A technological renaissance in mobile hydraulics market
As vehicle electrification accelerates, the role of the hydraulic system is being more closely examined. Battery life is paramount in electrified architectures and hydraulics have traditionally been an energy taxing technology. Improvements in the hydraulic system is therefore key to enabling a longer battery life for electrified vehicles. In this context, one might say a renaissance within hydraulic technology is underway – here, research analysts Brianna Jackson takes a deeper look.
So far, vehicle OEMs have explored a variety of solutions aimed at improving the efficiency of their vehicles. Within hydraulics, these changes range from incorporating novel technology to redesigning the entire system. Through trialling these new components and systems, one thing is crystal clear: improving vehicle efficiency through the hydraulic system will not be a one size fits all solution. Factors such as vehicle size, operating conditions, duty cycle, and the degree of control an application requires, determines the viability of the solution in question. As vehicle OEMs strive to achieve their electrification ambitions, these factors must be kept in mind as the balance between efficiency and practicality is struck.
There are many challenges that traditional hydraulic architectures are facing in the wake of electrified off-highway vehicles and the pros and cons of emerging hydraulic technologies within this context.
Why must the status quo change?
The advantage of traditional hydraulic systems has always been their ability to achieve unmatched power density at very low costs. From a vehicle OEM perspective, this benefit was so great that the efficiencies in the hydraulic system became an afterthought. While vehicle OEMs are not quick to eliminate or even alter this tried-and-true technology from their designs, a fact is becoming clear: the hydraulic system will need a significant boost in energy efficiency to accommodate electrification.
Some vehicle OEMs have begun to electrify certain portions of their portfolios and have made significant progress in evaluating hydraulic system redesigns. One example where electrification is beginning to emerge is in electric mini excavators. We estimate the market for hydraulics sold to this vehicle type to be approximately $1.6bn in 2021. Given the size, these vehicles will be a fertile testing ground for new hydraulic technology. The rate at which mini excavators are going electric is shown below.
Earlier in the year, Bobcat unveiled their electric compact track loader, the T7X. The electric track loader was brought to life as a result of a collaboration with Moog Construction. Aside from its electric powertrain, one of the vehicle’s most interesting design features is the replacement of hydraulic cylinders with ball screw mechanical actuators. As mentioned above, electromechanical actuators provide an advantage in terms of maintenance in comparison to their hydraulic counterparts. The most pressing constraint of replacing hydraulic cylinders however, is a loss of power density. Though, in applications with low power density requirements, electromechanical actuation offers benefits such as tighter control and less noise. Additionally, within an electrified vehicle, the removal of the hydraulic system can simplify the overall design.
There are many best use cases for replacing hydraulic cylinders with electromechanical actuators. These use cases included vehicles found within the material handling sector such as aerial work platforms and telehandlers. However, the construction sector might also see greater adoption of electromechanical actuators. In the right applications, replacing hydraulic actuation with electromechanical actuation can lead to a lower total cost of ownership (TCO) as result of fuel savings, reduced maintenance costs, and tax subsidies associated with implementing green technology.
