DE4122628A1 - Vehicle gearbox with double friction clutch and synchroniser - includes planetary gear train at output side for transmission of power to lower ratios of gearing - Google Patents

Abstract

The double friction clutch has a prim. part and two sec. parts on coaxial input shafts. A two-way multi-ratio gearbox has a countershaft and an output shaft with six pairs of gears and dog clutches. All movements are synchronised centrally using an electronic (76) hydraulic/pneumatic-mechanic arrangement by a pair of gear wheels and friction clutches (S1,S2). An oil pressure pump and retarder are geared to the prim. part. The electronic controller (76) regulates the friction clutches (S1,S2) via a pair of solenoid valves (82,83). USE/ADVANTAGE - Esp. in heavy goods vehicles, torque and speed conversion over entire range is possible with min. jerk, achieving high transmission efficiency in lightweight and compact mechanism.

Description

The invention relates to a gear system, in particular for drove a vehicle through an internal combustion engine, with the Features of the preamble of claim 1.

The transmission system according to the invention is particularly suitable for the drive of heavy duty vehicles with internal combustion engines, however also for other machines and devices that have a large rule require rich in the gear system.

For such drive systems, multi-speed dog clutch Manual transmission, also synchronized manual transmission with starting Friction clutch or with an upstream hydraulic converter, so-called called WSK gearbox (converter clutch transmission) known. These transmissions require an interruption when changing gears Power transmission and are therefore in certain operating conditions not anymore, especially on larger inclines and descents switchable. Another known type of transmission are so-called loads manual transmission with or without hydrodynamic torque converter. These known transmissions are under load, i.e. in everyone Operating state, switchable, but you need one for this Numerous friction clutches in the form of multi-plate clutches. This leads to a high weight and larger space requirements, to higher ones Power losses and poorer transmission efficiencies, as well as at higher manufacturing costs. To the construction effort in To keep limits, such known gearboxes are relative few gear steps and high gear jumps, which leads to Limitations in the optimal adjustment of torque and rotation number leads.

The object of the invention is to achieve a transmission plant, especially for heavy goods vehicles, to create the conversion of torque and speed over the entire driving range rich without practically noticeable interruption in traction in the drive strand allows; which for the optimal use of the drive machine in terms of performance and fuel consumption Translation range with the smallest possible gear change and one high transmission efficiency with low weight and low weight Has space requirements; which are easy and safe to use and which with relatively little construction effort and low costs is economically producible.

This object is achieved according to the invention by the characterizing Features of claim 1 solved.  

The gear system according to the invention combines the following Advantages:

• - power interruption-free switching process,
• - high efficiency,
• - light weight,
• - small space,
• - low manufacturing costs,
• - high number of gears possible,
• - small gear jump,
• - large control range,
• - simple and safe operation,
• - Use of a fully automated switching device.

Definitions for claim 1

• a) "Double friction clutch": The double friction clutch exists from 2 individual friction clutches (e.g. disc or Multi-plate clutches), in which the torque is caused by friction in the end. The two clutches are single even under load and at different speeds at the on and output operable. The primary parts of the two clutches are instinctively connected.
• b) "Two-way multi-speed manual transmission with positive shifting elements": This term is to be understood as a gear arrangement in which, in addition to the gear shift and power transmission stage (e.g. gear 3 ), a second force away for another gear stage (e.g. B. Gear 2 or 4 ) is selected in the transmission by switching a positive shifting element and can be prepared for power take-over when changing the power transmission in the double friction clutch. Claw or tooth clutches come into consideration as form-fitting shifting elements, which can only be shifted at synchronous speed and without load.
• c) "Central synchronization device": Below that is a syn chronizing device (e.g. independently operable Understand friction clutches), so in the entire transmission besystem is arranged so that all existing in the transmission which form-fitting switching elements individually for each Switching process before switching on to equal speed brought (synchronized).  
• d) "Gear shift device": The gear shift applied equipment consists of an electronic part with prepro programmed switching program to control the switching processes, an electrical or electrical / hydraulic or electrical / pneumatic actuator for performing the required switching operations for the individual mechanical Switching elements and built-in sensors for monitoring and feedback of the respective switching and operating status.

In a further embodiment of the transmission system according to the invention It is especially useful for systems with high weight performance and space requirements advantageous for the power transmission in the bottom to arrange a planetary gear set on the output side, the output wheelsets of the lower gears with the Input link and the wheelsets of the upper gears with the off gear link of the planetary gear set, with the central synchronizer synchronization synchronized, form-fitting couplings are connectable.

The arrangement of the gears, shafts and clutches will advantageously taken so that the individual gear pairs usable for at least 2 or more gear steps for power transmission and only a positive clutch for changing gears is switched on. Belong to the central synchronization device two switchable friction clutches, which on a common Shaft or be arranged separately on two waves can.

To start heavy loads, it is recommended that the fiction moderate transmission system with a wear-free start-up element (hydrodynamic coupling or converter), which mechanically bridged by a clutch for normal driving is. The starting element can be arranged separately from the gearbox or directly connected to the gearbox to form a block.

For downhill driving, the gear system can wear out loose brake element (e.g. hydraulic retarder), which according to the invention with the drive part of the double friction clutch lung is driven.

For drive systems that are a short distance from the drive Require flange to output flange, the Ab driven from the manual transmission or an additional output branch between those used to change gear or change gear Gear sets are arranged.

The transmission control or shifting device (cf. mung to claim 1 d) is programmed according to the invention so that those for a manually or automatically initiated gear change functions or switching cycles to be carried out in succession, such as:

• Clock 1: Synchronize the positive locking to be switched Clutch;
• Clock 2: Switch on the synchronized positive Clutch (force path preselection);
• Clock 3: Transfer of torque transmission from one to the other other friction clutch arranged on the drive side for the gear to be switched in each case;
• Cycle 4: Switch off the relieved positive clutch of the previously effective gear stage;

automatically, but can only be triggered if the previous one Switching cycle as correctly carried out via the respective sensors the electronics is confirmed. Takes place according to a given If there is no execution notification, the corresponding switching cycle repeated automatically.

Furthermore, it is advantageous, with high acceleration or deceleration of the vehicle with effective automatic gear change, to carry out the pre-selection of the power path for the next following gear stage immediately after the shifted gear stage takes effect, ie the program does not run as normal between bars 1 and 4 , but between bars 2 and 3 stop until the signal for the next gear change is given. This ensures the shortest switching times in these driving conditions.

The invention will now be described with reference to the drawings described by way of preferred embodiments as examples. Show in the drawings

Fig. 1 shows schematically a longitudinal section through a transmission system with 8 gear steps forward and 2 gear steps back and the force path diagram Fig. 1a.

Fig. 2 shows schematically a longitudinal section through a transmission system with 12 gear steps forward, 2 gear steps backwards, in front of a set starting element and side 2nd output.

Fig. 3 shows schematically a longitudinal section through a transmission system with 8 gears forward, 1 gear back, built-in planetary gear set for the lower gears and directly attached starting element.

Fig. 4 shows schematically the control and switching device belonging to the transmission system.

The transmission system according to the invention shown schematically in longitudinal section in Fig. 1 contains the following elements: The transmission arranged on the input side double friction clutch with the common primary part ( 1 ) and the two secondary parts ( 2 ) and ( 3 ); the 2-way manual transmission with the two input shafts ( 4 ) and ( 5 ), the countershaft ( 6 ) and the output shaft ( 7 ) with the gear pairs ( 8 ) for gear stages 1 , 3 , 5 , 8 and R 1 , ( 9 ) for gears 2 , 4 , 6 , 8 and R 2 , ( 10 ) for gears R 1 and R 2 , ( 11 ) for gears 1 and 2 , ( 12 ) for gears 3 and 4 , ( 13 ) for gears 5 and 6 , and the 8 associated positive shifting elements, e.g. B. tooth couplings ( 14 ); the central synchronizer with the pair of wheels ( 15 ) and the friction clutches S 1 and S 2 ; the wear-free braking element for downhill gradients (retarder) ( 16 ) and the oil pressure pump ( 17 ), which are connected to the primary part ( 1 ) of the double clutch via gears ( 18 ).

With the gear arrangement shown, it is in accordance with execution tion of the individual translations with preferably geometric Gear shift possible, the positive shifting elements for everyone Switching operations via the central synchronization device to syn chronize and the force paths of each of the force transmitting Gear level adjacent gear levels in the unloaded state Switch on only one positive switching element before to choose.

In Fig. 1a, the force curve in the individual gear stages is shown mathematically. The 7th Gear stage or the second highest gear stage in each case is switched without a loaded tooth engagement by direct connection of the input shaft ( 4 ) to the output shaft ( 7 ).

Fig. 2 shows another embodiment of the novel transmission system using the example of a 12-speed transmission. The higher number of gears is appropriate by further arrangement of gear pairs Fig. 1 it is sufficient. For the sake of simplicity, only the structural features changed compared to FIG. 1 are therefore explained in the description of FIG. 2. So z. B. to achieve a shorter overall length, the double friction clutch and the central synchronizing device are arranged on 2 shafts, namely: The double friction clutch with the two primary parts ( 21 ) and ( 21 ') connected via the gear pair ( 22 ), the two secondary parts ( 23 ) effective for all odd gear steps 1-3-5 etc. and ( 24 ) effective for all even gear steps 2-4-6 etc .; the central synchronizing device with the clutches S 1 and S 2 and the spur gear pair ( 25 ); the retarder ( 26 ) which is arranged on the countershaft and is operatively connected to the primary coupling part.

Furthermore, the arrangement according to the invention of the or a further output ( 27 , 28 , 29 ) between the shift wheel sets and a drive-side, arranged separately from the transmission, wear-free starting element, for. B. hydrodyne. Coupling ( 30 ) with primary driven oil supply pump ( 31 ).

Fig. 3 shows a further transmission system with 8 gears, namely: The wear-free Anfahrele mounted directly on the transmission element, for. B. hydrodyne. Converter ( 41 ) with mech. Lockup clutch ( 42 ) and the primary oil supply pump ( 43 ); the 2-way gearbox ( 44 ) with the double friction clutch ( 45 ) with attached retarder ( 46 ), the synchronizer ( 47 ), and an additional intermediate shaft ( 48 ) with clutch ( 49 ) for reverse gear. Furthermore, the arrangement of a tarpaulin set ( 50 ) is shown such that, for. B. the gear sets ( 51 ) and ( 52 ) for the lower gear stages with the input member ( 53 ) and the gear sets ( 54 ) and ( 55 ) for the upper gear stages with the output member ( 56 ) of the planetary gear set.

According to the invention, the characterizing features shown in FIGS. 1 to 3 for the individual gear systems can be interchanged or additionally arranged.

Fig. 4 shows schematically and for example an embodiment of the control and switching device belonging to the transmission system, namely: the current source ( 61 ), the oil or air pressure supply ( 62 ) with the pressure regulator ( 63 ) as energy sources; the gear selector switch ( 64 ), the accelerator pedal sensor ( 65 ), the brake pedal sensor ( 66 ) with the lines ( 67 ) for signal input by the driver; the pressure sensors ( 68 ) and ( 69 ) for the double friction clutch I and II, the speed sensors ( 70 ) for the drive, ( 71 ) for clutch I output, ( 72 ) for clutch II output, ( 73 ) for gearbox output , the position sensors ( 74 ) for the individual positive clutches and the lines ( 75 ) for the feedback of the operating state to the electronic control unit ( 76 ); the lines ( 77 ) via which the switching signals formed from the input and feedback signals in the electronic switching device according to a predetermined program, the solenoid valves ( 78 ) and ( 79 ) for the actuations ( 80 ) and ( 81 ) of the friction clutches I and II, the solenoid valves ( 82 ) and ( 83 ) for the actuations ( 84 ) and ( 85 ) of the synchronous clutches S 1 and S 2 , as well as the solenoid valves ( 86 ) for the actuations ( 87 ) of the individual positive coupling elements (in the picture only 1 × shown), to carry out the switching operations in the transmission.

Claims (12)

1. Transmission system, in particular for driving a vehicle characterized by a higher-performance internal combustion engine, by combining the following features:

• a) drive-side arrangement of a double friction clutch,
• b) use of a 2-way multi-speed manual transmission with positive shift elements with 6 and more gear stages,
• c) use of a central synchronization device consisting of 2 friction elements for all switching operations,
• d) Use of an electronic-hydraulic-mechanical or electronic-electrical-mechanical or electronic-pneumatic-mechanical switching device for actuating the positive and non-positive switching elements.

2. Gear system according to claim 1, characterized in that the power transmission for the lower gears via an output side Planetary gear set is done. 3. Gear system according to claim 1 and 2, characterized in that the driven wheelsets of the lower gear steps (e.g. 1st to 4th gear) with the input link of the planetary gear set and the gear sets of the upper gears and the direct drive through with the planet's output link wheelset drivably connectable and via the central synchro nisiereinrichtung are synchronized. 4. Transmission system according to claim 1, characterized by the arrangement of the positive switching elements of the 2-way gearbox such that all for the Main direction of rotation for power transmission effective gears and Planetary gear sets used for at least 2 or more gears can be.   5. Gear system according to claim 1, characterized by the arrangement of the positive switching elements of the 2-way manual transmission such that the force paths for those adjacent to the respective power-transmitting gear stage Gear stages by switching only one positive one Switching element can be selected. 6. Transmission system according to claim 1, characterized in that a wear-free starting ment, e.g. B. Hydrodyne. Coupling or converter between which Drive part of the double friction clutch and the drive motor is arranged. 7. Gear system according to claim 1 and 6, characterized in that the wear-free starting element with a bypass suitable for slip-free drives clutch is equipped. 8. Gear system according to claim 1, characterized in that the driving element of the Dop Oil friction clutch with a hydraulic brake (retarder) is driven. 9. Transmission system according to claim 1, characterized in that the or an additional output from the gearbox between wheelsets, which for Serve gear shift. 10. Transmission system according to claim 1, characterized in that the two friction clutches of the zen central synchronizer both individually and ge can be switched on together. 11. Transmission system according to claim 1, characterized by the arrangement of an electronic hydr. or electronic-pneumatic or electronic-electrical Switching device with a pre-programmed switching program such that the necessary for a gear change individually successive functions (switching cycles) each are triggered automatically when the previous function or the preceding switching cycle as correctly executed to the Electronics is reported. 12. Gear system according to claim 1, characterized by the programming of the switching device such that during acceleration or deceleration with automatic gear change the force path preselection for the the next following gear level immediately after the ge switched power transmission gear automatically triggered becomes.