Abstract: In an EGR valve, a valve element is moved with respect to a valve seat to adjust a passage section width of a measuring section, thereby regulating an EGR gas flow rate in a passage. The valve seat includes a valve hole, a first end face facing to a downstream side of the passage and a second end face facing to an upstream side of the passage. The inner circumferential surface of the valve hole has a concave curved shape with an inner diameter gradually increasing toward the second end face. The valve element is placed inside the valve hole to be movable in between a fully closed position and a fully open position. While the valve element is placed in the fully open position, passage section widths of parts of the measuring section in an EGR gas flow direction are approximate to each other.

Abstract: During a caulking process, a pressure is applied to a pressure receiving shoulder portion in the same direction as a direction of a clamping force generated by a caulking portion. The clamping force for holding an outer race can thereby be increased. Also, a pressure receiving surface of the pressure receiving shoulder portion is set higher than an end face. Thus, no pressure resulting from plastic deformation in a direction perpendicular to the direction of the clamping force of the caulking portion is generated. In addition, a groove is formed between the pressure receiving shoulder portion and an end serving as the caulking portion.

Abstract: During a caulking process, a pressure is applied to a pressure receiving shoulder portion in the same direction as a direction of a clamping force generated by a caulking portion. The clamping force for holding an outer race can thereby be increased. Also, a pressure receiving surface of the pressure receiving shoulder portion is set higher than an end face. Thus, no pressure resulting from plastic deformation in a direction perpendicular to the direction of the clamping force of the caulking portion is generated. In addition, a groove is formed between the pressure receiving shoulder portion and an end serving as the caulking portion.

Abstract: In an EGR valve, a valve element is moved with respect to a valve seat to adjust a passage section width of a measuring section, thereby regulating an EGR gas flow rate in a passage. The valve seat includes a valve hole, a first end face facing to a downstream side of the passage and a second end face facing to an upstream side of the passage. The inner circumferential surface of the valve hole has a concave curved shape with an inner diameter gradually increasing toward the second end face. The valve element is placed inside the valve hole to be movable in between a fully closed position and a fully open position. While the valve element is placed in the fully open position, passage section widths of parts of the measuring section in an EGR gas flow direction are approximate to each other.

Abstract: In addition to the pressure for swaging applied when swaging is performed, a pressure in the direction the same as the direction of the holding force exerted by a swaged portion is applied to a pressure receiving edge portion of a bearing holder by the pressure applied by a swaging roller. As a result, the elastic deformation in a circumferential wall portion that is not bent is advanced and the amount of elastic deformation of the bearing holder in the axial direction is reduced, so that it is possible to increase the difference in the amount of elastic deformation between the bearing holder and an outer race. Thus, the axial residual stress in the bearing holder is increased after the swaging is completed, as compared to the case of the ordinary swaging. Accordingly, it is possible to increase the holding force for holding the outer race.

Abstract: During a caulking process, a pressure is applied to a pressure receiving shoulder portion in the same direction as a direction of a clamping force generated by a caulking portion. The clamping force for holding an outer race can thereby be increased. Also, a pressure receiving surface of the pressure receiving shoulder portion is set higher than an end face. Thus, no pressure resulting from plastic deformation in a direction perpendicular to the direction of the clamping force of the caulking portion is generated. In addition, a groove is formed between the pressure receiving shoulder portion and an end serving as the caulking portion.

Abstract: During a caulking process, a pressure is applied to a pressure receiving shoulder portion in the same direction as a direction of a clamping force generated by a caulking portion. The clamping force for holding an outer race can thereby be increased. Also, a pressure receiving surface of the pressure receiving shoulder portion is set higher than an end face. Thus, no pressure resulting from plastic deformation in a direction perpendicular to the direction of the clamping force of the caulking portion is generated. In addition, a groove is formed between the pressure receiving shoulder portion and an end serving as the caulking portion.

Abstract: In addition to the pressure for swaging applied when swaging is performed, a pressure in the direction the same as the direction of the holding force exerted by a swaged portion is applied to a pressure receiving edge portion of a bearing holder by the pressure applied by a swaging roller. As a result, the elastic deformation in a circumferential wall portion that is not bent is advanced and the amount of elastic deformation of the bearing holder in the axial direction is reduced, so that it is possible to increase the difference in the amount of elastic deformation between the bearing holder and an outer race. Thus, the axial residual stress in the bearing holder is increased after the swaging is completed, as compared to the case of the ordinary swaging. Accordingly, it is possible to increase the holding force for holding the outer race.