Nsk Corporation

Yuuki Mizushima

Kazuto Kobayashi

Nobuyuki Hagiwara

Yuu Yasuda

Mizuki Watanabe

Keita Itagaki

Tatsuya Kobayashi

A steering rack () meshes with a pinion rotatably driven by the input shaft () of a steering gear () constituting an automotive steering device. The steering rack () is provided with a an axially extending rod part () of round cross section, and a plurality of rack teeth () formed on a radial one side surface of an axial portion of the rod part (), the rack teeth () meshing with the pinion. At least one dummy tooth () is formed in portions that are axial parts of the rod part () and are adjacent to both axial sides of the plurality of rack teeth (). The dummy tooth () has a tooth height less than the rack teeth () and does not mesh with the pinion.

Steering rack and method for manufacturing the same

With respect to the manufacture of cylindrical rolling bodies, excess material on an outside section in the radial direction and recesses in both end surfaces in the axial direction are not generated as much as possible in the intermediate material that is removed from a molding device for performing compression molding. Annular concave sectionsare provided on the inner-circumferential surfacesof molding concave sectionsprovided in a stationary-side moldand a movable-side mold. The stationary-side moldand the movable-side moldare brought close to each other in the axial direction while compressing the intermediate materialin a state in which both side sections in the axial direction of the intermediate materialare inserted into the molding concave sections. At this time, a part of the material of the intermediate materialis made to enter inside the annular concave sections, and undercut sectionsare formed on the outer side in the radial direction of a compression-molded intermediate material. After that, when removing both side sections in the axial direction of the intermediate materialfrom the inside of the molding concave sectionsin the axial direction, the undercut sectionsare drawn through or handled by stepped sectionsexisting at the end sections in the axial direction of the annular concave sections

Molding device for manufacturing cylindrical rolling body, manufacturing method for cylindrical rolling body, manufacturing method for rolling bearing, manufacturing method for vehicle, and manufacturing method for mechanical apparatus

A steering rack meshes with a pinion rotatably driven by the input shaft of a steering gear constituting an automotive steering device. The steering rack is provided with a an axially extending rod part of round cross section, and a plurality of rack teeth formed on a radial one side surface of an axial portion of the rod part, the rack teeth meshing with the pinion. At least one dummy tooth is formed in portions that are axial parts of the rod part and are adjacent to both axial sides of the plurality of rack teeth. The dummy tooth has a tooth height less than the rack teeth and does not mesh with the pinion.

A steering rack includes a rack shaft (), a plurality of rack teeth () formed on the rack shaft and each having a tooth trace inclined with respect to a first direction perpendicular to an axial direction of the rack shaft, and a dummy tooth () aligned with the rack teeth and formed on the rack shaft. The dummy tooth () is non-uniformly formed in a second direction parallel to the tooth trace of the rack tooth ().

Steering rack and manufacturing method therefor

Provided are a manufacturing method and manufacturing device that allow the depth of rack teeth to be adequately maintained across the axial direction. A stepped surface () is provided on one surface in the axial direction of a pressure punch () that moves together with a teeth-forming punch (). The teeth-forming punch () is displaced downward and rack teeth are formed on the upper surface of an intermediate material (). At the same time, the surface on the end in the axial direction of the intermediate material () is pressed in the axial direction by a movable die () due to the engagement between the stepped surface () and the surface on the other side in the axial direction of the movable die ().

Rack, method for manufacturing rack, and device for manufacturing rack

Characteristics of joint sections using rivetsthat join flat sectionsof a pair of cage elements are improved regardless of differences in the volumes of the rivets. A head sectionand a crimped sectionof a rivetcomprise flange sectionsand convex sections. The inside surfaces of the flange sectionspress against the outside surfaces of the flat sections. The convex sectionshave a truncated cone shape with the maximum diameter being on the flange sectionside. The diameter dof the apex of the convex sectionsis equal to or less than the inner diameter Rof circular holes, and the outer diameter Dof the flange sectionsis equal to or greater than the outer diameter Dof the bottom section of the convex sections. Furthermore, the amount of protrusion Lthat the flange sectionsprotrude from the convex sectionsis equal to or less than two times the thickness Tin the axial direction of the flange sections

Growing community of inventors

Fujisawa, Japan

Yuuki Mizushima