Part 2: The Re-Windings of Starter Generators & AC Generators

August 5, 2024

Rewinding is a complex and precise process that restores components to their optimal condition, ensuring the starter generator performs reliably and efficiently.

“Windings” are the precisely configured coils of induction wire that facilitate the generation of electrical voltage within generator units.

Highly specialized equipment and processes are required to restore or replace the coils of induction wire in Starter Generator/ AC Generator Sub Components (Stator, Armature, AC Rotor, AC Stator, Exciter Stator, Exciter Rotor, and PMG Stator).

Stators are the stationary part of Starter Generators/ AC Generators. They contain coils of wire that interact with the magnetic field created by the Armature or Rotor. Stators are essential for generating electrical power when the generator function is active.

The Rotor or Armature rotating within the Stator contains the magnets or electromagnets that create the magnetic field necessary for generating electricity. Rewinding involves replacing the old windings with new ones. This is necessary when Windings become damaged or degraded due to factors like high temperatures, mechanical stress, or electrical overloads. Rewinding is central to the operation of starter generators and must be performed by certified technicians.

The Rewind Process

Rewinding is a complex and precise process that involves several key steps. This procedure restores components to their optimal condition, ensuring the starter generator performs reliably and efficiently.

Disassembly and Inspection: The Rewind process begins with the complete disassembly of the Sub components of the Generators. Each component is meticulously inspected for signs of wear, damage, or degradation. This step is crucial for identifying issues that require rewinding, such as insulation breakdown, physical damage to the windings, or other mechanical faults.

Removing Old Windings: The old windings on the stator, armature, and rotor are carefully removed. This step requires precision to avoid damaging the core and other components. Specialized tools are used to strip away the old windings, ensuring the integrity of the core and slots where new windings will be placed.

Preparing for Rewinding: Before new Windings can be installed, the core and other relevant parts are thoroughly cleaned and prepared. This includes removing residual insulation, cleaning the slots, and ensuring the core is free from contaminants. Proper preparation is critical for the success of the rewinding process.

Rewinding the Components: The actual rewinding process involves installing new coils around the cores of the Stator, Armature, and Rotor. This step requires highly specialized equipment and processes to ensure the Windings are correctly positioned to meet the necessary electrical specifications. The type of wire, number of turns, winding pattern, and lead connection are critical factors influencing the performance of the starter generator & AC Generator.

Insulation and Impregnation: After the new Windings are in place, they must be insulated to protect against electrical shorts and other issues. The Windings are often impregnated with varnish or resin, enhancing insulation and protecting against environmental factors like moisture and dust. This process also secures the Windings and reduces vibrations during operation.

Reassembly and Testing: Once the Windings are insulated and the impregnation process is complete. The Quality Control Inspector tests each component carefully to ensure proper operation. Testing includes checking electrical physical and visual parameters, and ensuring it meets all relevant Aviation performance standards.

Rewinding the subcomponents of the Starter Generator & AC Generator is a meticulous and complex process critical to aviation Maintenance, Repair and Overhaul (MRO) activities.

As the aviation industry advances, expert MRO services are essential in maintaining high standards of air travel safety and efficiency.

PAG Rewind Services (PRS)

PAG Rewind Support Brief PDF

PAG Insider: Moty Zeharia – President, PRS

Part 1: The Windings of Starter Generators

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PAG supports operators in the Airline, Business and General Aviation (BGA), and the Military markets through its Inventory Supported Maintenance, Repair, and Overhaul (ISMRO®) business model, with focused capabilities in Avionics, Engines, Components, and Manufacturing/DER Services

At PAG, employees get the exchange of talent, experiences, and resources of multiple companies all while working for one. With 24 Repair Stations, and over 1.1-million-square-feet of sales and service facilities in the United States, Canada, Australia, Singapore, and Brazil – PAG’s 27 locations and customer-focused business model serve aviation customers through Supply Chain and Inventory Supported Maintenance, Repair and Overhaul (ISMRO®) services. PAG is one of only 11 companies, outside of OEMs, to collectively hold all FAA certifications.

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