Siemens linear direct-drive motors, from CNC Design , are available up to rated forces of 10,375N and achieve traversing velocities of more than 800m/min. The complete series of direct-drive motors can provide dynamic performance, precision and cost-efficiency in all applications.
Current is directly transformed into motion without having to go through an intermediate mechanical step – this is the principle of operation of Siemens synchronous direct drives. Similar to a magnetic levitation train, the force is transferred without contacting. The driving force is achieved through a travelling electromagnetic field in the generally moved primary section as opposed to the magnetic secondary section. The primary section is mounted on linear guides travelling at high speed and with track precision. The force transmission elements, which are generally required for a conventional electromechanical drive, for example, gear units, ball screw, belts or rack and pinion, are no longer required.
The following are the advantages of these linear motors:
- The mounting space required is reduced
- The mechanical design of the machine is simplified
- The machine availability is increased
- The operating cost is lowered
The traversing ranges that can be achieved with 1FN3 linear motors start at approximately 20mm and their length is limited solely by the maximum cable length for connecting the primary section or the maximum length of the position measuring system. Any traversing length can be implemented by mounting magnetic secondary sections side by side spaced at 120mm or 184mm lengthwise.
The principle of operation of a linear synchronous direct drive results in a high temperature increase of the primary section. However, for Siemens linear motors, this thermal stressing is neutralised to a significant extent. The motors which are designed for high continuous forces have integrated water cooling. For precision applications, CNC Design offer motors with the Thermo-Sandwich type of construction. With this special type of construction, second precision water cooling reliably limits the temperature rise at the mechanical interfaces to the machine to a maximum of 2ºK or 4ºK.
Since mechanical power transmission elements and the associated backlash and frictional losses are dispensed with, linear motors have the following characteristics:
- Dynamic response
- High traversing velocities
- Easy installation
- Enable a simple, compact machine design
- High electrical efficiency
- When suitable measuring systems and cooling methods are employed, linear motors achieve a positioning accuracy in the nanometre range
- Machining centres
- Turning machines
- Grinding machines
- Punching/cutting machines
- Laser- or water jet-cutting machines
- Machines for processing wood/glass/plastics
- Interlinking, handling, robotics
- Measuring machines
- Electronics production (pick and place, bonders)
1FN3 linear motor – continuous load version: The high-rated power of this series means the drives can be subject to high process forces and permanent acceleration. In addition, it has low minimal cogging force.
1FN3 linear motor – peak load version: This motor is a drive for accelerating loads as a result of the high ratio between the peak and continuous load. The primary sections are designed as standard for water cooling. However, with the appropriate system design, natural cooling is also possible in certain cases.
The new ‘electrical gear rack’ 1FN6: With the linear motor 1FN6 from Siemens, CNC Design also offer another synchronous variant of a linear motor that is characterised by its non-magnetic secondary section. This can be used to implement high dynamic applications with long traversing paths cost-effectively. The non-magnetic secondary section also allows a highly dynamic linear motor to be used under environmental conditions in which magnetic secondary sections are undesirable. Maximum forces between 900 and 8080N give the motors an impressive acceleration capability at maximum velocities of 170 to 540m/min.
As the shape of the secondary section is reminiscent of a gear rack, and due to its possible use in place of classical racks and pinion systems, the term ‘electrical gear rack’ has been coined for the 1FN6 linear motor.
Following are the typical areas of application of the electrical gear rack 1FN6 motors:
- Conveyors, assembly and transfer lines
- Handling gantries and robotic applications with long traversing paths
- Water jet and laser-cutting machines with long horizontal traversing axes