JP2016114078A - Half-split bearing - Google Patents

Abstract

The amount of leaked oil is suppressed as compared with the prior art. A base material layer has an inner peripheral surface that is a surface on the side where a shaft is accommodated, and two joint surfaces that are abutted against other half bearings. Crush reliefs having a depth d and a height h are provided on the inner peripheral surface 13 side of the joint surfaces 14 and 15, respectively. The crush relief is provided with coating layers 11 and 12 made of resin. Since the resin that is the material of the covering layers 11 and 12 is a softer material than the metal that is the material of the base material layer 10 such as an aluminum alloy or a copper alloy, the resin from the shaft 2 or other half bearings is used for assembly. Even if it receives stress, it deforms or wears, and becomes a shape that fits with the shaft 2 and other half bearings. As a result, the half bearing 1 is less likely to be displaced or deformed compared to the prior art. [Selection] Figure 1

Description

  The present invention relates to a technique for suppressing the amount of oil leaked from a half bearing.

  In an internal combustion engine, a bearing including a pair of semi-cylindrical bearings (referred to as half bearings) is used to rotatably support a crank shaft (main shaft), a connecting rod shaft, and the like. When the joint surfaces of the pair of half bearings face each other and are assembled to, for example, a journal portion of a crankshaft, positional deviation or deformation may occur on the end surface in the circumferential direction of the half bearing. In order to absorb these misalignments and deformations, a crush relief may be provided on the half bearing. The crush relief is a relief space formed by reducing the thickness of the wall portion in the circumferential end region of each half bearing in the radial direction from the original inner peripheral surface concentric with the rotation center.

  A half bearing provided with a crush relief has been proposed for various purposes. For example, the crash relief described in Patent Document 1 has a given size, thereby absorbing misalignment and deformation that occur during assembly and improving foreign matter capture and discharge.

JP 2013-170680 A

However, since the crush relief is obtained by reducing the thickness of the wall portion from the original inner peripheral surface in the radial direction, by providing the crush relief, an opening portion through which lubricating oil leaks between the shaft and the joint surface is provided. The amount of oil leaked increased.
One of the objects of the present invention is to provide a half bearing in which the amount of leaked oil is suppressed as compared with the prior art.

  In order to solve the above-described problems, a half bearing according to the present invention is a half bearing that forms a cylindrical bearing that accommodates a shaft on the inner peripheral surface side as a whole by abutting with another pair of half bearings. A base material layer having two joint surfaces and the inner peripheral surface to be brought into contact with the other half bearing, and a crash extending in an axial direction on the inner peripheral surface side in each of the two joint surfaces It has a relief and a first covering layer that is made of a material softer than the base material layer and covers the crush relief and comes into contact with the shaft.

  Preferably, the first covering layer may have a portion that covers the crush relief to a position closer to the rotation center of the shaft than the inner peripheral surface.

  Moreover, it is preferable to have a second coating layer that covers the inner peripheral surface and contacts the shaft.

  According to the present invention, the amount of leaked oil can be suppressed as compared with the prior art.

The figure which shows the outline | summary of the half bearing which concerns on this invention. The figure which shows an example of the conventional half bearing.

1. Embodiment Hereinafter, the structure of the half bearing 1 which concerns on one Embodiment of this invention is demonstrated. In the figure, a space in which each component of the half bearing 1 is arranged is represented as an xyz right-handed coordinate space. Among the coordinate symbols shown in the figure, a symbol in which two oblique lines intersecting each other in a white circle represent an arrow heading from the front side to the back side of the page. A direction along the x-axis in space is referred to as an x-axis direction. Of the x-axis directions, the direction in which the x component increases is referred to as + x direction, and the direction in which the x component decreases is referred to as -x direction. For the y and z components, the y-axis direction, + y direction, -y direction, z-axis direction, + z direction, and -z direction are defined according to the above definition.

  FIG. 1 is a diagram showing an outline of the half bearing 1. The half bearing 1 is an upper half bearing that forms a cylindrical plain bearing that accommodates the shaft 2 as a whole by abutting with a pair of lower half bearings (not shown). The shaft 2 accommodated in the half bearing 1 is a crank shaft (main shaft). In FIG. 1, the half bearing 1 is arranged such that a shaft 2 to be accommodated is along the x-axis direction. In FIG. 1, the + z direction is upward.

  FIG. 1A shows the shape of the half bearing 1 as viewed in the direction from the bottom to the top (+ z direction). The half bearing 1 has a base material layer 10 made of a metal such as an aluminum alloy or a copper alloy. The base material layer 10 has an inner peripheral surface 13 which is a surface on the side where the shaft 2 is accommodated in a cylindrical bearing formed by abutting with another half bearing. The inner circumferential surface 13 is a circumferential surface at a distance of a radius r from the rotation center O of the shaft 2. A groove (not shown) for supplying lubricating oil along the circumferential direction and an oil hole (not shown) for supplying lubricating oil from the outer peripheral surface 19 are formed in the inner peripheral surface 13 along the circumferential direction. Good.

  FIG. 1B shows a cross-sectional view of the half bearing 1 cut along the center in the width direction (x-axis direction) (arrow Ib-Ib in FIG. 1A). The shaft 2 accommodated in the inner peripheral surface 13 rotates along the arrow D0. The upstream side and the downstream side are defined by the rotation direction indicated by the arrow D0.

  The base material layer 10 has two joint surfaces 14 and 15 to be brought into contact with other half bearings. That is, the base material layer 10 is an example of a base material layer having two joint surfaces and an inner peripheral surface that are brought into contact with another half bearing. The joining surface 14 is an upstream joining surface, and the joining surface 15 is a downstream joining surface. The joint surfaces 14 and 15 are joint surfaces that abut against the joint surface of the halved bearing on the lower side (−z direction).

  As shown in FIG. 1, crush reliefs having a depth d and a height h are provided on the inner peripheral surface 13 side of the joining surfaces 14 and 15, respectively. The crush relief is a space in which the base material layer 10 is cut, and is a relief space that absorbs misalignment and deformation that occur during assembly.

  The depth d of each crush relief is an amount by which the thickness is reduced from the inner peripheral surface 13 of the half bearing 1 that is concentric with the rotation center O of the shaft 2. Since the inner peripheral surface 13 is at a distance of radius r from the rotation center O as described above, the base material layer 10 on the bonding surfaces 14 and 15 is provided with a radius relief from the rotation center O (radius r + depth). D).

  The height h of each crush relief is the height from the horizontal plane to one end where the crush relief is provided (upward) when the joint surfaces 14 and 15 are placed on the horizontal plane as the lower end surface. Distance). The crash relief shown in FIG. 1 is merely an example, and does not indicate the actual size.

  These crush reliefs are provided with coating layers 11 and 12 made of resin. The resin that is the material of the coating layers 11 and 12 is a softer material than the metal such as an aluminum alloy or a copper alloy that is the material of the base material layer 10. The covering layers 11 and 12 are not limited to resin as long as the material is softer than the material of the base material layer 10, and may be, for example, plating, a hard film, a solid lubricant, or a soft metal. That is, the coating layers 11 and 12 are an example of the 1st coating layer which is comprised with a softer material than a base material layer, coat | covers a crush relief, and contacts a axis | shaft.

  FIG. 2 is a view showing an example of a conventional half bearing. The half bearing 7 shown in FIG. 2 is obtained by removing the covering layers 11 and 12 from the half bearing 1 described above. That is, the half bearing 7 is formed of, for example, only the base material layer 70, and the crush reliefs 71 and 72 having a depth d and a height h are provided on the joining surfaces 74 and 75 provided on the base material layer 70, respectively. These crush reliefs 71 and 72 are not provided with a coating layer. A groove (not shown) for supplying lubricating oil along the circumferential direction and an oil hole (not shown) for supplying lubricating oil from the outer peripheral surface 79 are formed in the inner peripheral surface 73 along the circumferential direction. May be.

  As shown in FIG. 2, when the crush reliefs 71 and 72 are provided and a coating layer is not provided thereon, a space is generated between the joint surfaces 74 and 75 and the shaft 2. If there is a space between the joining surfaces 74 and 75 and the shaft 2, the lubricating oil supplied to the inner peripheral surface 73 is likely to leak outside through the space.

  On the other hand, as shown in FIG. 1, when the coating layers 11 and 12 are provided in each crush relief, the shaft 2 contacts the coating layers 11 and 12 at the joint surfaces 14 and 15, and the shaft 2 and the half bearing It is difficult to create a space between them. Therefore, the lubricating oil supplied to the inner peripheral surface 13 is blocked by the coating layers 11 and 12 and hardly leaks to the outside from between the joint surfaces 14 and 15 and the shaft 2, and the amount of leaked oil is suppressed.

  Moreover, since the coating layers 11 and 12 are softer than the base material layer 10, even if stress is received from the shaft 2 or other half bearings during assembly, the coating layers 11 and 12 are deformed or worn, and the shaft 2 And a shape that fits with other half bearings. That is, the half bearing 1 is provided with the coating layers 11 and 12 on the crush relief, so that the force generated when assembled to the other half bearing and the shaft 2 is absorbed. Compared to this, displacement and deformation are less likely to occur.

2. Modification The above is the description of the embodiment, but the contents of this embodiment can be modified as follows. Further, the following modifications may be combined.

2-1. Covering Layer Thickness The covering layers 11 and 12 may be partially or entirely thicker than the depth of the crush relief. That is, the coating layers 11 and 12 may have a portion that covers the crush relief to a position closer to the rotation center O of the shaft 2 than the inner peripheral surface 13. The portions of the covering layers 11 and 12 that are provided to a position closer to the rotation center O of the shaft 2 than the inner peripheral surface 13 are in contact with the shaft 2 at the start of rotation, but are softer than the material of the base material layer 10 Since it is made of a material, it is easily scraped by friction with the shaft 2 as compared with the base material layer 10. As a result, the covering layers 11 and 12 have a shape that is compatible with the shaft 2, and the amount of leaked oil is suppressed.

2-2. Inner peripheral surface coating layer A portion of the inner peripheral surface 13 that comes into contact with the shaft 2 through the lubricating oil may be provided with a coating layer (second coating layer). In particular, when a groove for supplying lubricating oil is provided on the inner peripheral surface 13, the edge of the groove is in contact with the shaft 2, and there is a possibility that the half bearing 1 and the shaft 2 may be damaged when a biased load is applied. is there. Therefore, it is desirable to reduce the frictional resistance of the inner peripheral surface 13 in order to avoid these damages. Therefore, a coating layer for reducing the frictional resistance may be provided on a portion of the inner peripheral surface 13 that is in contact with the shaft 2. The coating layer is desirably softer than the base material layer 10 and may be, for example, a resin, plating, a hard film, a solid lubricant, a soft metal, or the like. Further, it may be obtained by modifying the surface of the inner peripheral surface 13 by chemical treatment or heat treatment.

2-3. Others In the above-described embodiment, the shaft 2 is a crankshaft (main shaft), but may be a connecting rod shaft. Further, the half bearing 1 is not limited to the upper side but may be the lower side.

DESCRIPTION OF SYMBOLS 1 ... Half bearing, 10 ... Base material layer, 11, 12 ... Cover layer, 13 ... Inner peripheral surface, 14, 15 ... Joining surface, 19 ... Outer peripheral surface, 2 ... Shaft, 7 ... Half bearing, 71, 72 ... Crush relief, 73 ... Inner peripheral surface, 74,75 ... Joint surface, 79 ... Outer peripheral surface

Claims (3)

A half bearing that forms a cylindrical bearing that accommodates a shaft on the inner peripheral surface side as a whole by abutting with another pair of half bearings,
A base material layer having two joint surfaces to be abutted with the other half bearing and the inner peripheral surface;
In each of the two joint surfaces, a crush relief extending in the axial direction on the inner peripheral surface side;
A half bearing, comprising: a first covering layer made of a material softer than the base material layer and covering the crush relief and contacting the shaft. 2. The half bearing according to claim 1, wherein the first covering layer has a portion that covers the crush relief up to a position closer to a rotation center of the shaft than the inner peripheral surface. The half bearing according to claim 1, further comprising a second coating layer that covers the inner peripheral surface and contacts the shaft.

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