Search results
Results from the WOW.Com Content Network
A lubricant (sometimes shortened to lube) is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, transporting foreign particles, or heating or cooling the surfaces.
[10] Spatial diffusion is the gradual spread of culture, ideas, and institutions across space over time, in which the desirability of one place adopting the traits of a separate place overcome the friction of distance. Time geography explores how human activity is affected by the constraints of movement, especially temporal costs. [11]
Fluid friction describes the friction between layers of a viscous fluid that are moving relative to each other. [7] [8] Lubricated friction is a case of fluid friction where a lubricant fluid separates two solid surfaces. [9] [10] [11] Skin friction is a component of drag, the force resisting the motion of a fluid across the surface of a body.
The load then starts sliding, and the friction coefficient decreases to the value corresponding to load times the dynamic friction. Since this frictional force will be lower than the static value, the load accelerates until the decompressing spring can no longer generate enough force to overcome dynamic friction, and the load stops moving.
Friction drive – Mechanical power transmission by friction between components; Lubrication – The presence of a material to reduce friction between two surfaces; Metallurgy – Field of science that studies the physical and chemical behavior of metals; Multibody system – Tool to study dynamic behavior of interconnected rigid or flexible bodies
As an example, a 10 mm (0.394 in) shaft made of 303 stainless steel will form a tight fit with allowance of 3–10 μm (0.00012–0.00039 in). A slip fit can be formed when the bore diameter is 12–20 μm (0.00047–0.00079 in) wider than the rod; or, if the rod is made 12–20 μm under the given bore diameter.
In real life, though, there is often a situation where the surfaces are not completely dry, but also not so lubricated that they do not touch. This "boundary friction" produces various effects, like an increase in lubrication through the generation of shearing forces , or an oscillation effect during motion, as the friction increases and decreases.
Sliding friction (also called kinetic friction) is a contact force that resists the sliding motion of two objects or an object and a surface. Sliding friction is almost always less than that of static friction; this is why it is easier to move an object once it starts moving rather than to get the object to begin moving from a rest position.