In this article from our series on Lift tables types and their advantages and disadvantages, we take a closer look at belt-driven lift tables.
Modern belt-driven lift tables typically use flat belts. However, many of the positive and negative characteristics described here are also applicable to other types of lift tables with traction elements.
How a belt-driven lift table works
In this type of lift table, the belt is connected on one side to an electric motor via a gearbox and on the other side to the scissor mechanism or a lifting carriage.
Simply put, the scissor lift table operates by rolling the belt up and down on a shaft. By shortening the length of the belt, the scissor arms become steeper, raising the platform to lift the load upward. Conversely, unrolling the belt extends its length, which lowers the load.
No hydraulic oil
One advantage of belt-driven lift tables is the elimination of hydraulic oil as a pressure medium: There is no risk of leaks caused by improperly installed hydraulic lines or material failure. Therefore, belt-driven lift tables are particularly well-suited for use in food processing areas or other sensitive environments, as no precautions are necessary to prevent contamination from hydraulic oil.
Placement of the drive unit outside the lift table
Since the traction element in belt-driven lift tables can easily be routed externally via a pulley, positioning the drive unit outside the lift table is not an issue. However, this arrangement does not offer the same flexibility as with hydraulic scissor lift tables.
Shock- and vibration-dampening power transmission
During peak forces while lifting or lowering, the belt’s elasticity acts as a shock absorber. This effect is also noticeable with vibrations, significantly reducing the risk of resonance. The dampening properties of the flat belt protect the drive system from undesirable force impacts.
Uneven load on the belts
Earlier designs relied on a single belt for power transmission. If this belt was damaged, it posed a significant safety risk to nearby individuals. To minimize this risk, modern lift tables now use up to six belts, depending on the load capacity.
However, this improved design introduces a new challenge: Due to belt stretch, the belts are unevenly loaded during the lifting process and are subject to constant tension fluctuations.
Limited usability at higher temperatures
The material of the belts limits their usability in higher temperature environments. While high temperatures can also pose problems for other types of lift tables, solutions such as oil coolers can often be used to regulate heat. Unfortunately, this option is not available for belt-driven lift tables. Therefore, either a different type of lift table must be used, or the surrounding conditions must be appropriately adjusted.
Sensitivity to external influences
Belts, especially under load, are sensitive to external influences. This includes mechanical impacts as well as contamination from oil, gasoline, water, dirt or dust. A theoretical solution would be to protect the belts through encapsulation. However, due to the movement of the scissor, this is rather difficult to implement.
Lifelong belt retensioning
Due to the continuous stretching of the traction element during operation, it is necessary to regularly retension the belts throughout the entire service life of the lift table.
Energy demand during lifting and lowering
In hydraulic lift tables, the energy balance is often improved by the fact that the electric motor only needs to operate during the lifting process. The energy for lowering the scissor lift is provided solely by the potential energy of the load and the lift table's own weight.
In contrast, belt-driven lift tables typically require the electric motor for both lifting and lowering, to roll the belt up and down. While the lowering process could theoretically be assisted by the lift table's own weight, this would make it difficult to fix the load at a specific height.
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