Types of automotive drives. What drive is better for driving - front, rear or full
All modern serial cars Have two axes and four wheels. Through the wheel torque from the engine of the car is transmitted to the road linen. In this article, we will look at the types of car drives, how many wheels are driven by the engine and how it affects the car behavior on the road.
On this issue, cars can be divided into two groups: monopriferous and all-wheel drive. In its turn, these groups can also be divided into subgroups. But everything is in order.
Monoprifer
Monopriforms that the car has only one axis from two. Chronologically, on cars first began to apply rear drive . The rear wheels were leading, front controlled. Technology of that time did not allow combining the drive to the axis and the possibility of controlling it. On the modern cars The drive to the rear wheels is extended to a lesser extent.
Such type of drive usually equip the Class E Cars and above, occasionally "D" class. Smaller popularity is caused by a feature of the layout of such cars. From the engine to the rear axle it is necessary to stretch the drive shaft for transmission of torque.
This requires a transmission tunnel in the body, which takes space on the back row of the seats. Also, rear-wheel drive cars impose increased requirements for driving skills (especially in winter or on a slippery road). But it is believed that such cars are better manageability.
Front-wheel drive
First serial cars With such a type of drive appeared in the 30s of the 20th century. Today, this type of drive is the main for most serial cars.
Its popularity contributes to lower weight and safer behavior on the road, in comparison with the rear-wheel drive cars.
The absence of a transmission tunnel allows you to increase the volume and size of the cabin, with the same external dimensions. The overwhelming majority of the car from "A" to "E" class are equipped with this type of drive.
Four-wheel drive
The engine torque can be transmitted to the front and rear wheels, i.e. Both axes leading. PP can be divided into three subspecies: Permanent PP, PP connected and automatically connected PP.
Permanent full drive. In a car with such a system, both axes and all four wheels are leading. This system allows you to ride both on solid roads and off-road. In the transmission of such a car is necessarily present inter-seed differential.
A small retreat, differential is a mechanical device that distributes the torque obtained from the drive shaft is proportional between the driving wheels, automatically compensating for the difference in the speed of their rotation.
It can be said that the differential sends a moment on the drive wheels, allowing them to rotate with different (differentiated) angular velocities. The differential is installed on all the driving axes (and front and rear).
In such systems, the inter-sieve differential may be free with forced blocking or self-locking. Machines with free differential on asphalt possess mediocre handling, due to its features of the redistribution of torque.
The solution to this problem was the use of self-locking inter-axis differential. Automakers are used by self-blocks of various designs, but their main task is not to accept the axis disconnection, when the wheel is slipped another.
Connected full drive. This type appeared first. The system is characterized by the absence of an inter-axis differential, with a rigid connection of the front axle. Those. Front and rear wheels are spinning at the same speed.
This type of PP cannot be used on the roads with a solid coating. The wheels of any machine rotate at the same speed, only with rectilinear motion. When turning, one of the wheels of each axis begins to spin faster than the second. And the speed of the axes themselves also ceases to be the same. This is due to the fact that the wheels go through different trajectories.
The one that the turn is of a bigger way than that inside. Also the axis. Impossible with high speeds in this case. It will not allow this disgusting handling, and the load on the transmission will quickly bring it out of order, not to mention the wear of the tires. Differential just allows one axis to overtake the other when their difference occurs.
Short-term, straightforward movement on solid coating will not harm the car, but any turn will cause difficulties. In the mud, on sand or gravel, nothing interferes with the wheels, if necessary, slip through the weak grip of the wheels with the soil.
This type of PP is perfect for the operation of the car on off-road, with a non-frequent way out on the roads with a solid coating. The design of its transmission is simple and reliable, with proper operation it is very reliable.
Automatically connected full drive. Further improvement PP systems led to the appearance of electronic controlled systems with the transfer and redistribution of torque. On such cars, the computer is responsible for the redistribution of the torque to one or another axis, by means of an electronic-controlled coupling (which replaced the inter-semicircle differential).
Over the past 20 years, such systems have made a big step forward. They got rid of the world's illogy and departure of the coupling. At first, the speed of processing information from wheel sensors was low enough, which led to delay.
Modern serial systems got rid of these problems with software. But there is one "but": this type of transmission is suitable only for operation on solid coatings with episodic minimal departures on off-road, like a broken primer.
Most of the electron-controlled couplings are not designed for serious off-road, when they slip, they overheat and disconnect. And for this, enough and ten minutes of ice drift or slip in the snow. And if it is regularly overheating, it can and easily fail.
One of the time will call the integration into this system of PP of various electronic assistants. ABS, stabilization system, anti-pussy system, body roll rins and steering corners - all this and much more integrates in this system full drive. Than more than a carThe more difficult these systems.
On off-road, these systems can simulate blocking intercoles differentials using brakes, and on the asphalt significantly improve the car handling. But all these systems become unnecessarily difficult, which promises the difficulty of repair.
Dispute disputes in the driver's concoct about front-wheel drive Car better or rear. Each makes their arguments. But no one in the right mind will deny that without availability positive qualities In whatever the device, no manufacturer will make it at a loss. It remains only to understand all the pros and cons front drive at the car.
Front wheel drive.
Let's start with the transmission device front-wheel drive car and the history of her appearance. With the front-wheel drive design, the torque from the engine is transmitted to the front wheels. This type of car drive or, in English transcription, FWD (Front Wheel Drive) began to be used massively in the machines a slightly later rear. In 1929, he began to use Carl Wan Ranst "Cord L29" in the serial production of the car. In the 70s and 80s, there is a sharp increase in the production of front-wheel drive cars. Today, their number significantly exceeds the release of rear-wheel drive models. This is mainly massive and not expensive models of cars. Depending on the type of engine installation, the following car layouts distinguish with front-wheel drive: Longitudinal engine installation in front of the axis, longitudinal engine installation over the axis, longitudinal engine installation over the axis, the transverse engine installation in front of the axis, the transverse engine setting over the axis, the transverse installation of the engine over the axis.
Driver front drive car.
Mix three types of layouts power aggregate for front drive:
- The sequential layout at which the engine, the main transmission and the gearbox are placed on each other on the same axis;
- With parallel layout, the engine and transmission are located on parallel to each other axes at one level in height;
- The last type is "storey" layout - the engine is located above the transmission.
Modern technologies make it possible to practically equalize the front and rear-wheel drive cars from the point of view of consumer qualities, safety and manageability, but we will still analyze the advantages and disadvantages of front-wheel drive cars. So, about the advantages:
- front-wheel drive carsare usually more compact, their assembly is less costly, therefore, they are more economical and cheap;
- due to the fact that the front leading wheels are loaded quite strongly due to the engine, the passability of the front-wheel drive car in most cases is significantly better than that of the rear-wheel drive machine;
- with insufficient driving experience, front-wheel drive car easier to master, especially when parking in winter timesince its drive wheels direct the car more accurately to the parking lot;
- the energy generated by the engine is used when turning with a large efficiency, since the front leading wheels rotate, and do not move by tangent;
- in the cabin there is no need to place a cardan tunnel, due to the lack of a cardan in the design, in connection with which the volume of the cab is increasing.
However, despite a large number of positive moments, cars with front-wheel drive Possess and sufficient disadvantages, namely:
- they have a bad, in comparison with rear-wheel drive, maneuverability in turns due to the limited angle by hinges of equal corner speeds (Sls);
- due to the simultaneous execution by the front wheels of two functions - thrust and turn, rear wheels Just "dragged" for them, which leads to insufficiently "acute" manageability;
- the engine is rigidly fixed with the car body, and this leads to the transfer of vibrations from the power unit on the body;
- when overclocking the car on her steering wheel a reactive force is transmitted;
- due to redistribution when starting the load back, the front wheels are unloaded, which leads to a challenge of the car;
- for the front-wheel drive car there is a capacity limit. When installing the engine more powerful 200 hp Significantly increases the load on the nodes of the chassis, which leads to a bad handover of the machine.
All of the above says that before starting to manage front-wheel drive car, you need to thoroughly examine theory, if possible with an experienced instructor. It is particularly attentive to be when driving in a slippery road and remember that the yield from the rear-wheel drive and front-wheel drive machines differ radically.
Types of drive.
Almost every car enthusiast knows how the actuator has a car, well, or at least knows which drive on his car. Let's figure it out, what other types of actuators exist and what are their differences. So, in order for the car to go, it is necessary that the torque from the motor of the car is transmitted to its wheels. Depending on how many wheels this torque will receive, depends on the type of drive.
There are three types of drive: front, rear and complete.
Front car drive.
Front-wheel drive cars Get all the engine energy to the front wheels. At a minimum, it is logical, because on most cars the engine is in front and the front part is more loaded, and therefore it has a greater grip of the front wheels with the road. More often such a drive is found on modern budget class cars, but it also happens on expensive models. The front-wheel drive car is pronounced in turns on an inhomogeneous coating, but much less to a lesser extent than cars with rear-wheel drive. But still cars with front-wheel drive are much more likely endowed with a different disadvantage - insufficient turning, that is, the demolition of the front leading wheels to the outer radius during the passage of turns. And if this "ailment" in most regular situations does not make anything about himself, then with active driving, it can cause a lot of trouble to the driver. If there is insufficient rotation, the dynamic stabilization system considered by us can enter and liquidate a potentially dangerous situation. In addition, with an active start, the front of the car is unloaded, as a result of which no longer has the maximum clutch level with the road. For this reason, the front-wheel drive vehicles are difficult to realize the entire potential of the engine during acceleration, if its power exceeds the value of 200 hp For the best behavior of the car on the road, it is equipped with Anti-test system Or blocking an interstole differential to avoid slipping the leading wheels.
Benefits Front drive:
disadvantages front type drive:
- Vibration from the motor due to the rigid fastening is transmitted to the body.
- The steering wheel with intensive acceleration transmits reactive efforts (expressed by the form of impetus). Therefore, front-wheel drive cars with a capacity of more than 250 hp As a rule, they are not issued due to the inability to realize the potential of the engine.
- For sharp start There is a redistribution of weight back, the front axle is unloaded, and leading wheels have a tendency to slip.
- Demolition of the front of the car.
Rear car drive.
With rear drive, the engine energy is fully entered on the rear wheels. Positive side This drive is excellent handling and dynamics, the lack of vibration (transmitted to the body and steering wheel) has a positive effect on comfort for both the driver and passengers. Therefore, on modern cars, rear-wheel drive is used on premium brand models or on sports modelsIn which the gambling handling and the "pure steering wheel" is important, which will not be transmitted vibrations, worsening the "sense of car". One of the main minuses of the rear drive is a tendency to drift, especially on a slippery road. This effect is manifested in the excess of thrust on the drive wheels rear part The car begins to enter - it is called a drift or excessive turning.
Advantages of the rear drive:
The steering wheel does not affect the reactive moments during acceleration, which improves the quality of control over the car.
With a quick and sharp acceleration from the place of weight, the car is redistributed back and leading wheels are less prone to slip and loss of adhesion with the road, which makes it possible to more effectively.
The load on the axes is well distributed, the work is optimally distributed between the front and rear tires, which prevents their rapid wear.
Disadvantages of the rear drive:
Horregious in production, which is reflected in the final price of the car.
Cars with rear wheel type harder in comparison with front-wheel drive. They, as a rule, always in the center of the body there is a tunnel, "eating" useful volume of the cabin and reducing the comfort of the rear passengers.
Patency in snow and dirt is worse than the front or all-wheel drive machines.
Template to the rear axle car.
Four car drive.
When the engine energy is transmitted to all four wheels of the car, such a drive is called full. In bad weather or complex road conditions The motorists often arise about the acquisition of a car with a drive to all wheels or, in other words, all-wheel drive car. When mentioning this type of car, SUVs come to mind the midst, but modern conditions This is most likely the established stereotype: all-wheel drive transmission today is not the prerogative of "jeeps", but a completely traditional common scheme, albeit with many variations in execution, but occurring even on small-caps. The advantages of all-wheel drive cars include good permeability and the ability to start from the place without slipping the wheels almost on any road surface. The main minus of the full drive is heavier and expensive. In some moments, the behavior of a machine with a full drive on the road can be unpredictable. It may occur, due to the uneven distribution of torque on the wheels (for example, one wheel loses the grip with the main coating of the road). This type Drive requires neat driving.
No matter what drive future owner Chooses a modern car, it will be equipped with a system of dynamic stabilization that will make your trip as comfortable and safe for unpredictable road conditions. Before reading the various options for the full drive, it is necessary to define such a device as the differential and the reasons for its need for a scheme design of any type of drive for cars.
The differential is a gear device transmitting torque to drive wheels and providing them with different rotation speed to ensure the turn of a / m without wear of the tires (in the inner wheel path shorter than that of external).Differential is one of the main design elements of the transmission.
The location of the differential in the transport transmission:
In the rear-wheel drive car for drive wheels - in the crankcase rear bridge;
In front-wheel drive car for drive drive - in the gearbox;
In the all-wheel drive car for drive wheels - in the front and rear axle crankcase;
In the all-wheel drive car for drive leading bridges - in the transfer box.
Differentials used to drive leading wheels are called interstoles. The inter-axis differential is established between the leading bridges of the all-wheel drive vehicle.
The presence of differentials is the main stumbling block in the full drive technology, since it has a huge impact on the behavior of the car on the road. If you consider the simplest example of AWD with three "free" differentials, it becomes clear that the car can be immobilized with the clutch loss of at least one of the four wheels. A feature of a simple "free" differential is that it redistributes power in favor of an axis having less resistance.
Thus, if one wheel loses the clutch with an expensive, all developed power is transmitted to it. At the same time, the all-wheel drive car has twice the chances of losing the clutch of one drive wheel with an expensive than a car with a drive per axle. And since the use of a all-wheel drive vehicle involves a more frequent ride in bad road conditions for it becomes very important to have any blocking of differentials: inter-axis, interstole or everyone together.
Automakers introduced a sufficiently large number of layout diagrams and formulas, so let's try to clarify some points. In turn, the four-wheel drive can be divided into subtypes.
Connected full drive(PART-TIME)
PART-TIME 4WD, (English "Part Time" is part of the time) - a complete drive of temporary use. When driving on the roads with a firm coating, all the thrust is transmitted only to one bridge, as a rule of rear. The second bridge is connected by the driver using the lever or buttons.
In vehicles with a plug-in full-wheel drive, there is no inter-axis differential, which would allow cardan shafts to rotate with different speeds when the car turns. With the full drive of the front and rear drive shafts through disposal box It is toughly connected to each other and rotate at one speed. In the turn of the front wheels of the car pass a bigger way than the rear, which appears stresses in transmission, increased rubber wear and so on. We can weaken these effects only by slipping the wheels. Therefore, the use of such a complete drive is limited to sections with a very low clutch coefficient (dirt, snow, ice, sand). On the road with a dry solid coating, connect the four-wheel drive of this type is not recommended, in order to avoid serious breakdowns.
Automatic connected full drive (Tod - Torque on Demand - torque on demand).
In such a system of full drive in normal road conditions, only one bridge is leading. The four-wheel drive is connected if necessary. As a rule, this happens when the wheels are slipped and, as soon as the slip is eliminated, the four-wheel drive turns off. To connect the second bridge, an ussociation can be used, or a multi-disc clutch driven by hydraulic pump, self-locking when the difference in the speed of rotation of the front and rear axle appears; or a multi-disc clutch with electronically controlthat receives information about slipping from ABS sensors and capturing the slightest difference in speed of rotation of the front and rear axles.
Almost every motorist has an idea of \u200b\u200bthe varieties of car drives, well, or to an extreme case, it knows which type of drive leads to its vehicle. Let's try in this article to figure out which acts still exist and what is their significant difference. So, so that the car is in motion, torque from the engine should pass on the wheels of the machine. But how many wheels will take a torque, and on which axis depends on the type of drive.
Drives can be three types: rear, front and full. Consider in more detail their difference, as well as the pros and cons of operation of the car with different types drives.
Rear-wheel drive
If the car is equipped with rear-wheel drive, all the engine energy will be fully transmitted to rear axle. You can meet this type on domestic "classics", as well as Japanese, European and american cars high-class. There are, of course, the indisputable advantages of this option - the dynamics, start from the place, the lack of vibration, which to some extent increases comfort during the operation of the car. By minuses include excessive tendency to drift, especially on slippery road surface. Patency, relatively with the front drive slightly lower.
Drive front
Cars equipped with front-wheel drive, all the energy of the motor, respectively, take on the front axle. This type of drive is encountered more often on budget modern cars, but you can also meet on more expensive models. The front-wheel drive cars are less susceptible to skidding on a slippery road and turns than rear-wheel drive cars, and also have a relatively better cross-country cross-country. Pros of this type of drive is practicality, adequate price and ease of operation. Beginner drivers will easily get used to driving a car on the front drive.
Finally, all-wheel drive cars. In contrast to the above options, the full drive system is the distribution of the torque of the engine to the front and rear axle, namely, all four wheels. The distribution can be carried out in different ways, so the full drive system is divided into subtypes:
- The motor energy can be distributed between the wheels unevenly, depending on the road situation and the state of the roadbed.
- All engine energy is supplied to the main master axis (it can be anterior or rear, depending on the car model), but in the case of slipping the main leading wheels, part of the energy is redistributed to the second axis, introducing it also to work.
- And, of course, the uniform distribution of energy between all the wheels.
Watch a video lesson about the types of car drives - their advantages and disadvantages:
As we found out, all types of drives have their advantages and disadvantages. With what drive to choose a car - solve only you.
Drive machine
Drive machine
the power device that reports the machine with the energy necessary for work. The drive usually includes a source of energy, transmitter and controls. The source of energy can be a muscular force (animal or human), a mechanical device (eg, spring or grease mechanism) or (thermal, electric, pneumatic, hydraulic, etc.). Use and unconventional sources (solar panels, wind energy), which are promising as sources that do not pollute environment. The drive is embedded in stationary machines (machines, rolling mills and other equipment); installed on moving working machines; Applied to various vehicles (Cars, locomotives, etc.). As stationary is most often used in which the source of mechanical energy is the electric motor. On mobile workers and transport vehicles Mostly apply heat engines with direct mechanical and electrical transmission. The leading role belongs engines internal combustion which are installed on cars, locomotives, vessels; gas turbines - on airplanes, gas turbobs; nuclear power installations - on icebreakers, submarines. The electric drive was widely used in utility household cars (sewing, kitchen, washing), instrument (plans, drills). Hydraulic and pneumatic drives are also common (eg, in manual machines), where the source of energy is fluid under pressure or compressed compressor supplied. Combining an electrical drive with the machine made it possible to create machine machines, and then automatic lines. Automation of the machine drive control allows you to adjust the speed according to a specified program, redistribution of the load, remote switching on and off, accurate stop or reversal of motion. Automation of the drive increases, improves the performance of machines in general, improves working conditions.
Encyclopedia "Technique". - M.: Rosman. 2006 .
Watch what is "drive of cars" in other dictionaries:
drive unit - A device for actuating machines and mechanisms. Note The drive consists of a source of energy, a mechanism for transmitting energy (motion) and control instruments. The source of energy is the engine (thermal, electric, ... ...
Drive, power supply device, resulting in a movement machine or mechanism. P. is usually from the source of energy, transmission mechanism and control equipment. The source of energy is the engine (thermal, electric, pneumatic, ... ... Great Soviet Encyclopedia
Drive: In the mechanics, the drive (also the same power drive) a set of devices designed to actuate machines. It consists of a motor, transmission and control systems. Distinguish the drive group (for several cars) and ... ... Wikipedia
Drive, in the technique, device for actuating machines. Consists of an engine, power transmission and control system. There are groups of group (for several machines or working bodies) and individual (for a separate machine or for ... ... encyclopedic Dictionary
drive machine - Drive system consisting of a motor and related devices to drive one or more solid bodies that are part of the machine. [Collection of recommended terms. Issue 99. The theory of mechanisms and machines. Academy of Sciences of the USSR. ... ... Technical translator directory
Drive (device) - Drive, device for actuating machines and mechanisms. Consists of an energy source, transmission, control instrument. Distinguish manual drive (from muscular strength through mechanical transmission), electric, pneumatic, ... ... Illustrated Encyclopedic Dictionary
Device for actuating machines. Consists of an engine, power transmission and control system. There are groups of group (for several cars) and individual ... Big Encyclopedic Dictionary
Dictionary Ozhegova
Drive, a, husband. 1. See lead. 2. Forced delivery to the bodies of the inquiry or the court did not appear on the call of the person, as well as the temporary arrest for interrogation (official). P. in the police. II. Drive, and a drive, a, husband. Device or system of devices ... ... Explanatory dictionary of Ozhegov
DRIVE UNIT - A device consisting of a source of energy transmitting energy (movement) of mechanisms and systems (devices) of control to drive transport machines, various machines and mechanisms of millions of their braking. Sources of energy (movement) ... ... Large polytechnic encyclopedia
Books
- Engineering of transporting machines and devices, S. A. Ivanov. Posted general About transporting machines and general purpose devices. The theoretical foundations for calculating continuous transport machines are set forth: productivity, forces ... electronic book
- Electric drive Study Guide for Academic Bachelor, R. F. Bekishev, Yu. N. Dementiev. Currently, electromechanical energy transformation is used in almost all technical objectswhere the knowledge and work of engineers of many specialties are synthesized. Therefore…
