DE10145790A1 - Short construction power shift transmission has gearwheel in transmission path of reverse gear rigidly connected to first input shaft, or rigidly connected to second input shaft whereby first gear is driven by respective other shaft - Google Patents

Abstract

The short construction power shift transmission has two input shafts, an output shaft (13) and an eccentric auxiliary shaft (50). A gearwheel in the transmission path of the reverse gear is rigidly connected to the first input shaft (23), or rigidly connected to the second input shaft (24), or can be connected, whereby the first gear is driven by the respective other input shaft, and therefore can be selected up and down by the selecting of double clutches.

Description

State of the art

DE 198 50 549 A1 describes a multi-speed transmission 10 ( 10 a) which has two input shafts 12 , 13 and one output shaft 25 . Each of the input shafts 12 , 13 is connected to a clutch 29 , 30 and can be separated therewith from the internal combustion engine 11 of the motor vehicle. Furthermore, one or two electric machines 34 , 35 , 40 are assigned to the two input shafts 12 , 13 and connected to them in a non-positive manner, which are located on the side of the clutches 29 , 30 facing away from the internal combustion engine 11 . In particular, a starter and an alternator for the internal combustion engine 11 can be dispensed with by means of the electric machine (s) 34 , 35 , 40 . Furthermore, both the synchronous speed of the input shaft 12 , 13 of a target gear can be set in a simple manner and various operating states can be implemented. Group load shifting is not possible here and double clutches are required.

Patent specification DE 41 02 202 C2 (D1) describes a gear arrangement in which an internal combustion engine is connected directly to the side gear 11 of a differential gear 10 . The parallel side gear 12 is connected to an electric motor 5 via a spur gear 24 , 25 . The pinion gears 13 and 14 lead to a further gear 3 via the pinion shaft 15 and a spur gear 16 , 20 . The differential gear 10 can neither be blocked nor fixed on one side (side gear 12 ), so that the side gear 12 must always have the same torque as the side gear 11 when the motor vehicle is driven, so that a torque transmission to the pinion shaft 15 can take place. This torque must therefore be permanently supplied by the electric motor 5 . The function specified in the description that the electric motor can serve as a generator during the driving process leads to the state that the pinion shaft 15 (almost) stands and the side gear 12 rotates backwards relative to the side gear 11 and thus drives the generator. For the locomotion of the vehicle, a drive torque must therefore be permanently supplied by the electric motor 5 , which will ultimately quickly lead to the discharge of the vehicle electrical system battery.

The published patent application DE 196 50 723 A1 (D2) presents a control system for vehicle drive units, in which a motor generator 21 is connected directly to the sun gear of a planetary gear set 30 . The planetary gear set can be blocked via a clutch 36 . In contrast to the present application, the vehicle drive unit described in D2 requires a starting clutch 31 , the sun gear of the planetary gear set 30 cannot be fixed (the planetary gear set 30 therefore does not have the function of a group transmission for doubling the number of gears) and the motor generator 21 is not used to synchronize the gears of the transmission 4 .

Patent specification DE 196 06 771 C2 (D3) describes a hybrid drive in which two electric machines 3 and 4 and switchable planetary gear sets 5 , 6 , between the input shaft 1 (connected to the internal combustion engine) and the output shaft 12 (leading to the drive wheels). 16 are arranged. The switchable planetary gears serve as a stepped gearbox and in cooperation with the electrical machines, a switchable stepless gearbox results, which means that favorable operating points can be selected. However, it is a hybrid drive in which, except when the clutch 11 is closed, a torque generated by the electric machine 3 is always required for torque transmission, in which no planetary gear set coupled to the electric machine serves as a group transmission for doubling the number of gears, and in which no synchronization processes with the help of a planetary gear set and an electric machine.

In the published patent application DE 198 18 108 A1 (D4), a hybrid drive is also presented, whereby - similar to D2 - an electric machine 2 acts on the sun gear of a planetary gear set 35 (see, for example, FIG. 2) and that this planetary gear set is over a clutch 36 can be blocked. Similar to D2, however, the sun gear of the planetary gear set 35 cannot be fixed and this planetary gear set therefore does not have the function of a group transmission for doubling the number of gears, and the electric machine 2 is not used for synchronizing the gears of the transmission 4 .

The application WO 98/406 47 relates to a drive unit for motor vehicles with a transmission 18 , the transmission being able to be coupled to the internal combustion engine via a friction clutch and an electrical machine being able to be coupled to the transmission 18 with the aid of a clutch and an intermediate transmission. The electric machine serves as a starter motor, as a generator and for gear synchronization. This requires at least two friction clutches and the advantages that are possible with three-shaft operation are not used.

The patent application US 560 32 42 describes a gear arrangement in which at least one electric or hydraulic lathe synchronization of gears with two shafts allows. Here are at least two friction clutches (or a double-acting friction clutch) required and no synchronization operations are possible that span multiple groups go away.

The previous application 199 01 414 (G1) describes the integral structure of gears consisting of at least one planetary gear set coupled with at least one (predominantly) unsynchronized countershaft transmission. A wave of one Planetary gear set (mainly the sun gear shaft here) is directly connected to the crankshaft of the internal combustion engine connected, the second shaft (here mainly the bridge shaft) is directly connected to the integrated one Countershaft gear connected, while the third shaft (here mainly the ring gear shaft) with a Brake and a lathe is connected. The planetary gear set can also be equipped with a (claw) clutch be blocked. This means that several functions can be carried out. With the brake released and released (claw) clutch can be turned with the help of the lathe so that a gear can be switched on synchronized (e.g. 1st gear when the vehicle is stationary). Becomes then apply the brake, this gear is activated in the lower group, i. H. the Drive wheels start to move. So all gears of the countershaft transmission can be shifted then this is the bottom group of gears. If the gears of the Countershaft transmission - again synchronized via the lathe - switched in sequence and then the planetary gear set is blocked, so you get the upper group of gears. Become two Planetary sets each coupled with a countershaft transmission, the gears alternating the are assigned to both planetary gears, there is a power shift in the lower group of gears possible without torque interruption. In addition to the synchronization tasks, an electrical Lathe also take over the functions of starter motor and generator.

Additional application 199 21 064 (G2) preceding this application describes an arrangement of the lathe in alignment with the shaft (s) of the planetary gear (the Planetary gear) with which the lathe is directly coupled to the planetary gear (s) can be. A necessary reduction for the starter operation takes place via an internal one Power split of the planetary gear (s). For multi-part electrical lathes can u. U. without additional mechanical switching purely electrically between the functions Synchronization mode, starter mode and generator mode can be switched. Further Improvements in details are given.

The additional application prior to this application 199 33 373 (G3) describes the simplified structure of a 6-speed gearbox compared to the previous applications Transmission (+ reverse gear), in which the lower 3 gears by applying brakes without Torque interruption can be switched. There is also a possibility of Installation of the gearbox specified in the rear area. Further detail improvements will be made demonstrated.

Preliminary remark on further registrations

In the book
Alfred Krappel and 26 co-authors
Crankshaft start generator (KSG)
Basis for future vehicle concepts
expert publishing house Renningen
ISBN 3-8169-1808-5
different possibilities and applications of crankshaft start generators (KSG) are described. These are electrical machines that are directly connected to the crankshaft of internal combustion engines of motor vehicles. They can be used both as starters with high torque (at low speeds) and as generators with high power (at higher speeds). In the further additional registrations, the possibilities provided by the KSG are expanded in such a way that the KSG is integrated into the transmission and takes over the additional tasks of transmission synchronization and power shifting. It is therefore called the GSSG transmission synchronization start generator here. Of course, the tasks performed by the GSSG can also be used for gearbox synchronization and power shifting from a different type of lathe, e.g. B. a hydraulic unit to be taken over.

The additional application 199 62 854 (G4) preceding this application describes Applications that take advantage of the high torque of the GSSG, even without planetary gear To be able to carry out synchronization and powershift operations. The input shaft of the Transmission divided into two sections, each of which alternately gears are assigned. to A friction clutch can be used to increase the starting torque, otherwise it is sufficient Claw couplings. Arrangements with group gears are described, but each group their own synchronization and load switching device required.

The additional application 100 01 602 (G5) preceding this application describes other applications that use the high torque of the GSSG for synchronization and Take advantage of powershift operations, but now again using at least one planetary gear set. in the In contrast to the applications in G1, G2 and G3, a single or a double is now sufficient Acting planetary gear set for all powershift operations, while in G1, G2, G3 for powershift operations two sets of panettes are required and load switching is only possible in the lower group. The gearboxes described with further groups each need their own for each further group own synchronization and load switching devices.

The previous additional application 100 13 734 ( 66 ) preceding this application describes further applications which take advantage of the high torque of GSSG for synchronization and powershift operations. Here, any number of group transmissions can be connected in series, all of which are synchronized and powershifted by a single GSSG. The specified variants are designed for a relatively large number of gears and the return from shaft 13 to shaft 1 can be difficult under certain circumstances. In addition, not all possible gears are used.

Additional application 100 21 837 (G7) preceding this application describes extensions and refinements of application G7 and nested transmission designs.

The additional application 100 34 656 (G8) preceding this application describes the Use of KSG in boats, mainly in sailing boats. In addition to his previous one The KSG serves tasks as a clutch replacement, as an electric drive and as a shaft generator.

The previous application 100 62 693.9 (G9) describes load switching Group transmissions in which a GSSG 9 is an integral part. For one main and one Sub-group are given simplified construction options, with no eccentric countershafts occur and only geometrical gear gradations are used.

The previous application 101 33 629.2 (G10) describes this application Powershift gearbox that has additional forward and multiple reverse gears via an eccentric countershaft produce. A shortened hollow shaft is not used here and the auxiliary shaft is provided with additional ones Gears or shift sleeves returned.

In the patent DE 195 24 233 C2 a six-speed transmission with 2 countershafts and one described additional shaft for the reverse gear, using two output gears and a gear of the input shaft is responsible for two gears. Here are not the benefits of one eccentric auxiliary shaft is used and no load switching is possible.

The previous application 101 41 309.2 describes this additional application Power shift transmission with eccentric countershafts. There are no "load circuits" between the 1st and the Reverse gear possible and the gearboxes are more voluminous than in this application

Advantages of the invention

In this application, powershift transmissions are described in which 1st gear and one Reverse gear can be switched on at the same time and only activated by switching clutches become. In addition, space-saving designs are presented and another as a friction free-wheel working double clutch.

Description of the invention

The description is based on the associated principle drawings. Show it

FIG. 1 schematic diagrams of 6-speed transmissions in versions 1,

Fig. 2 shows a schematic representations of a 6-speed transmission, in a variant 2,

Fig. 3 Schematic representations of a 6-speed transmission with gears terrain as Option 3,

Fig. 4 shows a schematic illustrations of a dual clutch in a variant as Reibfreilauf 4.

Preliminary remarks

The transmission variants, preferably for motor vehicles, all have concentric input shafts 23 and 24 , which can optionally be coupled to an internal combustion engine via a shaft 1 (one possibility for this is described in variant 4). In all transmission variants, a shaft 13 leads to the drive wheels or to the differential.

As in known double clutch transmissions, the drive torque is transmitted when the vehicle is driven via one of the two shafts 23 or 24 , while the next expected gear can run idle via the other shaft. Different coupling and synchronization options can be used for all variants, such as those used for. B. in variant 4 and described in the application 101 33 629.2.

All transmission variants are automatic manual transmissions, i.e. H. is switched z. B. via electrical, pneumatic or hydraulic actuators with the help of an electronic Control unit.

The reference numerals are largely adapted to the previous applications, therefore there are gaps in the numbering order.

Variants 1

The variant 1a outlined in Fig. 1a) is a gearbox in countershaft construction with (at least) 6 gears and progressive gear gradation. Shafts 23 and 24 can be coupled to the crankshaft of an internal combustion engine via a shaft 1 (e.g. according to variant 4). The gear 3 e provides the axle reduction and the associated shaft 13 leads to the differential gear. The gears 3.1 , 3.2 , 4.1 , 4.2 , 3 a1, 3 a2, 4 a1, 4 a2 produce gears 3 to 6 with closed shift sleeves 35 and 35 a, the 3rd gear with the shift sleeve 34 closed to the right, the 4th Gear with closed shift sleeve 37 , the 5th gear with the shift sleeve 34 closed to the left and the 6th gear with the closed shift sleeve 33 a. In these gears, the rotation of the shaft 21 is transmitted via the gear 3 c to the gear 3 e and thus the shaft 13 .

As already described in the application 101 33 629.2, 1st and 2nd gear are generated via an eccentric countershaft 50 , here coupling via gear 3 d to gear 3 e and gear 3 b1 in the immediate vicinity of gear 3 e is attached, which results in much more favorable installation conditions. With the shift sleeves 35 , 37 , 33 a and 36 a open, the 1st gear works with the shift sleeve 34 closed to the right and the shift sleeve 35 a closed via the shaft 21 a, the gears 3 a1, 3.1 , 3 b1, shift sleeve 36 , shaft 50 and Gear 3 d on gear 3 e. The 2nd gear works with a closed shift sleeve 33 , whereby this double assignment with shift sleeves of the gear 4.1 provides power shift possibilities between 1st and 2nd gear and between 2nd and 3rd gear, because in 2nd gear shift sleeve 35 a can be loosened, shift sleeve 35 and shift sleeve 34 are closed to the right. With this, the 3rd gear is switched on and runs along empty. The 3rd gear is shifted by connecting shaft 24 to shaft 1 .

This design with the gear 3 b1 in the immediate vicinity of the gear 3 e causes a greatly reduced construction volume, but has the consequence that a hollow shaft 21 a must be present in addition to the shaft 21 and that the shift sleeves 33 and 33 a are spatially separated.

In variant 1a, the reverse gear is realized via an additional shaft 50 a and the gears 3 b2 and 3 c1. Compared to the variant 1d and the variants of the application 101 41 309.2, there is one shaft and one more gear here, but these gears can be quite small and there are wide translation adaptation options for the reverse gear. The reverse gear is transmitted when the shift sleeves 36 and 36 a are closed and the shift sleeve 37 is open from the shaft 23 via the gear pairs 3.2 , 3 b2, 3 c1, 3 b1 and 3 d, 3 e.

Since the loose wheel of the fourth gear on the shaft 21 a is located and is connected to the 4th gear via the shift sleeve 37 may be in the reverse gear also (runs over the toothed wheel 3.2 of the 4th gear) shift sleeve 34 to the right and shift sleeve 35 a be closed , This means that 1st gear is switched on at the same time as reverse gear and shaft 24 rotates in reverse in reverse gear. 1st gear is activated by uncoupling shaft 23 from shaft 1 and connecting shaft 24 to shaft 1 . In 1st gear shift sleeve 36 a can remain closed. Thus the reverse gear remains switched on and shaft 23 rotates in reverse in 1st gear. When using double clutches, you can switch back and forth between the 1st and reverse gear simply by switching the clutches.

FIG. 1b), the spatial position of the axes to each other and shows where which gears mesh with each other, wherein the diameters of the gears 3 and 3 b1 c2 can be chosen freely within wide limits.

In Fig. 1c), finally, the relative position of the translations is shown in logarithmic scale. With the dimensions of the gears 3 b2 and 3 c1 shown, the reverse gear is somewhat lower in translation than the first gear, as shown in FIG. 1 c).

In Fig. 1d), a variant is fragmentary 1d, dispensed in an additional shaft 50 a and the reverse gear is realized by a meshing with the pinion gear 3 3 a2 b2. The 1st and 2nd gear continue to work via the gears 3.1 and 3 b1, whereby the gears 3.1 and 3.2 have swapped their positions compared to variant 1a, so that one can make do with a gearshift sleeve 33 (compared to gearshift sleeves 33 and 33a in the Variant 1a). The part of the transmission not shown can be carried out identically to variant 1a.

The 1st gear is driven via the shaft 21a from the shaft 24 , while the reverse gear is driven by the shaft 23 when the shift sleeve 37 is open. Therefore, the transmission can be designed so that shift sleeve 36 can be closed simultaneously to the right and left.

In this state, a double clutch can be used to switch back and forth between reverse gear and 1st gear by simply switching the double clutch, the respectively unused shaft 23 or 24 rotating in reverse.

Compared to variant 1a, there is one shaft and one gear less. But the gear 3 b2 turns out quite large and the choice of the translation of the reverse gear is limited. (The position of the axes is not drawn separately, see registration 101 33 629.2.)

In Figure 1e.) Outlined variant 1e is an opposite variation 1a simplified version with a shift sleeve 33 without the hollow shaft 21 a. For this, this transmission is not as compact as the variant 1a.

From the 3rd gear up, the shift sleeves 35 and 35 a are closed and the 3rd gear works with the shift sleeve 33 closed to the left, the 4th gear with the shift sleeve 37 closed, the 5th gear with the shift sleeve 33 closed to the right and the 6th Gear with shift sleeve 34 closed to the right. So here the waves 23 and 24 have exchanged their tasks compared to variant 1a. For 1st and 2nd gear shift sleeve 35 must be open and shift sleeve 36 must be closed, 1st gear working with shift sleeve 33 closed to the left and 2nd gear with shift sleeve 34 closed to the left (therefore gear 3.1 must be in this position sit). In the 2nd gear shift sleeve 35 a can be opened and with the shift sleeve 35 closed and the shift sleeve 33 closed to the left, a power shift into 3rd gear is possible.

The 1st gear is driven by the shaft 23 , while the reverse gear works with the open sleeve 37 and the closed sleeve 36 a via shaft 24 . For this reason, reverse gear and 1st gear can also be engaged at the same time and activated alternately by switching a double clutch.

The position of the axes is similar to that of variant 1a and therefore not specially drawn. A somewhat more compact solution is also possible here, for example by B. meshes the gear for the lower gears with the gear 3.2 and the gear for the reverse gear with the gear 4.1 . Then these gears move closer to the gear 3 e.

Variant 2

The variant 2 outlined in Fig. 2a) is also a gearbox in countershaft construction with (at least) 6 gears and progressive gear gradation, but is now designed for rear-wheel drive. The shaft 13 belonging to the gear 4 c leads to the differential gear (with integrated reduction gear). The shafts 23 and 24 can optionally be coupled to the crankshaft of an internal combustion engine.

With the shift sleeve 33 closed to the left and the shift sleeve 35 closed to the right, the 3rd gear works with the shift sleeve 37 closed to the left via the gear pair 3.2 , 3 a2, the 4th gear with the gear sleeve 35 additionally closed to the left via the gear pair 4 , 4 a and the 5th gear with the shift sleeve 37 closed to the right via the gear pair 3.1 , 3 a1, wherein in these gears the gear pair 4 b, 4 c is coupled from shaft 21 to shaft 13 . Finally, the 6th gear works with the closed shift sleeve 34 as a direct connection from shaft 24 to shaft 13 .

In 1st and 2nd gear shift sleeve 35 must be open on both sides and shift sleeve 36 must be closed. These gears work via the gears 4 e and 4 f with the shafts 50 and 50 b, the gear 4 f only ensuring an acceptable diameter of the gears 3 b1 and 4 e and the reversal of the direction of rotation associated with the gear 4 f is thereby compensated, that the gear 3 b1 meshes with the gear 3 a1 and not with the gear 3.1 . In 1st gear shift sleeve 33 is open and shift sleeve 37 is closed on both sides, while in 2nd gear shift sleeve 33 is closed to the right. The 2nd gear works via wave 24 without wave 21 involvement. For this reason, shift sleeve 37 can be closed to the left and shift sleeve 35 to the right in 2nd gear and thus shifted to 3rd gear.

For the reverse gear, the gears 3 c1 and 4 d, the shaft 50 a and the shift sleeve 36 a are responsible and the reverse gear works with closed shift sleeves 36 and 36 a from the shaft 24 . In this state, shift sleeve 37 can be closed on both sides at the same time, as a result of which 1st gear is switched on and shaft 23 also rotates backwards. You can switch between reverse and 1st gear by connecting either shaft 23 or shaft 24 to shaft 1 .

In Fig. 2b) the spatial position of the axes is shown and it is shown where which gears mesh with each other. With the dimensions shown, the translations are sketched as in Fig. 1c). Variant 2 is intended to show that the concept presented in variant 1 is also possible for rear-wheel drive in a slightly modified form.

Variant 3

Variant 3 outlined in FIG. 3a) is a 6-speed transmission with additional off-road gears and has characteristics comparable to variant 2 of application 101 41 309.2, except that the reverse gears are implemented differently here. The off-road gears result because the 2nd gear is transmitted via shaft 21 .

Gears 2 to 6 require open shift sleeves 36 and 36 a and closed shift sleeves 35 a, 37 a and 37 b, with the 2nd gear with the shift sleeve 35 closed to the right via the gear pair 4.3 , 4 a3, the 3rd gear with the left closed gearshift sleeve 33 via gear pair 3.2 , 3 a2, the 4th gear with gearshift sleeve 34 closed to the right via gear pair 4.2 , 4 a2, 5th gear with gearshift sleeve 33 closed to the right via gear pair 3.1 , 3 a1 and the 6th Gear works with the shift sleeve 34 closed to the left via the gear pair 4.1 , 4 a1. For 1st gear shift sleeve 37 a must be open, shift sleeve 36 and shift sleeve 33 must be closed to the left and works from shaft 23 via gears 3.2 , 3 a2, 3 a1, 3.1 and 3 b1 on shaft 50 and from there via the gear pair 3 d, 3 e on wave 13 . The 1st gear works completely independently of the shaft 21 , therefore a power shift from 1st to 2nd gear is possible.

With the shift sleeves 36 , 37 b and 35 a still closed, the 1st off-road gear works with the shift sleeve 35 closed to the left, the 2nd off-road gear is identical to the 1st gear, the 3rd off-road gear works with the shift sleeve 34 closed to the right, the 4th Off-road gear with shift sleeve 33 closed to the right and the 5th off-road gear with shift sleeve 34 closed to the left, these gears all being transmitted to shaft 13 via shaft 50 and the gear pair 3 d, 3 e. In the 5th Cross-country gear can be opened shift sleeve 37 b. This enables a power shift to 3rd gear, which is identical to the 6th off-road gear. In addition, from the 2nd off-road gear, which is identical to the 1st gear, a power shift to 2nd gear is possible, so that there are two power-shiftable transitions from the off-road to the road aisles.

The reverse gears work with closed shift sleeves 36 , 36 a, 37 b and open shift sleeves 35 a and 37 a, with the shift sleeve 35 to the left in the lower reverse gear, the shift sleeve 33 to the left in the middle reverse gear and the shift sleeve 34 to the right in the upper reverse gear have to be. If here the gear 4 a2 is designed as an idler gear and can be connected to the shaft 21 a via an additional (not shown) shift sleeve, a "power shift" can also be carried out between the 1st gear and the upper reverse gear.

Fig. 3b) shows the spatial position of the axes to each other and where which gears mesh with each other. In Fig. 3c), finally, the relative position of the gear ratios is given in a logarithmic representation, where S represents the road and G for the road gears.

Variant 4

The in Fig. 4a) and 4b) sketched dual clutch variant 4 consists of a shaft 1 coupled to the crankshaft of an internal combustion engine, two coupling parts 93 and 94 connected to the shaft 1 in a rotationally fixed but axially displaceable manner and two friction surfaces 23 a and 24 a, which with the shafts 23 and 24 are connected. An enlarged detail of the coupling part 94 from view a (arrow) is sketched in FIG. 4b). It consists of a driver 94 a and a friction surface 94 b. The parts 94 a and 94 b are connected with pins (or sheets) 94 c, which are held in bores (or slots) in the parts 94 a and 94 b.

In Fig. 4b) the arrow F indicates the direction of the peripheral force in the clutch when the internal combustion engine is operating in the traction mode. The holes (or slots) are now inclined in the direction of the circumferential force when viewed from the left. The parts 94 a and 94 b engage in a tooth-like manner in such a way that in the relieved state, the teeth engage in one another straight (with slight pretensioning of the pins or sheets). The circumferential force is transmitted via these teeth during train operation. In overrun mode, this device acts as a frictional freewheel, the peripheral force at which the freewheeling function starts can be easily controlled by the contact pressure

In normal driving operation, the contact pressure of the clutch parts 93 and 94 should be selected so that the forces occurring in overrun mode do not film into a freewheeling function. In the case of upshifts, the contact pressure should be reduced in such a way that the traction torque is still transmitted, but the change in speed during the upshift process enables a free-running function with as little friction as possible, thereby minimizing the heat losses during the upshifts.

Claims (5)

1. Short power shift transmission with two input shafts 23 and 24 , an output shaft 13 and an eccentric auxiliary shaft 50 , characterized in that a gear in the transmission path of the reverse gear (the reverse gears) is fixed to the shaft 23 (variants 1a, 1d) or fixed with the shaft 24 is connected (variants 1e, 2) or could be connected (variant 3) that the 1st gear is driven by the other of the shafts 23 and 24 and that between the 1st and reverse gear by switching between double clutches and can be switched. 2. Short power shift transmission according to claim 1, characterized in that the 1st gear from a gear 4.2 via a shift sleeve 35 a and a hollow shaft 21 a to a gear 3 a1 and from there on to the shaft 50 that the 2nd . gear is also transmitted further on this shaft 21 a to the gear 3 a1 and from there to the shaft 50 so that this gear in a gear wheel 3 is mounted e closest gearwheel plane eel, that a fixedly connected to the shaft 23. gear 3.2 is attached in the next gear level, that a gear 3 b1 in the gear 3 e next and a gear 3 b2 in the next gear level and thus short-circuit powershift transmissions can be realized and that the 3rd gear from the gear 4.2 via a clutch 35 and a shaft 21 is transmitted independently of the 2nd gear to a gear 3 c (variant 1a). 3. Short power shift transmission according to claim 1, characterized in that a fixed to the shaft 23 gear 3.2 is attached to the gear 3 e next gear plane and that the shaft 21 a firmly connected gear 3 a1 is attached in the next gear plane and that gears 3 b1 and 3 b2 are mounted in these two gear levels closest to the gear 3 e and thus short power shift transmissions can be realized (variant 1d). 4. Short power shift transmission according to claim 1, characterized in that the reverse gear (gears) is transmitted via a shift sleeve 36 a and a shaft 50 a to a gear 3 c1 and that this gear 3 c1 meshes with the gear 3 b1 (variants 1a , 1e, 2, 3). 5. Short power shift transmission with a double clutch with two coupling parts 93 and 94 and that (using the example of the part 94 ) this part 94 consists of a driver 94 a and a friction surface 94 b, which are connected to each other by inclined pins (or sheets) 94 c are characterized in that the parts 94 a and 94 b are interlocked with each other, that the circumferential forces are transmitted via the toothing in pulling operation and that there is a frictional freewheeling function in overrun which can be controlled by the contact pressure of the clutch.