CN117989017A

CN117989017A - Engine and motorcycle

Info

Publication number: CN117989017A
Application number: CN202211348985.8A
Authority: CN
Inventors: 关力; 刘欢; 周彬; 杨景
Original assignee: Zhejiang CFMOTO Power Co Ltd
Current assignee: Zhejiang CFMOTO Power Co Ltd
Priority date: 2022-10-31
Filing date: 2022-10-31
Publication date: 2024-05-07

Abstract

The application relates to the technical field of engines, in particular to an engine and a motorcycle thereof, wherein the engine comprises a cylinder head cover, a cylinder head and an oil return structure, the oil return structure comprises an oil storage tank and an oil return channel, and the oil storage tank is integrated in the cylinder head; the oil return channel is arranged in the cylinder head cover, one end of the oil return channel is communicated with the oil-gas separation cavity, the other end of the oil return channel is communicated with the oil storage tank and is in sealing connection with the oil storage tank to form a siphon oil return structure, and an opening communicated with the oil storage tank is arranged as an oil return hole; the engine oil separated in the oil-gas separation cavity is converged into the oil storage tank through the oil return channel and the oil return hole. The oil return structure can effectively prevent engine oil from flowing back under various working conditions; and the oil return structure is arranged in the cylinder head cover and can prevent the interference of external structures, so that the problem of unstable installation is solved, the original space in the cylinder head cover is fully utilized, the occupation of the space outside the cylinder head cover is reduced, and the whole volume of the engine is reduced.

Description

Engine and motorcycle

Technical Field

The application relates to the technical field of engines, in particular to an engine and a motorcycle.

Background

At present, oil-gas separation structures are arranged in a cylinder head cover of an engine, oil gas entering the cylinder head cover is separated through the oil-gas separation structures, and separated engine oil is drained into an oil pan through an external pipeline.

However, in the existing scheme, the external pipeline is arranged outside the cylinder head cover and directly communicates the oil-gas separation structure with the oil pan, so that engine oil separated from the oil-gas separation structure is introduced into the oil pan through the external pipeline; the disadvantage of this solution is that: the hidden danger that the unstable oil leak that leads to of installation exists in external pipeline, occupation space is more, and external pipeline is longer, leads to the pressure loss increase, and the engine oil backward flow is unsmooth, leads to the engine oil backward flow even, and oil-gas separation's effect is difficult to guarantee.

Disclosure of Invention

Based on this, it is necessary to provide an engine and a motorcycle which prevent oil channeling and backflow, and which are high in stability and small in occupied space.

Aiming at the technical problems, the application provides the following technical scheme:

the utility model provides an engine, engine includes cylinder head cover, cylinder head and oil return structure, and the cylinder head cover is established on the cylinder head, and is equipped with the oil-gas separation chamber in the cylinder head cover, and oil-gas separation chamber and oil return structure intercommunication, oil return structure includes: the oil storage tank is integrated in the cylinder cover; and one part of the oil return channel is arranged in the cylinder head cover, the other part of the oil return channel is arranged in the cylinder head cover, one end of the oil return channel is communicated with the oil-gas separation cavity, the other end of the oil return channel is communicated with the oil storage tank and is in sealing connection to form a siphonic oil return structure, an opening communicated with the oil storage tank of the oil return channel is provided with an oil return hole, and engine oil separated in the oil-gas separation cavity is converged into the oil storage tank through the oil return channel and the oil return hole.

Further, along the vertical height direction of the engine, the aperture of the oil return hole is d1, and the height difference between the oil return hole and the oil storage tank is H, wherein H/d1 is 1.2< 3.3.

Further, the height difference between the oil return hole and the oil storage tank is H, and the range is 5-10mm.

Further, the oil return passage is integrally formed with the oil reservoir.

Further, the oil storage tank is cast and formed in the cylinder head cover and communicated with the oil return channel to form an integrated structure.

Further, the oil storage tank is connected with the oil return channel to form a U-shaped structure for settling impurities in the oil.

Further, the high aperture of the oil return hole is D ₁ which is larger than pi D/2, wherein D is the diameter of the oil return channel.

Further, along the vertical height direction of the engine, the distance L between the oil return port of the oil return channel and the oil-gas separation cavity and the oil return hole is greater than 4.3mm.

Further, the distance L between the oil return port of the oil return channel and the oil-gas separation cavity and the oil return hole is 60-90 mm along the vertical height direction of the engine.

Further, the engine also comprises a cylinder block and an oil pan, wherein the cylinder block is communicated with the oil pan; the oil return structure further comprises an oil return cavity, the oil return cavity is integrated in the cylinder cover and is communicated with the oil storage tank and the cylinder body, and engine oil collected in the oil storage tank overflows to the oil return cavity and flows into the cylinder body to return to the oil pan.

The application also provides another technical scheme, which comprises the following specific contents:

a motorcycle comprising an engine, the engine being any one of the above.

Compared with the prior art, the oil return structure of the engine is characterized in that the oil return structure is arranged in the cylinder head cover and comprises the oil return channel and the oil storage tank which are arranged in the cylinder head cover, the oil return channel is communicated with the oil storage tank and is in sealing connection to form a siphon structure, when engine oil is converged in the oil storage tank and the liquid level of the engine oil is higher than that of the oil return hole, the oil return hole can be effectively sealed, self sealing of the engine oil is realized, and the engine oil channeling is effectively prevented, so that the engine can effectively prevent the engine oil from flowing back under various working conditions; and the oil return structure is arranged in the cylinder head cover, so that the interference of an external structure is prevented, the problem of unstable installation is solved, the original space in the cylinder head cover is fully utilized, the occupation of the space outside the cylinder head cover can be reduced, and the whole size of the engine is reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments or the conventional techniques of the present application, the drawings required for the descriptions of the embodiments or the conventional techniques will be briefly described below, and it is apparent that the drawings in the following descriptions are only some embodiments of the present application, and other drawings may be obtained according to the drawings without inventive effort for those skilled in the art.

Fig. 1 is an exploded view of a cylinder cooling water jacket provided in an embodiment of the present application.

Fig. 2 is a top view of the cylinder cooling water jacket provided in fig. 1.

Fig. 3 is a schematic structural view of a cylinder head water jacket according to an embodiment of the present application.

Fig. 4 is a left side view of fig. 3.

Fig. 5 is a schematic structural view of a head jacket according to another embodiment of the present application.

Fig. 6 is a right side view of fig. 5.

Fig. 7 is a schematic structural view of a gasket according to an embodiment of the present application.

Fig. 8 is a schematic structural diagram of an oil return structure according to an embodiment of the present application.

Fig. 9 is a sectional view A-A of fig. 8 (vehicle normal running state).

Fig. 10 is a sectional view A-A of fig. 8 (running state when the vehicle is on an upward slope of 45 °).

Fig. 11 is a sectional view A-A of fig. 8 (running state when the vehicle is running down a slope of 45 °).

Fig. 12 is a sectional view B-B of fig. 8 (running state when the vehicle is bent by 60 ° right).

Fig. 13 is a sectional view B-B of fig. 8 (running state when the vehicle is bent left by 60 °).

Fig. 14 is a schematic view of an engine according to an embodiment of the application.

Fig. 15 is a C-C step sectional view (oil return schematic) in fig. 14.

FIG. 16 is a schematic diagram illustrating the distribution of the shaft systems inside the engine according to an embodiment of the present application.

Fig. 17 is a D-D cross-sectional view of fig. 16.

Fig. 18 is a schematic view showing a structure in which a main shaft is installed in a cylinder block according to an embodiment of the present application.

Fig. 19 is a schematic structural view of a first cylinder according to an embodiment of the present application.

Fig. 20 is a schematic view of a spindle and bearing housing assembly in an embodiment of the application.

Fig. 21 is a schematic view of a clutch gear according to an embodiment of the present application assembled to a cylinder block.

Fig. 22 is a right side view of fig. 21.

Fig. 23 is an exploded view of fig. 21.

Fig. 24 is a schematic view of a sleeve according to an embodiment of the present application.

Fig. 25 is a sectional view of the main shaft mounted in the first cylinder body through the bearing housing.

Fig. 26 is a schematic view of a bearing housing according to an embodiment of the present application.

Fig. 27 is a cross-sectional view of the bearing housing of fig. 26.

Fig. 28 is a cross-sectional view of a spindle mounted in a first cylinder through a bearing housing in another embodiment.

Fig. 29 is a schematic view of a bearing housing provided in another embodiment of the present application.

Fig. 30 is a cross-sectional view of the bearing housing of fig. 29.

Fig. 31 is a schematic view of an assembly of a clutch gear and a driving gear of an oil pump according to an embodiment of the application.

Fig. 32 is an exploded view of fig. 31.

Fig. 33 is a cross-sectional view of the clutch large gear and the oil pump driving gear assembly of fig. 31.

Fig. 34 is a schematic structural view of a camshaft according to an embodiment of the present application.

Fig. 35 is a schematic structural view of a valve train according to an embodiment of the present application.

Fig. 36 is an E-E sectional view of fig. 35.

Fig. 37 is a schematic view of a motorcycle according to an embodiment of the present application.

Reference numerals: 1000. a motorcycle; 100. an engine; 10. a body group; 11. a cylinder head cover; 12. a cylinder block; 121. a first cylinder; 1211. a first splicing surface; 122. a second cylinder; 1221. a second splicing surface; 123. a first mounting hole; 124. a second mounting hole; 1241. a first mounting groove; 1242. a second mounting groove; 125. a receiving groove; 126. a connection part; 127. a fitting hole; 128. a connecting piece; 13. a cylinder cooling water jacket; 131. an intake side; 132. an exhaust side; 133. a cylinder head water jacket; 1331. a water outlet; 1332. a shunt channel; 1333. avoidance holes; 1334. an exhaust passage; 134. a cylinder water jacket; 1341. a water inlet; 135. A sealing gasket; 1351. a first water hole; 1352. a second water hole; 1353. a third water hole; 136. a spark plug hole; 137. an oil return structure; 1371. an oil storage tank; 1372. an oil return passage; 1373. an oil return hole; 1374. an oil return cavity; 14. an oil pan; 15. a cylinder head; 20. a transmission mechanism; 21. a crankshaft; 22. a balance shaft; 23. An output gear; 24. a balance gear; 30. a speed change mechanism; 31. a main shaft; 32. a secondary shaft; 33. a variable speed drive gear; 34. a variable speed driven gear; 35. a mounting gap; 36. a bearing seat; 361. a base; 3611. a through hole; 3612. a second threaded portion; 3613. a limit part; 3614. a step surface; 362. a limiting piece; 3621. a ring structure; 3621a, a first screw portion; 3622. a limiting plate; 3622a, annular plate body; 3622b, connecting lugs; 363. a fastener; 37. a bearing; 40. a clutch; 41. a clutch gear; 411. a second positioning hole; 50. a shaft sleeve; 51. a body; 52. a clamping part; 53. an avoidance groove; 60. a lubrication system; 61. an oil pump driving gear; 611. a first positioning hole; 62. a positioning piece; 63. an oil pump gear; 70. a valve train; 71. a cam shaft; 711. an adjusting section; 712. an edge; 72. valve clearance; 200. a frame; 300. a walking system; 300a, a front wheel assembly; 300b, rear wheel assembly; 400. a suspension system.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the application, whereby the application is not limited to the specific embodiments disclosed below.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When a component is considered to be "connected" to another component, it can be directly connected to the other component or intervening components may also be present. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and the like are used in the description of the present application for the purpose of illustration only and do not represent the only embodiment.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present application, unless expressly stated or limited otherwise, a first feature "up" or "down" on a second feature may be that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through intermedial media. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely under the second feature, or simply indicating that the first feature is less level than the second feature.

Unless defined otherwise, all technical and scientific terms used in the specification of the present application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and/or" as used in the description of the present application includes any and all combinations of one or more of the associated listed items.

As shown in fig. 37, an embodiment of the present application provides a motorcycle 1000, the motorcycle 1000 including a frame 200, a traveling system 300, a suspension system 400, and an engine 100, wherein the traveling system 300 includes a front wheel assembly 300a and a rear wheel assembly 300b, and the traveling system 300 is connected to the frame 200 through the suspension system 400, and the engine 100 is used to drive the traveling system 300 to move. In the embodiment of the present application, the motorcycle 1000 may be a two-wheeled motorcycle, a three-wheeled motorcycle or a four-wheeled motorcycle.

An embodiment of the present application provides an engine 100, the engine 100 being used in a motorcycle 1000. The engine 100 is mainly composed of a block 10, a valve train 70, a transmission system, a fuel supply system, an ignition system, a cooling system, a lubrication system 60, a starting system, and the like.

As shown in fig. 14 and 16, the body group 10 includes a cylinder head cover 11, a cylinder head 15, a cylinder block 12 (i.e., crankcase), an oil pan 14, and a cylinder cooling jacket 13, the cylinder head 15 is provided to cover the cylinder block 12, the cylinder head cover 11 is provided to cover the cylinder head 15, the oil pan 14 is provided to the bottom of the cylinder block 12, for collecting engine oil flowing back inside the engine 100 and storing engine oil of the engine 100. The cylinder cooling water jacket 13 is used to cool the engine 100 and cool the engine 100.

In one embodiment, as shown in fig. 1, the cylinder cooling water jacket 13 includes a head water jacket 133 and a block water jacket 134, the head water jacket 133 being mounted within the cylinder head 15, the block water jacket 134 being mounted within the cylinder block 12. The cylinder cooling water jacket 13 is provided with a water outlet 1331, a water inlet 1341 and a cooling channel (not shown) communicating the water inlet 1341 and the water outlet 1331. Specifically, the water inlet 1341 is formed in the cylinder water jacket 134, the water outlet 1331 is formed in the cylinder water jacket 133, cooling water jackets which are mutually communicated are formed in the cylinder water jacket 134 and the cylinder water jacket 133, and cooling medium flows from the water inlet 1341 of the cylinder water jacket 134, exchanges heat through an internal cooling channel, and finally flows out of the water outlet 1331 of the cylinder water jacket 133. Of course, other cooling liquids may be used as the cooling medium.

As shown in fig. 1, along the width direction of the cylinder cooling water jacket 13, the cylinder cooling water jacket 13 has an air inlet side 131 and an air outlet side 132 which are oppositely arranged, a water outlet 1331 is arranged on the air inlet side 131 of the cylinder head water jacket 133, a water inlet 1341 is arranged on the air outlet side 132 of the cylinder body water jacket 134, compared with the technical scheme that the water outlet is arranged along the length direction of the cylinder head water jacket, the width of the whole machine is reduced, in addition, cooling medium flows in through the water inlet 1341 of the air outlet side 132, the cooling medium passes through each cylinder and is gathered to the water outlet 1331, and because the water outlet 1331 is arranged on the air inlet side 131, water flows from one side of the cylinder cooling water jacket 13 to each cylinder along the width direction and flows to the other side and is gathered to the water outlet 1331, so that the uniformity of water flow of each cylinder is improved. In addition, since the temperature of the air flow on the exhaust side 132 is generally higher, the water inlet 1341 is provided on the exhaust side 132, and the cooling medium can preferentially cool the exhaust side 132 when entering the water inlet 1341, so that the cooling effect is better, and the problem of abrasion of the seat ring caused by overheating of the exhaust side 132 is avoided. It should be noted that the arrangement is such that the pressure loss of the water flow flowing through the cylinder cooling water jacket 13 is reduced, and the smaller the pressure loss is, the smaller the flow resistance is, thereby reducing the power requirement on the water pump and reducing the equipment cost.

As shown in fig. 3, a plurality of spark plug holes 136 are provided between the intake side 131 and the exhaust side 132 of the cylinder cooling water jacket 13, and the plurality of spark plug holes 136 are provided to extend in the longitudinal direction of the cylinder cooling water jacket 13; an intake port corresponding to the spark plug 136 is provided between the spark plug 136 and the intake side 131, and an exhaust port is provided between the spark plug 136 and the exhaust side 132.

In one embodiment, the water outlet 1331 is disposed in a middle region of the air intake side 131, that is, a region near a median line along the width direction of the cylinder cooling water jacket 13, in this embodiment, as shown in fig. 3, three spark plug holes 136 are opened on the cylinder cooling water jacket 13, and the middle region is a region corresponding to the middle second spark plug hole 136. The cooling medium is discharged from the water outlets 1331 which are converged to the middle region from the positions of the cylinder cover water jacket 133, so that the flow of the cooling medium in the cylinder cover water jacket 133 is uniformly distributed.

As shown in fig. 1 and 2, a bypass passage 1332 is provided in the head jacket 133, and the bypass passage 1332 extends from the spark plug hole 136 to the exhaust side 132 in the width direction of the head jacket 133 and communicates with the cooling passage in the vicinity of the spark plug hole 136 and in the vicinity of the exhaust side 132, so that the cooling medium can flow to the exhaust side 132 through the cooling passage in the vicinity of the spark plug hole 136, enhancing the flow of the cooling medium in the exhaust side 132, and thereby enhancing the cooling of the exhaust side 132.

With continued reference to fig. 3, the intake side 131 of the cylinder head water jacket 133 is further provided with a relief hole 1333, the cylinder head 15 is fastened and mounted with the cylinder block 12 by a fastener, the relief hole 1333 is used for relieving the fastener, and the fastener can be connected with the cylinder head 15 through the relief hole 1333.

The cylinder head is usually installed to avoid the bolt of the engine 100, so that the cylinder head water jacket is provided with a avoidance position of the bolt in design, and a low point position exists between the main body of the cylinder head water jacket and the water outlet, for example, as in a position A in fig. 3, thus the air accumulation of the cylinder head water jacket 133 may occur, and the air return bubble is blocked at the low point position A, so that the problems of cavitation of the cylinder head water jacket 133 and noise increase occur. For this purpose, as shown in fig. 3 to 6, the head jacket 133 is provided with an exhaust passage 1334, the exhaust passage 1334 is inclined toward the intake side 131 along the exhaust side 132, and an end of the exhaust passage 1334 near the exhaust side 132 is lower than an end near the intake side 131 and is communicated with the cooling passage for guiding bubbles in the cooling passage, so that the bubbles are discharged out of the water outlet 1331 along the exhaust passage 1334, the low point position a is eliminated, and the accumulation of the bubbles is prevented.

In one embodiment, as shown in fig. 3 and 4, the exhaust passage 1334 is provided at an end of the head water jacket 133 along the length direction of the head water jacket 133, forming a guide slope at an edge of the head water jacket 133, and the exhaust passage 1334 is integrated on the head water jacket 133 as a part of the cooling passage. Of course, in other embodiments, the location and specific structure at which the exhaust passage 1334 is provided is not limited to that described above or shown in the drawings.

For example, as shown in fig. 5 and 6, in another embodiment, the exhaust passage 1334 is provided extending in the width direction of the head water jacket 133, and the exhaust passage 1334 communicates with the cooling passage at the plug port and the water outlet 1331, respectively, and the return oil bubbles rise from the position corresponding to the plug hole 136, so that the bubbles can be delivered to the water outlet 1331 along the exhaust passage 1334 and discharged, avoiding the bubbles from flowing to the lower point of the end of the head water jacket 133, by communicating the exhaust passage 1334 at the cooling passage portion corresponding to the plug hole 136.

As shown in fig. 1, the cylinder cooling water jacket 13 further includes a gasket 135, and the gasket 135 is disposed between the cylinder head water jacket 133 and the cylinder block water jacket 134, for ensuring sealing of the contact surface of the cylinder head water jacket 133 and the cylinder block water jacket 134, and preventing air leakage, water leakage, and oil leakage.

In this embodiment, as shown in fig. 7, a first water hole 1351 and a second water hole 1352 are formed in the sealing pad 135, wherein the first water hole 1351 is distributed on the air inlet side 131, the second water hole 1352 is distributed on the air outlet side 132, and the cooling medium is respectively fed through the first water hole 1351 and the second water hole 1352, so as to improve the cooling effect.

As shown in fig. 7, a portion of the second water holes 1352 is disposed on the exhaust side 132 near the nose bridge region, that is, near the region near the spark plug hole 136, so that the cooling medium can flow into the cooling channel at the nose bridge region through the second water holes 1352, which is beneficial to improving the cooling of the nose bridge region, and significantly improving the flow rate of the cooling medium in the region near the spark plug hole 136, which can improve the cooling uniformity of each cylinder block by more than four times, and significantly reducing the distribution of the cylinder block flow rate separation region, thereby improving the cooling effect of the engine 100.

In one embodiment, the flow rate of the cooling medium on the exhaust side 132 is greater than 1.5m/s, and the flow rate of the cooling medium on the intake side 131 is greater than 1m/s, so as to ensure uniform and timely heat exchange.

With continued reference to fig. 7, the number of the second water holes 1352 is greater than the number of the first water holes 1351, and the plurality of second water holes 1352 are arranged on the exhaust side 132 along the length direction of the cylinder water jacket 134, so as to enhance the flow of the cooling medium on the exhaust side 132, thereby enhancing the cooling effect on the exhaust side 132.

Further, in one embodiment, the ratio of the number of the first water holes 1351 to the number of the second water holes 1352 is in the range of 0.45-0.6, so as to ensure that the water flow on the exhaust side 132 is 60% -75% of the total flow, thereby avoiding the temperature rise of the air inlet side 131 while ensuring the cooling and flow performances.

In another embodiment, the second water holes 1352 have a larger aperture than the first water holes 1351, thereby increasing the flow rate of the cooling medium flowing through the exhaust side 132. Of course, in other embodiments, the apertures of the first water holes 1351 and the second water holes 1352 are not limited, and the apertures may be equal or may be set according to the flow requirements of different areas.

Further, the ratio of the pore diameter of the first water hole 1351 to the pore diameter of the second water hole 1352 is in the range of 0.4 to 0.8, for example, the pore diameter ratio of the first water hole 1351 to the second water hole 1352 is 0.4, 0.5, 0.6, 0.7, 0.8, etc. Specifically, in one embodiment, the first water holes 1351 have a diameter of 2mm to 3mm, and the corresponding second water holes 1352 have a diameter of 4mm to 5mm.

As shown in fig. 1 and 7, in an embodiment, the sealing pad 135 is further provided with a third water hole 1353, and along the length direction of the sealing pad 135, the third water hole 1353 is disposed on a side of the sealing pad 135 away from the water outlet 1331, and more cooling medium flows from the water inlet 1341 to the water outlet 1331 through the cooling channel, so that the flow rate of the cooling medium near the spark plug hole 136 of the water outlet 1331 is reduced and the flow rate is lower, therefore, by adding the third water hole 1353 to water, the flow rate and the flow rate of the cooling medium near the spark plug hole 136 are increased, so that the cooling effect of the location is effectively improved, and the overall cooling uniformity of the cylinder head 15 is balanced.

The third water holes 1353 are formed as waist holes, and the hole junction range of the third water holes 1353 is 20-48mm 2, so as to ensure the cooling effect near the spark plug holes 136.

As shown in fig. 8 and 9, an oil-gas separation chamber (not shown) is provided in the cylinder head cover 11, and the engine body group 10 further includes an oil return structure 137, where the oil return structure 137 is communicated with the lowest point of the oil-gas separation chamber, so as to prevent the separated engine oil from flowing back into the oil-gas separation chamber and prevent the oil from bouncing up.

In one embodiment, as shown in fig. 9, the oil return structure 137 includes an oil reservoir 1371 and an oil return passage 1372, the oil reservoir 1371 being integrated in the cylinder head 15 and communicating with the cylinder block 12 and the oil pan 14; one part of the oil return channel 1372 is arranged in the cylinder head 15, the other part of the oil return channel 1372 is arranged in the cylinder head cover 11, one end of the oil return channel 1372 is communicated with the oil-gas separation cavity, the other end of the oil storage groove 1371 is communicated and is in sealing connection to form a siphon oil return structure 137, and an opening of the oil return channel 1372 communicated with the oil storage groove 1371 is set to be an oil return hole 1373. Thus, the oil separated by the oil-gas separation structure is collected and flows into the oil storage tank 1371 through the oil return channel 1372, based on the siphon principle, when the collected oil is gradually increased to be filled in the oil return holes 1373 at the oil storage tank 1371 and the oil return channel 1372, self-sealing of the oil return channel 1372 can be realized, the height of the oil level S1 in the oil storage tank 1371 is ensured to be greater than or equal to the height of the oil return hole 1373 when the vehicle runs along the height direction of the cylinder head cover 11, and therefore the oil and the oil gas can be prevented from flowing into the oil-gas separation structure.

As shown in fig. 9, the oil return channel 1372 and the oil storage tank 1371 are integrally formed, so that the processing mode is simple, and the processing difficulty and the processing cost are reduced. Of course, in other embodiments, the oil return channel 1372 and the oil reservoir 1371 may be formed separately and sealed by welding or the like.

In one embodiment, the oil reservoir 1371 is formed in the cylinder head 15 by casting, and the oil return passage 1372 is formed in the cylinder head cover 11 and the cylinder head 15 by being formed in a unitary structure communicating with the oil reservoir. Of course, other forms of processing may be used to form the oil return structure 137.

As shown in fig. 9, the oil storage tank 1371 is connected with the oil return channel 1372 to form a U-shaped structure, so that the engine oil is collected in the oil storage tank 1371, so that impurities in the oil are settled in the oil storage tank 1371, and the impurities are prevented from flowing back into the cylinder block 12. Specifically, the oil storage tank 1371 is cast to form an L-shaped tank structure, and the L-shaped tank structure is communicated with the oil return channel 1372 to form a U-shaped structure, which, of course, in other embodiments, does not limit the specific structure shape of the oil return structure 137.

In one embodiment, as shown in fig. 9, the diameter D ₁ of the oil return hole 1373 is larger than pi D/2, where D is the diameter of the oil return channel 1372. It can be appreciated that if the hole diameter of the oil return hole 1373 is too large, the volume of the oil storage tank 1371 is too large, so that the occupied air drop is too large, if the hole diameter of the oil return hole 1373 is too small, the oil drainage is not smooth, and therefore, the hole diameter d ₁ of the oil return hole 1373 needs to be reasonably set to meet the effects of balanced occupied space and smooth oil drainage.

The phenomenon that oil and gas are reversed and flow to the oil-gas separation structure occurs easily when the oil and gas are reversed in the limit position of the motorcycle, so in the embodiment, in the vertical height direction along the motorcycle 1000 body, the height difference between the oil storage tank 1371 and the oil return hole 1373 is H, the ratio of H to the aperture d ₁ of the oil return hole 1373 is more than 1.2 and less than 3.3, and the condition that the oil level in the oil storage tank 1371 is higher than or equal to the height of the oil return hole 1373 in any driving state and in the limit position is ensured, thereby realizing self sealing of the oil return hole 1373 and preventing oil and gas from being reversed. For example, as shown in fig. 9 to 13, fig. 9 is a schematic view of the oil return structure 137 in a normal running state of the vehicle, and fig. 10 is a schematic view of the oil return structure 137 when the vehicle is ascending 45 °. FIG. 11 is a schematic illustration of the oil return structure 137 when the vehicle is traveling 45 ° downhill; fig. 12 is a schematic view of the oil return structure 137 when the vehicle is bent by 60 ° right; fig. 13 is a schematic view of the oil return structure 137 when the vehicle is bent by 60 ° left; in the various limit driving states shown in fig. 10 and 13, when the relation between the height of the oil return hole 1373 and the height of the oil storage groove 1371 is ensured to be met, the oil level of the oil storage groove 1371 is higher than the height of the oil return hole 1373, so that the oil return channel 1372 is always in a self-sealing state, the reverse movement of engine oil and oil gas is effectively prevented, the occupied space of the oil return structure 137 is reduced, and the requirement of light weight is met.

It should be noted that, in the limit state of the motorcycle 1000, the ratio of H/d ₁ is ensured to be in the range of 1.2 and 3.3, which means that when the aperture of the oil return hole 1373 and the groove depth of the oil storage groove 1371 are determined in the design stage, the limit state of the motorcycle 1000 is simulated, so as to determine the aperture of the oil return hole 1373 and the groove depth of the oil storage groove 1371, and the oil return structure is manufactured according to the data of the aperture and the groove depth, so that the oil and gas can be effectively prevented from flowing backwards under the limit working condition in the actual application.

In an embodiment, the height difference between the oil return hole 1373 and the oil storage groove 1371 is set to be 5-10mm, so that oil and gas can be prevented from flowing backwards at all limit positions.

In one embodiment, as shown in fig. 9, the distance L between the oil return channel 1372 and the oil-gas separation chamber is greater than 4.3mm along the vertical height direction of the engine 100, so as to ensure that the oil return channel 1372 has a sufficient height, and further increase the difficulty of oil backflow.

In one embodiment, the distance L between the oil return passage 1372 and the communication port of the oil-gas separation chamber and the oil return hole 1373 is set in the range of 60mm to 90mm in the vertical height direction of the engine 100. For example, the length L of the oil return channel 1372 is set to 60mm, 70mm, 85mm, 90mm, or the like, so that the size and the oil return height of the engine 100 can be considered, so that the engine 100 occupies a smaller volume and the oil return difficulty is higher.

As shown in fig. 14 and 15, the oil return structure 137 further includes an oil return cavity 1374, the oil return cavity 1374 is integrated in the cylinder head 15, and the oil return cavity 1374 is communicated with the oil storage tank 1371 and the cylinder body 12, the oil collected in the oil storage tank 1371 overflows to the oil return cavity 1374 and flows into the cylinder body 12 to return to the oil pan 14, in this embodiment, the original cavity in the cylinder body 12 is reused for oil return, as shown in fig. 15, the oil flows to the timing system in the cylinder body 12 through the oil return cavity 1374, and returns to the oil pan 14 through the cavity in the cylinder body 12.

As shown in fig. 16 and 17, the transmission system includes a transmission mechanism 20, the transmission mechanism 20 including a crankshaft 21 and a balance shaft 22, the crankshaft 21 and the balance shaft 22 being drivingly connected, the crankshaft 21 converting a force of the fuel gas acting on the body thereof into a torque of the crankshaft 21 to output power.

With continued reference to fig. 16 and 17, the transmission mechanism 20 further includes an output gear 23 and a balance gear 24, wherein the output gear 23 is disposed on the crankshaft 21, the balance gear 24 is disposed on the balance shaft 22, the output gear 23 is meshed with the balance gear 24, and the crankshaft 21 and the balance shaft 22 are in gear engagement transmission.

With continued reference to fig. 16 and 17, the transmission system further includes a speed change mechanism 30 and a clutch 40, the clutch 40 includes a clutch gear 41, the speed change mechanism 30 includes a main shaft 31, a countershaft 32, and a plurality of sets of speed change driving gears 33 and a plurality of sets of speed change driven gears 34, the crankshaft 21 is located between the main shaft 31 and the balance shaft 22, and the countershaft 32 is located on a side of the main shaft 31 away from the crankshaft 21; the clutch large gear 41 is provided at an end of the main shaft 31 and is capable of meshing with the output gear 23, thereby transmitting power of the crankshaft 21 to the main shaft 31; the multiple groups of variable speed driving gears 33 are arranged on the main shaft 31, the multiple groups of variable speed driven gears 34 are arranged on the auxiliary shaft 32, and when the variable speed driving gears 33 are meshed with different variable speed driven gears 34 to drive power, the rotation speed ratio of the main shaft 31 to the auxiliary shaft 32 can be changed, so that the speed change is realized.

As shown in fig. 16 and 17, the axis of the main shaft and the axis of the crankshaft define a first plane, the axis of the main shaft and the axis of the auxiliary shaft define a second plane, an included angle θ is formed between the first plane and the second plane, and 0 ° < θ <180 °, so that the main shaft is respectively offset from the crankshaft and the auxiliary shaft, thereby enabling the space along the width direction of the cylinder block 12 to be reduced, enabling the layout of each shaft to be more compact, further enabling the size of the engine 100 along the width direction of the cylinder block 12 to be smaller, and occupying less space, thereby providing more degrees of freedom for mounting each component on the motorcycle 1000.

In an embodiment, the included angle θ between the first plane and the second plane is set to be 114 ° to 124 °, and an excessively small included angle θ may cause motion interference between the main shaft 31 and the crankshaft 21, and an excessively large included angle θ may cause an excessively large occupied space for installing each shaft system, thereby causing an excessively large volume of the cylinder block 12, which violates the requirement of light weight. Therefore, the included angle θ is controlled to be 114 ° to 124 °, and the requirement of light weight is satisfied while ensuring normal movement of the crankshaft 21.

More preferably, the included angle θ between the first plane and the second plane is set to 119 °, although in other embodiments, the included angle θ may be 114 °, 115 °, 118 °, 122 °, 123 °, 124 °, and the like.

As shown in fig. 16, the axis of the auxiliary shaft 32 and the axis of the crankshaft 21 determine a third plane, and an included angle between the third plane and the first plane is α, and 19 ° < α <23 °, so that the distance between the main shaft 31 and the crankshaft 21 in the height direction is balanced, and the distance between the crankshaft 21 and the auxiliary shaft 32 in the horizontal direction is balanced, so that the dimensions of the engine in the width direction and the length direction are considered, and the requirement of light weight is considered on the premise of realizing the engine function.

Preferably, in this embodiment, the number of the balance gears 24 is one, and the output gear 23 is directly meshed with the balance gears 24 to drive the balance gears 24 to move, thereby driving the balance shaft 22 to rotate. The driving wheel and the driven wheel for driving the balance shaft 22 do not need to be specially arranged in the embodiment, so the arrangement of the embodiment reduces occupied space, simultaneously effectively reduces the weight of the engine 100, realizes the light-weight requirement and reduces carbon emission.

As shown in fig. 16, since the balance gear 24 and the clutch large gear 41 are simultaneously driven by the output gear 23 in the present embodiment, the sliding force of the meshing between the output gear 23 and the balance gear 24 is F1, the sliding force of the meshing between the output gear 23 and the clutch large gear 41 is F2, and F1 and F2 are different, and therefore the balance F1 and F2 are required at the time of setting, for this reason, in the present embodiment, the center distance L between the output gear 23 and the clutch large gear 41 is in the range of 115mm to 120mm to ensure that the sliding force F1 and the sliding force F2 meet the requirements, so that the output gear 23 can simultaneously drive the balance gear 24 and the clutch large gear 41.

As shown in fig. 16, in one embodiment, the crankshaft 21, the balance shaft 22 and the auxiliary shaft 32 are relatively flush, and the main shaft 31 is located relatively above the positioning plane, in other words, in the height direction of the motorcycle 1000, the main shaft 31 is higher than the crankshaft 21, the balance shaft 22 and the auxiliary shaft 32, and the heights of the crankshaft 21, the balance shaft 22 and the auxiliary shaft 32 are substantially the same, so as to adjust the structure of the cylinder block 12 and the layout of other internal components, and avoid the structural modification of the cylinder block 12 as much as possible.

As shown in fig. 18 and 19, the cylinder block 12 is provided with a first mounting hole 123 for supporting and positioning the main shaft 31, and a plurality of second mounting holes 124 for supporting and positioning the auxiliary shaft 32, the balance shaft 22, and the crankshaft 21, respectively. At the time of installation, the main shaft 31 is inserted into the cylinder block 12 through the first installation hole 123, and the end of the main shaft 31 is restricted in the first installation hole 123.

As shown in fig. 18 and 19, in the case where the mounting heights corresponding to the crankshaft 21, the counter shaft 32, and the balance shaft 22 are substantially the same, the cylinder block 12 includes a first cylinder block 121 and a second cylinder block 122, the first cylinder block 121 has a first mating surface 1211 thereon, and the second cylinder block 122 has a second mating surface 1221 thereon, and the first mating surface 1211 is aligned with the second mating surface 1221 so that the first cylinder block 121 and the second cylinder block 122 are mated to form the cylinder block 12. The first splicing surface 1211 is provided with a first mounting groove 1241, the second splicing surface 1221 is provided with a second mounting groove 1242, and the first mounting groove 1241 and the second mounting groove 1242 are spliced to form a second mounting hole 124 during splicing, so that the auxiliary shaft 32, the crankshaft 21 and the balance shaft 22 are arranged in the cylinder body 12 and are positioned and limited through the corresponding second mounting hole 124, the installation is simple and convenient, the arrangement scheme of the crankshaft 21, the balance shaft 22 and the auxiliary shaft 32 has less structural change on the cylinder body 12, the cylinder body 12 is divided into the first cylinder body 121 and the second cylinder body 122, the first cylinder body 121 and the second cylinder body 122 can be manufactured respectively, and the processing rate is improved. Specifically, for example, as shown in fig. 18 and 19, when the crankshaft 21 is mounted, both ends of the crankshaft 21 are respectively installed in the corresponding first mounting grooves 1241 of the first cylinder block 121, the second cylinder block 122 is covered on the first cylinder block 121, and the second mounting grooves 1242 in which the crankshaft 21 is supported are made to correspond to the corresponding first mounting grooves 1241, so that the crankshaft 21 is positioned and limited by the first mounting grooves 1241 and the second mounting grooves 1242.

As shown in fig. 18, 19 and 23, the first cylinder 121 is provided with a receiving groove 125, the first mounting hole 123 communicates with the receiving groove 125, and the clutch gear 41 is mounted in the receiving groove 125 and located at an end of the main shaft 31.

With continued reference to fig. 18 and 23, a connecting portion 126 is disposed between the accommodating groove 125 and the first mounting groove 1241, and an assembly hole 127 is formed at the connecting portion 126; the cylinder block 12 further includes a connecting member 128, and the connecting member 128 is inserted into the fitting hole 127 to connect the first cylinder block 121 and the second cylinder block 122. Specifically, the connecting member 128 is provided as a fastening structure such as a bolt or a screw, and when the first cylinder 121 is mounted, the first cylinder 122 is aligned with the second cylinder 122, and the connecting member 128 is inserted into the mounting hole 127 to fasten the first cylinder 121 and the second cylinder 122.

Referring to fig. 20 to 23, the transmission system further includes a clutch sleeve 50, the clutch 40 is sleeved on the main shaft 31, the clutch sleeve 50 is located between the main shaft 31 and the clutch 40, and the clutch sleeve 50 is used for accommodating and connecting the main shaft 31, so that the main shaft 31 stably rotates and transmitting an axial force of the main shaft 31 to the clutch 40.

With continued reference to fig. 21 to 23, since the output gear 23 of the present application drives the balance gear 24 and the clutch gear 41 at the same time, in order to ensure that the sliding force between the output gear 23 and the clutch gear 41 meets the requirement, the diameter of the clutch gear 41 is increased in this embodiment, the clutch gear 41 can be just installed in the accommodating groove 125 when installed, and due to the limitation of the cylinder block 12 structure, no movable space can be reserved between the clutch gear 41 and the accommodating groove 125, and the connection portion 126 between the clutch gear 41 and the cylinder block 12 interferes, so that the clutch gear 41 and the clutch sleeve 50 cannot be assembled into a whole when installed and then installed in the accommodating groove 125. In this embodiment, there is a mounting gap 35 between the clutch gear 41 and the main shaft 31, the mounting gap 35 is used for mounting the clutch sleeve 50, when mounting, the clutch gear 41 is first sleeved on the main shaft 31, and then the clutch gear 41 is adjusted to move radially, so that the clutch gear 41 avoids the connecting portion 126 and is smoothly mounted in the accommodating groove 125, and then the clutch sleeve 50 is mounted between the main shaft 31 and the clutch gear 41, wherein the mounting gap 35 provides a moving space for radial movement of the clutch gear 41.

If the clamping portion 52 is not present on the sleeve 50, the purpose of firstly installing the clutch gear 41 and then installing the clutch sleeve 50 cannot be achieved, and the clutch sleeve 50 and the clutch gear 41 cannot be detached respectively during the detachment, therefore, as shown in fig. 24, this embodiment provides a sleeve 50 structure, the sleeve 50 structure includes a body 51 and the clamping portion 52, and the sleeve 50 structure is installed between the assembled rotor and the rotating shaft by matching the clamping portion 52 with a clamp such as pliers when the sleeve 50 structure is installed or detached, and the sleeve 50 structure can be detached before the rotor by the clamp when the sleeve 50 structure is detached. In this embodiment, the clutch sleeve 50 is configured as the sleeve 50, during assembly, the clutch gear 41 is first mounted in the accommodating groove 125, then the clutch sleeve 50 is mounted between the clutch gear 41 and the spindle 31 by matching the clamp with the clamping portion 52, and similarly, during disassembly, in order to avoid the connecting portion 126, the clutch sleeve 50 is first disassembled by matching the clamp with the clamping portion 52, leaving the mounting gap 35 free, and then the clutch gear 41 is disassembled, so that the clutch gear 41 can adjust its position through the mounting gap 35. The clamping part 52 is arranged on the clutch shaft sleeve 50 to solve the problem of installation interference of the clutch large gear 41, and the cylinder body 12 does not need to be changed and enlarged to adapt to the change of the volume of the clutch large gear 41, so that the improvement cost is reduced, the cylinder body 12 is prevented from becoming large, and the requirement of light weight is met.

As shown in fig. 24, the clamping portion 52 is a protrusion, the protrusion is provided on the body 51, and the protrusion is provided to extend in the axial direction of the clutch collar 50, so that the clutch collar 50 can be mounted or dismounted by clamping the protrusion with pliers when the clutch collar 50 is mounted or dismounted, which is time-saving and labor-saving. Of course, in other embodiments, the specific structure of the clamping portion 52 is not limited to that described above or shown in the drawings, for example, a clamping groove may be formed on the periphery of the protruding portion, so that the pliers can be matched with the clamping groove when clamping the protruding portion, that is, at least a portion of the pliers abuts against the clamping groove to realize the limit of the pliers, so as to prevent the pliers from unstable clamping or sliding out of the pliers due to insufficient friction force when clamping the protruding portion.

With continued reference to fig. 24, the clutch shaft sleeve 50 is provided with a avoidance groove 53, and the clamping portion 52 is disposed in the avoidance groove 53, so that the clamping portion 52 can be prevented from extending out of the clutch shaft sleeve 50 to interfere with other structures to affect the installation of other structures, and the avoidance groove 53 is provided to reduce the weight of the clutch shaft sleeve 50 without affecting the rotation of the clutch gear 41, thereby realizing the light-weight requirement.

As shown in fig. 24, the number of the clamping parts 52 is two, and the two clamping parts 52 are symmetrically arranged about the axis of the clutch sleeve 50, so that the clamping parts 52 are simultaneously clamped by two pliers when the clutch sleeve 50 is mounted or dismounted, preventing the clutch sleeve 50 from tilting, and thus, the clutch sleeve 50 can be mounted and dismounted rapidly and stably. Of course, in other embodiments, the number of the clamping portions 52 provided is not limited to the above, and for example, one, three, four, and the like may be provided.

As shown in fig. 25 to 30, the transmission mechanism 20 further includes a bearing housing 36 and a bearing 37, the bearing 37 is provided in the bearing housing 36, the bearing housing 36 is provided in the first mounting hole 123, and the end portion of the main shaft 31 is mounted in the bearing 37. Wherein, bearing frame 36 is used for filling the clearance between first mounting hole 123 and bearing 37 to make main shaft 31 installation stable, avoid producing the noise. The bearing 37 is assembled with the bearing housing 36 at the time of installation, and then installed in the first installation hole 123.

As shown in fig. 25 and 30, the bearing seat 36 includes a seat body 361 and a limiting member 362, a through hole 3611 is formed in the seat body 361 along an axial direction of the seat body 361, a limiting portion 3613 extending along an inner side of the seat body 361 is provided at one end of the seat body 361 for stopping the bearing 37 mounted in the through hole 3611, a limiting member 362 is mounted at the other end of the seat body 361 for stopping the bearing 37 so as to prevent the bearing 37 from being separated from the seat body 361, and the bearing 37 is limited in the seat body 361 by a combined action of the limiting portion 3613 and the limiting member 362, so that the bearing 37 is prevented from being displaced to affect the operation of the spindle 31.

As shown in fig. 27 or 30, in one embodiment, the limiting portion 3613 is configured as a step structure, and the step structure is disposed on a side wall in the through hole 3611; the step structure has a step surface 3614, and when the step structure is installed, the bearing 37 abuts against the step surface 3614, and the bearing 37 is stopped by the step surface 3614, so that the limit of the bearing 37 is realized. Of course, in other embodiments, the specific structure of the limiting portion 3613 is not limited, for example, the limiting portion 3613 may be provided as a convex structure.

Specifically, as shown in fig. 27 or 30, the step structure is formed by punching, and through holes 3611 with different diameters are punched on the base 361, so that the step structure is formed between adjacent through holes 3611, the processing mode is simple, and the processing cost is solved. Of course, in other embodiments, a protrusion extending along the axis of the through hole 3611 may be welded to the end of the through hole 3611, by which the bearing 37 is stopped.

As shown in fig. 26 and 27, in one embodiment, the limiting member 362 is a limiting plate 3622, and the limiting plate 3622 covers an end of the base 361 away from the limiting portion 3613 to prevent the bearing 37 in the base 361 from falling out of the base 361. In other embodiments, the specific structure and mounting of the limiter 362 is not limited to that described above or shown in the figures.

For example, in another embodiment, as shown in fig. 29 and 30, the limiting member 362 is provided as an annular structure 3621, a first threaded portion 3621a is provided on the circumferential side of the annular structure 3621, a second threaded portion 3612 is provided on the side wall of the through hole 3611 of the base 361, the annular structure 3621 is installed in the through hole 3611 and is located at one end of the base 361 away from the limiting portion 3613, the first threaded portion 3621a and the second threaded portion 3612 are in threaded connection, positioning of the annular structure 3621 is achieved, at this time, the annular structure 3621 stops the bearing 37 located in the base 361, the bearing 37 is prevented from being separated from the base 361, and axial limiting of the bearing 37 is achieved by cooperation of the limiting portion 3613 and the annular structure 3621.

Specifically, the annular structure 3621 is set to be a hollow bolt, the hollow bolt is simple to manufacture and can be purchased directly, and the mould and other self-made parts are not needed, so that resources are saved, and the cost is reduced.

With continued reference to fig. 26 and 27, the bearing housing 36 further includes fasteners 363, the fasteners 363 securing the limiting plate 3622 to the housing 361. In one embodiment, the fastener 363 is a bolt, but may be other fastening structures such as a screw.

Further, as shown in fig. 27, the limiting plate 3622 includes an annular plate body 3622a and at least two connecting lugs 3622b, the inner diameter of the annular plate body 3622a is smaller than the inner diameter of the through hole 3611, so as to stop and limit the bearing 37 and prevent the bearing 37 from being separated from the through hole 3611; the connection lugs 3622b are disposed along the circumferential direction of the annular plate body 3622a for connection with the seat body 361. When the fastening member 363 is attached, the connection lug 3622b is connected to the base 361, thereby fixing the annular plate 3622 a.

As shown in fig. 26, the outer diameter of the annular plate 3622a is smaller than the outer diameter of the seat 361, so that the annular plate 3622a is prevented from protruding from the outer side wall of the seat 361 to affect the installation of the bearing seat 36, and the weight can be reduced.

In one embodiment, as shown in fig. 16 and 31 to 33, the lubrication system 60 further includes an oil pump (not shown in the drawings), an oil pump driving gear 61, and a positioning member 62, and the oil pump driving gear 61 is provided on the main shaft 31. Wherein, offer the first locating hole 611 that extends along its axial on the engine oil pump driving gear 61, offer the second locating hole 411 that extends along its axial on the clutch gear wheel 41, adjust engine oil pump driving gear 61 during the installation, so that first locating hole 611 and corresponding with second locating hole 411, locating piece 62 inserts simultaneously and locates in first locating hole 611 and the second locating hole 411, realize the location installation of engine oil pump driving gear 61, prevent engine oil pump driving gear 61 and produce circumferential rotation for clutch gear wheel 41 simultaneously, so make engine oil pump driving gear 61 and clutch gear wheel 41 synchronous motion. Compared with the mode of adopting interference fit positioning installation, the oil pump driving gear 61 is more firmly installed, the rotation displacement of the oil pump driving gear 61 is effectively prevented, and therefore the engagement of the oil pump driving gear 61 and the oil pump gear 63 is stable; compared with the installation mode of spline fit of the oil pump driving gear and the clutch gearwheel, the installation and positioning mode of the embodiment is simpler, only the first positioning hole 611 and the second positioning hole 411 are respectively formed in the oil pump driving gear 61 and the clutch gearwheel 41, and a plurality of spline teeth are not required to be machined, so that the cost is saved, and the machining efficiency is improved.

As shown in fig. 32, the positioning member 62 is a pin, which has a simple structure and low cost, however, in other embodiments, the specific structure of the positioning member 62 is not limited to the above, and for example, the positioning member 62 may be a fastening structure such as a bolt or a screw.

As shown in fig. 32, the number of the positioning members 62 is two, the two positioning members 62 are symmetrically arranged about the axis of the oil pump driving gear 61, the corresponding number of the first positioning holes 611 and the second positioning holes 411 is two, the two first positioning holes 611 are symmetrically arranged about the axis of the oil pump driving gear 61, and the two second positioning holes 411 are symmetrically arranged about the axis of the clutch gear 41, so that two-point positioning of the oil pump driving gear 61 is realized, and the positioning and limiting stability is improved. In other embodiments, the number of positioning members 62 is not limited, and for example, three or four may be provided.

As shown in fig. 15, the lubrication system 60 further includes an oil pump gear 63, the oil pump gear 63 is meshed with the oil pump driving gear 61, and the oil pump driving gear 61 transmits power to the oil pump gear 63, so as to drive the oil pump gear 63 to rotate, thereby realizing the transmission of engine oil.

In one embodiment, as shown in fig. 34 to 36, the valve train 70 mainly includes a timing gear system (not shown), a cam shaft 71, a valve train assembly including a valve and a transmission member that moves the valve, and a gap between the transmission member and the valve becomes a valve gap 72, wherein the valve includes an intake valve and an exhaust valve. The valve train 70 timely opens and closes the intake valve and the exhaust valve of each cylinder according to the working condition of the engine 100, so that the fresh mixed gas timely fills the cylinders, and the exhaust gas can be timely discharged out of the cylinders.

As shown in fig. 34, an adjusting portion 711 wound around the circumference of the camshaft 71 is disposed on the camshaft 71, the camshaft 71 can be rotated by matching an external tool with the adjusting portion 711, the camshaft 71 drives a corresponding driving member to act, after multiple adjustments are performed, the valve clearance 72 of each cylinder of the engine 100 is quickly adjusted, and the manner of rotating the camshaft 71 by the adjusting portion is more labor-saving and convenient, so that the valve clearance 72 can be quickly adjusted, and the adjusting efficiency is improved.

In one embodiment, as shown in fig. 34, the circumferential side wall of the adjusting portion 711 is provided with an edge 712, and a wrench tool is used to engage the edge 712 to rotate the cam shaft 71 quickly and in a labor-saving manner.

In an embodiment, at least four edges 712 are disposed on the circumferential outer wall of the adjusting portion 711, and the number of the edges 712 is even, so as to be matched with a conventional wrench on the market, so that the camshaft 71 is more convenient to use.

Further, the inscribed circle diameter of the adjustment portion 711 is greater than or equal to the diameter of the camshaft 71 to ensure the strength of the camshaft 71 at the position of the adjustment portion 711.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of the application should be determined from the following claims.

Claims

1. The utility model provides an engine, the engine includes cylinder head cover, cylinder head and oil return structure, the cylinder head cover is established on the cylinder head cover, just be equipped with the oil-gas separation chamber in the cylinder head cover, the oil-gas separation chamber with oil return structure intercommunication, its characterized in that, oil return structure includes:

The oil storage tank is integrated in the cylinder cover;

The oil return channel, oil return channel part is offered in the cylinder head, and another part is separately located in the cylinder head cover, oil return channel one end with oil-gas separation chamber intercommunication, oil return channel's the other end with oil storage tank intercommunication and sealing connection form the siphon oil return structure, oil return channel with the opening of oil storage tank intercommunication is established to the oil return hole, the engine oil of oil-gas separation intracavity separation is through oil return channel with the oil return hole gathers to in the oil storage tank.

2. The engine according to claim 1, wherein the oil return hole has a hole diameter d1 and a height difference from the oil reservoir is H in a vertical height direction of the engine, wherein 1.2< H/d1<3.3.

3. The engine of claim 2, wherein the oil gallery and the oil reservoir have a height difference H in the range of 5-10mm.

4. The engine of claim 1, wherein the oil return passage is integrally formed with the oil reservoir.

5. The engine of claim 1, wherein the oil reservoir is connected to the oil return passage to form a U-shaped structure for settling impurities in the oil.

6. The engine of claim 1, wherein the oil return hole has a diameter D ₁ that is greater than pi D/2, where D is the diameter of the oil return passage.

7. The engine according to claim 1, wherein a distance L between a communication port of the oil return passage and the oil-gas separation chamber and the oil return hole is greater than 4.3mm in a vertical height direction of the engine.

8. The engine according to claim 7, wherein a distance L between the oil return passage and the communication port of the oil-gas separation chamber and the oil return hole is in a range of 60mm to 90mm in a vertical height direction of the engine.

9. The engine of claim 1, further comprising a cylinder block and an oil pan, the cylinder block in communication with the oil pan;

The oil return structure further comprises an oil return cavity, the oil return cavity is integrated in the cylinder cover and is respectively communicated with the oil storage tank and the cylinder body, and engine oil collected in the oil storage tank overflows to the oil return cavity and flows into the cylinder body to return oil to the oil pan.

10. A motorcycle comprising an engine as claimed in any one of claims 1 to 9.