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Table of Contents
Categories
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Adapter Sleeves (9)
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Ball Bearings (11)
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Ball Screw Bearings (2)
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Ceramic Bearings (27)
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Pillow Block Bearings (4)
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Plain Bearings (32)
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Roller Bearings (12)
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Slewing Bearings (43)
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Sliding Block (3)
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Stainless Steel Bearings (27)
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Super Precision Bearings (6)
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Thin Section Bearings (9)
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Track Rollers (4)
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Universal Joints (1)
Enhancing Performance: Key Tips For Linear Bearing Selection
Linear bearings are a key mechanical element used to support and guide linear motion in motion systems. The main principle of operation is based on reducing friction between moving parts to achieve smooth linear motion.
1. Rolling and sliding elements
- Linear bearings are mainly divided into two main categories: rolling bearings and plain bearings. Rolling bearings use rolling elements such as balls or rollers, which reduce friction by rolling and provide a large load carrying capacity. Sliding bearings, on the other hand, use sliding elements such as blocks or plates to reduce friction by sliding, and have the advantages of simple structure and low noise.
2. Construction and design
- The construction and design of a linear bearing consists mainly of an outer ring, an inner ring, rolling elements/sliding elements and a cage. The outer ring is usually mounted on a support in the motion system, the inner ring connects the moving parts, and the rolling elements or sliding elements realise relative motion between the inner and outer rings. The cage is used to hold the rolling elements in place and to ensure that they maintain a suitable clearance and relative position during operation.
3. Load carrying capacity and friction
- The key to the performance of linear bearings is their load carrying capacity and coefficient of friction. Rolling bearings provide a high load carrying capacity due to the use of rolling elements and are suitable for applications with high loads and speeds. Sliding bearings, on the other hand, have low friction and are suitable for applications with high noise and vibration requirements.
4. Application areas
- Linear bearings are widely used in CNC machine tools, printing machines, automated production lines and other fields. In these applications, linear bearings achieve efficient operation and precise control of equipment by providing reliable linear motion support.
Assessment Of Load Requirements
The performance of linear bearings is directly dependent on their ability to withstand various types of loads, so a careful assessment of load requirements is a vital step when selecting linear bearings
Static and dynamic loads
- Static load: This is a constant external force or load that is applied to a linear bearing when it stops moving. Static load assessment should take into account the equipment in the stationary state may withstand the maximum force, to ensure that the bearing can stably support the equipment.
- Dynamic loads: These are variable external forces or loads that are applied to the linear bearing when it is in motion. This aspect of the assessment needs to take into account the inertia of the system in the process of movement, acceleration and other factors, in order to ensure that the bearings in the dynamic working conditions can also effectively withstand the load.
Compound loads
- Compound load: In practice, linear bearings are often subjected to different directions and sizes of force at the same time. Therefore, comprehensive consideration of the load in each direction, a reasonable composite load assessment, is to ensure that the bearing all-round stable operation of the key.
Sudden load and shock load
- Sudden load: In some special working conditions, the equipment may be subjected to sudden and instantaneous large loads, such as starting, stopping or encountering resistance. Evaluating the bearing’s ability to withstand sudden loads is an important consideration to ensure system robustness.
- Shock loads: There are application scenarios where linear bearings may be subjected to shock loads, such as equipment operating in a vibrating environment. The bearing must be able to effectively absorb and mitigate shock forces to prevent damage.
Load distribution
- Load distribution: In the case of long linear bearings, it is necessary to consider the distribution of the load over the length of the bearing. Reasonable load distribution design helps to equalise the bearing forces and prevent local overloading.
Temperature factor
- Temperature factor: Partial loads may cause heat generation in the bearing, especially at high speeds. Evaluate the bearing’s ability to withstand the heat generated to ensure that the system can still operate stably in a high-temperature environment.
Speed And Accuracy Considerations
Speed Considerations
- Linear Speed Requirements: Linear speed requirements vary from application to application. High-speed motion systems require bearings with high linear speed ratings to ensure that no stalling or vibration occurs during motion.
- Lubrication programme: For high-speed motion, choosing the right lubrication programme is crucial. Grease selection and regular maintenance can reduce friction, reduce wear and improve bearing life.
Precision considerations
- Positioning accuracy: Certain applications require extremely high positioning accuracy, such as CNC machine tools or precision measurement systems. Choose linear bearings with high positioning accuracy to ensure that the system can stay at the target position accurately and reliably.
- Stiffness and preload: High accuracy requirements often require high bearing stiffness and preload. The rigidity of the bearing affects the rigidity and vibration suppression capability of the system, while moderate preloading helps reduce the gap and improve the accuracy of the system.
Wear Resistance And Life Prediction
The key to predicting the wear resistance and life of linear bearings is to select wear-resistant materials, optimize the lubrication system, and accurately evaluate actual load, speed and other working conditions to maximize performance and extend service life.
Consider Environmental Conditions
When purchasing linear bearings, you need to fully consider factors in different working environments, such as temperature, humidity, dust and chemicals. To address these challenges, it is crucial to select bearing materials and designs that are suitable for the specific environment. For example, choose high-temperature resistant materials and heat dissipation designs in high-temperature environments, and choose stainless steel in humid or corrosive environments. Through effective sealing and protection design, the bearings are ensured to operate stably in various environments and extend their service life.
Choose The Right Material
When choosing linear bearings, appropriate material selection is key, such as alloy steel to provide strength and hardness, stainless steel to cope with corrosion, ceramics to adapt to high speeds and high temperatures, combined with lubricating materials such as PTFE or PEEK, and effective sealing and protection designs to ensure that they can operate in different environments. for optimal performance and longevity.
References
1.More information about “Linear Bearings” from Wikipedia;
2.Understanding” Linear Bearings” from BEARINGSDIRECT
