One Hydraulic System, Four Presses, Huge Savings

When an automotive tire manufacturing plant needed to add four new presses, All World Machinery Supply's engineers stepped in with a cost- and space-saving hydraulic power solution to handle the customer’s requirements.

A Unique Request

In 2018, the plant contacted All World for hydraulic power solutions. They were installing a new cell with four room-sized tire curing presses to increase production. Initially, they received a proposal for one hydraulic pump per machine, totaling four machines. However, the manufacturer challenged All World to design a more budget-friendly solution, operating the four machines from a single centralized system.

For additional customization, the manufacturer requested that the pump configuration be designed to accommodate a potential third pump. They also required a control cabinet that adhered to their safety standards and wanted an Allen Bradley PLC and HMI touchscreen for the control system.

The Perfect Solution

To be efficient and space-saving, All World engineers developed a concept for two 37 kW, 220 liter-per-minute hydraulic power systems for the four presses. Each system would be capable of 4,000 psi, although engineers programmed them for 1,300 psi and a flow of 200 liters per minute, for a combined output of 400 liters per minute with the two units working in tandem. The unit would be built with the capability to accommodate an additional pump system to be added later.

The system would not only be efficient with two pumps compared to four, but All World upped the ante on efficiency by utilizing energy-efficient SUT pumps by Daikin. Daikin Super Units feature Daikin IPM motors with an inverter control that offers up to 30% energy savings. Unlike standard hydraulic power units provided by OEMs for machine tools, hydraulic systems with servo drives eliminate unnecessary energy consumption during pressure-holding or idling states. The unit only works as hard as it needs to maintain a constant hydraulic pressure.

“Since it is variable speed, it’s very energy conservative,” Engineering Manager Frank Grube said. “Because of less energy consumed, our hydraulic system runs much cooler and quieter.”

For even more reduced temperature, engineers added an auxiliary circulation pump to cool the hydraulic oil through a water jacket. This was mainly because of the high ambient temperature from the tire vulcanizing process.

To meet safety requirements for the control cabinet, it was designed with two separate enclosures within one for DC/control level power and one for high voltage AC power. That enabled maintenance technicians to only have to wear arc flash gear when working within the AC panel.

“If technicians are working on the high voltage panel, they will have to wear arc flash gear but can work in the PLC control side without the gear,” Grube said.

Because the system included one Allan Bradley PLC and HMI touchscreen, as opposed to two for the two hydraulic power units, it added to the cost savings.

Engineers designed the PLC to communicate with the inverter drives for the pump main system control. The PLC control can monitor each of the pump’s motor rpm’s, motor temperature, the inverter drive temperature, system pressure, system flow rate, and any current alarms the drive might have. Networked to the presses in the plant, the control system enables maintenance and engineering staff to view the pumps’ status and condition via their computers.
To enable the accommodation of a potential third pump, engineers designed the pump configuration with a third pump and motor mount pad on top of the hydraulic tank. They also designed the electrical cabinets to accept the additional drive that would come with an additional pump system.

Building Upon Efficiency

After successfully running the two-pump system in July of 2021, the customer requested a third pump for backup. The addition of the third pump enables repairs or maintenance on a pump while keeping the presses running with the other two pumps still online. With backup pumps already in stock, the manufacturer could quickly replace one if the need arises.

In the future, the customer is planning to rotate the two pumps in operation to reduce system wear.

“It puts longevity into each of the pumps. They are extending the lifespan by 30% of each pump by doing this,” Grube said.

A Cost-Saving Solution

By developing hydraulic power units capable of powering four presses simultaneously and designing a third hydraulic system to serve as a backup, the manufacturer has seen major increases in efficiency. The system effectively minimizes downtime during maintenance.

This innovative design is estimated to have reduced the costs of tire press operations by two-thirds and cut floor space usage in half when compared to four individual conventional hydraulic systems. Additionally, the system features centralized control and integrated safety mechanisms within the control cabinet.

"Rather than constructing separate hydraulic systems for each machine, we created a centralized system to operate all four," explained Sr. Technology Director Darrell Janesak. "This approach saved money, floor space, and energy. Our goal is to take the customer's concepts, desires, and needs and deliver a solution that is as efficient as possible."