The ETR251/46 gear rack drive is a low-maintenance, purpose-designed drive for starting and closing swinging-air flow vents in Venlo-type greenhouses. The combination of TR251/46 gear rack drive and aEP RW engine gearbox contributes to an optimum greenhouse weather because of accurate positioning of the air flow vents.
The self-supporting TR251/46 planetary gearbox equipment rack drive comprises a zinc-plated C-profile with an integral compact gear rack drive unit. The TR251/46 gear rack drive is mounted to a greenhouse gutter using the item clamp-mounting forks or bows.
Thanks 
to the apparatus reduction stage (i-2.76) and the pinion of the TR251/46 equipment rack drive, the drive torque is effectively changed into a maximum rack force of 4200 N. Track rollers in the C-profile and information blocks ensure stable expansion and retraction of the rack. The drive shafts of the TR251/46 equipment rack drive have long, flat-sided journals. This makes it possible to fit drive shafts (prefab) fitted with weld/sleeve couplings or chain couplings, once the house units have already been mounted. The drive shafts are locked in the couplings by the accompanying shaft retaining clips. The TR251/46 gear rack drive is simple to maintain.
A ETR251/46 gear rack drive with other C-profile lengths and rack lengths is available on request.