POWER SKIVING TOOL

Abstract

A power skiving tool, having a shank extending along a longitudinal axis of the tool and a cutting head arranged at a front end of the shank. The cutting head comprises a plurality of circumferentially arranged teeth, wherein each of these teeth comprises a planar rake face at a front end of the cutting head that faces away from the shank, wherein the rake face is inclined at an angle other than 90 with respect to the longitudinal axis. A transition face is in each case arranged between the rake faces of two adjacent teeth. The transition face is arranged at the front end of the cutting head and adjoins the rake faces of the two adjacent teeth. Surface normals in all points of the transition face form an angle greater than 0 with the rake faces of the two adjacent teeth.

Claims

1. A power skiving tool, having a shank extending along a longitudinal axis of the tool and a cutting head arranged at a front end of the shank, wherein the cutting head comprises a plurality of circumferentially arranged teeth, wherein each of these teeth comprises a planar rake face at a front end of the cutting head that faces away from the shank, wherein the rake face is inclined at an angle other than 90 with respect to the longitudinal axis, wherein a transition face is in each case arranged between the rake faces of two adjacent teeth, which transition face is arranged at the front end of the cutting head and adjoins the rake faces of the two adjacent teeth, wherein surface normals in all points of the transition face form an angle greater than 0 with the rake faces of the two adjacent teeth.

2. The power skiving tool according to claim 1, wherein the surface normals in all points of the transition face form an angle greater than 10 with the rake faces of the two adjacent teeth.

3. The power skiving tool according to claim 1, wherein the transition face comprises a concave surface section.

4. The power skiving tool according to claim 1, wherein the transition face comprises a convex surface section.

5. The power skiving tool according to claim 1, wherein the transition face comprises a planar surface section.

6. The power skiving tool according to claim 1, wherein the transition face comprises a concave surface section and a planar surface section, wherein the planar surface section adjoins the concave surface section.

7. The power skiving tool according to claim 1, wherein the transition face comprises a concave surface section, a planar surface section and a convex surface section, wherein the planar surface section is arranged between the concave surface section and the convex surface section.

8. The power skiving tool according to claim 7, wherein the concave surface section adjoins the rake face of one of the two adjacent teeth, and wherein the convex surface section adjoins the rake face of the other one of the two adjacent teeth.

9. The power skiving tool according to claim 5, wherein the planar surface section adjoins one of the rake faces of the two adjacent teeth.

10. The power skiving tool according to claim 1, wherein the transition face comprises a concave surface section and a planar surface section, wherein the planar surface section adjoins the concave surface section, and wherein the planar surface section adjoins one of the rake faces of the two adjacent teeth.

11. The power skiving tool according to claim 1, wherein the transition face comprises a concave surface section and a convex surface section, wherein the concave surface section adjoins the rake face of one of the two adjacent teeth and the convex surface section adjoins the rake face of the other one of the two adjacent teeth.

12. The power skiving tool according to claim 11, wherein the concave surface section adjoins the convex surface section.

13. The power skiving tool according to claim 1, wherein each of the teeth tapers radially outwards at an acute angle.

14. The power skiving tool according to claim 1, wherein each of the teeth comprises a circumferentially arranged flank that is oriented skew to the longitudinal axis.

15. The power skiving tool according to claim 1, wherein the cutting head is releasably attached to the shank.

16. The power skiving tool according to claim 1, wherein the shank is made of steel and the teeth of the cutting head are made of carbide.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG. 1 shows a perspective view of an embodiment of the herein presented power skiving tool;

[0037] FIG. 2 shows a side view of the power skiving tool shown in FIG. 1;

[0038] FIG. 3 shows a plan view from above of the power skiving tool shown in FIG. 2;

[0039] FIG. 4 shows a plan view from below of the power skiving tool shown in FIG. 2;

[0040] FIG. 5 shows a detailed view of a cutting head of the power skiving tool according to a first embodiment in a plan view from a radial direction;

[0041] FIG. 6 shows a detailed view of the cutting head of the power skiving tool according to a second embodiment in a plan view from a radial direction;

[0042] FIG. 7 shows a detailed view of the cutting head of the power skiving tool according to a third embodiment in a plan view from a radial direction; and

[0043] FIG. 8 shows a detailed view of a cutting head of a power skiving tool according to the prior art in a plan view from a radial direction.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0044] FIG. 1 shows a perspective view of an embodiment of the power skiving tool. The power skiving tool is denoted therein in its entirety with reference numeral 10.

[0045] The power skiving tool 10 comprises a shank 12 which extends along a longitudinal axis 14. In the shown embodiment, the shank 12 is cylindrical. In principle, however, it may also have a different shape, e.g. cuboid.

[0046] Furthermore, the power skiving tool 10 comprises a cutting head 16 which is arranged at a front end of the shank 12. A plurality of teeth 18 are arranged on the cutting head 16, which are distributed over the circumference of the cutting head 16.

[0047] Each of these teeth 18 comprises a rake face 20 at a front end of the teeth 18 that faces away from the shank 12. The teeth 18 taper radially outwards at an acute angle. Each of the teeth 18 comprises a circumferentially arranged flank 26 which represents the radially outermost part of each tooth 18 and thus also the radially outermost part of the cutting head 16. In the embodiment shown here, the flanks 26 are oriented skew to the longitudinal axis 14 of the power skiving tool 10 or the shank 12.

[0048] The rake faces 20 of each tooth 18 are in each case inclined at an angle other than 90 (not orthogonal) with respect to the longitudinal axis 14. Preferably, the rake faces 20 of all teeth 18 have the same inclination relative to the longitudinal axis 14. However, it is obvious that the rake faces 20 are not parallel to each other from a geometric point of view due to their star-shaped arrangement. However, the rake faces 20 of two adjacent teeth 18 run approximately parallel to one another.

[0049] Each of FIGS. 5-7 shows a detailed view of the front end of the cutting head 16 in a plan view from a radial direction. The front end of the teeth 18 has a slightly different shape according to the three different embodiments shown in FIG. 5-7. However, the three herein shown embodiments have in common that a transition face 22 is located between the rake faces 20 of two adjacent teeth 18. This transition face 22 is inclined relative to the adjacent rake faces 20.

[0050] The transition faces 22 are differently shaped depending on the embodiment, which will be discussed in more detail below. Common to all embodiments shown herein is that a tangent to the transition face 22, which tangent is indicated in the figures by a dotted line, is arranged at an angle , which is less than 90, preferably less than 80, with respect to the adjacent rake face 20 that lies in a planar plane. This angle is preferably less than 90 at all points of the transition face 22, and particularly preferably less than 80. Accordingly, the surface normals 23, which are each oriented orthogonally to the transition face 22, form an angle greater than 0, particularly preferably an angle greater than 10 (10 including) with the adjacent rake faces. In FIGS. 5-7, the tangent and the surface normal 23 are each drawn at a point which has a maximum tangent gradient compared to the other points of the transition face 22. The angle is therefore, depending on the point on the transition face 22 in the range: 0<90, preferably in the range 1090.

[0051] In the first embodiment shown in FIG. 5, the transition face 22 comprises a concave surface section 28, a convex surface section 30 and a planar surface section 32. The concave surface section 28 of the transition face 22 directly adjoins one end of one of the two adjacent rake faces 20. The convex surface section 30 of the transition face 22 directly adjoins one end of the other of the two adjacent rake faces 20. The planar surface section 32 is arranged between the concave surface section 28 and the convex surface section 30.

[0052] Preferably, the transition face 22 has a continuously changing curvature. The transition between the concave surface section 28 and the planar surface section 32 is therefore just as continuous as the transition between the planar surface section 32 and the convex surface section 30. The transitions are preferably not only continuous, but merge tangentially into each other. In the embodiment shown in FIG. 5, the rake faces 20 also preferably merge continuously and tangentially into the concave surface section 28 or the convex surface section 30.

[0053] The embodiment shown in FIG. 6 differs from the embodiment shown in FIG. 5 in that an edge (not rounded) is provided instead of the convex surface section 30 between the planar surface section 32 and the adjacent rake face 20. Here, the planar surface section 32 of the transition face 22 directly adjoins one of the two adjacent rake faces 20.

[0054] In the embodiment shown in FIG. 7, the transition face 22 does not comprise a planar surface section 32. Instead, the concave surface section 28, that adjoins one of the two adjacent rake faces 20, merges directly into the convex surface section 30, that adjoins the other one of the two adjacent rake faces 20. The transition between the concave surface section 28 and the convex surface section 30 is preferably a continuous and tangential transition. In FIG. 7, the dashed line, which indicates the aforementioned angle between the transition face 22 and the rake face 20, is arranged as a tangent at the turning point or the turning line 36 between the concave surface section 28 and the convex surface section 30. This point or line (in 3D) represents the point of maximum slope of the tangent at the transition face 22 in the embodiment shown in FIG. 7.

[0055] It goes without saying that instead of describing the angle mentioned above by means of a tangent to the transition face 22, the corresponding opposite angle may also be described by means of the surface normal, which is oriented perpendicular to the transition face 22 at the respective point. Following the above-mentioned condition of <90 or <80, this means that the surface normal 23 encloses an angle greater than 0, preferably greater than 10 (10 including) with the rake faces 20 of two adjacent teeth 18 at all points of the transition face 22 (except at the edges of the transition face 22). This inclination of the transition face 22 relative to the adjacent rake faces 20 effectively prevents the problem of an undesirable formation of an interfering contour at the tooth tips of the gearing to be produced.

[0056] It goes without saying that further embodiments are conceivable which result from combinations and permutations of the arrangements of the individual surface sections 28, 30, 32 of the transition face 22 shown in FIG. 5-7, without leaving the spirit and scope of the present disclosure.

[0057] It is to be understood that the foregoing is a description of one or more preferred exemplary embodiments of the invention. The invention is not limited to the particular embodiment(s) disclosed herein, but rather is defined solely by the claims below. Furthermore, the statements contained in the foregoing description relate to particular embodiments and are not to be construed as limitations on the scope of the invention or on the definition of terms used in the claims, except where a term or phrase is expressly defined above. Various other embodiments and various changes and modifications to the disclosed embodiment(s) will become apparent to those skilled in the art. All such other embodiments, changes, and modifications are intended to come within the scope of the appended claims.

[0058] As used in this specification and claims, the terms for example, e.g., for instance, such as, and like, and the verbs comprising, having, including, and their other verb forms, when used in conjunction with a listing of one or more components or other items, are each to be construed as open-ended, meaning that the listing is not to be considered as excluding other, additional components or items. Other terms are to be construed using their broadest reasonable meaning unless they are used in a context that requires a different interpretation.