Engine

Abstract

The invention discloses an engine. The engine comprises a shell, a crank connecting rod mechanism and a timing system. An accommodating space is formed in the shell; the crank connecting rod mechanism is at least partially arranged in the accommodating space; at least part of the timing system is arranged in the containing space, the timing system comprises a timing chain, and the timing chain is in transmission connection with the crank-link mechanism; the crank connecting rod mechanism comprises a crankshaft, a connecting seat and a split type balancing weight, the crankshaft is fixedly connected with the connecting seat, the split type balancing weight comprises a connecting hole and a clamping part, the connecting seat comprises a first seat body and a second seat body, the connecting hole sleeves the first seat body, and the clamping part is clamped on the second seat body, so that the split type balancing weight is detachably connected with the connecting seat. By means of the arrangement, the crank connecting rod mechanism is arranged to be of a split type structure, the mass of the crankshaft is reduced, and therefore light weight of the crankshaft can be achieved.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to an engine. Background Art

[0002] In the prior art, the engine includes a crank-connecting rod mechanism, which includes structures such as a crankshaft and a crank. The mass of the crankshaft is often proportional to the mass of the engine. When the engine is large, the crankshaft will be large, and when the engine is small, the crankshaft will be small. However, since most crankshafts require subsequent machining, in order to avoid increasing the difficulty of the crankshaft machining process, the volume and mass of the crankshaft are appropriately increased to facilitate the subsequent machining of the crankshaft. At the same time, as an important component structure of the engine, the crankshaft has a relatively high mass and volume, which leads to a relatively high mass and volume of the engine. Summary of the Invention

[0003] In order to address the deficiencies of the prior art, the present application aims to provide an engine with a crankshaft having a lighter mass and a smaller volume.

[0004] To achieve the above objectives, this application adopts the following technical solutions:

[0005] An engine includes a housing, a crank-connecting rod mechanism, and a timing system. The housing defines a housing space; the crank-connecting rod mechanism is at least partially disposed within the housing space; the timing system is at least partially disposed within the housing space, and the timing system includes a timing chain, which is drivingly connected to the crank-connecting rod mechanism. The crank-connecting rod mechanism includes a crankshaft, a connecting seat, and a split counterweight. The crankshaft is fixedly connected to the connecting seat. The split counterweight includes a connecting hole and a clamping portion. The connecting seat includes a first seat body and a second seat body. The connecting hole is sleeved on the first seat body, and the clamping portion is clamped to the second seat body to enable the split counterweight to be detachably connected to the connecting seat.

[0006] Furthermore, the crank-connecting rod mechanism also includes a timing sprocket and a drive gear, the timing sprocket and the drive gear are fixedly connected to the same end of the crankshaft, and the split counterweight is located between the timing sprocket and the drive gear.

[0007] Furthermore, a first mounting hole is provided on the split counterweight block, and a second mounting hole corresponding to the first mounting hole is provided on the connecting seat, and the first mounting hole and the second mounting hole are connected by a fastener.

[0008] Furthermore, a counterweight groove is provided on the split counterweight block, and the crank-connecting rod mechanism includes a counterweight piece, which is clamped in the counterweight groove.

[0009] Furthermore, the timing sprocket includes a timing threaded hole, and the axis of the timing threaded hole substantially coincides with the axis of the crankshaft.

[0010] Furthermore, the crank-connecting rod mechanism further includes a plurality of fixed counterweights, which are fixedly connected to the crankshaft and are substantially distributed along the axial direction of the crank-connecting rod mechanism.

[0011] Furthermore, a ratio of a maximum thickness to a minimum thickness of the fixed counterweight along the axial direction of the crank-connecting rod mechanism is greater than or equal to 3.2 and less than or equal to 4.7.

[0012] Furthermore, a ratio of a maximum thickness to a minimum thickness of the fixed counterweight along the axial direction of the crank-connecting rod mechanism is greater than or equal to 3.5 and less than or equal to 4.3.

[0013] Furthermore, the ratio of the maximum length to the minimum length of the fixed counterweight along the length direction of the engine is greater than or equal to 2.2 and less than or equal to 3.2.

[0014] Furthermore, the ratio of the maximum length to the minimum length of the fixed counterweight along the length direction of the engine is greater than or equal to 2.5 and less than or equal to 2.9.

[0015] The above-mentioned engine can set the crank-connecting rod mechanism as a split structure, which reduces the mass of the crankshaft and is conducive to achieving lightweighting of the crankshaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the overall structure of the engine provided in an embodiment of the present application.

[0017] Figure 2 This is an exploded diagram of the structure of the engine provided in an embodiment of the present application.

[0018] Figure 3 Schematic diagram of the internal structure of the engine provided in an embodiment of the present application.

[0019] Figure 4 A sectional view of the local structure of the engine provided in an embodiment of the present application.

[0020] Figure 5 Provided in the embodiments of this application Figure 3 A partial enlarged view of point A in the middle.

[0021] Figure 6 This is a left side view of the engine provided in an embodiment of the present application.

[0022] Figure 7 A partial exploded view of the crank-connecting rod mechanism of the engine provided in an embodiment of the present application.

[0023] Figure 8 A partial schematic diagram of the crank-connecting rod mechanism of the engine provided in an embodiment of the present application.

[0024] Figure 9A partial cross-sectional view of the crank-connecting rod mechanism of the engine provided in an embodiment of the present application.

[0025] Figure 10 A cross-sectional view of a cylinder head of an engine provided in an embodiment of the present application.

[0026] Figure 11 A cross-sectional view of a tensioner of an engine provided in an embodiment of the present application.

[0027] Figure 12 A schematic diagram of the connection between the crank-connecting rod mechanism and the timing system of the engine provided in an embodiment of the present application.

[0028] Figure 13 A partial cross-sectional view of a cylinder head and a cylinder head cover of an engine provided in an embodiment of the present application.

[0029] Figure 14 Provided in the embodiments of this application Figure 13 A partial enlarged view of point B in the middle.

[0030] Figure 15 A schematic diagram of the partial structure of the crankcase and water pump of the engine provided in an embodiment of the present application.

[0031] Figure 16 This is a partial structural diagram of the crankcase and water pump of the engine provided in an embodiment of the present application from another angle.

[0032] Figure 17 This is a left side view of the crankcase of the engine provided in an embodiment of the present application.

[0033] Figure 18 A partial connection diagram of the crankshaft-connecting rod mechanism and crankcase of the engine provided in an embodiment of the present application.

[0034] Figure 19 Provided in the embodiments of this application Figure 18 A partial enlarged view of point C in the middle.

[0035] Figure 20 A top view of a gasket of an engine provided in an embodiment of the present application.

[0036] Figure 21 An exploded view of the cylinder head, cylinder block and gasket of the engine provided in an embodiment of the present application.

[0037] Figure 22 A schematic diagram of the overall structure of the cylinder head of the engine provided in an embodiment of the present application.

[0038] Figure 23 A schematic diagram of the connection between the air filter and the intake assembly of the engine provided in an embodiment of the present application.

[0039] Figure 24 Provided in the embodiments of this application Figure 23 A partial enlarged view of point D in the middle.

[0040] Figure 25 A schematic diagram of the partial structure of the air intake assembly of the engine provided in an embodiment of the present application.

[0041] Figure 26 A top view of the crankcase of the engine provided in an embodiment of the present application.

[0042] Figure 27 A partial structural diagram of the crankcase and fuel injection structure of the engine provided in an embodiment of the present application.

[0043] Figure 28 Provided in the embodiments of this application Figure 27 A partial enlarged view of point E in the middle. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the specific implementation of the present application will be clearly and completely described below in conjunction with the drawings in the implementation of the present application.

[0045] like Figure 1 and Figure 2An engine 100 is shown, comprising a housing 11, a crankshaft-connecting rod mechanism 12, a timing system 13, a gear mechanism 14, and an intake mechanism 15. The housing 11 forms the basic framework of the engine 100, and defines a housing space 101 therein for housing and protecting the internal components of the engine 100. The housing 11 includes a cylinder head cover 111, a cylinder head 112, a cylinder block 113, and a crankcase 114. The housing space 101 is essentially formed by the interconnection of the cylinder head cover 111, the cylinder head 112, the cylinder block 113, and the crankcase 114. The crankshaft-connecting rod mechanism 12 is at least partially disposed within the crankcase 114 and includes a connecting rod assembly 121, which is at least partially located within the cylinder block 113. The timing system 13 is at least partially disposed within the housing space 101 and is in driving connection with the crankshaft-connecting rod mechanism 12. Specifically, the timing system 13 includes a timing ring gear 131 and a timing chain 132. The timing ring gear 131 and the timing chain 132 are meshed, and the timing ring gear 131 is connected to the crankshaft-connecting rod mechanism 12 via the timing chain 132. The intake mechanism 15 is at least partially disposed within the accommodating space 101. When the engine 100 is operating, fuel and air are mixed to form a combustible mixture, which is then delivered to the combustion chamber of the engine 100. The combustible mixture releases a large amount of heat upon combustion, rapidly increasing the pressure and temperature of the gas within the cylinder block 113, thereby driving the connecting rod assembly 121 to move. The combustion chamber of the engine 100 is formed by the bottom of the cylinder head 112 and the top of the cylinder block 113. The crankshaft-connecting rod mechanism 12 is connected to the connecting rod assembly 121. The movement of the connecting rod assembly 121 drives the crankshaft-connecting rod mechanism 12, thereby outputting power through the crankshaft-connecting rod mechanism 12. The timing system 13 is connected to the crank-connecting rod mechanism 12 through a timing chain 132. The movement of the crank-connecting rod mechanism 12 can also drive the timing system 13 to move, so that the timing system 13 can control the intake of the intake mechanism 15. In order to clearly explain the technical solution of this application, the following is also defined: Figure 1 The front, rear, left, right, top, and bottom are shown. It will be understood that in the embodiment of the present application, the front-to-back direction refers to the length direction of the engine 100, the left-to-right direction refers to the width direction of the engine 100, and the top-to-bottom direction refers to the height direction of the engine 100. Among them, the cylinder head cover 111, the cylinder head 112, the cylinder block 113, and the crankcase 114 are distributed along the top-to-bottom direction of the engine 100, with the cylinder block 113 disposed on the upper side of the crankcase 114, the cylinder head 112 disposed on the upper side of the cylinder block 113, and the cylinder head cover 111 disposed on the upper side of the cylinder head 112.

[0046] like Figures 2 to 4As shown, as an implementation, the engine 100 includes a starting device 17. The crank-connecting rod mechanism 12 is located in the accommodating space 101. The crank-connecting rod mechanism 12 includes a crankshaft 122 and a drive gear 123. The crankshaft 122 and the drive gear 123 are fixedly connected. The starting device 17 is located in the accommodating space 101 and includes a starting gear 171. The starting gear 171 is in transmission connection with the crankshaft 122. Specifically, along the width direction of the engine 100, the starting gear 171 is basically located at the left end of the crankshaft 122, and the drive gear 123 is basically located at the right end of the crankshaft 122. The crank-connecting rod mechanism 12 also includes at least one connecting rod assembly 121 in transmission connection with the crankshaft 122. The connecting rod assembly 121 is sleeved on the crankshaft 122, and the connecting rod assembly 121 is at least partially located between the drive gear 123 and the starting gear 171. Through the above arrangement, the structure among the connecting rod assembly 121 , the driving gear 123 and the starting gear 171 is more compact, thereby facilitating improvement of the structural compactness of the crank-connecting rod mechanism 12 and the starting device 17 .

[0047] In this embodiment, the distance D1 between the starting gear 171 and the drive gear 123 along the width of the engine 100 is greater than or equal to 220 mm and less than or equal to 300 mm. Furthermore, the distance D1 between the starting gear 171 and the drive gear 123 along the width of the engine 100 is greater than or equal to 230 mm and less than or equal to 360 mm. Furthermore, the distance D1 between the starting gear 171 and the drive gear 123 along the width of the engine 100 is 234 mm. This arrangement prevents the crankshaft 121 from being excessively long due to an excessively large distance D1 between the starting gear 171 and the drive gear 123, thereby preventing the crankshaft 121 from occupying a large space and thus improving the structural compactness of the engine 100. It also prevents the connecting rod assembly 121 from being too thin and having reduced strength due to an excessively small distance D1 between the starting gear 171 and the drive gear 123, thereby preventing the connecting rod assembly 121 from being too thin and having reduced strength, thereby improving the structural strength of the connecting rod assembly 121.

[0048] In this embodiment, the drive gear 123 and the starter gear 171 are arranged at both ends of the crankshaft 122 along the width direction of the engine 100. Along the width direction of the engine 100, the ratio of the maximum width W1 of the housing 11 to the displacement of the engine 100 is greater than or equal to 0.6 mm / mL and less than or equal to 1.2 mm / mL. Specifically, along the width direction of the engine 100, the ratio of the maximum width W1 of the housing 11 to the displacement of the engine 100 is greater than or equal to 0.7 mm / mL and less than or equal to 1.1 mm / mL. More specifically, along the width direction of the engine 100, the ratio of the maximum width W1 of the housing 11 to the displacement of the engine 100 is greater than or equal to 0.8 mm / mL and less than or equal to 1 mm / mL. Furthermore, the ratio of the maximum width W1 of the housing 11 to the displacement of the engine 100 is 0.85 mm / mL. Through the above-mentioned arrangement, it is possible to avoid the width of the housing 11 being too large due to the ratio of the width of the housing 11 to the displacement of the engine 100 being too large, thereby preventing the housing 11 from occupying a large space, which is beneficial to improving the space utilization of the engine 100; it is also possible to avoid the displacement of the engine 100 being too large due to the ratio of the width of the housing 11 to the displacement of the engine 100 being too small, thereby preventing the energy consumption of the engine 100 from being too high, which is beneficial to improving the energy efficiency of the engine 100.

[0049] As an implementation, starting device 17 further includes a starter 172 and a transmission member 173. Along the height direction of engine 100, starter 172 and transmission member 173 are at least partially located above starting gear 171, and starter 172 is connected to starting gear 171 via transmission member 173. Specifically, starter 172 and transmission member 173 are both located on a side away from drive gear 123, allowing starter 172 and transmission member 173 to be located close to starting gear 171. This arrangement makes the starter 172, transmission member 173, and starting gear 171 more compact, thereby facilitating improved structural compactness of starting device 17, and, in turn, improved structural compactness of engine 100.

[0050] As an implementation, the engine 100 includes a timing system 13 and a magneto 25. Both the timing system 13 and the magneto 25 are at least partially disposed in the accommodating space 101. The timing system 13 and the magneto 25 are disposed at both ends of the crankshaft 122 along the width direction of the engine 100, wherein the timing system 13 and the drive gear 123 are disposed at the same end, and the magneto 25 and the starter gear 171 are disposed at the same end. Specifically, the magneto 25 is used to provide electrical energy to the engine 100, and the timing system 13 is used to provide gas to the engine 100. Since the timing system 13 and the magneto 25 are relatively large, in this embodiment, the timing system 13 and the magneto 25 are disposed separately to avoid the timing system 13 and the magneto 25 being disposed too close to each other and occupying a large space, thereby facilitating improved space utilization of the engine 100.

[0051] As an implementation, the timing system 13 includes a timing chain 132, which is in transmission connection with the crank-connecting rod mechanism 12. Specifically, the crank-connecting rod mechanism 12 also includes a timing sprocket 124, which is fixedly connected to the crankshaft 122 and in transmission connection with the timing chain 132. The timing sprocket 124 and the drive gear 123 are arranged at the same end. Through this arrangement, the timing sprocket 124 and the crankshaft 122 are integrated, thereby facilitating the improvement of the structural strength of the timing sprocket 124 and the crankshaft 122. At the same time, the structure between the timing sprocket 124 and the drive gear 123 is more compact, thereby further facilitating the improvement of the structural compactness of the timing sprocket 124 and the drive gear 123.

[0052] As an implementation, the engine 100 further includes a speed change mechanism 18, which is at least partially disposed within the accommodation space 101. The speed change mechanism 18 includes a speed change main shaft 181 and a speed change countershaft 18a, both of which are located behind the crankshaft 122. The speed change main shaft 181 is provided with a driven gear 182 and a transmission gear 183. The driven gear 182 is in transmission connection with the drive gear 123, and the driven gear 182 and the transmission gear 183 rotate synchronously. This arrangement allows the speed change mechanism 18 to be positioned close to the crankshaft 122, thereby improving the structural compactness of the speed change mechanism 18 and the crank-connecting rod mechanism 12. Furthermore, the length of the speed change main shaft 181 along the width direction of the engine 100 can be adjusted according to the position of the crankshaft 122. Both the driven gear 182 and the transmission gear 183 are positioned away from the starter gear 171, thereby improving the center of gravity stability of the engine 100.

[0053] As an implementation, the engine 100 further includes a lubrication system 19, which is at least partially disposed within the accommodating space 101. The lubrication system 19 includes an oil pump 191, which is in transmission connection with the transmission gear 183. Specifically, along the height of the engine 100, the oil pump 191 is disposed below the transmission gear 183 and is capable of providing lubricating oil to the transmission gear 183 and the like. This arrangement allows the transmission gear 183 and the oil pump 191 to operate synchronously, allowing the oil pump 191 to promptly provide lubricating oil to the engine 100, thereby improving the lubrication performance of the lubrication system 19.

[0054] As an implementation, the engine 100 further includes a cooling system 21, which is at least partially disposed within the accommodating space 101. The cooling system 21 includes a water pump 211, which is in driving connection with the transmission gear 183. Specifically, the water pump 211 is disposed below the transmission gear 183 along the height of the engine 100. The water pump 211 can provide coolant to the transmission gear 183 and other components. This arrangement allows the transmission gear 183 and the water pump 211 to operate synchronously, allowing the water pump 211 to promptly provide coolant to the engine 100, thereby improving the cooling performance of the cooling system 21.

[0055] like Figure 5 As shown, as an implementation method, the oil pump 191 includes an oil pump shaft 1911, and the water pump 211 includes a water pump shaft 2111. The axis of the oil pump shaft 1911 basically coincides with the axis of the water pump shaft 2111. A pump body gear 1912 is also provided between the water pump 211 and the oil pump 191. The pump body gear 1912 is transmission-connected to the transmission gear 183. The pump body gear 1912 is located below the transmission gear 183. The oil pump shaft 1911 and the water pump shaft 2111 are simultaneously connected to the pump body gear 1912, so that the pump body gear 1912 can drive the oil pump shaft 1911 and the water pump shaft 2111 to achieve synchronous rotation of the oil pump shaft 1911 and the water pump shaft 2111. Through the above-mentioned arrangement, the oil pump 191 and the water pump 211 can work at the same time, which is beneficial to improving the working efficiency of the oil pump 191 and the water pump 211. At the same time, the transmission gear 183 can drive the operation of the oil pump 191 and the water pump 211 at the same time, so as to reduce the number of internal parts of the engine 100, thereby helping to improve the layout rationality and space utilization of the engine 100.

[0056] like Figure 6As shown, as an implementation method, a reference plane 106 perpendicular to the length direction of the engine 100 is defined, and the engine 100 includes a cylinder block 113, and a cylinder hole 1133 is provided in the cylinder block 113. The angle β between the axis of the cylinder hole 1133 and the reference plane 106 is greater than or equal to 15° and less than or equal to 45°. Furthermore, the angle β between the axis of the cylinder hole 1133 and the reference plane 106 is greater than or equal to 17° and less than or equal to 37°. Furthermore, the angle β between the axis of the cylinder hole 1133 and the reference plane 106 is 30°. Through the above arrangement, it is possible to avoid strong vibration of the engine 100 due to the angle β between the axis of the cylinder hole 1133 and the reference plane 106 being too large or too small, thereby improving the working stability of the engine 100. It should be noted that a connecting rod assembly 121 (see Figure 2 ), the connecting rod assembly 121 generates reciprocating motion with variable acceleration during operation, thereby generating inertial force, which in turn causes vibration of the engine 100. In this application, the angle between the axis of the cylinder bore 1133 and the reference plane 106 is adjusted to effectively improve the vibration of the engine 100. Furthermore, the power-to-weight ratio of the engine 100 in this application is much greater than that of other engines in the field. The power-to-weight ratio refers to the ratio of the maximum power of the engine 100 per unit displacement to its own mass. The power-to-weight ratio of the engine 100 in this application is 1.18.

[0057] like Figure 7As shown, as an implementation method, the crank-connecting rod mechanism 12 also includes a connecting seat 125 and a split counterweight 126, the crankshaft 122 is fixedly connected to the connecting seat 125, the split counterweight 126 includes a connecting hole 1261 and a clamping portion 1262, the connecting seat 125 includes a first seat body 1251 and a second seat body 1252, the connecting hole 1261 is sleeved on the first seat body 1251, and the clamping portion 1262 is clamped on the second seat body 1252, so that the split counterweight 126 and the connecting seat 125 can be detachably connected. Specifically, the split counterweight 126 can be connected to the crankshaft 122 via the connecting seat 125. Since the drive gear 123 is integrally formed with the crankshaft 122, the gear teeth of the drive gear 123 need to be machined. In this embodiment, the split counterweight 126 and the connecting seat 125 can be placed close to the drive gear 123. When the drive gear 123 needs to be machined, the split counterweight 126 can be removed from the connecting seat 125 to facilitate the machining of the drive gear 123, thereby improving the machining efficiency of the crankshaft 122. Furthermore, a first mounting hole 1263 is provided on the split counterweight 126, and a second mounting hole 1253 corresponding to the first mounting hole 1263 is provided on the connecting seat 125. The first mounting hole 1263 and the second mounting hole 1253 are detachably connected by fasteners, that is, the split counterweight 126 and the connecting seat 125 are detachably connected by fasteners. Specifically, the fasteners can be configured as bolts to connect the split counterweight 126 to the connecting base 125. This arrangement can increase the speed of disassembly of the split counterweight 126 and the connecting base 125, thereby facilitating improved assembly efficiency of the split counterweight 126 and the connecting base 125. It should be noted that the number of the first mounting holes 1263 and the second mounting holes 1253 can be designed as needed to improve the stability of the connection between the split counterweight 126 and the connecting base 125.

[0058] Exemplarily, the split counterweight 126 is further provided with a counterweight slot 1264, and the crank-connecting rod mechanism 12 includes a counterweight member 127, which is engaged with the counterweight slot 1264. Specifically, the counterweight slot 1264 can be configured as a circular keyway, and the counterweight member 127 can be configured as a cylinder, so that the cylinder can be tightly engaged with the circular keyway, thereby not only facilitating the connection strength between the cylinder and the circular keyway, but also facilitating the quality of the split counterweight 126 because the counterweight member 127 is configured as a metal material. Through the above configuration, the shapes of the counterweight slot 1264 and the counterweight member 127 can be configured according to actual needs, thereby facilitating the assembly performance of the counterweight slot 1264 and the counterweight member 127.

[0059] As an implementation method, the timing sprocket 124 and the drive gear 123 are located at the same end of the crankshaft 122, and the timing sprocket 124 and the drive gear 123 are both fixedly connected to the crankshaft 122, and the split counterweight 126 is located between the timing sprocket 124 and the drive gear 123. Through the above arrangement, the structure of the timing sprocket 124, the drive gear 123, and the split counterweight 126 can be made more compact, thereby facilitating improvement of the structural compactness of the timing sprocket 124, the drive gear 123, and the split counterweight 126.

[0060] In this embodiment, the timing sprocket 124 includes a timing threaded hole 1241, the central axis of which substantially coincides with the central axis of the crankshaft 122. Specifically, the timing threaded hole 1241 is machined along the axis of the crankshaft 122. When the crankshaft 122 and the timing system 13 are adjusted, the rotation angle of the crankshaft 122 can be adjusted using a fastener that cooperates with the timing threaded hole 1241, thereby improving the assembly efficiency of the crankshaft 122 and the timing system 13.

[0061] like Figure 7 and Figure 8 As shown, as an implementation, the crank-connecting rod mechanism 12 further includes a plurality of fixed counterweights 128, which are fixedly connected to the crankshaft 122 and are generally distributed along the axial direction of the crank-connecting rod mechanism 12. Specifically, the fixed counterweights 128 cooperate with the connecting rod assembly 121 to prevent vibration of the crankshaft 122, thereby improving the stability of the crankshaft 122. Both the fixed counterweights 128 and the split counterweights 126 can improve the stability of the crankshaft 122 during rotation, thereby promoting the rotational stability of the crank-connecting rod mechanism 12.

[0062] like Figure 8As shown, as an implementation, along the axial direction of the crank-connecting rod mechanism 12, the ratio of the maximum thickness W2 to the minimum thickness W3 of the fixed counterweight 128 is greater than or equal to 3.2 and less than or equal to 4.7. Specifically, along the axial direction of the crank-connecting rod mechanism 12, the ratio of the maximum thickness W2 to the minimum thickness W3 of the fixed counterweight 128 is greater than or equal to 3.5 and less than or equal to 4.3. More specifically, along the axial direction of the crank-connecting rod mechanism 12, the ratio of the maximum thickness W2 to the minimum thickness W3 of the fixed counterweight 128 is 3.9. Through the above-mentioned arrangement, it is possible to avoid the minimum thickness W3 of the fixed counterweight 128 being too small due to the ratio of the maximum thickness W2 to the minimum thickness W3 of the fixed counterweight 128 along the axial direction of the crank-connecting rod mechanism 12 being too large, so as to prevent the structural strength of the fixed counterweight 128 from being too low, thereby helping to improve the structural stability of the fixed counterweight 128; it is also possible to avoid the minimum thickness W3 of the fixed counterweight 128 being too thick due to the ratio of the maximum thickness W2 to the minimum thickness W3 of the fixed counterweight 128 along the axial direction of the crank-connecting rod mechanism 12 being too small, thereby preventing the mass of the fixed counterweight 128 from being too high, thereby helping to improve the lightweighting of the fixed counterweight 128, thereby reducing the mass and volume of the crankshaft 122 itself, and further helping to improve the lightweighting of the crankshaft 122.

[0063] like Figure 7 As Figure 9 As shown, as an implementation, along the length of the engine 100, the ratio of the maximum length L1 to the minimum length L2 of the fixed counterweight 128 is greater than or equal to 2.2 and less than or equal to 3.2. Furthermore, along the length of the engine 100, the ratio of the maximum length L1 to the minimum length L2 of the fixed counterweight 128 is greater than or equal to 2.5 and less than or equal to 2.9. Furthermore, along the length of the engine 100, the ratio of the maximum length L1 to the minimum length L2 of the fixed counterweight 128 is 2.7. Through the above-mentioned arrangement, it is possible to avoid the maximum length L1 of the fixed counterweight 128 being too large due to the ratio of the maximum length L1 to the minimum length L2 of the fixed counterweight 128 along the length direction of the engine 100 being too large, thereby preventing the fixed counterweight 128 from occupying a large space, thereby facilitating the improvement of the space utilization rate of the crank-connecting rod mechanism 12; it is also possible to avoid the minimum length L2 of the fixed counterweight 128 being too small due to the ratio of the maximum length L1 to the minimum length L2 of the fixed counterweight 128 along the length direction of the engine 100 being too small, thereby preventing the structural strength of the fixed counterweight 128 from being too low, thereby facilitating the improvement of the structural stability of the fixed counterweight 128.

[0064] like Figure 2 and Figure 10As shown, as an implementation, engine 100 includes a cylinder head 112, and a cylinder block 113 is connected to cylinder head 112. Lubrication system 19 includes a main oil gallery 192, which at least partially passes through cylinder block 113 and cylinder head 112. Main oil gallery 192 is located at least partially within cylinder head 112. Engine 100 also includes a detection mechanism 22. Timing system 13 and detection mechanism 22 are located at least partially within cylinder head 112. Detection mechanism 22 is capable of detecting oil pressure within cylinder head 112.

[0065] like Figure 10 and Figure 11 As shown, as an implementation, the timing system 13 includes a tensioning assembly 133. A tensioning hole 1121 is provided on the cylinder head 112. The tensioning assembly 133 is at least partially located in the tensioning hole 1121. An external oil groove 1331 is formed between the tensioning assembly 133 and the tensioning hole 1121. The lubrication system 19 includes a secondary oil passage 193 connected to the main oil passage 192. The secondary oil passage 193 is located in the cylinder head 112 and connected to the external oil groove 1331. Specifically, the detection mechanism 22 includes an oil pressure detector (not shown). Oil pressure detectors are provided in the main oil passage 192, the secondary oil passage 193, and the external oil groove 1331. Through the above configuration, the oil pressure detector can detect the oil pressure in the main oil gallery 192, the auxiliary oil gallery 193, and the outer oil groove 1331, thereby facilitating the dimensioning of the main oil gallery 192, the auxiliary oil gallery 193, and the outer oil groove 1331. This facilitates adjusting the oil pressure in the cylinder head 112 to ensure stable operation of the tensioner assembly 133, thereby improving the operational stability of the timing system 13. Furthermore, when the oil pressure in the main oil gallery 192, the auxiliary oil gallery 193, and the outer oil groove 1331 decreases, the tensioner assembly 133 may produce abnormal noise for a prolonged period of time, resulting in a loud noise during the startup of the engine 100. Therefore, it is necessary to detect the oil pressure detector in the oil gallery 192, the auxiliary oil gallery 193, and the outer oil groove 1331, and provide the detection data to external maintenance personnel so that the cause of the abnormal noise of the tensioner 133 can be promptly identified, thereby improving the maintenance performance of the engine 100.

[0066] As an implementation, tensioning assembly 133 is internally formed with an inner oil chamber 1332. The inner oil chamber 1332 is located within tensioning assembly 133. Tensioning assembly 133 is provided with at least two oil delivery holes 1333, which connect the outer oil groove 1331 and the inner oil chamber 1332. Specifically, the oil delivery holes 1333 can transfer oil from the outer oil groove 1331 to the inner oil chamber 1332, thereby generating oil pressure within the inner oil chamber 1332 and enabling the operation of tensioning assembly 133. This arrangement improves the operating efficiency of tensioning assembly 133. The number of oil delivery holes 1333 can be adjusted based on the detection results of detection mechanism 22 to ensure that the oil pressure within tensioning assembly 133 meets the required level. It should be noted that the faster the oil flow into the inner oil chamber 1332, the faster the tensioning assembly 133 responds, thereby increasing the operating efficiency of the timing system 13 and reducing the duration of abnormal noise from the timing chain 132 during startup.

[0067] As an implementation, the diameter of oil delivery hole 1333 is greater than or equal to 3 mm and less than or equal to 5 mm. Specifically, the diameter of oil delivery hole 1333 is greater than or equal to 3.5 mm and less than or equal to 4.5 mm. More specifically, the diameter of oil delivery hole 1333 is 4 mm. This configuration prevents a reduction in oil delivery volume from oil delivery hole 1333 due to an overly small diameter of oil delivery hole 1333, thereby preventing excessively low oil pressure in internal oil chamber 1332 and thereby improving the reaction speed of tensioning assembly 133. It also prevents a reduction in the wall thickness of tensioning assembly 133 due to an overly large diameter of oil delivery hole 1333, thereby preventing a reduction in the structural strength of tensioning assembly 133 and thereby improving the service life of tensioning assembly 133.

[0068] like Figure 1 、 Figure 11 and Figure 12 As shown, as one implementation, the timing system 13 includes a tensioning plate 134 for tensioning the timing chain 132. The timing chain 132 and tensioning plate 134 are located within the crankcase 114. The tensioning assembly 133 passes through the tensioning hole 1121 and abuts against the tensioning plate 134. Specifically, the tensioning assembly 133 includes a fixed portion 1334 and a telescopic portion 1335 that can slide within the fixed portion 1334. The fixed portion 1334 is connected to the cylinder head 112, and the telescopic portion 1335 abuts against the tensioning plate 134. This arrangement allows the oil pressure within the inner oil chamber 1332 to push the telescopic portion 1335 to move, causing the telescopic portion 1335 to move the tensioning plate 134 toward the timing chain 132, thereby tensioning the timing chain 132. This, in turn, helps reduce the duration of abnormal noise from the timing chain 132 and improves the operating efficiency of the tensioning assembly 133.

[0069] As an implementation, the tensioning assembly 133 further includes a pressure relief hole 1336, which is provided through the telescopic portion 1335 and communicates with the inner oil chamber 1332. The pressure relief hole 1336 is provided at the end of the telescopic portion 1335 that abuts the tensioning plate 134. Specifically, the pressure relief hole 1336 can maintain the oil pressure in the inner oil chamber 1332 within a stable range, thereby enabling the telescopic portion 1335 to provide a substantially constant thrust on the timing chain 132, thereby preventing the telescopic portion 1335 from causing the timing chain 132 to malfunction due to excessive thrust, thereby improving the operating stability of the timing system 13.

[0070] As an implementation, the tensioning assembly 133 includes a return spring 1337 located within the inner oil chamber 1332. The fixed portion 1334 and the telescopic portion 1335 are connected via the return spring 1337. Specifically, the return spring 1337 can maintain a substantially constant oil pressure within the inner oil chamber 1332, allowing the fixed portion 1334 and the telescopic portion 1335 to extend and retract within a certain length. This improves the fit between the fixed portion 1334 and the telescopic portion 1335, prevents the telescopic portion 1335 from detaching from the fixed portion 1334 and falling into the cylinder head 112, and further improves the service life of the cylinder head 112 and the tensioning assembly 133.

[0071] like Figure 3 、 Figure 13 and Figure 14 As an implementation method, the diameter of the auxiliary oil passage 193 is greater than or equal to 4 mm and less than or equal to 6 mm. Furthermore, the diameter of the main oil passage 192 is greater than or equal to 5 mm and less than or equal to 7 mm. Furthermore, the diameter of the main oil passage 192 is 6 mm. Through the above arrangement, it is possible to avoid the excessive volume of the main oil passage 192 due to an excessively large diameter of the main oil passage 192, thereby preventing waste of space in the cylinder head 112 and thus improving the space utilization of the cylinder head 112. It is also possible to avoid a low oil delivery volume in the main oil passage 192 due to an excessively small diameter of the main oil passage 192, thereby preventing low oil pressure in the auxiliary oil passage 193, the outer oil groove 1331, and the inner oil chamber 1332, thereby improving the oil pressure in the auxiliary oil passage 193, the outer oil groove 1331, and the inner oil chamber 1332, and at the same time improving the working efficiency of the tensioning assembly 133.

[0072] like Figure 13 and Figure 14As shown, as an implementation method, the cylinder head 112 includes an intake port 1122 and an intake seat ring 1123, one end of the intake seat ring 1123 abuts against one end of the intake port 1122 to form an intake connecting end 1124, the end of the intake connecting end 1124 close to the intake port 1122 is set as a first connecting end 1124a, and the end of the intake connecting end 1124 close to the intake seat ring 1123 is set as a second connecting end 1124b, defining a longitudinal plane 107 perpendicular to the width direction of the engine 100, the projection of the first connecting end 1124a along the width direction of the engine 100 on the longitudinal plane 107 is set as a first projection, and the projection of the second connecting end 1124b along the width direction of the engine 100 on the longitudinal plane 107 is set as a second projection, the first projection has a preset tangent at the connection between the first connecting end and the second connecting end, the second projection has a preset extension direction, and the angle between the preset tangent and the preset extension direction is greater than or equal to 0° and less than or equal to 4.9°. Specifically, the angle between the preset tangent and the preset extension direction is greater than or equal to 1° and less than or equal to 2.1°. More specifically, the angle between the preset tangent and the preset extension direction is 1.3°. Through the above-mentioned setting, it is possible to avoid the increase in the intake resistance of the second connecting end 1124b due to the excessively large angle between the preset tangent and the preset extension direction, so as to prevent the flow coefficient of the intake duct 1122 from decreasing, thereby facilitating the improvement of the intake volume of the intake duct 1122. It should be noted that when the angle between the preset tangent and the preset extension direction is equal to 0°, that is, the first connecting end 1124a and the second connecting end 1124b can achieve a smooth transition, so that the intake resistance of the intake duct 1122 is minimized, that is, the flow coefficient of the intake duct 1122 is the highest, thereby facilitating the improvement of the intake performance of the engine 100.

[0073] As an implementation, cylinder block 113 includes cylinder bore 1133, and the radius of curvature of first connection end 1124a is substantially equal to the radius of curvature of second connection end 1124b. Specifically, the radius of curvature primarily describes the degree of curvature of a curve at a particular point on the curve. This arrangement allows gas within intake duct 1122 to smoothly pass through intake connection end 1124, thereby increasing the intake volume of intake duct 1122 and enabling sufficient combustion of the gas within cylinder bore 1133, thereby improving the power performance of engine 100.

[0074] like Figure 3As shown, as an implementation, the engine 100 further includes an intake mechanism 15, which includes an intake rod 156. The intake rod 156 is at least partially located in the intake passage 1122. Specifically, the intake rod 156 is movable in the cylinder head 112. When the gas in the intake passage 1122 passes through the intake seat ring 1123 and enters the cylinder bore 1133, the intake rod 156 moves in a direction away from the intake seat ring 1123 to separate the intake rod 156 from the intake seat ring 1123, so that the gas in the intake passage 1122 can quickly enter the cylinder bore 1133. When the gas in the intake passage 1122 stops supplying gas to the cylinder bore 1133, the intake rod 156 moves in a direction close to the intake seat ring 1123 to engage with the intake seat ring 1123. Through the above arrangement, the intake seat ring 1123 is machined and cut, so that the intake rod 156 fits easily onto the machined surface of the intake seat ring 1123, thereby improving the fit between the intake seat ring 1123 and the intake rod 156. In addition, because the axis of the intake seat ring 1123 is substantially parallel to the axis of the intake rod 156, the fit between the intake rod 156 and the intake seat ring 1123 is more compact, thereby improving the structural compactness of the intake rod 156 and the intake seat ring 1123.

[0075] As an implementation, the cylinder head 112 further includes an exhaust port 1125 and an exhaust seat ring 1126. One end of the exhaust seat ring 1126 abuts against one end of the exhaust port 1125 to form an exhaust connection end 1127. The end of the exhaust connection end 1127 proximal to the exhaust port 1125 is defined as a third connection end 1127a, and the end of the exhaust connection end 1127 proximal to the exhaust seat ring 1126 is defined as a fourth connection end 1127b. The projection of the third connection end 1127a along the width direction of the engine 100 onto the longitudinal plane 107 is defined as a third projection, and the projection of the fourth connection end 1127b along the width direction of the engine 100 onto the longitudinal plane 107 is defined as a fourth projection. The third projection has a reference tangent at the junction of the third and fourth connection ends, and the second projection has a reference extension direction. The angle between the reference tangent and the reference extension direction is greater than or equal to 0° and less than or equal to 5.2°. Specifically, the angle between the reference tangent and the reference extension direction is greater than or equal to 1.5° and less than or equal to 3.5°. More specifically, the angle between the reference tangent and the reference extension direction is 2.2°. This configuration prevents an increase in exhaust resistance at fourth connection end 1127b due to an excessively large angle between the reference tangent and the reference extension direction, thereby preventing a decrease in the flow coefficient of exhaust duct 1125 and thereby facilitating an increase in exhaust volume from exhaust duct 1125. It should be noted that when the angle between the reference tangent and the reference extension direction is 0°, a smooth transition between third connection end 1127a and fourth connection end 1127b is achieved, minimizing exhaust resistance from exhaust duct 1125 and maximizing the flow coefficient of exhaust duct 1125, thereby facilitating improved exhaust performance from engine 100.

[0076] As an implementation, the radius of curvature of the third connection end 1127a is substantially equal to the radius of curvature of the fourth connection end 1127b. This configuration allows the gas within the cylinder bore 1133 to smoothly pass through the exhaust connection end 1127, thereby increasing the exhaust volume of the exhaust passage 1125 and allowing fully combusted gas within the cylinder bore 1133 to be quickly discharged, thereby improving the power performance of the engine 100.

[0077] As an implementation, the engine 100 includes an ignition mechanism 16, which extends substantially along the axis of the cylinder bore 1133. When viewed along the axis of the cylinder bore 1133, the intake duct 1122 and the exhaust duct 1125 are disposed around the ignition mechanism 16. With this arrangement, the ignition mechanism 16 is disposed at the center of the intake duct 1122 and the exhaust duct 1125, allowing the ignition mechanism 16 to ignite the gas within the cylinder block 113, thereby facilitating improved ignition efficiency of the engine 100.

[0078] As an implementation, the intake seat ring 1123 communicates with the cylinder bore 1133, and the included angle α between the axis of the cylinder bore 1133 and the axis of the intake seat ring 1123 is greater than or equal to 9° and less than or equal to 17°. Furthermore, the included angle α between the axis of the cylinder bore 1133 and the axis of the intake seat ring 1123 is greater than or equal to 11° and less than or equal to 15°. Furthermore, the included angle α between the axis of the cylinder bore 1133 and the axis of the intake seat ring 1123 is 13°. Through the above-mentioned arrangement, it is possible to avoid a low flow coefficient in the intake duct 1122 due to an excessively large angle α between the axis of the cylinder hole 1133 and the axis of the intake seat ring 1123, thereby helping to improve the flow coefficient of the intake duct 1122; it is also possible to avoid a reduction in the arrangement space of the intake rod 156 and the ignition mechanism 16 due to an excessively small angle α between the axis of the cylinder hole 1133 and the axis of the intake seat ring 1123, thereby helping to improve the rationality of the layout of the engine 100.

[0079] like Figure 6 、 Figure 13 and Figure 14 As an implementation, engine 100 includes a throttle assembly 151, which is in communication with intake duct 1122. Throttle assembly 151 is capable of injecting ambient air into intake duct 1122, which then passes through intake seat 1123 and into cylinder bore 1133. Specifically, throttle assembly 151 is disposed on the exterior of cylinder head 112 and is detachably connected thereto. This arrangement enhances the connection strength between throttle assembly 151 and cylinder head 112, thereby improving the stability of the connection between throttle assembly 151 and cylinder head 112 and, in turn, the structural strength of engine 100.

[0080] As an implementation, the aperture of the first connection end 1124a is larger than the aperture of the third connection end 1127a, and the aperture of the second connection end 1124b is larger than the aperture of the fourth connection end 1127b. This arrangement minimizes the intake resistance of the intake duct 1122 and the exhaust resistance of the exhaust duct 1125, thereby improving the flow coefficients of the intake duct 1122 and the exhaust duct 1125, and thereby enhancing the overall performance of the engine 100.

[0081] like Figure 15 and Figure 16 As shown, as one implementation, water pump 211 includes a water pump bearing 2112 and a water pump housing 2113. Water pump housing 2113 is used to protect the components of water pump 211. Water pump housing 2113 surrounds and forms a receiving space 2113a, within which water pump bearing 2112 is disposed. This improves the operating stability of water pump bearing 2112, and thereby the operating stability of water pump 211.

[0082] An oil collection structure 1143 is provided on the crankcase 114, and a flow guide structure 2114 is provided on the water pump housing 2113. The oil collection structure 1143 is positioned near the water pump 211 and extends from the crankcase 114. The flow guide structure 2114 is provided on the water pump housing 2113 and is positioned below the oil collection structure 1143. One end of the flow guide structure 2114 communicates with the outside world, while the other end communicates with the accommodating space 2112. Along the height of the engine 100, the flow guide structure 2114 and the oil collection structure 1143 at least partially overlap. This arrangement allows the oil mist within the crankcase 114 to concentrate and adhere to the oil collection structure 1143. The oil mist then splashes through the oil collection structure 1143 onto the flow guide structure 2114 and is then transported to the surface of the water pump bearing 2112 to lubricate the water pump bearing 2112, thereby improving lubricating oil utilization. In addition, the working stability of the water pump bearing 2112 is improved, thereby improving the working stability of the water pump 211. It should be noted that due to the separation of lubricating oil molecules during high-speed movement of the engine 100, a large number of fine lubricating oil droplets are released into the air, thereby forming oil mist.

[0083] Specifically, the guide structure 2114 includes a guide groove 2114a and a guide hole 2114b. One end of the guide groove 2114a is connected to the outside world, and the other end of the guide groove 2114a is connected to the guide hole 2114b. Along the height direction of the engine 100, the oil collection structure 1143 and the guide hole 2114b at least partially overlap. Through the above arrangement, the oil mist splashed from the oil collection structure 1143 to the guide groove 2114a can be transported to the guide hole 2114b through the guide groove 2114a, so that the oil mist in the guide hole 2114b can be transported to the surface of the water pump bearing 2112, which not only lubricates the water pump bearing 2112 and improves the utilization rate of the lubricating oil, but also improves the working stability of the water pump bearing 2112, thereby improving the working stability of the water pump 2111. In addition, the oil mist is not only splashed to the guide hole 2114b through the oil collecting structure 1143 and transported to the surface of the water pump bearing 2112, but can also be transported to the surface of the water pump bearing 2112 through the guide groove 2114a. The guide hole 2114b can be set as a circular hole.

[0084] More specifically, the diameter of the guide hole 2114b can be greater than or equal to 2 mm and less than or equal to 9 mm. As another implementation, the diameter of the guide hole 2114b can be greater than or equal to 3 mm and less than or equal to 8 mm. In this embodiment, the diameter of the guide hole 2114b can be greater than or equal to 4 mm and less than or equal to 7 mm. Through the above arrangement, it is possible to prevent the diameter of the guide hole 2114b from being too large, which would cause impurities other than oil mist, such as iron filings, to enter the water pump 211, thereby preventing the water pump 211 from operating unstably, thereby improving the operating stability of the water pump 211 and further improving the operating stability of the engine 100. It is also possible to prevent the diameter of the guide hole 2114b from being too small, which would cause the oil mist to be unable to be fully transported from the guide hole 2114b to the water pump bearing 2112, thereby avoiding reducing the utilization rate of the lubricating oil and further improving the utilization rate of the lubricating oil.

[0085] In this embodiment, a preset straight line 108 is defined, and the preset straight line 108 extends along the length direction of the engine 100. The width of the guide groove 2114a extending in a direction perpendicular to the preset straight line 108 is equal to the diameter of the guide hole 2114b, so that the oil mist attached to the guide groove 2114a can be splashed to the guide groove 2114a through the oil collecting structure 1143 and all the oil mist can be transported to the guide hole 2114b to improve the utilization rate of the lubricating oil.

[0086] like Figure 17 As shown, as another implementation, the oil collection structure 1143 includes an oil collection housing 1143a, an oil inlet 1143c, and an oil outlet 1143e. The oil collection housing 1143a is surrounded by a receiving space 1143b, and the oil inlet 1143c and the oil outlet 1143e are arranged within the receiving space 1143b. This allows oil mist to adhere to the inner wall of the receiving space 1143b through the oil inlet 1143c and then splash through the oil outlet 1143e to the flow guide structure 2114. The oil mist is then transported by the flow guide structure 2114 to the surface of the water pump bearing 2112 to lubricate the water pump bearing 2112, thereby improving the operating stability of the water pump bearing 2112 and the operating stability of the engine 100. Specifically, a plane perpendicular to the height of the engine 100 is defined as a first projection plane. The projection of the oil inlet 1143c along the height of the engine 100 onto the first projection plane is defined as a first projection surface. The projection of the oil outlet 1143e along the height of the engine 100 onto the first projection plane is defined as a second projection surface. The first projection surface and the second projection surface at least partially overlap, and the area of ​​the first projection surface is greater than the area of ​​the second projection surface. This arrangement increases the amount of oil mist adhering to the oil inlet 1143c, allowing the oil mist to continuously splash from the oil outlet 1143e onto the flow guide structure 2114 and then be transported to the surface of the water pump bearing 2112 to lubricate the water pump bearing 2112, thereby improving the operating stability of the water pump bearing 2112.

[0087] In this embodiment, the projection of guide hole 2114b onto the first projection plane along the height direction of engine 100 forms a third projection plane. The third projection plane at least partially overlaps with the second projection plane and is larger than the second projection plane. This arrangement reduces the loss of lubricating oil caused by splashing from the oil outlet into guide hole 2114b and prevents oil mist from oil outlet 1143e from splashing outside of guide hole 2114b, thereby improving lubricating oil utilization.

[0088] like Figure 2 and Figure 17 As shown, as another implementation, the housing 11 includes an oil pan 117, and the crankcase 114 includes a crankcase body 1144 and a crankcase side cover 1145. The crankcase body 1144 is connected to the crankcase side cover 1145, and the oil pan 117 is connected to the crankcase 114. A guide portion 1144a is provided on the crankcase body 1144, at least partially away from the crankcase side cover 1145. The guide portion 1144a connects the crankcase body 1144 and the crankcase side cover 1145, allowing oil mist within the crankcase side cover 1145 to be transported into the crankcase body 1144 through the guide portion 1144a, thereby transporting the oil mist to the oil pan 117, thereby improving the utilization rate of the lubricating oil. Specifically, the guide portion 1144a is located at the lowest end near the connection between the crankcase body 1144 and the crankcase side cover 1145. Through the above arrangement, the oil mist attached to the inner wall of the crankcase side cover 1145 slides down to the lowest point of the crankcase side cover 1145 due to gravity, so that the oil mist at the lowest point is transported to the crankcase body 1144 through the guide part 1144a and then transported to the oil pan 117, thereby improving the utilization rate of the lubricating oil.

[0089] like Figure 18 and Figure 19 As shown, as an implementation, the speed change mechanism 18 includes a transmission structure 184, and the housing 11 also includes a transmission housing 115. The transmission structure 184 is used to change the torque and speed of the engine 100 to ensure that the engine 100 always maintains an optimal operating state. The transmission structure 184 is disposed within the transmission housing 115, thereby improving the operating stability of the transmission structure 184.

[0090] A raised structure 185 is provided on the transmission housing 115. The raised structure 185 is positioned near the transmission structure 184 and extends from the transmission housing 115. The raised structure 185 is used to collect oil mist, causing it to splash onto the surface of the transmission structure 184, thereby lubricating the transmission structure 184. Along the height of the engine 100, the raised structure 185 and the transmission structure 184 at least partially overlap. When the engine 100 is operating, the oil mist attached to the raised structure 185 can be splashed onto the surface of the transmission structure 184 by gravity, thereby lubricating the transmission structure 184 and improving the operating efficiency of the transmission structure 184. Furthermore, the utilization rate of the oil mist is improved, thereby improving the utilization rate of the lubricating oil. Specifically, the raised structure 185 includes a splashing portion 1851 and a raised portion 1852. The raised portion 1852 is used to collect the oil mist from the engine 100, and the splashing portion 1851 is used to splash the oil mist attached to the raised portion 1852 onto the transmission structure 184. Raised portion 1852 is formed with a splashing portion 1851, which extends at least partially along transmission structure 184. Raised portion 1852 and splashing portion 1851 are connected. This arrangement allows oil mist adhering to raised portion 1852 and splashing portion 1851 to be splashed onto the surface of transmission structure 184 via splashing portion 1851, thereby lubricating transmission structure 184, thereby improving the operating efficiency of transmission structure 184 and, in turn, the operating efficiency of engine 100.

[0091] As an implementation method, the splash portion 1851 can be configured as a hemispherical shape. This configuration allows the oil mist attached to the protrusion 1852 and the splash portion 1851 to be transported to the lowest point of the splash portion 1851 through the spherical arc surface due to gravity, so that the oil mist concentrated in the splash portion 1851 is splashed onto the surface of the meshing portion 1843 to lubricate the meshing portion 1843, thereby improving the operating stability of the mainshaft gear 1841 and the countershaft gear 1842.

[0092] As an implementation, the raised portion 1852 is formed with a recessed portion 1853, which at least partially extends away from the transmission structure 184. The splash portion 1851 is disposed below the recessed portion 1853 and is connected to the splash portion 1851. This arrangement improves the space utilization of the raised portion 1852 and the compactness of the raised structure 185.

[0093] As an implementation method, the raised portion 1852 is further provided with guide grooves 1852b, which are connected to the splash portion 1851 and are located on both sides of the splash portion 1851. This arrangement increases the contact area of ​​the oil mist with the raised portion 1852, thereby increasing the amount of oil mist adhering to the raised portion 1852. The oil mist is transported to the splash portion 1851 through the guide grooves 1852b, where it is splashed onto the surface of the transmission structure 184, thereby improving the utilization rate of the lubricating oil. More specifically, the transmission structure 184 includes several mainshaft gears 1841 and several countershaft gears 1842. The meshing of the mainshaft gears 1841 and the countershaft gears 1842 allows the mainshaft gears 1841 and the countershaft gears 1842 to work in pairs to change torque, thereby achieving speed change. A meshing portion 1843 is formed where a main shaft gear 1841 meshes with a counter shaft gear 1842, and the number of splashing portions 1851 is the same as the number of meshing portions 1843. This arrangement allows the oil mist concentrated in the splashing portions 1851 to splash onto the meshing portions 1843 to lubricate the meshing portions 1843, thereby further lubricating the transmission structure 184, thereby improving the operating stability of the transmission structure 184 and increasing the utilization rate of the lubricating oil.

[0094] In this embodiment, a preset straight line 109 is defined, extending along the length of the transmission housing 115. Along the preset straight line 109, the meshing portion 1843 and the splashing portion 1851 at least partially overlap. Through this arrangement, oil mist adhering to the splashing portion 1851 and the raised portion 1852 can be splashed onto the surface of the meshing portion 1843 via the splashing portion 1851, thereby lubricating the meshing portion 1843 and improving the operating stability of the mainshaft gear 1841 and the countershaft gear 1842. Specifically, the splashing portion 1851 has a first end 1851a disposed away from the transmission housing 115, and the raised portion 1852 has a second end 1852a disposed closer to the transmission housing 115. The distance between the first end 1851a and the second end 1852a is a first distance L3. The length of the first distance L3 can be greater than or equal to 8 mm and less than or equal to 13 mm. Specifically, the length of the first distance L3 can be greater than or equal to 9 mm and less than or equal to 12 mm. More specifically, the length of the first distance L3 can also be greater than or equal to 10 mm and less than or equal to 11 mm. This configuration can prevent the protrusion structure 185 from being too long, which would cause interference between the protrusion structure 185 and the mainshaft gear 1841, and also prevent interference between the camshaft 135 and the countershaft gear 1842, thereby improving the working efficiency of the transmission structure 184.

[0095] like Figure 20 and Figure 21 As shown, as an implementation, the housing 11 includes a gasket 118 , which is disposed between the cylinder head 112 and the cylinder block 113 .

[0096] Specifically, gasket 118 includes a gasket body 1181 having a protrusion 1182 formed therein. Protrusion 1182 at least partially extends outward and is connected to gasket body 1181. When cylinder head 112 and cylinder block 113 are assembled, gasket 181 is positioned at the joint between cylinder head 112 and cylinder block 113. Protrusion 1182 at least partially protrudes from cylinder head 112, and protrusion 1182 at least partially protrudes from cylinder block 113. The provision of protrusion 1182 allows an operator to visually inspect whether gasket 118 is installed between cylinder head 112 and cylinder block 113, thereby improving the assembly efficiency of both cylinder head 112 and gasket 118, as well as cylinder block 113 and gasket 118.

[0097] As an implementation, the housing 11 includes a fixing member for fixingly connecting the cylinder head 112 and the cylinder block 113. The gasket body 1181 includes a through hole 1181a for passing the fixing member through, and the through hole 1181a is connected to the protrusion 1182. This arrangement allows the fixing member and the gasket body 1181 to be integrally formed, thereby preventing the protrusion 1182 from falling off the gasket body 1181 due to improper operation by the operator, such as excessive force during assembly.

[0098] Specifically, the protrusion 1182 extends at least partially along the length of the engine 100. The length of the protrusion 1182 along the length of the engine 100 is a second length L4. The length of the gasket 118 along the length of the engine 100 is a third length L5. The ratio of the second length L4 to the third length L5 is greater than or equal to 0.5 and less than or equal to 4. Specifically, the ratio of the second length L4 to the third length L5 is greater than or equal to 1 and less than or equal to 1.5. More specifically, the ratio of the second length L4 to the third length L5 is greater than or equal to 1.1 and less than or equal to 1.3. This arrangement prevents the protrusion 1182 from being too long, thereby preventing it from interfering with components of the cylinder block 113 and / or cylinder head 112, thereby improving the operating stability of the cylinder block 113 and cylinder head 112. It also prevents the protrusion 1182 from being too short, thereby preventing the operator from being able to directly observe whether the gasket 118 is installed, thereby improving the assembly efficiency of the gasket 118.

[0099] As an implementation, the protrusion 1182 extends at least partially along the width of the engine 100. The width of the protrusion 1182 along the width of the engine 100 is a first width W4. The width of the gasket 118 along the width of the engine 100 is a second width W5. The ratio of the first width W4 to the second width W5 is greater than or equal to 0.01 and less than or equal to 0.07. Specifically, the ratio of the first width W4 to the second width W5 is greater than or equal to 0.02 and less than or equal to 0.06. More specifically, the ratio of the first width W4 to the second width W5 is greater than or equal to 0.03 and less than or equal to 0.05. Through the above-mentioned arrangement, it is possible to prevent the protrusion 1182 from being too wide and causing interference between the protrusion 1182 and the cylinder block 113, and the protrusion 1182 and the cylinder head 112, thereby improving the working stability of the cylinder block 113 and the cylinder head 112; it is also possible to prevent the protrusion 1182 from being too narrow and causing the operator to be unable to directly observe whether the gasket 118 is installed, thereby improving the assembly efficiency of the gasket 118.

[0100] As an implementation method, a weight-reducing hole 1182a is further provided on the protrusion 1182, and the weight-reducing hole 1182a is connected to the protrusion 1182. Through the above-mentioned arrangement, the gasket body 1181 can be lightweight, and the cost of producing the gasket 118 is also reduced. In this embodiment, the diameter of the weight-reducing hole 1182a can be greater than or equal to 1 mm and less than or equal to 7 mm; specifically, the diameter of the weight-reducing hole 1182a can be greater than or equal to 2 mm and less than or equal to 6 mm; more specifically, the diameter of the weight-reducing hole 1182a can be greater than or equal to 3 mm and less than or equal to 5 mm. Through the above-mentioned arrangement, the weight-reducing hole 1182a can be prevented from being too large, which may lead to insufficient structural strength of the protrusion 1182, thereby improving the structural strength of the protrusion 1182.

[0101] like Figure 21 and Figure 22As shown, as an implementation, gasket 118 includes a first guide portion 1183, a second guide portion 1184, and a third guide portion 1185. The first guide portion 1183, the second guide portion 1184, and the third guide portion 1185 are used to control the flow of coolant from cylinder block 113 to cylinder head 112. The first guide portion 1183 is positioned near water outlet 1128, the second guide portion 1184 is positioned near water inlet 1134, and the third guide portion 1185 is positioned near ignition mechanism 16. The flow rate of coolant passing through first guide portion 1183 per unit time is smaller than the flow rate of coolant passing through second guide portion 1184 per unit time, and the flow rate of coolant passing through third guide portion 1185 per unit time is greater than the flow rate of coolant passing through second guide portion 1184 per unit time. More specifically, by reducing the flow rate of second guide 1184, the amount of coolant flowing from cylinder block 113 to cylinder head 112 is reduced, allowing more of the coolant originally flowing to cylinder head 112 to remain within cylinder block 113, thereby improving the cooling efficiency of the coolant. By adding third guide 1185, the coolant flow rate near ignition mechanism 16 is increased, thereby enhancing the cooling effect of ignition mechanism 16. With this arrangement, due to the reduced flow rate per unit time of first guide 1183, coolant passing through second guide 1184 enters outlet 1128 after fully cooling cylinder head 112, thereby achieving cross-flow of coolant within cylinder head 112, improving coolant utilization, and enhancing the cooling effect of cylinder head 112. Positioning third guide 1185 near ignition mechanism 16 ensures that ignition mechanism 16 is adequately cooled, maintaining the temperature within ignition mechanism 16 at its optimal operating temperature and improving its operating efficiency. In addition, the coolant flowing through the cylinder block 113 can fully cool the cylinder block 113, thereby also reducing the temperature of the cylinder block 113, so that the components on the cylinder block 113 are always maintained at the optimal operating temperature, thereby improving the working efficiency of the components on the cylinder block 113.

[0102] As an implementation, the number of first guides 1183 is smaller than the number of second guides 1184, so that the amount of coolant passing through the first guides 1183 per unit time is smaller than the amount of coolant passing through the second guides 1184 per unit time. After sufficiently cooling the cylinder head 112, the coolant passing through the second guides 1184 enters the water outlet 1128, thereby achieving cross-flow of the coolant within the cylinder head 112, thereby improving the cooling efficiency of the cylinder head 112, and improving the cooling efficiency of the cylinder block 113 and the cylinder head 112. Specifically, the gasket 118 includes an upper protrusion 1186, a lower protrusion 1187, and a recessed portion 1188. The raised portion 1186 is positioned near the water outlet 1128, the lower raised portion 1187 is positioned near the water outlet 1128, and the recessed portion 1188 is positioned near the ignition mechanism 16. The upper raised portion 1186 and the lower raised portion 1187 are connected, and the recessed portion 1188 is connected to the upper raised portion 1186. The first guide portion 1183 is positioned on the upper raised portion 1186, the second guide portion 1184 is positioned on the lower raised portion 1187, and the third guide portion 1185 is positioned on the recessed portion 1188. This arrangement allows the first guide portion 1183, the second guide portion 1184, and the third guide portion 1185 to be positioned in key areas of the cylinder water jacket 212, ensuring flow velocity in these key areas within the cylinder water jacket 212 and thereby improving the cooling efficiency of the coolant within the cylinder water jacket 212 on the cylinder block 113 and cylinder head 112. It should be noted that the key area refers to the position where the cylinder head 112 is connected and / or driven by the components on the cylinder head 112, and the position where the cylinder block 113 is connected and / or driven by the components on the cylinder block 113.

[0103] As an implementation method, the first guide portion 1183, the second guide portion 1184, and the third guide portion 1185 can be configured as a first guide hole, a second guide hole, and a third guide hole. The first guide hole, the second guide hole, and the third guide hole can be configured as circular holes. This configuration can improve the structural strength of the first guide portion 1183, the second guide hole 1184, and the third guide hole 1185, and can also reduce wear on the gasket 118 caused by excessive flow of coolant through the first guide hole, the second guide hole, and the third guide hole, thereby increasing the service life of the gasket 118. Furthermore, circular holes are easy to machine, reducing machining costs. Specifically, the diameter of the first guide hole can be greater than or equal to 2 mm and less than or equal to 3 mm. More specifically, the diameter of the first guide hole can be greater than or equal to 2.3 mm and less than or equal to 2.7 mm. In this embodiment, the diameter of the first guide hole can be 2.5 mm. Through the above-mentioned arrangement, it is possible to prevent the diameter of the first guide hole from being too large, which would result in an excessive flow of coolant passing through the first guide hole per unit time, thereby preventing the total amount of coolant in the cylinder block 113 from being reduced, thereby improving the cooling effect of the cylinder block 113; it is also possible to prevent the diameter of the first guide hole from being too large, which would result in an excessively small flow of coolant passing through the first guide hole per unit time, thereby preventing an excessive amount of coolant from being retained in the cylinder block 113, thereby improving the utilization rate of the coolant.

[0104] As another implementation, the diameter of the third guide hole can be greater than or equal to 3.2 mm and less than or equal to 4.8 mm. Specifically, the diameter of the third guide hole can be greater than or equal to 3.6 mm and less than or equal to 4.4 mm. More specifically, the diameter of the third guide hole can be greater than or equal to 3.8 mm and less than or equal to 4.1 mm. This arrangement prevents the third guide hole from being too large in diameter, which could result in insufficient strength of the recessed portion 1188, thereby improving the structural strength of the recessed portion 1188. It also prevents the third guide hole 1185a from being too small in diameter, which could result in insufficient coolant flowing through the third guide hole 1185a per unit time. This prevents insufficient coolant flowing through the ignition mechanism 16, which could increase the temperature of the ignition mechanism 16 and prevent the ignition mechanism 16 from operating in a high-temperature environment, thereby improving the operating efficiency of the ignition mechanism 16. As an implementation, a single third guide portion 1185 is provided. This arrangement improves the cooling effect of the ignition mechanism 16, ensuring that the ignition mechanism 16 is always maintained within the optimal operating temperature, thereby improving the operating efficiency of the ignition mechanism 16.

[0105] As another implementation, the number of first air guides 1183 on the upper protrusion 1186 can be set to a multiple of 2, and the first air guides 1183 are evenly distributed on the upper protrusion 1186. Through the above arrangement, each upper protrusion 1186 is provided with a first air guide 1183, so that coolant can enter the cylinder head 112 through the first air guide 1183 to fully cool the cylinder head 112, thereby improving the cooling efficiency of the cylinder head 112 and ensuring that the components on the cylinder head 112 always maintain an optimal operating temperature. Specifically, the number of first air guides 1183 is multiple, wherein the distance between two first air guides 1183 is greater than or equal to 28 mm and less than or equal to 72 mm. More specifically, the number of first air guides 1183 is multiple, wherein the distance between two first air guides 1183 is greater than or equal to 32 mm and less than or equal to 64 mm. As another implementation, there are multiple first air guides, with the distance between two first air guides being greater than or equal to 35 mm and less than or equal to 57 mm. This arrangement prevents the distance between the first air guides 1183 from being too large, thereby preventing the cylinder head 112 from being adequately cooled, thereby improving the cooling effect of the cylinder head 112. It also prevents the distance between the first air guides 1183 from being too small, thereby reducing the structural strength of the gasket 118, thereby increasing the structural strength of the gasket 118 and further improving the service life of the gasket 118.

[0106] like Figure 23 As shown, as an implementation, the engine 100 includes an air filter 23, and the air intake assembly 15 includes a first air intake pipe 157, which is at least partially disposed within the housing 11. The air filter 23 is connected to the first air intake pipe 157, allowing air to enter the air filter 23 from the first air intake pipe 157, so that the filtered air can participate in the operation of the engine 100. The air intake assembly 15 includes a second air intake pipe 158, one end of which is connected to the outside world, and the other end of which is connected to the first air intake pipe 157. Through this arrangement, external air can enter the air filter 23 through both the first air intake pipe 157 and the second air intake pipe 158, thereby adapting to the layout of the engine 100 in different environments and improving the versatility of the air filter 23. In addition, the ram air intake volume of the engine 100 is increased, and the air in the air filter 23 enters the combustion chamber through the intake manifold 15a, so that the fuel and air in the combustion chamber (not shown) are fully contacted and burned, thereby increasing the power of the engine 100 and also improving the working efficiency of the engine 100.

[0107] In this embodiment, one or more second intake pipes 158 can be provided, and the number of first intake pipes 157 and second intake pipes 158 matches the number of intake pipes. This arrangement increases the total amount of air delivered to the air filter 23, thereby maintaining an optimal air-fuel ratio within the combustion chamber and improving the operating efficiency of the engine 100. The air-fuel ratio refers to the mass ratio between air and fuel when the engine 100 is operating. The second intake pipe 158 can be cylindrical. During the layout of the engine 100, the intake assembly 15 needs to bend to accommodate different environmental configurations. Therefore, a cylindrical shape not only reduces ventilation resistance when the intake assembly 15 is bent, increases the intake volume of the intake assembly 15, but also improves the environmental adaptability of the intake assembly 15, allowing the engine 100 to be deployed in various environments. The second intake pipe 158 can be configured as a rubber or plastic tube, for example.

[0108] like Figures 23 to 25As shown, as another implementation, the air intake assembly 15 further includes a connecting structure 159, which is disposed on the first air intake pipe 157 and adjacent to the second air intake pipe 158. This arrangement allows the second air intake pipe 158 to be directly removed from the connecting structure 159 if damaged, and a new one connected to the connecting structure 159. This improves the assembly efficiency of the air intake assembly 15 and the air intake pipes. The connecting structure 159 can be cylindrical in shape. Specifically, the second air intake pipe 158 and the connecting structure 159 have an interference fit. The above arrangement improves the connection stability between the connecting structure 159 and the second intake pipe 158 and prevents air loss at the joint between the connecting structure 159 and the second intake pipe 158, thereby improving the sealing between the connecting structure 159 and the second intake pipe 158. This increases the amount of air entering the air filter 23, maintains the air-fuel ratio in the combustion chamber, and improves the operating efficiency of the engine 100. More specifically, the connecting structure 159 includes a first clamping portion 1591, and the second intake pipe 158 includes a second clamping portion 1581. The first clamping portion 1591 is located near the second intake pipe 158, while the second clamping portion 1581 is located near the connecting structure 159. The inner contour of the second clamping portion 1581 is consistent with the outer contour of the first clamping portion 1591, thereby enabling the first clamping portion 1591 and the second clamping portion 1581 to be clamped together. The above arrangement improves the connection stability between the connecting structure 159 and the second intake pipe 158, prevents air loss at the connection between the connecting structure 159 and the second intake pipe 158, increases the amount of air entering the air filter 23, and thereby increases the air content within the combustion chamber, thereby maintaining an optimal air-fuel ratio in the combustion chamber and improving the operating efficiency of the engine 100. The second clamping portion 1581 can be configured as a clamping hole, thereby reducing the number of processing and assembly steps for the second clamping portion, thereby improving the assembly efficiency of the first clamping portion 1591 and the second clamping portion 1581.

[0109] As one implementation, the connecting structure 159 is further provided with a mating portion 1592 that extends along the second air inlet pipe 158. The connecting structure 159 forms an interference fit with the second air inlet pipe 158 via the mating portion 1592. This arrangement further improves the connection stability and sealing between the connecting structure 159 and the second air inlet pipe 158. Furthermore, a limiting portion 1593 is used to prevent displacement of the second air inlet pipe 158 due to vibration caused by a large amount of air entering the second air inlet pipe 158, thereby improving the stability of the second air inlet pipe 158. As another implementation, the connecting structure 159 is further provided with a limiting portion 1593 that extends along the second air inlet pipe 158. When the second air inlet pipe 158 is assembled with the connecting structure 159, one end of the second air inlet pipe 158 abuts the limiting portion 1593. Through the above arrangement, when the connecting structure 159 and the second air intake pipe 158 need to be assembled, the setting position of the second air intake pipe 158 can be determined by the position of the limiting portion 1593, thereby improving the assembly efficiency of the connecting structure 159 and the second air intake pipe 158.

[0110] As an implementation, the connection structure 159 includes a first connection port 1594, and the second intake pipe 158 includes a second connection port 1582, which is sleeved onto the first connection port 1594. This arrangement improves the sealing performance of the first connection port 1594 and the second connection port 1582, thereby reducing air loss when air enters the connection between the connection structure 159 and the second intake pipe 158, thereby increasing the amount of air entering the air filter 23. This allows the fuel in the combustion chamber to fully contact the air for combustion, thereby improving the operating efficiency of the engine 100. It should be noted that the first connecting port 1594 is at least partially arranged in the second intake pipe 158, and the second intake pipe 158 is connected to the outside through the first intake pipe 157, so that air can enter the second intake pipe 158 through the first intake pipe 157 and then be transported to the first connecting port 1594, and then enter the first intake pipe 157 through the first connecting port 1594 and enter the air filter 23, and finally a sufficient amount of air can enter the combustion chamber to ensure the stable operation of the engine 100.

[0111] like Figure 26 and Figure 27As shown, as one implementation, engine 100 includes a lubrication system 19. The crankshaft-connecting rod mechanism 12 includes a crankshaft 122. The lubrication system 19 includes an oil injection structure 194 for transporting oil to the crankshaft 122. The crankshaft-connecting rod mechanism 12 also includes a crankshaft thrust groove 129, which is used to limit the displacement of the crankshaft 122. The oil injection structure 194 is in communication with the crankshaft thrust groove 129. This arrangement allows lubricating oil in the oil injection structure 194 to be transported to the crankshaft 122 via the crankshaft thrust groove 129, thereby lubricating the crankshaft 122 and improving the operating stability of the crankshaft 122. Specifically, engine 100 includes a housing 11, which includes a crankcase 114. The oil injection structure 194 includes an oil injection rod 1941 and an oil delivery portion 1942. The oil delivery portion 1942 is used to deliver lubricating oil to the oil injection rod 1941, which then sprays the lubricating oil onto the crankshaft 122 for lubrication. The oil injection rod 1941 is connected to the oil delivery portion 1942. The crankshaft thrust groove 129 is in communication with the oil delivery portion 1942. The crankcase 114 is provided with a mounting portion 1146. One end of the oil injection rod 1941 is positioned within the mounting portion 1146, while the other end of the oil injection rod 1941 is fixedly connected to the crankcase 114. This arrangement improves the connection stability between the oil injection rod 1941 and the crankcase 114 and allows the lubricating oil in the oil injection rod 1941 to be sprayed onto the surface of the crankshaft 122 for lubrication. This improves the operating stability of the crankshaft 122 and, consequently, the engine 100.

[0112] like Figures 26 to 28 Specifically, oil spray rod 1941 is formed around a receiving chamber 1941a for passing lubricating oil. Oil spray rod 1941 further includes an oil spray portion 1941b, one end of which communicates with the outside world, while the other end of oil spray portion 1941b communicates with receiving chamber 1941a. This arrangement allows lubricating oil in receiving chamber 1941a to be sprayed onto the surface of crankshaft 122 through oil spray portion 1941b, thereby lubricating crankshaft 122 and improving the operating stability of crankshaft 122, thereby improving the operating stability of engine 100.

[0113] As an implementation, the crankshaft 122 includes a connecting rod journal (not shown), which is at least partially disposed within the crankcase 114, defining a predetermined straight line 10a. When viewed from the predetermined straight line 10a, the oil spray portion 1941b at least partially overlaps with the connecting rod journal. This arrangement allows lubricating oil in the accommodating cavity 1941a to be sprayed directly onto the connecting rod's diameter through the oil spray portion 1941b, thereby improving lubrication at the connecting rod's diameter and thereby enhancing the operating stability of the crankshaft 122 during operation, thereby further improving the operating stability of the engine 100. More specifically, the number of oil spray portions 1941b matches the number of connecting rod journals. This arrangement allows lubricating oil in the accommodating cavity 1941a to be sprayed onto each connecting rod journal through the oil spray portion 1941b, further improving the operating stability of the crankshaft 122 during operation and, consequently, the engine 100.

[0114] In this embodiment, the diameter of the oil spray portion 1941b can be greater than or equal to 0.1 mm and less than or equal to 2 mm; specifically, the diameter of the oil spray portion 1941b is greater than or equal to 0.2 mm and less than or equal to 1.8 mm; more specifically, the diameter of the oil spray portion 1941b is greater than or equal to 0.5 mm and less than or equal to 1.3 mm. This configuration prevents the oil spray portion 1941b from being too large in diameter, which would result in excessive lubricating oil being sprayed from the oil spray portion 1941b and thus waste of lubricating oil; and prevents the oil spray portion 1941b from being too small in diameter, which would result in insufficient lubricating oil being sprayed onto the connecting rod shaft diameter and thus prevent incomplete lubrication of the connecting rod shaft diameter. This improves the operating stability of the connecting rod shaft diameter and, in turn, the operating stability of the crankshaft 122.

[0115] As an implementation, the diameter of oil delivery portion 1942 can be greater than or equal to 0.5 mm and less than or equal to 5 mm; specifically, the diameter of oil delivery portion 1942 can be greater than or equal to 1 mm and less than or equal to 4 mm; more specifically, the diameter of oil delivery portion 1942 can be greater than or equal to 2 mm and less than or equal to 3 mm. This configuration prevents oil delivery portion 1942 from being too small, which would result in insufficient lubricating oil passing through, thus preventing the lubricating oil from being unable to be transported from oil delivery portion 1942 to oil injection portion 1941b, thereby allowing lubrication of the connecting rod shaft diameter, improving the operating stability of the connecting rod shaft diameter, and thus improving the operating stability of crankshaft 122.

[0116] As an implementation, the oil delivery portion 1942 is equidistant from both ends of the oil spray rod 1941, i.e., the oil delivery portion 1942 is equidistant from both ends of the oil spray rod 1941, allowing the oil delivery portion 1942 to be positioned centrally within the oil spray rod 1941. This arrangement allows lubricating oil in the oil delivery portion 1942 to be evenly delivered to both ends of the oil spray rod 1941, thereby evenly delivering lubricating oil from the oil spray rod 1941 to each oil spray portion 1941b. Consequently, the lubricating oil in the oil spray rod 1941 is sprayed through the oil spray portions 1941b to each connecting rod journal, further improving the operating stability of the crankshaft 122 during operation and, consequently, the engine 100. The oil spray structure 194 includes a clamping portion 1943, which extends at least partially along the crankcase 114 and is used to prevent lubricating oil leakage. The crankcase 114 is provided with a mounting portion 1146 for mounting the oil injection structure 194, and the clamping portion 1943 abuts against the mounting portion 1146. Through the above arrangement, the lubricating oil in the oil injection structure 194 can be prevented from leaking through the abutment between the clamping portion 1943 and the mounting portion 1146, thereby improving the sealing between the crankcase 114 and the oil injection structure 194. In addition, the clamping portion 1943 abuts against the mounting portion 1146, and there is no need to provide an additional sealing ring, thereby simplifying the structure of the oil injection structure 194 and reducing costs. Specifically, a connecting space 1147a is formed around the mounting portion 1146, and the clamping portion 1943 is at least partially disposed in the connecting space 1147a. The inner wall of the connecting space 1147a is substantially consistent in shape with the outer edge of the clamping portion 1943. Through the above arrangement, the lubricating oil in the oil injection structure 194 can be further prevented from leaking through the abutment point between the clamping portion 1943 and the mounting portion 1146 , thereby further improving the sealing between the crankcase 114 and the oil injection structure 194 .

[0117] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the claims appended to this application.

Claims

1. An engine, comprising: a housing, wherein the housing is formed with a receiving space; a crank-connecting rod mechanism, wherein the crank-connecting rod mechanism is at least partially disposed in the accommodating space; a timing system, the timing system being at least partially disposed in the accommodation space, the timing system comprising a timing chain, the timing chain being in driving connection with the crank-connecting rod mechanism; It is characterized in that the crank-connecting rod mechanism includes a crankshaft, a connecting seat and a split counterweight block, the crankshaft is fixedly connected to the connecting seat, the split counterweight block includes a connecting hole and a clamping portion, the connecting seat includes a first seat body and a second seat body, the connecting hole is sleeved on the first seat body, and the clamping portion is clamped on the second seat body so that the split counterweight block can be detachably connected to the connecting seat.

2. The engine according to claim 1, characterized in that The crank-connecting rod mechanism further includes a timing sprocket and a driving gear. The timing sprocket and the driving gear are both fixedly connected to the same end of the crankshaft. The split counterweight is located between the timing sprocket and the driving gear.

3. The engine according to claim 2, characterized in that The split counterweight block is provided with a first mounting hole, and the connecting seat is provided with a second mounting hole corresponding to the first mounting hole, and the first mounting hole and the second mounting hole are connected by a fastener.

4. The engine according to claim 2, characterized in that The split counterweight block is further provided with a counterweight groove, and the crank-connecting rod mechanism includes a counterweight piece, which is clamped in the counterweight groove.

5. The engine according to claim 2, characterized in that The timing sprocket includes a timing threaded hole, and the central axis of the timing threaded hole substantially coincides with the central axis of the crankshaft.

6. The engine according to claim 5, characterized in that The crank-connecting rod mechanism further includes a plurality of fixed counterweight blocks, which are fixedly connected to the crankshaft and are substantially distributed along the axial direction of the crank-connecting rod mechanism.

7. The engine according to claim 6, characterized in that The ratio of the maximum thickness to the minimum thickness of the fixed counterweight along the axial direction of the crank-connecting rod mechanism is greater than or equal to 3.2 and less than or equal to 4.

7.

8. The engine according to claim 7, characterized in that The ratio of the maximum thickness to the minimum thickness of the fixed counterweight along the axial direction of the crank-connecting rod mechanism is greater than or equal to 3.5 and less than or equal to 4.

3.

9. The engine according to claim 8, characterized in that A ratio of a maximum length to a minimum length of the fixed counterweight along the length direction of the engine is greater than or equal to 2.2 and less than or equal to 3.

2.

10. The engine according to claim 8, characterized in that A ratio of a maximum length to a minimum length of the fixed counterweight along the length direction of the engine is greater than or equal to 2.5 and less than or equal to 2.9.

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