Linear guides are linear assemblies that have twin parallel tracks that contain load-bearing balls or rollers. For many industrial applications, it is very important to provide low friction and high rigidity for loads ranging from a few grams to thousands of kilograms. Due to their size, accuracy classes, and load capacity, linear guides meet virtually any requirement. There are many reasons for using linear guides, but the most obvious advantages over other types of guides are load capacity, travel accuracy, and rigidity.
For example, round guides can only withstand downward and upward loads, while linear guides can withstand both downward/upward loads and momentary loads. And unlike crossed roller guides, where the movement is limited to up to 1 meter, linear guides can provide very long travel lengths. In addition, linear guides have greater rigidity and often have better load/life characteristics.
Linear guides from the company Tuli d.o.o. also provide a high level of travel accuracy thanks to the precise machining of one or both edges of the rail, which act as reference surfaces. With two, four, or six rows of rolling elements, the stability is also high and the deflection of the bearing block is minimal. Together, these features result in a linear guide system that is perfectly suited for applications requiring high accuracy, high rigidity, and long life.
Advantages of using linear guides:
1) They are efficient as they offer low friction and high rigidity for loads ranging from a few grams to several tons. The size and precision range allow linear rails to be used for almost any requirement in the industrial sector.
2) More reliable and bigger load options – linear guides withstand both tensile loads and torque. Similarly, linear rails can provide very large travel length, unlike round guides, therefore they can provide more options for their usage.
3) It is especially important that the linear rails/guides provide very precise movement, so in an application where accuracy, stability, and long life are important, this is the best option recommended by professionals.
Costs related to linear guides:
The cost of the frame in which the linear guide rail is to be mounted depends on its use. By definition, there are precautions that we need to take if we want to use that particular linear guide rail as much as possible. For example, linear guides must be installed in a clean environment and kept clean to protect guideways and bearings. Due to the accumulation of dust and other contaminants, the given guide rail can also lose the lubrication level, so we can increase the service life by ensuring continuous lubrication.
Of course, the price of linear guides also depends on what size we need or what material they are made of, since in case of higher load capacity demand, the bigger roller is necessary and, of course, more expensive. In terms of costs, maintenance costs should also be mentioned, which also depends on the frequency of use, the degree of contamination and the environment, but most manufacturers, such as Tuli, also sell linear guides with minimal maintenance requirements.
Use cases of linear guides
Linear actuators – In case of gear units driven by belts or even pneumatic cylinders, linear guides are often used as a guide mechanism as they are also able to withstand moment loads. Their travel speed can reach up to 5 m / sec, which is especially important in such systems.
Overhead transport – If the load is transported under the rail, as is often the case with overhead transport systems in industrial use, linear guides/rails are a good choice. Their high load capacity allows the transport of heavy loads, and the rigidity of the linear rail promotes the stability of the entire system.
Linear stages – These types of platforms are very high precision systems, which means that high travel accuracy and minimal deflection are paramount. Even if the load falls in the middle of a given platform, it is advisable to use a dual rail system to ensure even greater stability.
Machine tools – Like linear stages, machine tools require very high travel accuracy and stability for the tool to produce high quality parts. The parallel use of two rails – usually with two bearings per rail – ensures that deflection is minimized. Machine tools receive very high loads, so adjusting additional bearing blocks increases stability.
Robot transport units – Six-axis robots provide flexible movement for applications that require multi-directional rotation. But if the robot needs to move to another workstation, two-rail systems can act as a “seventh axis” and move the robot to the other workstation. A significant advantage of linear rails in these applications is the ability to connect a large number of rails to achieve a quite big travel length which can be 10-15 meters as well.
In use, it should also be considered to use a linear guide (like the Tuli linear rail guides) consisting of one or two rails. Because linear rails have load-bearing balls (or rollers) on each side of the rail, they can withstand high loads, even if only one rail is used. As a result, many applications use a single linear rail to save space or prevent problems with discrepancies between other system components. For high torque loads, linear rails can be used in pairs, allowing the load to be distributed across the bearing blocks. In this configuration, the drive mechanism can be mounted between the linear rails to obtain a compact system.
Of course, there are also use cases for which the use of linear guides/rails may not be the best. For example, linear guides are generally not suitable for use in a consumer space, for example for doors, often due to cost. Linear rails require very precise mounting surfaces, not only to take advantage of the high accuracy, but also to avoid jamming of the bearing block, which can reduce service life.