Spray arm for a dishwasher and dishwasher

Abstract

The present application relates to a spray arm for a washing machine and the washing machine, the spray arm comprising a body and a nozzle, a water outlet is formed on the top wall of the body, the nozzle is rotatably connected at the water outlet, a lower part of the nozzle is provided with an impeller in a flow channel and rotatable under the impact of water flow, the impeller is formed with a first flow channel with side water inlet and top water outlet, an upper part of the nozzle is provided with a second flow channel for directional guiding of water flow, the second flow channel is located outside the flow channel and communicates with the first flow channel, a water outlet is formed on the top wall of the nozzle and communicates with the end of the second flow channel. Before the water column is sprayed, the water flow first collects in the first flow channel, then gathers in the second flow channel, and finally is sprayed from the inclined nozzle. The triple action force is conducive to increasing the rotation speed of the nozzle, the flow guiding effect of the first flow channel and the second flow channel makes the water flow into the nozzle more stable, and it is convenient to divide the water flow towards the water outlet, reduces the energy loss, so as to maintain a high water pressure and jet lift.

Description

Technical Field

[0001] This invention relates to the field of dishwasher technology, specifically to a spray arm for a cleaning machine and the cleaning machine itself. Background Technology

[0002] Dishwashers typically include a spray arm that rinses dishes or fruits and vegetables by spraying water jets. For example, Chinese patents CN204813755U ("Dishwasher Spray Arm Base, Dishwasher Spray Arm Device and Dishwasher") and CN209932651U ("A Spray Arm for a Cleaning Machine") disclose the corresponding spray arm structures.

[0003] For the spray arm with the above structure, the water inlet is located on one side wall of the spray arm, and water exits to both sides through this inlet. The spray arm rotates due to the viscous force of the water dispersed in the flow channel. A first spray hole is opened on the other side wall of the spray arm for spraying a water jet. In existing dishwashers, once the dish rack structure is fixed, the position of the dishes on the rack remains unchanged. However, the water jet sprayed by the spray arm is roughly in a straight line (strip), which results in a limited spray range, failing to cover all surfaces of the dishes and creating cleaning dead zones, thus affecting the cleaning effect. Furthermore, for dishwashers with a rectangular washing chamber, cleaning dead zones are also prone to occur.

[0004] Chinese utility model patent CN204445748U, entitled "A Dishwasher Sprayer and Dishwasher" (application number: CN201520047405.0), discloses a structure in which the sprayer includes a water storage cavity, a spray surface, and a mounting surface. The spray surface has multiple spray holes communicating with the water storage cavity. The mounting surface has a water inlet. A nozzle is mounted on the spray surface, and the nozzle has at least two spray holes. The nozzle has a water channel communicating with the water storage cavity, and the spray holes are connected to the water channel. While the sprayer rotates and sprays, the nozzles on the sprayer also spray simultaneously. Because each nozzle has at least two spray holes, the effective spray area is increased, and dead zones are reduced.

[0005] The sprayer with the above-described structure helps reduce cleaning dead zones. However, when spraying water jets, the power for the nozzle rotation mainly comes from the force of the water jet being ejected through the deflecting spray holes. This means the nozzle rotation speed depends on the pressure of the sprayed water jet. If the water pressure in the sprayer is low, the nozzle rotation speed will be very low, directly affecting the sweeping frequency of the water jet from the deflecting spray holes, and thus affecting the cleaning effect. At the same time, the water entering the nozzle is prone to collision and turbulence, leading to water flow energy loss, affecting the head of the sprayed water jet, and thus affecting the cleaning effect. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a spray arm for a cleaning machine that, in view of the current state of the prior art, reduces the water pressure requirements of the rotation speed by collecting and concentrating water in sequence, thereby enabling the nozzle to maintain a high rotation speed and high head, and thus improve the cleaning effect.

[0007] The second technical problem to be solved by the present invention is to provide a spray arm for a cleaning machine that can stabilize and divert the water entering the nozzle, thereby reducing energy loss and maintaining a high jet head, in light of the current state of the prior art.

[0008] The third technical problem to be solved by the present invention is to provide a cleaning machine that uses the above-mentioned spray arm, in view of the current state of the prior art.

[0009] The technical solution adopted by the present invention to solve at least one of the above-mentioned technical problems is as follows:

[0010] A spray arm for a cleaning machine includes a body and a nozzle. The body is hollow to form a flow channel. The body is provided with a water inlet and a first spray hole that are connected to the flow channel. A water outlet is opened on the top wall of the body. The nozzle is rotatably connected to the water outlet. An impeller is provided at the lower part of the nozzle, located in the flow channel and rotating under the impact of water flow. A first flow channel with side water inlet and top water outlet is formed in the impeller. A second flow channel that can directionally guide the water flow is provided at the upper part of the nozzle. The second flow channel is located outside the flow channel and is connected to the first flow channel. A spray hole is opened on the top wall of the nozzle and is arranged at an inclination and connected to the end of the second flow channel.

[0011] Preferably, the nozzle comprises a top plate, a middle plate, and a bottom plate arranged sequentially from top to bottom. Multiple radially extending blades are disposed between the middle plate and the bottom plate. The blades, the middle plate, and the bottom plate together enclose a first flow channel. A water inlet communicating with the first flow channel is opened in the central part of the middle plate. A second flow channel is located between the top plate and the middle plate and communicates with the water inlet. With this structure, a centrifugal impeller structure is formed at the lower part of the nozzle. The impeller draws water circumferentially and exits from the top, which not only allows for a larger rotational speed under water flow impact but also increases the suction force, thus improving the jet head.

[0012] Preferably, a partition extending outward from the edge of the water outlet is provided between the top plate and the middle plate, and the partition encloses the second flow channel.

[0013] Preferably, the second flow channel includes at least two branch flow channels extending radially along the nozzle, and the spray nozzle is arranged corresponding to the end of each branch flow channel. In this invention, the first flow channel draws water from the outer periphery towards the center, concentrating the water flow and providing the nozzle with a first level of rotational power; the second flow channel radially branches the water flow from the center, concentrating the water flow and providing the nozzle with a second level of rotational power; when the water flows out through the inclined spray nozzle, it provides a third level of rotational power to the nozzle; thereby effectively increasing the rotational speed of the nozzle.

[0014] Each blade extends circumferentially spirally between the middle plate and the bottom plate, and the branch flow channel also extends spirally circumferentially around the nozzle, with the spiral direction of the blades consistent with that of the branch flow channel. This structure facilitates further improvement of the nozzle rotation speed.

[0015] Preferably, the outer end of each blade, together with the middle plate and the bottom plate, forms the inlet of the first flow channel, and the inner end of each blade, together with the middle plate and the bottom plate, forms the outlet of the first flow channel, which is arranged below the edge of the water inlet.

[0016] Preferably, the outer bottom wall of the base plate is provided with a flow guiding structure for radially guiding the water flow in the flow channel. The flow guiding structure is a guide cone surface that gradually extends downwards from the outside to the inside. This structure facilitates guiding the water in the flow channel towards the inlet of the first flow channel, reducing energy loss.

[0017] In this invention, a cover plate is provided on the main body, which together with the top wall of the main body encloses an air-collecting cavity. The air-collecting cavity is connected to the outside air. The cover plate has a second water spray hole arranged corresponding to the first water spray hole, and there is an air-intake gap between the first and second water spray holes. According to the Venturi effect, when the water column is ejected through the first and second water spray holes, a negative pressure is generated at the gap, thereby drawing the surrounding water into the water column, thus forming a cavitation water column containing air bubbles. When the cavitation water column hits the surface of the object to be cleaned, the instantaneous bursting of the air bubbles can increase the peeling force on the contaminants and improve the cleaning effect.

[0018] Preferably, the upper part of the nozzle is rotatably arranged through the air collection chamber, and the cover plate has an installation port for the nozzle to pass through, with the water spray nozzle protruding above the cover plate. Preferably, the upper part of the nozzle is provided with a circumferentially arranged wall, and the outer surface of the wall is provided with a guide channel that spirals circumferentially in the direction of nozzle rotation to introduce outside air into the air collection chamber. With the above structure, air can be drawn into the air collection chamber by utilizing the disturbance of the surrounding airflow caused by the rotation of the nozzle, providing sufficient air volume for the water spray holes on the spray arm to generate a cavitation water column with a high bubble content. A notch can be provided at the bottom edge of the air collection chamber, which can also serve to supplement air intake or drain accumulated water.

[0019] To facilitate assembly, the outer peripheral wall of the nozzle is provided with a convex ring that can cooperate with the inner top wall of the body for positioning and a convex clip that can cooperate with the outer top wall of the body for positioning.

[0020] In this invention, the top wall of the nozzle is provided with a jet sleeve extending axially along the water outlet. This jet sleeve has air intake holes that automatically draw in air along with the jet to form a cavitation water column. This structure allows the nozzle to also spray a cavitation water column carrying air bubbles, thereby improving the cleaning effect.

[0021] Preferably, the inner diameter of the jet sleeve includes a first conical section, a direct current section, and a second conical section connected in sequence along the water flow direction. The inner diameter of the first conical section gradually decreases along the water flow direction, and the inner diameter of the second conical section gradually increases along the water flow direction. The air intake hole is opened on the side wall of the jet sleeve and is connected to the direct current section.

[0022] A cleaning machine includes a housing and a water pumping mechanism, and also includes the aforementioned spray arm, which is rotatably disposed in the housing. The water pumping mechanism is used to pump water from the bottom of the housing to the spray arm.

[0023] Compared with the prior art, the advantages of the present invention are as follows: The present invention is equipped with a nozzle on the spray arm that can rotate with the spray arm and rotate simultaneously. The water jet sprayed by the nozzle cooperates with the water jet sprayed by the spray hole, which is conducive to spreading the cleaning range and eliminating cleaning dead corners, thereby improving the cleaning effect. In the present invention, before the nozzle sprays out the water jet, the water flow first passes through the first flow channel to collect water, the second flow channel to collect water, and then sprays out from the inclined nozzle. The triple action helps to increase the nozzle rotation speed, and the guiding effect of the first flow channel and the second flow channel makes the water flow into the nozzle more stable and facilitates the diversion of water towards the spray hole, reducing energy loss, thereby maintaining a high water pressure and spray head. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the spray arm according to an embodiment of the present invention;

[0025] Figure 2 for Figure 1 A sectional view;

[0026] Figure 3 for Figure 2 Enlarged view of section A;

[0027] Figure 4 for Figure 2 Enlarged view of section B;

[0028] Figure 5 This is a schematic diagram of the nozzle structure according to an embodiment of the present invention;

[0029] Figure 6 for Figure 5 Another angle view;

[0030] Figure 7 This is a cross-sectional view of the nozzle according to an embodiment of the present invention;

[0031] Figure 8 This is a schematic diagram of the lower part of the nozzle in an embodiment of the present invention;

[0032] Figure 9 This is a schematic diagram of the upper part of the nozzle in an embodiment of the present invention;

[0033] Figure 10 This is a cross-sectional view of the upper part of the nozzle in an embodiment of the present invention. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0035] like Figures 1-10 As shown, the spray arm for the cleaning machine in this embodiment includes a body 1 and a nozzle 2. The body 1 extends along the length direction and has a hollow interior forming a flow channel 11. A water inlet 12 connected to the flow channel 11 is provided in the center of the bottom wall of the body 1. Several first water spray holes 13 connected to the flow channel 11 are opened on the top wall of the body 1. A water outlet 14 is also opened on the top wall of the body 1 near the end of the flow channel 11. The nozzle 2 is rotatably connected to the water outlet 14.

[0036] In this embodiment, the nozzle 2 includes a top plate 21, a middle plate 22, and a bottom plate 23 arranged sequentially from top to bottom. The top plate 21 and the middle plate 22 form the upper part of the nozzle 2, and the middle plate 22 and the bottom plate 23 form the lower part of the nozzle 2. The lower part of the nozzle 2 is housed in the flow channel 11 and is provided with an impeller 24 that can rotate under the impact of water flow. A first flow channel 241 with side water inlet and top water outlet is formed in the impeller 24. The upper part of the nozzle 2 is located above the flow channel 11 and is provided with a second flow channel 25 that can guide the water flow in a direction. The second flow channel 25 is connected to the first flow channel 241. A spray nozzle 26 is provided on the top wall of the nozzle 2, which is arranged at an inclination and connected to the end of the second flow channel 25.

[0037] Specifically, multiple radially extending blades 27 are arranged between the middle plate 22 and the bottom plate 23. The blades 27, together with the middle plate 22 and the bottom plate 23, enclose a first flow channel 241. A water inlet 221 communicating with the first flow channel 241 is opened in the central part of the middle plate 22. A second flow channel 25 is located between the top plate 21 and the middle plate 22 and communicates with the water inlet 221. A baffle 28 extending outward from the edge of the water inlet 221 is arranged between the top plate 21 and the middle plate 22, and the baffle 28 encloses the second flow channel 25. The second flow channel 25 includes four branch flow channels 251 extending radially along the nozzle 2, and the nozzle 26 is arranged corresponding to the end of the branch flow channel 251. Each blade 27 extends circumferentially spirally between the middle plate 22 and the bottom plate 23, and the branch flow channels 251 also extend spirally around the nozzle 2, and the spiral direction of the blades 27 is consistent with the spiral direction of the branch flow channels 251. The outer ends of each blade 27 together with the middle plate 22 and the bottom plate 23 form the inlet 242 of the first flow channel 241, and the inner ends of each blade 27 together with the middle plate 22 and the bottom plate 23 form the outlet 243 of the first flow channel 241. The outlet 243 is arranged below the edge of the through-hole 221.

[0038] A centrifugal impeller 24 structure is formed at the lower part of the nozzle 2. The water intake direction of the impeller 24 is circumferential water intake and top water outlet. This not only allows for a large rotational speed under the impact of water flow, but also increases the water suction force, which is beneficial to improving the jet head. In this embodiment, the first flow channel 241 draws water from the outer periphery to the center, and in this process, the water flow is concentrated, providing the first rotational power for the nozzle 2; the second flow channel 25 radially divides the water flow from the center, and in this process, water is concentrated, providing the second rotational power for the nozzle 2; when the water flows out through the inclined nozzle 26, it provides the third rotational power for the nozzle 2; thereby effectively improving the rotational speed of the nozzle 2.

[0039] In this embodiment, a flow guiding structure is provided on the outer bottom wall of the base plate 23 to guide the water flow in the flow channel 11 radially. The flow guiding structure in this embodiment is a flow guiding cone surface 29 that gradually extends downward from the outside to the inside. Of course, the flow guiding structure is not limited to this structure. This structure is beneficial for guiding the water in the flow channel 11 to the inlet 242 of the first flow channel 241, thereby reducing energy loss.

[0040] In this embodiment, a cover plate 3 is provided on the main body 1, which together with the top wall of the main body 1 encloses the air collecting cavity 31. The air collecting cavity 31 is connected to the outside air. The cover plate 3 has a second water spray hole 32 arranged corresponding to the first water spray hole 13, and there is an air intake gap 33 between the first water spray hole 13 and the second water spray hole 32. According to the Venturi effect, when the water column is ejected through the first water spray hole 13 and the second water spray hole 32, a negative pressure is generated at the gap 33, which draws the surrounding water into the water column, thereby forming a cavitation water column containing air bubbles. When the cavitation water column hits the surface of the object to be cleaned, the instantaneous bursting of the air bubbles can increase the peeling force on the contaminants and improve the cleaning effect.

[0041] In this embodiment, the upper part of the nozzle 2 is rotatably arranged through the air collection chamber 31, and the cover plate 3 has an installation port 34 for the nozzle 2 to pass through, with the water spray nozzle 26 exposed above the cover plate 3. The upper part of the nozzle 2 is provided with a circumferentially arranged surrounding wall 20, making the upper part of the nozzle 2 appear cylindrical. The outer surface of the surrounding wall 20 is provided with a drainage channel 200 that spirals circumferentially in the direction of nozzle 2 rotation to introduce outside air into the air collection chamber 31. With this structure, air can be drawn into the air collection chamber 31 by utilizing the disturbance of the surrounding airflow caused by the rotation of the nozzle 2, providing sufficient air volume for the water spray holes on the spray arm to generate a cavitation water column with a high bubble content. A notch 311 can be provided at the bottom edge of the air collection chamber 31, which can serve to supplement air intake or drain accumulated water.

[0042] To facilitate assembly, the outer peripheral wall of the nozzle 2 is provided with a convex ring 201 that can cooperate with and limit the inner top wall of the body 1 and a convex clip 202 that can cooperate with and limit the outer top wall of the body 1.

[0043] In this embodiment, a jet sleeve 261 extending axially along the water outlet 26 is provided on the top wall of the nozzle 2. The jet sleeve 261 is provided with an air intake hole 262 that can automatically draw in air with the jet to form a cavitation water column. With this structure, the nozzle 2 can also spray a cavitation water column carrying air bubbles, thereby improving the cleaning effect.

[0044] The inner diameter of the jet sleeve 261, along the water flow direction, includes a first conical section 2611, a direct-flow section 2612, and a second conical section 2613 connected in sequence. The inner diameter of the first conical section 2611 gradually decreases along the water flow direction, while the inner diameter of the second conical section 2613 gradually increases along the water flow direction. An air intake hole 262 is located on the side wall of the jet sleeve 261 and is connected to the direct-flow section 2612. This structure enables passive air supply via a flow-guided method.

[0045] A cleaning machine includes a housing and a water pumping mechanism, and also includes the aforementioned spray arm, which is rotatably disposed in the housing. The water pumping mechanism is used to pump water from the bottom of the housing to the spray arm.

[0046] The cleaning machine of this embodiment includes a housing and a water pumping mechanism (not shown in the figure), and also includes the above-mentioned spray arm 1. The spray arm 1 is rotatably disposed in the housing, and the water pumping mechanism is used to pump water from the bottom of the housing to the spray arm 1.

[0047] In this embodiment, a nozzle 2 is provided on the spray arm that can rotate with the spray arm and rotate simultaneously. The water jet sprayed by the nozzle 2 cooperates with the water jet sprayed by the spray hole 13, which helps to spread the cleaning range and eliminate cleaning dead corners, thereby improving the cleaning effect. In this embodiment, before the nozzle 2 sprays out the water jet, the water flow first passes through the first flow channel 241 to collect water, the second flow channel 25 to collect water, and then sprays out from the inclined nozzle 2. The triple force helps to increase the rotation speed of the nozzle 2, and the guiding effect of the first flow channel 241 and the second flow channel 25 makes the water flow into the nozzle 2 more stable and facilitates the diversion of water towards the spray hole 26, reducing energy loss and thus maintaining a high water pressure and spray head.

[0048] The specification and claims of this invention use terms indicating direction, such as "front," "rear," "upper," "lower," "left," "right," "side," "top," and "bottom," to describe various exemplary structural parts and elements of the invention. However, these terms are used herein merely for ease of explanation and are determined based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this invention can be arranged in different orientations, these terms indicating direction are for illustrative purposes only and should not be considered as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

Claims

1. A spray arm for a cleaning machine, comprising a body (1) and a nozzle (2), wherein the body (1) is hollow to form a flow channel (11), the body (1) is provided with a water inlet (12) communicating with the flow channel (11) and a first spray hole (13), and a water outlet (14) is opened on the top wall of the body (1), and the nozzle (2) is rotatably connected to the water outlet (14), characterized in that: The nozzle (2) is provided with an impeller (24) located in the flow channel (11) and capable of rotating under the impact of water flow at the lower part. A first flow channel (241) with side water inlet and top water outlet is formed in the impeller (24). A second flow channel (25) capable of directional guidance of water flow is provided at the upper part of the nozzle (2). The second flow channel (25) is located outside the flow channel and is connected to the first flow channel (241). A spray nozzle (26) with an inclined arrangement and connected to the end of the second flow channel (25) is provided on the top wall of the nozzle (2). The main body (1) is provided with an air collection chamber (31) that can supply air to the first water spray hole (13) to output a cavitation water column carrying air bubbles. The nozzle (2) is arranged through the air collection chamber (31), and its side wall is provided with a drainage channel (200) that extends spirally in the circumferential direction with the rotation direction of the nozzle (2) to introduce outside air into the air collection chamber (31).

2. The spray arm for a cleaning machine according to claim 1, characterized in that: The nozzle (2) includes a top plate (21), a middle plate (22) and a bottom plate (23) arranged sequentially from top to bottom. A plurality of radially extending blades (27) are provided between the middle plate (22) and the bottom plate (23). The blades (27), the middle plate (22) and the bottom plate (23) together enclose a first flow channel (241). A water outlet (221) communicating with the first flow channel (241) is opened in the center of the middle plate (22). The second flow channel (25) is located between the top plate (21) and the middle plate (22) and is connected to the water outlet (221).

3. The spray arm for a cleaning machine according to claim 2, characterized in that: A partition (28) extending outward from the edge of the water outlet (221) is provided between the top plate (21) and the middle plate (22), and the partition (28) encloses the second flow channel (25).

4. The spray arm for a cleaning machine according to claim 3, characterized in that: The second flow channel (25) includes at least two branch flow channels (251) extending radially along the nozzle (2), and the spray nozzle (26) is arranged at the end of the branch flow channel (251).

5. The spray arm for a cleaning machine according to claim 4, characterized in that: Each blade (27) extends circumferentially spirally between the middle plate (22) and the bottom plate (23), and the branch flow channel (251) also extends spirally around the nozzle (2), and the spiral direction of the blade (27) is consistent with the spiral direction of the branch flow channel (251).

6. The spray arm for a cleaning machine according to claim 2, characterized in that: The outer ends of each blade (27) together with the middle plate (22) and the bottom plate (23) form the inlet (242) of the first flow channel (241), and the inner ends of each blade (27) together with the middle plate (22) and the bottom plate (23) form the outlet (243) of the first flow channel (241), which is arranged below the edge of the water outlet (221).

7. The spray arm for a cleaning machine according to claim 2, characterized in that: The bottom wall of the base plate (23) is provided with a flow guiding structure for guiding the water flow in the flow channel (11) radially.

8. The spray arm for a cleaning machine according to claim 7, characterized in that: The flow guiding structure is a flow guiding cone surface (29) that extends gradually downward from the outside to the inside.

9. The spray arm for a cleaning machine according to any one of claims 1 to 8, characterized in that: The main body (1) is provided with a cover plate (3) that can enclose the air collection chamber (31) together with the top wall of the main body (1). The air collection chamber (31) is connected to the outside air. The cover plate (3) has a second water spray hole (32) arranged corresponding to the first water spray hole (13), and there is an air intake gap (33) between the first water spray hole (13) and the second water spray hole (32).

10. The spray arm for a cleaning machine according to claim 9, characterized in that: The nozzle (2) is rotatably arranged through the air collection chamber (31) at its upper part, and the cover plate (3) has an installation port (34) through which the nozzle (2) can pass. The water spray nozzle (26) is exposed above the cover plate (3).

11. The spray arm for a cleaning machine according to claim 10, characterized in that: The nozzle (2) is provided with a circumferentially arranged enclosure (20) on its upper part. The outer surface of the enclosure (20) is provided with a flow channel (200) that extends spirally in the circumferential direction with the rotation direction of the nozzle (2) to introduce outside air into the air collection chamber (31).

12. The spray arm for a cleaning machine according to claim 10, characterized in that: The outer peripheral wall of the nozzle (2) is provided with a convex ring (201) that can cooperate with the inner top wall of the body (1) for positioning and a convex clip (202) that can cooperate with the outer top wall of the body (1) for positioning and.

13. The spray arm for a cleaning machine according to any one of claims 1 to 8, characterized in that: The top wall of the nozzle (2) is provided with a jet sleeve (261) extending axially along the water outlet (26), and the jet sleeve (261) is provided with an air intake hole (262) that can automatically draw in air with the jet to form a cavitation water column.

14. The spray arm for a cleaning machine according to claim 13, characterized in that: The inner diameter of the jet sleeve (261) includes a first conical section (2611), a direct current section (2612), and a second conical section (2613) connected in sequence along the water flow direction. The inner diameter of the first conical section (2611) gradually decreases along the water flow direction, and the inner diameter of the second conical section (2612) gradually increases along the water flow direction. The air vent (262) is opened on the side wall of the jet sleeve (261) and is connected to the direct current section (2612).

15. A cleaning machine, comprising a housing and a water pumping mechanism, characterized in that: It also includes the spray arm as described in any one of claims 1 to 14, the spray arm being rotatably disposed in the housing, and the water pumping mechanism being used to pump water from the bottom of the housing to the spray arm.

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