Jaw crusher regular disassembly inspection tutorial

Jaw crusher regular disassembly inspection tutorial

1. Pre-work & Safety Preparation

1.1 Lockout-Tagout (LOTO)

  • Stop the crusher completely, cut off the main power supply, hang warning lock and tag.
  • Release the hydraulic pressure if fitted with hydraulic adjustment / hydraulic clearing system.
  • Wait until the machine cools down; hot parts may cause burns.
  • Clear residual materials inside the crushing cavity with dedicated tools, never use hands.
  • Prepare protective gear: safety helmet, anti-cut gloves, safety shoes, goggles.

1.2 Tools & Spare Parts Ready

  • Torque wrench, slings, hoist, pry bar, oil pump, cleaning brush, kerosene / cleaning agent, rag, feeler gauge, caliper.
  • Prepare spare parts: toggle plate, toggle seat, jaw plate, liner, bearing, sealing ring, bolts, grease.
  • Record form: take photos of original assembly state before disassembly for reference.

2. Disassembly Sequence (Follow the order strictly)

Note: Do not force prying or hammering on casting surfaces to avoid crack.

  1. Remove feed hopper guard, side safety guards and drive belt guard.
  2. Unload V-belts, separate flywheel and pulley from the eccentric shaft end.
  3. Discharge all lubricating grease from lubrication points and oil tank.
  4. Remove toggle plate tension spring and tie rod assembly.
  5. Take out toggle plate first (toggle plate is the safety part; take it out before moving jaw).
  6. Disconnect the toggle seat from frame.
  7. Lift the movable jaw assembly carefully with hoist.
  8. Remove jaw plates (fixed jaw plate + movable jaw plate, check wedge blocks).
  9. Disassemble eccentric shaft bearing end caps, then pull out eccentric shaft and bearings.
  10. Take out frame inner side liners for inspection.

3. Item-by-item Inspection Standard

3.1 Jaw Plates & Side Liners

  • Check wear depth: When tooth height wears down by 2/3, or local deep groove, crack, breakage appears, replace.
  • Check fastening wedges and bolts: loose, deformed, cracked bolts must be replaced.
  • Check contact surface between liner and frame: no gap, no erosion pit.

3.2 Toggle Plate & Toggle Seat

  • Check for hidden cracks, abrasion on contact surface. Minor wear can be surfacing repaired; crack → direct replacement.
  • Check toggle seat contact surface flatness; if uneven, grind or replace.

3.3 Movable Jaw Assembly & Bearings

  • Movable jaw body: check casting crack at bearing housing, ear position.
  • Bearings: check clearance, pitting, noise, heating, rust. Measure bearing clearance; exceed limit → replace.
  • Bearing seals: aging, hardening, oil leakage → replace oil seal.

3.4 Eccentric Shaft

  • Check shaft journal surface: scratch, wear, oval deformation. Light scratch can be polished; serious wear needs surfacing repair or shaft replacement.
  • Check thread part for sliding wire and deformation.

3.5 Spring, Tie Rod & Adjusting Wedge

  • Tension spring: fatigue deformation, crack, broken → replace. Spring elasticity failure will lead to unstable running.
  • Tie rod: check thread and rod body bending, crack.
  • Discharge gap adjusting mechanism: check adjusting wedge tooth wear, jam.

3.6 Frame & Foundation

  • Frame: focus on welding position, bearing pedestal, side wall for fatigue crack.
  • Anchor bolts: check elongation and looseness, retorque as required.

3.7 Lubrication Components

  • Oil pipe, oil nozzle, oil passage: clean blockage, check oil pipe rupture.
  • Check oil filter, oil cooler if equipped.

4. Cleaning & Repair before Reassembly

  • Clean all oil passages, bearing chambers, contact surfaces thoroughly with cleaning agent, blow dry with compressed air.
  • Polish slight burrs and scratches on mating surfaces.
  • Repair small surface wear by hard surfacing (follow welding procedure for crusher cast steel).
  • Discard any cracked castings directly; do not weld repair for load-bearing cracks.

5. Reassembly Key Points

Reassemble in reverse order of disassembly, focus on these rules:

  1. All mating surfaces evenly coated with specified grease before assembly.
  2. Bearing installation: control interference, do not knock bearing roller directly.
  3. Jaw plate installation: ensure uniform compression of wedge blocks, locking bolts tightened to specified torque.
  4. Toggle plate must sit fully on both toggle seats, no offset.
  5. Tension spring pre-tightening force: adjust according to manufacturer’s parameter, not too tight or too loose.
  6. Adjust the discharge opening to the required gap, use feeler gauge to verify.
  7. After all assembly, manually turn flywheel 2–3 circles, confirm no jamming, no friction.

6. Post-assembly Test Run

  1. No-load test run: 30 min. Check vibration, temperature of bearings (bearing temperature rise ≤35℃, max temperature <70℃), oil leakage, abnormal noise.
  2. Load test run: gradual feeding, run 2h. Check current, discharging size, fastening status of all parts.
  3. Fill in inspection record: wear data, replaced parts, torque value, test run condition.

7. Inspection Cycle Reference

  • Small jaw crusher: Minor disassembly inspection every 1500 working hours; full disassembly inspection every 6000 working hours.
  • Heavy-duty / high-hardness stone crushing: shorten cycle to 1000h for minor inspection, 4000h for full disassembly.

8. Common Pitfalls Warning

❌ Do not disassemble under pressure or power-on state ❌ Do not reuse cracked toggle plate ❌ Do not mix different grease types ❌ Do not omit LOTO procedure for quick inspection ❌ Do not over-tighten jaw plate bolts to crush jaw plate