SE1550398A1

SE1550398A1 - Group transmission

Info

Publication number: SE1550398A1
Application number: SE1550398A
Authority: SE
Inventors: Bernd Woelfle
Original assignee: Zahnradfabrik Friedrichshafen
Priority date: 2014-04-07
Filing date: 2015-04-02
Publication date: 2015-10-08
Also published as: CN204628506U; DE102014206680A1

Abstract

The invention relates to a group transmission, comprising two transmission groups (1, 2) which lie so as to adjoin one another, are surrounded in each case in respectively associated housing parts (23, 24) of a common transmission housing (4), and between which a retarder (3) is arranged. In order to then integrate the retarder (3) into the group transmission with as little outlay on production as possible, at least one housing part (24) of the two transmission groups (1, 2) which lie so as to adjoin one another is at the same time involved in the configuration of a retarder housing.Fig. 1

Description

lO Group transmission The invention relates to a transmission, groupcomprising two transmission groups which lie so as to adjoin one another, are surrounded in each case in respectively associated housing parts of a common transmission housing, and between which a retarder is arranged.

Retarders are used in motor vehicles and, in particular here, in commercial vehicles and serve to relieve a respective service brake of the respective vehicle, for example when driving along relatively long downhill sections. Here, retarders are usually configured in theform of hydrodynamic retarders which comprise a rotorand a stator. Here, the rotor is connected fixedly tothe respective shaft to be braked of the drive train soas to rotate with it and, has ablade into a working space which is defined between the rotor just like the stator, system. If a quantity' of liquid. is introducedand the stator,blademovement with the shaft and accelerates the said liquidThe liquid is subsequently supported on the blade system of the rotor drives the introduced liquid via its system during its common rotational in the direction of the blade system of the stator. the stator and is guided back to the blade system ofthe rotor again, this having a retarding action on therotor and therefore also the shaft. of the Here, the magnitude braking torque to be brought about can be regulated via the introduced quantity of liquid. Here, within a drive train, a hydrodynamic retarder is also partially integrated into the transmission of the respective commercial vehicle, as a result of which the retarder is protected. as far as possible from environmental influences and, in addition, lower noise emissions can be achieved. lO A transmission of a motor vehicle is apparent from EP O635 413 Al, which group transmissions, two transmission groups which lie so as transmission has, as to adjoin one another in the form of a main group and a range group which is connected downstream of it. Here,the transmission groups are surrounded in a commontransmission housing which is assembled from aplurality of housing parts. Here, the transmission housing is split, inter alia, between the transmission groups, with the result that firstly the main group issurrounded by associated housing parts and secondly therange group is also enclosed by an associated housingpart.

Furthermore, a hydrodynamic retarder is provided between the two transmission groups, which hydrodynamic retarder is arranged in a retarder housing which lies within the transmission housing and is thereforeintegrated into the group transmission. Here, theretarder housing is split in two, a stator of the retarder being configured in one piece with one housinghalf which is incorporated fixedly in terms of movementwith an assembly housing which is fastened on the sideof the of the The second half of the retarder housing is then likewise housing part main transmission. connected. fixedly' in terms of movement to the firsthalf and, the hydrodynamic retarder. together with it, encloses the inner rotor of Proceeding' from. the above-described. prior* art, it isthen the object of the present invention to provide a group transmission, into which a retarder is integrated with as little production outlay as possible.

This object is achieved proceeding from the precharacterizing clause of Claim l in conjunction with its characterizing features. The dependent claims which follow it in each case represent advantageous developments of the invention. lO According to the invention, a group transmission comprises two transmission. groups which. lie so as to adjoin one another, are surrounded in each case in respectively associated housing parts of a commonand between which a retarder is the transmission housing,transmission isof the arranged. A housing of group therefore of split configuration, a division said transmission housing then being provided betweenthe transmission groups in the region of the position of the retarder.

In the context of the invention, the retarder is preferably a hydrodynamic retarder which is composed of a stator and a rotor, the rotor and stator being provided in each case with blade systems in a nmnnerskilleddefining a working space between them.is then arranged. on one of the shaftswith the result that, if a the of the which is known to a person in the art and Here, the rotor of the group transmission, liquid is introduced into working space retarder, which liquid can be oil or else also water, a braking action is generated on the said shaft. In principle,however, the retarder can also be an electrodynamicretarder.

The invention then comprises the technical teaching that at least one housing part of the two transmissiongroups which lie so as to adjoin one another is at the same time also involved in a configuration of a retarder housing. In other words, at least one of the housing parts of the two transmission groups, between which the retarder is positioned, is therefore at the same time also part of a retarder housing of theretarder.

Here, a configuration of this type of a grouptransmission has the advantage that the productionoutlay of the group transmission according to the invention can be reduced, by at least one housing part lO also at the same time serving to configure a retarder housing of a retarder which lies in between. A retarder housing' part which would otherwise have to beadditionally provided can be dispensed with because thesaid at least one housing part performs a doublefunction, that is to say serves to enclose theassociated transmission group and the retarder. Ingeneral, the positioning of the retarder within atransmission housing has the advantage that the retarder is protected against environmental influences and, in addition, noise emissions are reduced. Finally, a modular construction can be realised which, in themanner of a kit principle, makes the configuration of agroup transmission with a retarder or else without aretarder possible without problems. This is becausemerely the further retarder housing parts have to bearranged on the at least one housing part in order to configure the retarder housing.

Although. a retarder is also integrated. into a group transmission in the case of EP O 635 413 Al, a retarderhousing is formed by separate retarder housing parts inthis case. To this extent, the none of the housing parts ofat thewith. the result that transmission groups serves same time to configure the retarder* housing, the production outlay is correspondingly increased.

In accordance with one embodiment of the invention, in addition to the at least one housing part, at least one retarder housing part is involved in the formation of the retarder housing. In one development of this embodiment, a transmission the housing part of a groupretarder housing together with an annularwhich result, a forms retarder housing part and a stator of the housing supports a stator retarder. As a configuration of the retarder housing can be realizedwith low production outlay. As an alternative to the abovementioned development, however, a housing part of a transmission group can also define the housing of the lO retarder together with a single, further retarder stator then likewisethe further case thethe housing' part, in this being configured on side of one retarder housing part. Furthermore, a retarder housing can also be defined by interaction of the housing parts of the two transmission groups which lie so as toadjoin one another with an annular retarder housingpart.

According to a further refinement of the invention, thestator housing additionally supports a stationary part of a shifting element of the transmission group which lies in each case next to it. The stator housingtherefore additionally forms a part of a shiftingelement, via which a rotating component of the transmission group which lies so as to adjoin it can be brought to a standstill. As a result, a compactconstruction can be realized in the correspondingregion. Furthermore, it is additionally conceivablewithin the scope of the invention that the stator housing additionally serves to receive a bearing of one of the shafts of the group transmission.

According to a further embodiment of the invention, ait can beof thethe rotor of the retarder is guided such that displaced axially with respect to a stator retarder. In a development of this embodiment, rotor is then guided via a helical toothing system which brings about a displacement of the rotor in thedirection. of the stator during filling of a workingspace which lies between the rotor and the stator, therotor being prestressed by means of a spring element in an opposite direction to this. In other words, a rotor of the retarder can therefore be moved axially relative to a stator of the retarder, the said rotor being element in an the via athe prestressed opposite the spring direction to stator in course of development of the embodiment. Furthermore, the rotor is guided on a helical toothing system which converts a lO rotation of the rotor into its movement with respect tothe stator during filling of the working space betweenthe the thethe rotor and stator. Fan losses of hydrodynamic retarder are low on account of relatively' great axial spacing' between. the rotor andthe stator which is set in the unfilled state. At thesame time, a movement of the rotor in the direction ofthe stator is automatically initiated by means of theguidance of the rotor on the helical toothing system, as soon as the working space is filled with liquid.

Here, an axial travel of the rotor on the helicaltoothing system is particularly preferably limited viasecuring rings. Furthermore, the helical toothingsystem is provided, in particular, by a sleeve whichconnects shafts of the two transmission groups, whichlie so as to adjoin one another, to one another.

However, guidance of the rotor on a helical toothing system can also be realized by an individual shaft of one of the two transmission groups.

It is a further refinement of the invention that a rotor of the retarder is incorporated into the force flow via a step-up stage. As a result, a rotational speed of the motor and therefore also a braking effectwhich can be produced can advantageously be increased.in the context of the invention, Here, a step-up stage can be realized. as a spur gear stage or else as aplanetary stage.In one development of the invention, the retarder is arranged. spatially' between. a main group and. a range group. Here, the main group is preferably configured as a spur gear multi-step transmission with a plurality of spur gear stages which define individual transmission ratios, whereas the range group is present, in particular, as a planetary transmission. lO According to a further, advantageous embodiment of the invention, a rotor of the retarder is coupled. to adriven shaft or to a shaft which connects thetransmission groups to one another. In the second- mentioned case, a braking action of the retarder can therefore also be transmitted via the transmissiongroup which follows in the force flow direction,whereas, in the first-mentioned case, a braking action can be caused even when the following transmission group is shifted into neutral. To this extent, in the last-mentioned case, braking can be carried out via theretarder even when a shift operation is being carriedout in the following transmission group.

In one development of the invention, a rotor of theretarder is provided axially on both sides with in eachcase one blade system, opposite which in each case oneThe can be associated blade lies.whichincreased significantly as a result of a double rotor of this stator with an system braking action can be brought abouttype with. stators which. lie axially' on bothsides.

Furthermore, it is conceivable within. the context ofthe invention to provide a heat exchanger in the regionof the receptacle of the retarder on the housing of thegroup transmission, via which heat exchanger heat which is produced. during' operation. of the retarder can be discharged. As a result, an excessively hightemperature in this region can be prevented.The invention is not restricted to the specified combination of the features of the main claim or of the claims which are dependent thereon. Moreover, optionsarise to combine individual features with one another,even in so far as they are apparent from the claims,the following description of preferred embodiments ordirectly from the drawings. The reference of the claims to the drawings by way of using reference numerals is lO not intended to restrict the scope of protection of the claims.

Advantageous refinements of the invention which will be explained in the following text are shown in the drawings, in which: Fig. l shows a diagrammatic illustration of a grouptransmission in accordance with a firstembodiment of the invention, Fig. 2 shows a sectional view of the grouptransmission from Fig. l, Fig. 3 shows a diagrammatic view of a grouptransmission in accordance with a secondpossible refinement of the invention, Fig. 4 shows a diagrammatic illustration of a grouptransmission according to a third embodimentof the invention, Fig. 5 shows a diagrammatic view of a grouptransmission in accordance with a fourthpossible refinement of the invention, and Fig. 6 shows a diagrammatic illustration of a group transmission in accordance with a fifth embodiment of the invention.transmission in A diagrammatic view of a groupaccordance with a first embodiment of the invention isapparent from Fig. l, the said group transmission beingl and 2, just like the composed. of two transmission. groups betweenwhich a retarder 3 is accommodated. Here,transmission groups l and 2, the retarder 3 is likewiseaccommodated in a transmission housing 4 of the grouptransmission and is into accordingly' also integrated the group transmission.

In the present case,the the transmission group 1 is a main group of group transmission, whereas the transmission group 2 is configured. as a range groupthereof. As the which is connected downstream additionally be Can seen from Fig. 1, transmissiongroup 2 is configured here in a planetary design with aplanetary stage 5, the sun gear 6 of which is coupledto the output of that transmission. group 1. which isconnected. upstrean1 of it and. the planet spider' 7 ofwhich. is connected. to a stage 5 transmission.the still remaining' internal gear* 9 of planetary can either be brought to a standstill via a shifting device 10 or else can be coupled fixedly to the planet spider 7 so as to rotate with it, in order to produce two different transmission ratios of the transmission group 2.

The retarder 3 which is seated between the transmissiongroups 1 and 2 is configured as a hydrodynamic retarderand accordingly has a stator 11 and a rotor 12 which isconnected to the output of the transmission group 1 and the sun gear 6 of the transmission group 2 and therefore its drive. As can be seen, in particular, from. the sectional view in Fig. 2, the rotor 12 is placed. here on a sleeve 13 which. connectsshaft 14 input shaft 15 of the transmission group 2 an outputof the transmission group 1 fixedly' to anso as torotate with it. Here, the sleeve 13 guides the rotor 12axially displaceably on a helical toothing system 16,on which the rotor 12 can be moved axially relative tothe stator 11. Here, a displacement of the rotor 12 inthe direction of the stator 11 takes place counter to aspring element 17 which lies in between and prestressesthe rotor 12 into a first position. Fan losses whichare caused by circulation of air between blade systems19 and 20 of the stator 11 and the rotor 12 are low onaccount of the spacing between the stator 11 and the rotor 12 in this first position.

If, however, a liquid is then introduced into theworking' space 18, the said. liquid. is driven. via theblade system 20 of the rotor 12 and is conveyed in thedirection of the stationary blade system. 19 of thestator 11, where it is supported and is in turn guidedback to the blade system. 20 of the rotor 12. Fromfilling of the working space 18, the rotor 12 is rotated on account of the support of the liquid on theblade toothing system 16 into an axial movement of the rotor system. 20, which is converted. via the helical 12 counter to the spring element 17. As a consequence, the rotor 12 is moved towards the stator 11 counter to the spring element 17, and the spacing between thestator 11 and the rotor 12 is reduced in this way. Thetwo possible axial positions of the rotor 12 are defined by two securing rings 21 and 22 on the sleeve13.

As a special feature, the transmission. housing 14 isthen formed by two housing parts 23 and 24 and aretarder housing' part 25, the housing' part 23 substantially' enclosing' the transmission group 1 andthe housing part 24 enclosing the transmission group 2.Here, the housing part 24 is at the same time also partof a retarder housing 26, in which the retarder 3 isencapsulated within the group transmission. As can beseen in Fig. 2, the said retarder housing 26 is thusformed. by the housing' part 24, the retarder housingpart 25 and a stator housing 27, of which the latter atthe same time also forms the stator blade system 19.The housing part 24 therefore assumes a double functionwithin the transmission housing 4, namely the enclosingof the transmission group 2 and also of the retarder 3.transmission Furthermore, a formation of a groupin between can in the without a retarder 3 which lies principle also be realized on account of positioning of the retarder housing part 25 between the housing parts 23 and 24; optionally either' a housing lO ll part which bridges the spacing is then to be providedbetween the housing parts 23 and 24 or else the twohousing parts 23 and 24 are fastened directly to oneanother.

Apart from. the configuration of the stator ll, thestator housing 27 also serves to receive a bearing 28,which the Furthermore, via sleeve l3 is mounted. rotatably.the stator housing 27 guides a clutch body29 as a stationary part of a shifting element of thewhich a heat exchanger 30 is also arranged in the transmission group l lies adjacently. In addition, region of the retarder housing part 25, via which heat exchanger 30 the heat which is produced duringoperation of the retarder 3 can be discharged.Furthermore, a diagrammatic illustration of a group transmission in accordance with a second possible refinement of the invention is apparent from Fig. 3.

Here, this refinement corresponds substantially to thevariant according to Figs l and 2, a difference beingthat the rotor 3l of a retarder 32 is not incorporateddirectly, but rather via a step-up stage 33 between the transmission groups l and 2. Here, the step-up stage 33is realized as a planetary stage 34,the stage 34 stator 36 of the retarder 32, a sun gear 35 of planetary being coupled rigidly to awhereas the rotor 3l isconnected to a planet spider 37 of the planetary stage 34 and an internal gear 38 is connected to the output of the transmission group l and the input of thetransmission group 2 which is connected downstream.Otherwise, the refinement according to Fig. 3 corresponds to the variant according to Figs l and 2,with the result that reference is made to what has beendescribed in this regard.

Furthermore, a third embodiment of a group transmissionis apparent from Fig. 4, this variant corresponding as far as possible to the embodiment according to Fig. 3. 12 In contrast thereto, the internal gear 38 of the step-to the output of the up stage 33 is not attached, however, the transmission group 1 and the input of transmission group 2, but rather is connected fixedlyto the planet spider 7 and therefore also the drivenshaft 8 so as to rotate with them. As a consequence, abraking' action can be generated. via the retarder 32 even when a shift operation is being performed in the transmission group 2. Otherwise, the refinement thencorresponds to the variant according to Fig. 3, withthe result that reference is made to what has been described in this regard.

Furthermore, Fig. 5 shows a diagrammatic view of agroup transmission in accordance with a fourth possiblerefinement of the invention. in contrast to the1 and 2, equipped with two stators 40 and 41, Here,variant according to Figs a retarder 39 isbetween which arotor 42 runs which is provided axially on both sideswith bladeaction can be generated in interaction with the stators40 and 41 by the therefore configured as a double rotor than is possible systems. A considerably higher braking way of said rotor 42 which is in the case of a rotor and a stator with in each case only one blade system.

Finally, a diagrammatic illustration of a grouptransmission in accordance with a fifth embodiment ofthe invention is also apparent from Fig. 6. Here, thisembodiment corresponds substantially to the variant according to Fig. 4, a step-up stage 43 being formed by44 and 45Whereas the spur gear stage 44 couples a rotor 46 of the retarder 47 to a shaft 48, the said shaft 48 is in two spur gear stages in contrast thereto. turn connected by means of the spur gear stage 45 tothe driven shaft 8 of the group transmission. To thisextent, a rotational movement of the driven shaft 8 isstepped out via the two spur gear stages 44 and 45 into a rotational movement of the rotor 46. 13 A retarder with low production outlay can be integratedinto a housing of the respective transmission by meansof the refinements according to the invention of a group transmission.

Claims

14 Patent Claims

1. Group transmission, comprising two transmission groups (1, 2) which lie so as to adjoin one another,are surrounded in each case in respectively associated(23, 24) housing parts of a common transmission housing (4), and between which a retarder (3; 32; 39; 47) isarranged, characterized. in that at least one housingpart (24) of the two transmission groups (1, 2) whichlie so as to adjoin one another is at the same timeinvolved in a configuration of a retarder housing (26).

2. Group transmission according to Claim 1, characterized in that, in addition to the at least one housing part (24), at least one retarder housing part(25) is involved in the formation of the retarderhousing (26).

3. Group transmission according to Claim 2,characterized in that a housing part (24) of atransmission group (2) forms the retarder housing (26)together with an annular retarder housing part (25) anda stator housing (27) which supports a stator (11; 36;40) of the retarder (3; 32; 39; 47).

4. Group transmission according to Claim 3,characterized in that the stator housing (27) additionally supports a stationary part of a shiftingelement of the transmission group (1) which lies in each case next to it. transmissioncharacterized in that aretarder (3; 32; 47) is

5. Group according to Claim 1, rotor (12; 31; 46) of theguided. such. that it can bedisplaced axially with respect to a stator (11; 36) of the retarder (3; 32; 47). _l5_

6. Group transmission according to Claim 5,characterized in that the rotor (12; 31; 46) is guidedvia a helical toothing system (16) which brings about a displacement of the rotor (12; 31; 46) in the directionof the stator (11; 36) during filling of a workingspace which lies between the rotor (12; 31; 46) and thestator (11; 36), the rotor (12; 31; 46) beingprestressed. by' means of a spring' element (17) in anopposite direction to this.

7. Group transmission according to Claim 1,characterized in that a rotor (31; 46) of the retarder(32; 47) is incorporated. into the force flow via astep-up stage (33; 43).

8. Group transmission according to Claim 1, characterized in that the retarder (3; 32; 39; 47) isarranged between a main group and a range group.

9. Group transmission according to Claim 1,(12; 31; 42; 46) of the is coupled to a driven shaft characterized in that a rotorretarder (3; 32; 39; 47) (8) or to a shaft which connects the transmissiongroups to one another.

10. Group transmission according to Claim 1, (42) (39) is provided axially on both sides with in each case one characterized in that a rotor of the retarder blade system, in each case one stator (40, 41) opposite which with an associated blade system lies.