What is the difference between static and dynamic load capacity for linear rails?

Understanding the load capacity of any structure in an engineering environment is paramount, and is a standard consideration during the design phase. Linear rail loads are no exception, but it is important that the dynamic load capacity is the calculation used when designing a linear motion system which involves linear guide rails in order to avoid a catastrophic failure when the linear rails and their associated actuators are put to use.

How are linear rail loads important in linear motion design?

Linear rails have two parallel tracks that contain rollers to support a moving load, providing guidance and support for a load carried by an actuator between two points. Linear rails are used in a whole range of applications and can carry loads that vary from extremely light electronic components, through to large loads weighing thousands of kilograms in heavy industry.

Understanding the intended purpose of the linear rails, including the size of the load, the load weight and the speed and nature of the movement is critical to selecting the right linear guide rails for the application.

What is the difference between dynamic and static loads?

Static loading is the load on an actuator when it is in a fixed position. Static loads are independent of time. For instance, any dead load on a structure is a static load. 

However, a dynamic load is the load the actuator handles when activated and in motion. The dynamic load capacity of an actuator refers to how much work the machine can do and how much can be pushed or pulled. When calculating a dynamic load capacity for a linear rail, it is essential to encompass acceleration and deceleration of the load and the time of the motion. An example of this would be to say that it’s the difference between gently resting a bowling ball on a floor and dropping a bowling ball onto a floor.

How is load capacity calculated?

Load capacity is the maximum allowable force applied to a structure in a specified direction while meeting the integrity requirements. This maximum force usually includes static (mass × gravity) and dynamic (mass × acceleration) forces.

Why is it so important to calculate dynamic load capacity for linear guide rails accurately?

A linear rail system that hasn’t considered dynamic load capacity during the design phase will likely fail catastrophically in application. It could range from a loss of precision through increased friction or binding of the linear rails due to deformation to total structural integrity failure, damaging both the actuator assembly and the product and any bystanders.

Find linear rail solutions at Matara

Matara offers a wide range of linear rail options, from miniature or compact to wide types and varieties designed for heavy linear rail loads. We can cut linear rails to length to suit your overall structure design. The dynamic load capacity is critical when selecting the right linear guide rail for your application.

Be sure to trust Matara to find the perfect linear motion solution for you. If you have any questions, contact us; a team member will be happy to help. If you want to learn more about linear rails, check out our technical articles and case studies.