Provided is a spline structure with which contact surface area between an outer-side member and balls can be ensured, and contact surface area between an inner-side member and the balls can be ensured. This spline structure is provided with an outer-side member having a first track groove on the inner surface, an inner-side member having a second track groove on the outer surface, and balls disposed between the first track groove and the second track groove so as to allow the inner-side member to be inclined relative to the outer-side member. A bottom part extending along the length direction of the first track groove has a linear shape. A bottom part extending along the length direction of the second track groove has a concave curved shape.

A method produces a synchronizer ring for a synchronizing device in which blocking teeth extending radially outwards or radially inwards are produced by a forging method. The blocking teeth each have a flank portion and two oblique top flanks merging into a common top ridge. A depression is formed on the rear side of a blocking tooth opposite the top ridge.

A ball cage for universal use both in a cross-groove type plunging constant velocity joint and in a cross-groove type fixed constant velocity joint has an external contour with sections of different curvature. Axial edge sections of the external contour are designed as spherical sections located on the circumference of an imaginary sphere, whereas a center section of the external contour located axially between the edge sections runs radially inside the diameter of the imaginary sphere.

A friction material has a first outermost surface and a second outermost surface spaced apart from the first outermost surface. The friction material includes a base which forms at least a portion of the first outermost surface. The base includes fibers present in an amount of from 20 to 80 weight percent, a filler present in an amount of from 20 to 80 weight percent, and a deposit which forms at least a portion of the second outermost surface and includes a friction adjusting agent. The friction material further includes a resin disposed throughout the friction material. The deposit is disposed in the friction material in a gradated pattern. At least a portion of the deposit is exposed to the environment and the second outermost surface has a surface roughness of from 2 to 11 micrometers as determined by non-contact laser measurement according to ISO 25178.

A method may be employed to produce a variable-length steering shaft. The method may involve positioning a shaft core within a mold cavity of an injection molding tool coaxially with respect to a mold surface that delimits a toothing region, injecting molten plastic into the mold cavity between the shaft core and the mold surface of the mold cavity, removing a toothed shaft from the injection molding tool after the molten plastic has solidified, providing a hollow shaft and axially inserting the toothing region into an internal toothing of the hollow shaft. To make it possible to provide an improved sliding coating with the least possible manufacturing outlay, the injection of the molten plastic may be performed from one axial end region of the mold cavity.

A wet-type multi plate clutch is configured to be used for a transmission in an automobile. A clutch pack is provided with a plurality of drive plates and a plurality of driven plates. The drive plates have single surfaces on which first clutch facings are fixed and opposed surfaces on which annular grooves are formed along entire peripheral lengths. The driven plates have single surfaces on which second clutch facings are fixed and opposed surfaces on which annular grooves are formed along entire peripheral lengths. The sliding surfaces of the drive plates and the driven plates are arranged between the first and second clutch facings, which are axially adjacent with each other.

A number of variations may include a product including a single clutch pack having a plurality of clutch plates, and a first friction material on a first plate of the plurality of clutch plates, and a second friction material on a second plate of the plurality of plates, the first friction material being different than the second friction material, and constructed and arranged to provide a tailored combination of torque capacity and response time that would be produced by a clutch pack having solely the first friction material on plates thereof or the second friction material on plates thereof.

A friction part includes a friction surface with a first row of first friction lining pieces arranged radially inwardly, a second row of second friction lining pieces arranged between the first friction lining pieces and a third row of third friction lining pieces, and the third row of third friction lining pieces arranged radially outwardly. Stem grooves are formed between adjacent pairs of the first friction lining pieces. Radially inner branch grooves emerge from the stem grooves and are delimited by the adjacent pairs of the first friction lining pieces and by the second friction lining pieces. Radially outer branch grooves are delimited by the second friction lining pieces and the third friction lining pieces. The radially inner branch grooves and the radially outer branch grooves are connected to each other by offset grooves with a tangential offset between the radially inner branch grooves and the radially outer branch grooves.

A method of manufacturing a spline telescopic shaft includes a masking step in which, in a prescribed axial-direction region of an intermediate manufacturing product, partial tooth grooves that are equally spaced circumferentially are respectively covered by masking members that are equally spaced circumferentially; a resin coating step in which a resin layer is formed, and inner surfaces of the partial tooth grooves covered by the masking members are left as metal exposed portions that are equally spaced circumferentially; and a coating film forming step in which, in a state where the intermediate manufacturing product provided with the resin layer is centered with respect to a broach via the metal exposed portions, the intermediate manufacturing product and the broach are caused to slide relative to each other in an axial direction by press-fitting such that the resin layer is shaved to form a resin coating film.

In a sliding shaft, an outer circumferential surface of a male shaft is coated with a resin coating layer formed by a fluidized bed powder coating method using a powder coating material containing a base resin and at least either a carbon black or a metal oxide as an antistatic agent. A steering device includes this sliding shaft as an intermediate shaft transmitting steering force.