Optimal use of linear ball bearings and linear bearings in guide systems with the highest precision

Linear guide systems are characterized by low-friction motion and the ability to absorb lateral forces without being severely deformed. Linear ball bearings and linear bearings are used in guiding systems where precision, long life, and maintenance-free operation are essential.

What is a linear bearing?

A linear bearing is a type of bearing that allows an object to be moved in a straight line. It is probably the most common type of bearing used in many industrial applications to move an object in a linear motion. Linear bearings consist of elements that contain sliding surfaces or rollers and/or balls as rolling elements, which run between two guide bars or a segment of a rail that serves as a guide.

What are the features and structure of linear motion?

Linear motion is a type of motion in which an object or system moves along a straight line. It describes a simple straight-line movement without considering other descriptive factors of the movement such as speed, etc.

Properties:

• A linear, straight-line motion
• Speed not equal to 0
• No change in direction of movement

Structure:

• Speed: The speed is the rate at which an object is moved in a particular direction.
• Acceleration: Acceleration is the change in the velocity of an object in a particular direction.
• Distance: Distance is the distance an object has traveled in a particular direction.
• Position: Position is the place where an object is located in a particular direction.

Properties of Linear Ball Bearings

Linear ball bearings are highly accurate, linear rolling bearings. They consist of a number of balls guided in a sleeve or track. The balls are arranged on the outside of the bearing sleeve and run on a hardened steel raceway. This raceway can be made of a variety of materials, including steel, cast iron, aluminum and plastic. Linear ball bearings have a high degree of precision and are suitable for a wide range of applications.

For more information, check out our blogs Linear ball bearings – Selection, installation and maintenance and Benefits of precise linear movements: everything about linear shafts

Applications of Linear Ball Bearings

Linear ball bearings are used in a variety of industrial applications. They are commonly used in machines, machine tools and robots to ensure high precision and long machine life. Unlike ball bearings, which are used to support rotating elements, linear ball bearings are used to guide linear motion.

Advantages of Linear Ball Bearings

Linear ball bearings offer a number of advantages. They are robust and durable and can be used at high speeds. They are very reliable and allow linear guidance with high precision. Because of their quality, they are suitable for guiding highly accurate linear movements. Other advantages of linear ball bearings include low weight, low noise, and low maintenance.

Different types of linear ball bearings

Straight linear ball bearings are usually suspended by a longitudinal support that holds the balls in a straight line on a flat surface. They are often a substitute for traditional ball bearings in applications where very high precision and accuracy are required.

Flanged linear ball bearings are mounted between two flanges attached to both ends of the linear ball bearing. This allows linear movement of a linear ball bearing. Flanged linear ball bearings are more robust and have a longer service life than straight linear ball bearings.

How to install straight linear ball bearings

Straight linear ball bearings can either be embedded in a bearing housing or placed directly in the support structure of the machine body.

If the linear ball bearing is used in a block shape, i.e., as in a fully configured bearing block, there are some advantages. Different standard shapes and various configuration options of these bearing blocks make the integration of linear ball bearings into new or existing systems much easier. The installation of the block form variant can also be used to compensate for a radial offset between the machine housing and the linear guide.

After placing the straight linear ball bearing in the bearing block or machine housing, it is held in position relative to the housing with either a retaining ring (or clamping ring) or a stop plate.

Once you have installed the linear ball bearing, you can use it in your applications. Be sure to check and maintain it regularly to make sure it is working properly.

Positioning and Internal Load Distribution

Linear ball bearings should be positioned wherever possible so that the load does not rest directly on a row of the ball guides arranged in the linear ball bearing, because the unfavorable load distribution affects the performance of the linear ball bearing. If instead the linear ball bearings are placed so that the direction of the load acting is exactly between two rows of the ball guides, the load distribution on both rows of balls significantly reduces the load on the bearing.

For more information on how to install linear ball bearings, please refer to our blog Linear ball bearings – Selection, installation and maintenance.

More linear motion options - linear slides, maintenance-free bushings

Linear slides and maintenance-free bushings are another way to enable guided linear motion. They enable smooth, silent and precise motion in high load applications.

Linear Slide Guides

In a linear slide guide, no rolling elements are used between the guide and linear bearings. The surfaces of the linear bearing and linear shaft or linear guide profile slide together.

Linear slides allow for very precise linear motion. They consist of a rail profile mounted on a guide profile. Linear slides are suitable for high loads and moderate speeds. They are usually require less maintenance than guide systems with linear ball bearings.

You can also find further information on this topic in our blog Profile rail guides – Types / function / service life / maintenance / alternatives.

Maintenance-free plain bearing bushings

Maintenance-free plain bearing bushings are easy to install, require little or no maintenance, and provide long service life. They are suitable both for supporting rotating elements and as linear guide bearings. At the same time, maintenance-free slide bushings are very reliable and can also be used in harsh environments. Depending on the application and the amount of load and temperature expected, they are made of a metal alloy, plastic or a composite material.

Maintenance-free bushings are also suitable for higher loads due to their better load distribution compared to linear ball bearings. Due to their simple design, they are also usually less expensive and require less maintenance than linear ball bearings. For a deep dive into plain bearing bushings, see our blog Plain bearings in practice: selection and assembly.