What are linear rails used for?
The best way to smoothly and precisely move items is by using a range of products known as linear rails. The term ‘linear rail’ is actually interchangeable with linear guides, linear guideways, or Linear slides. Linear rails are crucial in various industries. We’ve put together this guide to give you a better understanding, covering:
What is a linear rail?
A linear rail is a device that facilitates the vertical or horizontal movement and load support of an apparatus. Picture it as a sleek track that guides a stable mechanism – called a carriage or slider – smoothly along with minimal friction. It’s a simple mechanical system that does one job very well.
The primary components of a typical linear rail bearing include the rail itself and a carriage or slider containing ball bearings, which we’ll learn more about shortly. The rail is usually a long, straight piece of metal made from hardened steel or aluminium.
The carriage is fixed to the rail and connects to the object that needs to move. The design of the system ensures high accuracy and repeatability, which results in the longevity and reliability of the system.
Linear rails are found in a wide variety of applications across a spectrum of industries, ranging from manufacturing and automation to robotics and 3D printing.
Types of linear rails
Linear rails are designed in multiple configurations, each with their own unique characteristics and properties. They can be tailored for varied tasks and applications but they fundamentally achieve the same thing. Linear rails are designed so that they’re compatible with two types of common carriage bearing mechanisms:
Ball bearing carriage: This device contains recirculating ball bearings in the carriage, ensuring a smooth and low-friction movement. Widely adopted for their reliability and cost-effectiveness, ball bearing linear rails find applications in industries ranging from manufacturing and automation to packaging.
Roller bearing carriage: Roller bearing carriages, as the name suggests, replaces ball bearings with rollers. This design enhances load capacity and allows for smoother motion over longer distances of the linear rail bearing. Industries dealing with heavier loads and longer travel distances often opt for roller compatible linear rails to ensure stability and durability.
Below is a selection of other linear slide rails, carriages, bearings and shafts from our range.
Linear Guide Rail
- For use with recirculating ball carriages
- Offers higher load capacity
- Cost effective
- Rigid and precise
- Available in multiple sizes and lengths
- Material: Hardened and ground steel
Flanged Carriage - Standard
- Retained ball cage allowing the carriages to be removed from the rail without the balls falling out
- Highly accurate
- Handles high-load capacities to provide smooth, consistent linear motion
- Material: Hardened and ground steel
Linear Compact Rail
- Raceways are hardened and ground
- Often used in pairs to allow for misalignments
- Designed for use with roller bearing carriages
- Material: Carbon steel and electrolytic zinc-plate (excluding the raceway)
- Variety of sizes available for different load capacities
As well as linear rails, linear shafts can be used for specific applications and come in different shapes, sizes and materials. They’re often used for low-cost applications with simple designs and light loads. However, it’s essential when choosing the right product that you know exactly what type of application is suitable.
To help you understand more, our experts have put together the guide, How to Select the Ideal Linear Shaft for Your Application.
Hardened Stainless Shafts
- Corrosion resistant hardened stainless steel
- Suitable for use with linear bearings
- Tolerance: H6
- Available in steel
However, when selecting a linear shaft for your application, it's crucial to consider the type of linear bushing or bearing that complements your specific needs. The different types of linear bearings and rails play a vital role in reducing friction to offer a smoother glide.
To learn more, see our guide, How to Select the Right Linear Bushings for Your Application.
Closed Linear Ball Bushings
- For use with hardened shafts only
- Ball bearings circulate between the inner and outer races, providing smooth, linear motion
- Withstands temperatures from -20°C to 80°C
- Ideal for applications that require frequent changes or fine adjustments, such as 3D printing machines, CNC machines and automated manufacturing processes
- Material: Hardened and ground body made of bearing steel; stainless steel
Common applications of linear rails
Linear rails offer an effective solution to applications requiring movement. They’ve become indispensable components in a wide range of industry applications but load capacities, rigidities, and accuracies can alter depending on the environment they’re used in. Let’s cover them below:
| Application | Description |
|---|---|
| Manufacturing and automation | Perfect for assembly lines and robotic systems. Linear rails support the movement of components throughout the working environment, simultaneously increasing productivity. |
| Computer Numerical Control (CNC) machining | In CNC machining where cutting, milling and drilling are used for shaping materials, linear rails are an essential component. They provide a smooth and consistent motion allowing intricate designs to be made. |
| Medical equipment | From robotic surgical equipment to diagnostic machines, linear rails are essential. Offering unparalleled smooth and controlled movements, the high precision needed for these machines to operate are vital. |
| 3D Printing | 3D printing requires vertical and horizontal movements when creating products. Linear rails are essential to achieve this, but also offer precision, accuracy and reliability, as 3D designs can be intricate pieces of work and often rely on repeatable motions. |
What are the benefits of using linear rails?
When it comes to precision motion in mechanical systems, the choice of a guiding mechanism is pivotal. Linear rails stand out as a preferred solution for multiple reasons, outshining alternative mechanisms with their unique set of advantages. Let’s take a closer look:
Durability:
Linear rails are durable, which is important when you need stability for heavy loads or fast movements. The design, especially in rails with many rolling elements, helps reduce any bending in the linear guide bearing block.
Precision:
Linear rails ensure accurate and reliable positioning of moving components along a linear path. With tight manufacturing tolerances, linear rails minimise errors in positioning, allowing for consistent performance even under heavy loads and varying operating conditions. Their role in maintaining smooth, stable motion and resisting deformation ensures that mechanical systems can achieve the necessary precision.
Low friction, high efficiency:
Using rolling mechanisms in linear rails decreases friction by a huge amount, compared to sliding mechanisms. This means the movement is smoother, there's less wear and tear, and the whole system works more efficiently. Recirculating ball systems have even lower friction and higher efficiency.
Long service life:
Linear rails are made to last, which makes them stay in service for a long time. The careful design, along with sturdy materials like steel or aluminium, helps linear rails handle continuous use without wearing out quickly. This lasting quality is essential because it helps cut down on maintenance expenses and boosts the overall dependability of the system.
Versatility across industries:
Linear rails are used in many different industries, showing how versatile they are. They work well in guiding tools for CNC machines, helping 3D printers move, and ensuring precision in medical equipment. Linear rails can easily fit into different environments, making them a top choice for engineers and manufacturers.
Consistency and repeatability:
Linear rails are exceptional at ensuring consistent and repeatable movement. This is useful in tasks where you need to copy detailed patterns or duplicate components. Because linear rails are consistently reliable, they make manufacturing with them far more efficient than anything else.
Questions?
We’re always happy to help. If you need advice about our range of linear rails, email us at sales@essentracomponents.co.uk or speak to one of our experts for further information on the ideal solution for your application 0345 528 0474.