Engine box body and engine

Abstract

According to the engine box body and the engine, double balance shafts which are respectively arranged on the upper side and the lower side of an engine crankshaft are arranged in a crankshaft cavity, so that the vibration reduction performance of the engine is improved, and the safe and comfortable riding requirements of consumers are met; a breathing hole and a breathing pump which are communicated with the crankshaft chamber and the magneto chamber are arranged between the crankshaft chamber and the magneto chamber, so that the problem that the effect of discharging backflow lubricating oil from the crankshaft chamber by gravity caused by expansion of the crankshaft chamber is weakened is solved; by means of the structure, the oil suction port of the breathing pump can normally suck lubricating oil and waste gas from the crankshaft cavity to the magneto cavity, the air pressure in the crankshaft cavity can be balanced, the dry type crankshaft cavity characteristic that no excessive lubricating oil exists in the crankshaft cavity is kept, and meanwhile power loss caused by up-and-down movement of an engine piston due to air pressure unbalance is eliminated.

Description

Technical Field

[0001] This utility model relates to the field of motorcycle engine technology, and in particular to an engine housing and an engine. Background Technology

[0002] Motorcycle vibration is closely related to the engine. When a traditional engine is working, the high-speed reciprocating motion of the piston and the rotation of the crankshaft will generate vibration. This vibration not only damages the motorcycle's parts, but also makes it difficult to meet consumers' demands for riding comfort. Therefore, it has driven the development of engine housing structure technology.

[0003] Compared to traditional engine block structures, existing engine block structures generally house the crankshaft and a single balance shaft within the crankshaft chamber, offering some vibration damping performance. However, this is insufficient to meet the vibration damping requirements of large-displacement, high-speed engines. Consequently, some engine block structures employing a dual balance shaft design have emerged. While this design further enhances vibration damping performance, it also leads to an enlargement of the crankshaft chamber. The relative position of the breather pump's oil inlet to the crankshaft chamber becomes smaller, and the connection between the crankshaft chamber and the breather pump's oil inlet becomes relatively slower. Gravity's effect on the discharge of lubricating oil from the crankshaft chamber is weakened, causing lubricating oil to become trapped within the crankshaft chamber. The breather pump's oil inlet is unable to draw air from the magneto chamber, resulting in a pressure imbalance within the crankshaft chamber. This causes additional power loss due to the up-and-down movement of the engine pistons.

[0004] Therefore, it is necessary to improve the existing engine housing structure. In addition to having good vibration reduction performance, it is also necessary to solve the problem of the crankshaft chamber being blocked by lubricating oil due to the expansion of the crankshaft chamber. This will allow the crankshaft chamber to draw in air normally from the magneto chamber when the piston moves upward, balance the air pressure in the crankshaft chamber, eliminate the additional power loss caused by the up and down movement of the engine piston due to air pressure imbalance, and meet the safety and comfort riding needs of consumers. Utility Model Content

[0005] In view of the shortcomings of the current engine housing structure, the purpose of this utility model is to provide an engine housing and engine that, while having good vibration reduction performance, can also solve the problem of crankshaft chamber blockage caused by crankshaft chamber expansion, so that the crankshaft chamber can normally draw in air from the magneto chamber when the piston moves upward, thereby balancing the air pressure in the crankshaft chamber, eliminating the additional power loss caused by the up and down movement of the engine piston due to air pressure imbalance, and meeting the consumer's needs for safe and comfortable riding.

[0006] To achieve the purpose of this utility model, this utility model provides an engine housing, which includes a crankshaft chamber and a magneto chamber, and a vent is formed between the crankshaft chamber and the magneto chamber to connect the crankshaft chamber and the magneto chamber.

[0007] Furthermore, a balance shaft is provided in the crankshaft chamber, the balance shaft including an upper balance shaft and a lower balance shaft, the upper balance shaft and the lower balance shaft being arranged on the upper and lower sides of the engine crankshaft respectively.

[0008] Furthermore, the breather hole is located on the upper part of the engine crankshaft and is equipped with a one-way valve structure that allows the breather hole to vent one-way into the crankshaft chamber.

[0009] Furthermore, a supporting inner plate is formed on the crankshaft chamber between the crankshaft chamber and the magneto chamber. The supporting inner plate supports the balance shaft and the crankshaft, and the vent is opened on the supporting inner plate.

[0010] Furthermore, the one-way valve structure is a reed-type one-way valve, which includes a reed that can close or open the vent hole, and the reed covers the vent hole.

[0011] Furthermore, the engine housing is also equipped with a breathing pump and a main oil passage suction pump;

[0012] The breathing pump draws lubricating oil and exhaust gas from the crankshaft chamber into the magneto chamber, and the main oil passage suction pump draws lubricating oil from the magneto chamber for lubrication.

[0013] Furthermore, a housing channel is provided at the bottom of the engine housing, the housing channel having an inlet for introducing lubricating oil and an outlet connected to the oil suction port of the breathing pump.

[0014] Furthermore, the reed closes the breather hole when the piston moves downward, and the crankshaft chamber is under positive pressure. The lubricating oil and exhaust gas in the crankshaft chamber are introduced to the oil inlet of the breather pump through the housing channel, and then sucked into the magneto chamber by the breather pump.

[0015] When the piston moves upward, the reed opens the vent due to the negative pressure in the crankshaft chamber, and air from the magneto chamber is introduced into the crankshaft chamber through the vent.

[0016] Furthermore, the crankshaft chamber is a dry crankshaft chamber, and the breather hole is located between the crankshaft and the upper balance shaft.

[0017] The engine of this utility model includes the aforementioned engine housing.

[0018] The beneficial effects of this utility model are as follows: This utility model provides an engine housing and engine, in which dual balance shafts are arranged on the upper and lower sides of the engine crankshaft within the crankshaft chamber, improving the engine's vibration damping performance and meeting consumers' needs for safe and comfortable riding. Furthermore, a breather hole and a breather pump are provided between the crankshaft chamber and the magneto chamber, connecting the two chambers. This solves the problem of reduced gravity's effect on the discharge of lubricating oil from the crankshaft chamber due to the expansion of the crankshaft chamber. This allows the breather pump's suction port to normally draw lubricating oil and exhaust gas from the crankshaft chamber to the magneto chamber, and also balances the air pressure within the crankshaft chamber. This maintains the dry crankshaft chamber characteristics of having minimal lubricating oil, while also eliminating power loss caused by the up-and-down movement of the engine piston due to air pressure imbalance. Attached Figure Description

[0019] Figure 1 This is a longitudinal sectional view of the engine housing of this utility model;

[0020] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0021] Figure 3 This is a side view of the engine housing when the piston is moving upwards;

[0022] Figure 4 This is a side view of the engine housing when the piston is moving downwards;

[0023] Figure 5 This is a schematic diagram of the structure where the magneto chamber is exchanged with the outside air.

[0024] Explanation of reference numerals in the attached drawings: 1. Engine housing; 101. Breathing port; 1011. Reed-type one-way valve; 10111. Reed; 102. Housing passage; 103. Support inner plate; 2. Crankshaft chamber; 3. Magneto chamber; 301. Labyrinth-shaped ventilation duct; 302. Exhaust nozzle; 4. Upper balance shaft; 5. Lower balance shaft; 6. Oil suction pump; 601. Breathing pump; 602. Main oil passage oil suction pump; 7. Magneto; 8. Crankshaft. Detailed Implementation

[0025] The following is in conjunction with the appendix Figure 1-5 The present invention will be described in further detail below.

[0026] This utility model discloses an engine housing 1, which includes a crankshaft chamber 2 and a magneto chamber 3. A vent 101 is formed between the crankshaft chamber 2 and the magneto chamber 3, connecting them. The crankshaft chamber 2 is used to receive and temporarily store lubricating oil. During engine operation, components such as the crankshaft 8 and connecting rods are in a state of high-speed movement and mutual friction. The lubricating oil in the crankshaft chamber 2 is transported to the magneto chamber 3 through the housing channel 102. Since the engine generates a large amount of heat during operation, the lubricating oil in the crankshaft chamber 2 can absorb this heat, cooling the components and preventing problems such as material performance degradation and part deformation due to overheating, thus extending the engine's service life. Further details are omitted here. The magneto chamber 3 is used to draw in air and mix it with the lubricating oil from the crankshaft chamber 2. In the prior art, the magneto chamber 3 generally includes a ventilation duct, a crankcase forced ventilation valve, and an oil-gas separator. The ventilation duct connects the crankcase and the intake manifold, etc., for air intake. To facilitate the flow of lubricating oil vapor, the crankcase forced ventilation valve is typically installed on the ventilation duct leading to the intake manifold. It automatically adjusts the airflow to the crankcase according to different engine operating conditions. An oil-gas separator, generally located in the crankcase ventilation system, separates the lubricating oil and air from the lubricating oil vapor. During engine operation, a negative pressure is created in the intake manifold. Under this negative pressure, outside air enters the magneto chamber 3 through the ventilation duct and then enters the crankshaft chamber 2. Due to the reciprocating motion of the piston, the pressurized lubricating oil vapor, exhaust gas, and air drawn in from the outside mix in the crankshaft chamber 2. Further details are omitted here. The breather hole 101 is located on the side of the crankshaft chamber 2 near the magneto chamber 3 and is connected to the corresponding position in the magneto chamber 3. This allows for a shorter path between the crankshaft chamber 2 and the magneto chamber 3, facilitating better air guidance and reducing machining difficulty. The breather hole 101 is typically circular in shape, making it easy to machine. While ensuring connectivity, it also ensures uniform stress on the hole wall. Further details are omitted here.

[0027] In this embodiment, a balance shaft is provided inside the crankshaft chamber 2. The balance shaft includes an upper balance shaft 4 and a lower balance shaft 5, which are located on the upper and lower sides of the engine crankshaft 8, respectively. The balance shaft is used to reduce vibration. During engine operation, the reciprocating motion of the piston and the rotation of the crankshaft generate unbalanced inertial forces and inertial torques, causing engine vibration. The balance shaft generates forces and torques opposite to these unbalanced forces through its own rotation, effectively reducing vibration and reducing collisions and friction between engine components, thereby reducing engine noise and improving riding comfort. Compared to setting a single balance shaft, the dual balance shaft design can... The upper balance shaft 4 and lower balance shaft 5 are respectively located on the upper and lower sides of the engine crankshaft 8, which can better balance the forces on different parts of the engine. The upper balance shaft 4 can balance the inertial force generated when the piston moves upward, while the lower balance shaft 5 can balance the forces generated when the piston moves downward and the crankshaft rotates, making the overall force distribution of the engine more uniform, reducing the stress on each component, reducing component wear, and extending the service life of the engine.

[0028] In this embodiment, the breather hole 101 is located on the upper part of the engine crankshaft 8 and is equipped with a one-way valve structure that allows the breather hole 101 to ventilate in one direction to the crankshaft chamber 2. Positioning the breather hole 101 on the upper part of the engine crankshaft 8 facilitates the smooth discharge of gas when the air pressure inside the crankshaft chamber 2 changes. Since hot air typically rises, the breather hole on the upper part of the crankshaft 8 can more effectively discharge gas from the crankshaft chamber 2. The lower part of the crankshaft chamber 2 is typically an area where lubricating oil accumulates. If the breather hole 101 is located on the lower part of the crankshaft 8, lubricating oil would be discharged along with the gas, resulting in oil loss. The one-way valve structure ensures that the breather hole 101 can only ventilate in one direction to the crankshaft chamber 2. When the air pressure inside the crankshaft chamber 2 is higher than the external pressure, the one-way valve structure closes, preventing external dust and impurities from entering the crankshaft chamber 2 through the breather hole 101. This protects the internal components of the engine, reduces wear and malfunctions, and maintains the air pressure balance inside the crankshaft chamber 2, which is beneficial for the normal operation of the engine.

[0029] In this embodiment, a support inner plate 103 is formed on the crankshaft chamber 2 between the crankshaft chamber 2 and the magneto chamber 3. The support inner plate 103 supports the balance shaft and the crankshaft 8. The vent 101 is formed on the support inner plate 103. During the prefabrication of the crankshaft chamber 2, the support inner plate 103 is directly cast at the position adjacent to the crankshaft chamber 2 and the magneto chamber 3. The support inner plate 103 and the crankshaft chamber 2 have good connection strength and integrity, avoiding problems such as loosening or breakage during subsequent use. Further details are omitted here. The inner support plate 103 is used to support the balance shaft and crankshaft 8. According to existing technology, corresponding mounting holes can be machined on the inner support plate 103 for mounting the balance shaft and crankshaft 8. The size and position of the mounting holes are set according to actual production needs to ensure that the balance shaft and crankshaft 8 can be accurately installed and operate stably. After the inner support plate 103 is machined, a vent 101 is opened at a suitable position according to design requirements. The shape and size of the vent 101 can be selected according to actual ventilation needs; common shapes include circular or square, etc., which will not be elaborated here.

[0030] In this embodiment, the one-way valve structure is a reed-type one-way valve 1011. The reed-type one-way valve 1011 includes a reed 10111, which can close or open the breather hole 101. The reed 10111 covers the breather hole 101. The reed-type one-way valve 1011 is mainly composed of the reed 10111, without a complex mechanical structure or combination of multiple parts, resulting in lower manufacturing costs and relatively easy installation and maintenance. Because the reed 10111 has a relatively high... The good elasticity allows it to respond quickly to changes in air pressure within the crankshaft chamber 2. When the air pressure in the crankshaft chamber 2 decreases, the reed 10111 opens rapidly, and when the air pressure in the crankshaft chamber 2 increases, the reed 10111 closes in time, ensuring effective regulation of the pressure within the crankshaft chamber 2. In the closed state, the reed 10111 can tightly cover the breather hole 101, providing good sealing performance, preventing gas leakage, and ensuring the normal operation of the engine. Further details are omitted here.

[0031] In this embodiment, the engine housing 1 is further equipped with a breather pump 601 and a main oil passage suction pump 602. The breather pump 601 draws lubricating oil and exhaust gas from the crankshaft chamber 2 into the magneto chamber 3, and the main oil passage suction pump 602 draws out lubricating oil from the magneto chamber 3 for lubrication. When the breather pump 601 is working, it delivers lubricating oil and / or exhaust gas from the crankshaft chamber 2 to the magneto chamber 3, providing a basis for the mixing of lubricating oil and air in the magneto chamber 3, and ensuring that the lubricating oil at the bottom of the crankshaft chamber 2 is extracted in a timely manner, preventing the accumulation of lubricating oil in the crankshaft chamber 2 and thus avoiding the saturation of the breather hole 101. The lubricating oil is submerged to ensure the normal operation of the engine, which will not be elaborated here. The function of the main oil passage suction pump 602 is to draw out the lubricating oil in the magneto chamber 3 for lubrication. Its flow rate is determined according to the overall lubrication requirements of the engine and the amount of lubricating oil stored in the magneto chamber. Through the working mechanism of the main oil passage suction pump 602 itself, such as the gear meshing of a gear pump or the reciprocating motion of a plunger pump, a negative pressure is generated at the suction end to draw the lubricating oil in the magneto chamber 3 into the pump. Then, through pressurization and other operations, the lubricating oil is drawn out and used to lubricate related components to ensure the normal operation of the engine, which will not be elaborated here.

[0032] In this embodiment, a housing channel 102 is also provided at the bottom of the engine housing 1. The housing channel 102 has an inlet for introducing lubricating oil and an outlet connected to the oil suction port of the breathing pump 601. During engine operation, some lubricating oil accumulates at the bottom of the crankshaft chamber 2. The housing channel 102 connects the bottom of the crankshaft chamber 2 to the oil suction port of the breathing pump 601, so that the lubricating oil at the bottom of the crankshaft chamber 2 can be introduced to the oil suction port of the breathing pump 601 through the housing channel 102, avoiding the problem of lubricating oil blockage in the crankshaft chamber 2 and ensuring the normal operation of the engine. At the same time, the housing channel 102 is located near the lower balance shaft 5. The oil flow generated when the lower balance shaft 5 is running is conducive to the lubricating oil being better introduced into the housing channel 102 and then sucked in by the breathing pump 601. This will not be elaborated further here.

[0033] In this embodiment, the reed 10111 closes the vent 101 when the piston moves downward, and the crankshaft chamber 2 is under positive pressure. The lubricating oil and exhaust gas in the crankshaft chamber 2 are introduced to the oil inlet of the vent pump 601 through the housing channel 102, and then sucked into the magneto chamber 3 by the vent pump 601. When the piston moves downward, the air pressure in the crankshaft chamber 2 increases, and the reed 10111 closes the vent 101 when the piston moves downward, preventing the gas in the crankshaft chamber 2 from flowing to the magneto chamber 3. As the piston moves downward, the lubricating oil in the crankshaft chamber 2 accumulates at the bottom of the crankshaft chamber 2 under the influence of gravity and crankshaft rotation. The lubricating oil is introduced into the suction port of the breathing pump 601 along the housing channel 102. When the breathing pump 601 is working, it generates suction to draw in the lubricating oil flowing through the housing channel 102 and then delivers the lubricating oil to the magneto chamber 3, thus realizing the transfer of lubricating oil from the crankshaft chamber 2 to the magneto chamber 3.

[0034] When the piston moves upward, the reed 10111 opens the breather 101 due to the negative pressure in the crankshaft chamber 2. Air from the magneto chamber 3 is introduced into the crankshaft chamber 2 through the breather 101. When the piston moves upward, the air pressure in the crankshaft chamber 2 decreases, forming a certain negative pressure. There is a pressure difference on both sides of the reed-type one-way valve 1011. The air pressure in the magneto chamber 3 is relatively high, while the air pressure in the crankshaft chamber 2 is relatively low. When this pressure difference reaches a certain level, it overcomes the elasticity of the reed 10111 in the reed-type one-way valve 1011, and the reed 10111 is pushed open. The breather 101 opens, and air from the magneto chamber 3 flows into the crankshaft chamber 2 through the breather 101 under the action of the pressure difference, maintaining the air pressure balance in the crankshaft chamber 2 and preventing the oil suction port of the breather pump 601 from being "blocked" by lubricating oil and unable to draw air from the crankshaft chamber 2.

[0035] In this embodiment, the crankshaft chamber 2 is a dry crankshaft chamber. A dry crankshaft chamber refers to a chamber structure in which the crankcase does not store a large amount of lubricating oil, and the crankshaft and lubricating oil are basically not in direct contact. Because the crankshaft is not directly immersed in lubricating oil, the amount of lubricating oil splashed onto the crankshaft is relatively small, effectively reducing lubricating oil consumption caused by the crankshaft rotation carrying lubricating oil out of the crankcase, and improving the efficiency of lubricating oil use. The dry crankshaft chamber facilitates precise control of the flow and circulation of lubricating oil. The lubricating oil is transferred and distributed through specific housing channels and / or an oil suction pump, avoiding unnecessary accumulation and chaotic flow of lubricating oil in the crankshaft chamber 2. The dry crankshaft chamber reduces the contact between lubricating oil and external contaminants, lowering the possibility of lubricating oil contamination and ensuring the normal operation of the engine.

[0036] The breather hole 101 is located between the crankshaft 8 and the upper balance shaft 4. When the piston moves upward, the reed-type one-way valve 1011 opens, and air in the magneto chamber 3 is introduced into the crankshaft chamber 2 through the breather hole 101. If the breather hole 101 is too low, the air will be obstructed by the lubricating oil and cannot smoothly enter the crankshaft chamber 2. Furthermore, air bubbles will be generated when passing through the lubricating oil, affecting the air inflow efficiency and the air pressure balance in the crankshaft chamber 2. By placing the breather hole 101 between the crankshaft 8 and the upper balance shaft 4, it is ensured that when the piston moves upward, the air in the magneto chamber 3 can smoothly enter the crankshaft chamber 2 through the breather hole 101 without being blocked by the lubricating oil, thereby achieving air pressure balance in the crankshaft chamber 2, maintaining the normal operation of the engine, and improving the reliability and stability of the engine. To prevent impurities from entering the breather hole 101, a filter device or protective structure, such as a metal filter or a protective cover, can be installed around the breather hole 101, which will not be elaborated here.

[0037] In this embodiment, the magneto chamber 3 is equipped with a labyrinth-shaped ventilation duct 301 and an exhaust nozzle 302. When the piston moves downwards, the exhaust gas in the crankshaft chamber 2 is introduced into the magneto chamber 3 through the housing channel 102 and the breathing pump 601, and then discharged to the atmosphere through the labyrinth-shaped ventilation duct 301 and the exhaust nozzle 302. When the piston moves upwards, the exhaust nozzle 302 and the labyrinth-shaped ventilation duct 301 introduce air into the magneto chamber 3, and then the air enters the crankshaft chamber 3 through the breathing hole 101. The crankshaft chamber 2, where the labyrinth-shaped ventilation duct 301 connects to the outside, is also equipped with an exhaust nozzle 302. When the piston moves downward, the reed-type one-way valve 1011 closes, and the exhaust gas in the crankshaft chamber 2, under pressure, flows through the housing channel 102 to the oil suction port of the breather pump 601, where it is drawn in. The breather pump 601 draws the exhaust gas into the magneto chamber 3. The exhaust gas entering the magneto chamber 3 then passes through the labyrinth-shaped ventilation duct 301 located within the magneto chamber 3. The ventilation duct 301 allows for the separation and filtration of impurities such as oil mist in the exhaust gas through multiple turns and collisions during its flow. It also ensures the exhaust gas is smoothly discharged into the atmosphere via the exhaust nozzle 302. When the piston moves upward, the reed-type one-way valve 1011 opens, allowing outside air to first enter the labyrinthine ventilation duct 301 through the exhaust nozzle 302 and then be introduced into the magneto chamber 3. As the air flows through the labyrinthine ventilation duct 301, some dust and other impurities are blocked or filtered. The air entering the magneto chamber 3, under the influence of pressure difference, enters the crankshaft chamber 2 through the breather hole 101. This design, through the rational use of the piston's reciprocating motion, the breather pump 601, and the labyrinthine ventilation duct 301, achieves gas exchange between the crankshaft chamber 2 and the outside environment. Simultaneously, it treats the exhaust gas and the air entering the engine, ensuring normal engine operation and reducing pollution emissions.

[0038] The engine in this embodiment includes the engine housing 1. Dual balance shafts are arranged on the upper and lower sides of the engine crankshaft within the crankshaft chamber 2, improving the engine's vibration damping performance and meeting consumers' needs for safe and comfortable riding. A breather 101 and a breather pump 601 are also provided between the crankshaft chamber 2 and the magneto chamber 3, connecting the two chambers. This addresses the weakening effect of gravity on the discharge of lubricating oil from the crankshaft chamber 2 caused by the expansion of the crankshaft chamber 2. This allows the oil inlet of the breather pump 601 to normally draw lubricating oil and exhaust gas from the crankshaft chamber 2 into the magneto chamber 3. It also balances the air pressure within the crankshaft chamber 2, maintaining the dry crankshaft chamber characteristics of the crankshaft chamber 2 without excessive lubricating oil, while also eliminating power loss caused by the up-and-down movement of the engine piston due to air pressure imbalance.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. An engine housing, characterized in that: The engine housing includes a crankshaft chamber and a magneto chamber, with a vent forming between the crankshaft chamber and the magneto chamber; The crankshaft chamber is provided with a balance shaft, which includes an upper balance shaft and a lower balance shaft, located on the upper and lower sides of the engine crankshaft respectively.

2. The engine housing according to claim 1, characterized in that: The breather hole is located on the upper part of the engine crankshaft and is equipped with a one-way valve structure that allows one-way ventilation from the breather hole to the crankshaft chamber.

3. The engine housing according to claim 1, characterized in that: A supporting inner plate is formed on the crankshaft chamber between the crankshaft chamber and the magneto chamber. The supporting inner plate supports the balance shaft and the crankshaft, and the vent is opened on the supporting inner plate.

4. The engine housing according to claim 2, characterized in that: The one-way valve is a reed-type one-way valve, which includes a reed that can close or open the vent hole, and the reed covers the vent hole.

5. The engine housing according to claim 1, characterized in that: The engine housing is also equipped with a breathing pump and a main oil passage suction pump. The breathing pump draws lubricating oil and exhaust gas from the crankshaft chamber into the magneto chamber, and the main oil passage suction pump draws lubricating oil from the magneto chamber for lubrication.

6. The engine housing according to claim 1, characterized in that: A housing channel is also provided at the bottom of the engine housing, the housing channel having an inlet for introducing lubricating oil and an outlet that is connected to the oil suction port of the breathing pump.

7. The engine housing according to claim 4, characterized in that: The reed closes the vent hole when the piston moves downward, and the crankshaft chamber is under positive pressure. The lubricating oil and exhaust gas in the crankshaft chamber are introduced into the oil inlet of the vent pump through the housing channel, and then sucked into the magneto chamber by the vent pump. When the piston moves upward, the reed opens the vent due to the negative pressure in the crankshaft chamber, and air from the magneto chamber is introduced into the crankshaft chamber through the vent.

8. The engine housing according to claim 2, characterized in that: The crankshaft chamber is a dry crankshaft chamber, and the breather hole is located between the crankshaft and the upper balance shaft.

9. An engine, characterized in that: Includes the engine housing as described in any one of claims 1-8.

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