There are three typical scenarios in which the drum rope guide device (i.e. steel wire rope sleeve or rope guide) of emulsion crane is prone to damage, mainly due to mechanical friction, operational violations, and environmental erosion. The specific analysis is as follows:

1. Excessive wear caused by mechanical friction

Scenario description: When the diameter of the pulley or drum is less than 20 times the diameter of the steel wire rope (standard requirement D ≥ 20d), or the groove distance of the drum rope is too small, the pressure on the contact surface between the steel wire rope and the guide device increases, and frequent bending and stretching lead to surface metal fatigue.

Damage mechanism:

External wear: The outer circumference of the steel wire rope rubs against the pulley groove and drum wall for a long time, causing the fine steel wire to be worn flat, the rope diameter to become thinner, and the breaking load to decrease.

Internal wear: Micro motion wear occurs between the rope core and the steel wire due to repeated bending, reducing overall strength.

Case support: In a refinery accident, failure to replace the steel wire rope with a diameter reduced by 8% in a timely manner resulted in brittle fracture during overload and equipment falling.

Solution:

Choose standard diameter steel wire rope or softer material (such as 6 × 36+IWRC fatigue resistant structure).

Replace the drum that meets the groove spacing requirements and reduce the contact surface pressure.

2. Structural damage caused by operational violations

Scenario description: When lifting diagonally, swinging heavy objects, or overloading, the direction of force on the steel wire rope deviates from the vertical axis, causing the guiding device to bear lateral force.

Damage mechanism:

Deformation damage: Lateral force causes the steel wire rope to twist or the rope guide to deviate, leading to rope disorder and further exacerbating friction.

Overload fracture: When overloaded, the single wire rope experiences a sudden increase in force, posing a risk of shear. If the guiding device gets stuck, it may directly fracture.

Case support: A crane caused damage to the rope guide due to oblique lifting, and the pressure behind the tangled rope on the drum caused the connecting bolts of the reducer to break, resulting in the equipment falling.

Solution:

Install an electronic force gauge that automatically alarms when overloaded by 10%.

Standardize the operating procedures, prohibit inclined lifting, and ensure that the lifted object is vertical.

3. Material degradation caused by environmental erosion

Scenario description: When working outdoors, the steel wire rope is exposed to sunlight, rain, or corrosive gases for a long time, causing the metal parts of the guiding device to rust.

Damage mechanism:

Corrosion damage: Corrosion reduces the cross-sectional area of the steel wire rope, reduces its elasticity and impact resistance, and increases the risk of wire breakage.

Lubrication failure: Accumulation of dirt or insufficient lubrication leads to an increase in friction coefficient, accelerating wear.

Case support: Due to failure to follow safety operating procedures and incorrect binding methods, a certain enterprise caused the steel wire rope to bend and experience stress, accelerating corrosion and wire breakage.

Solution:

Choose galvanized steel wire rope (such as 8 × 19S+ZF coating) or stainless steel material guide device.

Lubrication management should be carried out monthly, and in humid environments, it should be increased to once every two weeks. Penetrating lubricants (such as graphite based grease) should be used.

Install a nylon sheath and focus on protecting the pulley section.

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment