Multiple-ratio individual-activation transmission device

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 (TP 1, TP 2 ) belonging to two different power paths ( 8 a and 8 b ) between an upstream rotary member and a downstream rotary member. Said device comprises two gear-type transfer elements (TR 1, TR 2 ) of different ratios, interposed between one of the rotary members and one of said planetary trains (TP 1, TP 2 ).

1 . A multiple-ratio transmission device, comprising:
 a frame ( 1 );   an upstream rotary element ( 2 ) and a downstream rotary element ( 4 );   two planetary gearsets (TP 1 , TP 2 ) belonging to two different power paths ( 8   a  and  8   b ) between the upstream rotary element and the downstream rotary element;   two meshing transfers (TR 1 , TR 2 ) having different transfer ratios, located between one ( 2 ;  4 ) of the upstream and downstream rotary elements and the respective one of said planetary gearsets (TP 1 , TP 2 ); and   selective-coupling means (B 1  to B 3 , C 4  to C 6 , BR) to make each planetary gearset operate selectively in direct local drive (C 5  respectively C 6 ) or according to at least one different transmission ratio (B 3 , respectively B 2 );   characterized in that the two planetary gearsets (TP 1 , TP 2 ) are coaxial.   
     
     
         2 . A device according to  claim 1 , characterized in that the two transfers (TR 1 , TR 2 ) linked with the two coaxial planetary gearsets (TP 1 , TP 2 ) comprise two toothed wheels (T 21 , T 22 ; T 41 , T 42 ) integral with a same ( 2 ; 4 ) upstream or downstream rotary element. 
     
     
         3 . A device according to  claim 1 , characterized in that the two planetary gearsets (TP 1 , TP 2 ) are coaxial with one ( 2 ) of the upstream or downstream rotary elements, and the meshing transfers (TR 1 , TR 2 ) are each operatively mounted between the respective planetary gearset and the other ( 4 ) of said rotary elements. 
     
     
         4 . A device according to  claim 1 , characterized by comprising, between the upstream rotary element ( 2 ) and the downstream rotary element ( 4 ), at least one third power path ( 8   c ) comprising a third planetary gearset (TP 3 ), capable of a direct local drive and coaxial with the two coaxial planetary gearsets (TP 1 , TP 2 ), the third planetary gearset (TP 3 ) being mounted operatively in series with a third meshing transfer (TR 3 ) defining, between the upstream rotary element ( 2 ) and the downstream rotary element ( 4 ), when the third planetary gearset is in a state of direct local drive, a transmission ratio different from each of those defined by the two above-mentioned meshing transfers (TR 1 , TR 2 ) when their respective planetary gearset is in a state of direct local drive. 
     
     
         5 . A transmission device according to  claim 1 , characterized by comprising a third planetary gearset (TP 3 ), capable of direct drive and having an axis (A 2 ) different from that (A 1 ) of the two above-mentioned coaxial planetary gearsets (TP 1 , TP 2 ), the third planetary gearset (TP 3 ) being mounted operatively in series with a third meshing transfer (TR 3 ) defining, between the upstream rotary element ( 2 ) and the downstream rotary element ( 4 ), when the third planetary gearset is in a state of direct local drive, a transmission ratio different from each of those defined by the two above-mentioned meshing transfers (TR 1 , TR 2 ) when their respective planetary gearset is in a state of direct local drive. 
     
     
         6 . A device according to  claim 5 , characterized in that the two first coaxial planetary gearsets (TP 1 , TP 2 ) are mounted along a first intermediate axis (A 1 ), and the third planetary gearset (TP 3 ) is mounted along a second intermediate axis (A 2 ). 
     
     
         7 . A device according to  claim 6 , characterized in that a first (TR 1 ) of the two coaxial transfers and the third transfer (TR 3 ) comprise a common toothed wheel (T 21 ) on one ( 2 ) of the upstream or downstream rotary elements meshing with two pinions (T 31 , T 33 ) each mounted about a respective one of the intermediate axes (A 1 , A 2 ). 
     
     
         8 . A device according to  claim 6 , characterized in that at least two of the power paths ( 8   a,    8   c ) each passing through the respective one of the two layshafts (A 1 , A 2 ) are connected on the one hand to one ( 2 ) of the upstream or downstream rotary elements by the above-mentioned transfers and on the other hand to the other ( 4 ) of the upstream or downstream rotary elements by meshing according to different transmission ratios (PA 1 , PA 2 ). 
     
     
         9 . A device according to  claim 1 , characterized in that one (TP 3 ) of the planetary gearsets comprises at least two epicyclic gearsets having a common input (E 3 ) and a common output (S 3 ),
 one ( 107  to  109 ) of these epicyclic gearsets having a planet carrier (PS 3 ) which is free in relation to both the common input (E 3 ) and the common output (S 3 ) and being able to be immobilized with respect to the frame by means of one of the selective-coupling means (BR) to produce a reverse gear,   the other ( 110  to  112 ) of these epicyclic gearsets having a planet carrier (PS 4 ) permanently connected to one (S 3 ) of said common input and output, and being able to produce two forward ratios, each by activation of a respective one (B 1 , C 4 ) of the selective-coupling means.   
     
     
         10 . A device according to  claim 1 , characterized in that at least one of the planetary gearsets (TP 1 ; TP 2 ; TP 3 ) comprises an epicyclic gearset comprising:
 a planet carrier (PS 1 ; PS 2 ; PS 4 ) permanently connected, at least indirectly, to a first ( 4 ) of the upstream and downstream rotary elements, and capable of being selectively connected, at least indirectly, to the second ( 2 ) of said upstream and downstream rotary elements by one (C 5 ; C 6 ; C 4 ) of the selective-coupling means, thus forming a direct local drive;   a sun wheel ( 101 ;  104 ;  110 ) and a ring gear ( 103 ;  106 ;  112 ), one ( 103 ;  104 ;  110 ) of which is permanently connected to said second ( 2 ) rotary element; and the other ( 101 ;  106 ;  112 ) of which can be selectively connected to the frame ( 1 ) by one (B 3 ; B 2 ; B 1 ) of the selective-coupling means.   
     
     
         11 . A device according to  claim 4 , in which the three planetary gearsets comprise:
 a first gearset (TP 1 ), the input (E 1 ) of which is connected to a ring gear ( 103 ) and the output (S 1 ) is connected to a planet carrier (PS 1 ), this first gearset being capable of a direct local drive to produce a fifth ratio, and a gear reduction by locking a sun wheel ( 101 ) to produce a third ratio;   a second gearset (TP 2 ), the input (E 2 ) of which is connected to a sun wheel ( 104 ) and the output (S 2 ) is connected to a planet carrier (PS 2 ), this second gearset being capable of a direct local drive to produce a sixth ratio, and a gear reduction by locking a ring gear ( 106 ) to produce a second ratio; and   a third gearset (TP 3 ), the input (E 3 ) of which is connected to a sun wheel ( 110 ) and the output (S 3 ) is connected to a planet carrier (PS 4 ), this third gearset being capable of a direct local drive to produce a fourth ratio, and a gear reduction by locking a ring gear ( 112 ) to produce a first ratio.   
     
     
         12 . A device according to  claim 11 , characterized in that one of the planetary gearsets, preferably the third planetary gearset (TP 3 ), moreover comprises an epicyclic gearset, the sun wheel ( 107 ) of which is connected to the input (E 3 ), the ring gear ( 109 ) is connected to the output and the planet carrier (PS 3 ) can be selectively locked to produce a reverse ratio. 
     
     
         13 . A device according to  claim 1 , characterized in that each transmission ratio is achieved by closing a selective-coupling means of one of the planetary gearsets (TP 1 , TP 2 , TP 3 ) and by placing or maintaining in an open state the other selective-coupling means of the transmission A device. 
     
     
         14 . A device according to  claim 1 , characterized in that the selective-coupling means (B 1  to B 3 , C 4  to C 6 , BR) are of the progressive type and are capable of ensuring progressive adaptation between the speed of rotation of a vehicle engine and the speed of the vehicle, in particular for setting the vehicle in motion from stationary by at least one of the selective-coupling means. 
     
     
         15 . A device according to  claim 1 , characterized in that the planetary gearsets (TP 1  to TP 3 ) and the transfers (TR 1  to TR 3 ) are in permanent meshing. 
     
     
         16 . A device according to  claim 1 , characterized in that at least one first ratio, obtained by actuation of a first selective-coupling means (B 2 ) between the frame ( 1 ) and an element ( 106 ) of a planetary gearset (TP 2 ), transmits a greater torque than at least one second gear obtained by actuation of a second selective-coupling means (C 6 ) achieving a direct local drive within said planetary gearset. 
     
     
         17 . A device according to  claim 1 , characterized in that the shortest of its ratios obtained by the local direct drives (C 4 , C 5 , C 6 ) is longer than the longest of the ratios obtained by selective coupling (BR, B 1 , B 2 , B 3 ) between the frame ( 1 ) and an element of a planetary gearset.