Tooth milling cutter and method for milling the teeth of toothed gear elements

Patent metadata

Field	Value
Publication number	US-9352406-B2
Application number	US-201113880406-A
Country	US
Kind code	B2
Filing date	Oct 14, 2011
Priority date	Oct 22, 2010
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

Method for milling a series of teeth of a toothed gear element with teeth in a straight line with a milling cutter rotatable about a milling cutter axis and having at its periphery interchangeable cutting inserts arranged such that, when the milling cutter is brought to the toothed gear element, they reach into gaps between adjacent teeth or generate these gaps, and a corresponding milling cutter. Cutting edges of mounted cutting inserts extend radially and perpendicularly relative to the milling cutter axis. During milling of the tooth profile, the milling cutter axis is aligned in a plane perpendicular to the longitudinal extent of the tooth back and, during entering of the cutting inserts, rotated about the milling cutter axis, into the surface or gaps between the teeth, and pivoted in this plane over an angular range covering all normals to the profile surface of the tooth to be produced.

First claim

The invention claimed is:

1. A method of milling a row of teeth of a toothed gear element with a straight tooth configuration, with a milling cutter which is rotatable about a milling cutter axis and has at its periphery interchangeable cutting inserts which are so arranged that when the milling cutter is approached to the toothed gear element the cutting inserts engage into the gaps between adjacent teeth or generate those gaps, wherein a milling cutter is used, in which the cutting inserts in their condition of being mounted to the milling cutter have at least one cutting edge extending radially and perpendicularly relative to the milling cutter axis,
wherein upon milling of the tooth profile the milling cutter axis is oriented in a plane perpendicularly to the longitudinal extent of the tooth back and during the engagement movement of the cutting inserts which rotate about the milling cutter axis into the surface or tooth gaps of a toothed gear element the milling cutter axis is pivoted in said plane over an angular range which covers the range of all normals to the profile surface of the tooth to be produced,
wherein the cutting inserts project radially from the outer periphery of the milling cutter main body and on mutually opposite sides have parallel cutting edges perpendicular to the milling cutter axis, and
wherein the mutually opposite cutting edges are respectively used successively for generating the flanks of adjacent teeth, which flanks are in opposite relationship at a tooth gap.

2. A method according to claim 1 wherein during the engagement movement and the pivotal movement of the rotating milling cutter and the cutting inserts the toothed gear element is translatorally displaced in the direction of the row of teeth or is rotated about an axis of the toothed gear element insofar as the toothed gear element is a gear wheel.

3. A method according to claim 1 wherein the cutting inserts additionally have a cutting edge which is disposed in a cylindrical surface around the milling cutter axis and has components parallel to the milling cutter axis, wherein said additional cutting edge is used to generate the tooth gap bottom, by the milling cutter being approached to the gear element radially and perpendicularly to the plane defined by two adjacent tooth backs, wherein the milling cutter axis is respectively disposed perpendicularly to a currently generated surface segment of the tooth profile.

4. A method according to claim 1 wherein the tooth profile delimiting a tooth gap is produced with the following steps:
a) producing a groove in the cylindrical surface of a gear wheel blank by the milling cutter cutting the surface open with the cutting circle defined by the cutting inserts in a depth corresponding to the tooth height parallel to the axis of the gear wheel,
b) pulling the milling cutter out of the groove and feeding it in an axial position of the tooth back along which the profile is to be produced at the tip of a tooth delimiting the groove or a corresponding tooth gap, wherein the gear wheel is rotated into a position and the milling cutter is correspondingly tracked therewith so that the cutting edges of the milling cutter are perpendicular to a normal to the radially outward end portion of the profile, and
c) rotating the gear wheel and simultaneously tracking the milling cutter by axial and radial translation, wherein the milling cutter axis retains its orientation in space and the profile of the tooth is continuously produced.

5. A method according to claim 1 wherein the process of engagement movement and pivotal movement is repeated in at least one further plane parallel to the first plane.

6. A method according to claim 1 wherein the tooth back extends on a conical surface which is inclined relative to the axis of the conical surface.

7. A method according to claim 6 wherein the angle of the conical surface, that is measured relative to the cone axis, is between 0 and 90°.

8. A method according to claim 6 comprising the following steps:
a) producing a groove in the conical surface of a gear wheel blank by the milling cutter cutting the surface open with the cutting circle defined by the cutting inserts in a depth corresponding to the tooth height at an angle of inclination to the cone axis, that corresponds to the cone angle of the tooth bottom of a bevel gear to be produced,
b) pulling the milling cutter out of the groove and feeding the milling cutter cutting circle in an axial position of the tooth back at which the profile is to be produced at the tip of a tooth delimiting the groove or a corresponding tooth gap, wherein the gear wheel is rotated about the cone axis and the milling cutter is correspondingly tracked therewith so that the cutting edges of the milling cutter are perpendicular to a normal to the radially outward end portion of the profile, and
c) rotating the gear wheel and simultaneously tracking the milling cutter by axial and radial translation, with respect to the milling cutter axis retains its orientation in space and the profile of the tooth is continuously produced.

9. A method according to claim 8 wherein the axial and radial translation of the milling cutter, that is related to the milling cutter axis, corresponds to a circular movement about a cone tip, lying on the cone axis, of the cone surfaces of the bevel gear to be produced, wherein the milling cutter axis respectively extends parallel to a tangent to the cone surface.

10. A milling cutter for producing tooth profiles by a method according to claim 1 comprising a rotatable, rotationally symmetrical main body and recesses at a periphery of the main body, in which cutting inserts are received,
wherein the cutting inserts have cutting edges which are disposed in a radial plane and which extend radially and which extend in the radial direction by at least 6 mm beyond the peripheral surface of the portion of the main body, that has the recesses.

11. A cutting insert for a milling cutter according to claim 10 wherein the cutting insert is in the form of a tangential reversible cutting insert which in the plan view onto the relief surface is of an elongate parallelogram shape of a length exceeding the width by at least twice and having a central fixing bore, wherein the edge of the fixing bore is at a spacing of at least 12 mm from the ends in the longitudinal direction of the parallelogram.

12. A cutting insert according to claim 11 wherein the cutting insert over at least 8 mm of its cutting portions provided at the longitudinal ends of the parallelogram has a tangential rake surface with two parallel cutting edges and relief surfaces adjoining same, which include an angle of less than 90 degrees with the rake surface.

13. A method of milling a row of teeth of a toothed gear element with a straight tooth configuration, wherein the toothed gear element is a bevel gear, comprising a milling cutter which is rotatable about a milling cutter axis and has at its periphery interchangeable cutting inserts which are so arranged that when the milling cutter is approached to the toothed gear element the cutting inserts engage into the gaps between adjacent teeth or generate those gaps, wherein a milling cutter is used, in which the cutting inserts in their condition of being mounted to the milling cutter have at least one cutting edge extending radially and perpendicularly relative to the milling cutter axis,
wherein upon milling of the tooth profile the milling cutter axis is oriented in a plane perpendicularly to an edge of a tooth back, that delimits the desired profile surface, and during the engagement movement of the cutting inserts which rotate about th

Assignees

• Scherbarth Stefan
• Sandvik Intellectual Property

Inventors

• Scherbarth Stefan

Classifications

• Y10T409/107791

  Using rotary cutter · CPC title

• B23F1/06 Primary

  by milling · CPC title

• B23F21/122

  having a shape similar to that of a gear or part thereof, with cutting edges situated on the tooth contour lines · CPC title

• B23F21/128

  in exchangeable arrangement · CPC title

• Y10T409/104134

  Adapted to cut bevel gear · CPC title