Screw-propelled vehicle
Vehicle propelled by load-bearing rotating helical flanges / From Wikipedia, the free encyclopedia
Dear Wikiwand AI, let's keep it short by simply answering these key questions:
Can you list the top facts and stats about Screw-propelled vehicle?
Summarize this article for a 10 year old
A screw-propelled vehicle is a land or amphibious vehicle designed to cope with difficult terrain, such as snow, ice, mud, and swamp. Such vehicles are distinguished by being moved by the rotation of one or more auger-like cylinders fitted with a helical flange that engages with the medium through or over which the vehicle is moving. They have been called Archimedes screw vehicles by the US military, where they are classified as a type of marginal terrain vehicle (MTV).[1] Modern vehicles called Amphirols and other similar vehicles have specialised uses.
This article has an unclear citation style. (October 2012) |
The weight of the vehicle is typically borne by one or more pairs of large flanged cylinders; sometimes a single flanged cylinder is used with additional stabilising skis. These cylinders each have a helical spiral flange like the thread of a screw. On each matched pair of cylinders, one will have its flange running clockwise and the other counter-clockwise. The flange engages with the surface on which the vehicle rests. Ideally this should be slightly soft material such as snow, sand or mud so that the flange can get a good bite. An engine is used to counter-rotate the cylinders—one cylinder turns clockwise and the other counter-clockwise. The counter-rotations cancel out so that the vehicle moves forwards (or backwards) along the axis of rotation.
The principle of the operation is the inverse of the screw conveyor. A screw conveyor uses a helical screw to move semi-solid materials horizontally or at a slight incline; in a screw propelled vehicle, the semi-solid substrate remains stationary and the machine itself moves.