JP6533049B2 - Half bearing - Google Patents

Description

  The present invention relates to a technology for suppressing the amount of oil supplied to a half bearing.

2. Description of the Related Art A slide bearing is widely used, in which two half bearings forming a pair are butted together to form an overall cylindrical shape and the shaft is accommodated on the side of the inner circumferential surface. Among them, there is known a slide bearing in which an oil groove is formed in the inner peripheral surface of one half bearing so as to distribute lubricating oil along the circumferential direction.
Patent Document 1 describes a half bearing in which oil grooves are formed in the entire circumferential direction of the half bearing and the joint is opened. Patent Document 2 describes a bearing in which the bottom of the oil groove is formed so as to be closer to the center position of the inner circumferential surface from the central portion in the circumferential direction toward the joint. Patent Document 3 describes a bearing in which the flow passage area of the oil groove is reduced at the joint portion side.

  In the bearing described in Patent Document 1, since the oil groove opens up to the joint of the half bearing, a relatively large amount of lubricating oil is required to secure the hydraulic pressure necessary for the engine. The bearing described in Patent Document 2 has a problem that foreign matter tends to be deposited at the end of the oil groove. The bearing described in Patent Document 3 is characterized in that the hydraulic pressure in the main hole can be easily secured because the flow passage area of the oil groove is small at the joint portion side.

Japanese Patent Application Laid-Open No. 63-109215 Japanese Examined Patent Publication 7-65615 Patent No. 4466020

However, even with the bearing described in Patent Document 3, since the oil groove is formed in the entire circumferential direction of the half bearing, a lubricating oil sufficient to fill the oil groove is required.
One of the objects of the present invention is to provide a half bearing in which the amount of leakage of lubricating oil (hereinafter referred to as the amount of leakage oil) is suppressed as compared with the prior art.

In order to solve the problems described above, the half bearing according to the present invention is an upper side that forms a cylindrical bearing that abuts with a pair of lower half bearings and accommodates a shaft on the side of the inner peripheral surface as a whole. The inner circumference from two joint surfaces in contact with the joint surface of the lower half bearing, and one joint surface of the two joint surfaces toward the other joint surface; A first region in which a groove is formed along the circumferential direction of the surface, and a second region on the side closer to the other joint surface than the first region of the inner peripheral surface, in which the groove is not formed And the other joint surface is disposed on the downstream side in the rotational direction of the shaft , the groove does not communicate with the lower half bearing, and the one joint is The starting point is a ridge line where the surface intersects with the inner circumferential surface, and the end point is a boundary between the first region and the second region, the starting point It is formed to be deeper farther from fine said end point and said Rukoto.

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

The perspective view which shows the outline of a half bearing. Sectional drawing which cut | disconnected the half bearing at the center (II-II of FIG. 1) of a groove | channel. The schematic for demonstrating the ratio of 2nd area | region length with respect to the radius of inner skin. The graph which shows the relationship between the ratio of the 2nd field length to the radius of inner skin, and the amount of leaked oil.

1. Embodiment Hereinafter, the structure of a half bearing 1 according to an embodiment of the present invention will be described. 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. The symbol which drew the black circle in the white circle among the coordinate symbols shown to a figure represents the arrow which goes to a front side from the back side of a paper surface. 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 perspective view showing an outline of a half bearing 1. The upper half side bearing 1 forms a cylindrical slide bearing which abuts with a lower half side bearing (not shown in FIG. 1) forming a pair and accommodates a shaft on the side of the inner peripheral surface 13 as a whole. It is a half bearing. In FIG. 1, the half bearing 1 is arranged such that the axis housed on the side of the inner circumferential surface 13 is along the x-axis direction. In FIG. 1, the + z direction is upward.

  As shown in FIG. 1, a groove 10 is formed on the inner circumferential surface 13 of the half bearing 1 along the circumferential direction at the center in the width direction (x-axis direction). An oil hole 19 penetrating toward the outer circumferential surface 14 is provided at a predetermined position of the groove 10. A casing (not shown) for supporting the half bearing 1 from the side of the outer peripheral surface 14 is provided with a lubricating oil filling port, and the lubricating oil is supplied to the oil hole 19 from this filling port.

  FIG. 2 is a cross-sectional view of the half bearing 1 cut at the center of the groove (II-II in FIG. 1). The half bearing 7 is shown by FIG. 2 (a) as an example of a prior art. The half bearing 7 is an example of the “bearing in which the flow passage area of the groove is reduced at the joint portion side” described in Patent Document 3. The outer peripheral surface 74 and the inner peripheral surface 73 of the half bearing 7 are both semicircular on the yz plane. The shaft accommodated in the inner circumferential surface 73 of the half bearing 7 rotates along the arrow D. The upstream side and the downstream side are defined by the rotation direction indicated by the arrow D. The joint surface 71 on the upstream side and the joint surface 72 on the downstream side are joint surfaces that abut on the joint surface of the lower half (−z direction side) half bearing.

  The half bearing 7 is provided with a groove 70 having an oil hole 79. The groove 70 starts from a ridgeline 710 where the bonding surface 71 on the upstream side intersects with the inner circumferential surface 73, and ends at a ridgeline 720 where the bonding surface 72 on the downstream side intersects the inner circumferential surface 73. The groove 70 has no depth at the start and end points, ie, the groove 70 is connected to the inner circumferential surface 73 at the start and end points. The groove 70 is formed to be deeper as it gets farther from the upstream joint surface 71 and the downstream joint surface 72. The position where the groove 70 is deepest is, for example, a central portion of the inner circumferential surface 73 which has the same distance from the ridgeline 710 and the ridgeline 720, and the depth thereof is t7.

  On the other hand, FIG. 2 (b) shows a half bearing 1 according to the present invention. The outer peripheral surface 14 and the inner peripheral surface 13 of the half bearing 1 are both semicircular on the yz plane. The shaft accommodated in the inner circumferential surface 13 of the half bearing 1 rotates along the arrow D. The upstream side and the downstream side are defined by the rotation direction indicated by the arrow D.

  The half bearing 1 has an upstream joint surface 11 and a downstream joint surface 12. Each of these is a joint surface to be abutted with the joint surface of the lower half (−z direction side) half bearing. The half bearing 1 also has a groove 10 along the circumferential direction on the inner circumferential surface 13. The groove 10 is common to the groove 70 in that it has an oil hole 19 (corresponding to the oil hole 79) and a ridge line 110 where the joint surface 11 on the upstream side intersects the inner circumferential surface 13 as a starting point It differs from the groove 70 in that the end point does not reach the downstream joint surface 12.

  The groove 10 ends a boundary line 130 located upstream of the ridgeline 120 at which the downstream joint surface 12 intersects the inner circumferential surface 13 with the inner circumferential surface 13. The boundary line 130 is a line along the x-axis direction. Thus, the inner circumferential surface 13 is divided into a first region from the ridge 110 to the boundary 130 and a second region from the boundary 130 to the ridge 120. That is, the boundary 130 is the boundary between the first area and the second area. The first region is a region in which the groove 10 is formed along the circumferential direction of the inner circumferential surface 13 from the joint surface 11 of the shaft. The second region is a region downstream of the first region in the rotation direction of the shaft, and is a region in which the groove 10 is not formed.

  The groove 10 is formed to be deeper as it goes away from the ridgeline 110 and the boundary 130. The position where the groove 10 is deepest is, for example, a position on the inner circumferential surface 13 where the distances from the ridgeline 110 and the boundary 130 are equal, and the depth is t1. This position is, for example, on the upstream side of the central portion in the circumferential direction of the inner circumferential surface.

  And, the groove 10 has no depth at the start point and the end point, that is, the groove 10 is connected to the inner circumferential surface 13 at the start point and the end point. With this configuration, the groove 10 does not communicate with the downstream joint surface 12, so the amount of lubricating oil leaked at the joint surface 12 is suppressed as compared to when the groove 10 communicates with the groove. In addition, since the groove 10 starts from the ridgeline 110 included in the joint surface 11 on the upstream side, foreign matter mixed in the inner circumferential surface 13 of the half bearing 1 passes from the joint surface 11 on the upstream side through the groove 10 and It is easy to be discharged to the outside of the split bearing 1.

2. Calculation Example Here, in the yz plane shown in FIG. 2B, the distance from the center 100 of the shaft accommodated by the half bearing 1 to the inner circumferential surface 13 is the radius r, and the boundary 130 on the inner circumferential surface 13 And the linear distance between the ridgelines 120 is L. The ratio of the length L to the radius r is preferably 7% or more. Below, this ratio is demonstrated based on a numerical calculation result.

  FIG. 3 is a schematic diagram for explaining the ratio of the second region length to the radius of the inner peripheral surface. Since the ridgeline 120 and the boundary 130 are on the inner circumferential surface 13, they are each separated by a radius r from the center 100 of the axis in the yz plane. Therefore, connecting the center 100, the ridgeline 120, and the boundary 130 in the yz plane results in an isosceles triangle. The base of this isosceles triangle is the length L of the second region, which is the distance between the boundary 130 and the ridge 120 by a straight line on the yz plane. The length L is not a length along the inner circumferential surface 13.

  The inventors of the present invention have two shafts which are housed in a half bearing formed by cutting up the groove 10 so that the length L / radius r is 0.07 or more, that is, the above ratio is 7% or more. Numerical calculation was performed to estimate the amount of leaked oil when rotating each at a typical rotation speed. The oil film analysis by Reynolds equation in consideration of mass conservation was used for this numerical calculation.

  FIG. 4 is a graph showing the calculation result, and is a graph showing the relationship between the ratio of the length of the second region to the radius of the inner circumferential surface and the amount of leaked oil. The horizontal axis in FIG. 4 is a percentage indicating the ratio of the length L of the second region to the radius r of the inner circumferential surface 13. The vertical axis in FIG. 4 indicates the amount of leaked oil per unit time when the shaft is rotated.

  The above calculation was performed for the case where the shaft housed on the side of the inner circumferential surface of the slide bearing was rotated at 2000 rpm, which is a low speed rotation, and 6600 rpm, which is a high speed rotation. At low speed rotation, the amount of oil leaked from the half bearing 7 according to the prior art is VL. On the other hand, assuming that the ratio of length L / radius r of the half bearing 1 according to the present invention is 7% or more, the amount of oil leakage becomes smaller than VL as shown by curve WL in FIG. As the percentage increases, the amount of leaked oil decreases. That is, it was found that by setting the ratio of the length of the second region to the radius of the inner peripheral surface to 7% or more, the amount of oil leakage at the time of low speed rotation is suppressed as compared with the prior art.

  Further, at high speed rotation, the amount of leaked oil of the half bearing 7 according to the prior art is VH. On the other hand, the leaked oil amount of the half bearing 1 according to the present invention is such that the curve WL at low speed rotation moves to the curve WH at high speed rotation. The rate of increase in the amount of leaked oil from the curve WL to the curve WH is higher than the rate of increase from the VL to the VH. That is, as in the half bearing 1 according to the present invention, by providing the second region in which the groove 10 is not formed on the side closer to the joint surface 12 than the first region in the inner circumferential surface 13, It has been found that the amount of oil leakage at high speed rotation is increased as compared with the prior art. Therefore, according to the half bearing 1, it has been found that the discharge performance of foreign matter at high speed rotation is improved as compared with the half bearing 7 according to the prior art.

  As described above, in the half bearing 1 according to the present invention, the second region in which the groove 10 is not formed is provided downstream of the first region in which the groove 10 is formed in the rotational direction of the shaft. The amount of leaked oil is reduced, and the amount of lubricating oil supplied can be suppressed.

  In particular, by setting the length L of the boundary line 130 and the ridge 120 which are both ends of the second region to 7% or more of the radius r of the inner circumferential surface 13, the leaked oil than in the conventional structure at low speed rotation of the shaft The amount decreases, and at the time of high-speed rotation of the shaft, although the amount of oil leakage increases, the foreign matter dischargeability is improved.

DESCRIPTION OF SYMBOLS 1 ... half bearing, 10 ... groove | channel, 100 ... center, 11 ... joint surface, 110 ... ridgeline, 12 ... joint surface, 120 ... ridgeline, 13 ... inner peripheral surface, 130 ... boundary line, 14 ... outer peripheral surface, 19 ... Oil hole, 7 ... half bearing, 70 ... groove, 71 ... joint surface, 710 ... ridge line, 72 ... joint surface, 720 ... ridge line, 73 ... inner circumferential surface, D ... arrow, L ... length, r ... radius, WH ... Curve, WL ... Curve

Claims (1)

An upper half bearing that forms a cylindrical bearing that abuts with a pair of lower half bearings and accommodates a shaft on the side of the inner circumferential surface as a whole,
Two joint surfaces to be abutted with the joint surfaces of the lower half bearings;
A first region in which a groove is formed along a circumferential direction of the inner circumferential surface from one of the two bonding surfaces toward the other of the two bonding surfaces;
A second region of the inner circumferential surface closer to the other joining surface than the first region and in which the groove is not formed;
Have
The other joint surface is disposed downstream of the rotation direction of the shaft ,
The groove does not communicate with the lower half bearing, and a boundary line between the first region and the second region starts from a ridge line at which one of the joint surfaces intersects the inner peripheral surface. the line and the end point, the start point and half bearing, characterized in that that will be formed so as deeper distance from the end point.

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