Top 10 hydraulic component manufacturers for robotics and automated machine

A hydraulic robot rarely runs on one supplier's parts. A pump from one company, valves from another, accumulators and filters from a third, and machined valve bodies, end caps, and rods from a contract shop each set a limit on force, response, cleanliness, or service life.

Key takeaway: choose hydraulic suppliers by role, not brand size. Servo specialists set control performance, pump makers set pressure, conditioning specialists keep the oil clean, and the shop that machines your custom parts decides whether the circuit seals.

A hydraulic manipulator arm with its cylinders, hoses, and a manifold block carrying cartridge valves. The manifold, valve bodies, end caps, and rods are typical custom machined parts in a hydraulic robot.

Image rights: original image generated for this article by XTJ CNC with an AI image tool. It shows no real product, brand or person, and XTJ CNC authorizes WHYPS to publish it.

Where do robots still use hydraulics?

Hydraulics wins where a robot must deliver large forces from a small actuator, absorb shock, or hold a heavy load. IIT researchers note it "is often selected for its high power density, robustness, and high-bandwidth control performance."

• Demolition robots: the remote-controlled Brokk 200 weighs 2,100 kg and runs at 18 MPa.

• Subsea manipulators: the Schilling TITAN 4 is a seven-function servo-hydraulic ROV arm that lifts 122 kg at full extension.

• Legged robots: IIT's HyQ quadrupeds drive 12 joints hydraulically, and HyQReal carries a Moog battery-powered hydraulic system on board.

• Forestry cranes: John Deere's 1510G forwarder crane works at 24 MPa.

Electric drives are taking lighter work. Boston Dynamics retired its hydraulic Atlas in April 2024 for an all-electric version. For the electric side of that choice, this comparison of robot actuator companies covers reducers, frameless motors, and joint modules.

What hydraulic components go into a robot?

Actuators

Linear cylinders push and pull booms, jaws, and leg links, while rotary and vane actuators suit wrists and slewing axes where a linkage won't fit. A servo-hydraulic axis draws from a central pump through a valve. An electro-hydrostatic actuator (EHA) pairs a servomotor and pump with one cylinder, which Moog says "eliminates the need for a hydraulic power unit (HPU). " Integrated smart actuators add the servo valve and sensors in one unit, which suits legged robots.

Servo and proportional valves

A servo valve has under 3% spool center overlap, and a proportional valve has more, per a Power & Motion definition. Servo valves give the sharper closed-loop response a force-controlled joint needs, but their filtration needs are "the most extreme for the entire hydraulic industry."

Pumps and power units

Axial piston pumps handle high-pressure, variable-displacement duty, while gear and vane pumps serve simpler auxiliary circuits. An HPU combines pump, motor, reservoir, filtration, and relief protection. Fixed rigs use a remote HPU; mobile robots carry one on board, as HyQReal does.

Manifolds and accumulators

A manifold block replaces hoses with drilled passages and takes cartridge valves directly, so there are fewer leak points and a stiffer flow path. Its cross-drilled galleries must break through cleanly with no burrs. Accumulators store fluid against a gas charge to supply flow peaks, damp pulsation, and provide what HYDAC calls "the classic emergency function in the event of power failure."

Filtration, seals, and pressure testing

Cleanliness is reported as an ISO 4406 code for particles at 4, 6, and 14 µm. HYDAC targets 16/14/11 for servo valves below 3,000 psi, so specify filtration from the most sensitive valve. Freudenberg's Merkel seal datasheets call for a sliding surface of Ra 0.05 to 0.3 µm. Pressure ratings must cover the spikes a robot sees when it strikes an obstacle, and ISO 10771-1 sets the fatigue pressure test method for metal parts such as manifolds and cylinder bodies.

Where do pneumatics fit?

At the gripper. Robotiq notes that "the speed and cost of pneumatic grippers are hard to beat," but grip force is "hardly programmable," and compressed air makes mid-stroke positioning imprecise. Grippers such as SMC's MHZ2 run at up to 0.7 MPa, far below hydraulic pressures, so heavy motion stays hydraulic or electric.

How we chose

Each company makes hydraulic hardware used in robots, manipulators, or automated machinery, and each figure comes from its own site or datasheet, checked in October 2026. Disclosure: XTJ CNC wrote this article and appears as entry one.

Top 10 hydraulic component manufacturers

1. XTJ CNC

Founded in 2005, with sites in Shenzhen and Dongguan, XTJ CNC machines custom parts to customer drawings. Its site lists hydraulic system components ("valve bodies, pump housings, cylinder end caps, and piston rods"), most machined from 4140 steel. The Dongguan branch holds ISO 9001:2015 and IATF 16949:2016 certificates, every quote starts with a free DFM review, and there's no MOQ for prototype runs.

Best for: teams designing their own hydraulic hardware who need valve bodies, pump housings, end caps, or rods machined to drawings.

Less suited to buyers wanting a complete, rated catalog of cylinders, valves, or pumps. Its certificates exclude product design, so rating stays with you or the component maker.

2. Moog

Moog of Elma, New York, makes D633 and D634 servo valves rated to 350 bar and developed most of HyQReal's hydraulic actuation system with IIT.

Best for: high-bandwidth closed-loop force and position control.

Less suited to buying an off-the-shelf hydraulic robot joint, since its legged-robot actuator work is documented through research projects rather than a current datasheet.

3. Parker Hannifin

Cleveland-based Parker Hannifin sells 2H and 3H industrial cylinders rated at 3,000 psi, plus a compact electro-hydraulic actuator delivering 21.3 kN.

Best for: standard catalog cylinders, valves, and compact actuators from one supplier.

Less suited to: very high-force axes from a self-contained unit, because the compact EHA tops out at 21.3 kN.

4. Bosch Rexroth

Bosch Rexroth of Lohr am Main, Germany, builds CytroMotion self-contained actuators of up to 110 kN, which it says "require no hydraulics know-how" to engineer and commission.

Best for: machine builders who want packaged, electrically controlled hydraulic force without a hydraulics team.

Less suited to: small or lightweight robot joints, since these units target presses and heavy industrial axes.

5. Danfoss power solutions

Danfoss, of Nordborg, Denmark, took over Eaton's industrial and mobile hydraulics in 2021. Its H1P piston pumps work at up to 480 bar delta pressure, and its PLUS+1 XM100 controller supports Level 3 autonomy.

Best for: construction, forestry, and agricultural machines, including ones moving toward autonomy.

Less suited to factory robots and grippers, as its ranges target mobile equipment builders.

6. Kawasaki Heavy Industries

Kobe-based Kawasaki makes K3V axial piston pumps rated at 34.3 MPa for excavators and has published research on Hydro Servo Muscle, an electro-hydraulic actuator for its Kaleido humanoid's legs.

Best for: excavators, cranes, and other heavy mobile machines.

Less suited to buyers wanting a hydraulic robot actuator today, since Hydro Servo Muscle is still in development.

7. HYDAC

HYDAC of Sulzbach/Saar, Germany, makes bladder accumulators rated up to 550 bar as standard and the CS 1000 sensor, which monitors contamination online in ISO 4406 codes.

Best for: energy storage, pulsation damping on servo axes, and fluid-condition monitoring.

Less suited to: motion hardware, since HYDAC keeps circuits clean and steady rather than moving the robot.

8. Atos

Atos of Sesto Calende, Italy, makes digital servoproportional valves rated to 350 bar, with an LEZ version that adds an axis controller closing the position loop of "any hydraulic actuator."

Best for: closed-loop electrohydraulic axes where the valve, transducer, and controller come from one supplier.

Less suited to: pneumatic or fully electric end-of-arm tooling, since the range is electrohydraulic only.

9. HAWE Hydraulik

Founded in Munich in 1949, family-owned HAWE makes compact hydraulic power packs and high-pressure pumps for pressures above 450 bar. Its INKA unit is used in machine tools and handling systems.

Best for: compact power packs and valves for machine tools and clamping and handling where space is tight.

Less suited to buyers wanting a valve, transducer, and axis controller as one package, since control integration stays with the machine builder.

10. Enerpac

Enerpac, owned by Milwaukee-based Enerpac Tool Group, makes RC-series cylinders rated at 700 bar and workholding for fixtures up to "robotic assisted machining centers."

Best for: high-force lifting, positioning, and clamping, including automated machining cells.

Less suited to: continuous servo-controlled motion, since its products are tools and clamps rather than servo axes.

How should you evaluate a supplier of machined hydraulic parts?

Catalog pumps and valves carry published ratings, but custom manifolds, valve bodies, end caps, and rods depend on the shop. Ask for a sample inspection report, then check:

• Bores and sealing surfaces: how bores are finished and measured against the seal maker's figures and whether cartridge cavities follow the valve maker's drawing.

• Cross-drilled galleries: how internal burrs are removed and inspected, because a loose burr ends up in a servo valve.

• Pressure testing: the test pressure and method were agreed on in the drawing before production.

• Cleanliness: the cleaning method, cleanliness requirement, and sealed packaging.

• Traceability and inspection: material certificates, CMM data, and first article inspection before a production run.

Which manufacturer fits your project?

• Your own manifold, valve body, or cylinder parts: a custom machining shop such as XTJ CNC.

• A fast closed-loop force or position axis: Moog or Atos.

• Hydraulic force without a central power unit: Parker Hannifin, Moog or Bosch Rexroth.

• An automated mobile machine: Danfoss Power Solutions or Kawasaki Heavy Industries.

• A fouling servo circuit or energy storage: HYDAC.

• Compact power or high-force clamping on a machine tool: HAWE Hydraulik or Enerpac.

• Light parts gripped at high speed: a pneumatic gripper from SMC or Festo.

Whatever the mix, put cleanliness codes, pressure ratings, seal finishes and test methods on every drawing, and pressure-test a pilot set before scaling to production.