For goods lifts, we specifically rely on two high-strength, positive-drive drive concepts: the chain drive (with or without a counterweight) and the drum drive.
The key regulatory advantage of these positive-engagement drives over conventional pulley drives lies in the elimination of the need for complex monitoring of unintended car movement (UCM – Unintended Car Movement) in both directions.
1. Chain drive (with or without a counterweight)
- Characteristics: Power is transmitted directly to the car via high-strength precision chains – with or without a supporting counterweight, depending on requirements and load capacity.
- Applications & advantages:
- Versions without a counterweight: Ideal in confined spaces or where there are accessible areas beneath the shaft. As no weight needs to be counterbalanced, there is no need for an additional safety catch on the counterweight.
- Models with a counterweight: To reduce the load on the drive unit for larger payloads. The counterweight reduces energy consumption whilst maintaining a consistently high load-bearing capacity.
- Very compact: The preferred solution for drives integrated directly into the shaft (MRL).
2. Drum drive (rope drum)
- Characteristics: In a drum drive, the hoisting ropes are wound onto a milled rope drum. The force transmission is entirely positive-lock due to the ropes being firmly clamped onto the drum.
- Application & advantages:
- Special configurations: Well-proven for side-mounted drives or where there is insufficient space for counterweights.
Why we do without drive sheaves in goods lifts
- No slippage: As the chain and drum provide a direct, positive-lock connection, rope slippage cannot occur.
- Simplified safety technology: By avoiding the use of drive sheaves, there is no need for the complex monitoring system against uncontrolled car movements in both directions (UCM), which would otherwise be required by standards.