JPS5820995A - Axial-flow fan - Google Patents

Abstract

PURPOSE:To prevent acting of a force to a threaded part or other component parts of an axial-flow fan and to protect the same against damages, by forming slits in an inner and an outer sleeves to have a slit section extending in parallel with a shaft at the position thereof near the stroke end, and thereby absorbing the moment acted to rotor blades during operation of the fan at said slit section parallel to the shaft. CONSTITUTION:Slits 17, 18 intersecting to each other are formed respectively in sleeves 11, 12 arranged in a double-cylinder form, and a guide pin 19 is inserted into these slits 17, 18. By reciprocating the guide pin 19 in the direction of a shaft 14, the inner and the outer sleeves 11, 12 are moved relatively and this relative motion of the sleeves 11, 12 is converted into a motion for changing the pitch of rotor blades 1. During operation of an axial-flow fan, a moment M is acted to the rotor blades 1 by the centrifugal force and it is transmitted to the inner sleeve 12 via bevel gears 9, 23. However, since the force is supported by the guide pin 19 between the slits 18 and 17 of the inner and outer sleeves and the guide pin 19 itself is held between a parallel slit section 24 and the slit 17 of the outer sleeve 11 parallel to the shaft 14, no axial component of force is produced. Thus, since no reaction force is acted to the threaded shaft 14 during operation of the fan, it can be protected against damages and wear.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides for the purpose of reversing the wind direction, etc.
The present invention relates to an axial blower equipped with a rotor blade pitch changing mechanism that simultaneously changes the mounting angle of the rotor blades when the rotor blades are stopped.

For axial flow blowers whose discharge direction can be switched between forward and reverse, the operation of the blower is temporarily stopped and the installation angle of the rotor blades is manually changed by 90 degrees or 180 degrees, and the discharge is continued while rotating in the forward direction or reversed. Switching direction. As a pitch changing mechanism that changes the mounting angle of the rotor blade.

Conventionally, the pitch of the rotor blades was changed by rotating a threaded rod on the rotation axis of the blower and transmitting the axial reciprocating motion of a nut fitted to the threaded rod to the axis of the rotor blades using a link mechanism. .

However, in such a conventional method, when the rotor blade is operated after setting the mounting angle, centrifugal force causes the direction of the rotor blade to change around the axis 2 of the rotor blade 1, as shown in Part 1. Moment that acts in a direction perpendicular to airflow 3)
M acts. 4 is the rotation direction. This moment) M
is applied to the threaded rod and nut via the link. Therefore, thrust is applied to the threaded portion during operation, which tends to cause damage and wear to the threaded portion.

The present invention provides a double cylinder with mutually intersecting slits.
By reciprocating the guide bin passing through both slits in the axial direction, a relative rotational movement is caused between the inner and outer cylinders, and the relative rotational movement is converted into a pitch changing movement of the rotor blades. By providing a slit section parallel to the axis near the stroke end.

Except for the above-mentioned drawbacks of conventional books, during operation, the moment of the rotor blades is taken by the parallel slits, and no force is applied to the axial movement mechanism (screws, etc.) of the guide bin, preventing damage and wear. The purpose of the present invention is to provide an axial flow blower that can perform the following steps.

The present invention will be explained with reference to the drawings based on examples.

In FIG. 2, the launch hub 6 is attached to the main shaft ``5'' and is rotatable around the shaft 2.A bevel gear 9 is provided at the end of the shaft 8 on the opposite side from the rotor blade 1. .

A bonnet 10 is provided on the front surface of the second inner hub 6, and an outer cylinder 11 is fixed thereto. Inside the outer cylinder 11, there is an inner cylinder 12.
is fitted so that the blower can rotate about the central shaft 13. A screw shaft 14 is rotatably held within the inner cylinder 12, and is rotated via a clutch 15 to cause the slide piece 16 to reciprocate in the axial direction.

As shown in FIGS. 4 and 5, the outer tube 11 and the inner tube 12 are provided with an outer tube slit 17 and an inner tube slit 1B which intersect with each other. 19 is a guide bin, which is attached to the slide piece 16 as shown in FIG.
Two rollers 20 and 21 are rotatably fitted around one circumference in the radial direction, and pass through the inner slit 18 and the outer slit 17. Gaitobi 1-19
Although the relative sliding speed between the inner cylinder slit 18 and the outer cylinder slit 5-17 differs at the inclined part.

There is no problem since the two rows 220 and 21 move independently.

7 langes 22 at the end of the inner cylinder 12.

A bevel gear 23 that meshes with the bevel gear 9 is attached.

The outer circumferential slit 17 is parallel to the axis over its entire length,
The inner cylinder slit 18 forms parallel slit portions 24 and 25 parallel to the axis near the stroke ends at both ends. Outer cylinder slit 17. A plurality of inner cylinder slits 18 may be provided.

The bevel gears 23 and 9 constitute a conversion mechanism that converts the relative rotational motion between the inner and outer tubes 12 and the outer cylinder 11 into a pitch changing motion of the rotor blades 1.

To explain the operation, for example, in the operating state 1, the runner hub 60 is in a position as shown by the solid line in FIG. 9, and the runner hub 60 rotation direction is 4.

The airflow is 3. At this time, the positions of the inner tube slit 18 degrees, the outer tube slit 178 and the guide pin 19 are as follows.

Assume that the guide bin 19 is at the rear stroke end as shown in FIG. When blowing air in this state is finished and the direction of the airflow is to be reversed, first the blower is stopped, and the slide piece 16 is moved by rotating the clutch 15 by power or human power.

The guide bin 19 is moved to the opposite stroke end to the position 19'. At this time, the outer cylinder slit 17
The inner cylinder slit 18 rotates by an angle θ, and the rotor blade 1 rotates 180 degrees via the bevel gear 23.9.
It will be in position 1. If the runner hub 6 is then reversely rotated in the direction of rotation 4', the airflow will flow in the opposite direction, in the direction of 5'.

During this blower operation, a moment M is generated in the rotor blade 1 due to centrifugal force, and the bevel gear? , 23 to the inner tube 12, but is supported between the inner slit 18 and the outer tube slit 17 by the shearing force of the guide bin 19'. At this time, the guide bin 19' is connected to the parallel slit portion 24. Since it is sandwiched between the outer peripheral slit 17 and K parallel to the shaft, no component force in the axial direction is generated, and therefore the screw shaft 14 does not share any reaction force during operation, resulting in damage to the screw.

No problems such as wear will occur.

Furthermore, if you want to return the airflow direction to the original.

The blower is stopped once, and the screw shaft 14 is reversed to position the slide piece 16 at the opposite stroke end. At this time, the inner cylinder 12 is rotated by the action of the guide pin 19 and returns to the state shown in FIG. 4.

Thereafter, when the two-inner hub 6 is rotated forward in the rotational direction 4, the airflow flows in the direction 6. At this time, a moment) M is applied to the rotor blade 1 due to centrifugal force, but the reaction force is received by the parallel slit portion 25 and the external slit 17 parallel to the axis, as in the case described above, so that the moment) M is applied to the rotor blade 1. No component force is generated, and the screw shaft 14 does not share any reaction force during operation.

6 and 7 show another embodiment, in which the outer cylinder slit 17
is inclined in the opposite direction to the inner cylinder slit 18, and there is a parallel slit part 27 parallel to the axis near the stroke end.
．． 28 are provided. By guide bin 190 stroke.

The inner cylinder 12 rotates by an angle ψ with respect to the outer cylinder 11.

FIG. 3 shows an example in which the handle 26 is manually driven. In Figure 10, 29 is the main electric elm.

50 is a brake, 31 is a variable pitch drive machine, and 32 is a clutch (jaw clutch, electromagnetic clutch, etc.). When the blower is stopped by the brake 30, the clutch 32 is engaged and the threaded shaft 14 is moved by the variable pitch drive pull. It is K-shaped so that it can be rotated.

In Fig. 11, 33 is a clutch, the electric motor 29 is turned off and left in a free state, the clutch 32.55 is turned on, the screw shaft 14 is fixed with the brake 30, and the variable pitch drive 31 rotates the runner hub 6 to move the internal slide piece 16. If the main motor 29 is a variable speed motor and is capable of rotating at a low speed for variable pitch, the clutches 32, 33 and the variable pitch drive machine 31 are unnecessary, and a brake 30 is provided on the screw shaft 14 as shown in FIG. The runner hub 6 side may be driven by the main electric motor 29.

As the conversion mechanism, a form gear may be used instead of a bevel gear. For example, a worm wheel is provided in place of the bevel gear 9, a worm that meshes with the worm wheel is provided parallel to the axis of the blower, and a small gear is provided on the worm shaft. A large gear meshing with the small gears (plurality) may be provided on the 7 flange 22, so that the rotation of the inner cylinder 12 causes all the moving parts 1!11 to simultaneously rotate by the same angle via the large gear.

As described above, when using gears such as bevel gears and form gears, the speed ratio can be arbitrarily selected, so the angle of change of the attachment angle of the rotor blade 1 can be arbitrarily selected.
It can be easily constructed even for 180 degrees. A linkage mechanism can also be used as the conversion mechanism.

For example, in place of the bevel gear 90 shown in Fig. 2, a lever 8 perpendicular to te is provided on the shaft 8, and the tip of the lever is pivotally attached to the outer periphery of a disk provided in place of the bevel gear 230. The lever may be rotated 10-- to rotate the rotor blade 1 by the same angle. Due to the nature of the link, it is difficult to change the mounting angle by 180 degrees, but angles smaller than that are possible. For example, it can be applied to a case where the airfoil shape is simply changed by 90 degrees, as shown by 1# in FIG. 3, and the airflow is directed in the opposite direction K, as shown by 3', while the rotational direction 4 remains unchanged.

According to the present invention, the rotor blades are reliably locked against the moment that is applied to them during operation, so there is no fear that the mounting angle will change, and the reaction force of the moment is not applied to the moving mechanism such as a screw that moves the guide pin in the axial direction. It is possible to provide an axial flow blower that can prevent damage and wear of various parts, and can have extremely great practical effects.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the moment applied to the moving blade K. 2 to 12 relate to an embodiment of the present invention, in which FIG. 2 is a longitudinal sectional view, FIG. 3 is a partial longitudinal sectional view of another embodiment, and FIGS. 4 and 5 are la2- 11- A sectional view taken along the lines 1-1 and 1-11 in FIG. 1, and FIGS. 6 and 7 are views corresponding to FIGS. 4 and 5 of another embodiment. FIG. 8 is a detailed sectional view of the guide bin, FIG. 9 is an explanatory diagram of changing the pitch of the moving blade, and FIGS. 10 and 11. FIG. 12 is a plan view of each different embodiment (a part of the rotor blade is omitted). 1.1', 1"...moving blade, 2...shaft, 3.3'...
·air current. 4.4'... Rotation direction, 5... Main shaft, 6... Runner/pull, 7... Bearing, 8... Shaft, 9... Bevel gear, 10... Bonnet, 11...・Outer cylinder, 12・
・・Inner cylinder, 13・・One rotation center axis, 14・・Screw shaft,
15...Clutch. 16...Slide piece, 17...Outer cylinder slit, 18
...Inner cylinder slit, 19.19'...Guide pin,
20.21...Roller, 2.2...Flange, 2
3... Bevel gear, 24.25... Parallel slit part, 26... Handle, 27.28... Parallel slit part, 29... Main electric motor, 30... Brake, 51...
...Variable pitch drive machine, 52.55...Clutch.

Claims (1)

[Claims] 1. In an axial flow blower equipped with a rotor blade pitch changing mechanism that changes the mounting angle of the rotor blades when stopped. The rotor blade pitch changing mechanism includes an outer cylinder and an inner cylinder that are held concentrically so as to be rotatable with respect to the rotation center axis of the blower, and the outer cylinder and the inner cylinder have outer cylinders that intersect with each other. A cylinder slit and an inner cylinder slit are respectively provided, and a guide bin is provided which penetrates the outer cylinder slit and the inner cylinder slit in the radial direction and is movable back and forth along the axial direction. A conversion mechanism is provided for converting the relative rotational movement between the inner cylinder and the outer cylinder caused by the axial movement K of the guide bin into a pitch changing movement of the rotor blade. An axial flow blower characterized in that each of the outer cylinder slit and the inner cylinder slit has a slit portion parallel to the axis near the stroke end. 2-