Centrifugal casting drives are used in foundries to shape molten metal into the desired part via a spinning process. The centrifugal casting process uses a rotating mold that spins at a constant speed for up to eight hours. This type of casting is desirable over static casting because it creates dense granular structure. It also can be used to create layers of metal with excellent cross bonding.
Key Business Challenges
Space limitation within centrifugal casting drives lends itself to hydraulic motors, which have been used since the 1970s. Those open loop systems relied on proportional reliefs for motion control when accelerating, decelerating and holding a constant speed.
Open loop systems are inherently inefficient both electrically and in terms of the kinetic energy they have to absorb upon deceleration. SG Morris developed a hydrostatic transmission to replace the open loop systems in centrifugal casting drives.
This hydrostatic transmission improved the caster in several ways by:
Providing more efficient speed control
Generating less heat while maintaining caster speed
Recovering speed more efficiently while molten metal is poured into the spinning caster
Dissipating deceleration via regenerative braking
Reducing contamination inherent in foundry operations
SG Morris revisited the project to create a control system that could get the most out of the hydrostatic transmission by increasing desired control stability. The project team worked to create an electric control system that was sophisticated enough to achieve its maximum efficiency potential.
SG Morris’ expert integration of Eaton P1 controls provided the answer. Once the new controls were integrated, control over speed and deceleration rate greatly improved. The new system dissipated energy more efficiently without overloading the motor. This is especially important to the customer because caster systems were their biggest source of wasted energy.
The P1 control system improved the system by:
Significantly lowering costs
Possibly qualifying the system for energy credits
In addition, the customer estimates that the energy and cycle savings will obtain capital pay back in approximately 12 months.
The customer has worked with SG Morris since 1975, and highly values their ability to provide complete package and service support. SG Morris personnel were able to provide expertise beyond their competition.