The engineers from Jung Antriebstechnik u. Automation GmbH JA² responded to calls from the pharmaceutical industry, the analysis sector and the medical technology industry for small but functional automation solutions with the development of a new modular mechatronic system called Quick- Lab. With the small QM02 linear motor modules for up to 160 mm stroke and the QA02 linear motor axes for strokes up to 220 mm, short-stroke applications can be realized with high dynamics and accuracy, e.g., in laboratory and analysis technology or in testing systems. Through the mechanical construction and precision guides in combination with two ball carriages, the modules and axes are very rigid and offer high repeatability during positioning of ±50 μm in spite of their lightweight construction and low moving mass. Depending on the load, travel speeds up to 3 m/s and acceleration up to 50 m/s² are possible. The axes and modules can be individually combined with one another. In this way, pick-and-place applications can be realized as can automatic solutions for separating, grouping, testing or plating samples or other sensitive products.
With a width of 22 mm, QuickLab perfectly covers the need for miniaturized single- and multi-axis handling systems. Moreover, the appropriate accessories such as weight force compensation, magnetic holding brakes, external position sensors and adapter plates are offered.
High dynamics and precision
"The linear motors are the 'heart' of our modular automation system and the requirements placed on them are very high," explains Wilhelm Jung, Managing Director at JA². "The motors must operate highly dynamically, be precisely controllable and have suitable dimensions. The linear motors from FAULHABER convinced here with their innovative functional principle, which differs from "classic" solutions:
Linear motors can be constructed in a number of different ways because all principles of "rotating" electric motors can generally be implemented in linear motors by mapping the round air gap onto a straight line. To do this, the originally circularly arranged electric excitation windings are basically unwound on a flat path. The magnetic field then pulls the rotor over the travel path. There are, however, still other possibilities: The LM2070 DC linear drives are not constructed as such "surface rotors" with carriage and guide. Instead, the forcer rod is guided within a 3-phase self-supporting coil. "This design produces an exceptionally good relationship between linear force and current and high dynamics. In addition, there are no cogging torques, thereby making the linear motors ideal for use in our modular QuickLab system."
Maximum performance in the smallest dimensions
The LM2070 linear motors are available with stroke lengths from 40 to 220 mm. Despite the compact stator dimensions of 20 x 20 x 70 mm (W x H x L), the small linear DC servomotor has impressive mechanical performance indicators.
The continuous force is 9.2 N, and up to 28 N of peak force is available. The robust plain bearing of the forcer rod easily handles the high speeds of up to 3 m/s. At the same time, the miniature powerhouse can be very precisely controlled. The integrated Hall sensors already ensure an absolute positioning accuracy of ±0.1 mm and a repeatability of ±50 μm. With an optional external sensor, these figures can be improved to ±0.01 mm and a repeatability of ±1 μm. On top of this comes practically maintenance-free operation as the motor has no moving wear parts. Moreover, the linear drive operates nearly noise-free. "This is important above all if personnel and handling systems work in the same room, as is often the case in laboratories," adds Wilhelm Jung.
Trailing-chain cable connection
An important point for handling systems is the connection technology. The linear motors are normally delivered with a max. 30 cm long cable connection. In automation systems, however, the switch cabinet is usually some distance from the actual drive. "Between the motor and the controller in the separate switch cabinet, there can then be 10, 20 or more meters," says Wilhelm Jung. With the QuickLab modular system, there is therefore a special, multi-shielded cable that transfers the motor power and the position sensor signal between motor and controller interference-free over up to 30 m. It is fastened with a cover directly to the motor with strain relief, can be plugged in and is also designed for use with cable chains, i.e., for mobile use. The single-cable technology simplifies installation thanks to the prefabrication of both ends.
The mechatronic kit tailor made for laboratory automation has already proven itself in practical use. Wilhelm Jung confirms this: "Many manufacturers and suppliers of analysis accessories today rely on our systems. Demand is currently enormous – including from other areas such as optics and testing technology." Always present as the driving force: the small, powerful LM2070 linear drives.