DE2436496A1 - Continuously adjustable transmission for vehicles - utilizes centrifugal force to move spherical ball members outward and operate lever mechanism - Google Patents

Abstract

The unit contains a number of roller elements, supported on two running paths, one of which is stationary. The second path is connected to a drive- or take-off shaft. The roller elements are contained in an intermediate unit, which is in active connection with a shaft, so that shaft and elements rotate together. Each element is revolvable on a pivot, the axis of which may be inclined, to give a continuous adjustment of the transmission ratio. The intermediate unit and the two running paths enclose a circular seat. The roller elements are contained with free play in the seat. The supporting force of the elements on the running paths is caused by the centrifugal force, applied onto the elements by the rotation of the drive shaft.

Description

Infinitely variable friction transmission The invention relates to a Infinitely variable friction gear with a continuously variable transmission between a drive shaft and a coaxial output shaft. One Transmission device with such a transmission is particularly useful suitable in motor vehicles.

The transmission comprises a number of rolling elements 1 supported on two tracks, one of which is fixed and the other with the drive or the Output shaft is connected. In addition, the rolling elements are in an intermediate organ mounted that with the other shaft so positively connected is that in the frictionally connected rotary unit of this other shaft each of the elements is rotatable about a pin, the axis of which for changing the The gear ratio of the transmission can be inclined. In one embodiment the drive shaft rotates the entire rolling elements around their axis, while the output shaft is positively connected to the moving track.

Such a gear unit works as follows: The drive shaft rotates all rolling elements or balls during their rotation1 and contact of the balls with the fixed raceway causes them to rotate about their respective pivot pins. This turning movement sets the other track, which with the output shaft is connected.

The speed ratio between the drive shaft and The output shaft is determined by the inclination of the axis of the pivot, which carry the bullets. You can change this inclination at the same time Change the distance from the axis of the trunnions, the contact points of the balls with the fixed and the moving track, which increases the gear ratio will be changed.

Known gear assemblies of this type generally comprise elastic ones Organs that exert a force that the rolling elements or balls against their raceways presses. These elastic organs exert a constant force, from which it follows that the supporting force or the pressure of the balls on the raceways is also constant is and not in every moment of the torque and the force to be transmitted can be customized. In addition, the devices allow by that the inclination of the pivot can be changed, not a sufficiently large one Area of change.

The invention avoids these disadvantages. When according to the invention Change gear, as already indicated above, limits the intermediate member with the two outer raceways an annular seat in which the rolling elements are stored with a certain amount of play. The supporting force of the rolling elements on their The raceway is created by the centrifugal force that occurs when the drive shaft rotates acts on the rolling elements.

According to a further feature, the device by which the Direction of the axes of the trunnions carrying the rolling elements can be changed can, a ring, its longitudinal position along the input and output shaft is changeable, and a series of small connecting rods or connecting rods that are between the ring and ~ each of the trunnions for the balls are hinged.

The invention also relates to a transmission device with force dissipation, in which a planetary gear and a device for continuous speed change are assembled, with the derivative or branching of the force between them two subunits occurs, depending on the application conditions of the transmission.

Such a device is the subject of the French patent specification No. 1,263,934, filed on May 3, 1960 by REGIE NATIONALE DES USINES RENAULT. In this known arrangement, the motor shaft drives the via a coupling drive shaft of the continuously variable transmission, which distributes the power between two causes concentric shafts, one of which is the output shaft of the gearbox forms, while the other carries a planetary gear, which is the drive element of the planetary gear forms. An output element of this transmission, in the present case the planet carrier, is connected to the output shaft. The main disadvantage of this arrangement is in that the continuously variable transmission takes all the torque and all of the Motor shaft supplied power must transmit and distribute what for the stepless Transmission results in very difficult working conditions. In addition, the overall efficiency such an arrangement may not be optimal, as the gearbox works in areas in which its actual efficiency is relatively low.

The aim of the invention is therefore to create a transmission device between a drive shaft and an output shaft including a planetary gear and a continuously variable transmission, which have the disadvantages of the known arrangements avoided and industrially, especially in automotive engineering, usable is.

The device according to the invention is characterized above all by this from that the drive shaft carries a planetary pinion with at least one planetary gear is in engagement, wherein the planetary gear is mounted on a planet carrier is in turn rotatable about the drive shaft, positively connected to two other Planetary gears that mesh with the planetary pinions that are coaxial with the drive shaft stand, of which one with the output shaft and the other with one Shaft is connected, which forms the output shaft of the continuously variable transmission. the The drive shaft of the continuously variable transmission is driven by the planetary carriers of the planetary transmission set in rotation.

The power split is thus at the level of the planetary gear, so that the continuously variable transmission can work in a range in which its efficiency is relatively high.

According to a further characteristic, a coupling is provided from one of the driving or driven elements, preferably with the drive or the output shaft of the continuously variable transmission is connected.

In a particularly advantageous embodiment of the invention the coupling in the kinematic chain between the planetary carriers and the drive shaft of the continuously variable transmission.

In a further advantageous embodiment, the clutch comprises with a closed drum that is positively connected to the planetary gear at least one fixed wing that extends radially outward from the inside and two chambers delimited one below the other at the height of the free edge of the wing stay in contact. The drum contains a certain amount of liquid, its Volume is significantly smaller than that of the drum.

Preferably a plurality of wings extend over part of the inner one Drum radius and thus delimit chambers, -the ones in the axial part of the drum with one another are connected.

For a more detailed explanation of the invention is referred to in the Referring to the example shown in the drawing. 1 shows a longitudinal section through the continuously variable transmission according to the invention, FIGS. 2 and 3 each have a section along the line 2-2 or 3-3 in FIG. 1, FIG. 4 shows a longitudinal section through an embodiment of the transmission device according to the invention, FIGS. 5 and 6 longitudinal sectional views the line 5-5 or 6-6 in Fig. 4, Fig. 7 shows the course of the transmission or transmission efficiency of such a transmission, depending on the transmission ratio, Fig. 8 is an enlarged, schematic sectional view of a coupling according to the invention, FIG. 9 a section along the line 9-9 in FIG. 8, and FIG. 10 shows a view analogous to FIG Variant.

The continuously variable transmission according to the invention or

Change gear V is located in a housing 1, the shape of which Is of minor importance, and in which on the one hand there is a hollow drive shaft 2 with the axis X-X and on the other hand an output shaft 3, concentric in the shaft 2 arranged, are located. The drive shaft is positively connected to a ring 4, which is bounded by a toroidal surface 5, the area for rolling elements 6 of spherical shape is sufficient, which are hereinafter referred to as spheres. The ring also has as many radial grooves 7 as balls, which will be discussed below will be explained in more detail.

Two raceways 9 and 10 are provided, with the raceway 9 is fixed and is positively connected to the housing, while the track 10 is formed by a ring, with a flange or a disc 11 frictionally connected, which in turn is rotatably connected to the output shaft. The careers are for example conical in shape. Each ball is hollow as shown in the drawing and includes a stepped blind hole 12 which is engaged by a pivot 13.

Between the pivot and the inner wall of the bore 12 is a Needle bearing 14 arranged. A balancing mass 15, preferably made of lead, is below provided in the blind hole. At the open end of the bore 12 is the pivot pin positively connected to a nut 16 on which at 17a the end of a small Link lever or a connecting rod is articulated, the other end at 17b is articulated on a ring 18 which is calibrated on the drive shaft and on this wave can slide. For the axial displacement of the ring 18 are shown in FIG. 3 actuating means are provided, designed as a crank 19, which is mounted on a plate 20 works.

The diameter of the balls 6, as well as the relative arrangement of the Intermediate organ 4, and the raceways 9, 10 are chosen so that the ball in Inside of these three elements with a certain amount of play. This floating arrangement of each ball is made possible by the two joint axes 17a and 17b of the small connecting levers 17.

The continuously variable transmission according to the invention works as follows, whereby reference is made to what has already been said in the introduction: lying in the state of rest the balls on the intermediate member 4 or on the raceways 9, 10, practically without every support pressure. When the drive shaft 2 is rotated, the tries on the Balls 6 centrifugal force acting the balls on the fixed and movable raceway to press.

The supporting pressure of the balls on this raceway is therefore not constant, but changes with the speed of the drive shaft, so that at every moment this support pressure can be adapted to the torque to be transmitted can.

The inventive Reael mechanism also allows one particularly important control range, since the Y-Y axis of a pivot is different from the illustration according to Fig. 1 in a position opposite (not shown) can go is rotated by approx. 100 ° compared to the first. This important control range enables a very significant change in the gear ratio, for example between -0.25 to +1.25, which has the advantage that the output shaft can rotate in both directions can run, whereby the zero point, which corresponds to the gear ratio zero, is run through continuously.

To avoid arch support as a result of a kind of knee joint effect goes the straight line that the two joint axes 17a and 17b of the small connecting levers 17 connects, in the position shown in Fig. 1, well below the center of the Rolling element over, which ensures that the through this Just and the angle formed on the axis 17a in the middle of the game its abutting Even / not equal to zero or / can change its direction.

The balancing mass 15 in the blind hole 12 allows a static and dynamic Balancing of the entire unit formed by the rolling element and its support 16, so that a very good function is achieved.

Fig. 4 shows a transmission device in a housing 101, with a drive shaft 102 which is connected to a motor, not shown, with an output shaft 103, with a continuously variable transmission 104 and with a Planetary gear 105.

The drive shaft 102 carries the sub-units at the right end a planetary pinion 106 which meshes with a plurality of planetary rotating gears 107, which are rotatably mounted on a planet carrier 108. The latter has two opposite Flanges 108a, 108b, the flange 108a being extended by a cylindrical wall 108c is, in which there are recesses 108d.

There are preferably three planetary trains, each one of which central planetary gear 1Q7 in mesh with the planet pinion 106 and two lateral planetary gears 109, 110, in engagement with a planetary pinion each 111 or 112, the pinion 111 with the output shaft 103 and the pinion 112 is positively connected to a hollow shaft 113, which is rotatable with respect to the The drive shaft is mounted and the output shaft of the continuously variable transmission form.

For this purpose, the shaft 113 has grooves at its left end a flange 114 which carries a raceway 115 for the ball elements 116. In addition, the continuously variable transmission includes an input member 117 with a Hollow shaft 118 firmly connected, which in turn is provided with a ring 119 which, is set in rotation as explained below. The input member 117 limits one Support surface 120 for the ball elements 116. The ball elements 116 are thus between the support surface 120, a fixed raceway 121 and a movable raceway 115 mounted, the two raceways radially outside the ball elements 116 are located. The latter are rotatably mounted on pins 122, the direction of which by means of suitable control elements can be changed, a small one for each pivot Connecting lever 123 comprise between a support 122a for the pivot pin and a fluted or calibrated ring 124 hinged on the shaft is displaceable, the displacement being carried out via suitable means 125 which are not shown in the drawing.

In the planetary gear are between the opposite flanges 108a and 108b planet carriers rotatably mounted between the three planetary gears. Cylindrical drums 126 contain wings 127 in the interior, from their cylindrical surface exit radially so that a free space 128 is created in the center of the drum. Respectively two wings thus delimit a curved chamber 129, the individual chambers are in communication via the axial part of the drum (Fig. 6).

Inside each drum there is a volume of liquid, smaller than the volume of the drum, which when passing from one chamber to another, if the drums rotate around their axis, a certain one in these transition phases Amount of energy derives. Each drum is on the outside of the planet carrier provided with a pinion 130, which is connected to the input shaft 118 of the gearbox Fixed wreath 119 engages.

The various ball bearings, needle roller bearings, etc. for good function the device are indispensable are not explained in detail. These form classic components, the structure of which the expert from the drawing is sufficient is informed. There are also lubricant channels in the various shafts provided, which are also not explained in detail.

The gearbox works as follows: The rotating input shaft 1.02 rotates with its planet gear 106 the planetary gears 107, 109, 110, the cause a power split, on the one hand directly to the output shaft i03, via the Planetary gear 109 and the planetary gear 111, and on the other hand in the direction of the continuously variable transmission via the planetary carrier 108, via clutch assemblies 126 to'129, pinion 130 and the one with the input shaft of the continuously variable transmission connected ring 119. The output shaft 113 of the continuously variable transmission is in turn positively connected to the third planetary gear 112, which is connected to the third planetary gear 110 is engaged.

The percentage of the total torque that the continuously variable transmission happens depends on the gear ratio set in the gearbox. at a change in the transmission ratio from 0.25 to 0.3, 0.7, 1 and 1.25 the force going through the continuously variable transmission increases from 25% to 0%, 40% and -on 25%.

From Fig. 7 it can be seen that this division has an overall efficiency from 95.5 to 99.7% results, the last value being a transmission ratio of 1 which is an excellent value.

Due to the presence of the clutch, which in the exemplary embodiment through drums 126 partially filled with liquid are formed, this is avoided In addition, when starting up and with strong load fluctuations, there is any slip in the area of the continuously variable transmission, i.e. especially between the rolling elements and their careers. This works together with the fact that according to a preferred Embodiment of the support pressure of the elements 116 on their raceways 115 and 121 caused by the centrifugal force to which these elements are subject, so that automatic adaptation to the working conditions of the continuously variable transmission results. This results in minimal loads in the area of the balls and their raceways, what preserves their lifespan.

The advantages of the proposed transmission also include the The fact that the space requirement is very high even with large torques to be transmitted is low, this is achieved through the simple structure of the planetary gear and by the arrangement of the coupling elements, the dimensions of this planetary gear and by the angular intervals between the three planetary gears.

Furthermore, the translation range is very large and continuous from -0.25 in reverse to 1.25 in forward.

One recognizes in Fig. 8 a frame 201 on which a device with a coupling according to the invention is mounted. Such a device can can also be built into considerably more complicated transmissions, the drawing represents only a trial assembly.

The device comprises a drive shaft 202 and one coaxial therewith Output shaft 203 with the axis X-X. The shaft 202 is with a planet carrier 204 with two flanges 204a and 204b- firmly connected, which are connected via struts 205 stand on which the planetary gears 2b6 are rotatably mounted, in the exemplary embodiment three pieces. The planetary gears are frictionally engaged with the output shaft connected planet pinion 207 in engagement.

Each planetary pinion gear 206 is provided with a cylindrical drum 210 firmly connected, which is coaxial with it and carries the radial wing 211, in the exemplary embodiment eight pieces, the radial length of which is slightly less than the drum radius. These Vane delimit chambers 212 which are curved in cross section and which are in the axial part 213 the drum open (Fig. 9). The latter contains a certain amount of liquid 214, which determines the properties of the clutch, that of the drum and its planetary gear is formed. The liquid is filled in through an axial opening 215 which is closed by a stopper, The operation of this device is based on of Fig. 9 explained. Those of the drum 210, the blades 211 and the liquid The structural unit formed 214 is referred to as a "turbine".

The planet carrier 204 connected to the drive shaft 202 is offset the turbines 210 in planetary rotation. The turbines can also a planetary rotation by rolling the pinion 206 on the planetary pinion 207 received. The liquid in them is thus subject to two combined Centrifugal forces: 1. those resulting from planetary motion with the axis X-X around the main center of the motion 01 (Fig. 9) 2. the one due to the planetary rotation around the relative center of motion 02.

The resultant of these two forces created by the instantaneous Rotation center 03 goes, generates a counter-torque Cx that is opposite to that Is torque CR applied to the planetary pinion 207. During the coupling period the vanes 211 convey the liquid from the outside to the main axis of movement. Addicted from this rotation the liquid flows along the inner radial edge of the blades and is determined by the resultant of the centrifugal forces acting on it via the Periphery thrown. This transition leads to some dissipation of energy in the form of warmth.

The torque Cx with the square of the speed of the planet carrier increasing, goes towards a maximum value, which is from the maximum speed of the drive shaft and depends on the lever arm a, which is equal to the distance by which the point ° 2 is from the straight line along which the force F acts is separated when the maximum torque greater than or equal to that Moment of resistance CR becomes, is the coupling phase completed.

There is no more planetary motion and the liquid remains stand opposite the turbine blades: it then functions as a simple counterweight.

When the torque C is greater than that counteracting it Torque CR, the pinion 206 rolls so far on the pinion 207 that the The center of gravity G of the liquid approaches the line of the centers 01, 02 so that the lever arm a of the force F decreases. The torque C decreases proportionally x, until it reaches a new equilibrium with CR.

In the extreme case, the lever arm becomes zero and the torque Cx Likewise. If the center of gravity is on the other side of the center line, rotate the torque Cx as well as the torque CR.

This arrangement ensures a self-regulation of the torque, depending on the torque to be overcome, which is due to the extremely simple, robust and reliable means is achieved. The whole unit fits completely into the planetary gear and does not require the housing to be enlarged.

Further advantages are: It is not subject to wear and tear like magnetic particle clutches.

It allows the use of any neutral, high density fluid, for example of "bromoform" with a density of 3.6.

It automatically adapts to the torque to be overcome and can serve as a torque limiter.

It works without friction and therefore requires no maintenance and it does not lead to abrasion or slippage due to the appearance of grease Friction surfaces or as a result of an inadmissibly large torque to be transmitted.

The variant according to FIG. 10 allows a maximum increase in torque at the same engine speed and with reduced dimensions. The Drive shaft 221 a planetary pinion 222, which is connected to a planet carrier 224 rotatably mounted first planetary gear 223 is in engagement.

This first planetary pinion is with a turbine 225 as above in Fig. 8 and 9, and firmly connected to a second planetary gear 226, which is in engagement with a second planetary pinion 227 which is connected to the output shaft 228 is positively connected.

The coupling with the turbines 225 works on the same principle like the coupling described earlier.

Claims (15)

Claims W Device for stepless speed change with a range of Rolling elements supported on two tracks, one track being fixed and the other is connected to a drive or output shaft, the rolling elements also in an intermediate organ that is positively connected to this other shaft are mounted so that they rotate together with this other shaft, and where each rolling element is rotatably mounted on a pivot, the axis of which is continuously variable Change of the gear ratio can be inclined, is therefore not possible It is noted that the intermediate organ (4) with the two outer raceways (9, 10) delimits an annular seat in which the rolling elements t6) with play are arranged, the supporting force of the rolling elements on the raceways through the centrifugal force acting on the rolling elements when the drive shaft rotates is effected. 2. Apparatus according to claim 1, characterized in that g e k e n n -z e i c h n e t that the mechanism for changing the direction of the rolling elements (6) supporting Pivot (13) can be changed, comprises a ring (18), its position along the axis (X-X) of the input and output shaft can be regulated, and that a number small connecting lever (17) between this ring and each of the trunnions for the ball is hinged. 3. Apparatus according to claim 2, characterized in that g e k e n n -z e i c h n e t that the intermediate member has a toroidal area (5) for the rolling elements and radial grooves (7) defining the passage of the extensions (16) of the pivot pins and the small connecting lever (17). 4. Device according to one of claims 1 to thereby g e k e n n it is clear that each rolling element (6) has a blind hole (12) for receiving it of the associated pivot pin (13) and a balancing mass (15). 5. Device for transferring force between a drive and a Output shaft, with a planetary gear and a change gear for continuously variable Change of speed, preferably according to one of Claims 1 to 4, characterized in that it is g e k e It is noted that the drive shaft (102) carries a planetary pinion (106), which is in engagement with at least one planetary gear (107) on a Planet carrier (108) is rotatably mounted, which in turn around the axis of the drive shaft rotates and positively connected to two further planetary gears (109, 110) with two planetary pinions (111, 112) coaxial with the drive shaft stand, one pinion (111) with the drive shaft (103) and the other pinion (112) is non-positively connected to a shaft (113) which is the output shaft the continuously variable speed control arrangement (104), the drive shaft (118) is driven by the planet carrier of the planetary gear. 6. Apparatus according to claim 5, characterized in that g e k e n n -z e i c h n e t that there is a clutch, one of which is driven or driving Element, preferably with the drive shaft (118) or the output shaft (113) of the Device for stepless speed change (104) is connected. 7. Apparatus according to claim 6, characterized in that g e k e n n -z e i c h n e-t that the coupling in the kinematic chain between the planet carrier (108) and the drive shaft (118) of the continuously variable transmission is arranged. 8. Device according to one of claims 5 to 7, characterized g e k e n It should be noted that the planetary gear has several arrangements of three planetary gears (107, 109, 110), which are rotatably mounted on the planet carrier (108), and several planetary gears (130) on the same planet carrier (108) are rotatably mounted, and with a toothed member (119) that is connected to the drive shaft (118) of the continuously variable transmission (104) is positively connected, in engagement stands. 9. Apparatus according to claim 8, characterized in that g e k e n n -z e i c h n e t that the toothed organ (119) is a ring with internal teeth. 10. Device according to one of claims 6 to 9, characterized g e k e it is noted that the coupling means have at least one drum (126; 210) include that on rotatably mounted on the planet carrier (108; 204) is, and at least one fixed wing (127; 211) which radially from the Inner wall of the drum goes out, and delimits the at least two chambers (129; 212) that are connected via their near-axis part (128; 213), and that the Drum volume is partially filled with a liquid. 11. The device according to claim 10, characterized in that g e k e n n -z e i c h n e t that each drum (126) is positively connected to a pinion (130), which is in engagement with the collar (119). 12. The apparatus of claim 10 or 11, characterized g e -k e n n z e i c h n e t that several blades (127; 211) extend over part of the drum radius extend and limit the same number of chambers (129; 212) which are mutually in the Near the axial part (128; 213) of the drum are connected. 13. Device according to one of claims 10 to 12, characterized g e k It is noted that the liquid used has a greater density than Has water. 14. Device according to one of claims 10 to 13, characterized g e k It is noted that the planet carrier (204) with the drive shaft (202) or the output shaft (203) is positively connected. 15. Device according to one of claims 10 to 13, characterized g e k A n i t i n e t that the -planet carrier free opposite the input shaft and the output shaft is supported, and that each planetary gear assembly a first planetary gear (223Z), which is frictionally engaged with the drive shaft (221) connected planet pinion (2.22) is in engagement, and a second planetary gear (226), which is connected to a planetary pinion in a force-locking manner with the output shaft (228) (227) is in engagement, wherein the two planetary wheels with a clutch (225) are positively connected.