Choosing the right linear bearing system is essential for reliable, accurate and long-lasting linear motion. But with several different technologies available, selecting the right solution isn’t always straightforward.
Linear bearings, motion guidance, vee bearings, track guidance and combined roller bearings each have different characteristics and advantages. The best choice will depend on factors such as load, speed, accuracy, operating environment, available space and the design of the application.
At Euro-Bearings, we supply all five types of linear motion products and can help customers select the most appropriate system for their application.
1. Linear Bearings
Linear bearings, or ball bushings, are a well-established solution for linear movement. They typically run on hardened and ground round shafts, with recirculating balls providing smooth, low-friction movement.
They are a popular choice for applications requiring:
- Smooth, low-friction movement
- Good accuracy
- High travel speeds
- Compact installation
- Cost-effective linear motion
Linear bearings are widely used in automation, machinery and general industrial applications.
For applications where the load, environment and accuracy requirements are relatively straightforward, a conventional linear bearing can provide an economical and effective solution. Stainless steel options are available.
2. Motion Guidance Systems
Motion guidance systems use a carriage running along a profiled rail. Unlike a conventional linear bearing running on a round shaft, the carriage and rail form an integrated linear guide system.
Recirculating balls run along precision raceways in the profiled rail, providing smooth and accurate movement with high rigidity.
Motion guidance systems are particularly suited to applications requiring:
- High accuracy
- High stiffness
- Smooth movement
- Good load capacity
- The ability to accommodate moment loads
- Compact linear guidance
They are commonly used in automation, machine tools, positioning systems and other applications where precise linear movement is important.
The profiled rail provides a rigid and accurate guidance surface, while the carriage can be mounted directly to the moving component. For precision applications, a motion guidance system may therefore be preferable to a conventional ball bushing and shaft arrangement. Also available in aluminium for applications requiring corrosion resistance.
3. Vee Bearings
Vee bearings use a V-shaped running surface that engages with a matching Vee rail or track.
This provides a simple and versatile approach to linear guidance and can be particularly useful in industrial environments where robustness and resistance to contamination are important.
Vee bearing systems can offer:
- Robust construction
- Good load capacity
- Low friction
- Long travel capability
- Resistance to contamination
- Flexible mounting options
One of the main advantages of Vee bearing systems is their flexibility. The rails can often be incorporated directly into the machine structure, allowing the guidance system to be designed around the application.
Vee bearings are suitable for a wide range of applications, including machinery, automation and material handling. They can be particularly attractive where a robust and relatively simple guidance system is required. Both steel and stainless steel options are available.
4. Track Guidance
Track guidance systems provide smooth and accurate linear movement using track bearings running along precision-ground rails. A key advantage of this system is the use of fully sealed, double-row ball bearings, which are much less susceptible to contamination than open recirculating-ball systems.
This makes track guidance particularly interesting for industrial applications where dust, dirt or other contaminants could affect conventional linear guidance.
The system combines an anodised aluminium extrusion with a steel or stainless-steel shaft, providing a lightweight yet robust guideway. Both open and closed carriage designs are available, giving engineers flexibility when integrating the system into a machine.
Track guidance systems can be used in a wide range of applications, including:
- Automation
- Industrial machinery
- Measuring devices
- Long-travel systems
- Applications exposed to contamination
The track bearings are sealed for life, while the carriage can incorporate lubrication and wiper elements to help keep the guideways clean and lightly lubricated.
For applications requiring corrosion resistance, the system can also be specified with stainless-steel bearings and shafts.
With its combination of sealed bearings, precision-ground running surfaces and lightweight aluminium guideways, track guidance provides a durable and versatile solution for industrial linear motion which is quick and easy to install.
5. Combined Roller Bearings
Combined roller bearings provide a robust solution for heavy-duty linear motion and are particularly useful where high loads and forces in different directions need to be accommodated.
A combined roller bearing incorporates radial and axial rollers in one unit. The radial roller carries the principal load, while the axial roller provides lateral guidance against the rail.
This allows the bearing to support the load while simultaneously controlling the movement of the carriage.
Combined roller bearings are particularly useful for:
- Heavy loads
- Radial, axial and moment loading
- Cantilevered applications
- Horizontal and vertical movement
- Telescopic systems
- Harsh industrial environments
A key advantage is their tolerance of dirt and contamination. Their robust construction makes them particularly suitable for industrial applications where dust, dirt and other contaminants could affect more sensitive linear guidance systems.
They can be used with profiled steel rails in horizontal, vertical and telescopic arrangements. A simple system can consist of two rails and four bearings, while more complex configurations can be designed for larger loads and longer travel.
Euro-Bearings has extensive experience with combined roller bearing systems and can assist with bearing selection, load calculations, rail configuration and bearing spacing.
Key Benefits at a Glance
Each linear bearing system has its own strengths:
- Linear bearings: smooth, economical and well suited to general-purpose applications.
- Motion guidance: high precision, rigidity and accuracy.
- Vee bearings: robust, compact and resistant to contamination.
- Track guidance: durable, quick to install and well suited to long-travel industrial applications.
- Combined roller bearings: heavy duty, multi-directional load capability and excellent tolerance of dirt and contamination.
The most suitable system will depend on the specific requirements of the machine, including its load, speed, accuracy and operating environment.
What Should You Consider When Selecting a System?
Before choosing a linear bearing system, consider five key factors.
- Load
Determine the total load and how it will be distributed across the bearings. Off-centre and cantilevered loads can create significant moments and change the load carried by individual bearings.
- Speed and Duty Cycle
Consider the maximum speed, acceleration, travel distance and number of cycles. A system designed for occasional movement may not be appropriate for continuous, high-speed operation. Recirculating ball bearings are capable of higher speeds than track bearings.
- Accuracy
How accurately does the moving component need to be guided?
For precision positioning, a profiled motion guidance system or linear bearing may be appropriate. For less demanding applications, track bearings may provide a more economical solution.
- Operating Environment
Dust, dirt, moisture and other contaminants can have a major effect on bearing performance.
In a clean environment, a conventional linear bearing or motion guidance system may be ideal. For harsher industrial environments, Vee bearings, track guidance or combined roller bearings may be more appropriate.
- Space and Installation
Consider the available space, mounting surfaces, alignment requirements and future maintenance.
The most suitable system isn’t necessarily the smallest or cheapest bearing. The complete installation, including the rail or shaft and mounting arrangement, needs to be considered.
Choose the Right Solution with Euro-Bearings
Selecting a linear bearing system can be challenging when an application has unusual loads, limited space or demanding operating conditions.
Euro-Bearings supplies a comprehensive range of linear motion products, including linear bearings, motion guidance systems, Vee bearings, track guidance and combined roller bearings.
Our technical team can help with product selection and application advice, whether you are designing a new machine or replacing an existing bearing.
If you’re unsure which system is right for your application, contact Euro-Bearings with details of the load, speed, travel, operating environment and available space. If you’re replacing an existing component, photographs, dimensions or the original part number can also help us identify a suitable solution.
From precision motion guidance to heavy-duty combined roller bearing systems, Euro-Bearings can help you select the right linear motion solution for your application.
Our Vee bearings and T-rails offer the user a simple way of constructing smooth running linear systems with a high load capacity and, in the case of the stainless steel version, corrosion resistance too. For this example we are selecting the following parts:
