Guidelines to Select Between Self-Contained Electro-Hydraulic and Electro-Mechanical Cylinders

Hagen, Daniel; Padovani, Damiano; Choux, Martin

doi:10.1109/iciea48937.2020.9248373

Cited by 11 publications

(7 citation statements)

References 12 publications

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“…In order to entirely avoid Pilot operated components, some researchers have chosen to upgrade the last two systems. EMA provides higher resolution [147], uses a single type of energy creating a unified energy system [148], has better controllability [86], and has no leakage. As an alternative, the EHA has a closed cycle architecture, in which the return flow from the actuator goes directly back to the inlet of the pump without using directional control (throttling) valves [149].…”

Section: Developmentsmentioning

confidence: 99%

A Review of Pilot-operated Hydraulic Valves – Development, Challenges, and a Comparative Study

Elsaed,

Linjama

2023

TJFP

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Hydraulic systems have been widely used due to their high power-to-weight ratio. Despite the growing instances of being superseded by the electromechanical counterparts at low power levels, the market was incapable of presenting alternatives for large-size applications. Additionally, in recent years, the demand for more significant heavy machinery (Mobile & Industrial) has increased, which led to the necessity of even higher flow and pressure Pilot-operated valves, despite the fact that these valves have several issues. One might think the alternative could be developing a hydraulic system that does not rely on Pilot-operated valves, but after decades of research, these systems could not get close to the performance of Pilot-operated Multistage valves. The paper presents a comprehensive study of the progress accomplished from the year 2016 to early 2022 in hydraulic Pilot-operated valves; they are widely employed among ordinary valves, proportional valves, and state-of-the-art digital hydraulics. Higher efficiency will be a primary factor in the success of the new designs. The academia presented several studies to improve the Pilot valves’ performance, but still, they are limited. There are no dramatic developments, and there are only a few upgrades.

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Section: Developmentsmentioning

confidence: 99%

A Review of Pilot-operated Hydraulic Valves – Development, Challenges, and a Comparative Study

Elsaed,

Linjama

2023

TJFP

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“…However, there are also examples where it can be of interest to use electro-mechanical actuators instead of hydraulic cylinders. In a study from 2020 by Hagen et al [34], a selfcontained electro-hydraulic actuator was compared with an electro-mechanical off-the-shelf actuator. The conclusions were that the electro-hydraulic solution is preferable when there are high impact forces, when the continuous power demand is above 2 kW (due to component availability), or when space, weight, or cost is critical.…”

Section: Electro-mechanic Actuationmentioning

confidence: 99%

On Electrified Fluid Power Systems in Mobile Machinery

Kärnell

2022

Linköping Studies in Science and Technology. Dissertations

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High power density in combination with flexible power distribution possibilities and extreme robustness are reasons why fluid power has been the preferred technology in mobile machinery, such as excavators and cranes, since the mid-20th century. In principle, the machines have been powered by a combustion engine which powers a pump, with the output from the pump being distributed to different functions via valves. However, a transformation is currently underway. Combustion engines are being replaced by electric motors, and batteries able to store energy corresponding to several hours of operation are often desired. Since batteries tend to be heavy and expensive, reducing the energy consumption is getting higher priority than ever before. There are applications where electrification means that hydraulic components are replaced by electric counterparts, but fluid power has characteristics that are highly desirable in mobile machinery. Therefore, many hydraulic actuators will remain. Conventional hydraulic systems, which are known for their inefficiency, should, however, be adapted to the new conditions brought about by electrification. The question, and the overall subject of this thesis, is: how? The research has focused on two main topics: pump-controlled systems, which are systems where each actuator has its own supply unit, and the use of variable displacement pumps in electrified systems.A large proportion of the losses in many conventional hydraulic systems is due to the simultaneous operation of functions that require different pressure levels. One way to avoid these losses is to use pump-controlled systems. How these systems should be designed is, however, far from obvious. In this thesis, different types of pump-controlled systems are compared, both statically and dynamically.Regarding variable displacement pumps, they have had a natural place in many conventional systems, but electrification may change this, since speedcontrol can now also be used for flow-and pressure control. However, there are still aspects relating to energy consumption and component dimensioning, among other things, that makes variable pumps relevant. These aspects are investigated here, and different types of variable pumps are reviewed.Linköping, August 2022 Samuel Kärnell v vi PapersThe following publications are included in the thesis and can be regarded as its foundation. They will be referred to by their Roman numerals. Apart from formatting changes, they are reproduced in their original form. Notice that they are not appended in chronological order. Instead, they are sorted based on the topics; the first three focus on displacement control and the last two on pump-controlled systems.[I] S. Kärnell and L. Ericson, "Classification and review of variable displacement fluid power pumps and motors," International Journal of Fluid Power (submitted), 2022.[II] S. Kärnell, A. Rankka, A. Dell'Amico, and L. Ericson, "Digital pumps in speed-controlled systems -an energy study for a loader crane application," in

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“…This has to do with energy-saving requirements [34,43,44]. The use of electrohydraulic elements is justified especially when we have high impact forces and high-power levels [45]. In the context of energy efficiency, electronic control is an important issue.…”

Section: Braking With a Frequency Invertermentioning

confidence: 99%

“…A solution may be the use of two independent pumps and electric motors driven by separate frequency inverters. Hagen et al [45] compared the use of electromechanical and electrohydraulic actuators in the motion control system of a single-boom crane. The study showed that the latter solution had 20% more continuous power capacity and 47% less installed electrical power.…”

Section: Braking With a Frequency Invertermentioning

confidence: 99%

Energy Efficiency and Limitations of the Methods of Controlling the Hydraulic Cylinder Piston Rod under Various Load Conditions

2021

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The article is an overview of various methods of braking and controlling the movement of the piston rod under various load conditions. The purpose of this review is to systematize the state of the art in terms of efficiency, energy consumption and limitations of each method. The article discusses systems with different types of hydraulic actuators, operating under passive, active and variable load during the duty cycle of the piston rod. The existing literature was analysed in terms of applicability, reduction of energy consumption of the systems and even the possibility of energy return. Attention was paid to the costs and the need for additional power sources, as well as the problems and limitations of the presented methods. Based on the simulation model, energy consumption tests were carried out in systems with an actuator loaded with a variable force. There is a comparison of all methods in terms of actuator type, load, energy consumption and the possibility of energy recovery.

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Guidelines to Select Between Self-Contained Electro-Hydraulic and Electro-Mechanical Cylinders

Cited by 11 publications

References 12 publications

A Review of Pilot-operated Hydraulic Valves – Development, Challenges, and a Comparative Study

A Review of Pilot-operated Hydraulic Valves – Development, Challenges, and a Comparative Study

On Electrified Fluid Power Systems in Mobile Machinery

Energy Efficiency and Limitations of the Methods of Controlling the Hydraulic Cylinder Piston Rod under Various Load Conditions

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