Gear Pair Comprising a Gear with a Surface Structure, Transmission Comprising Gear Pair, and Method for Producing a Gear

Abstract

A gear pair including at least one first gear with a microstructure and at least one additional gear is provided. The first gear has first teeth with first tooth flanks and the additional gear has additional teeth with additional tooth flanks. In order to transfer power from the first gear to the additional gear, a first tooth flank contacts an additional tooth flank on an imaginary tangential plane which touches both tooth flanks in a contact point. The addition of the speeds of the two tooth flanks in the contact point on the tangential plane produces a sum speed. The microstructure is designed as a depression on the first tooth flank and runs at least partly along a structure line on the first tooth flank, and the structure line is touched by a structure tangent in the contact point. The structure tangent lies on the tangential plane.

Claims

1. A gearwheel pair comprising: at least a first gearwheel with a microstructure; and a further gearwheel, wherein the first gearwheel includes first teeth with first tooth flanks, the further gearwheel includes further teeth with further tooth flanks, where a first tooth flank makes contact with a further tooth flank in an imaginary tangential plane which is tangent on the two tooth flanks at a contact point for transmission of power from the first gearwheel to the further gearwheel, addition of speeds of the two tooth flanks at the contact point results in a total speed in the tangential plane, the microstructure is configured as a depression on the first tooth flank and runs at least in sections along a structuring line on the first tooth flank, a structure tangent which lies in the tangential plane is tangent on the structuring line at the contact point, and the structure tangent and the total speed enclose an angle y, and the angle y is selected from a range which is greater than 25 and less than or equal to 90.

2. The gearwheel pair according to claim 1, wherein the first gearwheel is configured as an octoidally or involutely toothed bevel gear, pinion and/or ring gear.

3. The gearwheel pair according to claim 1, wherein the further gearwheel also has a microstructure in accordance with the first gearwheel.

4. The gearwheel pair according to claim 1, wherein the microstructure has a depth of less than 10 m at least in sections and of more than 0.1 m at least in sections.

5. The gearwheel pair according to claim 3, wherein the microstructure has a depth of less than 10 m at least in sections and of more than 0.1 m at least in sections.

6. The gearwheel pair according to claim 1, wherein, over its complete course, the microstructure has a depth of less than 10 m and of more than 0.1 m.

7. The gearwheel pair according to claim 3, wherein, over its complete course, the microstructure has a depth of less than 10 m and of more than 0.1 m.

8. The gearwheel pair according to claim 1, wherein a multiplicity of said microstructures are arranged on at least one of the first tooth flanks.

9. The gearwheel pair according to claim 7, wherein a multiplicity of said microstructures are arranged on at least one of the first tooth flanks.

10. A gear mechanism of a motor vehicle comprising: a gearwheel pair according to claim 1.

11. A method for producing a gearwheel for a gearwheel pair comprising: at least a first gearwheel with a microstructure; and a further gearwheel, wherein the first gearwheel includes first teeth with first tooth flanks, the further gearwheel includes further teeth with further tooth flanks, where a first tooth flank makes contact with a further tooth flank in an imaginary tangential plane which is tangent on the two tooth flanks at a contact point for transmission of power from the first gearwheel to the further gearwheel, addition of speeds of the two tooth flanks at the contact point results in a total speed in the tangential plane, the microstructure is configured as a depression on the first tooth flank and runs at least in sections along a structuring line on the first tooth flank, a structure tangent which lies in the tangential plane is tangent on the structuring line at the contact point, and the structure tangent and the total speed enclose an angle y, and the angle y is selected from a range which is greater than 25 and less than or equal to 90, the method comprising the acts of: providing a gearwheel; and applying at least one microstructure, wherein the microstructure or the microstructures runs/run along the structuring line.

12. The method according to claim 11, wherein the microstructures are applied by way of material erosion.

13. The method according to claim 11, wherein the microstructures are produced by way of a rolling movement of a tool which rolls on the first gearwheel, and the rolling movement is superimposed by an oscillation.

14. The method according to claim 11, wherein the microstructures are produced in a running-in phase with the use of a first lubricant with a first lubricant viscosity, and in relation to kinematic viscosity at 100 C., the first lubricant viscosity is selected from a range which is smaller than 5.0 cSt.

15. The method according to claim 11, wherein the microstructures are applied in the form of a hard coating.

16. The method according to claim 11, wherein the microstructures are covered at least in sections or completely by way of a hard coating.

17. The method according to claim 14, wherein the microstructures are covered at least in sections or completely by way of a hard coating.

18. The method according to claim 11, wherein a course of the structuring line is at least in sections or completely by way of a simulation method on a data processing system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG. 1 is a perspective view of a part of a first gearwheel.

[0048] FIG. 2 is a partial section through a first gearwheel.

[0049] FIG. 3 is a detail of the tangential plane.

DETAILED DESCRIPTION OF THE DRAWINGS

[0050] FIG. 1 shows a perspective partial section of the first gearwheel. The tooth 4 of the gearwheel extends in the longitudinal direction 11 and has a tooth height extent in the tooth height direction 12; the recess of the microstructure 2 extends substantially in the tooth depth direction 13. Said first gearwheel has a first tooth 4 with a first tooth flank 1. The microstructure 2 which is illustrated by way of the structuring line is applied on the first tooth flank 1. For the sake of clarity, only one microstructure 2 is shown; in reality, the first tooth flank 1 has a multiplicity of microstructures 2 of this type. At the contact point 9, the microstructure 2 has the course which is approximated by way of the structure tangent 3. Here, the structure tangent 3 lies in the tangential plane 8 at the contact point 9 and is tangent on both the first tooth flank 1 and the tooth flank (not shown) of the further gearwheel which makes contact with the first tooth flank at the contact point 9.

[0051] The total speed 7 prevails at the contact point 9. The first tooth 4 extends between the tooth root 6 and the tooth tip 5 in the tooth height direction. Starting from the tooth flank, the microstructure 2 extends into the material 10 of the first tooth 1 and is therefore configured as a recess on the first tooth flank 1.

[0052] FIG. 2 shows a sectional illustration through the first tooth flank 1. The tooth 4 of the gearwheel extends in the longitudinal direction 11, that is to say substantially in the direction orthogonally with respect to the plane of the illustration, and has a tooth height extent in the tooth height direction 12; the recess of the microstructure 2 extends substantially in the tooth depth direction 13. Here, the depth t of the microstructure 2 is shown greatly exaggerated, in comparison with the remaining geometry of the first tooth flank 1; this serves for improved representability.

[0053] The microstructure 2 is arranged at the contact point 9; it is once again to be noted that the tooth flank 1 in reality has a multiplicity of microstructures 2 of this type. The first tooth 4 extends between the tooth root 6 and the tooth tip 5. The microstructure 2 runs at least substantially into the plane of the illustration and therefore at least substantially in the tooth width direction. Starting from the tooth flank 1, the microstructure 2 extends into the material 10 of the first tooth 4. The tangential plane 8 is tangent on the tooth flank 1 at the contact point 9.

[0054] FIG. 3 shows a detail of the tangential plane 8. The contact point 9 lies in the tangential plane 8. At the contact point 9, the microstructure 2 can be approximated by way of the structure tangent 3. Furthermore, the total speed 7 lies at the contact point 9 in the tangential plane 8. The direction of the total speed 7 and the structure tangent 3 enclose the acute angle y. A particularly favorable characteristic of the degree of efficiency can be achieved by way of the microstructure 2 for the gearwheel pair according to the invention, in particular, by way of the orientation of the microstructure 2 transversely with respect to the total speed 7 at the respective contact point 9.

[0055] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.