Abstract: A nitride semiconductor epitaxial substrate includes: a Si substrate; a nitride semiconductor epitaxial layer disposed above the Si substrate; and a mixed crystal layer disposed between the Si substrate and the nitride semiconductor epitaxial layer, and containing Si and a group III metal element, the mixed crystal layer containing a high concentration of C. The mixed crystal layer has a concentration of at least 1.0×10+21 cm?3, and a transition metal element concentration of at most 5.0×10+16 cm?3.

Abstract: There is provided an oil feed member capable of preventing lubricant from being excessively fed from an oil feed member to lubrication portions of valve gears, and a lubricant feed mechanism for an engine provided with the same. An oil feed member for feeding lubricant to lubrication portions of valve gears for opening and closing intake valves and exhaust valves of an engine, the oil feed member including: an upper panel member and a lower panel member laid over each other; and an oil feed passage formed by recessing laid surfaces of the upper panel member and the lower panel member, wherein the oil feed passage includes basis oil passages formed on a downstream side, and an introduction oil passage formed on an upstream side and having a smaller lubricant flow area than that of the basis oil passages.

Abstract: Provided is a lubricant feed mechanism for an engine capable of achieving manufacturing cost reduction. A lubricant feed mechanism for an engine (1) is configured to feed lubricant through a cylinder head (10), a camshaft (an intake-side camshaft (40); an exhaust-side camshaft (42)), a cam cap (50), and an oil feed member (100) to a cam (a cam (40a); a cam (42a)) of a valve gear (30). The oil feed member (100) is formed by folding one panel member, and the inside surface of the oil feed member (100) in the folded state is recessed so as to form an oil passage (a first oil passage (114); a second oil passage (116); a third oil passage (118)) for guiding lubricant fed through the cam cap (50) to the cam.

Abstract: There is provided an oil feed member capable of preventing lubricant from being excessively fed from an oil feed member to lubrication portions of valve gears, and a lubricant feed mechanism for an engine provided with the same. An oil feed member for feeding lubricant to lubrication portions of valve gears for opening and closing intake valves and exhaust valves of an engine, the oil feed member including: an upper panel member and a lower panel member laid over each other; and an oil feed passage formed by recessing laid surfaces of the upper panel member and the lower panel member, wherein the oil feed passage includes basis oil passages formed on a downstream side, and an introduction oil passage formed on an upstream side and having a smaller lubricant flow area than that of the basis oil passages.

Abstract: Provided is a lubricant feed mechanism for an engine capable of achieving manufacturing cost reduction. A lubricant feed mechanism for an engine (1) is configured to feed lubricant through a cylinder head (10), a camshaft (an intake-side camshaft (40); an exhaust-side camshaft (42)), a cam cap (50), and an oil feed member (100) to a cam (a cam (40a); a cam (42a)) of a valve gear (30). The oil feed member (100) is formed by folding one panel member, and the inside surface of the oil feed member (100) in the folded state is recessed so as to form an oil passage (a first oil passage (114); a second oil passage (116); a third oil passage (118)) for guiding lubricant fed through the cam cap (50) to the cam.

Abstract: Provided is a lubricant feed mechanism for an engine in which space above a cam cap is not used. A lubricant feed mechanism for an engine is configured to feed lubricant through a cylinder head, a camshaft, and a cam cap to a cam of a valve gear. The mechanism includes an oil feed member that is disposed in the cam cap such that an upper end thereof is set at a lower level than an upper end of the cam cap in a height-wise direction and has an oil passage configured to guide lubricant to be fed through the cam cap to the cam.

Abstract: Provided is a lubricant feed mechanism for an engine in which space above a cam cap is not used. A lubricant feed mechanism for an engine is configured to feed lubricant through a cylinder head, a camshaft, and a cam cap to a cam of a valve gear. The mechanism includes an oil feed member that is disposed in the cam cap such that an upper end thereof is set at a lower level than an upper end of the cam cap in a height-wise direction and has an oil passage configured to guide lubricant to be fed through the cam cap to the cam.

Abstract: A sliding bearing 2 has a sliding surface 2a in sliding contact with an outer peripheral surface of a crankshaft 1 (rotating shaft) and a relief portion 4 formed along a circumferential direction on both axial end portions of the sliding surface 2a and retreated outward in a radial direction from the sliding surface 2a.

Abstract: A sliding bearing includes a center portion and end portions on a bearing surface 1. Convexo-concave portions are respectively formed in the center portion and the end portions. The average height of the vertexes of convex portions 1A in the center portion is set smaller than the average height of the vertexes of convex portions 1B in the end portions. Average height Lh of the convexo-concave portion 1A in the center portion and average height LH of the convexo-concave portions 1B in the end portions are set to the same height. The center portion may be formed flat.

Abstract: A sliding bearing 2 has a sliding surface 2a in sliding contact with an outer peripheral surface of a crankshaft 1 (rotating shaft) and a relief portion 4 formed along a circumferential direction on both axial end portions of the sliding surface 2a and retreated outward in a radial direction from the sliding surface 2a. The relief portion 4 is provided with a flat portion 4a formed on the axial end portion and a tapered portion 4b formed so as to become gradually deeper from the flat portion 4a toward a boundary portion between the relief portion 4 and the sliding surface 2a. A lubricant forms a disturbance or a swirl inside the tapered portion 4b and then, flows along the tapered portion 4b so as to form a high-pressure region W by a flow of the lubricant at a position of the flat portion 4a. A temperature of the lubricant can be rapidly raised and also, leakage of the lubricant can be suppressed.

Abstract: A sliding bearing structure for a shaft member includes: a shaft member; a bearing member rotates relative to the shaft member; an oil supply space to which lubrication is supplied between sliding surfaces of the shaft member and the bearing member; two annular grooves formed in a circumferential direction in an inner peripheral surface of the bearing member; and two annular seal members formed as separate pieces from the shaft member and the bearing member, and arranged in the annular grooves between the shaft member and the bearing member. Each annular seal member is formed in plural, and is made of material having a thermal expansion coefficient such that an inside diameter of the annular seal member is smaller than an inside diameter of the bearing member at a low temperature, and is the same as or larger than the inside diameter of the bearing member at a high temperature.

Abstract: A sliding support structure includes: a support member (12; 106) and a shaft member (10; 120) that relatively rotates with respect to the support member (12; 106) wherein lubricating oil is supplied to between a sliding surface of the shaft member and a sliding surface of the support member, the support member (12; 106) has a sliding surface portion (x) that corresponds to a load concentrating portion between the shaft member (10; 120) and the support member (12; 106), and sliding surface regions (Ya, Yb) that are higher in oil repellency than the sliding surface portion are respectively provided on upstream and downstream sides of the sliding surface portion in a flow direction of the lubricating oil.

Abstract: A sliding bearing includes a center portion and end portions on a bearing surface 1. Convexo-concave portions are respectively formed in the center portion and the end portions. The average height of the vertexes of convex portions 1A in the center portion is set smaller than the average height of the vertexes of convex portions 1B in the end portions. Average height Lh of the convexo-concave portion 1A in the center portion and average height LH of the convexo-concave portions 1B in the end portions are set to the same height. The center portion may be formed flat. It is possible to attain a reduction in friction without sacrificing conformability and a load capacity.

Abstract: A sliding bearing is constructed by an upper split bearing half and a lower split bearing half. The upper split bearing half has a sliding surface, in which an oil groove which allows a lubricating oil to flow therein is formed over the entire circumferential extent of the sliding surfaced. The oil groove extends through a crush relief to be open to a junction area, and the oil groove has a bottom which is formed so that a portion disposed toward the junction area as considered in the circumferential direction of the crush relief is located closer to the center of the upper split bearing half in comparison to a central portion. An ingress in large quantities of foreign particles within the oil groove onto the sliding surface of the sliding bearing and into a connecting rod bearing after passing through a lubricating oil feed passage is suppressed, and an oil leakage through the crush relief is reduced, allowing a lubricating oil pressure to be secured and augmented.

Abstract: A sliding bearing structure for a shaft member includes: a shaft member; a bearing member rotates relative to the shaft member; an oil supply space to which lubrication is supplied between sliding surfaces of the shaft member and the bearing member; two annular grooves formed in a circumferential direction in an inner peripheral surface of the bearing member; and two annular seal members formed as separate pieces from the shaft member and the bearing member, and arranged in the annular grooves between the shaft member and the bearing member. Each annular seal member is formed in plural, and is made of material having a thermal expansion coefficient such that an inside diameter of the annular seal member is smaller than an inside diameter of the bearing member at a low temperature, and is the same as or larger than the inside diameter of the bearing member at a high temperature.

Abstract: A sliding support structure includes: a support member (12; 106) and a shaft member (10; 120) that relatively rotates with respect to the support member (12;106) wherein lubricating oil is supplied to between a sliding surface of the shaft member and a sliding surface of the support member, the support member (12; 106) has a sliding surface portion (x) that corresponds to a load concentrating portion between the shaft member (10; 120) and the support member (12; 106), and sliding surface regions (Ya, Yb) that are higher in oil repellency than the sliding surface portion are respectively provided on upstream and downstream sides of the sliding surface portion in a flow direction of the lubricating oil.

Abstract: An oil-feeding device for a crankshaft where the amount of lubricant oil leaking from supporting areas of main journal portions is reduced without increasing friction of bearing members against the main journal portions. The oil-feeding device for a crankshaft includes upper bearing members and lower bearing members. The upper and lower bearing members have a half hollow cylindrical shape, are provided with crush relief portions at both ends, and jointly encompass main journal portions of a crank shaft. The upper bearing members have circumferentially extending oil grooves provided in the faces opposite the main journal portions, the grooves penetrating through oil passages of a cylinder block. The lower bearing members do not have oil grooves. The oil grooves do not extend in the crush relief portions, and therefore the leakage of lubricant oil, fed to the oil grooves, to the areas of the crush relief portions is suppressed.

Abstract: An oil-feeding device for a crankshaft where the amount of lubricant oil leaking from supporting areas of main journal portions is reduced without increasing friction of bearing members against the main journal portions. The oil-feeding device for a crankshaft includes upper bearing members and lower bearing members. The upper and lower bearing members have a half hollow cylindrical shape, are provided with crush relief portions at both ends, and jointly encompass main journal portions of a crank shaft. The upper bearing members have circumferentially extending oil grooves provided in the faces opposite the main journal portions, the grooves penetrating through oil passages of a cylinder block. The lower bearing members do not have oil grooves. The oil grooves do not extend in the crush relief portions, and therefore the leakage of lubricant oil, fed to the oil grooves, to the areas of the crush relief portions is suppressed.

Abstract: A sliding bearing 4 is constructed by an upper split bearing half 8 and a lower split bearing half 9. The upper split bearing half 8 has a sliding surface 8a, in which an oil groove 10 which allows an lubricating oil to flow therein is formed over the entire circumferential extent of the sliding surface 8a. The oil groove extends through a crush relief 8c to be open to a junction area 8b, and the oil groove has a bottom 10a which is formed so that a portion disposed toward the junction area as considered in the circumferential direction of the crush relief is located closer to the center of the upper split bearing half in comparison to a central portion. An ingress in large quantities of foreign particles within the oil groove onto the sliding surface of the sliding bearing and into a connecting rod bearing after passing through a lubricating oil feed passage is suppressed, and an oil leakage through the crush relief is reduced, allowing a lubricating oil pressure to be secured and augmented.