FR2481399A1 - GEARBOX FOR VEHICLES - Google Patents

Abstract

THE INVENTION RELATES TO A GEARBOX FOR AUTOMOTIVE VEHICLES WITH A TRANSVERSAL MOTOR, IN PARTICULAR A FIVE-SPEED GEARBOX. PRIMARY SHAFT 2 OF THE GEARBOX CARRIES 11 TO 16 SPROCKETS IN ROTATION, WHICH ARE IN ENGAGED WITH SPROCKETS 17, 18, 19, 24, 24, MOUNTED ON TWO INTERMEDIATE SHAFTS 3, 4 WHICH ARE PARALLEL TO L 'PRIMARY TREE. THE SPROCKETS CARRIED BY THE INTERMEDIATE SHAFTS ARE MOUNTED FREELY ROTATING AND CAN BE COUPLED TO THESE SHAFTS USING COUPLING SLEEVES 21, 22, 25. THE INTERMEDIATE SHAFTS EACH BEARING A SPROCKET 7, 8 ROTATING SHIM THAT ATTACKS THE CROWN 9 OF THE DIFFERENTIAL AND PLAY THE ROLE OF ATTACK PINION OF THE BRIDGE.

Description

The present invention relates to a gearbox for vehicles with

  motor, comprising a primary shaft

  or entry, with a certain number of fixed pinions secured-

ment in rotation on this shaft, a first intermediate shaft arranged parallel to the primary shaft, carrying a number of pinions which are engaged with the pinions of the primary shaft, are mounted to rotate freely on the intermediate shaft and can be jointly and severally

  in rotation to this intermediate shaft by means of coupling

lO plement, and an output pinion securely fixed in rotation on the intermediate shaft, a second intermediate shaft arranged parallel to the primary shaft and carrying a certain

  number of sprockets that are engaged with sprockets of the rear

primary bre, are mounted to rotate freely on the intermediate shaft and can be coupled together

  rotation to this intermediate shaft by means of coupling

  and an output shaft or secondary shaft propped solidly

  dary in rotation on the intermediate shaft, the two output pinions wedges solidly in rotation on their respective intermediate shafts being engaged with a

common gear.

  Gearboxes in which the disengageable pinions are mounted on an intermediate shaft instead of being mounted on the secondary shaft are used in front-wheel drive vehicles as well as in rear-engine vehicles. Usually, the engine and the gearbox are grouped into an engine group which includes a gearbox and a reduction gear equipped with a differential, in a common casing. The output pinion fixed in rotation on the intermediate shaft is engaged with the crown of the differential and serves as the drive pinion. differential. In such a construction,

the intermediate shaft therefore also serves as a secondary shaft.

  These known type gearboxes are relati-

vely long, that is to say that they have a great length in the axial direction and, they are therefore not particularly well suited for use in motor vehicles in which the engine has several cylinders in line and is mounted transversely to the vehicle, this due to the problem of space available

for the gearbox.

  It is also known to produce a gearbox comprising two intermediate shafts each of which carries an output pinion which is engaged with a pinion

  common carried by the secondary shaft, in a classic arrangement

sic with its axis of rotation merged with the axis of rotation

  lO tion of the primary tree. In this type of gearbox, all the shafts are arranged in the same plane. With this arrangement, it is possible to increase the number of gear ratios in a gearbox for a

conventional engine installation; for example, it is pos-

sible to increase the number of reports from four to six without increasing the length of the gearbox. However, this type of gearbox is not well suited for

  motor vehicles with an engine mounted transversely-

is lying. The object of the invention is, in general, to produce a gearbox of the type described above, which - is particularly well suited for use in motor vehicles equipped with a transverse engine which leaves only '' very limited space for the gearbox at the end of the engine. In particular, the goal is to achieve

a five-speed gearbox for transverse engines.

  According to the invention, this object is achieved when said output pinions are wedged on the ends of the shafts which are directed towards the input end of the primary shaft, one of the intermediate shafts being arranged in a separate plane. of the plane which is common to the primary shaft and to the other intermediate shaft and said output gears

  being engaged with an 'Onion comrUn Imnté -in an Exoen Position-

  relative to the primary tree.

  For example, a five-speed gearbox thus arranged does not have a length greater than that of a three-speed gearbox. In addition, all

  forward gears are obtained with two stages of in-

  grenages, which allows a relatively high efficiency and a relatively silent gearbox. By adopting different gear ratios between the

  respective output sprockets and the common sprocket (the crown-

differential) it is possible to achieve steps

  larger gears between gears, giving the possibility of better fuel economy

  and better performance than with a standard gearbox-

-if that.

  Other features and advantages of the invention

tion will appear during the description which follows.

In the accompanying drawings ,. given only as an example, - Fig. 1 is a schematic view at the end of a five-speed gearbox; - Fig. 2 is a longitudinal section along the line II-II of FIG. 1; Fig. 3 is a schematic view at the end of a

  alternative embodiment of a five-speed gearbox

ports according to the invention;

  - Fig. 4 is a longitudinal section along the.

line IV-IV of FIG. 3.

The gearbox shown in Figs. 1 and 2, comprises a casing 1 in which a primary shaft 2, a first intermediate shaft 3 and a second -25 intermediate shaft rotate. The casing 1 is made integral with a casing 5 which contains the reduction bridge with the differential 6 Each intermediate shaft 3, 4 carries a pinion, 7 or 8 respectively which is locked in rotation and is engaged with the crown 9 of the differential so that it forms by

  therefore the differential drive gear.

  The primary shaft 2 of the gearbox is driven by the motor (not shown) via

  of a conventional friction clutch comprising a disc 10.

  Six pinions 11, 12, 13, 14, 15 and 16 are fixed in rotation on the shaft 2. The pinions 11, 15 and 16 are engaged with pinions 17, 18 and 19 which are mounted freely rotatable

  on the intermediate shaft 3 and have coupling teeth

  ments 20. Two coupling sleeves 21, 22 are fixed in rotation but free in axial displacement on the shaft 3

  so the gables 17, 18 and 19 can be selective-

  ment coupled to the shaft 3 in a conventional manner. Similarly, the pinions 12, 14 of the primary shaft are engaged with pinions 23, 24 (provided with coupling teeth and which are freely rotatable on the second intermediate shaft 4. The pinions 23, 24 can be selectively mated

to the intermediate shaft 4 using a coupling sleeve-

  ment 25 movable in axial displacement.

  The coupling of the different pinions by displacement

  The coupling sleeves are cemented in the usual way, after having disengaged the clutch interposed between the engine and the gear boot. The ratios of one to five are thus obtained by locking the pinions 23, 24, 17

  18 and 19 on their respective trees in this order of success-

  assignment. The gear boot comprises a reverse device which comprises a separate intermediate shaft 26,

which carries a reverse gear 27 which can be

place axially to engage or out of engagement with the pinion 13 of the primary shaft and with a ring 28 which is itself locked in rotation with the coupling sleeve 25. Thus, in reverse gear, the

torque is transmitted from the pinion 13 to the crown 28 via the

  the reverse gear 27, which reverses the

  direction of rotation of the intermediate shaft 4.

  In the embodiment shown in Figs. 1 and 2, the pinions 7 and 8 mounted respectively on the two intermediate shafts are of the same dimensions and, by

Consequently, the gear ratios obtained in the different

different ratios are determined by the gear ratios

existing between the primary tree 2 and the intermediate trees

diaries 3, 4.

  Figs. 3 and 4 show an alternative embodiment of a five-speed gearbox according to the invention in which it has been possible to reduce the number of pinions by providing the intermediate shafts with

  differential drive gears 30 and 31, which have dimensions

  different things. The primary shaft no longer carries a pinion for each of the pinions of the two intermediate trees; on the contrary its pinions 12 and 14 are engaged with pinions

  of the same size 32 and 33 carried by the intermediate trees

diaries. Furthermore, there is no difference in construction between the two embodiments shown, except that, in the variant, the gearbox is more

  short, in axial length, which is an advantage.

Claims (5)

R E V E N D I C A T I O N S   1. Gearbox for motor vehicles, comprising a primary or input shaft, with a number of pinions fixed in rotation on this shaft, a first intermediate shaft, arranged parallel to the primary shaft, with a number of pinions which are engaged with the pinions of the primary shaft, are mounted freely rotatable   on the intermediate shaft and can be rotatably coupled tion with this intermediate shaft by means of coupling- ment, and an output pinion fixed in rotation on the shaft   intermediate, a second intermediate shaft arranged paral-   along with the primary shaft and carrying a number of pinions which are engaged with pinions of the primary shaft, are mounted to rotate freely on the intermediate shaft, and can be coupled together in rotation with this intermediate shaft by means of ac-   coupling, and an output shaft or secondary shaft locked in rotation with the intermediate shaft, the two output pinions locked in rotation on their respective intermediate shafts being engaged with a common pinion, this gearbox being characterized in that said output gears (7, 8; 30, 31) are wedged on the ends of their shafts which are directed towards the input end of the primary shaft (2), one of the intermediate shafts (3) being disposed in a plane distinct from the plane which is common to the primary shaft (2) and to the other intermediate shaft (4), and said output pinions being engaged with a common pinion (9) mounted in an eccentric position by relation to the primary tree. 2. Gearbox according to claim 1, characterized in that the output pinions (7,8; 30, 31) and said common pinion (9) respectively form drive pinions and the ring gear of the final reducer comprising a differential which is incorporated in the gearbox. 3. Gear boot according to any one of claims 1 and 2, characterized in that the input shaft or primary (2) carries separate pinions (11, 12, 14, 15, 16) corresponding respectively to each of the pinions (17,18, 19, 23, 24) which are freely rotatably mounted on the intermediate trees. 4. Transmission according to any one   claims 1 and 2, characterized in that the shaft   input or primary (2) carries pinions (12, 14) which are engaged with pinions (32, 33) which are mounted freely rotatable on the two intermediate shafts. 5. Transmission according to any one claims 1 to 4, characterized in that it comprises   five forward gears, the first intermediate shaft   (4) carrying pinions (23, 24) which correspond respectively-   ment to the first report and to the second report and the second intermediate shaft (23) carrying pinions (17, 18, 19) which correspond respectively to the third, to the fourth and the fifth report.