FR2897136A1 - Gearbox for e.g. motor truck, has high speed shaft coupled to intermediate shaft via speed reducing gear train that serves as input in planetary transmission which has planetary gearsets, clutches and brakes and is coupled to output shaft - Google Patents

Abstract

The gearbox has disk clutches and disk brakes for selecting gear ratios between a high speed shaft (B) and an output shaft (S) coupled to wheels of a vehicle. The high speed shaft is coupled to an intermediate shaft (C) via a speed reducing gear train (TE) that serves as an input in a planetary transmission by two ways. A planet carrier (4) and a wheel (5) of the train are coupled to the high speed shaft and the intermediate shaft, respectively. The planetary transmission has planetary gearsets (T1-T3), clutches (E1-E4) and brakes (F1, F2) and is coupled to the output shaft.

Description

Page 1 of 10

  The present invention relates to a gearbox with planetary transmission giving up to eleven gears in forward gear and two gears in reverse, for vehicles and particularly industrial vehicles capable of precise maneuvers at low speeds and also capable of high top speeds. , such as trucks and coaches.

  Patent FR 2 870 580 discloses an eight-speed gearbox whose input and output shafts can be aligned or parallel. In a first example, the aligned input and output shafts are connected through a hydraulic torque converter supported on a free wheel, then a first planetary gear train with two sets of satellites, followed by a double planetary gear of the Ravigneaux type. . The speeds of the double planetary gear are controlled by means of two brakes and selectively actuated gear while the sun gear of the first train remains fixed.

  In other examples, one of the brakes is assisted by a freewheel, or the double train is replaced by two associated trains, or one of the clutches is removed to have only six speeds forward; in all cases the movement output is done by a crown. Mention is also made of the parallel input and output shafts with the use of gears which are still in engagement, combined with two single trains, the planet and planet gear assembly of which is integral with the output shaft. The disadvantage of a planetary gear (10) with geared satellites (13 and 13a) between pinion and crown is that when the space between pinion and crown must be reduced the satellites become too small and rotate at speeds too high. This does not allow to obtain a reduction which could advantageously be lower than the cited value of 0.477. Another disadvantage attaches to the train Ravigneaux which does not allow to choose gear ratios that can lead to an opening of the gear ratios and extended speed jumps to speed easier to control. Finally, the coaxial assembly requires the use of a Ravigneaux train, the output of torque only by the crown induces higher gear constraints than a set of planetary carrier crowns simple planetary trains.

  The applicant has the problem of avoiding the aforementioned drawbacks and of obtaining, in a coaxial design, more gear ratios with increased opening. The Applicant has also posed the problem of crossing higher torque and power levels for application to heavy vehicles. That is to say, to design a transmission capable of offering up to eleven speeds forward and by lightening the number of components, eight and six speeds. To this end, the invention relates to a planetary transmission having up to eleven gears in forward gear, a brakeless dead point and two reverse gears between a drive shaft (A) connected to a first gear intermediate shaft (B) by a clutch (EA), the clutch and disc type gearbox for selecting 2897136 Page 2 of 10

  the gears, and of the type comprising a hydraulic torque converter with a freewheel reactor, said box being characterized in that said first intermediate shaft (B) is connected to a second intermediate shaft (C) by a speed-reducing gear (TE ) gear 5 always in engagement serving as input to a planetary transmission by two ways, one being a wheel (5) integral with the shaft (C) the other way being another component (4) of the reduction gear (TE), said planetary transmission comprising three simple planetary gear trains (T1, T2, T3), four clutches (E1, E2, E3, E4) and at least two brakes (F1, F2). According to a characteristic of the invention, the gearbox comprises, on the input channel passing through the planet carrier (4) of the gearbox (TE), an inverter train (TR) whose pinion (101) is integral with the satellite gates (4) whose satellites (102) meshing with a ring gear (103) integral with the pinion (11) of the train (T1) and whose satellite gate (104) is capable of being braked by a third brake (F3) , is connected to a clutch (E4).

  Other features and advantages will become apparent from the following description. In the accompanying drawing, given by way of example only, FIG. 1 is a schematic view with conventional representation of a gearbox of the invention at eleven forward gears, braked dead point and two gears, the input and output shafts of which are coaxial, FIG. 2 is an operating grid of the box of FIG. 1 showing by dark spots the brakes and clutches actuated for each gear ratio, FIG. 3 is a view similar to FIG. 1 of an eight-speed forward gearbox whose input and output shafts are coaxial, FIG. 4 is an operating grid similar to FIG. 2 of the box of FIG. 3, FIG. 5 is a view similar to FIG. 3 of a simplified six-speed forward gearbox, whose trains are of identical reasons FIG. 6 is an operating grid of the box of FIG. 5

  According to the exemplary embodiment of FIG. 1, the gearbox interposed between an input drive shaft (A) and an output shaft (S) connected to the wheels of a vehicle, the shafts (A) and (S) being coaxial, comprises elements known to upstream of the planetary transmission of the invention.

  35 KNOWN ELEMENTS: These are: a hydraulic torque converter (PTR) with pump (P), turbine (T), reactor (R) supported on a freewheel (RL) which allows rotation only in the direction of the motor . The shaft connected to the pump carries a disk clutch (EA) whose driven disk is connected to a first intermediate shaft (B) said fast shaft. The shaft (B) is also connected to the turbine of the torque converter. The box of the invention is selectively actuated by three brakes (F1, F2, F3) and four clutches (E1, E2, E3, E4) disc type as the brakes. 2897136 Page 3 of 10

  PLANETARY TRANSMISSION OF THE INVENTION: The fast shaft (B) coaxial with the shaft (A) rotates the planet carrier (4) of a planetary gear (TE) at the entrance of the mechanism of the invention. The bodies (B) and (4) are integral in rotation. The train (TE) has two pairs of parallel gear wheels still in engagement. The first being constituted by a pi-gnon (1) fixed to the housing (H) not shown and a wheel (2) geared to the pinion (1); the second being constituted by a wheel (5) meshing with a pinion (3) integral in rotation with the wheel (2). The wheel (5) coaxial with the fixed gear (1) drives the shaft (C). The gears (2) and (3) are carried by the planet carrier (4) to form planetary satellites (1) and (5). The diameter of (2) is greater than the diameter of (1), the diameter of (5) is greater than the diameter of (3) which is itself smaller than the diameter of (2). The ratios of their dimensions make the train (TE) a speed reducer of the shaft (C) relative to that of the shaft (B) so that the shaft (C) can be described as slow for differentiate from the fast shaft (B). The slow shaft (C) and the planet carrier (4) serve as inputs to an inverting planetary gear (TR) and the planetary assembly of the three trains (Ti, T2, T3). The planet carrier (4) of the train (TE) is positively connected in rotation to the pinion (101) of the inverter train (TR), to a clutch (E4) and by a tubular shaft (D66) to a clutch (E3). on which we will return later. The components of the inverting planetary gear (TR) are a pinion (101), satellites (102), a planet carrier (104) and a ring gear (103). The planet carrier (104) is extended by two groups of disks, one constituting the driven part of the clutch (E4), the other being able to be immobilized by the brake (F3). The pinion (101) is extended by a hollow shaft (D65) integral with the driving portion of the clutch (E4) and the planet carrier (4) of the train (TE), thus of the fast shaft (B). 25 Connections of the train (TR) with the train (T1): The crown (103) of the train (TR) is integral in rotation with a pinion (11) belonging to the train (Ti). The crown (103) also bears the brake discs by brake (F1 Train connections (T1) and (T2): The components of the train (Ti) other than its pinion (11) and its satellite carrier (66) are the satellites (12) and a crown ( The satellite gate (66) is extended by brake discs by the brake (F2) and rotatably connected to the planet carrier (7) of the train (T2) and to the driving portion of the vehicle. clutch (E3) The ring (13) of the train (Ti) is integral in rotation with the ring gear (23) of the train (T2) The ring gear (13) is extended by a tubular element (9) which, by means of a plate is connected to the output shaft (S) 35 Connections of the trains (T2) and (T3): The train (T2) comprises a pinion (21), a satellite carrier (7), satellites (22) and a crown (23) The pinion (21) of the train (T2) is solid rotating area of the pinion (31) of the train (T3). The 2 gears (21) and (31), of different diameters in this example, are extended by disks which are the driven part of the clutch (E2). The other components of the train (T3) are the satellite gate (8), the satellites (32) and the crown (33). The satellite carrier (8) is integral in rotation with the tubular element (9) and therefore the rings (13) and (23) and the output shaft (S). 2897136 Page 4 of 10

  The slow shaft (C) its clutches (El) and (E2) and the trains (T2) and (T3): The slow shaft carries the driving parts of the clutches (El) and (E2). The driven disks of the clutch (El) are integral with the crown (33). The driven portion (discs) of the clutch (E2) extends the pinions (21) and (31) of the trains (T2) and (T3) which it is integral in rotation. Clutches (E3, E4): The gears (11) and (21) of the trains (Ti, T2) are separated by the driving part of the clutch (E3) itself secured to the satellite carrier (66) common to the trains ( T1, T2). The driven portion of the clutch (E3) is connected to the planet carrier (4) of the train (TE) by a hollow shaft (D66). Finally, the driven part of the clutch (E3) is secured to the driving part 10 of the clutch (E4) by the hollow shafts (D65) and (D66) and the planet carrier (4) of the train (TE). The driven portion of the clutch (E4) is integral with the planet carrier (104) of the train (TR) and the brake (F3).

  OPERATION OF THE GEARBOX, SPEEDS, Fig. 1 and 2. As known the hydraulic torque converter (PTR) gradually couples the shaft (A) and the shaft (B) with some amplification of the engine torque. It facilitates shifting but must be short-circuited by the clutch (EA) to suppress its speed slip which would alter the transmission efficiency. The planetary operation of the train (TE) generates a constant speed of the clutches 20 (E1) and (E2), that is to say a speed of the shaft (C) which is reduced relative to that of the shaft (B) that is that of the inlet (A) when the clutch (EA) is tight. By the interplay of the inverter train (TR) the pinion (11) of the train (Ti) can turn upside down at a reduced speed when the brake (F3) is tightened, or at the speed of the input shaft (B). ) when the clutch (E4) is tight, or be stopped when the brake (F1) is tightened. The movement can also enter, at the level of the slow speed of the shaft (C), in the group of trains (Ti, T2, T3) by the pinions (31) and (21) and the ring (33), either by (E1) or by (E2) or by (E1) and (E2). The planet carrier (66) of the train (Ti) is a reaction element when the brake (F2) is tightened and it is also input element at the high speed of the shaft (B) when the clutch (E3) is tight. By combining some friction elements by two at a time, and only two, according to the grid of FIG. 2, the transmission gives eleven forward gears, two reverse gears and a braked dead point position, that is to say that the engine can turn without any action on the vehicle, while that it is immobilized by the simultaneous tightening of the two brakes (F1 and F2). The transmission of the invention lends itself to making gearboxes whose opening can vary from 14 to 20 as shown in Table No. 1 below. The opening is the ratio between the highest speed and the lowest speed. The eighth gear is a direct grip and the last three gears are overdrive up to 1.45. The jumps between reports (ratio of a speed to the speed immediately below or step in English) are 40 decreasing with the rise of the reports. In order to adjust the opening level and the favorable staggering of the steps, it suffices to choose the level (x) of the slow speed, the level (u) of the reverse speed given by the train of inversion (TR) and the reasons (ri, r2, r3) of the trains (Ti, T2, T3) Table n 1 gives the values of the steps (St) in examples of realizations where the reasons (r1) and (r2 ) are identical to r. Table n 1 opening rr3 xu St1 St2 St3 St4 St5 St6 St8 St8 St9 14 3.39 2.35 0.483 0.338 1.68 1.42 1.42 1.42 1.42 1.32 1.22 1.15 1.12 1. 08 15 3.25 2.5 0.43 0.305 1.71 1.4 1.4 1.4 1.38 1.33 1.27 1.17 1.1 1.07 16 3.35 2.43 0.415 0.29 1.71 1.41 1.41 1.41 1.41 1.35 1.26 1.17 1.1 1.07 17 3.63 2.43 0.415 0.29 1.79 1.47 1.41 1.41 1.41 1.37 1.25 1.16 1.1 1.06 18 3.93 2.43 0.415 0.29 1.85 1.53 1.41 1.41 1.41 1.38 1.24 1.15 1.1 1.06 19 4.12 2.53 0.387 0.284 1.85 1.54 1.4 1.4 1.45 1.43 1.25 1.15 1.08 1.05 20 4.3 2.6 0.38 0.28 1.93 1.57 1.4 1.38 1.45 1.45 1.25 1.14 1.08 1.06 According to the scheme of FIG. 3, concerning an EVE SPEED gearbox in forward gear, two reverse gears and a brakeless dead point, the inverter gear (TR) and the brake (F3) are removed. In FIG. 3 the bodies equivalent to those of FIG. 1 and having the same functions 15 carry the same references. It is the same planetary transmission with trains (Ti, T2, T3), with clutches (El, E2, E3, E4) and with brakes (F1, F2) whose connections are identical to those of FIG. 1 except for the pinion (11) whose extension carries the driven discs of the clutch (E4) whose driving portion has remained secured to the planet carrier (4), itself secured to the fast shaft (B). The operation is similar to this one of the eleven-speed gearbox from which the first, third and eleventh gear are suppressed. The combinations of switching members are represented by dark spots on the grid of FIG. 4. The transmission of the invention lends itself to making gearboxes whose opening can vary from 6.5 to 10. as shown in Table 2. The sixth gear is a direct catch and the last two speeds are overdriven. at 1.5. The jumps between reports are decreasing with the rise of the reports. In order to adjust the opening level and the favorable staggering of the steps, it suffices to choose the level (x) of the so-called slow speed and the reasons (ri, r2, r3) of the trains (Ti, T2, T3). Table 2 gives the values of the reverse ratio (AR), the first forward and the 30 steps in example embodiments where the reasons (r1), (r2) and (r3) are identical and equal designated by the only word reason.

  Page 6 of 10 Table 2 Opening reason x. AR 1 "St1 St2 St3 St4 St5 St6 St7 6.5 2.6 0.508 0.19 0.21 1.72 1.38 1.27 1.23 1.26 1.19 1. 16 7 2.5 0.475 0.19 0.19 1.71 1.4 1.32 1.25 1.28 1.21 1.16 7.5 2.5 0.447 0. 18 0.18 1.71 1.4 1.35 1.27 1.3 1.22 1.15 8 2.5 0.42 0.17 0.17 1.71 1.4 1.39 1.28 1.32 1.23 1.14 9 2.17 0.4 '0.18 0.16 1.68 1.46 1.48 1.28 1.32 1.28 1.14 10 2 0.375 0.19 0.15 1.67 1.5 1.56 1.29 1.33 1.31 1.14 Following the box scheme at SIX FRONT SPEEDS and a rear speed 5, the reduction gear (TE) is modified and the number of clutches reduced to three: two clutches (E1 and E2) connected to the slow shaft and a clutch (E3) whose driving portion is connected to the (B) In an arrangement suitable for suitable reduction ratios, the reduction gear (TE) comprises a pinion (201) fixed to the housing (H), two satellites (202) meshing together carried by the planet carrier (204). and geared on the ring gear (203) The planet carrier (204) is connected to the fast shaft (B) and to the driving portion of the clutch (E3); The disks led by (E3) are connected to the satellite carriers of the trains (T1) and (T2). The crown (203) drives the slow shaft (C) of the two clutches (El) and (E2). All other links are identical to those of Figs. 1 and FIG. 3. 15 Following the diagram of the box at SIX SPEEDS Fig. The trains (Ti, T2, T3) which have identical reasons may have the same dimensions. The following are respectively concerned: the gears (11, 21, 31), the satellites (1222, 32), the satellite gates (8, 66) and the crowns (1323, 33). This results in a constructive simplification where the trains (Ti, T2) have their common satellite gate and their crown (1323). The trains (T2, T3) have in common their pinion (2131). The output shaft (S), the brakes (F1, F2) and the clutches (El, E2, E3, E4) have the same connections with the trains (Ti, T2, T3) as in the previous boxes. 1 and FIG. 3. The operation is similar to this one of the eight-speed gearbox that suppresses fourth and sixth gear. The combinations of the switching members are represented by dark spots on the grid Fig. 6. The transmission of the invention lends itself to producing gearboxes whose opening can vary from 5 to 7. The last two speeds are overdrive up to 1.45. The jumps between reports are decreasing with the rise of the reports. In order to adjust the opening level and the favorable staggering of the steps, it suffices to choose the level (x) of the so-called slow speed and the reasons (r 1, r 2, r 3) of the trains (T1, T2, T3). Table 3 gives the values of the first report and steps in examples of realizations where the reasons (r 1), (r 2) and (r 3) are identical or possibly different for having the best steps. Opening reason reason x reason. 1 "Step1 Step2 Step3 Step4 Step5 r1 r2 r3 3 3 3 0.62 0.26 1.75 1.33 1.35 1.35 1.18 5.1 2.25 3 3 0.66 0.28 1.65 1.41 1.29 1.3 1.3 5.6 2.3 2.3 2.8 0.6 0.25 1.67 1.41 1.38 1.38 1.26 6 2. 25 2.25 2.25 0.56 0.23 1.7 1.44 1.41 1.42 1.22 6.85 2.1 1 3.5 2.9 0.55 0.215 1.7 1.5 1.5 1.37 1.31 5 ADVANTAGES The coaxial transmission of the invention with its three simple planetary gear trains, clutches and brakes is compatible at its input with different types of gearboxes (TE ) combined or not with an inverter train (TR), so that it is suitable for obtaining on the output shaft (S) of eleven six-speed forward, a braked dead point and one or two speeds in reverse Starting from the most complete gearbox with eleven speeds in Fig. 1, simply remove the reversing gear (TR) and its brake (F3) to obtain the 8-speed gearbox according to the Fig. 3, the opening of which may be suitable for most coach-type and medium-heavy-duty vehicles. Like the clutch (E4), the six-speed gearbox of FIG. 5 Suitable for buses and light commercial vehicles The planetary scheme has the advantage of being able to easily adjust the opening over a wide range, by providing a favorable staggering of the steps and by keeping the three planetary gears proportionate to their dimensioning. All speeds are achieved by clamping two friction members and switching to an adjacent speed occurs by changing only one of the two frictions. This facilitates the comfort of the gear changes and the control of the switching energy. The use of simple planetary trains, with their generally additive combination, facilitates the design and makes it possible to achieve a minimal size of the teeth.

  Satellite speeds and leak velocities between loose disks are set at levels that allow application to fast motors. The good mechanical efficiency, combined with the decay of the steps to the rise of the reports, is favorable to the motor efficiency and the reduction of consumption.

Claims (11)

  1. Planetary gearbox with up to eleven forward gears, one brakeless dead point, and two reverse gears between a drive shaft (A) connected to a first intermediate shaft (B) by a clutch (EA ), the gearbox having disc clutches and disc brakes for selecting gear ratios between the fast motor shaft (B) and an output shaft (S) connected to the wheels of a vehicle, said gearbox further comprising a hydraulic torque converter (PTR) combined with a free wheel (RL), being characterized in that said first fast intermediate shaft (B) is connected to a second intermediate shaft (C) by a speed reduction gear train (TE) ) always in gear reducing the speed of the shaft (C) described as slow relative to that of the shaft (B), and serving as input to a planetary transmission by two ways, one being a component of the train (TE) connected to the tree (B), the other being a component of the train (TE) connected to the shaft (G), said planetary transmission comprising three planetary gears (Ti, T2, T3), four clutches (E1, E2, E3, E4) and at least two brakes (FI, F2) and being connected to the output shaft (S).   Gearbox according to Claim 1, characterized in that the component of the gear (TE) connected to the shaft (B) is a planet carrier (4) and the component of the gearbox (TE) connected to the shaft ( C) is a gear (5)   Gearbox according to Claim 1, CHARACTERIZED IN THAT the gearbox (TE) comprises two gear pairs which are always engaged (2, 1) and (3, 5) and whose first central gear (1) is fixed to the gearbox. box casing (H), whose second central gear (5) is integral with the shaft (C), and whose planet gears (2, 3) are carried by a planet carrier (4) integral with the fast shaft (B), said planet carrier (4) being integral with a pinion (101) belonging to an inverting planetary gear (TR), and being integral with the driving or driving portions of the clutches (E3, E4) so as to enter the planetary transmission (Ti, T2, T3) either by the shaft (C) and one or both clutches (E1, E2) or by one of the clutches (E3, E4). 2897136 Page 9 of 10   4. Transmission according to claim 3 CHARACTERIZED IN THAT the inverter train (TR) comprises a pinion (101), satellites (102), a satellite door (104), and a ring (103), the pinion (101) being extended by a hollow shaft (D65) integral with the driving part of the clutch (E4), said hollow shaft (D65) being integral in rotation with the planet carrier (4) of the reducing gear (TE), said satellite gate (104) being connected to a brake disk (F3) and to the driven part of a clutch (E4), the ring gear (103) being connected to a brake disk (F1) and to the pinion (11) of a train (Ti) of the transmission (Ti, T2, T3), the planet carrier (4) of the reducing gear (TE) being also extended by a hollow shaft (D66) integral in rotation with the part driven clutch (E3).   5. Transmission according to claim 1 CHARACTERIZED IN THAT in the three-train transmission (T1, T2, T3), the trains (Ti, T2) have in common their satellite carriers (66, 7) and their crowns ( 13, 23), the trains (T2, T3) have in common their pinions (21, 31) while the planet carrier (8) of the train (T3) is integral in rotation with the rings (13, 23) of the trains (Ti ) and (T2) and that the gears (11) and (21) of the trains (Ti) and (T2) are separated by the driving portion of the clutch (E3) integral with the planet gates (66, 7).   6. Transmission according to claim 1 CHARACTERIZED IN THAT the driving parts of the clutches (E1, E2) are integral in rotation with the slow shaft (C), the driven portion of the clutch (El) being integral with the crown (33) of the train (T3), the driven portion of the clutch (E2) being secured to the gears (21, 31) of the trains (T2) and (T3), the driven portion of the clutch (E3) and the driving part of the clutch (E4) being integral in rotation with the hollow shaft (D66), the planet carrier (4) of the reduction gear (TE) and the fast shaft (B) as well as the pinion ( 101) of the inverter gear (TR), the driving portion of the clutch (E3) being integral with the planet gears (66,   7) trains (Ti) and (T2), the driven portion of the clutch (E4) being secured to the planet carrier (104) of the inverter train (TR) and brake brake disc (F3). 7. Transmission according to claim 1, of the type having only two brakes (F1) and 35 (F2), CHARACTERIZED IN THAT it is the reducing gear (TE) which serves to enter directly into the planetary transmission. three trains (Ti, T2, T3) on the one hand by its pinion (5) connected to the slow shaft (C) and the driving part of the clutches (El) and'E2), on the other hand by the track of its planet carrier (4) connected to the driving part of the clutch (E4) to the driven part of the clutch (E3) and to the fast shaft (B) so as to obtain eight transmission ratios between the fast shaft (B) and the output shaft (S). 2897136 Page 10 of 10   8. Transmission according to claim 1 CHARACTERIZED IN THAT the reducing gear (TE) comprises two sets of satellites (202) meshing with each other and 5 on the one hand a pinion (201) fixed to the housing (H) other part of a crown (203), and comprises a planet carrier (204) connected to the fast shaft (B), the box having only three clutches (E1, E2) grouped and (E3) whose driving part is secured in rotation of the planet carrier (204), the reducing gear (TE) enabling three planes to enter the planetary transmission (Ti, T2, T3), one channel being the driven part of (E3) connected to the planet carriers (6, 7) trains (T1) 10 and (T2), a second by the gears (21, 31) of the trains (T2) and (T3) and the third by the crown (33) of the train (T3), the latter two tracks being connected to the slow shaft (C) by the clutches (E1) and (E2), this box offering only six transmission ratios between the fast shaft (B) and the output (S) 15   9. Gearbox according to claim 8 CHARACTERIZED IN THAT the trains (Ti, T2, T3) have identical reasons and diametrical dimensions identical 20   10. Gearbox according to claims 1 to 10 CHARACTERIZED IN THAT the shafts (B), (C) and (S) are coaxial and aligned   11. Gearbox according to the preceding claims CHARACTERIZED IN THAT Between the gears (11) and (21) trains (T1) and (T2) is interposed the common part (66) of the satellite carriers (6) and (7). ) which is a leading or driven part of the clutch (E3)