FR2480204A1 - DRIVE SYSTEM FOR A VEHICLE HAVING AT LEAST TWO PAIR OF WHEELS - Google Patents

Abstract

THE INVENTION RELATES TO A DRIVE SYSTEM FOR A VEHICLE HAVING TWO PAIRS OF WHEELS. ACCORDING TO THE INVENTION, IT INCLUDES A MOTOR 1 WITH AN OUTPUT SHAFT 1A, A COMBINED FRONT AXLE GEARBOX MECHANISM 2 INCLUDING A POWER TRANSMISSION UNIT 4 AND A FIRST FINAL REDUCER 5, THE UNIT 4 HAVING SHAFTS OF ' INPUT AND OUTPUT 4A, 4B AND PINIONS 7A-7F, 8A-8F, THE FIRST REDUCER INCLUDING PINIONS 13, 15, 17 AND 17 THAT CAN DIVIDE THE ENGINE POWER INTO TWO COMPONENTS TO BE TRANSMITTED RESPECTIVELY TO ONE OF THE TWO PAIRS OF WHEELS 12, 12, A BIFURCAL GEAR 27, A DRIVE LINE INCLUDING AT LEAST ONE DRIVE SHAFT 34, 36 AND A SECOND FINAL REDUCER 25 HAVING SPROCKETS 38, 39 THAT CAN DISTRIBUTE THE MOTOR POWER INTO TWO COMPONENTS TO BE TRANSMITTED TO THE OTHER WHEELS 23 AND 23, AND A MEANS OF TRANSFER OF POWER AT A RIGHT ANGLE 24 BETWEEN GEAR 27 AND THE DRIVE LINE AND CONVERTING THE ROTATION OF GEAR 27 INTO ROTATION AROUND AN AXIS PERPENDICULAR TO THAT OF THE GEAR 27 THE INVENTION APPLIES IN PARTICULAR TO AUTOMOBILE INDUSTRY.

Description

248D204

  The present invention relates to a drive system for a vehicle having at least two pairs of wheels, consisting of a pair of front wheels and a pair of rear wheels, and more particularly to a four-wheel drive system.

  drive wheels for such a vehicle.

  In a known four-wheel drive system, a drive line is used comprising a motor and a power transmission unit arranged in series in a forward-to-back direction of the vehicle. The engine power supplied by the engine is distributed, by a power transfer mechanism, into two components, one of which is transmitted by a front wheel drive shaft, the latter of which and the other is transmitted by a transmission shaft. transmisEon

  rear wheels, axles thereof.

  Such a series arrangement of the engine and the power transmission unit requires an elongated chassis of the vehicle and for this reason deteriorates the stability of the pipe or steering due to the large projections of the vehicle. Furthermore, the transmission unit in the series arrangement of the engine and the transmission occupies part of the space that could otherwise be used for passengers or luggage, thereby encumbering the availability of space.

  for passengers or luggage in the vehicle.

  Above all, the fact of providing the driveshafts for the front and rear wheel axles and the power transfer mechanism in the

  training line using the motor and transmission

  in series, usually leads to an increase in the production price and an increase in the total weight

of the vehicle.

  The present invention aims to eliminate these problems of a conventional four-wheel drive vehicle, eliminating one of the driveshafts for the front and rear axles of a known four-wheel drive vehicle, and slightly modifying the drive system of a regular two-car

drive wheels.

  According to the present invention, there is provided a drive system for a vehicle having at least two pairs of wheels consisting of a pair of front wheels and a pair of rear wheels, comprising a power unit having an output shaft which is rotatable around a wheel. an axle in a lateral direction of the vehicle a combined front axle gearbox assembly comprising a power transmission unit and a first final gearbox, the transmission unit having input and output a-bres, each having a axis of rotation which is substantially parallel to an extension of the axis of rotation of the output shaft of the power unit and despignom mounted on the input and output shafts and arranged to selectively produce a certan number of reportsentreentre the rotational speeds of the input and output shafts, the first final gearbox having pinions arranged to distribute the drive power of the output shaft in two components to respectively transmit to one of the two aforementioned pairs of wheels, a bifurcated pinion engaging the first final gear to be driven by it for rotation about an axis which is substantially parallel to the axis of rotation of each of the input and output shafts, a transmission line having at least one transmission shaft extending in a forward-to-back direction of the vehicle and a second final gearbox having gears arranged to distribute the driving power of the

  line of training or transmission in two

  to transmit to the other of the two pairs of wheels, and a right-angle power transfer mechanism operatively between the forked gear and the transmission line and used to convert the rotation of the bifurcated gear in rotation about an axis which is substantially

  perpendicular to the axis of rotation of the bifurcated gear.

  In the drive system constructed and arranged at the base as described above, the combined front axle gearbox assembly may further contain a housing structure enclosing

  the power transmission unit and the first reduction

  fnlalet having an opening through o the final gear

  is maintained in engagement with the bifurcated pinion

above.

  The invention will be better understood, and other purposes, features, details and advantages thereof

  will become clearer during the description

  explanatoryqii will follow made with reference to the accompanying schematic drawings given solely by way of example illustrating several embodiments of the invention, and wherein: - Figure 1A is a schematic view of the general construction of a first embodiment preferred embodiment of the vehicle drive system according to the present invention; FIG. 1B is a fragmentary sectional view showing part of the detailed construction of the arrangement of the embodiment of FIG. 1A; FIG. 2A is a view substantially similar to FIG. 1A but shows the general construction of FIG. a second preferred embodiment of the vehicle drive system according to the invention; and FIG. 2B is a view substantially similar to FIG. 1B but showing a part of the detailed construction of the arrangement of the embodiment of FIG.

Figure 2A.

  Hereinafter, embodiments of the invention will be described.

  drive system according to the present invention.

  With reference to FIGS. 1A and 1B, the drive system according to the invention comprises a power unit illustrated as consisting of an engine

  with internal combustion 1 having an output shaft la.

  The proposed drive system according to the invention represents a motor arrangement placed transversely and thus, the motor 1 is installed on the chassis of a wheeled vehicle so that its output shaft extends horizontally in a lateral direction. of the chassis. Furthermore, the drive system according to the present invention is assumed, by way of example, to be of the engine design at the front and, thus,

  the engine 1 is placed at the front of the vehicle chassis.

  When the engine 1 is of the piston type. its output shaft is constituted by the crankshaft of the engine The drive system according to the invention further comprises a manual front axle combined gearbox mechanism 2 which consists roughly of a mechanical clutch 3, of a manual power transmission unit 4, and a front final gearbox 5. The mechanical clutch 3 comprises a driving member connected to the output shaft 1a of the engine 1 and a driven member engageable with the driving member and connected to a transmission input shaft 4a forming part of the transmission unit 4. The clutch unit 3 further comprises an axially movable pressure member on the transmission input shaft 4a and which is adapted to force the led organ into engagement

  with the driving member when it is actuated for a movement

  Axially on the shaft 4a. The pressure member is biased by means of a spring (not shown) to connect the driven member to the driving member, as is known.

well.

  The transmission input shaft 4a extends axially

  in alignment with the output shaft 1a of the internal combustion engine 1, and is journalled in suitable bearings supported on a housing structure 6 of the combined front axle gear assembly. The transmission unit 4 is assumed by way of example, to be of the five-speed type and a step

  rear, and it includes a total of six drive gears.

  are fixedly mounted or integral with the transmission input shaft 4a and which are axially spaced from each other on this shaft 4a. The drive sprockets consist of a first gear 7a, a 7b second gear, a third gear 7c, a fourth gear 7d, a fifth gear 7d

  and a pinion 7f reverse.

  The housing structure 6 further supports a transmission output shaft 4b which extends axially parallel to the transmission input shaft 4a and

  which has axial and opposite extreme parts respectively

  The transmission output shaft 4b is coaxially mounted, in total, with six driven gears which are axially spaced apart from each other on the shaft 4b and which are freely rotatable independently of one another. each other on the shaft 4b around the central axis of it. The pinions carried on the shaft 4b consist of a first driven pinion 8a, a driven pinion 8b of a second, a driven pinion 8c of a third, a driven pinion 8d of a fourth, a pinion fifth 8th led sprocket and a reverse 8f led sprocket. The first to fifth pinions 8a to 8a of the transmission output shaft 4b are in pairs and held in engagement with the driving or driving gears of the first to the fifth 7a to 7e, respectively, on the drive shaft. transmission input 4a. Furthermore, the driven gear 8f of reverse on the output shaft 4b can come into engagement with the gearmotor reverse gear 7f on the input shaft 4a via a reverse gear 9 axially axially mobile and coaxially rotatable on a shaft 4c intermediate gear. The shaft 4c also extends axially parallel to the transmission input shaft 4a and

it is attached to the structure 6.

  The power transmission unit 4 is assumed, by way of example, to be of the fully synchronized type - and thus it further comprises three sets of timing clutches, each of which is coaxially mounted on the transmission output shaft 4b. o It is rotary. The clutch clutch assemblies are illustrated as consisting of a first-second clutch clutch assembly a, a third-fourth clutch clutch assembly 10b, and a clutch assembly of synchronization of the fifth gear 10c. The assembly 10a is axially located between the first and second driven sprockets 8a and 8b and can selectively engage with these pinions 8a and 8b and likewise the assembly 10b is located axially between the driven third gears. and fourth 8c and 8d and it can come selectively in engagement with these pinions 8c and 8d. The assembly 10c is provided in association with the fifth driven gear

  8th and he can come into engagement with this pinion.

  As is well known and as will be seen with reference to FIG. 1B, each of the assemblies 10a and 10b

  is, basically, composed of an outer clutch hub-

  gear toothed on the transmission output shaft 4b between the pinions 8a and 8b or the pinions 8c and 8d, of two externally toothed timing or locking rings placed adjacent to the axial and opposed ends of the hub and which can come into engagement with

  him, and an inner annular coupling sleeve-

  dent gear retained in engagement with the hub where it is axially movable. The synchronization rings of each of the assemblies 10a and 10b are rotatable with

  the pinions 8a or 8b or the pinions 8c and 8d. respected

  tively. The synchronizing clutch assembly c is constructed as each of the assemblies 10a and 10b

  but it has only one synchronization ring

  rotation with the 8th gear. Each of the pinions 8a to 8e has or has a coupling section adjacent to the associated synchronizing ring. The coupling sleeve of each of the assemblies 10a, 10b and 10c is axially movable in engagement with the coupling section of one or other of the pinions 8a and 8b or pinions 8c and 8d or pinion 8e au- beyond the associated synchronization crown in order to establish a

  synchronized coupling between the output shaft of trans-

  mission 4b and the gear engaged by the sleeve. The coupling sleeve of each clutch assembly has a circumferential groove through which a shift control fork (not shown) is held in circumferentially sliding engagement with the sleeve. The forks thereby engaging the respective coupling sleeves of the individual clutch assemblies 10a, 10b and 10c are, in turn, carried on shift control rods or rails which are operatively connected or in engagement with a shift lever. manually controlled, by a suitable wheelhouse,

that this is not represented.

  The reverse gear 8f is formed as part of the coupling sleeve of the timing clutch assembly 10a from the first to the second. The intermediate gear 9 of reverse is engaged by a shift control fork (not shown) carried on the rod or the rail - gearshift control bearing the fork engaging the coupling sleeve of the assembly sync clutch 10c of the fifth gear. The shafts 4a to 4c and all the pinions and sets of clutches mounted on these trees are

locked in the structure 6.

  The construction and arrangement of the transmission unit 4 which has just been described and which is shown in FIGS. 1A and 1 are only given by way of example and can be modified from

many ways.

  On the output shaft 4b of the transmission unit 4 is fixedly mounted a transmission output gear 11 rotatable about the central axis of the shaft 4b.The output gear 11 is adapted to drive the final gear before 5 above mentioned being part of the combined gearbox-front axle assembly 2. The front gearbox 5 is also enclosed in the structure 6 and is adapted to allow power transfer from the transmission unit 4 to the wheels before which are schematically represented in 12 and 12 '

in Figure 1A.

  The front end gear 5 is composed of a differential assembly and comprises a ring 13 rotating about an axis parallel to the axis of rotation of the transmission output shaft 4b. The ring 13 is fixed or is integral with a differential shell 14 eigure 1B) which is rotatable with the ring 13 about the axis of rotation thereof relative to the extension of the structure 6 towards the rear 6a . The differential shell 14 bears two pairs of bevel gears 15 rotatably mounted on two shafts 16 (FIG. 1B) fixed to the shell 14 and extending at right angles to each other and relative to the axis of rotation. of the shell 14 as can be seen in FIG. 1B o only two of the pinions 15 are illustrated as being mounted on one of the shafts 16. The individual bevel gears 15 are thus rotatable not only together with the shell 14 and the shafts 16 about the axis of rotation of the shell 14 but also independently of each other about the central axes of the shafts 1, that is to say axes perpendicular to the axis of

rotation of the shell 14.

  The four bevel gears 15 are placed between and held in engagement with two side bevel gears 17 and 17 'which are rotatable about the axis of rotation of the shell 14 and which are also carried therein. The gears 17 and 17 'are keyed on the inner end portions of two lateral shafts 18 and 18' respectively, which extend from the rear extension 6a of the structure 6 in a lateral direction of the vehicle frame by openings formed in side and opposite walls of the extension 6a. The shafts 18 and 18 'are part of the sets of front axles which furthermore comprise the shafts 19 and 19' for driving the connected front wheels.

  to shafts 18 and 18 'by appropriate means of coupling

  such as homokinetic joints 20 and 20 'respectively. The front wheel drive shafts 19 and 19 'extend, in turn, outwardly from the constant velocity joints 20 and 20' in the lateral direction of the vehicle chassis and are connected at their outer axial ends to the axles. 21 and 21 'of the front wheels 12 and 12' by appropriate coupling means such as

  than constant velocity joints 22 and 22 ', respectively.

  The construction and arrangement of the final reducer before 5 which has just been described and which is shown in FIGS. 1A and 1B is of particular importance and can thus be modified in many ways, if

we wish it ..

  The rearward extension 6a of the structure 6 has, at its rear end, an opening 6b through which the rotation of the crown 13 of the final front gearbox 5 can still be transmitted to the rear wheels 23 and 23 'of the vehicle by a drive wheel and right-angle power transfer unit 24 and rear end gear 25 like this

  is schematically represented in FIG. 1A.

  As can be seen in FIGS. 1A and 1B the unit 24 comprises a hollow housing structure

  26 releasably connected to the rear extension 6a of the structure

  6 by a suitable fastening means such as bolts and nuts. The structure 26 has an opening contiguous to the opening 6b above mentioned in the rear extension 6a of the structure 6. The structure 26 comprises a bifurcated gear 27, a two-wheel drive and four-wheel drive clutch means. , and right angle power transfer means. Gear 27 has extensions

  or axial and opposite protuberances which are respectively

  The journals are journalled in appropriate bearings supported on the structure 26, and rotatable about an axis substantially parallel to the axis of rotation of the aforementioned ring 13. The gear 27 is held in engagement with the ring 13 and is securely connected to or integrally formed with a first externally splined coupling pinion which is coaxially rotatable with the gear 27. In Fig. 1B, the first coupling gear 28 is shown as being wedged on

  one of the axial extensions or protuberances of the engi-

  Bifurcated swim 27 and is held axially in position by means of an annular retaining element which is attached to this extension or protuberance. The first coupling gear 28 is part of the aforementioned two-wheel drive and four-wheel drive clutch means, which further comprises a second externally-engaged coupling gear.

cocoa 29.

  In line with the bifurcated gear 27 is a drive or drive bevel gear 30 which is part of the right angle power transfer means above. The gear 30 has an axial extension which is journalled in suitable bearings supported on

  structure 26 and is rotatable about a sensing axis

  The axial extension of the bevel gear 30 extends to the bifurcated gear 27, and the second mating gear 29 mentioned above is securely mounted therein. or formed therein, whereby the gear 29 is coaxially rotatable with the bevel gear 30. The second coupling gear 29 is axially spaced from the first coupling gear 28 and has a diameter and pitch of its teeth equal to those of first gear 28. In Fig. 1B, the second gear 29 is shown to be keyed on a part. reduced extreme axial extension of the gear 30 and is axially maintained in. position on the extreme part of the extension by means of an annular retaining element attached to this

extreme part of the extension.

  The first and second coupling gears 28 and 29 are coupled or decoupled from each other by means of an internally engaged coupling sleeve 31 which is part of the gear change clutch means.

  two-wheel drive and four-wheel drive above.

  The sleeve 31 is constantly engaged with one of the coupling gears 28 and 29 and is axially movable on the particular gear in and out of engagement with the other of the gears 28 and 29. In FIGS. 1B, the sleeve 31 is assumed, by way of example, to be held in engagement with the second gear 29 and is axially movable on the gear 29 in and out of engagement with the first gear 28. The sleeve 31 has a throat circumferentially by a fork (not shown) is held in circumferentially sliding engagement with the sleeve 31. The fork engaging thereby the sleeve 31 is in turn connected, by an appropriate mechanical linkage, to a means for changing the drive of two wheels four-wheel drive motor with manual override

  Or other. although this is not represented.

  The first and second coupling gears 28 and 29 and the sleeve 31 constructed and arranged as

  described above constitute, together, the means of

  passing clutch of two-wheel drive four-wheel drive above, and form a clutch means for selectively coupling the forked gear 27 to the gearing

conical drive 30.

  The gear 30 is held inert with a driven conical gear 32 which has an axial extension -supported in bearings supported on a rear extension 26a (FIG. 1B) of the hollow structure 26. The conical driven gear 32 is rotatable about an axis which extends at right angles to the axis of rotation of the conical bevel gear 29, that is to say in a forward-to-back direction of the vehicle frame. The set of driven and driven bevel gears 30 and 32 thus arranged constitutes the above-mentioned right-angle power transfer means and is adapted to convert the rotation of the sprocket or forked gear 27 about its axis of rotation, rotation about a perpendicular axis! C to this one. It may be mentioned here that the relation between the axis of rotation of the bifurcated gear 27 and the axis of rotation of the conical bevel gear 31 is telescopic. The two particular axes of rotation are substantially at right angles to one another, but they are not necessarily in perpendicular intersection relation to one relative

to the other.

  The axial extension of the conical driven gear 32 protrudes rearwardly from the rear extension 26a of the structure 26 through an opening formed therein.

  extension 26a and is connected by a coupling means

  suitable as a universal joint 33, to a first transmission shaft 34 which extends rearwardly of the universal joint 33 in a forward-to-back direction of the vehicle frame as schematically

shown in Figure 1A.

  The first shaft 34 is part of a transmission or drive line for the rear wheels 23 and 23 ', and is connected by a suitable coupling means such as a universal joint 35 to a second transmission shaft 36 which extends rearward of the seal also towards the rear of the vehicle chassis. The second shaft 36 is, in turn, connected rearwardly by a suitable coupling means such as a universal joint 37, to the rear end gear

25.

  As can be seen schematically in FIG. 1A, the rear end gear 25 consists of a driving conical pinion 38 connected to the second transmission shaft 36 mentioned above by a universal joint 37 and having an axis of rotation in the direction of front and back of the vehicle chassis. The pinion 38 is held in engagement with a conical ring 39 whose axis of rotation is at right angles to that of the driving pinion 38. The conical driving gear 38 and the ring gear 39 constitute, together, an angled power transfer means. the right to convert the rotation of the transmission-rbre 36 around its axis of rotation in a rotation of the ring 39 about a perpendicular axis, in intersection or non-intersection relation, to the axis of rotation of the transmission shaft 36. Such bevel gears 38 and 39 are housed in a stationary housing and are swirled in appropriate bearings

  (not shown) supported on the housing 40.

  As for the front end reducer described above 5, the rear end reducer 25 is composed of a differential assembly and, thus, it further comprises a rotating differential shell (not shown) which is fixed or integral with the above-mentioned ring gear. mentioned above 39. The shell is rotatable with the ring 39 about its central axis relative to the casing 40 mentioned above, and it carries two pairs of differential bevel gears 41 rotatably mounted on two crossed shafts (not shown) attached to the casing. The bevel gears 41 are thus rotatable not only together with the shafts and the rotary shell around the axis of rotation of the ring gear 39, but also independently of each other around the central axes of the crossed shafts, that is to say say perpendicular axes

  to the axis of rotation of the ring 39.

  The bevel gears 41 are placed between and held in engagement with two side bevel gears 42 and 42 'which are rotatable about the axis of rotation of the ring gear 39 and which are also carried in the rotary housing above. The lateral bevel gears 42 and 42 'are keyed on the inner end portions of two lateral shafts 43 and 43', respectively, which extend from the stationary casing 40 in a lateral direction of the vehicle frame by openings in opposite walls of this casing. 40. The lateral shafts 43 and 43 'are part of rear axle assemblies which furthermore comprise rear wheel drive shafts 44 and 44' connected to the lateral shafts 43 and 43 'by appropriate coupling means such as homokinetic joints 45 and 45 ', respectively. The shafts 44 and 44 'extend in turn outwardly from the constant velocity joints 45 and 45' in a lateral direction of the vehicle frame and are connected at their outer axial ends to the axles 46 and 46 'of the wheels. rear 23 and 23 'by appropriate coupling means such

  than homokinetic joints 47 and 47 ', respectively.

  The construction and arrangement of the final rear reducer 25 just described and which can be seen in FIG. 1A Salt simply given as an example and can therefore be changed or modified.

in many ways.

  We will now describe the operation of the vehicle drive system built and arranged as

  above, with reference to Figures 1A and 1B.

  When the engine 1 is in operation and the clutch unit 3 is in the coupled condition, the driving power supplied by the output shaft 1a of the engine 1 is transmitted by the clutch unit 3 to the engine shaft. 4a input of the power transmission unit 4. Before the clutch unit 3 is operated in coupled condition, the speed change lever (not shown) is manually operated, to select the rod or the shift control rail bearing the shift control fork to engage the timing clutch assembly Ia, 1Ob or 10c

  to set in motion on the transmission output shaft

  4b if one wishes to choose one of the transmission ratios for a forward. Further manipulation of the shift lever forces the particular shift control rod or rail to move axially with the

  fork and pews it forces the clutch assembly

  a synchronization geometry associated with moving axially on the transmission output shaft 4b in a direction tending to produce a synchronized coupling between the transmission output shaft 4b and the pinion 8a to 8e selected on the shaft 4b. If, on the other hand, it is desired to choose the reverse gear, the intermediate gear 9 is actuated to move axially on the shaft 4c to the position engaged with the reverse gear 7f and the reverse gear 8f

  on the shafts 4a and 4b, respectively.

  When one of the pinions 8a to 8e on the transmission output shaft 4b is connected thereto by the associated timing clutch 10a, 10b or 10c or the intermediate reverse gear 9 engages the 7f and 8f, the drive power transferred by the clutch unit 3 to the transmission input shaft 4a is transmitted to the transmission output shaft 4b by the selected pair of gears on the shafts 4a. and 4b or by the gables

  7f, 8f and 9. The rotation of the transmission output shaft

  4b mission thus driven at a speed proportional)) the ratio chosen, the rotational speed of the transmission input shaft 4a, is transmitted by the transmission output gear 11 on the shaft 4b to the crown

  13 of the final gearbox before 5. The driving force

  provided by the power transmission unit 4 is thus reduced by the final gear 5 and is transmitted

  by the lateral shafts 18 and 18 ', the homokinear joints

  20 and 20 ', the front wheel drive shafts 19 and 19', the constant velocity joints 22 and 22 'and the front axles 21 and 21', with the front wheels 12 and 12 '

respectively-.

  The driving power thus supplied to the crown 13 of the final final gearbox 5 is divided into three components, two of which are distributed to the front wheels 12 and 12 'and the other of which is transmitted to the bifurcated gear 27 of the transfer unit 24 and by the forked pinion 27 to the first coupling gear 28 of the clutch means of the change of two driving wheels and four driving wheels. If, in this case, the

  coupling sleeve 31 on the second coupling gear

  The first and second coupling gears 28 and 29 are disengaged from one another and thus the driving line for the wheels is held in an axial position free from the first coupling gear 28. rear 23 and 23 'is disconnected from the forked gear 27. Under these conditions, only the front wheels 12 and 12' are driven in

rotation by the engine 1.

  If, however, the coupling sleeve 31 is held in an axial position engaged with the first and second coupling gears 28 and 29, the power transmitted to the bifurcated gear 27 is further transmitted by the first coupling gear. 28, the sleeve 31 and the second coupling gear 29. to the conical bevel gear 30 of the right angle power transfer means and causes the conical bevel gear 32 to rotate about its axis of rotation in

  a forward-to-back direction of the vehicle chassis.

  The rotation of the conical bevel gear 32 is transmitted

  by the universal joint 33 the first transmission shaft

  342the universal joint 35, the second transmission shaft 36 and the universal joint 37, to the conical bevel gear 38 and more prt this one, to the crown

  taper 39 of the final gearbox 25. The power of drive

  provided by the power transmission unit 4 to the drive line of the rear wheels 23 and 23 'is thus finally reduced, in gear ratio, by means of the rear final gear 25 and is transmitted by the lateral shafts 43 and 43 ', the constant velocity joints 45 and 45', the rear wheel drive shafts 44 and 44 ', the constant velocity joints 47 and 47' and the rear wheel axles 46 and 46 ', to the rear wheels 23 and 23' respectively. In these conditions,

  not only the front wheels 12 and 12 'but also.

  the rear wheels 23 and 23 are rotated by the engine.

  In the embodiment of the training system

  As described above with reference to FIGS. 1A and 1B, a manually controlled power transmission was used. Such an embodiment of the present invention can however be easily modified to use an automatic transmission. Figs. 2A and 2B of the drawings show an embodiment using a front axle and automatically controlled combined axle assembly mechanism instead of manually operated mechanism 2 of Figs.

1A and 1B.

  As can be seen in FIGS. 2A and 2B, the automatic control mechanism 48 is essentially composed of a hydrodynamic clutch unit 49, an automatically controlled power transmission unit 50, and a front end reducer 51. The unit 49, the unit 50 and the gearbox 51 are enclosed in a structure 52 of the gearbox assembly axle front combined before juxtaposed with respect to the internal combustion engine 1 which is placed so that its output shaft extends axially in a lateral direction of the chassis of a vehicle as is schematically

shown in Figure 2A.

  The hydrodynamic clutch unit 49 is assumed here, by way of example, to consist of a three-membered torque converter, and is therefore illustrated as comprising a driving member consisting of a pump impeller 49a, a driven member consisting of a turbine wheel 49b, and a reaction member consisting of a stator 49c. The pump impeller 49a is connected by a converter drive plate 49d to the output shaft 1a of the motor 1 and is thus rotatable with this shaft about an axis substantially aligned with the rotational axis of the pump. tree. The turbine wheel 49b is connected to an input hollow shaft 50a of the transmission unit with which it is rotatable. The transmission input hollow shaft 50a is rotatable about an axis which is also substantially aligned with the axis of rotation of the output shaft of the motor. The stator 49c is placed between the pump impeller 49a and the impeller 49b and is connected to the structure 52 by a torque converter one-way clutch assembly 53. The construction and arrangement of the torque converter 49 as described above are well known and will not be described in addition to

details here.

  The power transmission unit 50 is assumed, by way of example, to be of the three-speed and reverse type, and is illustrated as including plant gear assemblies which are arranged in series with each other. other and coaxially

  on a hollow output shaft 50b of the transmission unit

  50. The shaft 50b is arranged in a coaxially surrounding relationship of an intermediate portion of the transmission input shaft 50a that extends partially through the output shaft 50b from the turbine wheel.

49b above mentioned.

  The planetary gear assemblies of the transmission unit 50 consist of a first set 54 and a second set 55. The first set 54 comprises an outer sun gear 54

  coaxially rotatable on the output shaft of trans-

  mission 50b, an internally toothed ring 54b coaxially surrounding the sun gear 54a, and at least two satellites 54c, each being held in engagement with the sun gear 54a and the keel 54b and being rotatable about an axis parallel to a common axis of rotation of sun gear 54a and crown 54b. Likewise, the second assembly 55 comprises an externally toothed sun gear 55a that is coaxially rotatable on the shaft

  transmission output 50b, an integral ring

  55b approximately coaxially surrounding the sun gear 55a, and at least two satellites 55c, each being held in engagement with the sun gear 55a and the ring 55b and being rotatable about an axis parallel to a common axis of rotation of the sun gear 55a and crown 55b. The satellites 54c of the first set 54 are jointly connected to a first gear carrier 56 and, likewise, the satellites 55c of the second set 55 are jointly connected to a second gear carrier 57. The satellites of each set are thus not only rotatable about their respective axes of rotation and can also rotate around the common axis of rotation of the sun gear and the crown of the assembly while driving around.

  the sun gear or crown of the set.

  The power transmission unit 50 further comprises two transmission clutch assemblies which are placed in series with each other in a direction in which the transmission output shaft 50b extends axially. The assemblies consist of a forward clutch assembly 58 to be actuated for selecting one of the first, second and third gear ratios and a clutch assembly 59 to be actuated for gear selection.

  Third gear reduction or reverse gear.

  The clutch assembly 58 comprises input members consisting of clutch plates connected to the transmission input shaft 50a and coaxially rotatable therewith, and outlet gears consisting of clutch disks connected to the clutch plate. 54b of the first set of planet gears 54, and rotatable with it. Furthermore, the clutch assembly 59 comprises input members consisting of disks connected to the transmission input shaft 50a and rotatable with it, and output members or clutch plates connected to respective sun springs 54a and 55a. first and second planetary gear sets 54 and 55, by a clutch drum 60 and a drum-shaped connecting shell 61, the

  output members being rotatable with the sun gears.

  The drum 60 is coaxially surrounded by a second brake band 62 actuated to brake the drum 60 and accordingly the sun gears 54a and a for the choice of the second gear ratio. The transmission unit 50 further comprises a low speed and reverse braking assembly 63 having stationary members consisting of, for example, brake plates attached to the structure 52 of the combined axle front gearbox assembly, and rotary members, consisting, for example, of coaxially rotatable brake disks with the gear carrier 57 of the second planetary gear set 55. The braking assembly 63 thus constructed

  and arranged is adapted to choose the gear ratio

  plication of first or reverse. The braking assembly 63 is operatively associated with a clutch assembly with a transmission path 64 which comprises a stationary member constituted, for example, by an external groove member fixedly connected to the structure 52 and a rotary member constituted by for example, an inner groove member connected and rotatable with the gear carrier 57 of the second planet gear assembly 55 and the rotatable members of the brake disks of the assembly 63. The one-way clutch assembly 64 further comprises a series of spring-loaded coupling members such as buttress segments (not shown) disposed in an amnular manner between the inner and outer groove members of the clutch assembly 64. The coupling members are arranged in to allow the internal groove member to rotate about the axis of rotation of the transmission input shaft 4a

  only in the "advance" direction, identical to the direc-

  rotation of the input shaft 4a.

  The gear carrier 56 of the first planetary gear set 54 and the ring gear 55b of the second planetary gear set 55 are jointly connected to the transmission output shaft 50b with which they are coaxially rotatable. Each of the friction devices such as the clutch assemblies 58 and 59, the braking band 62 and the braking assembly 63 of the transmission unit 50 thus constructed and arranged is actuated by a control or hydraulic control means such as a fluid-controlled piston for each of the assemblies 58 and 59, a fluid-controlled servo unit for the belt 62, or a fluid-controlled piston for the assembly 63. These actuation and servo means are selectively put into operation by the pressure of the fluid which is selectively

  distributed by and under the control of a hydrau-

  lique (not shown). Aini, 4 one of the three reports

  in advance ratio or the ratio of demultiplication

  Reverse folding can be achieved between the input and output shafts of transmission 50a and

  b when two of the friction units comprising the combination

  One-way clutch bleeds 64 are implemented. When all these friction devices are kept inoperative, the transmission unit 50 assumes a neutral condition without any drive torque

  transmitted from the input shaft 50a to the output shaft 50b.

  The hydraulic fluid to be delivered to the fluid controlled actuation and servocontrol means for these friction devices by the hydraulic control system is provided by a transmission oil pump assembly 65 mechanically connected and driven by the shaft. output of the motor 1 by means of a pump drive shaft 50c extending

  axially through the hollow input shaft of trans-

  mission 50a as shown. The pressurized fluid supplied by the oil pump assembly 65 is not only supplied as control or control fluid a.K respective actuation and servocontrol means for the friction devices of the transmission unit 50 but it is also supplied as a working fluid to the torque converter 49. The construction and arrangement of the torque converter 49 and the transmission unit 50 as described above are given only as 'example. and can thus be modified and / or changed

in many ways.

  On the output shaft 50b of the transmission unit

  50 is fixedly mounted a transmission output gear 66 which is rotatable about the central axis of the shaft 50b and which is illustrated as being, by way of example, axially connected to the torque converter 49 and the planetary gear assemblies 54 and 55. The gear 66 has opposed axial extensions of respective journal protuberances in appropriate bearings supported on the structure 52. The gear 66 is engaged with a rotary intermediate gear 67 by appropriate bearings on a shaft 68 extending parallel to the shaft

transmission output 50b.

  The front end gear 51 of the mechanism 48 of the embodiment of FIGS. 2A and 2B is provided in an extension 52a of the structure 52 towards the rear. The unit 51 is constructed and arranged as the unit 5 of the embodiment of Figs. 1A and 1B except that the rotary ring 13 with the differential shell 14 of the unit 51 is held in engagement with the gear transmission output 66 by the intermediate gear 67 in comparison with the ring 13 of the unit 5 o this ring 13 is maintained in engagement

  direct with the output gear 11.

  The extension 52a of the structure 52 towards the rear has, at its rear end, an opening 52b through which the rotation of the crown 13 is transmitted to a right-angle power transfer unit and a drive wheel change which is constructed and arranged as unit 24 of the embodiment of FIGS. 1A and 1B and which therefore comprises a bifurcated gear 27 kept in engagement with the ring gear 13. The housing structure 26 of the unit 24 of the embodiment of FIGS. 2B is thus also releasably connected to the extension 52a towards the rear of the structure 52 by appropriate fixing means such as bolts and nuts, and it has an opening contiguous to the opening 52b in the extension

52a of structure 52.

  The sets of front axles for the front wheels 12 and 12 'and the transmission line for the rear wheels 23 and 23' of the vehicle drive system of Figs. 2A and 2B are also similar to those of the embodiment of Figs. and 1B and for this

  reason, a detailed description of their

  construction will not be given here.

  When the motor 1 of the arrangement of FIG. 2A operates, the driving power supplied by the output shaft 1a of the motor 1 is transmitted, with multiplication of torque, by the torque converter 49, to the input shaft 50a of the transmission unit 50. If, under these conditions, the manual shift lever is held in its neutral position or in the neutral position, none of the friction devices of the unit 50 are maintained in operative condition and the transmission input shaft 50a rotates without

  impart driving power to the output shaft 50b.

  The shaft 50b is thus kept at rest and no motive power is transmitted to the final gear before 51 for the front wheels 12 and 12 'as well as at the

  driving line of the rear wheels 23 and 23 '.

  If, however, two friction devices of the unit are maintained in operating condition by the fluid pressure applied to the respective fluid actuated actuation or servo means, a first, second or third gear ratio or reverse is established in the transmission unit 50. The driving power supplied by the torque converter 49 to the input shaft 50a is therefore transmitted by the combination of some of the gears or signonscomposing the two gear sets 54b and 54b to the transmission output shaft 50b. The shaft 50b is thus driven for rotation at a proportional speed, according to the gear ratio chosen, to the transmission input shaft 50a. of the shaft 50b is transmitted by the transmission output gear 66, to the intermediate gear 67 and more by it to the crown 13 of the final gear before 51. The power m otrice thus transmitted to the final gear before 51

  is reduced in the ratio of transmission or

  by means of the unit 51 and is divided into three components, two of which are transmitted by the lateral shafts 18 and 18 'of the unit 51 to the front wheels 12 and 12' by the constant velocity joints 20 and 20 ', the shafts 19 and 19 'driving the front wheels, the CV joints 22 and 22' and the axles 21 and 21 'of the front wheels, respectively. The remaining component of the motive power transmitted to the final gear 51 is transmitted from the gearbox crown 13

  51, to the bifurcated gear 27 of the unit 24.

  If the coupling sleeve 31 of the clutch means forming part of the unit 24 is engaged only with one of the first and second coupling gears 28 and 29 such that the second gear 29 as illustrated, the bifurcated gear 27 and the first coupling gear 28

  can simply move away from the training line.

  However, the coupling sleeve 31 is held at the axial position connecting the first and second coupling gears 28 and 29, the driving power transmitted to the gearing 27 is further transmitted by the coupling gear 28, the sleeve 31 and the coupling gear 29 of the clutch means, to the smart and driven pins. 30 and 32 of the right angle power transfer means. The rotation of the driven bevel gear 32 is in turn transmitted to the rear wheels 23 and 23 'in the manner previously described.

  for the embodiment of Figures 1A and 1B.

  In each of the embodiments described above the ratio between the respective numbers of teeth of the ring 13 and the bifurcated gear 27, the ratio between the respective numbers of teeth of the leading and driven bevel gears 30 and 32 and the ratio between the respective shades of teeth of the driving bevel gear 38 and the driven bevel gear 39 of the final gear 25 are chosen so that the front wheels 12 and 12 'and the rear wheels 23 and 23' are driven in meta at reduced speeds at low speeds. ratios equal to the rotational speed of the output shaft

motor 1.

  It will be noted, on reading the description which

  precedes, that the vehicle drive system according to the present invention has, inter alia, the following points (1) the power unit constituted, for example, by the internal combustion engine 1, is placed relative to the chassis of the vehicle so that the output shaft extends axially in a lateral direction

of the vehicle chassis.

  (2) the power transmission unit 4 or 50 forming part of the mechanism 2 or 48 axle gear box. the combined front is positioned relative to the vehicle frame so that the input and output shafts 4a and 4b or 50a and 50b extend axially substantially parallel to an extension of the axis of rotation of the output shaft of the power unit such

  that the internal combustion engine 1.

  (3) the final gearbox before 5 or 51 is used not only to reduce the speed of the power supplied and distribute that power in two components to be distributed to the front wheels, but

  to relay the motive power to the training line

  rear wheels 23 and 23 'if and when the clutch means for changing the drive wheels between the final gear 5 or 51 and the drive line

  rear wheels 23 and 23 'is in coupled condition.

  In view of these outstanding characteristics of the drive system according to the invention, the availability of space for passengers and luggage in a traditional four-wheeled vehicle

  motor can be significantly improved. -

  In addition to the above-described main features of the vehicle drive system according to the invention, each of the embodiments of the system described above has a feature that the system can be selectively used as a two-wheel drive system or as a system. four-wheel drive by providing clutch means forming part of the power transfer unit

  at right angles and change of driving wheels 24.

  As in this case, such a unit 24 is provided between

  the final gear before 5 or 51 and the training line

  rear wheels 23 and 23 ', the driving system

  according to the present invention can be easily modified into a front-wheel drive system simply by removing the four-wheel drive unit

  24 and the entire line for the rear wheels 23 and 23 '.

  When the system shown in FIGS. 1A and 1B or the system represented in FIGS. 2A and 2B is thus used as a front-wheel drive system, the opening 6b of the extension 6a of the structure 6 of the system of FIGS. 1A and 1B or FIG. the opening 52b of the extension 52a of the structure 52 of the system of FIGS. 2A and 2B can be closed by a suitable plate (no

  shown) attached to extension 6a or 52a.

  Of course, the invention is not limited to the embodiments described and shown which have been given by way of example. In particular,

  it includes all the means constituting equiva-

  slow techniques of the means described, as well as their combinations, if they are executed according to his spirit and implemented in the context of protection

as claimed.

Claims (5)

R E V E N D I C A T IO N S   A drive system for a vehicle having at least two pairs of wheels consisting of a pair of front wheels and a pair of rear wheels, characterized in that it comprises: - a power unit (1) having a steering wheel rotary output (la) about an axis in a lateral direction of the vehicle; - a combined front axle gearbox mechanism (2) comprising a power transmission unit (4) and a first gear reduction gear (5), transmission unit having transmission input (4a) and output (4b) shafts, each having an axis of rotation substantially parallel to the extension of the axis of rotation of the output shaft. power unit and pinions (7a-7f, 8a-8f) mounted on said transmission input and output shafts and arranged to selectively produce a number of ratios between the rotational speeds of said input and output shafts. transmission output, said first final gear comprising sprockets (13, 15, 17, 17 ') arranged to distribute the driving power of said transmission output shaft into two components to be transmitted respectively to one of said pairs of wheels (12, 12'), - a pinion b. fury (27) engaging said first final gearbox to be driven by it for rotation about an axis substantially parallel to the axis of rotation of each of said input and output transmission shafts - a drive line having at least one a transmission shaft (34), (36) extending in a forward-to-back direction of the vehicle and a second gearbox (25) having pinions (38), (39) arranged to distribute the driving power of said transmission line; two-component drive to be transmitted to the other one of said pairs of wheels (23 23 '), a right-angle power transfer means (24) operatively between said bifurcated gear and said drive line and serving to convert the rotation of said rotational bifurcated sprocket around an axis substantially perpendicular to the axis of rotation of said forked sprocket.   System according to claim 1, characterized in that it further comprises clutch means (28, 29) placed between said bifurcated gear and said right angle power transfer means, and serving to form a wire connection. entralnementet interrupt said connection between said bifurcated gear and said means of power transfer.   A system according to claim 2, characterized in that the clutch means comprises a coaxially rotatable externally splined first coupling clutch (28) with the split gear, a second externally splined coupling gear (29) connected to the motor by means of a right-angle power transfer device, and an internally splined coupling member (31) now engaged and axially slidable on one of the first and second coupling gears, and axially movable in and out of engagement with the other Desdtis coupling gears.   4.A system according to any one of the claims   preceding, characterized in that the combined front axle gearbox mechanism above includes   plus a structure (6) enclosing a transmission unit   power mission and the first final reducer and having an opening (6b) where the first reducer   final is in engagement with the bifurcated gear.   The system of claim 3 characterized in that the right angle power transfer means comprises a conical bevel gear (30) engageable with the aforesaid bifurcated gear and rotatable about an axis substantially aligned with the axis. rotating said rotating and bifurcated gear about an axis substantially aligned with the axis of rotation of said bifurcated gear, and a driven bevel gear (32) engaged with said rotating bevel gear about a substantially perpendicular axis at the axece rotation of said driving conical gear, said driven bevel gear being connected to the drive shaft and the rotational axis of said driven bevel gear being substantially   aligned with the axis of rotation of said transmission shaft mission.