JP2016113976A - Propeller fan and refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a propeller fan in which an air flow can be easily fed to an inner edge side of each of the blades, a blade surface pressure of pressure surface of each of the blades is uniformed and an air blowing efficiency can be improved.SOLUTION: There are provided a hub formed into a cylindrical shape or a truncated cone shape in respect to a rotating axis, a plurality of blades for forming air flow arranged in a radial manner at the outer surface of the hub to form an air flow flowing in an axial direction of the hub and a connecting ring member connecting the plurality of blades to each other. The connecting ring member comprises an annular member formed with a shape of the end surface at a vertical section has a thickness size in a radial direction smaller than a thickness size in an axial direction and a plurality of connecting parts for connecting the annular member to the front edges of the plurality of blades or locations near the front edges at negative pressure surfaces of the plurality of blades in such a way that the annular member may be positioned at a negative pressure surface of the blade.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a propeller fan and a refrigerator including a connection ring member that connects a plurality of blades provided on an outer surface of a hub.

  Patent Document 1 discloses a propeller fan that includes a connecting ring member that connects blades for the purpose of preventing deformation of the blades while reducing the weight of each blade provided on the outer surface of the hub to reduce weight. Yes.

  This connecting ring member is formed in a substantially thin cylindrical shape, and is provided so as to pass through substantially the center with respect to the blade width of each blade when viewed from the axial direction, and in front of each blade when viewed from the radial direction. It is provided from the edge to the rear edge. In other words, the connecting ring member is provided so that each blade is completely partitioned between the inner edge side and the outer edge side at substantially the center of the blade width.

  By the way, in the propeller fan of patent document 1, since a connection ring member will become a boundary wall, an air flow will be divided into the inner side and the outer side of a connection ring member. Usually, even in the case of a propeller fan that does not include a connecting ring member, the blade surface pressure tends to be lower on the inner edge side of each blade than on the outer edge side, and the work rate tends to be lower. When the air flow is divided by the connecting ring member, this tendency becomes more prominent, and the blade surface pressure on the pressure surface of each blade is further non-uniform, and the inner edge side of each blade is less likely to contribute to blowing.

  On the other hand, the propeller fan of Patent Document 2 includes a connection ring member configured to be connected to the front edge of each blade and not to completely partition the inner edge side and the outer edge side of each blade.

  However, the connecting ring member described in Patent Document 2 has a circular shape in a longitudinal section, and a part of the air flow sucked into each blade as illustrated in FIG. 2 of Patent Document 2. However, an annular vortex is generated in the connecting ring member. For this reason, an air flow is easily introduced to the outer edge side of each blade, and the blade surface pressure of the pressure surface of each blade cannot be made uniform. Therefore, even if it is a connection ring member of patent document 2, like the connection ring member of patent document 1, the work rate of a propeller fan cannot be improved.

JP 2010-096084 A Japanese Utility Model Publication No. 62-204000

  Therefore, the present invention has been made in view of the problems described above, and air flow is easily introduced to the inner edge side of each blade, and the blade surface pressure of each blade is made uniform to improve the blowing efficiency. An object of the present invention is to provide a propeller fan that can be made to operate.

  That is, a hub formed in a cylindrical shape or a truncated cone shape with respect to the rotation axis, a plurality of blades provided radially on the outer surface of the hub and forming an air flow flowing in the axial direction of the hub, and the plurality A connecting ring member for connecting the blades of each other, and the connecting ring member is formed so that the shape of the end face in the longitudinal section is smaller in the radial thickness than the axial thickness. And a plurality of connections for connecting the annular body to the front edge of the plurality of blades or the vicinity of the front edge of the suction surface of the plurality of blades so that the annular body is located on the suction surface side of the blade. It comprises the part.

  If it is such, since the said connection part is provided so that the said annular body may be located in the suction surface side of the said blade, the said connection ring member exists in an upwind side with respect to the suction surface of each blade However, it does not exist on the pressure surface side of each blade. For this reason, the inner edge side and the outer edge side of each blade are completely partitioned by the connecting ring member, and the air flow is not divided.

  Furthermore, since the annular body is formed such that the shape of the end face in the longitudinal section is smaller in the radial thickness dimension than the axial thickness dimension, the air flow is less likely to generate vortex around the annular body, It is difficult to prevent the air flow from being guided to the inner edge side of each blade.

  Therefore, since the rectifying effect of guiding the air flow to the inner edge side of each blade can be exerted by the connecting ring member, the blade surface pressure on the pressure surface of each blade is made uniform, and the air is efficiently blown also on the inner edge side of each blade. Can be performed.

  The blades on the leeward side of the blades by the connecting ring member, so as not to partition the inner source side and the outer edge side of the blades except in the vicinity of the connecting portion, can enhance the effect of uniforming the blade surface pressure on the pressure surface. In order to achieve this, it is only necessary to form a gap between the air flow outflow edge of the annular body and the suction surfaces of the plurality of blades.

  In the connection ring member, as a specific shape that makes it difficult for an inflowing air flow to generate a vortex circulating around the annular body, both ends provided so that the annular body is coaxial with the hub are provided. A generally hollow thin cylindrical shape having an opening is mentioned.

  The arrangement of the annular body that exerts a rectifying effect so that an air flow substantially equal to that of the outer edge side flows into the inner edge side of each blade is the center of the blade when viewed from the axial direction. The thing provided so that it may pass through a part is mentioned.

  In order to be able to enjoy the effect that the air flow is guided to the inner edge side of each blade by the connecting ring member as much as possible in the wide range of each blade, the annular body further includes an upstream end surface of the hub. What is necessary is just to be provided in the upstream.

  The blade surface pressure is further uniformized by allowing the airflow to be received by the blade surface according to the difference in the air flow generated inside and outside the connecting ring member and the difference in rotation speed due to the difference in the rotation radius of each blade. In order to achieve this, the annular body is provided so as to have a predetermined radius smaller than the outer peripheral ends of the plurality of blades with the rotation axis as a center, and a radial direction is provided between the inside of the annular body and the outside of the annular body. The blade angles that are the inclination angles of the plurality of blades with respect to the plane may be different from each other.

  A specific shape of each of the blades that adjusts an inclination angle of the plurality of blades with respect to a radial plane in accordance with a difference in air flow between the inside and the outside of the connection ring member is as follows. The thing which has a step part in the provided radius is mentioned.

  If it is a refrigerator provided with the propeller fan of the present invention, even if it is provided in a limited narrow space such as in a duct, the required air volume can be efficiently supplied to, for example, a condenser to improve the operation efficiency of the refrigerator. it can.

  As described above, according to the propeller fan of the present invention, the connecting ring member is disposed on the windward side of each blade, and the end surface shape of the longitudinal section thereof is in the axial direction, which is the air flow direction rather than the radial direction. Therefore, it is possible to prevent the generation of vortices in the connecting ring member, guide the air flow toward the inner edge side of each blade, and improve the air blowing efficiency by equalizing the blade surface pressure.

The typical side view and typical top view of the propeller fan which concern on one Embodiment of this invention. The typical perspective view of the propeller fan in the embodiment. The typical perspective view of the propeller fan seen from another direction in the embodiment. The schematic diagram which compared the air flow of the propeller fan of the same embodiment with the air flow of the conventional propeller fan. The schematic diagram which compared the blade surface pressure distribution of the conventional propeller fan with the blade surface pressure distribution of the propeller fan of the embodiment.

  A propeller fan 100 and a refrigerator according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5.

  The propeller fan 100 of this embodiment is provided in a duct with the said condenser in order to ventilate to the condenser of a refrigerator.

  As shown in FIGS. 1 to 3, the propeller fan 100 is formed by resin molding, and includes a cylindrical hub 1, three blades 2 provided on the outer surface of the hub 1, And a connecting ring member 3 for connecting the blade 2.

  The hub 1 is formed in a cylindrical shape along the rotation axis, and is connected to a rotation shaft of a motor (not shown).

  Each blade 2 has a wing shape, and is attached while being inclined obliquely from the bottom surface side to the top surface side of the hub 1 in the side view of FIG. More specifically, each blade 2 has a front edge 21 on the upper surface side of the hub 1 and an inner edge 23 of the hub 1 on the outer surface of the hub 1 so that a rear edge 22 is disposed on the bottom surface side of the hub 1. It is provided on the side. Each blade 2 is formed so as to be convex toward the upper surface side of the hub 1, and the surface on the upper surface side of the hub 1 where the connecting ring member 3 is provided is a negative pressure surface 25. The rear surface is the pressure surface 26.

  Further, as shown in FIGS. 2 and 3, each blade 2 has a stepped portion 27 at a position where the connection ring member 3 is provided, and the inclination angle of each blade 2 with respect to a radial plane is the connection ring member. 3 is different between the inside and the outside. More specifically, each blade 2 is formed such that the inclination angle is larger on the inner edge 23 side of each blade 2 than on the outer edge 24 side of each blade 2.

  The connection ring member 3 is formed in a substantially thin cylindrical shape with both ends opened, and is arranged so as to be coaxial with the hub 1 as shown in FIGS. It is located on the windward side (upper surface side) and on the windward side of the negative pressure surface 25 of each blade 2.

  More specifically, the connecting ring member 3 includes an annular body 31 formed such that the shape of the end face in the longitudinal section is smaller in the radial thickness than the axial thickness, and the annular body 31 is Three annular members 31 are connected to the front edge 21 of the plurality of blades 2 or the vicinity of the front edge 21 of the suction surface 25 of the plurality of blades 2 so as to be positioned on the suction surface 25 side of the blade 2. And a connection part 32.

  In the present embodiment, the end face shape of the longitudinal section of the annular body 31 is formed in a rectangular shape extending in the axial direction, and the radial thickness direction is smaller than the axial thickness dimension. Further, a gap is formed between the outflow end (downstream end) of the air flow in the annular body 31 and the negative pressure surface 25 of each blade 2, and the air flow is caused by the connecting ring member 3 to each blade 2. In FIG. 2, the flow is completely partitioned so as not to be divided. Further, the annular body 31 is provided so as to have a predetermined radius smaller than the outer edges 24 of the plurality of blades 2 around the rotation axis. In the present embodiment, the radius of the annular body 31 is set so as to pass through a substantially central portion with respect to the blade width of the blade 2.

  The connection portion 32 is a portion where a step portion 27 is formed in each blade 2 and a portion where the annular body 31 is connected in the vicinity of the front edge 21 in the negative pressure surface 25 of each blade 2. is there. That is, the annular body 31 is present only on the windward side of the blades 2 at the radius provided by the arrangement of the connecting portions 32 and is not present at all on the pressure surface 26 side of the back surface. is there.

  The propeller fan 100 configured as described above will be described in comparison with the conventional propeller fans 101 and 102.

  4 and 5 show the first propeller fan 101 that does not include the connecting ring member and the connecting ring member from the leading edge to the trailing edge on the pressure surface of each blade as in the case of the propeller fan 102 disclosed in Patent Document 1. 2 is compared with the propeller fan 100 of the present embodiment.

  As shown in FIG. 4, in the first propeller fan 101, most of the air flow is concentrated on the outer edge side of each blade. Further, since the second propeller fan 102 is provided with the connecting link member, a slight rectifying effect is exhibited, and an air flow is also generated on the inner edge side of each blade as compared with the first propeller fan 101. However, in the second propeller fan 102, the connecting ring member is provided on the leeward side of the front edge of each blade, and functions as a partition plate on the pressure surface side. For this reason, the air flow is divided on the inner edge 23 side and the outer edge 24 side of each blade 2, and the rectifying effect by the connecting ring member 3 is limited.

  On the other hand, in the propeller fan 100 of this embodiment, the propeller fan 100 is provided on the upstream side of the negative pressure surface 25 of each blade 2, and between the outflow end side of the connection ring member 3 and the negative pressure surface 25 of each blade 2. A gap is formed. For this reason, since there is no partition plate on the pressure surface 26 side in each blade 2, the air flow is not divided, and the air flow is guided to the inner edge 23 side than the second propeller fan 100 by the connecting ring member 3. It ’s easy. Accordingly, the air flow can be guided substantially uniformly over the entire surface of each blade 2.

  FIG. 5 shows the blade surface pressure distribution at the pressure surface of each propeller fan 100, 101, 102.

  In the first propeller fan 101, the blade surface pressure is generally low, and the pressure is concentrated on the outer edge side of the blade. For this reason, among the three propeller fans 100, 101, 102, the air blowing performance is the lowest.

  Moreover, since the connection ring member exhibits the effect as a partition plate in the second propeller fan 102, it can be understood that the blade surface pressure is concentrated only on the outer edge side of the blade. Although the blade pressure increases on the outer edge side of the blade, the inner edge side hardly performs the function as a blade, and the air blowing performance is improved only to a limited extent.

  On the other hand, in the propeller fan 100 of the present embodiment, a pressure of a predetermined value or more is generated on the entire blade surface, and the uniformity thereof is high. Therefore, the blowing performance can be highest among the three propeller fans 100, 101, and 102. This is because, as shown in FIG. 4, more airflow can be introduced to the inner edge 23 side of each blade 2 than in the prior art, and each blade 2 responds to the difference in airflow between the inner edge 23 side and the outer edge 24 side. Giving an inclination angle with respect to the radial plane contributes.

  Thus, with the propeller fan 100 according to the present embodiment, the blade surface pressure on the pressure surface 26 of each blade 2 can be increased and the distribution thereof can be made uniform as compared with the conventional propeller fans 101 and 102. Can be improved.

  Moreover, the refrigerator using the propeller fan 100 of this embodiment can improve the heat exchange efficiency in a condenser or the like.

  Other embodiments will be described.

  In the embodiment, each blade has a step portion when viewed along the radial direction, but the step portion may not be provided. That is, each blade may be a blade having a curved surface continuous in the blade width direction.

  The connecting ring member only needs to be upstream of the suction surface of each blade in the provided radius. That is, depending on the provided radius, it may be downstream of the upper surface of the hub. In addition, the shape of the end face in the longitudinal section of the annular body is not limited to that shown in the embodiment, and any shape may be used as long as the air flow hardly generates vortices that circulate around the annular body. That is, the shape of the annular body may be determined such that the shape of the end face in the longitudinal section is smaller in the radial thickness than the axial thickness. For example, the annular body may have a wing shape. In addition, the radius of the ring member is not limited to that shown in the embodiment, and may be set as appropriate according to the shape and characteristics of the blade.

  The hub may have a truncated cone shape as well as a cylindrical shape. Further, the number of the blades is not limited to three and may be a plurality of other numbers.

  In addition, various modifications and combinations of the embodiments may be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 100 ... Propeller fan 1 ... Hub 2 ... Blade 21 ... Front edge 22 ... Rear edge 23 ... Inner edge 24 ... Outer edge 25 ... Negative pressure surface 26 ... Pressure surface 27 ... Step part 3 ... Connection ring member 31 ... Ring body 32 ... Connection part

Claims (8)

A hub formed in a cylindrical shape or a truncated cone shape with respect to the rotation axis;
A plurality of blades that are provided radially on the outer surface of the hub and that form an airflow flowing in the axial direction of the hub;
A connection ring member for connecting the plurality of blades to each other,
The connecting ring member is
An annular body formed such that the shape of the end face in the longitudinal section is smaller in the radial thickness dimension than the axial thickness dimension;
A plurality of connecting portions for connecting the annular body to the front edge of the plurality of blades or the vicinity of the front edge of the suction surface of the plurality of blades so that the annular body is located on the suction surface side of the blade; Propeller fan characterized by comprising.   The propeller fan according to claim 1, wherein a gap is formed between an outflow edge of the air flow of the annular body and suction surfaces of the plurality of blades.   3. The propeller fan according to claim 1, wherein the annular body has a substantially hollow thin cylindrical shape with both ends opened so as to be coaxial with the hub.   The propeller fan according to any one of claims 1 to 3, wherein the annular body is provided so as to pass through a central portion of the blade when viewed from an axial direction.   The propeller fan according to any one of claims 1 to 4, wherein the annular body is provided further upstream than an upstream end face of the hub. The annular body is provided so as to have a predetermined radius smaller than the outer peripheral ends of the plurality of blades around the rotation axis;
The propeller fan according to any one of claims 1 to 5, wherein blade angles, which are inclination angles of the plurality of blades with respect to a radial plane, are different between the inside of the annular body and the outside of the annular body.   The propeller fan according to any one of claims 1 to 6, wherein the plurality of blades have step portions at a radius where the annular body is provided.   The refrigerator provided with the propeller fan in any one of Claims 1 thru | or 7.