Top Ten Electric Motor Selection Tips

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10. Consider PMAC for same torque as AC Induction in a smaller, lighter motor.

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Permanent Magnet AC (PMAC) motors are a growing alternative to AC Induction motors, which for decades have been the workhorse of almost any electrical motor application.

PMAC motors preserve the reliability and simplicity of the ac induction motor while offering higher efficiency, synchronous operation, and the opportunity to use a smaller frame size.

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9. Use the best lamination bath impregnation process for optimum thermal management.

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Impregnating stators strengthens stator winding electrical insulation, protects against chemicals or harsh environments, and enhances thermal dissipation.

Driving out air pockets from the electric winding enhances the thermal conductivityof the winding.

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8. Balance at operational speeds using high standards.

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Bearing vibration readings are normally taken on three planes. Vertical vibration may indicate a mounting problem. Horizontal vibration may mean a balance problem, whereas axial vibration may indicate a bearing problem.

Unbalance can also be caused by centripetal forces at the bearings.

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7. Select low-friction bearings suited for application speeds.

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Ball bearings are more suitable for high-speed applications than roller bearings.

Consider additional forces such as unsymmetrical air gaps causing magnetic pull, out-of-balance forces, pitch errors in gears, and thrust loads.

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6. Consider rare earth versus ferrite (ceramic) magnets.

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Neodymium rare earth, samarium cobalt magnets or ferrite (ceramic) magnets are used in PMAC electric motors.

Rare earth magnets are two to three times stronger than ferrite or ceramic permanent magnets but are more expensive.

Samarium cobalt magnets are optimal for high-temperature applications because of their high energy density.

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5. Optimize design of rotor/stator laminations to show a sinusoidal magnetic field.

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ABM synchronous motors with high-performance permanent magnets come with a sinusoidal flux distribution as well as Electro-Motive-Force.

Stator windings for distributed windings are identical to asynchronous motor windings. It results in lowered vibration, noise and maintenance cost as well as increased overall performance.

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4. Select an inverter to provide sensorlessoperation & optimize programing.

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PMAC drives can “self-detect” and track the rotor’s permanent magnet position. Critical for a smooth motor start and also allows for optimum torque production.

Programming the controller settings to attain optimum efficiency is becoming more and more important with the ever-increasing efficiency regulations.

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3. Use high grade copper for more conductive windings and to optimize density.

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Use of more copper by optimizing the stator lamination slot design increases the cross-sectional area of stator windings. This lowers resistance of the windings and reduces losses due to current flow.

A high-efficiency electric motor can have up to 20 percent more copper in the stator winding.

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2. Optimize cooling fan for minimum power, while providing adequate cooling.

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A cool motor runs more efficiently. To obtain the best airflow, optimize the cooling fan and fan shroud design. Assuring a tight bond between the stator and motor housing provides the best cooling performance.

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  1. Select duty cycle for peaks/shocks in a specific time period.

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What torque and speed is needed when and how often?

What are the ambient conditions such as temperature, humidity and elevation?

Even the most efficient motor will not perform to its utmost efficiency if used for the wrong application.

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Choosing a Gearbox Drive and Electric Motor Supplier

When choosing manufacturing partners during a machine build, remember that there are two methods for choosing a gearbox and electric motor supplier. One is selecting a pre-engineered unit and the other is choosing a gearbox-motor combination and integrating them into the equipment.

Pre-engineered gearmotor solutions are suitable if a design engineer doesn’t have the time or engineering resources to build a gearmotor in-house — or if the design needs a quick setup. New modular approaches to support OEMs (and enable new machine tools, automation, and design software) now let engineers get reasonably priced gearmotors even in modest volumes.

Contact: Gabriel Venzin, President, ABM DRIVES INC, +1-513-576-1300, [email protected].

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The New GHX 250 – Doubling Service Life & Higher Protection Class

The New “GHX 250”: Doubling Service Life & Higher Protection Class 

With constant market observation ABM Drives, Inc. proactively develops and optimizes drive systems to maximize the benefits for customers and their projects. We are excited to present our new GHX 250 in protection class IP65: the GHX 250 excels with twice the service life, high efficiency as well as outstanding performance.

Powerful & DurableHoist Drive Unit GHX 250

GHX 250 – Product Highlights

    • Interface (Output shaft & Mounting) remain unchanged
      • GHX 250 will be 100% interchangeable with the existing GH 25000 & GH 25001
    • Enhanced possible field of application due to extended center distance
      • Installation of drum sizes up to 405 mm
    • Consequent classification of FEM 2m at all drum sizes at reeving 4:1
      • Doubling their service life
    • Increased speed up to 200 Hz (motor) in no-load condition for VFD version
      • Reduction of cycle time
    • Enhanced switching behavior in two-speed version
      • Reduced noise
    • Higher protection class IP65

GHX 250 Changeover Schedule

    • Samples for the GHX 250 can be ordered from August 2019.
    • Series-production starting in November 2019.
    • Replacement motors and spare parts will remain available for all existing GH 25000 & GH 25001 drives.

Product information will give you further details on the GHX 250 and its many benefits. Click the link below to access the:
New GHX 250 ABM NA Brochure

ABM Drives - Hoist Drive Unit GHX 250

Choosing a Gearbox Drive and Electric Motor Supplier

When choosing manufacturing partners during a machine build, remember that there are two methods for choosing a gearbox and electric motor supplier. One is selecting a pre-engineered unit and the other is choosing a gearbox-motor combination and integrating them into the equipment.

Pre-engineered gearmotor solutions are suitable if a design engineer doesn’t have the time or engineering resources to build a gearmotor in-house — or if the design needs a quick setup. New modular approaches to support OEMs (and enable new machine tools, automation, and design software) now let engineers get reasonably priced gearmotors even in modest volumes.

It’s true that one benefit to selecting a separate motor and gearbox and then combining them can less expensive than choosing a pre-engineered gearmotor. Another benefit to this approach is that one may be able to design the most optimized gearmotor for the application at hand … because this approach also gives the design engineer the most control over the final configuration and cost.

No matter the approach to gearmotor selection, be sure to continually improve the design by comparing predictions of performance with measurements. Then use the result of the analysis to improve next gearmotor iteration.

Contact: Gabriel Venzin, President, ABM DRIVES INC, +1-513-576-1300, [email protected].

Gearmotor Problems and Applications: Quietness, Extreme Conditions, and Efficiency

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Through a series of blog posts, we’ll be exploring aspects of gearmotors regarding specific problems and applications. Subscribe to our posts to get the latest information about gearmotor and electric motor selection and design.

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Simulation to optimize a proposed quiet gearmotor design can reduce overall design time by as much as 75% — and 3D models that completely define the gearmotor can be used by quality, manufacturing, and procurement teams to analyze, build, and inspect the gearmotor. 3D illustration courtesy ABM DRIVES INC.

Quiet Gear Motors

1. Why gear motor noise isn’t just a gear problem — it’s a system problem. Motion control in churches, libraries, auditoriums and theatres need quiet gearmotors for curtains, podiums and stages that need to rotate, lift or slide, unnoticed by the audience.

2. Electric motor and gearbox noise and vibration diagnosis, analysis and design reduction techniques.

3. To solve gear-noise design problems, the first step is to determine the type of noise that is objectionable.

4. Minimize gear noise in high-speed stages by fine machining and grinding and optimized gear geometry to minimize the impact of individual gear engagement impulses.

5. To minimize gear motor noise, all components should be optimally tuned to each other.

6. Reduce natural resonance by optimizing gear motor housing designs with ribbing and non-symmetrical components — especially on parallel-shaft gearbox types.

7. Excitation from the motor’s electromagnetic field can transfer to the rotor, so look for motor rotors that are sturdy and robust.

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A 3D CAD model of a gearmotor for extreme environments from ABM Drives.

Extreme Ambient Conditions

1. Designing your gear motor for decades of exposure to extreme ambient conditions with low maintenance

2. How to design a gear motor for extreme temperature swings such as when a forklift moves from a -30˚ C freezer to a +40° C dock door

3. Using gear motor heater jackets, motor heating bands or powered windings to prevent moisture build-up in high humidity environments

4. Typically gear motor rated installation altitude is a maximum of 1,000 m above sea level, for higher altitudes, you should consider derating the motor

5. Why is it critical to carefully determine what gear motor duty cycle and what peaks/shocks per a specific time period are experienced

Exploded view rendering of an AC induction electric motor illustrating housing, bearings and fan components.
Exploded view rendering of an AC induction electric motor illustrating housing, bearings and fan components.

High Efficiency Electric Motors

1. To effectively design high-efficiency electric motors, we must define “efficiency”. The construction materials, mechanical and electrical design dictate its final efficiency. When you consider that electric motor systems account for about 60% of global industrial electricity use, the potential savings become clear.

2. In order to make a motor more efficient we have to reduce losses in the motor. Optimize dimensions of rotor and stator laminations to provide the maximum in iron content. Quality of aluminum die casting of rotor package (use of high grade/pure aluminum). Materials/quality of steel, dimensions, impregnating medium for high-efficiency electric motor stator and rotor laminations. Use best – most penetrating – resin impregnation process – bath versus drip for optimum thermal management.

3. Electric motor stators cause of 60% of losses so in order to reduce these losses mass of stator winding must be kept larger as this increase in mass will reduce electrical resistance. Motors that are highly efficient contains 25% extra copper as compare to motors that are designed for standard efficiency models. The use of high quality of copper wire that meet standards per DIN EN 13601, UL Norm with proper number of insulation coats is important to high-efficiency electric motor design

4. Use high quality balancing machine; balance at motor output speeds application will run; has limited effect on efficiency but impacts operating noise and life expectancy that is also important for maximum use of resources

5. Tighten manufacturing tolerances to allow optimum air gap between rotor and stator. Selection of best suited, low friction bearings suited for output speeds. Assure tight bond between stator and motor housing to provide best cooling performance

6. High-efficiency permanent magnet electric motors. Type and quality of magnets (rare earth versus iron magnets etc.). Select inverter that can provide sensorless operation. Programming and optimization of inverter