WO2018077461A1

WO2018077461A1 - Shifting module of an automatic transmission

Info

Publication number: WO2018077461A1
Application number: PCT/EP2017/001204
Authority: WO
Inventors: Lars Didwiszus; Hansjörg KRAFT; Romain Poux
Original assignee: Wabco Europe Bvba
Priority date: 2016-10-27
Filing date: 2017-10-12
Publication date: 2018-05-03
Also published as: DE102016012858A1

Abstract

The invention relates to a shifting module (1) of an automatic transmission, comprising a module housing (2) in which multiple shifting rods (3, 4) are axially moveably mounted and a hydraulically or pneumatically actuatable shifting cylinder (5, 6) is associated with each shifting rod (3, 4) in order to actuate same. According to the invention, in order to be able to form a shifting module (1) of an automatic transmission of this type that is more compact than before without any reduction in functionality, at least two of the shifting rods (3, 4) are arranged in an axially staggered manner in the module housing (2), and the shifting cylinders (5, 6) associated with these shifting rods (3, 4) are each arranged in the region of the axially inner end of said shifting rod (3, 4).

Description

Switching module of an automated manual transmission

The invention relates to a switching module of an automated gearbox, with a module housing in which a plurality of shift rods are mounted axially movable and each shift rod for actuating the same is assigned a hydraulically or pneumatically actuated shift cylinder.

Automated manual transmissions of motor vehicles are often embodied in a countershaft design, the shiftable gear or gear ratios of the transmission being formed by spur gear stages, each of which comprises a fixed gear rotatably mounted on a fixed gear and a rotatably mounted on a further axially parallel gear shaft idler gear. The idler gears of axially adjacent spur gear stages are arranged in pairs on the same gear shaft, so that the reefing gear or gear ratios are alternately engaged and disengaged by a gear sleeve between these idler gears rotatably and axially slidably mounted on the gear shaft.

By an axial displacement of the shift sleeve in one or the other direction, the idler gear of the respective spur gear is rotatably connected by the engagement of a shift toothing of the shift sleeve in a gearing of the respective idler gear with the transmission shaft, whereby the corresponding gear or gear ratio is engaged. To interpret the engaged gear or gear ratio, the shift sleeve is moved in opposite directions, so that the respective gear teeth come out of engagement, and the idler gear of the spur gear is again freely rotatable relative to the gear shaft.

To their axial displacement, the shift sleeves each have an outer annular groove, in which a rigidly mounted on a transmission shaft to the parallel shaft shift rod shift fork or a pivotally mounted in the transmission housing and with an axis-parallel shift rod in control connection fork-shaped shift rocker engages. The axial displacement of the shift sleeves and thus the engagement and disengagement of the gear or translation stages is thus by an axial displacement of the Switching rods causes. The axial displacement of the shift rod takes place in an automated transmission by means of a switch actuator, which may be designed as a hydraulically or pneumatically actuated shift cylinder (piston-cylinder assembly) or as an electromechanical switching unit.

In the present case, it is assumed that a switching module having a module housing, in which a plurality of shift rails mounted axially movable and a corresponding number of hydraulic or pneumatic shift cylinders are arranged coaxially with these shift rails. Such a switching module is mounted in a manual transmission located on a usually located on the top of the transmission housing mounting opening, so that the shift forks mounted on the shift forks engage in the associated shift sleeves or engage drivers of the shift rails in corresponding receptacles of the associated shift rockers. At or in the switching module also designed mostly as solenoid valves hydraulic or pneumatic control valves for actuating the switching cylinder are arranged.

In DE 10 2005 015 482 A1, a switching module of an automated gearbox is described, in which all shift rods are arranged axially parallel side by side and most fluid-actuated shift cylinder in a arranged on the coupling end of the transmission housing module housing. The cylinder housing of the respective switching cylinder are components of a base plate and a cover of the module housing. The shift cylinders are designed as symmetrical three-position cylinders and each arranged coaxially over the associated shift rod. The solenoid valves of the shift cylinders are combined in a control module, which is mounted laterally on the module housing.

From US 8 1 17 934 B2, a switching mechanism of an automatic transmission is known in which the hydraulic shift cylinder is formed as an asymmetric three-position cylinder, which is arranged coaxially at the end of a shift rod. A similarly constructed asymmetrical three-position cylinder is known from DE 10 2010 009 338 A1, it is described in the switching device described there in each case. but used as a selector to shift a shift finger within a select gate.

The present invention is based on the object, a switching module of an automated manual transmission of the type mentioned without functional limitations more compact than previously possible form.

This object is achieved in conjunction with the features of the preamble of claim 1, characterized in that at least two of the switching rods of the switching module are arranged axially staggered in the module housing, and that the switching rods associated switching cylinder are each arranged in the region of the axially inner end of the respective shift rod ,

Advantageous embodiments and further developments of the switching module according to the invention are the subject of the dependent claims.

The invention is therefore based on a known switching module of an automatic transmission, with a module housing, in which a plurality of shift rods are mounted axially movable and each shift rod for actuating the same is assigned a hydraulically or pneumatically actuated shift cylinder.

To achieve more compact dimensions of the switching module according to the invention at least two of the shift rails are staggered axially, that is, one behind the other, arranged in the module housing. As a result, the installation space, which is usually occupied laterally or circumferentially by a shift rod and the associated shift cylinder, is saved, so that the mounting opening provided in the transmission housing for arranging the shift module can be made correspondingly smaller.

The switching cylinders assigned to the two shift rods can, in principle, be arranged at any point in relation to the shift rods. A coaxial arrangement of the shift cylinder centered to the shift rails or at the axially outer end of the However, shift rails would disadvantageously long switching pressure lines to the associated, mostly summarized in a control module solenoid valves and a correspondingly poor temporal response of the shift cylinder result. To achieve short switching pressure lines and a correspondingly good temporal response of the shift cylinder, the shift cylinder, which are assigned to the two axially staggered shift rails, therefore according to the invention in each case in the region of the axially inner end of the respective shift rod and thus axially adjacent to each other.

The two shift rails can be arranged exactly coaxially on a common geometric axis in the module housing, which has the advantage of saving a Umspann- or adjustment, for example, in the machining of the module housing in a processing machine.

According to the invention, however, it is also possible that the two shift rails with respect to a central transmission shaft, such as a transmission input shaft or a transmission output shaft, at least slightly radially and / or circumferentially offset are arranged in the module housing.

At least one of the two axially arranged inside the switching cylinder can be designed as an asymmetric two-position cylinder. A two-position cylinder can then be used as a shift cylinder when, as in a split group or a range group of a group transmission, only between two gear ratios is switched back and forth, and a middle neutral position in which both gear ratios are designed is not needed. The asymmetrical design of the shift cylinder results from the same axial end-side arrangement with respect to the shift rod.

At least one of the two axially arranged inside the switching cylinder can also be designed as an asymmetric three-position cylinder. The use of a three-position cylinder as a shift cylinder is required if, in addition to the alternate insertion of the two associated gear ratios, a mean neutral position ment should be present, in which both translation stages are designed. In this case, the asymmetric design of the shift cylinder results firstly from the end-side arrangement on the shift rod and secondly from the function as a three-position cylinder.

The cylinder housing of the two axially inner switching cylinder are each formed by an axially outwardly open, pot-cylindrical housing portion of the module housing according to an embodiment of the invention, and the cylinder housing these shift cylinders are axially outside each closed by a cylinder cover. The cylinder covers are mounted in the respective cylinder housing and provided with a central bore for the passage of the respective shift rod. The cylinder housing of the two shift cylinders are thus largely components of the module housing, whereby the manufacturing and assembly costs of the switching module is reduced.

The assembly of the shift cylinder takes place in a simple manner, that the

Shift rods are respectively axially inserted into the respective cylinder housing with assembled piston and plugged cylinder cover from the outside, and the cylinder cover are fixed in their intended position in the respective cylinder housing, for example by means of a locking ring.

The respective cylinder cover the shift cylinder are provided in a further embodiment of the switching module with a central tubular cylindrical bearing bush for the radial mounting of the associated shift rod, as a further storage of the shift rod can be avoided in the module housing.

To realize an inner end-side mounting of a shift rod in the module housing, the bottom wall of the cylinder housing at least one of the two in ^¬ nenliegenden shift cylinder can be provided with a central, cylindrical cylindrical bearing bush to the axial end radial bearing of the relevant shift rod.

In the case of a group transmission with a multi-stage main transmission, a two-stage splitter group which precedes this in terms of drive technology, and a drive mechanism nisch downstream two-stage range group are preferably the shift rails of the split group and the range group axially staggered in the module housing and the switching rods associated switching cylinder arranged in each case at the axially inner end of the respective shift rod. In such a group transmission, the shift fork of the split group on the drive side, ie in the direction of travel front, and the shift fork of the range group on the output side, ie in the rear direction, arranged on the respective associated shift rod, so that the possibility for corresponding shortening of the shift rails and sufficient space for axially centered Arrangement of the associated shift cylinder is given.

The invention will be explained in more detail with reference to two embodiments illustrated in the accompanying drawings. In the drawing shows

Fig. 1 shows a first embodiment of a switching module according to the invention in a fragmentary longitudinal center section, and

Fig. 2 shows a second embodiment of a switching module according to the invention in a fragmentary longitudinal center section.

In Fig. 1, a first embodiment of a switching module according to the invention 1 of an automatic transmission for a motor vehicle is shown in a section of a longitudinal center section. In the case of the manual transmission, it is an example of a group transmission with a multi-stage main transmission, a two-stage splitter group which precedes this in terms of drive engineering, and a two-stage range group disposed downstream of this drive technology. The main gear and the splitter group are executed in countershaft design and in each case over several or one

Shift sleeve switchable, engages in each of which a rigidly attached to an associated shift rod shift fork or a pivotally mounted in a transmission housing and standing in an associated switching rod in a stand connection fork-shaped shift rocker. The range group can be executed either in countershaft design or in planetary construction and is switchable via a shift sleeve into which a rigidly attached to an associated shift rod shift fork engages. The structure of such a group transmission is well known to the skilled person. The switching module 1 has a module housing 2, in which at least two shift rails 3, 4 are mounted axially movable, and each shift rod 3, 4 for actuating the same a hydraulically or pneumatically actuated shift cylinder 5, 6 is assigned. In the sectional view of Fig. 1, the shift rod 3 and the shift cylinder 5 of the splitter group and the left shift rod 4 and the shift cylinder 6 of the range group are shown on the right. To save space, the two shift rails 3, 4 are axially staggered, that is arranged axially one behind the other in the module housing 2. In order nevertheless to achieve short switching pressure lines to the associated solenoid valves and a correspondingly good temporal response of the actuation of the shift rods 5, 6, the relevant shift cylinder 5, 6 are each arranged at the axially inner end of the associated shift rod 3, 4.

The shift cylinder 5 for the split group is formed as an asymmetrically constructed three-position cylinder and has a mounted on the associated shift rod 3 piston 7, which is axially movable in a cylinder housing 8 and the interior of the cylinder housing 8 in an axially inner pressure chamber 9 and an axially outer Pressure chamber 10 divided. The cylinder housing 8 is formed by an axially outwardly open pot-cylindrical housing portion 1 1 of the module housing 2 and axially closed externally by a cylinder cover 12 which is secured by two in each case an annular groove inserted circlips 15, 16 on the cylinder housing 8.

For the axial passage of the shift rod 3 for the split group through the cylinder cover 12, this has a central bore 13 which is extended to the radial bearing of the shift rod 3 axially outward to a tubular cylindrical bearing bush 14. Axially inside, the shift rod 3 has an end bearing journal 17 with an enlarged diameter, which is guided axially movable for the end-side radial mounting of the shift rod 3 in a centrally arranged in the bottom wall 18 of the cylinder housing 8 pot cylindrical bearing bushing 19. The limited by the bearing pin 17 of the shift rod 3 interior 20 of the bearing bush 19 is connected via a vent hole 21 with the environment in connection. Axially and radially outside an annular piston 22 of the shift cylinder 5 for the splitter group is slidably guided on the piston 7. In the illustrated in Fig. 1 center position of the piston 7 of the annular piston 22 is at the same time with its axially inner end wall 23 at a formed by a shoulder annular abutment surface 26 of the piston 7 and with the axially inner end wall 25 of a radially outer annular ridge 24 at a by a Sales formed annular abutment surface 27 of the cylinder housing 8 at.

Starting from the illustrated center position of the piston 7, in which both associated gear ratios of the split group are designed, the piston 7 at aeration of the axially inner pressure chamber 9 of the shift cylinder 5 for the split group with entrainment of the annular piston 22 axially outward and at aeration of axially outer pressure chamber 10 of the shift cylinder 5 for the split group without entrainment of the annular piston 22 is displaced axially inward, whereby the respective assigned gear ratio of the split group is inserted.

With a simultaneous ventilation of both pressure chambers 9, 10, the piston 7 of the shift cylinder 5 is shifted for the split group in the illustrated center position and held in this, since the axially inner end surface 28 of the piston 7 is greater than the axially outer end surface 29 of the piston. 7 , but is smaller than the sum of the axially outer end surface 29 of the piston 7 and the axially outer end surface 30 of the annular piston 22nd

In the present case, the shift cylinder 6 shown in FIG. 1 in the left half of the drawing for the range group of the group transmission is also designed as an asymmetrically constructed three-position cylinder. It has a mounted on the associated shift rod 4 piston 31 which is guided axially movable in a cylinder housing 32 and the interior of the cylinder housing 32 in an axially inner pressure chamber 33 and an axially outer pressure chamber 34 divided. This cylinder housing 32 is also formed by an axially outwardly open pot cylindrical housing portion 35 of the module housing 2 and axially outwardly closed by a cylinder cover 36 which has a shoulder 39 in the cylinder housing 32 and one in an annular groove inserted retaining ring 40 is fixed in the cylinder housing 32. For the axial passage of the shift rod 4 of the shift cylinder 6 for the range group, this cylinder cover 36 has a central bore 37, which is extended to the radial bearing of the shift rod 4 axially outside to a tubular cylindrical bearing bush 38.

Axially and radially outside an annular piston 41 is slidably guided on the piston 31 of the shift cylinder 6 for the range group. In the middle position of the piston 31 shown in Fig. 1, the annular piston 41 is at the same time with its axially inner end wall 42 at an annular abutment surface 45 of the piston 31 formed by a shoulder and with the axially inner end wall 44 of a radially outer annular web 43 at one by a Sales formed annular abutment surface 46 of the cylinder housing 32 at.

Starting from the illustrated center position of the piston 31 of the shift cylinder 6 for the range group, in which both associated gear ratios of the range group are designed, the piston 31 at aeration of the axially inner pressure chamber 33 with entrainment of the annular piston 41 to axially outside and at aeration of axially externa ßeren pressure chamber 34 without entrainment of the annular piston 41 is displaced axially inward, whereby the respective assigned gear ratio of the range group is inserted. With a simultaneous ventilation of both pressure chambers 33, 34, the piston 31 is moved to the center position shown and held in this, since the axially inner end face 47 of the piston 31 is greater than the axially outer end face 48 of the piston 31, but smaller than the sum from the axially outer end face 48 of the piston 31 and the axially outer end face 49 of the annular piston 41st

A second embodiment of a switching module 1 'according to the invention shown in FIG. 2 in a section of a longitudinal middle section differs from the first embodiment of the switching module according to FIG. 1 only in that the switching cylinder 6' of the range group is now designed as an asymmetrically constructed two-position cylinder. The shift cylinder 6 'has a piston 50 mounted on the associated shift rod 4 and axially movable in the cylinder housing 32 and the interior of the cylinder housing 32 is divided into an axially inner pressure chamber 51 and an axially outer pressure chamber 52.

The cylinder housing 32 is identical to that of the shift cylinder 6 of FIG. 1 executed for manufacturing reasons and formed by an axially outwardly open pot cylindrical housing portion 35 of the module housing 2. Axially outside the cylinder housing 32 is closed by a likewise identical to the shift cylinder 6 of FIG. 1 executed cylinder cover 36 which is secured via a shoulder 39 in the cylinder housing 32 and a ring inserted into an annular groove 40 in the cylinder housing 32. For the axial passage of the shift rod 4, the cylinder cover 36 here also has a central bore 37, which is extended to the radial mounting of the shift rod 4 axially outward to a tubular cylindrical bearing bush 38.

Starting from the illustrated center position of the piston 50, in which both associated gear ratios of the range group are designed, which the piston 50 does not permanently occupy during operation, the piston 50 is at aeration of the axially inner pressure chamber 51 to axially outside and at aeration of axially outer pressure chamber 52 is displaced axially inward, whereby the respective assigned gear ratio of the range group is inserted.

In the embodiments of the switching module 1, 1 'according to FIGS. 1 and 2, the switching rods 3, 4 of the split group and the range group are arranged, for example, exactly coaxially to a common geometric axis 53 in the module housing 2. According to the invention, however, it is also possible that the two shift rails 3, 4 with respect to a central transmission shaft, such as a transmission input shaft or a transmission output shaft, at least slightly radially and / or circumferentially offset in the module housing 2 are arranged. List of Reference Numerals (part of the description)

1 switching module (first embodiment)

1 'switching module (second embodiment)

2 module housing

3 first shift rod

4 second shift rod

5 shift cylinder

6 shift cylinder (first embodiment)

6 'shift cylinder (second embodiment)

7 pistons

8 cylinder housing

9 Axial inner pressure chamber

10 Axial outer pressure chamber

1 1 housing section

12 First cylinder cover

13 central bore in the cylinder cover 12

14 bearing bush on the cylinder cover 12th

15 First circlip

16 Second circlip

17 journals

18 bottom wall of the module housing

19 bearing bush on the bottom wall

20 Interior of the bearing bush

21 Bleed hole of the bearing bush

22 ring pistons

23 Inner end wall

24 ring bridge

25 Inner end wall

26 stop surface

27 stop surface

28 Inner face Outer face Outer face Piston

Cylinder housing Inner pressure chamber Outer pressure chamber Housing section Cylinder cover

central bore

bearing bush

paragraph

circlip

annular piston

Inner end wall Ringsteg

Inner end wall stop surface

stop surface

Inner face Outer face Outer face Piston

Axial inner pressure chamber Axial outer pressure chamber Geometric axis

Claims

claims

1 . Switching module (1, 1 ') of an automated gearbox, with a module housing (2) in which a plurality of shift rails (3, 4) are mounted axially movable and each

Switching rod (3, 4) for actuating the same a hydraulically or pneumatically actuated shift cylinder (5, 6, 6 ') is assigned, characterized in that at least two of the shift rods (3, 4) are arranged axially staggered in the module housing (2), and that these switching rods (3, 4) associated switching cylinder (5, 6, 6 ') respectively in the region of the axially inner end of the respective shift rod (3, 4) are arranged.

2. Switching module according to claim 1, characterized in that the two shift rods (3, 4) are arranged coaxially on a common geometric axis in the module housing (2).

3. Switching module according to claim 1, characterized in that the two shift rods (3, 4) with respect to a central transmission shaft at least slightly radially and / or circumferentially offset in the module housing (2) are arranged.

4. Switching module according to one of claims 1 to 3, characterized in that at least one of the two axially inwardly arranged switching cylinder (6 ') is designed as an asymmetric two-position cylinder.

5. Switching module according to one of claims 1 to 3, characterized in that at least one of the two axially inwardly arranged switching cylinder (5, 6) is designed as an asymmetric three-position cylinder.

6. Switching module according to one of claims 1 to 5, characterized in that the cylinder housing (8, 32) of the two inner switching cylinder (5, 6, 6 ') in each case by an axially outwardly open, pot-cylindrical housing portion (1 1, 35) the module housing (2) are formed such that the cylinder housings (8, 32) of these switching cylinders (5, 6, 6 ') are closed axially on the outside by a respective cylinder cover (12, 36), and that the cylinder cover (12, 36) in the respective cylinder housing (8, 32) attached and with a central bore (13, 37) for the passage of the respective shift rod (3, 4) is provided.

7. Switching module according to claim 6, characterized in that the cylinder cover (12, 36) at least one of the two shift cylinders (5, 6, 6 ') with a central, tubular cylindrical bearing bush (14, 38) for the radial mounting of the associated

Shift rod (3, 4) is provided.

8. Switching module according to one of claims 1 to 7, characterized in that the bottom wall (18) of the cylinder housing (8) at least one of the two inner shift cylinder (5) with a central, pot-cylindrical bearing bush (19) for end-side radial mounting of relevant shift rod (3) is provided.

9. Switching module according to one of claims 1 to 8, characterized in that in a group transmission with a multi-stage main gear, a drive this upstream two-stage split group and this drive technically downstream two-stage range group, the shift rods (3, 4) of the split group and the range group axially staggered in the module housing (2) are arranged, and that the switching rods (3, 4) associated switching cylinder (5, 6, 6 ') respectively at the axially inner end of the respective shift rod (3, 4) are arranged.