Crankcase of motorcycle engine

Abstract

The utility model discloses a crankcase of a motorcycle engine, which comprises a left crankcase body and a right crankcase body, a left crankshaft cavity is arranged on one side of the left crankcase body, a left cover cavity is arranged on the other side of the left crankcase body, a first oil through hole is arranged between the left crankshaft cavity and the left cover cavity, and an oil storage cavity is arranged at the bottom of the left crankcase body; a left crankshaft cavity is formed in one side of the left box body, a right crankshaft cavity is formed in one side of the right box body, a right cover cavity is formed in the other side of the right box body, a transmission gear cavity is formed in the same side of the left crankshaft cavity on the left box body, the transmission gear cavity and the left crankshaft cavity are arranged in a mutually separated mode, and a first oil way is arranged between the transmission gear cavity and the oil storage cavity. And a second oil through hole is formed between the transmission gear cavity and the left cover cavity. According to the scheme, the problem that the performance of an engine is reduced due to the fact that a crankcase in the prior art easily causes large rotating resistance of a crankshaft is solved.

Description

Technical Field

[0001] The utility model relates to a crankcase of a motorcycle engine. Background Art

[0002] The crankcase of a motorcycle engine is a device on the engine where a crankshaft and various speed-changing gear mechanisms are installed. The crankcase surrounds the crankshaft and various speed-changing gear mechanisms by setting a housing, and injects engine oil into the housing to lubricate each moving part to ensure the normal use of the crankcase.

[0003] Chinese Patent Document CN209040985U discloses a motorcycle crankcase device, including: a crankcase, a crankshaft, a drive gear, an oil pump and a driven gear. Among them, the crankcase is jointly formed by a right crankcase and a left crankcase. There is an oil pan in the crankcase, and the oil pan is divided into a first oil return chamber, a second oil return chamber, a third oil return chamber and a fourth oil return chamber which are communicated with each other by two partitions; the crankshaft is arranged in the crankcase, the drive gear is arranged on the crankshaft and rotates coaxially with the crankshaft; the oil pump is arranged in the crankcase; in addition, the driven gear is arranged on the oil pump and is driven by the drive gear to rotate synchronously. The horizontal height of the above-mentioned fourth oil return chamber can be lower than that of the first oil return chamber, the second oil return chamber and the third oil return chamber to ensure that the position of the oil inlet of the oil pump is at the lowest horizontal height of all the oil chambers of the oil pan. The effect of the solution of the prior art is that: the engine oil return of the oil pan first enters the first oil return chamber through a notch, then partially enters the second oil return chamber or the third oil return chamber, and finally enters the fourth oil return chamber; in addition, the oil pump has an oil inlet of the oil pump, and the oil inlet of the oil pump is located in the fourth oil return chamber. Therefore, it can be ensured that only the engine oil with fewer bubbles can reach the vicinity of the oil inlet of the oil pump and then be sucked by the oil pump, thereby improving the main oil circuit oil pressure.

[0004] In the above-mentioned solution of the prior art, the performance of the crankcase is improved by reducing the bubbles in the engine oil. However, the internal structure of the crankcase is complex, which makes the resistance of the gas flow in the crankshaft cavity relatively large, so that it is easy to cause a relatively large resistance when the crankshaft rotates, and further reduces the performance of the engine. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a crankcase of a motorcycle engine to solve the problem that the crankcase in the prior art is easy to cause a large rotation resistance of the crankshaft and reduce the performance of the engine.

[0006] To achieve the above object, the basic solution of the utility model provides a crankcase of a motorcycle engine, which includes a left box body and a right box body. A left crankshaft cavity is provided on one side of the left box body, a left cover cavity is provided on the other side of the left box body, a first oil passage hole is provided between the left crankshaft cavity and the left cover cavity, and an oil storage cavity is provided at the bottom of the left box body; a right crankshaft cavity is provided on one side of the right box body, a right cover cavity is provided on the other side of the right box body, a transmission gear cavity is provided on the same side of the left box body as the left crankshaft cavity, the transmission gear cavity and the left crankshaft cavity are separated from each other, a first oil passage is provided between the transmission gear cavity and the oil storage cavity, and a second oil passage hole is provided between the transmission gear cavity and the left cover cavity.

[0007] The beneficial effects of this basic solution are as follows: The transmission gear cavity and the left crankshaft cavity are separated, making the inner wall of the crankshaft cavity smoother, thereby reducing the air flow resistance received by the crankshaft during rotation, which is beneficial to improving the performance of the engine; at the same time, the lubrication of the transmission gear cavity will not be interfered by the components in the crankshaft cavity, which is beneficial to ensuring the lubrication effect in the transmission gear cavity.

[0008] Preferably, the position of the second oil passage hole is lower than the position of the first oil passage hole. The lubricating oil in the transmission gear cavity flows back to the left cover cavity through the second oil passage hole, and the lubricating oil in the left cover cavity flows back to the left crankshaft cavity through the first oil passage hole. Since the position of the first oil passage hole is higher than the position of the second oil passage hole, a certain amount of lubricating oil will always be retained in the transmission gear cavity, which is beneficial to ensuring the lubrication effect in the transmission gear cavity and can also prevent the lubricating oil in the transmission gear cavity from generating too much resistance to the rotation of the gear and reducing the performance of the engine.

[0009] Preferably, a main oil passage communicating with the oil storage cavity is provided on the left box body, and an oil passage for entering the crankshaft bearing and an oil passage for entering the cylinder head communicating with the main oil passage are also provided on the left box body. The main oil passage, the oil passage for entering the crankshaft bearing, and the oil passage for entering the cylinder head are located on the same plane. With such a setting, it is beneficial to shorten the running route of the lubricating oil, thereby further reducing the response time of the lubricating oil and improving the lubrication effect.

[0010] Preferably, an independent oil pump installation cavity is separated in the right cover cavity, and a third oil passage hole is communicated between the oil pump installation cavity and the right crankshaft cavity. With such a setting, the amount of lubricating oil required in the oil pump installation cavity is reduced, which is beneficial to reducing the consumption of lubricating oil; at the same time, the space between the outer periphery of the oil pump installation cavity and the inner wall of the right cover cavity does not need to be lubricated with lubricating oil, so the processing requirements for the right cover cavity are reduced, which is beneficial to reducing the manufacturing cost.

[0011] Preferably, a right partition is provided below the right crankshaft mounting hole in the right crankshaft cavity, and the third oil passage hole is located below the right partition. With such an arrangement, the oil mist in the right crankshaft cavity can better enter the oil pump mounting cavity through the third oil passage hole via the right partition, thereby improving the lubrication effect in the oil pump mounting cavity.

[0012] Preferably, an independent exhaust gas labyrinth cavity is separately provided in the left crankshaft cavity, and an oil return port is communicated between the exhaust gas labyrinth cavity and the left cover cavity. With such an arrangement, the exhaust gas in the left crankshaft cavity enters the left cover cavity through the first oil passage hole, and then enters the exhaust gas labyrinth cavity from the left cover cavity through the oil return port for oil-gas separation, which is beneficial to improving the oil-gas separation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the left housing in an embodiment of the crankcase of a motorcycle engine according to the present utility model;

[0014] Figure 2 is Figure 1 the rear view;

[0015] Figure 3 It is a schematic diagram of the right housing in an embodiment of the crankcase of a motorcycle engine according to the present utility model;

[0016] Figure 4 is Figure 3 the rear view;

[0017] Figure 5 It is a schematic diagram of the distribution of the main oil passage, the oil passage into the crankshaft bearing and the oil passage into the cylinder head in the left housing. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The following is a further detailed description through specific embodiments:

[0019] The reference numerals in the accompanying drawings of the specification include: left crankshaft cavity 1, left crankshaft mounting hole 2, left partition 3, first oil passage hole 4, oil storage cavity 5, second oil passage hole 6, first oil passage 7, transmission gear cavity 8, oil return port 9, exhaust gas labyrinth cavity 10, left cover cavity 11, right crankshaft cavity 12, right crankshaft mounting hole 13, right partition 14, third oil passage hole 15, right cover cavity 16, oil pump mounting cavity 17, main oil passage 18, oil passage into cylinder head 19, oil passage into crankshaft bearing 20.

[0020] The embodiment is basically as shown in the attached Figures 1 to 5As shown: A crankcase of a motorcycle engine includes a left case body and a right case body, and the left case body and the right case body are detachably connected by bolts. One side of the left case body is provided with a left crankshaft cavity 1; on the left case body, on the same side as the left crankshaft cavity 1, there is a transmission gear cavity 8, and the transmission gear cavity 8 and the left crankshaft cavity 1 are separated from each other; inside the left crankshaft cavity 1, an independent exhaust gas labyrinth cavity 10 is separated. In this embodiment, the exhaust gas labyrinth cavity 10 extends vertically, and the top of the exhaust gas labyrinth cavity 10 is communicated with an exhaust gas nozzle. The other side of the left case body is provided with a left cover cavity 11, and a first oil passage hole 4 is provided between the left cover cavity 11 and the left crankshaft cavity 1, so that the oil mist in the left crankshaft cavity 1 can enter the left cover cavity 11 through the first oil passage hole 4, and the lubricating oil in the left cover cavity 11 can also flow back into the left crankshaft cavity 1 through the first oil passage hole 4. There is an oil return port 9 communicated between the exhaust gas labyrinth cavity 10 and the left cover cavity 11. In this embodiment, the oil return port 9 is located at the bottom of the exhaust gas labyrinth cavity 10, and the exhaust gas in the left cover cavity 11 can enter the exhaust gas labyrinth cavity 10 through the oil return port 9 for oil-gas separation. At the same time, the lubricating oil accumulated after separation in the exhaust gas labyrinth cavity 10 will flow back into the left cover cavity 11 through the oil return port 9. Inside the left crankshaft cavity 1, a left partition plate 3 is provided below the left crankshaft mounting hole 2.

[0021] The bottom of the left case body is provided with an oil storage cavity 5 for collecting the lubricating oil flowing back from the left crankshaft cavity 1. A first oil passage 7 is provided between the transmission gear cavity 8 and the oil storage cavity 5, and by using an oil pump, the lubricating oil in the oil storage cavity 5 enters the transmission gear cavity 8 through the first oil passage 7 for lubrication. A second oil passage hole 6 is provided between the transmission gear cavity 8 and the left cover cavity 11, so that the lubricating oil in the transmission gear cavity 8 flows back into the left cover cavity 11 through the second oil passage hole 6. In this embodiment, the position of the second oil passage hole 6 is lower than the position of the first oil passage hole 4.

[0022] In this embodiment, a main oil passage 18 communicated with the oil storage cavity 5 is provided on the left case body, and an oil passage 20 for entering the crankshaft bearing and an oil passage 19 for entering the cylinder head communicated with the main oil passage 18 are also provided on the left case body. The main oil passage 18, the oil passage 20 for entering the crankshaft bearing and the oil passage 19 for entering the cylinder head are on the same plane.

[0023] One side of the right case body is provided with a right crankshaft cavity 12, the other side of the right case body is provided with a right cover cavity 16, and an independent oil pump installation cavity 17 is separated inside the right cover cavity 16. A third oil passage hole 15 is communicated between the oil pump installation cavity 17 and the right crankshaft cavity 12. Inside the right crankshaft cavity 12, a right partition plate 14 is provided below the right crankshaft mounting hole 13, and the third oil passage hole 15 is located below the right partition plate 14.

[0024] Adopting this solution reduces the air flow resistance suffered by the crankshaft during rotation, which is beneficial to improving the performance of the engine; meanwhile, the lubrication of the transmission gear chamber 8 will not be interfered by the components in the crankshaft chamber, thereby being beneficial to ensuring the lubrication effect in the transmission gear chamber 8. Moreover, the response time of the lubricating oil is faster, which is beneficial to improving the lubrication effect.

[0025] The above are only embodiments of the present utility model, and common knowledge such as specific structures and characteristics well known in the art are not described in detail herein. It should be noted that for those skilled in the art, without departing from the structure of the present utility model, several deformations and improvements can still be made, and these should also be regarded as the protection scope of the present utility model, and these will not affect the implementation effect of the present utility model and the practicability of the patent.

Claims

1. A crankcase of a motorcycle engine, comprising a left case and a right case, wherein a left crankshaft cavity is disposed on one side of the left case, a left cover cavity is disposed on the other side of the left case, a first oil hole is disposed between the left crankshaft cavity and the left cover cavity, an oil storage cavity is disposed at the bottom of the left case; a right crankshaft cavity is disposed on one side of the right case, and a right cover cavity is disposed on the other side of the right case, characterized in that: A transmission gear chamber is arranged on the left case body on the same side as the left crankshaft chamber. The transmission gear chamber and the left crankshaft chamber are separated from each other. A first oil circuit is arranged between the transmission gear chamber and the oil storage chamber. A second oil hole is arranged between the transmission gear chamber and the left cover chamber.

2. A crankcase for a motorcycle engine according to claim 1, characterized in that: The second oil hole is located at a position lower than the first oil hole.

3. A crankcase for a motorcycle engine according to claim 1 or 2, characterized in that: The left case is provided with a main oil circuit connected to the oil storage chamber, and the left case is also provided with a crankshaft bearing oil circuit and a cylinder head oil circuit connected to the main oil circuit. The main oil circuit, the crankshaft bearing oil circuit and the cylinder head oil circuit are located on the same plane.

4. A crankcase for a motorcycle engine according to claim 3, characterized in that: An independent oil pump installation cavity is separated and arranged in the right cover cavity, and a third oil through hole is connected between the oil pump installation cavity and the right crankshaft cavity.

5. A crankcase for a motorcycle engine according to claim 4, characterized in that: A right partition is arranged in the right crankshaft cavity below the right mounting hole of the crankshaft, and the third oil hole is located below the right partition.

6. A crankcase for a motorcycle engine according to claim 5, characterized in that: An independent exhaust gas labyrinth chamber is separated and arranged in the left crankshaft chamber, and an oil return port is connected between the exhaust gas labyrinth chamber and the left cover chamber.

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