motor

(redirected from motor nerve conduction)
Also found in: Dictionary, Thesaurus, Medical.
Related to motor nerve conduction: nerve conduction test

motor

1. 
a. the engine, esp an internal-combustion engine, of a vehicle
b. (as modifier): a motor scooter
2. a machine that converts electrical energy into mechanical energy by means of the forces exerted on a current-carrying coil placed in a magnetic field
3. any device that converts another form of energy into mechanical energy to produce motion
4. 
a. Chiefly Brit a car or other motor vehicle
b. as modifier: motor spares
5. producing or causing motion
6. Physiol
a. of or relating to nerves or neurons that carry impulses that cause muscles to contract
b. of or relating to movement or to muscles that induce movement
www.formula1.com
www.fia.com
www.imca.com

motor

[′mōd·ər]
(electricity)
A machine that converts electric energy into mechanical energy by utilizing forces produced by magnetic fields on current-carrying conductors. Also known as electric motor.
(neuroscience)
Pertaining to efferent nerves which innervate muscles and glands.
(physiology)
That which causes action or movement.

Motor

A machine that converts electrical into mechanical energy. Motors that develop rotational mechanical motion are most common, but linear motors are also used. A rotary motor delivers mechanical power by means of a rotating shaft extending from one or both ends of its enclosure (see illustration). The shaft is attached internally to the rotor. Shaft bearings permit the rotor to turn freely. The rotor is mounted coaxially with the stationary part, or stator, of the motor. The small space between the rotor and stator is called the air gap, even though fluids other than air may fill this gap in certain applications.

In a motor, practically all of the electromechanical energy conversion takes place in the air gap. Commercial motors employ magnetic fields as the energy link between the electrical input and the mechanical output. The air-gap magnetic field is set up by current-carrying windings located in the rotor or the stator, or by a combination of windings and permanent magnets. The magnetic field exerts forces between the rotor and stator to produce the mechanical shaft torque; at the same time, in accord with Faraday's law, the magnetic field induces voltages in the windings. The voltage induced in the winding connected to the electrical energy source is often called a countervoltage because it is in opposition to the source voltage. By its magnitude and, in the case of alternating-current (ac) motors, its phase angle, the countervoltage controls the flow of current into the motor's electrical terminals and hence the electrical power input. The physical phenomena underlying motor operation are such that the power input is adjusted automatically to meet the requirements of the mechanical load on the shaft. See Electromagnetic induction, Magnet, Windings in electric machinery

Both the rotor and stator have a cylindrical core of ferromagnetic material, usually steel. The parts of the core that are subjected to alternating magnetic flux are built up of thin steel laminations that are electrically insulated from each other to impede the flow of eddy currents, which would otherwise greatly reduce motor efficiency. The windings consist of coils of insulated copper or aluminum wire or, in some cases, heavy, rigid insulated conductors. The coils may be placed around pole pieces, called salient poles, projecting into the air gap from one of the cores, or they may be embedded in radial slots cut into the core surface facing the air gap. In a slotted core, the core material remaining between the slots is in the form of teeth, which should not be confused with magnetic poles. See Eddy current

Direct-current (dc) motors usually have salient poles on the stator and slotted rotors. Polyphase ac synchronous motors usually have salient poles on the rotor and slotted stators. Rotors and stators are both slotted in induction motors. Permanent magnets may be inserted into salient pole pieces, or they may be cemented to the core surface to form the salient poles.

The windings and permanent magnets produce magnetic poles on the rotor and stator surfaces facing each other across the air gap. If a motor is to develop torque, the number of rotor poles must equal the number of stator poles, and this number must be even because the poles on either member must alternate in polarity (north, south, north, south) circularly around the air gap.

motor

A machine which converts electric power into mechanical power by means of a rotating shaft.
References in periodicals archive ?
8 12-79 >10 Glossary AE - above elbow Amp - amplitude BE - below elbow CMAP - compound motor action potential DML - distal motor latency DSL - distal sensory latency MNCV - motor nerve conduction velocity SNAP - sensory nerve action potential W - wrist Table 2.
Results of initial sensory and motor nerve conduction studies Nerve Site Lat (ms) Amp Left sural (antidromic) Calf (lateral 4.
These new compounds have significantly improved the motor nerve conduction velocity by 69% to 85% in an STZ-induced model.
Treatment with M40403 also restored normal motor nerve conduction velocity -- the speed at which the motor nerves transmit signals from the brain.
The motor nerve conduction velocities are generally normal, but the sensory nerve action potentials are usually absent.
The measurements of median nerve sensory distal latency, sensory amplitude, velocity of sensory nerve conduction, motor distal latency, motor amplitude, and velocity of motor nerve conduction were done using standard techniques.
Four weeks later sensory and motor nerve conduction velocities in treated and untreated limbs were measured and compared.