DE2115887A1 - Variable transmission - Google Patents

Description

P HH, 5,386.

. Wij / RV.

Dipl.-Ing. F.-J. FUPFERMANN

Ptteni.inwalt

Applicant: N. γ. Philips' Gloeüampenfabrieked
File No. PHN-5388

Registration dated: March 24, 1971

"Variable Transmission"

The invention relates to a variable transmission between two essentially parallel shafts, each with a guide wheel included, over which a friction ring is guided, a pair of planks doe ring with a pair of flanks at least one of the guide wheels in attack is and where the change in distance between the flanks of a Plank pair represents the position of the ring in relation to the guide wheel and thus

Gear ratio changes.

Such a transmission is for example aue der schveieeriechen Patent specification 390-023 known. The coupling waves are there provided with split guide wheels, with the guide wheels against • The spring force can be moved in the axial direction. Dor friction ring is iij A frame that can be moved with the aid of a control mechanism can be rotated assembled.

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-2- PHN. 5388.

Similar transmissions are also known that have an operating mechanism are provided, with which the distance between the parts of the guide wheels can be changed and thus also the position of the ring and thus the transmission ratio can be changed.

A disadvantage of these known variable transmissions is their intricate, and thereby costly and vulnerable, construction

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the gear ratio changing mechanism. Besides that the forces on the ring must be transmitted as a result of the between the shafts Often completely or to a large extent for a moment Mechanism are included, whereby this mechanism must be made difficult and takes up a lot of space.

The inventive construction with which it is intended is to avoid these disadvantages, has the characteristic that to

Change of the position of the ring in relation to one of the guide wheels of the ring is tiltable around the other guide wheel.

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The change in the gear ratio can, for example be arbitrarily adjustable with the help of a construction that is characterized in that the friction ring also has an adjusting wheel is performed, which is displaceable with the help of an operating mechanism is.

It is also possible to use the transmission according to another embodiment self-adjusting, which embodiment is characterized in that the friction ring is supported exclusively by the guide wheels on the two shafts and as a result of the guide wheel flanks forces exerted on the ring is automatically adjustable.

A preferred embodiment to be used is thereby characterized in that the guide wheel around which the ring can be tilted as

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2: 15887

Gear formed with external teeth and the friction ring with corresponding Internal gearing is provided.

A particular embodiment is characterized in that the friction ring is assembled from two annular elements which together form an annular whole and which annular elements are resiliently connected to each other.

The ring-shaped elements can by regularly on the circumference distributed resilient elements or .erbunden by a back made of resilient material.

An infinitely variable construction within very wide limits indicates that the gearbox has a differential gear is combined, whereby the movement of the incoming wave branches into two movements, namely in one movement of the outgoing wave Wave and a third wave, which movements have a variable relationship to each other, the third wave by the variable Gearbox is coupled to one of the other two shafts.

Such a combination with a differential gear can in particular be designed with the characteristic that the Differential mechanism from a planetary gear with a sun gear on the incoming shaft and with at least one planet gear, which with the outgoing shaft is connected, while the ring gear has an external toothing and thus with a gear arranged on the third shaft is in engagement and the guide wheels of the variable transmission are arranged on the third shaft and that shaft which is connected to the third shaft is coupled and the friction ring, which over the guide wheels

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is performed, assumes a position that determines the transmission ratio, those under the influence of the moment to be transmitted by the third wave

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is changeable.

Embodiments of the invention are in the drawings and are described in more detail below. Show it

Fig. 1 is an axial section through a variable transmission, ■ "

FIG. 2 shows a section perpendicular to the shafts according to FIG Line H-II in Fig. 1,

Fig. 3 is a schematic representation of the friction ring according to Fig. 1 in two layers,

4 shows a section perpendicular to the shafts through a variable transmission with a separate setting wheel, !

5 shows a section through part of a particular embodiment a split guide wheel and a friction ring to be fitted,

6 shows a section through the shafts of a variable transmission with a friction ring which is composed of two annular elements which are resiliently connected to one another,

7 and 8 show a section through modifications of the guide wheel and the friction ring,

9 shows a section according to the plane through the waves of a according to the invention gear, wherein a planetary gear with a variable Gear is combined, which variable gear has a self-adjusting friction ring guided by guide wheels, FIG. 10 shows a section along the line X-X in FIG.

11 shows a schematic and diagrammatic representation of the transmission according to FIG. 9,

Fig. 12 is a graph in which, for two cases

10 9 8 4 5/16? 7th

the relationship between the moment on the outgoing wave and the Relationship between the peripheral speeds of the incoming and outgoing Wave is applied.

As shown in Figs. 1 and 2, the guide

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wheels 1 and 2 are arranged on the shafts 3 and 4 to be coupled. About the Guide wheels 1 and 2 runs the metal friction ring 5 · This ring 5 is provided with an internal toothing, which with a corresponding external toothing of the guide wheel 2 is in engagement. The guide wheel 1 is made up of the two parts 7 and 8, between which the ring 5 is located. The radial distance between the shaft 3 and the points of contact 9 between the ring 5 and each of the parts 7 or 8 is for the

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Gear ratio when translating the rotary motion between shafts 3 and 4 determining. The part 8 of the guide wheel 1 forms a whole with the shaft 3. The shaft 1Q lies on the same longitudinal axis of the shaft 3. The shafts 3 and 10 are connected by a bolt 11, the shafts 3 and 10 being simultaneously adjustable with respect to one another in the axial direction with the aid of the bolt 11. A spring plate 12 is fixedly arranged on the shaft 10 * Plate-shaped spring elements 13 are tensioned between the spring plate 12 and the part 7 of the guide wheel. The part J is thereby displaceable in the axial direction over the shaft 3, so that the position of the ring 5 relative to the two parts 7 and 8 of the guide wheel 1 and there-

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by the position of the contact points 9 »that for the transmission ratio are determinative, is changeable. This change in position of the ring 5 compared to the split guide wheel 1 can be seen as a tilting of the ring to look at the guide wheel 2. The center M of the ring 5 shifts while using an arc of a circle, the center of which is on the Center line of shaft 4 lies. As below with the aid of FIG. 3 in more detail

103 «45/1 ß ** 7

is explained, the transmission can be designed in such a way that this change in position exerted on the ring under the influence of the guide wheels Forces takes place automatically.

In Fig. 3, the ring 5 is schematically in two positions opposite the guide wheels 1 and 2 shown while at the same time those forces which are exerted on the ring 5 by the guide wheel 1. One of the two layers is shown by a dashed line and -the Designations that refer to this position are accented. It is now assumed that the shaft 3 with the guide wheel 1 is the driving shaft and the direction of rotation is as indicated by the Arrows indicated; then in the first layer of the ring 5 »in the the center of the ring is in M, from the guide wheel 1 at the point of contact 9 a tangential force K and a radial force on the ring 5

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K exercised. In the steady state, the resulting moment of the forces K and K around the theoretical point of contact 14 between the ring 5 and the guide wheel 2 is nihil, ie that K..a = K .b. If the force K ₊ becomes greater, for example because the counteracting moment felt by the driven shaft 4 is greater, the moment Ka will become greater than K b and the ring will return to a new equilibrium position, for example with the center in M ', move »The point of contact 9 is ^{shifted according to 9 1} at a smaller radial distance from the shaft 3. The two parts 7 and 8 of the guide wheel 1, which, seen in section, enclose a groove narrowing in the direction of the shaft, are thereby pressed apart against the action of the spring elements 13 (see also FIG. 1). A new equilibrium position is achieved because compared to the new contact point 14 'between the ring 5' and the guide wheel 2, the moment arm a 'of the force K, ^{1 is} smaller than that

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Momentarra a for the force K., while the moment arm b ^{1 of} the force K 'has increased compared to the moment arm b of the force K. In addition, when the ring 5 is displaced relative to the parts 7 and 8, the force K will generally change and will be greater in the embodiment according to FIG. 1 K ¹

as K · The connection with the resilient elements between the parts 7 r

and 8 can, however, also be designed differently, for example in such a way that that the force exerted on one another via these resilient elements is constant is, regardless of the position of the parts 7 and 8 opposite one another. This creates a self-adjusting transmission mechanism received, which automatically increases with an increase in the counteracting The moment that the driven shaft 4 experiences is reduced to a lower one Adjusts the speed of this shaft. An increase in transmitted This counteracts performance, which is also evident from the fact that the greater force K 'has a smaller moment arm compared to the shaft has than the force K .. Conversely, there is also a decrease in the

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the performance are counteracted, so that the transmission mechanism in this execution will try to transfer the power and thus in general to keep the speed of the driving shaft 3 constant.

Except for the above-described effect on the speed The device can automatically keep the driving shaft constant can also be used to keep the speed of the driven shaft constant. In this case, the shaft 4 with the guide wheel 2 is the driving force The shaft and the directions of rotation of the guide wheels 1 and 2 are now opposite to the directions of the arrows. An increase in the force K, for example because the counteracting moment of the shaft 3 increases, again causes a shift of the contact point 9 to 9 ', with im

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generally the speed of the shaft 4 will decrease. One accordingly the decrease in the speed of the shaft 3 is counteracted because the point of contact 9 'at a smaller radial distance from the shaft 3 lies as the point of contact 9.

Instead of a toothed wheel, the guide wheel 2 can also be designed as a roller or with a groove for the ring, with the aid of the frictional forces transmit the movement between the ring 5 and the guide wheel 2 will. The only condition here is that the ring can be tilted around this guide wheel 2.

It is also possible to split the two guide wheels 1 and 2, as described above for guide wheel 1. If the guide wheels 1 and 2 are of identical design, they will change Circumstances, the ring theoretically opposite the two guide wheels change its position in the same sense and to the same extent, so that im

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transmission ratio no change occurs. However, the two give way Guide wheels 1 and 2 from each other, for example in the inclination of the Friction flanks or in the properties of the springs with which the guide wheel parts are coupled, however, is generally again one

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automatic setting of the transmission ratio by the ring to be possible. The change in position of the ring can be used as the combination a rectilinear movement and a rotation about one of the guide wheels can be described.

The described with reference to FIGS. 1 to 3 is automatic

adjusting gear "differs in its simple construction. Special mechanisms for moving the ring, for coupling the guide wheels or parts thereof with one another or for moving one or the both waves are superfluous. The mutable described above

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For this reason, transmissions can also be built very compactly.

Fig. 4 shows an embodiment in which the ring adjusts itself automatically but the position of the ring can be determined at the same time with the aid of a roller 23 over which the ring runs and which roller is displaceable from the outside. The roller 23 is mounted on a leg 24 of a toggle lever 25 which is rotatably mounted about the shaft 26. The position of the roller 23 can be adjusted with the aid of a bowden cable 27 which is passed through the housing 28 and attached to the end of the other leg 29 of the toggle lever 25. The roller 23 can also be arranged on the outside of the ring instead of on the inside of the ring 5. Is the inside of the ring 5 ^m i * a toothing provided as a roll 23 may be used in place a gear. It is also possible to let the roller 23 run in a circumferential groove in the toothing.

If the leg 24 is provided with an additional role, which lies opposite the roller 23 and rests on the outside of the ring 5,

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so the position of the ring 5 and thus the transmission ratio between the shafts 3 and 4 entirely determined by the position of the toggle lever 25. the The position of the toggle lever can be adjusted, for example, by manual operation will.

In Fig. 5, an embodiment is shown, wherein an in

Cross-section of U-shaped friction ring 15 is used. The flanks 16 and 17 on the inside of the legs of this ring 15 grip the flanks and 19 of parts 20 and 21 of a guide wheel. The guide wheels 20 and 21 are connected to each other by spring elements 22 and in the axial direction

device movable relative to each other, whereby the position of the annular transmission element 15 is changeable again. A ring 15 with an in Fig. 5 shown cross section 'could for example in one above variable transmission described are used, that consists of the parts

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20, 21 and 22 built-up guide wheel then replaces the guide wheel 1 Figs. 1 to 4. "....--.

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To transfer large amounts of power, 3 Λ 4 several guide wheels 1 or 2 can be arranged, with over each set a ring 5 or 15 is guided for such a parallel connection the self-adjusting transmission mechanism according to FIGS. 1 to 3 is entirely suitable. The rings 5 or 15 will automatically turn to one

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Set the same gear ratio because if one ring deviates from it wants to act on this ring forces that on the above the manner described will immediately compensate for the deviation.

Fig. 6 shows a section through the shafts of an embodiment with a friction ring, which consists of two annular elements 30 and 31 which are connected by spring parts 32. The guide wheel 33 on. the shaft 3 now does not need two mutually displaceable Divide to exist and is with a narrowing towards the center of the wheel 33 Provided a groove. The guide wheel 34 is located on the shaft 4

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is also provided with a groove for the friction ring. The transfer the movement between the guide wheels and the ring is done with the aid the frictional forces between the flanks of the ring and the walls of the grooves in the guide wheels. The insides of the annular elements and 31 also touch the bottom 35 of the groove of the guide wheel 34 »so that there will also be frictional forces. Instead of the leadership: rades 34 with the groove can consequently also have a friction roller on the shaft 4 sufficient.

The annular elements 30 and 31 can also have internal teeth which are in engagement with a gear on the shaft 4.

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The annular elements 30 and 31 are over the guide wheel 34 tiltable so that completely in accordance with the principle of the

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1 to 4 described embodiments the transmission ratio is changeable.

Fig. 7 shows an embodiment in which the friction ring is also is composed of two annular elements 36 and 37, which again are connected by spring parts 38. These spring parts 58 practice one another to directed forces on the elements 36 and 37, causing them to Clamp the inclined flanks 39 and 40 of the guide wheel 41 on the shaft 3. FIG. 8 shows a modification of the ring according to FIG. 7. The two ring-shaped ones However, elements 42 and 43 are now supported by a resilient back tied together. The elements 42 and 43 and the back 44 form a whole a material with elastic properties, for example from a Plastic. For reinforcement, the elements 42 and 43 have a metal core 45 or 46 provided «A variable gear according to the principle, as has been described with reference to FIGS. 1 to 4, can be with the Realize embodiments according to FIGS. 7 and 8 again in a simple manner.

A particularly compact transmission mechanism whose

Transmission ratio can be regulated within very wide limits obtained when using a variable transmission as described above is combined with a differential gear. Such a combination is shown in FIGS. 9-11.

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The transmission mechanism contains a planetary gear, that the shafts 47, 40 and 49 couple together. The incoming wave is driven, for example, by an electric motor 50, while on the other end of the shaft 47 is the sun gear 51 of the planetary gear

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net is. The planetary gear 52 of the planetary gear meshes with the sun gear 51. The planet gear 52 is rotatable about a spindle 53, one end of ^{which is firmly connected to the end part 54 of the} outgoing shaft 48, which end part 54 has a larger diameter than the remaining part of the shaft 48. The ring gear 55 of the planetary gear is internally toothed and an external toothing which meshes with the planetary gear or a gear 56 arranged on the third shaft 49

^ are. The planetary gearbox also has three support gears 57 » which are each rotatably mounted about a corresponding spindle 58. Every One end of the spindle 58 is also in the end part 54 of the outgoing Shaft 48 fixedly arranged.

The shafts 47 and 49 are further through a metal friction ring 59 coupled together, which ring has two guide wheels 60 and 61 led 1st. The guide wheel 60 is fixedly arranged on the shaft 47 and designed as a toothed wheel with internal teeth on the ring is engaged. The guide wheel 61 is divided, the Parts 62 and 63 are displaceable relative to one another in the axial direction,

w as described in the embodiment of FIGS.

On the outgoing shaft 48 is a gear 64 for driving a tool provided. In response to the opposing moment experienced by shaft 48, the transmission mechanism will automatically

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adjust automatically. Is the variator on a certain transmission ratio is set, the speed ratio of shafts 47 »48 and 49 is clearly determined. In the steady state, the ratio is between the moments to be transmitted by the shafts 47, 48 and 49 as well by the dimensions of the sun gear 51, the planet gear 52 »des

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Ring wheel 55 and gear 56 clearly determined. That changes

SAD ORIGINAL

Moment that the shaft 4-3 has to transmit because, for example, the driven Tool requires a different torque, the torque that must be transmitted by the shaft 49 will change proportionally

Change of the moment on the shaft 49 is used to change the position of the Ring 59 between the parts 62 and 65 of the guide wheel 6t and thus

the gear ratio automatically in the way as above has been described. In Fig. 11 the ring is divided into two

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different gear ratios corresponding positions shown, the ring being denoted by 59 'in the position shown by broken lines. The location of the automatic on the one to be transferred Moment of responsive variable transmission is mutable. This can for example, instead of between the shafts 47 and 49 also for coupling the

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Shafts 48 and 49 are used. This allows transmission mechanisms are obtained with different properties, which are related to the requirements that are placed on the tool to be driven, let adapt * In the graph of FIG. 12, the means Curve I shows the relationship between the moment M on the outgoing wave

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48 and the gear ratio between the incoming shaft 47 and following the outgoing shaft 48 in the example described above

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9 to 11. The transmission ratio is referred to as- ^ A: * A, where W and U ^ are the angular velocities of the outgoing shaft 47 ^and the incoming shaft 48, respectively. Curve I shows that a finite torque remains on the outgoing shaft, even if the speed of the outgoing shaft is zero. This property can be used to advantage to drive a wide variety of devices, such as mixers, mills, drills, lawn mowers, vehicles, motor vehicles, motor-driven wheels and similar vehicles.

10 9 8 4 57163 7

going shaft such an inhibition * that the speed of the shaft is the same When it becomes zero, the incoming shaft rotates with a power source coupled to it further while on the outgoing wave a finite moment

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remains present. This can prevent the transmission mechanism would turn defective even with such an inhibition of the outgoing shaft. Since at zero speed the outgoing Wave no power is transmitted through this wave, the incoming one needs Wave, apart from losses in the transmission mechanism, none P to supply power. In the transmission mechanism there is a so-called "revolving power", which is transmitted via the incoming shaft 47, the differential gear, the third shaft 49 and the variable gear is led around.

If in the above-described device after Fig. 9 to 11 the drive 'is coupled to the third shaft 49 which then essentially the incoming will be while the outgoing wave then takes the place of the third wave, the result shown in Fig. 12

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Curve II. This curve initially shows an increase in the Uberse.t-Zung ratio with an increase in the moment of the outgoing wave,

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while after exceeding a certain value when losing weight

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this moment the transfer ratio continues to increase

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Claims (9)

PATENT CLAIMS ί 1 «Variable transmission between two essentially parallel shafts with a guide wheel on each of the shafts over which a friction ring is guided, with a pair of planks of the ring on one Flank pair engages at least one of the guide wheels and the position of the ti Ring opposite the guide wheel and thus the transmission ratio 1! changes, characterized in that to change the position of the ring with respect to one of the guide wheels, the ring can be tilted around the other guide wheel is. 2. Variable transmission according to claim 1, characterized in that that the friction ring is guided at the same time via a setting wheel which can be moved with the aid of an operating mechanism. 3. Variable transmission according to claim 1, characterized in that that the friction ring exclusively from the guide wheels on the both shafts is supported and as a result of the guide wheel flanks forces exerted on the ring is automatically adjustable. 4. Variable transmission according to claim 1, 2 or 3 »characterized in that the guide wheel around which the ring can be tilted as Gear is designed with internal teeth and the friction ring is provided with corresponding internal teeth. % Variable transmission according to one of claims 1-4 »thereby characterized in that the friction ring is assembled from two annular elements which together form an annular whole and which annular elements are resiliently connected to one another. 6. Variable transmission according to claim 5 »characterized in that that the two ring-shaped elements through regular on the circumference distributed resilient elements are connected. 1 0 9:> 4 5/1 Γ Ί '- 7. Variable transmission according to claim 5, characterized in that that the two ring-shaped elements by a back from one resilient metal are connected. 8. Variable transmission according to one of the preceding claims, characterized in that the gearbox is combined with a differential gear ' where the movement of the incoming wave branches into two movements, namely one movement of the outgoing wave and a movement of a third wave, which movements have a variable relationship to one another, the third wave being variable Gearbox is coupled to one of the other two shafts. 9. Variable transmission according to claim 8, characterized in that that the differential mechanism consists of a planetary gear with a sun gear on the incoming shaft and with at least one planet gear coupled to the outgoing shaft, while the ring gear has an external toothing and thus with one on the third Shaft arranged gear is in mesh and the guide wheels of the variable Gearbox are arranged on the third shaft and the shaft coupled to the third shaft and the friction ring, which is Il wheels is guided, assumes a position that determines the transmission ratio, those under the influence of that to be transmitted by the third wave - 9 - moment is changeable. Blank page