Building the Future of Construction Equipment
Moog and Bobcat partner on an all-electric track loader.
Moog and Bobcat partner on an all-electric track loader.
Bob Vavra - (Power&Motion)
Doosan Bobcat won two awards at the 2022 CES Show in Las Vegas for its Bobcat T7X, billed as “the world’s first all-electric compact track loader.” Helping to power the T7X is a machine electrification system from Moog Inc. that delivers an integrated software framework, electric machine controller, lift and tilt electric cylinders, electric traction motors and power electronics. “With the help of Moog’s system, the T7X is a major step forward for the productivity, safety and sustainability of construction machinery,” Moog officials said in a press release.
In a video interview, Power & Motion discussed the partnership with Doosan Bobcat. Participating in that that video discussion were:
In a separate interview, Alfieri talked about the project and its innovative approach to developing the force and motion needed for the application from an electric system. Alfieri, a member of the Power & Motion Editorial Advisory Board, also discussed the future implications of electric actuation and motion control for the construction industry as a whole and in particular for hydraulics application.
Power & Motion: Talk about the first discussions with Doosan regarding the Bobcat T7X. What were their goals, and why was Moog selected as their partner on the project?
Alfieri: Doosan Bobcat had a vision for an all-electric machine. But they realized getting there would require partners to overcome challenges. One difficult challenge they—as well as any OEM—faced was finding electric cylinders of the size and force necessary to power the T7X’s lift and tilt. Through its research, Doosan Bobcat learned about Moog and its work for the agricultural and construction industry.
During a visit to Moog, Doosan Bobcat realized Moog was not only a provider of technology but also a systems integrator that could speed up the journey to reach Doosan Bobcat’s vision in much the same way Moog did in converting hydraulic full flight simulators to all-electric versions.
P&M: Talk about the engineering involved with transitioning from a traditional hydraulic system to an electric one. What are some of the engineering challenges your team faced in the process?
Alfieri: Transitioning from hydraulic to electric is about understanding an entire system, not just providing components, especially when an OEM wants to achieve all the performance required for a comparable or even better machine. It’s not a one-to-one (or pin-to-pin) replacement because there’s a lot of modification to do. We took a systemwide view, which is what enabled us to engineer a purely electric solution, including battery, and sized appropriately to get right run time for four hours of heavy-duty work and eight hours of normal-duty work.
To achieve the power wanted and prepare for a path toward next-gen autonomous features, we designed an electric system above 400 V. But that high voltage requires safety in terms of the electrical system (e.g., remove shock hazards) as well as the function of the machine to ensure the vehicle won’t make unintended moves. One way we achieved that is with a safe torque off feature.
P&M: The move toward electrification in construction and off-highway equipment is accelerating. Is this strictly an environmental issue, or are there practical advantages to moving to an all-electric fleet?
Alfieri: Some practical advantages would be the fact that all-electric machines like the T7X require almost no maintenance. When we replace the hydraulic system with an electric one, we’re also removing pumps, hoses, tanks and valves that can break or require service. For example, the Bobcat T7X has electric actuators and motors, so it uses only one quart of eco-friendly coolant compared to 57 gallons of fluid in its diesel/hydraulic equivalent model.
Another advantage for electric systems is that they become much more controllable, and as things become more automated, the vehicle owner or operator has more precise control. Regarding data, electric systems allow machine owners to collect data to make smarter decisions at the machine level and the construction site.
An all-electric machine is a software-enabled like a smartphone; the vehicle owner can achieve faster, more precise updates and features. And environmentally speaking, there’s less noise and less vibration, which helps operators work longer and reduce noise pollution in neighborhoods and communities near construction.
P&M: Given all of this, where do hydraulic systems continue to be valuable? What are the advantages of hydraulics in the off-highway environment?
Alfieri: Hydraulic systems continue to be appropriate for large machines, like heavy-duty excavators. That said, there are hybrid solutions, too, so a vehicle maker doesn’t have to choose an all-hydraulic or all-electric system. Moog has technology that covers hydraulic, electric and electro-hydraulic; we’re technologically neutral. These high-powered continuous duty machines can be designed for zero-emission, too.
Not long ago, Moog partnered with CASE to develop a zero-emission, electrically controlled hydraulic backhoe loader that weighed more than 15,800 lb. There will always be niche applications for hydraulic systems, and it’s important to have solutions to support those.
The construction industry will increasingly see electrified solutions for multi-axes machines, but for packaging and power-density reasons, hydraulic solutions will still be valuable. For example, the aircraft industry went to electric solutions, but the dimensions of the interior space of jet airliners’ wings still require hydraulic transmission to achieve the required power density to move the wings flaps, spoilers and slats.
P&M: How will Moog apply the lessons of the Bobcat project to other aspects of your business? What other applications will we see in the future?
Alfieri: We took a huge step with Doosan Bobcat, and there will be many more to follow, including converting different product types from hydraulic to electric and differently sized products from hydraulic to electric. This could include skid steers, tractor backhoe loaders, wheel loaders, mini-excavators and outside the construction industry to areas like airport handling equipment and even garbage trucks. This work starts to open opportunities for more electric systems, which are more controllable and offer additional productivity solutions through connectivity and automation in future machines.
P&M: What should the industry do to start preparing for a hybrid approach to off-highway equipment? Are we going to need changes in maintenance, supply and engineering for existing fleets?
Alfieri: Anyone in the industry should start asking themselves, and their business partners and suppliers how they’re preparing for an increasingly electrified future, so they can chart a course forward. The skills maintenance crews will have in the future will be more about electrification and software versus mechanical hydraulic. As machines increasingly become all-electric, maintenance will be more predictive because a vehicle owner can stream data from the machine and apply analytics to be smarter about maintaining a fleet and scheduling maintenance.
Troubleshooting and diagnostics will be possible via the web, and maintenance workers can, potentially, understand what needs to get fixed before they leave their office. In fact, repairs may not require a technician, and if they do, technicians can tell what parts they need before they even leave their office. It’s an opportunity for maintenance workers, and others, to develop a new set of skills to take on different types of jobs.
Other changes will include building of new electrical charging stations. And inevitably new suppliers and players will emerge.
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