Category: Industry Trends

Overview

The Moog Electrohydrostatic Pump Unit (EPU / EPU-G) is at the heart of

electrohydrostatic actuation systems enabling the deployment of a

decentralized drive system. This eliminates the need for a hydraulic power

unit and complex piping and helps reducing the overall machine footprint.

The compact product design features a unique interface that enables direct

mounting on to a cylinder or manifold thereby minimizing the requirement

of additional space on each axis.

Addressing customer needs for convenience, modularity, electrification,

energy efficiency, robustness, serviceability and sustainability, the compact

design and reduced complexity make it easy to handle and integrate without

requiring extensive hydraulic expertise.

The EPU-G (sizes 13 and 20) utilizes an internal gear pump to generate flow.

The EPU (sizes 19. 32. 80. 140 and 250) uses a radial piston pump available

in two versions: Fixed or dual displacement.

The Moog Electrohydrostatic Pump Unit ( / EPU-G) is at the heart of

electrohydrostatic actuation systems enabling the deployment of a

decentralized drive system.

This eliminates the need for a hydraulic power unit and complex piping

and helps reducing the overall machine footprint.

Benefits:

• High energy efficiency.

• Reduces oil volume by up to 90%, supporting sustainable and clean

operations, reducing maintenance and operating costs and the risk of fire.

• High-force capability provides a viable alternative to EH actuation.

• Unique manifold interface enables direct mounting reducing piping and 

maintenance efforts and machine footprint.

• Self-contained and compact product design reduces space requirements

for the machine.

• 4-quadrant operation.

Modern machine designs are more and more based on Electrohydrostatic Actu

ation Systems (EAS) instead of valve-based throttle control. During this trans

formation, the installed power of the used EPU-axes and their Servo Drives

often surpass the power of the formerly used hydraulic power unit, especially

when hydraulic accumulators were used.

Moog combines the best fitting power infeed with storage units to reduce the

installed power significantly. Together with the efficiency gain of the EAS and

the peak power reduction of the Moog Energy Management System, hydraulic

machines reach a new level of attractiveness.

The Energy Management System as add on to EAS provides multiple benefits

to machine end-users and to OEMs. Additionally, the EMS can also be used for

electromechanical actuation systems.

MOOG EVALUATION PROCESS

Through in-depth simulation of the application including energy management,

the best fitting storage and infeed is evaluated. In this process the customer is

pro-activly consulted on energy savings, grid loading and amortization, amongst

others.

ADVANTAGES

• Reduces installed power significantly and thus in-line components up to the

transformer (peak shaving)

• Maximizing machine efficiency through energy storing and minimizing losses

• Modular approach: For each application the right infeed and storage type

APPLICATIONS

• Material testing and simulation platforms

• Cyclic high pressure compression axis

• Metal forming and presses

Overview

Modern machine designs are increasingly based on Electrohydrostatic

Drive Systems (EAS) instead of valve-based throttle control.

The installed power of the EPU axes and their servo controllers often

exceeds the connected load of the previously used hydraulic power

unit, especially when conventional hydraulic accumulators are used.

Moog combines the best fitting power infeed with storage units to

reduce the installed power significantly. Together with the efficiency

gain of the EAS and the peak power reduction of the Moog Energy

Management System (EMS), hydraulic machines reach a new level

of attractiveness in terms of energy efficiency and reduced total cost

of ownership (TCO).

Benefits

• Reduces installed power significantly and thus in-line components

up to the transformer (peak shaving)

• Reduces energy and operating costs and extends the service life

of electronic components

• Maximizing machine efficiency through energy storing and minimizing

losses

• Modular approach: For each application the right infeed and storage

type

SMART ENERGY MANAGEMENT FOR ELECTROHYDROSTATIC

ACTUATION SYSTEMS

As an addition to the EAS portfolio, the Moog ESU Energy Management

System (EMS) offers machine operators and OEMs the opportunity to

significantly reduce energy and operating costs while increasing the

service life of electronic components. The EMS can also be used in

electromechanical drive systems.

HIGH PERFORMANCE DESIGN FOR SMART POWER MANAGEMENT

The Moog DE2020 energy management module improves the efficiency

of any machine and allows for a leaner and more cost-effective electrical

layout. During the regular load phase, a capacitor bank is pre-charged

carefully and a certain remaining capacity is retained.

The DE2020 meets peak loads by drawing energy from the capacitor

bank, while using the energy gains from braking processes and mechanical

inertia to recharge the capacitors by means of recuperation. 

Thus, the capacitors are ready for the next peak load. This helps increase

overall energy savings and, more importantly, allows for an overall smarter

electrical design of the machine.

Advantages

Among other advantages, there is a significant reduction in the dimensions

of the electrical panel (reduced by 50% compared to non-optimized systems)

and of the cable sections necessary to allow the currents to flow

(with consequent savings in wiring costs).

Furthermore, this system can also be used to compensate for fluctuations 

of the mains, using a pre-filter in combination with the capacitor bank, reducing

the risk of electrical malfunctions, while simultaneously increasing safety in the

event of a power failure, as it can supply the system with enough energy to

reach a safe-stop position.

TYPICAL WORK CYCLE

During normal machine activity, the DE2020 module will:

• Manage the input power profile, shaping the electrical power

coming from the input, leveling the peaks, and flatten the load

peak on the DC grid.

• Charge the accumulator energy banks and accurately control

the voltage across them.

• Provide additional energy during acceleration phases.

• Handle the kinetic energy obtained from running masses

during their braking phases.

• Provide the system with previously stored energy during

acceleration phases.

• Temporarily withstand DC grid failures or unexpected

disconnections of the DC power supply providing the system

with the necessary energy to bring the machine to a safe state.

DE2020 SYSTEM OVERVIEW

Modes of Operation:

• Power Leveling

In a typical machine cycle, accelerations require peaks of power; the

DE2020 can handle energy using energy storage accumulators in

order to guarantee a performance beyond the nominal power of the

electrical equipment.

• Energy Recovery

Usually while braking, the energy that motors give back to the

system is partially wasted as it is dissipated on the power supply

dynamic braking resistor. With the DE2020 module, this energy

is stored in  the accumulator energy banks, such as the Moog

Additional Bus Capacitor (ABC module) or larger in sizes, in order to

be saved and reused.

• Energy Backup

The DE2020 can use the energy stored in the accumulator energy

banks when the grid is down to ensure safe home movements of the

machine and/or to keep safely controlling critical axes during grid

failures. This feature makes the system more reliable and protected

against issues related to sudden losses of power from the grid.

Silencer® brushless controllers are available in a variety of voltage

and current ratings. All controllers have generous terminal blocks

to facilitate ease of wiring and they are designed for ease of mounting

in a small envelope, requiring minimal space in a cabinet / enclosure.

Silencer drives are compatible with Silencer Series Brushless DC Motors.

Silencer motors are available in sizes 12. 17. 23. 28. 34 and 42 in

standard frames with 1.2 to 4.15 inch diameters.

They offer speeds up to 20.000 rpm and continuous torques ranging from

1.2 to 519 oz-in. Standard options include gearheads, resolvers and encoders.