Abstract: The finishing process is applied to a surface of a roller 8 constituting a cam follower unit by the barrel finishing. When a position of a highest portion out of fine roughnesses existing on the surface is assumed as an outermost surface position, an occupation ratio of a sectional area of a virtual plane in a plane direction at a portion that is positioned at a depth of 2.0 ?m from the outermost surface position to an area of an overall surface of a portion that contacts the other member is set to 90% or more. With this configuration, a tough oil film can be formed between the surface of the roller 8 and the other member, and also the improvement of durability of a member such as the roller 8, or the like, which contacts the other member via a rolling contact or a sliding contact, can be achieved at a low cost.

Abstract: Even when used at a high rotation speed, outside parts in relation to the radial direction of a cage 3, of the circumferential parts of a pocket 7 are kept from being worn away by outside end surfaces 21 of rollers 2. Moreover the rollers 2 are kept from sliding on the inside the pockets 7, to thereby stabilize the performance of rotation support parts. The outside end surface 21 of the roller 2 is made a ball convex surface, so that the center part of the outside end surface 21 can be freely in contact with the inner peripheral surface of a second outside cylindrical portion 14. In a condition with the rollers 2 displaced radially outward of the cage 3 due to centrifugal force, a PV value of a rubbing part between the outside end surface 21 and the opposite surface is kept low, and the wear of this rubbing part is suppressed.

Abstract: As this radial needle bearing 7c, a radial needle bearing is used which includes a cage 10b. Respective pillar portions 12, 12 which make up the cage 10b are disposed more radially inwards than a circle pitch of respective needles 8, 8. In addition, the needles 8, 8 which are adjacent to each other in a circumferential direction are caused to approach each other, so as to secure the number of such needles 8, 8. As a result, no large bending stress is applied to a tappet roller 6 without increasing the thickness of the tappet roller 6.

Abstract: Even when used at a high rotation speed, outside parts in relation to the radial direction of a cage 3, of the circumferential parts of a pocket 7 are kept from being worn away by outside end surfaces 21 of rollers 2. Moreover the rollers 2 are kept from sliding on the inside the pockets 7, to thereby stabilize the performance of rotation support parts. The outside end surface 21 of the roller 2 is made a ball convex surface, so that the center part of the outside end surface 21 can be freely in contact with the inner peripheral surface of a second outside cylindrical portion 14. In a condition with the rollers 2 displaced radially outward of the cage 3 due to centrifugal force, a PV value of a rubbing part between the outside end surface 21 and the opposite surface is kept low, and the wear of this rubbing part is suppressed.

Abstract: The finishing process is applied to a surface of a roller 8 constituting a cam follower unit by the barrel finishing. When a position of a highest portion out of fine roughnesses existing on the surface is assumed as an outermost surface position, an occupation ratio of a sectional area of a virtual plane in a plane direction at a portion that is positioned at a depth of 2.0 ?m from the outermost surface position to an area of an overall surface of a portion that contacts the other member is set to 90% or more. With this configuration, a tough oil film can be formed between the surface of the roller 8 and the other member, and also the improvement of durability of a member such as the roller 8, or the like, which contacts the other member via a rolling contact or a sliding contact, can be achieved at a low cost.

Abstract: A roller bearing for rotatably supporting a rotating shaft of an internal combustion engine between a main body and a cap of the internal combustion engine. The roller bearing including: a plurality of rollers; a retainer which is cirumferentially splittable and supports the plurality of rollers; and an outer race which is cirumferentially splittable and forms a raceway surface for the plurality of rollers. The retainer is split into a plurality of retaining members. The outer race is split into a plurality of race plates. At least one of the race plates is provided with one of a projection and a cavity to be engaged with one of the main body and the cap to restrict a relative movement between the one of the race plates and the one of the cylinder head and the cap.

Abstract: The rocker arm 1 has a fitting surface 6 on the opposite sides of which guide surfaces 21 are formed, such that the guide surfaces 21 are inclined to be closer to each other toward their tip ends. Even when the valve stem 20 is displaced in the widthwise direction of the fitting surface 6, the outer peripheral surface of the base end portion of the valve stem 20 comes into contact with only the tip end of one of the guide surfaces 21. Consequently, lubrication is improved and friction moment is decreased in the contact area, so that friction resistance is suppressed between the guide surfaces 21 and the outer peripheral surface of the base end of the valve stem 20 to easily obtain high performance of the engine.

Abstract: A sheet metal rocker arm manufactured by the steps of punching one metal plate to form a blank having a predetermined contour and through holes, and subjecting this blank to a bending work based on a press work to form a pair of side walls parallel to each other and a connecting portion for connecting the both ends of the side walls in the width direction thereof. This rocker arm is also provided with at least a pair of though holes formed at positions which are aligned with each other on the both side walls and at least one engagement portion provided in a part of the connecting portion. The thickness of at least one engagement portion, is formed to be greater than the thickness of the both side walls.

Abstract: A sheet-metal rocker arm formed by the steps of punch-pressing a sheet of metal member to form a blank having a predetermined shape and a through-hole, of subjecting the blank to a bending process based on pressing to form a pair of substantially parallel side wall sections and a connection section for connecting the widthwise edges of the both side wall sections and to form at least one pair of circular holes in the both side wall sections at locations in alignment, of deforming the middle of the connection section in the thickness direction to form an engagement portion on one side of the connection section such that the engagement portion is recessed from the other portion of the connection section, and of forming on the other side of the connection section a bulge section, trapezoidal in cross section, which protrudes in an embanked-shape as the engagement portion is formed, whereby the widthwise edges of the middle of the bulge section corresponding to the top edge of the trapezoidal shape exist on the w

Abstract: A roller bearing for rotatably supporting a rotating shaft of an internal combustion engine between a main body and a cap of the internal combustion engine. The roller bearing including: a plurality of rollers; a retainer which is cirumferentially splittable and supports the plurality of rollers; and an outer race which is cirumferentially splittable and forms a raceway surface for the plurality of rollers. The retainer is split into a plurality of retaining members. The outer race is split into a plurality of race plates. At least one of the race plates is provided with one of a projection and a cavity to be engaged with one of the main body and the cap to restrict a relative movement between the one of the race plates and the one of the cylinder head and the cap.

Abstract: The rocker arm 1 has a fitting surface 6 on the opposite sides of which guide surfaces 21 are formed, such that the guide surfaces 21 are inclined to be closer to each other toward their tip ends. Even when the valve stem 20 is displaced in the widthwise direction of the fitting surface 6, the outer peripheral surface of the base end portion of the valve stem 20 comes into contact with only the tip end of one of the guide surfaces 21. Consequently, lubrication is improved and friction moment is decreased in the contact area, so that friction resistance is suppressed between the guide surfaces 21 and the outer peripheral surface of the base end of the valve stem 20 to easily obtain high performance of the engine.

Abstract: A sheet metal rocker arm manufactured by the steps of punching one metal plate to form a blank having a predetermined contour and through holes, and subjecting this blank to a bending work based on a press work to form a pair of side walls parallel to each other and a connecting portion for connecting the both ends of the side walls in the width direction thereof. This rocker arm is also provided with at least a pair of though holes formed at positions which are aligned with each other on the both side walls and at least one engagement portion provided in a part of the connecting portion. The thickness of at least one engagement portion, is formed to be greater than the thickness of the both side walls.

Abstract: A sheet-metal rocker arm formed by the steps of punch-pressing a sheet of metal member to form a blank having a predetermined shape and a through-hole, of subjecting the blank to a bending process based on pressing to form a pair of substantially parallel side wall sections and a connection section for connecting the widthwise edges of the both side wall sections and to form at least one pair of circular holes in the both side wall sections at locations in alignment, of deforming the middle of the connection section in the thickness direction to form an engagement portion on one side of the connection section such that the engagement portion is recessed from the other portion of the connection section, and of forming on the other side of the connection section a bulge section, trapezoidal in cross section, which protrudes in an embanked-shape as the engagement portion is formed, whereby the widthwise edges of the middle of the bulge section corresponding to the top edge of the trapezoidal shape exist on the w

Abstract: A sheet metal rocker arm manufactured by the steps of punching one metal plate to form a blank having a predetermined contour and through holes, and subjecting this blank to a bending work based on a press work to form a pair of side walls parallel to each other and a connecting portion for connecting the both ends of the side walls in the width direction thereof. This rocker arm is also provided with at least a pair of though holes formed at positions which are aligned with each other on the both side walls and at least one engagement portion provided in a part of the connecting portion. The thickness of at least one engagement portion, is formed to be greater than the thickness of the both side walls.

Abstract: A sheet metal rocker arm manufactured by the steps of punching one metal plate to form a blank having a predetermined contour and through holes, and subjecting this blank to a bending work based on a press work to form a pair of side walls parallel to each other and a connecting portion for connecting the both ends of the side walls in the width direction thereof. This rocker arm is also provided with at least a pair of though holes formed at positions which are aligned with each other on the both side walls and at least one engagement portion provided in a part of the connecting portion. The thickness of at least one engagement portion, is formed to be greater than the thickness of the both side walls.

Abstract: A sheet metal rocker arm manufactured by the steps of punching one metal plate to form a blank having a predetermined contour and through holes, and subjecting this blank to a bending work based on a press work to form a pair of side walls parallel to each other and a connecting portion for connecting the both ends of the side walls in the width direction thereof. This rocker arm is also provided with at least a pair of though holes formed at positions which are aligned with each other on the both side walls and at least one engagement portion provided in a part of the connecting portion. The thickness of at least one engagement portion, is formed to be greater than the thickness of the both side walls.

Abstract: A sheet metal rocker arm manufactured by the steps of punching one metal plate to form a blank having a predetermined contour and through holes, and subjecting this blank to a bending work based on a press work to form a pair of side walls parallel to each other and a connecting portion for connecting the both ends of the side walls in the width direction thereof. This rocker arm is also provided with at least a pair of though holes formed at positions which are aligned with each other on the both side walls and at least one engagement portion provided in a part of the connecting portion. The thickness of at least one engagement portion, is formed to be greater than the thickness of the both side walls.

Abstract: A sheet metal rocker arm manufactured by the steps of punching one metal plate to form a blank having a predetermined contour and through holes, and subjecting this blank to a bending work based on a press work to form a pair of side walls parallel to each other and a connecting portion for connecting the both ends of the side walls in the width direction thereof. This rocker arm is also provided with at least a pair of though holes formed at positions which are aligned with each other on the both side walls and at least one engagement portion provided in a part of the connecting portion. The thickness of at least one engagement portion, is formed to be greater than the thickness of the both side walls.

Abstract: A sheet metal rocker arm manufactured by the steps of punching one metal plate to form a blank having a predetermined contour and through holes, and subjecting this blank to a bending work based on a press work to form a pair of side walls parallel to each other and a connecting portion for connecting the both ends of the side walls in the width direction thereof. This rocker arm is also provided with at least a pair of though holes formed at positions which are aligned with each other on the both side walls and at least one engagement portion provided in a part of the connecting portion. The thickness of at least one engagement portion, is formed to be greater than the thickness of the both side walls.

Abstract: A sheet metal rocker arm manufactured by the steps of punching one metal plate to form a blank having a predetermined contour and through holes, and subjecting this blank to a bending work based on a press work to form a pair of side walls parallel to each other and a connecting portion for connecting the both ends of the side walls in the width direction thereof. This rocker arm is also provided with at least a pair of though holes formed at positions which are aligned with each other on the both side walls and at least one engagement portion provided in a part of the connecting portion. The thickness of at least one engagement portion, is formed to be greater than the thickness of the both side walls.