The rise of variable speed hydraulics
29 July 2026 
Rising energy costs, tighter sustainability targets and growing demand for smarter industrial equipment are accelerating the adoption of variable speed drive technology in hydraulics. H&P’s Aaron Blutstein spoke to Juraj Bittner, Product Manager, Industrial Solutions at Danfoss Power Solutions, about how changing attitudes towards efficiency, electrification and machine control are driving a new generation of hydraulic architectures
With energy prices remaining volatile and industrial sustainability targets tightening worldwide, hydraulic system design is undergoing one of its most significant transformations in decades. At the heart of that change is the growing adoption of variable speed drive (VSD) technology, a development increasingly reshaping how hydraulic machines are powered, controlled and optimised.
For many years, traditional constant speed hydraulic systems dominated industrial applications because of their robustness, simplicity and high-power density. But manufacturers are now under increasing pressure to improve energy efficiency, reduce operating costs, cut emissions and simplify machine architectures. In response, intelligent demand-driven hydraulic systems are moving steadily from specialist innovation to mainstream industrial strategy.
According to Juraj Bittner, Product Manager, Industrial Solutions at Danfoss Power Solutions, the momentum behind VSD adoption is accelerating quickly, particularly in sectors where energy consumption has become a major operational concern.
“People have become much more sensitive to energy efficiency,” Bittner explains. “Not necessarily because of the green movement, but simply for pragmatic reasons. Energy prices have become a real issue for industry.”
Matching power to demand
Traditional hydraulic systems typically operate at constant motor speed regardless of actual machine demand, with excess energy dissipated through throttling valves and pressure controls. Variable speed systems fundamentally change that model by dynamically adjusting motor and pump speed to deliver only the pressure and flow required during each stage of the duty cycle.
The efficiency gains can be substantial. Recent product developments entering the market illustrate how quickly variable speed hydraulic technology is maturing. Danfoss, for example, has recently expanded its Vickers by Danfoss Variable Speed Drive portfolio for industrial hydraulic applications, with systems designed to address both lower-dynamic and high-performance machine requirements across discrete and process manufacturing environments.
According to the company, VSD architectures can deliver energy savings of up to 60%, depending on the application and duty cycle, by continuously adjusting motor and pump speed to match real-time machine demand rather than operating at constant speed.
“Ultimately, you are no longer providing anything more than what is actually needed,” says Bittner. “That means no waste.” The Danfoss approach includes both induction motor and servo motor configurations. Induction motor systems are aimed at applications with lower dynamic and control requirements, while servo-based systems are intended for machines requiring faster response, higher precision and closed-loop pressure and flow control.
Bittner says one of the most significant advances is the integration of p/Q control functionality directly within the drive system itself, simplifying commissioning and reducing the level of PLC programming required from machine builders. The latest servo-based architectures also allow more precise pump-speed control, potentially reducing the need for some traditional pressure and flow control valves.
Beyond energy efficiency, this shift is helping manufacturers reduce heat generation, lower noise levels, simplify hydraulic architectures and, in some cases, reduce cooling requirements and overall machine footprint. Those factors are becoming increasingly important as industrial users seek both operational savings and more sustainable machine designs.
Applications with highly dynamic duty cycles, where machine demand fluctuates significantly throughout operation, are proving particularly well suited to the technology. Injection moulding, rubber processing, machine tools, presses, die casting, metal forming and food processing are among the strongest adoption sectors.
“In injection moulding, for example, adoption may already be around 40 to 50%,” says Bittner. “These industries are highly sensitive to energy consumption because efficiency directly affects the cost of the finished product.”
The nature of the duty cycle is critical. Systems with frequent idle periods, load variations, peaks and pauses offer the greatest opportunity for savings because the drive can continuously adapt output to actual demand.
Bittner compares it to driving a car: “Most industrial applications are not running at full power all the time, just like most cars are not permanently driven at maximum speed,” he explains. “You stop at traffic lights, you accelerate, you slow down. Industrial machines behave similarly, and that creates the opportunity for variable speed systems to save energy.”
More conservative sectors such as oil and gas and primary metals production have generally adopted the technology more slowly. Historically, many of these industries prioritised reliability and durability over efficiency gains, while low-cost or self-generated electricity reduced the urgency around energy consumption.
However, that mindset is beginning to change as sustainability targets and carbon accounting become increasingly important.
“In steel production especially, there is now much greater focus on the energy usage and carbon impact of manufacturing,” says Bittner. “That is creating new incentives to adopt these technologies.”
Rethinking hydraulic control
Beyond energy savings, one of the most significant developments enabled by modern servo VSD systems is the simplification of hydraulic circuit design itself.
Traditional hydraulic systems often rely on multiple proportional valves, pressure reducing valves and flow control valves to regulate machine motion. In contrast, servo-controlled VSD systems directly regulate pressure and flow through the motor and pump.
“The prime mover itself becomes the control mechanism,” Bittner explains. This allows many conventional control valves to be reduced or eliminated entirely, simplifying the hydraulic architecture while simultaneously improving efficiency and controllability.
“It’s a completely different concept for some customers,” he says. “For more conservative users, the idea that the motor itself is controlling pressure can initially feel unfamiliar. But once they see how well it performs, that hesitation usually disappears.”
The precise and highly dynamic pump speed control also improves machine responsiveness and accuracy while reducing throttling losses, heat generation and overall system complexity.
In many cases, the reduction in heat generation can allow downsizing, or even elimination, of oil coolers. Lower operating temperatures also help extend the lifespan of seals and hydraulic fluid.
Noise reduction is another significant benefit. Because the motor and pump operate only at the speed required, machines often run substantially quieter than traditional constant-speed systems, improving operator comfort and reducing workplace noise exposure.
Skills, digitalisation and electrification
Despite the advantages, integrating VSD technology into hydraulic systems does require a shift in engineering approach.
One of the biggest challenges, according to Bittner, is sizing the systems correctly. Traditional hydraulic systems often relied on generous safety margins and oversized components. Variable speed architectures, however, demand a much more detailed understanding of machine duty cycles and operational behaviour.
“To size these systems properly, you need to understand the machine cycle in detail,” he says. “You need to know the pressure peaks, the flow peaks, how long they last, how frequently they occur. Many companies simply did not need that level of information before.”
This creates both a technical and cultural challenge, particularly for smaller OEMs and engineers whose expertise has historically focused purely on hydraulics rather than electronic controls and drive technologies.
To help bridge that gap, Danfoss has integrated p/Q control functionality directly into the drive system itself.
The result is that machine builders do not need to develop complex PLC programming to calculate motor behaviour. Instead, the PLC simply requests the required pressure or flow while the drive handles the control logic internally.
“The machine builder only asks for the outcome,” says Bittner. “That makes implementation much easier, especially for smaller OEMs that may not have extensive software resources.”
The rise of digitalisation is also helping accelerate adoption of electronically controlled hydraulics.
Once installed, VSD systems effectively become intelligent data platforms capable of supporting condition monitoring, predictive maintenance, diagnostics and machine performance analysis.
“You solve two challenges with one investment,” Bittner explains. “You improve efficiency, but you also gain access to valuable operational data.”
At the same time, broader electrification trends are reshaping industrial machine design.
According to Bittner, rotary hydraulic functions are increasingly being replaced by electric drives as motor technologies improve in both performance and affordability. Linear motion, however, remains more resistant to full electrification because hydraulic cylinders still offer major advantages in force density, shock resistance, robustness and operation in harsh environments.
As a result, many industrial machines are evolving into hybrid architectures combining electric rotary motion with hydraulic linear actuation.
Looking ahead, Bittner expects both electromechanical and electrohydraulic actuator technologies to continue advancing rapidly.
For Bittner, the direction of travel is fairly clear, even if adoption will not happen at the same pace everywhere. Some industries will move quickly because the financial case already stacks up. Others, particularly more conservative sectors, are likely to take longer as engineers become more comfortable with electronically controlled hydraulic architectures and as existing machine platforms are gradually redesigned.
What does seem increasingly difficult to ignore is the broader combination of pressures now shaping industrial equipment design. Energy costs remain a concern, sustainability reporting is becoming more demanding, and machine builders are under pressure to simplify systems while improving performance and diagnostics at the same time.
In that environment, variable speed hydraulics are no longer being viewed simply as an efficiency upgrade. Increasingly, they are becoming part of a wider shift towards more intelligent, connected and adaptable machine design.
“As the economics continue improving and people become more familiar with the technology, variable speed systems will increasingly become the standard,” says Bittner.
For further information please visit: https://www.danfoss.com