ZellWag are a manufacturer of filling & sealing machines for semi or fully automated production lines. ZellWag have been using LinMot since 2002. Recently they have added the new Z-110g modular machine platform for large, production batches. This machine has taken even further advantage of the dynamic and compact motors from LinMot.
Heinrich Thomas, the managing director of ZellWag AG explains that they were one of the early innovative companies to place their trust in new linear drive technology. “Only linear motors could enable us to increase the flexibility and performance of machines in the way we and our users envisioned.”
“Compressed air cylinders have the disadvantage that they behave differently depending on the ambient temperature and are therefore not really capable of providing the necessary repeatability. Pneumatic cylinders also need maintenance, unlike linear motors which are largely maintenance free.”
Product changeover at the push of a button
An even greater influence on productivity, especially for small production runs, is the ability to use software to change the control parameters of the linear motors. Zellwag AG has put this to use in the concept of its machines for processing various types of and sizes of packages. A product changeover can be made at the push of a button, with no mechanical adjustments necessary.
For several years, however, another feature of linear motors has inexorably moved into users’ field of view: the exceptional energy efficiency of linear motors. Pneumatic actuators have high compressed air consumption, extremely high for screw driving processes, the managing director of Zellwag asserts. Because it takes a lot of energy to produce compressed air, of which only a small amount arrives at the actuator in the form of work output due to the poor efficiency of the compressed air system, the use of electric drives with an efficiency of over 90% presents the user with a way to lower operating costs and to improve the ecological balance. See our lifetime energy and cost analysis of linear motors versus pneumatics for more information.
Zellwag selects LinMot again
A recent internal evaluation of available technologies prior to the launch of the new Z-110 machine platform confirmed again, as expected, the technical, economic, and ecological advantages of linear motors from LinMot. This and over 100 Z-201 systems sold, with around 500 installed linear axes with no significant breakdowns have persuaded the responsible parties at Zellwag AG to use linear motors from LinMot to implement the critical processing steps on the new machine platform as well. These include filling (moving metering units), gripping and placing the plug and screw cap, and centering the riser tube for cases where pump spray heads are used as a closure. The result is the Z-110, characterized by a thoroughly modular structure and extremely flexible in application due to its direct drives and numerous options. It is designed for filling liquids of varying viscosity, including powders, and can process ampoules and glass bottles with diameters between 15 and 40 mm and heights from 24 to 100 mm. Depending on the equipment level, the system can process up to 7,200 units per hour.
Powerful and compact: linear axes with LinMot drives
Because the machine can contain up to 16 direct drives, with up to four independently transportable pump stations and a maximum of four pick & place units with electric servomotors as rotary axes (as well as additional options), the compact form factor of the linear axes was particularly important to the design of the Z-110. “Users require portable machines, so we integrated the electrical enclosure directly in the frame of the machine,” adds the managing director of Zellwag. “This meant that we had to be particularly frugal with space.” Here again, LinMot had the right solution available. The servo-controllers from the company’s E1130 series are just 40mm wide, 250 mm high, and 180 mm deep, although the HC variant can provide a peak current of 15 A. Ever since, these powerful controllers have handled both the actuation of the linear motors and the rotary servomotors in the Z-110 and communicate with the machine controller via the optional Profibus interface (DP).
Magnetic springs relieve linear motors
The linear motor axes installed vertically in the Z-110 are mechanically supported by MagSprings. These magnetic springs from LinMot provide a constant force over their entire stroke that is independent of position, speed, or orientation and thus compensates for the weight of the linear axis. The motor only has to provide the dynamic forces, so it can react faster and be smaller in size. If the MagSpring force is selected to be greater than the weight of the load, then the load can be moved to a safe position if the power is interrupted. MagSprings also require no maintenance, are not sensitive to wear, and take up only a little space.