Welcome to the Motion Control Classroom or MC² — a new online reference series for design engineers needing information about motion components and systems. Curated by Design World’s editorial team, each installment is a digital content hub with comprehensive background information, current trends, typical and emerging applications, and FAQs on one motion technology.
MINIATURE MOTION DESIGNS
In this Motion Control Classroom, we’ll cover miniature linear slides guides, sensors, encoders, gears, and motors that lend themselves to tiny designs.
The biggest driver of miniature motion designs is the medical-device industry … a trend likely to grow as COVID demands creative new approaches to medical manufacturing, distribution, and treatment — including more emphasis on automated status-monitoring systems, distributed laboratory operations, and home healthcare.
In this Motion Control Classroom, we detail the most common gear types for motion applications — as well as the contained gear trains known as gearboxes (those mechanical components consisting of a series of integrated gears) and other iterations to simplify integration and servotuning.
Topics include various gear subtypes and geometries as well as those related to gearing for washdown settings, exceptionally demanding motion designs, shaft-mount designs, and axes needing servogearing customization.
Vibration is mechanical oscillation (regular or otherwise) about some equilibrium — prone to becoming problematic in motor-driven motion designs where there’s looseness, backlash, windup, uneven effects from friction, machine-assembly imbalances, or shock loading. Noise is a manifestation of vibration that degrades the perceived quality of machines … and in many cases is an unacceptable byproduct of motion.
A common way to classify ac motors is based on the magnetic principle that produces rotation. So there are two fundamental types of ac motors; induction motors and synchronous motors. Induction motors are more common in motion control applications, but synchronous motors do find use in applications requiring precise and constant speed.
In addition to some basics of ac motors including motors for harsh environments, cogging, and the use of soft starters, this installment of Motion Control Classroom covers the basics of VFDs as well as various motor control methods including V/Hz control as well as some different motor braking methods.
Conveyor functions are as varied as the applications they complete. Conveyors for discrete product transport benefit from customization to satisfy requirements — including chain and belt size, morphology and material; support frames; controller, drive, and motor or motors; mode of engagement with the drive; encoder, vision, and switch feedback; tracks, bumpers, and gates; and HMIs and plant-level IT integration.
In the conveyor installment of Design World’s MC² we’ve written and collected more than a dozen references that detail these and other types of material handling with conveyors.
In this MC² we detail the operation of dc brush motors, also called permanent-magnet (PM) dc motors … as well as the use of these motors in various in motion designs. We also cover brushless dc (BLDC) motors and their application. As this MC² details, caveats and application considerations abound.
A lot of modern industrial automation equipment (including multi-axis machinery and robots) operates continuously to execute motion tasks that in some cases must be repeated thousands of times a day. Such motion can ultimately stress machine components — including the electrical cabling. So in this Motion Control Classroom, we outline ways for design engineers to ensure these cables (and their connectors) can withstand the rigors of motion applications — to last as long as the motors, actuators, and controllers they connect.
Recall that linear-motion supports take the form of guide rails, slides, and ways … and include profile rails, linear bearings, guide wheels, slides, and plain-bearing systems that bear load while employing either sliding or rolling to allow translational motion. At this MC² on linear systems, you’ll find resources on to help you choose from the vast array of these linear systems … and satisfy requirements for loading, stroke, speed, accuracy, and design life.
Couplings connect together two rotating shafts in order to transmit motion, or power. For this MC² on couplings, you’ll find resources on the basics of couplings and how to select the right one for your motion system. From technical overviews to selection tips, information is included on the many different kinds of couplings including bellows couplings, flexible couplings, gear couplings, beam couplings, and servo couplings, among others.
Encoders use optical or magnetic sensing to track the position of rotary and linear systems in motion control applications. In this installment of MC², you’ll learn the differences between various encoder technologies and how to choose the right design for your application, including examples of how and where each type is applied. You’ll also find resources explaining the difference between resolution and accuracy and how quadrature encoding can boost resolution.
For motion control applications that require high torque at low speeds, good holding torque, and relatively straightforward operation, stepper motors are often the best choice. And the basic premise of stepper motor construction gives them inherently high resolution and accurate positioning capabilities. In this installment of MC², you’ll learn the differences between various stepper motor designs and find resources describing best practices for selecting and operating a stepper motor and how to choose the best drive scheme for your application.
Gearmotors combine a gear reducer with either an ac or dc electric motor into one physical unit. In this installment of MC² featuring gearmotors, you’ll find resources covering the basics of gearmotors and gearmotor accessories, but also how to select the right gearmotor to meet your particular application’s requirements. You’ll also find information on gears and gearboxes, including gearbox service factor and service class.
Servo systems consist of four main components — motor, drive, controller, and feedback. In some cases, a standalone controller determines required motor moves and prompts the drive to supply the necessary electrical energy to make those moves happen. In other cases, drive and controller are integrated into one component. Either way, the drive core controls torque or velocity or position ... although in servo systems, the most common command parameter is torque. That control is via a torque-mode amplifier or linear drive function.
In this latest installment of the MC² series, you’ll find resources on integrated motors to differentiate the most common variations of these motion-control mainstays, and details on how to use the motors to satisfy requirements for loading, stroke, speed, accuracy, and design life.
Also be sure to check out our library on integrated-motor networking and application-specific considerations, including those related to 3D printing, conveying, robotics, and textile manufacture.