CMH type with ball-screw drive.

NIASA CMH rodless mechanical cylinders can form part of almost any type of machinery, as long as it exercises linear forces or moves one or more axes in a controlled manner. They are used separately, or combined with each other, given the multiple possibilities of combination offered.

Basically, they are mechanical elements that convert rotating entry movements into linear exit movements. They are characterized because their carriage (the element that exercises the force on the machine) is actioned by a nut, which in turn is pushed by a screw that turns.

Each carriage is fitted with either a single ballscrew nut (M), or a trapezoidal nut (TR) depending on desired speed, precision, work cycle, etc. (consult NIASA), and are supported by bearings on their ends. The carriages are mounted on a prismatic linear bearing rail that is fitted inside an extruded aluminum body. The set is protected from the exterior by the profile itself, its walls and a fastening band that crosses the cart in its movement, thus protecting the most critical part of the system.

When the loads and or times are important, the cylinders can include more than one carriage and/or complimentary prismatic guides can be added, with the aim of making the set more resistant.

Below is a list of some cases where rodless mechanical cylinders are applied, as well as the type of task that they perform.

Where a linear force is required:

• As a drive for feed mechanisms.

• As a transport device.

• As a head drive for industrial robots.

• As a positioning drive for industrial robots.

• …

Where movements are required in one axis:

• Positioning of material on saws, presses, shears, etc.

• Indexing of long parts for instance drilling of profiles etc.

• As a drive for bearing mounted loads requiring a controlled speed.

• …

Where movements are required in two or more axes:

• Parallel or crossed mounted table systems.

• Three axis positioning systems.

• Manipulators with numerical control.

• …

CMK type with a toothed belt drive.

Conceptually they are similar, but the difference compared with CMH type rodless mechanical cylinders is that the NIASA CMK is distinguished because the carriage is mounted on a linear bearing that is driven via a steel braided toothed belt.

This type of transfer enables linear speeds of up to 5 m/s to be reached, which is comparable to those offered by pneumatic cylinders, although with the advantage of being able to carry out an almost infinite number of intermediate stops on the run, with total control of speed and positioning.

These types of cylinders do not offer the precision of the CMH type, although in multiple applications it is sufficient with a positioning precision of around 0.3 mm, which can be achieved by this version. This is usually the case with handling machinery, mobile buffers for stores and shears, palletizers, painting equipment headers, and an unlimited number of additional applications.