Linear bushing for handling and automation

The technology of linear bushing as motion elements in many different types is used in high-precision motion applications, such as automation of transfer, assembly machinery, CNC machines, 3D printers, and locating. With various designs, modifications, and abundant sizes these elements can meet all applications and demands in a particular industry.

The motion elements are applied in the axial direction, while they are making rolling contact with linear schafts, that are available to purchase in a specialized online store Tuli. A web store offers components that are made with a tolerance class of H6 and have induction hardened surface from 58 to 62 HRC, meanwhile having a soft and tough base.

Linear bushing in main characteristics

Ball-bearing motion elements have a medium load capacity. When a machine is using these types of elements that they move on linear schafts, then both ends support a heavy load. This also results in higher friction, as two surfaces are sliding against each other. On the other hand, it can come to low frictional resistance when the steel balls are precisely guided by the cage. Stick-slip does not occur as the static and dynamic frictions are very low, even if the element is used with grease lubrication, oil lubrication, or without any lubrication.

Linear bushing LME LUU
Linear bushing LME presents most popular linear bearing in Europe

The other characteristic is that a motion element has a medium to high guidance accuracy that mainly depends on the clearance of bearing or a rail. It also requires medium to high maintenance. The advantage is that the tools are low in cost. The straight or linear bushing has a compact design with an integrated structure and hardened flanged outer cylinder.

Linear bushing with two types of installation

Straight ball bearing can be installed with two different installation parts, such as a retaining ring and a stopper plate or fixing plate. When installing, it is advisable to consider the bearing rows and dynamic load rating, as load position on the circumference can vary. Angle load on a linear bushing need to be installed according to rows or ball tracks and recommended housing inner-diameter tolerance.

Linear bushing LM/LME UU
These types of linear bearings are widely used in different linear motion applications

When securing the motion element with snap rings or stopper plates, it doesn’t require a large amount of strength. There is also a difference when installing a flanged type element, a clearance-adjustable type, or when mounting an open type. When inserting linear schafts, it is needed to align the center with the nut and insert it straight into the nut, while being careful that the retainer stays in place and that the balls don’t fall out.

Coated linear schafts and their hardness

Rod-shaped and elongated linear schafts provide motion for power transmission applications. Some of them have radial or axial holes that support structures when mounting or are grooved to place them with snap rings. There are different types, as solid or hollow elements with stepped or chamfered ends. Mostly there are made from aluminum, composite materials, alloy, carbon, and stainless steel, or even plastics.

These materials provide durability, corrosion resistance, electrical and thermal conductivity, and more. To improve durability, the linear schafts are also coated mostly with the process of anodizing, and with black oxide, ceramics, nickel or nitride coatings. Elements are also hardened to improve durability. Hardness can be measured in different ways, such as with Knoop hardness and Rockwell hardness test. When purchasing this motion element, it is good to know the specifications, such as weight, height, tolerance, length, and width, or diameter.

Different types of ball bearing linear bushing

There are many different types of ball bearings. For example, a clearance-adjustable model has a standard nut with a slit in the direction of the linear schafts, while the open type model has a nut with an equal cut to the width of one row of ball bearings. The flanged round type can be easily mounted as the spine nut can be attached to the housing. Flanged type can also have a square shape at one end that is flattened on four sides.

In the specialized online store Tuli it is possible to purchase an economy, standard, open, double, and flanged linear bushing. The web store also offers motion elements in type KH with compact dimensions, type LME with metal shield housing, and open type. Each product has listed specifications and prices.