JP4620825B2 - Fan sealing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal device for an axial flow type or mixed flow type fan used in a radiator for automobiles, and more specifically, a ring for interconnecting blade tips and a cylindrical portion of a shroud arranged on the radially outer side. The present invention relates to a fan sealing device provided with a labyrinth seal for preventing backflow therebetween.
[0002]
[Prior art]
Conventionally, an axial flow type or mixed flow type fan used in an automobile radiator or the like includes a boss portion that is rotated by a driving source such as an engine or a motor, and a plurality of blades that are radially connected to the boss portion. The air is blown in the axial direction by the rotation of the blade.
A fan such as a radiator for an automobile has a shroud cylindrical portion fitted on the outer periphery of the wing to prevent backflow near the tip of the wing as much as possible.
[0003]
On the other hand, in order to reinforce the strength of the wing due to the special shape, a method of interconnecting the tip edges with a ring is adopted. For such wings, the shroud tube is generally omitted because the backflow is reduced to some extent by the shielding effect of the ring.
However, none of the above-described backflow prevention methods can be said to be satisfactory from recent severe performance requirements. Therefore, as a more effective backflow prevention method, a combination of both the cylindrical portion of the shroud and the ring and a portion that exhibits a labyrinth seal effect between them is known. (For example, Japanese Patent Publication No. 40-4953, Japanese Utility Model Publication No. 53-128906, etc.)
[0004]
Generally, the labyrinth seal is used for the purpose of sealing a bearing portion of a rotating device, and is configured by alternately providing a throttle piece and a space portion between a shaft on the rotating side and a bearing portion on the fixed side. The flow of the seal part isentropically expanded when passing through the throttle port formed by the throttle piece, decelerates there, and recovers to a static temperature under an equal pressure in the expansion chamber (space part). A sealing effect is achieved by repeating the process of flowing into the throttle port.
The method described in the above publication accepts a ring that connects the outer peripheral part of the wing to a concave part provided on the inner peripheral surface of the cylindrical part of the shroud, with the rotating side as a ring and the stationary side as a cylindrical part of the shroud, and the concave part A seal portion is formed.
[0005]
[Problems to be solved by the invention]
However, in such a structure in which the ring is inserted into the concave portion of the cylindrical portion of the shroud, it is difficult to assemble by inserting a fan from the axial direction of the cylindrical portion of the shroud. In order to solve this problem, for example, the cylindrical portion of the shroud needs to be divided, and each divided portion needs to be assembled from the outside of the fan, resulting in another problem that the structure becomes complicated and the cost is increased. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a new fan sealing device that solves such problems.
[0006]
[Means for Solving the Problems]
That is, the invention according to claim 1 is an axial flow type or mixed flow type fan 1 sealing device in which a plurality of blades 3 are provided radially on a boss portion 2a.
A ring 4 for connecting the leading edges of the blades 3 to each other; and a shroud tubular portion 5 disposed with a gap on the radially outer side of the ring 4;
A plurality of annular throttle pieces S project from the outer periphery of the ring 4, and the inner periphery of the shroud tubular portion 5 is formed flat to prevent backflow between the ring 4 and the shroud tubular portion 5. A labyrinth seal portion 8 is formed,
The outer diameter of the aperture piece S is smaller than the inner diameter of the shroud tubular portion 5, and the ring 4 is configured to be detachable from the axial direction in the shroud tubular portion 5,
The labyrinth seal portion 8 is formed in a direct-through type by the throttle pieces S provided at both ends in the axial direction of the ring 4 or at both ends and an intermediate portion,
At least one end portion of the ring 4 in the axial direction is formed in an annular bell mouth M whose diameter gradually increases toward the end, and the height of the bell mouth M in the radial direction is the height of the other throttle piece S. Formed to the same height as it,
The bell mouth M is a fan sealing device characterized in that it prevents air flow disturbance and vortex generation at the end of the ring 4 and also serves as a throttle piece S.
[0007]
The present invention according to claim 2 is a sealing device for an axial flow type or mixed flow type fan 1 in which a plurality of blades 3 are provided radially on a boss portion 2a.
A ring 4 for connecting the leading edges of the blades 3 to each other; and a shroud tubular portion 5 disposed with a gap on the radially outer side of the ring 4;
A plurality of annular throttle pieces S project from the outer periphery of the ring 4, and a plurality of annular reverse throttle pieces R project from the inner circumference of the cylindrical portion 5 of the shroud. The ring 4 and the shroud cylinder A labyrinth seal portion 8 for preventing backflow is formed between the shape portion 5 and
The outer diameter of the diaphragm piece S is smaller than the inner diameter of the reverse diaphragm piece R of the shroud,
The ring 4 is configured to be detachable from the axial direction in the cylindrical portion 5 of the shroud,
The labyrinth seal portion 8 is located between the throttle pieces S provided at both ends in the axial direction of the ring 4 or between the both ends and the middle portion, and the respective throttle pieces S, and protrudes from the inner surface of the cylindrical portion 5 of the shroud. Formed in a staggered shape formed with the reverse drawn piece R provided,
At least one end portion of the ring 4 in the axial direction is formed in an annular bell mouth M whose diameter gradually increases toward the end, and the height of the bell mouth M in the radial direction is the height of the other throttle piece S. Formed to the same height as it,
The bell mouth M is a fan sealing device characterized in that it prevents air flow disturbance and vortex generation at the end of the ring 4 and also serves as a throttle piece S.
[0008]
The invention according to claim 3 is the invention according to claim 2 ,
The reverse flow f passing through the downstream throttle piece S2 via the reverse throttle piece R from the throttle piece S1 located on the upstream side in the reverse flow direction is divided by the reverse throttle piece R, and a part thereof is reversed by the downstream throttle piece S2. The heights H1 and H2 of the throttle pieces S1 and S2 from the outer peripheral surface 4a of the ring 4 and the height H3 of the reverse throttle piece R and the axial distance L between the throttle pieces S1 and S2 are selected. it is a sealing device of the fan.
The invention according to claim 4 is the invention according to claim 3 ,
The distance C between the upstream throttle piece S1 and the reverse throttle piece R is in the range of 0 ≦ C ≦ 0.75 (mm) (however, between H1, H2, and L, 0.2 ≦ H1 / L ≦ 1. 5 and 0.8H1 ≦ H2).
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1A is an example in which the sealing device of the present invention is applied to a cooling fan of a heat exchanger such as a radiator for an automobile, and FIG. 1B is a longitudinal sectional view thereof, and FIG. . The axial flow type or mixed flow type fan 1 includes a drive shaft 2 that is rotated by a crankshaft of an engine (not shown), a boss portion 2a to which the drive shaft 2 is coupled, and a plurality of radially attached to the boss portion 2a. The wing 3 is provided. The tip edges of the blades 3 are connected to each other by a ring 4, and a shroud cylindrical portion 5 is disposed on the radially outer side of the ring 4 with a predetermined gap.
The ring 4 is provided with a plurality of throttle pieces S such as annular partition pieces extending in the radial direction at predetermined intervals. In this example, an annular bell mouth M is provided at both ends of the ring 4 to prevent air flow turbulence and vortex generation, and the bell mouth M also serves as the throttle pieces S at both ends. ing.
[0010]
On the other hand, the shroud tubular portion 5 is connected to a heat exchanger 7 such as a radiator via a shallow funnel-shaped shroud body 6. In this example, the shroud tubular portion 5 and the shroud body 6 are formed separately. Both are fixed by a fastener or the like. Note that the shroud body 6 and the cylindrical portion 5 of the shroud may be integrally formed.
The inner peripheral surface of the cylindrical portion 5 of the shroud faces the outer peripheral edge of the diaphragm piece S of the ring 4 with a slight gap. A so-called direct labyrinth seal portion 8 is formed by the inner peripheral surface of the cylindrical portion 5 of the shroud and the plurality of throttle pieces S. In such a labyrinth seal portion 8, a throttle port is formed by the gap between the inner peripheral surface of the shroud cylindrical portion 5 and the tip of the throttle piece S, and the reverse flow from the downstream side of the blade 3 passes through the throttle port. The labyrinth seal effect is effectively exhibited by repeating the action of the isentropic expansion at the time and the decelerated reverse flow recovering to a static temperature with an equal pressure in the space (expansion chamber) in the middle of the adjacent throttle piece S. ing.
[0011]
In this way, there is a very small gap between the tip of each throttle piece S and the outer peripheral surface of the ring 4, but a portion overlapping in the radial direction between the ring 4 and the cylindrical portion 5 of the shroud. Does not exist. That is, the outer diameter of each throttle piece S is smaller than the inner diameter of the cylindrical portion 5 of the shroud. Therefore, the fan 1 can be easily assembled into the state shown in FIG. 1 by inserting the fan 1 into the cylindrical portion 5 of the shroud from the axial direction.
[0012]
FIG. 2 is a partial sectional view showing a modification of FIG. This example differs from the example of FIG. 1 in that a bell mouth M is formed only at one end of the ring 4 and a diaphragm piece S made up of a partition piece is provided at the other end and the middle without the bell mouth M. Are structured similarly. The throttle piece S made of a partition piece may be integrally formed into the ring 4, but may be attached to the ring 4 by adhesion or welding.
The bell mouth M also serves as a throttle piece S at one end, and a direct labyrinth seal portion 8 is formed by the inner peripheral surface of the cylindrical portion 5 of the shroud and the plurality of throttle pieces S of the ring 4. The operation is the same as in FIG.
[0013]
FIG. 3 is a partial sectional view showing another example of the sealing device of the present invention. In this example as well, the bell mouth M is formed only at one end of the ring 4 as in FIG. 2, and the throttle piece S made of a partition piece is provided at the other end and the middle without the bell mouth M. A plurality of reverse aperture pieces R are provided on the inner peripheral surface of the cylindrical portion 5. In this manner, by alternately providing the throttle pieces S and the reverse throttle pieces R at a predetermined interval, a so-called staggered labyrinth seal portion 8 is formed. And the front-end | tip of the aperture piece S and the reverse aperture piece R is comprised so that it may not overlap in a radial direction. That is, the outer diameter of the throttle piece S is smaller than the inner diameter of the reverse throttle piece R.
[0014]
FIG. 4 is an enlarged view of a part of FIG. 3 for explaining the operation of the staggered labyrinth seal portion 8 configured as described above. When the throttle piece located on the upstream side in the reverse flow direction is sandwiched by S1 and the throttle piece located on the downstream side is S2 across the reverse throttle piece R formed on the inner peripheral surface of the cylindrical portion 5 of the shroud, the reverse throttle piece R If the reverse flow f passing through the downstream throttle piece S2 is divided by the reverse throttle piece R and part of the reverse flow is reversed by the downstream throttle piece S2, the labyrinth seal effect can be effectively exhibited. It was confirmed by experiment.
In order to cause such a reverse flow f reversal action, the relationship between the height of the throttle pieces S1 and S2 from the outer peripheral surface 4a of the ring 4 and the height of the reverse throttle piece R and the distance between the throttle pieces S1 and S2 is determined. What is necessary is just to select in the predetermined range by experiment etc.
[0015]
FIG. 5 is a diagram for more specifically explaining the relationship between the above-described parts. The heights from the outer peripheral surface 4a of the ring 4 to the tips of the throttle pieces S1, S2 are respectively shown as H1, H2, and the height of the reverse throttle piece R, respectively. Assuming that H3, the distance in the axial direction between the throttle pieces S1 and S2 is L, and the distance between the tip of the throttle piece S1 and the tip of the reverse throttle piece R is C, the value of C is 0 ≦ C ≦ 0.75 (mm) (however, between H1, H2 and L, it is assumed that there is a relationship of 0.2 ≦ H1 / L ≦ 1.5 and 0.8H1 ≦ H2). It has been found that the labyrinth seal effect is effectively obtained even in the case of the staggered labyrinth seal portion 8 configured so that the tip of the piece and the reverse throttle piece do not overlap in the radial direction.
For reference, FIG. 6 shows experimental results of the distance C between the upstream throttle piece S1 and the reverse throttle piece R and the reverse flow rate.
The sealing device described so far is an example applied to an axial flow type fan, but it goes without saying that the present invention can be applied to a mixed flow type fan as well.
[0016]
【The invention's effect】
As described above, according to the fan sealing device of the present invention, an effective labyrinth seal portion is formed between the ring and the cylindrical portion of the shroud, and each blade connected by the ring is placed in the cylindrical portion of the shroud. It can be easily inserted from the axial direction.
Further , the labyrinth seal portion is formed in a straight-through type by the throttle pieces S provided at both ends in the axial direction of the ring or at both ends and the middle portion, and formed at the bell mouth M at least at one end portion in the axial direction of the ring 4; The height of the bell mouth M in the radial direction is formed to be the same as that of the other throttle piece S, and the bell mouth M prevents the air flow from being disturbed at the end of the ring 4 and the generation of vortices. Since the diaphragm piece S is also used, the above-described effects of the present invention can be exhibited with an efficient and simple structure.
[0017]
The labyrinth seal portion is a staggered type formed by a throttle piece S provided at both ends of the ring side in the axial direction or at both ends and an intermediate portion and a reverse throttle piece R provided at the cylindrical portion side of the shroud. And when it comprises so that the front-end | tip of a reverse aperture piece R may not overlap in a radial direction, it can exhibit the said effect of this invention, having a higher sealing effect by it.
Furthermore, in the fan sealing device having the staggered labyrinth seal portion, the reverse flow passing through the throttle piece S2 on the downstream side from the throttle piece S1 positioned on the upstream side in the reverse flow direction is converted into the reverse throttle piece R In this case, the above-mentioned effect of the present invention can be stably exhibited while having a higher sealing effect.
[Brief description of the drawings]
FIG. 1 is an example in which a sealing device of the present invention is applied to a cooling fan of an automotive heat exchanger, and a longitudinal sectional view and an AA arrow view thereof.
FIG. 2 is a partial sectional view showing a modification of FIG.
FIG. 3 is a partial cross-sectional view showing another example of the sealing device of the present invention.
4 is an enlarged view of a part of FIG. 3 for explaining the operation of the staggered labyrinth seal portion 8. FIG.
FIG. 5 is a diagram for more specifically explaining the relationship between each part in FIG. 4;
FIG. 6 is a diagram showing experimental results of an interval C between an upstream throttle piece S1 and a reverse throttle piece R and a reverse flow rate.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fan 2 Drive shaft 2a Boss part 3 Wing | blade 4 Ring 4a Outer peripheral surface 5 Shroud cylindrical part 6 Shroud main body 7 Heat exchanger 8 Labyrinth seal part S Restriction piece S1 Upstream restriction piece S2 Downstream restriction piece R Reverse restriction Fragment M bellmouth f backflow

Claims (4)

In the sealing device for the axial flow or mixed flow type fan 1 in which a plurality of blades 3 are provided radially on the boss portion 2a,
A ring 4 for connecting the leading edges of the blades 3 to each other; and a shroud tubular portion 5 disposed with a gap on the radially outer side of the ring 4;
A plurality of annular throttle pieces S project from the outer periphery of the ring 4, and the inner periphery of the shroud tubular portion 5 is formed flat to prevent backflow between the ring 4 and the shroud tubular portion 5. A labyrinth seal portion 8 is formed,
The outer diameter of the aperture piece S is smaller than the inner diameter of the cylindrical portion 5 of the shroud, and the ring 4 is configured to be detachable from the axial direction in the cylindrical portion 5 of the shroud,
The labyrinth seal portion 8 is formed in a direct-through type by the throttle pieces S provided at both ends in the axial direction of the ring 4 or at both ends and an intermediate portion,
At least one end portion of the ring 4 in the axial direction is formed in an annular bell mouth M whose diameter gradually increases toward the end, and the height of the bell mouth M in the radial direction is the height of the other throttle piece S. Formed to the same height as it,
The bell mouth M is a fan sealing device characterized in that the air flow at the end of the ring 4 is prevented from being disturbed and a vortex is generated, and also serves as a throttle piece S. In the sealing device for the axial flow or mixed flow type fan 1 in which a plurality of blades 3 are provided radially on the boss portion 2a,
A ring 4 for connecting the leading edges of the blades 3 to each other; and a shroud tubular portion 5 disposed with a gap on the radially outer side of the ring 4;
A plurality of annular throttle pieces S project from the outer periphery of the ring 4, and a plurality of annular reverse throttle pieces R project from the inner circumference of the cylindrical portion 5 of the shroud. The ring 4 and the shroud cylinder A labyrinth seal portion 8 for preventing backflow is formed between the shape portion 5 and
The outer diameter of the diaphragm piece S is smaller than the inner diameter of the reverse diaphragm piece R of the shroud,
The ring 4 is configured to be detachable from the axial direction in the cylindrical portion 5 of the shroud,
The labyrinth seal portion 8 is located between the throttle pieces S provided at both ends in the axial direction of the ring 4 or between the both ends and the middle portion, and the respective throttle pieces S, and protrudes from the inner surface of the cylindrical portion 5 of the shroud. Formed in a staggered shape formed with the reverse drawn piece R provided,
At least one end portion of the ring 4 in the axial direction is formed in an annular bell mouth M whose diameter gradually increases toward the end, and the height of the bell mouth M in the radial direction is the height of the other throttle piece S. Formed to the same height as it,
The bell mouth M is a fan sealing device characterized in that the air flow at the end of the ring 4 is prevented from being disturbed and a vortex is generated, and also serves as a throttle piece S. In claim 2,
The reverse flow f passing through the downstream throttle piece S2 via the reverse throttle piece R from the throttle piece S1 located on the upstream side in the reverse flow direction is divided by the reverse throttle piece R, and a part thereof is reversed by the downstream throttle piece S2. The heights H1 and H2 of the throttle pieces S1 and S2 from the outer peripheral surface 4a of the ring 4 and the height H3 of the reverse throttle piece R and the axial distance L between the throttle pieces S1 and S2 are selected. Fan sealing device. In claim 3,
The distance C between the upstream throttle piece S1 and the reverse throttle piece R is in the range of 0 ≦ C ≦ 0.75 (mm) (however, between H1, H2, and L, 0.2 ≦ H1 / L ≦ 1. 5 and 0.8H1 ≦ H2).

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