2021/04/01

Part 1: What Is An Electric Linear Actuator And How To Choose It?

Noticias/eventos

Contents

1. What Is An Electric Linear Actuator And How Does It Work?  

2. Common Styles Of Electric Linear Actuators

   2.1 Parallel Drive Actuator

   2.2 Right-Angle Actuator

   2.3 Inline Actuators

   2.4 Gear Motors

   2.5 Dual Motor

   2.6 Linear Slide Actuator

   2.7 Electric Lifting Column

3. How To Choose The Right Electric Linear Actuator For Your Application?  

4. Everything Is Variable; Everything Is Adaptable

 

 

What Is An Electric Linear Actuator And How Does It Work?

 

An electric linear actuator is a device that converts an AC or DC electric motor’s rotational motion into linear motion. The linear motion is created by rotating the actuator’s screw via the motor. The screw turns either clockwise or counter-clockwise, and this causes the shaft (which is basically a nut on the screw) to move in a line, up and down, creating the push/pull effect for the load.

 

Anywhere a machine pushes or pulls, raises or lowers, roughly positions, or rotates a load, an electric linear actuator can be used. Electric linear actuators also provide safe and clean movements with accurate motion control and full operator control. They are energy efficient and have a long lifespan that requires little to no maintenance. 

 

TiMOTION specializes in electric linear actuator solutions best suited for medical, industrial, workplace, and home furniture applications.

 

There are many components and options to an electromechanical linear actuator. TiMOTION is a vertically integrated company. We can customize, design, and manufacture all of these components in-house for customers depending on their application needs. We manufacture motors and components, including the spindle and drive nut, for our electric actuators. Also performed in-house, our plastic injection molding and PC board manufacturing ensure high product quality and durability. Building our own PC boards allows TiMOTION to optimize software and various movements needed within an application. A primary example of this is combining multiple linear actuators with position feedback to create synchronized movement.

 

We will discuss a new subject in each section related to an electric linear actuator's basics and the factors to consider when purchasing components for a linear motion system. This section of the white paper will discuss an electric actuator's common styles and how to select the right actuator for your applications. Next, we will review the internal and external components of a linear actuator. Then, we will cover the safety-related options that can be added to an actuator.

 

Following that, we will explain the various actuator load and speed characteristics to consider and how they can be adjusted to meet the applications’ needs. We will follow that with the multiple levels of IP ratings an actuator can have for liquid and dust protection, as well as lubrication that goes into an actuator. Finally, we will discuss different position feedback sensors used in electric linear motion systems.

 

 

Common Styles Of Electric Linear Actuators

 

TiMOTION designs and manufactures various linear actuators that are all interchangeably customizable to fit a customer's application needs. Some common styles of electric or electromechanical linear actuators include:

 

Parallel Drive Actuator

The motor is directly parallel to the drive spindle. Typically, these types of electric linear actuators are spur or spiral gear with more gear ratio options. Parallel drive actuators allow for a broader range of loads and speeds. However, parallel drive actuators with spur gear can operate louder than spiral gear and worm gear driven actuators.

 

TiMOTION’s Parallel Drive Actuators with Spur Gear

TA2P

MA2

MA5

 

TiMOTION’s Parallel Drive Actuators with Spiral Gear

TA16

TA29

VN1

 

 

Right-Angle or "L" Drive Actuator

The motor is set perpendicular to the drive spindle. Typically, these types of electric linear actuators are worm gear driven. Worm gear-driven motors have fewer gear ratio options. Because of that, they are less efficient than spur gear-driven motors but operate with low noise. One of the key benefits of a worm gear driven, right-angle electric linear actuator includes an increased self-locking ability. Some examples of right-angle drive actuators that TiMOTION manufactures can be seen in our TA23, TA31, TA37, and TA43 models.

 

TA23

 

Inline Actuators

An electric inline actuator has a longer retracted length but is explicitly designed to fit into smaller or compact spaces. The inline actuator is typically made up of a motor, planetary gear assembly, and drive spindle. These usually operate at a higher noise level. Examples of inline actuators can be seen in our JP3 and JP4 models.

 

JP4

 

Gear Motors

Gear motors allow for economical and flexible designs when matching them with various external spindle assemblies. The compact design is typically worm gear driven and an excellent choice for mechanical synchronization. Examples of gear motors can be seen in TiMOTION's TGM1, TGM2, TGM3, TGM4, TGM5, and TGM7 models.

 

TGM3 & TGM5

 

Dual Motor

A dual motor linear actuator creates movement in two directions, either individually or simultaneously. They are also typically worm gear-driven motors, which operate at a lower noise level. While these generally are more expensive per unit, the total system cost will be more economical due to fewer parts. An example of this can be seen in our TT1 model.

 

TT1

 

Linear Slide Actuator

This actuator style creates a linear movement without the use of an outer tube. It utilizes a plastic slide mechanism that travels across the actuator, attached to the frame of common household furniture (such as power recliners and couches), as seen in our TA5L and TA5P actuators. 

 

TA5P

 

Electric Lifting Column

TiMOTION manufactures lifting columns catering to the industrial, medical, and ergonomic markets. An electric column's primary advantage is its ability to lift high loads vertically while retaining a high degree of stability and bending movement compared with linear actuators. Our industrial and medical grade columns are designed for applications such as medical and bariatric beds and height-adjustable industrial workstations, where worker and patient safety is essential. Some examples of these columns are the TL3, TL10H, TL17, TL27and TL18AC.

 

Our office ergonomic columns come in various colors, shapes, orientations, as well as two (2) or three (3) stages for BIFMA compatibility depending on user preference. (The Business and Institutional Furniture Manufacturer’s Association, or BIFMA, is a not-for-profit trade association promoting and maintaining voluntary safety and performance standards for furniture products.) Some examples of TiMOTION’s office ergonomic columns can be seen on the TL4, TL5, TL7, TL9, TL13, TL14, and TL15.

 

TL3 & TL9

 

 

How To Choose The Right Electric Linear Actuator For Your Application?

 

Choosing the right electric actuator is an essential part of any successful automation project. There are many actuator models – parallel, L-shaped, or inline motor –used in a wide range of applications. Each project need is unique. To help you select the right actuator, consider the application and its technical constraints: speed, load, duty cycle, available space, environment, and more.

 

1. Define the Required Load

The load to be supported is a determining factor in the actuator choice and will define its various components (motor, nut, spindle, gears, ball bearings, etc.).

It is crucial to define which direction the actuator will operate (pull, push, vertical or horizontal movement) and over which length. It will also depend on the diameter of the actuator’s inner and outer tubes. All these factors influence the actuator's ability to lift loads and have an impact on its strength.

 

2. Define the Required Speed

The desired speed is a fundamental parameter in the selection of the actuator.

Not all mechanisms or materials are compatible with high speeds. High speed with a high load can cause premature wear of the actuator and affect its lifetime. Therefore, each device has speed and load that must not be exceeded to protect it from material damage. This speed depends, among other things, on the pitch and the motor characteristics.

 

3. Define the Duty Cycle

The duty cycle defines the ratio between the on-time and off-time of a device and varies considerably from one application to another. The duty cycle is essential to determine the actuator, its materials, and its mechanisms. It helps give the equipment an optimal lifetime and limit mechanical parts' wear or possible overheating. 

Electric actuators with parallel motors, for example, with their spur gears, will withstand a higher duty cycle and have a higher number of cycles.

 

4. Define the Available Space

The system’s available space also informs the choice of the actuator.

In addition to load, stroke, and speed, it is necessary to consider whether the actuator will have to operate in a restricted space and if there are any space restrictions to allow integration into the application.

 

For example, inline electric actuators, due to the motor's alignment with the spindle, are more compact, making them ideal for tight installation spaces. An actuator's mounting dimensions depend on the mounting configuration (inline, L-shaped, or parallel motor).

 

5. Define the Environment

The environment in which the equipment will operate is a crucial parameter to choose the right electric actuator.

 

Questions to consider: Does the equipment operate indoors or outdoors? Is it exposed to dust, solid contaminants, or moisture? Does it have to withstand intensive cleaning with detergents or high-pressure cleaning? Depending on the environmental requirements, the materials used and the ingress protection (IP) rating will differ. Does it require a silent operation? For example, L-shaped electric actuators, with their plastic worm gears, provide a quieter movement, ideal for medical or domestic equipment.

 

 

Everything Is Variable; Everything Is Adaptable

 

The choice of an electric actuator depends on many parameters. It is important to choose a linear actuator that meets the application requirements. Every application includes a list of requirements that must be met to choose the right electric actuator. Budget is also a factor in project planning. Some unavoidable technical constraints will require a larger budget. The important thing is to evaluate all these parameters to create the most suitable device.

 

We hope this has helped you develop a better understanding and foundation for electric linear actuators and their incorporation into linear motion systems. Next, we will review the critical components inside and outside of an electric linear actuator. If you have further questions and/or would like help with your next application, please contact our global team. We specialize in partnering with our clients while providing quality solutions for their actuation needs. TiMOTION would be glad to assist you.

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