—brakeless, adj./brayk/, n., v., braked, braking.n.1. a device for slowing or stopping a vehicle or other moving mechanism by the absorption or transfer of the energy of momentum, usually by means of friction.2. brakes, the drums, shoes, tubes, levers, etc., making up such a device on a vehicle.3. anything that has a slowing or stopping effect.4. Also called brakeman. a member of a bobsled team who operates the brake.5. Also called breaker. a tool or machine for breaking up flax or hemp, to separate the fiber.6. Also called press brake. a machine for bending sheet metal to a desired shape.7. Obs. an old instrument of torture.v.t.8. to slow or stop by means of or as if by means of a brake.9. to furnish with brakes.10. to process (flax or hemp) by crushing it in a brake.v.i.11. to use or run a brake.12. to stop or slow upon being braked.13. to run a hoisting machine.[1400-50; late ME < MD, MLG; akin to BREAK]Syn. 8. halt, arrest, stay, restrain; curb, curtail.brake2/brayk/, n.a place overgrown with bushes, brambles, or cane.brake3/brayk/, n.any of several large or coarse ferns, esp. the bracken, Pteridium aquilinum.[1275-1325; ME brake, prob. by back formation from braken BRACKEN, taken as pl.]brake4/brayk/, v. Archaic.pt. of break.
* * *Device for decreasing the speed of a body or stopping its motion.Most brakes act on rotating mechanical elements and absorb kinetic energy mechanically, hydrodynamically, or electrically. Mechanical brakes are the most common; they dissipate the kinetic energy as heat generated by mechanical friction between a rotating drum or disk and a stationary friction element. A hydrodynamic (fluid) brake has a rotor (rotating element) and a stator (stationary element). Resistance to rotation is created by fluid friction and circulation of the liquid (usually water) from a series of pockets in the rotor to a series of complementary pockets in the stator. See also air brake.
* * *▪ machine componentdevice for decreasing the speed of a body or for stopping its motion. Most brakes act on rotating mechanical elements and absorb kinetic energy either mechanically, hydrodynamically, or electrically.Mechanical brakes are the most common; they dissipate kinetic energy in the form of heat generated by mechanical friction between a rotating metallic drum or disk and a stationary friction element brought into contact with it by mechanical, hydraulic, or pneumatic means. The friction elements for drum brakes may be bands or shoes (blocks with one concave surface); for disk brakes they are pads or rings. Friction materials may be organic, metallic, or ceramic; molded asbestos is commonly used.Mechanical operation by means of rigid links is satisfactory for single brakes, but when several brakes are actuated from a single source, as on an automobile, it is difficult to obtain equal braking effectiveness on all wheels; for this reason, hydraulic actuation, with oil under the same pressure acting on all brakes, is preferable. The braking of railroad cars is effected by cast-iron shoes that bear directly on the circumference of the wheels and are activated by compressed air (see air brake).A hydrodynamic (fluid) brake has a rotor (rotating element) and a stator (stationary element) that resemble the impeller and runner in a hydraulic coupling. Resistance to rotation is created by fluid friction and circulation of the liquid (usually water) from a series of pockets in the rotor to a series of complementary pockets in the stator. Because the resistance to rotation—i.e., braking power—depends on the speed of the rotor, these brakes cannot completely stop a rotating member; however, if means for cooling the liquid are provided, they can dissipate large amounts of kinetic energy in a very effective manner.
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