Bendix doesn't return. Electric car starter: principle of operation and malfunctions. Electrical causes of failure

At the same time, during the operation of the vehicle, problems with starting are quite common. power plant arise precisely due to the failure of the car starter. In this article we will look at the main faults of the starter, as well as why the starter does not turn off after starting the engine.

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The design of a car engine starter and its operating principle

The main components of the starter:

electric motor;
solenoid relay;
gear with bendix;

In a nutshell, on crankshaft engine installed. When the starter is turned on, the starter gear meshes with the flywheel crown and the electric motor turns the crankshaft. After the engine starts, the starter overrunning clutch disengages the gear from the shaft when the engine speed exceeds the starter speed.

If we take a closer look at the starter, its electric motor consists of a housing, inside of which there is a stator and a rotor rotating in two bushings.
The brush assembly consists of three or four brushes, which are supplied with voltage from the battery. The brushes, in turn, connect to part of the rotor and supply voltage to it, causing the starter motor to rotate.
The gear and bendix, located on the rotor shaft, moving forward and backward along it, engage with the flywheel. The solenoid relay turns the electric starter into operation.

The principle of operation of the starter is as follows. The vehicle interior has an ignition switch that has several positions, including the “On” position and the “Start” position. When the key is turned in the ignition switch in the “Start” position, the current transmitted through the circuit from the battery is supplied to the starter solenoid relay.

The solenoid relay is an electromagnet with a coil and a core. Core under action electromagnetic field begins to move to the side, while the fork connecting the core and the bendix pushes the bendix and gear along the shaft forward to engage it with the flywheel.

The relay has two contacts, one of which is supplied with voltage from the battery, and the other is connected to the brushes of the electric motor. When the core reaches the end of the relay, with the gears already engaged with the flywheel, the copper plate located at the end of the core closes these two contacts and voltage flows to the electric motor.

As for the types of starters, there are:

A starter with a gearbox, which consists of several gears and is mounted directly to its housing. The electric motor of such starters has high efficiency and consumes much less current when starting the engine. It is installed on cars with and on gasoline cars with more powerful engines.
A starter without a gearbox, having high resistance to loads, ensures quick starting of the motor due to instant connection with the flywheel crown after current is applied.

In this case, starters may differ from each other, but not significantly. In most cases, their difference lies in the mechanics of automatic gear disengagement.

It usually takes a few seconds for the engine to start. But in practice, malfunctions may occur when, after starting the engine, the starter spins along with the engine, etc.

Starter malfunctions

First of all, it is important to remember that with numerous attempts and a long time to start the engine, the starter itself and the battery suffer. Moreover, prolonged rotation of the starter can damage the device.

Also, failure of the starter itself should not be ruled out. The starter can overheat when cranked for quite a long time, resulting in damage to the armature or rotor. With repeated attempts to start the car engine, there is a risk of damage to the splines on the coupling, which protects the starter from impacts from the teeth of a spinning flywheel.

One way or another, failure of the starter will require its repair or replacement. Among the main malfunctions of the electric starter, the following should be highlighted:

In the latter case, it is necessary to check the contacts on the solenoid relay circuit, the contact group of the ignition switch and check the starter bendix. If problems are identified, they must be corrected.

You can also check additional relay(installed separately), which serves to protect the starter from accidental combustion of contacts in the ignition switch, which occurs during wear or prolonged starting.

Checking the starter

First of all, without having certain skills and abilities, it is better to contact a service station, where experienced specialists will determine exactly what caused the starter to fail.

The initial check of the starter is carried out by measuring the voltage in the wire going to the control contact of the solenoid relay when turning the car's ignition key. In operating condition, the voltage should be 12 - 24 Volts (depending on the type vehicle when testing the starter of a car or truck). Neutral position the ignition key in the lock means that the voltage on the solenoid relay control wire should disappear.

In a similar way, performance is determined using a test lamp. When you turn the ignition key, the lamp should light up, respectively, when you turn the key to initial position the lamp goes out. If the contacts on the solenoid relay circuit are in order, then the problem should be looked for in the overrunning clutch bendix, which was mentioned earlier. If the overrunning clutch continues to spin after starting the engine, it is jammed on the starter shaft.

This happens when the Bendix gears wear out or the flywheel teeth wear out. This problem can only be solved by replacing the bendix or flywheel assembly. If the solenoid relay, gear and overrunning clutch (Bendix), as well as the flywheel and combustion lock are all fine, but the problem remains, then the starter must be removed for repair or replacement.

What's the result?

As you can see, any problems with starting the engine are a reason for diagnostics. Moreover, if the culprit is the starter, then the problem often tends to progress.

In practice, problems are indicated by the fact that the starter turns heavily or clicks, but does not turn the engine, knocks are heard, the starter does not turn off after starting the engine, etc.

Such symptoms indicate that in the future there is a high probability of needing to repair/replace not only the starter itself, but also the flywheel (and the flywheel itself is an expensive part). For this reason, it is optimal to perform starter diagnostics immediately after the first signs of malfunction appear.

Purpose and principle of operation of the retractor relay

On most vehicles, the retractor is mounted in the same unit with the starter, and is designed to control the freewheel. At the end of the clutch there is a gear that rotates at the moment of starting, but during its operation such rotation is not allowed, as it leads to damage to the starter or on-board electrical network if the starter starts working in generator mode.

To do this, the retractor extends the clutch only when it is necessary to start the engine, after which it returns to its original position, removing the gear from engagement with the flywheel. The peculiarity of the solenoid relay is that the starter can only operate when it is activated. This is done to prevent tooth fractures when the rotating gears of the clutch and flywheel meet.

Inside the relay there is a coil with an armature, which is acted upon by current after the circuit is closed. The magnetic field that arises around the coil moves the armature towards it, compressing the return spring and pushing the lever, which moves the freewheel. When starting the engine electrical circuit the coil opens, the magnetic field force disappears, and the return spring pushes the armature with the clutch to its original position.

Signs of a malfunctioning retractor

The following signs may indicate a retractor failure:

After starting the engine, the starter does not turn off; it rotates with high speed and a characteristic buzzing sound.
After turning the key in the ignition switch, a click occurs, indicating that the device is activated, but no rotation of the starter is observed. Sometimes, if there is a break in the coil, the armature is stuck in a certain position, or there is no power, there may be no click.
After turning the key in the lock, the starter begins to idle without affecting the engine flywheel.

Possible causes of malfunction

The solenoid relay may fail for the following reasons:

If the case is damaged.
If the magnet with windings is damaged.
In case of contact failure.
When the return spring weakens.
If problems arise with the anchor.

All relay failure occur due to physical wear, burning of contact plates, destruction of components, burnout of windings.

Checking the solenoid relay

It is possible to determine the functionality of the retractor without removing it from the car starter in the following way:

Check the wiring going to the relay for a break.
If the wiring is correct, the operation is checked traction relay. To do this, turn the ignition key and listen for the click; its absence indicates a malfunction of the relay.
If the activation click is heard, but the starter does not rotate, possible reason The malfunction is burning of the contact plates. To check the assumption on the relay, disconnect the terminal coming from the lock, after which, using a screwdriver, connect the terminal coming from the battery with the terminal that goes to the starter. The result will be the supply of electricity to its engine, bypassing the relay. If rotation begins, the retractor is faulty.
Checking the voltage going to the starter will allow you to determine what the problem is - in the wiring, battery or starter. The multimeter is connected to the positive terminal of the relay, where the battery voltage is suitable, and the negative terminal of the device is connected to ground. When the ignition is turned on at this moment, the voltage should be 12 V. If the value is lower, it is enough to start the engine, but it is enough for the relay to operate.

Checking the retractor relay with the starter removed

It is more convenient to check the functionality of the relay at starter removed. But before dismantling, several operations are performed to identify the problem:

Check the reliability of the terminals, the condition of the battery, remove oxides from the contacts and terminals of the battery.
Make sure that the wiring is securely fastened to the starter with nuts. If corrosion is noticeable, clean the contacts with fine sandpaper.
Check the condition of the starter enable relay.

The starter is removed after disconnecting the wires that go to it and unscrewing the mounting bolts. In some cars, this operation will take a lot of effort, since the unit may be located in a poorly accessible engine compartment.

After removing the starter, it is cleaned of dirt, the oxidized contacts are treated with sandpaper, and the test begins in the following order:

The unit is placed next to the battery, from the terminals of which there are wires with “crocodiles”.
The positive and negative terminals are connected to the corresponding contacts on the retractor.
The free end of the negative wire is touched to the starter housing and the result is observed:

If there is a distinct click in the relay, then it is working;
If the retractor does not show “signs of life,” it needs to be replaced or repaired.

Repair of a collapsible solenoid relay

The manufacturer equips starters with a non-separable or collapsible retractor device. If a non-separable relay breaks down, it must be replaced, but a dismountable relay can be repaired. The described method allows you to check the retracting relay of all models of the VAZ: 2101, 2102, 2103, 2104, 2105, 2106, 2107, 2108, 2109, 21099, 2110, 2111, 2112, 2113, 2114, Niva, Lada Priora, Kalina, Grant, Grant, Grant Vesta and most foreign cars.
Disassembly and repair of the relay is carried out in the following order:

Unscrew the nuts securing the housing cover.
If necessary, the ends of the windings are additionally soldered.
After removing the cover, inspect the power contacts:

If they burn, the damaged part is cleaned with sandpaper;
When worn out, replace.

The device is assembled in the reverse order and tested for functionality.
The repaired relay is installed back on the starter.

(real name - overrunning clutch) is a part designed to transmit torque from the starter to the car engine, as well as to protect it from the high operating speeds at which the engine operates. - This is a reliable part, and it breaks quite rarely. As a rule, the cause of failure is natural wear and tear. internal parts

or springs. To identify malfunctions, let’s first understand the device and operating principle of the Bendix.

Design and principle of operation Most overrunning clutches (we will call them the more popular word among motorists - bendix) consist of leading clip (or outer ring) containing rollers and pressure springs, as well as driven holder

. The driving holder has wedge channels, which on one side have a significant width. It is in them that the spring-loaded rollers rotate. In the narrow part of the channel, the rollers are locked between the driving and driven clips. As is clear from the above, the role of the springs is to drive the rollers into the narrow part of the channels. The principle of operation of the Bendix is the inertial effect on the gear coupling, which is part of it, until it engages with the engine flywheel. While the starter is inoperative (the engine is turned off or running in constant mode

) the bendix clutch is not engaged with the flywheel crown.

Bendix works according to the following algorithm:

Bendix interior The ignition key is turned and current flows from battery
is supplied to the starter motor, driving its armature. Thanks to the available coupling with screw grooves and rotational movement, the coupling, under its own weight, slides along the splines until it engages with the flywheel.
Under the action of the drive gear, the driven cage with the gear begins to rotate.
If the teeth of the clutch and the flywheel do not coincide, it rotates slightly until they are firmly engaged with each other.
The buffer spring included in the design serves to soften the starting moment of the engine. In addition, it is needed to prevent tooth breakage from impact when the gears engage.
When the engine starts, it begins to rotate the flywheel with greater speed angular velocity, than before the starter rotated. Therefore, the coupling is screwed in reverse direction and slides along the splines of the armature or gearbox (in the case of using a geared Bendix) and disengages with the flywheel. This saves the starter, which is not designed to operate at high speeds.

How to check starter bendix

If the starter bendix does not turn, then you can check its operation in two ways - visually by removing it from the car, and "aurally". Let's start the description with the latter, as it is simpler.

As stated above, the main function of the bendix is to engage the flywheel and spin the engine. Therefore, if at the moment of starting the engine you hear that the starter motor is spinning, and characteristic sounds are heard from the place where it is located. metal clanging sounds- This first sign of bendix malfunction.

And so, the bendix was removed, it is necessary to inspect it. In particular, check whether it rotates only in one direction (if it turns in both, it means it needs to be replaced) and whether the teeth are eaten. Also check to see if the spring is loose. You should also remove the fork from the Bendix, check its integrity, signs of wear, and if necessary, replace it. In addition, be sure to check if there is any play on the armature shaft. If this occurs, then the bendix should be replaced.

Possible causes of failure

As mentioned above, gear rotation is only possible in the direction of rotation of the starter armature. If rotation in the opposite direction is possible, this is an obvious malfunction, that is, the bendix must be repaired or replaced. There may be several reasons for this:

Reducing the diameter of the working rollers in the cage due to normal wear and tear. The way out is to select and purchase balls of a similar diameter. Some car enthusiasts use other metal objects, such as pieces of a drill, instead of balls. However, we still do not recommend doing it yourself, but buying balls of the required diameter.
The presence of flat surfaces on one side of the roller formed due to natural wear and tear. Repair recommendations are similar to the previous paragraph.
Grinding work surfaces driving or driven races in those places where they come into contact with the rollers. In this case, repair is hardly possible, since such excavation cannot be removed. That is, it is necessary to replace the bendix.

Note! It is often better to produce complete replacement Bendix than repairing it. This is due to the fact that its individual parts wear out approximately equally. Therefore, if one part fails, the others will soon fail. Accordingly, the unit will have to be repaired again.

Another cause of failure is wear of the gear teeth. Since this occurs for natural reasons, repairs in in this case impossible. It is necessary to either replace the mentioned gear or the entire Bendix.

Since the starter not only experiences heavy loads, but also comes into contact with the external environment, it is susceptible to such irritants as: moisture, dust, dirt and oil, then slipping on free running may also happen due to deposits in its grooves and rollers. A sign of such a malfunction is the noise of the armature when the starter is started and the immobility of the crankshaft.

How to change bendix on the starter

As a rule, in order to change the bendix, you need to remove the starter and disassemble it. Depending on the machine model, the procedure may have its own characteristics. We will describe the algorithm from the moment when the starter has already been removed and to replace the bendix it is necessary to disassemble its housing:

Bendix repair

Unscrew the tightening bolts and open the housing.
Unscrew the bolts securing the solenoid relay, and then remove the latter. When repairing, it is advisable to clean and wash all the insides.
Remove the bendix directly from the axle. To do this, you need to knock down the washer and pick out the restrictive ring.
Before installing a new bendix, an axle is a must (but no frills).
Typically, the most difficult procedure involves installing the retaining ring and washer. To solve this problem, craftsmen use different methods - they open the ring with open-end wrenches, use special clamps, sliding pliers, and so on.
After the bendix is installed, lubricate all rubbing parts of the starter. high temperature grease. However, do not overdo it with the amount, because excess will only interfere with the operation of the mechanism.
Please complete before installation. To do this, use the wires to “light” the car in winter period. With their help, supply voltage directly from the battery. Connect the “minus” to the starter housing, and the “plus” to the control contact of the solenoid relay. If the system is working properly, a click should be heard and the bendix should move forward. If this does not happen, it is necessary to replace the retractor.

Bendix repair

Replacing the bendix on the starter

Here are some tips from experienced motorists that will help you avoid possible problems and inconveniences when repairing or replacing a bendix:

Before installing a new or repaired bendix, always check its operation and the drive of the unit.
All plastic washers must be intact.
When buying a new Bendix, it is advisable to have the old one with you in order to verify their identity. Often similar parts have minor differences that are not visually memorable.
If you are disassembling a Bendix for the first time, it is advisable to write down the process on paper or put the individual parts in the order in which they are dismantled. Or use the manual with photographs, video instructions above, and so on.

Price issue

Finally, it’s worth adding that Bendix is an inexpensive spare part. For example, a Bendix VAZ 2101 (as well as other “classic” VAZs) costs about $5...6, Catalogue number- DR001C3. And the price of Bendix (no. 1006209923) for VAZ 2108-2110 cars is $12...15. Bendix cost for cars FORD brands Focus, Fiesta and Fusion - about 10...11 $. (cat. no. 1006209804). For cars TOYOTA Avensis and Corolla Bendix 1006209695 - $9...12.

Thus, repair is often impractical for Bendix. It's easier to buy a new one and simply replace it. Moreover, when repairing individual parts, there is a high probability of rapid failure of others.

One of the most common car problems is the inability to start the engine. There may be several accompanying signs - when igniting, clicks are heard in the starter or complete silence, slow rotation starter and, accordingly, the crankshaft. There can be quite a few reasons, and they are not always directly related to it. To better understand why the starter does not respond to turning the ignition key, it is necessary to study the engine starting circuit in more detail.

What is a starter

The starter is an electric motor direct current, combined with a retractor relay, which ensures its start and rotation of the crankshaft. In order to turn the crankshaft at a rotation speed that ensures the start of the working cycle, it is equipped with an engine sufficiently high power measured in kilowatts, and the required current for its operation can reach hundreds of amperes. Therefore, like any electromechanical device, the starter is subject to both electrical and mechanical failures.

How does the engine start?

When the driver turns the ignition key, electricity supplied to the solenoid relay. It moves the bendix until it engages with the teeth of the engine flywheel and at the same time closes the contacts of the starter itself, causing the crankshaft to rotate.

As soon as the engine's operating cycle begins, the ignition key is returned to the "ignition" position, the bendix is retracted and the gears are disengaged. Mechanical diagram quite simple, but all its components must work flawlessly, otherwise the engine will not start.

Reasons why the starter does not work

The starter may not work for the following reasons:

Ignition switch malfunction
Low battery
Poor or missing contact in the wiring
Worn bushings
Malfunction of the starter or its parts
Other faults

Malfunction of the ignition switch contact group

Power is supplied to the starter after a short circuit contact group in the ignition switch. To check, simply turn on the ignition. If they light up warning lamps on the panel when you turn the key, it is in good working order. If not, then the ignition switch itself is faulty. In addition, the key from the “starter” position must return to the “ignition” position on its own. If this does not happen, then the ignition switch will need to be replaced.

Battery condition

When the battery is low characteristic feature There will be a clicking sound from under the hood when you try to start the engine, which is produced by the retractor relay, as well as slow rotation of the crankshaft.

This occurs because with the low voltage supplied by a dead battery, the relay cannot be fully retracted and its core is thrown back by the return spring and the starter clicks. In addition, a low battery will be indicated by dim lights from the side lights and headlights, and after turning the key, the instrument lighting will go out almost completely.

At normal charge battery voltage at its terminals should be 12-12.4 volts. The voltage is measured with a multimeter. If it is below 11 volts, then starting will be difficult, in addition, the state of charge will not be enough to provide a large starting current.

No contact

Poor contact in any part of the circuit can lead to the fact that there is current, but the starter does not turn the crankshaft. Special attention care should be taken to ensure reliable contact with the “ground”, which is the car body. The negative wire from the battery to the body must be securely connected at both fastening points, the contact terminals must be cleaned and securely fixed. You should also pay attention to the “negative” wire connecting the body and the engine of the car - after all, the starter is attached directly to the engine cylinder block and voltage drops when the ignition is turned on are unacceptable here.

Another reason could be worn copper-graphite bushings on which the rotor rests. One of them is pressed into the rear housing cover, where the brushes of the electric motor itself are located, and the front end of the rotor rests on a bushing, which is pressed into a hole in the clutch housing or in the starter housing itself, if the structure is closed.

The first option has almost gone out of use, because the bushing located in the clutch housing quickly breaks, the rotor begins to rotate misaligned and quickly becomes unusable. The second option is widespread almost everywhere, and bushings in this version are much more durable.

However, they also wear out over time and play appears, which eventually leads to jamming.

Starter related problems

The main reasons are related specifically to the starter. There are quite a few elements susceptible to malfunction:

Solenoid relay malfunction
Contacts burning
Bendix malfunction
Gear wear
Winding short circuit

The retractor relay moves the bendix until it engages with the flywheel. When the relay gets stuck, it stops moving and this is enough for the starter not to respond. To check, it is necessary to apply voltage directly to the power contacts. If it works, then that's the reason.

Poor operation of the solenoid relay, which causes it to click, is often caused by burning of the contacts. A lot goes through them high current, therefore, in case of burning, it is necessary to disassemble the relay and clean the contacts. However, this measure is only temporary as these contacts from the factory are processed special coating, which wears off over time, and by cleaning the contacts, the wear process will only accelerate.

Bendix may also be the cause of the problem. To check it, you also need to close the contacts on the power relay. If the bendix is working properly, the rotor will rotate together with the bendix, but here it will be necessary to check the engagement of the gear with the flywheel. In addition, it is necessary to pay attention to the condition of the gear teeth and ring gear on the flywheel.

If they are worn or partially licked off, they may be slipping and not engaging well with each other. This malfunction will manifest itself in the form of a crackling sound when starting the engine or its free rotation without engagement with the flywheel. To ensure that the Bendix is working, the starter must be removed and manually checked for ease of movement of the gear.

Another reason could be a winding short circuit. In this case, even when voltage is applied directly to the starter contacts, it will remain silent. Removal and disassembly can confirm a short circuit.

Other reasons

Another reason bad work The relay may be faulty. It is almost always located in mounting block and switches the voltage supply to the solenoid relay. If it malfunctions, the starter will not show signs of life even if all other components are in full working order. To check, just listen to his work. When triggered, it always clearly clicks (the contacts inside it close). If it is silent, it means it needs to be replaced.

The immobilizer or security alarm installed on the car. They can be connected to the ignition or starter circuits and, when arming, simply open the starting circuit so that the starter does not respond to turning the key. To check, you should try to bypass it by connecting it directly to the battery. If it works, then the reason may be precisely in these security systems.

Thus, there are quite a few reasons why the starter does not respond to the ignition key or clicks, but all of them can be diagnosed and identified using a comprehensive and consistent approach.