The actuation market is projected to grow from an estimated USD $38.80 Billion in 2017 to USD $49.28 Billion by 2022. Given this growth trajectory, the focus is moving away from traditional actuation options that have a myriad of cumbersome deficiencies to more streamlined innovative solutions that provide higher efficiency (lower costs), increased uptime, and integrated-simple connectivity.
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The goal is to take advantage of enhanced technologies that can achieve higher efficiencies via factors such as less maintenance, advanced connectivity (field buses), lower weight, compact footprint, accuracy, and energy efficiency.
In response to the customer demand for these actuation efficiency goals, cutting-edge motion control/actuation specialists Kyntronics (Cleveland, OH), have developed its patent-pending Smart Hydraulic Actuator (SHA)–a major development in ‘power-on-demand’, servo-controlled, variable speed actuation. Made in the USA, this new actuation technology achieves the optimal technological compromise–combining the best advantages of hydraulics and electromechanical servo technology minus their disadvantages engineered in a all-in-one, scaleable, modular assembly.
New to the OEM market, the Kyntronics’ SHA advantage represents the world’s only standard, all-in-one (variable-speed motor, drive, cylinder) actuation system that precisely controls position, force, and speed in applications requiring from 500 lb (2,225N) to over 100,000 lb (445kN) of force capacity. High force and quick cycle times in a compact package, the all-inclusive system produces strokes up to 120in (3,048mm).
Ultimately, the unique system configuration delivers a myriad of benefits resulting in lower operating costs and better performance across a wide range of OEM applications.
Traditional actuation climate / issues:
Traditional actuation systems over the past several decades focused on three primary types: electromechanical, hydraulic, and pneumatic. With the advent of Kyntronics SHA, SMART electro-hydraulic actuators now represent a fourth category that leads the growth trajectory of next-generation actuation. Whereas traditional actuation systems all have their distinct advantages, each have inherent core disadvantages including:
electromechanical (EMA):
▪ Lower reliability due to the continuous mechanical wear.
▪ Prone to environmental contamination and degradation in performance.
▪ Expensive and difficult to control force.
▪ Backlash occurs/worsens over time because the motor is mechanically coupled to the output shaft.
▪ Most EMAs require a brake to hold the load in position when the drive is at rest. Every EMA is “back
drivable” without a brake.
▪ Unforgiving to modification–if the application parameters require greater speed or force, the entire EMA generally must be replaced.
hydraulic cylinder actuators:
▪ Oversized continuous running hydraulic power units are energy inefficient.
▪ Integrated network of hoses and fittings are prone to leaking and must be maintained.
▪ Susceptible to fluid contamination causing valve’s to malfunction and control issues–high maintenance.
▪ Expensive and difficult to control motion precisely.
▪ Expensive and difficult to provide control connectivity along with (IoT).
▪ Hydraulic solutions require extensive engineering and infrastructure, i.e.-fluid flow, power system, hose
Lengths, pipes, valves, wires, connections, etc.
pneumatic:
▪ Similar drawbacks to hydraulic (see above).
▪ Requires a pneumatic infrastructure of pipes, fittings & valves that often leak and waste energy.
▪ Periodic maintenance required for changing filters, fixing leaks, etc.
▪ Lower operating pressures typically require a larger footprint to provide the desired force.
Kyntronics Smart Hydraulic Actuator (SHA) innovation / solutions:
Kyntronics SHA is fully engineered as a standard modular product–rendering it inherently more cost effective as it leverages standard, off-the-shelf components. This all-in-one system combines the key benefits of an electronic servo system with the power density of hydraulics. The flexible system can be oriented in any position and features a compact footprint–combining the power to weight ratio advantage of hydraulic technology with the versatility, ease of installation, and control of electric servo technology.
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This true, ‘all-in-one’ actuation solution is powered by a servo motor that drives a hydraulic pump which generates pressure to act on a cylinder to provide optimal mechanical actuation force.
The configuration also features a servo drive controller, actuator, manifold, and built-in transducers–providing essential closed-loop precision force and position control. Fieldbus capabilities include Ethernet, CAN, & Serial.
A notable key benefit of the system is the way the differential volume is accounted for between a cylinder’s cap and rod ends. To compensate for this differential, the hydraulic cylinder includes an outer low-pressure cylinder with a second inner high-pressure cylinder–creating a chamber between the two.
Ultimately, the uniquely engineered product delivers high force density in a small footprint with precision, while offering superior “power-on-demand’ energy efficiency–only running when needed.
Essential Kyntronics SHA design configuration specs / benefits include:
Modularity: The modular configuration provides millions of product combinations while minimizing inventory and allowing assembly to individual application specifications–reducing lead time vs. custom solutions. The modular system starts with a servo motor driving a pump–eliminating the need for a proportional directional valve because the motor controls flow rate and direction. The actuator can be configured as desired for most any application. The Power Unit can be detached, the Drive/Controller can be detached, The Power Unit can be oriented as desired to properly fit into small machine cavities.
Reliablity: Hydraulic actuators are well known to outlast all other actuation solutions. There is no metal-to-metal wear points vs. roller or ball screw actuators. With the self-contained SHA, the fluid cannot become contaminated from external sources, these systems can run >100 million inches compared to <20 million for the Electrical-Mechanical actuators. With a simple rod seal replacement, the SHAs can run for years sometimes outlasting the machinery. The SHA is very shock load resistant, and suitable for challenging environments.
Energy efficiency: The Kyntronics SHA combination of hydraulics/electric servo far exceed traditional systems, and ‘power-on-demand’ capabilities deliver the most efficient (60%-80%) method of converting electrical power to mechanical power. The SHA also features a variable-speed pump that saves energy–with less heat and noise. When no pressure or flow is needed, the motor consumes no energy. Additionally, when holding force with no motion required, the check valves lock the actuator in position requiring no energy.
Small footprint / all-in-one package: High force in a compact package. Less size and weight results in less overall costs. Standard ‘drop-in’ solution–simply connects to power & I/O (or network) and can be oriented in any position–eliminating hoses and potential leaks.
No hydraulic infrastructure: Eliminates the need for a central hydraulic power unit, flex hoses, piping, or extra connections–fewer components and no leaks translate into substantial savings.
Rod-volume compensating mechanism: Patent-pending mechanism compensates for the differential volume between the cylinder’s rod and cap end volumes, as the piston rod extends and contracts. It features closed cell foam that is wrapped around the inner pressure cylinder. To compensate for the difference in volume, the hydraulic cylinder includes an outer low-pressure cylinder with a second inner high-pressure cylinder, which creates a chamber between the two. This chamber features compressible foam which serves the same purpose as an accumulator in conventional systems. The foam requires no initial pre-charge, or any maintenance. This design is easily scalable that compensates for any stroke or cylinder size.
Drive controller: A pre-engineered attached controller is a standard option. The controller is properly sized for the application and is pre-configured and tested at the factory to reduce set-up time and eliminate programming. Software tools are available to setup or alter desired motion profiles as required.
SHA conclusion / future:
According to Kyntronics’ President Wayne Foley, “The key inspiration for our research and development on the SHA product came from vital input from our customers who wanted to embrace the global trends of increasing automation, higher precision requirements, lower costs, and more connectivity.”
Noting the product’s vitality as a competitive and advanced alternative for the marketplace, Carl Richter, Kyntronics VP; General Manager, said, “Electro-hydraulic technology has been driving actuation market growth, and we strive to provide our customers and channel partners with unique solutions like the SHA that are ahead of the curve. Our nimble, responsive team of in-house engineers thrive on ‘solving the unsolvable’ actuation application problem and are equipped to provide the best combination of mechanics, electronics, software, and support solutions in actuation today.”
