New technology is popping up all over. Be sure you know what’s what before you begin implementing linear motion. The technology can bring accuracy and precision to many applications, but selecting components requires a bit of forethought. Our panel of industry experts discusses some new innovations.
What are some of the new technology innovations in linear motion today?
Brian Zlotorzycki, Heidenhain: There’s a focus toward streamlining the manufacturing process to make it quicker and less expensive to manufacture. On the performance side, manufacturers are always looking for ways to increase the coil density of the motor so that the performance can increase without increasing the size.
Brian Zlotorzycki is Etel motors product specialist at Heidenhain.
Derrick Stacey, B&R Industrial Automation:
There’s linear transport technology or long stator linear motors (LLMs). B&R has worked very closely with ATS Automation to form a partnership on the SuperTrak, the third generation of ATS’s LLM technology. SuperTrak’s initial design was released in 2002, but the industry has not seriously considered this as an enabling technology until recently (Figure 1). We can see this by the increase in competitive technology within this space and the increase in marketing surrounding them. SuperTrak is a fully mature technology in an emerging product market with a lot of lessons learned over the years that have led to optimizations and various technical improvements.
Looped LLMs, such as SuperTrak, take advantage of the dynamic movements of linear motors and the tight control of servos to have a highly flexible and high-performance motion system.
This system gives users efficient and cost-effective batch-size-one production capabilities. It is a highly configurable system that allows each product that the SuperTrak carries to have a different recipe.
Derrick Stacey is solutions engineer at B&R Industrial Automation.
Josh Teslow, Curtiss-Wright: There’s the use of high-tech plastics and easily replaceable guide bushings/anti-rotation parts. And sensor technology is more active. It’s still rare, but more companies are looking at integrating additional sensors in their machines to gauge health. A simple example is a temperature sensor in a bearing block. If the temperature suddenly rises, it’s an easy way to predict a failure before it happens. This will become more and more common as sensors continue to commoditize and controllers have additional low-cost inputs. And of course, the idea of integrating drive, motor and roller-screw actuator all into one body/unit. It’s still relatively new and definitely a game-changer.
Josh Teslow is applications engineer at Curtiss-Wright.
Clint Hayes, Bosch Rexroth: Higher-force actuators and components such as the planetary roller screws allow for electrification of applications traditionally driven by hydraulics. Linear motor technology is becoming more affordable and available, allowing linear-motion-system engineers to achieve the speeds of belt-driven actuators with precision and repeatability that rival the capabilities of ball-screw-driven actuators. There’s the integration of linear positional feedback into the linear guide rail system with either incremental or absolute feedback. And onboard sensor diagnostics within the linear bearings provide feedback on thermal properties, shock and acceleration.
Clint Hayes is product sales manager, linear motion technology at Bosch Rexroth.
Broc Grell, Nexen Group: Everyone is going faster and more accurate with every new machine. Linear-motion product manufactures are doing everything they can to keep up.
Broc Grell is applications engineer at Nexen Group.
Aaron Dietrich, Tolomatic: Design engineers typically reach for two electric actuator solutions: electromechanical actuators that are screw-driven, ball or roller, but are limited to a medium level of speed performance due to critical speed limitations; and tubular linear motors that can achieve speeds beyond pneumatic but tend to be very expensive due to their reliance on rare-earth magnets and complexity. New technologies in belt-driven, rod-style electromechanical actuators can meet the speeds of linear motors but at a lower cost. This new technology helps to provide a more cost-effective design vs. pneumatic cylinders but can achieve higher speeds, has much higher efficiency and has the flexibility of position control.
Aaron Dietrich is director of marketing at Tolomatic.
Matt Prellwitz, Beckhoff Automation: We’ve seen a move toward electrical actuators, rather than traditional hydraulic or pneumatic systems. For example, new linear actuators combine integrated electronics and an actuator in a single, compact, IP54-rated package. This solution offers a lifting height of 10 mm and a peak force of 800 N. In addition, 150 N of continuous force means the linear actuator is an ideal replacement for frequently messy hydraulic solutions or inaccurate pneumatic systems in machine applications with thermoforming or fluidic control, for example. Linear actuator accelerations of 7 m/s² and speeds of 100 mm/s enable exceptionally short control cycles, with response times typical of traditional hydraulic systems.
Matt Prellwitz is motion product specialist at Beckhoff Automation.
Jay Johnson, Sick: Within the past few years, there has been great progress made in the hydraulically driven motion industry, especially with mobile machinery. Precise closed loop motion control of hydraulic cylinders helps to reduce the wear and tear on off-road equipment, automates the task of making accurate repetitive movements, and provides safer operations. In this area Sick has made innovative strides in magnetic working principles for feedback devices, especially in magnetostriction. This technology offers very good precision at an excellent price-performance ratio. Traditional feedback signals such as quadrature, SSI, or HIPERFACE aren’t typically used in these applications because most mobile machine ECU controllers generally use CAN or analog. Therefore, expect these sensors to operate on the J1939 CAN network or PWM.
Jay Johnson is national product manager at Sick.