Automobile parts starter

2025,04,17

I. Core Technology Principles and Structural Design

1. Working principle

The starter controls gear meshing and circuit on/off through an electromagnetic switch (Solenoid), as follows:

Electromagnetic switch activation: After the ignition key is turned on, the electromagnetic switch coil is energized to generate a magnetic field, which drives the core to move.

Gear meshing: The core drives the fork, causing the drive gear (Bendix) to mesh with the flywheel gear ring.

Motor operation: The main circuit is connected, and the Dc Motor generates torque through the armature winding to drive the flywheel to rotate.

Automatic disengagement: After the engine starts, the flywheel speed exceeds that of the starter, the one-way clutch slips, and the gears automatically return to their original position.

2. Key components

Dc motor: It adopts a series-excited design, providing a large torque at low speeds and meeting the starting requirements. For example, the 3M™ 7810 model can withstand a high temperature of 260℃.

Electromagnetic switch: Composed of an attraction coil and a holding coil, it ensures reliable engagement and disengagement. For instance, Denso electromagnetic switches use copper-tungsten alloy contacts, which have strong arc resistance.

Transmission mechanism: It includes reduction gears (such as planetary gear sets) and one-way clutches to enhance the efficiency of torque output.

3. Technical Classification

Ordinary starter: Simple structure, suitable for small vehicles.

Reduction starter: It increases torque through gear reduction and is smaller in size (such as Bosch reduction starters).

Permanent magnet starter: Utilizing rare earth permanent magnet materials, it is lightweight and highly efficient (such as Valeo permanent magnet starters).

Ii. Common Fault Diagnosis and Solutions

1. The starter doesn't rotate

Cause of failure:

The battery power is insufficient or the connection is loose.

The coil of the electromagnetic switch is short-circuited or the contacts are eroded.

The armature winding or magnetic field coil is open-circuited.

Troubleshooting steps:

Check the battery voltage (it should be ≥12V) and clean the electrodes.

Test the resistance of the electromagnetic switch coil with a multimeter (the normal value is approximately 0.5-1Ω).

Disassemble the starter and check whether the armature and magnetic field coils are open-circuited.

2. The starter idles

Cause of failure:

The drive gear is worn or the flywheel gear ring is missing teeth.

The one-way clutch slips (such as the wear of the friction plates).

The travel adjustment of the electromagnetic switch is improper.

Solution:

Replace the drive gear or flywheel gear ring.

Inspect and repair the one-way clutch and replace the assembly if necessary.

Adjust the core stroke of the electromagnetic switch (standard value: 12-20mm).

3. The starter rotates weakly

Cause of failure:

The brush is worn or the spring pressure is insufficient.

The bearing is loose or the electric pivot shaft is bent.

The battery is aging or the electrolyte is insufficient.

Solution:

Replace the brush assembly (such as Bosch carbon brushes).

Check the bearing clearance and replace the worn parts.

Test the capacity of the battery and replace it if necessary.

Iii. Maintenance and Usage Suggestions

Key points for daily maintenance

Cleaning and lubrication: Regularly clean the carbon powder on the surface of the commutator and lubricate the bearings and forks with Vaseline.

Check the connection: Ensure that the battery electrodes and the terminals of the electromagnetic switch are firm and free from oxidation.

Avoid frequent startups: Each startup should not exceed 5 seconds, with an interval of more than 15 seconds.

2. Response to extreme environments

Low-temperature start: Use a -40 ℃ low-temperature type battery and preheat the engine before starting (such as in diesel vehicles).

High-temperature environment: Avoid continuous start-up for a long time to prevent the motor from overheating.

3. Life Management

Design life: Up to 100,000 kilometers or 5 years under normal use.

Influencing factors: Frequent starts and stops (such as urban congestion), low-temperature environment, and battery depletion.

Replacement standard: Irreparable mechanical wear (such as gear breakage) or circuit failure occurs.

Author:

Mr. yin chang

E-mail:

yinchanghaoshuai@163.com