Torque Cylinder

Bore diameter: Φ200mm – Φ420mm

Rod diameter: Φ120mm – Φ260mm

Stroke: 180mm – 300mm (micro-motion for torque and steering)

Operating pressure: continuous 21 MPa, max 25 MPa

Max push force: 3,460 kN (at 25 MPa, Φ420mm bore)

Max pull force: 1,960 kN (at 25 MPa, Φ420mm bore with Φ260mm rod)

Breakaway pressure: ≤0.3 MPa

Piston velocity: 0.01 – 0.1 m/s (low-frequency micro-motion, primarily static torque)

Operating frequency: 0–2 attitude corrections per advance cycle; torque is continuously alternating

Internal leakage: ≤0.025 ml/min (at 21 MPa, over seal service life)

Static holding: ≤1.5 mm drift over 24 h under rated torque (with counterbalance valve)

Temperature range: -20℃ to +80℃ (standard); -40℃ to +120℃ customizable

Suitable for: Φ4m–Φ12m double shield TBMs (hard rock and mixed-face conditions)

Integrated Heavy-Duty Torque & Steering Design

The barrel is made of high yield-ratio quenched & tempered alloy steel forgings or ultra-heavy-wall tube, with a large-diameter forged piston rod hard chrome plated (HV900–1100). FEA-optimized gland and clevis roots, plus 100% UT/MT inspected welds, yield a fatigue life exceeding 1.2 million alternating torque cycles. It easily handles the pulsating shocks from rock fragmentation while enabling active bidirectional steering.

Multi-Stage Sealing & Rock Dust Protection

To combat the harsh mix of rock dust, cuttings, and fissure water around the front shield, the gland exterior incorporates a three-stage defense of wiper + stainless steel scraper + labyrinth seal. The main seal is a hydrolysis-resistant polyurethane/filled PTFE composite with an accumulator buffer chamber to absorb pressure pulsations, guaranteeing zero leakage over long drives.

Integrated Safety Counterbalance Valve

Each cylinder is equipped with a high-flow counterbalance valve or dual pilot-operated check valve for static locking. In the event of a hose burst or system pressure loss, the cylinder instantly locks its position, preventing cutterhead rotation or sag due to reaction torque — protecting both crew and machine.

Low-Friction Precision Micro-Adjustment

Low-friction seals and wear-resistant guide rings keep breakaway pressure ≤0.3 MPa, enabling smooth, stick-slip free attitude correction. Combined with electro-hydraulic closed-loop control and optional built-in displacement sensors (±0.2 mm accuracy), precise steering guidance is achieved.

Full Corrosion & Temperature Resistance

External surfaces receive a moisture-resistant epoxy coating; rod plating options include Ni/Cr, laser cladding, or ceramic spray. All fasteners are stainless steel, suited for high rock temperatures and corrosive groundwater.

Maintenance-Free Pivots & Compact Layout

Self-lubricating composite bushings in both clevises eliminate daily greasing and offer long service life. Mounting length and port orientations are tailored to the shield geometry, fitting the tight radial space within the double shield.

Special bore/thrust rating for extra-large TBMs

Group synchronous valve block with displacement sensor set

Full stainless steel body and piston rod

High-pressure seal upgrade (42 MPa)

Explosion-proof / mining certifications

Custom mounting dimensions, port configurations, and paint finish