Oil-cooled submersible sewage pump

Abstract

An oil cooling type submersible sewage pump comprises a pump body, a motor shaft and a motor, the pump body comprises an upper cover, an end cover, a heat dissipation wall, a pump body outer wall, a connecting oil path and a pump cover, the upper cover, the end cover and the pump cover are provided with guide holes for the motor shaft to pass through, the motor shaft enters from one end of the pump body and passes through the end cover, the upper cover and the heat dissipation wall to pass out from the other end of the pump body, the motor is installed on the outer wall of the motor shaft, the cooling oil storage chamber, the first connecting oil path, the heat dissipation cavity and the second connecting oil path are sequentially connected to form a complete cooling loop, the cooling oil can conduct heat with the external environment through the pump body wall, so that the heat in the pump body can be conducted out, thus the submersible sewage pump can prolong the working time in the complex environment without external cooling pipeline, and the shutdown cooling condition is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of submersible sewage pump technology, specifically relating to an oil-cooled submersible sewage pump. Background Technology

[0002] Submersible sewage pumps are essential equipment for deep well water extraction. During operation, the entire unit is submerged in water to extract groundwater to the surface. They are vital for domestic water supply, mine rescue operations, industrial cooling, farmland irrigation, seawater lifting, and ship ballast adjustment.

[0003] Because submersible sewage pumps operate by being completely submerged in sewage, with the motor and related electrical control components housed within the pump body, the motor drives the impeller via a shaft to perform work, thus conveying the liquid. The heat generated during motor operation accumulates inside the pump, relying solely on the pump body for heat exchange with the external environment. Submersible sewage pumps typically use rigid metals like stainless steel or cast iron as the pump body material. These materials generally have low specific heat capacity, leading to rapid temperature increases during operation, which can easily affect the motor and related electrical control components. If the pump's internal temperature remains above its allowable operating temperature for an extended period, the motor winding resistance increases, copper losses rise, and motor efficiency decreases. The electrical control components may overheat, causing logic control malfunctions or damage, ultimately leading to equipment overheating and shutdown. Therefore, submersible sewage pumps require external cooling pipes to maintain normal motor operation. This results in shorter operating times and frequent shutdowns for cooling in environments without access to cooling pipes.

[0004] Therefore, it is important to design an oil-cooled submersible sewage pump to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide an oil-cooled submersible sewage pump to solve the problem of short working time of submersible sewage pumps when cooling pipes cannot be connected, and to increase the maximum working temperature of submersible sewage pumps.

[0006] The technical solution provided by this utility model is as follows: An oil-cooled submersible sewage pump includes a pump body, a motor shaft, and a motor. The pump body includes an upper cover, an end cover, a heat dissipation wall, an outer wall of the pump body, a connecting oil passage, and a pump cover. The upper cover, the end cover, and the pump cover are all provided with guide holes for the motor shaft to pass through. The motor shaft enters from one end of the pump body through the end cover, passes through the motor chamber formed by the end cover, the upper cover, and the heat dissipation wall, and exits from one end of the pump cover. The motor is mounted on the outer side wall of the motor shaft located within the motor chamber. The pump cover is connected to the upper cover. A cooling oil storage chamber is formed. The connecting oil circuit includes a first connecting oil circuit and a second connecting oil circuit. The first connecting oil circuit and the second connecting oil circuit are machined inside the upper cover. The upper cover is connected to the heat dissipation wall and the outer wall of the pump body to form a heat dissipation cavity. An oil outlet and an oil return port are provided in the heat dissipation cavity. The outlet of the first connecting oil circuit is connected to the oil outlet, and the inlet of the second connecting oil circuit is connected to the oil return port. The cooling oil storage chamber, the first connecting oil circuit, the heat dissipation cavity, and the second connecting oil circuit are sequentially connected end to end to form a complete cooling loop.

[0007] Furthermore, a first mechanical seal assembly and a dividing ring for limiting the end of the first mechanical seal assembly are installed on the outer wall of the motor shaft. The first mechanical seal assembly is located in the cooling oil storage chamber. The two ends of the first mechanical seal assembly abut against the dividing ring and the pump cover, respectively. A second mechanical seal assembly is installed on the outer wall of the motor shaft corresponding to the portion located in the cooling oil storage chamber. One end of the second mechanical seal assembly is provided with a small impeller for driving the flow of cooling oil. The small impeller is fixed to the outer wall of the motor shaft. The two ends of the second mechanical seal assembly abut against the upper cover and the small impeller, respectively.

[0008] Furthermore, the first connecting oil circuit includes a first main oil circuit and a first auxiliary oil circuit, and the second connecting oil circuit includes a second main oil circuit and a second auxiliary oil circuit.

[0009] Furthermore, the pump body has two external oil passage openings on its outer side, and these openings are sealed with oil plugs.

[0010] Furthermore, the flow cross-sectional area of ​​the oil outlet and the oil return port is the same.

[0011] Furthermore, a suction pipe with a diameter larger than that of the small impeller is coaxially installed on the outer side of the small impeller. The suction pipe is completely located in the cooling oil storage chamber and is connected to the upper cover.

[0012] Furthermore, the heat dissipation wall uses aluminum as the base material.

[0013] The beneficial effects of this utility model are as follows: By designing a self-circulating cooling oil circuit inside the submersible sewage pump, the self-circulating oil circuit eliminates the need for an external cooling pipe connection. Cooling is achieved by relying on the cooling oil carried within the pump itself. The large capacity of the entire oil circuit allows the submersible sewage pump to store a large amount of cooling oil. The specific heat capacity of the cooling oil is much higher than that of the pump body's metal material. The large amount of cooling oil inside the pump increases the overall specific heat capacity of the pump, reducing the rate of temperature rise inside the pump body. This allows for continuous operation even in high ambient temperatures, and extends the time it takes for the temperature in the motor area inside the pump body to reach the critical operating value. Simultaneously, the cooling oil conducts heat through the pump body wall to the external environment, allowing heat to be dissipated from the pump body. Therefore, the submersible sewage pump can extend its operating time in complex environments where external cooling pipes are not possible, reducing the need for shutdowns for cooling. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the internal structure of the present invention;

[0015] Figure 2 This is a magnified view of part A in the diagram;

[0016] Figure 3 This is a partial top view of the structure of this utility model. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0018] It should be noted that if the embodiments of this utility model involve directional indicators such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, horizontal, longitudinal, counterclockwise, clockwise, circumferential, radial, axial, etc., then the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture as shown in the attached figure. If the specific posture changes, the directional indicators will also change accordingly.

[0019] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0020] See Figures 1 to 3This utility model provides an oil-cooled submersible sewage pump, including a pump body 1, a motor shaft 2, and a motor 3. The pump body 1 includes an upper cover 11, an end cover 12, a heat dissipation wall 13, an outer wall of the pump body 14, a connecting oil passage 15, and a pump cover 16. The upper cover 11, end cover 12, and pump cover 16 are all provided with guide holes for the motor shaft 2 to pass through. The heat dissipation wall 13 has a through space. The end cover 12 is installed at the upper end of the heat dissipation wall 13, and the upper cover 11 is installed at the lower end of the heat dissipation wall 13. The end cover 12, the heat dissipation wall 13, and the upper cover 11 are vertically stacked along the axial direction to form a closed motor chamber 17. The motor shaft 2 enters from one end of the pump body 1 through the end cover 12, with the end cover 12 as the upper surface and the upper cover 11 as the lower surface. The heat dissipation wall 13, formed by bolts, creates a cylindrical motor chamber 17 that extends from one end of the pump cover 16 of the pump body 1. The motor 3 is mounted on the outer side wall of the motor shaft 2 located within the motor chamber 17. The upper end of the pump cover 16 forms a cooling oil storage chamber 18 with the lower end of the upper cover 11, which stores cooling oil. The upper cover 11 has a first connecting oil passage 151 and a second connecting oil passage 152 machined using a drilling and tapping process. (The first connecting oil passage 151 includes a first main oil passage 1511 and a first auxiliary oil passage 1512, and the second connecting oil passage 152 includes a second main oil passage 1521 and a second auxiliary oil passage 1522. For ease of machining, the first connecting oil passage 151...) The second connecting oil passage 152 is formed by connecting a main oil passage and a secondary oil passage. The main oil passage is responsible for transporting cooling oil to the key component, the heat dissipation chamber 19. The outer wall 14 of the pump body has a through space. The heat dissipation wall 13 is installed inside the outer wall 14 of the pump body, forming a concentric circle structure. The upper end of the heat dissipation wall 13 is closedly connected to the upper end of the outer wall 14 of the pump body. The lower end of the heat dissipation wall 13 and the lower end of the outer wall 14 of the pump body are both connected to the upper cover 11. The three together form a closed heat dissipation chamber 19. The outer wall 14 of the pump body and the heat dissipation wall 13 are connected together by bolts. The volume space inside the heat dissipation chamber 19 is an annular cylinder. This volume space shape can maximize the contact with the heat dissipation wall 13, thereby increasing heat exchange. To maximize heat dissipation surface area and improve heat exchange efficiency, the heat dissipation cavity 19 is equipped with an oil outlet 191 and an oil return port 192. The flow cross-sectional areas of the oil outlet 191 and the oil return port 192 are the same. The oil outlet 191 is positioned at the lowest point within the heat dissipation cavity 19, while the oil return port 192 is positioned at the highest point within the heat dissipation cavity 19. The height of the oil return port 192 is designed to be the maximum possible height within the cavity, maximizing the effective volume within the heat dissipation cavity 19 for this specific shape. This enhances the cooling capacity of the entire submersible pump, ensuring that the coolant reaches its maximum effective volume within the heat dissipation cavity 19. The outlet of the first main oil passage 1511, located on the left side of the pump body 1, is connected to the oil outlet 191.The inlet of the second main oil passage 1521, located on the right side of the pump body 1, is connected to the return oil port 192. The first auxiliary oil passage 1512 connects the cooling oil in the cooling oil storage chamber 18 with the cooling oil in the first main oil passage 1511. The second auxiliary oil passage 1522 connects the cooling oil in the heat dissipation chamber 19 with the cooling oil in the second main oil passage 1521. The cooling oil storage chamber 18, the connecting oil passage 15, and the heat dissipation chamber 19 are sequentially connected end-to-end to form a complete cooling loop.

[0021] A first mechanical seal assembly 1821 and a dividing ring 181 for limiting the end of the first mechanical seal assembly 1821 are installed on the outer wall of the motor shaft 2. The first mechanical seal assembly 1821 is located in the cooling oil storage chamber 18. The two ends of the first mechanical seal assembly 1821 abut against the dividing ring 181 and the pump cover 16, respectively. A second mechanical seal assembly 1822 is installed on the outer wall of the motor shaft 2 corresponding to the portion located in the cooling oil storage chamber 18. One end of the second mechanical seal assembly 1822 is provided with a small impeller 20 for driving the flow of cooling oil. The small impeller 20 is fixed to the outer wall of the motor shaft 2. The two ends of the second mechanical seal assembly 1822 abut against the upper cover 11, respectively. Along with the small impeller 20, the two sets of mechanical seal assemblies provide multiple safety measures for the operation of the submersible pump. The first mechanical seal assembly 1821 serves as the first safety measure, preventing external sewage from entering the cooling oil storage chamber 18. Even if the first mechanical seal assembly 1821 fails and external sewage enters the cooling oil storage chamber 18, it will only contaminate the cooling oil in the cooling oil storage chamber 18. The second mechanical seal assembly 1822 serves as the second safety measure, preventing sewage intruding into the cooling oil storage chamber 18 from flowing to the motor chamber 17 and causing short circuit damage to the motor. Therefore, it reduces the risk of cooling oil leakage from the cooling oil storage chamber 18 and the impact of cooling oil contamination caused by sewage intrusion into the pump body.

[0022] Based on the above structure, the cooling oil circulation in the cooling loop is as follows: Cooling oil leaves the cooling oil storage chamber 18 under the agitation of the small impeller 20, flows into the first main oil passage 1511 via the first auxiliary oil passage 1512, and flows into the heat dissipation chamber 19 from the oil outlet 191. After heat exchange is completed in the heat dissipation chamber 19, it flows into the second main oil passage 1521 from the oil return port 192, and returns to the cooling oil storage chamber 18 via the second auxiliary oil passage 1522. The specific heat capacity of the cooling oil is greater than that of the metal material of the pump body 1. The addition of cooling oil increases the specific heat capacity of the entire submersible pump, meaning that the temperature rise rate of the submersible pump will be slower than that of a submersible pump without cooling oil. This allows the submersible pump to operate for longer without needing to be shut down for cooling. The cooling oil will fill the entire... In the cooling loop, the cooling oil in the cooling oil storage chamber 18 conducts heat with the external sewage through the pump cover, causing some of the heat of the coolant to be carried away by the flowing sewage, further reducing the temperature rise rate. The heat conduction between the heat dissipation chamber 19 and the cooling oil in the cooling oil storage chamber 18 is carried out through the cooling oil in the connecting oil passage 15. The limited diameter of the oil passage in the connecting oil passage 15 results in a slower heat conduction speed between the heat dissipation chamber 19 and the cooling oil storage chamber 18, causing a difference in their temperature rise rates. This means that the heat absorption capacity of the cooling oil in the cooling oil storage chamber 18 is not fully utilized. The function of the small impeller 20 is to make the cooling oil flow in the cooling loop, fully utilize the heat absorption capacity of all the cooling oil in the pump body 1, and thus extend the working time.

[0023] Preferably, the main oil circuit and the auxiliary oil circuit included in the connecting oil circuit 15 are both straight. The pressure loss in the oil circuit is mainly composed of friction loss along the fluid and pipe wall and local loss of eddy currents at pipe bends. The more straight sections and the fewer bends, the more these two types of losses will be significantly reduced, thereby reducing the loss of mechanical energy converted from electrical energy in the connecting oil circuit 15 and improving the overall flow efficiency.

[0024] Preferably, the auxiliary oil passage is threaded at the drilled hole during the drilling process to serve as an external opening for the oil passage. Two external openings for the oil passage are provided on the outside of the pump body 1. Oil plugs 184 are installed on the external openings for sealing. The external openings for the oil passage allow the pump body 1 to be disassembled for basic maintenance of the cooling loop. The oil plugs 184 are threaded to the external openings for the oil passage, ensuring that the tightening force is sufficient to withstand the pressure generated by the cooling loop during operation, preventing the oil plugs 184 from being pushed out of the external openings for the oil passage. The sealing ring on the oil plugs 184 provides sufficient sealing for the cooling loop.

[0025] Preferably, a suction pipe 183 with a diameter larger than that of the small impeller 20 is coaxially installed on the outer side of the small impeller 20. The suction pipe 183 is completely located inside the cooling oil storage chamber 18. The suction pipe 183 is connected to the upper cover 11 by bolts, so that the surface of the small impeller 20 is flush with the lower surface of the suction pipe 183. The function of the suction pipe 183 is to guide the cooling oil in the cooling oil storage chamber 18 evenly to the small impeller 20 with minimal loss, ensuring that the liquid can smoothly enter the connecting oil passage 15, reducing turbulence and energy loss when the cooling oil enters the small impeller 20, and improving the overall efficiency of the pump.

[0026] Preferably, the heat dissipation wall 13 uses aluminum as the base material. The high thermal conductivity of aluminum can transfer heat from the high temperature area to the low temperature area more quickly, reduce local overheating, improve heat dissipation efficiency, and allow the cooling oil to carry away more heat when passing through the heat dissipation cavity 19, thereby reducing the temperature rise rate of the core area, i.e., the motor 3.

[0027] The above description is only a preferred embodiment of the present utility model. Any technical solution that achieves the purpose of the present utility model by essentially the same means shall fall within the protection scope of the present utility model.

Claims

1. An oil-cooled submersible sewage pump, characterized in that: The pump body (1) includes a pump body (1), a motor shaft (2), and a motor (3). The pump body (1) includes an upper cover (11), an end cover (12), a heat dissipation wall (13), an outer wall of the pump body (14), a connecting oil passage (15), and a pump cover (16). The upper cover (11), the end cover (12), and the pump cover (16) are all provided with guide holes for the motor shaft (2) to pass through. The motor shaft (2) enters from one end of the end cover (12) of the pump body (1), passes through the motor chamber (17) formed by the end cover (12), the upper cover (11), and the heat dissipation wall (13), and exits from one end of the pump cover (16) of the pump body (1). The motor (3) is installed on the outer side wall of the motor shaft (2) located inside the motor chamber (17). The pump cover (16) is connected to the upper cover (11) to form a cooling oil storage chamber (16). 8) The connecting oil passage (15) includes a first connecting oil passage (151) and a second connecting oil passage (152). The first connecting oil passage (151) and the second connecting oil passage (152) are machined inside the upper cover (11). The upper cover (11) is connected to the heat dissipation wall (13) and the outer wall of the pump body (14) to form a heat dissipation cavity (19). The heat dissipation cavity (19) is provided with an oil outlet (191) and an oil return port (192). The outlet of the first connecting oil passage (151) is connected to the oil outlet (191), and the inlet of the second connecting oil passage (152) is connected to the oil return port (192). The cooling oil storage chamber (18), the first connecting oil passage (151), the heat dissipation cavity (19), and the second connecting oil passage (152) are connected sequentially to form a complete cooling loop.

2. The oil-cooled submersible sewage pump according to claim 1, characterized in that: A first mechanical seal assembly (1821) and a dividing ring (181) for limiting the end of the first mechanical seal assembly (1821) are installed on the outer wall of the motor shaft (2). The first mechanical seal assembly (1821) is located in the cooling oil storage chamber (18). The two ends of the first mechanical seal assembly (1821) abut against the dividing ring (181) and the pump cover (16) respectively. A second mechanical seal assembly (1822) is installed on the outer wall of the motor shaft (2) corresponding to the part of the cooling oil storage chamber (18). One end of the second mechanical seal assembly (1822) is provided with a small impeller (20) for driving the flow of cooling oil. The small impeller (20) is fixed on the outer wall of the motor shaft (2). The two ends of the second mechanical seal assembly (1822) abut against the upper cover (11) and the small impeller (20) respectively.

3. The oil-cooled submersible sewage pump according to claim 1, characterized in that: The first connecting oil circuit (151) includes a first main oil circuit (1511) and a first auxiliary oil circuit (1512), and the second connecting oil circuit (152) includes a second main oil circuit (1521) and a second auxiliary oil circuit (1522).

4. The oil-cooled submersible sewage pump according to claim 1, characterized in that: The pump body (1) has two external oil passage openings on its outer side, and the external oil passage openings are sealed with oil plugs (184).

5. An oil-cooled submersible sewage pump according to claim 1, characterized in that: The flow cross-sectional area of ​​the oil outlet (191) and the oil return outlet (192) is the same.

6. An oil-cooled submersible sewage pump according to claim 2, characterized in that: A suction pipe (183) with a diameter larger than that of the small impeller (20) is coaxially installed on the outside of the small impeller (20). The suction pipe (183) is completely located inside the cooling oil storage chamber (18) and is connected to the upper cover (11).

7. An oil-cooled submersible sewage pump according to claim 1, characterized in that: The heat dissipation wall (13) uses aluminum as the base material.

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