JP6166064B2 - Plain bearing - Google Patents

Description

  The present invention relates to a slide bearing technique, and more particularly to a slide bearing technique in which a half member in which a cylinder is divided into two in parallel with an axial direction is vertically arranged.

  2. Description of the Related Art Conventionally, a bearing for supporting an engine crankshaft and having a half crack structure in which two members divided into two cylindrical shapes are combined is known. Further, in order to reduce the sliding area of the bearing and obtain a friction reduction effect, there is a structure in which the width of the bearing is narrowed. However, when the bearing width was narrowed, the amount of spilled oil increased. Therefore, a bearing in which relief portions (narrow grooves) are formed on the entire circumference at both ends in the axial direction of the bearing is known (for example, see Patent Document 1).

Japanese translation of PCT publication No. 2003-532036

  However, in conventional bearings with narrow grooves on the entire circumference, the load capacity decreases due to the reduction in sliding area, the oil film thickness necessary for good lubrication cannot be secured, and the total spilled oil The amount was large.

  Then, in view of the subject which concerns, this invention provides the bearing which can acquire the friction reduction effect and can suppress the total oil spill amount.

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

That is, according to claim 1, a slide bearing in which a half member divided into two parallel to the axial direction of a cylinder is arranged vertically, and only in the axial direction both ends of the lower half member, the circumferential direction The narrow groove is provided from the downstream mating surface in the rotation direction of the shaft toward the upstream side, and the corner on the upstream end side in the rotation direction of the narrow groove is formed at a right angle or has a small radius of curvature. It is formed in a rounded shape that is less than the groove depth.

  According to a second aspect of the present invention, the narrow groove is formed by press molding.

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

  That is, by providing a narrow groove that does not hinder the generation of oil film pressure, it is possible to obtain a friction reduction effect while reducing the sliding area, and to suppress the total amount of oil spilled.

The front view which shows the slide bearing which concerns on embodiment of this invention. (A) The top view which shows the half member which comprises the slide bearing which concerns on embodiment of this invention. (B) Similarly AA sectional view. (C) Similarly, a cross-sectional view along the line BB. (A) The three-dimensional graph which shows the gradient of the oil film pressure of the slide bearing which provided the narrow groove. (B) A three-dimensional graph (calculated value) showing the gradient of the oil film pressure of a slide bearing without a narrow groove. (A) AA sectional view showing the lower half member which constitutes the slide bearing concerning the embodiment of the present invention. (B) The encircled partial enlarged view of (a) when the rotation direction upstream corner is similarly formed at a right angle. (C) The encircled partial enlarged view of (a) when the same is formed by rounding the corner on the upstream side in the rotational direction. (A) The cross-sectional enlarged view which shows the bottom face of the narrow groove concerning embodiment of this invention. (B) The cross-sectional enlarged view which shows the bottom face surface of the fine groove shape | molded by the cutting process of the comparative example.

  Next, embodiments of the invention will be described. FIG. 1 is a front view of the sliding bearing 1, where the top and bottom of the screen is the vertical direction, and the front and back directions of the screen are the axial directions (front and back directions).

First, the half member 2 which comprises the slide bearing 1 which concerns on 1st embodiment is demonstrated using FIG.1 and FIG.2.
The slide bearing 1 is a cylindrical member and is applied to a slide bearing structure of an engine crankshaft 11 as shown in FIG. The plain bearing 1 is composed of two halved members 2 and 2. The two halved members 2 and 2 have a shape obtained by dividing a cylinder into two in parallel to the axial direction, and are formed so that the cross section is a semicircular shape. In the present embodiment, the half members 2 and 2 are arranged up and down, and mating surfaces are arranged on the left and right. When the crankshaft 11 is pivotally supported by the slide bearing 1, a predetermined gap is formed, and lubricating oil is supplied to the gap from an oil passage (not shown).

  In FIG. 2A, the upper and lower half members 2 are shown. In the present embodiment, the rotation direction of the crankshaft 11 is the clockwise direction when viewed from the front as indicated by the arrow in FIG. Also, the bearing angle ω is 0 degree at the right end position in FIG. 2B, and the counterclockwise direction in FIG. 2B is positive. That is, in FIG. 2B, the bearing angle ω at the left end position is defined as 180 degrees, and the bearing angle ω at the lower end position is defined as 270 degrees.

On the inner periphery of the upper half member 2, a groove is provided in the circumferential direction, and a circular hole is provided in the center. In addition, mating surfaces are arranged on the left and right of the upper half member 2.
A narrow groove 3 is formed at the axial end of the inner sliding surface of the lower half member 2.
The narrow groove 3 is provided in the lower half member 2. In the present embodiment, two narrow grooves 3 are provided in parallel in the axial direction. Specifically, the narrow groove 3 is provided in a circumferential direction from the mating surface on the downstream side in the rotation direction of the crankshaft 11 (bearing angle ω is 180 degrees) toward the direction in which the bearing angle ω is positive (counterclockwise direction). It is done. That is, in the lower half member 2, the right mating surface in FIG. 2B is the upstream mating surface in the rotational direction, and the left mating surface in FIG. 2B is the downstream mating surface in the rotational direction.
The narrow groove 3 is formed to have a depth d shallower than the bearing thickness D, as shown in FIG. The narrow groove is formed to have a width of w.

  By providing the narrow groove 3 at the axial end of the half member 2, the pressure gradient at the axial end of the half member 2 can be changed as shown in FIG. That is, compared with the case where there is no narrow groove 3 shown in FIG. 3B, the amount of oil sucked back increases as the pressure gradient descending from the bearing end toward the center in the narrow groove 3 increases. The total amount of oil spilled is suppressed.

  Moreover, as shown in FIG.4 (b), the rotation direction upstream corner | angular part 3a of the narrow groove 3 is formed at right angle. Here, the rotation direction upstream corner 3 a is a corner formed at the end opposite to the rotation direction downstream mating surface and formed by the bottom surface and the side surface of the narrow groove 3. In other words, at the upstream end of the narrow groove 3, the bottom surface and the side surface of the narrow groove 3 are formed so as to be orthogonal to each other.

Further, as shown in FIG. 4C, the upstream corner 3a in the rotation direction of the narrow groove 3 can be formed by rounding so that the radius of curvature R is equal to or less than the depth d of the narrow groove 3. In other words, at the upstream end of the narrow groove 3, the contact portion between the bottom surface and the side surface of the narrow groove 3 is rounded so that the bottom surface and the side surface of the narrow groove 3 are smoothly continuous. It is.
Here, the radius of curvature R when rounding is formed to be equal to or less than the depth d of the narrow groove 3. By comprising in this way, compared with the case where the curvature radius R is large, the inclination from the bottom face of the narrow groove 3 to a side surface becomes steep.

  The narrow groove 3 is formed by press molding. The press molding is a method of molding the narrow groove 3 by plastically deforming the bearing surface by various press machines such as a hydraulic press, a mechanical press, a crank press, and a hydraulic press.

  As shown in FIG. 5A, the processing groove formed on the bottom surface of the narrow groove 3 can be flattened by forming the narrow groove 3 by press molding. For example, as shown in FIG. 5 (b), when the fine groove 3 is formed by cutting, the machining trace formed on the bottom surface of the fine groove 3 becomes jagged. By forming the groove 3 by press molding, a processing mark formed on the bottom surface of the narrow groove 3 can be flattened.

  Further, as shown in FIG. 5 (a), the apex angle portion 3b formed between the surface of the half member and the end side surface of the bearing is chamfered by forming the narrow groove 3 by press molding. The As a comparative example, as shown in FIG. 5B, when the narrow groove 3 is formed by cutting, the apex portion 3b is not chamfered.

As described above, the slide bearing 1 is formed by vertically arranging the half members 2 and 2 which are divided into two in parallel with the axial direction, and the narrow groove 3 in the circumferential direction is formed at the axial end portion of the slide bearing 1. And the corner on the upstream side in the rotational direction of the narrow groove 3 is formed at a right angle or rounded so that the radius of curvature R is equal to or less than the depth d of the narrow groove 3.
By configuring in this way, by providing a narrow groove that does not hinder the generation of oil film pressure, it is possible to obtain a friction reduction effect while reducing the sliding area, and to suppress the total amount of oil spilled Can do. In addition, at the corner on the upstream side in the rotation direction of the narrow groove 3, the bottom surface and the side surface of the narrow groove 3 are orthogonal to each other or the bottom surface and the side surface of the narrow groove 3 are smoothly continuous. Since it can be formed so that the inclination becomes steep, the negative pressure gradient and the amount of suck back increase.

The narrow groove 3 is formed by press molding.
By configuring in this way, the corners on the upstream side in the rotation direction of the narrow grooves 3 can be easily formed at a right angle or rounded so that the radius of curvature R is equal to or less than the depth d of the narrow grooves.
Further, the machining time can be shortened compared to the cutting process, and the occurrence of burrs can be prevented.

DESCRIPTION OF SYMBOLS 1 Slide bearing 2 Half member 3 Narrow groove 3a Rotation direction upstream corner 11 Crankshaft

Claims (2)

A slide bearing in which a half member divided into two in parallel with the axial direction is arranged vertically,
Only at both axial ends of the lower half member, a narrow groove is provided in the circumferential direction,
The narrow groove is provided from the downstream mating surface in the rotation direction of the shaft toward the upstream side,
The corner portion on the upstream end side in the rotational direction of the narrow groove was formed at a right angle or formed into a rounded shape with a radius of curvature equal to or less than the depth of the narrow groove
A plain bearing characterized by that. The narrow groove was formed by press molding,
The plain bearing according to claim 1, wherein:

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