Daewoo Nexia

since 1994 of release

Repair and car operation

The hydrotransformer (GT) carries out two main functions: carries out smooth transfer of a torque from the engine to transmission and increases torque size at loading increase.

GT consists of three main knots: a pump wheel (a leading element), a turbine wheel (a conducted element) and a reactor wheel (a jet element). The pump wheel is connected by welding to GT casing. The ring space in a casing of GT is filled with working liquid (transmission oil). GT casing 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, the pump wheel of GT is rigidly connected with cranked shaft of the engine and always the cranked shaft rotates with the same speed, as.

At operation of the engine the pump wheel of GT works as the centrifugal pump, forcing working liquid (oil) to move from the center to the wheel periphery between his shovels. At the same time working liquid gets district speed, is directed ny clockwise. On an exit of their interscapular channels of a pump wheel working liquid gets on shovels of a turbine wheel. Thanks to a special shape of shovels of the turbine, the stream of working liquid changes the direction of the movement, having power impact on a turbine wheel and forcing it to rotate in the same party, as a pump wheel. At operation of the engine idling the energy transferred by a pump wheel of working liquid, is insignificant, and the torque arising on a turbine ear is also small. By the included transfer and the idling engine the size of a torque of the turbine is insufficient to touch the car from a place. The increase in a corner of opening of a butterfly valve leads to increase in frequency of rotation of a pump wheel, kinetic energy of working liquid, hydrodynamic forces on shovels of a turbine wheel and, respectively, a torque on entrance to a transmission shaft.

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

The torque transferred двигате Lem to a turbine wheel, arises благода ря to change of the direction of movement of working liquid when passing interscapular channels of the turbine. The size of the moment depends on change of the moment of number of movement of working liquid on an entrance and an exit from a turbine wheel. For promotion of a stream of the working liquid leaving a turbine wheel, and giving to it rotations on an hour hand the reactor established between an exit of turbine and an entrance pump wheels is used. The reactor provides an unaccented input of working liquid on shovels of a pump wheel and high efficiency of the pump.

Function of the reactor is change of the direction of district speed of the working liquid circulating in GT. District speed of liquid on an entrance in the reactor направленa counter-clockwise. On an exit from the reactor working liquid gains the district speed directed clockwise and coinciding with the direction of rotation of a pump wheel. Thanks to operation of the reactor, kinetic energy of working liquid on an exit from a pump wheel and a torque on a turbine wheel increase. The torque of the turbine exceeds an engine torque.

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

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

In process of increase in frequency of rotation of the turbine GT and the car dispersal the direction of a stream of working liquid leaving channels of a turbine wheel, will change. At a certain ratio of speeds of rotation of pump and turbine wheels the direction of the torque operating on shovels of the reactor from a stream of liquid, will change on return and MCX will be unblocked by the reactor. The reactor will freely rotate, without influencing a stream of the working liquid circulating in GT. At this GT works in a hydrocoupling mode without transformation of a torque of the engine. Speeds of rotation of pump and turbine wheels in this operating mode of GT differ slightly.

Planetary transfer

Planetary transfer serves for increase in a torque of the engine. The name "planetary" is connected with features of a design of transfer for which figurative movement of gear wheels is characteristic. All gear wheels of planetary transfer are in continuous 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 at the same time there are some gear wheels which distribute among themselves loading. It promotes bigger durability and smaller mass of planetary transfer. Thanks to a coaxial arrangement of entrance and target shaft planetary transfer is very compact.

A planetary row consists of a solar gear wheel, эпицикла with internal teeths, drove also satellites which make relative and figurative movement. Planetary transfer can increase a torque or speed of rotation of a target shaft, to change the 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 torque, 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 torque 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 conducting эпицикле. At rotation эпицикла satellites, running in a motionless solar wheel, bring into rotation drove (a conducted link of a planetary row) 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 row. Thus all links rotate with identical speed. Satellites remain motionless relatively 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 leading drove. Drove rotates together with satellites which run in a motionless solar gear wheel and bring into rotation эпицикл with greater speed, than speed drove.

Backing transfer

Change of the 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 rather motionless axes and work, as intermediate gear wheels. Irrespective of the fact which the link is the leader (a solar wheel or эпицикл), the conducted link of planetary transfer will rotate in the opposite direction rather leading link.

Friction clutch of blocking of the hydrotransformer
Scheme of work of a friction clutch of blocking


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

Multidisk friction clutches

Scheme of work of a multidisk friction clutch


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

Kulachkovye of the coupling of a free wheeling

Cams and separator of MCX


Scheme kulachkovy MCX


The coupling of a free wheeling (MCX) allows the detail established on it to rotate only in one direction.

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

The cam has a special symmetric profile. One of the extent of cross-section section of a cam is executed more, and another – is less, than a gap And between an internal ring and a holder. At a perekatyvaniye 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.