JP2013047463A - Variable axial-flow fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fan that minimizes an increase in size of power supply equipment by minimizing an increase in centrifugal force acting on the mass of a hub ring, in increasing the size of the diameter of an inner tube of a casing or increasing the rotation speed of an impeller.SOLUTION: The variable axial-flow fan includes a hub ring 1, a blade 4, a blade fixing means (blade bracket 2), a blade angle change transmission means (carrier shaft 8, link 15), and a casing inner cylinder 17. The outer diameter of the hub ring 1 is made smaller than that of the casing inner cylinder 17, thereby reducing a centrifugal force to be applied on the hub ring 1, reducing production cost thereof, and minimizing an increase in size of power supply equipment, as well as increasing rotation speed of the impeller 24 and the size of the casing inner cylinder 17.

Description

  The present invention relates to a moving blade mechanism of a blower capable of changing an air volume by arbitrarily changing an angle of a moving blade.

  For example, an axial blower used for a ventilator in a road tunnel often incorporates control for changing the amount of air blown in response to a change in traffic volume in the tunnel. As a method of changing the air flow rate, there is a method of changing the rotational speed of the blower using an inverter or the like. However, many large-sized blowers are also used to change the air flow rate by changing the angle of the blades of the blower without using an expensive inverter.

  In a moving blade mechanism of a blower capable of making the air volume variable, a method of rotating the shaft of a moving blade arranged in an impeller using hydraulic pressure or air pressure is known.

  The method will be described below with reference to FIGS.

  As shown in FIG. 8, the axial blower 115 used for the ventilation device in the road tunnel is provided with a casing inner cylinder 114 so as to be concentric with the casing outer cylinder 117. An impeller 116 is provided concentrically with the casing inner cylinder 114. In the impeller 116, a blade 105 is attached to the outer peripheral side of the hub ring 101 having the same outer diameter as the casing inner cylinder 114. Note that a moving blade variable mechanism (not shown) and an electric motor (not shown), which will be described later, are housed inside the casing inner cylinder 114.

  A moving blade variable mechanism that changes the angle of the blade 105 will be described with reference to FIG. As shown in FIG. 9, the bracket retainer 102 for holding the blade 105 is in close contact with the blade mounting hole 113 formed in the hub ring 101 from the inner surface side and is attached with the fastening bolt 109. The blade bracket 103 is disposed on the inner surface of the hub ring 101 and holds the blade 105 rotatably. The blade 105 is coupled to the blade bracket 103 by a screw 106 processed into the blade 105. A counterweight 111 is coupled to the blade bracket 103 via a counterbalance member 112. The counter balance member 112 supports the counterweight 111 at an appropriate position with respect to the blade 105. The counterweight 111 is for balancing the force generated by the blade 105 and the force generated by the counterweight 111. When the impeller is rotating, a force is generated on the blade 105 to rotate in a direction in which the attachment angle between the blade 105 and the hub ring 101 is reduced by centrifugal force. By arranging the counterweight 111 at an appropriate position with respect to the blade 105, the counterweight 111 generates a force to rotate in a direction in which the attachment angle between the blade 105 and the hub ring 101 is increased by a centrifugal force, thereby achieving balance. A cam floor 108 for transmitting a driving force from a moving blade variable mechanism (not shown) inside the hub ring 101 to the blade 105 is coupled to the inner peripheral end 107 of the blade 105. Since the bearing 104 is disposed between the blade bracket 103 and the bracket retainer 102, the blade 105 rotates about its axis by applying a driving force from a moving blade variable mechanism powered by hydraulic pressure or air pressure to the cam floor 108. Thus, the angle of the blade 105 can be changed.

Japanese Patent Laid-Open No. 11-2199

  In such a conventional configuration, when the impeller rotates, the centrifugal force acting on all the mechanisms for changing the angle such as the blade 105 and the blade bracket 103 is held by the hub ring 101. The centrifugal force also acts on the member of the hub ring 101. For this reason, the hub ring 101 needs to be strong enough to hold all the forces. When the rotational speed of the impeller 116 is high, the centrifugal force acting on the hub ring 101 increases accordingly. Further, in the high static pressure type blower, since the hub ratio (ratio of the hub diameter to the diameter) is increased, the outer diameter of the casing inner cylinder 114 is increased even if the diameter is the same. In that case, since the outer diameter of the hub ring 101 also increases, the centrifugal force acting on the hub ring 101 also increases accordingly. In order to ensure the strength against the increasing centrifugal force, it is necessary to increase the thickness of the outer peripheral portion of the hub ring 101 or to change the material of the outer peripheral portion of the hub ring 101 to one having higher strength.

  When the thickness of the outer peripheral portion of the hub ring 101 is increased, the mass of the entire impeller 116 is increased, and the motor bearing needs to be enlarged in order to maintain the mass. As a result, it is necessary to increase the frame size of the electric motor. Moreover, since it is necessary to increase the size of the power supply facility due to an increase in the start-up current and an increase in the start-up time, there is a problem that the manufacturing cost of the device is increased. Moreover, if the material of the outer peripheral part of the hub ring 101 is changed to a material having higher strength, the material cost increases due to the higher unit price of the material. Also, depending on the material, there is a problem that the manufacturing cost of the equipment becomes high because extra man-hours such as having to heat up during welding work are required. The present invention solves such a conventional problem, and realizes a blower that can increase the size and speed of an impeller while minimizing changes in the material and thickness of the outer peripheral portion of the hub ring. It is an object.

In order to solve such a problem, the present invention
A hub ring attached to the rotating shaft;
Blade fixing means provided radially on the outer peripheral side of the hub ring;
A blade provided at the tip of the blade fixing means;
Blade angle change transmission means for changing the blade angle outside the hub ring;
A casing inner cylinder located concentrically with the hub ring,
The outer diameter of the hub ring is smaller than the outer diameter of the casing inner cylinder,
The blade angle change transmission means is attached to the outer peripheral side of the hub ring,
The distance from the center of rotation to the outer peripheral side end of the blade fixing means has a moving blade variable mechanism that is located at substantially the same position as the outer diameter of the casing inner cylinder.

  According to the present invention, the centrifugal force generated in the blade fixing means, the blade, and the blade angle change transmission means is held by the hub ring. In addition, the centrifugal force generated in the hub ring is also held by the hub ring itself, but the outer diameter of the hub ring is smaller than the outer diameter of the casing inner cylinder. Even when the height is increased, an increase in centrifugal force generated in the hub ring can be minimized as compared with the impeller having the conventional configuration. For this reason, the outer diameter of the casing inner cylinder can be made larger than before without changing the material of the hub ring to a material with higher strength and without increasing the thickness, or the rotational speed of the impeller can be reduced. Can be high. Therefore, it is not necessary to increase the man-hours such as the addition of residual heat during production by changing the material, so that the production cost of the device can be suppressed. Further, since the increase in the mass of the impeller can be minimized, the frame size of the motor and the power supply equipment can be minimized. Therefore, the manufacturing cost of equipment can be suppressed.

Sectional drawing of the axial-flow fan by Embodiment 1 of this invention Coaxial flow blower perspective view The block diagram which shows the principal part structure of a coaxial flow fan The perspective view which shows the principal part structure of a coaxial flow fan The perspective view which shows the principal part structure of the plate of a coaxial flow fan The perspective view which shows the principal part structure of the cover of a coaxial flow fan The perspective view which shows the principal part structure of the baffle plate of a coaxial flow fan Perspective view of a conventional axial blower Configuration diagram showing conventional configuration

The first means of the present invention is:
A hub ring attached to the rotating shaft;
Blade fixing means provided radially on the outer peripheral side of the hub ring;
A blade provided at the tip of the blade fixing means;
Blade angle change transmission means for changing the blade angle outside the hub ring;
A casing inner cylinder located concentrically with the hub ring,
The outer diameter of the hub ring is smaller than the outer diameter of the casing inner cylinder,
The blade angle change transmission means is attached to the outer peripheral side of the hub ring,
The distance from the center of rotation to the outer peripheral side end of the blade fixing means has a moving blade variable mechanism that is located at substantially the same position as the outer diameter of the casing inner cylinder.

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

(Embodiment 1)
1st Embodiment of this invention is described using FIGS.

  As shown in FIGS. 1 and 2, the axial blower 23 according to the present embodiment includes an impeller 24 concentrically with the casing outer cylinder 30 inside the casing outer cylinder 30. A casing inner cylinder 17 is provided in front and rear of the impeller 24 in the axial direction. The impeller 24 is provided with the hub ring 1 around the rotation shaft 14. A blade changing mechanism and a blade 4 which will be described later are attached to the hub ring 1 in a radial manner.

  The moving blade variable mechanism will be described in detail with reference to FIGS. The hub ring 1 is a steel cylinder, and has a rotating shaft 14 at a portion that forms the central axis of the tube, and rotates about the rotating shaft 14. Circular blade bracket mounting openings 10 are machined at equal intervals on the outer periphery of the hub ring 1, and a blade bracket 2 serving as a blade fixing means is disposed on the outer surface of the blade bracket mounting opening 10. . The blade bracket 2 has a rod shape with a circular cross section, and has a diameter at both ends larger than the diameter of the central portion. One of the blade brackets 2 is held by a blade bracket fixing nut 12 via a bearing 3 and a washer 13 on the inner surface side of the hub ring 1 through a blade bracket mounting opening 10. That is, the blade bracket 2 is rotatable with respect to the hub ring 1 about the blade bracket mounting opening 10 as an axis. The blade bracket mounting opening 10 is formed by concentrically opening different diameters. In other words, a small-diameter circular opening (opening 10b) is concentrically formed in the large-diameter circular opening (opening 10a). Large-diameter circular openings (openings 10 a) are provided on the outer peripheral side and the inner peripheral side of the hub ring 1. Since the blade bracket 2 is pulled in the radial direction by centrifugal force when the impeller 24 rotates, the angle of the blade 4 can be changed smoothly by arranging the bearing 3 only on the inner peripheral side of the hub ring 1. A blade 4 is connected to an end portion on the outer peripheral side of the blade bracket 2 by a blade fixing screw 5. Further, the counter balance member 7 is connected to the inner side of the outer peripheral end of the blade bracket 2 by a counter balance member fixing screw 9. A counterweight 6 and a carrier shaft 8 serving as blade angle change transmission means are fixed to the counterbalance member 7. The carrier shaft 8 transmits the driving force from the actuating wheel 16 provided in the hub ring 1 to the blade bracket 2 through the link 15 which is also a blade angle change transmission means, and changes the angle of the blade 4. Become.

  By arranging the counterweight 6 at an appropriate position with respect to the blade 4, a force in a direction in which the mounting angle with respect to the hub ring 1 acting on the blade 4 is reduced by the centrifugal force generated when the impeller 24 rotates is reduced. , It can act to counteract. Here, the shape of the counter balance member 7 is determined so that the counterweight 6 can be arranged at an appropriate position. In addition, the position of the carrier shaft 8 is determined in order to appropriately transmit the driving force from the actuating wheel 16 driven by hydraulic pressure or air pressure to the blade 4, and the shape of the counter balance member 7 is used to maintain the position. To decide.

  In the above configuration, the centrifugal force acting on the blade bracket 2 and the blade 4 connected thereto, the blade fixing screw 5, the counter balance member 7, the counter weight 6, and the carrier shaft 8 when the impeller 24 rotates is transmitted via the bearing 3. , It is received by the hub ring 1 attached to the rotary shaft 14. That is, the outer diameter (hub ring outer diameter B) of the hub ring 1 can be kept small without being influenced by the outer diameter of the casing inner cylinder 17 (casing inner cylinder outer diameter A) of the axial blower. Therefore, even when the casing inner cylinder outer diameter A of the axial-flow fan is increased in order to increase the static pressure, the hub ring outer diameter B is hardly changed, and the centrifugal force of the member disposed outside the outer peripheral surface of the hub ring 1 is changed. It is only necessary to improve the strength of the hub ring 1 corresponding to the increase in the thickness of the hub ring 1, and the thickness of the hub ring 1 need not be increased. Moreover, it is not necessary to change to a material with higher strength. As a result, it is possible to manufacture by the conventional manufacturing method, and an effect that the increase of the manufacturing cost can be minimized is obtained. Further, since the increase in the mass of the impeller 24 as a whole can be minimized, the size of the motor frame can be increased by increasing the size of the bearing of the motor, and the power supply facility can be increased by increasing the starting current or the starting time. The effect that it can be minimized is obtained.

  Further, according to such a configuration, even when the impeller 24 is designed at a high rotational speed, the centrifugal force is received by the hub ring 1 in the central portion, so it is necessary to increase the hub ring outer diameter B. Absent.

  Further, by arranging the plate 20 as the air flow blocking means between the plurality of blade brackets 2 as shown in FIG. 5, the air generated in the casing inner cylinder 17 due to the pressure difference between the blade inflow side and the outflow side during the operation of the blower. The effect that backflow can be prevented is obtained.

  Further, as shown in FIG. 6, a cylindrical cover 21 is disposed on the outer peripheral portion of the plate 20 so as to be flush with the outer diameter of the casing inner cylinder 17. The cover 21 is provided with an opening 31 for attaching the blade 4 to the blade bracket 2. With such a configuration, it is possible to obtain an effect that the airflow flowing in the vicinity of the outer surface of the casing inner cylinder 17 can be made smoother to reduce the efficiency of the blower and prevent the generation of noise. In FIG. 6, the cover 21 is provided on the outer periphery of the plate 20, but the cover 21 may be provided on the outer periphery of the radial framework.

  Further, as shown in FIG. 7, by providing a curved or flat rectifying plate 22 as an airflow generating means on the side surface of the plate 20, an airflow flowing from the inside of the casing inner cylinder 17 to the outer peripheral side is generated, thereby The effect of preventing the entrainment of air from the outer peripheral side to the inner side of the casing inner cylinder 17, smoothing the airflow flowing near the outer surface of the casing inner cylinder 17, and reducing the efficiency of the blower and preventing noise generation. Get.

  Since it is possible to provide a blower having a relatively large air volume and a variable air volume, it can be widely applied to ventilation applications in large spaces such as factories, parking lots, road tunnels, and warehouses.

DESCRIPTION OF SYMBOLS 1 Hub ring 2 Blade bracket 3 Bearing 4 Blade 5 Blade fixing screw 6 Counterweight 7 Counter balance member 8 Carrier shaft 9 Counter balance member fixing screw 10 Blade bracket mounting opening 10a (large diameter) opening 10b (small diameter) opening 12 blade Bracket fixing nut 13 Washer 14 Rotating shaft 15 Link 16 Actuating wheel 17 Casing inner cylinder 20 Plate 21 Cover 22 Rectifier plate 23 Axial blower 24 Impeller 30 Casing outer cylinder 31 Opening A Casing inner cylinder outer diameter B Hub ring outer diameter 101 Hub ring 102 Bracket retainer 103 Blade bracket 104 Bearing 105 Blade 106 Screw 107 Inner peripheral side end 108 Cam floor 109 Fastening bolt 111 Counter Weight 112 Counter balance member 113 Blade mounting hole 114 Casing inner cylinder 115 Axial blower 116 Impeller 117 Casing outer cylinder

Claims (4)

A hub ring attached to the rotating shaft;
Blade fixing means provided radially on the outer peripheral side of the hub ring;
A blade provided at the tip of the blade fixing means;
Blade angle change transmission means for changing the blade angle outside the hub ring;
A casing inner cylinder located concentrically with the hub ring,
The outer diameter of the hub ring is smaller than the outer diameter of the casing inner cylinder,
The blade angle change transmission means is attached to the outer peripheral side of the hub ring,
The variable axial flow fan in which the distance from the center of rotation to the outer peripheral side end of the blade fixing means is set to the same position as the outer diameter of the casing inner cylinder. 2. The variable axial flow fan according to claim 1, further comprising an airflow shielding unit located between a plurality of the blade fixing units and provided in a range from an outer peripheral part of the hub ring to an outer peripheral surface of the casing inner cylinder. The blade mounting opening is provided in a cylindrical cover having substantially the same diameter as the casing inner cylinder,
The variable axial flow fan according to claim 1 or 2, wherein the hub ring, the blade fixing means, and the blade angle change transmitting means are provided inside the cover. The variable axial flow fan according to claim 1 or 2, wherein an airflow generating means is provided on a circumference having substantially the same diameter as the casing inner cylinder.

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