JPH07107400B2 - Variable blade axial fan - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a variable blade axial flow fan, and more specifically,
The present invention relates to a variable-blade axial-flow fan with an improved variable-blade blade swirl device for the variable-blade axial-flow fan.

(Prior Art) Conventionally, in a variable blade mechanism of a variable blade axial flow fan, for example, a variable blade blade turning device as shown in FIG. 6 has been adopted.

That is, the variable wing blade turning device 101 includes the blade 103.
In order to support (partly not shown), a locking portion 107 is integrally cut out and formed on the hub body 105 side. A blade bracket 109 is fitted in the locking portion 107, and the blade 103 is fixed to the blade bracket 109 with a plurality of tightening bolts 111. A bearing 113 is provided between the blade bracket 109 and the hub body 105, and the blade 103 is rotatably supported.

The counter balance member 115 is provided on the base 117 of the blade 103, and the counter balance member 119 is provided.
A counter balance 123 is fixedly attached by a bolt 121. Reference numeral 125 is a cam floor, which is fixed to the base 117 of the blade 103, and the blade 103 is rotated via the cam floor 125 by an operating mechanism (not shown).

(Problems to be Solved by the Invention) By the way, a conventional variable blade blade swirl device 101 for a variable blade axial fan has a hub body 105 for supporting a blade 103.
Since the locking portion 107 is integrally machined on the side, it is the most difficult in terms of machine work, requires a highly accurate machine tool, and requires complicated processing, which 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 due to the notch effect due to the mounting hole, spot facing, etc. However, there was a limitation in design strength, and there was a problem in strength. In addition, the fastening bolt 11
It is difficult to prevent loosening of item 1, there is a cost increase, doubts about reliability, obstacles during overhaul and inspection, etc.
There was also a problem that the shape of 129 was restricted and the aerodynamic best shape was restricted.

The counter balance member 115 has a problem that it takes time to disassemble and is easily loosened, and subtle readjustment of the counter balance angle cannot be easily and surely performed at an arbitrary angle.

An object of the present invention is to solve the above-mentioned problems, in which a complicated hub side shape necessary for incorporating the blade of the variable blade blade turning device into the hub body is attached as a separate component, and there is a problem in strength and loosening prevention. By abolishing the fastening bolts, fastening with a large-diameter screw, and adopting a wedge member for connecting the counter balance member and the blade, great strength and reliability are improved, and cost is reduced by simplifying the structure. It is to provide a variable blade axial flow fan designed.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention is provided with a plurality of blades (5) mounted at appropriate intervals on the circumference of a hub body (7). A variable-blade axial-flow fan equipped with a swirl device for swirling each of the blades (5),
A bracket retainer (17) made of a light alloy is detachably attached to the hub body (7), and a large diameter screw (11) is formed on the outer peripheral portion of the base portion (9) of the blade (5) and the screw (11). ) On the blade bracket (13)
The blade bracket (13) is attached to the bracket retainer (17) and is rotatably provided to the bracket retainer (17) via a bearing (15), and the base portion of the blade (5) is A wedge member (27) is interposed between the outer circumference of (9) and the lower inner circumference of the blade bracket (13), and the tip of a fixing screw (31) penetrating from below the counter balance portion (19) is A variable blade axial flow fan was constructed by screwing the wedge member (27).

(Operation) By adopting the variable blade axial flow fan of the present invention, the bracket retainer (1) made of a light alloy is attached to the hub body (7).
7) is provided, and the blade bracket (13) is screwed into a large-diameter screw (11) formed on the outer peripheral portion of the base (9) of the blade (5), and the blade bracket (13) and the bracket retainer ( A blade (5) was rotatably provided between the two (17) with a bearing (15) interposed. Therefore, the hub body (7) does not require complicated processing, and the blade (5) is firmly screwed to the blade bracket (13), so loosening is prevented and the strength is improved.

Further, a wedge member (29) is provided between the base portion (9) of the blade (5) and the blade bracket (13), and the wedge member (29) is tightened to firmly fasten the counterbalance member to the blade by the tapered surface. To be done.

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

(Embodiment) An embodiment of the present invention will be described in detail below with reference to the drawings.

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

Referring to FIG. 3 to FIG. 5, a variable blade axial flow fan 1
Has a variable pitch, that is, a blade 5 provided with a variable blade blade swivel device 3 whose pitch can be changed,
Although a plurality of hub bodies 7 are omitted, the hub body 7 is connected to an electric motor or the like.

The configuration of the blade 5 provided with the variable blade blade turning device 3 is such that the screw 9 is provided on the base portion 9 of the blade 5 and the screw 11 is provided.
A blade bracket 13 is screwed on the blade 11. The blade bracket 13 is engaged with a bracket retainer 17 mounted on the hub body 7 side via a thrust bearing 15.

With the above configuration, the blade 5 is provided with the thrust bearing 15
Since it is rotatably provided with respect to the hub body 7, the blade pitch can be adjusted while the hub body 7 is in operation.

As an adjusting mechanism for the blade 5, a counter balance member is provided at the tip of the base 9 of the blade 5 (downward in FIG. 3).
19 and the cam floor member 21 are locked.

That is, the counterbalance member 19 has counterweights 25 fixed to the left and right ends of the counterbalance member 23, and is screwed to a taper ring 29, which is a wedge member 27 mounted between the base portion 9 of the blade 5 and the blade bracket 13. The counterbalance member 19 is fixed to the blade 5 with the fixing screws 31 fitted together.

Further, the cam floor member 21 is the counter balance member.
A cam lever 35, which is provided on the outer side of 19 and rotatably supports a cam floor 33, is mounted on the base portion 9 of the blade 5.

With the above structure, the blade 5 can be rotated via the cam floor 33 by the actuator 37 described later.

The actuator 37 is provided inside the hub body 7, and an actuator ring 39 locked to the hub body 7 and a slide shaft bearing 43 integrally provided on the hub cap 41 make the cam disk 45 move forward and backward (see FIG. 3). It is mounted so that it can move in the left-right direction). The cam floor 33 is fitted around the tip side (right side in FIG. 3) of the cam disc 45, 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 disc 45. Has been done.

A flow path 51 communicating with the air inflow hole of the rotary seal 49 is bored in the shaft center of the cam disk 45.
An air chamber 53 is formed inside the 45. A coil spring 55 is placed between the cam disc 45 and the hub cap 41.
Is mounted to constantly urge the cam disk 45 toward the actuator ring 39.

With the above configuration, the compressed air supplied from the compressed air source (not shown) flows from the rotary seal 49 through the flow path 51 into the air chamber 53. The pressing force of the compressed air flowing into the air chamber 53 moves the cam disk 45 to the left in FIG. 3 against the biasing force of the coil spring 55. Due to the movement of the cam disc 45, the cam floor 33 fitted into the cam disc 45 is rotated, and the blade 5 is rotated via the cam lever 35.
The pitch of the blades 5 can be freely changed during operation.

Although compressed air is used as the operation source in this embodiment, hydraulic pressure may be used or mechanical operation may be performed by an electric motor or the like.

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

Referring to FIG. 1 and FIG. 2, the bracket retainer 17 is fixed to the hub body 7 with a plurality of fastening bolts 57, and the blade bracket is attached to the screw 11 provided on the base portion 9 of the blade 5.
A thrust bearing 15 is mounted between the blade bracket 13 and the bracket retainer 17 by screwing 13 together. A locking portion 59 having a complicated stepped shape is formed on the surface of the bracket retainer 17 in contact with the plate 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 to the hub body 7 as a separate component,
Locking part by shaving from the hub body 7 as in the past
Unlike the case where 59 was formed, they were combined by separate members.
Therefore, the hub body 7 can be simply and cylindrically machined without precision, and the number of parts is increased by the division, but the hub body 7 can be manufactured at low cost.

Further, the blade bracket 13 and the blade base 9 are connected by a large-diameter screw 11, which has the effects of improving strength and preventing loosening, and can greatly improve reliability. Further, as compared with the conventional case, since the blade root portion 61 has no fastening bolts, the strength does not decrease due to the notch, and the shape of the blade root portion 61 is not restricted, so that the performance can be improved.

A wedge member 27 is provided to prevent the blade bracket 13 screwed onto the base portion 9 of the blade 5 from loosening. That is, a taper ring 29, which is a wedge member 27, is engaged with the base portion 9 of the blade 5, and the taper ring 29 is screwed by a plurality of fixing screws 31 penetrating the counter balance member 23 of the counter balance member 19. There is. 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 the taper surface 63 exerts a wedge effect, so that the blade bracket 13 can be fixed to the blade 5 via the counter balance member 23. The fixing screw
When you loosen 31, taper ring 29 and blade bracket 13
A gap is formed in the taper surface 63 between them, and the tightened state can be released.

For this reason, the structure is simple and highly reliable, and the subtle adjustment of the counter balance angle can be easily performed at any angle.
It is possible to flexibly respond to changes in the control method at the installation site.

Lower side of the counter balance member 19 (lower side in FIG. 1)
A cam floor member 21 is attached to the. That is,
A cam lever 35 that rotatably supports the cam floor 33 is fastened to the tip of the base portion 9 of the blade 5 by a bolt or the like.

With the above configuration, the cam floor member 21 is moved from the cam floor 33 to the cam lever 35 by the operation of the actuator 37 described above.
The blade angle can be freely changed during the pitch operation by rotating the blade 5 via.

As described above, the conventional retainer is stopped and the bracket retainer 17 is provided, so the number of parts increases, but
It is the most difficult and high precision machine tool in machining and the hub body processing that requires skill is simple and does not require precision, and it is possible to manufacture inexpensively and efficiently. Further, the bracket retainer 17, which is a separate component, can be processed at a low price by a general-purpose automatic lathe or the like, and since it is possible to easily obtain higher precision than necessary, it is possible to improve reliability and reduce the number of assembling steps.

By manufacturing the bracket retainer 17 with a light alloy, since the light alloy has flexibility, the natural frequency can be reduced, shock waves can be absorbed, and the wear of the thrust bearing 15 can be reduced. The life of the bearing 15 can be significantly extended. Further, since the light alloy is a soft material, the bearing 15 is brought into a uniform and highly flat contact state, and a very stable mounted state can be obtained. Therefore, the reliability of the bearing 15 can be significantly improved.

By providing the bracket retainer 17 made of a light alloy, it contributes to a great reduction in weight and a great reduction in the load on the main shaft and the bearing of the impeller drive unit. Especially, since the bracket retainer 17 made of a light alloy is located on the outer peripheral portion of the hub body 7 and the number of blade retainers is the same as the number of the blades 5, the reduction of the flywheel effect due to the weight reduction is a great advantage. This significantly reduces the load on the drive system.

In addition, the blade mounting portion of the hub body was thick due to the hub structure, and the occurrence of shrinkage cavities in casting was high, leading to a decrease in yield.However, by providing the light alloy bracket retainer 17, the required casting At the same time as the skin conditions are alleviated, the thickness can be reduced by evenly distributing the load, and the yield can be significantly improved.

Further, the hub body is made of cast steel or the like which is relatively corrosive. Further, the bearing for swiveling the blade is located at the blade mounting portion of the hub main body opening, and is easily affected by corrosion of the hub opening due to external influences, and special consideration such as sealing and anticorrosive material was required. However, by separating the bearing mounting portion from the hub body and protecting it by the bracket retainer 17 made of a light alloy having high corrosion resistance, the corrosion resistance of the bearing 15 is improved, and it is possible to operate in a more severe environment.

Further, the mounting structure of the blade 5 is simplified by using the screw 11, so that reliability and cost reduction can be obtained, and the shape of the blade root 61 is not restricted as compared with the conventional bolt assembly, and the best aerodynamic shape can be obtained. It can be designed and performance can be improved.

Further, as the loosening prevention of the blade bracket 13 and the blade 5, a strong wedge effect is exerted by the counterbalance member 23 and the tapered surface 63 of the taper ring 29 which is the wedge member 27 so that the blade can be securely fixed. . Also,
The wedge member 27 also serves to mount and fix the counter balance member 19, so that the subtle adjustment of the counter balance angle can be easily and surely made at an arbitrary angle, and it is possible to flexibly respond to a change in the control method at the installation site. It will be possible.

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

[Effects of the Invention] As can be understood from the above description of the embodiments, according to the present invention, the hub body (7) is made of a light alloy because it has the structure as described in the claims. By installing the bracket retainer (17) detachably,
The hub body (7) can be manufactured at low cost by simple and cylindrical hole processing that does not require precision.

In addition, since the bracket retainer (17) is made of a light alloy, the light alloy has flexibility, so that the natural frequency can be reduced, the shock wave can be absorbed, and the bearing (1
The wear of 5) is reduced and the life of the bearing (15) can be significantly extended. Also, since light alloys are soft materials,
The bearing (15) is in a uniform and highly flat contact state, and a very stable mounting state can be obtained. Therefore,
The reliability of the bearing (15) can be significantly improved.

By providing the bracket retainer 17 made of a light alloy, it contributes to a great reduction in weight and a great reduction in the load on the main shaft and the bearing of the impeller drive unit. Especially, since the bracket retainer 17 made of a light alloy is located on the outer peripheral portion of the hub body 7 and the number of blade retainers is the same as the number of the blades 5, the reduction of the flywheel effect due to the weight reduction is a great advantage. This significantly reduces the load on the drive system.

Further, the blade mounting portion of the hub body was thick due to the hub structure, the occurrence of shrinkage cavities on the casting was high, and the yield was lowered.However, by providing the light alloy bracket retainer 17, the required casting At the same time as the skin conditions are alleviated, the thickness can be reduced by evenly distributing the load, and the yield can be significantly improved.

Further, the hub body is made of cast steel or the like which is relatively corrosive. Further, the bearing for swiveling the blade is located at the blade mounting portion of the hub main body opening, and is easily affected by corrosion of the hub opening due to external influences, and special consideration such as sealing and anticorrosive material was required. However, by separating the bearing mounting portion from the hub body and protecting it by the bracket retainer 17 made of a light alloy having high corrosion resistance, the corrosion resistance of the bearing 15 is improved, and it is possible to operate in a more severe environment.

Further, a large diameter screw (11) is formed on the outer peripheral portion of the base portion (9) of the blade 5, and a blade bracket (13) is screwed onto the screw (11), and the blade bracket (13) is attached to the bracket retainer. The blade (5) can be attached to the bracket retainer (17) via the bearing (15) so that the blade (5) can be attached to the bracket retainer (17) with a large diameter screw (11). ), The reliability of strength can be improved. Moreover, the shape of the root portion of the blade (5) is not restricted as compared with the conventional bolt assembly, and the best aerodynamic shape can be designed and the performance can be improved.

Further, the blade (5) and the blade bracket (13) are fixed via the wedge member (27) for fixing the counter balance member (19) to the blade (5).
It can be securely and easily fixed, exerts a locking effect, and in addition, the counterbalance member (19) can be assembled at an arbitrary angle and repeated readjustment can be performed.

[Brief description of drawings]

1 and 2 show a main part according to the present invention. FIG. 1 is an enlarged view of an I arrow part in FIG. 4, and FIG.
FIG. 3 is a plan view, FIG. 3 to FIG. 5 show a variable blade axial flow fan of one embodiment for carrying out the present invention, FIG. 3 is a sectional view, and FIG. 4 includes a partial sectional view in FIG. FIG. 5 is a front view, FIG. 5 is a view on arrow V in FIG. 4, and FIG. 6 is a cross-sectional view of a conventional variable blade blade turning device. 1 …… Variable blade axial fan 3 …… Variable blade blade swivel device 5 …… Blade, 7 …… Hub body 9 …… Base 13 …… Blade bracket 15 …… Thrust bearing 17 …… Bracket retainer 19 …… Counter balance Member 27 ... Wedge member

Claims (1)

[Claims] 1. A variable blade axial flow comprising a plurality of blades (5) mounted at appropriate intervals on the circumference of a hub body (7), and equipped with a swirling device for swiveling each blade (5). In the fan, a bracket retainer (17) made of a light alloy is detachably provided on the hub body (7), and a large diameter screw (11) is formed on an outer peripheral portion of a base portion (9) of the blade (5). At the same time, a blade bracket (13) is screwed onto the screw (11), the blade bracket (13) is attached to the bracket retainer (17), and a bearing (15) is attached to the bracket retainer (17).
Rotatably provided via a wedge member (27) between the outer periphery of the base portion (9) of the blade (5) and the inner periphery of the lower portion of the blade bracket (13), and the counter balance portion ( A variable-blade axial-flow fan, characterized in that a tip of a fixing screw (31) penetrating from below of 19) is screwed into the wedge member (27).