JP7516193B2 - Blower and washing machine equipped with same - Google Patents

Description

The present invention relates to a blower and a washing machine equipped with the same.

For example, Patent Document 1 proposes a blower that is highly efficient. Patent Document 1 discloses that in an electric blower for a vacuum cleaner, the diameters of the diffuser and the ring-shaped member are approximately the same, the hub surface of the diffuser and the surface of the ring-shaped member on the diffuser side form curved surfaces that approach the motor side as they approach the outer periphery, the curvature of the curved surface on the diffuser side of the ring-shaped member is greater than the curvature of the curved surface on the hub surface of the diffuser, and the blade height of the diffuser vane is longer on the diffuser outer periphery side than on the diffuser center side.

JP 2016-3563 A

In the invention described in Patent Document 1, in order to guide the flow to the return flow passage located downstream of the diffuser flow passage, the hub surface is curved and the curvature is provided on the return flow passage side, thereby achieving high efficiency. However, in the blower described in Patent Document 1, the outlet surface of the diffuser flow passage is perpendicular to the axial direction, so if the diffuser flow passage is provided close to the wall surface, the flow will collide perpendicularly with the wall surface when being guided from the diffuser flow passage to the return flow passage, which may result in large losses and noise.

The present invention aims to solve the above-mentioned problems of the conventional art and provide a highly efficient and low-noise blower.

In order to achieve the above object, a blower of the present invention comprises an electric motor, a rotating shaft rotatably provided on the electric motor, an impeller provided on the rotating shaft, a diffuser flow path constituted by a diffuser outer bottom surface portion provided downstream of the impeller and formed on an outer peripheral edge portion of a bottom plate facing the axial direction of the impeller, a plurality of diffuser vanes arranged in a circumferential direction on an upper surface of the diffuser outer bottom surface portion, and a lid portion covering an upper portion of a gap formed by adjacent diffuser vanes, and a scroll flow path provided radially outside the impeller, and a scroll flow path provided radially outside the impeller, a notch is formed in the impeller , a lid-side notch is formed on an outer periphery of the lid portion , the scroll passage has a passage formed on the electric motor side and a passage formed on the bell-mouth side opposite the electric motor, the passage on the electric motor side with respect to the impeller has a wider passage cross-sectional area when the diffuser passage is divided perpendicular to the axial direction and at the center of the height of the diffuser passage, than the passage on the opposite side to the electric motor, and an outlet surface which is a plane connecting an intersection of the notch and the adjacent diffuser vane in the diffuser passage and an intersection of the lid-side notch and the adjacent diffuser vane is inclined radially outward with respect to the axial direction of the rotating shaft with respect to the notch, and is inclined toward the electric motor-side passage having the wider passage cross-sectional area of the scroll passage .

The present invention provides a highly efficient, low-noise blower.

FIG. 2 is a vertical cross-sectional view showing a washing machine equipped with a blower. FIG. 2 is an external perspective view showing a blower. FIG. 2 is an exploded perspective view of the blower as viewed from the bell-mouth side. FIG. 2 is an exploded perspective view of the blower as viewed from the electric motor side. FIG. FIG. FIG. 4 is a plan view showing the diffuser vane. FIG. 2 is a perspective view of a portion of the diffuser as viewed from the leading edge side. FIG. 2 is a perspective view of a portion of the diffuser as viewed from the trailing edge side. 3 is a cross-sectional view taken along line VIII-VIII in FIG. 2. FIG. 9 is an enlarged view of the bell mouth and its periphery in FIG. 8 . FIG. 2 is a meridian plane schematic diagram of a blower.

The following describes in detail the embodiment of the present invention with reference to the drawings.

Figure 1 is a vertical cross-sectional view of a washing machine equipped with a blower according to this embodiment. Note that, although a vertical washer-dryer will be used as an example below, the invention can also be applied to a drum-type washer-dryer with an opening for loading and unloading laundry on the front side.

As shown in FIG. 1, the washing machine S includes an outer frame 1 which is a housing, an outer tub 2 which stores wash water, a rotating tub 3, a drive motor 10, a blower 22, etc. The outer tub 2 is built into the outer frame 1 and is supported by the outer frame 1 in a vibration-proof manner. The rotating tub 3 is a washing and spin-drying tub which contains laundry such as clothes to be washed and dried, and is provided inside the outer tub 2. The rotating tub 3 is supported within the outer tub 2 so that it can rotate freely.

Agitator blade 4 that agitates and washes the laundry is provided at the bottom of the rotating tub 3 and can rotate freely. This agitator blade 4 rotates repeatedly in forward and reverse directions during the washing and drying operations. In addition, the agitator blade 4 rotates at high speed together with the rotating tub 3 during the spin-drying operation, and dehydrates the water contained in the laundry inside the rotating tub 3.

The drive motor 10 is provided inside the outer frame 1 and drives the agitator blades 4 and the rotating tank 3 to rotate. The drive motor 10 is, for example, a DC brushless motor. The DC brushless motor is controlled by vector control. In this embodiment, the drive motor 10 directly drives the agitator blades 4 and the rotating tank 3 to rotate, but they may also be driven using a belt or the like (not shown).

An outer lid 5 is provided on the top of the outer frame 1. This outer lid 5 is attached to a top cover 6 provided on the top of the outer frame 1 so as to be freely opened and closed. An inner lid 34 is provided on the top of the outer tub 2 so as to be freely opened and closed. By opening the outer lid 5 and the inner lid 34, laundry can be put in and taken out of the spin tub 3.

A water supply unit 7 is provided on the rear side of the top cover 6 within the outer frame 1. This water supply unit 7 has a water supply box (not shown) with multiple water channels inside, and supplies tap water or bath water from a water supply hose connection port 8 to the outer tub 2. A detergent and finishing agent injection device 35 is provided on the front side of the top cover 6. The detergent and finishing agent are poured between the outer tub 2 and the rotating tub 3 by an injection hose 36.

The washing machine S also has a drying mechanism. This drying mechanism circulates and blows drying air to dry the laundry in the rotating tub 3, and performs dehumidification. The drying mechanism is mainly made up of a drying air circulation path 9 and a blower 22. The drying air circulation path 9 has a bottom circulation path 20 connected to communicate with the bottom of the outer tub 2, and a dehumidification vertical passage 21 extending upward from the bottom circulation path 20.

The suction side of the blower 22 is connected to the upper side of the dehumidification vertical passage 21. The discharge side of the blower 22 is connected so as to communicate with the return connection circulation path 25. In addition, a drying filter 45 is disposed between the blower 22 and the dehumidification vertical passage 21 to prevent foreign matter from entering the blower 22. Details of the blower 22 will be described later.

The return connection circuit 25 has an upper bellows hose 23 and is connected to communicate with the upper part of the outer tank 2 via the upper bellows hose 23. The bottom circuit 20 also has a lower bellows hose 26 and is connected to communicate with the bottom part of the outer tank 2 via the lower bellows hose 26.

The lower bellows hose 26 is connected to the bottom recess 31 of the outer tub 2. This bottom recess 31 is connected to the wash water drainage channel 42 and the wash water circulation channel 43 via the lower communication pipe 41. The wash water drainage channel 42 is provided with a drain valve 44. The wash water circulation channel 43 is provided with a foreign object removal trap 32.

The drain valve 44 is closed during the washing and drying operations. The drain valve 44 also opens during draining to drain the washing water accumulated in the outer tub 2 from the washing water drainage channel 42 to the outside of the washing machine S (outside the machine).

The washing water circulation water channel 43 is connected to the washing water circulation water vertical water channel 46. This washing water circulation water vertical water channel 46 rises along the outer surface of the outer tub 2 and extends to the upper side of the rotating tub 3, and is connected so as to communicate with the laundry lint removal device 33 provided on the upper side of the rotating tub 3.

The washing water that accumulates in the outer tub 2 flows through the washing water circulation vertical water channel 46 and is poured from the washing lint removal device 33 so that it is sprayed onto the rotating tub 3. Since the washing is done while this spraying and pouring of water continues, the washing is done with a small amount of water.

The washing machine S also has a water level sensor 47 that detects the level of the wash water stored in the outer tub 2. An air trap 50 is provided near the bottom of the outer tub 2. An air tube 49 is connected to the air trap 50 so as to communicate with it. The water level sensor 47 is connected to the upper end of the air tube 49 so as to communicate with it. The water level sensor 47 detects the fluctuation in the water level in the outer tub 2 to detect the water level.

In addition, in the washing machine S, the drying air flows through the rotating tub 3 as the centrifugal impeller 300 (see FIG. 2) of the blower 22 rotates, drying the laundry in the rotating tub 3. The drying air, from which moisture has been condensed in the dehumidification area, is reheated by the electric heater 24 (see FIG. 3) of the blower 22 and flows through the rotating tub 3, further evaporating moisture from the laundry. This moisture removal is repeated by circulating the drying air, thereby drying the laundry.

Figure 2 is an external perspective view showing the blower of this embodiment.

As shown in FIG. 2, the blower 22 is configured to include a fan cover 51, a fan casing 52, an electric motor 100, a centrifugal impeller 300, a diffuser 400 (see FIG. 3), and an electric heater 24 (see FIG. 3). When the blower 22 is mounted in a washing machine S (see FIG. 1), for example, the blower 22 is installed in the outer frame 1 (see FIG. 1) with the fan cover 51 of the blower 22 facing substantially downward.

The fan cover 51 is formed with an intake port 57 and an exhaust port 58. The intake 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.

Figure 3 is an exploded perspective view of the blower of this embodiment as seen from the bellmouth side.

As shown in FIG. 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 portion) of the centrifugal impeller 300. In addition, the intake port 57 is provided with a bell mouth 57a.

The exhaust port 58 is a circular through hole and is located downstream of the electric heater 24. The diameter of the exhaust port 58 is larger than the diameter of the suction port 57. The suction port 57 and the exhaust port 58 are formed to face in approximately the same direction.

The fan cover 51 has a generally annular protrusion 51a formed around the suction port 57, protruding toward the bell mouth 57a in the axial direction Ax. The axial direction Ax refers to the direction in which the rotating shaft 101 of the electric motor 100 extends. The fan cover 51 also has a generally rectangular protrusion 51b formed at the position where the electric heater 24 is provided.

Furthermore, screw fixing portions 91 that are screwed to the fan casing 52 are formed at multiple locations on the periphery of the fan cover 51.

The fan casing 52 has a shape corresponding 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, the diffuser 400, and the electric heater 24 are disposed.

The fan casing 52 has a scroll passage 70A formed on the rear side (motor 100 side) where the diffuser 400 is arranged. The scroll passage 70A is configured so that the passage width is narrow on the tongue end 71 side and gradually widens in the clockwise direction from the tongue end 71. The tongue end 71 is the starting point of the scroll passage 70A. The outlet of the scroll passage 70A is the casing discharge port 59.

The fan casing 52 is also formed with an introduction passage 72a that introduces air from the scroll flow passage 70A to the electric heater 24. The electric heater 24 is equipped with a number of fins, and heats the air that flows out of the scroll flow passage 70A and passes through the introduction passage 72a. The introduction passage 72a is configured so that the flow passage width increases toward the electric heater 24. More specifically, the introduction passage 72a is configured to increase in width to approximately the same width as the heating portion of the electric heater 24 (the portion where the fins 24a are arranged). By combining the fan casing 52 and the fan cover 51, the introduction passage 72 is formed in a shape that follows the rectangular heating portion of the electric heater 24.

Furthermore, the fan casing 52 has a flow path 77 formed downstream of the electric heater 24 that communicates with the exhaust port 58 of the fan cover 51. The bottom surface 77a of this flow path 77 is inclined upward toward the exhaust port 58.

The fan casing 52 also has a shape that protrudes in the width direction so that the position outside the heating portion of the electric heater 24 (the fins 24a portion) does not interfere with the air flow.

The fan casing 52 has a shaft insertion hole 80 formed at the center of the scroll passage 70A, into which the rotating shaft 101 of the electric motor 100 is inserted. The outer peripheral edge of the fan casing 52 has a screw insertion portion 92 formed at a position corresponding to the screw fixing portion 91 of the fan cover 51, into which a screw (not shown) is inserted.

The fan casing 52 has multiple screw holes 93 (four in this embodiment) between the shaft insertion hole 80 and the scroll passage 70 for fixing the diffuser 400 to the fan casing 52. These screw holes 93 are formed to surround the shaft insertion hole 80. The fan casing 52 also has a circular recess 93a formed around the periphery of the screw holes 93.

Furthermore, a fan casing groove 94A (concave groove) is formed on the radial outer periphery of the screw hole 93 in the fan casing 52. This fan casing groove 94A is formed in an annular shape between the suction port 57 and the scroll flow passage 70A.

The electric motor 100 has a rotating shaft 101 that is connected to the centrifugal impeller 300 at its radial center, and is attached to the fan casing 52. The electric motor 100 also has a rotor that is fixed to the rotating shaft 101, a stator that is 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.

The centrifugal impeller 300 is constructed by combining a shroud plate 301, a hub plate 311, and blades 321. The shroud plate 301 has a circular suction opening 302 formed in the radial center. The hub plate 311 has an axial hole (not shown) for fixing the rotating shaft 101. The blades 321 are constructed by sandwiching the shroud plate 301 and the hub plate 311 from both sides in the axial direction Ax.

In addition, the centrifugal impeller 300 has the inner diameter end of the blade 321 located radially outward of the suction opening 302 (see FIG. 3). In addition, the centrifugal impeller 300 is configured so that the outer diameter end of the blade 321 approximately coincides with the outer peripheral edge of the shroud plate 301 and the outer peripheral edge of the hub plate 311.

In this embodiment, a closed-type centrifugal impeller 300 having a shroud plate 301 has been described as an example, but an open-type centrifugal impeller in which the hub plate 311 and the blades 321 are integrally molded from resin may also be used. This reduces the number of parts, and costs can be reduced. Resin molding also makes it easier to create a three-dimensional shape, which also improves efficiency. Note that three-dimensionalization means adding an additional twist to the blades, which further improves efficiency.

In addition, in this embodiment, a turbofan with backward-inverted blades is used as an example, but a sirocco fan with forward-inverted blades may also be used. The shape of the impeller is not limited to a centrifugal type, and may be a mixed-flow type. By using a mixed-flow type, the outer diameter of the impeller can be reduced, making it possible to reduce the size of the blower 22.

Figure 4 is an exploded perspective view of the blower of this embodiment as seen from the motor side.

As shown in FIG. 4, the fan cover 51 has a substantially annular scroll passage 70B formed on the back side of the annular protrusion 51a (see FIG. 3). This scroll passage 70B is formed at a position opposite the scroll passage 70A described above, and is configured so that the passage width gradually increases from the tongue end 71B toward the downstream side. The tongue end 71B is the starting point of the scroll passage 70B, and is shaped to overlap with the tongue end 71A of the fan casing 52 in the axial direction Ax.

The fan cover 51 has a scroll passage 70B formed on the bell mouth 57a side where the diffuser 400 is located. The scroll passage 70B is configured so that the passage width is narrow on the tongue end 71B side and gradually widens in the counterclockwise direction from the tongue end 71B. The tongue end 71A is the starting point of the scroll passage 70A. The outlet of the scroll passage 70A is the casing discharge port 59.

Furthermore, the fan cover 51 is formed with an inlet passage 72b that introduces air from the scroll flow passage 70B to the electric heater 24 (see FIG. 3). This inlet passage 72b of the fan cover 51 is also configured so that the flow passage width increases from the tongue end portion 71B toward the downstream, similar to the inlet passage 72a of the fan casing 52. By combining the inlet passage 72a of the fan casing 52 and the inlet passage 72b of the fan cover 51, an inlet passage 72 shaped to fit the rectangular heating portion of the electric heater 24 is formed.

In addition, a fan cover groove portion 94B is formed on the inside of the fan cover 51 between the suction port 57 and the scroll flow passage 70B. This fan cover groove portion 94B is an annular groove portion.

Figure 5 is a perspective view of the diffuser.

As shown in FIG. 5, the diffuser 400 is made of, for example, synthetic resin and has a circular bottom plate 400a that faces the axial Ax surface of the centrifugal impeller 300 (see FIG. 3). A circular through hole 400b is formed in the center of the bottom plate 400a in the radial direction. The through hole 400b is formed to have a larger diameter than the shaft insertion hole 80 (see FIG. 3) of the fan casing 52. In addition, the bottom plate 400a has screw insertion holes 430 formed in multiple locations around the through hole 400b, through which screws (not shown) for fixing the diffuser 400 to the fan casing 52 are inserted. The screw insertion holes 430 are formed at positions corresponding (facing) to the screw holes 93 (see FIG. 3) of the fan casing 52.

The diffuser 400 also has recesses 430a formed around the periphery of the screw insertion holes 430 to prevent the heads of the screws (not shown) from protruding from the surface (top surface) of the bottom plate 400a. This reduces the distance between the bottom plate 400a and the centrifugal impeller 300 when the centrifugal impeller 300 (see FIG. 3) rotates, preventing the centrifugal impeller 300 from coming into contact with the screws (not shown).

A diffuser outer bottom surface portion (side wall) 400c is formed on the entire outer peripheral edge of the bottom plate 400a, which is one step higher in the axial direction Ax than the bottom plate 400a. Diffuser vanes 401 (vanes) are formed at equal intervals along the circumferential direction on the upper surface (surface on the fan cover 51 side) of the diffuser outer bottom surface portion 400c in the axial direction Ax.

The diffuser 400 has a circular opening 461 formed on the upper surface side (suction port 57 side). This opening 461 is located slightly radially inward from the inner end (leading edge 412) of the diffuser vane 401.

The diffuser 400 also has an annular rib 462 formed along the edge of the opening 461 that protrudes in the axial direction Ax.

The diffuser 400 also has approximately triangular communication sections 420A and 420B perpendicular to the axial direction Ax at the outer periphery. The communication section 420A is made of a surface perpendicular to the axial direction Ax and is located on the scroll flow passage 70A (see FIG. 3). The communication section 420B is made of a surface perpendicular to the axial direction Ax and is located on the scroll flow passage 70B (see FIG. 4).

Figure 6 is an exploded perspective view of the diffuser. Note that Figure 6 is a perspective view of the diffuser 400 seen from the bottom side.

As shown in FIG. 6 , the diffuser 400 includes a diffuser body 450 on which diffuser vanes 401 are formed at equal intervals in the circumferential direction, and a diffuser lid portion (side wall) 460 that closes the peripheral portion of the diffuser body 450 from above.
In this embodiment, the diffuser vanes 401 are formed at equal intervals in the circumferential direction, but the diffuser vanes 401 may be arranged at unequal intervals in the circumferential direction. This makes it possible to shift the phase of the pressure fluctuations that occur when the flow from the centrifugal impeller 300 collides with the diffuser vanes 401, thereby reducing the noise of the blower 22.

The diffuser body 450 has diffuser vanes 401 arranged at intervals in the circumferential direction on the diffuser outer bottom surface portion 400c at the outer peripheral edge of the bottom plate 400a. The diffuser vanes 401 are formed to extend and curve slightly so that they are positioned from the inside to the outside in the radial direction.

In addition, an annular rib 452 is formed on the underside of the diffuser body 450 so as to pass radially outside all of the screw insertion holes 430.

The diffuser body 450 is also provided with a shielding member 453 that protrudes in the axial direction Ax and shields the scroll passage 70A. This shielding member 453 is disposed at the position of the tongue end 71A of the scroll passage 70A (the starting point of the scroll passage 70A). The shielding member 453 is also configured with a shielding portion 453a that shields the passage wall surface on the scroll passage 70A side, and a shielding portion 453b that shields the passage wall surface (side surface) from the outer peripheral side surface of the diffuser 400.

The diffuser lid 460 has a lid 463 that covers the upper part (the side facing the bottom plate 400a) of the gap formed between the tip-end diffuser vane 401 and the base-end diffuser vane 401 of two circumferentially adjacent diffuser vanes 401. The lids 463 are formed integrally with the lids 463 of similar shapes lined up in the circumferential direction. In addition, a lid-side notch 464 is formed on the outer periphery of the lid 463.

Figure 7 is a plan view showing the diffuser vane. Note that Figure 7 shows the diffuser lid 460 removed from the diffuser 400.

As shown in FIG. 7, the diffuser vane 401 is formed in a thin plate shape and extends in the circumferential direction in a plan view. The diffuser vane 401 has a trailing edge 402 (the other end or the outer end) located radially outward from its leading edge 412 (one end or the inner end).

A diffuser passage 410, which will be described later, is formed between adjacent diffuser vanes 401A, 401B. This diffuser passage 410 is configured so that its radial width gradually increases from the leading edge 412 side toward the trailing edge 402 side. In other words, the diffuser passage 410 refers to a passage surrounded by adjacent diffuser vanes 401A, 401B, the diffuser outer bottom surface portion 400c, and the diffuser lid portion 460.

Further, a notch 405 is formed on the outer peripheral edge of the diffuser outer bottom surface portion 400c at a position radially inward of the trailing edge 402 of the diffuser vane 401, so as to extend approximately perpendicularly from the suction surface 404 of the diffuser vane 401A to the pressure surface 403 of the adjacent diffuser vane 401B. Note that the pressure surface 403 refers to the entire surface from the leading edge 412 to the trailing edge 402 facing radially outward of the diffuser vane 401, and the suction surface 404 refers to the entire surface from the leading edge 412 to the trailing edge 402 facing radially inward of the diffuser vane 401.
8 and 9 are perspective views of a part of the diffuser cut away, with FIG. 8 showing a perspective view seen from the leading edge side and FIG. 9 showing a perspective view seen from the trailing edge side.
As shown in Figures 8 and 9, in the diffuser flow passage 410, the portion surrounded by the adjacent diffuser vanes 401A, 401B, the diffuser outer bottom portion 400c, and the lid portion 463, and which extends from an inlet surface 480 which is a surface connecting the intersection of the diffuser inlet bottom surface side throat 481 and the adjacent diffuser vane 401A, 401B and the intersection of the diffuser inlet lid side throat 482 and the adjacent diffuser vane 401A, 401B, to an outlet surface 490 which is a surface connecting the intersection of the cut-out portion 405 and the adjacent diffuser vane 401A, 401B and the intersection of the lid side cut-out portion 464 and the adjacent diffuser vane 401A, 401B, is an overlapping flow passage 495.

The diffuser inlet bottom throat 481 is the position on the diffuser outer bottom portion 400c where the diffuser flow passage 410 is narrowest, and the diffuser inlet lid throat 482 is the position on the lid portion 463 where the diffuser flow passage 410 is narrowest.
8, the diffuser vane 401 is formed to be shorter in the radial direction on the cover portion 463 side than on the diffuser outer bottom surface portion 400c side, and therefore the leading edge 412 is formed to be inclined radially outward with respect to the axial direction Ax when the diffuser outer bottom surface portion 400c side is used as a reference. As a result, the inlet surface 480 has a structure inclined with respect to the axial direction of the rotating shaft 101, and the inlet surface 480 is inclined radially outward with respect to the diffuser inlet bottom surface side throat 481 when viewed from the bellmouth 57a side in the axial direction Ax.

As shown in FIG. 9, the cover portion 463 is formed to be radially longer than the diffuser outer bottom surface portion 400c that constitutes the bottom surface of the diffuser flow passage 410. As a result, the flow passage cross-sectional area B1 of the communication portion 420B is formed to be smaller than the flow passage cross-sectional area A1 of the communication portion 420A.

In addition, the cover portion 463 is formed to be radially longer than the diffuser outer bottom surface portion 400c that constitutes the bottom surface of the diffuser flow passage 410, so that the outlet surface 490 of the overlapping flow passage 495 is inclined radially outward when viewed from the bell mouth 57a side in the axial direction Ax with the notch portion 405 as a reference. As a result, the outlet surface 490 is inclined toward the electric motor 100 side in the axial direction Ax, making it easier to guide the flow toward the scroll flow passage 70A side. In other words, the outlet surface 490 in the diffuser flow passage 410 is inclined with respect to the axial direction of the rotating shaft 101, specifically, it is inclined toward the scroll flow passage 70A side, which has a larger flow passage cross-sectional area, making it easier to guide the flow toward the scroll flow passage 70A side.

Furthermore, by inclining the inlet surface 480 and the outlet surface 490 in the same direction, the flow path length of the overlapping flow path 495 is ensured on the diffuser outer bottom surface portion 400c side and the lid portion 463 side.
FIG. 10 is a cross-sectional view taken along line VIII-VIII in FIG.

As shown in FIG. 10, a bell mouth 57a is formed in the suction port 57 of the fan cover 51. The fan cover 51 also has a seal member housing 51c formed around the bell mouth 57a, in which a ring-shaped seal member 60 is housed. The seal member 60 is sandwiched between the bell mouth 57a and the seal member housing 51c, so that a portion of the seal member 60 is exposed toward the suction opening 302. The seal member 60 is disposed to face the tip of the suction opening 302 of the centrifugal impeller 300. The bell mouth 57a and the seal member housing 51c are fixed with screws from the inside of the fan cover 51.

A scroll passage 70 is formed on the outer periphery of the diffuser 400. This scroll passage 70 has a scroll passage 70A formed on the motor 100 side and a scroll passage 70B formed on the bell mouth 57a side (suction port 57).

The scroll passage 70 has a U-shaped cross section in a cross section parallel to the rotating shaft 101 passing through the rotating shaft 101. In other words, the scroll passage 70 is formed to surround both sides of the outer peripheral edge of the diffuser 400 in the axial direction Ax and the outer peripheral side surface of the diffuser 400.

The outer peripheral wall surface of the scroll flow passage 70A is formed by a flow passage wall surface 52s formed in the fan casing 52. This flow passage wall surface 52s is formed in a concave shape in cross section. That is, the flow passage wall surface 52s is composed of a bottom surface 52s1 located on the bottom side (the electric motor 100 side), an inner surface 52s2 located on the radial inside, and an outer surface 52s3 located on the radial outside.

The inner circumferential wall surface (side wall) of the scroll passage 70A is formed by the outer circumferential portion of the bottom plate 400a of the diffuser 400, as shown by the hatched diagonal lines in FIG. 8. The outer circumferential portion of the bottom plate 400a includes the entire diffuser outer bottom surface portion 400c. In other words, the inner circumferential wall surface (side wall) of the scroll passage 70A is formed by the bottom plate 400a located radially outward of the annular rib 452 of the diffuser 400.

The outer peripheral wall surface of the scroll flow passage 70B is formed by a flow passage wall surface 51s formed on the fan cover 51. This flow passage wall surface 51s is formed in a concave shape in cross section. That is, the flow passage wall surface 51s is composed of a top surface 51s1 located on the ceiling side (the bell mouth 57a side), an inner surface 51s2 located on the radial inside, and an outer surface 51s3 located on the radial outside.

The inner circumferential wall surface (side wall) of the scroll passage 70B is formed by the diffuser lid portion 460 of the diffuser 400, as shown by the hatched diagonal lines in FIG. 8. In other words, the inner circumferential wall surface (side wall) of the scroll passage 70B is formed by the diffuser lid portion 460 located radially outward of the annular rib 462 of the diffuser 400.

In addition, in a cross section passing through the rotation axis 101 and parallel to the rotation axis 101, the inner surface 52s2 of the scroll passage 70A is located radially inward from the inner surface 51s2 of the scroll passage 70B.

Figure 11 is an enlarged view of the scroll passage in Figure 10.

11 , when the diffuser passage 410 is divided by a line H that is perpendicular to the axial direction Ax and at the center of the diffuser passage height, a passage cross-sectional area A10 of the scroll passage 70A is configured to be larger than a passage cross-sectional area B10 of the scroll passage 70B. In other words, the scroll passage 70A on the electric motor 100 side is configured to have a larger passage cross-sectional area than the scroll passage 70B on the bell mouth 57a side (the side opposite to the electric motor 100 side).
12 is a meridian plane schematic diagram showing the centrifugal impeller 300, diffuser 400, and scroll passage 70 of the blower. Note that the meridian plane diagram is a diagram in which the shape of the passage in a cross section of the blower cut along the rotation axis is superimposed with the shape of the rotational projection of the blades of the centrifugal impeller 300 and the diffuser vane 401.

The outlet surface 490 is inclined toward the scroll flow passage 70A because the lid portion 463 is formed radially longer than the diffuser outer bottom surface portion 400c. As a result, as shown in FIG. 11, more air flows through the scroll flow passage 70A with the larger flow passage cross-sectional area A10, and less air flows through the scroll flow passage 70B with the smaller flow passage cross-sectional area B10, so the efficiency of the blower 22 can be improved. In addition, because it is possible to prevent the flow from colliding perpendicularly with the outer surfaces 51s3 and 52s3, the turbulent noise generated when the flows collide is reduced, and the noise level of the blower 22 is reduced.

The inlet surface 480 is inclined toward the scroll passage 70A because the diffuser vane 401 is formed to be radially shorter on the lid 463 side than on the diffuser outer bottom surface 400c side. This creates a pressure gradient in the overlapping passage 495 from the diffuser outer bottom surface 400c toward the lid side 463, promoting the three-dimensional flow in the overlapping passage 495, thereby reducing the increase in blade passing frequency noise caused by standing waves in the overlapping passage 495.

In addition, since both the inlet surface 480 and the outlet surface 490 are inclined toward the scroll flow passage 70A, the flow path length of the overlapping flow passage 495 can be secured on the diffuser outer bottom surface portion 400c side and the lid portion 463 side, so that the flow can be decelerated within the overlapping flow passage 495, and good static pressure recovery can be achieved.

In this embodiment, both the inlet surface 480 and the outlet surface 490 are inclined, but if the generated blade passing frequency noise is small, only the outlet surface 490 may be inclined. In that case, it becomes easier to match the angle between the flow from the centrifugal impeller 300 and the leading edge 412 of the diffuser 400, and it becomes easier to suppress flow separation that occurs at the leading edge 412, so the blower 22 can operate over a wide flow rate range.

In addition, in this embodiment, the inclination of the inlet surface 480 is greater than the inclination of the outlet surface 490 in order to increase the amount of reduction in blade passing frequency noise, but this is not limited thereto, and the inclination of the outlet surface 490 may be greater in order to increase the amount of reduction in turbulent noise caused by the flow colliding with the outer surfaces 51s3 and 52s3. This makes it possible to reduce noise according to the purpose, and the noise level of the blower 22 can be reduced.

In the blower 22 configured in this manner, the centrifugal impeller 300 rotates in the W direction (see FIG. 3), and air is sucked through the suction opening 302 through the bell mouth 57a, and then the air (fluid) is discharged from the outer periphery of the centrifugal impeller 300. The discharged air passes through the diffuser passage 410, and changes direction to flow into the approximately triangular communication section 420A on the motor 100 side and the communication section 420B on the bell mouth 57a side. Then, it flows into the scroll passages 70A and 70B provided on both sides of the diffuser 400 in the axial direction Ax.

The air flowing into the scroll flow passages 70A and 70B passes through the casing discharge port 59 and is introduced into the introduction passages 72a and 72b.

As described above, the blower 22 of the present embodiment includes the electric motor 100, the rotating shaft 101 rotatably provided on the electric motor 100, the centrifugal impeller 300 provided on the rotating shaft 101, the bellmouth 57a provided at the suction opening 302 of the centrifugal impeller 300, the diffuser passage 410 provided downstream of the centrifugal impeller 300 and constituted by a plurality of diffuser vanes 401 arranged in the circumferential direction, and the scroll passages 70A, 70B provided on the outer radial outside of the centrifugal impeller 300 of the diffuser passage 410.
The outlet surface 490 is inclined toward the scroll passage 70A because the cover portion 463 is formed to be longer in the radial direction than the diffuser outer bottom surface portion 400c. As a result, more air flows into the scroll passage 70A having the larger passage cross-sectional area A10, and less air flows into the scroll passage 70B having the smaller passage cross-sectional area B10. Since it is possible to prevent the flows from colliding perpendicularly with the outer sides 51s3 and 52s3, turbulent noise generated when the flows collide is reduced, and a highly efficient and low-noise blower 22 can be realized.

The inlet surface 480 is inclined toward the scroll passage 70A because the diffuser vane 401 is formed to be radially shorter on the lid 463 side than on the diffuser outer bottom surface 400c side. This creates a pressure gradient in the overlapping passage 495 from the diffuser outer bottom surface 400c toward the lid side 463, promoting the three-dimensional flow in the overlapping passage 495, reducing the increase in blade passing frequency noise caused by standing waves in the overlapping passage 495, resulting in a lower noise blower 22.

In addition, since the inlet surface 480 and the outlet surface 490 are both inclined toward the scroll flow passage 70A, the flow passage length of the overlapping flow passage 495 can be secured on the diffuser outer bottom surface portion 400c side and the lid portion 463 side, and the flow can be decelerated within the overlapping flow passage 495, resulting in good static pressure recovery and a more efficient blower 22.

The blower 22 of this embodiment is also provided in the washing machine S. This allows for easy installation and reduces the input power to the blower 22 during drying operation, making it possible to provide a washing machine S with reduced power consumption.

The present invention is not limited to the above-described embodiment, but includes various modifications.

REFERENCE SIGNS LIST 1 Outer frame 2 Outer tub 3 Rotating tub 22 Blower 51 Fan cover 52 Fan casing 57 Inlet 57a Bell mouth 58 Outlet 59 Casing outlet 70, 70A, 70B Scroll passage 100 Electric motor 101 Rotating shaft 300 Centrifugal impeller 400 Diffuser 400c Diffuser outer bottom surface 405 Cutout 410 Diffuser passage 412 Leading edge 460 Diffuser lid 463 Lid 464 Lid cutout 480 Inlet surface 481 Diffuser inlet bottom surface throat 482 Diffuser inlet lid throat 490 Outlet surface 495 Overlapping passage

Claims (5)

An electric motor;
A rotating shaft rotatably provided on the electric motor;
An impeller provided on the rotating shaft;
a diffuser flow path provided downstream of the impeller and including a diffuser outer bottom surface portion formed on an outer peripheral edge portion of a bottom plate facing the axial direction of the impeller, a plurality of diffuser vanes arranged in a circumferential direction on an upper surface of the diffuser outer bottom surface portion in the axial direction, and a lid portion covering an upper portion of a gap formed between adjacent diffuser vanes;
A scroll flow passage provided radially outside the impeller,
a notch is formed in an outer peripheral edge of the diffuser outer bottom surface portion at a position radially inward from a trailing edge of the diffuser vane, the notch extending from the negative pressure surface of the diffuser vane substantially perpendicular to the pressure surface of the adjacent diffuser vane,
A lid-side notch is formed on the outer periphery of the lid,
the scroll passage has a passage formed on the electric motor side and a passage formed on a bell-mouth side opposite to the electric motor, the passage on the electric motor side with respect to the impeller has a wider passage cross-sectional area when the diffuser passage is divided perpendicular to the axial direction and at the height center of the diffuser passage, than the passage on the opposite side to the electric motor,
an outlet surface which is a plane connecting an intersection of the cut-out portion in the diffuser passage with the adjacent diffuser vane and an intersection of the cover-side cut-out portion with the adjacent diffuser vane is inclined radially outward with respect to the axial direction of the rotating shaft with respect to the cut-out portion, and is inclined toward the flow passage on the electric motor side, where the flow passage cross-sectional area of the scroll flow passage is larger . The blower according to claim 1 ,
an inlet surface which is a plane connecting an intersection between a diffuser inlet bottom side throat in the diffuser flow passage and an adjacent diffuser vane and an intersection between a diffuser inlet lid side throat and an adjacent diffuser vane is inclined radially outward with respect to the axial direction of the rotation shaft with respect to the diffuser outer bottom side. The blower according to claim 2 ,
A blower, characterized in that the inlet surface and the outlet surface are inclined in the same direction with respect to the axial direction. The blower according to claim 2 or 3 ,
The blower, wherein the inlet surface is inclined more toward the axial direction than the outlet surface. A washing machine comprising the blower according to any one of claims 1 to 4 .

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