We recently asked several industry experts about trends they’re seeing in the design and use of linear actuators, linear guides, and stages. Here’s what those experts had to say.
Meet the experts
Saurabh Khetan | Product line manager — Leadscrews • Thomson Industries Inc.
Justin Lackey | Product manager — Systems • Bosch Rexroth
Kelly Walden | V.P. of manufacturing • Bishop-Wisecarver Corp.
Jeff Maina | Senior applications engineer • PBC Linear
Samuel Orozco | Product marketing manager — Electric actuators • Emerson
Nathan Andaya | Director — Techline strategic business unit • LINAK U.S.
Andrew Jung | Director of engineering • Bishop-Wisecarver
Andy Zaske | V.P. of sales and marketing • Tolomatic
Dave Walden | Applications engineer • PBC Linear
Sandro Quintero | Business development for electric automation • Festo
Eric Falasco | Product manager — Screws, bushing/shafting, small handling modules • Bosch Rexroth
Eric Rice | Product market manager — electric automation • Festo
Lindsey Brimage | Portfolio program manager • Thomson Industries Inc.
What linear designs are on the rise?
Khetan: We’ve recently seen more robotics and green energy applications. We believe this may be due to shifting perceptions of alternative technologies. Many of our products, including a recently launched miniature leadscrew line, are also used in laboratory automation applications.
Lackey: The medical industry has the largest growth potential outside of the semiconductor industry with serial lab-testing devices, laboratory automation, and surgery-performing robot platforms. We’ve begun supplying highly customized electro-mechanical cylinders and other fine-adjustment control subassemblies for medical robotics. Rexroth even offers a custom-designed subassembly to replace traditional respirators that went through the FDA approval process when the COVID-19 outbreak started in early 2020.
The aerospace industry (much like the semiconductor and medical industries) has also shown strong demand for custom solutions beyond standard catalog product … especially for X and XY table subassemblies.
K. Walden:Linear bearings are a critical component in any automation system. Consumers are constantly looking for new bearing materials and designs needing little or no maintenance; allowing predictive performance; and featuring process-safe materials. Bishop-Wisecarver offers various linear-motion guide wheels and specialty linear bearings to satisfy these needs.
Engineers are also designing a greater number of high-speed automated systems with both linear and curvilinear motion. Where system performance requirements and budgets allow, OEMs are moving increasingly toward linear motors and flexible control. This imparts increased agility in manufacturing processes. We provide unique system offerings catered to these needs with in-house product assembly and testing.
Maina: PBC Linear developed the H-Bot to satisfy applications having high dynamics. This high-speed multi-axis gantry reduced dynamic payloads and significantly simplified wire management to drive motors. We now offer this H-Bot design for other applications as well.
Orozco: Due to electric actuators’ high precision and repeatability, packaging facilities using smart conveyors increasingly rely on electric linear motion products. Smart conveyors use sensors in coordination with linear and rotary motor-based units to accurately perform high-rate sorting tasks — allowing packages to reach their factory destination faster and more efficiently. Motors have also boosted torque and speed output, so now large motors assembled to electric actuators with appropriate screws for heavy-duty applications can perform some tasks such as metal forming and tube bending traditionally associated with hydraulic actuators. Electric actuators in such applications accept programming to apply more or less force and stroke.
Andaya: LINAK has been providing electric linear motion since 1984 and has seen rising demand across many industries for this technology. Originally, we serviced the hospital and care markets, and then offered linear components for height-adjustable desks. Now, we’ve grown tremendously in the mobile agriculture and industrial automation markets, and our local and regional applications engineers and sales team have helped design actuators into many other applications. We’ve also supported vigorous testing to transition companies from hydraulic and pneumatic technologies to electric motors.
Jung: We mainly provide electric actuators with servo or stepper motors and can also create customized solutions. Demand for the robot transfer unit (seventh axis) is increasing for different robot sizes. Ballscrews and leadscrews are used for applications requiring higher accuracy and durability, and demand for rack and pinion sets is increasing as design load capacities increase.
Lackey: Over the last few years, there’s been a growing need for completely engineered linear solutions. As the goal is to keep profitability up and costs down, we see many companies reducing or minimizing design and electrical engineer headcounts … and here, our open-market tools can help minimize overhead.
Zaske: Engineering resources are at a premium, but business opportunities for automation are accelerating. This creates tension and opportunity for manufacturers and distributors to increase their value add to customers. Tolomatic has seen increased interest in our Integrated Motor Actuator (IMA) product line, which incorporates a servomotor into the actuator body. This in turn results in few components, a smaller overall package, and increased performance attributes. We’ve also had more requests to put complete assemblies together — for example, gantry systems with transition plates, cable management, and end adapters.
Detail any recent miniaturization or integration of feedback devices in linear components.
Khetan: There’s an increasing need for ever-smaller linear-motion components. This is due to the desire for smaller end-use OEM devices that can perform the same functionality with less floor space. Our recently launched miniature leadscrew line addresses this need.
K. Walden:We’ve received an influx of customer inquiries for miniature ballscrews, which has prompted us to develop a miniature metric ballscrew line (releasing early 2023) to complement our popular leadscrews. The ballscrew usage profile has expanded across a wide range of industries, including medical, semiconductor, aviation, and other precision automation applications.
Quintero: To shrink or eliminate the control cabinet, the industry will see greater drive-motor-actuator integration for on-machine electric motion, which removes the servodrive from the cabinet. The Festo Simplified Motion Series exemplifies this trend and removes components from the control cabinet for machine mounting. We offer seven different linear actuator types for simple applications requiring two positions and more complex tasks for which infinite positions can be assigned through IO-Link. Personnel can program the unit through a keypad or IO-Link, and simplified motion provides ease of use. The offering’s cost is comparable to that of pneumatics.
Falasco: Our Small Handling & SMS linear modules using leadscrew, ballscrew, and belt drive components are highly suited for laboratory automation applications. We’ve seen early success for these, especially in the medical testing lab, optics, and metrology lab applications. Though these modules are less configurable, they’re more economical and readily available, so more industries will likely consider them for low-cost/quick-ship types of applications.
Rice: For a Z-axis on a Cartesian system, Festo has developed a mini linear slide with a built-in rod actuator. This construction creates a compact and lightweight Z-axis that has precise positioning and accurate repeatability. We also offer a cantilevered Z-axis in which we mount the Z-axis actuator on the Y-axis, and the actuator body moves up and down. Belt actuation delivers rapid acceleration, and the cantilevered Z-axis keeps the mass of the motor centered on the Y-axis for stability. This design reduces the number of components and weight of the Z-axis, and it improves accuracy and efficiency.
Orozco: Miniaturization has great benefits because it can reduce weight and space. For example, miniaturizing precise screw technologies can reduce power consumption on electric actuators and open new opportunities for semiconductor applications and medical automation equipment. Additionally, feedback devices such as encoders have improved. Servomotors have thrived because of encoders that provide position feedback. Enhanced stepper motors are also closing the gap with closed-loop systems that allow encoders for positional feedback. Linear motion endusers benefit from enhanced feedback technologies that motors and encoders provide to actuators. They can verify motor speed and position and help identify or detect motor stall.
What about application-specific electric and pneumatic actuators?
Orozco: In 2022, Emerson launched its SPRA series, which is a rod-style electric actuator. SPRA is a highly competitive electric actuator that can meet a maximum dynamic load capacity of 106 kN (23,830 lb-ft) and has three screw technologies (leadscrew, ballscrew, and roller screw) that cover a wide range of applications. We’re offering SPRA because of the industry trend to change from pneumatic to electric, where the latter is energy-efficient, has better repeatability and precision, and can be flexible and programmed to perform many strokes at different speeds with different forces.
The option to multitask influences customers’ preference for electric actuators. However, it’s important to understand that electric cannot fully substitute pneumatic applications where higher velocity is required. Though, with advancements in motor and screw technology, electric actuators are shortening the gap with pneumatic applications in terms of speed.
Rice: Sometimes, compressed air is simply not available, or the enduser wants to decrease energy consumption by cutting back on compressed air. In these situations, OEMs look for solutions that move away from compressed air without the complexity of a servo-driven axis. The Festo Simplified Motion Series of electric actuators with an onboard motor and integrated drive provides electric motion with the same ease of use as pneumatics and at roughly the same cost. Personnel can program directly at the unit for two-position motion through an onboard keypad or use IO-Link to program three or more positions.
Brimage: Shock loads are a challenge for designers looking to convert fluid power to electrical power, because electrical solutions on the market can’t handle axial shock loads. However, the industry advances with innovations to continue our transition to cleaner machines. For example, we recently launched an electric actuator featuring optional mechanical shock-load damping; the latter lets the actuator handle some shock load and replace hydraulics in more applications. Compared to hydraulics, the electric actuator has better controllability and efficiency — important features when transitioning to battery-electric operation. Applications include material handling, construction, agricultural equipment, and others that require clean, precise, and quiet actuation.
Read the rest of our 14 experts’ insights in Part 2 of this series.
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