic lathe or the like, and higher accuracy than necessary can be easily obtained, so that reliability can be improved and the number of assembly steps can be reduced.

When a shock wave (load) such as centrifugal force acts on the blade 5, the load of the bracket retainer 17 is received by the inner peripheral surface 7 A of the hub body 7 from the blade bracket 13 and the bearing 15. Since the light alloy has flexibility by being made of a light alloy, the flange portion 17F of the bracket retainer 17 is provided.
As a result, the effects of lowering the natural frequency, absorbing shock waves, and the like are obtained, the wear of the thrust bearing 15 is reduced, and the life of the bearing 15 can be greatly extended. Further, since the light alloy is a soft material, the bearing 15 is in a uniform and highly flat contact state, so that a very stable mounting state can be obtained. Thus, the reliability of the bearing 15 can be greatly improved.

The provision of the bracket retainer 17 made of a light alloy contributes to a significant reduction in weight, and greatly reduces the load on the main shaft and the bearing 15 of the impeller drive unit. In particular, since the portion of the bracket retainer 17 made of light alloy is located on the outer peripheral portion of the hub body 7 and the number thereof is as many as the number of the blades 5, the reduction of the flywheel effect accompanying the weight reduction is a very great advantage. This significantly reduces the load on the drive system.

The blade mounting portion of the hub body 7 is
The hub structure became thicker, and shrinkage cavities were higher on casting and the yield was reduced.However, the provision of the light alloy bracket retainer 17 eased the required casting surface conditions, The wall thickness can be reduced by the uniform distribution of the load, and the yield can be greatly improved.

The hub body 7 is made of cast steel or the like which is relatively easily corroded. In addition, the bearing for turning the blade is located at the blade mounting portion of the opening of the hub main body, is easily affected by corrosion of the hub opening due to external influences, and special considerations such as seals, rust preventive materials, etc. were required. However, the mounting portion of the bearing 15 is separated from the hub body 7 and protected by a bracket retainer 17 made of a light corrosion-resistant light alloy.
Has improved corrosion resistance and can be operated in a harsher environment.

Also, the mounting structure of the blade 5 is simplified by the screw 11 and the reliability and cost can be reduced. The shape of the blade root 61 is not restricted as compared with the conventional bolt assembly, and the aerodynamic It can be designed in the best shape, and the performance can be improved.

The counterbalance member 23 is used to prevent the blade bracket 13 and the blade 5 from loosening.
And the tapered surface 63 of the tapered ring 29, which is the wedge member 27, exerts a strong wedge effect and can be fixed, so that secure locking can be obtained. In addition, the wedge member 27 also serves to fix the counterbalance member 19, so that fine adjustment of the counterbalance angle can be easily and reliably performed at an arbitrary angle, and flexibly responds to changes in the control method at the installation site. It becomes possible.

The present invention is not limited to the above-described embodiment, but can be embodied in other modes by making appropriate changes.

[0045]

As will be understood from the above description of the embodiments, according to the present invention, since the hub body (7) is made of a light alloy, the hub body (7) is constructed as described in the claims. At the same time, a hollow cylindrical bracket retainer (17) having a flange portion (17F) at the bottom is detachably provided. A large-diameter screw (11) is provided on the outer periphery of the base (9) having a smaller diameter than the flange (9F) below the flange (9F) formed below the blade (5).
And an inner peripheral surface of a hollow cylindrical blade bracket (13) having a flange portion (13F) at a lower portion was screwed together.

As a result, since the base (9) of the blade (5) is firmly connected to the blade bracket (13), loosening can be prevented and strength can be improved.

By manufacturing the bracket retainer (17) provided with the flange portion (17F) at the lower portion with a light alloy, the light alloy has flexibility. And the bearing (1
5) is not directly attached to the hub body (7), but the bearing (1) is provided between the lower surface of the bracket retainer (7) and the upper surface of the blade bracket (13) via the bracket retainer (17).
By providing 5), the wear of the bearing (15) is reduced, and the life of the bearing (15) can be greatly extended.
Further, since the light alloy is a soft material, the bearing (15) is in a uniform and highly flat adhered state, and a very stable mounting state can be obtained. Thus, the bearing (15)
Can be significantly improved.

The provision of the bracket retainer (17) made of a light alloy contributes to a significant reduction in weight and a great reduction in the load on the main shaft and the bearing of the impeller drive unit. In particular, the portion of the bracket retainer (17) made of light alloy is located on the outer peripheral portion of the hub body (7) and the number thereof is the same as that of the blade (5). This is a very great advantage, and greatly reduces the load on the drive system.

Further, the blade mounting portion of the hub body (5) is thick in the hub structure, and shrinkage cavities on the casting are high, and the yield is lowered. However, the bracket retainer (17) made of a light alloy is used. With the provision, the required conditions of the casting surface are alleviated, and at the same time, the thickness can be reduced by the uniform distribution of the load, and the yield can be greatly improved.

The hub body (7) is made of cast steel or the like which is relatively easily corroded. In addition, the bearing for turning the blade is located at the blade mounting portion of the opening of the hub main body, is easily affected by corrosion of the hub opening due to external influences, and special considerations such as seals, rust preventive materials, etc. were required. But the bearing (1
The mounting portion of (5) is separated from the hub body (7) via the bracket retainer (17), and is protected by the bracket retainer 17 of a light corrosion-resistant light alloy.
5) The corrosion resistance is improved, and operation in a more severe environment is possible.

A large-diameter screw (11) is formed on the outer periphery of the base (9) of the blade (5), and a blade bracket (13) is screwed onto the screw (11). ) Is mounted on the bracket retainer (17), and the bearing (15) is rotated between the lower surface of the flange portion (17F) of the bracket retainer (17) and the upper surface of the flange portion (13F) of the blade bracket (13). Since the blade (5) is freely mounted, the blade (5) is firmly assembled with the large-diameter screw (11) having a sufficient strength margin, so that the reliability in strength can be improved. In addition, the shape of the root portion of the blade (5) is not restricted as compared with the conventional bolt assembly, and the blade (5) can be designed to have the best aerodynamic shape, and the performance can be improved.

Since the cam floor member (21) is locked to the lowermost end (9A) of the base (9) of the blade (5), fine adjustment of the cam floor member (21) can be easily performed.

[Brief description of the drawings]

FIG. 1 shows a main part according to the present invention, and FIG. 1 is an enlarged view of a part viewed from an arrow I in FIG.

FIG. 2 is a plan view of FIG.

FIG. 3 is a sectional view in FIG.

FIG. 4 is a front view showing a variable blade axial flow fan according to an embodiment of the present invention, including a partial cross section in FIG. 3;

FIG. 5 is a view as seen from the arrow V in FIG. 4;

FIG. 6 is a sectional view of a conventional variable wing blade turning device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 variable blade axial flow fan 3 variable blade blade turning device 5 blade 7 hub body 7H mounting hole 7A inner peripheral surface 9 base 9F upper flange portion 13 blade bracket 13F flange portion 15 thrust bearing 17 bracket retainer 17F flange portion 19 counterbalance member

Claims (1)

(57) [Claims] 1. A variable blade axial flow comprising a plurality of blades (5) mounted on a circumference of a hub body (7) at appropriate intervals and provided with a swirler for rotating each of the blades (5). A hollow cylindrical bracket retainer (17) made of a light alloy and provided with a flange portion (17F) at a lower portion of the hub body (7); A large-diameter screw (11) is formed on the outer peripheral portion of the base portion (9) smaller in diameter than the flange portion (9F) below the flange portion (9F) formed at the same time. The inner peripheral surface of the hollow cylindrical blade bracket (13) provided with (13F) is screwed together, and the outer peripheral surface of the blade bracket (13) is fixed to the bracket retainer (17).
Of the bracket retainer (17) and a rotation between the lower surface of the flange portion (17F) of the bracket retainer (17) and the upper surface of the flange portion (13F) of the blade bracket (13) via a bearing (15). The lowermost end (9A) of the base (9), which is freely provided and protrudes inward from the lower surface of the flange (13F) of the blade bracket (13).
A variable blade axial flow fan characterized in that a cam floor member (21) is engaged with the fan.