Linear Motion Control
Most screw driven linear motion systems accept NEMA 23, 34, or metric 60 mm frame motors. The motor can be full-step, half-step, or micro-step; or a DC motor-based analog or digital servo system, depending on resolution, speed, and torque. Controllers provide circuitry for position sensors to detect position. Some sensing devices are well-suited for linear systems, such as linear variable differential transformers, optical linear encoders, force transducers, and proximity switches.
DC and Can Stack
DC and can stack motors are commonly used in high-volume applications. They have the best price/performance point, but are not typically prepackaged and ready to integrate with PLCs and motion controllers.
DC Stepper (Step Motor)
Popular choices for linear applications because of their low cost and prepackaged drive systems. They integrate easily with PLCs and motion controllers. Step motors are available in open-loop and closed-loop configurations. A drawback is the significant decrease in torque output as the rpm decreases.
AC Brushless Servo
Servo essentially means “closed loop”. Servo motors are more expensive than step motors. They have no significant drop in torque output as rpm increases and also run quieter and use less energy.
Installed on the back of the motor to provide feedback to the control unit or drive.
Mounted on a linear table to allow the encoder to read true table position and not shaft angle position. They offer the best way to monitor and control position with high accuracy and resolution.
Some step motors come with a simple control system prepackaged with the motor, which can control simple machines. But, it should not be used to control a large number of axes, complex motion paths, or continuous motion from a PLC. Although its expensive, it is more efficient to install a dedicated motion controller than to have a PLC act as the upper control system to manage I/O and send commands to the controller.
Key Manufacturers of Linear Motion Control Products We Offer
- Danaher Motion
- Festo Corporation
- Lee Controls
- Nexen Group
- Nook Industries
- PBC Linear
- THK America
- Thomson Industries
- Warner Linear
Content on this page was created using excerpts from the Power Transmission Handbook (5th Edition), which is written and sold by the Power Transmission Distributor’s Association (PTDA). The Power Transmission Handbook is just under 400 pages and is a valuable resource for anyone involved or interested in the power transmission industry.