JP7071094B2 - Half-thrust bearings, thrust bearings, bearing devices and internal combustion engines - Google Patents

Description

The present invention relates to a semi-annular half-thrust bearing for receiving an axial force of a crank shaft in an internal combustion engine such as an automobile, a ship, or a general industrial machine, and in particular, sliding for receiving an axial force. It relates to a half-thrust bearing having a surface and a back surface on the opposite side of the sliding surface, and a resin coating layer coated on the substrate forms the sliding surface. Further, the present invention relates to a thrust bearing having the half-split thrust bearing, a bearing device provided with the thrust bearing, and an internal combustion engine provided with the bearing device.

In the journal portion, the crank shaft of the internal combustion engine is rotatably supported under the cylinder block of the internal combustion engine via a main bearing formed by combining a pair of half bearings in a cylindrical shape. One or both of the pair of half-split bearings are used in combination with half-split thrust bearings that receive axial force on the crank shaft. The half-split thrust bearing is arranged on one or both of the axial end faces of the half-split bearing. The half-thrust bearing receives an axial force generated on the crank shaft. That is, it is arranged for the purpose of supporting the axial force input to the crank shaft when the crank shaft and the transmission are connected by the clutch.

As the half-split thrust bearing, a bimetal in which a thin bearing alloy layer is bonded to a back metal layer made of steel or the like is used, but a bearing in which a resin layer is coated on the bimetal is also well known (Reference 1 and the like). By coating a soft and elastic resin layer with low friction, it is possible to improve lubricity and suppress seizure and wear of bearings.

Japanese Unexamined Patent Publication No. 2013-130273

In recent years, the performance and functionality of engines have been improved. Along with this, the rigidity of mating members such as shafts has been reduced, and there is a demand for higher surface pressure of bearings. Such conditions are a harsh usage environment for bearings. In particular, it is desired to have excellent seizure resistance by applying an idling stop system or a hybrid vehicle.

In such a bearing, a fluid lubricating film such as lubricating oil is formed between the surface of the mating member (for example, a shaft member) and the sliding surface of the sliding member during operation, so that the bearing slides on the surface of the mating member. Direct contact with the sliding surface of the member is prevented. The resin-coated layer applied to the thrust bearing by the conventional technique is coated with a uniform layer thickness, but the oil film pressure is insufficient and the bearing capacity is insufficient, which may lead to seizure under the above-mentioned usage environment. There is. It is necessary to form an oil film on the entire sliding surface in order to prevent seizure, but the above-mentioned conventional technique is insufficient to have excellent seizure resistance in a harsh engine environment.

An object of the present invention is to provide a half-split thrust bearing having excellent seizure resistance by promoting excellent oil film formation, and thus to provide a thrust bearing.

According to one aspect of the present invention, a resin having a semicircular shape, having a sliding surface for receiving an axial force, and a back surface on the opposite side of the sliding surface, and coated on a substrate. A half-thrust bearing in which a coating layer forms the sliding surface is provided. This half-split thrust bearing is characterized in that the thickness of the resin coating layer changes along the circumferential direction.
Here, the "semicircle shape" is a shape in which the inner circumference and the outer circumference are defined by two semicircles, but these do not have to be geometrically strictly semicircles. For example, a part of the outer peripheral surface or the inner peripheral surface may project radially (for example, at the circumferential end surface), and an extension portion may be present from the circumferential end surface (for example, in the direction perpendicular to the circumferential end surface).

According to one specific example of the present invention, it is preferable that the thickness of the resin coating layer is maximized on at least one end side of the central portion in the circumferential direction. Further, it is preferable that the thickness of the resin coating layer decreases toward both ends in the circumferential direction of the half-split thrust bearing.

According to one specific example of the present invention, it is preferable that the thickness of the resin coating layer is maximized at a position of at least 5 ° to 45 ° or 135 ° to 175 ° in the circumferential angle. It is more preferable that the thickness of the resin coating layer is maximized at a position of at least 10 ° to 35 ° or 145 ° to 170 ° in the circumferential angle.

According to one specific example of the present invention, it is preferable that the thickness of the resin coating layer is maximum at two positions of 5 ° to 45 ° and 135 ° to 175 ° in inscribed angle. It is more preferable that the thickness of the resin coating layer is maximized at two positions of 10 ° to 35 ° and 145 ° to 170 ° in inscribed angle.

According to one specific example of the present invention, there is an intermediate position where the thickness of the resin coating layer is minimized between the two maximum thicknesses of the resin coating layer, and the thickness of the resin coating layer at the intermediate position is determined. It is preferably 50% to 90% of the maximum thickness of the two maximum thicknesses of the resin coating layer. The thickness of the resin coating layer at this intermediate position is more preferably 65% to 90% of the maximum thickness.

According to a specific example of the present invention, when the half-split thrust bearing is viewed along the circumferential direction of the half-split thrust bearing, the sliding surface of the half-split thrust bearing has a circumferential angle of 5 ° to 45 ° or 135. It is preferable to have a convex contour protruding at a position of ° to 175 °. The protruding position of the convex contour is more preferably 10 ° to 35 ° or 145 ° to 170 ° in terms of inscribed angle. The protruding position of the convex contour may be a position of 75 ° to 105 ° in inscribed angle.

Further, it is preferable that there are two protrusions of the contour at an inscribed angle of 5 ° to 45 ° and 135 ° to 175 °, and two protrusions at an inscribed angle of 10 ° to 35 ° and 145 ° to 170 °. It is more preferred to be present.

According to another aspect of the present invention, the present invention is a thrust bearing composed of two half-split thrust bearings, and at least one of the two half-split thrust bearings is the above-mentioned half-split thrust of the present invention. Thrust bearings, which are bearings, are provided.

According to a specific example of the present invention, the half-split thrust bearing is preferably a half-split thrust bearing for receiving an axial force of a crank shaft of an internal combustion engine.

According to still another aspect of the present invention, the present invention also provides a bearing device provided with the above-mentioned half-thrust bearing of the present invention.

According to still another aspect of the present invention, the present invention also provides an internal combustion engine equipped with the above-mentioned bearing device of the present invention.

The resin-coated half-thrust bearing of the present invention promotes oil film formation by controlling the distribution of the thickness of the resin-coated layer in the circumferential direction, and improves seizure resistance without impairing the low friction function. Can be made to.

The configuration of the present invention and many advantages thereof will be described in more detail below with reference to the accompanying schematic drawings. The drawings show some non-limiting examples for illustrative purposes.

An exploded perspective view of the bearing device. Sectional view of the bearing device. The front view of an example of the half-split thrust bearing of this invention. Y1 arrow side view of the half-split thrust bearing of FIG. An expanded view of a cross section of an example of the half-split thrust bearing of the present invention cut in the circumferential direction at the central portion in the radial direction. Another example of the half-split thrust bearing of the present invention is a developed view of a cross section cut in the circumferential direction at the center in the radial direction. Another example of the half-split thrust bearing of the present invention is a developed view of a cross section cut in the circumferential direction at the center in the radial direction. Another example of the half-split thrust bearing of the present invention is a developed view of a cross section cut in the circumferential direction at the center in the radial direction. Another example of the half-split thrust bearing of the present invention is a developed view of a cross section cut in the circumferential direction at the center in the radial direction.

First, the entire configuration of an example of the bearing device 1 having the half-split thrust bearing 8 of the present invention will be described with reference to FIGS. 1 and 2. As shown in FIGS. 1 and 2, the bearing housing 4 configured by attaching the bearing cap 3 to the lower portion of the cylinder block 2 is formed with a bearing hole (holding hole) 5 which is a circular hole penetrating between both side surfaces. The bearing holes 6 and 6 which are annular recesses are formed on the peripheral edge of the bearing hole 5 on the side surface. Half-split bearings 7 and 7 that rotatably support the journal portion 11 of the crank shaft are combined and fitted in the bearing hole 5 in a cylindrical shape. Half-split thrust bearings 8 and 8 that receive an axial force f (see FIG. 2) via the thrust collar surface 12 of the crank shaft are combined and fitted to the receiving seats 6 and 6 in an annular shape. The half-split thrust bearing 8 may not be combined in an annular shape, and may be fitted only to the cylinder block 2 side, for example.

Next, a front view and a perspective view of an example of the half-split thrust bearing 8 of the present invention are shown in FIGS. 3 and 4. The half-split thrust bearing 8 has a resin coating layer 88 on a substrate 89 formed on a semicircular flat plate. The substrate 89 is usually preferably composed of a bimetal in which a thin bearing alloy layer is bonded to a steel back metal layer, but the substrate 89 may be composed of only the back metal or other configurations. The half-split thrust bearing 8 includes a sliding surface 81 (bearing surface) facing in the axial direction, and the sliding surface 81 is composed of a resin coating layer. On the sliding surface 81, one oil groove 81a (two oil grooves are shown in FIG. 3) is formed between both end faces 83 and 83 in the circumferential direction in order to improve the oil retention property of the lubricating oil. You may.

The half-thrust bearing 8 defines a reference plane 84 that is perpendicular to the axial direction, and within this reference plane 84, a substantially flat back surface 84a adapted to be disposed on the seat 6 of the cylinder block 2. (See FIG. 4). The back surface 84a is also the bottom surface of the substrate 89. The substrate 89 has an upper surface 82 opposite to the reference surface 84 (back surface 84a) in the axial direction, and the upper surface of the substrate is coated with a resin coating layer 88. The surface of the resin coating layer 88 forms a sliding surface 81 separated from the reference surface 84 (rear surface 84a) in the axial direction, and the sliding surface 81 has an axial force f (axial force f) via the thrust collar surface 12 of the crank shaft. (See Fig. 2).

FIG. 5 is a developed view of a half-split thrust bearing 8 cut at a predetermined radius, and both ends of the half-split thrust bearing 8 in the lateral direction shown in FIG. 5 are in the circumferential direction of the half-split thrust bearing 8. Both end faces 83 (circumferential angle 0 °, 180 °), the lateral center of the half-split thrust bearing 8 shown in FIG. 5 indicates the circumferential center 85 (circumferential angle 90 °) of the half-split thrust bearing 8. .. The inscribed angle refers to the angle from both end faces 83 in the circumferential direction centered on the center of the annular shape of the half-split thrust bearing 8. In the present specification, the rear end surface of the crank shaft in the sliding direction (indicated by the arrow SD in FIG. 3) is set to 0 °, and the rear end surface in the sliding direction is set to 180 ° (see FIG. 3). (However, even if the front end surface in the sliding direction is set to 0 °, the scope of the present invention is not affected.)

In the half-split thrust bearing 8 of the present invention, the thickness of the resin coating layer 88 changes along the circumferential direction. As a result, the formation of an oil film can be promoted as the crank shaft rotates.
5 to 9 show an example of the thickness distribution of the resin coating layer 88 of the half-split thrust bearing 8 of the present invention.

According to an example of the distribution of the resin coating layer 88 on the substrate 89 shown in FIG. 5, in the resin coating layer 88, the thickness of the resin coating layer is closer to the end portion of the rear end in the sliding direction than the central portion in the circumferential direction. It becomes the maximum (that is, the maximum) at, and becomes smaller toward both ends 83 in the circumferential direction of the half-split thrust bearing. The position where the thickness of the resin coating layer is maximum or maximum is a position of 5 ° to 45 ° in the inscribed angle, preferably a position of 10 ° to 35 ° in the inscribed angle. It should be noted that the maximum position is not one, and a plurality of maximum portions may be formed, but it is desirable that one of them is present at the above-mentioned inscribed angle position.

FIG. 6 shows an example in which two maximum thickness portions of the resin coating layer are formed. The resin coating layer 88 has two maximum portions in which the thickness of the resin coating layer 88 is maximum on both ends, and the thickness of the resin coating layer 88 decreases toward both ends 83 in the circumferential direction of the half-split thrust bearing. The position where the thickness of the resin coating layer is maximized is at the position of 5 ° to 45 ° and 135 ° to 175 ° in the inscribed angle, preferably at the position of 10 ° to 35 ° and 145 ° to 170 ° in the inscribed angle. be. The thicknesses of the two maximals may be the same or different. Further, the two maximum portions may be present at a control position with respect to the inscribed angle of 90 °, or may be present at a non-control position.

In this case, there is an intermediate position between the two maximum thicknesses of the resin coating layer, which is the minimum thickness of the resin coating layer. The thickness of the resin coating layer at the intermediate position is preferably 50% to 90% of the maximum thickness of the two maximum thicknesses of the resin coating layer, and is 65% to 90% of the maximum thickness. Is even more preferable. The maximum thickness of the resin coating layer is preferably about 2 to 30 μm, and the thickness at the intermediate position is preferably about 1 to 27 μm.

By controlling the distribution shape to such a shape, the formation of an oil film is promoted, and the seizure resistance is improved without impairing the low friction function. This mechanism is as follows.
Since the resin is an elastic body, the stretching action occurs, so that the stretching action is exerted mainly on the thick part of the resin coating layer, and the oil film pressure due to the flow distribution of the lubricating oil is generated, which is excellent. Oil film formation can be promoted and seizure resistance is improved.

It is preferable that the circumferential thickness distribution of these resin coating layers 88 is established at any radial position. However, it is sufficient that this thickness distribution is established at the radial position in the center of the radial direction. Even in this case, oil film formation is promoted. Even when the circumferential thickness distribution of the resin coating layer 88 is established at any radial position, it is not necessary that the inscribed angles of the circumferential central portion 86 match. However, it is preferable to satisfy the above angle range at any radial position.

The circumferential thickness distribution of the resin coating layer 88 is an overall distribution, and small irregularities are present when viewed locally, but such local irregularities may be present.

The upper surface 82 of the substrate 89 of the half-split thrust bearing 8 is preferably a flat surface as shown in FIGS. 5 and 6. In this case, the thickness distribution of the resin coating layer 88 becomes the contour shape of the sliding surface 81. However, the upper surface 82 of the substrate 89 does not have to be a flat surface. For example, as shown in FIG. 7, the central portion in the circumferential direction may be lowered, or other shapes may be used. The height difference between the circumferential central portion and the circumferential end portion of the contour shape of the sliding surface 81 is preferably about 1 to 15 μm.

The thrust relief 87 may be formed in any shape (FIG. 8). The thrust relief 87 is a wall thickness reduction region formed in a region adjacent to both end faces in the circumferential direction on the sliding surface 81 side so that the wall thickness gradually decreases toward the end face, and is a region of the half-split thrust bearing 8. It extends over the radial end face. The thrust relief 87 is misaligned between the circumferential end faces 83 and 83 of the pair of half-split thrust bearings 8 and 8 due to misalignment when the half-split thrust bearing 8 is assembled in the split type bearing housing 4. Formed to alleviate.

Further, in the half-split thrust bearing 8 of the present invention, when the axial distance from the reference surface 84 to the sliding surface 81 is seen along the circumferential direction of the half-split thrust bearing, the half-split thrust bearing 8 is seen. It is preferable that the sliding surface of the split thrust bearing has a convex contour protruding at a position of 5 ° to 45 ° or 135 ° to 175 ° in a circumferential angle, and 10 ° to 10 ° in a circumferential angle. It is more preferable to have a convex contour protruding at a position of 35 ° or 145 ° to 170 °. The contour of the sliding surface 81 may be composed of a curved line or a straight line.
Further, it is preferable that two protrusions of the contour are present at the inscribed angles of 5 ° to 45 ° and 135 ° to 175 °, and are present at the inscribed angles of 10 ° to 35 ° and 145 ° to 170 °. Is even more preferable. In this case, the heights of the two convex portions may be the same or different. Further, the two convex portions may be present at a control position with respect to the inscribed angle of 90 °, or may be present at a non-control position.

When the upper surface 82 of the substrate 89 of the half-split thrust bearing 8 is a flat surface, the contour of the sliding surface 81 is determined by the thickness distribution of the resin coating layer 88, and is at the maximum thickness of the resin coating layer 88. The sliding surface 81 is the most protruding. When the internal combustion engine operates, the protruding portion of the sliding surface 81 slides most strongly with the crank shaft. Therefore, the contour protrudes in the above angle range, so that the protruding portion is caused by the rotational movement of the mating shaft material. Oil film pressure is generated due to the wedge action at the center. Furthermore, the generation of oil film pressure due to the stretching action of the resin coating layer described above and the effect of retaining lubricating oil between adjacent protrusions can be combined to promote excellent oil film formation, thereby improving seizure resistance. At the same time, wear is suppressed.
However, as shown in FIG. 7, the upper surface 82 of the substrate 89 of the half-split thrust bearing 8 does not have to be a flat surface. In this case, it is preferable that the maximum protrusion of the contour of the sliding surface 81 substantially coincides with the maximum position of the thickness of the resin coating layer 88, but it does not have to coincide. If they match, the above effects can be obtained, but even if they do not match, the effects of wedge action and stretch action are exhibited, so that excellent oil film formation is promoted over a wide range of the thrust bearing surface. Can be done. Therefore, for example, as shown in FIG. 9, it may have a convex contour that protrudes at a position of 75 ° to 105 ° in a circumferential angle.

The resin forming the resin coating layer 88 is, for example, PAI (polyetherimide), PI (polyetherimide), PBI (polybenzoimidazole), PA (polyamide), phenol, epoxy, POM (polyacetal), PEEK (polyetheretherketone). ), PE (polyethylene), PPS (polyphenylene sulfide), PEI (polyetherimide) and a synthetic resin composed of one or more selected from a fluororesin and an elastomer.
The resin coating layer may contain, in addition to the resin, a solid lubricant and / or a filler. Examples of solid lubricants include graphite, MoS ₂ , WS ₂ , h-BN, PTFE, melamine cyanurate, graphite fluoride, phthalocyanine, graphene nanoplatelets, fullerene, ultra high molecular weight polyethylene and Nε-lauroyl-L-. There is one type or two or more types selected from lysine, and by containing a solid lubricant, the sliding characteristics of the sliding layer can be enhanced. The preferred solid lubricant content is 10-70% by volume. Examples of the filler include oxides such as CaF ₂ , CaCO ₃ , talc, mica, mulite, calcium phosphate, iron oxide, aluminum oxide, chromium oxide, cerium oxide, zirconium oxide, titanium oxide, silicon oxide and magnesium oxide, and Mo. ₂ There is one or more selected from carbides such as C (molybdenum carbide) and SiC, nitrides such as aluminum nitride, silicon nitride, c-BN and diamond, and by containing this filler. , It is possible to improve the wear resistance of the sliding layer. The preferred filler content is 1-25% by volume.

As described above, the substrate 89 of the half-split thrust bearing 8 preferably includes a back metal layer and a bearing alloy layer provided on the back metal layer. A metal plate such as an Fe alloy, Cu, or Cu alloy can be used as the back metal layer, and the bearing alloy layer can be formed from an alloy such as a copper alloy, an aluminum alloy, or a tin alloy. A plating layer such as a tin alloy, a bismuth alloy, or a lead alloy and a metal overlay layer vapor-deposited by the PVD method may be provided on the bearing alloy layer. It is also possible to use only a bearing alloy layer such as a high-strength aluminum alloy or a copper alloy without a backing metal layer. A porous metal layer may be formed on the surface of the back metal layer, that is, on the side of the interface with the bearing alloy layer, but the porous metal layer may have the same composition as the back metal layer or may use a different composition or material. It is possible. By providing the porous metal layer on the surface of the back metal layer, the bonding strength between the sliding layer and the back metal layer can be increased. The porous metal layer can be formed by sintering a metal powder such as Cu, Cu alloy, Fe, or Fe alloy on the surface of a metal plate, strip, or the like. The porosity of the porous metal layer may be about 20 to 60%, and the thickness of the porous metal layer may be about 0.05 to 0.50 mm. In this case, the thickness of the sliding layer coated on the surface of the porous metal layer may be about 0.05 to 0.40 mm. However, the dimensions described here are examples, and the present invention is not limited to this value, and it is possible to change to different dimensions.

Next, a method of applying the resin coating layer 88 on the substrate 89 will be described. For the coating of the resin coating layer 88, for example, it is preferable to use a coating method such as a spray, a roll, a pad, or a screen. In these coating methods, the thickness of the resin coating layer 88 is controlled by partially controlling the amount of resin discharged, the amount of adhesion, and the amount of transfer, thereby controlling the layer thickness distribution shape over the entire sliding surface. As an example of controlling the amount of resin discharged, for example, a large number of discharge nozzles are arranged in a row in a direction perpendicular to the line. By arranging both ends in the circumferential direction toward the flow direction of the line, flowing the half-thrust bearing 8 through the line, and adjusting the amount of resin discharged from each discharge nozzle, the desired thickness distribution of the resin coating layer can be obtained. It becomes controllable.

A flat semicircular substrate (outer diameter 150 mm, inner diameter 110 mm, thickness 3.0 mm) to which a bearing alloy layer of an aluminum alloy (Al—Sn—Si) on a steel back metal was bonded was prepared. As the resin, PAI is used, and a large number of paint ejection nozzles are arranged in a row in a row in the direction perpendicular to the line by a spray coating method on the surface of the bearing alloy layer, and the substrate is flowed through the line to apply the resin. A coating layer was formed. In this way, samples A and B of the half-split thrust bearing in which the thickness of the resin coating layer is maximized near the peripheral end portion, and samples C in which the thickness of the resin coating layer is substantially uniform were prepared. The thickness of the resin coating layers of Samples A and B was 10 μm at the maximum thickness (circumferential angle 50 °) and 4 μm at the minimum thickness. The thickness of the resin coating layer of Sample C was set to 10 μm almost uniformly. The thickness of the resin coating layer was measured by cutting out a sample at each inscribed angle in the center of the radial direction and observing the cross section with an optical microscope.

The seizure test was performed using the samples A to C under the conditions shown in Table 2. Using S55C as the mating shaft material, the mating shaft is brought into contact with the sample while rotating the sample at 1000 rpm, the load is increased at a rate of 1 MPa / 10 min, and the maximum surface pressure at which seizure does not occur is defined as the non-seizure surface pressure. bottom. VG68 was supplied as a lubricating oil at 100 ° C. at a rate of 200 cc / min. As shown in Table 1, the test results show that Sample C, which has a substantially uniform thickness of the resin coating layer, has a non-seizure surface pressure of 6 MPa, whereas Sample A, which has a convex portion near the peripheral end, has a convex portion. The non-seizure surface pressure of B was 7 MPa, and the seizure resistance was improved by having a convex portion near the peripheral end.

Next, a position where the thickness of the resin coating layer of the half-split thrust bearing is maximized (hereinafter referred to as a convex portion position) is formed near both ends in the circumferential direction of the half-split thrust bearing, and the convex portion position is changed. The effect on seizure property was investigated. As shown in Table 3, Samples 1 to 8 in which the position of the convex portion was changed by the circumferential angle from 5 ° to 50 ° were prepared. Here, two convex portions were provided at control positions with respect to the inscribed angle of 90 ° (Table 3 shows the smaller inscribed angle). The thickness of the resin coating layer was 10 μm at the convex portion and 4 μm at the minimum thickness portion between the two convex portions. Other than that, the material and the manufacturing method are the same as those of sample A. These samples were subjected to a seizure test under the above conditions. The results are shown in Table 3. The sample with the convex position at an inscribed angle of 5 ° to 45 ° (Samples 1 to 7) had a non-seizure surface pressure of 8 MPa or more, but the sample with a convex position at an inscribed angle of 50 ° (Sample 8). ), The non-seizure surface pressure was 7 MPa. Further, the non-seizure surface pressure of the samples (Samples 2 to 5) having the convex portion at an inscribed angle of 10 ° to 35 ° was 10 MPa, which was a larger value. It is considered that the oil film formation was promoted by having the convex portion in the inscribed angle range, and the non-seizure surface pressure was improved.

Next, the thickness of the resin coating layer thickness minimum portion between the two convex portions was changed while the convex portion positions were fixed at two angles of 25 ° and 155 °. While the thickness of the resin coating layer remains 10 μm at the convex portion, the ratio of the thickness of the resin coating layer minimum thickness to the maximum thickness (shown as the film pressure ratio% in Table 4) is 47.1% to 94. Samples 11 to 17 changed to 2% were prepared, and the effect on seizure resistance was investigated. The test results are shown in Table 4.

From the results shown in Table 4, the samples 12 to 16 having a film thickness ratio of 50% to 90% have a non-seizure surface pressure of 11 MPa or more, and the samples 11 having a film film ratio of less than 50% or more than 90%. A value greater than 17 was obtained. In particular, it was found that the non-seizure surface pressure of the samples 14 to 16 having a film thickness ratio of 65% to 90% became a large value of 12 MPa, and the seizure resistance was improved.

1 Bearing device 11 Journal part 12 Thrust collar surface 2 Cylinder block 3 Bearing cap 4 Bearing housing 5 Bearing hole (holding hole)
6 Seat 7 Half bearing
8 Half-split thrust bearing 81 Sliding surface 81a Oil groove 82 Top surface of board 83 Circumferential end surface 84 Reference surface 84a Back surface 85 Circumferential center 86 Circumferential center 87 Thrust relief 88 Resin coating layer 89 Substrate
f Axial force SD sliding direction

Claims (7)

A semi-annular half-thrust bearing having a sliding surface for receiving an axial force and a back surface on the opposite side of the sliding surface, and a resin coating layer coated on a substrate is described above. In the half-thrust bearing forming the sliding surface, the thickness of the resin coating layer changes in a curved shape along the circumferential direction.
The thickness of the resin coating layer is maximum at two positions of 10 ° to 35 ° and 145 ° to 170 ° in circumference, and the resin coating is between the maximum thicknesses of the two resin coating layers. There is an intermediate position where the thickness of the layer is minimized, and the thickness of the resin coating layer at the intermediate position is 65% to 90% of the maximum thickness of the maximum thickness of the two resin coating layers. Half-split thrust bearing characterized by being present. Claim 1 is characterized in that the thickness of the resin coating layer at the intermediate position is 76.6% to 88.3% of the maximum thickness of the maximum thicknesses of the two resin coating layers. Half-split thrust bearing described in . When the half-split thrust bearing is viewed along the circumferential direction of the half-split thrust bearing, the sliding surface of the half-split thrust bearing is positioned at 10 ° to 35 ° and 145 ° to 170 ° in terms of circumferential angle. The half-thrust bearing according to claim 1 or 2, wherein the bearing has a convex contour protruding from the bearing. A thrust bearing composed of two half-split thrust bearings, wherein at least one of the two half-split thrust bearings is the half-split thrust bearing according to any one of claims 1 to 3. Thrust bearings that are characterized by being present. The half-split thrust bearing according to any one of claims 1 to 3, wherein the half-split thrust bearing is for receiving an axial force of a crank shaft of an internal combustion engine. The bearing device provided with the half-split thrust bearing according to any one of claims 1 to 3. An internal combustion engine having the bearing device according to claim 6.

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