Automatic Transaxle System: Other Hyundai Elantra III facelift

Functions

FUNCTION CHART

Scheme 58

Oil pump

The oil pump is made of the aluminum (the reaction shaft support) to loose the weight and selects the parachoid type to improve the processing and the capacity efficiency at the low RPM range.

Scheme 59

Brakes

The automatic transaxle (A4CF2) uses the low and reverse brake and the second brake. The low and reverse brake is fixed by the low and reverse annulus gear and overdrive planetary carrier.

1. The disc type return spring is applied to the low and reverse brake and it minimizes the slip of the friction material from the uniform spring operation power to improve the durability and reduce the length.

The overdrive sun gear is held on the transaxle case by the second brake.

Scheme 60

Clutch

The multiple clutches and the one way clutch are used as the transaxle device.

The retainer of each clutch is composed of the precision sheet metal parts to realize the productivity and the light weight. The hydraulic centrifugal oil pressure balance device places inside the clutch assembly.

Generally the oil remained in the piston oil pressure chamber pushes the piston by the centrifugal force. But to prevent the piston from being pushed, the oil filled in between the piston and the return spring retainer occurs the centrifugal force and both of the power is offset so that the piston don't move. In result, it improves the durability and the shift control ability.

Scheme 61

Scheme 62

1. Underdrive Clutch The driving force of input shaft is delivered to the underdrive sun gear. The operating oil pressure in the underdrive clutch components operates between the piston and the retainer and pushes the piston to the clutch discs to deliver the driving force from the retainer to the hub.
2. Reverse clutch and overdrive clutch The reverse clutch is engaged at the reverse and delivers the driving force of input shaft to the reverse sun gear. The overdrive clutch is engaged at the 3rd and 4th speed and delivers the driving force of input shaft to the overdrive planetary carrier and the low and reverse annulus gear. The operating oil pressure of the reverse clutch operates between the reverse clutch retainer and overdrive clutch retainer and it has the whole overdrive clutch moved to deliver into the hub via retainer.

Scheme 63

Parking System

The parking system for A4CF2 model is the cam type.

The roller type installed to the existing new generation AT needs the support to move the roller when operating the parking system and is so complicated. But the cam type for A4CF2 model doesn't need the support and the structure is simply. It only needs the guide to prevent from moving the cam idly.

Scheme 64

Main Features

The VFS (Variable Force Solenoid) installed in the valve body is applied to transaxle (A4CF2). VFS varies the line pressure from 4.5bar to 10.5bar according to throttle open angle and shift range to improve the fuel consumption and shift ability. And the reducing valve which is installed in the valve body makes the solenoid control pressure using the reducing pressure instead of the line pressure like the HIVEC transaxle.

The material of spool valve in the valve body is changed from the steel to aluminum to reduce the oil leakage by the thermal expansion between the valve body and spool valve at the high temperature.

The switch valve, the solenoid valve and the fail safe valve are operated to drive the vehicle at the 3rd speed and reverse even thought the malfunction of the electronic control parts occur.

Scheme 65

Scheme 66

Sensor And Actuator Function

SENSOR - ACTUATOR FUNCTION

Scheme 67

ECM-TCM CAN Communication error management

ECM-TCM CAN COMMUNICATION ERROR MANAGEMENT

Standard Hydraulic Pressure Table

STANDARD HYDRAULIC PRESSURE