Types of gearboxes. The principle of operation of a manual transmission What does a manual transmission mean

Every car enthusiast has seen or even driven a car with a manual transmission, because training in most driving schools, as a rule, takes place on the “mechanics”. But not everyone knows the history of the origin of this unit, the principle of its operation, advantages and disadvantages. That is what we will talk about in this article.

Autolady and mechanical box transmissions are incompatible concepts. Believe me, driving a car, painting lips, talking on the phone and shifting gears is really difficult.

To begin with, let's figure out what the decoding of the abbreviation for manual transmission is and what it generally means. Manual transmission stands for manual transmission and means that gear shifting is carried out mechanically, that is, manually.

If you try to hold short description mechanical box, we can say that it is a block with many gears inside, which is closely adjacent to the engine and transfers its energy to the wheels. Interaction with the manual transmission occurs using the gear lever and clutch pedal.

We owe the appearance of a manual transmission to a woman. Yes, yes, you heard right and this woman was none other than the wife of Karl Benz Bertha Benz. It was she who, after completing her famous “tour” in a Motorwagen car, expressed her dissatisfaction with her husband about the fact that the engine thrust was not enough to overcome even a small hillock. This happened on August 5, 1888. Not daring to argue with a woman, Karl Benz in 1893 he produced the car "Benz Velo", on which the torque from the engine to the wheels was transmitted by a 2-speed planetary manual gearbox.

Bertha Benz is the wife of Karl Benz, Benz's first Motorwagen and the famous tour from Mannheim to Pforzheim and back, which Bertha Benz made in 1888.

Further, the manual transmission or MT (manual transmission) evolved only by increasing the number of gears and this process was quite fast. First two-stage boxes with reverse gear were put on the very first stock cars Ford brands already at the beginning of the 20th century. Three-speed gearboxes were also not long in coming and appeared as early as 1910. They were applied to European cars, and later on the American ones. Three-speed manual transmissions had widespread up until the early 1960s.

Further out into the light four-speed boxes, which, by the way, appeared a very long time ago, but due to the fact that the first samples were without synchronizers, they were not popular. When, in the 1960s, the 4-speed gearbox acquired synchronizers, then she got her wide application. In the USA, "four-steps" were used for a long time only on sports cars, and in Europe they immediately began to be installed almost everywhere.

The first 5-speed gearbox also appeared in the 1960s, but it received mass use only 20 years later. In such boxes there were four main forward gears, and the fifth, overdrive, was built into the box itself. Prior to this, overdrive (aka “overdrive”) was a separate unit.

In the 1990s, six-speed manual transmissions appeared. They also had four main speeds, but they already had two boosters. After another 10 years, a 7-speed “box” appears, which has five basic and two overdrive gears.

Mechanical seven-speed gearboxes were installed on sports Porsche cars 911 and Chevrolet Corvette Stingray, in order to more efficiently use the torque of a powerful engine.

This is where the development of the manual transmission has ended so far - the design idea has gone into the development of automatic transmissions. On this moment the descendants of "mechanics" are robotic boxes gears. They have the same device and specifications, like the MT, but switch gears and control the clutch independently.

Device

A manual transmission is a set of shafts with gears. All these details are located in one case. "Mechanics" is three-shaft and two-shaft.

The first option is installed on cars with a classic layout - front-engine rear-wheel drive. These are our beloved “penny” and “six”. Such manual transmissions include primary, secondary and intermediate shafts.

Drawing of a mechanical gearbox, which shows that the design of the "mechanics" is quite simple - a set of gears, drive and driven shafts, shift clutches.

The input shaft (aka the drive one) connects the box to the engine flywheel through the clutch. The secondary (slave) is connected to cardan shaft, and the intermediate one serves to transfer rotation from the input shaft to the secondary one.

On the input shaft is the drive gear, which drives the intermediate shaft, and on it, in turn, is its own gear set. They are rigidly connected to the shaft and, often, are one with it. On the secondary shaft is a set of driven gears that are in the splines of the shaft and move along them. They can also rotate in hubs.

Three-shaft manual transmissions have large dimensions and weight than two-shaft, but they can be implemented in direct transmission of torque from the input shaft immediately to the output. Also, three-shaft manual transmissions have the ability to achieve large gear ratios and a wider power range than their two-shaft competitor.

Three-shaft "boxes" are currently installed on all cars with a classic layout, as well as on trucks and SUVs.

This simple diagram shows the main components of a three-shaft manual transmission.

On most modern front wheel drive vehicles two-shaft manual transmissions are installed. In them, the torque is transmitted from the gears of the input shaft to the gears output shaft. The input shaft, like the three-shaft manual transmission, is connected to the engine, and the secondary transmits torque to the wheels. The shafts are parallel to each other.

Due to the lack of an intermediate shaft, such boxes are more compact and have less weight, but due to the large number of additional gears, the efficiency of this type of manual transmission is lower. The advantage of two-shaft manual transmissions lies in the possibility of combining the engine and transmission into a single power unit of a relatively small size. Such characteristics allow the use of this type of manual transmission in vehicles with rear motor and front-wheel drive, as well as on heavy motorcycles.

The principle of gear shifting

In manual transmissions, gear shift clutches are located between the gears of the output shaft. Depending on the number of couplings, the boxes are divided into several types - two-way, three-way, four-way, and so on. For example, three-way manual transmissions have three clutches, each of which can block two gears on each shaft. It follows that a three-way manual transmission can have 4 or 5 gears. forward. Four-way can already have 6, 7 or 8 gears. Go ahead.

On the gears of the output shaft there are toothed rims. They are connected to the rear ends of the drive shaft, and the mating rims are on the engagement clutches. When you switch gears by moving the gear lever, then due to a special drive through the sliders, the gear shift forks move, which move the above clutches. The manual transmission has a special locking mechanism that prevents the inclusion of several gears at once.

When the engagement clutch approaches the required gear, their rims are connected and the clutch blocks the transmission gear. Then they begin to rotate together, and thus the torque is directed to the wheels.

Animated shift diagram of a 4-speed gearbox. The first rod includes the first and second gears, the second rod - the third and fourth, and the third rod for reverse gear.

In order to change gears without bumps and shocks, synchronizers are provided in the manual transmission. They equalize the speeds of rotation of the gear and the clutch and do not allow the clutch to do its work until the specified speeds are equal.

Management of "mechanics"

The classic way to shift gears in a manual transmission is by using a special lever. It is located directly on the lid of the box, or connected to it through an extension cord. It is he who acts on the gearshift forks, and you yourself control the lever itself.

With this control scheme, the speeds turn on most clearly. Also, this scheme has a long service life, but it also has disadvantages. The classic manual transmission control scheme is highly dependent on the layout of the car. In many cases, the lever can be moved forward or backward relative to the driver, creating uncomfortable conditions for shifting. In addition, due to the fact that the lever has direct contact with the box, vibration from the engine is transmitted to it.

The second manual transmission control scheme is when the lever is located at a distance from the box and is connected to it with the help of rods. This solution allows you to install the lever in a place convenient for the driver, regardless of the layout of the car. In addition, with this scheme, vibration is not transmitted to the lever. But these boxes have their own characteristics. Firstly, the rods become loose over time, as a result of which they need to be adjusted or even changed, and secondly, there is a reduced clarity of gear shifting.

The gear lever and clutch pedal are mandatory attributes for operating a manual transmission. If you can somehow put up with the clutch pedal, then the shift lever makes it difficult to drive a car, especially for beginners and women.

The above two schemes are the main ones. But there are also others. For example, switching with pneumatic or electromechanical actuators. Such schemes are used mainly on trucks, buses and agricultural vehicles, so we will not consider them in detail. There is also a sequential control of the "mechanics". In it, the speeds are switched sequentially using a rocking lever, joystick or “petals”. Sequential switching mainly used on sports cars and motorcycles. On such manual transmissions, as a rule, the clutch is automated.

Advantages and disadvantages

And finally, let's look at the pros and cons of manual transmissions. Let's start with the pleasant.

The cost of manual transmission is lower than that of any other boxes. They are also cheaper to repair and maintain, and they are required less frequently than on automatic transmissions. In addition, the manual transmission has more long term service and during operation it is more difficult to break. On average, depending on the model, a manual transmission “walks” 200-300 thousand kilometers, which in some cases is comparable to the service life of a car. The peculiarities of automatic transmissions are that they have a bunch of all sorts of rules that motorists consciously or unconsciously often violate, thereby reducing the life of the box.

A manual transmission increases the dynamic qualities of the car, since it has more high efficiency and technical characteristics that favorably affect the acceleration of the car. In addition, given how much a manual transmission weighs (25-30 kg), compared to "automatic", whose weight is at least 50 kg, also leads to a decrease total weight car.

The advantages include also a large set of driving techniques on the "mechanics". The driver has the right to determine how to drive. This is especially true when driving off-road or on slippery roads.

The manual transmission is also good in “broken” situations. If you have a "mechanics", then you can start the car "from the pusher", as well as tow it to any distance and at any speed without damage to the box, which is absolutely impossible to do on the "machine".

Features such as no need for a separate cooling system and low consumption fuel, also characterize "mechanics" as a more advantageous option.

Perhaps the only drawback of a manual transmission is the very fact of interaction with it - the driver constantly needs to switch gears, synchronously manipulate the gas and brake pedals and monitor engine speed. This is especially annoying in traffic jams and creates inconvenience for novice drivers and for the fair sex.

Someone gets used to this need, and someone can’t put up with it, but be that as it may, manual transmissions are gradually becoming obsolete and, according to experts, the time will soon come when new cars will not be equipped at all manual transmission. Technical progress relentless and the faster automatic transmissions improve, the faster people mechanical ones will be abandoned, but there will always be fans for whom the feeling of complete control over the car is more valuable than comfort.

The video demonstrates how to make a manual transmission with your own hands ... from 116 Lego parts. The downside of this box is that you won't be able to drive it, the upside is that it doesn't need gear oil.

The control mechanism by which the gears are switched on and off is usually located in the gearbox cover and is actuated by a rocker lever.

Consider the device of the control mechanism (switching) five step box gears. The gear lever swings freely in the spherical seat of the gearbox cover, resting on it with a ball thickening and holding it with a spring and a retainer (pin).

Rice. Gear Shift Mechanism:
1 - slider; 2 - upper cover of the gearbox housing; 3 - fork for switching 1st gear and ZX; 4 - switching fork II and 3rd gear; 5 - fork for switching IV and V gears; 6 - ball of the locking device; 7 - latch body; 8 - retainer spring; 9 - pin of the locking device; 10 - retainer ball; 11 - ventilation cap; 12 - safety device spring; 13 - stock; 14 - pusher

The lower end of the lever enters the groove of one of the three forks, each of which moves the synchronizer carriage or the 1st gear and reverse gear. To reduce the travel of the gear lever when engaging 1st gear or reverse gear, there is an intermediate lever mounted on the axle.

Fixation of the on or off position in the gearbox is provided with the help of detents, consisting of balls 10 and springs 8, placed vertically in the tides top cover 2 gearbox housings. The balls go into the upper recesses of the sliders. Each slider 1 has three recesses: one (middle) for the neutral position and two for the corresponding gears. The distances between the recesses are chosen so as to ensure that the corresponding gear rims engage for the entire length of the teeth.

To prevent accidental switching on of two gears at the same time, a locking device is used, consisting of a pin 9 and two balls 6. There are side recesses for the balls on the sliders, and the pin is installed in the horizontal hole of the middle slider. The sum of the diameters of all balls and the length of the pin is equal to the distance between the extreme sliders, summed up with the size of one recess on the slider. As a result, when one of the sliders is moved, the other two are locked by balls in the neutral position. To engage 1st gear or reverse gear, it is necessary to apply additional force to compress the spring of the safety device to the stop with the gear lever and thereby prevent the possibility of accidental engagement of reverse gear when moving forward.

The gearshift drive in vehicle gearboxes is installed both lever directly on the gearbox cover and remote (for example, on a KamAZ car).

The need for a gearbox (gearbox) is caused by the fact that any modern engine has a relatively narrow crankshaft speed range, in which both torque and power have their maximum values ​​for a given fuel consumption. In addition, any engine cannot be spun indefinitely - for any motor there is a certain “red zone”, that is, such a crankshaft speed that is simply unacceptable to exceed, otherwise serious damage cannot be avoided.

What is a gearbox?

It is customary to call a gearbox a mechanism, the main purpose of which is to transfer rotational motion from the engine crankshaft to the cardan or front axle shafts (in the rear or front wheel drive models respectively), thereby controlling that vehicle by changing parameters such as rotational speed and torque, as well as the direction of travel (forward or reverse).

Naturally, no box is able to increase the power of the motor, but on the other hand, it is able to change what is, for its best coordination with real operating conditions, changing the gear ratio between its input and output so as to provide the most favorable fuel-economic and traction and speed properties. In addition, the "duties" of the gearbox include the implementation of the idle mode of the engine and the ability of the car to move in reverse.

The need to use gearboxes is due to the difference in the angular velocities of the crankshaft and drive wheels, which does not allow driving the drive wheels directly from the crankshaft. Yes, crank modern engine has, as a rule, an angular velocity in the range between 500 and 9000 rpm, and angular velocity drive wheels can be between 0 and 1800 rpm.

It follows from this that it will not work in any way to combine one with the other in this parameter without using a gearbox. Finally, they have a rather narrow range in which they have favorable torque characteristics - from 3000 to 7000 rpm, which cannot be “tied” to real operating conditions if you try to do without devices such as gearboxes.

How to get around these problems?

The easiest way is by changing parameters such as the speed of the driven gear and the torque on its shaft using specially selected gears. Now, starting the movement, the choice of the first gear will mean that we have selected a pair of gears with that value gear ratio, which corresponds to the included first gear. Since gear ratios usually decrease with increasing gear number, then in this case we will have the highest gear ratio, the lowest rotational speed of the drive wheels, but the maximum possible torque value.

During further acceleration, one after the other turn on next broadcasts, due to which the speed of the wheels increases, but the torque drops. Even this brief description shows - the gearbox performs important features, without which there would be no talk about any ride. So, the gearbox, in essence, is a multi-stage gearbox, with the help of which it is possible to convert the rotational movement of the crankshaft into forward movement car.

Gear ratio - what kind of animal?

This concept denotes the ratio of the rotation speeds of two interacting gears. In other words, the ratio between the number of teeth on the driving and driven gears is the gear ratio. Different gears naturally require different gear ratios - the maximum gear ratio is applied in the lowest gear (1st) and the minimum gear ratio is applied in the highest gear. "Direct" transmission corresponds to a gear ratio equal to 1. When selecting gear ratios, they tend to choose such that they are not integers.

We can give such an example: we have two gears connected to each other, on each of which we put a marker on the mark - opposite each other. If this pair of gears has a gear ratio equal, for example, to two, then this means that exactly two revolutions from the start of rotation, the marks applied to the gears will coincide again. And every two turns this picture will be repeated - the same pair of teeth will match, that is, it is this pair that is loaded more than others, and for this reason it will break or wear out much faster. For this reason, the selection of gear ratios is a rather responsible operation, and their values ​​are chosen as fractional ones.

Mechanical box device

Scheme of a three-shaft rear-wheel drive gearbox of a car

The device of a three-shaft manual gearbox (we will mention the differences between the two-shaft version below) provides for the placement of three shafts in the crankcase of the box - primary, secondary and intermediate. The input shaft (or drive shaft), thanks to the clutch mechanism, can articulate with and rotate with it. The output shaft (or driven) has a permanent connection with the cardan shaft. The rotation of the primary shaft with the help of an intermediate shaft can be transmitted to the secondary.

The primary and secondary shafts are located in series, and the secondary shaft is supported by a bearing pressed into the input shaft shank. Thus, these two shafts do not have a rigid connection with each other, and their rotation occurs independently. The intermediate shaft is mounted parallel to the said shafts.

Gears are installed on all shafts. The input shaft carries a drive gear that rotates the intermediate shaft. The latter carries a block of gears, rigidly connected to it and often performed with it as a whole. The secondary shaft carries the driven gears - these gears have the ability to move along the splines along the shaft.

On the last shaft there are also clutches that include certain gears. Depending on the number of clutches, gearboxes are two-way, three-way, etc. A modern four-way gearbox, for example, may have 6 or 7 direct gears plus reverse.

In a manual box, the shift from one gear to another is carried out by the driver using a special lever located inside the passenger compartment of the car. In order to avoid switching on two gears at the same time (it is fraught with a breakdown of the box), a special lock is installed in it, and in order to avoid spontaneous shutdown gears have a special locking mechanism.

Operating principles

Suppose the crankshaft speed is 1000 rpm, and thanks to the clutch mechanism, the corresponding torque is received input shaft gearboxes. If we now turn on the first gear, then the gear rigidly fixed on this shaft will engage with another gear, which is larger in size and has four times, for example, more teeth.

Therefore, the shaft on which the second gear is mounted will rotate at a speed of four times less speed crankshaft, that is, 250 rpm. The speed of rotation has decreased four times according to the ratio of the teeth of the gears, and the torque will increase by the same number of times on the second gear.

The use of different gear ratios of pairs of gears allows you to receive from the engine and transfer further to the driving wheels of the car different torques. In other words, a rotation of the engine crankshaft of 1000 rpm can be converted, by choosing the appropriate gears, into rotation of the driving wheels of a car at a speed of, for example, 333 or 250 rpm, etc.

Reverse gear

The implementation of the possibility of moving the car in reverse is ensured by the presence in the gearbox of an appropriate mechanism, consisting of an additional shaft and a reverse gear mounted on it. If you select reverse, then this gear will be additionally included between the secondary and intermediate shafts, due to which the secondary shaft of the gearbox will rotate in the opposite direction compared to the usual direction due to an odd number of gears coupled to each other.

Classifications of modern hand boxes

By number of gears

All boxes are conditionally divided into types depending on the number of gear stages they implement. There are 4-, 5-, 6-, and even 7-speed gearboxes. The increase in the number of gears is based on the need to transmit torque within the most efficient limits. So, if the engine has the highest torque value at relatively low speeds, then accelerate it to more high speed it makes no sense - the power it develops will only fall with increasing speed. In such situations, a much more efficient solution would be to use the appropriate box;

By number of shafts

Gearboxes are 3-shaft and 2-shaft depending on how many shafts they contain. 3-shaft boxes (described above) are equipped with cars with both front and rear rear wheel drive, and 2-shaft boxes are equipped mainly with front-wheel drive cars. A 2-shaft box, as the name implies, contains only two shafts, although in general their location and purpose are similar to a 3-shaft box. The differences are in the arrangement of the shafts relative to each other - it is parallel in a 2-shaft box. The second difference is in the scheme for creating gears - in a 3-shaft box, one gear is realized by two pairs of gears, and in a 2-shaft box - by only one pair. 2-shaft boxes do not have a direct transmission, but they can have not one, but several driven shafts at once.

Advantages of mechanical boxes:

• the cost and weight of the "mechanics" are relatively lower than the same parameters for other types of boxes;
• The efficiency of the "mechanics" is higher than that of other types of boxes;
• thanks to its high reliability, "mechanics" has a long service life;
• manual box provides big choice driving styles in various conditions vehicle operation, for example, off-road, mud, ice;
• a car with “mechanics”, if necessary, can be towed anywhere without fear unpleasant consequences from the side of the box;
• the presence of a manual gearbox provides the ability to start the car from the “pusher” and allows the transmission to be disconnected from the engine.

Disadvantages of mechanical boxes:

• in conditions long drive around the city or in traffic jams is much more tiring for the driver;
  requires the driver to have certain driving skills such as smooth transition between transmissions;
• a relatively long shift time, since it needs to temporarily disconnect the box from the engine (clutch disengagement);
• relatively small resource of the clutch mechanism.

New developments in the world of checkpoints

The current variety of gearboxes is not a frozen metal collector, but absorbing everything new - the world of gearboxes. However, conventional boxes that appeared simultaneously with the advent of the car have the lowest development rates, and robotic ones have the highest, while the latter cease to be ordinary modernized boxes, moving further and further away from them - it affects full control electronics and drives, and their design is carried out according to its own special technology. That is, these boxes, in fact, are increasingly moving away from the mechanics that gave rise to them.

This can also be seen from the results best robot boxes from Ferrari provide gear shifting in no more than 60 ms, and DSG (Volkswagen) gearboxes are capable of shifting individual gears in 8 ms! Thereby Volkswagen Golf, for example, equipped with a 7-speed gearbox of this type, is about 20% more economical than the same car, but equipped with traditional "mechanics".

IN last years the characteristics of lubrication systems have improved dramatically - today's gearboxes are often equipped with a pressure lubrication system, and sometimes also combined with an engine. This solution makes it possible to dramatically increase the life of the gearbox relative to the usual lubrication system due to the oil present in the engine crankcase, as well as provide the necessary cooling of the gearbox due to constant oil circulation. Today, there is already a fairly large number of mechanical boxes, but using for their lubrication ATF oil, that is, oil for .

In conclusion, it is worth saying that the trend of our time is that the device of a manual transmission is becoming more and more complicated in pursuit of dynamics, speed, economy ... What it will be like in the future, it is difficult to say, probably no one will say.

Autoleek

Today we will consider the device of a manual transmission, its positive and negative sides, as well as the most common malfunctions. Despite the very wide choose vehicles equipped automatic transmission, vehicles with manual transmission are still relevant. This is due to the fact that the reliability and resource reserve of mechanics is significantly higher than that of automatic analogues. In addition, cars with mechanics are much more frisky, and their control requires more activity from the driver when driving.

In the photo - the handle of the 7-speed gearbox

The transmission is designed to change the frequency of the torque transmitted from the internal combustion engine. In a manual unit, the driver himself decides which gear ratio should be included in a particular situation.

Modern passenger cars are usually equipped with five speed transmissions: four base and one overdrive. This is perhaps the most best option for most drivers. These models include domestic and many imported vehicles, such as. However, there are models with big amount steps. Manual transmissions with six or seven gears usually have five base stages and two or one overdrive.

Overdrive, or overdrive, has a gear ratio less than one. In other words, when overdrive is engaged, the driven shaft rotates faster than the drive shaft.

Six or seven step mechanics equipped with more expensive vehicles. For example, a gearbox or has six gear positions, and a Porsche 911 latest generation equipped with a seven-speed manual gearbox.

It is worth noting that already budget models, For example, Kia Rio or Hyundai Solaris 2016-2017 models are equipped with a 6-speed gearbox.

Advantages of a six-speed transmission

Naturally, six or seven step gearbox compares favorably with five-stage units. First of all, it should be noted that the switching process is much less exhausting. ICE resource, since, the transition from one speed limit to another more smooth. In addition, the fuel consumption of six-speed manual transmissions is somewhat lower, especially in the extra-urban driving cycle. Acceleration dynamics are much higher due to the fact that the gears are short.

In every modern car, equipped with a six-speed manual, there is an electronic equipment that notifies the driver of the need to switch. There is a similar thing in cars with a five-speed gearbox, but not always.

Manual transmission device

The transmission of a car is a multi-stage gearbox, the principle of operation of which is to alternately mesh individual gear pairs.

Clutch

The smoothness of switching from one gear to another in mechanics occurs due to the presence of a clutch assembly. It allows you to interrupt the connection of the transmission with the power unit for the time of switching. Its mechanism is an intermediate link between the car engine and gearbox. In addition to ensuring smooth shifting, the clutch assembly reduces vibrations transmitted from the internal combustion engine.

The clutch is divided according to the type of design and three types: friction, hydraulic, and electromagnetic.

The friction type is the most popular and can be single-disk, double-disk, multi-disk.

Today's vehicles are usually equipped with single disc models.

The principle of operation of the node is quite simple. The flywheel mounted on the crankshaft of the internal combustion engine acts as a drive disk. The driven disk is pressed against it with the help of a pressure plate, and pressing the clutch weakens this connection. The diaphragm spring provides optimal compression of the driven disc with the flywheel.

The pressure plate with the diaphragm is a one-piece design - the clutch basket. Baskets are both push and pull, but the first type is the most common.

With the help of splines, the driven disk is joined to the primary axis of the manual transmission. The smoothness of the transmission is due to the damper springs located on the disc hub. In addition, the slave is equipped friction linings, which are able to withstand high temperatures for a short time, when the clutch is engaged.

Gear shift

In each gearbox, shafts are located in parallel, on which gears are located. There are three-shaft and two-shaft transmissions. The shafts are called driving (primary), driven (secondary), also in the three-shaft type there is also an intermediate one.

Three-shaft type

The input shaft receives from the internal combustion engine, and from its axis, with the help of a rigid engagement with the drive shaft gear, the rotation is transmitted to the intermediate shaft. The secondary and primary axles are in the same plane and are joined together by a bearing. Due to this, their rotation occurs either completely independently or through an intermediate shaft. The gears on the secondary shaft do not have a rigid fixation, and are separated from each other by synchronizers that fit tightly on the shaft, but can walk along its axis with the help of splines. The end face of the synchronizer has gear rims that allow it to engage with similar rims on the gear wheel.

In the neutral position, the wheels rotate freely on the shaft, and the synchronizers are open. When the gear is engaged, the fork displaces the clutch and engages it with a certain gear.

From the secondary axis, the rotation goes to , or and to front wheel drive cars. To enable reverse gear, an intermediate wheel is installed in the gearbox, which changes the rotation from the intermediate axle to the opposite.

Three-axle units are the most popular and are installed in almost every modern car.

Twin shaft type

The input shaft of a two-axle unit has many gears, not just one. Since there is no intermediate axle, its place is taken by the driven one with synchronizer couplings and gears installed on it. By by and large the difference lies in the presence of only one pair of engagements between the axles for each stage, and not two.

Switching is carried out in a similar way - a fork, controlled by a shift knob using a rod, shifts the clutch along the secondary shaft to the appropriate position.

The two-shaft type is characterized by high efficiency, but is limited in increasing the gear ratio, which is why given type structures are rarely used. Due to the possibility of combining the gearbox, clutch assembly, and the internal combustion engine itself into a single unit, almost all small cars are equipped with this particular type of transmission. An example of the use of two-axle mechanics in a front-mounted car power unit can be considered a Citroen C3.

Important to remember!

Due to the fact that the intermediate gear that provides reverse rotation of the reverse output shaft does not have a synchronizer, the reverse gear should only be engaged after a complete stop vehicle. Otherwise, the gearbox will fail after such a switch.

Synchronizer clutch

Each modern transmission has synchro-clutches. Their presence is important to simplify the switching mode. Without synchronizers, switching would have to be done double release clutch to equalize the speed of the axles. On some types of special equipment where gearboxes have a large number of steps, couplings are not used, since this is impossible.

On the inner circumference of the hub are splined grooves that allow the synchronizer to move along its own axis. When switching, the fork shifts the synchronizer along the splines until it mates with its pair at the end of a certain gear. When switching a stage, a significant force is applied to one of the blocking rings. Ultimately, the locking ring turns all the way.

In the photo - removing the synchronizer clutch

Further displacement of the synchronizer clutch without switching the stage is not possible. When the synchronizer enters into engagement with the gear crown, secure fixation elements.

Pros and cons of mechanics

The manual unit has both its advantages and disadvantages.

Pros:

Less costly transmission maintenance.

High efficiency.

Does not require separate cooling.

Cars with manual transmission are less voracious and have better dynamics.

The simplicity of the mechanics significantly increases the reliability of the unit.

Wider range of driving mode selection.

The vehicle is allowed to be towed.

Minuses:

Smooth starting and shifting require driving skills that only come with time.

A small resource of the clutch assembly.

At long trips the driver of a vehicle with mechanics is much more tired than the driver of a car with automatic transmission.

The limited steps do not allow you to smoothly change the gear ratio.

Possible problems

Despite the simplicity of the design, the unit can break. When identifying abnormal work The checkpoint is recommended to contact a car service as soon as possible. You can try to solve the problem yourself, but this will require both appropriate tools and certain skills.

The first thing to dwell on is the occurrence extraneous noise when shifting into neutral. This can happen if the oil in the box has long exhausted its resource or it is not left at all. Usually, drivers change it extremely rarely, but if the transmission does not work correctly, the first thing you should pay attention to is the condition of the oil.

It can also leak due to the poor condition of the seals and gaskets. In this case, when changing the oil, other defective elements should also be changed. However, worn out bearings, gears, misalignment of the shaft axes can also be the cause of this problem. In this case, the box should be dismantled and completely sorted out, replacing worn-out structural elements.

There are situations when the driver has to make more effort to change gear than usual. This may be due to the failure of the switching mechanism itself or the incomplete disengagement of the clutch. However, damage to the stem lever may have caused the problem. To eliminate it, it is necessary to adjust the shifting or clutch mechanism, and it may also be necessary to replace damaged elements.

Some drivers have experienced transmission problems. This is often associated with wear of gears, forks, rods, bearings of the driven or intermediate shafts, as well as weakening their fixation. Since there can be quite a few reasons, in order to get rid of a manual transmission malfunction, it is necessary to completely sort out with the replacement of all defective structural elements.

Incompletely depressing the clutch pedal or driving the car with the clutch partially depressed is fraught with damage to the assembly parts. There is rapid wear of the clutch disc, and the petals of the diaphragm spring can simply break off. In addition, incomplete disengagement of the clutch when switching will soon lead to licking of the gears.

It is also worth mentioning that strong vibration transmission with the internal combustion engine running indicates that the docking of the two units is unreliable. Most likely, in this case, the fault is the weakening bolted connections; in this case, it will be enough to tighten them only more strongly. However, it is possible that the vibration is associated with the destruction of the supports, and then a very time-consuming repair will be required.

The occurrence of incorrect noise when shifting gears is most often associated with a clutch malfunction. The output shaft bearing may also be the culprit.

Careful use of any mechanism is a guarantee of its durability. The unpretentiousness of the mechanical unit attracts car owners. And yet, there are some recommendations regarding the use of manual transmission.

The first thing to remember is the importance of fully depressing the clutch pedal before changing gear. This is perhaps crucial point in the use of mechanics. Also, the included gear must correspond to the driving mode. In addition, it is worth remembering that before switching to downshift, the speed must be reduced.

Despite the fact that, unlike the automatic machine, the mechanics can work without oil at all, this is quite strongly reflected in its general condition. It is recommended to check the level and condition of the lubricant after passing 20,000 km. Even though the majority experienced car owners in general, they never change the oil in mechanics, this is still completely wrong. It is advisable to change it at least after every 70,000 km of run.

If you're a new driver or have only driven an automatic car up until now, the thought of mechanics can be daunting at first. Fortunately, everyone can understand how to start a car with a manual transmission and how to change gears. To do this, you need to understand what a clutch is, learn how to use the gear lever and then practice starting, stopping and shifting gears at different speeds. The only way to really learn is to practice and practice again.

Steps

Part 1

Engine starting

Start learning on a level surface. If this is your first time driving a car with a manual transmission, take your time. As soon as you get into the car, fasten your seat belt. While you are learning, it is best to roll down the windows. This will allow you to hear the engine better and change gears accordingly.

• A car with a manual transmission has three pedals. On the left side is the clutch pedal, in the middle is the brake, and on the right is the gas. The pedal arrangement is the same for both left-hand drive and right-hand drive vehicles.

1. Understand the purpose of the clutch. Before pressing on an unfamiliar pedal on the left, familiarize yourself with its functions.

   • The clutch disengages the running engine from the wheels and allows you to change gear without the grinding of individual gear teeth.
   • Depress the clutch before shifting gears.

2. Adjust the seat so that you can freely depress the clutch pedal (left, next to the brake pedal) fully to the floor with your left foot.

   Depress the clutch pedal and hold it in that position. This good moment to feel the difference between the clutch pedal and the gas and brake pedals, and to learn how to release the clutch slowly.

   • If you used to drive only with an automatic transmission, it may be uncomfortable for you to press the pedal with your left foot, but over time you will get used to it.

3. Move the shift lever to neutral position. This is the middle position where the lever can move freely from side to side. The vehicle is not in gear when:

   • the shift lever is in neutral and/or
   • the clutch pedal is fully depressed.
   • Do not attempt to shift gears without depressing the clutch.

4. Start the engine using the ignition key with the clutch pedal fully depressed. Make sure the shift lever is in neutral. For safety reasons, before starting the engine, park the machine in hand brake especially if you are still a beginner.

   • Some cars will start in neutral without the clutch being depressed, but this is rare.

5. Remove your foot from the clutch (assuming the shift lever is in neutral). If you are on a flat surface, the car will remain stationary, if you are on a slope, it will go down. When you're ready to go straight to driving, don't forget to release the handbrake.

   Stop. To stop under control, shift gears as you decrease until you reach first. When you need to come to a complete stop, move your right foot from the gas to the brake and apply. As soon as you slow down to a speed of about 15 km/h, you will feel a vibration. Fully depress the clutch pedal and move the gearshift lever to neutral. Use the brake pedal to stop completely.

   • You can stop in any gear. To do this, fully depress the clutch and apply the brakes while shifting into neutral. Only use this method if you need to stop quickly, as you have less control over the vehicle.

Part 4

Practice and problem solving

1. Take a few simple lessons from an experienced driver. If you already have driver license, you can practice on your own on any road, however experienced instructor or have a partner help you learn gear shifting faster. Start on a flat, empty area (such as an empty parking lot), then move onto quiet streets. Practice on the same route until you start mastering all the necessary skills.

2. At first, avoid stopping and starting on steep hills. When you first learn to drive with a manual transmission, choose routes that do not involve stops (say, traffic lights) at the top of a hill. You will need very good reaction and coordination to keep the shifter, clutch, brake and gas under control, otherwise you may roll back when shifting into first gear.

   • You need to learn how to quickly (but smoothly) transfer your right foot from the brake to the gas while releasing the clutch with your left. In order not to roll back, you can use the handbrake, but do not forget to remove the car from it in order to move forward.

3. Learn to park, especially on a hill. Unlike automatic box, in manual there is no parking gear. If you just shift to "neutral", the car may roll forward or backward, especially if the road where it is is on a slope. Always put the handbrake on your car, but remember that it alone is not enough to keep it in place.

   • If you are parking on an incline (the car is "looking" up), stop the engine for neutral gear, then shift to first and apply the handbrake. If you're parking downhill (the car is "looking" down), do the same, but shift into reverse. This way you will not let the car roll down the hill.
   • On particularly steep slopes, or as an extra precaution, you can chock the wheels.

4. Stop completely before shifting from forward to reverse (and vice versa). A complete stop when changing direction will help avoid serious damage and costly repairs to the transmission.

   • Before shifting from reverse to forward, it is highly recommended to come to a complete stop. In most vehicles with manual box it is possible to shift into first or second gear while reversing slowly, but this is not recommended to avoid overloading the clutch.
   • Some cars have a reverse lock mechanism so you don't accidentally engage it. Before using reverse, you need to learn about this mechanism and how to disable it.

• If the car stalls, release the clutch as slowly as possible. Pause at the moment of friction (when the car starts to move) and continue to release the clutch very slowly.
• During frosts, it is not recommended to leave the car for a long time on the handbrake. The moisture freezes and you won't be able to release the handbrake. If the car is parked on a level surface, leave it in first gear. Don't forget to apply the handbrake when depressing the clutch, otherwise the car will start moving.
• Do not confuse the brake and clutch pedals.
• With a manual transmission, you can easily do wheel spin.
• Cars with a manual transmission are standard.
• Learn to recognize your engine sounds, you should eventually be able to tell when to change gears without relying on the tachometer.
• If you feel like the car is stalling or the engine is not running smoothly, depress the clutch and wait for the engine to stabilize.
• Don't forget to fully depress the clutch before changing gear.
• If there is no indication of the gear position on the gear lever, consult someone who is well versed in this. You don't want to drive backwards into anything or anyone while you think you're in first gear.
• If you know that you will have to park on steep slope, take a stone or brick with you, which must be carefully placed under the wheel. Is not bad idea because the brakes, like all parts, wear out and may not hold your car on a slope.