Centrifugal separator and washing machine equipped with a centrifugal separator

Abstract

The centrifugal separator (200) includes a drive unit (240), a centrifugal separation unit (204), and a swirling flow generation unit (205). The swirling flow generation unit (205) includes a fluid inlet unit (250) and a cylindrical unit (270). The fluid inlet unit (250) has a first peripheral wall portion (252) formed with an inlet (285) for introducing washing water, and guides the washing water flowing into the inner inflow space (261) in a manner that causes the washing water to swirl. The cylindrical unit (270) swirls the washing water swirling in the fluid inlet unit (250) and introduces it into the centrifugal separation unit (204). The centrifugal separator (200) is configured to prevent at least a part of the washing water swirling in the cylindrical unit (270) from flowing into the inlet (285) of the fluid inlet unit (250).

Description

Technical Field

[0001] The present invention relates to a centrifugal separator and a washing machine including the centrifugal separator. Background Art

[0002] Sometimes, a centrifugal separator (see, for example, Patent Document 1) is used to separate and remove foreign substances from liquid fluids such as washing water, bathtub water, and organic wastewater. Figure 7 FIG. 1 is a cross-sectional view schematically showing the structure of a conventional centrifugal separator 300 disclosed in Patent Document 1. Figure 8 FIG. 2 is a cross-sectional view schematically showing the structure of the conventional centrifugal separator 300 as viewed from below. As Figure 7 shown, the centrifugal separator 300 disclosed in Patent Document 1 includes a swirl flow generating unit 320 that makes the washing water before flowing into the centrifugal separation unit 310 into a swirl flow, and an introduction pipe 330 for introducing the washing water into the swirl flow generating unit 320.

[0003] As Figure 8 shown, the swirl flow generating unit 320 has an annular peripheral wall portion 322, and an inlet 321 through which the washing water flows from the introduction pipe 330 is formed in the annular peripheral wall portion 322. In the swirl flow generating unit 320, the washing water flowing in from the inlet 321 flows along the inner peripheral surface of the peripheral wall portion 322, thereby generating a swirl flow flowing in the direction indicated by the arrow in Figure 8 FIG. 1.

[0004] As Figure 7 shown, the centrifugal separation unit 310 includes: a rotating cylinder 311 disposed within a housing 340; and a pump unit 312 constituted by a plurality of pump vanes integrally formed with the rotating cylinder 311. The rotating cylinder 311 and the pump unit 312 are coaxially disposed with respect to a circular space surrounded by the peripheral wall portion 322 of the swirl flow generating unit 320. A drive unit 350 is disposed outside the housing 340 to drive the rotating cylinder 311 and the pump unit 312.

[0005] When the drive unit 350 drives the pump unit 312, as indicated by the arrow in Figure 7 FIG. 2, the washing water flowing out from the washing tub of the washing machine sequentially passes through the introduction pipe 330, the swirl flow generating unit 320, and the rotating cylinder 311. When the washing water flows into the swirl flow generating unit 320 through the introduction pipe 330, the washing water flows along the inner peripheral surface of the peripheral wall portion 322. Therefore, the washing water becomes a swirl flow within the peripheral wall portion 322. The washing water that has become a swirl flow then flows from the swirl flow generating unit 320 into the rotating cylinder 311. The rotating cylinder 311 is driven by the drive unit 350 to rotate, so that the angular velocity of the swirl flow increases due to the rotation of the rotating cylinder 311, and the centrifugal force acting on the foreign substances contained in the swirl flow becomes larger. As a result, the foreign substances are centrifugally separated in the rotating cylinder 311.

[0006] Prior art documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Laid-Open No. 2018-183277 Summary of the Invention

[0009] In such a conventional centrifuge 300, the washing water is pressurized by the pump section 312. Therefore, the pressure of the washing water at the discharge port 315 of the centrifugal separation section 310 is higher than the pressure of the washing water at the opening 345 at the lower end of the housing 340. Due to this pressure difference, a part of the washing water flowing from the rotary drum 311 toward the discharge port 315 flows backward from between the outer peripheral surface of the rotary drum 311 and the housing 340 toward the opening 345. Further, the washing water flowing backward to the opening 345 at the lower end of the housing 340 may flow backward to the swirling flow generation section 320.

[0010] This backward-flowing washing water may obstruct the flow of the washing water flowing in from the introduction pipe 330 at the inlet 321 of the swirling flow generation section 320. In this case, the swirling flow in the swirling flow generation section 320 becomes turbulent. Therefore, there is a risk that the angular velocity of the swirling flow decreases and the centrifugal force acting on the foreign matter in the centrifugal separation section 310 decreases.

[0011] Accordingly, the present invention provides a centrifuge configured to suppress a decrease in the centrifugal force acting on foreign matter in the centrifugal separation section, and a washing machine including the centrifuge.

[0012] The centrifuge of the present invention separates foreign matter contained in a liquid fluid, and includes: a drive section that generates a driving force; a centrifugal separation section; and a swirling flow generation section that is coupled to the centrifugal separation section. The centrifugal separation section has a housing and a rotary drum disposed within the housing and rotated by the driving force of the drive section, and the centrifugal separation section centrifugally separates foreign matter from the fluid within the rotary drum. The swirling flow generation section includes a fluid inflow section and a cylindrical section. The fluid inflow section has a first peripheral wall section formed with an inlet for allowing the fluid to flow in, and the first peripheral wall section guides the fluid so as to swirl the fluid flowing into the inner inflow space. The cylindrical section is located between the fluid inflow section and the centrifugal separation section with a predetermined axial length, swirls the fluid swirling in the fluid inflow section, and introduces the fluid into the centrifugal separation section. The centrifuge is configured to suppress at least a part of the fluid swirling in the cylindrical section from flowing into the fluid inflow section.

[0013] The centrifugal separator of the present invention separates foreign matters contained in a liquid fluid. The centrifugal separator includes: a drive unit that generates a driving force; a centrifugal separation unit; and a swirling flow generation unit that is coupled to the centrifugal separation unit. The centrifugal separation unit has a housing and a rotating cylinder disposed within the housing and rotated by the driving force of the drive unit. The centrifugal separation unit centrifugally separates foreign matters from the fluid within the rotating cylinder. The swirling flow generation unit includes a fluid inlet portion, a cylindrical portion, and an inflow prevention portion. The fluid inlet portion has a first peripheral wall portion formed with an inlet for allowing the fluid to flow in, and the first peripheral wall portion guides the fluid flowing into the inner inflow space so as to swirl the fluid. The cylindrical portion is located between the fluid inlet portion and the centrifugal separation unit, swirls the fluid swirling in the fluid inlet portion, and introduces the fluid into the centrifugal separation unit. The inflow prevention portion prevents a part of the fluid swirling within the cylindrical portion from flowing into the fluid inlet portion.

[0014] The washing machine of the present invention includes: the above-described centrifugal separator; and a washing tub that washes laundry. The centrifugal separator is connected to the washing tub such that the fluid within the washing tub flows into the centrifugal separator.

[0015] In the above-described centrifugal separator and the washing machine equipped with the centrifugal separator, when the fluid flows backward from the centrifugal separation unit to the swirling flow generation unit, it is possible to suppress a decrease in the centrifugal force acting on the foreign matters in the centrifugal separation unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a longitudinal sectional view schematically showing the structure of the washing machine according to the first embodiment.

[0017] Figure 2 is a longitudinal sectional view schematically showing the structure of the centrifugal separator mounted on the washing machine.

[0018] Figure 3 is a sectional view schematically showing the structure of the centrifugal separator as viewed from below.

[0019] Figure 4 is a longitudinal sectional view schematically showing the structure of the centrifugal separator according to the second embodiment.

[0020] Figure 5A is a longitudinal sectional view showing the structure of a modified example of the centrifugal separator according to the second embodiment.

[0021] Figure 5B is a longitudinal sectional view showing the structure of a modified example of the centrifugal separator according to the second embodiment.

[0022] Figure 6 is a longitudinal sectional view schematically showing the structure of the centrifugal separator according to the third embodiment.

[0023] Figure 7 This is a cross-sectional view schematically showing the structure of a conventional centrifuge.

[0024] Figure 8 This is a cross-sectional view schematically showing the structure of a conventional centrifuge as viewed from below. Detailed Embodiment

[0025] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, for the ease of understanding by those skilled in the art, detailed descriptions of known matters or repeated descriptions of substantially the same structures may sometimes be omitted. In addition, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present invention, and are not intended to limit the subject matter described in the claims.

[0026] (First Embodiment)

[0027] As Figure 1 shown, the washing machine according to the first embodiment of the present invention is configured as a rotary drum type washing machine 100. Figure 1 This is a longitudinal sectional view schematically showing the structure of the washing machine 100. In addition, in the present embodiment, as an example of the washing machine, a rotary drum type washing machine will be described. However, the washing machine of the present invention is not limited thereto. In short, the washing machine of the present invention is a washing machine that uses washing water to wash laundry. That is, the present invention can also be applied to a washing machine having any structure such as a structure that performs pounding washing like a rotary drum type washing machine, a structure that performs agitation cleaning like a vertical washing machine, or a structure that performs pressing washing or rinsing in a housing. In addition, in the present embodiment, the vertical direction in the state where the washing machine 100 is provided as Figure 1 shown may be referred to as the up-and-down direction. In addition, the left side in Figure 1 may be referred to as the front side of the washing machine 100, and the right side in Figure 1 may be referred to as the rear side of the washing machine 100.

[0028] (Overall Structure of the Washing Machine)

[0029] The washing machine 100 includes: a housing 110 formed with an inlet for loading laundry 101; and a door portion 111 for opening and closing the inlet of the housing 110. Specifically, the inlet is formed in the front wall of the housing 110, and the door portion 111 is detachably mounted on the front wall of the housing 110. Various internal devices for performing a washing process, a rinsing process, and a dehydration process are housed in the housing 110.

[0030] Inside the outer casing 110, there is a washing tub 115 for washing the laundry 101. The washing tub 115 includes: a water tank 112 having an opening portion that opens towards the door portion 111 in the closed state; and a rotary drum 120 configured to be rotatable within the water tank 112. In addition, the laundry 101 can be either clothing or other products such as fibrous materials other than clothing that can be washed in the washing machine 100.

[0031] The water tank 112 is provided to accumulate washing water (an example of the liquid fluid of the present invention) during the cleaning process and the rinsing process. The water tank 112 is elastically supported by a suspension mechanism 114 fixed to the bottom wall of the outer casing 110.

[0032] In order to suppress the leakage of the washing water from the opening portion of the water tank 112, a sealing member 113 is provided at the opening portion of the water tank 112. The sealing member 113 is compressed by the door portion 111 when the door portion 111 closes the inlet.

[0033] A water supply port 116 is provided at the upper portion of the peripheral wall of the water tank 112, and the washing water flows in through the water supply port 116 during the cleaning process and the rinsing process. In addition, a discharge port 117 and an inflow port 118 are provided at the lower portion of the water tank 112. The discharge port 117 is used to discharge the washing water used for the laundry 101 during the cleaning process and the rinsing process, and the inflow port 118 allows the washing water discharged from the discharge port 117 to return to the water tank 112.

[0034] The rotary drum 120 is disposed within the water tank 112 in a posture inclined forward. The rotary drum 120 opens towards the inlet of the outer casing 110 (the door portion 111 in the closed state), and the laundry 101 is accommodated inside the rotary drum 120 through the opening portion of the rotary drum 120. A plurality of small holes 124 are formed in the peripheral wall and the rear wall of the rotary drum 120, and during the cleaning process and the rinsing process, the washing water flows in and out of the rotary drum 120 through these small holes 124.

[0035] A protrusion 123 is disposed inside the rotary drum 120. In addition, a drive unit 121 for rotating the rotary drum 120 and the protrusion 123 is mounted on the outer surface of the rear wall of the water tank 112. When the rotary drum 120 and the protrusion 123 rotate, the laundry 101 held inside the rotary drum 120 can be moved.

[0036] The protrusion 123 protrudes from the central portion of the rear wall of the rotary drum 120 towards the opening portion of the rotary drum 120. The protrusion 123 is configured to be rotatable together with the rotary drum 120, and by the rotation of the protrusion 123, the laundry 101 inside the rotary drum is stirred or lifted.

[0037] The drive unit 121 may also be a motor (e.g., a brushless DC motor) configured to be capable of forward and reverse rotation. The shaft of the motor projects into the interior of the water tank 112 through a through-hole provided in the rear wall of the water tank 112, and is connected to the rotary drum 120 and the protrusion 123. The drive unit 121 is configured to be capable of changing the rotational speed of the rotary drum 120 and the protrusion 123 under frequency conversion control.

[0038] A water supply unit 139 is provided above the water tank 112, and the water supply unit 139 is configured to supply washing water to the laundry 101 in the rotary drum 120. The water supply unit 139 includes a water supply path 130 disposed above the water tank 112, a water supply valve 131 provided in the water supply path 130, and a detergent box 132.

[0039] The upstream end of the water supply path 130 is configured to be exposed to the outer surface of the housing 110 and can be connected to a hose (not shown) extending from a faucet 102 of a water pipe. The downstream end of the water supply path 130 is connected to the water supply port 116 of the water tank 112.

[0040] The water supply valve 131 is configured to be able to open and close the water supply path 130, and is disposed upstream of the detergent box 132 in the flow direction of the washing water in the water supply path 130. The detergent box 132 is configured to be able to accommodate detergent. In addition, the detergent box 132 is configured to allow the washing water to pass through the detergent box 132 when the water supply valve 131 is opened.

[0041] A circulation path 143 is provided below the water tank 112, and both ends of the circulation path 143 are connected to the discharge port 117 and the inflow port 118 of the water tank 112. A centrifugal separator 200 is provided on the circulation path 143, and the centrifugal separator 200 is configured to centrifugally separate foreign substances (fibers, etc.) from the washing water flowing through the circulation path 143. The circulation path 143 has a drain pipe 144 extending between the centrifugal separator 200 and the discharge port 117, and a return pipe 145 extending between the centrifugal separator 200 and the inflow port 118. The drain pipe 144 and the return pipe 145 can be formed of a general hose member having a circular cross-section.

[0042] A discharge path 140 branches off from the drain pipe 144. A drain valve 142 for opening and closing the discharge path 140 is provided in the discharge path 140.

[0043] A control unit 170 is provided to control the above-described drive unit 121, water supply valve 131, drain valve 142, and centrifugal separator 200. The control unit 170 is disposed near the lower part of the front wall of the housing 110. The control unit 170 is electrically connected to the drive unit 121, water supply valve 131, drain valve 142, and centrifugal separator 200.

[0044] In addition to the control unit 170, a plurality of instruments (not shown) are provided to detect the torque applied to the drive unit 121, the rotational speed of the drive unit 121, and the amount of washing water supplied to the water tank 112, respectively. The above-mentioned instruments are connected to the control unit 170. The detection values of the above-mentioned instruments are used for the control performed by the control unit 170.

[0045] As an example, the control unit 170 can be composed of a microcomputer and peripheral circuits, can be composed of an arithmetic processing unit and a storage unit storing a control program, can be composed of a hard logic circuit, or can be composed of a combination of the above components. When the control unit 170 is composed of an arithmetic processing unit and a storage unit, an MPU (MicroProcessing Unit) and a CPU (Central Processing Unit) can be used as the arithmetic processing unit. As the storage unit, a memory storing a control program can be used. The control program stored in the memory is executed by the arithmetic processing unit. If the control unit 170 is composed of a hard logic circuit, the processing speed can be increased. The hard logic circuit can be composed of one semiconductor chip or multiple semiconductor chips.

[0046] (Structure of the centrifuge)

[0047] Figure 2 It is a longitudinal sectional view schematically showing the structure of the centrifuge 200 mounted on the washing machine 100. The centrifuge 200 is configured to centrifugally separate foreign substances contained in the washing water flowing through the circulation path 143. As Figure 2 shown, the centrifuge 200 includes: a centrifugal separation unit 204 that centrifugally separates foreign substances in the washing water; a drive unit 240 that generates a driving force for driving the centrifugal separation unit 204; and a swirling flow generation unit 205 that is disposed below the centrifugal separation unit 204 and generates a swirling flow. The centrifuge 200 is mounted in the washing machine 100 such that the rotation axis of the swirling flow is substantially vertical. An inflow unit 260 connected to the drain pipe 144 is connected to the lower part of the swirling flow generation unit 205.

[0048] The swirling flow generation unit 205 includes: a fluid inflow unit 250 that allows the washing water to flow in from the inflow unit 260 and swirl; and a cylindrical unit 270 that is disposed above the fluid inflow unit 250 and allows the swirling washing water to flow out toward the centrifugal separation unit 204.

[0049] Figure 3 It is a sectional view schematically showing the structure of the centrifuge 200 observed from the lower side. As Figure 3 shown, the fluid inflow unit 250 has an annular first peripheral wall portion 252, and an inlet 285 for the washing water to flow in is formed in the first peripheral wall portion 252. As Figure 2As shown, a bottom wall portion 251 that blocks the lower side (the bottom side of the centrifuge 200) of the inflow space 261 and a facing wall portion 253 that faces the bottom wall portion 251 in the vertical direction (the rotation axis direction of the swirling flow) are provided in the inflow space 261 surrounded by the first peripheral wall portion 252. The facing wall portion 253 is connected to the lower end of the cylindrical portion 270 (the fluid inflow portion 250 side). In the inflow space 261 surrounded by the first peripheral wall portion 252, the bottom wall portion 251, and the facing wall portion 253, a swirling flow that flows in the direction of arrow A shown Figure 3 is generated. In the following description, the end portion on the upstream side in the flow direction of the swirling flow of the first peripheral wall portion 252 is referred to as the "upstream end 282". In the following description, the end portion on the side of the first peripheral wall portion 252 opposite to the side where the upstream end 282 is located is referred to as the "downstream end 257". That is, it can also be said that the downstream end 257 is located on the downstream side of one full circle along the first peripheral wall portion 252 from the upstream end 282 in the flow direction of the swirling flow. The inlet 285 is formed as the space between the upstream end 282 and the downstream end 257.

[0050] The first peripheral wall portion 252 includes a first arcuate wall portion 255 and a second arcuate wall portion 254 that are continuously connected to each other. The first arcuate wall portion 255 is provided on the downstream side of the second arcuate wall portion 254 in the flow direction of the swirling flow shown by arrow A.

[0051] The first arcuate wall portion 255 constitutes the downstream end 257 of the first peripheral wall portion 252 and extends curvedly from the downstream end 257 with a certain radius of curvature. The first arcuate wall portion 255 surrounds Figure 3 roughly half of the circular space 256 shown. In addition, the circular space 256 has a center that coincides with the center of curvature of the first arcuate wall portion 255 and a radius that is equal to the radius of curvature of the inner peripheral surface of the first arcuate wall portion 255.

[0052] The second arcuate wall portion 254 constitutes the upstream end 282 of the first peripheral wall portion 252 and is connected to the first arcuate wall portion 255. The second arcuate wall portion 254 has a larger radius of curvature than the first arcuate wall portion 255 and extends curvedly from the connection portion 258 of the second arcuate wall portion 254 and the first arcuate wall portion 255 toward the upstream end 282 in a manner where the radius of curvature gradually increases.

[0053] At the connection portion 258, the directions of the tangents of the inner peripheral surfaces of the second arcuate wall portion 254 and the first arcuate wall portion 255 are the same. Therefore, the inner peripheral surfaces of the second arcuate wall portion 254 and the first arcuate wall portion 255 are continuous. In addition, the direction of the tangent of the inner peripheral surface of the second arcuate wall portion 254 at the upstream end 282 and the direction of the tangent of the circular space 256 at the formation position of the downstream end 257 are substantially parallel.

[0054] The second arcuate wall portion 254 is bent with a larger radius of curvature than the first arcuate wall portion 255. Therefore, in the radial direction of the circular space 256, a curved space 283 that bends along the outer periphery of the circular space 256 is formed outside the circular space 256. That is, the above-mentioned inflow space 261 that generates the swirling flow is composed of the curved space 283 and the circular space 256.

[0055] The curved space 283 has a shape that gradually narrows from the upstream end 282 of the second arcuate wall portion 254 toward the connecting portion 258 between the second arcuate wall portion 254 and the first arcuate wall portion 255 when viewed from above. The curved space 283 is provided to gradually merge the washing water flowing into the first peripheral wall portion 252 through the inlet 285 with the swirling flow in the first peripheral wall portion 252.

[0056] The bottom wall portion 251 has a shape that combines the circular space 256 and the curved space 283 when viewed from above, and integrally closes the inflow space 261 of the fluid inflow portion 250. On the other hand, the opposing wall portion 253 has a shape equal to that of the curved space 283 when viewed from above. The opposing wall portion 253 is disposed opposite to the bottom wall portion 251 at the formation position of the curved space 283, and closes the curved space 283 on the side opposite to the side where the bottom wall portion 251 is located. As Figure 2 shown, the opposing wall portion 253 and the bottom wall portion 251 form a rectangular inlet 285 along with the upstream end 282 of the second arcuate wall portion 254 and the downstream end 257 of the first arcuate wall portion 255. That is, the inlet 285 is located at a position radially outside the circular space 256.

[0057] As Figure 3 shown, the opposing wall portion 253 and the first arcuate wall portion 255 form a circular opening 284 coaxial with the circular space 256 on the upper side (cylindrical portion 270 side) of the fluid inflow portion 250. The washing water that has become a swirling flow in the fluid inflow portion 250 flows out of the fluid inflow portion 250 through the opening 284.

[0058] The inflow portion 260 includes: an inner wall portion 268 connected to the downstream end 257 of the first peripheral wall portion 252 of the fluid inflow portion 250; an outer wall portion 267 connected to the upstream end 282 of the first peripheral wall portion 252 of the fluid inflow portion 250; an upper wall of the inflow portion; and a lower wall of the inflow portion. The inner wall portion 268 extends toward the drain pipe 144 in the tangential direction of the circular space 256 at the position of the downstream end 257 of the first peripheral wall portion 252. The outer wall portion 267 extends in the tangential direction of the second arcuate wall portion 254 at the upstream end 282 of the first peripheral wall portion 252. Since the tangential direction of the second arcuate wall portion 254 at the upstream end 282 of the second arcuate wall portion 254 is the same as the tangential direction of the circular space 256 at the formation position of the downstream end 257, the outer wall portion 267 extends in parallel with the inner wall portion 268. That is, the inflow portion 260 is a flow path formed by the inner wall portion 268, the outer wall portion 267, the upper wall of the inflow portion, and the lower wall of the inflow portion.

[0059] A hose member constituting the drain pipe 144 is connected to the inflow portion 260. Therefore, the inflow portion 260 is formed such that the cross-sectional shape gradually changes from circular to rectangular in the range from the drain pipe 144 to the inlet 285.

[0060] As Figure 2 shown, the cylindrical portion 270 is formed by the second peripheral wall portion 271, which has a predetermined axial length upward in the vertical direction (toward the centrifugal separation portion 204) from the opening 284 of the fluid inflow portion 250 in such a manner that the swirling flow generated in the fluid inflow portion 250 passes through. That is, the lower end of the cylindrical portion 270 is connected to the fluid inflow portion 250, and the upper end of the cylindrical portion 270 is connected to a housing 210 (described later) of the centrifugal separation portion 204. In addition, the axial length of the cylindrical portion 270 is preferably at least 50% of the diameter of the inlet 285 (the dimension in the axial direction of the cylindrical portion 270), and more preferably at least 100%. Thereby, the swirling flow contains an upward component and becomes a more stable and powerful flow.

[0061] Inside the cylindrical portion 270, a cylindrical inner space 272 is formed by the second peripheral wall portion 271. The inner diameter of the inner space 272 is equal to the diameter of the circular space 256, and the inner space 272 is coaxial with the circular space 256 of the fluid inlet portion 250. Moreover, the inlet 285 of the fluid inlet portion 250 is located at a position radially outside the circular space 256 of the fluid inlet portion 250. Therefore, the inlet 285 is located at a position radially outside the inner space 272. Accordingly, the flow of the washing water flowing in from the inlet 285 can smoothly merge with the washing water swirling in the circular space 256, generating a swirling flow along the first peripheral wall portion 252 of the fluid inlet portion 250. In addition, the center of swirl of the swirling flow flowing in the fluid inlet portion 250 can be made substantially coincident with the central axis of the cylindrical portion 270 and the rotation axis of the rotating cylinder 220.

[0062] As Figure 2 shown, the centrifugal separation portion 204 is configured to allow the swirling flow generated in the fluid inlet portion 250 to flow in and separate foreign substances from the flowing-in swirling flow. The centrifugal separation portion 204 includes a housing 210, a rotating cylinder 220 that rotates within the housing 210, and a pump portion 230 that sucks up the swirling washing water in the fluid inlet portion 250 via the rotating cylinder 220.

[0063] The housing 210 is connected to the upper end (centrifugal separation portion 204 side) of the cylindrical portion 270, and the inner space of the housing 210 communicates with the circular space 256 in the fluid inlet portion 250 via the inner space 272 of the cylindrical portion 270.

[0064] The housing 210 includes: a cylinder accommodating portion 211 that is connected to the upper end of the cylindrical portion 270; and a pump accommodating portion 212 that is connected to the cylinder accommodating portion 211 on the side opposite to the side where the cylindrical portion 270 is located. The cylinder accommodating portion 211 is a cylindrical portion having an inner diameter larger than the inner diameter of the cylindrical portion 270. The pump accommodating portion 212 is a disk-shaped portion having an inner space that opens toward the cylinder accommodating portion 211. The pump accommodating portion 212 includes: a cylindrical third peripheral wall portion 213; and an end wall portion 214 that closes the inner space surrounded by the third peripheral wall portion 213 on the side opposite to the side where the cylinder accommodating portion 211 is located. As Figure 1 shown, a discharge pipe 216 is connected to the third peripheral wall portion 213, and the discharge pipe 216 is used to cause the washing water in the pump accommodating portion 212 to flow toward the return pipe 145.

[0065] The rotating cylinder 220 is provided to rotate within the cylinder accommodating portion 211 and centrifugally separate foreign substances contained in the washing water swirling within the rotating cylinder 220. The rotating cylinder 220 is disposed within the cylinder accommodating portion 211 of the housing 210 in a manner coaxial with the circular space 256 of the fluid inlet portion 250 and the inner space 272 of the cylindrical portion 270. AsFigure 2 As shown by arrow B, a gap is formed between the outer peripheral surface 225 of the housing 210 and the rotary cylinder 220 to communicate the pump housing portion 212 and the cylindrical portion 270.

[0066] The rotary cylinder 220 includes a fourth peripheral wall portion 221, an annular plate portion 222, and an annular plate portion 223. The annular plate portion 222 projects radially inward from the end portion of the fourth peripheral wall portion 221 on the side of the cylindrical portion 270. The annular plate portion 223 projects radially inward from the end portion of the fourth peripheral wall portion 221 on the side of the pump housing portion 212. The inner peripheral surface of the fourth peripheral wall portion 221 is the portion to which the foreign matter separated by centrifugation adheres.

[0067] The annular plate portion 222 is provided to increase the contact area between the rotary cylinder 220 and the washing water flowing into the cylinder housing portion 211. That is, by providing the annular plate portion 222, the rotational force transmitted from the rotary cylinder 220 to the washing water in the cylinder housing portion 211 can be increased. The opening of the annular plate portion 222 is formed coaxially with the cylindrical portion 270 so that the washing water that has become a swirling flow in the circular space 256 in the fluid inlet portion 250 flows into the rotary cylinder 220 via the cylindrical portion 270.

[0068] The annular plate portion 223 is provided to prevent the foreign matter adhering to the fourth peripheral wall portion 221 from flowing out to the pump housing portion 212. In addition, similar to the annular plate portion 222, the annular plate portion 223 serves to increase the rotational force transmitted from the rotary cylinder 220 to the washing water in the cylinder housing portion 211. The central opening of the annular plate portion 223 is provided to allow the washing water in the rotary cylinder 220 to flow out to the pump housing portion 212.

[0069] As Figure 2 shown, the pump section 230 includes: a plurality of pump vanes 231 integrally formed with respect to the outer surface of the annular plate portion 223 facing the pump housing portion 212 side; and a mounting plate portion 232 connected to the above-mentioned pump vanes 231 on the side opposite to the side where the annular plate portion 223 is located.

[0070] As Figure 3 shown, the plurality of pump vanes 231 are radially arranged in the pump housing portion 212. In the pump section 230, by the rotation of the plurality of pump vanes 231, a pressure difference is generated between the side of the rotary cylinder 220 and the side of the ejection pipe 216 in the pump section 230. As a result, the washing water in the rotary cylinder 220 is sucked into the pump housing portion 212, and the washing water in the pump section 230 is ejected to the ejection pipe 216. Here, the rotational direction of the pump vanes 231 when the washing water flows from the rotary cylinder 220 via the pump housing portion 212 to the ejection pipe 216 is referred to as the "forward rotation direction".

[0071] The mounting plate portion 232 is provided to transmit the driving force of the driving portion 240 to the rotating cylinder 220 and the plurality of pump vanes 231.

[0072] The driving portion 240 is composed of an electric mechanism. That is, the driving portion 240 includes: a motor main body 241 disposed outside the housing 210; and a drive shaft 242 that protrudes from the motor main body 241 into the pump accommodating portion 212 of the housing 210 and is connected to the mounting plate portion 232. The motor main body 241 is configured to be controlled by the control portion 170 to rotate the drive shaft 242 forward.

[0073] (Description of the operation)

[0074] The operation of the washing machine 100 will be described below. As described below, the washing machine 100 sequentially performs a washing process, a rinsing process, and a dehydration process under the control of the control portion 170.

[0075] When the washing process starts, the control portion 170 controls the water supply valve 131 and the drain valve 142 to open the water supply path 130 and close the discharge path 140. When the water supply valve 131 opens the water supply path 130, the washing water flows in the water supply path 130 and flows into the detergent box 132. The washing water dissolves the detergent in the detergent box 132 and flows out of the detergent box 132. Thereafter, the washing water containing the detergent flows into the water tank 112 through the water supply port 116 of the water tank 112. At this time, since the drain valve 142 is closed, the washing water accumulates in the water tank 112.

[0076] When a predetermined amount of washing water accumulates in the water tank 112, the control portion 170 controls the driving portion 121 to rotate the rotating drum 120 and the protrusion 123. As a result, the laundry 101 is agitated in the rotating drum 120 and thus washed.

[0077] During the period when the laundry 101 is being washed in the rotating drum 120, a centrifugal separation process of foreign substances is performed by the centrifugal separator 200. That is, the control portion 170 controls the driving portion 240 of the centrifugal separator 200 to rotate the pump portion 230 and the rotating cylinder 220 of the centrifugal separator 200 in the forward rotation direction. By the rotational drive of the pump portion 230, the washing water in the water tank 112 flows out through the discharge port 117 of the water tank 112 into the drain pipe 144. This washing water contains foreign substances such as fibers and sebum separated from the laundry 101 during the washing process of the laundry 101. The washing water containing the foreign substances flows into the inflow portion 260 of the centrifugal separator 200 through the drain pipe 144. The washing water sequentially passes through the drain pipe 144 and the inlet 285 in the inflow portion 260.

[0078] The washing water flows into the curved space 283 through the inlet 285. In the curved space 283, the washing water flows along the inner circumferential surface of the second arc-shaped wall portion 254 within the curved space 283 and flows into the circular space 256. The washing water that has flowed into the circular space 256 flows along the inner circumferential surface of the first arc-shaped wall portion 255. As a result of flowing along the inner circumferential surfaces of the second arc-shaped wall portion 254 and the first arc-shaped wall portion 255, a swirling flow is generated in the fluid inlet portion 250.

[0079] The washing water that has become a swirling flow within the fluid inlet portion 250 is sucked up by the suction force of the pump portion 230 and flows into the cylindrical portion 270. The cylindrical portion 270 is coaxial with the circular space 256 and has an inner diameter equal to the diameter of the circular space 256. Therefore, the washing water flows into the cylindrical portion 270 while generally maintaining the state of the swirling flow generated within the circular space 256. After that, the swirling flow flows into the rotating cylinder 220 through the cylindrical portion 270. At this time, the opening at the center of the annular plate portion 222 of the rotating cylinder 220 is coaxial with the cylindrical portion 270, and the washing water can flow into the rotating cylinder 220 while maintaining the swirling flow state.

[0080] At this time, since the rotating cylinder 220 is driven by the driving portion 240 to rotate, the rotational force of the rotating cylinder 220 is transmitted to the washing water that has formed a swirling flow. As a result of the rotational force of the rotating cylinder 220 being transmitted to the washing water, the angular velocity of the swirling flow increases, and the centrifugal force acting on the foreign matter contained in the swirling flow increases. Therefore, the foreign matter moves toward the fourth peripheral wall portion 221 of the rotating cylinder 220 under the action of the centrifugal force and becomes a state of being pressed against the fourth peripheral wall portion 221. As a result, the washing water within the rotating cylinder 220 becomes a state in which foreign matter is centrifugally separated.

[0081] When the rotary cylinder 220 is driven to rotate, the washing water is pressurized by the pump section 230. As a result, the pressure of the washing water at the ejection port 215 of the pump housing section 212 is greater than the pressure of the washing water at the opening 219 at the lower end of the housing 210. Due to this pressure difference, a part of the washing water flowing from the rotary cylinder 220 toward the ejection port 215 sometimes flows backward through the opening 219 between the housing 210 and the outer peripheral surface 225 of the rotary cylinder 220 into the internal space 272 of the cylindrical section 270. The backward-flowing washing water that thus flows into the internal space 272 may merge with the swirling flow in the cylindrical section 270 and further flow backward downward, disturbing the swirling flow. However, the backward-flowing washing water that flows into the internal space 272 is guided again toward the rotary cylinder 220 by the swirling flow having an upward component in the internal space 272 and does not flow into the circular space 256 of the fluid inlet section 250. That is, even if the flow of the swirling flow in the cylindrical section 270 is disturbed by the backward-flowing washing water, at least a part of the backward-flowing washing water that is part of the swirling washing water does not flow into the circular space 256, and a swirling flow can be generated in the fluid inlet section 250 without disturbing the swirling of the washing water.

[0082] In addition, the inlet 285 of the fluid inlet section 250 is formed outside the circular space 256. Therefore, the inflowing washing water is not easily affected by the backward-flowing washing water, and a swirling flow can be generated at the inlet 285 of the fluid inlet section 250 without disturbing the inflow of the washing water. Furthermore, the swirling center of the swirling flow flowing in the fluid inlet section 250 can be made to be substantially aligned with the central axis of the cylindrical section 270 and the rotation axis of the rotary cylinder 220, and the washing water can flow into the cylindrical section 270 while maintaining the state of the swirling flow.

[0083] The washing water from which foreign matter has been centrifugally separated flows into the pump housing section 212 through the openings in the annular plate section 223 under the suction force of the pump section 230. At this time, the foreign matter pressed against the fourth peripheral wall section 221 of the rotary cylinder 220 is also subject to the suction force of the pump section 230, but the annular plate section 223 prevents the foreign matter from flowing into the pump housing section 212.

[0084] The washing water flowing into the pump housing section 212 is ejected from the pump section 230 and flows into the return pipe 145 through the ejection pipe 216 connected to the pump housing section 212. The washing water returns to the water tank 112 through the return pipe 145. That is, the centrifugal separator 200 can return the washing water from which foreign matter has been removed to the water tank 112.

[0085] During the above-described cleaning process, the washing machine 100 may also perform intermediate dehydration processing (dehydration processing performed during the cleaning process). At this time, the control unit 170 controls the drain valve 142 to open the discharge path 140. In addition, the control unit 170 controls the drive unit 121 to increase the rotational speed of the rotary drum 120, thereby centrifugally separating the moisture contained in the laundry 101.

[0086] When performing the intermediate dehydration processing, the control unit 170 controls the drive unit 240 of the centrifuge 200 to stop the pump unit 230 and the rotary drum 220. As a result, the centrifugal force acting on the foreign matter disappears, and thus it is easy to peel off the foreign matter attached to the fourth peripheral wall portion 221 of the rotary drum 220.

[0087] The control unit 170 opens the discharge path 140 to cause the washing water to flow in a direction opposite to that during the centrifugal separation process of the foreign matter performed by the centrifuge 200. That is, the washing water in the housing 210 and the foreign matter peeled off from the fourth peripheral wall portion 221 of the rotary drum 220 sequentially pass through the cylindrical portion 270, the fluid inflow portion 250, the inflow portion 260, and the drain pipe 144 under the action of gravity. Then, the washing water and the foreign matter that have passed through the drain pipe 144 can be discharged to the outside of the washing machine 100 through the discharge path 140.

[0088] In the rinsing process, similarly to the cleaning process, control is performed to accumulate a predetermined amount of water in the water tank 112. After the predetermined amount of water has accumulated in the water tank 112, the control unit 170 controls the drive unit 121 for the rotary drum 120 to agitate the laundry 101 in the rotary drum 120. After agitating the laundry 101 for a period of time sufficient to remove the detergent from the laundry 101, the control unit 170 controls the drain valve 142 to open the discharge path 140. In addition, during the rinsing process, intermediate dehydration processing similar to that performed in the cleaning process can also be performed. Further, in the rinsing process, the centrifugal separation process of foreign matter performed by the centrifuge 200 can be performed in the same manner as in the cleaning process.

[0089] After the rinsing process, the control unit 170 controls the drive unit 121 for the rotary drum 120 to cause the washing machine 100 to perform a dehydration process. In the dehydration process, the control unit 170 controls the drive unit 121 to increase the rotational speed of the rotary drum 120 higher than the rotational speed of the rotary drum 120 in the cleaning process and the rinsing process. As a result, the moisture is centrifugally separated from the laundry 101 in the rotary drum 120.

[0090] In the centrifugal separator 200 configured in this manner, the cylindrical portion 270 is formed to have a predetermined axial length from the opening portion 284 of the fluid inflow portion 250 toward the centrifugal separation portion 204. By making the cylindrical portion 270 have a predetermined axial length, the swirling flow contains an upward component, becoming a smoother and more powerful flow.

[0091] Therefore, for the centrifugal separator 200, even when the washing water flows backward from between the housing 210 and the outer peripheral surface 225 of the rotating cylinder 220 toward the cylindrical portion 270, an upward force can be applied to the washing water. As a result, the centrifugal separator 200 can suppress the inflow of the backward-flowing washing water from the cylindrical portion 270 into the fluid inflow portion 250. Consequently, for the centrifugal separator 200, a swirling flow can be generated in the swirling flow generating portion 205 without disturbing the swirling of the washing water.

[0092] In addition, in the fluid inflow portion 250, an inlet 285 and a curved space 283 are provided outside the circular space 256. The washing water flowing in from the inflow portion 260 through the inlet 285 flows into the curved space 283 before flowing into the circular space 256. The curved space 283 gradually narrows in the downstream direction along the flow direction of the swirling flow in the fluid inflow portion 250. Therefore, the washing water flowing into the curved space 283 gradually merges with the washing water swirling in the circular space 256. As a result, a swirling flow along the first peripheral wall portion 252 of the fluid inflow portion 250 can be generated, and the swirling center of the swirling flow flowing in the fluid inflow portion 250 can be made to coincide approximately with the central axis of the cylindrical portion 270 and the rotation axis of the rotating cylinder 220. Therefore, even when the washing water flows backward from between the housing 210 and the rotating cylinder 220 toward the cylindrical portion 270, the washing water flowing in from the inflow portion 260 is not easily affected by the backward-flowing washing water, and the swirling flow in the circular space 256 is not easily disturbed. As a result, for the centrifugal separator 200, a swirling flow can be generated in the fluid inflow portion 250 without disturbing the swirling of the washing water.

[0093] In addition, various changes or improvements can be made to the washing machine 100 of the first embodiment.

[0094] For example, in the present embodiment, with respect to the centrifugal separator 200, the cylindrical portion 270 having a predetermined axial length and the fluid inlet portion 250 having an inlet 285 formed outside the circular space 256 are described in combination, but it may also be a structure including only any one of them. Thus, with respect to the centrifugal separator 200, a swirling flow can be generated in the swirling flow generating portion 205 without disturbing the swirling of the washing water, and a decrease in the centrifugal force acting on the foreign matter in the centrifugal separation portion 204 can be suppressed. As in the present embodiment, by combining the two structures, a decrease in the centrifugal force acting on the foreign matter in the centrifugal separation portion 204 can be more effectively suppressed with respect to the centrifugal separator 200.

[0095] For example, the centrifugal separator 200 is mounted in the washing machine 100 such that the rotation axis of the swirling flow is substantially vertical, but is not limited thereto. That is, the centrifugal separator 200 may be mounted in the washing machine 100 such that the rotation axis of the swirling flow is substantially horizontal.

[0096] One aspect of the centrifugal separator 200 according to the first embodiment is configured to separate foreign matter contained in washing water (an example of the liquid fluid of the present invention). The centrifugal separator 200 includes: a drive unit 240 that generates a driving force; a centrifugal separation unit 204; and a swirling flow generation unit 205 that is coupled to the centrifugal separation unit 204. The centrifugal separation unit 204 includes a housing 210 and a rotating cylinder 220 disposed within the housing 210 and rotated by the driving force of the drive unit 240, and the centrifugal separation unit 204 centrifugally separates foreign matter from the washing water within the rotating cylinder 220. The swirling flow generation unit 205 includes a fluid inlet portion 250 and a cylindrical portion 270. The fluid inlet portion 250 has a first peripheral wall portion 252 formed with an inlet 285 for allowing the washing water to flow in, and the first peripheral wall portion 252 guides the washing water flowing into the inner side of the first peripheral wall portion 252, i.e., the inflow space 261, in a manner that causes the washing water to swirl. The cylindrical portion 270 is located between the fluid inlet portion 250 and the centrifugal separation unit 204 with a second peripheral wall portion 271 having a predetermined axial length, swirls the washing water swirling in the fluid inlet portion 250, and guides it to the centrifugal separation unit 204. The centrifugal separator 200 is configured to suppress a part of the washing water swirling in the cylindrical portion 270 from flowing into the fluid inlet portion 250.

[0097] According to the above structure, the swirling flow generating unit 205 is configured to suppress the inflow of the washing water from the cylindrical portion 270 into the fluid inflow portion 250. Therefore, even when a part of the washing water in the centrifugal separation portion 204 flows backward from between the outer peripheral surface 225 of the housing 210 and the rotary cylinder 220 into the cylindrical portion 270, the centrifugal separator 200 can suppress the inflow of the backward-flowing washing water from the cylindrical portion 270 into the fluid inflow portion 250. Thereby, the centrifugal separator 200 can suppress the following situation: the backward-flowing washing water from the cylindrical portion 270 flows into the washing water flowing into the fluid inflow portion 250 through the inlet 285 from the inflow portion 260, resulting in the disturbance of the swirling flow in the fluid inflow portion 250. Therefore, the centrifugal separator 200 can suppress the reduction of the centrifugal force acting on the foreign matter in the centrifugal separation portion 204.

[0098] In addition, the centrifugal separator 200 according to one aspect of the first embodiment is configured to separate foreign matters contained in the washing water (an example of the liquid fluid of the present invention). The centrifugal separator 200 includes: a drive unit 240 that generates a driving force; a centrifugal separation unit 204; and a swirling flow generating unit 205 that is coupled to the centrifugal separation unit 204. The centrifugal separation unit 204 has a housing 210 and a rotary cylinder 220 disposed within the housing 210 and rotated by the driving force of the drive unit 240. The centrifugal separation unit 204 centrifugally separates foreign matters from the washing water within the rotary cylinder 220. The swirling flow generating unit 205 includes a fluid inflow portion 250 and a cylindrical portion 270. The fluid inflow portion 250 has a first peripheral wall portion 252, and an inlet 285 for allowing the washing water to flow in is formed in the first peripheral wall portion 252. The first peripheral wall portion 252 guides the washing water flowing into the inner inflow space 261 in a manner that causes the washing water to swirl. The cylindrical portion 270 has a second peripheral wall portion 271 and is located between the fluid inflow portion 250 and the centrifugal separation portion 204, causes the washing water swirling in the fluid inflow portion 250 to swirl, and guides it into the centrifugal separation portion 204. Alternatively, the inlet 285 of the fluid inflow portion 250 is defined as the space between the upstream end 282 and the downstream end 257. The upstream end 282 is located at a position on the upstream side in the flow direction of the swirling flow in the first peripheral wall portion 252. The downstream end 257 is located on the side opposite to the side where the upstream end 282 is located in the flow direction of the swirling flow. Alternatively, the first peripheral wall portion 252 has a first arcuate wall portion 255 and a second arcuate wall portion 254. The first arcuate wall portion 255 is curved from the downstream end 257 with a predetermined radius of curvature. The second arcuate wall portion 254 is curved in an arc shape from the upstream end 282 with a radius of curvature larger than the predetermined radius of curvature and extends, and is connected to the first arcuate wall portion 255. It may also be configured such that the second arcuate wall portion 254 is located at a position radially outside the second peripheral wall portion 271 of the cylindrical portion 270.

[0099] According to the above structure, the inlet 285 of the fluid inlet portion 250 is formed by the first arcuate wall portion 255 and the second arcuate wall portion 254 at a position radially outside the second peripheral wall portion 271 of the cylindrical portion 270. Thus, for the centrifuge 200 of the first embodiment, even when the washing water flows backward from between the housing 210 and the rotating cylinder 220 toward the cylindrical portion 270, it is possible to make the inlet 285 of the fluid inlet portion 250 less affected. As a result, for the centrifuge 200 of the first embodiment, it is possible to generate a swirling flow in the fluid inlet portion 250 without disturbing the swirling of the washing water.

[0100] Another aspect of the washing machine 100 of the above-described embodiment includes: the above-described centrifuge 200; and a washing tub 115 that washes the laundry 101. The centrifuge 200 is connected to the washing tub 115 such that the washing water in the washing tub 115 flows into the centrifuge 200.

[0101] According to the above structure, in the washing machine 100 of the first embodiment, it is possible to suppress a decrease in the centrifugal force acting on foreign matter in the centrifugal separation portion 204 of the centrifuge 200 of the first embodiment. Therefore, it is possible to effectively separate foreign matter contained in the washing water in the centrifuge 200. Also, in the washing machine 100 of the first embodiment, it is possible to suppress the reattachment of the separated foreign matter to the laundry 101 and improve the cleaning effect.

[0102] (Second Embodiment)

[0103] Figure 4 is a longitudinal sectional view schematically showing the structure of the centrifuge 200 of the second embodiment. In the first embodiment, the cylindrical portion 270 is formed to have a second peripheral wall portion 271 vertically upward (toward the centrifugal separation portion 204) from the opening portion 284 of the fluid inlet portion 250. Instead, as Figure 4 shown, the second peripheral wall portion 271 of the cylindrical portion 270 is formed in a conical shape. In the second embodiment, the centrifuge 200 in which the second peripheral wall portion 271 of the cylindrical portion 270 is formed in a conical shape will be described. In addition, except for the cylindrical portion 270, Figure 4 the structure of the centrifuge 200 of the second embodiment shown is the same as the structure of the centrifuge 200 of the first embodiment shown in Figure 2 .

[0104] As Figure 4As shown, the cylindrical portion 270 of the swirling flow generation unit 205 is formed to extend with a gradually decreasing inner diameter from the lower end of the housing 210 (the cylindrical portion 270 side) toward the upper end of the fluid inlet portion 250 (the cylindrical portion 270 side). That is, the second peripheral wall portion 271 of the cylindrical portion 270 is formed in a conical shape with a larger inner diameter toward the upper side (the centrifugal separation unit 204 side) and a smaller inner diameter toward the lower side (the fluid inlet portion 250 side).

[0105] In the centrifugal separator 200 configured in this way, when the washing water swirling in the cylindrical portion 270 reaches near the second peripheral wall portion 271 that is inclined to expand upward, a swirling flow containing an upward component as shown by the arrow C in Figure 4 is generated near the second peripheral wall portion 271. That is, when the rotating cylinder 220 is driven to rotate, near the second peripheral wall portion 271, an upward (toward the centrifugal separation unit 204) force is applied to the washing water that has a centrifugal force acting radially outward of the cylindrical portion 270 due to swirling by the second peripheral wall portion 271 of the cylindrical portion 270. As a result, a swirling flow containing an upward component as shown by the arrow C in Figure 4 is generated near the second peripheral wall portion 271. Thus, the swirling flow contains an upward component and becomes a more stable and powerful flow.

[0106] Figure 4 The arrow B in

[0107] shows the washing water flowing backward from between the outer peripheral surface 225 of the housing 210 and the rotating cylinder 220 into the cylindrical portion 270. At this time, for the centrifugal separator 200 of the second embodiment, near the second peripheral wall portion 271, an upward (toward the centrifugal separation unit 204) force is applied to the washing water, thereby being able to suppress the inflow of the backward-flowing washing water from the cylindrical portion 270 into the fluid inlet portion 250. As a result, for the centrifugal separator 200 of the second embodiment, a swirling flow can be generated in the swirling flow generation unit 205 without disturbing the swirling of the washing water. Figure 5A and Figure 5B are longitudinal sectional views showing the structure of the centrifugal separator 200 according to a modified example of the second embodiment. For example, it may be as shown in Figure 5AAs shown, the second peripheral wall portion 271 includes a cylindrical portion 274 and a conical portion 273. The cylindrical portion 274 is a portion formed by vertically extending downward from the lower end of the housing 210 to the middle portion of the second peripheral wall portion 271. The conical portion 273 is a portion formed by extending with its inner diameter gradually decreasing from the lower side (fluid inflow portion 250 side) of the cylindrical portion 274 toward the upper end of the fluid inflow portion 250. Thus, an upward force is exerted on the swirling washing water near the conical portion 273. Therefore, for the centrifuge 200 of this modification, even when the washing water flows backward to the cylindrical portion 270 through the space between the housing 210 and the rotating cylinder 220, the inflow of the washing water from the cylindrical portion 270 into the fluid inflow portion 250 can be suppressed.

[0108] Alternatively, it may be that, as Figure 5B shown, the second peripheral wall portion 271 includes a conical portion 273 and two cylindrical portions 274 and 275. The two cylindrical portions 274 and 275 are portions respectively connected to the lower end (cylindrical portion 270 side) of the housing 210 and the upper end (cylindrical portion 270 side) of the fluid inflow portion 250. The conical portion 273 is a portion connecting the two cylindrical portions 274 and 275. The conical portion 273 is formed by extending with its inner diameter gradually decreasing from the cylindrical portion 274 connected to the lower end of the housing 210 toward the cylindrical portion 275 connected to the upper end of the fluid inflow portion 250. Thus, an upward force is exerted on the swirling washing water near the conical portion 273. Therefore, for the centrifuge 200 of this modification, even when the washing water flows backward to the cylindrical portion 270 through the space between the housing 210 and the rotating cylinder 220, the inflow of the washing water from the cylindrical portion 270 into the fluid inflow portion 250 can be suppressed.

[0109] Similar to the first embodiment, a centrifugal separator 200 according to an aspect of the second embodiment is configured to separate foreign matters contained in washing water (an example of the liquid fluid of the present invention). The centrifugal separator 200 includes: a drive unit 240 that generates a driving force; a centrifugal separation unit 204; and a swirling flow generation unit 205 that is coupled to the centrifugal separation unit 204. The centrifugal separation unit 204 has a housing 210 and a rotating cylinder 220 that is disposed within the housing 210 and rotates by the driving force of the drive unit 240. The centrifugal separation unit 204 centrifugally separates foreign matters from the washing water within the rotating cylinder 220. The swirling flow generation unit 205 includes a fluid inflow unit 250 and a cylindrical unit 270. The fluid inflow unit 250 has a first peripheral wall portion 252 that is formed with an inlet 285 through which the washing water flows in, and the first peripheral wall portion 252 guides the washing water so as to swirl the washing water flowing into the inner inflow space 261. The cylindrical unit 270 has a second peripheral wall portion 271 and is located between the fluid inflow unit 250 and the centrifugal separation unit 204, swirls the washing water swirling in the fluid inflow unit 250, and guides it to the centrifugal separation unit 204. The centrifugal separator 200 according to an aspect of the second embodiment is configured to suppress at least a part of the washing water swirling in the cylindrical unit 270 from flowing into the fluid inflow unit 250.

[0110] In the above structure, similar to the first embodiment, it may be that the inlet 285 of the fluid inflow unit 250 is defined as the space between the upstream end 282 and the downstream end 257. The upstream end 282 is located at a position on the upstream side in the flow direction of the swirling flow on the first peripheral wall portion 252. The downstream end 257 is located on the side opposite to the side where the upstream end 282 is located at a position where it makes one full circle along the first peripheral wall portion 252 in the flow direction of the swirling flow. It may also be that the first peripheral wall portion 252 has a first arcuate wall portion 255 and a second arcuate wall portion 254. The first arcuate wall portion 255 bends from the downstream end 257 with a predetermined radius of curvature. The second arcuate wall portion 254 bends in an arc shape from the upstream end 282 with a radius of curvature larger than the predetermined radius of curvature and extends, and is connected to the first arcuate wall portion 255. It may also be configured such that the second arcuate wall portion 254 is located at a position radially outside the second peripheral wall portion 271 of the cylindrical unit 270, thereby providing the inlet 285 outside the circular space 256.

[0111] In the above structure, it may be that at least a part of the cylindrical unit 270 in the axial direction of the second peripheral wall portion 271 is formed in a conical shape with a diameter gradually decreasing from the housing 210 toward the fluid inflow unit 250.

[0112] According to the above structure, the conical second peripheral wall portion 271 is used to apply an upward (towards the centrifugal separation portion 204) force to the washing water that has a centrifugal force acting radially outward of the cylindrical portion 270 due to rotation. As a result, a swirling flow containing an upward component along the conical second peripheral wall portion 271 is generated near the conical second peripheral wall portion 271. Therefore, even when the washing water in the centrifugal separation portion 204 flows backward from between the housing 210 and the outer peripheral surface 225 of the rotating cylinder 220 to the cylindrical portion 270, an upward (towards the centrifugal separation portion 204) force can be applied to the washing water. Thus, the centrifugal separator 200 of the second embodiment can suppress the reverse-flow washing water from flowing into the fluid inlet portion 250. As a result, for the centrifugal separator 200 of the second embodiment, a swirling flow can be generated in the fluid inlet portion 250 without disturbing the swirling of the washing water.

[0113] In addition, by providing the inlet 285 outside the circular space 256, similar to the first embodiment, even when the washing water flows backward from between the housing 210 and the rotating cylinder 220 to the cylindrical portion 270, the washing water flowing in from the inlet portion 260 is not easily affected by the reverse-flow washing water. For the centrifugal separator 200, a swirling flow can be generated in the swirling flow generating portion 205 without disturbing the swirling of the washing water.

[0114] Similar to the first embodiment, on the other hand, the washing machine 100 of the above-described embodiment includes: the above-described centrifugal separator 200; and a washing tub 115 that washes the laundry 101. The centrifugal separator 200 is connected to the washing tub 115 in such a way that the washing water in the washing tub 115 flows into the centrifugal separator 200.

[0115] (Third Embodiment)

[0116] Figure 6 is a longitudinal sectional view schematically showing the structure of the centrifugal separator 200 of the third embodiment. In the first and second embodiments, the swirling flow containing an upward component realized by the axial length or conical shape of the second peripheral wall portion 271 of the cylindrical portion 270, or the structure of the inlet 285 disposed at a position outside the second peripheral wall portion 271 in the fluid inlet portion 250 suppresses the inflow of the washing water into the fluid inlet portion 250. Instead, the swirling flow generating portion 205 may include an inflow preventing portion 290 for preventing the inflow of the washing water into the fluid inlet portion 250. In the third embodiment, the centrifugal separator 200 including the swirling flow generating portion 205 including the inflow preventing portion 290 will be described. In addition, except for the inflow preventing portion 290, Figure 6 the structure of the centrifugal separator 200 of the third embodiment shown is the same as Figure 2The same structure as that of the centrifuge 200 of the first embodiment shown.

[0117] As Figure 6 shown, the cylindrical portion 270 is formed such that the inner diameter of the lower end of the cylindrical portion 270 (on the side of the fluid inlet portion 250) is larger than the diameter of the circular space 256 of the fluid inlet portion 250. Further, the opposing wall portion 253 of the fluid inlet portion 250 is formed so as to cover the upper side (on the side of the cylindrical portion 270) of the curved space 283 and extends to a position radially inward of the circular space 256 closer to the lower end (on the side of the fluid inlet portion 250) of the second peripheral wall portion 271 of the cylindrical portion 270. That is, the portion of the opposing wall portion 253 that coincides with the inner space 272 of the cylindrical portion 270 and the curved space 283 of the fluid inlet portion 250 in a top view functions as an inflow prevention portion 290 that separates the inner space 272 and the curved space 283. At this time, the inflow prevention portion 290 of the opposing wall portion 253 is arranged to project radially inward from the lower end (on the side of the fluid inlet portion 250) of the cylindrical portion 270.

[0118] Since the inflow prevention portion 290 separates the inner space 272 and the curved space 283, even when the washing water flows backward from the centrifugal separation portion 204 to the cylindrical portion 270, the inflow of the backward-flowing washing water from the inner space 272 of the cylindrical portion 270 to the fluid inlet portion 250 can be effectively suppressed. Therefore, the centrifuge 200 of the third embodiment can suppress the disturbance of the swirling flow caused by the backward-flowing washing water flowing into the cylindrical portion 270. As a result, in the fluid inlet portion 250, a swirling flow can be generated without disturbing the swirling of the washing water.

[0119] In addition, the cylindrical portion 270 is formed to extend from the upper surface of the opposing wall portion 253 (on the side of the cylindrical portion 270) toward the lower end of the housing 210 (on the side of the cylindrical portion 270), but is not limited thereto. Similar to the second embodiment, for example, the cylindrical portion 270 may be a conical shape that gradually increases in diameter as it extends from the upper surface of the opposing wall portion 253 toward the lower end of the housing 210 (on the side of the cylindrical portion 270).

[0120] The centrifuge 200 according to one aspect of the third embodiment is configured to separate foreign matters contained in washing water (an example of the liquid fluid of the present invention). The centrifuge 200 includes: a drive unit 240 that generates a driving force; a centrifugal separation unit 204; and a swirling flow generation unit 205 that is coupled to the centrifugal separation unit 204. The centrifugal separation unit 204 has a housing 210 and a rotating cylinder 220 disposed within the housing 210 and rotated by the driving force of the drive unit 240, and the centrifugal separation unit 204 centrifugally separates foreign matters from the washing water within the rotating cylinder 220. The swirling flow generation unit 205 includes a fluid inflow unit 250, a cylindrical portion 270, and an inflow prevention unit 290. The fluid inflow unit 250 has a first peripheral wall portion 252 formed with an inlet 285 through which the washing water flows in, and the first peripheral wall portion 252 guides the washing water flowing into the inner side of the first peripheral wall portion 252, i.e., the inflow space 261, in a manner that causes the washing water to swirl. The cylindrical portion 270 has a second peripheral wall portion 271 and is located between the fluid inflow unit 250 and the centrifugal separation unit 204, causing the washing water swirling in the fluid inflow unit 250 to swirl and guiding it into the centrifugal separation unit 204. The inflow prevention unit 290 prevents the reverse flow washing water flowing back from the washing water swirling in the cylindrical portion 270 from flowing into the fluid inflow unit 250.

[0121] According to the above structure, the inflow prevention unit 290 for preventing the washing water from flowing from the cylindrical portion 270 into the fluid inflow unit 250 is provided in the cylindrical portion 270 of the swirling flow generation unit 205. Therefore, for the centrifuge 200 of the third embodiment, even when the washing water flows back from the centrifugal separation unit 204 into the cylindrical portion 270, the inflow of the reverse flow washing water from the cylindrical portion 270 into the fluid inflow unit 250 can be suppressed.

[0122] In the above structure, it may also be that the inflow prevention unit 290 projects inwardly from the end portion on the fluid inflow unit 250 side of the cylindrical portion 270 at least on the cylindrical portion 270 side of the inlet 285.

[0123] According to the above structure, the inflow prevention unit 290 formed to project inwardly in the radial direction from the end portion of the cylindrical portion 270 can be used to suppress the inflow of the reverse flow washing water from the cylindrical portion 270 into the fluid inflow unit 250.

[0124] In the above structure, it is also possible that the inlet 285 of the fluid inlet portion 250 is defined as the space between the upstream end 282 and the downstream end 257. The upstream end 282 is located at a position upstream of the flow direction of the swirling flow on the first peripheral wall portion 252. The downstream end 257 is located on the side opposite to the side where the upstream end 282 is located in the flow direction of the swirling flow. It is also possible that the first peripheral wall portion 252 has a first arcuate wall portion 255 and a second arcuate wall portion 254. The first arcuate wall portion 255 bends from the downstream end 257 with a predetermined radius of curvature. The second arcuate wall portion 254 bends and extends in an arc shape from the upstream end 282 with a radius of curvature larger than the predetermined radius of curvature and is connected to the first arcuate wall portion 255.

[0125] According to the above structure, by using the first arcuate wall portion 255 and the second arcuate wall portion 254, an inlet 285 and a bending space 283 are formed outside the circular space 256 in the fluid inlet portion 250. Therefore, the washing water flowing in from the inflow portion 260 through the inlet 285 flows into the bending space 283 before flowing into the circular space 256. The bending space 283 gradually narrows in the downstream direction in the flow direction of the swirling flow in the fluid inlet portion 250. Therefore, the washing water flowing into the bending space 283 gradually merges with the washing water swirling in the circular space 256. Therefore, the washing water flowing in from the inflow portion 260 is not likely to disturb the swirling flow in the circular space 256. Furthermore, since the inflow prevention portion 290 separates the internal space 272 and the bending space 283, even when the washing water flows backward from the centrifugal separation portion 204 to the cylindrical portion 270, the inflow of the backward-flowing washing water from the internal space 272 of the cylindrical portion 270 into the fluid inlet portion 250 can be suppressed.

[0126] In the above structure, similarly to the second embodiment, the cylindrical portion 270 may also include a second peripheral wall portion 271 in which at least a part in the axial direction of the cylindrical portion 270 is formed in a conical shape with a diameter gradually decreasing from the housing 210 toward the fluid inlet portion 250.

[0127] Similarly to the first embodiment and the second embodiment, on the other hand, the washing machine 100 of the above embodiment includes: a centrifugal separator 200 of the third embodiment; and a washing tub 115 that washes the laundry 101. The centrifugal separator 200 of the third embodiment is connected to the washing tub 115 in such a manner that the washing water in the washing tub 115 flows into the centrifugal separator 200 of the third embodiment.

[0128] In the first embodiment, the second embodiment, and the third embodiment, the centrifuge 200 is mounted on a rotary drum type washing machine 100 and is used to centrifugally separate foreign matters (such as fibers) separated from the laundry 101. As an alternative, the centrifuge 200 may be mounted on a vertical washing machine. Or, the centrifuge 200 is not limited to being used in various washing machines, and may also be applied to a device for cleaning the water in a bathtub or organic wastewater.

[0129] It should be understood that the embodiments disclosed herein are illustrative in all aspects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0130] (Effects, etc.)

[0131] The centrifuge 200 and the washing machine 100 of the above embodiments have the following features and exhibit the following effects.

[0132] In one aspect of the above embodiment, the centrifugal separation mechanism is configured to separate foreign matters contained in a liquid fluid. The centrifuge includes: a drive unit that generates a driving force; a centrifugal separation unit; and a swirling flow generation unit that is coupled to the centrifugal separation unit. The centrifugal separation unit has a housing and a rotating cylinder disposed within the housing and rotated by the driving force of the drive unit, and the centrifugal separation unit centrifugally separates foreign matters from the fluid within the rotating cylinder. The swirling flow generation unit includes a fluid inlet portion and a cylindrical portion. The fluid inlet portion has a first peripheral wall portion formed with an inlet for allowing the fluid to flow in, and the first peripheral wall portion guides the fluid flowing into the inner inflow space thereof in a manner that causes the fluid to swirl. The cylindrical portion is located between the fluid inlet portion and the centrifugal separation unit with a second peripheral wall portion having a predetermined axial length, swirls the fluid swirling in the fluid inlet portion, and guides it into the centrifugal separation unit. The centrifugal separation mechanism is configured to inhibit at least a part of the fluid swirling in the cylindrical portion from flowing into the fluid inlet portion.

[0133] According to the above structure, the centrifugal separation mechanism of one aspect of the above embodiment is configured to suppress the inflow of fluid from the cylindrical portion into the fluid inflow portion. Therefore, for the centrifuge of one aspect of the above embodiment, even when a part of the fluid in the centrifugal separation portion flows backward from between the housing and the outer peripheral surface of the rotating cylinder into the cylindrical portion, it is possible to suppress the disturbance of the swirling flow in the cylindrical portion caused by the backward flow fluid, and it is possible to suppress the inflow of the backward flow fluid from the cylindrical portion into the fluid inflow portion. Thereby, the centrifuge of one aspect of the above embodiment can suppress the following situation: the backward flow fluid from the cylindrical portion flows into the fluid flowing into the fluid inflow portion through the inlet, causing the swirling flow in the fluid inflow portion to be disturbed. Therefore, the centrifuge of one aspect of the above embodiment can suppress the reduction of the centrifugal force acting on foreign matter in the centrifugal separation portion.

[0134] The centrifugal separation mechanism of one aspect of the above embodiment is configured to separate foreign matter contained in a liquid-like fluid. The centrifuge includes: a drive unit that generates a driving force; a centrifugal separation unit; and a swirling flow generation unit that is coupled to the centrifugal separation unit. The centrifugal separation unit has a housing and a rotating cylinder disposed within the housing and rotated by the driving force of the drive unit, and the centrifugal separation unit centrifugally separates foreign matter from the fluid within the rotating cylinder. The swirling flow generation unit includes a fluid inflow portion and a cylindrical portion. The fluid inflow portion has a first peripheral wall portion formed with an inlet through which the fluid flows in, and the first peripheral wall portion guides the fluid so as to swirl the fluid flowing into the inner inflow space of the first peripheral wall portion. The cylindrical portion has a second peripheral wall portion and is located between the fluid inflow portion and the centrifugal separation portion, swirls the fluid swirling in the fluid inflow portion, and guides it into the centrifugal separation portion. Further, the inlet of the fluid inflow portion may be defined as the space between the upstream end of the first peripheral wall portion located on the upstream side in the flow direction of the swirling flow and the downstream end of the first peripheral wall portion located on the side opposite to the upstream end side in the flow direction of the swirling flow. The first peripheral wall portion may have a first arcuate wall portion and a second arcuate wall portion. The first arcuate wall portion is curved from the downstream end with a predetermined radius of curvature, and the second arcuate wall portion is curved in an arc shape from the upstream end with a radius of curvature larger than the predetermined radius of curvature and extends and is connected to the first arcuate wall portion. It may be configured such that the second arcuate wall portion is located at a position radially outside the second peripheral wall portion of the cylindrical portion.

[0135] According to the above structure, the inlet of the fluid inflow portion is formed by the first arc-shaped wall portion and the second arc-shaped wall portion at a position radially outside the second peripheral wall portion of the cylindrical portion. Thus, for the centrifugal separator according to one aspect of the above-described embodiment, a swirling flow along the first peripheral wall portion of the fluid inflow portion can be generated, and the swirling center of the swirling flow flowing in the fluid inflow portion can be made substantially coincident with the central axis of the cylindrical portion and the rotation axis of the rotating cylinder. Therefore, even when the fluid flows backward from between the housing and the rotating cylinder into the cylindrical portion, the fluid flowing in from the inflow portion is not easily affected by the backward-flowing fluid, and the swirling flow in the circular space is not easily disturbed. As a result, for the centrifugal separator according to one aspect of the above-described embodiment, a swirling flow can be generated in the fluid inflow portion without disturbing the swirling of the fluid. Therefore, the centrifugal separator according to one aspect of the above-described embodiment can suppress a decrease in the centrifugal force acting on foreign matter in the centrifugal separation portion.

[0136] The centrifugal separator according to one aspect of the above-described embodiment is configured to separate foreign matter contained in a liquid fluid. The centrifugal separator includes: a drive unit that generates a driving force; a centrifugal separation unit; and a swirling flow generation unit that is coupled to the centrifugal separation unit. The centrifugal separation unit has a housing and a rotating cylinder disposed in the housing and rotated by the driving force of the drive unit, and the centrifugal separation unit centrifugally separates foreign matter from the fluid in the rotating cylinder.

[0137] The swirling flow generation unit includes a fluid inflow portion, a cylindrical portion, and an inflow prevention portion. The fluid inflow portion has a first peripheral wall portion that forms an inlet through which the fluid flows in, and the first peripheral wall portion guides the fluid so as to swirl the fluid in the inflow space inside the first peripheral wall portion. The cylindrical portion is located between the fluid inflow portion and the centrifugal separation portion, swirls the fluid swirling in the fluid inflow portion, and guides it to the centrifugal separation portion. The inflow prevention portion prevents a part of the fluid swirling in the cylindrical portion from flowing into the fluid inflow portion.

[0138] According to the above structure, an inflow prevention portion for preventing the fluid from flowing into the inlet of the fluid inflow portion from the cylindrical portion is provided in the swirling flow generation unit. Thus, for the centrifugal separator according to one aspect of the above-described embodiment, even when the fluid flows backward from the centrifugal separation portion into the cylindrical portion, the inflow of the backward-flowing fluid from the cylindrical portion into the fluid inflow portion can be suppressed. That is, the centrifugal separator according to one aspect of the above-described embodiment can suppress a decrease in the centrifugal force acting on foreign matter in the centrifugal separation portion.

[0139] In the above structure, it may also be that the inflow prevention portion projects inward at least from the end portion on the fluid inflow portion side of the cylindrical portion on the cylindrical portion side of the inlet.

[0140] According to the above structure, an inflow prevention portion formed to protrude radially inward from the lower end of the cylindrical portion can be used to suppress the inflow of the reverse flow fluid from the cylindrical portion into the fluid inflow portion.

[0141] In the above structure, it may also be that the inlet of the fluid inflow portion is defined as the space between the upstream end located on the upstream side in the flow direction of the swirling flow in the first peripheral wall portion and the downstream end located on the side opposite to the upstream end side in the flow direction of the swirling flow in the first peripheral wall portion. It may also be that the first peripheral wall portion has a first arcuate wall portion and a second arcuate wall portion. The first arcuate wall portion is bent from the downstream end with a predetermined radius of curvature, and the second arcuate wall portion is bent in an arc shape with a radius of curvature larger than the predetermined radius of curvature from the upstream end and extends and is connected to the first arcuate wall portion.

[0142] According to the above structure, a bent space is formed outside the circular space in the fluid inflow portion by the first arcuate wall portion and the second arcuate wall portion. Therefore, the fluid flowing in from the inflow portion through the inlet flows into the bent space before flowing into the circular space. The bent space gradually narrows in the downstream direction in the flow direction of the swirling flow in the fluid inflow portion. Therefore, the fluid flowing into the bent space gradually merges with the fluid swirling in the circular space. Therefore, the fluid flowing in from the inflow portion is less likely to disturb the swirling flow in the circular space.

[0143] In the above structure, the cylindrical portion may also include a second peripheral wall portion in which at least a part in the axial direction of the cylindrical portion is formed in a conical shape with a diameter gradually decreasing from the housing toward the fluid inflow portion.

[0144] According to the above structure, the conical second peripheral wall portion is used to apply an upward (toward the centrifugal separation portion) force to the fluid that has a centrifugal force acting radially outward of the cylindrical portion due to swirling. As a result, a swirling flow containing an upward component along the conical second peripheral wall portion is generated near the conical second peripheral wall portion. Therefore, for the centrifugal separator of one aspect of the above embodiment, even when the fluid in the centrifugal separation portion flows backward from between the housing and the outer peripheral surface of the rotating cylinder into the cylindrical portion, an upward (toward the centrifugal separation portion) force can be applied to the fluid. Therefore, the centrifugal separator of one aspect of the above embodiment can suppress the inflow of the reverse flow fluid from the cylindrical portion into the fluid inflow portion. As a result, for the centrifugal separator of one aspect of the above embodiment, a swirling flow can be generated in the fluid inflow portion without disturbing the swirling of the fluid.

[0145] Another aspect of the washing machine of the above embodiment includes: the above centrifugal separator; and a washing tub that washes the laundry. The centrifugal separator is connected to the washing tub in such a way that the fluid in the washing tub flows into the centrifugal separator.

[0146] According to the above structure, in the washing machine according to another aspect of the above embodiment, it is possible to suppress a decrease in the centrifugal force acting on foreign matter in the centrifugal separation unit of the centrifugal separator, and thus it is possible to effectively separate foreign matter contained in the fluid in the centrifugal separator. Further, in the washing machine according to another aspect of the above embodiment, it is possible to suppress the reattachment of the separated foreign matter to the laundry, and the cleaning effect can be improved.

[0147] Industrial applicability

[0148] The present invention is suitable for various devices for removing foreign matter in a fluid.

[0149] Explanation of reference numerals

[0150] 100, Washing machine; 101, Laundry; 102, Water faucet; 110, Outer casing; 111, Door part; 112, Water tank; 113, Sealing member; 114, Suspension mechanism; 115, Washing tub; 116, Water supply port; 117, Drain port; 118, Inlet; 120, Rotating drum; 121, Driving part; 123, Protrusion; 124, Small hole; 130, Water supply path; 131, Water supply valve; 132, Detergent box; 139, Water supply part; 140, Discharge path; 142, Drain valve; 143, Circulation path; 144, Drain pipe; 145, Return pipe; 170, Control part; 200, Centrifuge; 204, Centrifugal separation part; 205, Whirlpool generation part; 210, Housing; 211, Cylinder accommodation part; 212, Pump accommodation part; 213, Third peripheral wall part; 214, End wall part; 215, Jet outlet; 216, Jet pipe; 219, Opening; 220, Rotating cylinder; 221, Fourth peripheral wall part; 222, Annular plate part; 223, Annular plate part; 225, Outer peripheral surface; 230, Pump part; 231, Pump vane; 232, Mounting plate part; 240, Driving part (the driving part of the centrifuge); 241, Motor body; 242, Drive shaft; 250, Fluid inlet part; 251, Bottom wall part; 252, First peripheral wall part; 253, Opposite wall part; 254, Second arc-shaped wall part; 255, First arc-shaped wall part; 256, Circular space; 257, Downstream end; 258, Connection part; 260, Inlet part; 261, Inlet space; 267, Outer wall part; 268, Inner wall part; 270, Cylindrical part; 271, Second peripheral wall part; 272, Internal space; 273, Conical part; 274, Cylindrical part; 275, Cylindrical part; 282, Upstream end; 283, Bending space; 284, Opening; 285, Inlet; 290, Inflow prevention part; 300, Centrifuge; 310, Centrifugal separation part; 311, Rotating cylinder; 312, Pump part; 315, Jet outlet; 320, Whirlpool generation part; 321, Inlet; 322, Peripheral wall part; 330, Introduction pipe; 340, Housing; 345, Opening; 350, Driving part.

Claims

1. A centrifugal separator that separates foreign matter contained in a liquid fluid, wherein, the centrifugal separator includes: a drive unit that generates a driving force; a centrifugal separation unit having a housing and a rotating cylinder disposed within the housing and rotated by the driving force of the drive unit, the centrifugal separation unit centrifugally separating foreign matter from the fluid within the rotating cylinder; and a swirling flow generation unit coupled to the centrifugal separation unit, the swirling flow generation unit includes a fluid inlet portion and a cylindrical portion, the fluid inlet portion having a first peripheral wall portion formed with an inlet for the fluid to flow in, and the first peripheral wall portion guiding the fluid flowing into the inner inflow space of the first peripheral wall portion to swirl, the cylindrical portion having a second peripheral wall portion with a predetermined axial length and located between the fluid inlet portion and the centrifugal separation unit, swirling the fluid swirling in the fluid inlet portion and introducing it into the centrifugal separation unit, the centrifugal separator is configured to suppress a part of the fluid swirling within the cylindrical portion from flowing into the fluid inlet portion, the inlet of the fluid inlet portion is defined as the space between the upstream end of the first peripheral wall portion located on the upstream side in the flow direction of the swirling flow and the downstream end of the first peripheral wall portion located on the side opposite to the side where the upstream end is located in the flow direction of the swirling flow, the first peripheral wall portion has a first arcuate wall portion and a second arcuate wall portion, the first arcuate wall portion being bent from the downstream end with a predetermined radius of curvature, the second arcuate wall portion being bent in an arc shape and extending from the upstream end with a radius of curvature larger than the predetermined radius of curvature and connected to the first arcuate wall portion, the centrifugal separator is configured such that the second arcuate wall portion is located at a position radially outside the second peripheral wall portion of the cylindrical portion.

2. The centrifugal separator according to claim 1, wherein, the swirling flow generation unit further includes an inflow prevention portion that prevents a part of the fluid swirling within the cylindrical portion from flowing into the fluid inlet portion.

3. The centrifugal separator according to claim 2, wherein, the inflow prevention portion projects inwardly at least from the end portion on the fluid inlet portion side of the cylindrical portion on the cylindrical portion side of the inlet.

4. The centrifugal separator according to any one of claims 1 to 3, wherein, the cylindrical portion includes a second peripheral wall portion in which at least a part in the axial direction of the cylindrical portion is formed in a conical shape with a diameter gradually decreasing from the housing toward the fluid inlet portion.

5. A washing machine, wherein, the washing machine includes: the centrifugal separator according to any one of claims 1 to 4; and a washing tub that washes laundry, the centrifugal separator is connected to the washing tub in such a manner that the fluid in the washing tub flows into the centrifugal separator.

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