A lubrication structure for the water pump shaft of a motorcycle engine

Abstract

The present invention provides a lubrication structure for the water pump shaft of a motorcycle engine, belonging to the technical field of motorcycles. It solves the problem of poor lubrication effect of the water pump shaft of the existing motorcycle engine. In the lubrication structure for the water pump shaft of this motorcycle engine, the engine includes a box body. A through shaft hole is provided on the side wall of the box body. There is a bearing chamber communicated with the shaft hole on the outer side of the box body. The water pump shaft passes through the bearing chamber and the shaft hole and extends into the box body. There is also a lubricating oil passage on the side wall of the box body. The lubrication structure for the water pump shaft includes an oil inlet hole opened on the side wall of the box body. One end of this oil inlet hole is communicated with the lubricating oil passage, and the other end is communicated with the shaft hole. A return oil hole communicating the bearing chamber with the inner cavity of the box body is also opened on the side wall of the box body. The lubrication structure for the water pump shaft of this motorcycle engine effectively improves the lubrication effect of the rotation of the water pump shaft.

Description

Technical Field

[0001] The present invention belongs to the technical field of motorcycles and relates to a lubrication structure for a water pump shaft of a motorcycle engine. Background Art

[0002] Cooling water is required to circulate and cool in a motorcycle engine. Therefore, a water pump is also installed on the motorcycle engine to drive the cooling water to circulate. In order to simplify the structure, the water pump directly uses the engine power to operate, that is, the water pump shaft is directly rotatably installed on the box body. One end of the water pump shaft extends into the water pump housing and is provided with an impeller, and the other end extends into the box body and is in transmission connection with the crankshaft or the balance shaft. Therefore, there is a rotational mating relationship between the water pump shaft and the box body, that is, a shaft hole is opened on the box body, the water pump shaft rotatably passes through the shaft hole, and there is an interference fit between the outer peripheral surface of the water pump shaft and the hole wall of the shaft hole. Since relative friction will be generated between the outer peripheral surface of the water pump shaft and the hole wall of the shaft hole when the water pump shaft rotates, and since the box body is filled with an oil-gas mixture, these oil-gas mixtures contain lubricating oil particles, and the lubricating oil particles will penetrate into the shaft hole for lubrication. Therefore, the relative friction between the outer peripheral surface of the water pump shaft and the hole wall of the shaft hole is usually ignored. Moreover, when the water pump shaft is in transmission connection with the crankshaft through a chain, the inner end of the water pump shaft will be radially stressed. Therefore, long-term use will cause wear between the water pump shaft and the shaft hole, resulting in noise and instability.

[0003] In view of the above problems, the patent document (application number: 201920181171.7) a water pump for a motorcycle with self-lubricating and water-discharging functions includes a box body, a water pump mounting hole is provided on the box body, a water pump is mounted on the water pump mounting hole, the water pump has a water pump housing and a water pump shaft located in the water pump housing, the inner end of the water pump shaft is located in the box body, and a driving gear is provided on the water pump shaft to be in transmission with the power system in the box body. A self-lubricating bushing is installed between the water pump shaft and the water pump mounting hole to achieve lubrication between the water pump shaft and the mounting hole through the self-lubricating bushing. However, the self-lubricating bushing is a consumable part, and there is still wear after long-term use. Summary of the Invention

[0004] The object of the present invention is to address the above problems existing in the prior art and propose a lubrication structure for a water pump shaft of a motorcycle engine to solve the problem of poor lubrication effect of the water pump shaft of an existing motorcycle engine.

[0005] The object of the present invention can be achieved by the following technical solutions: A lubrication structure for the water pump shaft of a motorcycle engine. The engine includes a housing. A through shaft hole is provided on the side wall of the housing. There is a bearing chamber communicated with the shaft hole outside the housing. The water pump shaft passes through the bearing chamber and the shaft hole and extends into the housing. There is also a lubricating oil passage on the side wall of the housing. It is characterized in that the lubrication structure of the water pump shaft includes an oil inlet hole provided on the side wall of the housing. One end of the oil inlet hole is communicated with the lubricating oil passage, and the other end is communicated with the shaft hole. A return oil hole communicating the bearing chamber with the inner cavity of the housing is also provided on the side wall of the housing.

[0006] An oil pump is provided in the housing of the engine. A lubricating oil passage is also provided on the side wall of the housing. When the oil pump works, it can transport the lubricating oil in the oil sump to positions such as the cylinder block, cylinder head and cylinder head through the lubricating oil passage to lubricate and cool components such as the crankshaft, balance shaft and camshaft. The inner end of the water pump shaft extends into the housing and is drivingly connected to the crankshaft. The outer end is located in the water pump cavity and is provided with an impeller. When the engine works, the crankshaft drives the water pump shaft to rotate, and then drives the impeller to operate, that is, the water pump shaft rotates in the shaft hole of the housing. Therefore, an oil inlet hole is provided on the housing. The oil inlet hole can actively introduce the lubricating oil in the lubricating oil passage into the shaft hole. Through the rotation of the water pump shaft, the lubricating oil can fill the gap between the water pump shaft and the hole wall of the shaft hole, and then lubricate the water pump shaft. The lubricating oil after lubricating the shaft hole will leak to both ends of the shaft hole. That is, part of the lubricating oil flows and leaks towards the inner end of the shaft hole and directly flows into the inner cavity of the housing, that is, it flows back to the oil sump. The other part of the lubricating oil flows towards the outer end of the shaft hole and leaks into the bearing chamber. This part of the lubricating oil has the risk of polluting the cooling water. Therefore, a return oil hole is also provided on the side wall of the housing. The return oil hole communicates the bearing chamber with the inner cavity of the housing, that is, the lubricating oil leaking into the bearing chamber can flow back into the inner cavity of the housing through the return oil hole, and the cooling water is polluted by leaking into the water pump cavity. That is, the present application effectively improves the lubrication effect of the rotation of the water pump shaft by feeding oil through the oil inlet hole and returning oil through the return oil hole on the premise of avoiding pollution of the cooling water.

[0007] In the above-mentioned lubrication structure for the water pump shaft of a motorcycle engine, the oil inlet hole is arranged radially along the shaft hole and is located above the shaft hole. The return oil hole is arranged axially along the shaft hole and is located below the shaft hole. The lubricating oil of the oil inlet hole located above can flow downwards along the trend and flow into the shaft hole from the top of the shaft hole, improving the lubrication effect. The return oil hole located below enables the lubricating oil in the bearing chamber to flow back into the inner cavity of the housing, avoiding the infiltration of the lubricating oil into the cooling water.

[0008] In the above-mentioned lubrication structure for the water pump shaft of a motorcycle engine, the inner diameter of the bearing chamber is larger than the diameter of the shaft hole. One end of the return oil hole penetrates through the outer side surface of the housing and is communicated with the bottom of the bearing chamber. The other end of the return oil hole penetrates through the inner side surface of the housing. The return oil hole is communicated with the bottom of the bearing chamber, enabling the lubricating oil in the bearing chamber to flow back fully and in time, avoiding accumulation in the bearing chamber.

[0009] In the above-mentioned lubrication structure of the water pump shaft of the motorcycle engine, a pump housing is fixed on the outer wall of the box body. The pump housing has a cylindrical support portion therein. The outer wall of the box body has a cylindrical mounting portion. The support portion is inserted into the mounting portion, and the inner hole of the support portion is the above-mentioned bearing chamber. The support portion and the mounting portion form a socket joint, thus forming a closed bearing chamber, and the water pump shaft passes through the bearing chamber.

[0010] In the above-mentioned lubrication structure of the water pump shaft of the motorcycle engine, the mounting portion and the shaft hole are coaxially arranged, and the inner diameter of the mounting portion is larger than the aperture of the shaft hole. A return oil gap is formed between the end face of the end of the support portion inserted into the mounting portion and the outer wall of the box body. The return oil hole is communicated with the bottom of the return oil gap. The bottom of the return oil gap is lower than the bottom of the support portion and the bottom of the shaft hole. Therefore, the lubricating oil flowing into the shaft hole can first gather at the bottom of the return oil gap, avoiding directly flowing into the inner hole of the support portion, and the lubricating oil in the return oil gap can flow back into the inner cavity of the box body from the return oil hole in time.

[0011] In the above-mentioned lubrication structure of the water pump shaft of the motorcycle engine, a bearing is installed in the bearing chamber. The water pump shaft passes through the bearing. An oil seal is also arranged between the water pump shaft and the support portion. The above-mentioned bearing is located between the oil seal and the return oil gap. The oil seal can prevent the lubricating oil in the bearing chamber from seeping into the water pump cavity.

[0012] In the above-mentioned lubrication structure of the water pump shaft of the motorcycle engine, a circumferential annular convex edge is provided on the inner peripheral wall of the support portion. The above-mentioned oil seal is located between the convex edge and the water pump shaft, and the lower part of the convex edge is higher than the return oil hole. The oil seal is installed in the convex edge, and the lower part of the convex edge is relatively high, avoiding the lubricating oil in the bearing chamber from entering the inner hole of the convex edge and reducing the sealing pressure of the oil seal.

[0013] In the above-mentioned lubrication structure of the water pump shaft of the motorcycle engine, a circumferential annular retaining edge is provided on the outer peripheral wall of the water pump shaft. The retaining edge is located between the end face of the bearing and the outer side face of the box body, and the outer diameter of the retaining edge is larger than the aperture of the shaft hole. The retaining edge can prevent the lubricating oil from directly flowing along the water pump shaft to the oil seal, that is, the lubricating oil on the water pump shaft will flow downward along the retaining edge and fall into the return oil gap.

[0014] In the above-mentioned lubrication structure of the water pump shaft of the motorcycle engine, a flared groove is opened on the hole wall at the top of the shaft hole. The lower end of the oil inlet hole is communicated with the flared groove. The notch diameter of the flared groove is larger than the aperture of the oil inlet hole. An oil injector is also installed at the lower end of the oil inlet hole. The flared groove has a relatively large space. After the lubricating oil in the oil inlet hole enters the flared groove, the flow rate can be reduced, playing a buffering role, avoiding the lubricating oil from quickly flowing away from both ends of the shaft hole after entering the shaft hole. At the same time, the notch of the flared groove is relatively large, increasing the contact area between the internal lubricating oil and the outer peripheral surface of the water pump shaft, thereby improving the lubrication effect.

[0015] In the lubrication structure of the water pump shaft of the motorcycle engine described above, one end of the water pump shaft extending into the inner cavity of the box body has a disc-shaped portion for installing a sprocket, and one end of the oil return hole facing the inner cavity of the box body is opposite to the side surface of the disc-shaped portion. The disc-shaped portion is used to install the sprocket, and the oil return hole is opposite to the disc-shaped portion, so that when the oil pressure in the oil return hole is relatively high, it can be sprayed onto the disc-shaped portion, thereby lubricating the sprocket and chain.

[0016] Compared with the prior art, the lubrication structure of the water pump shaft of the motorcycle engine has the following advantages:

[0017] 1. Since the oil inlet hole and the oil return hole are opened on the box body, the oil inlet hole can actively introduce the lubricating oil in the lubricating oil passage into the shaft hole to lubricate the water pump shaft, and the lubricating oil leaking into the bearing chamber can flow back into the inner cavity of the box body through the oil return hole, thereby effectively improving the lubrication effect of the rotation of the water pump shaft on the premise of avoiding the pollution of the cooling water.

[0018] 2. Since an oil return gap is formed between the end face of the support portion and the outer wall of the box body, the lubricating oil flowing into the shaft hole can first gather at the bottom of the oil return gap, avoiding directly flowing into the inner hole of the support portion, and the lubricating oil in the oil return gap can flow back into the inner cavity of the box body through the oil return hole in time.

[0019] 3. Since an expansion groove is opened on the hole wall at the top of the shaft hole, the expansion groove has a relatively large space, which buffers the lubricating oil, avoids the lubricating oil from quickly flowing away from both ends of the shaft hole after entering the shaft hole, and at the same time, the opening of the expansion groove is relatively large, increasing the contact area between the internal lubricating oil and the outer peripheral surface of the water pump shaft, thereby improving the lubrication effect. Description of the Drawings

[0020] Figure 1 is a side view of a partial structure of the motorcycle engine.

[0021] Figure 2 is Figure 1 the structural sectional view at A-A in

[0022] Figure 3 is Figure 2 the enlarged view of the structure at B in

[0023] Figure 4 is Figure 2 the structural sectional view at C-C in

[0024] In the figure, 1. Box body; 11. Shaft hole; 12. Lubricating oil passage; 13. Oil inlet hole; 14. Expansion groove; 15. Oil return hole; 16. Installation portion; 17. Injector nozzle; 2. Pump housing; 21. Support portion; 22. Bearing chamber; 23. Oil return gap; 24. Convex edge; 3. Water pump shaft; 31. Stop edge; 32. Disc-shaped portion; 4. Bearing; 5. Oil seal; 6. Sealing ring. Detailed Embodiment

[0025] The following are specific embodiments of the present invention. In combination with the accompanying drawings, the technical solutions of the present invention will be further described, but the present invention is not limited to these embodiments.

[0026] As Figure 1 、 Figure 2 shown, a lubrication structure for a water pump shaft of a motorcycle engine. The engine includes a box body 1. A through shaft hole 11 is provided on the side wall of the box body 1. A pump housing 2 is fixed on the outer wall of the box body 1. A cylindrical support portion 21 is provided inside the pump housing 2. A cylindrical mounting portion 16 is provided on the outer wall of the box body 1. The support portion 21, the mounting portion 16 and the shaft hole 11 are coaxially arranged, and the inner diameters of the support portion 21 and the mounting portion 16 are both larger than the aperture of the shaft hole 11. The support portion 21 is inserted into the mounting portion 16, and a sealing ring 6 is provided between the outer peripheral surface of the support portion 21 and the inner peripheral surface of the mounting portion 16. The inner hole of the support portion 21 forms a bearing chamber 22. A bearing 4 is installed in the bearing chamber 22. The water pump shaft 3 is a stepped shaft. The water pump shaft 3 sequentially passes through the bearing 4 and the shaft hole 11. A larger diameter section of the water pump shaft 3 is rotatably arranged in the shaft hole 11, and a smaller diameter section is rotatably arranged in the bearing 4, so that one end of the water pump shaft 3 is located in the pump chamber of the pump housing 2, and the other end extends into the inner cavity of the box body 1. And a disc portion 32 is provided at the end of the water pump shaft 3 extending into the inner cavity of the box body 1. The disc portion 32 is used for installing a sprocket. An annular convex edge 24 is circumferentially provided on the inner peripheral wall of the support portion 21. The water pump shaft 3 passes through the convex edge 24. An oil seal 5 is provided between the outer peripheral surface of the water pump shaft 3 and the inner peripheral surface of the convex edge 24. The bearing 4 is located between the oil seal 5 and the shaft hole 11. In combination Figure 3 、 Figure 4 shown, a lubricating oil passage 12 is further provided on the side wall of the box body 1. The lubricating oil passage 12 is communicated with an oil pump in the engine. The lubrication structure of the water pump shaft includes an oil inlet hole 13 provided on the side wall of the box body 1. One end of the oil inlet hole 13 is communicated with the lubricating oil passage 12, and the other end is communicated with the shaft hole 11. A return oil hole 15 communicating the bearing chamber 22 with the inner cavity of the box body 1 is further provided on the side wall of the box body 1. The return oil hole 15 is lower than the lower part of the convex edge 24.

[0027] Specifically, the oil inlet hole 13 is arranged radially along the shaft hole 11 and is located above the shaft hole 11. The upper end of the oil inlet hole 13 is communicated with the lubricating oil passage 12. A flared groove 14 is formed on the hole wall at the top of the shaft hole 11. The lower end of the oil inlet hole 13 is communicated with the flared groove 14. The notch diameter of the flared groove 14 is larger than the aperture of the oil inlet hole 13. An oil injector 17 is further installed at the lower end of the oil inlet hole 13. A return oil gap 23 is formed between the end face of the end of the supporting part 21 inserted into the installation part 16 and the outer wall of the box body 1. The return oil hole 15 is arranged axially along the shaft hole 11 and is located below the shaft hole 11. One end of the return oil hole 15 penetrates through to the outer side surface of the side wall of the box body 1 and is communicated with the bottom of the return oil gap 23. The other end of the return oil hole 15 penetrates through to the inner side surface of the side wall of the box body 1, and the other end of the return oil hole 15 faces the disc part 32. A circumferential annular retaining edge 31 is provided on the outer peripheral wall of the water pump shaft 3. The retaining edge 31 is located between the end face of the bearing 4 and the outer side surface of the box body 1, and the outer diameter of the retaining edge 31 is larger than the aperture of the shaft hole 11, that is, the outer peripheral surface of the retaining edge 31 is relatively spaced from the bearing 4.

[0028] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art of the present invention can make various modifications or supplements to the described specific embodiments or use similar ways to substitute, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0029] Although terms such as the box body 1, the shaft hole 11, the lubricating oil passage 12, etc. are used more in this article, the possibility of using other terms is not excluded. The use of these terms is only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. A lubrication structure for the water pump shaft of a motorcycle engine. The engine includes a housing (1), and a through shaft hole (11) is provided on the side wall of the housing (1). A bearing chamber (22) communicating with the shaft hole (11) is provided outside the housing (1). The water pump shaft (3) passes through the bearing chamber (22) and the shaft hole (11) and extends into the housing (1). A lubricating oil passage (12) is further provided on the side wall of the housing (1), and it is characterized in that, The lubrication structure of the water pump shaft includes an oil inlet hole (13) opened on the side wall of the box body (1). One end of the oil inlet hole (13) is communicated with the lubricating oil passage (12), and the other end is communicated with the shaft hole (11). A return oil hole (15) is also opened on the side wall of the box body (1) to communicate the bearing chamber (22) with the inner cavity of the box body (1); a pump housing (2) is fixed on the outer wall of the box body (1). A cylindrical support portion (21) is provided in the pump housing (2). A cylindrical mounting portion (16) is provided on the outer wall of the box body (1). The support portion (21) is inserted into the mounting portion (16), and an oil return gap (23) is formed between the end face and the outer wall of the box body (1). The return oil hole (15) is communicated with the bottom of the oil return gap (23); a bearing (4) is installed in the bearing chamber (22). The water pump shaft (3) passes through the bearing (4). An oil seal (5) is further provided between the water pump shaft (3) and the support portion (21). The above-mentioned bearing (4) is located between the oil seal (5) and the oil return gap (23).

2. The lubrication structure of the water pump shaft of the motorcycle engine according to claim 1, wherein The oil inlet hole (13) is arranged radially along the shaft hole (11) and is located above the shaft hole (11). The return oil hole (15) is arranged axially along the shaft hole (11) and is located below the shaft hole (11).

3. The lubrication structure of the water pump shaft of a motorcycle engine according to claim 2, characterized in that, The inner diameter of the bearing chamber (22) is larger than the aperture of the shaft hole (11). One end of the return oil hole (15) penetrates to the outer side surface of the box body (1) and is communicated with the bottom of the bearing chamber (22), and the other end of the return oil hole (15) penetrates to the inner side surface of the box body (1).

4. The lubrication structure of the water pump shaft of a motorcycle engine according to claim 1 or 2 or 3, characterized in that, The mounting portion (16) is coaxially arranged with the shaft hole (11), and the inner diameter of the mounting portion (16) is larger than the aperture of the shaft hole (11).

5. The lubrication structure of the water pump shaft of a motorcycle engine according to claim 4, characterized in that, A circular convex edge (24) is circumferentially provided on the inner peripheral wall of the support portion (21). The above-mentioned oil seal (5) is located between the convex edge (24) and the water pump shaft (3). The lower part of the convex edge (24) is higher than the return oil hole (15).

6. The lubrication structure of the water pump shaft of a motorcycle engine according to claim 4, characterized in that, A circular retaining edge (31) is circumferentially provided on the outer peripheral wall of the water pump shaft (3). The retaining edge (31) is located between the end face of the bearing (4) and the outer side surface of the box body (1), and the outer diameter of the retaining edge (31) is larger than the aperture of the shaft hole (11).

7. The lubrication structure of the water pump shaft of a motorcycle engine according to claim 1 or 2 or 3, characterized in that, An expansion groove (14) is opened on the hole wall at the top of the shaft hole (11). The lower end of the oil inlet hole (13) is communicated with the expansion groove (14). The notch diameter of the expansion groove (14) is larger than the aperture of the oil inlet hole (13). An oil injector (17) is further installed at the lower end of the oil inlet hole (13).

8. The lubrication structure of the water pump shaft of a motorcycle engine according to claim 1 or 2 or 3, characterized in that, One end of the water pump shaft (3) extending into the inner cavity of the box body (1) has a disc-shaped portion (32) for installing a sprocket. One end of the return oil hole (15) facing the inner cavity of the box body (1) is opposite to the side surface of the disc-shaped portion (32).

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