Electric motors convert electrical energy into mechanical energy in the form of rotating motion. They are used to power a wide range of industrial and household equipment. The rotor windings are powered by direct or alternating current from the stator. Each rotor turn generates a magnetic field that interacts with the stationary field to produce force.
Types
Electric motors have two mechanical components, a fixed part called the stator and a moving part known as the rotor. They use magnetic circuits to turn electrical energy into mechanical power that turns a shaft, which can be used to propel machinery like pumps, fans, compressors, conveyor systems, and even electric cars.
There are many different types of electric motors that differ by construction, application, and even the way they’re energized. They can be powered by direct current (DC) charges from rectifiers or batteries, or alternating current (AC) charges from the power grid or electrical generators. They can also vary in size, number of stator and rotor magnetic poles, rotational speed, voltage, and current ratings.
Whether an buy electric motors runs on single- or three-phase power, and whether it has a starting mechanism that uses a capacitor or start windings or is self-starting, can further narrow down its category. Some manufacturers categorize motors based on their air-gap flux density, which is influenced by the magnetic core’s size, winding slots, and back-iron depth.
Other factors include if the motor has a salient- or non-salient-pole setup, which determines whether current flows around a part of the core called a pole face, making it a south or north pole of the electromagnetic field when AC current passes through. Some motors have a shaded-pole setup, in which there are windings around a portion of the rotor that delays the magnetic field phase for that pole. buy electric motor from surplusrecord. industrial electrical motors are the best buy of electric motor. used electric motor for sale at surplusrecord.
Budget
While price may be a deciding factor in motor purchase decisions, end-users should consider the long-term cost of ownership when making purchases. The total cost of ownership is comprised of the purchase price, energy costs and the cost of not running the motor.
The quality of raw materials and manufacturing processes can significantly impact the price of electric motors. For example, motors made from high-quality copper wires and laminations tend to be more expensive than those with lower-grade materials. Other significant cost components include design and engineering, labor and assembly, quality control and testing, overhead expenses, and profit margin.
In some cases, an investment in a higher-efficiency motor can be recouped in just two years through reduced energy bills. It is also possible to obtain additional savings through utility rebate programs.
Purchasing the right electric motors for your application is not an easy task, but with careful research you can find the best value. When evaluating different models, be sure to assess their features, including power ratings and efficiency levels, as well as noise and vibration levels.
Evaluate the environment in which your motor will operate to help determine if extra protection is necessary. Open drip-proof (ODP) motors are the most affordable option, while totally enclosed fan-cooled and explosion-proof motors provide more advanced protection. Enhanced safety features can increase your motor’s overall cost, but are essential for some applications. For instance, interlocks are useful for preventing equipment and devices from being switched on when the motor is in use.
Applications
Electric motors are used in a wide range of applications, from blowers and pumps to industrial fans and machine tools to household appliances and disk drives. Some are even used as regenerative braking in electric vehicles to recover power that would otherwise be lost as friction and heat. Most motors run on AC electrical networks, although some operate on DC power.
Motors use electrical current to generate magnetic fields in the rotor and stator. These fields push against each other, causing the rotor to rotate. The magnetic field strength is proportional to the current flowing through the conductors in the rotor.
The conversion of electrical energy into mechanical energy was explained by Michael Faraday in 1821. His two major physical principles were that an electrical conductor will experience a force when placed in a magnetic field, and any component of motion at right angles to the field will cause a corresponding motion in the other direction.
Using electricity to drive an engine is much more efficient than using gasoline. It doesn’t require a complicated fuel-injection system, starter motor, variable transmission, noise-dampening muffler, or pollution control devices. It also doesn’t produce a lot of noise, exhaust, or fumes and does not require a large tank to store fuel for long trips. The only drawbacks are the limited power range, size of battery, and time required for recharging over refueling.
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