Alternators and Starters

Genesis and application.

Starters.

The automotive starter is a key component of a vehicle's starting system, which enables the internal combustion engine to start. The history and development of the automotive starter design are closely linked to the evolution of motoring. In the early stages of car development, engines were started manually using a crank. This was a physically demanding and often dangerous solution, as the engine could 'bounce', which could lead to injury. In 1896, engineers began to experiment with different methods of starting engines mechanically. An example is the system proposed by Karl Benz, which used springs driven by a crank. In 1911, Charles Kettering, an engineer at General Motors, invented the first electric car starter. His invention was first used on the Cadillac car in 1912. This electric starter revolutionised cars by eliminating the need for a crank. In the decades that followed, electric starters became standard on most cars. Starter technology was continually improved, with improvements in reliability and performance. After the Second World War, with the development of automotive technology, starters became more advanced and reliable. In the 2000s, start-stop systems were introduced in response to increasing demands for fuel efficiency and emission reduction. These systems automatically switch off the engine when the car stops (e.g. at traffic lights) and restart it when the driver presses the clutch or accelerator pedal. This required the development of more robust and faster starters. Today's starters are part of more complex vehicle energy management systems. Many modern cars, especially hybrids and electric cars, use alternatives such as electric motors acting as starters.

Alternators.

The car alternator, a key component of a vehicle's electrical system, is responsible for supplying electricity and charging the battery. In the early 20th century, the first cars used direct current (DC) generators, which converted mechanical energy into electrical energy. However, these were less efficient and had a limited ability to charge the battery at low engine speeds. In the 1920s and 1930s, DC generators were gradually improved, but their efficiency still remained a problem, especially in vehicles requiring more electricity.

In the 1950s, with the increasing electrical requirements of vehicles, work began on more efficient energy sources. Alternating current (AC) alternators began to be tested in cars. The first mass-produced cars with alternators appeared in the 1960s. Alternators, unlike generators, generate an alternating current, which is then converted to direct current (DC) by means of rectifying diodes, allowing the battery to be charged more efficiently and powering the electrical equipment in the vehicle.

In the 1970s and 1980s, alternators became standard equipment on most cars. Many design improvements were made, such as better magnetic materials, more efficient cooling systems and more precise voltage regulators. Today's alternators are much more technologically advanced. They use microprocessors to precisely control the charging voltage and current. The use of modern materials, such as neodymium magnets, allows the alternator to be more efficient and smaller in size.

Today's vehicles are equipped with intelligent energy management systems that optimise alternator performance according to operating conditions. These systems can switch off the alternator during acceleration to reduce engine load and improve fuel efficiency. In hybrid and electric cars, traditional alternators are often replaced by more sophisticated charging and energy management systems. Fully electric vehicles do not need traditional alternators, as their power systems rely on large traction batteries and advanced energy conversion systems.

Construction and principle of operation.

Starter.

A car starter is a complex electromechanical device that plays a key role in starting an internal combustion engine. It consists of several basic components that work together to convert electrical energy into mechanical motion.

The basic component of a starter is a direct current (DC) electric motor. Inside the motor are carbon brushes that contact the commutator, allowing current to flow to the rotor windings. The rotor, the rotating part of the motor, is surrounded by a stator, which contains windings or permanent magnets that generate a magnetic field. When current flows through the rotor windings, a magnetic field is generated that reacts with the stator field, causing the rotor to rotate.

The starter also contains a coupling mechanism, called a bendix, which connects the starter to the engine flywheel. When the starter is activated, the bendix moves to mesh with the flywheel, allowing torque to be transmitted from the starter to the engine crankshaft. When the internal combustion engine is started, the bendix automatically disengages to avoid damage to the starter.

Another important component is the electromagnetic switch, also known as an automatic switch. It allows electricity to flow to the starter motor and move the coupling mechanism (bendix). When the driver turns the ignition key or button to start the engine, current from the battery flows to the solenoid. This creates a magnetic field in the coil, which attracts a moving pin inside the solenoid. This movement has two key effects:

1. The pull of the pin causes the internal contacts to close. These contacts act as a relay, allowing a large current to flow from the battery to the starter motor. The starter motor needs a large amount of current to generate enough torque to turn the crankshaft of the internal combustion engine. The closing of the contacts by the energised solenoid enables this current flow.
2. The movement of the pin moves the bendix mechanism, which meshes with the flywheel of the internal combustion engine. The bendix is connected to the rotor of the starter motor and when the solenoid attracts the pin, the bendix extends, meshing the sprocket with the flywheel. This meshing allows torque to be transmitted from the starter motor to the crankshaft of the internal combustion engine, causing it to start.

When the combustion engine is started and the ignition key is released, current stops flowing to the switch coil. The magnetic field disappears and a spring pulls the pin back to its original position. This disconnects the contacts, interrupting the flow of current to the starter motor causing the bendix to be disconnected from the engine flywheel.

The entire system is enclosed in a starter housing, which protects the internal components from dirt and mechanical damage. This housing is usually made of metal to ensure durability and resistance to harsh operating conditions.

Alternator.

A car alternator is a device made up of several key components that work together to generate electricity and charge the vehicle's battery. Its construction includes a rotor, stator, rectifier diodes, voltage regulator and housing.

The rotor is the central component of the alternator and consists of a shaft on which the windings are wound to form an electromagnet. When current flows through the rotor windings, it creates a magnetic field. The rotor rotates inside the stator thanks to a drive belt connected to the engine crankshaft.

The stator surrounds the rotor and consists of a core made of layers of thin steel plate and windings wound around it. When the rotor rotates, its magnetic field crosses the stator windings, inducing alternating current (AC) in them.

Rectifier diodes are electronic components that convert alternating current into direct current (DC). An alternator typically contains a set of six diodes that are connected to form a bridge rectifier. These diodes allow current to flow in one direction only, which eliminates AC oscillations and delivers a constant current to the vehicle's electrical system and battery.

The voltage regulator is a key component that controls the output voltage level of the alternator. Its main function is to maintain a constant output voltage, typically around 14.4V, regardless of engine speed and electrical load. The voltage regulator monitors the output voltage and adjusts the rotor excitation current accordingly to ensure a stable voltage.

The alternator housing protects the internal components from dirt and mechanical damage. It is usually made of aluminium, which provides strength and efficient heat dissipation. The housing also has vents and a fan to help cool the alternator during operation.

When the car's engine is running, the drive belt rotates the alternator rotor, generating a magnetic field that induces a current in the stator windings. This current is then rectified by diodes and regulated by a voltage regulator, allowing the vehicle's electrical system to be stably powered and the battery to be charged.

Remanufacturing process.

Starter.

Each starter in the remanufacturing process is disassembled into parts, which are then cleaned. All parts are thoroughly cleaned to remove dirt, oil, dust and other contaminants. Metal parts can be cleaned using chemicals or mechanical means such as sandblasting. Cleaning is crucial to ensure that the new components will function properly in a clean environment. The next step is a thorough assessment of the wear and condition of all components. Particular attention is paid to the condition of the carbon brushes, commutator, bearings, rotor and stator windings, as well as the bendix and switching solenoid. Any parts that are damaged, worn out or critical to the correct operation of the starter are replaced with new parts. Once assembled, the starter undergoes tests under load, where its operating parameters are verified. An appropriate technological process, high-quality spare parts and a final check of the starter's performance guarantee its correct operation after installation in the vehicle.

Alternator.

Each alternator in the remanufacturing process is disassembled into parts, which are then cleaned. All parts are thoroughly cleaned to remove dirt, oil, dust and other contaminants. Metal parts can be cleaned using chemicals or mechanical means such as sandblasting. Cleaning is crucial to ensure that the new components will function properly in a clean environment. The next step is a thorough assessment of the wear and tear and condition of all components. Worn or damaged parts are replaced with new or reconditioned parts. Typical components to be replaced include carbon brushes, slip rings, bearings and rectifier diodes. The voltage regulator can also be replaced if it is damaged. The rectifier diodes and voltage regulator are thoroughly tested to ensure proper operation. Damaged diodes are replaced and the voltage regulator is checked to ensure a stable output voltage. The assembled alternator is tested on a test bench to check its operation. Tests may include checking the output voltage, charging current and stability of operation at different speeds.

Causes and types of damage.

Symptoms that may indicate a defective starter:

1. No response to turning the key or pressing the Start button.
2. Too low a starter speed, the starter "spins" slower than usual.
3. Noise during starter operation.
4. Problems starting a warmed-up engine.
5. Irregular operation - sometimes it works, sometimes it doesn't.

The most common starter failures are:

1. Pollution.
2. Overvoltage.
3. Damage or wear to mechanical parts.
4. Damage or wear to electrical components.
5. Corrosion.
6. Overheating.

Symptoms that may indicate a faulty alternator:

1. Illumination of the charging light on the dashboard.
2. Unusual sounds coming from the engine compartment.
3. Voltage fluctuations in the system - dimming of lights, problems with the operation of devices such as the radio or navigation.
4. Difficulty starting the engine due to insufficient or no battery charge.

The most common alternator faults are:

1. Pollution.
2. Corrosion.
3. Damage or wear to mechanical parts.
4. Damage or wear to electrical components.
5. Overvoltage.