JP6208594B2 - Slide bearing and lubricating oil supply mechanism having the same - Google Patents

Description

  The present invention relates to a technology of a cylindrical slide bearing formed by combining a pair of semi-cylindrical bearings and rotatably supporting a shaft member, and a lubricating oil supply mechanism including the cylindrical bearing.

  Conventionally, a technique of a cylindrical slide bearing formed by combining a pair of semi-cylindrical bearings and rotatably supporting a shaft member has been publicly known. For example, as described in Patent Document 1.

  The half-shaped slide bearing (semi-cylindrical bearing) described in Patent Document 1 includes a crush relief formed at both ends of the inner peripheral surface, and from the vicinity of one crush relief to the vicinity of the other crush relief. An oil groove is formed, and an inflow blocking portion is formed between the oil groove and the crush relief, and prevents the lubricating oil in the oil groove from flowing into the crush relief.

  In the slide bearing configured as described above, the oil groove and the crush relief are blocked by the inflow blocking portion so as not to communicate with each other. Accordingly, it is possible to reduce the amount of lubricating oil leaking from the oil groove to the outside of the slide bearing through the crash relief. As a result, the lubricating oil in the oil groove can be sufficiently supplied to the inner peripheral surface of the slide bearing, and the occurrence of problems (such as seizure and wear) due to the insufficient amount of the lubricating oil can be suppressed.

  However, the technique described in Patent Document 1 is disadvantageous in that it is difficult for the lubricating oil in the oil groove to flow out to the outside, so that the temperature of the lubricating oil rises and the seizure tends to occur. It was.

JP-A-2005-249024

  The present invention has been made in view of the situation as described above, and the problem to be solved is a sliding bearing capable of suppressing an increase in the temperature of the lubricating oil, and a lubricating oil supply mechanism including the same. Is to provide.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

That is, in claim 1, a pair of upper and lower semi-cylindrical bearings is formed by combining a pair of upper and lower semi-cylindrical bearings, and rotatably supports the shaft member. The crush relief formed at the upstream and downstream ends of the shaft member on the inner peripheral surface of the semi-cylindrical bearing and the one of the crush reliefs communicate with each other. Each of the oil grooves formed in the pair of upper and lower semi-cylindrical bearings has a constant depth over the entire area. Of the pair of upper and lower semi-cylindrical bearings, the oil groove formed in the lower semi-cylindrical bearing has a cross-sectional area that is smaller than the other parts only at the downstream end. Is formed .

According to a second aspect of the present invention, there is provided a crankshaft having a communication oil passage that communicates the outer peripheral surface of the crank journal and the outer peripheral surface of the crank pin and guides the lubricating oil from the outer peripheral surface of the crank journal to the outer peripheral surface of the crank pin. The slide journal according to claim 1 is provided, and the crank journal is rotatably supported by the slide bearing.

  As effects of the present invention, the following effects can be obtained.

  According to the first aspect of the present invention, it is possible to suppress an increase in the temperature of the lubricating oil in the oil groove by urging the lubricating oil in the oil groove to be discharged from the crash relief to the outside. Thereby, the occurrence of seizure of the slide bearing can be suppressed.

According to the second aspect , it is possible to suppress an increase in the temperature of the lubricating oil supplied from the slide bearing to the crank pin. Thereby, the occurrence of seizure of the crankpin can be suppressed.

The side surface schematic diagram which showed schematic structure of the crankshaft. Front sectional drawing which showed the structure of the support part of a crank journal. Front sectional drawing which showed the main bearing and the crank journal. Front sectional drawing which showed the upper side bearing. Front sectional drawing which showed the lower side bearing. (A) AA sectional drawing in FIG. (B) BB sectional drawing in FIG. The front cross-sectional enlarged view which showed the downstream end part of the upper side bearing, and the upstream end part of the lower side bearing. The front cross-sectional enlarged view which showed the upstream edge part of the upper side bearing, and the downstream edge part of a lower side bearing. (A) The front cross-sectional enlarged view which showed the downstream edge part of the lower side bearing. (B) CC sectional drawing. (C) DD sectional drawing.

  In the following description, the vertical direction, the front-rear direction, and the left-right direction are defined according to the arrows shown in the drawing.

  First, the structure regarding the crankshaft 1 provided with the main bearing 2 which concerns on one Embodiment of the slide bearing which concerns on this invention, and the outline of the lubricating oil supply mechanism regarding the said crankshaft 1 are demonstrated using FIG.

  The crankshaft 1 is a member constituting an internal combustion engine (engine), and is used for converting the reciprocating motion of the piston into a rotational motion. The crankshaft 1 mainly includes a crank journal 1a, a crank arm 1b, a crankpin 1c, and a communication oil passage 1d.

  The crank journal 1 a is an embodiment of the shaft member according to the present invention, and is rotatably supported by the cylinder block 3 via the main bearing 2. The main bearing 2 is formed with a through hole 14 that communicates the outer peripheral surface and the inner peripheral surface thereof. The crank pin 1c is connected to the crank journal 1a via the crank arm 1b. The crank pin 1 c is rotatably connected to the connecting rod 5 via the connecting rod bearing 4. The communication oil passage 1d is formed in the crankshaft 1 so as to communicate the outer peripheral surface of the crank journal 1a and the outer peripheral surface of the crank pin 1c.

  In such a configuration, lubricating oil from a main oil hole (not shown) is supplied to the main bearing 2 through a lubricating oil passage 3 c formed in the cylinder block 3. Further, the lubricating oil is supplied to the inner peripheral surface side of the main bearing 2 through the through hole 14 of the main bearing 2. The sliding surfaces of the main bearing 2 and the crank journal 1a are lubricated by the lubricating oil.

  The lubricating oil supplied to the inner peripheral surface side of the main bearing 2 is further supplied to the outer peripheral surface of the crank pin 1c via the communication oil passage 1d. The sliding surfaces of the crank pin 1c and the connecting rod bearing 4 are lubricated by the lubricating oil.

  Below, the structure of the connection part (support part of the crank journal 1a) of the crank journal 1a and the cylinder block 3 is demonstrated using FIG.

  The cylinder block 3 includes a main body side housing 3a and a cap 3b fixed to the lower portion of the main body side housing 3a. A bearing portion 3d is formed on the lower end surface of the main body side housing 3a so as to be recessed in a semicircular shape when viewed from the front. A bearing 3e is formed on the upper end surface of the cap 3b so as to be recessed in a semicircular arc shape when viewed from the front. The crank journal 1a is supported so as to be sandwiched between the bearing portion 3d and the bearing portion 3e. At this time, the main bearing 2 is interposed between the cylinder block 3 and the crank journal 1a.

  In such a configuration, when the crank journal 1a rotates (in the present embodiment, it rotates clockwise when viewed from the front), the crank journal 1a is interposed between the outer peripheral surface of the crank journal 1a and the inner peripheral surface of the main bearing 2. An oil film of lubricating oil supplied through the lubricating oil passage 3c is formed. The crank journal 1a is rotatably supported by the cylinder block 3 through the oil film.

  Below, the structure of the main bearing 2 is demonstrated in detail using FIGS. 2-6.

  The main bearing 2 shown in FIGS. 2 and 3 is a cylindrical slide bearing that rotatably supports the crank journal 1a. The main bearing 2 includes a pair of semi-cylindrical bearings (upper side bearing 10 and lower side bearing 20). A cylindrical main bearing 2 is formed by combining the upper side bearing 10 and the lower side bearing 20 face to face.

  An upper bearing 10 shown in FIGS. 3, 4, and 6 (a) is an embodiment of a semi-cylindrical bearing according to the present invention, and is a member that forms the upper half of the main bearing 2. The upper bearing 10 is formed in a semi-cylindrical shape (a shape obtained by cutting a cylinder with a diameter passing through the axis). The upper side bearing 10 is disposed on the bearing portion 3d of the main body side housing 3a of the cylinder block 3 with its inner peripheral surface facing downward (see FIG. 2). The upper bearing 10 mainly includes an upstream crash relief 11, a downstream crash relief 12, an oil groove 13, and a through hole 14.

  The upstream crush relief 11 and the downstream crush relief 12 shown in FIGS. 3 and 4 are portions formed by cutting out the inner peripheral surface of the upper bearing 10 in a concave shape. The upstream crash relief 11 is formed at the lower left end of the upper bearing 10 (the end on the upstream side in the rotational direction of the crank journal 1a (hereinafter simply referred to as “upstream side”)). The downstream-side crash relief 12 is formed at the lower right end of the upper-side bearing 10 (the end on the downstream side in the rotation direction of the crank journal 1a (hereinafter simply referred to as “downstream side”)). By providing the upstream-side crash relief 11 and the downstream-side crash relief 12 in the upper-side bearing 10, even if deformation occurs in the vicinity of both end portions of the upper-side bearing 10, a malfunction (specifically, the deformation has occurred) It is possible to prevent the occurrence of a portion that hits the crank journal 1a.

  The oil groove 13 shown in FIGS. 3, 4, and 6 (a) guides the lubricating oil on the inner peripheral surface of the upper bearing 10, and appropriately stores the lubricating oil on the inner peripheral surface. . The oil groove 13 is formed on the inner peripheral surface of the upper side bearing 10. The oil groove 13 is formed so as to extend along the circumferential direction of the upper side bearing 10. One end portion (upstream end portion) of the oil groove 13 is communicated with the upstream crash relief 11. The other end portion (downstream end portion) of the oil groove 13 is communicated with the downstream crash relief 12. That is, the oil groove 13 is formed so that the upstream crash relief 11 and the downstream crash relief 12 communicate with each other.

  The oil groove 13 is formed in the front-rear center part of the upper side bearing 10 (see FIG. 6A). The oil groove 13 is formed to have a constant width in the front-rear direction over the entire region. The oil groove 13 is formed to have a constant depth over the entire area. Here, the opening of the communication oil passage 1d formed in the crank journal 1a is formed at the same position as the oil groove 13 in the front-rear direction. As a result, when the crank journal 1a rotates and the opening of the communication oil passage 1d and the oil groove 13 face each other, the lubricating oil in the oil groove 13 passes through the communication oil passage 1d and the crank pin 1c (see FIG. 1). ).

  The through hole 14 is an embodiment of the oil supply hole according to the present invention, and communicates the inner peripheral surface (more specifically, the oil groove 13) and the outer peripheral surface of the upper side bearing 10. The through hole 14 is formed in the left and right center part (upper end part) of the upper bearing 10.

  The lower bearing 20 shown in FIGS. 3, 5, and 6 (b) is an embodiment of the semicylindrical bearing according to the present invention, and is a member that forms the lower half of the main bearing 2. The lower bearing 20 is formed in a semi-cylindrical shape. The lower-side bearing 20 is disposed on the bearing portion 3e of the cap 3b of the cylinder block 3 with its inner peripheral surface facing upward (see FIG. 2). The lower bearing 20 mainly includes an upstream crash relief 21, a downstream crash relief 22, and an oil groove 23.

  The upstream side crash relief 21 and the downstream side crash relief 22 shown in FIGS. 3 and 5 are portions formed by cutting out the inner peripheral surface of the lower side bearing 20 into a concave shape. The upstream crash relief 21 is formed at the upper right end (upstream end) of the lower bearing 20. The downstream crash relief 22 is formed at the upper left end (downstream end) of the lower bearing 20. By providing the upstream side crash relief 21 and the downstream side crash relief 22 in the lower side bearing 20, even if deformation occurs near both ends of the lower side bearing 20, a malfunction (specifically, the deformation has occurred) It is possible to prevent the occurrence of a portion that hits the crank journal 1a.

  The oil groove 23 shown in FIGS. 3, 5, and 6 (b) is for guiding the lubricating oil on the inner peripheral surface of the lower bearing 20 and for appropriately storing the lubricating oil on the inner peripheral surface. . The oil groove 23 is formed on the inner peripheral surface of the lower side bearing 20. The oil groove 23 is formed so as to extend along the circumferential direction of the lower bearing 20. One end portion (upstream end portion) of the oil groove 23 communicates with the upstream crush relief 21. The other end (downstream end) of the oil groove 23 is communicated with the downstream crash relief 22. That is, the oil groove 23 is formed so that the upstream crash relief 21 and the downstream crash relief 22 communicate with each other.

  The oil groove 23 is formed in the front and rear center portion of the lower bearing 20 (see FIG. 6B). At this time, the crank journal oil groove 23 is formed to have a constant width in the front-rear direction over the entire region. The oil groove 23 is formed to have a constant depth over the entire area. Here, the opening of the communication oil passage 1d formed in the crank journal 1a is formed at the same position as the oil groove 23 in the front-rear direction. Accordingly, when the crank journal 1a rotates and the opening of the communication oil passage 1d and the oil groove 23 face each other, the lubricating oil in the oil groove 23 passes through the communication oil passage 1d and the crank pin 1c (see FIG. 1). ).

  Hereinafter, the flow of the lubricating oil in the upper side bearing 10 and the lower side bearing 20 will be described with reference to FIG.

  Lubricating oil supplied from the outside to the inner peripheral surface (oil groove 13) of the upper bearing 10 through the through hole 14 flows downward in the oil groove 13 with gravity and rotation of the crank journal 1a. To do. Particularly, the lubricating oil circulates in the oil groove 13 in the clockwise direction in the oil groove 13 by the crank journal 1a rotating in the clockwise direction in the front view. Part of the lubricating oil flowing through the oil groove 13 is supplied to the sliding surface between the upper side bearing 10 and the crank journal 1a, and an oil film is formed on the sliding surface.

  A part of the lubricating oil flowing to the end of the oil groove 13 (particularly, the end on the downstream side) is discharged to the outside of the upper bearing 10 (main bearing 2) via the downstream crash relief 12. Further, other lubricating oil is supplied to the oil groove 23 of the lower bearing 20 via the downstream crash relief 12 and the upstream crash relief 21. The lubricating oil circulates in the oil groove 23 clockwise in front view by the crank journal 1a rotating in the clockwise direction in front view. Part of the lubricating oil flowing in the oil groove 23 is supplied to the sliding surface between the lower bearing 20 and the crank journal 1a, and an oil film is formed on the sliding surface.

  A part of the lubricating oil flowing to the downstream end of the oil groove 23 is discharged to the outside of the lower bearing 20 (main bearing 2) through the downstream crash relief 22. The other lubricating oil is supplied to the inner peripheral surface (oil groove 13) of the upper bearing 10 through the downstream crash relief 22 and the upstream crash relief 11.

  Here, as shown in FIG. 7, the oil groove 23 of the lower bearing 20 is in communication with the upstream crush relief 21, so that lubricating oil is supplied into the oil groove 23 via the upstream crush relief 21. It is easy to be done. Further, as shown in FIG. 8, the oil groove 23 of the lower bearing 20 is in communication with the downstream crush relief 22, so that the lubricating oil that has circulated through the oil groove 23 passes through the downstream crush relief 22. It can be urged to be discharged to the outside.

  In this way, by making the oil groove 23 communicate with the upstream crush relief 21 and the downstream crush relief 22, the inflow of the lubricating oil into the oil groove 23 and the discharge of the lubricating oil from the oil groove 23 are promoted. Can do. Therefore, the lubricating oil that has become hot due to frictional heat (sliding heat) between the crank journal 1a and the main bearing 2 (lower bearing 20) is less likely to stay in the oil groove 23. As a result, an increase in the temperature of the lubricating oil in the oil groove 23 can be suppressed, and consequently the occurrence of seizure can be suppressed.

  Similarly, as shown in FIG. 8, since the oil groove 13 of the upper side bearing 10 communicates with the upstream crush relief 11, lubricating oil is supplied into the oil groove 13 through the upstream crush relief 11. It is easy to be done. Further, as shown in FIG. 7, the oil groove 13 of the upper bearing 10 is in communication with the downstream crush relief 12, so that the lubricating oil that has circulated through the oil groove 13 passes through the downstream crush relief 12. It can be urged to be discharged to the outside.

  In this way, the oil groove 13 is communicated with the upstream crush relief 11 and the downstream crush relief 12 to promote the inflow of the lubricating oil into the oil groove 13 and the discharge of the lubricating oil from the oil groove 13. As a result, an increase in the temperature of the lubricating oil in the oil groove 13 can be suppressed.

  As described above, the main bearing 2 (slide bearing) according to the present embodiment is formed by combining the pair of upper and lower upper side bearings 10 and the lower side bearing 20 (semi-cylindrical bearing), and the crank journal 1a (shaft member) is formed. A pair of upper and lower upper bearings 10 and 20 is a cylindrical main bearing 2 that is rotatably supported. Of the inner peripheral surfaces of the upper and lower bearings 10 and 20, the crank journal 1 a Crash reliefs (upstream crash relief 11 and downstream crash relief 12, upstream crash relief 21 and downstream crash relief 22) formed respectively at the upstream and downstream ends in the rotational direction, and the crash relief A shape is formed on the inner peripheral surfaces of the upper side bearing 10 and the lower side bearing 20 so as to communicate from one to the other. And the oil groove (oil groove 13 and the oil groove 23) which is, those having a.

By configuring in this way, it is possible to suppress an increase in the temperature of the lubricating oil in the oil groove by prompting the lubricating oil in the oil groove to be discharged from the crush relief to the outside. Thereby, the occurrence of seizure of the main bearing 2 can be suppressed.
Further, when the lubricating oil is supplied from the crank journal 1a to the crankpin 1c as in the present embodiment, an increase in the temperature of the lubricating oil supplied from the crank journal 1a (main bearing 2) to the crankpin 1c is suppressed. Can do. Thereby, the occurrence of seizure of the crankpin 1c can be suppressed.

  Further, the lubricating oil supply mechanism according to the present embodiment communicates the outer peripheral surface of the crank journal 1a and the outer peripheral surface of the crank pin 1c, and guides the lubricating oil from the outer peripheral surface of the crank journal 1a to the outer peripheral surface of the crank pin 1c. A crankshaft 1 having a communicating oil passage 1d and a main bearing 2 are provided, and the crank journal 1a is rotatably supported by the main bearing 2.

  By comprising in this way, the raise of the temperature of the lubricating oil supplied from the main bearing 2 to the crankpin 1c can be suppressed. Thereby, the occurrence of seizure of the crankpin 1c can be suppressed.

  In the present embodiment, the slide bearing according to the present invention is applied to the main bearing 2 that rotatably supports the crank journal 1a. However, the present invention is not limited to this. That is, the present invention can also be applied to other slide bearings (for example, the connecting rod bearing 4 interposed between the crankpin 1c and the connecting rod 5).

  In the present embodiment, both the upper bearing 10 and the lower bearing 20 are formed with oil grooves so as to communicate the crush reliefs at both ends. However, the present invention is not limited to this. . That is, only one of the upper side bearing 10 and the lower side bearing 20 may be formed with an oil groove so as to communicate the crush reliefs at both ends.

  In the present embodiment, the oil groove 23 is formed to have a constant depth over the entire region, but the present invention is not limited to this. For example, as shown in FIG. 9, the depth of the end 23 b on the downstream side of the oil groove 23 can be set shallower than the depth of the middle part 23 a of the oil groove 23. In this way, by reducing the depth of the downstream end portion 23 b of the oil groove 23, the amount of lubricating oil flowing out from the oil groove 23 to the downstream crash relief 22 can be limited. Accordingly, it is possible to secure the amount of lubricating oil (the amount of lubricating oil in the oil groove 23) necessary for lubricating the main bearing 2 while promoting the discharge of the lubricating oil to the outside.

  In addition, in the example shown in FIG. 9, although the depth of the edge part 23b of the oil groove 23 shall be set shallow, this invention is not limited to this. That is, the cross-sectional area of the end 23b of the oil groove 23 may be formed so as to be smaller than the cross-sectional area of the midway part 23a. For example, the front-rear direction width of the end 23b of the oil groove 23 can be set narrow. Further, by arbitrarily setting the cross-sectional area of the end portion 23b of the oil groove 23, the amount of lubricating oil flowing out to the downstream side crash relief 22 through the end portion 23b can be arbitrarily limited.

1 Crankshaft 1a Crank journal (shaft member)
1c Crankpin 1d Communication oil passage 2 Main bearing (slide bearing)
10 Upper bearing (semi-cylindrical bearing)
11 Upstream crash relief (crash relief)
12 Downstream crash relief (crash relief)
13 Oil groove 20 Lower bearing (semi-cylindrical bearing)
21 Upstream crash relief (crash relief)
22 Downstream crash relief (crash relief)
23 Oil groove

Claims (2)

A cylindrical sliding bearing formed by combining a pair of upper and lower semi-cylindrical bearings and rotatably supporting a shaft member,
Each of the pair of upper and lower semi-cylindrical bearings is
Of the inner peripheral surface of the semi-cylindrical bearing, crush relief formed respectively at the end in the rotational direction upstream and downstream of the shaft member;
An oil groove formed on the inner peripheral surface of the semi-cylindrical bearing so as to communicate from one to the other among the crush reliefs;
Comprising
Each of the oil grooves formed in the pair of upper and lower semi-cylindrical bearings,
It is formed to have a constant depth over the entire area ,
Of the pair of upper and lower semi-cylindrical bearings, the oil groove formed in the lower semi-cylindrical bearing is formed such that only the downstream end portion has a smaller cross-sectional area than the other portions. And plain bearings. A crankshaft having a communication oil passage that communicates the outer peripheral surface of the crank journal and the outer peripheral surface of the crankpin, and guides lubricating oil from the outer peripheral surface of the crank journal to the outer peripheral surface of the crankpin;
A plain bearing according to claim 1;
Comprising
The lubricating oil supply mechanism, wherein the crank journal is rotatably supported by the slide bearing.

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