Here at Townsend Bearings we stock a wide range of industrial gearboxes including right angle gearboxes. These are also known as worm boxes.
A worm drive is a gear arrangement in which a worm (a gear in the form of a screw) meshes with a worm gear (which is similar in appearance to a spur gear, and is also called a worm wheel).
Like other gear arrangements, a worm drive can reduce rotational speed or allow higher torque to be transmitted.
Worm drives are a compact means of substantially increasing torque and decreasing speed. Small electric motors are generally high-speed and low-torque; the addition of a worm drive increases the range of applications that it may be suitable for, especially when the worm drive’s compactness is considered.
A gearbox designed using a worm and worm-wheel will be considerably smaller than one made from plain spur gears and has its drive axes at 90° to each other. With a single start worm, for each 360° turn of the worm, the worm-gear advances only one tooth of the gear. Therefore, regardless of the worm’s size, the gear ratio is the “size of the worm gear – to – 1″.
Given a single start worm, a 20 tooth worm gear will reduce the speed by the ratio of 20:1. With spur gears, a gear of 12 teeth (the smallest size permissible, if designed to good engineering practices) would have to be matched with a 240 tooth gear to achieve the same ratio of 20:1. Therefore, if the diametrical pitch (DP) of each gear was the same, then, in terms of the physical size of the 240 tooth gear to that of the 20 tooth gear, the worm arrangement is considerably smaller in volume.
Worm drives are used in presses, conveyor systems, mining industry machines, rolling mills and on rudders. Worm gears are also used on many lift- and escalator-drive applications due to their compact size and the non-reversibility of the gear.
All of our catalogues are available to download in PDF format. To view our catalogues see links to the main Drives, Controllers and Couplings catalogue and main Industrial Gearbox sections below.
Industrial Worm Boxes Catalogue Sections
Industrial Worm Gearboxes – Dimensions
Industrial Worm Gearboxes – Performance
Industrial Worm Gearboxes – Technical Specifications
Industrial Worm Gearboxes – Combination Dimensions
Industrial Worm Gearboxes – Combination Performance