Stable, clean, and precisely guided

The finished, compact axle units of the Monocarrier series enable precise guiding and feed movements in a simple manner. (Image: Dr. Erich TRETTER GmbH + Co.)

Dr. TRETTER offers the Monocarrier series, ready-made, compact axle units that enable precise guiding and feed movements in a simple manner. They combine ball screw drive, linear guide, and axle profile into one unit. This saves the user from design and assembly work. The corrosion-resistant, maintenance-free linear axis finds application in various fields – for example, in analytical technology, semiconductor manufacturing, or PCB assembly as a small machine table or as a pick-&-place unit. Under appropriate boundary conditions, they are also used in cleanrooms or the food industry.

The carriage runs with zero play in a ball track and is driven by a ball screw drive. This is supported by two angular ball bearings on the fixed side and a radial ball bearing on the free side. Since the ball track is directly ground into the axle profile, the Monocarrier achieves a level of compactness unmatched by any axle unit built from standard elements. The Monocarrier is available in two versions: as a compact unit MCM and as a compact, rigid unit MCH, with the side cheeks of the axle profile being higher. The MCM and MCH types are partly bearing-supported or relatively quickly available. In the Dr. TRETTER standard, the Monocarrier has a driven carriage, but it can also be supplied with a second, trailing carriage upon request.

The Monocarrier MCM is available in six sizes: MCM02, MCM03, MCM05, MCM06, MCM08, and MCM10. Users can choose this version with various stroke lengths and spindle pitches. For example, with the MCM02 version, Dr. TRETTER meets the requirements for smaller installation dimensions. It is extremely compact, with a width of 28 millimeters and a height of 22 millimeters.

The MCH type essentially features the same characteristics as the MCM. However, the cheeks of the base body are significantly higher. This slightly increases the mass but significantly enhances the rigidity. This allows for higher loads to be accommodated and processed more precisely. The MCH is available in three sizes: MCH06, MCH09, and MCH10.

Both types are available in two accuracy classes: the standard accuracy class “H” and the precision version “P”. “H” at Dr. TRETTER stands for handling and is primarily intended for use in handling devices. In this class, the manufacturer guarantees track parallelism to the mounting and support surfaces, position repeatability, and reversal span. The “P” precision version has tighter tolerances for these values, and additionally, a ground ball screw of class C5 is used.

Optional accessories include motor mounts, limit switches, metal covers, and, for size 10, a bellows cover. All sizes, except the spindle, are standardly black-chromed and equipped with K1 lubrication units. The lubrication unit is a self-lubricating plastic wiper that contains lubricant in its porous base material. When the carriage moves, the unit continuously supplies the necessary minimal amounts to the ball tracks. This eliminates environmental and maintenance costs associated with the supply and disposal of lubricants. Therefore, the series is suitable for environments where contamination by lubricants must be avoided.