Oil-gas separation structure and engine system

Abstract

The utility model relates to the technical field of engines, and discloses an oil-gas separation structure and an engine system. The gas taking cover is provided with an inner bin body, and the inner bin body is provided with a centrifugal part; the oil accumulation bin communicates with the inner bin body and is located on the side, away from the second end of the air taking pipe, of the centrifugal part. During working, oil-gas mixed gas enters the inner bin body and then flows to the centrifugal part to form rotational flow, primary oil-gas separation is carried out under the action of centrifugal force, and then the oil-gas mixed gas flows into the gas taking pipe under the guiding action of the centrifugal part and finally flows into the respirator; the separated oil drops can fall into the oil accumulation bin, and the oil drops falling into the oil accumulation bin cannot be affected when the oil-gas mixture enters the gas taking pipe. Therefore, the structure can perform preliminary oil-gas separation on the oil-gas mixed gas before the oil-gas mixed gas enters the respirator, the difficulty of subsequent oil-gas separation by the respirator is reduced, and the phenomenon that separated oil drops are re-involved into the gas taking pipe by the oil-gas mixed gas is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to an engine technical field, especially an oil gas separation structure and engine system. BACKGROUND

[0002] The breather is a ventilator in the engine system, which functions to discharge the exhaust gas of the crankcase to keep the air pressure balance inside and outside the engine. The breather, while connecting the crankcase with the outside, also has the function of oil gas separation to avoid the oil gas mixture in the crankcase from being sprayed out to cause environmental pollution or even dangerous accidents.

[0003] In the prior art, the gas taking pipe of the breather is usually directly connected with the gas taking cavity of the crankcase. In this way, the oil droplets remaining in the gas taking cavity after oil gas separation are easily re-rolled into the gas taking pipe by the oil gas mixture, which increases the difficulty of oil gas separation and has the possibility of causing oil injection failure due to poor oil gas separation effect.

[0004] Therefore, how to improve the efficiency of oil gas separation of the breather has become a technical problem to be solved in the field. UTILITY MODEL CONTENT

[0005] The utility model aims to at least solve the technical problem of how to improve the efficiency of oil gas separation of the breather. The purpose is achieved by the following technical solutions:

[0006] In the first aspect, the utility model provides an oil gas separation structure suitable for an engine system, which comprises: a gas taking pipe extending in a first direction, a first end of the gas taking pipe being used to communicate with a breather; a gas taking cover having an inner warehouse body, a second end of the gas taking pipe being communicated with the inner warehouse body, the gas taking cover being provided with at least one air inlet hole, the air inlet hole being configured to enable the inner warehouse body to communicate with a gas taking cavity of a crankcase through the air inlet hole, the inner warehouse body being provided with a centrifugal part, the centrifugal part being configured to enable the oil gas mixture flowing into the inner warehouse body from the gas taking cavity to be introduced into the gas taking pipe from the second end of the gas taking pipe through the centrifugal part, and the centrifugal part being used to enable the oil gas mixture passing through the centrifugal part to form a rotational flow and perform oil gas separation; and an oil accumulation warehouse, the oil accumulation warehouse being communicated with the inner warehouse body and located on the side of the centrifugal part away from the second end of the gas taking pipe in the first direction.

[0007] The oil-gas separation structure, in operation, oil-gas mixture in the gas taking cavity of the crankcase enters the inner chamber of the gas taking cover through the gas inlet hole, and then flows to the centrifugal part and forms a cyclone along the centrifugal part, at this time, the oil-gas mixture realizes preliminary oil-gas separation under the action of centrifugal force, then, the oil-gas mixture after the preliminary oil-gas separation is introduced into the gas taking pipe from the second end of the gas taking pipe under the guidance of the centrifugal part, and finally flows into the breather from the first end of the gas taking pipe. As for the oil droplets separated in the above preliminary oil-gas separation process, since the oil accumulation chamber in the first direction is located on the side of the centrifugal part away from the second end of the gas taking pipe, that is, the position of the oil accumulation chamber is lower than the path of the oil-gas mixture entering the gas taking pipe, the oil droplets separated by the preliminary oil-gas separation will fall into the oil accumulation chamber under the action of their own gravity, and the oil-gas mixture entering the gas taking pipe will not affect the oil droplets that have fallen into the oil accumulation chamber. Therefore, the oil-gas separation structure can preliminarily separate the oil-gas mixture before the oil-gas mixture enters the breather, reducing the difficulty of subsequent oil-gas separation of the breather; and the oil droplets separated by the preliminary oil-gas separation will fall into the oil accumulation chamber, effectively reducing the phenomenon that the oil droplets separated from the oil-gas mixture are re-voluted into the gas taking pipe by the oil-gas mixture, thereby effectively improving the oil-gas separation efficiency of the breather.

[0008] In some embodiments of the present application, the gas taking cover comprises: a top plate located at one end of the gas taking cover away from the oil accumulation chamber; and a side plate arranged around the circumference of the gas taking pipe, the gas inlet hole is arranged on the side plate, and the inner wall of the side plate constitutes the centrifugal part.

[0009] In some embodiments of the present application, the inner wall of the side plate is connected with the inner wall of the oil accumulation chamber.

[0010] In some embodiments of the present application, a plurality of gas inlet holes are arranged on the side plate, and the plurality of gas inlet holes are arranged at intervals around the circumference of the gas taking pipe.

[0011] In some embodiments of the present application, the gas taking cover further comprises a shell, and the shell is configured to be connectable with the engine system body.

[0012] In some embodiments of the present application, the gas taking cover further comprises a screw, and the shell is provided with a threaded hole matched with the screw.

[0013] In some embodiments of the present application, the second end of the gas taking pipe is provided with a filter part, and the filter part is used for separating the oil-gas mixture entering the gas taking pipe from the second end of the gas taking pipe.

[0014] In some embodiments of the present application, a plurality of filter holes are arranged on the side wall of the second end of the gas taking pipe, the plurality of filter holes are arranged in an array to form a filter grid, the filter grid constitutes the filter part, and the filter grid is arranged around the circumference of the gas taking pipe.

[0015] In a second aspect, the utility model provides an engine system, the engine system includes the body, the respirator, the crankcase and the oil gas separation structure of above any one, the respirator communicates with the first end of the gas taking pipe, the gas taking cavity of the crankcase communicates through the air inlet hole with the inner storehouse body.

[0016] In some embodiments of the utility model, the oil accumulation storehouse is integrated in the body of the engine system.

[0017] The above description is only a summary of the technical scheme of the application, in order to more clearly understand the technical means of the application, which can be implemented according to the content of the specification, and in order to make the above and other purposes, characteristics and advantages of the application more obvious and easy to understand, the following specific embodiments of the application are described. BRIEF DESCRIPTION OF DRAWINGS

[0018] Various other advantages and benefits will become apparent to those of ordinary skill in the art, upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of preferred embodiments, and are not meant to limit the present utility. Furthermore, like reference numerals are intended to represent the same components throughout the drawings. In the drawings:

[0019] Figure 1 Partial structure sectional view of the oil gas separation structure provided by the embodiments of the utility model when being installed in the engine system is provided;

[0020] Figure 2 Structure schematic view of the gas taking cover in the oil gas separation structure provided by the embodiments of the utility model is provided;

[0021] Figure 3 Structure schematic view of the gas taking cover in the oil gas separation structure provided by the embodiments of the utility model in another angle is provided;

[0022] Figure 4 Flow path schematic view of the oil gas mixture in Figure 1 The angle is shown.

[0023] The reference signs are as follows:

[0024] 100, oil gas separation structure;

[0025] 1000, gas taking pipe;1100, filter grid;1110, filter hole;

[0026] 2000, gas taking cover;2100, top plate;2200, side plate;2300, shell;2310, screw hole;2010, inner storehouse body;2011, centrifugal part;2001, air inlet hole;

[0027] 3000, oil accumulation storehouse;

[0028] 200, body;

[0029] 300, gas taking cavity. DETAILED DESCRIPTION

[0030] Exemplary embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it is to be understood that the present disclosure can be embodied in various forms without being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0031] It is to be understood that the terms used herein are merely for the purpose of describing particular embodiments and are by no means to be taken as limiting unless otherwise defined in the context. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "includes", "including" and "has" are to be construed as containing, comprising, including or having, but not excluding any additional item, feature, step, process, component or element. The methods described herein do not require the particular order of steps described or illustrated, unless otherwise specifically noted. It should also be understood that additional or alternative steps can be employed.

[0032] Although the terms first, second, third, and the like can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first", "second", and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0033] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0034] Figure 1 A partial cross-sectional view of the oil-gas separation structure provided in this embodiment of the present invention when installed in an engine system; Figure 2 This is a schematic diagram of the gas sampling hood in the oil-gas separation structure provided in the embodiment of this utility model; Figure 3 A schematic diagram of the gas extraction hood in the oil-gas separation structure provided in this embodiment of the utility model from another angle; Figure 4 For oil and gas mixture in Figure 1 A schematic diagram of the flow path at the angle shown; Reference Figures 1 to 4 This utility model provides an oil-gas separation structure 100 suitable for engine systems. The oil-gas separation structure 100 includes: an air intake pipe 1000 extending along a first direction, with a first end of the air intake pipe 1000 connected to a breather; and an air intake hood 2000 having an inner chamber 2010, with a second end of the air intake pipe 1000 connected to the inner chamber 2010. The air intake hood 2000 is provided with at least one air inlet 2001, configured to allow the inner chamber 2010 to communicate with the crankcase's air intake chamber 300 through the air inlet 2001. The 2010 includes a centrifugal section 2011, which is configured to allow the oil-gas mixture flowing into the inner chamber 2010 from the gas intake chamber 300 to pass through the centrifugal section 2011 and then be introduced into the gas intake pipe 1000 from the second end of the gas intake pipe 1000. The centrifugal section 2011 is used to form a swirling flow of the oil-gas mixture passing through the centrifugal section 2011 and to perform oil-gas separation. The 2010 also includes an oil collection tank 3000, which is connected to the inner chamber 2010 and is located on the side of the centrifugal section 2011 away from the second end of the gas intake pipe 1000 along the first direction.

[0035] In this embodiment, when the oil-gas separation structure 100 is in operation, the oil-gas mixture in the gas taking cavity 300 of the crankcase enters the inner chamber body 2010 of the gas taking cover 2000 through the gas inlet hole 2001, and then flows to the centrifugal part 2011 and forms a cyclone along the centrifugal part 2011. The cyclone can be referred to as Figure 4 The oil-gas mixture is preliminarily separated under the action of the centrifugal force, as indicated by the dashed arrow, and then the oil-gas mixture after the preliminary oil-gas separation is introduced into the gas taking pipe 1000 from the second end of the gas taking pipe 1000 under the guidance of the centrifugal part 2011, and finally flows into the respirator from the first end of the gas taking pipe 1000.

[0036] As to the oil droplets separated in the above-mentioned preliminary oil-gas separation process, since the oil accumulation chamber 300 in the first direction is located on the side of the centrifugal part 2011 away from the second end of the gas taking pipe 1000, that is, the position of the oil accumulation chamber 300 is lower than the path of the oil-gas mixture entering the gas taking pipe 1000, the oil droplets separated by the preliminary oil-gas separation will fall into the oil accumulation chamber 300 under the action of their own gravity. The path of the separated oil droplets is indicated by the solid arrow, and the oil-gas mixture will not affect the oil droplets that have fallen into the oil accumulation chamber 300 when entering the gas taking pipe 1000. Figure 4

[0037] Therefore, the oil-gas separation structure 100 can preliminarily separate the oil-gas mixture before the oil-gas mixture enters the respirator, reducing the difficulty of subsequent oil-gas separation of the respirator. The oil droplets separated by the preliminary oil-gas separation will fall into the oil accumulation chamber 300, effectively reducing the phenomenon that the oil droplets separated from the oil-gas mixture are re-rolled into the gas taking pipe 1000 by the oil-gas mixture, thereby effectively improving the efficiency of the oil-gas separation of the respirator.

[0038] As Figures 1 to 3 indicated, according to an optional embodiment of the present application, the gas taking cover 2000 comprises: a top plate 2100 located at one end of the gas taking cover 2000 away from the oil accumulation chamber 300; and a side plate 2200 arranged around the circumference of the gas taking pipe 1000, the gas inlet hole 2001 is arranged on the side plate 2200, and the inner wall of the side plate 2200 constitutes the centrifugal part 2011.

[0039] In this embodiment, specifically, in combination with the detailed structure of the gas taking cover 2000, reference can be made to Figures 1 to 4 The working process of the oil-gas separation structure 100 is described in more detail as follows:

[0040] First, the oil-gas mixture in the gas taking cavity 300 of the crankcase enters the inner chamber body 2010 of the gas taking cover 2000 through the gas inlet hole 2001 on the side plate 2200;

[0041] ​Then, the oil-gas mixture firstly continues to flow upwards to the inner wall of the top plate 2100, and then flows downwards to the inner wall of the side plate 2200; it is easily understood that when the oil-gas mixture collides with the inner wall of the top plate 2100, the oil droplets in the oil-gas mixture are knocked out under the impact, and when the oil-gas mixture flows to the inner wall of the side plate 2200, the oil-gas mixture finally forms a cyclone and is separated under the action of centrifugal force, and the cyclone can refer to the path indicated by the dashed-dotted arrow in the figure. Figure 4

[0042] Finally, the oil-gas mixture after the preliminary oil-gas separation is introduced into the gas taking pipe 1000 from the second end of the gas taking pipe 1000, and finally flows into the respirator from the first end of the gas taking pipe 1000, and the oil droplets separated in the flow path of the oil-gas mixture also fall into the oil storage bin 3000, and the path of the separated oil droplets can refer to the path indicated by the solid arrow in the figure. Figure 4 The separated oil droplets will not be re-rolled into the gas taking pipe 1000 by the oil-gas mixture.

[0043] Therefore, the oil-gas mixture entering the inner bin body 2010 will undergo the above-mentioned "collision" and "centrifugal" twice preliminary oil-gas separation before entering the gas taking pipe 1000, thereby reducing the difficulty of subsequent oil-gas separation of the respirator; and since the oil droplets separated by the above-mentioned twice preliminary oil-gas separation also fall into the oil storage bin 3000, the phenomenon that the oil droplets separated from the oil-gas mixture are re-rolled into the gas taking pipe 1000 by the oil-gas mixture is effectively reduced, thereby effectively improving the efficiency of the oil-gas separation of the respirator; in addition, since the side plate 2200 is arranged around the circumference of the gas taking pipe 1000, all the oil-gas mixture entering the inner bin body 2010 flows through the side plate 2200 to form a cyclone before entering the gas taking pipe 1000, thereby being separated under the action of centrifugal force, thereby ensuring the efficiency of the above-mentioned "centrifugal" operation of the oil-gas mixture.

[0044] According to an optional embodiment of the present application, the inner wall of the side plate 2200 is connected with the inner wall of the oil storage bin 3000.

[0045] In this embodiment, since the inner wall of the side plate 2200 constitutes the centrifugal part 2011, and the inner wall of the side plate 2200 is connected with the inner wall of the oil storage bin 3000, it is explained that the side plate 2200 should satisfy the two functions of "centrifugal" (i.e. oil-gas separation under the action of centrifugal force) and "drainage" (i.e. guiding the separated oil into the oil storage bin 3000).

[0046] ​Therefore, it is not difficult to understand that the inner tank body 2010 as a whole should present a conical structure, that is, the side plate 2200 of each part (since the side plate 2200 as a whole is arranged around the circumference of the gas taking pipe 1000, each part here can be understood as the part of the side plate 2200 at any position relative to the gas taking pipe 1000) should be inclined relative to the first direction, so as to play the above-mentioned "draining" role, as shown in Figure 2 and Figure 3 .

[0047] Referring to Figure 2 and Figure 3 , in addition, in order to guarantee the above-mentioned "centrifugal" role, so that the oil-gas mixture passing through the side plate 2200 can form a cyclone, the side plate 2200 should be an arc-shaped plate, that is, the side plate 2200 of each part should be concave towards the direction away from the gas taking pipe 1000, and the specific size of the concave arc, depth, etc. can be determined according to actual working condition requirements, so as to guarantee that the oil-gas mixture passing through the inner wall of the side plate 2200 can produce a cyclone for oil-gas separation, and finally can enter the gas taking pipe 1000 from the second end of the gas taking pipe 1000 without entering the oil accumulation tank 3000, which is not limited.

[0048] Therefore, the setting mode of the inner wall of the side plate 2200 and the inner wall of the oil accumulation tank 3000 not only guarantees that the oil-gas mixture can be preliminarily separated by centrifugal force, but also enables the separated oil to flow along the inner wall of the side plate 2200 into the oil accumulation tank 3000, thereby playing a guiding effect on the oil during the process of falling from the inner tank body 2010 to the oil accumulation tank 3000.

[0049] Continuing to refer to Figure 2 and Figure 3 , according to an optional embodiment of the present application, a plurality of air inlet holes 2001 are arranged on the side plate 2200, and the plurality of air inlet holes 2001 are arranged at intervals around the circumference of the gas taking pipe 1000.

[0050] In this embodiment, since the side plate 2200 is arranged around the circumference of the gas taking pipe 1000, and the plurality of air inlet holes 2001 are also arranged at intervals around the circumference of the gas taking pipe 1000, the oil-gas mixture in the gas taking cavity 300 can enter the inner tank body 2010 of the gas taking cover 2000 through a plurality of paths (depending on the arrangement position of the plurality of air inlet holes 2001), thereby improving the flow efficiency of the oil-gas mixture, and further improving the efficiency of preliminarily separating the oil-gas mixture.

[0051] Among them, it is easy to understand that the plurality of air inlet holes 2001 can be uniformly and evenly arranged on the side plate 2200; and the number of air inlet holes 2001 should be determined according to actual working condition requirements, which is not limited, for example, eight air inlet holes 2001 can be arranged on the side plate 2200.

[0052] AsFigure 2 and Figure 3 As shown in FIG. 1, according to an optional embodiment of the present application, the gas extraction cover 2000 further comprises a shell 2300, which is configured to be connectable with the engine system body 200.

[0053] In this embodiment, it is easy to understand that the shell 2300 should be arranged outside the inner chamber body 2010; when assembling the engine system, the first end of the gas extraction pipe 1000 is communicated with the respirator, the inner chamber body 2010 is communicated with the gas extraction cavity 300 of the crankcase through the air inlet hole 2001, and the shell 2300 is connected with the engine system body 200, so as to improve the integration of the engine system as a whole.

[0054] With reference to FIG. 1, Figure 2 and Figure 3 Specifically, according to an optional embodiment of the present application, the gas extraction cover 2000 further comprises a screw (not shown in the figure), and the shell 2300 is provided with a threaded hole 2310 matched with the screw.

[0055] In this embodiment, a threaded hole 2310 corresponding to the screw can also be arranged on the engine system body 200; during assembly, the gas extraction cover 2000 is fixed to the engine system body 200 through the screw, and the screw assembly is simple and convenient to operate, has strong stability, and is convenient for subsequent disassembly of the gas extraction cover 2000 for maintenance.

[0056] It is easy to understand that a plurality of threaded holes 2310 can be arranged on the shell 2300, and the plurality of threaded holes 2310 can be uniformly and spacedly arranged, so as to further improve the connection stability between the gas extraction cover 2000 and the engine system body 200.

[0057] According to an optional embodiment of the present application, the second end of the gas extraction pipe 1000 is provided with a filter part, and the filter part is used for oil-gas separation of the oil-gas mixture entering the gas extraction pipe 1000 from the second end of the gas extraction pipe 1000.

[0058] In this embodiment, the purpose of arranging the filter part is to further increase a means for preliminarily separating the oil-gas mixture before entering the gas extraction pipe 1000.

[0059] With reference to FIG. 1, Figure 1 and Figure 4 Specifically, according to an optional embodiment of the present application, a plurality of filter holes 1110 are arranged on the side wall of the second end of the gas extraction pipe 1000, the plurality of filter holes 1110 are arranged in an array to form a filter grid 1100, the filter grid 1100 constitutes the filter part, and the filter grid 1100 is arranged around the circumference of the gas extraction pipe 1000.

[0060] In this embodiment, it is easy to understand that, since the filter grid 1100 is composed of a plurality of filter holes 1110, when the oil-gas mixture passes through the filter grid 1100, the oil droplets in the oil-gas mixture will be filtered out, and the gas will all enter the gas taking pipe 1000 through the filter holes 1110, thereby realizing another kind of preliminary oil-gas separation of the oil-gas mixture.

[0061] In addition, since the filter grid 1100 is arranged around the circumference of the sidewall of the second end of the gas taking pipe 1000, it is illustrated that the oil-gas mixture can also enter the gas taking pipe 1000 from the side of the gas taking pipe 1000, and the process can be referred to the path indicated by the straight-line dotted arrow in FIG. 1. Figure 4

[0062] Therefore, in this arrangement, the efficiency of the oil-gas mixture entering the gas taking pipe 1000 is improved, and a kind of preliminary oil-gas separation of the oil-gas mixture is also increased, so that the preliminary oil-gas separation of the oil-gas mixture before entering the gas taking pipe 1000 is more sufficient, and the difficulty of the subsequent respirator for oil-gas separation is further reduced.

[0063] The utility model embodiment further provides an engine system, the engine system includes the body 200, the respirator, the crankcase and the above-mentioned any kind of oil-gas separation structure 100, the respirator and the first end of the gas taking pipe 1000 intercommunication, the gas taking cavity 300 of the crankcase is communicated with the inner storehouse body 2010 through the air inlet hole 2001.

[0064] In this embodiment, as described above, the oil accumulation storehouse 3000 of the oil-gas separation structure 100 can be integrated in the body 200 of the engine system to improve the integration of the engine system as a whole, and other beneficial effects of the engine system are the same as those of any of the above-mentioned oil-gas separation structures 100, which can reduce the difficulty of the respirator for oil-gas separation, and effectively reduce the phenomenon that the oil droplets separated from the oil-gas mixture are re-rolled into the gas taking pipe 1000 by the oil-gas mixture, thereby effectively improving the efficiency of the oil-gas separation of the respirator, and the specific analysis is not repeated here.

[0065] As shown in FIG. 1, according to an optional embodiment of the utility model, the oil accumulation storehouse 3000 is integrated in the body 200 of the engine system. Figure 1

[0066] In this embodiment, specifically, the oil accumulation storehouse 3000 can be formed by directly slotting or punching on the body 200 (the specific process is not limited, as long as it can form the oil accumulation storehouse 3000 directly on the body 200), so that the separated engine oil after the preliminary oil-gas separation by the oil-gas separation structure 100 flows back into the body 200.

[0067] ​​Therefore, the oil accumulation tank 3000 is integrated into the engine system body 200 in a manner that further improves the integration of the overall engine system while realizing the reuse of oil.

[0068] The above merely provides the preferred embodiment of the present application, and the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which shall be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An oil and gas separation structure adapted for use in an engine system, characterized by, The oil-gas separation structure comprises: a gas extraction pipe extending in a first direction, a first end of the gas extraction pipe being configured to communicate with a breather; a gas extraction cover having an inner chamber, a second end of the gas extraction pipe being configured to communicate with the inner chamber, the gas extraction cover being provided with at least one gas inlet hole configured to enable the inner chamber to communicate with a gas extraction cavity of a crankcase through the gas inlet hole, the inner chamber being provided with a centrifugal portion configured to enable oil-gas mixture flowing into the inner chamber from the gas extraction cavity to be introduced into the gas extraction pipe from the second end of the gas extraction pipe after passing through the centrifugal portion, and the centrifugal portion being configured to enable the oil-gas mixture passing through the centrifugal portion to form a rotational flow and to separate oil and gas; and an oil accumulation chamber, the oil accumulation chamber being in communication with the inner chamber and located on a side of the centrifugal portion away from the second end of the gas extraction pipe in the first direction.

2. The oil and gas separation structure according to claim 1, characterized by, The gas extraction cover comprises: a top plate located at an end of the gas extraction cover away from the oil accumulation chamber; and a side plate arranged around a circumference of the gas extraction pipe, the gas inlet hole being arranged on the side plate, and an inner wall of the side plate constituting the centrifugal portion.

3. The oil and gas separation structure of claim 2, wherein, The inner wall of the side plate is connected to an inner wall of the oil accumulation chamber.

4. The oil and gas separation structure according to claim 2, characterized by, The side plate is provided with a plurality of gas inlet holes arranged at intervals around the circumference of the gas extraction pipe.

5. The oil and gas separation structure of claim 1, wherein, The gas extraction cover further comprises an outer shell configured to be connected to a body of the engine system.

6. The oil and gas separation structure according to claim 5, wherein The gas extraction cover further comprises a screw, and the outer shell is provided with a threaded hole matched with the screw.

7. The oil and gas separation structure according to any one of claims 1 to 6, wherein The second end of the gas extraction pipe is provided with a filter portion configured to enable oil-gas mixture entering the gas extraction pipe from the second end of the gas extraction pipe to be separated.

8. The oil and gas separation structure of claim 7, wherein, The side wall of the second end of the gas extraction pipe is provided with a plurality of filter holes arranged in an array to form a filter grid constituting the filter portion, and the filter grid is arranged around the circumference of the gas extraction pipe.

9. An engine system characterized by, The engine system comprises a body, a breather, a crankcase, and an oil-gas separation structure according to any one of claims 1-8, the breather being in communication with the first end of the gas extraction pipe, and the gas extraction cavity of the crankcase being in communication with the inner chamber through the gas inlet hole.

10. The engine system of claim 9, wherein, The oil accumulation chamber is integrated into the body of the engine system.

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