Plastic bushing construction

Oil-impregnated bronze bearings rely on a capillary action to create a lubricating oil film. High speed and rotational motion are both required to draw the oil out and maintain a full film of lubricant. Shaft oscillation, slow speed and intermittent use can all inhibit this process.

If movement stops, the oil on the surface of the bearing dries up. This can lead to squeaking and an increase in the coefficient of friction. High temperatures can also break down the oil. Other disadvantages include low chemical resistance and sensitivity to dirt, edge pressure and impacts.

iglide® engineered composite plastic bushings from igus®, however, are not prone to any of these problems because they are injection molded with a blend of base polymers, fibrous reinforcements and solid lubricants. Fibrous reinforcements maintain the bearings strength and resistance to high forces and edge loads. As movement occurs, tiny amounts of solid lubricant are released into the micro-finish of the shaft, helping to lower the coefficient of friction.

The solid lubricants cannot be pressed out once that transfer is made. iglide® materials can also withstand short-term temperatures of up to 572°F and long-term temperatures of up to 482°F.

Other advantages include low wear rates, quiet operation, high load capacity, and resistance to chemicals, dirt, dust, UV light and corrosion. igus® currently offers more than 30 plastic bushing materials to meet the requirements of almost any application.

Choosing the right shaft for your bearing material is critical because the service life of the bearing is affected by relative motion.

A rough shaft is too abrasive and will slowly wear away the bearing’s surface as it moves. Very smooth shafts can lead to even higher wear rates because it is challenging to lubricate the shaft properly.

Oil-impregnated sintered bronze bearings function best on very hard, expensive precision ground shafts. Plastic bearings, on the other hand, can run on all types of shafts.