WO2018024354A1

WO2018024354A1 - Method and tool for increasing the loadability of a gear wheel

Info

Publication number: WO2018024354A1
Application number: PCT/EP2017/000809
Authority: WO
Inventors: Markus Heilmann; Thomas Schimmer; Philipp Buratowski
Original assignee: Audi Ag
Priority date: 2016-08-03
Filing date: 2017-07-10
Publication date: 2018-02-08
Also published as: DE102016009467B4; DE102016009467A1; EP3493928A1

Abstract

The present invention relates to a method for increasing the loadability of the gear wheel (11), in which at least one forming body (15, 17, 19) is guided along the gear wheel (11) and the at least one forming body (15, 17, 19) enters into contact with at least one flank (21, 25) and/or at least one tooth root (29) of the gear wheel (11), and in which, by means of the contact between the at least one forming body (15, 17, 19) and the at least one flank (21, 25) and/or the at least one tooth root (29) of the gear wheel, residual compressive stresses are introduced into the at least one flank and/or the at least one tooth root of the gear wheel. The invention also relates to a tool for increasing the loadability of a gear wheel.

Description

Method and tool for increasing a load capacity of a

gear

The present invention relates to a method for increasing a

Resilience of a gear and a tool configured to perform the presented method.

Gears, in particular gears, are among the most highly stressed components in a transmission. Accordingly, defects requiring replacement of a gearbox are largely due to wear of flanks of respective teeth of a gear, due to tooth breakage or due to so-called "pitting" in which small recesses are introduced into a respective tooth during operation of a gearbox, caused to a wear-related

To counteract component failure, it is advantageous to harden a gear before use in a transmission by introducing compressive residual stresses or to increase a load capacity of the gear by introduced into the gear pressure compressive stresses. According to the prior art gears are hardened by means of strength-blasting processes, in which a respective gear with ceramic or

is bombarded with metallic bullets.

German patent document DE 196 19 401 C1 describes a method for the abrasive dressing of a grinding worm with a profiling tool.

The German document DE 196 248 42 A1 discloses a tool and a method for dressing grinding worms, in which both a profile and a form-dressing process is performed. A method for profiling of modified grinding worms is disclosed in the German publication DE 197 06 867 B4.

Against this background, a method for increasing a load capacity of a gear is presented in which at least one forming body is guided along the gear and the at least one forming body with at least one edge and / or at least one tooth root of the gear in contact, and wherein by means of the contact between the at least one forming body and the at least one flank and / or the at least one tooth root of the gear pressure compressive stresses in the at least one flank and / or the at least one tooth root of the

Gear are introduced.

The presented process, unlike a grinding process, does not chip, i. H. not marked by material removal, and serves

in particular for increasing a load capacity of a gear. For this purpose, it is provided that a respective toothed wheel with at least one

Forming body is machined, which comes into contact with at least one flank and / or at least one tooth root of a respective gear and on the at least one flank and / or the at least one tooth root of the gear exerts a pressure, so that residual compressive stresses in the at least one flank and / or the at least one tooth root of the gear are generated. By inventively provided

Applying residual compressive stresses, the gear is hardened and thus more resilient to an untreated condition.

In order to carry out the method presented, provision is made in particular for a respective toothed wheel to be clamped and to have at least one toothed wheel

Tool is processed, which comprises at least one Umformkörper and the at least one Umformkörper is moved along the gear, in order to come into contact with at least one flank and / or at least one tooth root of the toothed wheel and to pressurize the at least one flank and / or the at least one tooth root, which results in compressive residual stresses in the at least one flank and / or the at least one tooth root introduced and corresponding

Contact points of the gear are smooth-rolled or firmly rolled by the forming body. For this purpose, a respective forming body can be arranged rigidly or movably on a respective tool. In order to move the at least one forming body provided according to the invention along a respective toothed wheel, the toothed wheel, which has at least one deformable body or at least one deformable body

Molded tool or the gear and the

Tool moved together, d. H. to be turned in particular.

In particular, it is provided that the tool is designed as a toothed wheel, which engages over arranged on respective teeth of the gear forming in the gear to be machined to machine this.

In a possible embodiment of the presented method

provided that the at least one flank and the at least one tooth root of the gear are applied simultaneously or chronologically successively by means of the at least one Umformkörpers with a pressure, ie smoothed or rolled. It is conceivable that different flanks of a tooth of a respective toothed wheel are machined at the same time by inserting a forming body into respective recesses surrounding a tooth, which is shaped corresponding to the recesses. In this case, the forming body may further have a length which allows the forming body, at the same time, ie, when inserted into the recesses, respective tooth bases of the gear and respective flanks to apply pressure, so that compressive stresses are introduced into the flanks and the tooth roots. Of course, the at least one inventively provided forming body can also be designed such that this at a

Inserting into a respective recess of a gear contacted only a flank and / or a tooth root and accordingly introduces only in the flank and / or the tooth root compressive stresses. In this case, the forming body can also be designed such that during a movement of the Umformkörpers on the gear along first a flank and then a tooth root of a respective tooth or another flank of another tooth comes into contact with the Umformkörper to

Residual compressive stresses in the respective flank or the tooth root

contribute. -

In a further possible embodiment of the presented method, it is provided that a plurality of formed bodies is used in order to

To introduce residual compressive stresses in the gear, wherein respective Umformkörper are configured for processing a flank or a tooth root of the gear.

A respective forming body can, for example, together with a plurality of other forming bodies, which can be configured, for example, as rolling elements or pressure bodies, d. H. the movable or rigid at a corresponding

Tool are arranged to be arranged on a respective tool. In this case, respective Umformkörper for contacting different elements of a gear, ie a flank or a tooth root, be configured so that during a repeated orbit of the gear through a Umformkörper exhibiting tool both the Flanks and the tooth roots of the gear are pressurized by the Umformkörper with pressure and appropriate compressive residual stresses are introduced into the gear. In a further possible embodiment of the presented method, it is provided that a deformation of the at least one flank and / or the at least one tooth root of the gear is set by the at least one formed body by means of a variation of at least one parameter of the following list of parameters:

Forming body, temperature of the gear, by means of at least one forming body on the at least one flank and / or the tooth applied pressure, speed of at least one Umformkörpers, speed of the gear, and Achskreuzwinkel between the gear and the at least one Umformkörper.

It is provided according to the method presented in particular that by means of at least one Umformkörpers deformations on respective flanks and / or on at least one tooth root of a gear

caused by the gear becomes more resistant to pressure and / or friction. In order to control respective deformations to be generated by a forming body, various

Parameters, such as, for example, a pressure with which a respective forming body acts on the gear or a Achskreuzwinkel with which a respective forming body rolls on the gear can be adjusted. Different parameters can be different at different times

be pronounced, for example, an increasing intensification of

To achieve residual compressive stresses in the gear. For example, a reforming body at high temperatures, ie, temperatures near a melting point of a respective gear forming material lie on the gear and then the gear are cooled quickly.

In the context of the present invention, an axis cross-angle is to be understood in particular as meaning an angle between an axis which is centered on a honing tool and orthogonal on a transverse axis of the tool, such as a rotation axis of the tool

Honing tool, and a through a center of a gear and orthogonal on a transverse axis of the gear standing axis, such as. A rotational axis of the gear is formed.

In a further possible embodiment of the proposed method, it is provided that a Achskreuzwinkel between the at least one Umformkörper and the gear or a respective tooth is changed by a diameter of the at least one Umformkörpers at respective contact surfaces between the at least one Umformkörper and the gear in the course of at least one Umformkörpers is designed variable. By a variable, ie, for example, an oblique or curved, course of a contact point of a Umformkörpers a relative orientation of the Umformkörpers can be influenced to a respective gear without an axis of Umformkörpers must be moved. Due to an interaction between a shape of the gear and a shape of Umformkörpers the forming body automatically aligns with the gear and engages in accordance with a designated location in order to deform them and introduce corresponding compressive residual stresses in the site. In a further possible embodiment of the presented method, it is provided that at least one formed body

Hard finishing tool is. It is conceivable that the forming body provided according to the invention is part of a combination tool that combines a plurality of work steps. In this case, the combination tool, for example, a

Hard finishing tool include a respective gear first hard-worked before the gear by means of another

Forming body is selectively smoothed or rolled.

In a further possible embodiment of the presented method, it is provided that a toothed or a toothed wheel as a gear

externally toothed gear is selected and the at least one

Forming body is moved according to inside or outside of the gear on the gear along.

In order to machine an internally toothed gear according to the presented method, the forming body provided according to the invention can be moved in an interior space formed by the gear, so that the forming body rolls on respective teeth of the gear wheel and / or rolls off the gear with its teeth on the forming body.

In an externally toothed gear according to the invention

provided Umformkörper be guided externally around a respective gear around, so that the forming body rolls on respective teeth of the gear and / or the gear with its teeth on the Umformkörper or a forming body having tool, such as

Gear, unrolls. Furthermore, the present invention relates to a tool for increasing a load capacity of a gear, with at least one forming body, wherein the at least one forming body is configured to be guided along the gear and in contact with at least one flank and / or at least one tooth root of the gear and wherein the at least one forming body is further configured to be in contact between the at least one forming body and at least one flank and / or at least one tooth root of the gear

Compressive residual stresses in the at least one flank and / or the at least one tooth root of the gear to bring.

The presented tool is used in particular for carrying out the presented method. In a possible embodiment of the presented tool is

provided that the at least one forming body is arranged on a basic structure of the tool, which is substantially gear-shaped

is configured, and wherein the at least one forming body is configured as a substantially circular structure which is configured to contact the gear and to smoothly roll the gear and / or to roll, when the at least one forming body on the gear is moved along.

By means of a Umformkörpers, for example. As a roller burnishing roller, which is arranged on a tooth of a gear designed as a gear, in particular a tooth root of a gear can be efficiently pressurized, while the gear to be machined and the forming tool having each other, similar to the rolling two

Gear wheels in operation, unroll. In a further possible embodiment of the presented tool is provided that the tool is a combination tool with at least one designed as a rolling body forming body for smooth rolling and / or with at least one rigid forming body for deep rolling and / or with at least one hard finishing tool.

Further advantages and embodiments will become apparent from the description and the accompanying drawings. It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination indicated, but also in other combinations or in isolation, without departing from the scope of the present invention.

;

The invention is based on an embodiment in the drawing

schematically and will be described schematically and in detail with reference to the drawing. Figure 1 shows a schematic representation of a possible embodiment of the method according to the invention.

FIG. 1 shows a machine 1 with a first tool 3, a second tool 5 and a third tool 7. The tools 3, 5, and 7 rotate about their respective axes, as indicated by the arrows 9, and are thus in engagement with a gear 1 1 with respective forming bodies 15, 17, and 19 arranged on the tools 3, 5, and 7. While the gear 1 1 moves, as indicated by arrow 13, the forming bodies 15, 17 and 19 of the tools 3, 5 and 7 engage in recesses of the gear 1 1 a. The first tool 3 contacted doing with the forming body 15, a right flank 21 a tooth 23 of the gear 1 1. The second tool 5 contacted with the Umformkörper 17 a left flank 25 of a tooth 27 of the gear 1 1 and the third

Tool 7 contacted with the Umformkörper 19 a Zahnfuß 29 of the gear 1 1. Accordingly, in a movement of the gear 1 1 all flanks and roots of the gear 1 1 are contacted by the Umformkörper 15, 17 and 19 and depending on the configuration of the Umformkörpers as

Rolling body, which is arranged, for example. By means of an axis or a joint socket movable on the tool 3, 5 or 7, smooth-rolled or connected by means of a fixed to the tool 3, 5 or 7

Forming body firmly rolled.

A detailed view of a forming body 15 is shown on the tool 3. The forming body 15 is designed substantially round or spherical and sits in a receptacle 31 of the tool 3. Of course, respective receptacles 31 of the tools 3, 5 and 7 different

Umformkörper, such as, for example, a mixture of

Bear hard finishing tools, movable rolling elements and fixed forming bodies.

Claims

Patentans praise

Anspruch [en] A method of increasing a load bearing capacity of a toothed wheel in which at least one forming body is guided along the toothed wheel and the at least one forming body comes into contact with at least one flank and / or at least one tooth root of the toothed wheel and in which by means of the contact between the toothed wheel at least one forming body and the at least one flank and / or the at least one tooth root of the gear pressure compressive stresses are introduced into the at least one flank and / or the at least one tooth root of the gear.

2. The method of claim 1, wherein the at least one flank and the at least one tooth root of the gear simultaneously or chronologically successively by means of the at least one Umformkörpers be subjected to a pressure.

3. The method according to claim 1, wherein a deformation of the at least one flank and / or of the at least one tooth root of the toothed wheel is set by the at least one deformable body by means of a variation of at least one parameter of the following list of parameters: temperature of the deformable body, temperature of the gear, by means of the at least one Umformkörpers on the at least one edge and / or the at least one tooth root applied pressure, speed of the at least one Umformkörpers, speed of the gear, and

Achskreuzwinkel between the gear and the at least one

Converting body.

4. The method according to any one of the preceding claims, wherein a Achskreuzwinkel between the at least one Umformkörper and the gear or between the at least one Umformkörper and a respective tooth is changed by a diameter of the at least one Umformkörpers at respective contact surfaces between the

at least one Umformkörper and the gear in the course of at least one Umformkörpers or the at least one

Forming body bearing tool is designed variable.

5. The method according to any one of the preceding claims, in which a plurality of Umformkörper is arranged on a tool to

Apply compressive residual stresses in the gear, and are configured in the respective Umformkörper for processing the at least one flank or the at least one tooth root of the gear.

6. The method according to any one of the preceding claims, wherein the gear is moved along the at least one Umformkörper along and / or the at least one Umformkörper is moved along the gear.

7. The method according to any one of the preceding claims, wherein the at least one forming body is a hard finishing tool.

8. The method according to any one of the preceding claims, wherein the gear as an internally toothed or an externally toothed tool is selected and the at least one Umformkörper is moved according to inside or outside the gear on the gear along.

9. Tool for increasing a load capacity of a gear (1 1), comprising at least one Umformkörper (15, 17, 19), wherein the at least one Umformkörper (15, 17, 19) is configured to the gear (1 1) along to be guided and with at least one flank (21, 25) and / or at least one tooth root (29) of the gear (1 1) in contact, and wherein the at least one forming body (15, 17, 19) is further configured to be in contact between the at least one

Forming body (15, 17, 19) and the at least one flank (21, 25) and / or the at least one tooth root (29) of the toothed wheel (1 1)

Pressure tensions in the at least one flank (21, 25) and / or the at least one tooth root (29) bring.

10. Tool according to claim 9, wherein the at least one

Forming body (15, 17, 19) on a basic structure of the tool (3, 5, 7) is arranged, which is designed substantially gear-shaped, and in which the at least one forming body (15, 17, 19) designed as a substantially circular structure that is configured to contact the gear (11) and smoothly roll and / or roll the gear (11) smoothly when the at least one reforming body (15, 17, 19) on the gear (1 1) is moved along.

1 1. Tool according to claim s or 10, wherein the deformable body (15, 17, 19) is rigidly or movably arranged on the basic structure and is correspondingly configured, the gear (1 1) on at least one tooth flank (21, 25) and / or to firmly roll or smoothly roll at least one tooth root (29).