Mechanical engineering

250 entries in this trade.

inclined plane

One of the simple machines; a sloping surface such as a ramp such that an object can be raised with less effort than being lifted vertically.

induction motor

An alternating current motor in which currents in the secondary wiring of the rotor are created by induction from the magnetic field of the primary winding of the stator.

jack nut

A type of nut with a sheet metal body that mushrooms outward, on the far side of the hole through the substrate, when the screw is screwed in, thus providing anchoring with only one-sided access to the hole. It is nearly equivalent to the female portion of a molly bolt.

kinetics

The branch of mechanics concerned with motion of objects, as well as the reason i.e. the forces acting on such bodies. This, along with kinematics constitute dynamics, which is concerned purely with the effects of forces on moving bodies.

knife-edge

A small piece of metal, usually steel, sharpened to an acute edge or angle, and resting on a smooth surface, serving as the fulcrum of a pendulum, scalebeam, or other piece required to oscillate with minimal friction.

Lagrangian

A function summarizing the dynamics of a physical system, typically in non-relativistic contexts amounting to the kinetic energy minus the potential energy, L=T-V.

lever

A rigid piece which is capable of turning about one point, or axis (fulcrum), and in which are two or more other points where forces are applied;, used for transmitting and modifying force and motion.

limited-slip differential

A type of differential that allows its output shafts to rotate at different speeds but can limit the maximum difference in angular velocity between the output shafts, allowing greater torque to be applied to the slower-spinning shaft(s) and generally resulting in better traction than older-design differentials.

lockup

A condition in which one or more of a vehicle's wheels suddenly cease to rotate due to the application of excessive brake torque, causing the affected wheel(s) to skid.

Newton's second law

Newton's observation that the rate of change of the momentum of a body is directly proportional to, and in the same direction as, the net force acting on it. Often stated as F = ma: F = force, m = mass, a = acceleration.

normal mode

A mode of an oscillating system in which all parts of the system move sinusoidally with the same frequency and with a fixed phase relation. The motion described by the normal modes is called resonance.

open differential

A type of differential gear used in automobile construction, allowing for output shafts to have different angular velocity, while equalizing torque applied to each output shaft.

overdrive

A gear ratio higher than 1:1: one in which a single revolution of the driving element corresponds to more than one revolution of the driven element.

parallelogram of forces

A parallelogram, two adjacent sides of which are vectors having the same initial point and representing two forces acting simultaneously upon this point, such that the resultant of the forces is given by the diagonal of the parallelogram that passes through this point.

pendulum

A body suspended from a fixed support so that it swings freely back and forth under the influence of gravity, commonly used to regulate various devices such as clocks.

piston

A solid disk or cylinder that fits inside a hollow cylinder, and moves under pressure (as in an engine) or displaces fluid (as in a pump)

polygon of forces

A polygonal figure the sides of which are vectors representing several forces acting simultaneously upon one point, so that the vector necessary to make the figure closed is the resultant of those forces.

poppet valve

A valve (as in an internal combustion engine) which consists of a sliding shaft with a disk on the end (the disk being shaped to alternately plug and unplug a matching port). Such a valve is opened by either a cam or a solenoid and is closed by either a spring or a solenoid.

power

A measure of the effectiveness that a force producing a physical effect has over time. If linear, the quotient of: (force multiplied by the displacement of or in an object) ÷ time. If rotational, the quotient of: (force multiplied by the angle of displacement) ÷ time.