CVT transmission DAEWOO MATIZ E3CVT
The peculiarity of the spread of CVT transmissions (and of all innovations in general) lies in the psychological barrier of a person. And more this is due to his education, culture, learning ability and the ability to perceive a new.
If you look at the model range of cars produced for different countries, you can see that somewhere automatic transmissions are still not recognized, and somewhere more than 30 years they have been successfully operating them.
Despite the fact that the automatic transmission has only positive operational advantages, part of the population definitely does not understand this (and is unlikely to understand).
For example, TOYOTA, having launched a PRIUS hybrid car for the USA, specially introduced the braking mode when the gas pedal is released and the brake is not applied, similar to a classic car so that the owner does not feel the difference. Although this is not necessary for a hybrid electrical installation – you could leave a free roll
(except for recovery by depressing the brake pedal). But again, for the previous sensations of the driver who bought the hybrid PRIUS, this is implemented in software. And this is in a developed country, the inhabitants of which have been using cars with automatic transmission for more than 40 years. Perhaps in the future this option will be disabled, but for now: “The habit from above has been given to us” .
We note several positive advantages of automatic transmissions:
– higher driving safety (the driver, especially the inexperienced one, is not distracted or mistaken when shifting and choosing gears, holds the steering wheel with two hands during maneuvers and turns, etc. This increases the accuracy of control). When driving on rough terrain (ascents with bends and city mode), errors when starting uphill, kickbacks, overloading the motor to a stop, convulsive start, etc. are excluded. All components of the automatic transmission are constantly engaged, unlike the manual transmission, and in all driving modes, a certain gear is always engaged, inextricably linking the engine and wheels.
– safe engine start (allowed in the PARK provisions, while the rollback of the machine and spontaneous movement are excluded in case of errors of the driver who forgot to put the manual transmission to neutral)
– safe parking of the car (the wheels are always locked by the automatic transmission lock – otherwise, do not pull out the ignition key. Front-wheel drive cars with automatic transmission when parking on slopes are safer, since the parking lock locks one of the front wheels and the handbrake is both rear. Thus, three of the four wheels are locked Drivers with a manual gearbox only put on a hand brake – this is a two-wheel lock, or they only engage a transmission in violation of safety, holding the car only through motor compression).
-reduction of exhaust toxicity due to optimal engine operation in conjunction with automatic transmission. Manual transmission cars are more toxic due to illiteracy of drivers when choosing modes and control errors. Laziness, fatigue, traffic conditions often distract the driver from maintaining optimal engine operating conditions, he overloads the internal combustion engine, increasing exhaust toxicity. And since the main goal of civilized mankind is to live without disease and in their right mind, environmental pollution is given the primary role.
– increase in vehicle life due to optimal control modes of the ICE-automatic transmission bundle. Illiterate operation, overload, increased speed – all this affects both the resource of the engine and the transmission as a whole. Smooth torque transmission without impact and breaks reduces the load on all components. On a rough road, an engine ECU (manual engine control unit) with manual transmission can detect misfires due to uneven rotation, which increases exhaust toxicity.
-A large part of the population can safely drive a car with automatic transmission, since many drivers do not understand (and do not have to) the theory of the internal combustion engine, transmission, and engine building. Their main task is not to pose a threat to others from point A to point B. In other words, if a high-handed driver who has a high opinion of his racing skills, has lost control and crashed into a pole to death, then other traffic participants and pedestrians should not be hurt even putting yourself at risk for one “not head-on” .
-the resource of the automatic transmission itself is higher than the manual transmission, in which it is necessary to constantly change the clutch disc and release bearing. This is especially true in urban environments with mixed terrain (constant gear shifting). In automatic transmission only service oil change.
A slight increase in fuel consumption may not outweigh all the benefits of automatic transmission.
And examples of starting from a “pusher” with a seated battery, worn piston and burnt out candles are not indicative, as this is a technically faulty vehicle, which is not customary to travel in civilized countries.
Now the automatic transmission is gradually replaced by CVT CVT transmissions, the parameters of which are much higher than the automatic transmission. But the CVT on the behavior of the car is unusual and many drivers are confused between questions: “should – should not.” Therefore, the spread of CVT is restrained by this factor..
Many manufacturers complete their small-class machines with variable-speed transmissions, since small motors have low torque and can be “digested” by a fairly simple variable-speed gearbox. For example, such as on DAEWOO MATIZ for the domestic market of Korea .
Symbols E3CVT on the rear door distinguishes this car from a number of brothers with automatic transmission.
The transmission is very simple – two wedge pulleys, between which a rubber-metal chain is stretched. All this spins without any lubrication, since friction
small and thermal energy is easily dissipated by cooling the pulley housing and gearbox.
The driven pulley is always preloaded by a powerful spring (in it friction is higher than all, therefore a cooling impeller is installed).
Given that the CVT gearbox operates on the friction effect, in order to transfer torque from one shaft to another, the compressive force of the chain pulleys must exceed the engine torque reduced to the mass of the car, otherwise the chain will slip. For small engines and light vehicles, this force is small and, in this case, is realized by a spring, similar in size to the suspension in the suspension. Drive pulley driven. Its cone halves diverge and converge to the required distance, providing the necessary gear ratio in accordance with traffic conditions.
It is made very simple. The drive pulley consists of two halves, one of which is equipped with a spacer. It has two bearings and a powerful thrust thread.
When unscrewing a nut with a bearing, abutting against the side cover of the housing, pushes the conical half towards the other, clamping the chain and pushing it to a large diameter (increase gear ratio = high speed).
When twisting, one half of the cone moves away from the other and the chain can “crawl” to a small diameter (reduction in gear ratio = low speed).
The driven pulley helps the rebuild, the spring of which works only for compression and, possibly, has a progressive characteristic, since at small diameters of the chain, an increase in compression force is required due to a decrease in the contact area (fewer chain links are in contact with the surface of the pulley) .
The gear ratios are controlled by a conventional DC motor with permanent stator magnets. Through a system of gears (reduction gear), it acts on the movable part of the driving cone, which, through the thrust bearing, “decouples” the cone and thrust parts. The rotation of the drive gear moves half the cone by loosening or tightening the thrust nut.
The electric motor, reversing its rotation by commands from the control unit, moves half of the driving cone, thereby changing the gear ratios of the entire transmission. The position sensor of the driving pulley for the position feedback system is a linear resistor, the rod of which abuts against the side of the cone, moved by an electric motor. Such a servo servo system responds quickly enough to a change in CVT modes, since it is controlled by only one pulley (tuning), the driven pulley automatically selects the radius along which the drive circuit moves.
The design of the spacer mechanism is covered by a casing – but this does not save it from the dirt of Russian roads. Adhering to the lubrication of the persistent thread (the rest does not require lubrication, the servo gearbox is made of plastic, the bearings are closed), this unit wedges. Since the servo is plastic, it cuts the splines of the plastic gears due to overload.
And damage to the servo gear causes CVT to stop in one fixed gear. That is, the car will move – but only in one gear (with one constant gear ratio).
Therefore, after restoring the mobility of the spacer mechanism and replacing the cut gears, it is better to put the air filter in the air supply channel for cooling. The fence is taken from the grill in the bumper with large windows, through which even large debris flies into the box, which is abundant in our country, not only on the roads.
The oil in this box is poured only into the differential, the transmission itself is very compact due to air cooling and a simple control circuit.
Modern CVT transmissions for engines over 2 liters of working volume are much more complex both in design and control. But anyway, such a gearbox is much simpler than automatic transmission, better to drive and more comfortable for the driver. But such MATIZ cars are not delivered to Russia.
Daewoo Matiz for a girl Not everyone knows that Daewoo Matiz was not invented by Koreans at all, but Italians who worked in ItalDesign studio and created…
Daewoo Matiz Machine
Daewoo Matiz Machine The creation of a compact car Daewoo Matiz in the factory “Uz-Daewoo” started back in 2000. He replaced on the conveyor the archaic…
Daewoo matiz This car was first introduced to the public in 1998 at the Geneva Motor Show. This exhibition model had a 3-cylinder power unit with a…
How to “extend the life” of an automatic transmission
How to “extend the life” of an automatic transmission The automatic transmission today is gradually relegating to the secondary plan the classic…