Wire Rope Versus Roller Chain | We Compare the Two Lifting Mechanisms
We are often asked, what is the difference between a roller chain lifting mechanism and a wire rope lifting mechanism?
Vertical Lifts, also known as mezzanine lifts or freight lifts, are becoming more popular as the pressure increases on companies to deliver orders more quickly.
For those who don’t know, the purpose of a vertical reciprocating conveyor (VRC) is to move materials and/or goods from one level to another. While they are often referred to as freight elevators, VRCs are not for riders. Only materials and goods can be moved in a VRC.
One of the key components of a VRC is the lifting mechanism used to lift the platform up and down.
There are two types of lifting mechanisms: roller chain and wire rope. In this article, we’re going to look at the strengths and weaknesses, and which is best suited for different situations.
But first, we’re going to share how roller chains and wire ropes are constructed.
The roller chain is most commonly used in industrial and agricultural machinery, including many VRCs on the market.
According to Wikipedia, there are two types of links alternating in the roller chain — inner links and outer links.
The Inner links have two inner plates held together by two sleeves or bushings, upon which rotate two rollers. The outer links consist of two outer plates held together by pins passing through the bushings of the inner links.
The roller chain design reduces friction compared to simpler designs, resulting in higher efficiency and less wear.
Next up is wire rope.
Four components make up the wire rope: metal wires that form a singular strand, multi-wire strands, a wire core, and lubrication.
- Metal wires, the smallest component of the wire rope, make up multi-wire strands. The metal wires are manufactured in a variety of grades
- Multi-wire strands consist of two or more metal wires arranged and twisted in a specific grouping and laid in a helical pattern around the core.
- The core of the wire rope runs through the center of the rope. It supports the strands, and helps maintain their position under loading or bending stress.
- Lubrication, which is applied during the manufacturing process, penetrates to the wire rope’s core. Lubrication reduces friction and protects against corrosion.
Now, let’s take a look at the strengths and weaknesses of each lifting mechanism.
Wire Rope vs. Roller Chain Comparison
The chart above illustrates the primary differences between wire rope versus roller chain. Below we’ll discuss them in greater detail.
Strength, Load Capacities, and Work Environments
Overall, wire rope is stronger than chain. The multi-strands of continuous wires give wire rope its strength, whereas a chain is joined together with links. These joins are the weakest part of a chain and can break under heavy loads.
In addition to being stronger than chains, wire ropes also function better than chains in intense work environments. Wire ropes can stand up better to harsh environments and extreme heat. However, both can be used in outdoor environments.
When running high-duty cycles, Vertical Lifts that use wire rope perform better than chains. High-duty cycles generate heat in motors and components; wire rope dissipates heat more efficiently than chain. Using a chain in these high heat environments will always result in equipment failure and downtime.
Along the same lines, it’s important to note that chains should not be used in environments that are very dusty or dirty. The lubrication on the chain will attract these particles, creating an abrasive compound that will cause premature wear.
So, Vertical Lifts with chains should not be used in intense work environments, such as high-duty cycles or high load capacities (more than 50% of the maximum rated capacity.
Wire-rope vertical lifts require minimal maintenance. Unlike chains, wire ropes do not require lubrication, a demanding and time-consuming task. Over the life of the unit, both the chain and wire rope will need to be replaced. Chains are more susceptible to wear and tear, but wire ropes will experience their share as well. Wire ropes can experience corrosion, cuts, or shearing, tension failure, or fatigue breaks.
In reality, cost should not be a factor. The environment and application should dictate which type of lifting mechanism is needed. Cost is relative when comparing wire rope and chain. The upfront cost for a wire rope is greater than chain. However, chains incur higher maintenance costs. The last thing you want is to overload your lift or deal with costly and time-consuming breakdowns or equipment failure caused by the wrong lift for the job.
Whether it’s a hoist, crane, or vertical material lift, either wire rope or roller chain will be part of the lifting mechanism. It’s important that you do your research before investing in a vertical material lift or any lifting mechanism. One is not better than the other — what’s important is to make sure the correct lifting mechanism is used for the appropriate application.