Tool for producing crown wheels, and method for producing such a tool

Tool for producing crown wheels by means of a generating process, in which the tool and a workpiece rotate at a constant ratio of the speeds of rotation and move relative to each other so that the tool works continuously, said tool comprising:

• a disc having an axis of rotation and a periphery with machining elements provided on said periphery, cutting edges of the machining elements defining an outer surface of a profile determining the shape of the teeth of a crown wheel to be produced by the tool, said profile extending substantially helically over the periphery of the disc thereby defining a helix direction, and each cross-section of said helical profile at right angles to the helix direction of the profile being produced being of the shape of a segment of an imaginary gear wheel of infinitely small thickness with a center point thereof on a circle in a plane at right angles to the axis of rotation of the tool, and the center point lies on said axis of rotation, and the pitch of the helical profile is such that for one complete revolution about the axis of rotation of the tool, viewed in cross-section to the helical profile, the imaginary gear wheel rotates about its center point over one or more tooth pitches, in each cross-section of the helical profile the outer contour of the cross-section being composed of at least a part of the outer contour of the tooth profile of the imaginary gear wheel with involute gear teeth and lines connecting thereto, such that each of the teeth having a tooth tip and two tooth flanks bounded by the outer contour of the cross-section, the distance between each of the two tooth flanks and a line at right angles to the axis of rotation of the tool and passing through the tooth tip remains the same or increases from the tooth tip to the axis of rotation of the tool, and in each cross-section of the helical profile the outer contour of the cross-section at least being composed of a part of the outer contour of the imaginary gear wheel with involute teeth and a part of the outer contour of the tooth profile of one or more gear racks with different pressure angles which can mesh with the imaginary gear wheel, so that straight parts connect in a contacting manner to parts of the outer contour of the cross-section with an involute form.

Tool for producing crown wheels by means of a generating process, in which the tool and a workpiece rotate at a constant ratio of the speeds of rotation and move relative to each other so that the tool works continuously, said tool comprising:

• a disc having an axis of rotation and a periphery with machining elements provided on said periphery, cutting edges of the machining elements defining an outer surface of a profile determining the shape of the teeth of a crown wheel to be produced by the tool, said profile extending substantially helically over the periphery of the disc thereby defining a helix direction, and each cross-section of said helical profile at right angles to the helix direction of the profile being produced being of the shape of a segment of an imaginary gear wheel of infinitely small thickness with a center point thereof on a circle in a plane at right angles to the axis of rotation of the tool, and the center point lies on said axis of rotation, and the pitch of the helical profile is such that for one complete revolution about the axis of rotation of the tool, viewed in cross-section to the helical profile, the imaginary gear wheel rotates about its center point over one or more tooth pitches, in each cross-section of the helical profile the outer contour of the cross-section being composed of at least a part of the outer contour of the tooth profile of the imaginary gear wheel with involute gear teeth and lines connecting thereto, such that each of the teeth having a tooth tip and two tooth flanks bounded by the outer contour of the cross-section, the distance between each of the two tooth flanks and a line at right angles to the axis of rotation of the tool and passing through the tooth tip remains the same or increases from the tooth tip to the axis of rotation of the tool, and in each cross-section of the helical profile the two tooth flanks of at least one of the teeth bounded by the outer contour of the cross-section coincide in a pointed tooth tip.

Tool for producing crown wheels by means of a generating process, in which the tool and a workpiece rotate at a constant ratio of the speeds of rotation and move relative to each other so that the tool works continuously, said tool comprising:

• a disc having an axis of rotation and a periphery with machining elements provided on said periphery, cutting edges of the machining elements defining an outer surface of a profile determining the shape of the teeth of a crown wheel to be produced by the tool, said profile extending substantially helically over the periphery of the disc thereby defining a helix direction, and each cross-section of said helical profile at right angles to the helix direction of the profile being produced being of the shape of a segment of an imaginary gear wheel of infinitely small thickness with a center point thereof on a circle in a plane at right angles to the axis of rotation of the tool, and the center point lies on said axis of rotation, and the pitch of the helical profile is such that for one complete revolution about the axis of rotation of the tool, viewed in cross-section to the helical profile, the imaginary gear wheel rotates about its center point over one or more tooth pitches, in each cross-section of the helical profile the outer contour of the cross-section being composed of at least a part of the outer contour of the tooth profile of the imaginary gear wheel with involute gear teeth and lines connecting thereto, such that each of the teeth having a tooth tip and two tooth flanks bounded by the outer contour of the cross-section, the distance between each of the two tooth flanks and a line at right angles to the axis of rotation of the tool and passing through the tooth tip remains the same or increases from the tooth tip to the axis of rotation of the tool, and in each cross-section of the helical profile the tooth tips of the teeth bounded by the outer contour of the cross-section lie on a circle with a center point which coincides with the center point of the imaginary gear wheel and with a radius which is greater than the radius of the tip circle of a pinion which has to mesh with a crown wheel to be produced by the tool.

Tool for producing crown wheels by means of a generating process, in which the tool and a workpiece rotate at a constant ratio of the speeds of rotation and move relative to each other so that the tool works continuously, said tool comprising:

• a disc having an axis of rotation and a periphery with machining elements provided on said periphery, cutting edges of the machining elements defining an outer surface of a profile determining the shape of the teeth of a crown wheel to be produced by the tool, said profile extending substantially helically over the periphery of the disc thereby defining a helix direction, and each cross-section of said helical profile at right angles to the helix direction of the profile being produced being of the shape of a segment of an imaginary gear wheel of infinitely small thickness with a center point thereof on a circle in a plane at right angles to the axis of rotation of the tool, and the center point lies on said axis of rotation, and the pitch of the helical profile is such that for one complete revolution about the axis of rotation of the tool, viewed in cross-section to the helical profile, the imaginary gear wheel rotates about its center point over one or more tooth pitches, in each cross-section of the helical profile the outer contour of the cross-section being composed of at least a part of the outer contour of the tooth profile of the imaginary gear wheel with involute gear teeth and lines connecting thereto, such that each of the teeth having a tooth tip and two tooth flanks bounded by the outer contour of the cross-section, the distance between each of the two tooth flanks and a line at right angles to the axis of rotation of the tool and passing through the tooth tip remains the same or increases from the tooth tip to the axis of rotation of the tool, and the tool is a cutting tool in the form of a disc having disposed on the periphery and regularly distributed over the periphery cutter teeth which are provided with cutting edges which lie in the outer surface of the helical profile.

Tool for producing crown wheels by means of a generating process, in which the tool and a workpiece rotate at a constant ratio of the speeds of rotation and move relative to each other so that the tool works continuously, said tool comprising:

• a disc having an axis of rotation and a periphery with machining elements provided on said periphery, cutting edges of the machining elements defining an outer surface of a profile determining the shape of the teeth of a crown wheel to be produced by the tool, said profile extending substantially helically over the periphery of the disc thereby defining a helix direction, and each cross-section of said helical profile at right angles to the helix direction of the profile being produced being of the shape of a segment of an imaginary gear wheel of infinitely small thickness with a center point thereof on a circle in a plane at right angles to the axis of rotation of the tool, and the center point lies on said axis of rotation, and the pitch of the helical profile is such that for one complete revolution about the axis of rotation of the tool, viewed in cross-section to the helical profile, the imaginary gear wheel rotates about its center point over one or more tooth pitches, in each cross-section of the helical profile the outer contour of the cross-section being composed of at least a part of the outer contour of the tooth profile of the imaginary gear wheel with involute gear teeth and lines connecting thereto, such that each of the teeth having a tooth tip and two tooth flanks bounded by the outer contour of the cross-section, the distance between each of the two tooth flanks and a line at right angles to the axis of rotation of the tool and passing through the tooth tip remains the same or increases from the tooth tip to the axis of rotation of the tool, and in each cross-section of the helical profile the two tooth flanks of at least one of the teeth bounded by the outer contour of the cross-section coincide in a rounded tooth tip.