DE1652793A1 - Device for producing involute gears - Google Patents

Description

DIPL..ING. H. LEINWEBER

Postal check account : Bank account; PK / 2/66 Telephone Tel.-Adr. Munich 22045 Dresdner tank AG. Lw / Va / Kg mad »« (MII) With »Ufapat MlNdM · Munich 2, MarlenplaU, account no. »27» 1652793 • MünclMn 2, Lotmrtal 7, 2nd Auig. (Kustermann-Patsag ·)

5th January 1968

Peter Herbert CIEFF, Nc-ops-tle upon Tyne (England) Device for producing involute gears

The invention relates to an apparatus for manufacturing or machining, for example by grinding, the prefabricated tooth flanks of cylindrical gear or toothed wheels with external or internal toothing, which have either a straight spur gear or a helical toothing in an involute or modified involute shape.

Although reference is mainly made in the following to a grinding method, it is clear that other methods for removing metal, for example by spark erosion, electrochemical machining or the like. for the purpose of Invention may be useful and included in the meaning of the term "slippery".

The invention is based on the object of creating an improved device in which a workpiece gear

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In an involute generating movement on stationary grinding wheels or, conversely, grinding wheels in an involute generating movement past a stationary workpiece gear will.

Most known gear grinding machines for the production of involute gears, e.g. the MAAG, KOLB and HURTH machines, the generating movement is between the workpiece gear, i.e. the gear to be ground, and the Grinding wheels with usually rectilinear generators by means of a circular rolling block and two steel belts as equivalents for the usual "disc-thread" unit of the theoretical one Involute construction generated.

The invention is based on the object of providing a simple, but very precise, robust and continuously adjustable To create an articulation mechanism with little suspension, which only uses cylindrical pivot pins and straight sliding surfaces as a means includes the steel belt drives to overcome the mentioned Kachteile, and to use it for example and inter alia in gear grinding machines of the type described below.

Further details, advantages and features of the invention emerge from the following description. In the drawing, the invention is illustrated by way of example, namely

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show «

Fig. 1 is an end view of a gear grinding machine for involute serration in which a rolling block and steel belts are used to generate involute,

2 shows the basic mechanism (Jj) according to the invention and the underlying mechanisms mathematical and kinetic principles (R),

3 shows the complete rolling motion generating mechanism SDUs according to the invention (L) and the underlying mathematical and kinematic principles (R),

Fig. 4 shows the structural defects of the full roll generation mechanism Fig. 3 (L) for the roll angle ranges τοη I

plus / minus 30 or plus / minus 40 arc graphs, and

Figure 5 is an end view of a gear grinding machine

for involute toothing similar to that of Fig. 1, however with the rolling motion generating mechanism from Fig. 3, in the case of the outer steel belt drive is replaced.

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Fig. 1 shows schematically the principle of the known production of τοπ involute teeth. Sole wheels 1 and 2 are driven by a motor to rotate about their respective axes of rotation 1a and 2a, but are on the other hand stationary with respect to the main machine frame 6. A workpiece gear 3, ie the gear to be ground, is fixed on a mandrel or a mandrel Fixed spindle 4, which is rotatably arranged in a linear reciprocating slide 5, the direction of the reciprocating movement being perpendicular to the rotation of the workpiece gear. A rolling segment 6 of the required size is arranged coaxially with the mandrel 4 and is in drive connection therewith. Thin, flexible steel strips (at least two in number) 7a and 7b are each wound from the right and left, including the roller segment, and attached to the roller segment 6 with their inner ends. The outer ends of the strips are anchored on the stationary Hctuptmaschinengestell 8 on which the carriage 5 by means of a so-called "Scotch ^Y .oke" -Mechanisiu8 9, 9a and 10 is reciprocated.

It is easily understandable for the person skilled in the art that each linear movement of the carriage 5 by an amount of a rotation Ton ^ \ jÖ of the rolling segment 6 and with it in Drive connection standing Werkettickzahnrads 5 is accompanied, so that

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is, where H ₃ , the effective radius of the Bollsegments 6 and «Δ J0 mean the angular rotation of the rolling segment in radians (rad) and that the rectilinear generators of the grinding wheels envelop involute tooth profiles on the workpiece tooth: wheel 3 during such a movement as curved lines.

The fundamental problem of generating movements for producing involute gears between the workpiece gear and the grinding wheels is therefore to be seen in the unwinding of a circle over a usually limited arc length 0.

Steel belt drives of the type just described can be made to operate with a high degree of accuracy, provided that R _{1 is} kept within tight tolerances and that the steel belts are properly and taut. However, they have a number of disadvantages, one of the greatest of which is the need to provide a new rolling segment 6 _{for each change in the rolling radius R r of the gear to be ground.} Another disadvantage is that it is impossible to run gear grinding machines of this type due to the "dynamic elongation" of the steel strips and the resulting profile errors on the machined gear wheel at high or very high speeds, especially when the gears to be ground have a large moment of inertia.

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According to FIG. 2, the rolling motion generating mechanism is according to the invention in its basic form essentially a rotating block sliding crank, the output part of which drives a main output slide via a sliding pivot pin part, that at right angles to the centers of the first and second main pivot pins of said rotary block slide crank mechanism connecting line is guided in a sliding manner.

Assuming the paper surface as the stationary base, a first main pivot pin 11 is provided around which a crank 12 with a radius H ₀ can rotate at an angle of plus / minus 0. At the outer end of the crank 12 and at a distance H ₀ from the center of the first main pivot bolt 11, a pivot bolt 13 is attached, which supports a sliding block 14 rotatably. This sliding block 14 is in a drive system with straight infc neren guides 15 which are formed in a lever 16. The lever 16 is rotatably held by a second main pivot pin 17 which is fixed on the base of the mechanism at a certain vertical distance from the first main pivot pin 11. The lever 16 is in the drive system via straight outer guides 19 with a guide block 18. This guide block 18 is pivotably connected to a main output slide 20 via a pivot pin 21, so that the main output slide 20 moves along a fixed straight guide rod 22.

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gen, whose center line runs at right angles to the line connecting the center points of the first main pivot pin 3 11 and the second main pivot pin 17 and lies at a certain predetermined vertical distance from the first main pivot pin 11.

It is clear to a person skilled in the art that a rotation of the crank 12 at an angle of plus / minus 0 is accompanied by a linear movement of the main output base 20 over a distance of plus / minus s, where the relationship a = f (0 ) is uniquely determined by the mass chosen for the main components of the mechanism. By Limes calculations, like

1-COSJ0 + 0 a O lim y - R ₀ Um «3B _Q

0 _ * 0 0 - * 0 ¹ ~ ⁰⁰⁸ *

It can now be shown that if the distance between the centers of the main _{pivot pins 11 and 17 is made equal to 2R 0} , the linear path of the main output slide 20 is equal to dee-arc 0 , with a high degree of accuracy for small values of plus / minus 0 degrees of arc and R ₀ = 1.

In order to expand the zero (plus / minus 0) useful range of the basic mechanism shown in FIG. 2, while maintaining its very high accuracy at small angles 0 , a simple change of the slide crank is added according to the invention, whereby the functions shown in FIG illustrated version -

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BATH ORIGINAL

shape results. All parts of the basic mechanism of Fig. Bind are still present and are therefore denoted by the same reference numerals. The crank 12 is extended radially and forms a small crank 23 with a radius r and a pivot pin 24 at a distance of this radius from the first main pivot pin 11, with all three pivot pins 13, 11 and 24 lying on one line. On the pivot pin 24, a connecting rod 25 is a Articulated length I, the other end of which is movably connected to an extension pivot pin 26 of the second main pivot pin 17. The second main pivot pin 17 is no longer stationary, but in the direction of a line running through the first main pivot pin 11 and at right angles to the center line of the fixed straight guide rod 22 by means of a line Slide 27 and straight guide rods 28 connected to it are movable.

Due to the angular movement of the crank 12 plus the crank around the first main pivot bolt 11 at an angle of plus / minus jÖ, a linear movement of the main output slide 20 of plus / minus 0 ait R ₀ = 1 is generated. The accuracy of the circle development is extraordinarily high according to the mechanism according to the invention. This results from FIG. 4, which shows "that with an" axial pivoting of the total angle of the crank 12 of 60 arc angles

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degrees (plus / minus 30 degrees of arc) the maximum structural error in the order of magnitude of +0.7. 10 mm per mm of radius R ₀ or less than 0.15 arc seconds. Even with a maximum pivoting of 80 arc degrees, the maximum structural error does not exceed the linear equivalent of 1 arc second.

FIG. 5 shows the mechanism according to the invention from FIG. 3, by modifying the requirements of a gear soleplate machine similar to that shown in Fig. 1 in a suitable manner is adapted. Essentially, the mechanism is now carried by the carriage 5 as a base. The levers 12 and 23 are with the spindle 4 of the workpiece gear in drive connection and the main output slide 20 consists of one piece with the straight guide rod 22, so that the pivot pin 13 now remains stationary on the center line of the machine.

For the person skilled in the art it is clear that the above example " The mechanism as described can be made in various modified embodiments, all of which are based on the basic "rotary block crank mechanism" and its kinematic variations. The use of the mechanism according to the invention is not restricted to gear grinding machines, but can also be used for other machines and devices in which a constant transmission ratio

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from a linear to an angular movement or from a * angular movement to a linear movement is necessary and especially if such a transmission is to be carried out with a high degree of accuracy and with an absolute minimum of dynamic suspension.

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Claims (2)

Claims; 1. Device for use in a gear grinding machine for the production of involute gears or similar machines for producing rectilinear relative rolling motion between a work gear and a rotatable one Grinding wheel with straight generator, characterized by a rotating block sliding crank mechanism and a slide crank mechanism, which are arranged in combination with one another that when a back and forth movement (s) is carried out, one of them carries a reverse gearwheel (5) Carriage (5) with a circular radius (R) the back gear wheel is rotatable relative to the slide in an angle (arc0) so that (s) - (R ₀ ) ι (arc0), wherein the arrangement of the rotary block slide crank mechanism comprises a crank (12) with a radius R _Q coaxially ium work gear is disposed, and communicates with this in drive connection further comprises a first sliding block (14) at the outer end of the crank (12 ) is articulated and is in contact with straight inner guides (15) of a lever (16), - 12 - 109809/0636 which is arranged at its upper end by means of a pair of straight ducts (19) to be slidable through a second slide block (18) attached to a fixed main machine frame is pivotally attached above the axis of the workpiece gear, while the lower end of the lever (16) is pivoted about a main pivot pin (17) which is attached to the carriage (5) below the axis of the workpiece gear and the is reciprocable relative to the carriage by means of the carriage crank mechanism, which has a crank (23) with a radius r as Extension of the crank (12) of length Ro, but by 180 degrees of arc out of phase with this, further comprises a connecting rod (25) of a length 1, one end of which is attached to the lever (23) and hinged at its other end to the main pivot bolt (17) is, and finally a carriage (27) »which the Hauptanlenkbolzen (17) in a pair of straight guides (28), the Carriages are attached, reciprocally movable, with all · cranks, levers, connecting rods, pivot pins, guides and carriage in the middle position of the link mechanism in FIG - 13 - 109809/0636 and the linkage mechanism is movable from its central position to either side in accordance with the above equation. 2. Device according to claim 1, characterized in that the distance in the middle position of the device between the main pivot pin (17) of the rotating block slide crank mechanism and the common axis of the rferkstückzahnrads (3) and the crank (12) with the radius B is exactly 2 ζ R. 109809/0636