Beyond Hydraulics

Hydraulic actuation is the invisible foundation of the modern built world. Every excavator breaking ground for a skyscraper, every forklift moving pallets through a warehouse, every crane lifting steel beams into place. They all push, pull, lift, and lower through pressurized fluid in high-pressure hoses. This technology is over a century old, and it works. But it comes with costs that most people outside of heavy industry never see.

Hydraulic fluid is toxic. Hoses degrade and leak. The EPA estimates that mobile hydraulic equipment in the U.S. alone releases millions of gallons of hydraulic fluid into the environment annually. Maintenance is constant and expensive: seals wear, fluid degrades, contamination causes cascading failures. The hydraulic power unit itself is heavy, inefficient (typical systems waste 50-70% of input energy as heat), and requires dedicated infrastructure on every machine.

As industries electrify everything from passenger vehicles to mining trucks, actuation remains the last holdout. Electric motors have replaced internal combustion in traction drives. Batteries have replaced diesel generators for auxiliary power. But the core work function, the push and pull that moves heavy loads, still runs on oil. The reason is simple: until recently, no electromechanical actuator could match hydraulic force density at industrial scale.

That is what RISE Robotics is trying to change. Their belt-driven actuators package the force output of a hydraulic cylinder into the same form factor, using the same mounting points, but powered entirely by electricity. No fluid. No hoses. No power unit. If it works at scale (and the evidence from their test programs suggests it can), the implications extend far beyond one company. It means every piece of hydraulic equipment on Earth is a candidate for retrofit or replacement.

The belt-driven actuator looks deceptively simple. A high-strength timing belt wraps around a pair of pulleys inside a cylindrical housing. An electric motor drives one pulley; the belt converts the rotary motion into linear extension and retraction. The geometry of the wrap determines the force multiplication. It’s the same principle as a block and tackle, except the “rope” is a precision-engineered belt and the “pulleys” are machined to micron tolerances.

The hard part is pushing. Belts are naturally good at pulling; tension is their default mode. But a hydraulic cylinder pushes and pulls with equal authority, because incompressible fluid transmits force in both directions. Making a belt transmit compressive force (literally pushing a rope) is the fundamental engineering challenge that RISE has spent years solving. Their solution involves proprietary guide systems that constrain the belt against buckling under compressive loads, maintaining rigidity across the full stroke while preserving the lightweight, maintenance-free advantages of the belt architecture.

The go-to-market challenge is equally formidable. Hydraulics is an entire ecosystem, not a single component. Every heavy equipment manufacturer has decades of hydraulic design expertise. Every maintenance shop stocks hydraulic seals and fluid. Every operator knows how hydraulic controls feel. Displacing all of that requires a migration path that doesn’t demand revolutionary change from conservative industrial buyers. RISE’s retrofit strategy is designed precisely for this: same cylinder dimensions, same mounting hardware, same operator experience. The machine doesn’t know the difference.

RISE has demonstrated that belt-driven actuation works, decisively: the SuperJammer arm lifted 7,015 lbs to earn the Guinness World Record for strongest robotic arm prototype. The open question is whether the total cost of ownership advantage (no fluid, no hoses, no power unit, reduced maintenance, higher efficiency) is large enough to overcome switching inertia in an industry that measures equipment lifetimes in decades. The Railgate 5500, their first commercial product and an all-electric liftgate for trucking, suggests the answer: 2x faster, 200 lbs lighter, 50% less energy, and no hydraulic infrastructure to maintain.