DE102017011276A1 - Method for producing a gear - Google Patents

Abstract

The invention relates to a method for producing a toothed wheel (10) having at least one tooth row (28) having a plurality of teeth (14), which is arranged in a first region (I) of the toothed wheel (10) and to a second region (II) of the toothed wheel A toothed wheel (10) is adjacent, which has a same or a larger diameter than the first portion (I) of the gear (10), wherein the teeth (14) of the at least one row of teeth (28) of the gear (10) to be produced using a first tool (16) and at least one second tool (24) different from the first tool (16) are at least partially machined and / or finished, wherein with the first tool (16) material of a first section (18) of a tooth flank (22) a tooth (14) of a respective row of teeth (28) of the gear (10) to be produced and thereby the tooth edge (22) is partially worked out and then with the second tool (24) material of a second Ab section (19) of the tooth flank (22) is removed and thereby the tooth flank (22) of the respective tooth (14) of the respective row of teeth (28) of the gear (10) to be produced is completely worked out or finished.

Description

The invention relates to a method for producing a gear, in particular a helical gear and in particular a double-helical gear or a gear with an arrow toothing.

Gears with double helical gearing or arrow gearing have a first row of teeth and a second row of teeth. A distance is usually provided between the first row of teeth and the second row of teeth.

Gears with a double helical gearing are usually produced using a milling cutter. It is known to produce gears with a double helical toothing using a hob. So that the hob does not work into a processing area of the second row of teeth after the processing of the first row of teeth, the processing of the first row of teeth ends at a distance from the second row of teeth. Due to the manufacturing process, the aforementioned distance between the rows of teeth is created.

It is also known to produce double-helical gears with a minimized distance between the rows of teeth. Usually profile or end mill or loops are used with finger-shaped grinding pins. The molds used in this case have with their axis of rotation usually a radial or approximately radial alignment with the toothing and the gear rotation axis to produce gears with minimized or no gap. Gears without gap are known as Pfeilverzahnungen.

The US 2004/031152 A1 describes a method for producing a gear with an arrow toothing. First of all, the cylindrical properties of the toothed portion of the toothed wheel are worked out. Then grooves are worked out so that the tool used can leak in the subsequent final step in it.

The US 2012/114441 A1 describes a method of manufacturing a helical gear using a numerically controlled machining tool having at least 4 machining axes. In this case, control data for the milling cutter on the basis of geometric data of the first and second tooth flank, the transition region between the first and second tooth flank and the overall geometry of the tooth flanks generated. The control data indicates a guide path of the machining tool, the path extending obliquely to the profile direction of the tooth flanks and along the first and second tooth flank geometry and the transition area geometry. The workpiece is then processed based on the control data.

The WO 2015/109074 A1 describes a tool for machining a workpiece with a central longitudinal axis. The tool includes a mount to which the workpiece is mounted, a grinding spindle to remove material from the workpiece, the grinding spindle having a central longitudinal axis about which the spindle rotates and which is disposed to contact the central longitudinal axis of the spindle Tool cuts to produce a continuous tooth of a gear on the tool. Furthermore, the tool includes an electrochemical abrasive element configured to perform an electrochemical grinding operation on the grinding spindle and to soften the tool during machining.

Other known methods for pre-machining and finishing gear teeth utilize hobbing, slotting, generating grinding and profile grinding. However, such methods require sufficient overspill between the rows of teeth to avoid collision of the tool with the adjacent row of teeth.

However, methods are also known which use a profile tool in radial or almost radial employment to the gear. Such methods process a tooth of the gear along the entire tooth flank or in a linear cutting process in which the tooth flank is machined with a cylindrical, toroidal or spherical tool. In the described method, large tooth flank surfaces are machined with a comparatively small tool, so that they have an unfavorable relationship between tool cutting edges and the surface to be machined. This results in long processing times and high tool wear, which severely limits the number of machinable components with a single tool.

Object of the present invention is therefore to address at least some of the disadvantages mentioned. In particular, a solution is to be proposed with which a gear, especially a gear with double helical or helical toothing can be produced, which has a reduced distance between adjacent rows of teeth or even free of such a distance. At least an alternative should be given to known solutions.

The object is achieved by a method according to claim 1. Further Embodiments and further developments emerge from the dependent claims.

Accordingly, according to the invention, a method is proposed for producing a toothed wheel with at least one row of teeth having a plurality of teeth, which is arranged in a first area of the toothed wheel and adjoins a second area of the toothed wheel having the same or a larger diameter than the first area of the toothed wheel in which the teeth of the at least one row of teeth of the gear to be produced are at least partially worked out and / or finished by using a first tool and at least one second tool different from the first tool, with the first tool material of a first portion of a tooth flank of a tooth a respective row of teeth of the gear to be produced and thereby the tooth flank is partially worked out and then removed with the second tool material of a second portion of the tooth flank and thereby the tooth flank of the tooth respec gen tooth row of the gear to be produced completely worked out or finished.

The first and the second tool differ in their respective geometry and dimension. The fact that different tools are used to work out the respective teeth in geometry and dimension, the processing areas of the tools for the respective teeth split. Thus, with each tool, the optimum machining area for the respective tool can be processed. In particular, the first tool processes a first area of a tooth flank of a tooth. The first section is chosen so that the tooth flank of the respective tooth is preprocessed. The second tool then works on the tooth flank. It is provided that the second portion of the tooth flank is smaller than the first portion of the tooth flank. As a result, the second section of the tooth flank of the respective tooth to be machined is also selected such that the second tool processes a machining area which is optimal for the respective tool. As a result, the wear of the respective first and second tool is reduced. In addition, the respectively necessary processing time of the first and second tool is reduced, so that overall the processing time for producing the gear is reduced.

It is therefore envisaged to use the method according to the invention for producing double-toothed gears. Double-toothed gears have a first row of teeth and a second row of teeth with the respective rows of teeth arranged adjacent to one another. The method thus provides that first teeth of the at least one row of teeth of the gear are machined with the first and / or second tool and then at least partially worked out or teeth of at least one second row of teeth in the second region of the gear with the first and / or second tool completely worked out or finished. It should be noted that under a double-toothed gear in the context of this disclosure in particular also double-helical gears and their modifications and arrow-toothed gears are understood. In particular, the method is also applicable to the production of gears with more than two rows of teeth, for example. Three or four rows of teeth, which are referred to as multi-toothed gears.

Another embodiment of the method is characterized in that an outer region of the tooth flank of the respective tooth is machined as the first section and an inner region of the tooth flank of the respective tooth is processed as a second section relative to a longitudinal axis of the toothed wheel.

According to the invention, it is accordingly provided that the first tool first produces the first, that is to say outer, portions of the tooth flanks of the teeth of the first row of teeth, and then the first tool produces the first, that is, outer, portions of the tooth flanks of the teeth of the second row of teeth. Only then does the second tool make the second portions of the tooth flanks of the teeth of the first row of teeth and then the second portions of the tooth flanks of the teeth of the second row of teeth or first the second portions of the tooth flanks of the teeth of the second row of teeth and then the second portions of the tooth flanks of the teeth the second row of teeth, whereby the gear to be produced does not have to be re-clamped. However, it is also provided that the first tool first makes the first sections of the tooth flanks of the teeth of the first row of teeth, and then the second tool produces the second sections of the tooth flanks of the teeth of the second row. Subsequently, with the first tool, the first sections of the tooth flanks of the teeth of the second row of teeth are produced, and thereafter, with the second tool, the second sections of the tooth flanks of the teeth of the second row of teeth. As a result, the inventive method is particularly versatile, economical and flexible.

The longitudinal axis of the gear substantially corresponds to the axis of rotation of the gear. An outer region of the gear or the tooth flank is thus arranged substantially in the region of end faces of the gear. An inner region is thus located substantially in the middle of the gear, so removed from the faces. Now that the inner area of the second tool is finished, this area can be worked out specifically. This makes it possible to keep a distance between the first row of teeth and the second row of teeth small or to completely dispense with a distance between the first and the second row of teeth. Consequently, the dimensions of the gear can also be reduced, which in addition leads to weight savings.

Another embodiment of the method is characterized in that a machining direction of the first and / or second tool has an angle different from 0 ° or 180 ° with respect to the flank line of the gear.

Machining direction is to be understood in the context of this disclosure, the direction along which material is mainly removed, wherein substantially the machining direction along the respective tooth flank is provided. Provided are substantially linear machining directions along the tooth flank, wherein the substantially linear machining direction and a superimposed machining direction, for example, along a height of the tooth flank span a working plane. However, it is also envisaged that the angle between the substantially linear machining direction and the longitudinal axis of the gear changes during the machining, so that a curved machining direction is established. As a result, complex geometries of the tooth flanks are made possible. In particular, helical gears are enabled by gears. The width of the case-shaped processing paths overlap at least partially in the area in which the processing tracks have a smaller width.

Yet another embodiment of the method is characterized in that a travel path of at least the second tool is adapted adaptively using a geometrical measuring method to a geometry of the tooth flank of a respective tooth or the entirety of the teeth machined by the first tool. In this case, it is to be achieved that the second tool only processes the regions of the respective tooth flank which were not machined by the first tool in order to avoid double machining of respective regions or reworking of a transition region from the first region to the second region. In particular, a continuous and continuous transition from the first region of the respective tooth flank to the second region of the respective tooth flank should be achieved. As a result, however, the position at which the transition from the processing region of the first tool to the processing region of the second tool takes place can be selected as desired. In this case, the transition can be designed by fade-in and fade-out tool movement movements such that the tool movement moves the tooth profile correction provided for the tool to ensure a paragraph-free transition of the machining areas. The machined allowance is adaptively adapted to the tooth flank and tooth profile geometry measured on at least one tooth flank.

A development of the method provides that the geometric measuring method uses an average value of tooth positions of all teeth of the toothed wheel for adaptation.

An embodiment of the method is characterized in that with the second tool a Zahnfußgeometrie and / or tooth edges of a respective tooth flank of a tooth is completely or partially worked out or finished. This avoids reworking the gear.

A development of the method provides that the first tool used is a tool that has a larger tool diameter than the second tool. It is thereby achieved that the first tool essentially processes a considerable part of the respective tooth flank of the respective tooth and the second tool finishes the intended geometry of the respective tooth flank, the finishing work with the second tool being smaller or clearer than in the first area smaller area is limited. As a result, the wear of the respective gears is reduced.

An embodiment of the method is characterized in that the first, larger tool collides with the second area and does not allow complete, desired processing of the tooth flanks of the teeth of the first row of teeth.

An embodiment of the method provides that a hob or a hob grinding screw or a profile grinding wheel or a profile cutter or an involute cutter is used as the first tool. A hob is, for example, a roller-shaped, that is to say substantially cylindrical, tool which has a multiplicity of cutting teeth. By turning the hob, the cutting teeth mill the corresponding teeth of the gear in a blank of the gear. However, due to the rotation of the hob, the machining area at the front in the machining direction has a radius corresponding to the radius of the hob. In the case of the double-helical gears described here, an additional employment of the hob is due to the helix angle required. As a result, a hob requires a certain run-out area to fully work out a respective tooth of a gear. For double-toothed gears this fact leads to a characteristic distance between the first and the second row of teeth. Should this be kept as small as possible in its dimension, this leads to a diameter as small as possible and thus uneconomical Wälzfräswerkzeug. According to the invention, it is now provided to shorten the outlet area by processing only an outer edge area and / or a central area of the tooth flank with a hob. With a hob, a large processing surface, ie a large number of respective tooth flanks or teeth, can be processed economically. The processing time to machine a gear can be shortened considerably with this method.

A further embodiment of the method provides that the second tool used is a finger milling cutter or grinder or a grinding pin or a pin-shaped milling cutter. Finger or pencil cutters are usually smaller in diameter than hob cutters or grinders. As a result, however, these allow machining with significantly less tool overflow and serve for the pre-machining and finishing of a tooth flank or a tooth of a toothed wheel. According to the invention, it is provided to use such a milling cutter in order to finish the areas not machined by the hob, which have stopped due to the shortened outlet area.

Another embodiment of the method provides that a cutter or grinding pin is used, which has a cylindrical or conical shape with a straight, convex or concave tool edge. As a result, different tooth flank geometries can be generated in each case.

A further embodiment of the method is characterized in that a rotational axis of the first tool is aligned perpendicular to a rotational axis of the second tool. As a result, different processing directions are possible, whereby a fine machining of the tooth flanks is improved.

A development of the method provides that the first and second tools are used on the same or on several machine tools.

• 1a zeigt eine perspektivische Darstellung eines Fräs- oder Schleifverfahrens mit einem Profilwerkzeug nach dem Stand der Technik.
• 1b zeigt eine Schnittansicht eines Fräs- oder Schleifverfahrens mit einem Profilwerkzeug nach dem Stand der Technik.
• 2 zeigt eine Schnittansicht eines Zahnrads mit einer ersten und einer zweiten Zahnreihe und dazwischen liegendem Abstand nach dem Stand der Technik.
• 3a und 3b zeigen eine Schnittansicht einer schematischen Darstellung einer Ausführungsform des erfindungsgemäßen Verfahrens sowie eine Detailansicht dazu.
• 3c zeigt eine Schnittansicht einer schematischen Darstellung einer weiteren Ausführungsform des erfindungsgemäßen Verfahrens.
• 4a und 4b zeigen eine perspektivische Ansicht eines Zahns eines Zahnrads sowie eine Detailansicht eines finger- oder stiftförmigen Werkzeuges dazu.
• 5 zeigt eine Schnittansicht einer Zahnflanke sowie von Werkzeugen zur Verwendung in einer Ausführungsform des erfindungsgemäßen Verfahrens.
• 6 zeigt eine Schnittansicht einer Zahnflanke sowie eines weiteren Werkzeugs zur Verwendung in einer Ausführungsform des erfindungsgemäßen Verfahrens.
• 7 zeigt eine Schnittansicht von Zahnflanken sowie eines weiteren Werkzeugs zur Verwendung in einer Ausführungsform des erfindungsgemäßen Verfahrens.

The invention will be described in detail below with reference to the accompanying drawings and exemplary embodiments.

• 1a shows a perspective view of a milling or grinding process with a profile tool according to the prior art.
• 1b shows a sectional view of a milling or grinding process with a profile tool according to the prior art.
• 2 shows a sectional view of a gear with a first and a second row of teeth and intervening distance according to the prior art.
• 3a and 3b show a sectional view of a schematic representation of an embodiment of the method according to the invention and a detailed view thereto.
• 3c shows a sectional view of a schematic representation of another embodiment of the method according to the invention.
• 4a and 4b show a perspective view of a tooth of a gear and a detailed view of a finger or pin-shaped tool thereto.
• 5 shows a sectional view of a tooth flank and tools for use in an embodiment of the method according to the invention.
• 6 shows a sectional view of a tooth flank and another tool for use in an embodiment of the method according to the invention.
• 7 shows a sectional view of tooth flanks and another tool for use in an embodiment of the method according to the invention.

In the 1a and 1b is a general schematic principle of a method of manufacturing gears 100 with a double helical toothing 102 using a profile tool, for example a profile grinding wheel or a profile milling cutter 104 shown. 1a shows a schematic view of a double-helical gear 100 with a first row of teeth 106 and a second row of teeth 108 , In such a procedure, the profile tool mills 104 by machining material from a respective workpiece 112 respective teeth 110 from the workpiece 112 out. Due to the radius 114 of the profile tool 104 it is necessary that the profile tool 104 about the actually predetermined length of the respective tooth 110 also runs out so that also a Zahnfußbereich completely from the profile tool 104 is processed. Due to this discharge area arises to avoid collisions of the profile tool 104 with teeth 110 the adjacent row of teeth, here the second row of teeth 108 , a distance 116 between the first and second rows of teeth 106 . 108 , This distance 116 is also called a jetty. Due to a large radius of the profile tool 104 , this jetty can 116 assume a value in the range of up to 50% of the tool diameter. In Wälzfräs- or Wälzschleifverfahren an even greater distance is required by the required inclination of the helical tool so that the tool during the processing of the first row of teeth 106 not with the second row of teeth 108 collided. This in 1a illustrated gear 100 has a substantially cylindrical shape. The teeth 110 are radially outside of the gear 100 arranged so that the gear 100 is formed with an external toothing.

1b and 2 show that in 1a described method in a sectional view. In this view, it becomes even more apparent that the profile tool 104 due to the outlet area due to the radius 114 when working on the tooth 110 the row of teeth 108 with a tooth 110 the row of teeth 106 can collide. To prevent the collision, points the gear 100 between the first row of teeth 106 and the second row of teeth 108 the distance 116 on.

The gear 100 has an external toothing as already described. The external toothing is as a double helical toothing 102 educated. The double helical gearing 102 indicates the first row of teeth 106 and the second row of teeth 108 on. Due to the helical teeth are in the shown sectional views in the first row of teeth 106 a first tooth 110a and a second tooth 110b visible and in the second row of teeth 108 are a third tooth 110c and a fourth tooth 110d visible. Between the respective teeth 110 is in each case an intermediate area 118 educated.

Between the first row of teeth 106 and the second row of teeth 108 is a jetty 116 educated. Also in 2 is a reduced bridge area 120 , which is achievable with the method according to the invention, indicated. The reduced bridge area 120 points opposite to the web occurring with the method according to the prior art 116 a shortened extension.

In 3a Now, the inventive method is shown schematically. The method is shown by way of example on a toothed wheel 10 with a double helical toothing 12 , The gear 10 has a first row of teeth 28 and a second row of teeth 30 on. According to the invention, a respective tooth 14 of the gear 10 first of a first tool 16 processed. The first tool 16 For example, as shown, it may be a profile tool. It should be noted that the first tool 16 may also be a Wälzschleifschnecke, a hob, a Profilscheibenfräser, a profile grinding wheel or an involute cutter.

Since in this example a helical toothing 12 is shown in this illustration, note that the profile tool 16 not along a longitudinal axis 17 the teeth 14 works out, but moves along a flank line and works, relative to the longitudinal axis 17 is inclined and protrudes in this representation of the presentation level. The processing sections described below 18 . 19 are therefore on the longitudinal axis 17 projected. The longitudinal axis 17 corresponds substantially to the axis of rotation of the gear.

The profile tool 16 Edits a first section 18 of the tooth 14 , The first paragraph 18 extends with respect to the longitudinal axis 17 of the gear 10 from a peripheral area of the gear 10 towards a middle area 20 of the gear 10 up to a second section 19 of the gear 10 , The hob 16 wears in the first section 18 Material from the workpiece and thereby forms a tooth flank 22 of the tooth 14 , The first paragraph 18 of the tooth 14 This is done by selecting the tool size of the first tool 16 certainly. For example, when using a hob, the hob diameter determines the extent of the first section 18 , When using a Wälzschleifers determines the grinding worm diameter, the extension of the first section 18 In the case of discontinuous gear grinding, it is the grinding wheel diameter and in the case of involute milling it is the diameter of the involute cutter. In general, tools are selected as large as possible to ensure economical machining, thereby maximizing the number of usable cutting edges on tools with particular cutting edge or abrasive grains on undefined cutting tools.

According to the invention, the second section 19 of the tooth 14 or the tooth flank 22 with a second tool 24 processed. The second tool 24 For example, it may be a form milling cutter which images or approximates the tooth flank profile. Alternatively, it is also conceivable that the second tool 24 an end mill, Gesenkfräser, ball cutter, barrel cutter or the like. May be. The second tool 24 is thus a milling or grinding tool with a substantially radial orientation of the tool rotation axis with respect to the gear rotation axis.

It is essential that the first row of teeth 28 in a first area I of the gear 10 is formed and attached to a second area II of the gear 10 borders. The second area II limits the processing area of the respective Tools 16 . 24 and forms a collision contour B , In the embodiment described above, the collision contour B the second row of teeth 30 ,

The second section 19 is in 3b shown the cutout A in 3b shows enlarged. The second section 19 is essentially characterized in that it is that of the first tool 16 includes unprocessed area. The second tool 24 thus contributes in the second section 19 the remaining material 25 of the trainee tooth 14 or the trainee tooth flank 22 off, so the second tool 24 the tooth flank 22 finished training. The tooth 14 or the tooth flank 22 or their geometry is thus by using the first tool 16 and the second tool 24 worked out.

3b shows clearly that the first tool 16 no outlet area for complete working out of the tooth flank 22 provided or no outlet area needed, but has a relation to the prior art shortened processing area. This is made clear by the fact that a contour of the second section 19 or the remaining material 25 a rounding 26 having in the processing of the substantially round or cylindrical first tool 16 , So, for example, the hob is justified, the first section 18 edited. By compared to the prior art shortened processing area of the first tool 16 and finishing with the second tool 24 is the middle area or the bridge area 20 shortened trained. This also reduces the width of the gear 10 Overall, which in turn can save weight.

The second tool 24 is significantly smaller in size than the first tool 16 selected. That is possible because of the second tool 24 section to be machined much lower compared to the first tool 16 is. This is the second tool 24 significantly more flexible and can adaptively adapt to the rest of the tooth flank geometry, so the edge geometry of the first tool 16 was trained. The through this second tool 24 machined surface generally overlaps with the tool 16 finished tooth flank area. As a result, a paragraph-free transition is achieved on the tooth flank. In particular, but the second tool 24 the second section 19 specifically edit. The first paragraph 18 and the second section 19 define the first area I or first component region of the gear 10 , The first row of teeth 28 is thus in this first area I of the gear 10 arranged. The second row of teeth 30 is in the second area II of the gear 10 arranged.

The middle area 20 essentially comprises the initially described area, in which the web between the first row of teeth 28 and the second row of teeth 30 or the collision contour B is trained. At the collision contour B it may be a second row of teeth, or any other component contour not equal to a toothing.

3c shows a further possibility of applying the method according to the invention, in which the first row of teeth 28 in the first area I is formed and attached to the second area II borders. The second area II remains unprocessed in this application and forms a collision contour B , 3c shows the profile tool 16 as well as the finger or pen tool 24 in a position where both tools 16 . 24 a collision contour B achieved. According to the invention, the finger or pencil tool is achieved 24 with its axis of rotation a position that is considerably closer to the collision contour B lies. The profile tool 16 However, it can not be moved further to the middle of the gear without the collision contour B to hurt. As the finger or pen tool 24 closer to the collision contour B can be introduced as the first tool 16 , the second tool 24 the tooth 14 or the tooth flank in the second region 19 work out. As a result, according to the invention, the web area 20 be carried out small.

Like from the 3a to 3c clearly visible, are the respective axes of rotation of the first tool 16 and the second tool 24 aligned perpendicular to each other.

4a shows an enlarged perspective view of a tooth 14 with a respective Zahnfußgeometrie 32 and a respective tooth flank geometry 34 , On the tooth flank geometry 34 are each a profile line 33 and a flank line 38 shown. The profile line 33 runs along the profile of the tooth 14 essentially radially on the tooth flank geometry 34 , The flank line 38 runs along the tooth flank 22 substantially in the direction of the longitudinal axis of the gear, wherein the flank line 38 is inclined at a helical toothing with respect to the longitudinal axis of the gear. The Zahnfußgeometrie 32 has a first radius R1 and a second radius R2 on. The radii R1 and R2 go into each other.

4b shows a second tool 24 That's for working on the tooth root geometry 32 is used. Thus, the Zahnfußgeometrie 32 Part of the second section 19 or from the second section 19 to be covered by the second tool 24 is edited or worked out. The second tool 24 has a shaft area 36 and a editing area 40 on. The editing area 40 again has a header 42 on. The head area 42 is on the left side of the 4b shown enlarged. Starting from the shaft area 36 the working area tapers 40 to the head area 42 , One type of taper is, for example, a conical transition from the shaft area 36 to the head area 42 ,

The head area 42 is formed substantially spherical. Advantageously, the head area 42 several partial geometries. The head area 42 has at least two partial geometries, namely radius R1 and the radius R2 , The radii R1 and R2 go tangentially into each other. This sweeps over the radius R1 a cutting area of at least about 30 ° along the head area 42 , This is the center M1 of the radius R1 outside a rotation axis RA of the tool 24 , The middle-point M2 of the radius R2 is however on the rotation axis RA arranged. The radius R1 is larger than the radius R2 , Inventive feature is that the radius R1 includes at least one angle of about 30 ° to about 45 °, starting from the flank normal. This typically corresponds to the area of the highest tooth flexion stress, which can thus be provided with as large a local radius as possible.

The head area 42 is designed to the Zahnfußgeometrie 32 to edit. In an alternative embodiment, the head area 42 a separate tool used exclusively to machine the root of the tooth.

The second tool 24 is thus adapted to a first radius range R1 and a second radius range R2 at the Zahnfußgeometrie 32 train, so work out. This is made possible by the second tool 24 the Zahnfußgeometrie 32 with the respective different areas of the head area 42 processed.

Alternatively, it is provided that the second tool 24 also a third part geometry with a third radius R3 has, with which a third radius range of Zahnfußgeometrie can be worked out. The middle-point M3 of the radius R3 is on the axis of rotation RA of the tool 24 arranged. The middle-point M3 and the center M2 However, they are at different heights of the axis of rotation RA arranged. It is envisaged that the center M3 closer to the edge of the tool 24 is arranged as the center M2 , The radius R3 is smaller than the radii R1 and R2 such that R1>R2> R3. This allows a larger radius to be generated in an area where maximum stresses occur in the root of the tooth at an angle of about 30 ° to 45 ° to the root center than in a central root area.

The at least two radii of the head area 42 of the tool 24 may also be in modified form. The modified shape is generated by the Zahnfußgeometrie 32 is transferred to a tool geometry, where the tool 24 under an angle of attack, a so-called lead angle, is made to the profile line.

The following 5 to 7 describe the formation of a respective tooth flank geometry. The goal in producing tooth profiles is to minimize the deviation from the ideal involute and thus the profile line, including tooth corrections. For example, the respective tool can be guided several times in multiple paths along the tooth flank. For several tool paths, the superimposition of the tool geometry leads to an approximation to the ideal shape. However, the overlay may also result in deviations from the ideal tooth flank geometry at the transitions from one lane to another lane.

It is now proposed to use milling tools with cylindrical or conical ( 5 ), convex ( 7 ) or concave ( 6 ) Use tool geometry. All tools shown have at their edge a respective cutting edge for removing material.

5 shows on the left side a section of a tooth flank geometry 34 a tooth 14 , On the right side of the 5 are two tools 24a and 24b shown. The tooth 14 represents an involute toothing. The tooth flank geometry 34 of the tooth 14 was there with the respective flank 44a . 44b from one of the tools 24a or 24b generated.

The tools 24a and 24b are designed as substantially cylindrical tools and each have a straight tool edge 44a . 44b on.

The tool 24a has a shaft area 36a on, to which a processing area 40a followed. To the editing area 40a closes a head area 42a on. The transition from the shaft area 36a as well as the transition from the editing area 40a in the head area 42a is essentially straight. The head area 42a and the editing area 40a include a cutting edge for removing material. The head area 42a has a cutting radius in the transition region at its edge region RK1 on, leaving the head area 42a is rounded. In an area around the rotation axis RA has the head area 42a of the tool 24a a straight section 43a on. The tool 24a thus has a cutting edge with a cutting radius RK1 and a straight cutting area, the processing area 40a , on.

The tool 24b also has a shaft area 36b on, to which a processing area 40b followed. To the editing area 40b closes a head area 42b on. The transition from the shaft area 36b to the editing area 40b has an angle 48b on. The editing area 40b tapers off the shaft area 36b towards the head area 42b , where the tool edge 44b is tapering straight. The head area 42b is essentially round. The transition from the editing area 40b in the head area 42b is therefore essentially tangential. The head area 42b is essentially the same as in 4b described header area 42 so on the revelation to the head area 42 of the tool 24 in 4b is referenced.

The tooth flank geometry 34 (left side of 5 ) has several sections 34a . 34b and 34c on. The length 46 a section 34a . 34b . 34c This corresponds essentially to a machining area of a tool 24 ( 4 ), 24a, 24b. The tools 24a . 24b are designed to the tooth flank 22 in which material is removed, causing the tooth flank geometry 34 arises. The tools carry this 24a or 24b line by line material from the tooth flank 22 from. The length 46 corresponds to the line spacing with which the tooth flank 22 is processed. The tools process the sections 34a . 34b and 34c with the same area of your tool edge 44a or 44b by moving it axially along its longitudinal axis by the amount 46 shifted and tangential to the tooth flank 34 be aligned. Alternatively, the processing is done with different, offset in length areas of the tool edge 44a or 44b in that the tool is not displaced axially, but only on the area of the tooth flank to be machined 34a . 34b or 34c is realigned. This leads to a uniform distribution of tool wear along the edge of the tool.

6 shows a tooth on the left side 14 with a tooth flank 22 and a tooth flank geometry 35 , On the right in 6 is a tool 24c shown.

The tool 24c has a shaft area 36c on, to which a processing area 40c followed. To the editing area 40c closes a head area 42c on. The transition from the shaft area 36c to the editing area 40c has an angle 48c on. The editing area 40 tapers off the shaft area 36c towards the head area 42c , It is thus conical. The tool edge 44c is concave, ie the tool edge 44c has a curvature with a radius RW1 on.

By line-by-line machining of the tooth flank 22 with the tool 24c becomes the tooth flank geometry 35 or generates the tooth flank profile. An example is a line spacing or the processing length 46 shown. The tooth flank profile 35 has a curvature with the radius RE1 on, which is called involute radius. The radius RE1 the tooth flank geometry 35 is smaller than the tool edge radius RW1 the tool edge 44c or in other words, the tool edge radius RW1 greater than the radius RE1 the tooth flank profile. The tool edge radius RW1 is used in the manufacture of the tool 24c specified. This embodiment of the tool edge 44c This leads to a largely tangential transition from web to web in parallel tool paths and a faceting of the tooth flank geometry 35 is reduced. At the same time it avoids that the tool 24c , as with the use of a profile cutter, on the entire tooth profile height is simultaneously engaged, whereby higher Abdrängkräfte can arise and the profile accuracy is completely determined by the tool profile shape.

7 shows a tooth on the left side 14 with a tooth flank 22 with parallel milling paths 37d . 37e , On the right side of 7 is a tool 24d shown that a shaft area 36d has, to which a processing area 40d followed. To the editing area 40d closes a head area 42d on. The editing area 36d has a tool edge 44d on. The tool edge 44d is convex and has a radius RW2 on. This is the transition from the shaft area 36d formed tangentially to the processing area substantially. The head area 42d is essentially round and has a radius RK2 , The radius RK2 is smaller than the radius RW2 ,

By a line by line editing of the tooth flank 22 with the tool 24d arise the tooth flank geometries or milling paths 37d and 37e , The tooth flank geometry 37d arises by a line by line editing of the tooth flank 22 with the head area 42d and the radius RK2 , The tooth flank geometry 37e arises by a line by line editing of the tooth flank 22 with the editing area 40d or the tool edge 44d with the radius RW2 , By removing material from the tooth flank 22 thus creates a tooth flank geometry 37d . 37e in form of Wave pattern with a respective distance 46 , When using the tool 24d In the area of the tooth root, a smaller profile deviation is achieved. The number of required tool paths can be significantly reduced, which leads to a minimization of the processing time and to an increase of the tool stand path and thus to a more uniform gear quality.

Further embodiments of the tools are characterized in that they have the contour of a respective tooth profile shape, so-called profile tools. These tools can be derived from the contour, ie the geometry, in the profile direction or a geometry derived from the tooth geometry or tooth flank geometry. A non-exclusive example is the profile line that corresponds to a profile that is determined from a projection of a tool set at an angle to a feed direction.

The advantage of the method according to the invention lies in the flexibility of the generatable tooth flank geometries 34 . 35 . 37d . 37e by using respective tools 24a - 24d be used. This can optionally be a tool 24a - 24d be selected and used in the machine platform.

By using a probe, geometric input conditions such as the tooth flank position and tooth flank orientation of the tooth flank 22 after processing with the first tool 16 be determined. These are used for correct positioning and alignment of the second tool 24a - 24d by correcting the generated machining paths by the amount of deviation from the nominal geometry. This allows the travel of the second tool 24 Adaptive to that of the first tool 16 Outlined geometry of the tooth flank 22 a tooth 14 be adjusted. Alternatively, the travel of the second tool 24 be adapted to the worked out by the first tool geometry of the totality of the teeth, in which case first an average of the first tool 16 machined tooth flanks 22 is determined.

By the inventive use of the second tools 24 , which are formed substantially finger-shaped, now only the areas of the tooth flank 22 machined with the first tools 16 are unreachable. As a result, for a large part of the respective surface of the tooth flank 22 the use of the second tools 24 made more economical, since the surface to be machined or the material to be removed is considerably reduced and for the largest portion of the tooth flank 22 efficient processing with a larger tool 16 he follows.

LIST OF REFERENCE NUMBERS

10

gear

12

Double helical gear

14

tooth

16

first tool

17

longitudinal axis

18

first section

19

second part

20

Mid-range / bridge area

22

tooth flank

24, 24a, 24b, 24c, 24d

second tool

25

remaining material

26

curve

28

first row of teeth

30

second row of teeth

32

Zahnfußgeometrie

33

profile line

34, 34a, 34b 34c

Tooth flank geometry

35

Tooth flank geometry

36, 36a, 36b, 36c, 36d

shaft area

37d, 37e

Tooth flank geometry, milling path

38

flank line

40, 40a, 40b, 40c, 40d

editing area

42, 42a, 42b, 42c, 42d

head area

43a

level section

44, 44a, 44b, 44c, 44d

tool edge

46

line spacing

48b, 48c

corner

100

gear

102

Double helical gear

104

hobs

106

first row of teeth

108

second row of teeth

110

teeth

112

workpiece

114

Radius hob

116

Distance between rows of teeth / bridge

118

intermediate area

120

reduced bridge area

A

neckline

B

collision contour

I, II

first, second area

M1, M2, M3

Focus

RA

axis of rotation

R, R1, R2, R3

Radius of tooth root geometry

RE1

Radius of curvature tooth flank geometry

RK, RK1, RK2

Radius of curvature tool head

RW1, RW2

Radius of curvature of the tool flank

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2004031152 A1 [0005]
• US 2012114441 A1 [0006]
• WO 2015/109074 A1 [0007]

Claims (14)

Method for producing a toothed wheel (10) having at least one row of teeth (28) having a plurality of teeth (14), which is arranged in a first area (I) of the toothed wheel (10) and is connected to a second area (II) of the toothed wheel (10). having a diameter equal to or greater than the first portion (I) of the gear (10), wherein the teeth (14) of the at least one row of teeth (28) of the gear (10) to be produced using a first tool (16 ) and at least one second tool (24) different from the first tool (16) are at least partially machined and / or finished, with the first tool (16) material of a first section (18) of a tooth flank (22) of a tooth (14 ) of a respective row of teeth (28) of the gear (10) to be produced and thereby the tooth flank (22) is partially worked out and then with the second tool (24) material of a second portion (19) of the tooth flank e (22) is removed and thereby the tooth flank (22) of the respective tooth (14) of the respective row of teeth (28) of the gear (10) to be produced is completely machined or finished. Method according to Claim 1 , characterized in that with the first and / or second tool (16, 24) first teeth (14) of the at least one row of teeth (28) of the gear (10) are worked out and then with the first and / or second tool (16, 24) teeth (14) of at least one second row of teeth (30) in the second region (II) of the gear at least partially worked or completely worked out or finished. Method according to Claim 1 or 2 , characterized in that with respect to a longitudinal axis (17) of the gear (10) as the first portion (18) an outer region of the tooth flank (22) of the respective tooth (14) is processed and as the second portion (19) an inner region of the Tooth flank (22) of the respective tooth (14) is processed. Method according to one of Claims 1 to 3 , characterized in that a machining direction of the first and / or second tool (16, 24) has a different angle of 0 ° or 180 ° with respect to a flank line (38) of the gear. Method according to one of the preceding claims, characterized in that a travel path of at least the second tool (24) adaptively using a geometrical measuring method to one of the first tool (16) worked out geometry of the tooth flank (22) of a respective tooth (14) or Whole teeth are adjusted. Method according to Claim 5 , characterized in that the geometric measuring method uses an average of tooth positions of all teeth (14) of the gear (10) for adaptation. Method according to one of the preceding claims, characterized in that with the second tool (24) a Zahnfußgeometrie (32) and / or tooth edges of a respective tooth flank (22) of a tooth (14) is completely or partially worked or finished. Method according to one of the preceding claims, characterized in that a tool is used as the first tool (16) having a larger diameter tool than the second tool (24). Method according to one of the preceding claims, characterized in that the first, larger tool collides with the second region and does not allow complete, desired machining of the tooth flanks of the teeth (14) of the first row of teeth (28). Method according to one of the preceding claims, characterized in that the first tool (16) used is a hobbing cutter or a hobbing grinding screw or a profile grinding wheel or a profile milling cutter or an involute milling cutter. Method according to one of the preceding claims, characterized in that a finger milling cutter or grinder or a grinding pin or pin-shaped milling cutter is used as the second tool (24). Method according to Claim 11 , characterized in that a cutter or grinding pin is used, which has a cylindrical and / or conical shape with a straight, convex or concave tool edge. Method according to one of the preceding claims, characterized in that a rotation axis of the first tool (16) is aligned perpendicular to a rotational axis of the second tool (24). Method according to one of the preceding claims, characterized in that the first and second tools (16, 24) are used on the same or on several machine tools.

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