Friction is an intrinsic physical phenomenon to curling. Without it, objects in motion would move endlessly, without slowing down. This would cause many safety-related problems: Cars or trains could ...

• Excessive seal friction wastes energy, accelerates wear, and can lead to premature failure. • Too little friction makes a seal prone to leak. • Pressure-activated hydraulic seals minimize both ...

A simple one-piece sleeve is sometimes better for reducing friction than complex rolling-element bearings. Besides being greaseless, journal bearings can be made out of high-tech plastics for weight ...