FR2623869A1 - MULTI-SPEED MECHANICAL TRANSMISSION FOR AN INDUSTRIAL VEHICLE - Google Patents

Abstract

The invention relates to a transmission for a vehicle. The transmission 1 comprises a main transmission unit 5 defining several forward speeds and a division unit 2 defining at least one forward speed and one reverse speed; the division unit 2 is arranged upstream of the main transmission unit 5 and is controlled by electro-pneumatic devices actuated by a pair of selectors placed on a gearshift lever serving to mechanically actuate the main unit transmission 5. Application to industrial vehicles.

Description

The present invention relates to a transmission

  sion, and in particular a multi-speed transmission

for an industrial vehicle.

  Industrial vehicles are generally equipped, in known manner, with a transmission comprising a large number of forward speeds (for example eight, ten, twelve or sixteen) and at least one reverse speed. The different speeds are obtained by connecting in series a main transmission unit or "I basic gearbox", comprising from three to six forward gears plus a reverse gear, a ratio multiplier or divider comprising two or three forward gears, and possibly a gearbox of

  range generally comprising two ratios.

  Known transmissions of the type described have certain disadvantages. The incorporation of the reverse ratio plus a large number of forward gears in the main transmission unit, which is mechanically actuated in a known manner by means of a lever, means that the overall arrangement of operating positions of the lever, or the control gate, is quite complicated

and difficult to operate.

  In addition, the complexity of the main transmission unit, that is to say the number and dispersion of the values of the various transmission ratios that it comprises, results in an overall dimensioning of the gears and consequently transmission itself and by a large number

  selection forks. The subject of the present invention

  tion is to create a transmission, particularly for

  an industrial vehicle, which does not present the incon-

  above mentioned known type transmissions.

  Said object is produced according to the present invention by a transmission for a vehicle, of the type comprising at least one main transmission unit and a division unit in combination

  mutual recognition, characterized in that the said main unit

  the transmission unit defines a plurality of forward gears and said dividing unit defines at least two forward gears and at least one gears ratio.

reverse.

  Other advantages and features of the invention will be highlighted later in the

  description, given by way of non-limiting example,

  with reference to the accompanying drawings in which:

  FIG. 1 is a sectional view of a first embodiment

  a transmission for an industrial vehicle constructed in accordance with the present invention; FIG. 2 represents a shift lever for the transmission of FIG. 1, showing the relative positions of actuation.

  FIG. 3 is a sectional view of a second embodiment

of the present invention.

  In Figure 1, reference numeral 1 generally designates a transmission for an industrial vehicle. The transmission 1 comprises a division unit 2 which is driven by a pinion placed at the end of a crankshaft 4, and a main transmission unit 5 connected to the output of the division unit 2. The division unit 2 and the main transmission unit 5 are housed in

  respective parts of transmission case 6.

  The division unit 2 comprises a main shaft 7 supported at one end by a bearing housed in the pinion 3, and supported at its other end, which defines the output gear of the division unit

  2, by a second bearing 13 housed in a corresponding seat.

  14 in the transmission housing 6.

  The pinion is permanently engaged with a toothed wheel 15 keyed on an auxiliary shaft or intermediate shaft 16, which is consequently driven by the pinion 3. Two toothed wheels 18, 19 are mounted on the main shaft 7 by means of a bearing 17 and they are permanently engaged respectively with a toothed wheel 20 keyed on

  the intermediate shaft 16 and with a peripheral toothing

  21 is also mounted idle on the main shaft 7, by means of a respective roller bearing 24, another pinion which is angularly coupled, by a not shown pinion gear, with a second peripheral toothing 26 of the intermediate shaft 19. Finally it is provided on the main shaft 7 two sleeves

  teeth 27, 28 fixed by keying and which are interpo-

  in the axial direction respectively between the pinion 3 and the toothed wheel 18 and between the gears 19 and 25. In a known manner, one or the other of the sleeves 27, 28 can be rigidly coupled with a adjacent toothed wheels by a respective conventional sliding sleeve 29 and 30 and by respective synchronizing means so as to thereby form an angular coupling establishing a predetermined transmission ratio between the crankshaft 4 and the main shaft 7. In particular, when the sleeve 29 is moved to the left, considering the drawing, it angularly locks the pinion 3 on the shaft 7 so as to establish a transmission ratio equal to

  the unit between the shaft 4 and the shaft 7 (direct connection).

  On the other hand, by coupling the toothed wheel 18 (sleeve 29 to the right) o of the toothed wheel 19 (sleeve 30 to the left), two other transmission ratios are obtained with increase of the gear ratio in the same direction (ratio

walking forward).

  Coupling the gearwheel (sleeve to the right) causes the transmission to take place in the opposite direction (reverse gear) due to the use of said reversing gear. The main transmission unit 5 comprises a reduction unit 34 having two transmission ratios and an epicyclic reduction gear having two transmission ratios, which gives the total

four transmission reports.

  The gear unit 34 comprises a shaft 36

  coaxial with the main shaft of the division unit 2.

  This shaft 36 is supported by the pinion 10 and the housing 6 of the transmission via respective bearings 37. On the shaft 36 are mounted a pinion 38 and a keyed sleeve 39 which is interposed in the axial direction between the pinion 10 and the pinion

crazy 38.

  The pinion 10 drives a first toothed portion 40 of a second intermediate shaft 43, a second toothed portion 44 is engaged with the pinion

  idle 38. A sliding sleeve 45 can couple angularly

  gear pinion 39 with pinion 10 or with pinion 38 so as to obtain in the first case a direct connection between the main shaft of division unit 2 and shaft 36, and in the second case a ratio of reduced transmission by means of pairs of

sprockets 10-40 and 44-38.

  - The epicyclic reduction gear 35 comprises a central pinion 46 formed on an end portion of the shaft 36, an outer ring with internal teeth 47 coaxial with the central pinion 46 and three or more planet pinions 48, only one of which is visible and is engaged with the central pinion 46 and the ring gear 47 and rotates loosely on respective journals 49 mounted on a planet carrier 50 consisting of a terminal flange of the output shaft

  51 of the epicyclic reduction gear 35.

  The inner ring gear 47, which is substantially bell-shaped, comprises a tubular portion 54 mounted on the shaft 51 by means of a ball bearing 55. The respective pinions 56, 57 are keyed onto the tubular portion 54 of FIG. the ring gear 47 and the output shaft 51. Another sliding sleeve 58 can couple the aforementioned pinions 56, 57 with each other (position to the right) so as to rigidly connect the planet carrier 50 together. with the ring gear 47 and thus to obtain a direct connection between the shaft 36 and

  the output shaft 51. In this respect, in this configuration,

  the satellites 48 do not rotate around the axis of their own trunnions 49 but are subjected to a revolution about the axis of the central gear 46 so as to lock angularly

  this central pinion 46 with the ring gear 47.

  Alternatively, if the sleeve is moved to the left considering the drawing, it couples the pinion 56 with a toothed sleeve 59 secured to the casing 6 of the transmission-so as to block the ring gear 47 and to obtain a motion transmission with a reduction ratio between the central pinion 46 and the planet carrier 50, that is to say between

the shaft 36 and the output shaft 51.

  Finally, the output shaft 51 is provided with an extreme flange 60 remote from the planet carrier 50

  and with the aid of which, when it is in service, the trans-

  mission 1 is connected to the transmission elements of

movement to the wheels of the vehicle.

  The main transmission unit 5 is conveniently operated by means of a mechanical lever

  64 of a conventional type having four positions.

  FIG. 2 represents an embodiment of the control gate of the lever, this figure showing the relative positions corresponding to the different forward speeds. The division unit 2 is advantageously brought into its various positions by means of hydraulic or pneumatic actuating devices 61 which are electrically controlled by respective selectors 65, 66 arranged on the shift lever 64. actuation 61 are of the double-dip type and allow actuation in three positions (left-neutral-right) rods

  respectively 62 carrying conventional forks

  63 to move the sleeves 29, 30. Specifically

  The three position selector 65 controls the engagement of the three forward speeds of the division unit 2, which can be achieved by rotating a radial lever 66 to the required position relative to the shift lever. speed 64. The two-position selector 66 controls the engagement and the release of the reverse, respectively by raising and lowering a button

  end 68 provided on the lever 64.

  The operation of the transmission 1 has been

  highlighted in the description above and

  therefore will not be described in detail. It should be noted that the transmission 1 is provided with twelve forward speeds corresponding to the combination

  of the three forward ratios of the unit of divi-

  2 with the four gears of the main transmission unit 5, and also four reverse speeds corresponding to the four speeds of the main transmission unit 5 when the gait

  back was engaged in division unit 2.

  In FIG. 3, the reference numeral 74 designates as a whole a transmission for an industrial vehicle, comprising a dividing unit and a main transmission unit 76. The main transmission unit 76 consists of an associated first stage 77 at division unit 75 and a

  second stage consisting of a epicyclic reduction gear

  identical to the epicyclic reduction gear 35 of the transmission 1, so that the reference numerals of FIG. 1 have been used in FIG.

  description will not be repeated later. The unit

  splitter 75 comprises a hollow shaft 78 which is driven at one end by an input shaft 80 via a splined connection 79. The hollow shaft 78 defines at its other end a toothed hub

  84 and is supported at said respective ends

  transmission housing 85 and the input shaft 86 of the main transmission unit 76 to the

  rolling bearing means conical 87.

  On the hollow shaft 78 are keyed two pinions 88, 89 between which is interposed a spacing member 90 while a third pinion 94 is mounted idle in a position adjacent the toothed hub 84. Two idler gears 95, 96 and a Interlocked keyed 97 toothed hub are mounted on the input shaft

  86 of the main transmission unit 76.

  Pinion 95 comprises a tubular portion 98 which extends axially towards the toothed hub

84 of the hollow shaft 78.

  A first sliding sleeve 99 of a type

  classical is arranged to couple angularly

  the pinion 94 or the tubular portion 98 of the pinion with the toothed hub, that is to say with the hollow shaft 78, using a known type of synchronization means. Similarly, a second sliding sleeve can rigidly connect the pinion 95 or the pinion

96 with the toothed hub 97.

  The transmission 74 comprises a single intermediate shaft 104 whose axis is parallel to the axes of the shafts 78 and 86. On the intermediate shaft 104, supported at its ends by tapered roller bearings 105, there is provided a coupled pinion 106 angularly with the pinion 88 by a reversing gear, not shown, and a fixed gear 107 which is engaged with the idler gear 94. The gear 107 comprises a tubular portion 108 which extends in a radial direction towards the pinion 10.6. On the tubular portion 108 is mounted fou a third pinion 109 engaged with the pinion 89. A toothed hub is keyed on the intermediate shaft 104 in a position located axially between the pinion 106 and the tubular portion 108 of the pinion 107 and can to be rigidly connected, by means of a sliding sleeve 114 and a synchronization means, with the pinion 106 or with the pinion 109. Finally, two pinions 115, 116 are provided on the intermediate shaft 104, these gears being respectively engaged with the pinion

and pinion 96.

  The input shaft 86 of the main transmission unit 76, also supported by the transmission casing 85 via two roller bearings 117, one of which is mounted on the tubular portion 98 of the pinion 95, defines at one end the

  central gear 46 of the epicyclic reduction gear 35.

  The transmission 74 operates in the following manner. During a movement of the sleeve 114 to the left, a movement is transmitted by the hollow shaft 78 to the intermediate shaft 104 by means of the pair of pinions 88, 106 and the reversing gear. The reverse gear is therefore engaged, with four possible ratios of the main transmission unit 76 which are obtained by combining with the positions of the sleeve 58 of the epicyclic reduction gear the positions of the sleeve 100 which, when moved to the left, establishes a motion transmission to the input shaft 86 by means of the pair of pinions 115-95 while, when it is moved to the right, it provides motion transmission by means of the pair of

sprockets 116-96.

  When the sleeve 114 is moved to the right as far as the position indicated in the figure, or when the sleeve 99 is moved to the left, two different forward gear ratios of the dividing unit 75 are obtained. which, when combined with the aforesaid four reports of the main transmission unit 76, make it possible to obtain

  eight forward speeds. If the sleeve is now

  naked in its idle position and if the sleeve 99 is moved to the right, four other forward gears can be obtained by combining the positions of the sleeves 100 and 58. Specifically, when the sleeve 100 is moved to the left or to the right , the movement is transmitted from the hollow shaft 78 to the pinion 95 and the shaft 86 so as to establish a direct connection between the hollow shaft 78 and the shaft 86, or the intermediate shaft 104, respectively, and

  then the shaft 86 by means of the pair of sprockets 116-

  86. The epicyclic reduction gear 35 operates as described above. The transmission 74 therefore comprises twelve forward gears and four reverse gears as well as the transmission 1. Again in this case (FIG. 2), the actuation is effected by means of a mechanical lever 64 to four positions, which controls the main transmission unit 76, by means of a selector 67 which controls the engagement of the forward speeds in the division unit 76, and by means of a selector to two positions 68

  which controls the engagement of the reverse gear.

  The advantages of transmissions 1, 74 con-

  trout in accordance with the present invention are

  an examination of their characteristics.

  First, the control gate is simpler and more functional because the number of positions of the shift lever is equal to the number of speeds (forward) of

  the main transmission unit, while the

  The speeds of the dividing unit are obtained by means of actuating means which are operated by means of fluid. In addition, the division of relations between

  the unit of division and the main unit of transmission

  the distribution of the actual values of the ratios makes it possible to reduce the dimensions of the gears and / or the distances between their axes and the number of selection forks, with the consequence that

  a reduction in the overall dimensions of the transmission

  if we. The transmission 74 has a pair of gears less than a conventional transmission having the same

number of speeds.

  Finally, it is obvious that modifications may be made to transmissions 1 and 74 without

  depart from the scope of the present invention. In particular

  bind, the transmission 1 or 74 may be of the type with two intermediate shafts. The number of reports of the main unit of transmission may vary, this number being for example equal to two, three, five or six, and also the number of reports of the division unit may vary and may be equal for example to two or he

four plus reverse.

  In this way, the selection positions and the control gate vary, but all the advantages indicated above are still preserved, for example.

  compared to the corresponding known constructions.

Claims (11)

  1. Transmission for a vehicle, of the type   at least one main transmission unit and a division unit in mutual combination, characterized in that said main transmission unit (5, 76) defines a plurality of forward gears and said division unit (2, 75) defines at least two forward and backward gears   minus a reverse gear.   2. Transmission according to claim 1, characterized in that said division unit (2, 75) defines at least three forward gears.   3. Transmission according to one of claims 1   or 2, characterized in that said division unit   (2, 75) is disposed upstream of said main unit transmission blade (5, 76).   4. Transmission according to any of the   1 to 3, characterized in that it comprises fluid actuated actuating means (61) for engaging speeds of said dividing unit (2, 75).   5. Transmission according to any of the   1 to 4, characterized in that it comprises a mechanical operating lever (64) for engaging the speeds of said main transmission unit (5, 76).   6. Transmission according to one of the claims   4 or 5, characterized in that said means of action-   fluid control means comprises a first selector (65) arranged to control the selective engagement of the forward speeds of said dividing unit (2, 75) and a second selector (66) arranged to control the engagement and disengagement of   reverse in said division unit (2, 75).   7. Transmission according to claim 6, characterized in that said selectors (65, 66)   are arranged on said mechanical operating lever that (64).   8. Transmission according to any of the   Claims 1 to 7, characterized in that   transmission unit (5, 76) comprises at least one   at least two stages (34, 77, 35) placed in series.   9. Transmission according to claim 8, characterized in that said division unit (2) and said first stage (34) of said main unit   transmission (76) are separated and placed in series.   10. Transmission according to claim 8, characterized in that said division unit (75) and said first stage (77) of said main transmission unit (76) are integrally associated and comprise at least one common intermediate shaft. (104).   11. Transmission according to claim 10, characterized in that it comprises means (110, 114) for coupling at least one pair of pinions (88, 106; 89, 109) with said intermediate shaft. (104).