Daewoo Nexia

Since 1994 of release

Repair and car operation

11.4. The basic knots of a transmission

THE GENERAL DATA

Transmission HYDRA-МАТIC 4Т40Е


The hydrotransformer


The scheme of a stream of a working liquid in the hydrotransformer (without the reactor)


The reactor in gathering with roller муфтой a free wheeling


The scheme of a stream of a working liquid in the hydrotransformer at the stopped reactor


The scheme of a stream of a working liquid in the hydrotransformer at freely rotating reactor


Automatically the transmission includes three basic knots: planetary transfer, the hydrotransformer and a hydraulic control system

The hydrotransformer (ГТ) carries out two basic functions: carries out smooth transfer of a twisting moment from the engine to transmission and increases twisting moment size at loading increase.

ГТ consists of three basic knots: a pump wheel (a leading element), a turbine wheel (a conducted element) and реакторного wheels (a jet element). The pump wheel is connected by welding to casing ГТ. The ring space in casing ГТ is filled by a working liquid (трансмиссионным oil). Casing ГТ by means of bolts is attached to a disk with the gear wreath serving for gearing with a gear wheel of a starter. The disk is established directly on cranked to an engine shaft. Thus, pump wheel ГТ is rigidly connected with cranked shaft of the engine and always the cranked shaft rotates with the same speed, as.

At engine work pump wheel ГТ works as the centrifugal pump, forcing a working liquid (oil) to move from the centre to wheel periphery between its shovels. Simultaneously the working liquid gets district speed, is directed ную clockwise. On their exit межлопаточных channels of a pump wheel the working liquid gets on shovels of a turbine wheel. Thanks to the special form of shovels of the turbine, the stream of a working liquid changes a direction of the movement, having power influence on a turbine wheel and forcing it to rotate in the same party, as a pump wheel. At engine work idling the energy transferred by a pump wheel of a working liquid, is insignificant, and the twisting moment arising on a turbine ear also is small. By the included transfer and the idling engine the size of a twisting moment of the turbine is insufficient to touch the car from a place. The increase in a corner of opening throttle заслонки leads to increase in frequency of rotation of a pump wheel, kinetic energy of a working liquid, hydrodynamic forces at shovels of a turbine wheel and, accordingly, a twisting moment on entrance to a transmission shaft.

Working liquid, transferring energy to a turbine wheel, moves in межлопаточ ных turbine channels in a direction from periphery to the centre and on an exit from a turbine wheel gets the district speed directed counter-clockwise.

The twisting moment transferred двигате лем to a turbine wheel, arises благода ря to change of a direction of movement of a working liquid at passage межлопаточных turbine channels. The moment size depends on change of the moment of quantity of movement of a working liquid on an input and an exit from a turbine wheel. For promotion of a stream of the working liquid leaving a turbine wheel, and giving to it of rotation on an hour hand the reactor established between an exit turbine and an input pump wheels is used. The reactor provides an unaccented input of a working liquid on shovels of a pump wheel and high EFFICIENCY of the pump.

Reactor function is change of a direction of district speed of the working liquid circulating in ГТ. District speed of a liquid on an input in the reactor направленa counter-clockwise. On an exit from the reactor the working liquid gets the district speed directed clockwise and coinciding with a direction of rotation of a pump wheel. Thanks to reactor action, kinetic energy of a working liquid on an exit from a pump wheel and a twisting moment on a turbine wheel increase. The turbine twisting moment exceeds an engine twisting moment.

The stream of a working liquid proceeding through межлопаточные channels of the reactor, influences a reactor wheel in a direction counter-clockwise and gets jammed МСХ the reactor which provides a reactor immovability in a mode of transformation of a twisting moment.

By full pressing a pedal акселерато ра and the motionless car the twisting moment on turbine GT will have the maximum value exceeding a twisting moment of the engine.

In process of increase in frequency of rotation of turbine GT and the dispersal of the car the direction of a stream of a working liquid leaving channels of a turbine wheel, will change. At a certain parity of speeds of rotation of pump and turbine wheels the direction of the twisting moment operating on shovels of the reactor from outside of a stream of a liquid, will change on the return and МСХ will unblock the reactor. The reactor will freely rotate, without influencing a stream of the working liquid circulating in ГТ. Thus ГТ works in a mode гидромуфты without transformation of a twisting moment of the engine. Speeds of rotation of pump and turbine wheels in this operating mode ГТ differ slightly.

Planetary transfer

Planetary transfer serves for increase in a twisting moment of the engine. The name "planetary" is connected with features of a design of transfer for which portable movement of gear wheels is characteristic. All gear wheels of planetary transfer are in constant gearing that excludes shock inclusion of transfers, possible at introduction of gear wheels in gearing with each other. At each step of planetary transfer in gearing simultaneously there are some gear wheels which distribute among themselves loading. It promotes большей to durability and smaller weight of planetary transfer. Thanks to a coaxial arrangement of entrance and target shaft planetary transfer is very compact.

A planetary number consists of a solar gear wheel, эпицикла with internal teeths, drove also satellites which make relative and portable movement. Planetary transfer can increase a twisting moment or speed of rotation of a target shaft, to change a direction of rotation of a target shaft to the return and rigidly to connect among themselves (directly) entrance and target shaft. If transfer works in a mode of increase in a twisting moment, say that the lowering step of transfer as angular speed of a target shaft decreases in comparison with speed of an entrance shaft is included. At constant speed of rotation of an entrance shaft the twisting moment and angular speed of a target shaft change in a return proportion.

Lowering step

The lowering step turns out at the stopped solar gear wheel and the leader эпицикле. At rotation эпицикла satellites, running in a motionless solar wheel, result in rotation drove (a conducted link of a planetary number) with the slowed down speed. Drove rotates in the same party, as эпицикл.

Direct transfer

Direct transfer turns out at rigid connection among themselves any two links of a planetary number. Thus all links rotate with identical speed. Satellites remain motionless rather drove, blocking among themselves a solar gear wheel and эпицикл.

Accelerating step

Accelerating step (from above) and backing transfer (from below).

The accelerating step turns out at the stopped solar gear wheel and the leader drove. Drove rotates together with satellites which run in a motionless solar gear wheel and result in rotation эпицикл with greater speed, than speed drove.

Backing transfer

Change of a direction of rotation of a leading link turns out at stopped drove. A leading link can be as a solar gear wheel, and эпицикл. According to conducted a link will be эпицикл or a solar gear wheel. In this case satellites rotate concerning motionless axes and work, as intermediate gear wheels. Irrespective of the fact which the link is conducting (a solar wheel or эпицикл), the conducted link of planetary transfer will rotate in the opposite direction concerning a leading link.

Friction clutch of blocking of the hydrotransformer
The scheme of work of a friction clutch of blocking


At inclusion of a friction clutch of blocking ГТ, the friction clutch disk incorporates to casing ГТ and capacity of the engine is transferred directly to a shaft of a turbine wheel. Blocking excludes sliding ГТ. In a nave of a disk of a blocking friction clutch it is built in spring damper, reducing dynamic loadings transmissions at blocking ГТ. Демпфер has possibility of axial movings and relative turn on 45 degrees.

Multidisk friction clutches

The scheme of work of a multidisk friction clutch


Multidisk friction clutches join гидравлически by means of ring cylinders of management (сервоцилиндров).

Кулачковые муфты a free wheeling

Cams and separator МСХ


The scheme кулачковой МСХ


Муфта a free wheeling (МСХ) allows the detail established on it to rotate only in one direction.

МСХ consists of an internal ring, a holder and cams with a separator.

The cam has a special symmetric profile. One of the sizes of cross-section section of a cam is executed more, and another – is less, than a backlash And between an internal ring and a holder. At перекатывании cams block with each other or release an internal ring and a holder. Thanks to it, probably relative rotation of details only in one direction.