Servo presses used in differential sub-assembly station

A customer recently approached FEC wanting to automate part of the assembly of a differential for an all-terrain vehicle (ATV); the previous process involved four people and three hydraulic machines. FEC's challenge was to build a machine that would achieve a cycle time of 18 seconds for assembling two bearings and seals, a needle roller bearing and a pinion gear into over 20 variants of the differential housing.

FEC built a machine that incorporated five of its 30kN Slimline series servo presses. The pinion/needle roller bearing is positioned in three axes using servo control to accommodate part variations and two different insertion angles. A PC and HMI are used for model setup and for users to select which model is being assembled; the system has capacity for 500 different models in total. Furthermore, the software on the PC enables cycle data and load/distance curves to be stored for future analysis.

Error-proof assembly

Depending on which of the 22 model variations is built, the assembly machine requires the correct combination of jigs and fixtures from the 44 that are available. Relying solely on the operator to pick the correct jigs and fixtures would result in an unacceptable risk of human error, so a barcode-based Poke-yoke system was devised. When the operative uses the HMI to select a model for assembly, the HMI presents an on-screen list of the required jigs and fixtures, and these must be scanned with the barcode scanner before the machine will run; scanning the correct item results in it being highlighted in green on the list, whereas an incorrect item will be highlighted in red.

FEC succeeded in delivering an automated assembly cell that achieved the required 18-second cycle time, with no chance of the incorrect jigs and fixtures being used. The benefits for the customer were substantial. This project is an excellent illustration of FEC's capability as a full-service supplier of turn-key assembly systems to OEM and Tier 1 and Tier 2 suppliers worldwide; the company also supplies fastening and pressing components and systems for incorporating in a wide variety of fully-automated and semi-automated assembly operations. Go to www.fec-eu.com for more information.