A gear includes an inner hub formed of metal material, the inner hub having an outer surface defining a plurality of outer teeth. The gear also includes an outer ring formed of non-metal material, the outer ring having an inner diameter that is smooth. The outer ring is disposed in an interference fit with the outer teeth of the inner hub.

A method and equipment for forming a front toothing having a plurality of radial teeth on an annular collar of an inner ring of a wheel hub, wherein a plurality of first knives are axially and sequentially impressed on the annular collar and have a first predetermined circumferential profile (P1) configured to form radial reliefs which are spaced by imprints and have a rounded circumferential profile corresponding to the profile of the ridges of the radial teeth to be obtained; thereafter, a plurality of second knives are axially and sequentially impressed on the annular collar inside the imprints and have a third predetermined circumferential profile (P3) configured to reproduce in reverse at least part of respective opposite flanks of the radial teeth of the front toothing to be obtained.

A bicycle sprocket includes a first sprocket body and a plurality of first sprocket teeth. The first sprocket teeth include a plurality of tooth tip portions and a plurality of tooth bottom portions. The tooth bottom portions include at least one first tooth bottom portion and at least one second tooth bottom portion. The at least one first tooth bottom portion has a first tooth bottom shape. The at least one second tooth bottom portion has a second tooth bottom shape. The first tooth bottom shape is different from the second tooth bottom shape.

Equipment including a rigid plate provided with a plurality of cutters configured to be impressed in sequence against a swaged annular collar of an inner ring of a wheel hub, the collar being formed with a first radial profile; the cutters sliding axially through the plate and towards a first face of the plate resting in abutment against the collar; wherein the first face of the plate is provided in the region of the cutters with a concave annular seat having a second radial profile configured to copy at least partly the first radial profile of the collar, the annular seat being configured to be passed through by the cutters during the step for impression against the collar and to contain any radial flow of the metallic material which forms the collar.

Equipment including a rigid plate provided with a plurality of cutters configured to be impressed in sequence against a swaged annular collar of an inner ring of a wheel hub, the collar being formed with a first radial profile; the cutters sliding axially through the plate and towards a first face of the plate resting in abutment against the collar; wherein the first face of the plate is provided in the region of the cutters with a concave annular seat having a second radial profile configured to copy at least partly the first radial profile of the collar, the annular seat being configured to be passed through by the cutters during the step for impression against the collar and to contain any radial flow of the metallic material which forms the collar.

A method of manufacturing a mechanical part of the present invention includes a first process of forming, by performing a folding processing to an end portion of the material, a portion to be processed having a structure, in which a plurality of layers respectively having a thickness corresponding to a plate thickness of a material overlap each other, in the material such that a plate thickness direction of the layer is orthogonal to a plate thickness direction of the material; and a second process of changing, by performing a forging processing to the portion to be processed, a shape of the portion to be processed to a target shape while press-welding the layers of the portion to be processed to each other by plastic deformation.

A method of manufacturing a mechanical part of the present invention includes a first process of forming, by performing a folding processing to an end portion of the material, a portion to be processed having a structure, in which a plurality of layers respectively having a thickness corresponding to a plate thickness of a material overlap each other, in the material such that a plate thickness direction of the layer is orthogonal to a plate thickness direction of the material; and a second process of changing, by performing a forging processing to the portion to be processed, a shape of the portion to be processed to a target shape while press-welding the layers of the portion to be processed to each other by plastic deformation.

In a die for compressing and sizing a sintered body at straight portions, upper taper portions are provided on a die upper portion and a core rod upper portion, and the straight portions are provided at a die lower portion and a core rod lower portion. The die upper portion and the core rod upper portion have Young's moduluses higher than the die lower portion and the core rod lower portion. The die upper portion and the core rod upper portion are made of materials having Young's moduluses that are at least 50 GPa higher than that of the sintered body. The sintered body can be densified with a smaller ironing margin. Since the sintered body is ironed without being compressed, by the upper taper portions and the core rod upper portion having high Young's moduluses, the die is prevented from breaking and being abraded due to ironing.

There is provided a method of forming a ring gear, including providing a tube having an inner surface comprising gear teeth, the tube being a hollow tube formed by extrusion. The method also includes inserting a shaping tool into the tube, the shaping tool having tool teeth to mate with the gear teeth, and extended and retracted configurations. The shaping tool may be inserted into the tube in its retracted configuration. Moreover, the method includes extending the shaping tool into its extended configuration to cause the tool teeth to mate with the gear teeth and to exert a radially outward force on the tube. Furthermore, the method includes fixing a shape of an outer perimeter of the tube, retracting the shaping tool into its retracted configuration to reduce the radially outward force exerted by the shaping tool on the tube, and removing the shaping tool from the tube.

The present invention relates to a freewheel (2) comprising an inner ring (30), an outer ring (28), a clamping gap (32) between the inner ring (30) and the outer ring (28), a side wall (40) for lateral limitation of the clamping gap (32) and at least one clamping element (34) in the clamping gap (32) which is biased by means of a spring element (66), wherein the spring element (66) is supported or supportable on one side on the clamping element (34) and on the other side on a support projection (70), which is formed by a supporting tongue (74) bent out of the side wall (40) and projecting into the clamping gap (32). In addition, the present invention relates to a method for producing such a freewheel (2).