Crankshaft oil supply system

Abstract

The present invention relates to an engine lubrication system, and in particular to a crankshaft oil supply system, wherein an upper oil storage groove is circumferentially arranged on the inner circumference of an upper bearing shell, and a lower oil storage groove is arranged downward from the parting surface between the lower bearing shell and the upper bearing shell on the inner circumference of the lower bearing shell, and the ends of the lower oil storage groove and the upper oil storage groove are connected. The present invention opens oil grooves on the left and right parting surfaces of the lower bearing shell, solves the problem of insufficient oil supply to the crankshaft bearing shell, increases the oil supply duration angle, increases the oil supply to the crankshaft main journal and the connecting rod journal, and reduces the occurrence of the failure of burning the bearing shell.

Description

Technical Field

[0001] The invention relates to an engine lubrication system, in particular to a crankshaft oil supply system. Background Art

[0002] In the prior art, the crankshaft oil supply system consists of a crankshaft, an upper bearing shell, and a lower bearing shell. The crankshaft oil supply is generally to open an oil groove in the upper bearing shell, and the lower bearing shell has no oil groove. A hole is drilled in the crankshaft main journal to lead the engine oil to the connecting rod journal for lubrication. The crankshaft oil supply is generally to open an oil groove in the upper bearing shell. When the oil hole of the crankshaft main shaft is in communication with the upper oil groove, the engine oil enters the crankshaft main journal and flows to the connecting rod journal through the oil hole of the main shaft. It plays the role of lubricating, cooling, flushing, and rust prevention on the connecting rod journal.

[0003] For example, Chinese patent CN211175051U discloses a crankshaft thrust plate forced lubrication structure, which includes a body bearing seat and a bearing cover, a bolt hole seat is provided on the bearing cover, the bearing cover is installed at the bottom of the body bearing seat by bolts, the upper bearing shell and the lower bearing shell are installed on the inner circumference of the body bearing seat and the bearing cover respectively, thrust plates are installed on both side surfaces of the bearing cover, a body main oil channel is arranged inside the body bearing seat, a through hole is opened in the middle of the outer circumference of the upper bearing shell, an arc-shaped oil storage groove is opened on the inner circumference of the upper bearing shell, and the middle of the arc-shaped oil storage groove is connected with the body main oil channel through the through hole; an oil passage independent of the bolt hole inside the bolt hole seat is opened inside the bearing cover, one end of the oil passage is connected with the end of the arc-shaped oil storage groove of the upper bearing shell, and the other end leads to the side of the bearing cover in contact with the thrust plate. This structure only has an oil storage groove on the upper bearing shell. The connecting rod bearing has a large oil cut-off angle in the top dead center area, which can easily cause bearing burning. When the oil hole of the crankshaft main shaft is located at the lower bearing shell without an oil groove, no oil can pass through, making it impossible to lubricate and dissipate heat for the connecting rod journal.

[0004] The prior art also has a structure in which an oil storage tank is provided on the lower bearing shell, such as the thrust plate forced lubrication structure disclosed in Chinese patent CN205423551U, which includes: a main bearing shell, the inner circumferential surface of which is provided with an oil storage tank along the circumferential direction, and an oil inlet hole connected to the oil storage tank; thrust plates, arranged in pairs on the two side end surfaces of the main bearing shell; and a main bearing cap, which presses the main bearing shell from above and is fixed to the engine body through bolts passing through the main bearing cap bolt holes, the main bearing cap bolt holes being connected to the oil storage tank of the main bearing shell; the main bearing cap is provided with a thrust plate lubricating oil passage, the inlet of the thrust plate lubricating oil passage is connected to the main bearing cap bolt holes, and the outlet of the thrust plate lubricating oil passage is provided on the outer side of the thrust plate. However, the upper bearing shell of this structure does not have an oil storage tank, and the oil storage tank is provided on the entire lower bearing shell, which affects the bearing capacity of the lower bearing shell, so the force on the lower bearing shell is relatively large, which is easy to cause damage to the lower bearing shell. Summary of the invention

[0005] The present invention provides a crankshaft oil supply system, in which oil grooves are opened on the left and right parting surfaces of the lower bearing shell, thereby solving the problem of insufficient oil supply to the crankshaft bearing shell, increasing the oil supply duration angle, increasing the oil supply to the crankshaft main journal and the connecting rod journal, and reducing the occurrence of bearing burnout failures.

[0006] The technical solution of the present invention is as follows:

[0007] A crankshaft oil supply system comprises a main journal, an upper bearing shell, a lower bearing shell and an oil channel, wherein the upper bearing shell is press-fitted on the upper part of the lower bearing shell, the oil channel connects the main journal and the connecting rod journal, an upper oil storage tank is circumferentially arranged on the inner circumference of the upper bearing shell, a lower oil storage tank is arranged on the inner circumference of the lower shaft downward from the parting surface between the upper bearing shell and the upper bearing shell, the lower oil storage tank is connected to the end of the upper oil storage tank, the arc angle of the lower oil storage tank is 25 to 35 degrees, the upper bearing shell is provided with an oil inlet hole connecting the upper oil storage tank and the main oil channel of the body, and the opening of the oil channel on the main journal is arranged at the longitudinal position corresponding to the upper oil storage tank.

[0008] Under the premise of not changing the crankshaft, the present invention grooves the lower parting surface of the lower bearing shell at an angle of 25 to 35 degrees. The load in this area is relatively small. The angle greater than 25 degrees is to increase the arc angle of the lower oil storage tank as much as possible, and the angle less than 35 degrees is to prevent the lower oil storage tank from being too large to affect the bearing capacity of the lower bearing shell.

[0009] The problem of poor bearing capacity of the lower bearing shell caused by opening an oil storage tank in the entire lower bearing shell is avoided. The present invention does not affect the bearing capacity of the lower shell, and increases the angle coverage of the oil storage tank and the oil supply to the connecting rod shell.

[0010] The invention reduces the oil cut-off angle of the connecting rod bearing in the top dead center area, reduces the risk of bearing burning, has a simple structure, is reliable, has low cost, and can be interchanged between the old and the new.

[0011] Preferably, the lower oil storage tanks are arranged in pairs at the upper positions on both sides of the upper bearing shell, and oil grooves are opened on the left and right parting surfaces of the lower bearing shell. The two lower oil storage tanks are used to further increase the oil supply angle, which increases the oil supply duration angle by 25 to 35° compared with a single lower oil storage tank. The oil supply duration angle can be increased to 230 to 250°, thereby increasing the oil supply to the crankshaft main journal and connecting rod journal and reducing the occurrence of bearing burning failures.

[0012] Preferably, when the connecting rod journal is at the top dead center position, the opening of the oil channel on the main journal is arranged at the lower part of the lower oil storage tank. When viewed from the crankshaft axis, the angle between the axis of the oil channel and the vertical direction is 25 to 30°, thereby avoiding the oil cut-off phenomenon of the connecting rod bearing at the top dead center. At the same time, the curvature of the lower oil storage tank is minimized to avoid affecting the load-bearing capacity of the lower bearing.

[0013] Preferably, the surface roughness of the parting surface of the upper bearing and the lower oil storage tank is 1.6μm, the surface roughness of the inner surface of the upper bearing and the lower oil storage tank is 0.8μm, and the surface roughness of the outer surface of the upper bearing and the lower oil storage tank is 0.8μm. The above-mentioned roughness sizes are used to avoid leakage of lubricating oil and ensure the pressure of the lubrication system.

[0014] Furthermore, the width of the lower bearing is 21 mm, the thickness of the lower bearing is 2 mm, and the length of the lower oil storage tank vertically extending downward from the parting surface is 14 mm.

[0015] Preferably, the lower oil storage tank is arranged in the middle of the axial position of the lower bearing shell when viewed from the axial direction of the crankshaft, so as to facilitate the positioning and processing of the lower oil storage tank and avoid the influence of the lower oil storage tank on the overall strength of the lower bearing shell.

[0016] The beneficial effects of the present invention are:

[0017] 1. The groove is cut downward on the parting surface of the lower bearing, which reduces the oil cut-off angle of the connecting rod bearing in the top dead center area and reduces the failure of bearing burning. The structure is simple and the cost is low. The original bearing can be directly interchanged, which greatly reduces the maintenance cost.

[0018] 2. Slots are made in the part of the lower bearing where the load is relatively small. This increases the oil supply to the connecting rod bearing without affecting the bearing capacity of the lower bearing, thus ensuring the bearing capacity of the lower bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention discloses a cross-sectional structural diagram of a lower bearing shell of a crankshaft oil supply system.

[0020] Figure 2 The present invention is a top view of a lower bearing shell of a crankshaft oil supply system.

[0021] Figure 3 It is a cross-sectional view of a lower bearing shell of a crankshaft oil supply system described in the present invention.

[0022] Figure 4 The present invention is a top view of an upper bearing shell of a crankshaft oil supply system.

[0023] Figure 5 It is a schematic diagram of the working state of a crankshaft oil supply system described in the present invention.

[0024] Figure 6 Positional relationship diagram of the main journal and connecting rod journal according to the present invention.

[0025] In the figure: 1-main journal, 2-upper bearing shell, 201-upper oil storage tank, 202-oil inlet hole, 3-lower bearing shell, 301-lower oil storage tank, 4-oil channel, 5-connecting rod journal. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0027] In the description of the present invention, it is necessary to understand that the terms "left", "right", "up", "down", "front", "back", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or structure referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0028] Embodiment 1:

[0029] like Figure 1 to Figure 4 As shown, a crankshaft oil supply system comprises a main journal 1, an upper bearing shell 2, a lower bearing shell 3 and an oil passage 4, wherein the upper bearing shell 2 is pressed and fitted on the upper part of the lower bearing shell 3;

[0030] like Figure 6 As shown, the oil passage 4 is connected to the main journal 1 and the connecting rod journal 5, an upper oil storage groove 201 is circumferentially arranged on the inner circumference of the upper bearing shell 2, and a lower oil storage groove 301 is arranged downward from the parting surface between the lower bearing shell 3 and the upper bearing shell 2 on the inner circumference of the lower bearing shell 3, and the lower oil storage groove 301 is connected to the end of the upper oil storage groove 201;

[0031] like Figure 3 As shown, the arc angle of the lower oil storage tank 301 is 25-35°, and the upper bearing 2 is provided with an oil inlet hole 202 connecting the upper oil storage tank 201 and the main oil channel of the engine body;

[0032] The opening of the oil passage 4 on the main journal 1 is arranged at a longitudinal position corresponding to the upper oil storage groove 201 .

[0033] The working principle of this embodiment is as follows:

[0034] like Figure 5As shown, the arrow shows the flow direction of the engine oil. When the engine is running and the crankshaft rotates, the engine oil enters the upper oil storage tank 201 from the main oil channel, and then fills the upper oil storage tank 201 and the lower oil storage tank 301. When the opening of the oil channel 4 on the main journal 1 is in communication with the upper oil storage tank 201 or the lower oil tank of the upper bearing shell 2, the engine oil enters the oil channel 4 under pressure and flows to the connecting rod journal 5 through the oil channel 4. It plays the role of lubricating, cooling, flushing, and rust prevention on the connecting rod journal 5.

[0035] In this embodiment, the lower oil storage tank 301 is provided with an oil supply duration angle increased from the original 180 degrees to 205-215 degrees, thereby increasing the oil supply to the crankshaft main journal 1 and the connecting rod journal and reducing the occurrence of burning shoe failures.

[0036] Embodiment 2:

[0037] like Figures 1 to 6 As shown, a crankshaft oil supply system includes a main journal 1, an upper bearing shell 2, a lower bearing shell 3 and an oil channel 4, the upper bearing shell 2 is pressed and fitted on the upper part of the lower bearing shell 3, the main journal 1 is arranged in an inner cavity formed by the upper bearing shell 2 and the lower bearing shell 3, the oil channel 4 connects the main journal 1 and the connecting rod journal 5, an upper oil storage groove 201 is circumferentially arranged on the inner circumference of the upper bearing shell 2, a lower oil storage groove 301 is arranged on the inner circumference of the lower bearing shell 3 downward from the parting surface between it and the upper bearing shell 2, the lower oil storage groove 301 is connected to the end of the upper oil storage groove 201, the arc angle of the lower oil storage groove 301 is 25°, the upper bearing shell 2 is provided with an oil inlet hole 202 connecting the upper oil storage groove 201 and the main oil channel of the body, and the opening of the oil channel 4 on the main journal 1 is arranged at the longitudinal position corresponding to the upper oil storage groove 201.

[0038] In this embodiment, without changing the crankshaft, a groove is formed at an angle α of 25° below the parting surface of the lower bearing shell 3. The load in this size area is relatively small, thereby avoiding the problem of poor bearing capacity of the lower bearing shell 3 caused by opening an oil storage tank in the entire lower bearing shell 3. This embodiment does not affect the bearing capacity of the lower shell, and increases the angle coverage range of the oil storage tank, and increases the oil supply to the connecting rod shell.

[0039] This embodiment reduces the oil cut-off angle of the connecting rod bearing in the top dead center area, reduces the risk of bearing burning, has a simple structure, is reliable, low cost, and can be interchanged with the old and new ones.

[0040] In this embodiment, the lower oil storage tanks 301 are arranged in pairs at the upper positions on both sides of the upper bearing 2. The two lower oil storage tanks 301 are used to further increase the oil supply angle, which increases the oil supply continuous angle by 25° compared with a single lower oil storage tank 301. The oil supply continuous angle can be increased to 230°, thereby increasing the oil supply to the crankshaft main journal 1 and the connecting rod journal and reducing the occurrence of bearing burning failures.

[0041] like Figure 5 As shown, in this embodiment, when the connecting rod journal 5 is at the top dead center position, the opening of the oil channel 4 on the main journal 1 is arranged at the lower part of the lower oil storage tank 301, and the angle β between the axis of the oil channel 4 and the vertical direction when viewed from the crankshaft axis is 25°, thereby avoiding the oil cut-off phenomenon of the connecting rod bearing at the top dead center, and at the same time, minimizing the curvature of the lower oil storage tank 301 to avoid affecting the load-bearing capacity of the lower bearing 3.

[0042] like Figure 2 and Figure 3 As shown, in this embodiment, the surface roughness of the parting surface of the upper bearing 2 and the lower oil storage tank 301 is 1.6μm, the surface roughness of the inner surface of the upper bearing 2 and the lower oil storage tank 301 is 0.8μm, and the surface roughness of the outer surface of the upper bearing 2 and the lower oil storage tank 301 is 0.8μm. The above-mentioned roughness sizes are used to avoid leakage of lubricating oil and ensure the pressure of the lubrication system.

[0043] like Figure 1 As shown, further, in this embodiment, the width D of the lower bearing shell 3 is 21 mm, the thickness h of the lower bearing shell 3 is 2 mm, and the length H of the lower oil storage tank 301 vertically extending downward from the parting surface is 14 mm.

[0044] like Figure 2 As shown, in this embodiment, the lower oil storage tank 301 is arranged in the middle of the axial position of the lower bearing shell 3 from the axial direction of the crankshaft, so as to facilitate the positioning and processing of the lower oil storage tank 301 and avoid the influence of the lower oil storage tank 301 on the overall strength of the lower bearing shell 3.

[0045] Embodiment 3:

[0046] The difference between this embodiment and the above-mentioned embodiment 2 is that: Figure 3 The arc angle α of the lower oil storage tank 301 is shown to be 35°, which increases the oil supply duration angle to the greatest extent. When viewed from the crankshaft axis, the angle β between the axis of the oil channel 4 and the vertical direction is 30°.

Claims

1. A crankshaft oil supply system, comprising a main journal (1), an upper bearing shell (2), a lower bearing shell (3) and an oil passage (4), wherein the upper bearing shell (2) is press-fitted on the upper part of the lower bearing shell (3), and the oil passage (4) is connected to the main journal (1) and the connecting rod journal (5), characterized in that: An upper oil storage groove (201) is circumferentially arranged on the inner circumference of the upper bearing shell (2); a lower oil storage groove (301) is arranged on the inner circumference of the lower bearing shell (3) downward from the parting surface between the lower bearing shell (3) and the upper bearing shell (2); the lower oil storage groove (301) is connected to the ends of the upper oil storage groove (201); the arc angle of the lower oil storage groove (301) is 25-35 degrees; the upper bearing shell (2) is provided with an oil inlet hole (202) connecting the upper oil storage groove (201) and the main oil channel of the engine body; the oil channel (4) is opened on the main journal (1) The opening of the oil passage (4) is arranged at a longitudinal position corresponding to the upper oil storage groove (201); the lower oil storage grooves (301) are arranged in pairs at upper positions on both sides of the upper bearing shell (2); when the connecting rod journal (5) is at the top dead center position, the opening of the oil passage (4) on the main journal (1) is arranged at the lower part of the lower oil storage groove (301), and the angle between the axis of the oil passage (4) and the vertical direction when viewed from the crankshaft axis is 25 to 30 degrees; when viewed from the crankshaft axis, the lower oil storage groove (301) is arranged in the middle of the axial position of the lower bearing shell (3).

2. A crankshaft oil supply system according to claim 1, characterized in that: The surface roughness of the parting surfaces of the upper bearing shell (2) and the lower oil storage tank (301) is 1.6 μm, the surface roughness of the inner surfaces of the upper bearing shell (2) and the lower oil storage tank (301) is 0.8 μm, and the surface roughness of the outer surface of the upper bearing shell (2) is 0.8 μm.

3. A crankshaft oil supply system according to claim 1 or 2, characterized in that: The width of the lower bearing shell (3) is 21 mm, the thickness of the lower bearing shell (3) is 2 mm, and the length of the lower oil storage groove (301) extending vertically downward from the parting surface is 14 mm.

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