opis skrzyĹ„ automatycznych BMW.pdf

Table of Contents

Transmission Fundamentals

Subject

Page

Standard/Automatic Transmission Comparison ............................... 3

Hydraulic Transmission vs. Electro-Hydraulic Transmission .......... 4

Transmission Identification ................................................................. 5

Transmission Hydraulics ..................................................................... 6

Transmission Fluid Application ---------------------------------------- 7

Torque Converter ................................................................................. 8

Torque Converter Clutch .................................................................... 10

Transmission Oil Pump ........................................................................12

Crescent Type Pump ........................................................................... 12

Vane Type Pump ................................................................................. 13

Hydraulic Control Components ......................................................... 14

Electro-Hydraulic Valve Body ............................................................... 14

Shift Valves .......................................................................................... 15

Pressure Regulation ............................................................................ 16

Apply Components .............................................................................. 18

Multi-Plate Clutches and Brakes ........................................................... 18

Band Brakes ..........................................................................................20

One-Way Clutches ................................................................................ 21

Planetary Gear Set ............................................................................... 22

Compound Planetary Gear Sets ......................................................... 23

Simpson Gear Set .................................................................................. 23

Ravigneaux Gear Set ...............................................................................24

Wilson Gear Set .......................................................................................25

Lepeletier Gear Set ..................................................................................26

Planetary Gear Set Operation ..............................................................27

Shift Control ..........................................................................................34

Transmission Control Module ............................................................. 38

Review Questions .................................................................................39

Initial Print Date:1/15/03

Revision Date:

Model: All with BMW Automatic Transmission

Production: All

Objectives:

After completion of this module you will be able to:

• Recognize automatic transmission advantages.

• Identify BMW Automatic Transmissions.

• Understand Basic Transmission Hydraulics.

• Understand Transmission Fluid Application.

• Understand the Operation of Multi Plate Clutches and Brakes.

• Understand Torque Converter Operation.

• Understand Basic Planetary Gear Sets and Basic Power Flow.

Transmission Fundamentals

Standard/Automatic Transmission Comparison

In today's modern vehicles, the automatic transmission has become a vital part of the pow-

ertrain. Automatic transmissions provide overall better fuel economy and efficiency while

adapting to changing road conditions and driving habits. Standard transmissions offer

more driver interaction with the vehicle, however automatic transmissions reduce driver

fatigue and increase safety by shifting automatically. Automatic transmissions also offer

improved driveability in stop and go traffic. If there is a disadvantage to an automatic trans-

mission, it would be complexity and cost of manufacturing.

Standard Transmission

Automatic Transmission

• Drive torque must be interrupted

to change gears.

• Gear teeth are in constant mesh

due to planetary design.

• Higher loads on driveline from

abrupt clutch application.

• Smoother application of drive

torque reduces loads on driveline.

• Clutch must be disengaged when

vehicle is stopped to prevent

stalling.

• Due to fluid coupling in the torque

converter, transmission can stay in

gear when vehicle is stopped.

• High radial loads on housing.

• Minimal radial loads on housing.

• Gear set design requires more

space than planetary type.

• Compact design of gear set. Space

requirement is minimized.

• Requires some Maintenance

(clutch).

• Maintenance free operation.

(Lifetime fluid and no clutch).

• Requires driver intervention for

shifting.

• Automatic shifting reduces driver

fatigue and increases safety.

Transmission Fundamentals

Hydraulic Transmission vs. Electro-hydraulic Transmission

Since the introduction of the automatic transmission there have been numerous refine-

ments to improve shift comfort as well as fuel economy. Early automatic transmissions

used only hydraulic control, there was no electronic intervention. In 1986 BMW introduced

their first EH (Electro-Hydraulic) transmission into production vehicles.

The acronym EGS is used by BMW for its electronic transmission control system. EGS

stands for “Electronic Transmission Control” which comes from the German words

“ E lektronisch G etriebe S teurung”. In order to comply with SAE terminology we will refer

to the EGS control module as the TCM “ T ransmission C ontrol M odule”.

EH controlled transmissions allow for optimized shift points by closely monitoring changing

conditions. Engine speed, road speed and throttle angle are some of the inputs that are

monitored by the TCM to determine optimal shift points. The TCM will then process this

information and control shift point via electronic solenoids mounted on the valve body.

With the introduction of Adaptive Transmission Control, shift comfort and fuel economy was

further improved. The TCM now monitors throttle angle deviations, wheel speeds and CAN

Bus information to fine tune shift points.

Transmission Fundamentals

Transmission Identification

BMW automatic transmission are manufactured by two suppliers for the US market:

• Zahnradfabrik Friedrichshafen: Commonly referred to as ZF. ZF manufactures

both manual and automatic transmissions.

• GM Powertrain - Hydramatic: Hydramatic is a manufacturing division of General

Motors located in Strasbourg France. Hydramatic supplies automatic transmissions

to BMW for four and six-cylinder vehicles.

BMW has developed an internal numbering system for their transmissions for parts order-

ing, information research and identification. Also each manufacturer uses their own inter-

nal identification system. Here is a breakdown of these identification codes:

BMW Identification Code Breakdown

A5S 440Z

A = Automatic

S= Standard

Number of Gears

Overdrive Ratio

S = Top Gear Overdrive

D = Top Gear Direct Drive

Maximum Input Torque Rating in Nm.

Manufacturer

Z = ZF

R = Hydramatic

G = Getrag

ZF Identification Code Breakdown

5HP 24

Number of Gears

HP = Hydraulic Planetary

(automatic)

Internal ZF Designation

Hydramatic Transmissions have internal designations as well, however there are not used

often.

Transmission Fundamentals

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika: