JP2019060500A - bearing - Google Patents

Abstract

To suppress amount of leaked oil as compared with a prior art.SOLUTION: A half-split bearing 1 includes a base material layer 10. The base material layer 10 includes an inner peripheral surface 13 as a surface in a side in which a bearing 2 is stored in a cylindrical bearing formed by abutting with the other half-split bearing. The base material layer 10 includes two junction surfaces 14, 15 allowed to abut with the other half-split bearing. In at least an edge area of the inner peripheral surface 13 of the base material layer 10, a coating layer 17 composed of a material softer than a material of the base material layer 10 is provided. Since no crush reliefs are provided on the base material layer 10, the bearing 2 slides on the coating layer 17 in the junction surfaces 14, 15, thus preventing lubricant supplied onto the inner peripheral surface 13 from easily leaking out of an area between the junction surfaces 14, 15 and the shaft 2 since the lubricant is blocked by the coating layer 17. The coating layer 17 is softer than the base material layer 10, thus absorbing stress received from the shaft 2 or the like in assembly.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technology for suppressing the amount of oil leakage from a bearing.

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

  Half bearings provided with crush relief for various purposes have been proposed. For example, the crush relief described in Patent Document 1 has a given size to absorb displacement and deformation that occur during assembly, as well as to improve the foreign matter trapping and discharging properties.

JP, 2013-170680, A

However, since the crush relief is obtained by reducing the thickness of the wall in the radial direction from the original inner circumferential surface, by providing this, the opening from which the lubricating oil leaks from the shaft at the joint surface is provided Space was created, and the amount of leaked oil was increasing.
One of the objects of the present invention is to provide a half bearing in which the amount of oil leakage is suppressed as compared with the prior art.

  In order to solve the problems described above, a half bearing according to the present invention is a half bearing that forms a cylindrical bearing that abuts on another pair of half bearings and accommodates a shaft on the side of the inner peripheral surface as a whole. A base layer having two joint surfaces abutting against the other half bearings and the inner peripheral surface and not provided with a crush relief, and two of the inner peripheral surfaces of the joint surfaces; And a cover layer made of a material softer than the base material layer, which covers any end area adjacent thereto and slides with the shaft.

  Preferably, the covering layer covers the entire inner circumferential surface including the end region.

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

The figure which shows the outline of a half bearing. The figure which shows an example of the conventional half bearing.

1. Embodiments The structure of a half bearing 1 according to an embodiment of the present invention will be described below. In the drawing, a space in which each configuration of the half bearing 1 is disposed is represented as an xyz right-handed coordinate space. Among the coordinate symbols shown in the figure, symbols in which two diagonal lines crossing each other in a white circle represent arrows pointing from the near side to the far side of the drawing. The direction along the x axis in space is called the x axis direction. Further, in the x-axis direction, the direction in which the x component increases is referred to as the + x direction, and the direction in which the x component decreases is referred to as the −x direction. The y-axis direction, the + y-direction, the −y-direction, the z-axis direction, the + z-direction, and the −z-direction are also defined for the y and z components in accordance with the above definition.

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

  The shape of the half bearing 1 as seen from the lower side to the upper side (+ z direction) is shown in FIG. The half bearing 1 has a base layer 10 made of metal such as aluminum alloy or copper alloy. This base material layer 10 has an inner peripheral surface 13 which is a surface on the side on which 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. Even if grooves (not shown) for supplying lubricating oil along the circumferential direction and oil holes (not shown) for supplying lubricating oil from the outer peripheral surface 19 are formed in the inner peripheral surface 13. Good. The radius ra of the shaft 2 is equal to or less than the radius r of the inner circumferential surface 13 (ra ≦ r).

  A cross-sectional view of the half bearing 1 cut at the center in the width direction (x-axis direction) (arrow Ib-Ib in FIG. 1A) is shown in FIG. The shaft 2 accommodated in the inner circumferential 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 layer 10 has two joint surfaces 14 and 15 to be in abutment with other half bearings. That is, the base material layer 10 is an example of a base material layer having two bonding surfaces and an inner peripheral surface which are brought into abutment with another half bearing. The bonding surface 14 is a bonding surface on the upstream side, and the bonding surface 15 is a bonding surface on the downstream side. Each of the joint surfaces 14 and 15 is a joint surface to be abutted with the joint surface of the lower half (−z direction) half bearing.

  The base layer 10 is not provided with a crush relief. That is, in the inner peripheral surface 13 of the base material layer 10, the end regions of the bonding surfaces 14 and 15 are at the same distance as the other regions from the rotation center of the axis 2 at the radius r and the wall thickness is It has not been reduced.

  A covering layer 17 made of resin is provided on the entire surface of the inner circumferential surface 13 of the base layer 10. The resin that is the material of the covering layer 17 is a material that is softer than a metal such as an aluminum alloy or a copper alloy that is the material of the base layer 10. The covering layer 17 is not limited to the resin as long as it is a softer material than the material of the base layer 10, and may be, for example, plating, a hard film, a solid lubricant, a soft metal or the like.

  Since the covering layer 17 is sandwiched between the inner circumferential surface 13 and the shaft 2, the total of the thickness t of the covering layer 17 and the radius ra of the shaft 2 is equal to or less than the radius r of the inner circumferential surface 13 (t + ra ≦ r) .

  FIG. 2 is a view showing an example of a conventional half bearing. The conventional half bearing 7 has a base layer 70 corresponding to the base layer 10 of the half bearing 1. The base layer 70 is formed of a metal such as an aluminum alloy or a copper alloy. The base layer 70 has an inner peripheral surface 73, bonding surfaces 74 and 75, and an outer peripheral surface 79 which correspond to the inner peripheral surface 13, the bonding surfaces 14 and 15, and the outer peripheral surface 19 of the base material layer 10, respectively. The half bearing 7 accommodates the shaft 2 of radius ra on the side of the inner circumferential surface 73. The inner circumferential surface 73 is at a distance of a radius r (ra ≦ r) from the rotation center O of the shaft 2.

  However, as shown in FIG. 2, crush reliefs 71 and 72 having a depth d and a height h are provided on the inner peripheral surface 73 side of the joint surfaces 74 and 75, respectively. The crush reliefs 71 and 72 are spaces obtained by cutting the base material layer 70, and are relief spaces that absorb displacement and deformation that occur during assembly. Therefore, in the half bearing 7, the inner circumferential surface 73 and the joint surfaces 74, 75 are not adjacent to each other, and are separated by the crush reliefs 71, 72.

  The depth d of each of the crush reliefs 71 and 72 is an amount of reduction in thickness from the inner circumferential surface 73 of the half bearing 7 concentric with the rotation center O of the shaft 2. As described above, since the inner circumferential surface 73 is at a distance of radius r from the rotation center O, the base material layer 70 at the joint surfaces 74 and 75 is provided with the crush reliefs 71 and 72 from the rotation center O ( It is at a distance of radius r + depth d).

  Further, the height h of each of the crush reliefs 71 and 72 is from the horizontal plane to one end where the crush relief is provided when the joint surfaces 74 and 75 are placed on the horizontal plane as the lower end face. It is height.

  A covering layer 77 of thickness t is provided on the entire surface of the inner circumferential surface 73 (t + ra ≦ r). In general, for the covering layer 77, a material such as a resin softer than the base layer 70 is used. The half bearing 7 is in contact with the shaft 2 via the covering layer 77. Since the crush reliefs 71 and 72 are provided, both ends in the circumferential direction of the inner circumferential surface 73 do not reach the joint surfaces 74 and 75, and the covering layer 77 is not provided on the crush reliefs 71 and 72. 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 in the circumferential direction. May be

  As shown in FIG. 2, when the crush reliefs 71 and 72 are provided, a space is generated between the joint surfaces 74 and 75 and the shaft 2. If there is a space between the joint surfaces 74 and 75 and the shaft 2, the lubricating oil supplied to the inner circumferential surface 73 is likely to leak out through the space.

  On the other hand, as shown in FIG. 1, the cover layer 17 made of a material softer than the base layer 10 is provided with no crush relief on the inner peripheral surface 13, and the entire surface of the inner peripheral surface 13 Covering the end region adjacent to either of the surfaces 14, 15, the shaft 2 slides with the covering layer 17 at either of the joint surfaces 14, 15, and the shaft 2 and the half bearing 1 It is difficult to create a space between Therefore, the lubricating oil supplied to the inner circumferential surface 13 is blocked by the coating layer 17 and hardly leaks out from between the joint surfaces 14 and 15 and the shaft 2, so that the amount of leaked oil is suppressed.

  In addition, since the covering layer 17 is softer than the base layer 10, the shaft 2 or the like may be deformed or worn even if stress is applied from the shaft 2 or other half bearings during assembly. It becomes a shape compatible with half bearings. That is, the half bearing 1 is provided with the covering layer 17 in the end region of the inner circumferential surface 13, and the force generated when assembling to the other half bearings and the shaft 2 is absorbed, compared to the prior art. As a result, it is difficult for displacement and deformation to occur.

2. Although the embodiment has been described above, the contents of this embodiment can be modified as follows. Also, the following modifications may be combined.

2-1. In the embodiment described above, the covering layer 17 made of resin is provided on the entire surface of the inner circumferential surface 13 of the base layer 10, but the covering layer 17 is the entire surface of the inner circumferential surface 13. It does not have to be provided on the end surface of the inner peripheral surface 13 as long as it covers the end region adjacent to one of the bonding surfaces 14 and 15. The lubricating oil held on the side of the inner circumferential surface 13 leaks to the outside mainly through the joint surfaces 14 and 15. Therefore, if the end region of the inner circumferential surface 13 is covered, the effect of suppressing the amount of leakage oil is obtained. Will occur.

2-2. Thickness in which the covering layer is provided The covering layer 17 may be provided thicker in the end region of the inner circumferential surface 13 than in the other regions of the inner circumferential surface 13. Further, the covering layer 17 may be provided in the end region of the inner circumferential surface 13 to a position closer to the rotation center O of the shaft 2 than the circumferential surface of the shaft 2.

  A portion of the covering layer 17 provided to a position closer to the rotation center O of the shaft 2 than the circumferential surface of the shaft 2 slides with the shaft 2 at the start of rotation, but softer than the material of the base layer 10 Since it is made of a material, it is scraped by friction with the shaft 2. As a result, the covering layer 17 has a shape compatible with the shaft 2 and the amount of oil leakage is suppressed.

2-3. Method of Manufacturing Coating Layer The coating layer 17 may be manufactured by modifying the surface of the inner circumferential surface 13 by chemical treatment, heat treatment, or the like. In short, the covering layer 17 may be made of a material softer than the base layer 10 and may reduce the frictional resistance between the shaft 2 and the half bearing 1.

2-4. Others In the above-described embodiment, the shaft 2 is a crankshaft (main shaft), but may be a shaft of a connecting rod. 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, 13 ... Inner peripheral surface, 14, 15 ... Bonding surface, 17 ... Coating layer, 19 ... Outer peripheral surface, 2 ... Axis, 7 ... Half bearing, 70 ... Base material layer 71, 72: Crush relief, 73: inner circumferential surface, 74, 75: bonding surface, 77: coating layer, 79: outer circumferential surface.

Claims (2)

A bearing having a pair of half bearings which buttably accommodates a shaft on the side of the inner circumferential surface,
The half bearing is
A base material layer having two joint surfaces abutting the other half bearing pair and the inner circumferential surface and not provided with a crush relief;
Coating of defined thickness composed of a material softer than the substrate layer, covering the end area adjacent to either of the two joining surfaces of the inner circumferential surface and sliding with the shaft Layers,
Bearings characterized by having each. The bearing according to claim 1, wherein the covering layer covers the entire inner peripheral surface including the end region.

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