EP1982096A1

EP1982096A1 - Multiple ratio and individual actuation transmission device

Info

Publication number: EP1982096A1
Application number: EP07730869A
Authority: EP
Inventors: Roumen Antonov; Cyril Mougeot
Original assignee: Antonov Automotive Technologies BV; Antonov Automotive Europe BV
Current assignee: Antonov Automotive Technologies Ltd
Priority date: 2006-01-27
Filing date: 2007-01-26
Publication date: 2008-10-22
Also published as: WO2007085741A1; CN101405521A; US20100234168A1; FR2896844A1; JP2009524783A; FR2896844B1

Abstract

The invention concerns a multiple ratio transmission device with permanent meshing, in particular for making a gearbox capable of providing gear shifts without interrupting the power transmission, for example an automatic control or sequential control gearbox. Said device comprises three coaxial planetary trains using selective coupling means so that each provides local direct drive or at least one transmission ratio. According to the invention, said device comprises two coaxial planetary trains (TP1, TP2) belonging to two different power paths (8a and 8b) between an upstream rotary member and a downstream rotary member. Said device comprises two gear-type transfer elements (TR1, TR2) of different ratios, interposed between one of the rotary members and one of said planetary trains (TP1, TP2).

Description

"Multi-report transmission device and individual activation"

The present invention relates to a multi-gear transmission device permanently meshing, in particular to achieve a gearbox capable of achieving gear changes without breaking power transmission. The present invention is particularly geared to automatic or sequential control gearboxes. This device comprises coaxial planetary gear trains using selective coupling means to each provide a local direct grip or at least a transmission ratio.

In the field of transmission devices, multi-ratio devices are frequently used to drive a load from a mechanical power source. A typical case is that of a gearbox used between a heat engine and a load to be actuated, in particular the driving wheels of a motor vehicle.

In particular for producing automatic or sequential-controlled gearboxes, gearboxes made using planetary gears, for example epicyclic gear trains, are known.

EP 0 434 525 discloses a gearbox using a planetary double gear, epicyclic type or Ravigneaux type. This gearbox uses five coupling devices (two brakes and three clutches) to achieve six gears plus one reverse. Each ratio is obtained by jointly activating two of the five couplings.

This type of box, however, has certain disadvantages. Thus, the joint activation of these two couplings requires a synchronization of their order. In particular, this type of transmission can not conveniently "skip a report", ie move from one report to another that is not the ratio immediately below or immediately higher. These reasons also make it difficult to use these couplings to start the vehicle from the stop, so that this type of device is most often used in series with a clutch or upstream torque converter.

This type of transmission device currently equips a number of recent vehicles. WO 2005/050060 discloses a five-speed transmission device plus reverse. This device uses two planetary gears mounted along two parallel intermediate axes. On the input shaft, the same transfer pinion meshes with two driven transfer gears each located on one of the intermediate axes and each driving the input member of a planetary gear.

Each planetary gear comprises a clutch making a direct local engagement, and two planetary gear trains each providing a transmission ratio by blocking one of their elements with a respective brake. One of these planetary gear consists of two epicyclic gear trains each with two cascading satellites, and a ratio forms the reverse gear. Local direct taps are therefore made in number equal to that of the intermediate axes and an epicyclic gear train is required for each of the ratios except two, ie four epicyclic gear trains for six ratios in all (five in forward gear and one in gear). back). For each report other than the local direct sockets, the power is transmitted by an epicyclic gear train and two gear transfers.

The aim of the invention is to overcome the disadvantages of the prior art, in particular by improving the capacities and performances with respect to currently known transmissions.

The invention seeks in particular at least one of the following objectives:

- to obtain a greater number of reports, to obtain a better design flexibility in the choice of the reports to be made, to limit or reduce the size of the device, or to adapt it to its environment, to simplify and make reliable the selection and the control of the reports ,

- improve the reliability and flexibility of operation, - improve the efficiency of the transmission, or

- Limit or reduce the number of gears or teeth to achieve.

For this purpose, the invention proposes a multi-ratio transmission device comprising:

- a building; an upstream rotary member and a downstream rotary member;

- Two coaxial planetary gear belonging to two different power paths between the upstream rotary member and the downstream rotary member;

two gear transfers having different transfer ratios, interposed between one of the upstream and downstream rotary members on the one hand and a respective one of said planetary gears on the other hand; and

- Selective coupling means for selectively operating each planetary gear in local direct drive or at least a different transmission ratio. Thus, the invention makes it possible in particular to obtain a greater number of ratios by limiting the size and the complexity, since the direct catches of the two planetary gears provide different transmission ratios because these trains are functionally mounted in series. with gear transfers defining different transfer ratios.

The invention offers the possibility of making several local direct taps without having to provide. a corresponding number of intermediate shafts, and even, as will be seen below, no intermediate shaft at all, according to at least one embodiment. The realization is simplified, and the number of reports operating with relatively few meshes is increased. The number of gables and the number of trees are diminished. The weight, congestion and cost are therefore also diminished.

At the same time, there is a reasonable number of ratios which are realized by epicyclic gear trains operating with a local ratio different from 1: 1. These ratios are preferably the lower ratios of the transmission device (ie those for which the speed of the downstream member is lower for a given speed of the upstream member). This is very advantageous for the control, as will be seen later. According to an embodiment that can be described as longitudinal, the two planetary gear trains are coaxial with one of the rotational members - upstream or downstream, and the gear transfers are functionally mounted each between a respective planetary gear and the other said rotary members, downstream or upstream respectively. It is particularly in such an embodiment that the intermediate shafts are not necessary at all.

Preferably, the device comprises, between the upstream rotary member and the downstream rotary member, at least a third power path comprising a third planetary gear, capable of direct engagement and coaxial with the two aforementioned planetary gears, and is mounted operatively in series with a third gear transfer defining between the upstream rotary member and the downstream rotary member, when the third sun gear is in direct engagement, a transmission ratio different from each of those defined by the two transfers by gearing when their respective planetary gear is in direct contact.

The local direct connection of this third planetary gear thus provides a new global ratio different from the two others obtained by the direct catches of the two other planetary gears. According to another embodiment of the invention, which can be described as "transversal", the transmission device comprises a third planetary gear, capable of direct engagement and having an axis different from that of the two coaxial planetary geared above, and which is functionally mounted in series with a third gear transfer defining between the upstream rotational member and the downstream rotational member, when the third sun gear is in direct engagement, a transmission ratio different from each of those defined by the two gear transfers. mentioned above when their respective planetary gear is in direct contact.

Here again, the local direct catch of this third planetary gear thus provides a new global ratio different from the two others obtained by the direct catches of the two other planetary trains.

Moreover, this embodiment makes it possible to produce a particularly compact gearbox, in particular in length according to the direction of the axes. For example, a gearbox designed for a torque of 25.0Nm can be made with a longitudinal dimension less than 360mm, or even 350mm, against at least 380 to 390mm for a conventional gearbox as described in EP 0 434 525 B1 having an equivalent number of reports. In addition, the first two coaxial planetary gear can be mounted along a first intermediate axis, and the third planetary gear is mounted along a second intermediate axis.

According to another particularity of this embodiment, a first of the two transfers and the third transfer comprise a common gear on one of the upstream or downstream rotary members, meshing with two pinions each mounted on a respective one of the intermediate axes.

The two transfers associated with two coaxial planetary gear wheels may also comprise two integral toothed wheels of the same rotary member upstream or downstream.

More particularly, at least two power paths borrowing two different intermediate axes are connected firstly to one of the upstream or downstream rotary members by the aforementioned transfers and secondly to the other of the upstream or downstream rotary members by meshing according to different or identical local transmission ratios.

This feature allows in particular a good flexibility in the choice of reports during the design of the gearbox.

Other features and advantages of the invention will emerge from the detailed description of non-limiting embodiments, and the accompanying drawings in which:

FIG. 1 schematically illustrates an exemplary embodiment of the invention providing six ratios plus a reverse gear, in a transverse arrangement with two intermediate axes, on each

. of which the planetary trains are represented only in half-view; FIG. 2 is an end view diagrammatically illustrating the organization of the various axes in a transversal arrangement with two intermediate axes according to FIG. 1, and

- Figure 3 schematically illustrates an embodiment of the invention providing six reports plus a reverse, in a longitudinal arrangement where the planetary gear, shown in half-view, are coaxial with the input shaft.

In the embodiment of FIGS. 1 and 2, the transmission device according to the invention comprises an upstream rotary member 2 constituted by an input shaft, which is typically connected, in use, in such a way permanent to the power shaft of an automobile engine, in particular an internal combustion engine, without the interposition of a clutch or other variable coupling device such as a torque converter. In other words, the typical connection between the shaft 2 and the motor is such that any rotation of the motor shaft is necessarily accompanied by a rotation of the shaft 2, and the shaft 2 is not the same. shutdown only if the motor shaft is stationary.

The transmission device further comprises a downstream rotary member 4 constituting here an output shaft intended to be connected to the drive wheels of a motor vehicle by means of a differential, or which can itself contribute to a drive shaft. input of this differential. The connection between the shaft 4 and the drive wheels of the vehicle is typically such that at least one drive wheel rotates when the shaft 4 rotates. For the clarity of Figure 1, the output shaft 4 is shown both at the top and bottom and two intermediate axes A1 and A2 which will be described later are shown in the same plane that is to say the Figure 1, that the axes of the bodies 2 and 4. In reality, the trees 2 and 4 and the two intermediate axes A1 and A2 are at the four corners of a quadrilateral, as shown in Figure 2. At least when it operates according to its "lower" ratios, the device is used to reduce (ie reduce) the speed of rotation of the upstream member 2 in a lower speed of the downstream member 4, and therefore for increase the transmitted torque.

The transmission device connects the input shaft 2 to the output shaft 4 according to three power paths 8a, 8b and 8c symbolized by arrows which are functionally in parallel between the rotary members 2 and 4. Each path 8a, 8b or 8c passes through a respective one of three planetary trains TP1, TP2 and TP3.

In the transverse embodiment of FIGS. 1 and 2, the three planetary gears TP1, TP2 and TP3 are arranged along the intermediate axes A1 and A2 which are parallel to the axes of the upstream 2 and downstream 4 rotary members but which are not coaxial with them. Thus, the first two planetary gears TP1 and TP2 are mounted along a first intermediate axis A1, and the third planetary gear TP3 is arranged along a second intermediate axis A2.

Between the input shaft 2 and an input member E1, E2 or E3 of each planetary gear TPl, TP2 or TP3 respectively, there is a gear transfer TR1, TR2 or TR3 respectively. The pairs T21-T31, T22-T32 and T21-T33 have different transfer ratios.

A transfer transfer gear T21 integral with the upstream member 2, belonging to the transfers TR1 and TR3, meshes with two driven transfer gears T31 and T33, respectively arranged along the two intermediate axes A1 and A2 and integral with the inputs E1 and E3 respectively . So that the toothed wheels T31 and T33 have different diameters, the intermediate axes A1 and A2 are at different distances from the input shaft 2. On the other hand, a transfer pinion driving T22 integral with the upstream member 2 and belonging to the transfer TR2 meshes with a driven transfer pinion T32, disposed on the first intermediate axis Al and integral with the input E2.

The outputs S1, S2 and S3 of the three planetary gears are in driving connection with an intermediate shaft 31 or 32 itself connected to a ring CDiff integral with the downstream rotary member 4. In this example, the ring CDiff is the drive ring of the differential rotating case driving the driving wheels of the vehicle.

The outputs S1 and S2 of the first two planetary gears TP1 and TP2 are integral with a first 31 of the intermediate shafts which is integral in rotation with a first output pinion PA1 which meshes with the ring gear.

Differential CDiff. In this example, the outputs S1 and S2 are thus integral in rotation with each other. The output S3 of the third planetary gear TP3 is rotatably connected to the second intermediate shaft 32 which is provided with a second output pinion PA2, which also meshes with the ring CDiff of the differential 4. The intermediate shafts 31 and 32. extend along the intermediate axes A1 and A2 respectively. The transmission device further comprises a number of selective coupling devices BR, B1, B2, B3, C4, C5, C6 which will be described in detail below. The design is such that each transmission ratio is achieved by activation, that is to say setting in the coupled state, of only one of the selective coupling means, and deactivation, that is to say setting or keeping uncoupled from all other selective coupling means. The neutral state in which the rotary members 2 and 4 are independent of each other is obtained by deactivating all the selective coupling means. The various selective coupling means are here produced in the form of friction mechanisms by multi-disk clamping in an oil bath. These means are called "brakes" when their activation makes the coupling of a movable element with the frame 1 or any integral part thereof. These means are called "clutches" when their activation performs the mutual coupling of two rotating elements so that they rotate integrally with each other.

The first planetary gear TP1 comprises a first epicyclic gear train coaxial with the first intermediate axis A1. This epicyclic gear train comprises a pinion forming a central sun gear 101 meshing with one or more eccentric planet gear wheels 102. These satellites 102 are mounted idle on the branches of a planet carrier PSl, and mesh themselves with a ring 103 coaxial with the sun gear 101, with the carrier PSl and the axis Al.

Within this first epicyclic gear, the ring 103 is integral with the input El, and thus the driven transfer pinion T31. The ring gear 103 is thus in permanent drive connection with one of the upstream and downstream rotary members, in this case the input shaft 2.

The carrier planet PSl is integral with the output Sl and thus the first intermediate shaft 31. The carrier PSl is thus in permanent drive connection with the other of the upstream and downstream rotary members, that is to say downstream body 4 .

A clutch C5 selectively allows to couple and disconnect the ring 103 with the planet carrier PSl, and thus the input El with the output Sl. When the clutch C5 is in the coupling state, the first planetary gear TPl is in a local direct state between its input El and its output Sl.

The geometry of the first transfer TR1 and the first output gear PA1 then provides a transmission ratio, corresponding in this example to the fifth gear.

A brake B3, functionally mounted between the sun gear 101 and the frame 1, selectively allows to block and release the rotation of the sun gear 101 relative to the fixed frame 1. When the sun gear 101 is blocked, the rotation of the ring gear 103 drives the planet carrier PS1 according to a local gear ratio determined by the geometry of this epicyclic gear train.

When the brake B3 is blocked the geometry of the epicyclic train combines with those of the first transfer TR1 and the first output gear PA1 to give an overall transmission ratio, corresponding in this example to the third report.

The second planetary gear TP2 comprises a second epicyclic gear train coaxial with the first intermediate axis A1. This second epicyclic gear train comprises eccentric satellites 105 mounted idly on the branches of a planet carrier PS2, and which meshes with a central sun gear 104 and with a ring 106 coaxial with the sun gear 104, with the satellite carrier PS2 and with Tax Ai. The central sun gear 104 is integral in rotation with the input E2 of the planetary gear TP2, and is thus permanently connected to one of the upstream and downstream rotary members, in this case the upstream rotary member 2. The door -satellites PS2 is integral with the output S2 and therefore the first intermediate shaft 31. It is thus permanently connected to one of the upstream and downstream rotary members, in this case the output member 4.

A brake B2 functionally mounted between the ring gear 106 and the frame 1, selectively enables the rotation of the ring gear 106 to be locked and released relative to the fixed frame 1.

When the ring gear 106 is immobilized, the sun gear 104, driven by the input shaft 2, drives the planet carrier PS2 according to a local reduction depending on the geometry of the epicyclic gear train, the transfer TR2 and the meshing ratio between PA1. and CDiff. By activating the B2 brake thus creates a global transmission ratio, constituting in the present example the second report.

A clutch C6 mounted functionally between the input E2 and the output S2 of the second planetary gear TP2 selectively enables the train TP2 to be in direct local engagement when the clutch C6 is closed, or to leave the input E2 and the output S2. to rotate at different speeds, especially for operation in the second gear when the brake B2 is closed.

The local direct tap in the second train TP2 provides an overall ratio determined by the geometry of the second transfer TR2 and the first output gear PA1. In this example, this global report is the sixth report.

The third planetary gear TP3 comprises a third and a fourth epicyclic gear, coaxial with each other and with the second intermediate axis A2.

These two planetary gear trains have a common input E3 and a common output S3. The common input E3 is integral with the driven transfer wheel T33. The common output S3 is secured to the second intermediate shaft 32 and thus the output gear PA2. The third epicyclic gear includes one or more eccentric planet gears 108 mounted idly on the branches of a planet carrier

PS3 and meshing on the one hand with a central sun gear 107 and the other hand with a ^gear ring 109 coaxial with the sun gear 107 and with the intermediate shaft 32. The fourth planetary gear comprises one or more planetary gears 111 eccentric mounted idly on the branches of a satellite carrier

PS4 and meshing on the one hand with a central sun gear 110 and on the other hand with a ring gear 112 coaxial with the sun gear 110 and with the intermediate shaft 32. The central sun wheels 107 and 110 of these third and fourth planetary gear trains are both integral with the common input E3, and thus the driven transfer wheel T33. The ring gear 109 of the third epicyclic gear train and the planet carrier PS4 of the fourth epicyclic gear train are integral with the common output S3 and therefore of the second intermediate shaft 32.

The planet carrier PS3 of the third epicyclic gear 107 to 109 is free with respect to the common input E3 and the common output S3, and can be selectively immobilized with respect to the frame 1 by means of one of the coupling means selective, the brake BR, to perform a reverse.

When the PS3 planet carrier is immobilized, the sun gear 107 linked to the input E3 drives the crown 109 in the reverse direction by means of the satellites 108. The ring gear 109 then drives the common output S3 and therefore the second gear. intermediate shaft 32, thereby providing a reverse gear. -

The ring gear 112 of the fourth epicyclic gear train is free with respect to the common input E3 and the common output S3 and can be selectively locked and released in rotation relative to the frame 1 by means of one of the selective coupling means, the Brake Bl. When the ring gear 112 is immobilized, the sun gear 110, linked to the input E3, drives the planet carrier PS4 in a local reduction gear depending on the geometry of the epicyclic gear train.

By activating the brake B1 and releasing the other selective coupling means, a global transmission ratio is thus created which depends on the geometry of the epicyclic gear train, the third transfer TR3 and the second output gear PA2. This global report is the first report in this example.

In addition, the clutch C4, part of the selective coupling means, couples and uncouples _^ selectively input E3 and the output S3 relative to each other. When the clutch C4 is activated, the planetary gear TP3 operates in a local direct drive providing a transmission ratio, here the fourth gear, which depends on the ratio of the transfer TR3 and the gear ratio PA2-CDiff.

According to a variant not shown here, the output gears PA1 and PA2 of the intermediate shafts 31 and 32 may have different dimensions and contribute to determining different ratios. The longitudinal embodiment illustrated in Figure 3 will be described only for its differences with the previous.

The three planetary gear trains TP1, TP2 and TP3 are coaxial with the input shaft 2, and the gear transfers TR1, TR2 and TR3, whose transfer ratios are different, are functionally mounted each between the output S1, S2 or S3 of a respective planetary gear and the output shaft 4, the output shaft 4 is integral with three driven transfer gears T41, T42, T43 which mesh respectively with driving transfer gears T21 integral with the output Sl, T22 integral with the output S2, and T23 integral with the output S3. The driving gears T21, T22, T23 are coaxial with the input shaft 2. There is no longer any intermediate axis A1 and A2, nor intermediate shaft 31, 32.

The input shaft 2 is permanently integral in rotation with the inputs El, E2 and E3 of the three planetary gear trains TP1 ₇ TP2 and TP3. In the example shown in Figure 3, where the shaft 4 is connected to the driving wheels by its left end 4f, we find first, from left to right, the train TP3 producing the highest torque (in Nm) , then the TP2 train, the lowest ratio of which is the second report, then the TPl train whose smallest report is the third report. ^Thus', the shaft 4 should be of sufficient size for the maximum torque transmitted to the wheels in the region to the left of the transfer pinion T43. An intermediate value section is sufficient between the driven transfer gears T42 and T43, and a lower value section is sufficient for the driven transfer pins T41 and T42. But we can also consider, as shown in Figure 3, that the right end 4b is also connected to the driving wheels in place of the end 4f, or in addition to the end 4f.

The input member 2 is connected to the motor shaft (not shown) also on the left side of FIG. 3, thus on the same side as the connection of the output member 4 with the differential (not shown), and on the same side as the planetary trains TP2 and TP3 whose input members E2, E3 are integral with the central planetary wheels 104, and respectively 107 and 110. The architecture is thus considerably simplified, as illustrated in FIG. 3. Each global ratio obtained by direct input in a train TP1, TP2 or TP3 is equal to the corresponding transfer ratio TR1, TR2 or TR3. Each overall ratio obtained by a gear reduction operation in a train TP1, TP2 or TP3 is equal to the corresponding transfer ratio multiplied by the local gear ratio in the train of which a brake B1, B2, B3 or BR is activated.

In both embodiments described herein, the upstream and downstream rotating members are connected to each other by permanent meshing. Gear changes are not made by operating synchronizers or jaw clutches, but by clutches or brakes oil bath that allow smooth transitions between reports, without breaking the transmission of power. The control gear changes is simplified because no clutch is required between the vehicle engine and the input member 2. The output is not degraded by a torque converter.

As detailed above, each transmission ratio is achieved by closing a single selective coupling means of one of the three planetary gears TP1, TP2 and TP3 and opening or keeping in the open state the other means of transmission. selective coupling of the transmission device. This simplifies the control and allows a fairly simple joint regulation of the pressurization of the hydraulic chamber of the selective coupling means being closed, and the pressure decrease in the hydraulic chamber of the selective coupling means opening up. Such a regulation makes it possible to avoid jolts on the one hand, and to avoid or limit the rupture of the flow of energy through the transmission on the other hand.

It is possible to skip one or more reports, simply by releasing the current coupling and directly controlling the activation of the coupling corresponding to the chosen gear that is not contiguous to the previous gear.

More particularly, the selective coupling means B1, B2, B3, C4, C5, C6 and BR are of the progressive type and capable of ensuring the progressive adaptation between the speed of rotation of a vehicle engine and the speed of the vehicle. vehicle. Bl and BR brakes are able to serve as a means progressive starting of the vehicle from the stop, first speed forward or reverse respectively.

For this, we start from an initial situation where the input member 2 rotates with the vehicle engine and the output member 4 is at a standstill with the wheels of the vehicle, all the coupling means being deactivated .

To start the vehicle, the brake B1 or the brake BR is closed with the desired progressivity.

Typically, each of the selective coupling means comprises a multi-disk friction device oil bath. Each of the two elements to be coupled carries a series of disks. The disks of one element alternate with those of the other element. During activation, the disks of these two series are clamped against each other by a thrust piece, actuated by pressurizing a hydraulic chamber. In each planetary gear TPl, TP2 or TP3, the highest forward gear is obtained by activating a clutch and the ratio

^* the weakest is obtained by activation of a brake acting on the crown

(brake Bl or B2) or on the sun gear (brake B3). The braking torque exerted by these brakes is much lower (about 1.5 to 2.5 times lower) than the torque transmitted to the output Sl, S2 or S3 of the train during operation on the corresponding transmission ratio.

Preferably, reports obtained by local direct catches

C4, C5, C6 have mostly smaller gear ratios

(correspond to higher ratios) than the ratios obtained by selective coupling BR, B1, B2, B3 between the frame and a member of a planetary gear.

In the embodiments described here, only the higher ratios

(4 °, 5 ° and 6 °) use a coupling type clutch, ie the reports that produce the lowest torque on the output member 4. The lower ratios (MA, 1 °, 2 ° and 3 °) all use brake type couplings.

The embodiment is simplified and more robust, because the brakes are easier to control and cool more effectively because they have a stationary part linked to the frame. By limiting the braking requirements at the selective coupling means, it is also possible to limit the phenomena of hydraulic drag and the losses and overheating due to this drag. It is also possible to limit the hydraulic control pressure required, and therefore the power of the pump that generates it.

To activate a report of the transmission device, it is sufficient to control the activation of only one of the selective coupling means, while releasing the others. The breakeven is simply obtained by leaving them all free.

In the embodiments described here, the activation of the various brakes and clutches gives the following ratios, the values of which are given by way of example in the following table where, for each report, the value of the ratio is indicated in the column selective coupling means activated:

Compared to many known devices, the invention allows in particular a greater flexibility in the choice of staging ratios combined with a limited size of the device.

Compared with the teaching of the document WO 2005/050060, the invention makes it possible in particular to reduce the number of teeth to be produced and to improve the compactness and bulk of the transmission device.

In these different embodiments, adding an additional report as an additional local direct tap is of interest from the point of view of transmission efficiency. Indeed, within a power path, a local direct drive has a better performance than a gear drive.

Moreover, by limiting the number of meshing occurring in series in the different power paths, the invention makes it possible to limit the losses in the transmission. Compared to a conventional transmission such As described in EP O 434 525, there is for example a gain of about 5% to 6% efficiency, which affects the performance and consumption of the engine and the vehicle.

Of course, the invention is not limited to the examples that have just been described and many adjustments can be made to these examples without departing from the scope of the invention.

It would be possible to operate at least one of the epicyclic gear trains either in a local direct drive ratio or in an overdrive ratio, for example by connecting the input of the train to its carrier, while the sun gear and crown are associated one at the exit and the other at a brake.

In a transverse embodiment different from that of FIGS. 1 and 2, it would be possible to connect each of the outputs S1 and S2 of the trains TP1 and TP2 with the output member 4 by a respective gear transfer having a transfer ratio which is not the same for these two trains. The shaft 31 common to the two trains is then removed or replaced by a common intermediate shaft integral with the two inputs E1 and E2 of the two trains, and driven by a gear from the input member 2.

In a longitudinal embodiment different from that of FIG. 3, the outputs S1, S2 and S3 could be integral with the output shaft 4 while each of the inputs E1, E2 and E3 would be connected with the input member. 2 by a transfer having a different transfer ratio for each train TP1, TP2 and TP3. In this case, the trains are typically coaxial with the output member 4. It is quite clear that this device can also be used in the other direction, in overdrive, and that the names "upstream" and "downstream" can be exchanged in other configurations.

Claims

A multi-report transmission device, comprising:

- a frame (1);

an upstream rotary member (2) and a downstream rotary member (4);

two planetary gears (TP1, TP2) belonging to two different power paths (8a and 8b) between the upstream rotary member and the downstream rotary member;

two gear transfers (TR1, TR2) having different transfer ratios interposed between the one (2; 4) of the upstream and downstream rotary members and the respective one of said planetary gears (TP1, TP2); and

selective coupling means (Bl to B3, C4 to C6, BR) for selectively operating each planetary gear in local direct drive

(C5 respectively C6) or according to at least one transmission ratio (B3, respectively B2) different; characterized in that the two planetary gears (TP1, TP2) are coaxial.

2. Device according to claim 1, characterized in that the two transfers (TR1, TR2) associated with the two planetary gear trains (TP1, TP2) coaxial comprise two toothed wheels (T21, T22, T41, T42) integral with the same ( 2; 4) rotating member, upstream or downstream.

3. Device according to claim 1 or 2, characterized in that the two planetary gear trains (TP1, TP2) are coaxial with one (2) of the upstream or downstream rotary members, and the gear transfers (TR1, TR2) are functionally mounted each between one respective planetary gear and the other (4) of said rotary members. .

4. Device according to one of claims 1 to 3, characterized in that ^'it comprises, between the upstream rotary member (2) and the downstream rotary member (4), at least a third power path (8c ) comprising a third planetary gear (TP3), capable of direct local and coaxial engagement with the two coaxial planetary gear trains (TP1, TP2), the third planetary gear (TP3) being operatively connected in series with a third gear transfer (TR3) defining between the upstream rotary member (2) and the downstream rotary member ( 4), when the third sun gear is in a local direct drive state, a transmission ratio different from each of those defined by the two aforementioned gear transfers (TR1, TR2) when their respective sun gear is in a setting state local direct.

5. Transmission device according to claim 1 or 2, characterized in that it comprises a third planetary gear (TP3), capable of direct engagement and having an axis (A2) different from that (Al) of the two planetary gear (TPl , TP2), the third sun gear (TP3) being operatively connected in series with a third gear transfer (TR3) defining between the upstream rotational member (2) and the downstream rotational member (4), when the third planetary gear is in a local direct drive state, a gear ratio different from each of those defined by the two gear transfers (TR1, TR2) above when their respective planetary gear is in local direct drive state.

6. Device according to claim 5, characterized in that the first two planetary gear trains (TP1, TP2) coaxial are mounted along a first intermediate axis (Al), and the third planetary gear (TP3) is mounted along a second intermediate axis ( A2).

7. Device according to claim 6, characterized in that a first [TRl] of the two coaxial transfers and the third transfer (TR3) comprise a common gear (T21) on one (2) of the upstream or downstream rotating members , meshing with two pinions (T31, T33) each mounted along respective one of the intermediate axes (A1, A2).

8. Device according to claim 6 or 7, characterized in that at least two of the power paths (8a, 8c) each passing through a respective one of the two intermediate axes (Al, A2) are connected firstly to Mon (2) upstream or downstream rotary members by the aforementioned transfers and secondly to the other (4) upstream or downstream rotating members by meshing in different transmission ratios (PAl, PA2).

9. Device according to one of claims 1 to 8, characterized in that one (TP3) planetary gear comprises at least two epicyclic gear trains having a common input (E3) and a common output (S3), one (107 to 109) of these epicyclic gear trains having a planet carrier

(PS3) free with respect to the common input (E3) and the common output (S3) and able to be immobilized with respect to the frame by means of one of the selective coupling means (BR) for reversing, the other (110 to 112) of these epicyclic gear trains having a planet carrier (PS4) permanently connected to one (S3) of said common input and output, and capable of two forward gears, each by activation of the respective one (B1, C4) of the selective coupling means.

10. Device according to one of claims 1 to 9, characterized in that at least one of the planetary gear trains (TP1, TP2, TP3) comprises an epicyclic gear train comprising: a planet carrier (PS1, PS2, PS4) connected permanently, at least indirectly, to a first (4) of the upstream and downstream rotary members, and which can be selectively connected, at least indirectly, to the second (2) of said upstream and downstream rotary members by a (C5; C6 C4) selective coupling means, thus creating a local direct connection;

- a sun gear (101; 104; 110) and a ring gear (103; 106; 112) one of which (103; 104; 110) is permanently connected to said second (2) rotary member; and the other (101; 106; 112) can be selectively connected to the frame (1) by one (B3; B2; B1) selective coupling means.

11. Device according to one of claims 4 to 8, wherein the three planetary trains comprise: a first train (TP1) whose input (El) is connected to a ring gear (103) and the output (Sl) is connected to a planet carrier (PS1), this first train being capable of a local direct connection to make a fifth gear, and a reduction gear by locking a sun gear (101) to make a third gear;

a second train (TP2) whose input (E2) is connected to a sun gear (104) and the output (S2) is connected to a planet carrier (PS2), this second train being capable of a local direct connection to make a sixth gear, and a reduction by locking a ring (106) to make a second gear; and

a third train (TP3) whose input (E3) is connected to a sun gear (110) and the output (S3) is connected to a planet carrier (PS4), this third train being capable of a local direct connection to achieve a fourth ratio, and a reduction by locking a ring (112) to achieve a first report.

12. Device according to claim 11, characterized in that one of the planetary gear, preferably the third sun gear (TP3), further comprises an epicyclic gear whose sun gear (107) is connected to the input (E3). the ring gear (109) is connected to the output and the planet carrier (PS3) can be selectively blocked to make a reverse gear.

13. Device according to one of claims 1 to 12, characterized in that each transmission ratio is achieved by closing a single means of selective coupling of one of the planetary gear (TP1, TP2, TP3) and put or keeping the other selective coupling means of the transmission device in the open state.

14. Device according to one of claims 1 to 12, characterized in that the selective coupling means (Bl to B3, C4 to C6, BR) are of the progressive type and capable of ensuring the gradual adaptation between the speed rotation of a vehicle engine and the speed of the vehicle, in particular for the movement of the vehicle from the stop by at least one of the selective coupling means.

15. Device according to one of claims 1 to 14, characterized in that the planetary gear (TP1 to TP3) and the transfers (TR1 to TR3) are in permanent meshing.

16. Device according to one of claims 1 to 15, characterized in that at least a first ratio, obtained by activation of a first selective coupling means (B2) between the frame (1) and an element (106). ) of a planetary gear (TP2), transmits a larger torque than at least a second ratio obtained by activation of a second selective coupling means (C6) making a local direct connection within said planetary gear.

17. Device according to one of claims 1 to 16, characterized in that the shortest of its reports obtained by local direct catches (C4, C5, C6) is longer than the longest reports obtained by selective coupling ( BR, B1, B2, B3) between the frame (1) and a member of a planetary gear.