HOW AIR BEARINGS WORK1 Airfloat（空气轴承WORK1Airfloat如何）.pdf

AIRFLOAT, LLC · 2230 Brush College Rd · Decatur, IL 62526 · (217) 423-6001 · Fax (217) 422-1049 HOW AIR BEARINGS WORK WHAT IS AN AIR BEARING The Airfloat compliant air bearing supports loads on a cushion of air. It is a unique air support device, but may be compared with two other forms of air supported devices: the classical air bearing, and air cushion or “Hovercraft”. The rigid air bearing can support large loads with small unit pressures when a film of air is forced between the support surface and the ground, but because this film is only a few thousands of an inch thick, a very smooth and very flat surface is required. Principal advantages of the rigid air bearing are its low power requirements and low noise characteristics. Disadvantages are that the bearing and the surface must be very flat, smooth and parallel. Air cushion devices were initially of the single plenum type. A large flow of low pressure air is supplied to counteract leakage out of the air gap. Improved forms employ the skirted plenum, which helps contain the air bubble, decreasing the amount of air required. The main advantage of the air cushion is its high ground clearance, allowing it to move over objects up to several feet in height. The main disadvantage is the great air flow required, causing very high power consumption. The load capacity is limited by the low operating pressures. Airfloat compliant bearings combine the advantages of both the rigid air bearing and the air cushion. Its load carrying capacity is high, its power requirements are low, its noise level and dust disturbance levels are low. It can tolerate some surface imperfections and obstacles, and it is omni-directional. A comparison of the three types is shown in Figure 1-1. Airfloat uses a flexible diaphragm beneath the load support surface. Air is pumped into the diaphragm and passes freely through the diaphragm holes and into