How a Car Starter Works

Summary

In this video, the mechanics of a car starter motor are explored in detail. The starter motor, located between the engine and transmission, consists of two main parts: the solenoid and the electric motor. The solenoid engages the flywheel when activated by turning the ignition key, allowing the motor to crank the engine. The electric motor operates through brushes and coils, creating an electromagnetic field to rotate the armature. Key failure points include worn contacts in the solenoid and brushes in the motor. The video offers a deep dive into the workings and potential issues of starter motors, making complex concepts easy to understand.

Takeaways

• 😀 The starter motor helps rotate the engine during cranking to start the car.
• 😀 The starter motor consists of two main parts: the solenoid and the electric motor.
• 😀 The solenoid engages a gear with the flywheel, allowing the engine to rotate.
• 😀 When the ignition key is turned, the starter relay sends 12 volts to the solenoid to activate it.
• 😀 The plunger inside the solenoid moves to bridge the electrical contacts, sending 12 volts to the motor.
• 😀 The electric motor is powered by 12 volts from the battery, which drives the engine’s rotation.
• 😀 The starter motor uses a gear reduction mechanism to increase torque and turn the engine more efficiently.
• 😀 Common failure points include worn-out or oxidized contacts, causing no-start conditions.
• 😀 Brushes inside the motor can wear down over time, leading to a loss of contact with the armature and motor failure.
• 😀 The armature inside the motor contains coils that create an electromagnetic field, causing rotation.
• 😀 A spring-loaded mechanism helps return the drive gear after the motor finishes turning the engine over.

Q & A

What is the main role of a starter motor in a car?

The starter motor helps rotate the engine while cranking, enabling the car's engine to start.

Where is the starter motor typically located in a car?

The starter motor is usually mounted at the interface between the engine and the transmission, where the flywheel is located.

What are the two main components of a starter motor?

The two main components of a starter motor are the solenoid and the electric motor.

How does the solenoid work in the starter motor system?

The solenoid is responsible for pushing and pulling the gear to engage with the flywheel or flex plate, initiating the rotation of the engine.

What triggers the operation of the solenoid and starter motor?

When you turn the key to the start position, the ignition switch sends 12 volts to the starter relay, which triggers the solenoid and powers the starter motor.

What is the purpose of the contact plate in the starter motor?

The contact plate bridges the electrical contacts, allowing 12 volts to flow through to the starter motor, powering it to crank the engine.

What is the significance of the helical gear in the starter motor?

The helical gear inside the starter motor helps rotate the drive gear as it is pushed out, making it easier for the gear to engage with the flywheel.

What are the common failure points in a starter motor?

The common failure points in a starter motor include the solenoid contacts, brushes, and field coils, which can wear out or malfunction over time.

Why can the starter motor’s brushes wear out?

The brushes wear out due to friction against the armature, which can cause them to lose contact, preventing the motor from operating correctly.

How does the armature function in the starter motor?

The armature, a coil wrapped around a magnet-like material, is energized by the brushes, creating a magnetic field that causes it to rotate and drive the gear to start the engine.