This time we will learn about the automatic transmission on the car. Transmission on a car serves to move the kinetic energy of the engine to the wheels and adjust the rotation speed to fit the needs. Transmission set ratio variation between speed and torque.
In the automatic
transmission car is not found the clutch pedal, shift to a higher gear or lower
is done automatically, in accordance with the amount of emphasis on the
accelerator pedal and the car speed.
Types of transmission
Based
on the wheel drive position , automatic transmission is divided into two kinds,
namely:
a.
Automatic Transmission Rear Wheel Driving.
b.
Automatic Transmission Front Wheel Driving.
Based
on the transmission power transfer is divided into:
1.
Planetary Gear Transmission
In
this type of comparison gears carried by a planet gear controlled hydraulically
through a band clamping shaft connected to one of the gears.
2. Continously
Variable Transmission
CVT
(Continue Variable Transmission) is a system that forwards round the machine
automatically using centrifugal force (thrust force caused by rotation).
CVT
works through 2 puley (v-belt). The smaller the diameter puley will form the
wider range and the larger diameter puley will form a narrow range. CVT is
divided into three types, namely:
1. Belt CVT
n this type which serves as the power transfer to the drive pulley is a belt of this type is used in almost all automatic car and motorcycle.
2.
Chain CVT
In
this type of transfer of power from the engine is done through a wide chain.
3. Toroidal CVT
This type Use a roller to transfer torque between the input
plate (which is connected to the crankshaft) and plate output (which is
connected to a drive shaft) angle changes relate directly to the shaft roller
which produces gear ratio changes.
Planetary Gear Transmission Components
An automatic
transmission is composed of three main parts, namely:
1. Torque Converter
Torque converter
functions convert rotary power generated by the engine which is then forwarded
to the planetary gear unit.
The main components of the torque converter is:
1. Impeller, connected with flywheel through rotating housing. Serves as
the drive components (driving member).
2. Turbine, connected with the output shaft to the transmission.
Functioning as a component driven (driven member).
3. The stator, static
component which serves directing oil from the turbine to the impeller to
multiply torque.
Torque converter connects the engine to the
transmission hydraulic system. So there is no direct mechanical conection
between the engine with the transmission. Oil that enters the torque converter
comes from the transmission control valve (ratio valve) are combined with oil
from the torque converter charging pump to the inlet passage. Because the
impeller is connected directly to the engine, the impeller is always rotating
in the same direction with the same engine speed. This makes the oil entering
the inlet passage thrown by the blades in the impeller to turbine.
Oil from the turbine is directed by the stator to
increase the strength to the impeller. Because the sator, torque converter can
increase torque. Increase in torque occurs when the turbine gets load or in
other words when the rotation of the turbine is lower than the rotation of the
impeller. The greater the difference the rotation, the greater the torque is increased.
The highest Increase in torque occurs when the drive shaft stop (stall
position) where the turbine is not moving while impeller trying to rotate the
turbine.
Planetary gear Unit
function to receive input from the torque converter and changing the speed and
torque according to driving conditions.
Components of the planetary
gear set are:
1. Planetary gear, or pinion gear or idler gear. Besides rotates
on the shaft, planetary gear also rotates around the sun gear.
2. Carrier
3. Ring gear
4. Sun gear also called
centered gear.
if the sun gear is driven,
and the ring gear held, the planetary gears at the carrier will be forced to
move along the ring gear in the same direction as the sun gear and the carrier
will rotate at a lower speed.
3. Planet Gear Holding
Devices
Holding Devices used in the composition of planetary
gears. Holding devices there are three types, which include; Multiplate
clutches, brake band, and one way clutches.
a. multi-plate clutches serves to hold the components
of the planetary gear that does not rotate.
b. band brake serves to hold the components planetary
gear unit so as not rotating
c. One Way Clutches serves to hold the planetary gear
in one direction of rotation.
4. Hydraulic Control System
====
0 comments:
Post a Comment