PIN WEAR AND BREAKAGE

WEAR OF THE FINGER SURFACE

Uniform one-sided wear of the finger. Corresponds to the wear of the sleeve at the point of contact with the finger. This is called wear of the hinge from the inside and often causes repair of the running systems or replacement of its components.

Causes

The friction of the finger and the inner surface of the sleeve at the point of contact.

Factors that accelerate wear and tear

  • Wear of seals (for track chains with a closed joint or with a liquid joint lubrication)
  • Too much tension in the chain
  • Using machines on the ground with high abrasiveness (for tracks with a dry joint)
  • High speed of movement.

The effect produced

Too free movement of the finger and the sleeve in the hinge can lead to the so-called "curvature" of the chain. The increased chain pitch causes the bushing to beat against the tooth profile before it comes into contact with its base. This accelerates the wear of the track bushings and the teeth of the drive wheel. The risk of a broken finger. Strong friction between the links and the edges of the roller due to the forced need to maintain the alignment of the chain.

Prevention and elimination

  • Maintain normal tension in the chain.
  • Check the track daily for leakage of liquid lubricant.
  • Minimize the impact of controlled factors on the running system.

DESTRUCTION OF THE FINGER

Causes:

The crack begins on the outer surface and quickly spreads throughout the finger. It occurs more often in tracks with liquid lubrication of hinges due to the presence of lubrication channels that weaken the cross-section of the finger.

Factors that accelerate the appearance of a defect

  • High-strength grounds
  • Compacted hard ground
  • Defects in the finger material
  • The use of excessively wide shoes

The effect produced

The separation of the calf, the unexpected descent of the caterpillar from the machine.

Prevention and elimination

To eliminate or reduce the influence of controlled factors, especially the possibility of non-removable and compacted materials (stones, etc.) getting into the contact zone between the caterpillar bushings and the drive wheel elements, use the least possible shoe width.


WEAR OF ONE OR BOTH ENDS OF THE FINGER

Causes

  • Sliding contact of the finger with the side protection of the tractor running system and with stones.
  • "Serpentine" of the track chain or misalignment of the trolley frame and / or components of the running system.

Factors that accelerate wear and tear

  • Work on an inclined surface
  • Sharp turns
  • Using shoes that are too wide
  • Wear of the roller edge

The effect produced

  • Problems when removing the fingers in the event of a rollover of the track bushings with liquid lubrication of the hinge.
  • Wear on the end of the finger can cause the landing hole in the link to break, which reduces the possibility of its reuse.
  • The ends of the finger and the hole for filling the liquid lubricant must be repaired before a new assembly.

Prevention and elimination

  • Wear is unavoidable if the tractor has a chassis protection system installed. So, it is recommended to avoid using this system in the absence of a clear need for this.
  • Eliminate or minimize the influence of controlled factors on the running system.