Aircraft and Helicopter Starter Generator Parts - Complete Guide

Starter generators are essential components in aircraft and helicopters, responsible for initiating the engine start process and generating electrical power for various systems once the engine is running. These devices combine the functionalities of both a starter motor and a generator, playing a critical role in ensuring reliable engine starts and consistent electrical power supply. This article delves into the various parts that constitute aircraft and helicopter starter generators, their functions, and the significance of each part in the overall system.

1. Overview of Starter Generators

Starter generators are hybrid devices used in aviation to reduce weight and space while providing efficient engine starting and power generation. In the starting phase, the starter generator acts as a motor to crank the engine. Once the engine reaches a certain speed and self-sustains, the starter generator switches to its generator mode, producing electrical power for the aircraft's systems.

2. Key Components of Starter Generators

Understanding the various parts of starter generators is crucial for maintenance and troubleshooting. Each component has a specific function that contributes to the overall performance of the starter generator system.

2.1. Armature

• Function: The armature is a rotating coil or group of coils that converts electrical energy into mechanical energy (in starter mode) and mechanical energy into electrical energy (in generator mode).

• Construction: Typically constructed with copper windings around a laminated iron core, the armature is connected to the commutator.

• Significance: The armature's efficient conversion capabilities are vital for both starting the engine and generating electrical power.

2.2. Field Windings

• Function: These are electromagnets that create a magnetic field necessary for the operation of the starter generator.

• Construction: Comprised of wire coils wound around a magnetic core, energized to produce a magnetic field.

• Significance: Proper functioning of the field windings ensures efficient energy conversion and consistent power generation.

2.3. Commutator

• Function: The commutator is a rotary switch in the armature that reverses the direction of current flow through the windings, allowing for smooth rotation.

• Construction: Made up of segments of conductive material (usually copper), insulated from each other and mounted on the armature shaft.

• Significance: Ensures that electrical contact is maintained with the brushes, enabling continuous operation.

2.4. Brushes

• Function: Brushes maintain electrical contact with the rotating commutator, allowing current to flow between the stationary and rotating parts.

• Construction: Typically made of carbon or graphite, which provides good conductivity and wear resistance.

• Significance: Wear and tear on brushes can affect performance, making their condition crucial for reliable operation.

2.5. Bearings

• Function: Bearings support the rotating armature, reducing friction and wear on the moving parts.

• Construction: Usually made of metal (such as steel) and designed to withstand the operational loads and speeds.

• Significance: Properly functioning bearings ensure smooth rotation and longevity of the starter generator.

2.6. Drive Mechanism

• Function: This component engages the armature with the engine to crank it during the start sequence.

• Construction: Often includes gears and clutches that allow for disengagement once the engine is running.

• Significance: Reliable engagement and disengagement are critical for effective starting and preventing damage.

2.7. Voltage Regulator

• Function: Regulates the voltage output of the generator to ensure consistent power supply to the aircraft's electrical systems.

• Construction: Includes electronic components that adjust the field current to control the output voltage.

• Significance: Protects the aircraft's electrical systems from voltage fluctuations and ensures stable operation.

2.8. Rectifiers

• Function: Convert alternating current (AC) generated by the armature into direct current (DC) used by the aircraft's electrical systems.

• Construction: Comprises diodes that allow current to flow in only one direction, converting AC to DC.

• Significance: Essential for providing the correct type of electrical power required by the aircraft’s systems.

2.9. Cooling System

• Function: Prevents overheating of the starter generator during operation by dissipating heat.

• Construction: Can include fans, vents, and heat sinks to enhance airflow and heat dissipation.

• Significance: Maintains optimal operating temperatures, preventing damage and ensuring efficiency.

3. Starter Generator Parts and Their Specifications

Several manufacturers produce specific parts for aircraft and helicopter starter generators, ensuring compatibility and reliability. Here are some notable parts and their specifications:

• Aircraft Parts Corp 160SG143Q-2

• Application: Used in various aircraft models.

• Features: Known for durability and reliability in starter generator applications.

• Thales AES 8260-150

• Application: Widely used in both military and civilian aircraft.

• Features: Provides robust performance and efficient power generation.

• Thales AES 20032-2

• Application: Suitable for a range of helicopter models.

• Features: Ensures reliable engine starts and stable electrical output.

• Bell Helicopter Textron 206-062-200-141

• Application: Specifically designed for Bell helicopters.

• Features: Tailored to meet the rigorous demands of helicopter operations.

4. Maintenance and Troubleshooting

Proper maintenance and troubleshooting of starter generators involve regular inspection and servicing of each component. Here are some common practices and considerations:

4.1. Regular Inspections

• Brush Wear: Check for excessive wear or damage to brushes and replace them as necessary.

• Commutator Condition: Inspect the commutator for wear, pitting, or scoring and perform resurfacing if needed.

• Bearing Health: Ensure bearings are lubricated and free of wear to prevent rotational friction and noise.

4.2. Performance Testing

• Output Voltage: Test the generator output voltage to ensure it meets specified parameters.

• Current Flow: Measure the current flow through the field windings and armature to detect any irregularities.

• Noise and Vibration: Monitor for unusual noise or vibration, which could indicate bearing issues or misalignment.

4.3. Component Replacement

• Field Windings: Replace field windings if they show signs of insulation breakdown or short circuits.

• Rectifiers and Regulators: Replace faulty rectifiers and voltage regulators to maintain proper electrical output.

5. Technological Advances

Advancements in technology have led to the development of more efficient and reliable starter generators. Modern systems incorporate features such as:

• Digital Control Systems: Enhanced monitoring and control of voltage and current for improved performance and diagnostics.

• Lightweight Materials: Use of advanced composites and materials to reduce weight and improve efficiency.

• Integrated Health Monitoring: Systems that provide real-time data on the condition of the starter generator, enabling predictive maintenance.

6. Conclusion

Starter generators are indispensable components in aircraft and helicopters, providing the necessary functions of engine starting and power generation. Each part of the starter generator, from the armature to the cooling system, plays a crucial role in its operation. Regular maintenance and awareness of technological advances are essential for ensuring these systems remain reliable and efficient.

As aviation technology continues to evolve, starter generators will likely become even more sophisticated, further enhancing the safety and performance of aircraft and helicopters. By understanding and properly maintaining components like those from Aircraft Parts Corp (160SG143Q-2), Thales AES (8260-150, 20032-2), and Bell Helicopter Textron (206-062-200-141), operators can ensure the longevity and reliability of their starter generator systems.