The linear motor has arguably been around since the 1850s with Frenchman Paul Fromont’s invention. More recently, and more famously, Eric Laithwaite’s designs in the 1960s formed the basis of Maglev trains.
But, while widely accepted in Japan, the US, and Germany, the application of linear motors has been slow in the UK.
The two main reasons for this are cost and integration. As well as being more expensive than their ballscrew, or pneumatic equivalents, linear motors are also considered more complex to control and integrate.
To combat these concerns, THK and linear motor expert Thrust Tube have launched the RDM-M system.
This pre-assembled, modular linear motor package simplifies the specification process by providing a linear guide and a linear motor in a single high acceleration ‘off the shelf’ unit. The 2um accuracy of the RDM-M compares with +/-100um of a conventional ball screw design.
The RDM-M features THK’s Caged Ball LM guide technology, along with a linear servo motor that provides acceleration rates of up to 7G at operating velocities from a few microns up to 14 m/s. With these vital statistics it’s clear that the RDM-M is best suited to high speed, high duty cycle applications and it is here that linear motors become cost-effective. THK says it’s ideal for applications such as PCB testing, electronics manufacture, photo plotting, laser stencil cutting and stud welding.
A further benefit offered by the fusion of these technologies is the creation of a platform that’s supplied ready-to-use with a four week lead-time from ordering.This reduces specification and installation time. A linear encoder and cabling are built into the system as standard, and matched drives and controls are available. The system comes in a variety of size and power options with an upper stroke length of 2m.