JP3858496B2 - Clothes dryer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a clothes dryer, and more particularly to a labyrinth seal in a dehumidifying clothes dryer.
[0002]
[Prior art]
A typical structure example of a conventional dehumidifying clothes dryer is shown in FIG. 12 in the form of a side sectional view. The clothes dryer is covered with a box-type housing 1, and a door 2 for taking in and out clothes to be dried is provided on the front surface of the clothes dryer, and a rotating drum 4 forming a drying chamber 3 is housed inside the clothes dryer. It has been. On the other hand, a double-sided fan 5 is provided on the rear surface of the box-shaped housing 1. The double-sided fan 5 includes a hot air fan that circulates warm air 9 that dries clothes in the drying chamber 3 and a cold air fan that supplies and exhausts cooling air 10 that cools and dehumidifies the hot air 9 by heat exchange. By being configured, it has two functions of heat exchange and air blowing, and is rotated by a motor 7 via a belt 6. The motor 7 is also a drive source for rotating the rotary drum 4.
[0003]
In addition, a casing 14 that partitions the hot air 9 and the cooling air 10 is provided on the outer periphery of the double-sided fan 5. Between the casing 14 and the double-sided fan 5, leakage of the hot air 9 to the outside and the cooling air 10. A labyrinth seal 8 is provided to suppress or prevent intrusion into the inside of the. The labyrinth seal 8 will be described below with reference to FIG. 13 showing an enlarged portion (A portion). In addition, the code | symbol 11 in FIG. 12 is an electric heater which is a heating means, 12 is a lint filter, 13 is a drain discharge port which discharge | emits the collect | recovered water | moisture content (condensed water).
[0004]
As shown in FIG. 13, the double-sided fan 5 is provided with a fan-side sealing wall 5a on its outer peripheral portion so as to rotate integrally therewith, while the casing 14 faces the fan-side sealing wall 5a. Thus, the casing side sealing wall portion 14a is provided. Between these, a plurality of annular seal pieces 15 provided so as to protrude from the fan-side seal wall 5a in a concentric arrangement and the casing-side seal wall 14a protrude in the same concentric arrangement. A labyrinth seal 8 is formed by a plurality of annular seal pieces 16 provided in this manner.
[0005]
More specifically, the annular seal pieces 15 of the fan-side seal wall 5a and the annular seal pieces 16 of the casing-side seal wall 14a are alternately arranged in the radial direction, and the annular seal pieces 15 from both sides are arranged. And 16 are loosely fitted so as to alternately bite into the gap in the radial direction (concentric arrangement direction) of the adjacent annular seal pieces on the other side in a non-contact manner in the axial direction (direction perpendicular to the radial direction). By combining them, the flow resistance against the air flow passing through the labyrinth seal 8 is generated. Hereinafter, the type in which the annular seal pieces 15 and 16 projecting from both sides as in the above-described conventional example are loosely arranged so as to bite alternately is referred to as an “alternate piece labyrinth seal”.
[0006]
Further, in the labyrinth seal 8, the fan-side annular seal piece 15 is provided so as to protrude from the fan-side seal wall 5 a toward the drum 4 side, and the casing-side annular seal piece 16 is provided on the casing side. The labyrinth seal 8 is provided so as to protrude from the sealing wall portion 14a toward the non-drum side, and the outflow direction of the warm air 9 in the labyrinth seal 8 is a flow from the radially inner periphery toward the outer periphery. Hereinafter, the type in which the outflow direction of the warm air 9 is directed to the outer peripheral side in the radial direction will be referred to as “outward radial flow”.
[0007]
In FIG. 13, the hot air leaking slightly in the labyrinth seal 8 is indicated by a dotted arrow 17. In general, the labyrinth seal 8 in which a plurality of annular seal pieces are arranged in the radial direction is referred to as “radial flow labyrinth”.
[0008]
JP-A-7-155498 discloses a configuration of the labyrinth seal 8 shown in FIG. 13, that is, an alternating piece labyrinth seal corresponding to an outward radial flow labyrinth.
[0009]
[Problems to be solved by the invention]
In the alternating piece labyrinth seal 8 disclosed in Japanese Patent Laid-Open No. 7-155498, the casing wall 14 is inclined so as not to interfere with the fan performance as shown in FIG. For this reason, the protruding heights of the seal pieces 15 and 16 are gradually increased as they move away from the rotation center of the double-sided fan 5, but the "labyrinth effect" is being obtained mainly by frictional resistance caused by the viscosity of the fluid. Therefore, as much as possible, an axial loose fitting bite depth constituted by the seal piece 16 protruding from the casing side seal wall portion 14a and the seal piece 15 protruding from the fan side seal wall portion 5a is taken, The total biting depth is made as long as possible. Here, the “labyrinth effect” means a function that integrates all the functions of reducing the amount of leakage or the function of flow resistance.
[0010]
The prior art has the following problems. One is contact between seal pieces due to thermal deformation. The double-sided fan 5, the casing 14, the labyrinth seal 8, and the like are often formed of a synthetic resin material such as polypropylene, and during operation, the warm air 9 is 60 to 70 ° C and the cooling air 10 is about 30 to 40 ° C. For example, as shown in FIG. 14, the double-sided fan 5 is warped toward the cooling air 10 as indicated by the arrow in the figure due to thermal deformation due to the temperature difference between the front and back sides, and accordingly, the fan located on the outer peripheral side of the double-sided fan 5 On the field that the seal piece 15 of the side seal wall 5a is inclined and the flow path cross-sectional area is changed, the flow resistance is changed and the labyrinth effect is changed, and the seal pieces 15 and 16 are in contact with each other. Problems occur.
[0011]
In the figure, a black circle portion indicated by 50 is an example of the contact portion. Depending on the situation, other parts may come into contact. Further, since the depth of biting in the axial direction of the seal pieces 15 and 16 is deep and the clearance in the radial direction is narrow, the seal pieces 15 and 16 can be connected to each other unless the dimensional accuracy of the seal and the environmental temperature are controlled finely even during molding and production. May come into contact at the time of assembly.
[0012]
Another is a decrease in the labyrinth effect. In the radial flow labyrinth, the centrifugal force due to rotation directly affects the leakage performance of hot air, and in the outward radial flow labyrinth as shown in FIG. 13, the centrifugal force promotes the leakage of hot air, so the labyrinth effect is reduced. It is disadvantageous. In particular, when the double-sided fan 5 rotates at high speed, it cannot be ignored further.
[0013]
In view of the above-mentioned problems, the first object of the present invention is that the productivity of the labyrinth seal 8 is good and the seal pieces 15 and 16 are in contact with each other even if the double-sided fan 5 is thermally deformed due to a temperature change during operation. An object of the present invention is to provide a labyrinth seal structure that is difficult to perform.
[0014]
The second object is to provide a structure in which the leakage of hot air is promoted by the centrifugal force due to rotation and the labyrinth effect is not reduced.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, the present invention firstly supplies and exhausts a warm air fan that circulates warm air for drying clothes in a drum-shaped drying chamber and cooling air that cools and dehumidifies the warm air by heat exchange. The double-sided fan that has two functions of heat exchange and air blowing, the casing that partitions the hot air and the cooling air, and the double-sided fan that rotate integrally with the cold-air fan are configured integrally with the front and back sides. Between the fan-side sealing wall provided on the outer periphery of the double-sided fan and the stationary casing-side sealing wall provided on the casing so as to face the fan-side sealing wall. A labyrinth seal provided, and the labyrinth seal includes a plurality of annular seal pieces provided so as to protrude from the fan-side sealing wall portion toward the side opposite to the drum in a concentric arrangement. A plurality of annular seal pieces provided so as to protrude from the casing side seal wall portion toward the drum side in the same concentric arrangement are combined in a non-contact manner, and the outflow direction of the hot air in the labyrinth seal is a radial direction. The labyrinth seal was configured to have an inward radial flow from the outer peripheral side toward the inner peripheral side.
[0016]
Secondly, the concept of labyrinth effect is completely different. Whereas the main dominating factor of the flow resistance in the conventional labyrinth seal is the frictional resistance due to the viscosity of the fluid, the present invention uses the shape resistance due to the sudden expansion flow and / or the rapid contraction flow. I tried to do it. Specifically, each annular seal piece of the fan-side seal wall and each annular seal piece of the casing-side seal wall are opposed to each other with the opposite annular seal pieces facing each other. The flow path resistance was generated by shifting the position of the gap between the tips of the opposed annular seal pieces according to the concentric arrangement of the annular seal pieces.
[0017]
In other words, the flow cross-sectional area is suddenly changed several times along the flow direction of the fluid, thereby generating a large deceleration flow and acceleration flow several times in the flow, and further generating many unstable small vortices. Increased road resistance. Here, the seal configuration in which the respective annular seal pieces protruding from both sides are protruded so as to face each other without causing the respective annular seal pieces to freely fit together is referred to as an “opposing piece type labyrinth seal”. To.
[0018]
As described above, when the counter piece labyrinth seal is configured as an inward radial flow labyrinth, the centrifugal force due to rotation suppresses the leakage of hot air, so the labyrinth effect is good and the productivity of the labyrinth seal is also good. Moreover, even if the double-sided fan is thermally deformed due to a temperature change during operation, a labyrinth seal structure is obtained in which the seal pieces do not easily come into contact with each other.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described based on several examples.
[0020]
FIG. 1 has the same structure as the dehumidifying clothes dryer shown in FIG. 12, and only the labyrinth seal 8 is the “opposite piece labyrinth seal” according to the present invention, which is an “inward radial flow labyrinth”. FIG. 2 is an enlarged cross-sectional view of the labyrinth seal 8 part (B) of FIG. The labyrinth seal 8 is a plurality of (six as an example in FIG. 2) annular seals provided so as to protrude from the fan side seal wall 5a in a concentric arrangement toward the opposite drum side (right side in the figure). A plurality of (six as an example in FIG. 2) annular seal pieces provided so as to protrude from the casing 15 and the casing side sealing wall 14a in the same concentric arrangement toward the drum side (left side in the figure). 16 in a non-contact manner without loosely fitting between adjacent annular seal pieces, and the outflow direction 17 of the warm air 9 in the labyrinth seal 8 is an inner side from the radially outer peripheral side 8a toward the inner peripheral side 8b. The labyrinth seal 8 is configured to have a radial flow direction.
[0021]
Further, in order to obtain the labyrinth effect by the shape resistance due to the sudden expansion flow and / or the rapid contraction flow, the annular seal pieces 15 of the fan side sealing wall portion 5a and the annular portions of the casing side sealing wall portion 14a are provided. The seal pieces 16 are arranged so that the respective annular seal pieces are opposed to each other so that the tip surfaces of the seal pieces face each other, and the position of the gap Wa50 between the tips of the opposed annular seal pieces 15 and 16 is annular. The seal pieces are alternately shifted in the axial direction according to a concentric arrangement of the seal pieces.
[0022]
In the present invention, the sizes of the axial gap Wa50 and the radial gap Wr51 that are alternately provided are not particularly limited. In view of properties, it is desirable that the minimum is 2-3 mm and the maximum is 7-8 mm. In FIG. 2, the heights of the long and short pieces of the annular seal piece 15 are represented by 15h and 15l, respectively, and the heights of the long and short pieces of the annular seal piece 16 are represented by 16h and 16l, respectively. The height may be an arbitrary dimension, and each height may be separated.
[0023]
When the labyrinth seal 8 is configured as described above, the leaked hot air flow 17 repeats a sudden expansion flow and a rapid contraction flow each time it passes through the gaps 50 and 51, and a large number of unstable small vortices are generated each time the seal piece. It occurs and disappears at the corners of the pipe, and the flow resistance (pressure loss) due to shape resistance such as sudden expansion flow, rapid contraction flow, and vortex increases. Furthermore, in the present invention, since the configuration is an inward radial flow labyrinth, the flow 17 of the leaking hot air is pushed back to the hot air 9 side (inside) by the centrifugal force due to rotation, and the leakage is further suppressed. And the labyrinth effect improves remarkably compared with the past by these two effect | actions.
[0024]
3 and 4 show an embodiment of the seal cross-sectional shape of the annular seal pieces 15 and 16. In FIG. 2, the cross-sectional shape of the annular seal piece is substantially rectangular, but in FIG. 3, the annular seal piece is configured to be tapered and the tip is narrowed. In FIG. 4, the tip of the annular seal piece is inclined. It is cut. 4 is most preferably provided so as to oppose the direction in which the main flow of the leaked hot air 17 flows in the labyrinth seal 8. It is most preferable that the tip of the seal piece is inclined at both of the annular seal pieces 15 and 16, but depending on the situation, only one of them or only some of the annular seal pieces may be provided. Also good. Of course, the shapes of the annular seal pieces 15 and 16 are not limited to these.
[0025]
5 and 6 show an example of the position of the outer periphery of the double-sided fan 5 where the fan-side sealing wall 5a is provided. In FIG. 2, the fan-side sealing wall 5a is provided at the axially central portion 5b of the outer periphery of the double-sided fan 5, but in FIG. 5, the fan-side sealing wall 5a is provided on the opposite drum-side end 5c of the double-sided fan 5. In FIG. 6, the fan-side sealing wall 5 a is provided at the drum-side end 5 d of the double-sided fan 5. Needless to say, the fan-side sealing wall 5a need not be limited to the above position, and may be selected according to productivity, fan performance, sealing performance, and the like.
[0026]
Further, the positions of the axial gaps 50 that are alternately shifted may be regularly provided as shown in FIG. 2, but may be irregular as shown in FIGS. Further, the number of annular seal pieces 15 and 16 protruding from the fan-side sealing wall 5a and the casing-side sealing wall 14a may be six as shown in FIGS. 2 and 5, or as shown in FIG. The number of necessary seal pieces may be determined according to the amount of leakage of hot air 9 to be suppressed. Needless to say, a smaller number of seal pieces is better.
[0027]
In the embodiment of FIGS. 2, 5 and 6, the distance between the fan-side sealing wall 5a and the casing-side sealing wall 14a becomes narrower from the radially outer peripheral side 8a to the inner peripheral side 8b. Although the casing-side sealing wall 14a is inclined, the fan-side sealing wall 5a may be inclined, as shown in FIG. Further, as shown in FIG. 8, it is not necessary to incline any of the walls 5a and 14a so that the distance between the fan-side sealing wall 5a and the casing-side sealing wall 14a is always constant.
[0028]
Next, an example of how to assemble the casing-side sealing wall 14a having the annular seal piece 16 will be described. As can be seen from each of the drawings, if the casing-side sealing wall 14a is integrally molded and fixedly attached to the casing 14 from the beginning, the double-sided fan 5 having the annular seal piece 15 cannot be attached to the rotary shaft 32. For this reason, as an assembly order, it is necessary to attach the double-sided fan 5 having the annular seal piece 15 to the rotating shaft 32 first, and then attach the casing-side sealing wall 14a to the casing 14.
[0029]
FIG. 9 shows an embodiment of the mounting method. The casing 14 is already provided up to the vicinity of the upper part of the fan-side sealing wall 5a. First, the double-sided fan 5 having the annular seal piece 15 is inserted into the casing 14. Thereafter, the casing-side sealing wall 14a is attached to the casing 14 so as to cover the double-sided fan 5. In the illustrated embodiment, a mounting rib 14b is provided at the base of the casing-side sealing wall 14a, and the rib 14b is attached to the casing 14 with a screw 54. For this reason, it is easy to attach and detach the casing-side sealing wall 14a, and the replacement is possible when the double-sided fan 5 is out of order.
[0030]
On the other hand, FIG. 10 shows another embodiment of the mounting method. The casing 14 has already been provided behind the fan-side sealing wall 5a, and the casing-side sealing wall 14a is formed by a rib 14b provided at the end thereof. It is the structure attached with the screw | thread 54. FIG. The method for attaching the casing-side seal wall 14a is not limited to the method shown in FIGS. 9 and 10, and the fan 5 having the annular seal piece 15 is attached to the rotating shaft 32 before the casing-side seal wall 14a is attached. It only needs to be able to be easily attached.
[0031]
FIG. 11 is another embodiment showing how to attach the casing-side sealing wall 14a. For example, in FIG. 9, the water (condensed water) from the mounting joint 52 of the casing 14 and the casing-side sealing wall 14a. This is an example in which a rubber-like sealing material 53 or packing is provided at the joint portion 52 as a countermeasure for a case where leakage of warm air 9 or the like is feared to the outside. This method can also be easily implemented in FIG.
[0032]
In general, the labyrinth seal 8 and the double-sided fan 5 and the casing 14 of a clothes dryer are often molded and manufactured from a resin such as polypropylene or a synthetic resin material. When such a clothes dryer is frequently used for drying clothes containing various oil components, the oil component is impregnated into the resin, and the double-sided fan 5 and the casing 14 are deformed by swelling, and the labyrinth seal 8 In some cases, the seal pieces 15 and 16 contact each other.
[0033]
In the labyrinth seal 8 of the present invention for a clothes dryer which is often used in such a manner, the following may be performed. First, the exposed surface of the double-sided fan 5 and / or the casing 14 that comes into contact with air, particularly the surface that contacts the oil component, is coated and coated with a material that does not impregnate the oil component, for example, a synthetic resin that does not contain a rubber component. do it. Further, a paint that is difficult to impregnate the oil component may be applied to the exposed surface.
[0034]
Alternatively, the material constituting the double-sided fan 5 and / or the casing 14 main body may be made of a material not impregnated with an oil component. The material in this case may also be a synthetic resin such as polypropylene that does not contain a rubber component. Further, the double-sided fan 5 and / or the entire casing 14 including the labyrinth seal 8 may be made of a metal such as aluminum or magnesium and a non-metallic material instead of the resin material.
[0035]
In the above configuration, at least the exposed surface of the double-sided fan 5 and / or the casing 14 may be made of a material not impregnated with an oil component, and the exposed surface may be a hydrophilic surface. In this case, desirably, the material not impregnated with the oil component has a hydrophilic property. Furthermore, it is even more preferable that the double-sided fan 5 and / or the entire casing 14 including the labyrinth seal 8 can be made of a material having a low coefficient of thermal expansion (linear expansion coefficient).
[0036]
【The invention's effect】
According to the labyrinth seal configuration of the present invention, in addition to the dramatic increase in pressure loss due to the shape resistance caused by the sudden expansion flow and / or the sudden contraction flow due to the opposed one-piece labyrinth seal, inward radial flow labyrinth Thus, the centrifugal force due to rotation pushes back the leaked warm air and condensed water and works in a direction to suppress the leakage, and as a result, a labyrinth effect (seal performance) higher than conventional can be obtained.
[0037]
Furthermore, since the two annular seal pieces do not loosely fit in a non-contact manner through a narrow gap as in the prior art, a labyrinth seal suitable for high production and avoiding the risk of contact during operation, and A clothes dryer can be provided.
[Brief description of the drawings]
FIG. 1 is a side sectional view of a clothes dryer according to the present invention.
FIG. 2 is a side cross-sectional view of an opposed piece-shaped inward radial flow labyrinth.
FIG. 3 is a side sectional view of an annular seal piece having a taper.
FIG. 4 is a side sectional view of an annular seal piece with the tip cut off.
FIG. 5 is a side cross-sectional view of a facing piece seal.
FIG. 6 is a side cross-sectional view of an opposed piece seal.
FIG. 7 is a side cross-sectional view of an opposed piece seal.
FIG. 8 is a side cross-sectional view of an opposed piece seal.
FIG. 9 is a side cross-sectional view of a mounting structure of a sealing wall.
FIG. 10 is a side sectional view of a mounting structure of a sealing wall.
FIG. 11 is a side cross-sectional view of an attachment structure having a sealing material.
FIG. 12 is a side sectional view of a conventional clothes dryer.
FIG. 13 is a side sectional view of a conventional labyrinth seal.
FIG. 14 is a diagram showing a contact state of a conventional labyrinth seal.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Box-shaped housing | casing, 2 ... Door, 3 ... Drying chamber, 4 ... Rotary drum, 5 ... Double-sided fan, 6 ... Belt, 7 ... Motor, 8 ... Labyrinth seal, 9 ... Hot air, 10 ... Cooling air,
DESCRIPTION OF SYMBOLS 11 ... Electric heater, 12 ... Waste thread filter, 13 ... Drain discharge port, 14 ... Casing, 15 ... Double-sided fan side annular seal piece, 16 ... Casing side annular seal piece, 17 ... Leak warm air, 32 ... Central axis, 50 ... axial gap, 51 ... radial gap, 52 ... joint, 53 ... sealing material, 54 ... screw.

Claims (1)

A hot air fan that circulates warm air that dries clothes in a drum-shaped drying chamber and a cold air fan that supplies and exhausts cooling air that cools and dehumidifies the hot air by heat exchange are integrated into the front and back to form heat. A double-sided fan having both functions of replacement and air blowing, a casing for partitioning the warm air and the cooling air, and a fan-side seal provided on an outer peripheral portion of the double-sided fan so as to rotate integrally with the double-sided fan In a clothes dryer comprising a labyrinth seal provided between a wall for use and a stationary casing side seal for use provided in the casing so as to face the fan-side seal wall,
The labyrinth seal is configured such that the outflow direction of the warm air at the labyrinth seal is an inward radial flow from the outer peripheral side to the inner peripheral side in the radial direction, and the labyrinth seal is concentric from the fan side sealing wall. A plurality of annular seal pieces projecting in a general arrangement and a plurality of annular seal pieces projecting in a concentric arrangement from the casing-side sealing wall, and a fan-side annular seal piece and a casing-side annular ring fan, and in accordance with position concentric arrangement of the gap between the tip between opposed annular seal piece in the axial direction of the fan as the sealing piece the tip of each of the annular seal piece faces with a gap A clothes dryer characterized by being alternately arranged on the side seal wall part side and the casing side seal wall part side.

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