To create a beverage sorting system, a mechanical engineer needs several solid gantry frames on which X-Z-axis handling systems are mounted. By means of linear handling, full and empty beverage crates are to be sorted onto the respective lines of the system in a pick & place application. It must be possible to grip several boxes at the same time, remove bottles from the crate and to clean and sort the bottles before placing them in crates. Given the high dynamics created by the large masses, the frames must not swing open and must not deform by more than a few millimetres, even when acceleration is superimposed. The linear units accelerate at approx. 4 m/s². It should be possible to hang a load of up to 200 kg on the Z-axes. With an unsupported length of 4 m, the beams must not deflect by more than 2 mm. The customer requires a repeat accuracy of less than 0.5 mm to ensure the gripper can grip the products cleanly. For mounting, the individual components must be divided into compact transport sizes that can still be easily assembled on site.
In order to be able to meet these special requirements, a gantry frame made of Series 60 aluminium profiles was constructed. The arrangement of the supports and the connection of the linear axes were planned together with the customer. For the complete frames, mk used a calculation based on the principles of engineering mechanics for the static and dynamic load case. Among other things, the deformations, the strength of the profiles and connections as well as the stability were taken into account.
In order to achieve the required accuracy, the frames were designed for extreme rigidity and low deflection. To be able to absorb the maximum load and the forces from the dynamics, solid profiles from Series 60 were used with M12 screws. Transverse beams were connected to large angle brackets and supported with truss struts. The deflection could then be reduced to less than 2 mm at a length of 4 m. The anchoring was also fixed solidly and rigidly to the floor with a mechanism for height adjustment.
The frames were pre-assembled at mk, nuts were inserted for the connection and separation points were marked.