Portal linear units HSB-gamma®
with toothed belt drive or rack-and-pinion drive

Our HSB-gamma® portal linear units are the classic drives for creating a wide range of multi-axis systems.

A closed and highly rigid aluminium profile which we have developed ourselves is the basis for every HSB-gamma® linear unit. Powerful ball guiding rails ensure high load capacities. The profiles are precisely machined on all mating faces for use with ball guiding rails.

HSB-gamma® linear units are currently available in 5 sizes - from HSB-gamma® 90 to HSB-gamma® 280. In order to satisfy the range of options demanded in practice, various drive variants are offered here as well.

Drive variants

1. Toothed belt drive

Application area: for low and medium feed forces involving long strokes. We use toothed belts as drive components for low to medium precision. The version used is either the ZSS, which features a circulating toothed belt, or the ZSSD, which features two independently travelling carriages.
Our ASS/ASH versions with a powered carriage are fitted with an omega drive.

The ZSS version with circulating toothed belt and drive at the profile end is used for all standard applications where the position of the profile is fixed and the carriage moves, even in the case of long strokes.

The use of the ASS version may be appropriate in the context of very long strokes and if the elongation of the toothed belt poses a problem.


The ASH version is primarily used where the profile moves along a boom and the position of the carriage is fixed. This drive is used especially for applications as the Z-axis in multi-axis systems. The carriage plate is optimised such that it can easily be installed directly on the carriage of a ZSS or ASS.

Our ZSSD version is a special variant of our ZSS in which two carriages are each driven independently by a dedicated toothed belt.

2. Rack-and-pinion drive

Our rack-and-pinion drive is used for all applications where greater feed forces are required, or where the elongation of a toothed belt is undesirable. Different rack-and-pinion drives can be installed.

As standard, we use helical, inductively-hardened racks in conjunction with case-hardened and milled drive pinions.

The AZSS variant is the standard version and is predominantly used in horizontal applications.


The AZSH variant only differs from the AZSS variant in the shape of the carriage plate. This is configured so that direct installation as a vertical drive on a unit of type AZSS is possible without an intermediate plate.

Guide variants

Profile guide

Our linear units with ball guiding rail are suitable for medium to heavy loads. They have low friction but are nevertheless very stiff. It permits high speeds up to 5 m/s. Their accuracy lies in the precision range.


common product specific information HSB-gamma®