FR2885666A1 - Gearbox system with epicycloidal gears, for use in automobile transmission systems, has extra clutch for obtaining at least three additional gears - Google Patents

Abstract

A gearbox system with epicycloidal gears (EG's), having coaxial input and output elements (2, 3), two EG's (4, 5), a multiplication EG (6), a division EG gear (7) and five clutches for obtaining multiple transmission ratios, also has a multiplication EG (7), a division EG (7) and an extra clutch for obtaining at least three additional gears. A gearbox system with epicycloidal gears (EG's), having coaxial input and output elements (2, 3), two EG's (4, 5) and five clutches for obtaining multiple transmission ratios, also has a multiplication EG (7), a division EG (7) and an extra clutch for obtaining at least three additional gears. Each clutch acts between an element of an EG and an earth, inlet or outlet element or another element of the EG's. Each EG comprises a sun wheel, satellite pinions (supported on a satellite holder) and a crown wheel.

Description

Epicyc gearbox system: loïdaux

  The present invention relates to the field of transmissions, particularly for motor vehicles, consisting of planetary gear controlled by friction elements such as clutches and brakes to obtain a plurality of staggered transmission ratios. Conventionally, such transmissions are associated with a starting member such as a hydraulic torque converter or a coupler, with or without a bridging clutch.

  Such four-speed transmissions employing two planetary gear trains, five friction elements and a hydraulic torque converter are known.

  The document FR-A-2 656 055 describes a multi-speed automatic transmission comprising a first power path according to a first fixed speed ratio comprising a first and a second clutch, and a second power path following a second fixed speed ratio greater than first and same direction and having a third clutch, and secondly a double planetary gear concentric to the output shaft having a first element connected to the input shaft by the first power path by means of the first clutch a second element secured to the output shaft, a third element connected to the output shaft by the second power path by means of the third clutch and immobilized by means of a first brake, and a fourth element connected to the input shaft by the first power path by means of the second clutch and immobilized by means of a second brake. Such an arrangement can make it possible to obtain forward speeds and a rear speed while being relatively complex.

  The present invention aims to obtain a gearbox with planetary gear trains of relatively simple and economic structure to obtain a high number of speeds, for example seven, from a reasonable number of couplers, for example six.

  The epicyclic gearbox system comprises an input element, an output element coaxial with the input element, two planetary gear trains, five couplers for obtaining a plurality of transmission ratios, and, in a hanger, a epicyclic speed multiplier train, an epicyclic speed divider train, and an additional coupler for obtaining at least three additional speeds, each coupler acting between on the one hand an element of one of said epicyclic gear trains and on the other hand the earth element , the input element, the output element or another element of said epicyclic gear trains, each epicyclic gear train comprising a sun gear, planet gears supported by a planet carrier, and a ring gear. The addition of a speed multiplier train and a gear divider train makes it possible to obtain fifth, sixth and seventh speeds in addition to the input and output trains supplying the first four speeds. A coupler can be formed by a clutch or a brake.

  Advantageously, the system comprises a single power input from which a limitation of the friction losses.

  In one embodiment, the sun gear of the input gear is disengageably connected to the divider.

  In another embodiment, the sun gear of the input gear is disengageably connected to the ground.

  In one embodiment, the solar gear of the output gear is disengageably connected to the ground.

  In one embodiment, the solar gear of the output gear is disengageably connected to the multiplier gear.

  In one embodiment, the multi-axis train comprises planet gears permanently connected to the input, and a ring gear disengageably connected to the output gear.

  In one embodiment, the solar gear of the multiplier train is permanently connected to the earth.

  In one embodiment, the solar gear of the divider train is permanently connected to the earth.

  In one embodiment, the planet gears of the divider train are permanently connected to the input.

  In one embodiment, the planet gears of the divider train are arranged in two concentric circles, a pinion of one of the circles meshing with a pinion of the other circle.

  In one embodiment, the ring gear of the divider train is releasably connected to the input gear.

  In one embodiment, the ring of the multiplier train is disengageably connected to the output gear.

  In one embodiment, the ring gear of the input gear is permanently connected to the output.

  In one embodiment, the planet gears of the input gear are disengageably connected to the divider train.

  In another embodiment, the pinions of the output gear are permanently connected to the output.

  In one embodiment, the crown of the output gear is disengageably connected to the ground.

  In one embodiment, the ring gear of the output gear is permanently connected to the input gear.

  In one embodiment, the ring gear of the output gear is disengageably connected to the divider train.

  In another embodiment, the glue crown output gear is permanently connected to the output.

  In one embodiment, the planet gears of the output gear are arranged in two concentric circles, a pinion of the small diameter circle meshing with a pinion of the large diameter circle.

  In one embodiment, the small diameter circle sprockets have fewer teeth than the number of teeth of the large diameter circle sprockets.

  In one embodiment, the planet gears of the input gear are coaxial, of the same number of teeth and integral in rotation with planet gears of the output gear.

  Advantageously, the system is equipped with a damper associated with the input, said damper being disposed directly between said inlet and the output of a heat engine. The output of the engine can be formed by a shaft driven directly by a crankshaft of the engine. It is thus possible to dispense with the presence of a torque converter of the hydraulic type of mass, of size and of high cost and which also generates significant losses of energy by heating. One or more of the couplers may be dimensioned such that they are able to ensure the movement of the vehicle from the stop and this repeatedly.

  The system can consist only of four trains associated with six couplers.

  The present invention will be better understood by studying the detailed description of some embodiments taken by way of non-limiting examples and illustrated by the accompanying drawings, in which: FIG. 1 is a schematic view of a gearbox with epicyclic gear trains according to a first embodiment; FIG. 2 represents the selection grid of the couplers; FIG. 3 is a diagram showing the staggering of the speeds; - Figures 4 to 6 are schematic views of an epicyclic gearbox according to other embodiments.

  As can be seen in FIG. 1, the transmission 1 comprises, in a casing, not shown, an input shaft 2, an output shaft 3 parallel to the input shaft 2, an input gear 4, an output train 5, a multiplier train 6, and a divider train 7. The input shaft 2 is connected to a heat engine 8 by a torque damper 9.

  The input gear 4 comprises a sun gear 10, a planet carrier 11 provided with circumferentially regularly spaced planet gears 12 and a ring gear 13. The ring gear 13 is connected to the output shaft 3. The output gear 5 comprises a sun gear 14, a porteatellites 15 carrying a plurality of planet gears 16 and a ring 17. The planet carrier 15 is connected to the output shaft 3. In other words, the crown 13 of the input train 4 and the doorsatellites 15 of the output gear 5 are continuously connected with the output shaft 3. The ring 17 of the gear train 5 is permanently connected to the planet carrier 1 1 of the gear train. entry 4.

  The multiplier train 6 comprises a sun gear 18, a porteatellites 19 carrying a plurality of planet gears 20 and a ring gear 21. The planet carrier 19 is permanently rotatably connected to the input shaft 2. The gearing solar 18 is permanently connected to the ground, in other words immobilized.

  The divider train 7 comprises a sun gear 22, a double planet carrier 23 carrying two series of planet gears, an inner series 24 and an outer series 25, and a ring 26. The inner planet gears 24 mesh with the gear The outer planet gears 25 meshes with the ring gear 26 and with the inner planet gears 24. In other words, the planet gears are arranged in two concentric circles of different diameters. The planet carrier 23 is permanently rotatably connected to the input shaft 2. The sun gear 22 is permanently connected to the earth, in other words immobilized. The number of teeth of the inner planet gears 24 may be different from the number of teeth of the outer planet gears 25.

  The transmission further comprises six ccuplers called brakes when they act between an element of the planetary gear trains and the ground, that is to say a fixed point such as the case of the gearbox and called clutches when they act between an element of the epicyclic gear trains and the input shaft, the output shaft or another element of said planetary gear trains.

  The clutch 27 is disposed between the ring 26 of the divider train 7 and the sun gear 10 of the input gear 4. The clutch 28 is disposed between the ring 26 of the divider train 7 and the planet carrier 11 of the landing gear. input 4, said planet carrier 11 being permanently connected to the ring 17 of the output gear 5. The brake 29 is disposed between the ring 10 and the earth and allows to lock the ring 10 temporarily. The brake 30 is disposed between the ring 17 of the output gear 5 and the earth and makes it possible to lock the ring 17 and the porteatellites 11 of the input gear 4 temporarily. The brake 31 is disposed between the sun gear 14 of the output gear 5 and the earth and makes it possible to lock the sun gear 14 temporarily. The clutch 32 is disposed between the sun gear 14 of the output gear 5 and the ring gear 21 of the multiplier train 6 and makes it possible to drive said sun gear 14 at a high rotational speed temporarily. For reasons of construction, the clutches 27 and 29, on the one hand, and the crown 26 of the divider train 7, on the other hand, are connected by a central intermediate shaft 33 disposed inside the input trains 4 and output 5 and in the extension of the input shaft 2.The ring 17 of the output gear 5 can either be driven at the same speed as the intermediate shaft 33, either left free or immobilized.

  Transmission works the same way. The intermediate shaft 33 is driven by the divider train 7 at a speed lower than the input speed. When the clutch 27 and the brake 30 are engaged, the sun gear 10 of the input gear 4 is driven at the same speed as the intermediate shaft 33. The planet carrier 11 of the input gear 4 , and the ring 17 of the output gear 5 are immobilized by said brake 30. As a result, the planet gears 12 of the input gear 4 are driven in a direction of rotation opposite to that of the intermediate shaft 33. 12 of the input gear ring 4, meshing with the planet gears 11, rotates in the same direction of rotation as said planet gears 11. The output shaft 3 integral in rotation with the crown 12 is thus driven in one direction rotation opposite that of the intermediate shaft 33, from which a reverse gear.

  To obtain the first forward speed ratio, the clutch 27 and the brake 31 are engaged. The sun gear 14 of the output gear 5 is immobilized. The output shaft is driven by the planet carrier 15 of the output gear 5 whose planet gears 16 meshing with the ring 17 and with the sun gear 14. input train 4 is driven at the same speed as the intermediate shaft 33. The permanent connection between the planet carrier 11 of the input gear 4 and the ring 17 of the output gear 5 transmits an internal torque and ensures a reduction . This results in a sharp overall reduction in l. speed.

  To obtain the second gear, the clutch 28 and the brake 31 are engaged. As before, the sun gear 14 of the output gear 5 is immobilized. The solar gear 10 of the input gear 4 is free. The ring 17 of the output gear 5 and the planet carrier 11 of the input gear 4 are coupled to the intermediate shaft 33 in rotation. The ring 17 of the output gear 5 intera, it with the porteatellites 15 integral with the output shaft 3 from which an output speed slightly higher than the previous at equal entry speed. The torque passes through the divider train 7 and the output gear 5.

  To obtain the third gear, clutches 27 and 28 are engaged. The sun gear 10 and the planet carrier 11 of the input gear 4 are driven at the same speed as the intermediate shaft 33. The ring 13 of the input gear 4 e-: the output shaft 3 therefore rotate. at the same speed. The torque passes through the divider train 7 and the input train 4. The gear ratio depends on the reduction offered by the divider train 7.

  To obtain the fourth speed, the clutch 28 and the brake 29 are engaged. The solar gear 10 of the input gear 4 is immobilized. The planet carrier 11 of the input gear 4 is coupled to the intermediate shaft 33. The ring 13 of the input gear 4 is driven at a higher speed than in the previous speed because of the reaction of the planet gears 12 on the solar gear 10 still. The torque passes through the divider train 7 and the input train 4. The gear ratio depends on the reductions offered by the divider train 7 and the input gear 4.

  For the fifth, sixth and seventh speeds: the clutch 32 is actuated. The brakes 30 and 31 are kept inactive: ifs. The sun gear 14 of the output gear 5 is coupled to the ring 21 of the multiplier train 6. The ring 21 of the multiplier train 6 is driven at a high speed by the cooperation with the planet gears 20 of the planet carrier 19 meshing with each other. same with the immobilized solar gear 18. and driven at a high speed.

  In fifth gear, the clutch 28 is also engaged. The ring 17 of the output gear 5 is driven by the intermediate shaft 33 via said clutch 23. The planet carrier 15 of the output gear 5 is driven at an intermediate speed between the speed of the sun gear 14 which is equal to the speed of the crown 21 and the speed of the crown 17 of the output gear 5. The torque passes through the divider train 7, the multiplier train 6 and the input gear 4. The gear ratio depends on the reductions offered by these three trains.

  In sixth gear, the brake 29 is actuated and blocks the sun gear 10 of the input gear 4, while the sun gear 14 of the output gear 5 rotates at a high speed. The ring 17 of the output gear 5 and the planet carrier 11 of the input gear 4 integral in rotation are driven by reaction and transmit an internal torque. By reaction of the planet gears 12 of the input gear 4 on the sun gear 10, the ring gear 13 of the input gear 4 is driven at a speed greater than the preceding speed, the output shaft 3 being rotatably secured. of the crown 13 of the input train 4. The torque passes through the multiplier train 6, the input train 4 and the output train 5. The gear ratio depends on the reductions offered by these three trains.

  To obtain the seventh speed, the clutch 27 is engaged. As a result, the sun gear 10 of the input trunk 4 is driven by the intermediate shaft 33, resulting in an increase in the speed of the planet carrier 11 and the ring gear 17 of the output gear 5. and an increase in the speed of the planet carrier 15 and the output shaft 3. The torque passes through the four trains 4 and the speed ratio depends on the reductions offered by said four trains.

  This gives seven suitably stepped forward gears as shown in the diagram of Figure 3 and a reverse speed whose transmission ratio is of the same order of magnitude as the first speed but of reversed sign.

  The embodiment illustrated in FIG. 4 offers the same gearing and the same gearshift. The transmission differs from that illustrated in FIG. 1 in that the input 4 and output 5 trains form a Ravigneaux train. In other words, the input train 4 is a simple train without a crown. the output gear 5 comprises a ring gear 17 connected to the output shaft 3, a sun gear 14 disengageably connected to earth by the brake 31 or to the ring gear 21 of the multiplier gear 6, and a double gear carrier. 34 bearing two sets of satellite gears, an inner series 35 and an outer series 36. The inner 3: 3 satellite gears mesh with the sun gear 14 and with the outer planet gears 36. The outer planet gears 36 meshing with the crown 17 and with the inner planet gears 35. In other words, the planet gears are arranged in two concentric circles of different diameters. The planet carrier 34 is permanently connected to the planet carrier 11 of the input gear 4. The planet gears 12 of the input gear 4 are permanently connected to the outer planet gears 36. provision is equivalent to providing the input gear 4 with a ring permanently connected to the ring 17 of the output gear 5 and to the output shaft 3.

  The clutch 28 temporarily couples, on the one hand, the intermediate shaft 33, and on the other hand, the planet carrier 11 of the input gear 4 and the double planet carrier 34. The brake 30 enables to temporarily couple to the ground, the planet carrier 11 of trair. 4 and the double planet carrier 34. The other elements of the transmission are similar to those of FIG.

  The transmission works as follows. When engaging the clutch 27 and the brake 30, the sun gear 10 of the input gear 4 is driven at the same speed as the intermediate shaft 33. The planet carrier 11 of the input gear 4 is immobilized by said brake 30. As a result, the planet gears 12 of the input gear 4 are driven in a direction of rotation opposite that of the intermediate shaft 33. The ring 17 of the output gear 5, meshing with the planet gears 36 connected to the planet gears 12, rotate in the same direction of rotation as said planet gears 12. The output shaft 3 integral in rotation with the ring gear 17 is thus driven in a direction of rotation opposite to that of the intermediate shaft 33, from which a reverse gear.

  To obtain the first forward speed ratio, the clutch 27 and the brake 31 are engaged. The sun gear 14 of the output gear 5 is immobilized. The solar gear 10 of the input gear 4 is driven at the same speed as the intermediate gear 33. The output shaft 3 and the intermediate shaft 33 rotate in the same direction. The planet carrier 34 of the output gear 5 and the planet carrier 11 of the input gear 4 are rotated by the sun gear 10 and by the reaction of the inner planet gears 35 on the immobilized sun gear 14, where the rotation of the ring 17 connected to the output shaft 3. This results in a strong overall reduction in speed.

  To obtain the second gear, the clutch 28 and the brake 31 are engaged. As before, the sun gear 14 of the output gear 5 is immobilized. The solar gear 10 of the input gear 4 is free. The planet carrier 11 of the input gear 4 and the double planet carrier 34 of the output gear 5 are coupled to the intermediate shaft 33 in rotation. The rotation of the outer gears 36 is ensured by the reaction of the inner gears 35 on the sun gear 14. The torque passes through the divider train 7 and the output gear 5. The gear ratio depends on the reduction offered by the divider train 7 and the output train 5.

  To obtain the third gear, clutches 27 and 28 are engaged. The sun gear 10, planet carriers 11 and 34 are driven at the same speed as the intermediate shaft 33. The ring gear 17 and the output shaft 3 therefore rotate at the same speed as the intermediate shaft 33. The torque passes through the divider train 7, the output gear 5 and the input gear 4. The gear ratio depends on the reduction offered by the divider train 7.

  To obtain the fourth speed, the clutch 28 and the brake 29 are engaged. The solar gear 10 of the input gear 4 is immobilized. The planet carrier 34 of the output gear 5 is coupled to the intermediate shaft 33. The ring 17 of the output gear 5 is driven at a higher speed than in the previous speed because of the reaction of the planet gears 12 on the planet. solar gear 10 still. The torque passes through the divider train 7, the output gear 5 and the input gear 4. The gear ratio depends on the reductions offered by the divider train 7, the output gear 5 and the input gear 4.

  For the fifth, sixth and seventh speeds, the clutch 32 is actuated in engagement with the same effect as in the made of previous embodiment.

  In fifth gear, the clutch 28 is also engaged. The planet carrier 34 of the output gear 5 is coupled to the intermediate shaft 33. The ring 17 of the output gear 5 is driven at a higher speed than in the previous speed because of the reaction of the outer planet gears 36 on the planet. the inner planet gears 35 driven by the sun gear 14 of the output gear 5 whose speed is equal to that of the ring gear 19 of the multiplier train 6. The torque passes through the divider train 7, the multiplier train 6 and the train of exit 5. The gear ratio depends on the discounts offered by these three trains.

  In sixth gear, the brake 29 is actuated and blocks the sun gear 10 of the input gear 4, while the sun gear 14 of the output gear 5 rotates at a high speed. The inner satellite gears 35 are driven by the sun gear 14, and drive outer satellite onions 36. The planet carriers 11 and 34 rotate freely. By reaction of the planet gears 12 of the input gear 4 on the sun gear 10, the ring 17 of the output gear 5 and the shaft; output 3 are driven at a higher speed than the previous speed. The torque passes through the multiplier train 6, the input train 4 and the output train 5. The gear ratio depends on the reductions offered by these three trains.

  To obtain the seventh speed, the clutch 27 is engaged. As a result, the sun gear 10 of the input gear 4 is driven by the intermediate shaft 33, hence an increase in the speed of the planet carriers 11 and 34 and the crown 17 of the output gear 5 and The torque passes through the four trains and the gear ratio depends on the reductions offered by said four trains.

  The embodiment illustrated in FIG. 1 provides the same gear stagger and the same gear grid. The transmission of the input 4 and output 5 trains form a Ravigneaux train identical to that illustrated in FIG. 4. The multiplier 6 and divider 7 trains form a stepped double train. More specifically, the divider train 7 comprises a sun gear 22 permanently connected to the input shaft 2, a fixed ring gear 26 and a single planet carrier 23 provided with a single row of planet gears 24 meshing with the sun gear. 22 and the ring 26. The multiplier gear 6 without crown, comprises a sun gear 18 connected to the clutch 32 and can thus be coupled to the sun gear 14 of the output gear 5 or left free, and a planet carrier 19 permanently connected to the intermediate shaft 33 and provided with a row of planet gears 20 meshing with the sun gear 18. The planet carriers 19 and 23 are permanently connected in rotation. The planet gears 20 and 24 are permanently connected in rotation, the planet gears 20 of the multiplier train 6 are of much greater diameter than the planet gears 24 of the divider train 7 for driving the sun gear 18 at a speed greater than that of the input shaft 2. Thus, the gear multiplier 6 and divider 7 provide a slow speed on the intermediate shaft 33 and a fast speed on the sun gear 18.

  The transmission works as follows. The intermediate shaft 33 is permanently driven at a speed lower than that of the input shaft 2, via the divider train 7. The operation is similar to that of the embodiment of FIG. set of speeds.

  The embodiment illustrated in the figure, has the same gearing and the same gearshift. The input 4 and output 5 trains are identical to those shown in FIG. 4. The multiplier 6 and divider 7 trains are identical to those illustrated in FIG. 5. The operation of the transmission is similar.

  In one embodiment, a hydraulic converter is disposed between the engine and the transmission.

  In the embodiment shown, a rotary damper 9 is arranged directly between the motor 8 and the transmission 1 which eliminates the disadvantages of mass, size, cost and low efficiency of a hydraulic converter. Dan: this case, the setting in motion of the vehicle while passing in reverse, or in first speed is done thanks to the brake 30 for the reverse to the brake 31 for the forward movement. The brakes 30 and 31 are then dimensioned more strongly than the other couplers to be able to ensure the moving of the vehicle from the stop without wear too fast. Alternatively, the movement of the vehicle in forward or reverse can be effected by the use of the clutch 27 which is actuated engaged both in reverse and first forward speed. Thus, we obtain a gearbox with compact planetary gear trains and

  economic while allowing to obtain at least seven speeds by the implementation of six couplers actuated in two by two. For economic reasons, it is possible to choose crowns, sun gears and pinions-si.tellites having the same number of teeth between the three trains. On the contrary, if it is desired to favor a chosen and regular staging of the different speeds, provision will be made to use different numbers of teeth.

Claims (31)

  An epicyclic gearbox system comprising an input element, an output element coaxial with the input element, two planetary gear trains (4, 5), and five clutches for obtaining a plurality of gear ratios. transmission, characterized in that it further comprises a planetary speed multiplier epicyclic gear train (6), a speed divider epicyclic gear train (7), and an additional clutch to obtain at least three additional speeds, each clutch acting between on the one hand an element of one of said epicyclic gear trains and, on the other hand, the earth element, the input element, the output element or another element of said epicyclic gear trains, each epicyclic gear train comprising a sun gear, satellite gears supported by a planet carrier, and a crown.   2-System according to claim 1, characterized in that it comprises a single power input.   3-System according to claim 1 or 2, characterized in that the sun gear of the input gear (4) is disengageably connected to the divider (7).   4-system according to any one of the preceding claims, characterized in that the sun gear of the input gear (4) is disengageably connected to the ground.   5-System according to any one of the preceding claims, characterized in that the gear so surface of the output gear (5) is disengageably connected to the ground.   6-System according to any one of the preceding claims, characterized in that the gear so. area of the output gear (5) is disengageably connected to the multiplier gear (6).   7-System according to any one of the preceding claims, characterized in that the multiplier train (6) comprises a porteatellites permanently connected to the input, and a ring releasably connected to the output gear (: 5) .   8-System according to any one of the preceding claims, characterized in that the solar gear of the multiplier train (6) is permanently connected to the earth.   9-System according to any one of the preceding claims, characterized in that the solar gear of the divider train (7) is permanently connected to the earth.   10-System according to any one of the preceding claims, characterized in that the planet carrier of the divider train (7) is permanently connected to the input.   11-System according to any one of the preceding claims, characterized in that the planet gears of the divider train (7) are arranged in two ncentric circles cc, a gear of one of the circles meshing with a gear of the other circle.   12-System according to any one of the preceding claims, characterized in that the ring gear of the divider (7) is connected disengageably to the input gear.   13-System according to any one of the preceding claims, characterized in that the neck of the multiplier train (6) is disengageably connected to the output gear (5).   14-System according to any one of the preceding claims, characterized in that the ring -train input (4) is permanently connected to the output.   15-System according to any one of the preceding claims, characterized in that the planet carrier of the input gear (4) is disengageably connected to the divider (7).   16-System according to any one of claims 1 to 6, characterized in that the planet carrier of the output gear (5) is permanently connected to the output.   17-System according to any one of claims 1 to 6, characterized in that the ring of the output gear (5) is disengageably connected to the ground.   18-System according to any one of claims 1 to 6, characterized in that the ring gear output (5) is permanently connected to the input gear (4).   19-System according to any one of claims 1 to 6, characterized in that the ring gear of the output (5) is connected disengageably to the divider (7).   20-System according to any one of claims 1 to 13, characterized in that the ring of the output gear (5) is permanently connected to the output.   21-System according to any one of claims 1 to 13 and 20, characterized in that the planet gears of the output gear (5) are arranged in two concentric circles, a pinion of the small diameter circle meshing with a pinion of the circle of large diameter.   22-System according to claim 21, characterized in that the pinion of the small diameter circle have a number of teeth less than the number of teeth of the large diameter circle pinions.   23. System according to any one of the claims 1 to 13 and 20 to 22, characterized in that the planet gears of the input gear (4) are coaxial, of the same number of teeth and integral in rotation. with satellite gears of the output gear (5).   24-System according to any one of claims 1 to 13 and 20 to 23, characterized in that the input gear (4; is devoid of crown.   25-System according to any one of claims 1 to 6, characterized in that the multiplier train (6) is devoid of crown.   26-System according to any one of claims 1 to 6 and 25, characterized in that the sun gear of the multiplier train (6) is disengageably connected to the output gear (5).   27-System according to any one of claims 1 to 6, characterized in that the solar gear of the divider train (7) is permanently connected to the input.   28-System according to any one of claims 1 to 6, characterized in that the planet gears of the divider train (7) are permanently connected to the multiplier train (6).   29-System according to claim 28, characterized in that the planet pinions of the divider (7) and the planet pinions of the multiplier train (6) are rotationally integral, coaxial and have different numbers of teeth.   30-System according to any one of claims 1 to 6, characterized in that the ring gear of the divider (7) is permanently connected to the ground.   31-System according to any one of the preceding claims, characterized in that the shafts of the input (4), output (5), divider (7) and multiplier (6) are coaxial.