Oil-gas separation structure of a camshaft assembly

Abstract

The present invention provides an oil-gas separation structure of a camshaft assembly, belonging to the field of engine technology. It solves the problem of inconvenient processing of existing oil-gas separation structures. The oil-gas separation structure of the camshaft assembly includes an oil-gas passage and a torsion joint that penetrate the camshaft along the axial direction of the camshaft. The outer wall of the torsion joint at the air inlet end has a separation convex strip that is spirally arranged along the axial direction of the camshaft. The air inlet end of the torsion joint is inserted into the air outlet of the oil-gas passage. A spiral separation oil passage for oil to pass through is formed between the inner wall of the oil-gas passage, the outer wall of the torsion joint and the separation convex strip. The oil-gas separation structure of the camshaft assembly has the advantage of easy processing.

Description

Technical Field

[0001] The invention belongs to the technical field of engines and relates to a camshaft assembly, in particular to an oil-gas separation structure of the camshaft assembly. Background Art

[0002] When the engine is working, some of the combustible oil-gas mixture and exhaust gas containing engine oil will enter the crankcase through the piston ring, thereby increasing the crankcase pressure and threatening the stability of the engine system. This requires an oil-gas separation device to be installed in the engine system. The main function of the oil-gas separation device is to extract the oil-gas mixture from the crankcase and separate the oil and gas using a specific method. The separated gas re-enters the cylinder for combustion or is discharged, and the separated oil returns to the oil pan to be used again.

[0003] In order to achieve oil-gas separation, people have made improvements to the structure of traditional camshafts, and some have even applied for patents. For example, Chinese patent literature discloses a camshaft, a camshaft assembly and an engine system [Patent No.: 201621455679.4; Authorization Announcement No.: CN206299419U]. The interior of the camshaft has a cylindrical cavity extending along the axial direction of the camshaft, and the cavity wall of the cavity is provided with a spiral guide groove for condensing the engine oil and an oil drain hole penetrating the cavity wall for discharging the engine oil.

[0004] The camshaft of this structure uses the different densities of the oil and air in the oil-gas mixture. When the oil-gas mixture rotates with the camshaft, the oil adheres to the wall of the cavity and flows along the guide groove before being discharged through the oil drain hole, and the gas is discharged from the bleed valve. However, the camshaft of this structure has a long length, and it is necessary to open the guide groove on the wall of the cavity and drill the oil drain hole on the camshaft, which is troublesome to process and increases the manufacturing cost. At the same time, due to the setting of the oil drain hole, although the gas in the camshaft cavity basically will not overflow through the oil drain hole, it is inevitable that some gas will overflow from the oil drain hole, resulting in a lower oil and gas separation efficiency. Summary of the invention

[0005] The purpose of the present invention is to address the above-mentioned problems existing in the prior art and to propose an oil-gas separation structure for a camshaft assembly, the technical problem to be solved is how to facilitate the processing of the oil-gas separation structure.

[0006] The objective of the present invention can be achieved through the following technical solutions: an oil-gas separation structure of a camshaft assembly, comprising an oil-gas passage running through the camshaft along the axial direction of the camshaft, characterized in that the oil-gas separation structure also comprises a torsion joint, the outer wall of the air inlet end of the torsion joint has a separation ridge spirally arranged along the axial direction of the camshaft, the air inlet end of the torsion joint is passed through the air outlet of the oil-gas passage, and a spiral separation oil passage for the engine oil to pass through is formed between the inner wall of the oil-gas passage, the outer wall of the torsion joint and the separation ridge.

[0007] Since the density of the engine oil is greater than the density of the gas, when the engine working camshaft rotates, the engine oil will be thrown onto the inner wall of the oil and gas channel under the action of centrifugal force, and the exhaust gas will flow along the oil and gas channel toward the tortuous joint. The flow of exhaust gas will push the engine oil to move along the inner wall of the oil and gas channel toward the outlet of the oil and gas channel, and the exhaust gas will be discharged through the tortuous joint. The engine oil moves along the separation oil channel and is discharged and recycled for reuse, realizing oil and gas separation. The tortuous joint is firmly connected to the crankcase. Since the separation rib is spiral, the separation oil channel is spiral, and the engine oil moves forward in a spiral shape when the camshaft rotates. The engine oil can be better discharged under the action of centrifugal force. At the same time, the separation rib is spirally raised, and the separation rib is perpendicular to the flow direction of the exhaust gas. The separation rib can effectively block the exhaust gas, so that the exhaust gas cannot enter the engine again through the separation oil channel, so that the oil and gas are separated completely. The oil-gas separation structure is to set separation convex strips on the outer wall of the curved joint to achieve oil-gas separation. Compared with setting guide grooves and drilling oil drain holes on the inner wall of the camshaft oil-gas channel, it is convenient to process and reduces costs.

[0008] In the oil-gas separation structure of the above-mentioned camshaft assembly, one section of the inner wall of the oil-gas channel is a constricted section that is annularly protruding inward, and the connection between the two ends of the constricted section and the inner wall of the oil-gas channel is arc-shaped. The flow area of ​​the oil-gas channel at the constricted section becomes smaller, so that the flow rate of the exhaust gas becomes faster. When the exhaust gas passes through the constricted section, the flow area suddenly becomes larger, and the exhaust gas is ejected outward. With the centrifugal force of the camshaft rotating oil itself, the oil can be better pushed to the inner wall of the oil-gas channel, so that the oil can be better discharged from the separation oil channel for recycling and reuse, realizing oil-gas separation and improving oil-gas separation efficiency; at the same time, the connection between the two ends of the constricted section is arc-shaped, so that the oil can better move along the inner wall of the oil-gas channel without being blocked.

[0009] In the oil-gas separation structure of the camshaft assembly described above, the camshaft has a concave section that is annular and inwardly concave, and the concave section is arranged corresponding to the necking section. The space inside the engine is limited, and the arrangement of the concave section increases the space, which can be used for the embedding of components such as cams, and the space is reasonably utilized to make the engine structure compact; at the same time, the position of the concave section of the camshaft is exactly the position of the necking section, and it is only necessary to squeeze the section of the camshaft inward to naturally form the concave section and the necking section, which is convenient for processing.

[0010] In the above-mentioned oil-gas separation structure of the camshaft assembly, the separation ridge is in contact with the inner wall of the oil-gas passage. This structure ensures that the engine oil moves along the separation oil passage, and the exhaust gas does not enter the engine again from there, and the oil-gas separation is complete.

[0011] In the above-mentioned oil-gas separation structure of a camshaft assembly, the separation convex strip and the curved joint are an integrated structure. The integrated structure has good stability and high firmness, and the separation convex strip can be processed on the surface by turning and milling, which is convenient for processing.

[0012] In the above-mentioned oil-gas separation structure of a camshaft assembly, the spiral direction of the separation oil passage is consistent with the rotation direction of the camshaft. The separation oil passage is consistent with the flow direction of the engine oil, so that the engine oil can flow more quickly and improve the oil-gas separation efficiency.

[0013] In the above-mentioned oil-gas separation structure of a camshaft assembly, the intake end of the tortuous joint and the middle part of the tortuous joint have a transition section, and the outer diameter of the transition section gradually decreases along the direction from the intake end of the tortuous joint toward the middle part of the tortuous joint. This structure prevents the oil in the oil-gas channel from being blocked and can be better discharged, thereby improving the oil-gas separation efficiency.

[0014] In the oil-gas separation structure of the above-mentioned camshaft assembly, the intake end of the camshaft is fixedly connected with a sprocket, and the oil-gas separation structure also includes a centrifugal valve fixedly connected to the outer side of the sprocket, and the centrifugal valve has a plurality of protruding separation plates on the side close to the sprocket, and the separation plates are arc-shaped, and all the separation plates are arranged at intervals and distributed in a ring shape, and the inner ends of all the separation plates form a gas passage space, and the middle of the sprocket has a through gas passage, and the gas passage space is connected with the oil-gas passage through the gas passage. The sprocket drives the centrifugal valve and the camshaft to rotate, and the centrifugal valve rotates to generate centripetal force, and the separation plates rotate to inhale the oil-gas mixture. Since the density of the engine oil is greater than the density of the gas, part of the engine oil is thrown out, realizing the first oil-gas separation, and the engine oil content in the oil-gas mixture entering the oil-gas passage is significantly reduced; the gas passage space plays the role of collecting the oil-gas mixture, and the gas passage allows the collected oil-gas mixture to pass through the sprocket through the gas passage and enter the oil-gas passage.

[0015] In the oil-gas separation structure of the camshaft assembly, the centrifugal valve has a protruding guide protrusion, and the guide protrusion is located in the middle of the air passage space, and the outer wall of the guide protrusion is an inwardly concave arc-shaped guide surface, and the outer diameter of the guide surface gradually decreases along the centrifugal valve toward the sprocket. The guide protrusion and the guide surface play a guiding role, guiding the flow direction of the oil-gas mixture, so that the oil-gas mixture can better enter the oil-gas channel, better realize oil-gas separation, and improve the efficiency of oil-gas separation.

[0016] In the above-mentioned oil-gas separation structure of a camshaft assembly, the tip of the guide protrusion faces the radial middle of the oil-gas passage. This structure centers the guide protrusion, allowing the oil-gas mixture to enter the oil-gas passage more evenly, so that the oil-gas mixture in the oil-gas passage flows in a balanced manner and at a fast flow rate, thereby improving the efficiency of oil-gas separation.

[0017] Compared with the prior art, the oil-gas separation structure of a camshaft assembly provided by the present invention has the following advantages:

[0018] 1. The oil-gas separation structure first performs the first oil-gas separation through the centrifugal valve and the separation sheet, and then performs the second oil-gas separation through the torsion joint and the separation channel between the torsion joint and the camshaft, so as to make the oil-gas separation thorough and ensure the effective completion of the oil-gas separation.

[0019] 2. The oil-gas separation structure is provided with separation convex strips on the outer wall of the tortuous joint, which is convenient for processing and reduces costs compared with providing guide grooves and drilling oil drain holes on the inner wall of the camshaft oil-gas passage.

[0020] 3. The centrifugal valve, separation sheet and guide protrusion of the oil-gas separation structure realize oil-gas separation, and at the same time enable the oil-gas mixture to enter the oil-gas channel better, thereby improving the oil-gas separation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a sectional view of the overall structure of the oil-gas separation structure of the camshaft assembly.

[0022] Figure 2 It is a schematic diagram of the overall structure of the oil-gas separation structure of the camshaft assembly.

[0023] Figure 3 It is a schematic diagram of the overall structure of this curved joint.

[0024] Figure 4 It is a schematic diagram of the overall structure of the centrifugal valve and separation plate.

[0025] In the figure, 1, camshaft; 11, recessed section; 2, oil and gas channel; 21, necking section; 3, tortuous joint; 31, transition section; 32, separation rib; 4, separation oil channel; 5, sprocket; 51, air passage; 6, centrifugal valve; 7, separation plate; 8, air passage space; 9, guide protrusion; 91, guide surface. DETAILED DESCRIPTION

[0026] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0027] like Figure 1 , Figure 2 As shown, the camshaft assembly includes a camshaft 1, a sprocket 5 and an oil-gas separation structure, and the oil-gas separation structure includes an oil-gas channel 2 that penetrates the camshaft 1 axially, a torsion joint 3, a centrifugal valve 6, a separation plate 7 and a guide protrusion 9.

[0028] like Figure 3 As shown, the outer wall of the air inlet end of the tortuous joint 3 has a separation ridge 32 which is spirally arranged along the axial direction of the camshaft. The separation ridge 32 and the tortuous joint 3 are an integrated structure. The air inlet end of the tortuous joint 3 and the middle part of the tortuous joint 3 have a transition section 31. The outer diameter of the transition section 31 gradually decreases along the direction from the air inlet end of the tortuous joint 3 toward the middle part of the tortuous joint 3.

[0029] The inner wall of the oil and gas channel 2 is a concave section 21 that is annular and inwardly convex, and the connection between the two ends of the concave section 21 and the inner wall of the oil and gas channel 2 is arc-shaped. The camshaft 1 has a concave section 11 that is annular and inwardly concave, and the concave section 11 is corresponding to the concave section 21.

[0030] The air inlet end of the torsion joint 3 is inserted into the air outlet of the oil and gas channel 2, and the separation ridge 32 is in contact with the inner wall of the oil and gas channel 2. A spiral separation oil channel 4 for the oil to pass through is formed between the inner wall of the oil and gas channel 2, the outer wall of the torsion joint 3 and the separation ridge 32, and the spiral direction of the separation oil channel 4 is consistent with the rotation direction of the camshaft 1.

[0031] The sprocket 5 is fixedly connected to the intake end of the camshaft 1. Figure 4As shown, in this embodiment, the centrifugal valve 6 has eight protruding separation plates 7 on one side close to the sprocket 5. In actual production, the number of separation plates 7 can be five or twelve. The separation plates 7 are arc-shaped, and all the separation plates 7 are arranged at intervals and distributed in a ring shape. The inner ends of all the separation plates 7 surround a gas passage space 8. The centrifugal valve 6 has a protruding guide protrusion 9, and the guide protrusion 9 is located in the middle of the gas passage space 8. The outer wall of the guide protrusion 9 is an inwardly concave arc-shaped guide surface 91. Along the centrifugal valve 6 toward the sprocket 5, the outer diameter of the guide surface 91 gradually decreases. There is a through gas passage 51 in the middle of the sprocket 5. The gas passage space 8 is connected to the oil and gas passage 2 through the gas passage 51. The tip of the guide protrusion 9 is directly opposite to the middle of the oil and gas passage 2 in the radial direction.

[0032] When the engine is working, the sprocket 5 rotates to drive the camshaft 1 and the centrifugal valve 6 to rotate, and the centrifugal valve 6 rotates to drive the separation plate 7 to rotate, sucking the oil-gas mixture into the gas passage space 8. In this process, under the action of centrifugal force, the first oil-gas separation is achieved, so that the oil content in the oil-gas mixture entering the oil-gas passage 2 through the gas passage 51 is reduced. The oil-gas mixture moves along the oil-gas passage 2, and the camshaft 1 rotates. Under the action of centripetal force and the push of exhaust gas, the oil moves along the inner wall of the oil-gas passage 2 and is recycled again through the separation passage, while the exhaust gas is discharged through the tortuous joint 3, achieving the second oil-gas separation.

[0033] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0034] Although the camshaft 1, recessed section 11, oil and gas passage 2, constricted section 21, tortuous joint 3, transition section 31, separation ridge 32, separation oil passage 4, sprocket 51, air passage 51, centrifugal valve 6, separation sheet 7, air passage space 8, guide protrusion 9, guide surface 91 and other terms are used more frequently in this article, the possibility of using other terms is not excluded. The use of these terms is only for more convenient description and explanation of the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. An oil-gas separation structure of a camshaft assembly, comprising an oil-gas passage (2) in a camshaft (1) and extending axially through the camshaft (1), characterized in that The oil-gas separation structure also includes a torsion joint (3), the outer wall of the air inlet end of the torsion joint (3) having a separation convex strip (32) arranged in a spiral shape along the axial direction of the camshaft, the air inlet end of the torsion joint (3) is arranged in the air outlet of the oil-gas passage (2), and a spiral separation oil passage (4) for the passage of engine oil is formed between the inner wall of the oil-gas passage (2), the outer wall of the torsion joint (3) and the separation convex strip (32), one section of the inner wall of the oil-gas passage (2) is a concave section (21) arranged inwardly protruding in an annular shape, and the connection between the two ends of the concave section (21) and the inner wall of the oil-gas passage (2) is in an arc shape, and the camshaft (1) has a concave section (11) arranged inwardly concave in an annular shape, and the concave section (11) is arranged corresponding to the concave section (21).

2. The oil-gas separation structure of a camshaft assembly according to claim 1, characterized in that: The separation convex strip (32) is in contact with the inner wall of the oil and gas channel (2).

3. The oil-gas separation structure of a camshaft assembly according to claim 1, characterized in that: The separation convex strip (32) and the curved joint (3) are an integrated structure.

4. The oil-gas separation structure of a camshaft assembly according to claim 1, 2 or 3, characterized in that: The spiral direction of the separation oil passage (4) is consistent with the rotation direction of the camshaft (1).

5. The oil-gas separation structure of a camshaft assembly according to claim 1, 2 or 3, characterized in that: The air inlet end of the tortuous joint (3) and the middle part of the tortuous joint (3) have a transition section (31), and the outer diameter of the transition section (31) gradually decreases in the direction from the air inlet end of the tortuous joint (3) toward the middle part of the tortuous joint (3).

6. The oil-gas separation structure of a camshaft assembly according to claim 1, 2 or 3, characterized in that: The intake end of the camshaft (1) is fixedly connected to a sprocket (5), and the oil-gas separation structure also includes a centrifugal valve (6) fixedly connected to the outer side of the sprocket (5), and the centrifugal valve (6) has a plurality of protruding separation sheets (7) on the side close to the sprocket (5), and the separation sheets (7) are arc-shaped, and all the separation sheets (7) are arranged at intervals and distributed in a ring shape, and the inner ends of all the separation sheets (7) form a gas passage space (8), and the middle of the sprocket (5) has a penetrating gas passage (51), and the gas passage space (8) is connected to the oil-gas passage (2) through the gas passage (51).

7. The oil-gas separation structure of a camshaft assembly according to claim 6, characterized in that: The centrifugal valve (6) has a protruding guide protrusion (9), and the guide protrusion (9) is located in the middle of the air passage space (8). The outer wall of the guide protrusion (9) is an inwardly concave arc-shaped guide surface (91), and the outer diameter of the guide surface (91) gradually decreases along the centrifugal valve (6) toward the sprocket (5).

8. The oil-gas separation structure of a camshaft assembly according to claim 7, characterized in that: The tip of the guide protrusion (9) faces the radial middle of the oil and gas channel (2).

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