Category Archive: Actuators

Ball Screw Actuators vs. Roller Screw Actuators

Actuators are mechanical devices that convert energy into motion. These components are incorporated into a wide variety of products, from industrial equipment to household electronics. The energy source of an actuator can be electric, hydraulic, or pneumatic power.

High-quality, heavy-duty actuators are critical for industrial operations, where they are responsible for facilitating linear and rotary motion to convey materials and operate equipment. For heavy-duty operations, ball screw actuators and roller screw actuators are ideal. We will explain the characteristics, benefits, and differences between ball screw and roller screw actuators so you can choose the one that best suits your needs.

Ball Screw Actuators

Ball screw actuators convert rotary motion to linear motion. They feature a nut mounted on a grooved screw shaft. Inside the nut, recirculating balls roll within the groves of the screw shaft. As the screw turns, the nut moves up and down the shaft along the grooves, creating linear motion that can be finely controlled by turning the screw. Ball screw actuators provide precise control for medium-duty to heavy load-bearing applications and can accommodate high-speed processes.

Ball Screw Applications

Ball screw actuators provide smooth, energy-efficient motion with exceptional accuracy and precision control. They offer continuous high-speed, high-force movement for long periods of time. These benefits make ball screws ideal for:

  • Sawmills
  • Wind turbines
  • Solar panels
  • Vehicle power steering
  • Assembly equipment

Roller Screw Actuators

Roller screws have a similar construction to ball screws, but instead of recirculating balls, they contain rollers that are threaded to match the threads on the main screw shaft. Since the rollers do not touch each other, they do not interfere with each other’s motion and can operate significantly faster than ball screws. The individual rollers have greater surface area contact with the main shaft than recirculating balls, so they have higher axial load characteristics, higher dynamic load capabilities and thus longer life than comparable ball screws. They also generate more heat and require more lubrication at tighter intervals.

Roller Screw Applications

Roller screws can withstand high force and repetitive motions for long periods of time. They can be controlled with a high degree of precision, and their extensive surface area provides additional stress dispersion in high-force applications, such as:

  • Automotive and aerospace manufacturing
  • Metal casting and molding
  • Paint spraying
  • Pressing, inserting, and riveting
  • Precision CNC machining
  • Automated, high-speed manufacturing equipment

Which Actuator Is Right for You?

Ball and roller screws each offer unique advantages for different applications. To determine which actuator is ideal for your needs, consider the following:

  • Operational Life: In general, roller screws have a longer service life and offer good ROI when operated for extended periods of time. For projects lasting less than three years, ball screws are highly effective and make an excellent investment. Depending on the budget and length of your project, ball screws may be ideal for short-term, low-budget projects, while roller screws would be better for long-term applications.
  • Expected Force: Longevity is greatly affected by the amount of force exerted. Roller screws are better than ball screws for heavy loads over eight tons. For applications with lower load capacity, balls screws represent an excellent low-cost option.
  • Maintenance Frequency: Due to the amount of friction and heat they generate, roller screws often require more lubricant and maintenance than ball screws, especially in high-speed operations. Both types of actuators operate best with sufficient lubrication and regular preventative maintenance.
  • Contact Area: Due to the lack of contact between rollers and the bearing, roller screws transmit more force more quickly. Ball screws must make contact between balls and the bearing, so this can interfere with ball motion, reducing efficiency and increasing wear on the actuator elements.
  • Cost: Ball screw actuators are significantly less expensive to obtain, maintain, and repair. Components are readily available open-market, and their simple design makes them easy to fix. Roller screws, on the other hand, are more complex and contain more specialized components, which makes parts harder to source and more expensive to repair or replace.

Request a Quote on Quality Actuators from HyperCyl

HyperCyl is a leading developer and manufacturer of cutting-edge assembly and forming technology. We offer a selection of ball screw, roller screw, and other actuator designs to meet the needs of demanding applications in the commercial, manufacturing, defense, and automation industries. To learn more about our innovative motion solutions, contact us today or request a quote!

Hydraulic vs. Pneumatic vs. Electric Actuators

 

Actuators are mechanical devices that use energy to generate motion. Manual or automatic control commands initiate change in physical systems, creating motion to perform a task. Actuators allow machines to lift, block, clamp, eject and more.

Depending on the type of energy source used to produce motion, three main types of actuators are available: hydraulic, pneumatic and electric. Below we’ll review the characteristics of these actuators as well as their applications and advantages.

Hydraulic Actuators

Known as the most commonly used energy conversion system, hydraulic actuators are an especially popular choice for systems requiring high-force automation equipment. These actuators rely on oil fluid compression.

A variety of heavy-duty applications use hydraulic actuators to produce anywhere from ½ to 4,000 tons of force. These potential applications include:

  • Cargo handling
  • Large construction equipment
  • Military weapons
  • Marine propulsion
  • Transportation systems

Advantages of Hydraulic Actuators

Hydraulic actuators bring the following benefits to an operation:

  • Good strength-to-weight ratio: Hydraulic actuators can deliver tremendous force relative to their weight.
  • Safety: They include various safety features, including rod locks, dump valves that quickly dissipate energy, and bypass valves that close off high-pressure oil when generating motion.
  • Mobility: Hydraulic actuators are also compact enough to take on mobile operations, servicing trucks and other heavy transportation equipment.

Pneumatic Actuators

Most pneumatic actuators feature compression rates of 80 to 100 psi, making them a more stable and safe option for applications requiring less force. These actuators capture atmospheric air and compress it at higher pressures to generate motion. The specific parts of a pneumatic actuator include the actuator, storage tank, system of delivery hoses, motor and compressor unit.

Advantages of Pneumatic Actuators

The benefits of pneumatic actuators include:

  • Speed: The fastest actuators are pneumatic. Fast cycle rates contribute to greater productivity and profit.
  • Cost effectiveness: Pneumatic actuators have lower upfront costs compared to other actuators. They return their initial investment quickly, especially for moderate-duty applications.
  • Simplicity: Pneumatic actuators are relatively simple, so they are less likely to malfunction and easier to repair if they do.

Electric Actuators

Electric actuators use a motor to convert electric energy into torque, producing motion. They use a variety of mechanical components—gears, planetary roller screws, ball screws, lead screws—to generate linear energy from rotational energy.

Small electric actuators are best for low- to medium-duty applications, such as packaging, factory robotics, automotive manufacturing and medical devices. Large electric actuators can produce up to 50,000 lbs of force.

Advantages of Electric Actuators

Electric actuators provide the following main benefits:

  • Speed: Electric actuators respond quickly to generate motion, with speeds of up to 20 in./sec.
  • Precision: Unlike hydraulic and pneumatic actuators, electric actuators are highly precise because they are not subject to inherent tolerances.
  • Cleanliness: Electric actuators use electricity, a clean energy source, eliminating the risk of leaks.

Electric Actuators from Aries Engineering

Aries Engineering produces the HyperCyl-EMA, one of the most reliable electromechanical actuators on the market. This servo-driven actuator works well for precision assembly applications and as substitutes for hydraulic or pneumatic actuators. Our electric actuators are capable of 0.0025 mm, ram speeds of up to 500 mm/sec, and up to 50,000 lbs of output. The HyperCyl-EMA has served customers in the aerospace, automotive, defense, medical, appliance, electronics and transportation industries.

Find the Actuator You Need at Aries Engineering

Aries Engineering Co., Inc. manufactures a line of “hydra-pneumatic” presses and cylinders for many types of assembly applications. We pioneered oil/air compression in 1994 and continue to serve clients across the manufacturing, industrial automation, defense and commercial industries.

If you would like to find out more about our HyperCyl-EMA electric actuators and other products, contact us today. To get started on your next solution, request a quote at any time.

What Is a Servo Actuator?

Actuators are designed to convert energy from different sources, such as electric currents, pneumatic pressure, or hydraulic fluid pressure, into motion. There are three main types of actuators: pneumatic actuators, hydraulic actuators, and servo actuators.

Servo actuators use feedback signals to move or control mechanical systems in a highly efficient and safe manner. This is possible because servo actuators have a controller that can accurately compare, contrast, and calculate the potential differences between the desired results and system conditions on a real-time basis before the motion starts.

Servo actuators use a servo motor in either an open or closed-loop control system. Several servo actuator models have a food-grade approved coating of paint for more sanitary wash-down applications.

Servo actuators are available in both ball and roller screw configurations, like the HyperCyl-EMA, which has several options available for output force. They have an extended service life because they can easily be re-lubricated without disassembly.

How Does a Servo Actuator Work?

A servo system has three main core components:

  • A controlled device that allows the actuator to successfully operate
  • An output sensor/signal that acts as the main controller to tell the device what to do
  • A position sensor, encoder feedback, or load cell to provide accurate system feedback readings

Servo Actuator Control Systems

The control systems, which allow the actuators to operate, come in two different designs.

Closed-Loop Control System

Commonly referred to as feedback controllers, this type of control system is fully automatic and uses the input of the system and the output of the system controls to function. Closed-loop control systems are usually very accurate.

Open-Loop Control System

Commonly referred to as a non-feedback system, this type of control system is not automatic and doesn’t have a feedback loop. The output of the system depends on the input. However, the input or controller is independent of the output produced by the system. Open-loop systems do not measure the device’s output or use the information as input for further consideration.

How Do Servo Actuator Controls Work?

Servo actuators are controlled by a feedback signal generated by comparing the output signal and the reference-input signal rather than a variable-input signal. Whenever a command or reference-input signal is applied to the system, it is immediately compared with the system’s output-reference signal produced by the output sensor. Lastly, a third signal is produced by the servo actuator’s feedback system before it starts to move.

The device can also be programmed with certain instructions and autonomously perform the movements on its own. For example, the actuator can receive a command to go to a specific position and immediately follow the command. This makes them very different from comparable pneumatic valves (pneumatic actuators) and pumps (hydraulic actuators), which can only follow simple instructions to ‘power on’ or ‘power off’ on their own.

Applications of Servo Actuators

There are numerous applications of servo actuators. Some of these include toys, home electronics, computers, drones, and remote controlled cars.

Servo actuators also often play a crucial role in the function of both land- and sea-based vehicles – such as automobiles, airplanes, helicopters, and submarines.

Automobiles

Servo actuators can contribute to the function of these parts in automobiles:

  • Engine Cradle Assembly
  • Engine Sub-Assembly
  • Ball Joints and Bushings

Airplanes and Helicopters

Servo actuators adjust the wing angle of airplanes and control steering by moving the levers back and forth. Airplanes can easily “fly-by-wire” when they have a servo-controlled main system instead of an older hydraulic-powered one.

Servo actuators can also control the speed of a helicopter by moving a swash plate, which can tilt the pitch of the blades in a certain direction to give it more lift.

Submarines

Servo actuators can adjust the submarine’s steering, bay doors, hatches, and rudder.

Servo Actuators at HyperCyl

HyperCyl has been providing servo actuators and other high quality assembly and forming solutions for customers in the industrial automation, commercial, manufacturing, and defense industries for over 25 years. Please contact us or request a quote today to learn more about servo actuators or our other product and service offerings. Our highly experienced team members would be happy to use their expertise to talk with you and help you identify the appropriate actuator for your organization’s specific needs.