The ETR251/46 gear rack drive is a low-maintenance, purpose-designed drive for opening and closing swinging-environment vents in Venlo-type greenhouses. The mixture of TR251/46 gear rack drive and aEP RW engine gearbox contributes to an optimum greenhouse climate thanks to accurate positioning of the surroundings vents.
The self-supporting TR251/46 equipment rack drive planetary gearbox comprises a zinc-plated C-profile with a built-in compact equipment rack drive unit. The TR251/46 equipment rack drive is installed to a greenhouse gutter using the accessory clamp-mounting forks or bows.
Thanks to the gear reduction stage (i-2.76) and the pinion of the TR251/46 gear rack drive, the drive torque is effectively changed into a optimum rack force of 4200 N. Monitor 
rollers in the C-profile and guidebook blocks ensure stable extension and retraction of the rack. The drive shafts of the TR251/46 gear rack drive have lengthy, flat-sided journals. This makes it possible to fit drive shafts (prefab) installed with weld/sleeve couplings or chain couplings, once the house units have been mounted. The drive shafts are locked in the couplings by the accompanying shaft retaining clips. The TR251/46 equipment rack drive is simple to maintain.
A ETR251/46 gear rack drive with other C-profile lengths and rack lengths is on request.