Return Cylinder (Piston Type)

Bore diameter: Φ180 mm – Φ410 mm

Rod diameter: Φ120 mm – Φ360 mm

Stroke: ≤4,500 mm (per maximum daylight opening of the moving crosshead)

Operating pressure: continuous 28 MPa, max 31.5 MPa

Max push force: approx. 4,156 kN (at 31.5 MPa, Φ410 mm bore, full-bore side)

Max pull force: 2,612 kN (at 31.5 MPa, Φ410 mm bore with Φ360 mm rod, annular side, for retraction)

Breakaway pressure: ≤0.3 MPa

Piston velocity: 0.05 – 0.4 m/s (rapid retraction; higher speeds optional)

Operating frequency: synchronized with the main cylinder, one return cycle per forging stroke

Internal leakage: ≤0.02 ml/min (at 28 MPa, over seal service life)

Temperature range: -25 ℃ to +120 ℃ (standard); -40 ℃ to +150 ℃ customizable

Suitable for: 5 MN–200 MN open-die forging presses, die-forging presses, multi-directional forging presses, etc.

High Pull Force for Rapid Retraction

The large annular area produces up to 2,612 kN of pulling force, briskly and smoothly lifting the heavy moving crosshead back after each forging stroke, significantly shortening idle time and increasing forging rhythm. The double-acting design can also supply auxiliary push force as needed.

Long-Stroke, High-Rigidity Guidance

The barrel and piston rod are crafted from high-yield quenched and tempered alloy steel, with FEA-optimized stress zones. Wide bronze guide bushings with precision clearance control deliver high bending stiffness and stable guidance over the full reciprocating stroke, preventing rod buckling.

V-Pack Sealing, Long-Life & Easy Maintenance

A multi-layer V-ring polyurethane/fabric composite seal pack with replaceable adjustment shims automatically compensates for compression set from sustained alternating shock, maintaining zero external leakage. Seal replacement requires only gland removal, making maintenance extremely simple.

Built-in Displacement Sensor, Synchronized Closed-Loop

An internally integrated magnetostrictive displacement sensor (±0.05 mm repeatability) provides real-time crosshead position feedback to the master controller. Coupled with servo-synchronized control of multiple return cylinders, it ensures the crosshead remains level throughout its stroke and returns precisely to the home position without tilt.

Super-Nut Locking for Vibration Resistance

All cylinder tie-rod bolts utilize mechanical super-nuts that maintain a constant preload under the extreme high-frequency vibration of forging hammers, completely eliminating the risk of leakage or misalignment caused by bolt loosening.

Flexible Options: Booster Cylinder & Rotary Union

An optional integrated booster cylinder delivers the same force with a significantly smaller bore, reducing system cost. An optional high-pressure rotary union provides leak-free rotational freedom for piping, simplifying installation layout.

Internal Cushioning & Noise Reduction

Progressive end-of-stroke cushions automatically decelerate the piston at both extremes, absorbing impact energy, lowering noise, and protecting the crosshead and cylinder itself.

Precision Manufacturing & Maintenance-Free Pivots

Key components are precision CNC-machined to micron-level form tolerances. All pivot points feature self-lubricating bearings that require no grease, delivering low wear and long service life even under high-duty cycling.

Special bore, rod, and ultra-long stroke

Built-in redundant displacement sensors

Booster cylinder and rotary union integration

Full stainless steel body and piston rod (highly corrosive environments)

Explosion-proof / mining certifications

Special mounting flanges, spherical bearings, and port configurations