When you hear the term “inching drive,” you might think of a small actuator, possibly driven by a piezo or voice coil, suitable for short, precise movements in applications such as optical inspection. (At least, that’s what I envisioned when I first heard of an inching drive!) But inching drives are so named because of […]
Selecting a servo drive: 9 things you need to know
Sizing a motor for a servo application requires evaluating the move profile and torque requirements to determine the mechanical demands of the system, such as maximum velocity and acceleration, RMS and peak torque values, and load-to-motor inertia match. Once the motor is chosen, the next step is to select a drive. On the surface, selecting […]
Stepper drives: What’s the difference between an L/R drive and a chopper drive?
There are two fundamental types of stepper drives: L/R drives and chopper drives. L/R stepper drives are also referred to as “constant voltage” drives, because they supply constant voltage to the motor windings. The current produced in the windings depends on the motor’s time constant, which is the relationship between its inductance and resistance (L/R). The […]
When to use a programmable automation controller (PAC)
In a broad sense, a programmable automation controller (PAC) is an industrial controller that combines the functionality of a PLC with the processing capability of a PC. The term “Programmable Automation Controller” is generally accepted as having been coined by the ARC Advisory Group, which specified five characteristics that define a PAC: Multi-domain functionality A […]
Moments of inertia: Definitions and equations
The term “moment of inertia” is often used generically, but depending on the context and application, it can refer to one of three different moments of inertia: mass, planar, or polar. In order to know which one is needed for a given calculation or analysis, it’s important to understand the differences between them and how […]
Hysteresis loss and eddy current loss: What’s the difference?
All electric motors experience rotational losses during the conversion of electrical power to mechanical power. These losses are generally categorized as magnetic losses, mechanical losses, copper losses, brush losses, or stray losses, depending on the underlying cause and mechanism. Included in the category of magnetic losses are two types — hysteresis loss and eddy current loss. […]
Servo motor torque curves: What you need to know
Updated November 2019 || A servo motor, when coupled with a feedback device, servo amplifier, and error-correcting control loops, can maintain a tightly controlled position, torque, or speed in applications that require closed-loop operation and the ability to respond to disturbances. But another benefit of servo motors is their ability to produce significant torque over […]
Rotary bearings: Summary of types and variations
Rotary bearings are common components in motion systems. They’re used in gearboxes, motors, pulleys, fans, pumps—virtually any time a shaft is rotating, rotary bearings are there to reduce friction and support radial or axial loads. The classification of rotary bearings begins with the type of bearing that supports the load—ball or roller. Within the ball […]
What are the signs of gearbox misalignment?
Gearbox misalignment is widely recognized as the underlying cause for the majority of gearbox repairs and failures. It can degrade machine performance, reduce mean time between repair (MTBR), and decrease the operating life of the gearbox, motor, and driven equipment. Types and causes of gearbox misalignment Proper alignment between the shaft of a gearbox and […]
Duravant acquires QC Industries
Engineered equipment leader Duravant expands material handling product offerings in North America with QC Industries acquisition. Duravant, a global engineered equipment manufacturer serving the food processing, packaging, and material handling sectors, announced it has acquired QC Industries, a conveyor systems manufacturer headquartered in Cincinnati, OH. The investment extends Duravant’s material handling product portfolio with in-process […]