Cycloidal or planetary gears

(54) Name: Planetary gear

The invention relates to a planetary gear having at least one with. using an eccentric movable planet wheel, which engages at least one concentric center wheel. The planet wheel may be arranged inside or outside the concentric center wheel. In order to achieve shape locking, a closed cycloid curve is assigned, which is in engagement with a roller ring, the planetary wheel and, respectively. center wheel. The intervention acts either between an inside epicycloid curve and an outside roller ring or between an inside roller ring and an outside hypocycloid curve. The number of rolls of the outside roller ring or the other. the number of curve sections of the outlying hypocycloid curve is about once greater than the curve section number of the inside epicycloid curve, respectively. the number of rollers of the inner roller ring.

For explanation of the closed cycloid curve of the wafer discs of the initially described operation, reference is made to Fig. 3 of the accompanying drawing, which shows one of the possibilities of the kinematic generations of equidistants of a shortened epicycloid. At the outer perimeter

7506936-9 of a stationary basic circle with radius a rolls - without sliding - a rolling circle with radius b. The distance a + b = r moves around the center point M with the angular velocity V 1 and the rolling circle around an average point B with the angular velocity i^f'rf. A point C in the plane of the roller circle with the distance e = BC describes on a stationary plane xy an abbreviated epicycloid - abbreviated, since C is not on the periphery of the roller circle. To this shortened epicycloid, an equidistant is likewise generated on the first plane xy by the normal n, which goes from the point C via the relevant point of contact A of the rolling circle with the fixed base circle to a point IT. The equation distances point Q is at the normal n and has a constant distance q. From point C. At the transfer angle γ = 4 MAN, on both sides, the distance MB = r. This angle γ obtains a maximum when the distance MN = ez is perpendicular to n; ez always runs parallel to e. In Fig. 5, only half a curve section from the highest point S to the valley point T is shown. The ratio of radius a to b = z is chosen, respectively the ratio of angle / 5 to PC = z integer, so that a closed cycloid curve of integer curve sections is obtained. From Fig. 5, the mathematical description of the curve is derived as follows:

x = r.cosczie.cos (^ ir () i q.cos (J'i-i) y = r.sinc <ie.sinO) -: '/ Jq..sin (/ i ~ 0

The transfer angle s is derived as follows:

= are tg (sin /? / (1 / ra + cos /?))

This was the case for the shortening ratio: m = e (zil) / r.

In this case, the upper sign applies to an epicycloid (Fig. 5); the lower sign applies to a hypocycloid, for which the rolling circle is generated on the inner circumference of a basic circle.

From this mathematical description, one can conclude on the kinematic significance of the three parameters r, e and q. In order to better clarify the interaction of the wafer with the corresponding roller ring in the initially described operating mode, reference is made to Fig. 4 in the accompanying drawing. On the left side, for a given roller ring, the corresponding epicycloid and its equidistants are recorded, while on the right side of the same roller wreath is the hypocycloid with its equidistants. The basic circles of the two curves are further denoted by a and a. a ', their roller circles with b and a. b '. The center of the roller ring is 0, the center of the curves M, the center of the roller circles B and; the center of the rollers C. The distance OM is equal to e, the eccentricity or the crank is equal to and. parallel to the distance BC = e.

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The angular velocity introduced into the link 0 via the crank e produces in the link M a velocity vector which has the same direction as tangential force F = initiated torque / e.

As a result, the curve, as it rests on the fixed roller rim, is turned in the direction resp. W around its center point M. Power transmission can now normally be made to the affected surfaces. However, the normal of a cycloid must, in a known manner, pass through the contact points A and 2 respectively. A 'of the rolling circle and the basic circle. Through the straight lines CA and resp. C'A 'are therefore given these normals, whose extensions meet in the instantaneous poles T1 and 1, respectively. TT ".

Since the roll ring rollers have their mid points in 0 and their radii correspond to the constant equidistant distances q. = CQ and. q '- C'Q', at the same time these normals must also pass through point Q. Hereinafter reference is made to Fig. 3, on which a roll is dashed reproduced. The points Q are, on the one hand, points of creation of the curve plate and, on the other hand, touch points of the curve plate with the rollers of the roller ring, and consequently, in each of the initially described operating modes, determine two curve contours kinematically. This view, which also describes the contact points of the rollers with a cycloid curve, is not found in the prior art.

Hereinafter, the mathematical equidistant curve of an abbreviated cycloid is designated as the curve contour of a curve disk, such as curve disk cycloid, and the imagined mathematical equidistant curve of an abbreviated cycloid, which refers to the touch points of the roll crane rollers, as the reference cycloid.

Accordingly, there is thus an interchange with the epi- and hypocycloids, respectively, the curve disc cycloid within and. outside the reference cycloid.

When mathematically considering a gear assuming that factors such as manufacturing tolerances, elasticity and thermal expansion are not taken into account, these two curve contours, ie the curve disk cycloid and the reference cycloid and consequently also its parameters are identical. Accordingly, the parameters of the reference cycloid are not suitable for generating a curve disk cycloid, which in a practical exchange is to come into operation, This has been met so far that the curve disk cycloid has been emoirically corrected so that a reference circuit is prepared for the reference cycle. Compared to reference, the polypeptide is an enlarged curve disc cycloid and subsequently trimmed in the region of the top and bottom points (German Patent No. 464,992, German Additional Patent No. 459,025).

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The corrections described above lead to the following deficiencies in practical change:

1st Only one or two outer rolls will come due to the cut-out and cut-off rolls, respectively. removed the portions of the curve contour during a revolution of the eccentric for bearing on the cycloid curve, which is caused by the fact that no equal distances are given in the circumferential direction from the individual curve sections to the outer rollers. Consequently, a limited small distance along the entire curve contour must take over the entire power transmission.

2nd Unequal course of oscillation induction, especially at higher speeds, which is achieved by the fact that the instantaneous pole H of the curve disc cycloid and the reference cycloid during the process undergo kinematic deviations from its path pole path with radius e'z and its stop pole path with radius e. (ζ ί 1).

3rd Shocks after passing through the highest point S during a curve section's engagement with a roller.

4th Large rotation reversal games, which are not predetermined.

The invention is based on the task of providing gears of the type mentioned initially, in which the aforementioned deficiencies of known gears are largely remedied.

Starting from a planetary gear having at least one eccentric movable planet wheel and having at least one concentric center wheel, both wheels engaging via a closed curve disc cycloid formed at one wheel and a roller ring formed at the other wheel, whose contact points with curve disc cycloid points of a reference cycloid, according to the invention this task is solved by the fact that the value of parameter q. for the curve disc cycloid is greater than for the reference cycloid, and that the value of the parameter r in the case of a design of the i-disk disk cycloid as an epicycloid is greater and in the case of a design of the curve disk cycloid such as a hypo-ocloid is smaller than that of the reference cycloid.

This inventive design of the curve disc cycloid relative to the reference cycloid, which manifests itself in an enlargement of the curve edge, achieves a considerable enlargement of the engagement distance, which can amount to a variety of the hitherto usual order of magnitude. In the practical course, shortly after the position in one of the highest points, an even engagement is obtained between the existing curve section and the opposite roller, which, in the case of continued rotation through approximately the entire curve edge, uniformly yields support between the highest point and the valley.

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This uniform bearing makes it clear that almost half of all rollers are in load-transferring engagement with the associated curve flanks. Accordingly, the distance of engagement is extended by the fact that at correspondingly many flanks, correspondingly many rolls abut in contact areas of curved sections to curved sections; this can also be explained by the intended projection of all the contact zones of the co-existing rollers on a curve edge and this notion forms the basis of Figures 5 and 6 in the accompanying drawing. Of course, between the rollers that are to be engaged with each other and the curve sections initially rule a game. The previously described load transfer conditions adjust after applying a reversal angle.

The significant enlargement of the engagement distance against the prior art leads to the fact that now a gear of the same order of magnitude can transmit significantly higher torque and resp. that a gear for the same practical surfaces now in the inventive embodiment can be significantly / space-saving. Practical experiments have shown that in practice the distance of engagement can be enlarged 5 times the previous value and the gear according to the invention can be built correspondingly smaller.

A cycloid gear runs so much calmer and generally better the more it manages to allow the instantaneous poles of the two cycloids to rotate evenly. The instantaneous poles of known gears of the kind in question are relatively close to each other, but they do break out of the prescribed rotation paths. The paste of the inventive parameter dimension of the instantaneous poles of the two cycloids is almost more distant from each other than in conventional gears, in practice, after disengaging the reversing game, they collapse together and rotate in this position jointly on the circular stop pole path. Even from this point of view it becomes understandable that you get a substantially smoother and calmer running gear. For this view, reference is made to German patent specification 1,087,865.

In addition, the inventive parameter design also allows the individual rollers to continuously run from unloaded to loaded condition, so that shocks, as observed so far after passing through the highest point, are practically prevented. This also contributes to a larger running furnace and an extension of the life of the gear.

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To emphasize further is the rather considerable reduction of the friction losses, which are far smaller than the still comparatively small friction losses of the known cycloid exchangers.

The always-pre-ignition twist-turn game ^can is indicated as an angle θ * but also in the form of distances which occur between the rollers and their points of contact on the curve plate.

Thus, the instruction of patent claim 1 can also be mathematically reproduced by this rotation possibility of the planet wheel and the center wheel counter to each other rows Δ u as a function of the rolling wheel β and more closely / following relation = A-4 - Is.cos ymed its f

A rotation distance, as mentioned above

A qs Difference in the values ​​of the parameters q (see also requirement 3)

A. r »The difference in the values ​​of the parameters (see also requirement -5) = aro.tg 1 / m + cos /?

In further designing the invention, one may proceed such that one designs the curve disc cycloid with a larger parameter value e than the reference cycle. Thus, particular bearing clearance and elastic deformations of the drive shaft can be compensated.

In a further preferred embodiment, in the dimensioning of the parameter values ​​r and q, the differences of the parameter values ​​r to the difference of the parameter values ​​q are treated as + m ^ - 1 to 1 - / i - m ^, with the shortening ratio m = e / b With the difference of the parameter values ​​r and q, here is understood the difference between, for example, the parameter value r of the reference cycloid to that of the parameter r of the curve disc cycloid; for q, the same approach applies.

A further preferred variant is obtained by the minimization possibility of the twist reversal game according to the following relation:

& = (1 t 1 / z) * (arc cos (-m) - are cos (-m ^)) with m = shortening ratio of the reference cycloid and m ^ that of the curve disc cycloids.

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Finally, the possibility of determining, for a minimum possible surface pressure, also the parameter values, and in particular with respect to the shortening ratio m and the equidistant distances, results in the possibility of reducing the surface pressure in a preferred embodiment therein, that the equidistant q. is selected approximately as large as the smallest radius of curvature of the reference cycloid, which radius occurs in the vicinity of the turning point of the curvature edge and thus in the region of greatest surface pressure. At the site of the reference cycloid, the curve disc cycloid can also be used here, since the deviations are only very slight.

The invention will be further elucidated in the following with reference to the accompanying drawing, the general information having already been given above with reference to Figures 3 and 4.

The drawing shows:

Figs. 1 and 2 Fig. 3 Fig. 4 Fig. 5 · Fig. 6 Figs. 7 and 8 show a longitudinal section and a cross-section through an embodiment of a gear of the kind in question, a schematic diagram for developing an epicycloid curve, coordination between the roller rim and the epicycloid. on the one hand and roller ring and hypocycloid on the other hand, some curve plots of epicycloids with a reference cycloid changing parameter values ​​r and q. for viewing, the same curve plane as in Fig. 5 after going through the rotation reversal diagram to clarify the context:

Δ u = Ad -Λγ.οοβ / sm>,

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On a shaft 1, which is centrally stored by ball bearings 2, 3 in a two-part housing 4,5 and 2, respectively. an axis 6, two eccentric tread paths 7, 8 are eccentric¹'teten e = OM or e = OM 'arranged offset 180 ° to each other. Via roller bodies 9, 10 on the eccentric treads 7, 8 are stored with each closed cycloid curve 11, 12 provided with discs 13, 14. The closed cycloid curve 11, 12 engages rolling through the rollers 15 on the pins 16, which are fixed concentrically around the center axis 0-0. of the housing 4. In the wafer discs 13, 14 are concentric to the rotary shaft MM and resp. M'-M 'provided bores 17 and 17, respectively. 18, wherein the rollers 20 stored on pins 19 are gripped, which are fixed in a flange 21 of the shaft 6 concentric about its axis of rotation 0-0. The shaft 6 is stored in the housing part 5 via ball bearings 22, 23. The housing consisting of the parts 4, 5 is in a known manner closed by means of cover 24 »25 and sealed outwardly by sealing elements 26, 27 · The screws 28 can serve to secure the both housing portions 4, 5. The bores 29 can serve to secure the gear »

Depending on the purpose to be achieved with the gear, one or two of the parts 1, 6, 4, 5 can be operated »

The gear structure as such is known and already found use in the previous cycloid dimensions. In the case of Fig. 2, it is admittedly indicated by the common momentary pole 1i for the rollers a semicircle, which is to be achieved with the inventive dimensioning of the parameters r and q .. As already explained above, after the rotation reversal play, the poles of both cycloids momentarily coincide and they jointly cross the circular resting pole path.

Pigs 3 and 4 have already been mentioned initially for explanation of basic concepts.

In Figure 5, some flanks of epicycloids are shown, the development of which is counter-swelling according to Figure 3 · Eeference cycloid has parameters r, e and q find

This use in practiced gears such as the geometric location of the contact points of the roller ring with the associated curve disc cycloid; all the touch points are projected on a single edge.

Furthermore, a cycloid flank is shown, which is known in a known manner, which can be approximately expressed by a reduction of the parameter values ​​r₂ and q₂ against r and q of the reference cycloid. The designations in this known curve flank carry the index 2. It can be seen that this is a heavily curved, steep flank profile.

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As the third curve, the inventive, streaked flank profile is listed, whose designations bear the index 1.

For each cycloid, some significant points are indicated, such as the common center point M, the highest points S, S₂, Sp sub points T, T₂, Tp the mean points of the rolling circle B, B₂, Bp the generating points of the abbreviated cycloid C, C₂j Cp the points of equilibrium distances Q, Q₂, Qp as well as the instantaneous poles in question N, rr₂ and IT₁.

Fig. 6 shows the flank profiles described in Fig. 5 in their coordination after going through the pivot reversal game, which is shown as pivoting around the point M with the pivot reversal angle. It is assumed that at the practiced epicycloid gear the reference flank_profile of the reference cycloid is assigned xy-plane in the same shape and position. The two other flank profiles are assigned to two different wafer discs which, due to the required manufacturing tolerances, must be attached to a play and only after the rotation play has come through / engages with the reference cycloid. As already explained in connection with Fig. 5, one of the curve disc cycloids is formed in a conventional manner and the others are designed according to the invention.

When rotating the two latter curve edges, the reversal angle (f) moves the instantaneous pole of the inventively designed cycloid to the nominal pole N of the reference cycloid, while the instantaneous pole IT₂ of the conventionally formed curve disc cycloid is further removed from the instantaneous pole M of the reference cycloid than it is already - as shown in Figure 5 - prior to application of the

the angle of rotation of the island was at a distance from N.

All three flank profiles contact each other in the region of their turning points, the known steep flank profile having a short engagement distance E ₂ in common with the reference flank profile. The dotted flank profile according to the invention covers^kon the other hand, with the reference flank profile over a reasonably considerably longer engagement distance £.

It was mentioned in the preamble that the idea of ​​the invention can also be produced in a different way and more specifically by stretch indications u, which occur between the rollers and their points of contact on the curve plate.

In this context, the relationship is established:

_u _ Δ <1 - z ^ r.cos ^its z

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Figures 7 and 8 clarify this depending on the turning distance 4 u seen via the roll angle β and more precisely by varying the parameters

A q. And 4 Poor simplification of the drawings went so far, that on different.

one side /.._ r at constant 4 q and conversely different A q at constant Λ are the basis for the production. With respect to the reference cycloid, both parameters are varied.

Since the parameters 4 q and 4r are always 0 for the case of the reference cycloid refer to A u the value 0 and the abscissa represents the conditions of the reference cycloid.

From this it can be seen that, to a large extent, the sections running parallel to the abscissa, which show a constant torsion distance with respect to the reference cycloid, ensure a very smooth course of a admittedly relatively small loaded gear. If one goes to the area of ​​higher load, the load distribution, which would occur on the reference cycloid, can be taken into account. Namely, the force distribution along the reference cycloid is not constant but has a maximum, which is approximately in the region of the turning point between valley and highest point of the flank. If in this area the distance of rotation is enlarged, the neighboring areas, ie the rollers adjacent to the circumferential direction, must be forced to help carry a larger part of the total load, thereby resulting in the opportunity to distribute the load evenly over the flank gradient or the like. at the same time several rolls. From the illustrated waveforms, these appear with such an Au ratio. It should be taken into account that the hitherto known cycloid exchangers do not even exhibit the load distributions applicable to the reference cycloid. The loads at the known gears are even more severe · limited to a narrow flank area.

The exclusion curve curves, for example, already make it clear that, within the framework of the teachings of the invention, there are a number of adaptation possibilities available to the desired conditions. In addition to the above-mentioned favorable distribution of power, respectively. the smooth noise-free course of the gear can be rotated throwing bets and similar measures taken, which are included within the scope of the requirements.

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