Mobile robots operating in outdoor and industrial environments face many technical challenges when precision positioning is required. These autonomous systems must navigate unpredictable terrain while maintaining exacting accuracy for tasks like marking, measurement or material placement. The key to achieving this precision often lies in onboard gantry systems that can compensate for the limitations of wheeled or tracked mobility platforms.
Building gantry systems for mobile robots presents unique engineering obstacles, however. The systems must withstand harsh environmental conditions, operate in confined spaces and maintain sub-millimeter precision, all while running maintenance-free for long periods in remote locations.
One solution lies in linear motion systems that incorporate dry-running, self-lubricating motion plastics.
The Technical Challenge: Precision in Motion
Mobile robots in industries ranging from construction to agriculture require onboard positioning systems that can make fine adjustments while the platform operates in challenging conditions. Multi-axis gantry systems working with GPS, vision systems or other sensors enable these robots to achieve positioning accuracy that exceeds what the mobile platform alone can deliver.
Depending on the application, these gantry systems must also operate reliably in extreme and variable environmental conditions, including high-temperature environments, cold climates, sandy, dusty or muddy terrain, and exposure to wind-blown debris and contaminants
Conventional ball bearing systems and lubricated linear guides struggle in these applications for several reasons:
- Contamination susceptibility: External lubricants attract dirt, dust and debris, leading to accelerated wear and system failure.
- Maintenance requirements: Traditional systems require regular cleaning and relubrication — impractical for autonomous robots operating in remote locations.
- Environmental sensitivity: Moisture, temperature extremes and contaminants can cause corrosion and performance degradation in standard bearing materials.
- Accuracy degradation: As contamination builds up or components wear, positioning accuracy deteriorates over time.
Opportunity When Traditional Ball Bearings Fail
The igus drylin SHT linear guide system addresses this combination of challenges through its innovative material engineering and design. Part of a broader product range, the system is an ideal choice for applications where traditional ball bearings may fail due to exceptionally demanding environmental factors.
A key feature of the drylin SHT that makes this possible is its material composition. The system uses self-lubricating plastic nuts made of iglide J that run against cold-rolled stainless steel lead screws. The self-lubricating plastics eliminate the need for external lubrication that would attract additional dirt and debris, while the stainless steel components resist corrosion from moisture and chemicals. Together, this combination maintains high accuracy — even when sand, dust and mud would clog conventional systems.
iglide J material for maintenance-free bearing points.igus
In addition, the system's “turn-to-fit” feature supports manual clearance adjustments in 0.01-mm increments, ensuring optimal positioning accuracy even as conditions change throughout a project.
Benefits for Mobile Robot Applications
The SHT linear guide system delivers multiple advantages for mobile robotics:
- Maintenance-free operation: The self-lubricating nature of the plastic nuts eliminate the need for external lubrication, reducing maintenance needs and ensuring consistent performance in environments where traditional lubricants may attract dirt and debris.
- Dirt and debris resistance: The system’s components are resistant to dirt, dust and corrosion, making it suitable for construction environments with high levels of dirt and debris. Additional applications that would benefit from this feature include the automotive, food processing and marine industries.
- High durability and longevity: The system’s components are lab-tested under various conditions, guaranteeing it can withstand the rigors of harsh environments without compromised functionality.
- Versatility and customization: The drylin SHT can be customized to meet specific application requirements. Users can select from various shaft materials, thread options and clearance adjustments to tailor the system to their needs, ensuring it can be used in a wide range of applications — from medical devices to heavy-duty industrial machinery.
drylin SHT linear module.igus
Max Wahle is a Product Manager for Linear Actuators with igus. For more information, visit www.igus.com.
