FLENDER Gear Units for Bucket Elevators


Bucket elevators serve to vertically transport large masses of bulk material to different heights without creating dust, then dump it. The height to be overcome is frequently more than 200 meters. The weights to be moved are enormous.

The carrying elements in bucket elevators are central or double chain strands, link chains, or belts to which the buckets are attached. The drive is located at the upper station. The features specified for the drives destined for these applications are similar to those for steeply ascending belt conveyors. Bucket elevators require a comparatively high input power. The drive must be soft-starting because of the high starting power, and this is achieved by means of fluid couplings in the drive train. Bevel helical gear units are normally used for this purpose as single or twin drives on a base frame or swing base.

As world market leader for bucket elevator drives, Siemens has standardized the complete application-specific drive system, thus combining the advantages of proven and reliable components with fast availability. FLENDER gear units are a crucial element of the drive train. They are characterized by maximum performance and operational reliability as well as optimal availability. Auxiliary drives (maintenance or load drives) and backstops are supplied as standard. The gear unit and the auxiliary drive are therefore perfectly matched.

Technical data

  • Types: Bevel helical gear unit FLENDER SIG

  • Sizes: 15 sizes from 04 to 18

  • No. of gear stages: 3

  • Power ratings: 10 to 1,850 kW (auxiliary drive power from 0.75 to 37 kW)

  • Transmission ratios: 25 - 71

  • Nominal torques: 6.7 to 240 kNm

  • Mounting positions: Horizontal


  • Maximum power capacity

  • Maximum operational reliability

  • Fast availability

  • Modular design principle


  • Lime and cement industry

  • Powders

  • Fertilizers

  • Minerals etc.

  • Suitable for transporting hot material (up to 1000°C)