The bevel gear box GN 3971 is available in seven sizes with housing lengths between 1.26 and 2.36 in (32 and 60 mm) and widths between 0.71 and 1.38 in (18 and 35 mm). The gear ratio between the gear box shafts is always 1. The direction of rotation can be selected as desired. The gear shafts can receive axial and radial forces of 13.9 lbf (60 newtons) on the smallest model and 124 lbf (550 newtons) on the largest. The special tooth geometry of the bevel gears of case-hardened steel allows for particularly high torques relative to the size. This can be as high as 10 newton meters, depending on the operating speed.
Thanks to small center distances, the worm gear reducer GN 3975 measures only 2.36 in (60 mm) on the sides and only 1.38 in (35 mm) in width. An internal hardened steel screw moves a worm gear made of special brass. Seven versions provide gear ratios between 1:13 and 1:65. The maximum radial and axial force ranges between 44.96 and 112 lbf (200 and 500 newtons) on the input side and is always 112 lbf (500 newtons) on the output side. Starting with a gear ratio of 1:18, a static self-locking mechanism prevents the rotation of the worm gear from the output side, offering improved safety in many applications.
The encapsulated housings of anodized aluminum make both angular gears light and corrosion resistant. They also effectively dissipate the resulting frictional heat. Numerous fastening holes make it possible to mount the gear boxes in many positions. The shafts can be rotated in both directions and feature a threaded bore and parallel keys for a positive connection to the hub.
The bevel gear boxes and worm gear reducers have lifetime lubrication and therefore require no maintenance. The two gear boxes can also be combined, such as with the elastomer jaw coupling GN 2240.Back