{"id":1469,"date":"2026-08-26T05:03:29","date_gmt":"2026-08-26T05:03:29","guid":{"rendered":"https:\/\/ever-powers.com\/?post_type=product&p=1469"},"modified":"2026-08-26T05:05:04","modified_gmt":"2026-08-26T05:05:04","slug":"corn-header-lift-cylinder-ym4p-83-02b","status":"publish","type":"product","link":"https:\/\/ever-powers.com\/fr\/product\/corn-header-lift-cylinder-ym4p-83-02b\/","title":{"rendered":"Corn Header Lift Cylinder YM4P.83.02b \u2013 56mm Bore, 50mm Rod, 300mm Stroke"},"content":{"rendered":"

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YM4P.83.02b \u00b7 Corn Harvester Series<\/p>\n

Corn Header Lift Cylinder \u2014 High-Force, Low-Drift Header Height Control for 4-Row Corn Harvesters<\/h2>\n

Part No. YM4P.83.02b \u00a0|\u00a0 Bore: 56 mm \u00a0|\u00a0 Rod: 50 mm \u00a0|\u00a0 Stroke: 300 mm \u00a0|\u00a0 C\/C: 660 mm<\/p>\n<\/div>\n

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\"YM4P.83.02b<\/p>\n

YM4P.83.02b Header Lift Cylinder<\/p>\n<\/div>\n

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The YM4P.83.02b corn header lift cylinder<\/strong> controls one of the most consequential adjustments a corn harvester operator makes during a working day: the height of the cutting header above the ground. Get this wrong \u2014 too low and you’re ingesting soil and rocks through the snapping rolls; too high and you’re leaving ears on the stalks. The hydraulic cylinder that controls this position must hold the header absolutely steady under the combined weight of a multi-row cutting platform and the dynamic loads of forward travel across uneven ground.<\/p>\n

With a 56 mm bore and a notably thick 50 mm rod \u2014 giving a rod-to-bore ratio of 0.893 \u2014 this cylinder is configured as near-equal-area for a reason: the retract force must match the extend force closely enough to hold header height against both gravity and upward ground reaction forces with minimal position drift.<\/p>\n<\/div>\n<\/div>\n

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Hydraulic Cylinder for Corn Harvester Header Height Adjustment \u2014 Complete Technical Parameters<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Parameter<\/th>\nValue<\/th>\nEngineering Note<\/th>\n<\/tr>\n<\/thead>\n
Bore Diameter (D)<\/td>\n56 mm<\/td>\nAt 160 bar working pressure, push force \u2248 39.4 kN \u2014 sufficient to raise a loaded 4-row header assembly (typically 450\u2013600 kg) with full safety margin and speed.<\/td>\n<\/tr>\n
Rod Diameter (d)<\/td>\n50 mm<\/td>\nUnusually thick rod relative to bore (rod\/bore ratio = 0.893). This is a deliberate heavy-duty specification \u2014 the thick rod resists buckling under off-axis loads from header sway and provides near-equal retract force for header lowering control.<\/td>\n<\/tr>\n
Stroke (L)<\/td>\n300 mm<\/td>\nFull stroke of 300 mm covers the complete header height range \u2014 from minimum stubble clearance (~150 mm) to maximum transport\/headland height. Provides fine incremental control across the full working range.<\/td>\n<\/tr>\n
Mounting Distance (C\/C)<\/td>\n660 mm<\/td>\nCenter-to-center retracted. The 660 mm C\/C is the governing dimension for frame bracket compatibility. Always verify against platform bracket before ordering a replacement.<\/td>\n<\/tr>\n
Rated Working Pressure<\/td>\n160 bar (2,320 psi)<\/td>\nStandard agricultural hydraulic circuit pressure. Cylinder tube rated to 2.5\u00d7 working pressure per ISO 6020\/2 test protocol.<\/td>\n<\/tr>\n
Peak \/ Surge Pressure<\/td>\n250 bar (3,625 psi)<\/td>\nCovers transient spikes from emergency stop or obstacle impact on the header. Piston seal rated for full surge pressure without extrusion.<\/td>\n<\/tr>\n
Rod Surface Treatment<\/td>\nHard chrome, 25\u201330 \u00b5m<\/td>\nOn a 50 mm rod, even minor chrome pitting rapidly accelerates rod seal wear due to the large circumferential contact area. Specification requires 25 \u00b5m minimum chrome depth across full rod length.<\/td>\n<\/tr>\n
Internal Leakage<\/td>\n\u2264 3 cc\/min at rated pressure<\/td>\nLow bypass is critical here. A cylinder with excessive piston seal leakage will allow the header to slowly drop during stationary work (headland turns, inspections), requiring constant operator correction.<\/td>\n<\/tr>\n
Seal System<\/td>\nPU quad-ring + PTFE guide<\/td>\nQuad-ring geometry on piston maintains sealing force across temperature cycles without the permanent set that degrades standard O-ring piston seals in seasonal-use equipment.<\/td>\n<\/tr>\n
Cylinder Tube Material<\/td>\nE355 cold-drawn seamless<\/td>\nHoned bore Ra \u2264 0.4 \u00b5m. Wall thickness calculated for 250 bar burst with a safety factor of 4:1 on tube yield strength.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

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Engineering Reference \u00b7 Force & Rod Calculations<\/p>\n

Push Force (header raise):<\/strong> F = 160 bar \u00d7 \u03c0\/4 \u00d7 (0.056)\u00b2 \u2248 39,437 N (39.4 kN)<\/strong><\/p>\n

Pull Force (header lower):<\/strong> F = 160 bar \u00d7 \u03c0\/4 \u00d7 (0.056\u00b2 \u2212 0.050\u00b2) \u2248 8,670 N (8.7 kN)<\/strong><\/p>\n

The annular area is small (only 477 mm\u00b2 vs. 2,463 mm\u00b2 full bore) because the 50 mm rod occupies 80% of the bore cross-section. Pull force of 8.7 kN is more than adequate for header lowering \u2014 gravity assists the retract \u2014 while the 39.4 kN push force provides a 6:1 safety margin over a 600 kg header weight (5.9 kN at pivot).<\/p>\n

Rod buckling check (Euler):<\/strong> A 50 mm solid chrome rod at 300 mm stroke \u2014 with a slenderness ratio of ~6 \u2014 is far below the critical buckling load. This is an important validation for procurement engineers: the thick rod is not oversized for aesthetics but is the correct engineering specification for an extended, laterally loaded header-lift linkage.<\/p>\n<\/div>\n

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\"Corn<\/p>\n

Header height precision directly affects grain loss rate and harvesting efficiency<\/p>\n<\/div>\n

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Why the 56mm Bore \/ 50mm Rod Specification Is Not Interchangeable with Standard Lift Cylinders<\/h2>\n

The near-equal bore-to-rod diameter (56\/50) of this cylinder is unusual in agricultural hydraulics, where most lift cylinders use a rod diameter of 55\u201370% of bore. This specification is a precise engineering response to the operating conditions of a front-mounted corn header:<\/p>\n

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  • Off-axis bending loads:<\/strong> As the harvester traverses a furrow or ridge, the header can rock laterally by 5\u20138\u00b0 relative to the main frame. The cylinder pivot absorbs a portion of this as bending moment on the extended rod. A standard 32 mm or 36 mm rod on a 56 mm bore cylinder would develop significant deflection at mid-stroke, accelerating rod-seal wear and risking rod fatigue cracking after 2\u20133 seasons of intensive use.<\/li>\n
  • Vibration fatigue:<\/strong> The snapping rolls and gathering chains on a corn header generate structured vibration at 40\u2013120 Hz during operation. These vibrations transmit through the header frame directly into the lift cylinder mounting pins and rod. The 50 mm solid rod has a bending stiffness approximately 2.6\u00d7 that of a 38 mm rod at the same length \u2014 fundamentally different fatigue behaviour.<\/li>\n
  • Position hold under oscillating load:<\/strong> If the header is held at a fixed height while harvesting, the cylinder is effectively a structural member resisting both the header weight and the dynamic vertical loads from crop resistance. Piston seal leakage under cyclic loading is higher in cylinders with thin rods (lower compression stiffness) \u2014 the thick rod reduces this effect.<\/li>\n
  • Consequence of substitution:<\/strong> Replacing this cylinder with a standard-rod equivalent (same bore, 32\u201336 mm rod) is a false economy. The maintenance interval shortens materially, and the failure mode \u2014 a rod bent enough to score the wiper seal \u2014 typically requires cylinder replacement rather than a field seal kit swap.<\/li>\n<\/ul>\n

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    OEM Combine Header Cylinder Construction \u2014 Material and Process Standards<\/h2>\n
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    Cylinder Tube<\/p>\n

    E355 cold-drawn seamless steel tube, honed to Ra \u2264 0.4 \u00b5m. Wall thickness: 8 mm \u2014 calculated for 4:1 safety factor on tube yield at 250 bar burst. External surface: zinc phosphate primer + polyurethane topcoat, 80 \u00b5m minimum DFT, salt-spray tested to 500 hours.<\/p>\n<\/div>\n

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    Chrome Rod<\/p>\n

    Ck45 (1.1191) steel core, ground and polished to Ra \u2264 0.2 \u00b5m before chrome plating. Hard chrome 25\u201330 \u00b5m, HV 800+. Post-plate ground to h6 tolerance for seal fit. At 50 mm diameter, the rod’s second moment of area is 307,000 mm\u2074 \u2014 providing the structural rigidity this application demands.<\/p>\n<\/div>\n

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    Piston & Seals<\/p>\n

    Cast iron piston with bronze guide rings. Primary piston seal: PU quad-ring with PTFE energised backup. Rod seal: dual-lip PU. Wiper: polyurethane with steel-reinforced exclusion lip. All seals rated \u221225 \u00b0C to +100 \u00b0C on ISO VG 46\/68 mineral oil.<\/p>\n<\/div>\n

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    End Fixings<\/p>\n

    Both ends: clevis-type pin mount, \u00d825 mm pin bore, with grease nipple for lubrication of the pin\/bush interface. Bush material: sintered bronze (self-lubricating). Clevis eyes machined to H7 tolerance for pin fit. Grease type: NLGI #2 lithium-complex, compatible with food-grade alternatives for USDA-regulated harvest environments.<\/p>\n<\/div>\n<\/div>\n

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    Header Height Precision \u2014 How Cylinder Drift Rate Translates to Grain Loss in the Field<\/h2>\n

    For OEM engineers and technically sophisticated distributors, it is worth quantifying exactly what cylinder performance means in agronomic terms. Research data from major corn-growing regions consistently shows that header height is the single largest controllable variable in ear-loss rate:<\/p>\n