Air blower and washing and drying machine comprising the same

Abstract

To provide an air blower capable of realizing both reduction in size and increase in air volume.SOLUTION: An air blower 4 comprises an impeller 300, a spiral casing 51 that houses the impeller 300, and a heat source 6 that is installed downstream of the spiral casing 51 and through which airflow flowing out of the spiral casing 51 passes. The spiral casing 51 has flow passage parts 53, 60, including a scroll flow passage part 53 provided on an outer peripheral part of the impeller 300, that guide the airflow to the heat source 6. The flow passage parts 53, 60 have a first expansion ratio change part P1 and a second expansion ratio change part P2 in which a cross-sectional area of the flow passage increases from upstream to downstream and in which an expansion rate of the cross-sectional area of the flow passage changes. The expansion rate of a flow passage 531 between the first expansion ratio change part P1 and the second expansion ratio change part P2 is larger than the expansion rate of a flow passage 60 between the second expansion ratio change part P2 and the heat source 6.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a blower and a washer / dryer equipped with the same. [Background technology]

[0002] In a washer-dryer, high temperature and a large volume of dry air are important for improving drying performance. However, generating a large volume of dry air requires inputting more energy into the blower. A blower uses an electric motor to rotate an impeller to create an airflow. Air flowing in through the blower's intake port is pressurized and accelerated by the impeller and then decelerated in a stationary flow path, converting the kinetic energy of the air into pressure energy and increasing its pressure. When a blower is installed in a washer-dryer, an integrated motor-type blower in which the motor and impeller are directly connected is typically used. However, since the blower must be housed within the limited space inside the housing, the blower must be compact. For these reasons, a blower installed in a washer-dryer must be both compact and capable of generating a large volume of air.

[0003] When a blower is made smaller, the internal flow velocity increases if the flow rate remains the same before the downsizing. As the flow velocity increases, friction loss at the wall surface and separation loss due to sudden bends and expansions in the flow path increase, resulting in a decrease in efficiency. When efficiency decreases, more input energy is required to achieve the same flow rate and pressure, which in turn increases the power consumption of the washer-dryer. Therefore, in order to achieve a smaller, larger-volume blower, it is necessary to suppress flow separation while efficiently directing the flow into the air path to reduce the flow velocity.

[0004] Known air passage structures for blowers that achieve a small size and large air volume are those disclosed in Patent Document 1. Patent Document 1 discloses a structure that aims to increase efficiency and reduce noise by expanding the cross-sectional area of ​​the scroll passage of the blower near the tongue, where the cross-sectional area of ​​the passage is narrowest. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-221017 Summary of the Invention [Problem to be solved by the invention]

[0006] In the structure described in Patent Document 1, the cross-sectional area of ​​the flow passage is expanded around the tongue of the scroll flow passage, but the change in the cross-sectional area of ​​the flow passage between the upstream and downstream of the tongue becomes large, which raises concerns about increased loss due to the sudden expansion of the flow passage. For this reason, the blower described in Patent Document 1 has issues with improving efficiency, and it is difficult to say that it satisfactorily achieves both compactness and a large air volume.

[0007] An object of the present invention is to provide a blower that can be made compact and has a large air volume. [Means for solving the problem]

[0008] In order to achieve the above object, the blower of the present invention comprises: An electric motor, a rotating shaft rotatably provided in the electric motor; an impeller provided on the rotating shaft; a volute casing containing the impeller; a heat source disposed downstream of the volute casing and through which the flow flowing out of the volute casing passes; the volute casing has a flow path portion including a scroll flow path portion provided on an outer periphery of the impeller, and directing a flow to the heat source; the flow path section has a first expansion rate changing section and a second expansion rate changing section in which the cross-sectional area of ​​the flow path increases from the upstream side to the downstream side and the expansion rate of the cross-sectional area of ​​the flow path changes; The expansion ratio in the flow path between the first expansion ratio change section and the second expansion ratio change section is greater than the expansion ratio in the flow path between the second expansion ratio change section and the heat source. [Effects of the Invention]

[0009] According to the present invention, the efficiency of the blower can be improved by miniaturizing the blower while suppressing an increase in separation loss due to an increase in the flow path expansion ratio that accompanies the miniaturization, thereby enabling a blower that is both compact and capable of producing a large air volume. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing the internal structure of a washing / drying machine in which a blower according to the present invention is installed. [Figure 2] FIG. 4 is a cross-sectional view showing the internal structure of a blower according to a comparative example of the present invention. [Figure 3] 1 is a cross-sectional view showing a flow path structure of a blower according to an embodiment of the present invention. [Figure 4] 3 is a schematic diagram showing a change in flow path cross-sectional area in the flow direction of a blower according to an embodiment of the present invention. FIG. [Figure 5] FIG. 2 is an enlarged view of an enlarged flow path portion of a blower according to an embodiment of the present invention. [Figure 6] 1 is a schematic diagram of a flow path structure of a blower according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0011] Drying clothes in a washer-dryer, which can wash and dry clothes continuously, uses a fan and heat source to create high-temperature drying air, which is then blown into the washing tub to raise the temperature of the clothes and evaporate the moisture from them.

[0012] Dry air driven by the blower circulates through the air passage inside the washer / dryer. The high-temperature air that passes through the heat source picks up moisture from the wet clothes in the washing tub, and the hot, humid air is cooled in a cooling channel installed in the air passage, causing the moisture to condense. This cooled air is then passed through a heating section and heated again to create dry air that is then directed back at the clothes. By repeating this process, moisture contained in the clothes is removed, completing the drying process.

[0013] Therefore, in the drying process, it is important that the drying air is high temperature and has a large volume. To obtain a large volume and high temperature of drying air, it is necessary to input a large amount of energy into the blower. To obtain the desired performance in a washer-dryer, energy must be input to the blower efficiently.

[0014] A blower uses an electric motor to rotate an impeller to create a flow of air. The air flowing in through the blower's intake port is pressurized and accelerated by the impeller, and then decelerated in a stationary flow path, converting the kinetic energy of the air into pressure energy, increasing the pressure.

[0015] When installing a blower in a washer-dryer, it is common to use an integrated motor-type blower in which the motor and impeller are directly connected. However, since the blower must be housed within the limited space inside the housing, it is necessary to miniaturize the blower. Furthermore, in order to improve the drying performance required of washing machines in recent years, an increase in air volume is required. For these reasons, the blower installed in a washer-dryer must be both compact and capable of large air volume.

[0016] When a blower is downsized, the internal flow velocity increases if the flow rate remains the same. The increased flow velocity reduces efficiency due to increased friction loss on the wall and separation loss due to sharp bends and expansions in the flow path. This reduced efficiency requires more input energy to achieve the same flow rate and pressure, ultimately increasing the power consumption of the washer-dryer.

[0017] Therefore, in order to realize a small, large-volume blower, it is necessary to suppress flow separation and efficiently guide the flow into the air path to reduce the flow velocity.

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a cross-sectional view showing the internal structure of a washer-dryer S equipped with a blower 4 according to the present invention. In this embodiment, a drum-type washer-dryer will be described as an example of the washer-dryer S, but the present invention may also be applied to a vertical washer-dryer having an inner tub with a rotation shaft extending substantially vertically, and the configuration, features, and effects achieved thereby are similar to those of a drum-type washer-dryer.

[0019] The drum type washer-dryer S performs a process from washing to drying laundry. The drum type washer-dryer S includes a box body 1, an outer tub 2, an inner tub 3, a blower 4, a circulating air duct 5, a heater 6, a drying filter 7, and a heat exchanger 8.

[0020] The outer shell of the drum type washer-dryer S is formed by a box body 1. A door 1d is provided at the front of the box body 1 for loading and unloading laundry. A control device 1c that controls the drum type washer-dryer S is provided at the top of the box body 1. The control device 1c is made up of various circuits such as a microcomputer, a sensor circuit, and a drive circuit for rotating the inner tub three times.

[0021] Washing water is stored inside the outer tub 2. A water supply valve (not shown) that supplies water to the outer tub 2 is provided at the upper rear part of the box 1. The inner tub 3 is provided inside the outer tub 2, laundry is placed inside the inner tub 3, and the inner tub 3 rotates around a substantially horizontal rotation axis O.

[0022] During the drying process, the blower 4 supplies air (circulating air) for drying the laundry into the inner tub 3. The circulation air duct 5 connects the outer tub 2 and the blower 4. The circulation air duct 5 is provided with a duct 5d through which the drying air flows, a first bellows hose 5j1, and a second bellows hose 5j2. The circulation air duct 5 extends from an intake port 5i into the duct 5d to an outlet port 5o to the inner tub 3. The intake port 5i is an intake port that draws circulating air from the rear of the outer tub (into the circulation air duct), similar to the opening 2i in the fourth embodiment described below.

[0023] The first bellows hose 5j1 and the second bellows hose 5j2 deform to prevent the vibrations of the outer tub 2 that occur when the inner tub 3 rotates from being transmitted to the components (such as the blower 4 and heater 6) fixed to the box body 1.

[0024] The heater 6 is provided inside the circulating air duct 5. The heater 6 heats the circulating air sent from the fan 4 in the circulating air duct 5 during the drying process.

[0025] The drying filter 7 is provided inside the circulating air duct 5. The drying filter 7 captures lint carried by the circulating air before the blower 4 during the drying process.

[0026] Heat exchanger 8 is provided in circulating air passage 5 and cools and dehumidifies the circulating air. Water passage 8a2 is provided inside heat exchanger 8. The surface of pipe 8a that is in contact with the circulating air forms heat exchange surface 8a1.

[0027] One end of a first internal water supply hose 9a is provided at the lower end of the outer tub 2. The other end of the first internal water supply hose 9a is connected to a lint filter 10 that collects lint during washing and rinsing.

[0028] A circulation pump 11 for circulating the wash water is installed downstream of the lint filter 10. The downstream side of the circulation pump 11 is connected to a second internal water distribution hose 9b and a third internal water distribution hose 9c connected to a drain valve 12. The second internal water distribution hose 9b is connected to the top of the outer tub 2 and supplies wash water to the inner tub 3. The drain valve 12 is connected to an external drain hose 13 for draining the water outside the machine.

[0029] During the drying process, drying air for drying the laundry is generated by the blower 4. The drying air that has passed through the laundry in the inner tub 3 passes from the inner tub 3 through the outer tub 2 (dashed arrow β11 in FIG. 1), the intake port 5i (dashed arrow β12 in FIG. 1), the duct 5d (dashed arrow β13 in FIG. 1), the first bellows hose 5j1 (dashed arrow β14 in FIG. 1), the drying filter 7, the blower 4, the heater 6 (dashed arrow β15 in FIG. 1), and the second bellows hose 5j2, and is then circulated through the outlet 5o into the inner tub 3 (dashed arrow β16 in FIG. 1).

[0030] FIG. 2 is a cross-sectional view showing the internal structure of a blower 4 according to a comparative example of the present invention. The blower 4 mainly uses a centrifugal impeller 300. The impeller 300 is connected to a rotary shaft 101 rotatably mounted on an electric motor 100, and is rotated by the electric motor 100. The flow F driven by the rotating impeller 300 is collected through a scroll flow passage 53 formed by a blower casing (volute casing) 51, which is provided radially outside the impeller 300, and is then guided to the heater 6. In this case, an enlarged flow passage 60 is provided between the outlet of the scroll flow passage 53 and the heater 6, with the aim of directing the flow to the entire heater 6. The enlarged flow passage 60 is a flow passage whose cross-sectional area expands from the upstream side to the downstream side.

[0031] The flow F driven by the impeller 300 passes through the heater 6, then passes through the contracting flow path 61, and flows out of the fan through the fan outlet 400. The contracting flow path 61 is a flow path whose cross-sectional area decreases from the upstream side to the downstream side. In this figure, the fan outlet 400 is bent by 90 degrees, but this shape can take various forms depending on the internal structure of the washer-dryer S to be installed.

[0032] In reducing the size of the blower 4, it is assumed that the impeller 300 will be reduced in size in the radial direction and in the longitudinal direction A. Here, the longitudinal direction A is the direction in which air flows between the outlet of the scroll section flow path 53 and the blower outlet 400, and corresponds to the left-right direction in FIG.

[0033] When the diameter is reduced, the outer diameter of the blower casing 51 is reduced. That is, the outer diameter of the scroll passage section 53 is reduced. When the outer diameter of the scroll passage section 53 is reduced, the flow path cross-sectional area thereof is also reduced. If the flow rate passing through the scroll passage section 53 is the same, the flow velocity passing through the flow path cross-sectional area increases, and friction with the wall surface also increases. As a result, loss due to friction increases, and blower efficiency decreases.

[0034] To reduce the longitudinal direction A of the blower 4, it is necessary to shorten the distance 62 between the scroll passage section 53 and the heater 6 and the distance 63 between the heater 6 and the blower outlet 400. Shortening the distance 62 increases the expansion rate of the flow path cross-sectional area of ​​the enlarged passage section 60. When the expansion rate of the flow path cross-sectional area increases, the flow cannot flow along the wall of the enlarged passage section 60, and flow separation occurs. When flow separation occurs, losses occur in the flow field, reducing efficiency.

[0035] Furthermore, if the flow separates in the expanded flow path section 60, the separation area acts as a blockage, causing the flow to be biased toward the side where separation is not occurring. If the flow enters the heater 6 in a biased state, a temperature distribution occurs on the heater surface, reducing output. While reducing the output of the heater 6 may sound like an energy-saving solution, it actually reduces the energy that can be input during the drying operation, which ultimately extends the drying operation time of the washer-dryer and leads to increased power consumption.

[0036] On the other hand, when the distance 63 from the heater 6 to the blower outlet 400 is shortened, the reduced flow path 61 narrows the flow, so flow separation at the flow path wall is less likely to occur, and the loss is largely determined by the cross-sectional area of ​​the blower outlet 400.

[0037] From the above viewpoint, in order to realize a small size and large air volume of the blower 4 installed in the washer-dryer S, it is necessary to suppress separation of the flow in the scroll passage portion 53 and the enlarged passage portion 60.

[0038] The basic configuration of the fan 4 described with reference to Fig. 2 is also common to the fan 4 of this embodiment. Below, the fan 4 according to an embodiment of the present invention will be described, focusing on the differences from the fan 4 described with reference to Fig. 2.

[0039] Fig. 3 is a cross-sectional view showing the flow path structure of blower 4 according to one embodiment of the present invention. Fig. 4 is a schematic diagram showing the change in flow path cross-sectional area in the flow direction of blower 4 according to one embodiment of the present invention. Note that Fig. 3 shows only the internal flow path of blower casing 51.

[0040] Similar to the blower 4 of FIG. 2, the blower 4 of this embodiment includes an electric motor 100 (see FIG. 2), a rotating shaft 101 (see FIG. 2) rotatably mounted on the electric motor 100, an impeller 300 mounted on the rotating shaft 101, a blower casing (volute casing) 51 containing the impeller 300, and a heater (heat source) 6 installed downstream of the blower casing 51 and through which the flow flowing out of the blower casing 51 passes.

[0041] The blower casing 51 has a flow path portion that includes a scroll flow path portion 53 provided on the outer periphery of the impeller 300 and that guides the flow to the heater 6. This flow path portion is configured to include the scroll flow path portion 53 and an expanded flow path portion 60 that connects the scroll flow path portion 53 and the heater 6 and whose flow path cross-sectional area expands from the upstream side to the downstream side. The expanded flow path portion 60 is formed between an upstream end 601 and a downstream end 602. The upstream end 601 coincides with the outlet (downstream end) of the scroll flow path portion 53, and the downstream end 602 coincides with the upstream end face of the heater 6.

[0042] The scroll passage section 53 of the blower 4 often has a flow path cross-sectional area that changes linearly from the beginning of the scroll passage section 53 (0° position in the figure) to the end of the scroll passage section 53 (360° position) after one full rotation in the direction of rotation of the impeller 300. This is because the flow flowing outward in the radial direction from the impeller 300 is uniform in the circumferential direction, so the flow rate passing through the scroll passage increases linearly with the direction of rotation of the impeller 300. By linearly changing the cross-sectional area in accordance with this increase, the flow velocity within the scroll passage section 53 is maintained at a constant value and an increase in friction due to velocity changes is suppressed. On the other hand, the flow path cross-sectional area must be suddenly increased in the expanded flow passage section 60 connecting the scroll passage section 53 to the heater 6, which increases loss due to the sudden expansion of the flow path. Furthermore, biased flow into the heater 6 reduces heater input, raising concerns about increased drying operation time and power consumption.

[0043] In the blower 4 of this embodiment, the flow path section 53, 60, which is configured to include the scroll flow path section 53 and the enlarged flow path section 60, is provided with expansion ratio change sections at two locations, where the expansion ratio of the flow path cross-sectional area changes. Of the two expansion ratio change sections P1, P2, the expansion ratio change section P1 located on the upstream side is referred to as the first expansion ratio change section, and the expansion ratio change section P2 located on the downstream side is referred to as the second expansion ratio change section. In other words, the flow path section 53, 60 has the first expansion ratio change section P1 and the second expansion ratio change section P2.

[0044] In the first expansion ratio change section P1 and the second expansion ratio change section P2, the expansion ratios of the expansion ratio change sections P1 and P2 change so that the expansion ratio in the flow path 531 between the first expansion ratio change section P1 and the second expansion ratio change section P2 is greater than the expansion ratio in the flow path 60 between the second expansion ratio change section P2 and the heater 6. In addition, when the position of the end of the scroll flow path section 53 after one revolution from the start of the winding (0° position in the figure) in the rotation direction of the impeller 300 is defined as 360°, the first expansion ratio change section P1 is located upstream of 360°. For this reason, the scroll flow path section 53 has the first expansion ratio change section P1 in which the expansion ratio of the flow path cross-sectional area changes so that it is greater downstream than upstream.

[0045] According to this embodiment, the expansion ratio of the expanded flow passage section 60 connecting the end 601 of the scroll flow passage section 53 to the heater 6 is reduced, and separation of the flow from the wall surface of the expanded flow passage section 60 can be suppressed.

[0046] The second expansion ratio change section P2 is located downstream of the scroll passage section 53 and upstream of the heater 6. In this embodiment, the second expansion ratio change section P2 is located at a connection section 601 between the scroll passage section 53 and the expanded passage section. The second expansion ratio change section P2 may also be located within the expanded passage section 60, for example, at position 603. The second expansion ratio change section P2 should be located at a position that improves the effectiveness of suppressing flow separation from the wall surface of the expanded passage section 60. The expanded passage section 60 is located between the scroll passage section 53 and the heater 6 as a connection section. If the expansion ratio of the expanded passage section 60 is reduced, flow separation can be suppressed, thereby reducing loss. Furthermore, suppressing flow separation can improve flow uniformity upstream of the heater 6, thereby improving heater input and thereby shortening the drying operation time and reducing power consumption. That is, it is possible to reduce losses due to flow separation and suppress unevenness of the flow flowing into the heater 6, thereby improving heater input and shortening drying time.

[0047] FIG. 5 is an enlarged view of the enlarged flow path portion 60 of the blower 4 according to one embodiment of the present invention. When the expansion ratio of the expanded flow passage section 60 is defined as the expansion angle α as shown in the schematic diagram of the expanded flow passage section 60 in FIG. 5, if α exceeds 8°, the flow tends to separate from the wall surface. Therefore, it is important to reduce the angle α of the expanded flow passage section 60. In this case, the inventors found that the first expansion ratio change section P1 of the scroll flow passage section 53 is best located near 300° in the flow direction of the scroll flow passage section 53 (see FIG. 3). By increasing the expansion ratio near 300°, separation in the expanded flow passage section 60 can be suppressed. That is, in the blower 4 of this embodiment, when the outlet position 601 of the scroll flow passage section 53 is set to 0° with respect to the rotation direction of the impeller 300, the first expansion ratio change section P1 is located upstream of the 360° position 601 and downstream of the 300° position.

[0048] In the flow path shape of the scroll flow path section 53 shown in FIG. 3, the cross-sectional area expands radially outward at the 300° position where the expansion ratio changes. By expanding the cross-sectional area radially outward as shown in the figure, the expansion ratio at the first expansion ratio change section P1 increases, suppressing flow separation due to the suppression of the expansion ratio in the expansion flow path section 60 and suppressing collision loss on the flow path wall surface of the scroll flow path section 53. In this case, because the first expansion ratio change section P1 is located midway through the scroll flow path section 53, the flow discharged from the impeller 300 to the scroll flow path section 53 can reach the outer peripheral wall of the scroll flow path section 53, making it difficult for separation from the outer peripheral wall of the scroll flow path section 53 to occur. This makes it possible to improve efficiency and maintain heater input while miniaturizing the blower 4.

[0049] Fig. 6 is a schematic diagram of the flow path structure of a blower 4 according to one embodiment of the present invention. Fig. 6 shows cross sections perpendicular to the circumferential direction of the scroll flow path portion 53 at positions of 90°, 180°, 270°, and 360°. By increasing the rate of change of the flow passage cross-sectional area at the first expansion ratio change section P1, the cross-sectional area of ​​the scroll flow passage section 53 increases. In this case, to maximize efficiency, it is preferable to adjust the direction in which the flow passage cross-sectional area increases. Specifically, upstream of the first expansion ratio change section P1, the flow passage cross-sectional area of ​​the scroll flow passage section 53 is increased only in the direction of the rotation axis B of the impeller 300 as shown in FIG. 6 , and from 300°, where the expansion ratio changes, the cross-sectional area of ​​the scroll flow passage section 53 is increased in the direction of the rotation axis B and radially outward in accordance with the change in the expansion ratio.

[0050] That is, the expansion of the flow path cross-sectional area upstream of the first expansion ratio change section P1 occurs only in the direction B along the rotation axis, while the expansion of the flow path cross-sectional area downstream of the first expansion ratio change section P1 occurs in both the direction B along the rotation axis and the outer diameter direction C of the impeller 300. This structure suppresses separation of the flow in the expanded flow path section 60 leading to the heater 6, thereby achieving higher efficiency and shorter drying time and energy savings due to increased heater input.

[0051] Although the application example of the present invention has been described using a drum-type washer-dryer as an example, the present invention can also be applied to a vertical washer-dryer. Also, in this embodiment, the air outlet 5o is provided at the front of the drum-type washer-dryer, but the present invention can also be applied to a case where the air outlet 5o is provided in another location.

[0052] Some of the features of the present embodiment described above are listed below. (1) The blower 4 is an electric motor 100; a rotating shaft 101 rotatably provided on the electric motor 100; an impeller 300 provided on the rotary shaft 101; a volute casing 51 containing the impeller 300; a heat source 6 that is installed downstream of the volute casing 51 and through which the flow that flows out of the volute casing 51 passes; The volute casing 51 includes a scroll flow passage portion 53 provided on the outer periphery of the impeller 300, and has flow passage portions 53, 60 that guide the flow to the heat source 6. The flow path sections 53, 60 have a first expansion rate change section P1 and a second expansion rate change section P2 in which the cross-sectional area of ​​the flow path increases from the upstream side to the downstream side and the expansion rate of the cross-sectional area of ​​the flow path changes, The expansion ratio in the flow path 531 between the first expansion ratio change section P1 and the second expansion ratio change section P2 is greater than the expansion ratio in the flow path 60 between the second expansion ratio change section P2 and the heat source 6.

[0053] (2) When the outlet position 601 of the scroll passage section 53 is set at 0° with respect to the rotation direction of the impeller 300, the first expansion ratio change section P1 is disposed upstream of the 360° position 601.

[0054] (3) The first magnification change section P1 is located downstream from the 300° position.

[0055] (4) The flow path sections 53, 60 include a scroll flow path section 53 and an expanding flow path section 60 that connects the scroll flow path section 53 and the heat source 6 and whose flow path cross-sectional area expands from the upstream side to the downstream side, The second expansion ratio changing section P2 is provided at a connection section 601 between the scroll passage section 53 and the expansion passage section 60.

[0056] (5) The expansion of the flow passage cross-sectional area upstream of the first expansion ratio change section P1 is only in the direction B along the rotation axis, The expansion of the cross-sectional area of ​​the flow passage downstream of the first expansion ratio change section P1 occurs due to expansion in a direction B along the rotation axis and in an outer diameter direction C of the impeller 300.

[0057] (6) The scroll passage section 53 has a first expansion rate changing section P1 in which the expansion rate of the passage cross-sectional area changes so that it is larger downstream than upstream.

[0058] (7) A washer / dryer is equipped with the blower according to any one of (1) to (6).

[0059] According to this embodiment, the efficiency of the blower can be improved by miniaturizing the blower while suppressing an increase in separation loss due to an increase in the flow path expansion ratio that accompanies miniaturization. In addition, the flow velocity distribution into the heater located downstream of the blower can be made uniform, thereby improving the heating performance of the heater.

[0060] The present invention is not limited to the above-described embodiments, but includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the configurations. Furthermore, it is possible to add, delete, or replace part of the configuration of the embodiments with other configurations. [Explanation of symbols]

[0061] 4...blower, 6...heat source, 51...volute casing, 53...scroll flow path section, 53, 60...flow path section, 60...expanded flow path section, 100...electric motor, 101...rotating shaft of electric motor 100, 300...impeller, 601...outlet position of scroll flow path section 53 (360° position, connection section between scroll flow path section 53 and expanded flow path section 60), B...direction along the rotating shaft, C...outer diameter direction of impeller 300, P1...first expansion ratio change section, P2...second expansion ratio change section, S...washer-dryer.

Claims

1. An electric motor, a rotating shaft rotatably provided in the electric motor; an impeller provided on the rotating shaft; a volute casing containing the impeller; a heat source disposed downstream of the volute casing and through which the flow flowing out of the volute casing passes; the volute casing has a flow path portion including a scroll flow path portion provided on an outer periphery of the impeller, and directing a flow to the heat source; the flow path section has a first expansion rate changing section and a second expansion rate changing section in which the flow path cross-sectional area increases from the upstream side to the downstream side and the expansion rate of the flow path cross-sectional area changes, A blower in which the expansion ratio in the flow path between the first expansion ratio change section and the second expansion ratio change section is greater than the expansion ratio in the flow path between the second expansion ratio change section and the heat source.

2. The blower according to claim 1, the first expansion ratio change section is disposed upstream of a position 360° away from the rotation direction of the impeller when an outlet position of the scroll flow path section is defined as 0°.

3. The blower according to claim 2, The first expansion ratio change unit is a blower that is disposed downstream from the 300° position.

4. The blower according to claim 2, the flow path section includes the scroll flow path section and an expanding flow path section that connects the scroll flow path section and the heat source and whose flow path cross-sectional area expands from the upstream side to the downstream side, The second expansion ratio change section is provided at a connection between the scroll flow path section and the expansion flow path section.

5. The blower according to claim 1, the expansion of the flow path cross-sectional area upstream of the first expansion ratio change section is only in a direction along the rotation axis, The expansion of the flow path cross-sectional area downstream of the first expansion ratio change section is caused by expansion in the direction along the rotation shaft and in the outer diameter direction of the impeller.

6. The blower according to claim 1, The scroll flow passage portion has the first expansion rate changing portion, in which the expansion rate of the flow passage cross-sectional area changes so that it is larger on the downstream side than on the upstream side.

7. A washing / drying machine comprising the blower according to any one of claims 1 to 6.

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