Electric motors – Troubleshooting and repair
An electric motor is an electric machine that converts electrical energy into mechanical energy. Most electric motors work by the interaction between the motor's magnetic field and electric current in a wire winding to generate force in the form of torque applied to the motor shaft. Electric motors can be powered by direct current (DC) sources, such as batteries or rectifiers, or by alternating current (AC) sources, such as an electrical grid, inverters, or electric generators. An electric generator is mechanically identical to an electric motor, but operates with a reversed power flow, converting mechanical energy into electrical energy.
Electric motors can be classified based on considerations such as the type of power source, internal construction, application, and type of output motion. In addition to AC versus DC types, motors can be brushed or brushless, can be of various phases (see single-phase, two-phase, or three-phase), and can be air- or liquid-cooled. General purpose motors with standard dimensions and features provide cost-effective mechanical power for industrial use. The largest electric motors are used for marine propulsion, pipeline compression and pumped storage applications with outputs reaching 100 megawatts. Electric motors are found in industrial fans, blowers and pumps, machine tools, household appliances, power tools and disk drives. Small motors can be found in electric clocks. In certain applications, such as in regenerative braking with traction motors, electric motors can be used in reverse as generators to recover energy that might otherwise be lost as heat and friction.
Electric motors produce a linear or rotary force (torque) intended to propel an external mechanism, such as a fan or elevator. An electric motor is generally designed for continuous rotation or linear motion over a distance significant for its size. Magnetic solenoids are also transducers that convert electrical power into mechanical motion, but they can only produce motion over a limited distance.
Electric motors are much more efficient than another prime mover used in industry and transportation, the internal combustion engine (ICE); Electric motors typically have an efficiency above 95% while ICEs are well below 50%. They are also lightweight, physically smaller, mechanically simpler and cheaper to build, can provide instant and consistent torque at any speed, can run on electricity generated from renewable sources, and do not emit carbon into the atmosphere. For these reasons, electric motors are replacing internal combustion engines in transport and industry, although their use in vehicles is currently limited by the high cost and weight of batteries which can provide sufficient autonomy between recharges
Further information on electric motors:
For requests for engines and spare parts
https://www.unitecd.com/e-catalog/description-articles/?lingua=GB&category=Motor&prm=ric_ft
Buy books
Electric Motors and Drives: Fundamentals, Types and Applications
Bestselling reference on electric motors and drives for non-specialists, bridging the gap between mathematics and theory.
Mechanical Design of Electric Motors
Rapid increases in energy consumption and emphasis on environmental protection have posed challenges to the motor industry, as has the design and production of highly efficient, reliable, economical, energy-efficient, quiet, precisely controlled and durable electric motors.
Suitable for motor designers, engineers and manufacturers, as well as maintenance personnel, undergraduate and postgraduate level students and academic researchers, Mechanical Design of Electric Motors provides in-depth knowledge of modern electric motor design methods and developments. From engine classification, engine component design, model configuration and material and bearing selection, to power losses, engine cooling, design integration, vibration and acoustic noise, this text comprehensive covers the fundamentals, practical design and issues relating to the design, modeling and simulation, engineering analysis, manufacturing processes, test procedures and performance characteristics of today's electric motors.
Focusing on the mechanical design of modern electric motors, the book:
Discovers the design and manufacturing of major components and subsystems, such as rotors, shafts, stators, and frames
Examines various cooling techniques, including forced air, liquid, and phase change
Discusses the analysis and calculation of engine power losses
Addresses engine vibration and acoustic noise issues
Presents engineering analysis methods and case study results
Emphasizes construction, optimization, and applications
With research findings from the author's personal experience and significant contributions from others, Mechanical Design of Electric Motors highlights the innovative and advanced electric motors developed in recent decades.
Mechanical Design of Electric Motors
The importance of electric motors is well known in various fields of engineering. The book provides comprehensive coverage of various types of electric motors including DC motors, three-phase and single-phase induction motors, synchronous motors, universal motor, AC servo motor, linear induction motor and stepper motors. The book covers all the details of DC motors including torque equation, back emf, characteristics, types of starters, speed control methods and applications.
The book also covers the various testing methods of DC motors such as Swinburne test, brake test, delay test, field test and Hopkinson test. The book also explains three-phase induction motors in detail. Includes Rotating Magnetic Field Production, Construction, Operation, Effect of Slip, Torque Equation, Torque Ratios, Torque-Slip Characteristics, Losses, Power Flow, Equivalent Circuit, Effect of Harmonics on Performance, Circular Diagram, and Applications. This chapter also includes discussion of the induction generator. The book teaches the various starting methods and speed control methods of three-phase induction motors. The book incorporates the explanation of various single phase induction motors. The chapter on synchronous motor provides a detailed discussion of construction, working principle, behavior under load, phasor diagram analysis, Vee and Inverted Vee curves, chase, synchronous capacitor and applications. The book also teaches the various special machines such as single-phase commutator motor, universal motor, AC servo motor, linear induction motor and stepper motors. The book uses simple and lucid language to explain each topic. The book provides the logical method of explanation of various complicated topics and step-by-step methods to facilitate understanding. Each chapter is well supported with necessary illustrations, self-explanatory diagrams and a variety of solved problems. The book explains the philosophy of the topic which makes the understanding of the concepts very clear and makes the topic more interesting.
Motor Starting and Control Primer: An introduction to the starting techniques and control of electric motors
Whether you are a busy electrical engineer who needs to brush up on your knowledge of motor starting, a busy student new to the subject, or an interested layperson with an hour to spare, this book is the place to start. Steven McFadyen shares his expertise in the field of engine starting in a clear and easily accessible manner without time-consuming verbiage or self-congratulatory arguments. Complete with circuit diagrams and in-depth explanations of the most common motor starting methods and their challenges, this book is an invaluable reference. It has something to offer anyone who is eager to learn new things, while at the same time assisting working electrical engineers to design and implement reliable and functional motor starters.
