For linear guides with long stroke lengths, selecting the correct size and configuration is critical to the system’s stability, accuracy, and service life. The system size is not chosen based on length alone, but is always determined by a service life calculation tailored to the specific application.
Service Life Calculation as a Starting Point
To determine the correct type of guide and the appropriate size, detailed application data is required. This data, provided by the client, forms the foundation for our calculations. Key factors include speed, acceleration, cycle time, duty cycle, applied loads and moment loads, mounting orientation, and the center-to-center distances between rails and carriages. The required service life of the application also plays a vital role. Only once these parameters are defined can a technically sound decision be made regarding the guidance system.
The Impact of Speed and Acceleration
Speed significantly influences the service life of a guide. Higher acceleration leads to higher dynamic loads, which directly impacts the service life calculation. Velocity is equally decisive; at higher speeds, a higher safety factor is typically applied, affecting the theoretical service life and, consequently, the required system size. An apparently minor change in speed or acceleration can therefore lead to a different choice of guidance system.
Long Stroke Lengths and Joined Rails
For applications requiring a long stroke, rails can be supplied in a joined (butt-jointed) configuration. This allows for very long travel distances, such as robot tracks with a total length of up to approximately 30 meters. With such lengths, the focus shifts even more heavily toward stability and alignment. Joined rails must be correctly supported over their entire length to prevent deflection and additional stress within the guide.
The stability of a long-stroke system depends not only on the guide itself but also on the quality of the installation. The guides must be fully supported during mounting, and the mounting surface must meet specified tolerances. Deviations in flatness or parallelism can lead to increased friction, uneven loading of the carriages, and a shortened service life. On long sections, these deviations are often amplified.
Synergy Between Design and Application
Different considerations apply to low temperatures below the standard range. Materials contract and grease viscosity increases, which in turn increases frictional force and alters the effective preload. LM Systems therefore tailors rail and carriage combinations to these specific application conditions. This includes machinery in refrigerated production environments or handling equipment in cold storage logistics, where consistent movement remains essential despite low temperatures.
LM Systems delivers every guidance system custom-configured to the maximum stroke length of your application. Would you like to know which configuration best suits your machine? Feel free to contact us for technical advice.