Guias de esferas
Guias de esferas
Rotary Stroke Bearings in Machine Building
 Conversion Line Starlinger ad*starKON 60

Rotary Stroke Bearings. The complete solution.

The ad*starKON 60 from Starlinger is a state of the art conversion line to produce sacks from a fabric hose in a continuous production process. To form the bottom of the sack there are pressure pads driven by pneumatic cylinders and toggle levers. Each of the pressure pads is guided by two Mahr rotary stroke bearings in a parallel alignment.  


Andreas Baci, design engineer at Starlinger, explains: ‘Mahr provides the rotary stroke bearing as a complete solution, a set exactly adjusted to our machine. With rotary stoke bearings from Mahr we improved our results significantly compared to the formerly used roller cages.’

Pressure pad with Mahr rotary stroke bearings (Photo: Starlinger)

More design freedom 

Mahr is well known for their measuring tools and metrology systems. With the same precision they produce the guide bushes of the MarMotion high-precision rotary stroke bearings. In the catalog program, depending on their needs the users can find guide bushes with different kinds of sealing, e.g. to protect the bearings from coolants in a machine tool. A reliable sealing is very important for the use in the Starlinger conversion line, because the machines are running worldwide under various climatic conditions and in dusty environments. 
The rotary stroke bearing gives more freedom to the design engineer. It is not limited to the use as a linear guide, but can also be used for rotary motion. Even for combined linear-rotary motions the rotary stroke bearing proved its suitability. Different guiding tasks can be handled by only one bearing. 
Most commonly used is a ball cage made of brass. In ball cages from Mahr the balls are arranged in a helical formation. Thus, each ball is running on its own track for both linear motion and pure rotation. Starlinger choosed a ball cage made of plastic, which is also available from Mahr. This type of ball cage has a high resistance against abrasion and because of the lower mass these ball cages are suited for higher accelerations. The plastic ball cages are available as combinable elements that can be joint together to the required length. This allows to make long ball cages for long stroke paths at a low price.

Optimized preloading for highest guiding precision

Mahr recommends to order the rotary stroke bearing as a complete set consisting of guide bush, ball cage and guide shaft. The rotary stroke bearing is paired at the factory with a preloading optimized for a certain application. This results in a combination of high loading capacity and perfect guiding precision together with a minimized friction. The rotary stroke bearing requires low maintenance and provides a long service life. There is no need for difficult adjustments during installation. High-precision rotary stroke bearings perfectly fit in with machine tools, positioning and handling systems or grippers, measuring probes or optical devices.

In the Starlinger conversion line the rotary stroke bearings are running in 3-shifts with highest reliability and thus help to avoid expensive machine down-times in the production. Plastic sacks made of fabric provide high endurance and resistance to wear. They can be used for a wide range of applications with excellent cost efficiency. These features they have in common with high-precision rotary stroke bearings from Mahr.

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