As you know, to start the car engine you need to crank the crankshaft several times. On the first machines, this was done manually. But now all cars are equipped with starters that allow you to rotate the shaft without any effort. The driver only needs to insert the key into the lock and turn it into the third position. Further, the motor will start without any problems. What is this element, what is the purpose and principle of the starter? We will talk about this in our article today.
Appointment
Due to the revolutions of the crankshaft, the engine produces the energy necessary for the movement of the car. But the problem is that in a stationary state, the motor cannot produce any energy.
This raises the question of launching it. For this purpose, the starter was invented. We will consider the principle of its operation a little later. This element is able to unwind the shaft using an electric motor and an external power source. As the latter, a rechargeable battery is used. Depending on the model and type of car, the power of the starter can be different. But for most passenger cars, a 3-kilowatt electric motor is enough.
Device
The design of this element includes several parts:
- Starter anchor. It is made of alloy steel. Collector plates are pressed onto it, as well as the core.
- Starter Solenoid Relay The principle of its operation is extremely simple. The relay is used to supply power to the electric motor in case of turning the ignition key. The relay also pushes the freewheel. In the design of the element there is a movable jumper and power contacts.
- One way clutch (in common people - “Bendix”). It is a roller mechanism that transmits torque through the pinion gear to the flywheel crown.
- Brushes. Serve for supplying current to the starter armature plates. Thanks to the brushes, the power of the electric motor increases at the moment of its engagement with the flywheel.
- Body. It is in it that all of the above elements are combined. Typically, the housing has a cylindrical shape. Inside it is also the core and the field winding.
All modern starters have a similar design. Differences can only be minimal. So, on cars with an automatic transmission, the starter is equipped with holding windings. They serve to prevent the machine from starting up on “drive” and other modes except “neutral”.
Types
There are several types of mechanisms:
- With gearbox.
- Without him.
The principle of operation of the last type of starter is in direct contact with the rotating gear. The main advantage of this design is high maintainability and resistance to increased loads.
But on most cars, an element with a gearbox is installed. The principle of operation of this type of starter will be discussed later. Compared with its counterpart, the gear element has a higher efficiency, consumes less current, has a small size and maintains high performance over the entire period of operation.
Principle of operation
Since this element runs on battery power, a prerequisite for its launch is the presence of a voltage of 12V or higher in the network. As a rule, when the starter is started, the voltage “sags” by 1-1.5V, which is very significant. In this regard, it is not recommended to twist the starter for a long time (more than five seconds), since you can easily discharge the battery. The principle of operation of a car starter is quite simple. First, the driver puts the key in the lock and turns it to the extreme position. So he will start the ignition system. To start the starter, you need to turn the key again. At this time, the contacts will close, and the voltage will pass through the relay to the retractor winding. The relay itself may make a distinctive click. This suggests that the contacts are closed.
Further, the anchor of the retracting element moves inside the housing, thereby pushing the bendix and engaging it with the flywheel crown. When the anchor reaches the end point, the contacts are closed. Voltage is supplied to the winding of the starter motor. All this leads to rotation of the engine flywheel. At the same time, the crankshaft of the motor itself rotates. A combustible mixture begins to flow into the cylinders and the candles light up. Thus, the motor is driven.
After the speed of rotation of the flywheel has exceeded the frequency of rotation of the starter shaft, the bendix is disengaged. Thanks to the return spring, it is set to its original position. At the same time, the key in the lock returns to its original position. The power supply to the starter is cut off.
Thus, the principle of operation of the starter (including VAZ) is aimed at short-term rotation of the flywheel, due to which the engine is started. The element stops its operation as soon as the engine has started successfully.
What will happen if you do not turn off the starter when the engine is running?
Often, such problems are observed with a failed return spring. If the starter continues to rotate with the flywheel, you will hear a characteristic loud rattle. It occurs because the rotation speed of the crown does not coincide with that which the starter gear produces (a difference of 2 or more times). This can happen due to a broken ignition switch.
Note that this process is very harmful for gears and for the starter as a whole. Even a short crunch can cause serious problems with the electric motor.
Starter Requirements
This mechanism must meet several requirements:
- Reliability. It implies the absence of breakdowns in the next 60-80 thousand kilometers).
- Ability to start in low temperature conditions. Very often, the starter turns poorly at a temperature of -20 or lower. But usually the fault is the cold electrolyte in the battery. To warm it up, before starting it is recommended to “blink” a high beam a couple of times.
- The ability of the mechanism to restart multiple times over a short period of time.
Conclusion
So, we found out what a starter is, its principle of operation. As you can see, this is an integral element of any modern car. If it fails, it will be possible to start the engine only “from the pusher” (and on machines with automatic transmission it is completely impossible). Therefore, you need to monitor its condition and not ignore the damage.