FR2861447A1 - Gearbox for motor vehicles driving system, has jaw clutching to couple set of pinions on their shafts for selection of pinions, where pinions for first gear and reverse gear are driven by respective primary shafts - Google Patents

Abstract

The gearbox has two primary shafts (2, 3) and two secondary shafts (11, 12) with respective drive pinions (19, 25) engaging with gear tooth. Jaw clutching (20, 21, 26, 27) couples a set of pinions (6 -10, 13-15, 18, 22-24) on their shafts for selection of pinions and a corresponding gear. The pinions (7, 22) for first gear and pinions (9, 15, 23) for reverse gear are driven respectively by the shafts (2, 3). An independent claim is also included for a motor vehicle comprising a driving system with a gearbox.

Description

Gearbox for a motor vehicle

  The present invention relates to gearboxes for a motor vehicle, in particular gearboxes with a ratio change without discontinuity in the torque transmission.

  Document FR 2 802 600 discloses a gearbox of a parallel shaft and geared motor comprising a solid primary shaft and a concentric hollow primary shaft, at least two secondary shafts provided with respective drive gears intended to mesh with the same toothing. Sets of pinions comprise fixed gears borne by the primary shafts and idle gears carried by the secondary and may be selectively rotatably connected to the shafts which carry them by means of coupling means, of the type interconnection, to make gears independent engines corresponding to forward gears and a reverse gear. The primary shafts may be rotatably connected to the same drive shaft by respective clutches. Depending on whether a selected gear set is driven by the hollow primary shaft or the solid primary shaft, a driving torque is transmitted either by the hollow shaft or by the solid shaft. When changing gear with change of primary drive shaft, the clutches are actuated simultaneously through a state where at least one of the clutches transmits a torque by sliding, to allow gear changes without discontinuity in the transmission of the couple.

  Nevertheless, such gearboxes are not entirely satisfactory because they are not suitable for seamless torque transmission in all situations, and particularly during parking maneuvers, during which a discontinuity of the transmitted torque can be the cause of significant inconvenience for a user.

  An object of the invention is to provide a gearbox allowing gear changes without torque discontinuity including for passages of a reverse ratio to a forward gear, the gearbox remaining nevertheless compact and of reasonable manufacturing cost.

  Such a gearbox of a parallel-shaft and geared motor vehicle comprises a solid primary shaft and a concentric hollow primary shaft, at least two secondary shafts provided with respective drive gears intended to mesh with the same output toothing, games of fixed and crazy gears carried by the primary and secondary shafts and driven by the primary shafts, means of selective coupling of the idler gears on their shafts for the selection of a set of gears and a corresponding ratio. According to one aspect of the invention, a set of first gear gears is driven by a primary shaft, a set of reverse gears being driven by the other primary shaft.

  In the event of a change of gear from a first forward gear to a reverse gear ratio, the clutches pass through a state where at least one clutch transmits torque by slip to provide continuity in torque transmission. Thus, changes of report can be made gently and without being perceptible by the user.

  In one embodiment, a reverse gear set comprises a pinion mounted fixed on a primary shaft and rotatably coupled with a idler pinion, the idler gear mounted idle to a first secondary shaft and meshing with a reverse pinion gear. mounted crazy on a second secondary shaft with possibility of coupling. This arrangement allows a reversal of the direction of rotation to obtain a reverse, with a pinion gear disposed on a secondary shaft already present to preserve compactness of the box.

  Advantageously, a set of gears of a forward gear ratio comprises a fixed gear mounted on a primary shaft meshing with a pinion mounted idle on the first secondary shaft with possibility of coupling, a set of reverse gears including the first fixed gear of said primary shaft, the idle gear of the first secondary shaft forming a gear and meshing with a reverse gear idly mounted on a second secondary shaft with possibility of coupling. The reverse gear set has elements in common with a forward gear set, which preserves the compactness of the gearbox.

  The idler gear of the first secondary shaft may comprise a single toothing meshing simultaneously with the first fixed gear of the primary shaft and the reverse gear, which preserves the axial compactness of the box, or comprise teeth meshing with the first pinion. fixed of the first primary shaft and another toothing meshing with the reverse gear of the second primary shaft, which allows greater flexibility in the choice of the reverse ratio and the associated forward gear ratio.

  Preferably, the forward ratio is an even ratio, preferably the second ratio. Thus, the sets of first and second gear ratios are also driven by different primary shafts for transmission without torque discontinuity.

  In one embodiment, the sets of even gear ratios and the reverse gear are driven by a primary shaft, the sets of odd gear gears being driven by the other primary shaft, to allow for ascents and descents. of reports without discontinuity of transmission of torque.

  In one embodiment, a first primary shaft successively carries a first fixed gear meshing with an idle gear of a first secondary shaft, a second fixed gear meshing with a idle gear of a second secondary shaft, and a third fixed gear meshing with with a idler gear of said first secondary shaft to form first, third and fifth gear sprockets. The gearbox advantageously comprises a double clutch for the first and second idler sprockets of the first secondary shaft and a single clutch for the first idler gear of the second secondary shaft. In one embodiment, a second primary shaft carries a fourth fixed gear meshing with a third idler gear of a first secondary shaft forming a return to a second idler gear mounted on a second secondary shaft and forming a reverse gear, and a fifth fixed gear meshing simultaneously with a fourth idler gear mounted on said first secondary shaft and a third idler gear mounted on said second primary shaft to form reverse gear sets and second, fourth and sixth gear. The gearbox advantageously comprises a double clutch for the third and fourth idler gear of the first secondary shaft and a double clutch for the second and third idle gear of the second secondary shaft. The invention also relates to a motor vehicle comprising a drive system provided with of a gearbox according to one aspect of the invention.

  The present invention and advantages will be better understood from the study of the detailed description of embodiments taken by way of non-limiting example and illustrated by the appended drawings in which: FIG. 1 is a schematic view of a box speeds according to one aspect of the invention; and FIG. 2 is a schematic view of a gearbox according to a variant of the gearbox of FIG. 1.

  In Figure 1, a gearbox referenced 1 as a whole comprises a first solid primary shaft 2, and a second hollow primary shaft 3 mounted coaxially with the solid primary shaft 2 surrounding it. The primary shafts 2, 3 are rotatably mounted in a housing (not shown) and respectively provided on one side, at their ends, first and second progressive disengageable coupling devices, here in the form of clutches 4, 5 , in order to couple them in rotation with a drive shaft, for example an output shaft of an internal combustion engine of a motor vehicle.

  The first solid primary shaft 2 carries, from left to right in FIG. 1, a first fixed gear 6, a second fixed gear 7, a third fixed gear 8, and the first clutch 4. The second hollow primary shaft 3 is located on the first solid primary shaft 2 axially between the third fixed gear 8 and the first clutch 4.

  The second hollow primary shaft 3 carries, from left to right in FIG. 1, a fourth fixed gear 9, a fifth fixed gear 10, and the second clutch 5.

  The gearbox 1 comprises a first secondary shaft 11, at the top in FIG. 1, and a second secondary shaft 12, at the bottom in FIG. 1, the secondary shafts 11, 12 being parallel to the primary shafts 2, 3 and located in on both sides of these.

  The first secondary shaft 11 carries, from left to right in Figure 1, a first idler gear 13 meshing with the first fixed gear 6 of the first primary shaft 2, a second idler gear 14 meshing with the third fixed gear 6 of the first primary shaft 2, a third idler gear 15 having two teeth 16, 17 axially offset and of different radii, a first toothing 16 being located axially between the third idler gear 15 and a second toothing 17, the latter meshing with the fourth fixed gear 9 of the second hollow primary shaft 3, a fourth idle gear 18 meshing with the fifth fixed gear 10 of the second hollow primary shaft, and a fixed gear 19.

  The first secondary shaft 11 also carries means for coupling the idle gears 13, 14, 15, 18 in the form of double clutching means 20, 21, a double clutch 20 located between the first and second idle gear 13, 14, and a second double clutch 21 located axially between the third and fourth idle sprockets 15, 18. A double clutch is in a known manner in the form of a player integral in rotation with the shaft and can be moved axially to a pinion or lousy other selectively, to come to rotate in solidarity said idler gear with the shaft by frictional coupling and / or toothing, or maintained in a central position in which none of the idle gears is integral in rotation with the shaft.

  The second secondary shaft 12 carries, from left to right in Figure 1, a first idler gear 22 meshing with the second fixed gear 7 of the first hollow primary shaft 2, a second idler gear 23 meshing with the first toothing 16 of the third idler gear 15 of the first secondary shaft 11 (as illustrated by an arrow F1), a third idler gear 24 meshing with the fifth fixed toothing 10 of the second primary shaft 3, and a fixed gear 25.

  The second secondary shaft 12 also carries a single clutch 26 for the first idler gear 22, and a double clutch 27 located between the second idler gear 23 and the third idler gear 24.

  The fixed pinions 19 and 25 of the secondary shafts mesh with the same output toothing (not shown), which is for example a toothing of a wheel of a differential device located between the gearbox and wheels of a vehicle. .

  The gearbox 1 is shown schematically in the plane of Figure 1 for reasons of clarity. In fact, the secondary and primary shafts are not located in the same plane, which allows on the one hand the mutual gearing of the first toothing 16 of the third idler gear 15 of the first secondary shaft with the second idler gear 23 of the second secondary shaft 12, and other by the meshing of the fixed gears 19, 25 of the secondary shafts 11, 12 on the same output toothing.

  The first fixed gear 6 of the solid primary shaft 2 and the first idle gear 13 of the first secondary shaft 11 constitute a set of fifth gear gears forward. The coupling of the first idler gear 13 to the first secondary shaft 11 makes it possible to link in rotation the solid primary shaft 2 with the first secondary shaft 11.

  The other gear ratios are similarly obtained. The third fixed gear 8 of the first primary shaft 2 and the second idle gear 14 of the first secondary shaft constitute a set of gears third gear forward.

  The second fixed gear 7 of the solid primary shaft 2 and the first idle gear 22 of the second secondary shaft 12 constitute a set of first gear gears. The coupling of the idler gear 22 on the second secondary shaft 25 by means of the associated clutch 26 makes it possible to link in rotation the solid primary shaft 2 with the second secondary shaft 12.

  The fourth fixed gear 9 of the hollow primary shaft 3 and the second toothing 17 of the third idler gear 15 of the first secondary shaft 11 constitute a set of gears second gear forward.

  The fourth fixed gear 9 of the hollow primary shaft 3, the third idler gear 15 of the first secondary shaft 11 and the second idler gear 23 of the second secondary shaft 12 constitute a set of reverse gears.

  The fifth fixed gear 10 of the hollow primary shaft 3 and the fourth idle gear 18 of the first secondary shaft 11 constitute a set of gears sixth gear forward.

  The fifth fixed gear 10 of the hollow primary shaft 3 and the third idle gear 25 of the second secondary shaft 12 constitute a set of fourth gear gears.

  The operation of the gearbox 1 is described below.

  When the first gear is engaged, the single clutch 26 is actuated so as to couple the first idle gear 22 of the second secondary shaft 12, with said second secondary shaft 12, the other clutch 20, 21, 27 are inactive, the first clutch 4 is active and the second clutch is inactive 5.

  When the second gear is engaged, the second double clutch 21 of the first secondary shaft 11 is actuated so as to couple the third idler gear 15 of the first secondary shaft 11, with said first secondary shaft 11, the other interconnections 20, 26, 27 are inactive, the second clutch 5 is active and the first clutch is inactive 4.

  When the third gear is engaged, the first double clutch 20 of the first secondary shaft 11 is actuated so as to couple the second idle gear 14 of the first secondary shaft 11, with said first secondary shaft 11, the other interconnections 21, 26, 27 are inactive, the first clutch 4 is active and the second clutch is inactive 5.

  When the fourth gear is engaged, the double clutch 27 of the second secondary shaft 12 is actuated so as to couple the third idler gear 24 of the second secondary shaft 12, with said second secondary shaft 12, the other interconnections 20, 21, 26 are inactive the second clutch 5 is active, and the first clutch is inactive 4.

  When the fifth gear is engaged, the first double clutch 20 of the first secondary shaft 11 is actuated so as to couple the first idler gear 13 of the first secondary shaft 11, with said first secondary shaft 11, the other clutch 21, 26, 27 are inactive, the first clutch 4 is active and the second clutch is inactive 5.

  When the sixth gear is engaged, the second double clutch 21 of the first secondary shaft 11 is actuated so as to couple the fourth idler gear 18 of the first secondary shaft 11, with said first secondary shaft 11, the other interconnections 20, 26, 27 are inactive, the second clutch 5 is active and the first clutch is inactive 4.

  When the reverse gear is engaged, the double clutch 27 of the second secondary shaft 12 is actuated so as to couple the second idler gear 23 of the second secondary shaft 12, with said second secondary shaft 12, the other interconnections 20, 21, 26 are inactive, the second clutch 5 is active, and the first clutch is inactive 4. The torque is transmitted by the fourth fixed gear 9 of the solid primary shaft 3 to the third idler gear 15 of the first secondary shaft 11 via the second toothing 17, and returned via the first toothing 15 on the second idler rear gear 23 of the second secondary shaft 12, and the second secondary shaft 12 itself via the double clutch 27.

  Pinion gears of the odd forward gears, namely the first, third, and fifth gears, are driven by the first solid primary shaft 2. The gearsets of the forward gears, ie the second, fourth, and sixth gears gear ratios, and the set of reverse gears are driven by the second hollow primary shaft 3. The upshifts and downshifts are performed by rocking from one main shaft to the other by operating the clutches 4, 5 so that they are in a state where at least one clutch transmits the torque by sliding. The reverse gear can also be passed from the first forward gear without torque discontinuity, and vice versa.

  The pinion gears of the odd forward gears, namely the first, third and fifth gears, are grouped together at one free end of the solid primary shaft 2 which is not surrounded by the hollow primary shaft 3. Two sets of odd-ratio gears (third and fifth gear) comprise a pinion carried by a secondary shaft 11, a set of odd-ratio gear wheels (first gear) comprising a pinion carried by the other secondary shaft 12, said odd gear set being located axially between the sets of gears odd reports carried by the secondary shaft 11. This arrangement preserves the axial compactness of the gearbox.

  The sets of reverse gears and forward gears are grouped around the hollow primary shaft 3. The third idler gear 15 of the first secondary shaft 11 forms a pinion gear between the fourth fixed gear 9 of the primary shaft hollow 3 and the second idler gear 23 of the second secondary shaft 12. This results in a reversal of the direction of rotation which allows to obtain the reverse. The reverse gearset includes elements or gears in common with the second gear set, thereby limiting a number of gears and preserving the compactness of the gearbox 1.

  The set of second gear gears is completed to obtain the set of reverse gears by a toothing 16 and an idler gear 23 located axially between the second gear set of gears and a set of odd gear ratio, here the third. This arrangement allows to keep the axial compactness of the box. In addition, the reverse idle gear 23 carried by the second secondary shaft 12 shares a double clutch 27 with an idle gear a set of forward gear, here the idler gear of the set of gears fourth report. This limits a number of elements in the gearbox 1, while retaining the functions of the gearbox 1.

  The presence of two sets of teeth on the third idler gear 15 of the first secondary shaft 11 makes it possible to determine a reduction ratio between the pinions of the second gear gear set, and then to adapt the gear ratio between the first toothing 16 and the second idler gear 23. second secondary shaft to obtain a suitable reverse gear ratio.

  The sets of fourth and sixth gears include a common fixed gear, which limits the number of parts in the gearbox.

  Note that when the first clutch 4 and the solid primary shaft 2 transmit the torque, it is possible to actuate the second double clutch 21 of the first secondary shaft 11 or the double clutch 27 of the second secondary shaft 12 to prepare and anticipate the passage of the second, fourth or sixth gear, or reverse gear. Similarly, when the second clutch 5 and the hollow primary shaft 3 transmit torque, it is possible to actuate the first double clutch 20 of the first secondary shaft 11 or the single clutch 26 of the second secondary shaft 12 to prepare and anticipate the passage of the first, third or second report.

  In FIG. 2, where references to elements similar to those of FIG. 1 have been repeated, the gearbox 1 differs from the previous embodiment in that the sets of fourth and sixth gears 10, 18, 24 have been axially reversed with the gear sets of the reverse gear ratio and the second gear 9, 15, 23. In addition, the third idler gear 15 of the first secondary shaft 11 has a single toothing meshing with the fourth gear on the one hand fixed 9 of the hollow primary shaft, and secondly directly with the second reverse idler gear 23 of the second secondary shaft 12 (as illustrated by an arrow F1).

  The removal of the second toothing of the third idler gear 15 forming a reverse gears return reduces the axial size of the gearbox, but limits the design possibilities of the gearbox in terms of choice of gear ratios of reverse gear and second gear.

  Of course, the invention is not limited to the embodiments described above. For example, it would be possible for the sets of even gear gears to be driven by the solid shaft, the sets of odd gear gears being driven by the hollow primary shaft.

  Furthermore, it is conceivable to use as a reverse gear for the reverse a pinion of a set of gears of even ratio other than the second report. It will also be possible to modify the axial arrangement of the different sets of gears.

  Thanks to the invention, there is obtained a compact gearbox, allowing a torque transmission in different ratios, with gear changes without torque discontinuity, including when passing a reverse gear.

Claims (12)

  1. Gearbox of a parallel-shaft, geared motor vehicle comprising a solid primary shaft (2) and a concentric hollow primary shaft (3), at least two secondary shafts (11, 12) provided with respective drive pinions ( 19, 25) intended to mesh with the same toothing sets of fixed and crazy gears (6 to 10, 13 to 15, 18, 22 to 24) carried by the primary and secondary shafts and driven by the primary shafts, means for selectively coupling (20, 21, 26, 27) the idle gears on their shafts for the selection of a set of gears and a corresponding gear, characterized in that a set of first gear gears (7 , 22) is driven by a primary shaft (2), a set of reverse gears (9, 15, 23) being driven by the other primary shaft (3).   Gearbox according to Claim 1, characterized in that a set of reverse gear comprises a pinion (9) fixedly mounted on a primary shaft (3) and rotatably coupled to a gear (15). mounted idler on a first secondary shaft (11) and meshing with a reverse gear (23) idly mounted on a second secondary shaft (12) with possibility of coupling.   Gearbox according to any one of claims 1 or 2, characterized in that a set of gears of a forward gear comprises a pinion (9) fixedly mounted on a primary shaft meshing with a mounted pinion. idler (15) on the first sub-shaft (11) with possibility of coupling, a reverse gear set comprising the first fixed gear (9) of said primary shaft, the idle gear (15) of the first sub-shaft (11) forming a gear and meshing with a reverse gear (23) idly mounted on a second secondary shaft (12) with possibility of coupling.   4. Transmission according to claim 3, characterized in that the idler gear (15) of the first secondary shaft comprises a single toothing meshing simultaneously with the fixed gear (9) of the primary shaft and the reverse gear (23).   5. Gearbox according to claim 3, characterized in that the idler gear (15) of the first secondary shaft comprises a toothing (17) meshing with the fixed gear (9) of the first primary shaft and another toothing (16). meshing with the reverse gear (23) of the second primary shaft.   6. Transmission according to any one of claims 2 to 5, characterized in that the forward ratio is an even ratio, preferably the second ratio.   Gearbox according to one of the preceding claims, characterized in that the gear sets of the even gear ratios and the reverse gear ratio are driven by a primary shaft, the sets of odd gear gears being driven by the gearbox. other primary shaft.   8. Gearbox according to claim 7, characterized in that a first primary shaft carries successively in the axial direction a first fixed gear (6) meshing with a first idler gear (13) of a first secondary shaft, a a second fixed gear (7) meshing with a idler gear (22) of a second secondary shaft, and a third fixed gear (8) meshing with a second idler gear (14) of said first secondary shaft to form first gear sets third and fifth report.   9. Gearbox according to claim 8, characterized in that it comprises a double clutch (20) for the first and second idle gears (13, 14) of the first secondary shaft and a single clutch (26) for the first idler gear (22) of the second secondary shaft.   10. Gearbox according to any one of claims 7 to 9, characterized in that a second primary shaft carries a fourth fixed gear (9) meshing with a third idler gear (15) of a first secondary shaft forming returning to a second idle gear (23) on a second secondary shaft and forming a reverse gear, and a fifth fixed gear (10) meshing with a fourth pinion (18) idly mounted on said first secondary shaft (11) and a third idler gear (24) on said second primary shaft to form sets of reverse, second, fourth and sixth gears.   11. Gearbox according to claim 10, characterized in that it comprises a double clutch (21) for the third and fourth idle gears (15, 18) of the first secondary shaft and a double clutch (27) for the second and third idlers (23, 24) of the second secondary shaft.   12. Motor vehicle comprising a drive system with a gearbox according to any one of the preceding claims.