High-pressure water sealing structure of submersible sewage pump

Abstract

The invention provides a high-pressure water sealing structure of a submersible sewage pump, which belongs to the technical field of submersible pumps and comprises a pump body, a mechanical sealing chamber and a motor which are sequentially connected from front to back. The front end of the mechanical sealing chamber is in sealing connection with the rear end of the pump body, and a mechanical seal is arranged in the mechanical sealing chamber and divides the mechanical sealing chamber into a front high-pressure water sealing chamber and a rear oil sealing chamber; and a high-pressure water inlet hole is formed in the high-pressure water sealing chamber. External high-pressure clear water enters the high-pressure water sealing chamber through the high-pressure water inlet hole, the pressure of the external high-pressure clear water is larger than that of sewage in the pump body, and the sewage in the pump body is prevented from entering the mechanical sealing chamber by forming a pressure difference on the front side and the rear side of the rear protection plate, so that the mechanical sealing chamber and a mechanical seal can be prevented from being damaged by the sewage; further, mechanical seal failure is caused, stator winding insulation damage is caused, and faults of short circuit and grounding occur; and corrosive sewage is prevented from entering the bearing lubricating grease / oil to damage the bearing and even the pump shaft.

Description

Technical Field

[0001] The present invention belongs to the technical field of submersible pumps, and particularly relates to a high-pressure water sealing structure for a submersible sewage pump. Background Art

[0002] The sealing of a sewage submersible pump is one of its most critical and vulnerable parts, directly determining the pump's service life, reliability, and operating safety. Due to its harsh working environment (immersed in sewage containing solid particles, fibers, and corrosive substances), the design and reliability of the sealing structure are crucial.

[0003] Currently, the sewage submersible pump adopts a sealing method combining mechanical seal and packing seal. Through the synergistic effect of double seals, the sealing reliability and service life of the sewage submersible pump are improved under complex working conditions. Specifically, a packing seal is arranged between the pump body and the pump shaft of the sewage submersible pump as the first seal, directly bearing the pressure of the pumped corrosive sewage to prevent the corrosive sewage from entering the mechanical seal chamber; a mechanical seal is arranged between the motor and the pump body as the second seal to prevent the corrosive sewage from invading the motor cavity, resulting in failures such as stator winding insulation damage, short circuit, and grounding, and the motor burning out instantly or in a short time; it also prevents the corrosive sewage from entering the bearing grease / oil, damaging the lubrication and causing failures such as rapid bearing wear, rust, and jamming, generating noise and vibration, and ultimately damaging the bearing or even the pump shaft.

[0004] The problem with the current sealing structure is that: since a clearance needs to be reserved for the rotation of the pump shaft between the rear guard plate of the pump body and the pump shaft, and the pump body side is directly subjected to the pressure of high-pressure sewage, there is a possibility that the sewage enters the mechanical seal chamber under high pressure. And the entry of sewage into the mechanical seal chamber will corrode the mechanical seal chamber and the mechanical seal, thereby leading to seal failure and causing damage to the motor or bearing. Summary of the Invention

[0005] An embodiment of the present invention provides a high-pressure water sealing structure for a submersible sewage pump, aiming to solve the problem that the pump body is not tightly sealed, resulting in sewage entering the motor side and causing the seal failure on the motor side.

[0006] To achieve the above object, the technical solution adopted by the present invention is: to provide a high-pressure water sealing structure for a submersible sewage pump, including: a pump body, a mechanical seal chamber, and a motor connected in sequence from front to back;

[0007] The front end of the mechanical seal chamber is hermetically connected to the rear end of the pump body. A mechanical seal is arranged in the mechanical seal chamber, and the mechanical seal divides the mechanical seal chamber into a front high-pressure water seal chamber and a rear oil seal chamber; a high-pressure water inlet hole is arranged on the high-pressure water seal chamber;

[0008] External high-pressure clean water enters the high-pressure water sealing chamber through the high-pressure water inlet hole, and the pressure of the external high-pressure clean water is greater than the pressure of the sewage in the pump body, preventing the sewage in the pump body from entering the mechanical sealing chamber.

[0009] In an achievable manner, the relationship between the pressure P1 of the external high-pressure clean water and the pressure P2 of the sewage in the pump body is: P1 ≥ P2 + 5, with the unit Pa.

[0010] In an achievable manner, the axial cross-sectional shape of the high-pressure water sealing chamber is trapezoidal, with the large end of the trapezoid facing the pump body; the small end of the trapezoid faces the motor.

[0011] In an achievable manner, the high-pressure water inlet hole is inclinedly arranged on the high-pressure water sealing chamber, and the included angle between the high-pressure water inlet hole and the pump shaft is less than 90°. The impact direction of the high-pressure water faces the wear-resistant rear guard plate to prevent impact damage to other components.

[0012] In an achievable manner, the pump body includes a volute, a front guard plate installed at the front end of the volute, and a rear guard plate installed at the rear end of the volute; the rear end face of the rear guard plate and the front end face of the oil seal chamber form the high-pressure water sealing chamber.

[0013] In an achievable manner, a first sealing ring is arranged between the front end face of the mechanical sealing chamber and the rear end face of the rear guard plate to seal the high-pressure water sealing chamber.

[0014] In an achievable manner, a first limiting step is arranged radially on the rear end face of the rear guard plate, and a second limiting step is arranged on the front end face of the mechanical sealing chamber to cooperate with the first limiting step, forming a labyrinth seal between the mechanical sealing chamber and the rear guard plate and limiting the radial clearance between the rear guard plate and the pump shaft.

[0015] In an achievable manner, the shape formed by the mating surface between the mechanical sealing chamber and the rear guard plate along the axial cross-section is L-shaped.

[0016] In an achievable manner, a throttle ring is arranged between the rear guard plate and the impeller; a third limiting step is arranged in the central hole of the rear guard plate, and the throttle ring is axially abutted against the third limiting step.

[0017] In an achievable manner, a shaft sleeve is arranged on the pump shaft section passing through the mechanical sealing chamber, and a second sealing ring is arranged between the shaft sleeve and the impeller installed at the front end of the pump shaft to seal the high-pressure water sealing chamber.

[0018] The high-pressure water sealing structure of the submersible sewage pump provided by the present invention has the following beneficial effects compared with the prior art: Through mechanical sealing, the mechanical sealing chamber is divided into two chambers, front and rear. The oil in the rear oil seal chamber can play a cooling role to ensure that the motor bearings and mechanical seals do not overheat during operation. In the front high-pressure water sealing chamber, high-pressure clean water with a pressure higher than the sewage in the pump body is introduced, creating a pressure difference on both sides of the rear guard plate. The pressure difference prevents the sewage on the low-pressure side from flowing to the high-pressure side, thus avoiding the sewage in the pump body from flowing into the mechanical sealing chamber, preventing the sewage from corroding the mechanical sealing chamber and the mechanical seal, and further preventing the mechanical seal from failing, resulting in stator winding insulation damage, short circuit, and grounding faults. It also prevents corrosive sewage from entering the bearing grease / oil, damaging the lubrication and causing problems such as rapid bearing wear, rust, jamming, generating noise and vibration, and ultimately damaging the bearings and even the pump shaft.

[0019] This application uses high-pressure clean water for water sealing. Even if a small amount of clean water enters the oil seal chamber, the motor, and the bearings, it will not corrode the mechanical sealing chamber, the motor, and the bearings, thus reducing the failure frequency of the motor and bearings, reducing the number of shutdowns, and also reducing the maintenance cost. This further extends the service life of the pump and is beneficial to the smooth progress of the sewage discharge process.

[0020] This application utilizes the principle of pressure difference and uses high-pressure clean water for sealing to prevent the sewage on the low-pressure side from flowing to the high-pressure side. This structure requires the cooperation of external high-pressure water. By drilling holes in the mechanical sealing chamber and introducing high-pressure clean water, the structure is simple and easy to implement, and has a good sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural diagram of the high-pressure water sealing structure of the submersible sewage pump provided by the embodiment of the present invention;

[0022] Figure 2 It is a schematic structural diagram showing the injection direction of high-pressure clean water and the pressure difference provided by the present invention;

[0023] Description of the reference numerals:

[0024] 1, motor; 2, pump shaft; 3, mechanical sealing chamber; 31, oil seal chamber; 32, high-pressure water inlet hole; 33, partition wall; 34, high-pressure water sealing chamber; 4, volute; 5, first sealing ring; 6, rear guard plate; 7, impeller; 8, throttle ring; 9, front guard plate; 10, mechanical seal; 11, shaft sleeve; 12, second sealing ring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] In the present application, terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual quantity, primary-secondary or order relationship between these entities or operations.

[0027] Please refer to Figure 1 and Figure 2 Now, the high-pressure water sealing structure of the submersible sewage pump provided by the present invention will be described. The high-pressure water sealing structure of the submersible sewage pump includes a pump body, a mechanical seal chamber 3 and a motor 1 connected in sequence from front to back; the front end of the mechanical seal chamber 3 is hermetically connected to the rear end of the pump body, and a mechanical seal is arranged in the mechanical seal chamber 3. The mechanical seal divides the mechanical seal chamber 3 into a front high-pressure water sealing chamber 34 and a rear oil seal chamber 31; a high-pressure water inlet hole 32 is arranged on the high-pressure water sealing chamber 34.

[0028] The external high-pressure clean water enters the high-pressure water sealing chamber 34 through the high-pressure water inlet hole 32, and the pressure of the external high-pressure clean water is greater than the pressure of the sewage in the pump body, preventing the sewage in the pump body from entering the mechanical seal chamber 3. See Figure 2 for the arrow indication in. Among them, the arrow in the high-pressure water inlet hole 32 indicates the water flow direction; the arrows on both sides of the rear guard plate indicate the pressure directions of the high-pressure clean water and the sewage. The number of arrows on the high-pressure clean water side is large, indicating a large pressure; the number of arrows on the sewage side is small, indicating a small pressure.

[0029] Compared with the prior art, the beneficial effect of the high-pressure water sealing structure of the submersible sewage pump provided by the present invention is that: in the present application, the mechanical seal 10 divides the mechanical seal chamber 3 into two chambers, front and back. The oil in the rear oil seal chamber can play a cooling role to ensure that the bearings and mechanical seals of the motor 1 will not overheat during operation; and high-pressure clean water with a pressure higher than that of the sewage in the pump body is introduced into the front high-pressure water sealing chamber 34, forming a pressure difference on both sides of the rear guard plate 6. The pressure difference prevents the sewage on the low-pressure side from flowing to the high-pressure side, thereby avoiding the sewage in the pump body from flowing into the mechanical seal chamber 3, and thus being able to avoid the sewage from corroding the mechanical seal chamber 3 and the mechanical seal 10, which may lead to the failure of the mechanical seal 10, resulting in faults such as stator winding insulation damage, short circuit, and grounding; it also prevents corrosive sewage from entering the bearing grease / oil, damaging the lubrication and causing faults such as rapid wear, rust, and jamming of the bearings, generating noise and vibration, and ultimately damaging the bearings and even the pump shaft 2.

[0030] This application uses high-pressure clean water for water sealing. Even if a small amount of clean water enters the oil seal chamber, the motor 1 and the bearing, it will not cause corrosion to the mechanical seal chamber 3, the motor 1 and the bearing. Therefore, it can reduce the failure frequency of the motor 1 and the bearing, reduce the number of shutdowns, and also reduce the maintenance cost. Furthermore, it can extend the service life of the pump and is also beneficial to the smooth progress of the sewage discharge process.

[0031] This application utilizes the principle of pressure difference and uses high-pressure clean water for sealing to prevent the sewage on the low-pressure side from flowing to the high-pressure side. This structure requires the cooperation of external high-pressure water. Just drill a hole in the mechanical seal chamber 3 and introduce high-pressure clean water. The structure is simple and easy to implement, and has a good sealing effect.

[0032] During sewage discharge, continuously introduce external high-pressure clean water into the high-pressure water seal chamber 34 through the high-pressure water inlet hole 32, and continuously maintain the pressure of the high-pressure clean water greater than the pressure of the sewage in the pump body, then it can prevent the sewage from entering the high-pressure side, thus achieving the purpose of high-pressure water sealing.

[0033] Specifically, when implementing, the high-pressure water inlet hole 32 can be set as a threaded hole. Install the pipe joint on the high-pressure water inlet hole 32, insert the high-pressure water pipe on the pipe joint, and connect the high-pressure water pipe to the high-pressure water pump to pump water from the external water pool or water tank into the high-pressure water seal chamber 34.

[0034] Regarding the structure of the high-pressure water seal chamber 34, specifically, the front end of the high-pressure water seal chamber 34 is hermetically connected to the pump body, that is, the front end of the high-pressure water seal chamber 34 is sealed through the pump body; while the rear end of the high-pressure water seal chamber 34 is sealed by the mechanical seal 10, and the mechanical seal 10 is installed on the partition wall 33 in the mechanical seal chamber 3.

[0035] In this application, a bearing is provided between the rear end of the mechanical seal chamber 3 and the pump shaft 2 to ensure the flexibility of the rotation of the pump shaft 2.

[0036] Combined with Figure 1 It is described that the mechanical seal 10 is sleeved on the pump shaft 2 and is located in the oil seal chamber, constituting the second seal of the motor 1. As mentioned in the following embodiments, the throttle ring 8 on the rear guard plate 6 constitutes the first seal of the motor 1; and a pressure difference is formed between the high-pressure clean water and the sewage at the gap between the throttle ring 8 and the impeller 7; since the pressure of the high-pressure clean water is greater than the pressure of the sewage, the high-pressure clean water has a tendency to move into the volute 4 through this gap, thus being able to exclude the sewage outside the throttle ring 8 and also preventing the sewage from flowing into the mechanical seal chamber 3.

[0037] In some embodiments, refer to Figure 2As shown, the relationship between the pressure P1 of the external high-pressure clean water and the pressure P2 of the sewage in the pump body is: P1 ≥ P2 + 5, with the unit of Pa. By establishing a pressure difference of 5 Pa between the high-pressure clean water and the sewage, it is ensured that the sewage will not enter the high-pressure side from the low-pressure side, thus ensuring the reliability of the seal.

[0038] It can be seen that based on the original two seals, the present application adds a high-pressure clean water seal, providing an additional safeguard for the motor 1 and the bearing. As a result, the failure rate of the pump is significantly reduced, the service life of the pump is extended, and the maintenance frequency and cost are decreased.

[0039] In some embodiments, referring to Figure 1 As shown, the axial cross-sectional shape of the high-pressure water seal chamber 34 is trapezoidal, with the larger end facing the pump body and the smaller end facing the motor 1. Since the inner cavity of the pump has a relatively large volume, that is, the inner cavity of the pump has a relatively large diameter, the larger end of the high-pressure water seal chamber 34 facing the pump body can better form a connection. In other words, the area on the front end face of the rear guard plate 6 that bears the pressure of the sewage is equivalent to the area on the rear end face that bears the pressure exerted by the high-pressure clean water, making the sealing effect more stable and reliable. Similarly, the smaller end faces the motor 1 side, and the mechanical seal 10 separates the high-pressure water seal chamber and the oil seal chamber, preventing water from directly entering the motor and causing damage to the motor.

[0040] The axial cross-section mentioned in this article is a cross-section taken along the axis of the pump shaft 2 and in the direction of the pump shaft 2.

[0041] In some embodiments, referring to Figure 1 As shown, the high-pressure water inlet hole 32 is inclinedly arranged on the high-pressure water seal chamber 34, and the included angle between the high-pressure water inlet hole 32 and the pump shaft 2 is less than 90°. The impact direction of the high-pressure water is towards the wear-resistant rear guard plate, preventing impact damage to other components.

[0042] Such a setting enables the high-pressure clean water to enter the high-pressure water seal chamber 34 at an inclined angle, reducing the direct impact of the water flow on the pump shaft 2. At the same time, the water flow smoothly enters the high-pressure water seal chamber 34, reducing the impact and noise generated by the turbulent collision of the water flow. The inclined high-pressure water inlet hole 32 can also buffer the incoming high-pressure clean water. Before the water flow enters the high-pressure water seal chamber 34, it is first guided and buffered by the inclined channel, so that the impact force of the high-pressure clean water is dispersed and weakened to a certain extent.

[0043] In some embodiments, referring to Figure 1 As shown, the pump body includes a volute 4, a front guard plate 9 installed at the front end of the volute 4, and a guard plate 6 installed at the rear end of the volute 4. A high-pressure water seal chamber 34 is formed between the rear end face of the rear guard plate 6 and the front end face of the oil seal chamber.

[0044] Among them, a buffer expansion ring groove is provided on the rear end face of the rear guard plate 6. The buffer expansion ring groove is arranged in a circular ring with the pump shaft 2 as the center and forms a part of the high-pressure water sealing chamber 34; the extension line of the axis of the high-pressure water inlet hole 32 intersects with the buffer expansion ring groove. Such a design enables the high-pressure clean water to directly rush towards the buffer expansion ring groove when entering the high-pressure water sealing chamber 34. The water flow is buffered and weakened here, and then flows back into the high-pressure water sealing chamber 34.

[0045] Specifically, as shown by the arrow in Figure 2 When the high-pressure clean water enters the high-pressure water sealing chamber 34 through the high-pressure water inlet hole 32, it is initially buffered and expanded in the buffer expansion ring groove. This helps to reduce the impact force when the high-pressure water enters the high-pressure water sealing chamber 34 and reduces the impact damage of the water flow on the high-pressure water sealing chamber 34; at the same time, the buffering and expansion effect also reduces the vibration and noise generated by the water flow impact, improves the operating quality of the entire pump, and provides a strong guarantee for the efficient and stable operation of the pump.

[0046] In some embodiments, as shown in Figure 1 A first sealing ring 5 is provided between the front end face of the mechanical seal chamber 3 and the rear end face of the rear guard plate 6 to seal the high-pressure water sealing chamber 34. Such a setting can effectively prevent the high-pressure clean water in the high-pressure water sealing chamber 34 from leaking, and at the same time ensure the pressure difference between the high-pressure clean water in the high-pressure water sealing chamber 34 and the sewage in the pump body, thereby ensuring the normal operation of the equipment.

[0047] At the same time, through the reliable sealing of the high-pressure water sealing chamber 34, the intensity of the continuously introduced high-pressure clean water can also be alleviated, which is beneficial to reducing the use cost.

[0048] In some embodiments, as shown in Figure 1 A first limiting step is arranged radially on the rear end face of the rear guard plate 6, and a second limiting step cooperating with the first limiting step is arranged on the front end face of the mechanical seal chamber 3 to form a labyrinth seal between the mechanical seal chamber 3 and the rear guard plate 6 and limit the radial clearance between the rear guard plate 6 and the pump shaft 2. By adopting the labyrinth seal, the path passed by the high-pressure clean water during leakage can be increased, and the sealing effect can be improved.

[0049] Among them, the first sealing ring 5 is arranged on the second limiting step, and an annular groove for installing the first sealing ring 5 is arranged on the second limiting step.

[0050] In some embodiments, as shown in Figure 1 The shape formed by the mating surface between the mechanical seal chamber 3 and the rear guard plate 6 along the axial section is L-shaped. That is, in this embodiment, an L-shaped labyrinth seal is formed; a convex-shaped labyrinth seal with multiple bends can also be adopted.

[0051] Specifically, this L-shaped mating surface has many beneficial effects. First, the L-shaped mating surface provides reliable support and positioning for the radial mounting position of the rear guard plate 6, ensuring the clearance fit between the rear guard plate 6 and the pump shaft 2, and thus ensuring the flexibility of the rotation of the pump shaft 2. Second, the L-shaped configuration is conducive to improving the sealing performance, better blocking external impurities, dust, liquids, etc. from entering the inside of the mechanical seal chamber 3, avoiding contamination and damage to the mechanical seal, thereby extending the service life of the mechanical seal and ensuring the normal operation of the equipment.

[0052] In some embodiments, referring to Figure 1 as shown, a throttle ring 8 is provided between the rear guard plate 6 and the impeller 7; a third limiting step is provided in the central hole of the rear guard plate 6, and the throttle ring 8 abuts axially against the third limiting step. The cooperation between the throttle ring 8 and the impeller 7 constitutes the first sealing structure of the pump. Specifically, the throttle ring is mounted on the rear guard plate 6 to form a clearance seal with the hub of the impeller 7.

[0053] Through the above structural arrangement, the throttle ring 8 abuts axially against the third limiting step in the central hole of the rear guard plate 6, which can play a good positioning role, ensuring the stable position of the throttle ring 8 between the pump shaft 2 and the rear guard plate 6, and thus effectively ensuring the sealing performance of the first seal. This helps to prevent medium leakage, increase the pressure difference between the high-pressure water seal chamber 34 and the pump body. When the pump is running, it helps to maintain the pressure balance inside the pump and the pressure of the high-pressure clean water in the high-pressure water seal chamber 34, and reduce energy loss.

[0054] In some embodiments, referring to Figure 1 as shown, a shaft sleeve 11 is provided on the pump shaft section passing through the mechanical seal chamber 3, and a second sealing ring 12 is provided between the shaft sleeve 11 and the impeller 7 mounted at the front end of the pump shaft 2 to seal the high-pressure water seal chamber 34. The presence of the shaft sleeve 11 can play a good protective role for the pump shaft 2, reducing the direct friction between the pump shaft 2 and other components during long-term operation, effectively extending the service life of the pump shaft 2, and reducing the equipment maintenance cost; the setting of the second sealing ring 12 further enhances the sealing performance of the high-pressure water seal chamber 34, preventing the leakage of high-pressure clean water and ensuring the pressure difference between the high-pressure clean water in the high-pressure water seal chamber 34 and the sewage in the pump body.

[0055] The high-pressure water seal chamber 34 constructed in the mechanical seal chamber 3 of this application forms a pressure difference on the front and back sides of the rear guard plate 6, preventing the sewage on the low-pressure side from flowing to the high-pressure side, thereby avoiding the sewage in the pump body from flowing into the mechanical seal chamber 3. This can prevent the sewage from corroding the mechanical seal chamber 3 and the mechanical seal 10, which may otherwise lead to the failure of the mechanical seal 10, resulting in faults such as the insulation damage of the stator winding, short circuit, and grounding; it also prevents the corrosive sewage from entering the bearing grease / oil, damaging the lubrication and causing faults such as rapid wear, rust, and seizure of the bearing, generating noise and vibration, and ultimately damaging the bearing or even the pump shaft 2. Additionally, through the seal between the high-pressure water seal chamber 34 and the pump body, the leakage of high-pressure clean water is reduced, the energy consumption of the high-pressure pump and the leakage consumption of high-pressure clean water are decreased, which is beneficial to reducing energy consumption and the use cost.

[0056] In the above embodiments, the descriptions of each embodiment have their own focuses. For parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0057] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high-pressure water sealing structure of a submersible sewage pump, characterized in that, Including: A pump body, a mechanical seal chamber (3), and a motor (1) connected in sequence from front to back; The front end of the mechanical seal chamber (3) is sealingly connected to the rear end of the pump body. A mechanical seal (10) is arranged in the mechanical seal chamber (3). The mechanical seal (10) divides the mechanical seal chamber (3) into a front high-pressure water seal chamber (34) and a rear oil seal chamber (31). A high-pressure water inlet hole (32) is arranged on the high-pressure water seal chamber (34); External high-pressure clean water enters the high-pressure water seal chamber (34) through the high-pressure water inlet hole (32), and the pressure of the external high-pressure clean water is greater than the pressure of the sewage in the pump body, preventing the sewage in the pump body from entering the mechanical seal chamber (3).

2. The high-pressure water sealing structure of the submersible sewage pump according to claim 1, characterized in that, The relationship between the pressure P1 of the external high-pressure clean water and the pressure P2 of the sewage in the pump body is: P1≥P2 + 5, with the unit Pa.

3. The high-pressure water sealing structure of the submersible sewage pump according to claim 1, characterized in that, The axial cross-sectional shape of the high-pressure water seal chamber (34) is trapezoidal, with the large end of the trapezoid facing the pump body; the small end of the trapezoid faces the motor (1).

4. The high-pressure water sealing structure of the submersible sewage pump according to claim 1, characterized in that, The high-pressure water inlet hole (32) is inclinedly arranged on the high-pressure water seal chamber (34), and the included angle between the high-pressure water inlet hole (32) and the pump shaft (2) is less than 90°.

5. The high-pressure water sealing structure of the submersible sewage pump according to claim 4, characterized in that, The pump body includes a volute (4), a front guard plate (9) installed at the front end of the volute (4), an impeller (7) installed in the volute (4), and a rear guard plate (6) installed at the rear end of the volute (4). The rear end face of the rear guard plate (6) and the front end face of the oil seal chamber (31) form the high-pressure water seal chamber (34).

6. The high-pressure water sealing structure of the submersible sewage pump according to claim 5, characterized in that, A first sealing ring (5) is arranged between the front end face of the mechanical seal chamber (3) and the rear end face of the rear guard plate (6) to seal the high-pressure water seal chamber (34).

7. The high-pressure water seal structure of the submersible sewage pump according to claim 6, characterized in that, A first limiting step is arranged radially on the rear end face of the rear guard plate (6), and a second limiting step cooperating with the first limiting step is arranged on the front end face of the mechanical seal chamber (3), forming a labyrinth seal between the mechanical seal chamber (3) and the rear guard plate (6) and limiting the radial clearance between the rear guard plate (6) and the pump shaft (2).

8. The high-pressure water sealing structure of the submersible sewage pump according to claim 7, characterized in that, The shape formed by the mating surface between the mechanical seal chamber (3) and the rear guard plate (6) along the axial cross-section is L-shaped.

9. The high-pressure water sealing structure of the submersible sewage pump according to claim 5, characterized in that, A throttle ring (8) is arranged between the rear guard plate (6) and the impeller (7). A third limiting step is arranged in the central hole of the rear guard plate (6), and the throttle ring (8) abuts axially against the third limiting step.

10. The high-pressure water sealing structure of the submersible sewage pump according to claim 1, characterized in that, A shaft sleeve (11) is arranged on the pump shaft section passing through the mechanical seal chamber (3). A second sealing ring (12) is arranged between the shaft sleeve (11) and the impeller (7) installed at the front end of the pump shaft (2) to seal the high-pressure water seal chamber (34).

Images