A water pump compensation system for an outboard motor

Abstract

The application discloses an outboard engine water pump compensation system and relates to the technical field of outboard engines. The outboard engine water pump compensation system comprises an upper water pipe, a water pump shell is arranged at the bottom of the upper water pipe, two water pump inner shells are arranged in the water pump shell, water pump impellers are arranged in the water pump inner shells, a water pump shell sealing gasket is arranged at the bottom of the water pump shell, and a water pump pad is arranged at the bottom of the water pump shell sealing gasket. The series of structures are arranged, the cooling efficiency is prevented from being reduced or the engine overheating risk is avoided due to the change of working conditions, the reliability of the system is remarkably improved, the water pumping capacity is improved as a whole, the wear of the impeller is reduced, the service life of the high-pressure cavity water pump impeller and the whole system is prolonged, the lubrication and durability of the transmission component are ensured, the sealing property of water pumping is optimized, the overall efficiency is improved, and the maintenance requirement is reduced.

Description

An outboard motor water pump compensation system Technical Field

[0001] This invention relates to the field of outboard motor technology, specifically to an outboard motor water pump compensation system. Background Technology

[0002] In the field of marine propulsion, outboard motors are a widely used power unit, and the performance of their cooling system is directly related to the reliability and lifespan of the engine.

[0003] Currently, the outboard motor water pump cooling system, driven by the engine, rotates the drive shaft. There is an eccentricity between the water pump impeller and the pump housing. When the impeller rotates, a pressure difference exists in the water storage chamber formed by the pump housing and the impeller, allowing for continuous intake of cooling water. However, at high speeds, the impeller blades are subjected to high water pressure, causing water in the high-pressure chamber to leak into a subsequent medium- or low-pressure chamber. This results in insufficient water storage in the high-pressure chamber, leading to air leakage and weak water output during discharge, causing the engine to overheat rapidly. Blindly increasing the impeller hardness to improve pump pressure can cause the impeller blades to break off and become damaged. These damaged blade fragments are highly likely to enter the engine with the cooling water, causing blockages in the engine's cooling system. Furthermore, the engine's cooling water passages are intricate and complex. If the coolant pressure is low, it cannot overcome the resistance of the bends inside the engine, causing the coolant to not reach the top, resulting in increased engine temperature. Alternatively, the coolant passages may become clogged, making cleaning difficult. In addition, some parts are disposable, and if they are disassembled, a large number of new parts need to be replaced, thus lengthening the entire maintenance cycle. Summary of the Invention

[0004] The purpose of this invention is to provide an outboard motor water pump compensation system to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an outboard motor water pump compensation system, comprising a water inlet pipe, a water pump housing at the bottom of the water inlet pipe, two water pump inner shells installed inside the water pump housing, a water pump impeller inside each of the two water pump inner shells, a water pump housing gasket at the bottom end of the water pump housing, a water pump pad at the bottom end of the water pump housing gasket, a first oil seal housing gasket at the bottom end of the water pump pad, an oil seal housing component at the bottom end of the first oil seal housing gasket, and an active pump impeller installed at the middle position of the water pump impeller near the water inlet pipe. A driven shaft is installed at the middle position of the other pump impeller. Both the driving shaft and the driven shaft are connected to the two pump impellers by semi-circular keys. A pump housing extends from the top of both the driving shaft and the driven shaft, and an oil seal housing extends from the bottom of both the driving shaft and the driven shaft. A second oil seal housing gasket is provided at the bottom end of the oil seal housing. A U-shaped compensating pipe is installed on the top of the pump housing between the driving shaft and the driven shaft. A high-pressure pumping zone is provided at the bottom end of the oil seal housing near the driving shaft, and a medium-low pressure pumping zone is provided at the bottom end of the oil seal housing near the driven shaft.

[0006] Preferably, a water pipe sealing ring is connected between the bottom outer surface of the water inlet pipe and the top of the water pump housing, and two compensating pipe sealing rings are connected between the bottom outer surface of the U-shaped compensating pipe and the top of the water pump housing. The water pipe sealing rings ensure the seal at the connection between the water inlet pipe and the water pump housing, preventing leakage of cooling water in the final stage before entering the engine and ensuring water pressure. The compensating pipe sealing rings ensure the seal at the connection between the U-shaped compensating pipe and the water pump housing, allowing all the cooling water in the low-pressure chamber to be effectively delivered to the high-pressure chamber through the compensating pipe, avoiding pressure loss and flow rate loss.

[0007] Preferably, the second oil seal housing gasket on the outer surface of the bottom extension end of the drive shaft and driven shaft is provided with two O-rings. The bottom end of the two O-rings is provided with two oil seals on the outer surface of the drive shaft and driven shaft. The O-rings and oil seals constitute a multi-stage sealing system. Its main function is to prevent gear oil in the underwater housing cavity from leaking upward along the drive shaft and driven shaft, while preventing external water from flowing back into the gearbox, ensuring reliable lubrication of the transmission system, and completely isolating it from the water system.

[0008] Preferably, axial limiting rings are installed on the outer surfaces of both the drive shaft and the driven shaft below the oil seal. A drive gear is installed on the outer surface of the axial limiting ring of the drive shaft, and a driven gear is provided on the outer surface of the axial limiting ring of the driven shaft. An intermediate gear meshes between the drive gear and the driven gear. The axial limiting rings are used to accurately position the gears axially, ensuring stable gear meshing and smooth transmission. The drive gear, driven gear, and intermediate gear constitute a reduction transmission system. The power of the drive shaft is transmitted to the intermediate gear through the drive gear, which then drives the driven gear, thereby causing the driven shaft to rotate. The design of this gear set determines that the speed of the driven shaft is lower than that of the drive shaft, realizing the functional requirement of the impeller in the medium and low pressure chamber continuously maintaining medium and low speed operation.

[0009] Preferably, the intermediate gear is provided with a first anti-wear plate inside, and a tapered roller bearing is provided at the bottom of the intermediate gear. The first anti-wear plate reduces the wear between the intermediate gear and other contacting parts, and improves the service life of the transmission parts. The tapered roller bearing is used to bear the radial and axial loads transmitted by the intermediate gear, ensuring its smooth rotation, and cooperates with the tooling press-fit to achieve complete axial limit.

[0010] Preferably, a first needle roller bearing is provided on the outer surface of the bottom extension end of the drive shaft and the bottom end of the driven shaft. A second anti-wear plate is connected between the bottom of the driven shaft and the corresponding first needle roller bearing. A second needle roller bearing is provided on the outer surface of the top extension end of the driven shaft. The first and second needle roller bearings support the bottom and top of the drive shaft and the driven shaft, respectively, bear radial loads, ensure the coaxiality and stability of the dual-shaft rotation, and reduce friction. The second anti-wear plate is installed between the bottom of the driven shaft and the bearing to prevent wear between the shaft end and the bearing seat.

[0011] Preferably, a drive gear is installed at the bottom of the drive shaft. The drive gear inputs the power from the power source to the drive shaft through a spline connection. It is the power input end of the entire water pump system. At the same time, the drive gear also meshes with the gear shifting mechanism of the outboard motor to realize the propulsion function.

[0012] Preferably, the bottom of the U-shaped compensating pipe and the bottom of the water inlet pipe are both connected to the water pump housing. The compensating water enters the high-pressure water flow collection area inside the water pump housing through this U-shaped compensating pipe. The connection between the water inlet pipe and the water pump housing indicates that the collected cooling water is finally pressure-sent to the engine through this path. These two connections are the structural basis for ensuring that the cooling water flows according to the designed path.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] This outboard motor uses a water pump compensation system. By employing a dual-chamber design with high-pressure and medium-low-pressure water storage chambers working in tandem with a pressure compensation mechanism, it effectively solves the problem of unstable water pressure from a single water pump system at high speeds. When the water pressure in the high-pressure water storage chamber tends to decrease due to high-speed operation, the medium-low-pressure water storage chamber automatically increases the water intake rate of its pump impeller through an internally connected compensation pipe, replenishing cooling water to the high-pressure chamber. This dynamic compensation ensures that the total amount and pressure of cooling water flowing to the engine remain stable, avoiding the risk of decreased cooling efficiency or engine overheating due to changes in operating conditions, and significantly improving the system's reliability.

[0015] This outboard motor uses a water pump compensation system. Through the coordinated operation of dual pump impellers and a unique transmission design, it achieves dynamic balance and self-adaptation of system output, and enhances pumping capacity. The high-pressure chamber impeller is directly driven by the drive shaft at high speed, providing the main cooling flow. The medium- and low-pressure chamber impellers are driven by the driven shaft after reduction through a gear set, maintaining medium- and low-speed operation to provide compensation flow. The two water flows eventually merge, keeping the overall pump system dynamically stable. If the high-pressure chamber lacks water, the medium- and low-pressure chambers increase their water replenishment rate; once the high-pressure chamber stabilizes, the medium- and low-pressure chambers return to normal operation. This design not only ensures a continuous and stable supply of cooling water but also improves overall pumping capacity by distributing the load through the dual impellers.

[0016] This outboard motor uses a water pump compensation system. Through the continuous compensation effect of the medium- and low-pressure water storage chambers on the high-pressure water storage chamber, it effectively balances the stress on the impeller of the high-pressure pump, extending its service life. The intervention of the compensating water flow in the medium- and low-pressure chambers helps balance the pressure difference on both sides of the high-pressure impeller, resulting in more uniform stress on the impeller blades. This reduces the stress and deformation of the blades caused by prolonged exposure to unilateral high pressure, reduces impeller wear, and extends the service life of the high-pressure pump impeller and the entire system.

[0017] The outboard motor's water pump compensation system, through integrated transmission and sealing design, achieves complex functions while ensuring structural compactness and operational reliability. It adopts a reduction transmission mechanism consisting of a drive shaft, driven shaft, and intermediate gear, which is compact and efficient. At the same time, the use of multi-layered seals (such as O-rings, oil seals, and various gaskets) effectively isolates the water flow channel from the gear transmission cavity, preventing gear oil leakage and external water intrusion, ensuring the lubrication and durability of transmission components, optimizing the water pump's sealing performance, improving overall efficiency, and reducing maintenance requirements. Attached Figure Description

[0018] Figure 1 is a schematic diagram of the overall structure of the present invention in disassembled state;

[0019] Figure 2 is a three-dimensional structural diagram of the present invention;

[0020] Figure 3 is a bottom-view perspective view of the overall structure of the present invention;

[0021] Figure 4 is a schematic diagram of the structure of the oil seal housing of the present invention;

[0022] Figure 5 is a top view of the structure of the oil seal housing of the present invention;

[0023] Figure 6 is a schematic diagram of the water pump pad structure of the present invention;

[0024] Figure 7 is a schematic diagram of the combined state of the water pump housing sealing gasket and the water pump impeller structure of the present invention;

[0025] Figure 8 is a simplified diagram of the water flow principle of the present invention.

[0026] In the diagram: 1. Water inlet pipe; 2. Water pipe sealing ring; 3. Water pump housing; 4. Water pump inner shell; 5. Water pump impeller; 6. Oil seal housing; 7. O-ring; 8. Oil seal; 9. Drive gear; 10. Axial limiting ring; 11. Tapered roller bearing; 12. First needle roller bearing; 13. Drive shaft; 14. Drive gear; 15. Second needle roller bearing; 16. U-shaped compensating pipe; 17. Compensating pipe sealing ring; 18. Water pump housing gasket; 19. Water pump pad; 20. First oil seal housing gasket; 21. Second oil seal housing gasket; 22. Driven gear; 23. Intermediate gear; 24. First wear-resistant plate; 25. Driven shaft; 26. Second wear-resistant plate; 27. High-pressure pumping zone; 28. Medium and low-pressure pumping zone; 29. ​​Semicircular key. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] As shown in Figures 1 to 8, the outboard motor water pump compensation system in this embodiment includes a water inlet pipe 1, which serves as the final channel for delivering cooling water to the engine. A water pump housing 3 is located at the bottom of the water inlet pipe 1. The water pump housing 3 serves as the main pressure-bearing and water-collecting housing of the water pump system, collecting the water flow from the two pump chambers and guiding it to the engine. Two water pump inner shells 4 are installed inside the water pump housing 3. The water pump inner shells 4, together with water pump impellers 5, form a sealed pump chamber. Their eccentric design is key to generating the suction pressure difference. Water pump impellers 5 are installed inside both water pump inner shells 4. The water pump impellers 5 are the core working components, generating suction and pressure through rotation to achieve water pumping. The bottom of the water pump housing... A water pump housing gasket 18 is provided at one end, a water pump pad 19 is provided at the bottom end of the water pump housing gasket 18, and a first oil seal housing gasket 20 is provided at the bottom end of the water pump pad 19. These stacked sealing and spacer components work together to separate the high-pressure water flow channel and the gear transmission cavity below. At the same time, the holes designed on them form a specific drainage path for cooling water to flow from the pump cavity to the water pump housing 3. An oil seal housing 6 is provided at the bottom end of the first oil seal housing gasket 20. The oil seal housing 6 forms two independent water storage chambers, one for high pressure and one for medium and low pressure, and integrates the water inlet and the internal drainage channel. The drive shaft 13 is installed in the middle of the water pump impeller 5 near the water inlet pipe 1. A driven shaft 25 is installed at the middle position of each water pump impeller 5. Both the drive shaft 13 and the driven shaft 25 are connected to the two water pump impellers 5 via semi-circular keys 29. The top of both the drive shaft 13 and the driven shaft 25 extends into a water pump housing 3, and the bottom of both extends into an oil seal housing 6. The design of the drive shaft 13 and the driven shaft 25 is the core of achieving independent and linked transmission between the two chambers. The drive shaft 13 directly transmits power to drive the high-pressure chamber impeller, while the driven shaft 25 drives the medium and low-pressure chamber impellers after speed reduction via a gear set, achieving a compensation function. A second oil seal housing gasket 21 is provided at the bottom of the oil seal housing 6, which is used to seal the outer surface of the oil seal. The bottom of housing 6 prevents gear oil leakage and encloses the transmission components within its cavity. A U-shaped compensating pipe 16 is installed on the top of the water pump housing 3 between the drive shaft 13 and the driven shaft 25. The U-shaped compensating pipe 16 serves as a dedicated channel to directionally transport the cooling water pumped from the medium and low pressure chamber to the high pressure chamber, so as to replenish water when the demand of the high pressure chamber increases. A high pressure chamber water pumping area 27 is provided at the bottom of the oil seal housing 6 near the drive shaft 13, and a medium and low pressure water pumping area 28 is provided at the bottom of the oil seal housing 6 near the driven shaft 25. The high pressure chamber water pumping area 27 and the medium and low pressure water pumping area 28 are water inlets on the oil seal housing 6, corresponding to the high pressure water storage chamber and the medium and low pressure water storage chamber, respectively, and directly draw water from the external water source.

[0030] Specifically, a water pipe sealing ring 2 is connected between the bottom outer surface of the water inlet pipe 1 and the top of the water pump housing 3. Two compensating pipe sealing rings 17 are connected between the bottom outer surface of the U-shaped compensating pipe 16 and the top of the water pump housing 3. The water pipe sealing ring 2 ensures the seal at the connection between the water inlet pipe 1 and the water pump housing 3, preventing leakage of cooling water in the final stage before entering the engine and ensuring water pressure. The compensating pipe sealing rings 17 ensure the seal at the connection between the U-shaped compensating pipe 16 and the water pump housing 3, so that the cooling water in the medium and low pressure chamber can be effectively transported to the high pressure chamber through the compensating pipe, avoiding pressure loss and flow loss.

[0031] Furthermore, two O-rings 7 are provided inside the second oil seal housing gasket 21 on the outer surface of the bottom extension end of the drive shaft 13 and the driven shaft 25. Two oil seals 8 are provided on the outer surface of the drive shaft 13 and the driven shaft 25 at the bottom end of the two O-rings 7. The O-rings 7 and the oil seals 8 constitute a multi-stage sealing system. Its main function is to prevent gear oil in the underwater housing cavity from leaking upward along the drive shaft 13 and the driven shaft 25, while preventing external water from flowing back into the gearbox, ensuring reliable lubrication of the transmission system, and completely isolating it from the water system.

[0032] Furthermore, axial limiting rings 10 are installed on the outer surfaces of the drive shaft 13 and driven shaft 25 below the oil seal 8. A drive gear 9 is installed on the outer surface of the axial limiting ring 10 of the drive shaft 13, and a driven gear 22 is provided on the outer surface of the axial limiting ring 10 of the driven shaft 25. An intermediate gear 23 is connected to the drive gear 9 and the driven gear 22 through meshing. The axial limiting ring 10 is used to accurately position the gears axially, ensuring stable gear meshing position and smooth transmission. The drive gear 9, driven gear 22 and intermediate gear 23 constitute a reduction transmission system. The power of the drive shaft 13 is transmitted to the intermediate gear 23 through the drive gear 9, which then drives the driven gear 22, thereby driving the driven shaft 25 to rotate. The design of this gear set determines that the speed of the driven shaft 25 is lower than that of the drive shaft 13, realizing the functional requirement of the impeller in the medium and low pressure chamber continuously maintaining medium and low speed operation.

[0033] Furthermore, the intermediate gear 23 is provided with a first anti-wear plate 24 inside, and a tapered roller bearing 11 is provided at the bottom of the intermediate gear 23. The first anti-wear plate 24 reduces the wear between the intermediate gear 23 and other contacting parts, and improves the service life of the transmission parts. The tapered roller bearing 11 is used to bear the radial and axial loads transmitted by the intermediate gear 23, ensuring its smooth rotation, and cooperates with the tooling press to achieve complete axial limit.

[0034] Furthermore, a first needle roller bearing 12 is provided on the outer surface of the bottom extension end of the drive shaft 13 and the bottom end of the driven shaft 25. A second anti-wear plate 26 is connected between the bottom of the driven shaft 25 and the corresponding first needle roller bearing 12. A second needle roller bearing 15 is provided on the outer surface of the top extension end of the driven shaft 25. The first needle roller bearing 12 and the second needle roller bearing 15 support the bottom and top of the drive shaft 13 and the driven shaft 25 respectively, bear radial loads, ensure the coaxiality and stability of the dual-shaft rotation, and reduce friction. The second anti-wear plate 26 is installed between the bottom of the driven shaft 25 and the bearing to prevent wear between the shaft end and the bearing seat.

[0035] Furthermore, a drive gear 14 is installed at the bottom of the drive shaft 13. The drive gear 14 inputs the power from the power source to the drive shaft 13 through a spline connection, which is the power input end of the entire water pump system. At the same time, the drive gear 14 also meshes with the gear shifting mechanism of the outboard motor to realize the propulsion function.

[0036] Furthermore, the bottom of the U-shaped compensating pipe 16 and the bottom of the water inlet pipe 1 are both connected to the water pump housing 3. The compensating water enters the high-pressure water flow collection area inside the water pump housing 3 through this U-shaped compensating pipe 16. The connection between the water inlet pipe 1 and the water pump housing 3 indicates that the collected cooling water is finally pressure-sent to the engine through this path. These two connections are the structural basis for ensuring that the cooling water flows according to the designed path.

[0037] The usage method of this embodiment is as follows: The system mainly consists of a cooling water passage, a dual-pump chamber structure, a transmission compensation mechanism, and a sealing system. The cooling water passage begins at two independent water inlets at the bottom of the oil seal housing 6: a high-pressure water intake zone 27 and a medium-low pressure water intake zone 28. The water flow is ultimately delivered to the engine via the upper water pipe 1. The dual-pump chamber structure is the core of the system, which includes two pump chambers composed of a water pump inner shell 4 and a water pump impeller 5. These are located in the high-pressure water storage chamber and the medium-low pressure water storage chamber inside the oil seal housing 6, respectively. The key to the transmission compensation mechanism lies in the dual-shaft design of the drive shaft 13 and the driven shaft 25. Power is input from the drive gear 14 at the bottom, directly driving the high-pressure chamber impeller to rotate at high speed, providing the main cooling flow. Simultaneously, the drive shaft 13, through a reduction gear set consisting of the drive gear 9, intermediate gear 23, and driven gear 22, drives the driven shaft 25 to rotate at a lower speed, thus driving the low-pressure chamber impeller to continuously operate at a low-to-medium speed. The water pumped out of the low-pressure chamber does not directly participate in cooling; instead, it is introduced into the high-pressure chamber's outlet area as makeup water through the U-shaped compensation pipe 16 connected between the two chambers. Its working principle is dynamically adaptive: when the engine load increases and the high-pressure chamber water pressure tends to decrease... The pressure difference between the two chambers reduces the pumping resistance of the low-pressure chamber, automatically increasing its pumping rate and supplementing more cooling water to the high-pressure chamber through the U-shaped compensation pipe 16. When the pressure in the high-pressure chamber stabilizes, the compensation flow rate remains at the baseline level. This design enables on-demand water replenishment to the high-pressure chamber, effectively avoiding water shortages. After the two water flows converge inside the water pump housing 3, the stable and sufficient cooling water is pumped to the engine through specific drainage holes on the water pump pad 19 and the well-sealed water inlet pipe 1. The water pipe sealing ring 2 and the compensation pipe sealing ring 17 ensure leak-proof connection at critical joints, while the multi-layered stacked water pump housing... The shell gasket 18, water pump gasket 19, first oil seal shell gasket 20, and second oil seal shell gasket 21 work together to effectively isolate the high-pressure water flow area above and the transmission cavity containing the gear below. The transmission cavity is sealed by a multi-stage sealing system consisting of O-rings 7 and oil seals 8 to prevent gear oil leakage and external water backflow. The drive shaft 13 and driven shaft 25 are supported by the first needle roller bearing 12, the second needle roller bearing 15, and the tapered roller bearing 11 to ensure stable rotation. The axial limit ring 10, the first anti-wear plate 24, and the second anti-wear plate 26 are used for precise axial positioning and to reduce wear.

[0038] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An outboard motor water pump compensation system, comprising a water inlet pipe (1), characterized in that: The bottom of the water inlet pipe (1) is provided with a water pump housing (3). Inside the water pump housing (3) are two water pump inner shells (4). Inside each of the two water pump inner shells (4) is a water pump impeller (5). At the bottom end of the water pump housing (3) is a water pump housing gasket (18). At the bottom end of the water pump housing gasket (18) is a water pump pad (19). At the bottom end of the water pump pad (19) is a first oil seal housing gasket (20). An oil seal housing component (6) is provided at the bottom end of the oil seal housing gasket (20). A drive shaft (13) is installed at the middle position of the water pump impeller (5) near the water inlet pipe (1), and a driven shaft (25) is installed at the middle position of the other water pump impeller (5). The drive shaft (13) and the driven shaft (25) are respectively connected to the two water pump impellers (5) by a semi-circular key (29). The top of the drive shaft (13) and the driven shaft (25) extend out of the water pump. The housing (3) has an oil seal housing (6) extending from the bottom of both the drive shaft (13) and the driven shaft (25). A second oil seal housing gasket (21) is provided at the bottom end of the oil seal housing (6). A U-shaped compensating pipe (16) is installed on the top of the water pump housing (3) between the drive shaft (13) and the driven shaft (25). A high-pressure chamber pumping area (27) is provided at the bottom end of the oil seal housing (6) near the drive shaft (13). A medium-low pressure pumping zone (28) is provided at the position of the driving shaft (25); a driving gear (9) is installed on the outer surface of the axial limiting ring (10) of the driving shaft (13), and a driven gear (22) is provided on the outer surface of the axial limiting ring (10) of the driven shaft (25). An intermediate gear (23) is meshed between the driving gear (9) and the driven gear (22); the bottom of the U-shaped compensation pipe (16) and the bottom of the water inlet pipe (1) are both in communication with the water pump housing (3).

2. The outboard motor water pump compensation system according to claim 1, characterized in that: A water pipe sealing ring (2) is connected between the bottom outer surface of the water pipe (1) and the top of the water pump housing (3), and two compensation pipe sealing rings (17) are connected between the bottom outer surface of the U-shaped compensation pipe (16) and the top of the water pump housing (3).

3. The outboard motor water pump compensation system according to claim 1, characterized in that: Two O-rings (7) are provided inside the second oil seal housing gasket (21) on the outer surface of the bottom extension end of the drive shaft (13) and driven shaft (25). Two oil seals (8) are provided on the outer surface of the drive shaft (13) and driven shaft (25) at the bottom end of the two O-rings (7).

4. The outboard motor water pump compensation system according to claim 3, characterized in that: Axial limiting rings (10) are installed on the outer surfaces of the drive shaft (13) and driven shaft (25) below the oil seal (8).

5. The outboard motor water pump compensation system according to claim 4, characterized in that: The intermediate gear (23) is provided with a first anti-wear plate (24) inside, and a tapered roller bearing (11) is provided at the bottom of the intermediate gear (23).

6. The outboard motor water pump compensation system according to claim 1, characterized in that: The bottom extension of the drive shaft (13) and the bottom of the driven shaft (25) are both provided with a first needle roller bearing (12). The bottom of the driven shaft (25) and the corresponding first needle roller bearing (12) are connected together with a second anti-wear plate (26). The top extension of the driven shaft (25) is provided with a second needle roller bearing (15).

7. The outboard motor water pump compensation system according to claim 1, characterized in that: A drive gear (14) is mounted on the bottom of the drive shaft (13).

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