Blower and washing machine and dryer equipped with the same

Abstract

To provide a blower equipped with a centrifugal impeller and a heater in which the flow of air to the heater becomes uniform and the increase of flow path resistance is suppressed.SOLUTION: A blower includes: an electric motor; a centrifugal impeller provided on a rotating shaft of the electric motor; a scroll passage provided around the centrifugal impeller; an enlarged passage provided at a downstream end of the scroll passage; and a heater provided at a downstream end of the enlarged flow path, where the enlarged passage is provided with a convex portion extending from a radially outer wall surface to a radially inner wall surface when viewed from the centrifugal impeller.SELECTED DRAWING: Figure 6

Description

【Technical Field】 【0004】 , , , , , , , , , 【0005】 , , , , , 【0001】 The present disclosure relates to a blower, a washing and drying machine, and a dryer including the same. 【Background Art】 【0002】 Drying of clothes by a washing and drying machine that can continuously perform washing and drying is performed by creating high-temperature and low-humidity air using a blower and heating means, blowing this air into the washing tub, raising the temperature of the clothes, evaporating moisture from the clothes, and discharging the evaporated moisture outside the machine. At this time, in order to improve the heating efficiency in the heating means, it is desirable that the flow generated by the blower be supplied to the heating means at a uniform flow rate. 【0003】 In Patent Document 1, in a warm air unit 22 built into a washing and drying machine, in order to make the flow rate distribution discharged from a discharge port 208 toward a heater 24 for heating uniform by the rotation of a blower fan 202, a raised portion 211 that protrudes so as to narrow the discharge port 208 toward a nose portion 210 is provided on the rear end portion 209 side, which is located between the rear end portion 209 and one end portion of the heater 24 and has a shape in which the center facing the rear end portion 209 bulges high. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document1】 Japanese Patent Application Laid-Open No. 2009-285235 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 The hot air unit described in Patent Document 1 is configured to equalize the flow by providing a raised section toward the nose (tongue) of the blower. However, in the configuration described in Patent Document 1, because the raised section is provided toward the nose, the rise of the raised section is located within the scroll, and the cross-sectional area of ​​the flow path near the impeller where the flow velocity is high becomes small. As a result, frictional losses between the fluid and the wall surface increase, and there are concerns that the efficiency of the blower will decrease. 【0006】 This disclosure aims to ensure that the airflow to the heater is uniform and to suppress an increase in flow resistance in a blower equipped with a centrifugal impeller and a heater. [Means for solving the problem] 【0007】 The blower of this disclosure comprises an electric motor, a centrifugal impeller mounted on the rotating shaft of the electric motor, a scroll channel provided around the centrifugal impeller, an expanding channel provided at the downstream end of the scroll channel, and a heater provided at the downstream end of the expanding channel, wherein the expanding channel is provided with a convex portion extending from the radially outer wall surface to the radially inner wall surface as viewed from the centrifugal impeller. [Effects of the Invention] 【0008】 According to this disclosure, in a blower equipped with a centrifugal impeller and a heater, it is possible to ensure that the airflow to the heater is uniform and to suppress an increase in flow resistance. [Brief explanation of the drawing] 【0009】 [Figure 1] This is a longitudinal cross-sectional view showing a washing machine equipped with a blower according to an embodiment. [Figure 2] This is an external perspective view showing the blower of the embodiment. [Figure 3] This is an exploded perspective view of the blower in the embodiment, seen from the fan cover side. [Figure 4] This is an exploded perspective view of the blower in the embodiment, seen from the motor side. [Figure 5] This is an exploded perspective view showing the electric heater of the embodiment. [Figure 6] This is a plan view showing the blower in the embodiment with the fan cover removed. [Modes for carrying out the invention] 【0010】 The embodiments of this disclosure will be described in detail below with reference to the drawings. 【0011】 Figure 1 is a vertical cross-sectional view showing a washing machine equipped with a blower according to an embodiment. In the following description, a vertical washing machine and dryer will be used as an example, but the invention can also be applied to drum-type washing machines and dryers with a laundry loading / unloading opening on the front side. 【0012】 As shown in Figure 1, the washing machine S comprises an outer frame 1 which is the housing, an outer tub 2 for storing washing water, a rotating tub 3, a drive motor 10, a blower 22, and the like. The outer tub 2 is built into the outer frame 1 and is vibration-damped and supported by the outer frame 1. The rotating tub 3 is a washing tub and spin-drying tub that holds laundry such as clothes to be washed and dried, and is located inside the outer tub 2. The rotating tub 3 is also rotatably supported within the outer tub 2. 【0013】 At the bottom of the rotating tub 3, a rotatable agitator blade 4 is provided to agitate and wash the laundry. This agitator blade 4 repeatedly rotates in forward and reverse directions during washing and drying cycles. In addition, during the spin-drying cycle, the agitator blade 4 rotates at high speed together with the rotating tub 3. Most of the water is removed from the laundry in the rotating tub 3 through the spin-drying process. 【0014】 Furthermore, an outer cover 5 is provided on the top of the outer frame 1. This outer cover 5 is attached to the top cover 6, which is located on the top of the outer frame 1, so as to be able to be opened and closed. An inner cover 34 is attached to the top of the outer tub 2 so as to be able to be opened and closed. By opening the outer cover 5 and the inner cover 34, laundry can be loaded into and unloaded from the rotating tub 3. Note that the left side of the diagram is the front of the washing machine S. 【0015】 In addition, the washing machine S includes a drying mechanism. This drying mechanism circulates and blows drying air for drying the laundry in the rotating tub 3 and dehumidifies it. The drying mechanism is mainly composed of a drying air circulation path 9 and a blower 22. The drying air circulation path 9 includes a bottom circulation path 20 connected to communicate with the bottom of the outer tub 2 and a dehumidifying vertical passage 21 extending upward from the bottom circulation path 20. 【0016】 The suction side of the blower 22 is connected to the upper side of the dehumidifying vertical passage 21. The discharge side of the blower 22 is connected to communicate with a return connection circulation path 25. Also, a drying filter 45 is disposed between the blower 22 and the dehumidifying vertical passage 21 to prevent foreign matter from flowing into the blower 22. The blower 22 incorporates an electric heater. 【0017】 The return connection circulation path 25 has an upper bellows hose 23 and is connected to communicate with the upper part of the outer tub 2 through this upper bellows hose 23. The bottom circulation path 20 also has a lower bellows hose 26 and is connected to communicate with the bottom of the outer tub 2 through this lower bellows hose 26. 【0018】 The lower bellows hose 26 is connected to the bottom drop-in portion 31 of the outer tub 2. This bottom drop-in portion 31 communicates with a washing water drainage path 42 and a washing water circulation water path 43 through a lower communication pipe 41. A drain valve 44 is provided in the washing water drainage path 42. A foreign matter removal trap 32 is provided in the washing water circulation water path 43. 【0019】 In summary, in the drying mechanism, the drying air sent from the blower 22 is configured to pass through the return connection circulation path 25, the outer tub 2, the bottom drop-in portion 31, the lower bellows hose 26, and the drying air circulation path 9 in this order and return to the blower 22. 【0020】 The drain valve 44 is closed during the washing operation and the drying operation. Also, the drain valve 44 opens during drainage of the washing water and discharges the washing water accumulated in the outer tub 2 from the washing water drainage path 42 to the outside (outside the machine) of the washing machine S. 【0021】 In the washing machine S, the centrifugal impeller 300 (see FIG. 2) of the blower 22 rotates, causing the drying air to flow through the rotary drum 3, thereby drying the laundry in the rotary drum 3. Also, the electric heater 24 (see FIG. 3) of the blower 22 reheats the drying air in which moisture has condensed in the dehumidification area, and the reheated air flows through the rotary drum 3, further evaporating the moisture from the laundry. By repeating this moisture removal through the circulation of the drying air, the laundry is dried. 【0022】 Hereinafter, the blower of the embodiment will be described in detail. 【Embodiment】 【0023】 FIG. 2 is an external perspective view showing the blower of the embodiment. 【0024】 As shown in FIG. 2, the blower 22 includes a fan cover 51, a fan casing 52, an electric motor 100, and a centrifugal impeller 300. The fan cover 51 and the fan casing 52 constitute the casing 500. The blower 22 is installed, for example, inside the outer frame 1 (see FIG. 1) of the washing machine S (see FIG. 1) such that the fan cover 51 of the blower 22 faces substantially downward. However, the mounting method of the blower 22 is not limited to this. 【0025】 The fan cover 51 is formed with a suction port 57 and an exhaust port 58. The suction port 57 is connected to the dehumidification vertical passage 21 (see FIG. 1) via the drying filter 45 (see FIG. 1). The exhaust port 58 is connected to the return connection circulation path 25 (see FIG. 1) of the drying air circulation path. 【0026】 FIG. 3 is an exploded perspective view of the blower of the present embodiment as viewed from the fan cover side. 【0027】 FIG. 4 is an exploded perspective view of the blower of the present embodiment as viewed from the electric motor side. 【0028】 As shown in Figure 3, the fan cover 51 has an elongated shape in one direction, with an intake port 57 formed on one side in the longitudinal direction and an exhaust port 58 formed on the other side in the longitudinal direction. The intake port 57 is a circular through-hole and faces the center of the intake opening 302 (intake section) of the centrifugal impeller 300. 【0029】 The discharge port 58 is a circular through-hole located downstream of the electric heater 24. The diameter of the discharge port 58 is larger than the diameter of the suction port 57. Furthermore, the suction port 57 and the discharge port 58 are positioned in approximately the same direction. 【0030】 Furthermore, multiple screw fixing portions 91 are formed on the periphery of the fan cover 51, which are screw-fixed to the fan casing 52. 【0031】 The fan casing 52 has a shape that corresponds to the fan cover 51. When the fan casing 52 and the fan cover 51 are combined, a space is formed between the fan cover 51 and the fan casing 52 in which the centrifugal impeller 300 and the electric heater 24 are arranged. 【0032】 Furthermore, the fan casing 52 has a shaft insertion hole 80 into which the rotating shaft 101 of the electric motor 100 is inserted. Also, a screw insertion portion 92 is formed on the outer peripheral edge of the fan casing 52 at a position corresponding to the screw fixing portion 91 of the fan cover 51, through which a screw (not shown) is inserted. 【0033】 Furthermore, the fan casing 52 and the fan cover 51 form a scroll channel 70 around the outer circumference (radially outward) of the centrifugal impeller 300. This scroll channel 70 is formed with a narrower channel width on the tongue side 71, and the channel width gradually widens clockwise from the tongue side 71. The tongue side 71 is the starting point of the scroll channel 70. The outlet of the scroll channel 70 is the scroll discharge port 72. 【0034】 Furthermore, an expanded flow path 73 is provided between the scroll discharge port 72 and the electric heater 24. The expanded flow path 73 is provided such that the outlet 74 of the expanded flow path has a larger cross-sectional area than the inlet (scroll discharge port 72) of the expanded flow path 73. 【0035】 Furthermore, the expanding channel 73 has a protrusion 75 that rises from the radially outer wall surface 76 toward the radially inner wall surface 77 when viewed from the centrifugal impeller 300. If the plane passing through the apex A of the protrusion 75 and parallel to the expanding channel outlet 74 is defined as the cross-section 78 of the protrusion channel, then the area of ​​the cross-section 78 of the protrusion channel is smaller than that of the scroll outlet 72. Note that the scroll outlet 72, the expanding channel outlet 74, and the cross-section 78 of the protrusion channel are planes parallel to the front surface (considered to be a plane) of the electric heater 24. Here, the normal to the scroll outlet 72 (channel cross-section) does not intersect with the rotation axis 101 (rotation center axis) of the centrifugal impeller 300. For this reason, the radially outer wall surface 76 can be said to be located radially further away from the rotation axis 101 than the radially inner wall surface 77. For this reason, the terms "radially outer" and "radially inner" are used in this specification. 【0036】 Furthermore, the flow path length L1 from the apex A of the protrusion 75 to the expanded flow path outlet 74 is set to be greater than the width L2 of the heating section 201 of the electric heater 24. 【0037】 The electric motor 100 has a rotating shaft 101 connected to a centrifugal impeller 300 at its radial center and is mounted on the fan casing 52. The electric motor 100 also has a rotor fixed to the rotating shaft 101, a stator provided around the rotor, and bearings that rotatably support the rotating shaft 101. The electric motor 100 also has a substantially cylindrical case 102 that houses the rotor, stator, and bearings. 【0038】 The centrifugal impeller 300 is composed of a shroud plate 301, a hub plate 311, and a blade 321. The shroud plate 301 has a circular suction opening 302 formed in its radial center. The hub plate 311 has an axial hole (not shown) for fixing the rotating shaft 101. The blade 321 is composed of the shroud plate 301 and the hub plate 311 sandwiched from both sides in the axial direction Ax. 【0039】 Figure 5 is an exploded perspective view showing the electric heater of this embodiment. 【0040】 As shown in this figure, the electric heater 24 is composed of a rectangular heating section 201 which is a heat-generating area and has many fins, a terminal section 202 which connects the heating section 201 to an electrical circuit, a heating section fixing device 203 which fixes the heating section 201, and a terminal section fixing device 204 which fixes the terminal section 202. 【0041】 As shown in Figure 3, in the blower 22, the centrifugal impeller 300 rotates in the W direction, drawing air (fluid) through the intake port 57 and into the intake opening 302, and the air flows out from the outer circumference of the centrifugal impeller 300. The flowing air passes through the scroll channel 70 and flows into the expanding channel 73. Then, the air passes through the electric heater 24, is heated, and flows to the discharge port 58. The heated air flowing out from the discharge port 58 passes through the return connection circulation path 25 and flows into the outer tank 2 (see Figure 1). 【0042】 Next, the features and effects of this embodiment will be described. 【0043】 Figure 6 is a plan view showing the blower in this embodiment with the fan cover removed. 【0044】 In Figure 6, the flow from the centrifugal impeller 300 flows into the scroll channel 70, and then flows into the expanding channel 73. At that time, at the inlet of the expanding channel 73 (scroll outlet 72), due to the effect of centrifugal force, the flow velocity on the radially outer wall surface 76 is greater than that on the radially inner wall surface 77, resulting in a biased flow. If the expanding channel 73 does not have a protrusion 75, the flow reaches the electric heater 24 with that flow velocity distribution, and it is not possible to provide a uniform flow to the electric heater 24. 【0045】 Here, the scroll outlet 72 is defined as a plane that passes through the tongue portion 71 and is parallel to the front surface of the electric heater 24. In this figure, it coincides with the position of the rising portion (upstream end) of the convex portion 75. However, the rising portion of the convex portion 75 is not limited to this position and may be located downstream of this position. The flow path upstream of the scroll outlet 72 is included in the scroll flow path 70. The scroll flow path 70 is intentionally designed without any convex or concave portions. Therefore, the flow path walls of the scroll flow path 70 have a shape that is close to the shape that is theoretically appropriate for a scroll flow path 70. 【0046】 As shown in Figure 6, when the expanded channel 73 has a protrusion 75, the direction of the flow on the radially outer side is changed by the protrusion 75, and a portion of the flow is directed radially inward. As a result, the flow bias in the expanded channel 73 is reduced, and the flow velocity of the air flowing into the electric heater 24 can be made nearly uniform. 【0047】 In this case, if the flow path length L1 cannot be secured to a sufficient length, the flow may reach the electric heater 24 before it has been altered by the protrusion 75 and before it has diffused, making it impossible to provide a uniform flow to the electric heater 24. 【0048】 Therefore, in this embodiment, the protrusions 75 are provided such that the flow path length L1 is at least greater than the width L2 of the heating section of the electric heater 24. This allows the flow altered by the protrusions 75 to diffuse sufficiently before reaching the electric heater 24, and the electric heater 24 can provide a uniform flow. 【0049】 Furthermore, when drawing a line B (shown as a dotted line in the figure) that passes through the apex A of the protrusion 75 and is perpendicular to the upstream surface of the electric heater 24, it is desirable that line B passes radially towards the outer wall surface 76 rather than the center of the heating portion 201 (Figure 5) of the electric heater 24. This ensures that the flow altered by the protrusion 75 does not become too biased towards the radially inner wall surface 77 before reaching the electric heater 24, thereby providing a more uniform flow to the heater. 【0050】 Furthermore, in this embodiment, the protrusion 75 is provided not within the scroll channel 70, but within the expanding channel 73 downstream of it. This makes it possible to provide the protrusion 75 without narrowing the cross-sectional area of ​​the channel around the centrifugal impeller 300, which has a high flow velocity, and to provide a uniform flow to the electric heater 24 without significantly increasing frictional losses between the fluid and the wall surface forming the scroll channel 70. 【0051】 As described above, the blower 22 of this embodiment comprises an electric motor 100, a rotating shaft 101 rotatably mounted on the electric motor 100, a centrifugal impeller 300 mounted on the rotating shaft 101, a scroll channel 70 provided around the centrifugal impeller 300, an expanding channel 73 provided downstream of the scroll channel 70, a protrusion 75 provided within the expanding channel 73, and an electric heater 24 provided downstream of the expanding channel. 【0052】 The protrusions 75 within the enlarged flow channel 73 allow a portion of the flow that is biased radially outward to be guided radially inward, making it possible to provide a uniform flow to the electric heater 24. 【0053】 Furthermore, since the convex portion 75 is provided such that the flow path length L1 is greater than the width L2 of the heating section of the electric heater 24, the flow altered by the convex portion 75 diffuses sufficiently before reaching the electric heater 24, allowing the electric heater 24 to provide a uniform flow. 【0054】 Furthermore, by arranging the convex portion 75 such that when a line B is drawn passing through the apex A of the convex portion 75 and perpendicular to the upstream side surface of the electric heater 24, line B passes on the radially outer wall surface 76 side of the center of the heating portion 201 of the electric heater 24, the altered flow reaches the electric heater 24 without being excessively biased toward the radially inner wall surface 77 side, thereby providing a more uniform flow to the electric heater 24. 【0055】 Furthermore, by providing the protrusion 75 not within the scroll channel 70 but within the expanded channel 73 downstream of it, the protrusion 75 can be provided without narrowing the cross-sectional area of ​​the channel around the centrifugal impeller 300, which has a high flow velocity. This makes it possible to provide a uniform flow to the electric heater 24 without significantly increasing frictional losses between the fluid and the wall surface forming the scroll channel 70. 【0056】 Furthermore, regarding the slope of the curve of the protrusion 75 shown in Figure 6, the slope is gentler downstream of the apex A of the protrusion 75 than upstream. This configuration suppresses the separation of the airflow passing near the protrusion 75. As a result, the efficiency of the blower is improved and noise is suppressed. 【0057】 Furthermore, the blower 22 in this embodiment is provided in the washing machine S. The blower 22 can improve the heating efficiency of the electric heater 24 while suppressing performance degradation, thereby reducing the power consumption of the washing machine S. 【0058】 Furthermore, in the hot air unit described in Patent Document 1, a raised portion is provided upstream of the scroll outlet as defined above. As a result, the flow resistance in the scroll channel, which is upstream of the scroll outlet, is large. Also, the distance from the top of the raised portion to the heater is very short compared to the width of the heater. Therefore, the air that has passed through the scroll outlet reaches the heater before its flow velocity distribution becomes uniform. 【0059】 The embodiments of this disclosure can solve the problems described in Patent Document 1. 【0060】 The following describes preferred embodiments related to this disclosure. 【0061】 In a blower, the expanded flow path extends from the scroll outlet, which is the downstream end of the scroll flow path, to the front of the heating section of the heater, and the scroll outlet is parallel to the front of the heating section. 【0062】 The length of the flow path from the apex of the protrusion to the front of the heater's heating element is set to be longer than the width of the heater's heating element. 【0063】 The protrusion is positioned such that a perpendicular line from the front surface of the heater's heating element, passing through its apex, passes radially outward from the center of the heating element towards the outer wall surface of the expanding flow path. 【0064】 The washer-dryer is equipped with the aforementioned blower. 【0065】 The dryer is equipped with the blower described above. [Explanation of Symbols] 【0066】 1: Outer frame, 2: Outer tank, 3: Rotating tank, 9: Drying air circulation path, 20: Bottom circulation path, 21: Dehumidifying vertical passage, 22: Blower, 23: Upper corrugated hose, 24: Electric heater, 25: Return connection circulation path, 26: Lower corrugated hose, 31: Bottom inlet, 45: Drying filter, 51: Fan cover, 52: Fan casing, 57: Intake, 58: Outlet, 70: Screw Roll channel, 71: tongue, 72: scroll outlet, 73: widening channel, 74: widening channel outlet, 75: convex, 76: radial outer wall, 77: radial inner wall, 78: cross-section of convex channel, 100: electric motor, 101: rotating shaft, 201: heating section, 300: centrifugal impeller, 301: shroud plate, 302: suction opening, 311: hub plate, 321: blade, S: washing machine.

Claims

[Claim 1] Electric motor and, A centrifugal impeller is provided on the rotating shaft of the aforementioned electric motor, A scroll channel provided around the centrifugal impeller, An enlarged channel is provided at the downstream end of the aforementioned scroll channel, The system comprises a heater provided at the downstream end of the enlarged channel, The enlarged channel is provided with a protrusion extending from the radially outer wall surface toward the radially inner wall surface as viewed from the centrifugal impeller. A blower in which the length of the flow path from the apex of the protrusion to the front surface of the heating element of the heater is longer than the width of the heating element of the heater. [Claim 2] The enlarged flow path extends from the scroll discharge port, which is the downstream end of the scroll flow path, to the front surface of the heating section of the heater. The blower according to claim 1, wherein the scroll discharge port is parallel to the front surface of the heating section. [Claim 3] The blower according to claim 1, wherein the convex portion is provided such that a perpendicular line on the front surface of the heating portion of the heater, passing through the apex of the convex portion, passes on the radially outer wall surface side of the expanding flow path rather than the center of the heating portion. [Claim 4] A washing machine and dryer comprising a blower according to any one of claims 1 to 3. [Claim 5] A dryer comprising a blower according to any one of claims 1 to 3.

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