Réducteur pour herse rotative EP-PH90 — 70 à 90 kW, rapport de réduction de 1,96:1

EP-PH90 Power Harrow Gearbox — Product Overview

Purpose-Built for Power Harrow Implements

Power harrows operate fundamentally differently from rotary tillers. Where a tiller uses horizontally spinning blades to cut and invert soil, a power harrow drives vertical tines in opposing rotation to shatter clods and level the surface without disturbing the soil horizon. This gentler action requires a slower, higher-torque output than standard tillage — exactly what the EP-PH90 power harrow gearbox delivers. The 1.96 : 1 reduction converts 540 rpm PTO input into 275 rpm, providing nearly twice the torque multiplication of a typical 1.5 : 1 boîte de vitesses pour cultivateur rotatif.

Shared Involute Spline Input Platform

The EP-PH90 uses the same 6×28×34.93×8.69 involute spline input as the EP-225 multi-ratio intermediate gearbox, meaning a single arbre de transmission de prise de force can connect to both gearboxes interchangeably. Farms operating both a power harrow and a rotary tiller on the same tractor can swap between the EP-PH90 and the EP-225 without purchasing separate drive shafts — a practical cost saving for mixed-implement operations.

Power Class & Application

Rated at 70–90 KW (95–120 HP), the EP-PH90 is sized for mid-to-large tractors running power harrows with 2.5–4.0 meter working widths. The 6×36×44×11 spline output provides generous tooth contact area for the high torque loads generated during aggressive clod-breaking in heavy clay or compacted soil, while the CNC-machined HT250 cast-iron housing ensures long-term dimensional stability under sustained field operation.

Spécifications techniques complètes

All specifications verified against the Korea Ever-Power engineering drawing for the EP-PH90 (catalog reference P07). Dimensional values measured at 20°C ambient, no-load condition.

How a Power Harrow Works — And Why It Needs a Dedicated Gearbox

The Vertical-Tine Principle

A power harrow uses pairs of counter-rotating vertical tines mounted on individual gear-driven rotors. Each pair of tines spins in opposite directions, breaking surface clods and mixing the top 5–15 cm of soil without inverting deeper layers. This preserves the natural soil horizon — keeping organic matter in the top layer and undisturbed subsoil below — which is critical for preserving soil biology and long-term fertility in Korean agricultural soils.

Why 275 rpm Is the Optimal Speed

Power harrow tines must rotate fast enough to shatter clods but slow enough to avoid pulverizing soil structure into dust. Agronomic research and field experience across European and Asian farming systems converge on 250–300 rpm as the ideal tine speed range. The EP-PH90’s 275 rpm output sits at the center of this window. Running faster (as a standard 1.5 : 1 gearbox would deliver at 352 rpm) over-processes the soil, creating a hard pan below the tillage depth and destroying beneficial mycorrhizal networks.

Torque Multiplication at 1.96 : 1

The deeper 1.96 : 1 reduction ratio multiplies input torque by nearly 2× — delivering approximately 31% more torque at the output shaft than a standard 1.533 : 1 gearbox at the same input power. This additional torque reserve is essential because power harrow tines encounter higher instantaneous resistance than tiller blades: each tine must break individual clods through compression and shear rather than slicing through soil in a continuous cut. The torque spikes during clod-breaking can momentarily exceed twice the steady-state load, and the EP-PH90’s deep reduction ensures sufficient margin to absorb these transients without stalling.

Power Harrow vs. Rotary Tiller — Why the Gearbox Must Be Different

Farmers transitioning from rotary tillers to power harrows sometimes ask whether they can use the same intermediate gearbox for both implements. The answer is no — and understanding why will protect both your soil quality and your equipment investment:

Dimensions clés et interface de montage

Scénarios d'application sur le terrain

Precision Seedbed Preparation

Power harrows excel at creating fine, uniform seedbeds for precision-seeded crops such as vegetables, sugar beet, and small grains. Korean vegetable farms increasingly adopt power harrows because the crumb-structured seedbed they produce improves seed-to-soil contact, accelerates germination uniformity, and reduces the need for secondary tillage passes. The EP-PH90’s 275 rpm output produces the optimal crumb size (5–15 mm aggregates) for mechanical transplanting and direct seeding equipment.

Conservation Tillage Programs

Agricultural sustainability programs in Korea and Japan promote reduced-inversion tillage to preserve soil organic carbon and microbial biodiversity. Power harrows driven by the EP-PH90 meet this requirement by working only the top 5–15 cm of soil without flipping the profile. This makes the EP-PH90 a key component in farms transitioning from conventional full-inversion tillage to conservation agriculture practices.

Combined Harrow-Drill Operations

Modern power harrow implements are frequently mounted in combination with seed drills, creating a single-pass seedbed-and-sow machine. The EP-PH90’s 70–90 KW power rating accommodates the additional draft load of the seed drill component, while its 275 rpm output maintains consistent seedbed quality even as ground speed varies across the field. This combination reduces field traffic, saving fuel and minimizing soil compaction from tractor wheel passes.

Why Choose the EP-PH90 for Your Power Harrow

Installation & Commissioning

Mounting the EP-PH90 to the Harrow Frame

❶ Position the EP-PH90 on the harrow frame using the 60 × 70 mm base bolt pattern. Insert mounting bolts finger-tight to allow final alignment adjustment.

❷ Engage the 6×36×44×11 output spline into the harrow’s central distribution gearbox. Verify full spline engagement depth before tightening the base bolts.

❸ Torque all mounting bolts to specification in a star pattern. Re-check torque after the first 8 operating hours.

❹ Connect the PTO drive shaft to the 6×28×34.93×8.69 involute spline input. Install the shaft safety guard and verify free rotation.

❺ Fill gear oil (SAE 80W-90 GL-5) through the breather port — approximately 2,5 litres. Run a 5-minute idle test at low PTO speed, then verify at full 540 rpm before field engagement.

Programme de maintenance

◆ Avant chaque séance de travail — Check oil level; inspect seals and mounting bolts.

◆ Après les 100 premières heures — Première vidange d'huile : vidanger, rincer, remplir avec de l'huile neuve SAE 80W-90 GL-5.

◆ Toutes les 500 heures / annuellement — Full oil change; inspect magnetic drain plug for debris.

◆ Toutes les 1 000 heures — Inspect both input and output splines for wear; check all bolt torques.

◆ Climats froids (en dessous de −20°C) — Switch to SAE 75W-90 full-synthetic GL-5.

Produits complémentaires et composants de transmission

Arbres de transmission de prise de force

Korea Ever-Power supplies matched cardan shafts pre-configured for the 6×28×34.93×8.69 involute spline input. Because the EP-PH90 shares this input profile with the EP-225, a single drive shaft serves both your power harrow and rotary tiller operations — reducing your PTO shaft inventory to one universal unit.

Associations de boîtes de vitesses saisonnières

Farms using the EP-PH90 for spring seedbed preparation often run a boîte de vitesses pour presse à balles rondes during straw season and a standard tillage gearbox for autumn incorporation. Korea Ever-Power manufactures the complete range of intermediate, speed-increaser, and rear-drive gearboxes to cover every seasonal implement in your lineup.

Foire aux questions

Avis clients et rapports de terrain