The braking system of a loader must ensure safety, reliability, and adaptability to various working conditions. Below is a detailed breakdown of its core structure and working principles.

1. Main Types of Braking Systems

(1) Service Brake System (Primary Braking)

Function: Deceleration and stopping during operation.

Common Designs:

• Oil-immersed multi-disc brakes (heat-resistant, long lifespan).

• Hydraulic disc brakes (fast response, better heat dissipation).

Applications:

• Hydraulic disc brakes (small/medium wheel loaders).

• Wet multi-disc brakes (large/track loaders).

(2) Parking Brake System (Secondary Braking)

Function: Prevents rolling when parked.

Implementation:

• Mechanical handbrake (cable-operated).

• Hydraulic or spring-actuated parking brake (auto-locking).

(3) Emergency Brake System

Function: Backup braking if primary brakes fail (often linked to parking brake).

2. Key Design Considerations

(1) Power Transmission Methods

• Air-over-hydraulic braking (for large loaders):
  Compressed air → hydraulic pressure → brake caliper action (high braking force).

• Full hydraulic braking (common in small/medium loaders):
  Direct hydraulic pump supply (simpler structure).

(2) Safety Redundancy

• Dual-circuit hydraulic system: Maintains 50% braking force if one circuit fails.

• Fail-safe mechanism: Spring-applied brakes engage automatically if hydraulic pressure is lost.

(3) Adaptation to Special Conditions

• Slope braking: Dynamic pressure distribution prevents rollback.

• Slippery surfaces: Optional ABS (anti-lock) or TCS (traction control).

3. Typical Braking Process (Wheel Loader Example)

1. Pedal press: Hydraulic fluid activates calipers to clamp discs.

2. Friction heat: Kinetic energy converts to heat (requires cooling design, e.g., ventilated discs).

3. Energy recovery (electric models): Regenerative braking recharges batteries.

4. Brake release: Hydraulic pressure drops, return springs disengage pads.

4. Maintenance & Troubleshooting

Routine Checks:

• Brake fluid level/quality (every 250 hours).

• Pad/disc thickness (replace if <3mm remaining).

Common Failures:

• Weak braking: Hydraulic leaks/air ingress → bleed system.

• Uneven braking: Stuck caliper piston → clean/replace.

• Noise: Worn pads/contaminants → inspect and repair.

5. Technological Advancements

• Electro-hydraulic braking (EHB): Sensors enable precise brake force distribution.

• Brake-by-wire (BBW): Eliminates hydraulic lines (ideal for electric loaders).

• Smart braking systems: Auto-adjusts force based on load/terrain to prevent tipping.

Conclusion

Loader braking systems combine hydraulic and mechanical mechanisms, balancing stopping power, heat dissipation, and reliability. Users should select appropriate types (e.g., wet brakes for mining) and perform regular maintenance to ensure safety.