Planetary gearsets offer applications advantages over other gearsets, including multiple kinematic combinations, power density, big reductions from compact setups, and pure torsional reactions. Planetary gearboxes also boost overall design efficiency. Losses never exceed 3% per stage, so the sets transmit most energy for productive motion output. In applications driven by servo systems, gearboxes also reduce […]
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What are thermal overload relays and what motion components do they protect?
Heat is a major factor in the performance and life of a motor, and one of the primary sources of motor heating is current running through the motor windings. Since heating is an unavoidable condition of motor operation, it’s important to protect the motor from overheating, or thermal overload. In a previous post, we described […]
What’s the difference between dynamic braking and regenerative braking?
When a motor’s rotor speed is greater than its synchronous, or designated, speed, it can act as a generator, creating electrical energy from mechanical energy. This electrical energy needs somewhere to go, and there are two ways to deal with it — dissipate it as heat, or reuse it. Dynamic braking takes the energy generated […]
What are busbars and how are they used in motion control applications?
Busbars are components that facilitate the distribution of power to electrical equipment, supplementing or replacing traditional wiring in applications such as commercial facilities, data centers, and industrial plants. At their most basic, busbars are relatively simple bars, strips, or rods made of copper, brass, or aluminum, but in many cases, they’re constructed in specific shapes […]
What are bearing currents and what causes them?
Pulse-width modulation is a fundamental operating principle of variable frequency drives (VFDs), but the high-frequency switching that delivers pulses of voltage from the drive to the motor can cause bearing currents — high-frequency currents that flow through the motor bearings, often leading to damage and premature failure. To achieve pulse-width modulation, insulated gate bipolar transistors (IGBTs) […]
Universal Robots takes the gold in 2020 LEAP Awards in Industrial Automation category
The winners of the 2020 LEAP Awards (Leadership in Engineering Achievement Program) were announced yesterday in a digital ceremony, with products across 12 categories, including Industrial Automation. Critical to LEAP’s success is the involvement of the engineering community. No one at WTWH Media was involved in selecting the winners. Instead, our editorial team assembled a […]
New online encoder selection tool targets MRO needs
Sensor manufacturer POSITAL has released its intuitive online tool EncoderMatch.com. This new web platform, which combines a search engine, product configurator and ordering tool, is aimed at the MRO/spare parts business. With a few mouse clicks, maintenance staff and technical buyers can quickly find cost-effective replacements for encoders in existing machines or systems – regardless […]
What is cable ringing between AC drives and motors and how can it be avoided?
Variable frequency drives use a technique referred to as pulse-width modulation (PWM) to provide voltage of varying frequency to an AC induction motor. The inverter, or output, stage of the VFD uses insulated gate bipolar transistors (IGBTs) that switch on-and-off rapidly, creating trapezoidal pulses of varying width to simulate AC sinusoidal voltage. But the windings in […]
What’s the difference between resistance, reactance, and impedance?
DC circuits are relatively easy to analyze, due to current flowing in one direction, with resistance being the main element of the circuit. AC circuits, on the other hand, are more complex, since voltage and current alternate direction with a given frequency. Whereas DC circuits have resistance, AC circuits often have resistance and another property, known […]
What are drive isolation transformers and how do the differ from line reactors?
A variable frequency drive alters the speed of an AC induction motor by rectifying incoming AC power to DC, storing the DC power in a bus, and then converting the DC power back to AC at the voltage and frequency required to meet the load demands. Although this matching of the motor speed to the […]
