Transmission Gears / Automatic Transmissions
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Product Specifications:
| Materials used in face gears:
s: |
Manganese steel, Carbon Steel, Alloy Steel
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| Standards: |
ASTM, BS, IS, AISI, SAE |
| We offer these with customized
changes as per the specifications provided by the clients. |
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Do You Know...
For providing variable gearing experiences in some restricted speed
machines or engines (simple machines), only torque converter is
used. This torque converter is although not a automatic
transmission, but is capable in providing variable gearing ratios.
Examples: forklift cars and some modern lawn mowers. |
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Transmission gears are highly demanded gears for their usage in
tractors, trucks, jeeps and cars. Transmission gears are used in automobiles
to transmit heat from the engine to driving axle. This transmission is done
through belts, fluids, gears, etc. Transmission gears are used in the
automotive and other industries. These gears are used for minimizing noise
and vibration, thus ensuring smooth functioning of the machines.
An Automatic transmission can automatically change the gear ratio when the
vehicle moves. It is an automobile gearbox that can provide relaxation to
the drivers from shifting the gears manually.
A set selection of possible gear ranges with a parking pawl feature is
found in most of the automatic transmissions. This feature helps in locking
the output shaft of the transmission. The earlier automatic transmissions
had few disadvantages. These disadvantages were related to their fuel
inefficiency and power. The second were the small size of their engines.
That is why, the invention of the modern automatic transmissions have been
possible, but, still today, the earlier transmissions are still more
efficient.
Automatic Transmission Modes
To select the mode of an Automatic Transmission, the gear shift lever must
be moved. The gear shaft lever can be located on the floor just in front of
the driver or on the steering column of the vehicle. In order to select the
gear-mode, the driver must move a gear shift lever which can be located on
the steering column or on the floor next to the driver. By pushing in the
shift lock button or pulling the handle (shift lock button) out, the driver
can select gears or modes. Automatic Transmission have different modes and
the modes depend upon the various models and transmission make-up. Some of
the popular used modes are as follows:
Park (P)
When this mode of Automatic Transmission is selected, the transmission
mechanically gets locked. This locking doesn't allow the cars to move in any
directions. The use of emergency brakes or hand brakes are recommended to
use in this case, because in this mode, a pin restricts the transmission to
move ahead. This mode also increases the duration of both the park mechanism
and the transmission. The damage can be avoided, if the pin mode is applied
when the car/vehicle comes in a complete rest position. Park is such a 2-way
mode in which the car can be started.
Reverse ®
The car can be put into the reverse gear and can be moved in the backward
direction by using the reverse ® mode. Before selecting this mode,
first, the drivers should bring the car in the complete rest position and
then push in the shift lock button. If without bringing the car in complete
rest position, the reverse mode is applied by the driver, then the
transmission can get damaged. In some modern transmissions, some safety
measures are present which prevent the transmission from such kind of
damage. One of the measure is the present of physical barrier linked to the
brake pedal on either side of the reverse position.
Neutral or No gear (N)
Under this mode, the transmission and wheels of the cars are disconnected
from each other and allow the car to move freely. Only in this selection,
the car can be started safely.
Drive (D)
The car is allowed to get accelerated through a range of gears and to move
forward into this Drive (D) automatic transmission mode. The model of the
automatic transmission decides about the number of gears which will be
present in this mode. Some of the common range regarding the number of gears
that will be there in this mode irrespective of the transmission model are:
from 3,4 (the most common), 5,6 (Audi direct shift gearbox), 7 (Mercedes 7G
gearbox) etc.
Types of Automatic Transmission
The Automatic Transmission has been categorized into two groups. These two
groups are as follows:
Continuously Variable Transmission or CVT
By changing the diameter of a pair of chain-linked pulleys or a pair of
belts, cones, wheels etc., this kind of automatic transmissions can adjust
its gear ratio. In some CTV, there is a hydrostatic drive which comprises a
hydraulic motor and a variable displacement pump. This facilitates in
transmitting power without gears. Alike the manual driving, CVT is also fuel
efficient driving.
Manually controlled automatic transmissions
The drivers get a certain extent of freedom for manual control over the
transmission's shifts from most of the automatic transmission's. The
exception of this freedom is found in the case of the reverse, neutral and
forward modes of gearing. This manual controls have different forms. Some of
the different forms of manual control are as follows:
- Throttle kick-down : On the Throttle linkage, a switch is
included in most of the automatic transmission. If the throttle is
completely engaged then this switch will force the transmission towards
the down shifts into the lower ratio.
- Mode selection : Allow the driver to choose any one shifting
program out of the preset programs.
- Low gear ranges : Selector positions or switches may have
present in many transmissions. This allows the driver in limiting the
highest ratio that the transmission may engage.
- Manual controls : In some transmissions, the driver may have
full control in changing the gear ratio. This control can be obtained
either through the use of paddles or buttons. This control is obtained
by overriding the hydraulic controller. Such kind of control is useful
in avoiding unwanted up-shifts or down-shifts in cornering etc.
