JPH07238899A - Blade moving mechanism in movable blade fluid apparatus - Google Patents

Abstract

PURPOSE:To lower an initial cost by simplifying the structure of a blade moving mechanism in a movable blade fluid apparatus such as a pump, a water wheel, a blower, and the like. CONSTITUTION:Each blade shaft 3 of four impeller blades 4 is rotatively attached around a vertical shaft line Cl by passing through the circumferential wall 2A of an impeller boss 2 fixed to a main shaft 1 from its outer side, and a horizontal key groove 6 is formed in a position where is further inside than each circumferential wall 2A of each blade shaft 3. The setting angle of the impeller blades 4 against the impeller boss 2 can be set in desired value according to the direction of a tip end surface against the horizontal shaft lines of the balde shafts 3 by tightening a positioning key 7 on the circumferential wall 2A inner surface of the impeller boss 2 by a bolt 8 in such a condition that the positioning key 7 is fitted into the key groove 6 and a setting angle set surface is brought in contact with the groove bottom 6A of a key groove 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade moving mechanism in a movable blade fluid device such as a pump, a water turbine or a blower having a movable blade.

[0002]

2. Description of the Related Art Conventionally, a spindle 1 shown in FIGS.
A plurality of blade shafts 3, 3 extending in the radial direction of the main shaft 1 are rotatably attached to the impeller boss 2 fixed to the main shaft 1 about the longitudinal axis C1. In the movable blade fluid device to which the impeller blades 4, 4, ... Are attached, the impeller blades 4, 4, ... Are pointed to one point by a blade moving mechanism (not shown) equipped inside the main shaft 1 and the impeller boss 2. Rotate to the open side indicated by the chain line arrow or the closed side indicated by the two-dot chain line arrow to obtain the impeller blades 4, 4, ...
Pumps with movable blades configured to hold ... are well known.

However, the conventional blade moving mechanism has a drawback that the structure is extremely complicated and the initial cost is high. Therefore, there is a demand for the development of a blade moving mechanism having a simple structure and a low initial cost.

[0004]

The problem to be solved is that the structure is extremely complicated and the initial cost is high.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a plurality of blade shafts are rotatably mounted around a longitudinal axis by penetrating from the outside a peripheral wall of an impeller boss fixed to a main shaft. In a movable blade fluid device having impeller blades attached to each of them, a lateral key groove having a groove bottom parallel to the horizontal axis is formed at a position inside the peripheral wall of each blade shaft, and the key groove is formed in the key groove. Positioning with a mounting angle setting surface that fits into contact with the groove bottom of the key groove to restrict rotation of the blade shaft about the vertical axis and sets the mounting angle of the impeller blade to a desired value The key is characterized in that it is removably fastened to the inner surface of the peripheral wall by a fastening member, and the object is achieved by simplifying the structure and reducing the initial cost.

[0006]

According to the present invention, the rotation of the main shaft causes the impeller boss and the plurality of impeller blades to rotate simultaneously. Then, a positioning key is fitted in a lateral key groove formed in a position on the blade shaft inside the peripheral wall of the impeller boss, and the orientation of the mounting angle setting surface of the positioning key with respect to the horizontal axis of the blade shaft is set. By selecting and specifying, with the mounting angle setting surface in contact with the groove bottom parallel to the horizontal axis of the positioning key, by fastening the positioning key to the inner surface of the peripheral wall of the impeller boss by the fastening member, The attachment angle of the impeller blade to the impeller boss can be set to a desired value. That is, when the mounting angle setting surface of the positioning key that contacts the groove bottom is oriented parallel to the horizontal axis of the blade shaft, the mounting angle of the impeller blade to the impeller boss can be set to a neutral value. On the other hand, if the mounting angle setting surface of the positioning key that abuts the groove bottom is oriented with an inclination that allows the blade axis to rotate in the positive direction around the vertical axis with respect to the horizontal axis of the blade axis, this inclination The angle of attachment of the impeller blade to the impeller boss can be set to a value smaller than the neutral value depending on the degree. On the other hand, if the mounting angle setting surface of the positioning key that abuts the groove bottom is oriented with respect to the horizontal axis of the blade axis with an inclination that allows the blade axis to rotate in the opposite direction around the vertical axis, this inclination The angle of attachment of the impeller blade to the impeller boss can be set to a value larger than the neutral value depending on the degree.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional side view showing a part of an axial flow pump to which the present invention is applied, and FIG. 2 is an enlarged sectional view taken along line AA of FIG.
It should be noted that the same or corresponding parts as those of the conventional example shown in FIGS. 1 and 2, the peripheral wall 2 of the impeller boss 2 fixed to the tip of the main shaft 1.
A has four through holes 2a, 2a at equal intervals in the circumferential direction.
(However, only two through holes 2a, 2a are shown in FIG. 1) are formed, and four blade shafts 3, 3 extending in the radial direction of the main shaft 1 in these through holes 2a, 2a. However, only two blade shafts 3 and 3 are shown in FIG. 1) so that the blade shafts 3 and 3 can be rotated about the vertical axis C1 from the outer side to the inner side of the peripheral wall 2A. Impeller blades 4, 4 ... (However, in FIG. 1, two impeller blades 4, 4 are provided.
(Only shown) is installed. .. are formed in the central portion 2B of the impeller boss 2. Four concave portions 2b, 2b ... (However, FIG. 1 shows only two concave portions 2a, 2a. ) Is rotatably fitted around the vertical axis C1 and the tip end opening of the impeller boss 2 is normally closed by a detachably attached cover 5.

A lateral key groove 6 having a groove bottom 6A parallel to the horizontal axis C2 of each blade shaft 3 is formed at a position inside the peripheral wall 2A of the impeller boss 2 in the blade shafts 3, 3 ... ing. A positioning key 7 for restricting rotation of the blade shafts 3, 3, ... About the axis and for setting the mounting angle of the impeller blades 4, 4 ,. The positioning key 7 is detachably fastened to the inner surface of the peripheral wall 2A by a fastening member 8.

That is, the positioning key 7 has a mounting angle setting surface 7A oriented parallel to the horizontal axis C2 of the blade shaft 3. Therefore, with the positioning key 7 fitted in the key groove 6 and the mounting angle setting surface 7A abutting on the groove bottom 6A,
Two female screw holes 9 each having a fastening member 8 formed of a pair of bolts formed on the inner surface of the peripheral wall 2A of the impeller boss 2,
9 (however, only one female screw hole 9 is shown in FIG. 1), so that the installation angle of the impeller blades 4, 4, ... With respect to the impeller boss 2 is set to a neutral value θ. it can. In the figure, 10 is a pump casing and 11 is a suction cover.

With such a construction, the main shaft 1 is rotated by activating a motor (not shown), and the impeller boss 2 is rotated.
It is possible to obtain the operating state of the pump in which the four impeller blades 4, 4, ... Simultaneously rotate. As a result, a pumping operation is started in which water is sucked from the suction cover 11 and is caused to flow into the pump casing 10, as indicated by an arrow W.
In this case, the four impeller blades 4, 4, ... Are subjected to a combined load such as twisting due to fluid force and centrifugal force due to rotation. However, the positioning key 7 is fitted into the lateral keyways 6 formed in the blade shafts 3 of the four impeller blades 4, 4, ... Bottom 6
Since it is screwed into the female screw holes 9 in the inner surface of the peripheral wall 2A of the impeller boss 2 by a fastening member 8 formed of a pair of bolts in a state of being brought into contact with A, the impeller blade for the impeller boss 2 is provided. The mounting angle θ of 4, 4 ... Does not change. In other words, the impeller blades 4, 4 ...
Even if a load such as a twist due to a fluid force or a centrifugal force due to rotation acts in combination, the mounting angle θ of the impeller blades 4, 4, ... With respect to the impeller boss 2 does not change.

Impeller blades 4, 4 for the impeller boss 2 ...
When changing the mounting angle of the pump to change the performance of the pump, first, the main shaft 1, the impeller boss 2, and the main shaft 1 are stopped by stopping the prime mover or turning off the clutch interposed between the prime mover and the main shaft 1. Stop the rotation of the four impeller blades 4, 4 ... Then, the screwing fastening of the fastening member 8 is released, and the positioning key 7 is removed from the key grooves 6 of all the blade shafts 3, 3. Subsequently, as shown in FIG. 3, the mounting angle setting surface 7A of the positioning key 7 that comes into contact with the groove bottom 6A is the horizontal axis C of the blade shaft 3.
The positioning key 7 which is oriented with an inclination capable of rotating the blade shaft 3 in the positive direction around the vertical axis C1 with respect to 2 is specified, and the positioning key 7 is fitted into the key groove 6 and The attachment angle setting surface 7A is brought into contact with the groove bottom 6A, and the fastening member 8 is screwed and fastened to the female screw holes 9 in the inner surface of the peripheral wall 2A of the impeller boss 2 to thereby impeller blade for the impeller boss 2. Set the mounting angles of 4, 4 ... to the mounting angle setting surface 7
A small value θ1 can be set according to the inclination α1 of A.

Further, as described above, the pump is stopped, the positioning keys 7 are removed from the key grooves 6 of all the blade shafts 3, 3, ..., Then, as shown in FIG. 4, they are brought into contact with the groove bottom 6A. The mounting angle setting surface 7A of the positioning key 7 is the horizontal axis C2 of the blade shaft 3.
In contrast to this, the positioning key 7 which is oriented with an inclination that allows the blade shaft 3 to rotate in the opposite direction around the vertical axis C1 is specified, and the positioning key 7 is fitted into the key groove 6 and When the mounting angle setting surface 7A is in contact with the groove bottom 6A, the fastening member 8 is screwed and fastened to the female screw holes 9 in the inner surface of the peripheral wall 2A of the impeller boss 2. , 4 ... for the mounting angle setting surface 7
A large value θ2 can be set according to the gradient α2 of A.

As described above, by varying the mounting angle of the impeller blades 4, 4, ... With respect to the impeller boss 2, it is possible to start the operation of the pump with the pump performance that changes according to the variation of the mounting angle. When the operation of the pump is started, a load such as a twist due to a fluid force or a centrifugal force due to the rotation acts on the four impeller blades 4, 4, ... Having a varying mounting angle. However, because the mounting angles of the impeller blades 4, 4, ... Are maintained without changing for the above-mentioned reason, the pump operation can be continued due to the pump performance that changes in accordance with the changing mounting angle. Moreover, these actions can be realized with a simple structure as compared with the conventional blade moving mechanism, so that the initial cost can be reduced.

FIG. 5 shows a modified example of the present invention, in which a pair of arc-shaped elongated holes 12, 12 are formed in the positioning key 7. The positioning key 7 is fitted into the key groove 6, and the mounting angle setting surface 7A is brought into contact with the groove bottom 6A in a state in which the mounting angle setting surface 7A is oriented parallel to the horizontal axis C2 of the blade shaft 3, and the long hole is provided via the washer 13. 1
The fastening members 8 inserted into the blades 2 and 12 are respectively threaded female holes 9 and 9 on the inner surface of the peripheral wall 2A of the impeller boss 2 (see FIG. 1).
The installation angle of the impeller blades 4, 4, ... With respect to the impeller boss 2 can be set to a neutral value θ by screwing.

Further, the impeller blades 4 with respect to the impeller boss 2 are
When changing the mounting angle of 4 ... to change the performance of the pump, first, stop the prime mover or turn off the clutch interposed between the prime mover and the main shaft 1 to turn the main shaft 1 and the impeller. Boss 2 and four impeller blades 4, 4
Stop the rotation of. Then, the threaded fastening of the fastening member 8 is loosened. Then, as shown in FIG. 6, the blade shaft 3 is rotated counterclockwise. Along with this rotation, the positioning key 7 rotates counterclockwise with the mounting angle setting surface 7A in contact with the groove bottom 6A. The fastening member 8 is screwed and fastened at a predetermined rotation position. As a result, the impeller blade 4, with respect to the impeller boss 2,
The mounting angle of 4 ... Can be set to a large value θ2 according to the counterclockwise rotation amount of the blade shaft 3 and the positioning key 7.

Further, as described above, the pump is stopped,
After loosening the screwed fastening of the fastening member 8, as shown in FIG. 8, the blade shaft 3 is rotated clockwise as shown in FIG. 7. Along with this rotation, the positioning key 7 rotates clockwise with the mounting angle setting surface 7A in contact with the groove bottom 6A. The fastening member 8 is screwed and fastened at a predetermined rotation position. As a result, the mounting angle of the impeller blades 4, 4, ... With respect to the impeller boss 2 can be set to a small value θ1 according to the amount of clockwise rotation of the blade shaft 3 and the positioning key 7.

In the above embodiment, four impeller blades 4, 4, ...
Although an axial flow pump having ... Is described, the present invention can be applied to an axial flow pump having an arbitrary number of impeller blades 4. The present invention is not limited to the axial flow pump described in the embodiments, but can be applied as a blade moving mechanism in a movable blade fluid device such as a water turbine or a blower.

[0018]

As described above, according to the present invention, the orientation of the mounting angle setting surface of the positioning key abutting on the groove bottom of the key groove is selected and specified, and the positioning key is fixed by the fastening member to the peripheral wall of the impeller boss. By fastening to the inner surface, the mounting angle of the impeller blade with respect to the impeller boss can be set to a desired value. Moreover, since it can be realized with a simple structure as compared with the conventional blade moving mechanism, the initial cost can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a part of an axial flow pump to which the present invention is applied.

FIG. 2 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 3 is an explanatory diagram when a mounting angle of an impeller blade is set to be small.

FIG. 4 is an explanatory view when a mounting angle of an impeller blade is set to be large.

FIG. 5 is an enlarged bottom view showing a modified example of the present invention.

FIG. 6 is an explanatory diagram when a large installation angle is set for the impeller blades.

FIG. 7 is an explanatory diagram when the installation angle of the impeller blades is set small.

FIG. 8 is a front view showing an example of a movable wing.

FIG. 9 is a plan view of FIG.

[Explanation of symbols]

 1 main shaft 2 impeller boss 2A peripheral wall of impeller boss 3 blade shaft 4 impeller blade 6 key groove 6A groove bottom 7 positioning key mounting angle setting surface 7A 7A mounting angle setting surface 8 fastening member C1 longitudinal axis C2 blade axis Horizontal axis

Claims (1)

[Claims] 1. A plurality of impeller shafts are rotatably mounted around a longitudinal axis through a peripheral wall of an impeller boss fixed to a main shaft from the outside, and impeller blades are attached to the respective impeller shafts. In the movable blade fluid device, a lateral key groove having a groove bottom parallel to the horizontal axis is formed at a position inside the peripheral wall of each of the blade shafts, and the key groove is fitted into the key groove to A positioning key having an attachment angle setting surface that abuts on the groove bottom to restrict the rotation of the blade shaft about the vertical axis and sets the installation angle of the impeller blade to a desired value is fastened to the inner surface of the peripheral wall. A blade moving mechanism in a movable blade fluid device, which is detachably fastened by a member.