Pitch Cylinder

Bore: Φ100 mm

Rod: Φ50 mm

Stroke: 410 mm (per feed beam pitch angle range)

Operating pressure: continuous 22 MPa, max 25 MPa

Max push force: 196 kN (at 25 MPa, full-bore side)

Max pull force: 147 kN (at 25 MPa, annular side)

Breakaway pressure: ≤0.3 MPa

Piston velocity: <0.5 m/s (rapid pitch response)

Operating frequency: high-frequency intermittent, several pitch adjustments per drilling cycle

Internal leakage: ≤0.03 ml/min (at 22 MPa, over seal service life)

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

Suitable for: fully hydraulic drilling jumbos, mining jumbos, etc.

Precision Pitch Positioning

The barrel is forged from high-yield-ratio quenched and tempered alloy steel, with UT/MT inspected welds and FEA-optimized ends. The large-diameter thick-walled piston rod is precision hard-chrome plated, maintaining high structural rigidity despite frequent impacts and heavy vibration, ensuring accurate pitch angle.

High Side-Load Resistance & Guidance

Embedded wide bronze or composite guide rings with precision clearance control absorb radial forces from feed beam side loads and drilling recoil, preventing rod scoring and ensuring long-term smooth motion.

Multi-Stage Seals & Dust Protection

Multiple heavy-duty wipers and a metal scraper ring at the gland effectively block rock dust, cuttings, and slurry. The main seal is a hydrolysis-resistant polyurethane and filled PTFE composite, guaranteeing zero external leakage under high-pressure, high-frequency, and rock dust conditions.

Internal Cushioning for Noise Reduction

Progressive cushioning devices at both piston ends automatically decelerate and absorb impact energy at end strokes, eliminating rigid impacts, reducing noise, and protecting the articulation points and the cylinder itself.

Compact Maintenance-Free Design

The optimized envelope and mounting dimensions fit the compact boom-tip space. Self-lubricating composite bushings at all pivot points eliminate daily greasing and provide long service life under high-frequency pitch positioning.

Optional Smart Monitoring

A built-in displacement sensor can be integrated to provide real-time pitch angle feedback, supporting automated drilling positioning via the jumbo’s electronic control system.

Special bore, rod, and stroke

Built-in displacement sensor

Full stainless steel body and piston rod

Explosion-proof / mining certifications

Special mounting distances and port configurations