A transfer press stamping line had an older DC main motor that was past life expectancy. A direct motor replacement was not available but DC motors can still be sourced. DC motors require frequent maintenance to service brushes but had been the state of the art when the original press was installed. There was not a direct replacement in form factor so changes needed to be made regardless of the direction. The line was fully utilized and there was very little time available for modifications. The customer also wanted a system that was easier to maintain and would be serviced and supported for the foreseeable future.
ONYX Engineering provided an engineered solution that replace the DC motor with a synchronous AC motor and variable frequency drive panel system that could match the motor performance of their older DC motor with better flexibility and MTTR. Since the motor shafts were dissimilar, a custom belt pulley needed to be manufactured to mate with the multi-belt arrangement that coupled to the flywheel. An engineered adapter plate was also designed so that the shaft height matched the existing arrangement. A variable frequency drive panel was provided with new cable runs and encoder feedback to regulate speed. Drive performance and speeds were matched with previous DC drive decreasing time required for commissioning. A newer ethernet interface was designed and integrated with the updated PLC controls and operator interface. The entire changeover and commissioning activities were performed over the Christmas shutdown period of 5 days. Production resumed at the normal scheduled time with no impact on production.
The Motor and drive replacements increased the usability and efficiency of the existing equipment. It provides trouble-free operation of the presses and an updated stock of components which should provide worry free operation of the main motor on the press for the foreseeable future. All of this was achieved on schedule and within budget with little or no impact on production.