The complexity of wire rope structures, environments, and motion states makes their lubrication less understood and often overlooked. A wire rope consists of multiple moving elements (steel wires, strands, core, etc.), between which there is more or less relative movement, similar to gear, bearing, and chain pairs. When subjected to tension, bending, and torsion, each steel wire, strand, and core within the rope experiences friction and wear against each other. When passing through pulleys or other steering/pressing devices, sliding occurs, also causing relative friction and wear. The following specific phenomena occur:
- Continuous wear and adhesive wear occur at actual contact friction points due to insufficient lubrication and excessive pressure.
- Abrasive wear caused by the adhesion and incorporation of dust and abrasives.
- Corrosion and chemical erosion when wire ropes are exposed to moisture, acids, alkalis, or acidic gases. Internal corrosion of steel wires and strands is extremely dangerous as it is difficult to detect and can continuously reduce strength. External corrosion is easily noticeable and can be quickly prevented, while detecting external corrosion can also signal internal corrosion caused by lubrication failure.
- Fatigue, an insidious gradual accumulation leading to sudden failure, caused by structural changes and strength reduction of steel wires due to overload, impact, or excessive bending.
- Indentation and deformation due to excessive specific pressure and insufficient oil film strength between steel wires, or between steel wires and rope sheaves/drums.
- Frictional heat from direct metal contact can cause high temperatures and subsequent rapid cooling, potentially quenching steel wires to form brittle hardness. If the steel wire surface becomes brittle, it is more prone to cracking, fatigue, and eventual fracture.
- In practice, wire ropes must be pre-lubricated during manufacturing and require ongoing maintenance lubrication during use. The choice of lubricant, need for continuous lubrication, and lubrication cycle should be determined by the specific operating conditions.
Recognizing the importance of proper wire rope lubrication and adopting more reasonable and scientific lubrication methods can extend wire rope service life, eliminate costly replacements, and enhance safety. Two issues that negatively impact wire rope life are wear and corrosion. Stress loads accelerate wear; impact loads, heavy or sudden loads, or rapid acceleration/deceleration. Corrosion is caused by smoke, acids, saltwater, sulfur, gases, salt-laden air, and humidity; and can be accelerated by elevated temperatures.
Manual application of wire rope grease is not only time-consuming, messy, and uneven but also poses significant safety hazards. On the other hand, this approach is highly likely to result in ineffective lubrication maintenance, as the lubricant cannot penetrate into the core of the wire rope to thoroughly address internal lubrication and corrosion protection. The recommended solution is an efficient automatic lubrication system. With the VMAXX®️ automatic cleaning and lubrication system, the right amount of lubricant is injected once to thoroughly and fully lubricate from the wire rope surface to the core, ensuring efficiency and safety.