What are the types of slack adjusters?

Detailed Explanation of Slack Adjuster Types

1. Mechanical Adjusters

▸ Ratchet Lever Type

Principle: During braking, the push rod pushes the lever, causing the pawl to rotate the ratchet, resulting in a slight extension of the screw to compensate for wear slack.
Features: Simple and durable structure, produces a crisp "click" sound during operation, a mainstream design for trucks.

▸ Self-Locking Thread Type

Principle: The helical gear clutch at the end of the push rod engages the moment the brake is released, rotating the screw in the opposite direction to achieve compensation.
Features: Anti-reverse design, suitable for heavy-duty scenarios such as mining machinery.

2. Hydraulic Adjusters

▸ Piston Compensation Type

Principle: Utilizes brake fluid pressure to push the compensation piston, with a one-way valve locking the displacement.
Features: Integrated into the brake caliper, high compensation accuracy, commonly used in passenger cars/precision equipment.

▸ Electro-Hydraulic Type

Principle: Sensors monitor the slack, and the ECU controls a solenoid valve to drive the compensation cylinder.
Features: Strong self-adaptability, standard equipment in new energy vehicles, requires matching with the vehicle's overall control system.

3. Pneumatic Adjusters

▸Diaphragm Driven Type

Principle: Brake air pressure deforms a rubber diaphragm, which in turn rotates a screw via a ratchet mechanism.
Features: Resistant to mud and water corrosion; standard configuration for commercial air-brake vehicles.

▸Piston Type

Principle: Compressed air directly drives a piston; mechanical structure similar to a hydraulic type.
Features: Fast response; commonly used in heavy-duty trailers.

4. Special Condition Variations

▸Antifreeze Reinforced Type

Features: Low-temperature grease lubrication + nickel-plated housing; suitable for extremely cold regions down to -40℃.

▸Pollution-Resistant Heavy-Duty Type

Features: Fully sealed cast steel housing; increased worm gear module and anti-link module for increased wear resistance.

▸Compact Rocker Arm Type

Features: External rocker arm for direction switching; suitable for space-constrained engineering applications and construction machinery.

5. Practical Selection Guide