FR2880094A1 - Gear box for motor vehicle, has primary line with its rotation guided by ball bearings that are situated between drive pinion of main secondary shaft and other pinions of gearbox, where drive pinion is mounted in overhanging - Google Patents

Abstract

The gearbox has a primary line (5) with its rotation guided by ball bearings (19, 20) situated between a drive pinion (14) of a main secondary shaft (12) and other pinions of the gearbox. The pinion (14) is mounted in overhanging, of side of hydraulic clutches, with respect to bearing (42, 43) on which the shaft is mounted. The bearings (42, 43) are housed in a casing (10) of a mechanical box and in a partition (21), respectively.

Description

Gearbox with pinion mounted cantilever.

  The invention relates to the field of gearboxes used in particular in motor vehicles. Such gearboxes include several parallel shafts provided with a plurality of gears and synchronizers.

  In this field, the patent application DE 198 21 164 has described a gearbox comprising two secondary shafts each provided with a drive gear meshing the same ring gear, and guided in rotation by tapered roller bearings located at each end of the secondary trees. In addition, the box is equipped with two multidisc clutches coaxial and offset along the axis of the engine.

  Such a box has the disadvantage of a large footprint, and especially at the location of the housing surrounding the ring of the differential. Indeed, the architecture of the body of a vehicle defines support rails between which the engine block is implanted. This block includes the gearbox which contains the gears, the clutch, and the differential, as well as the engine and ancillary equipment such as the hydraulic distributor supplying the clutches, or the robots for controlling the forks of the synchronization systems. Because of its function, the differential uses a large crown. The transmission case has, at the location of the differential, a disc shape projecting transversely to the axis of the engine block. This form is very disadvantageous for the implantation of the engine block in certain type of vehicle.

  The invention proposes a gearbox which solves these disadvantages and in particular which reduces the size of the gearbox at the location of the housing surrounding the ring gear of the differential, so as to facilitate the implantation of the engine block containing the gear box. speeds.

  In one embodiment of the invention, the motor vehicle gearbox is parallel shafts provided with a plurality of pinions, and comprises at least one primary shaft connected to the vehicle engine by a clutch, at least one shaft secondary rotatably mounted on two bearings and provided with a pinion meshing with a differential ring. The drive gear of the secondary shaft is mounted cantilevered, on the side of the clutch, relative to the two bearings.

  It is conceivable, having reversed the position of a guide bearing of the secondary shaft and the pinion, the distance between the differential ring and the motor has been reduced.

  The invention is all the more advantageous that the gearbox comprises a solid primary shaft and a hollow primary shaft, coaxial and alternately connected to two coaxial clutches. Indeed, the fact of providing two clutches, often offset along the primary axes, increases the distance between the differential and the motor. The invention reduces this disadvantage.

  According to one characteristic of the invention, the gearbox comprises two secondary shafts each provided with a pinion meshing with the same differential ring.

  According to another characteristic of the invention, the gearbox comprises a mechanical assembly containing the pinions and the differential, the primary shaft and the secondary shaft being each mounted in rotation on a first bearing, housed in a housing of the mechanical assembly, and on a second bearing housed in a fixed partition relative to said housing. The pinion gear is located between said partition and the clutches. Advantageously, the mechanical assembly is separated from the clutches by a clutch housing, and the partition is fixed on the clutch housing.

  According to yet another characteristic of the invention, the gears of the mechanical assembly are lubricated with oil. The clutch housing is traversed by the two primary shafts. A first seal seals the oil between the two primary shafts. A second seal seals oil between one of the primary shafts and the clutch housing.

  Other features and advantages of the invention will appear on reading the detailed description of two embodiments taken as non-limiting examples, and illustrated by the accompanying drawings, in which: FIG. 1 is an extended section; a first embodiment of the invention, according to the broken plane II of Figure 3; FIG 2 is a representation of the kinematics of the gearbox of the first embodiment; FIG. 3 is a schematic transverse representation of the first embodiment; - Figure 4 is a representation, in plan view, of the implementation of the gearbox in a vehicle; and FIG. 5 is a representation of the kinematics of the gearbox of a second embodiment.

  As illustrated in Figures 1 to 3, the gearbox comprises a mechanical assembly 1 comprising a plurality of gears and a differential 2 connected to the wheels of the vehicle. A clutch assembly 3 is connected on one side to a drive shaft 4 and on the other side to a primary line 5 emanating from the mechanical assembly 1.

  The primary line 5 comprises a solid primary shaft 6 driven in rotation by a hydraulic clutch 7 and a hollow primary shaft 8 driven in rotation by a hydraulic clutch 9.

  The primary shafts 6 and 8 and the clutches 7 and 9 are coaxial with the drive shaft 4.

  The mechanical assembly 1 is housed in a housing 10. The clutch assembly 3 is housed in a housing 11 traversed by the solid primary shaft 6 and the hollow primary shaft 8.

  The mechanical assembly 1 also comprises a main secondary shaft 12 and an auxiliary secondary shaft 13, both provided with synchronizers. The main secondary shaft 12 is provided with a driving pinion 14 meshing with a ring 15 of the differential 2. The mechanical assembly 1 also comprises an intermediate shaft 16.

  The hollow primary shaft 8 is guided in rotation around the solid primary shaft 6 by a pair of needle bearings 17 and 18 located between the two primary shafts. The rotation of the primary line 5 is guided by a pair of ball bearings 19 and 20. The bearing 19 guides the end of the solid primary shaft 6 into the housing 10 on one side of a bottom area of the housing. mechanical assembly 1, and the bearing 20 guides the hollow primary shaft 8 on the side of a front zone of the mechanical assembly in a partition 21. The partition 21 is fixed on the housing 11, itself fixed on the housing 10.

  The primary line 5 comprises a pair 22 of return teeth, freely rotatable about the solid primary shaft through a needle bearing 23. The immobilization in axial translation of the primary line 5 is achieved by the ball bearings 19 and on the one hand, and by roller stops 24 and 25 on either side of the pair 22 in contact with, respectively, the pinion 30 forming a radial shoulder of the solid primary shaft 6, and the pinion 33 forming a radial shoulder of the hollow primary shaft 8.

  The primary line 5 passes through the casing 11. The sealing of this crossing is ensured in both directions by two double lip seals 26 and 27 preventing oil from the hydraulic clutches 7 and 9 from coming into contact with the mechanical assembly lubricating oil 1. The seal 26 is located between the roller thrust bearing 25 and the needle bearing 19. Such a seal could equally well be at the end of the hollow primary shaft 8 on the clutch side 7. The seal 27 is housed between the casing 11 and the hollow primary shaft 8.

  From left to right of FIG. 1, the solid primary shaft 6 has three fixed toothing 28, 29, 30. The return torque 22 has two toothing 31, 32, and the hollow primary shaft has two fixed toothing 33 and 34 .

  The main secondary shaft 12 is provided from left to right in FIG. 1 with a first gear 35, a fifth gear 36, a main gear 37, a sixth gear 38 and a gear. A second pinion 39. The first, fifth, sixth, second gears are rotatably mounted by means of needle bearings. The idler gear 37 is fixedly mounted on the main secondary shaft 12 by splines.

  Dual synchronizers 40 and 41 are mounted on a synchronizer body attached to the main secondary shaft 12 by means of splines. The dual synchronizer 40 is located between the first gear 35 and the fifth gear 36 while the dual synchronizer 41 is located between the sixth gear 38 and the second gear 39. Each of these synchronizers 40, 41 is provided with a walkman that can take exclusively three positions: a neutral position, a synchronized position on one side and a synchronized position on the other.

  The main secondary shaft 12 is rotatably mounted on two bearings 42, 43. The first bearing 42 is placed at the end of the main secondary shaft 12 at the bottom of the box and housed in the casing 10 of the mechanical gearbox 1. The second bearing 43 is located between the drive gear 14 and the second gear 39 and housed in the partition 21. Thus, the pinion 14 is cantilevered.

  The auxiliary secondary shaft 13 is provided, from left to right in FIG. 1, with a roller bearing 44 housed in the casing 10 of a third gear 46, a hub 49, a body 47 of synchronizer 48, a roller bearing 45, housed in the housing 11. The third gear 46 and the body 47 of the synchronizer 48 are fixedly mounted on the auxiliary secondary shaft 13 by means of splines.

  The hub 49 is rotatably mounted around the secondary auxiliary shaft 13 by means of needle bearings 50, and occupies the entire length between the pinion 46 and the synchronizer body 47 which are themselves immobilized in axial translation by the Roller bearings 44 and 45. The hub 49 is equipped from left to right in FIG. 1 with an auxiliary idler gear 51, a fourth gear 52, a double synchronizer body 54, a pinion 55 and a wheel 56. The pinion 51, the synchronizer body 53, and the wheel 56 are fixed on the hub 49 by means of splines. The pinions 52 and 55 are free to rotate around the hub 49 by means of needle bearings 57. The pinions 52 and 55 and the wheel 56 are provided with synchronization means cooperating with the players of the synchronizers 54 and 48. adjustable return 49a is composed by the hub 49, the pinion 51, the pinion 55, and the synchronizer 54 in the synchronized state with the pinion 55. The synchronizer 54 is able to secure the pinions 51 and 55, without causing the rotation of auxiliary secondary shaft 13.

  The secondary auxiliary shaft 13 is pierced by a channel 58a for lubricating the needle bearings 50. The hub 49 is pierced with a transverse lubrication channel 58 communicating the bearings 50 and 57.

  The intermediate shaft 16 is provided with a hub 59, free to rotate around the intermediate shaft 16 by means of needle bearings 60, and on which are fixed two teeth 61 and 62. A return device 59a comprises the hub 59 and the two sets of teeth 61, 62.

  The differential 2 comprises a body 63 supporting the ring gear 15 and rotatably mounted on two roller bearings 64, 65 respectively housed in the casing 10 of the mechanical assembly 1 and in the casing 11 of the clutch assembly 3. An axis 66, perpendicular to the axis of the ring 15, is fixed in the body 63, and supports two satellites 67, 68 with conical teeth, free to rotate about the axis 66, and meshing both simultaneously with two bevel gears 69, 70. The bevel gears 69, 70 are coaxial with the ring 15, and each drive a shaft respectively 71 and 72 connected to a wheel of the vehicle.

  The shaft 71 is rotatably mounted in a bore of the body 63 of the differential 2. The shaft 72 is rotatably mounted in a collar 73 fixed to the body 63. The oil seal between the mechanical assembly 1 and the outside is provided by two lip seals 74 and 75 housed, one between the housing 10 and the shaft 72, the other between the housing 11 and the shaft 71.

  The clutch assembly 3 is delimited by the casing 11 and a cover 76 closed with each other in a sealed manner. The drive shaft 4 passes through the cover 76 in an oiltight manner by means of a seal 77.

  The clutch assembly 3 comprises a hydraulic distributor 78 surrounding the hollow primary shaft 8 and alternately operating bodies 79 and 80 each supporting a plurality of disks. A clutch bell 81, connected to the drive shaft 4, also comprises a plurality of disks cooperating with each of the bodies 79 and 80, one of which is integral with the solid primary shaft 6 and the other integral with the hollow primary shaft 8 with grooves.

  The kinematics of the gearbox illustrated in FIGS. 1 to 3 will now be described, relying essentially on the diagram of FIG. 2.

  The reports of first and fifth pass the torque of the drive shaft 4 by, successively, the clutch 7, the solid primary shaft 6, the teeth respectively 28 and 29, respectively first 33 and fifth gear 36, the dual synchronizer 40, the main auxiliary shaft 12, and the drive pinion 14.

  The reports of sixth and second pass the torque of the motor shaft 4 by, successively, the clutch 9, the hollow primary shaft 8, the teeth respectively 33 and 34, the gears respectively sixth 38 and second 39 , the double synchronizer 41, the main auxiliary shaft 12, and the drive pinion 14.

  The third ratio passes the torque of the motor shaft 4 by, successively, the clutch 7, the solid primary shaft 6; the toothing 30, the third gear 46, the single synchronizer 48, the hub 49, the auxiliary idler gear 51, the intermediate return torque 22, the main idler gear 37, the main secondary shaft 12, and the pinion of attack 14.

  The fourth gear ratio passes the torque of the motor shaft 4 by successively, the clutch 9, the toothing 33, the fourth gear 52, the double synchronizer 54, the hub 49, the auxiliary drive gear 51, the torque intermediate return gear 22, the main return gear 37, the main secondary shaft 12, and the drive pinion 14.

  The reverse gear ratio passes the torque of the drive shaft 4 by, successively, the clutch 9, the toothing 34, the teeth 61 and 62 of the hub 59 of the intermediate shaft 16, the reverse gear 55, the double synchronizer 54, the hub 49, the auxiliary idler gear 51, the intermediate return torque 22, the main idler gear 37, the main secondary shaft 12, and the driving pinion 14.

  The first, third and fifth gear ratios are obtained by the solid primary shaft 6 via the clutch 7 while the reverse, second, fourth and sixth gear ratios are obtained via the clutch 9. a ratio to an adjacent higher or lower ratio is without torque discontinuity. Indeed, the shift sequence is to engage the synchronizer of the adjacent report simultaneously with that of the current report. Thus, the primary shaft, not yet connected with the drive shaft 4, is rotated. The hydraulic distributor 78 begins clutching the clutch which was free so that gradually the torque changes from the clutch initially clamped to the free clutch while the one that was tightened is gradually released. During this transition phase, the incompatibility of the reports is concealed by the simultaneous slippage of the two clutches. This transition without torque discontinuity also takes place between the first and reverse gears, which is particularly useful for maneuvering the vehicle in a parking lot.

  The high ratio gears are rather in the central area of the primary and secondary shafts while the first, second and reverse low ratio gears are located in the vicinity of the axis support bearings. The high forward gears cause the engine power to pass with a high rotational speed, low torque and low forces on the teeth. Putting the high ratio gears in the central zone of the shafts of the gearbox greatly reduces the deflection of these shafts or, alternatively, increases the power transmitted by the gearbox.

  FIG. 3 illustrates the transverse juxtaposition of the front part of the mechanical assembly 1. We find the main intermeshing which freeze the different interaxles of the gearbox. The distance between the primary line 5 and the main secondary shaft 12 is fixed in particular by the meshing of the toothing 34 with the second gear 39. The distance between the primary line 5 and the intermediate shaft 16 is fixed by the meshing of the toothing 34 with the pinion 61. The distance between the intermediate shaft 16 and the auxiliary secondary shaft 13 is fixed by meshing of the pinion 62 with the reverse pinion 55. The distance between the primary line 5 and the secondary auxiliary shaft 13 is not shown in FIG. 3 because it is fixed by meshes located in the rear part of the gearbox, in particular the meshes of the third gear 46 with the toothing 30. The distance between the axis of the differential ring 15 and the main secondary axis 12 is fixed by the meshing of the pinion gear 4 with the ring gear 15. Moreover, the secondary shafts 12 and 13 do not have a directly meshing pinion e to be between them. The secondary auxiliary shaft 13 does not drive the differential ring 15. Intermediate shafts 16, auxiliary secondary 13 and primary line 5 are bonded together but can take any position around the main secondary shaft 12.

  We will now describe, with the help of Figure 4, the implementation of the gearbox in the vehicle.

  A motor vehicle 100 is equipped with four wheels 101. An engine block 102 comprises in particular the engine 103 and the gearbox 104. Support rails 105 secure the engine block 102 in the vehicle body 100.

  The gearbox 104 comprises a casing in which different zones corresponding to each of the gearbox components are distinguished. A clutch zone 106, a primary shaft zone 107, a main secondary shaft zone 108, an auxiliary secondary shaft zone 109, an intermediate shaft zone 110 and a differential zone 111 are thus distinguished.

  An axis 112 comprises a portion 112a corresponding to the axis of the crankshaft of the engine 103, a portion 112b of the clutches 7 and 9 and a portion 112c of the primary line 5. An axis 113 connects the wheels 101 and comprises a portion 113a corresponding to the wheel axes and a portion 113b corresponding to the ring 15 of the differential. The arrangements of the various axes from left to right are found in FIGS. 3 and 4: the intermediate shaft 16, then the axis of the primary line 5, then the axis of the secondary auxiliary shaft 13, then the axis of the main secondary shaft 12, and finally the axis 113b of the differential ring 15.

  The overall length of the primary axes 6 and 8 and the main secondary shaft 12 are substantially identical. The size of the secondary auxiliary shaft 13 is smaller and the size of the intermediate shaft 16 is even smaller.

  The support spar 105 passes over the primary shaft area 107 and the main secondary shaft 108 in the extension of the auxiliary secondary shaft area 109 and the intermediate shaft 110. distance between the zone 111 of the gearbox housing surrounding the differential and the motor 103, makes it possible to widen the support spar 105. The mechanical strength of the support spar 105 makes it possible to improve the diffusion of energy during an impact. front frontal. Thus, the gearbox according to the invention can be implanted in vehicles having better energy absorption in the event of a frontal impact.

  A second embodiment shown in FIG. 5 will now be described. The gearbox comprises a solid primary shaft 201 and a hollow primary shaft 202 respectively driven by a clutch 203 and a clutch 204. The gearbox also comprises two shafts. secondary 205 and 206 each provided with a pinion 207 and 208 meshing with the same differential ring 209.

  The set of the solid primary shaft 201 and the hollow primary shaft 202 are rotatably mounted on a rolling bearing 240 located at the left end of the solid primary shaft 201 and on a bearing 241 located on the hollow primary shaft 202 between the clutches 203 and 204 and the teeth of the hollow primary shaft 202. The secondary shaft 205 is rotatably mounted on two bearings 242 and 243 located on the same side of the pinion gear 207. Similarly, the secondary shaft 206 is rotatably mounted on two bearings 244 and 245 located on the same side of the pinion gear 208, so that the two pinions 207 and 208 are both cantilevered with respect to secondary trees 205 and 206.

  A partition 246 receives the bearings 241, 243 and 245 so that all the gears of the gearbox are situated to the left of the partition 246 in FIG. 5 while the two drive gears 207 and 208 as well as the clutches 203 and 204 are situated to the right of the partition 246 in FIG.

  From left to right of FIG. 5, the solid primary shaft 201 comprises the fixed toothing 210, 211 and 212, the hollow primary shaft 202 comprises the fixed toothing 213, 214 and 215. The main secondary shaft 205 comprises on the left on the right in FIG. 5, a first idle gear 216, a double synchronizer 217, a third idle gear 218, a fourth idle gear 219, a double synchronizer 220, a second idle gear 221. The first gear 216 and third 218 are alternately secured to the auxiliary secondary shaft 205 by the synchronizer 217. Similarly, the fourth and second gears 219, 221 are alternately secured to the auxiliary secondary shaft 205 by the synchronizer 220.

  The secondary auxiliary shaft 206 is provided from left to right in FIG. 5, a fifth idler gear 222, a simple synchronizer 223, a wheel 224 arranged on the body 223a of the simple synchronizer 223, and a hub 225 mounted free to rotate about the secondary auxiliary shaft 206. The hub 225 is equipped with a double synchronizer 226 fixedly mounted on the hub 225, a idler gear 227 mounted to rotate freely about the hub 225 and a sixth gear 228 fixedly mounted on the hub 225 and thus free to rotate about the auxiliary secondary shaft 206.

  The body 223a of the simple synchronizer 223 is provided with a sliding device 232 capable of selectively securing the fifth pinion 222 with the auxiliary secondary shaft 206. The double synchronizer 226 allows, in a neutral position, to leave the pinions 227, 228 and 208 independent of each other. The synchronizer 226 is provided with a sliding device 226a capable of cooperating with synchronization means of the wheel 224 in order to selectively join the sixth gear 228 with the auxiliary secondary shaft 206 and with the pinion gear 208. In a second position of the player 226a, the synchronizer 226 secures the pinion 227 with the hub 225 and with the sixth gear 228, without driving the auxiliary secondary shaft 206, and thus provides a reversing device 225a reversible modulable. This device 225a makes it possible to obtain several reverse gears, each having a sequence of four meshes.

  The gearbox comprises an intermediate shaft 229, non-coaxial with none of the primary shafts 201, 202, or any of the secondary shafts 205, 206. The intermediate shaft 229 has two fixed pinions 230 and 231 integral in rotation, meshing respectively with the toothing 212 and the idler gear 227. A return device 229a is composed of the intermediate shaft 229 and the two gears 230 and 231. In a first reverse ratio, the two synchronizers 217 and 226 are biased. The synchronizer 217 secures the first gear 216 with the main secondary shaft 205 and the synchronizer 226 secures the idle gear 227 with the free hub 225. The engine torque passes via the clutch 204 through a first, then a second, and then a third, then a fourth engrènements. The first meshing links the toothing 215 with the sixth gear 228, belonging to the deflection device 225a. The second meshing links the gear 227 of the deflection device 225a with the gear 231 belonging to the deflection device 229a. The third meshing links the gear 230 of the return device 229a to the toothing 212. The fourth meshing links the toothing 210 with the first gear 216. The solid primary shaft equipped with the two sets of teeth 210 and 212 is free to rotate relative to to the hollow primary shaft, performs the functions of a return device 201a.

  In a second reverse ratio, the engine torque passes via the clutch 203 through the third meshing already described, then the second meshing already described, then the first meshing already described, and finally with the meshing connecting the toothing 214 with the second pinion 221. The hollow primary shaft, equipped with two sets of teeth 215 and 214 and free to rotate relative to the solid primary shaft, forms a deflection device 202a.

  In each of the two embodiments, the distance between the driving pinion (s) and the clutches is reduced by the fact that the bearings carrying the secondary shafts are located between the pinion gear and the other pinions of the gearbox. and not between the pinion gear and the clutches. Thus, the size of the gearbox at the location of the housing surrounding the differential ring has been greatly reduced.

Claims (6)

  A motor vehicle gearbox, with parallel shafts provided with a plurality of pinions, comprising at least one primary shaft (6, 8) connected to the motor (4) of the vehicle (100) by a clutch (7, 9). and at least one secondary shaft (12) rotatably mounted on two bearings (42, 43), and provided with a pinion gear (14) meshing with a differential ring (15), characterized in that the pinion driving (14) of the secondary shaft (12) is mounted cantilevered, the side of the clutch (7-9), relative to the two bearings (42, 43).   2- gearbox according to claim 1, characterized in that it comprises a solid primary shaft (6) and a hollow primary shaft (8), coaxial and alternately connected to two coaxial clutches (7, 9).   3- gearbox according to one of the preceding claims, characterized in that it comprises two secondary shafts (205, 206) each provided with a pinion gear (207, 208) meshing with the same ring gear (209). ) differential.   4- Gearbox according to one of the preceding claims, characterized in that it comprises a mechanical assembly (1) containing the pinions and the differential (2), the primary shaft (6, 8) and the shaft secondary (12, 13) being each rotatably mounted on a first bearing (19, 42) housed in a housing (10) of the mechanical assembly (1), and on a second bearing (20, 43) housed in a partition (21) fixed relative to said housing (10), the pinion (14) being located between said partition (21) and the clutches (7, 9).   5- gearbox according to claim 4, characterized in that it comprises a clutch housing (11) separating the mechanical assembly (1) clutches (7, 9), and in that the partition ( 21) is fixed on the clutch housing (11).   Gearbox according to Claim 5, characterized in that the pinions of the mechanical assembly (1) are lubricated by oil, and the clutch housing (11) is traversed by the two primary shafts ( 6, 8), and that a first seal (26) seals the oil between the two primary shafts (6, 8), a second seal (27) sealing the oil between one of the primary shafts (8) and the clutch housing (11).