The Critical Link: Transmitting Power to the Rotor
In the architecture of a Rotary Tiller (Enxada Rotativa), the central gearbox receives power from the tractor PTO, but it is the Side Gearbox (Caixa Lateral) that performs the final, critical task: delivering torque to the rotor shaft that engages the soil. This component operates in the harshest possible environment—literally dragging through the dirt, submerged in mud, and subjected to the violent shock loads of C-blades striking rocks and roots.
For the Brazilian market, with its diverse soil profiles ranging from the abrasive sands of Western Bahia to the heavy red clays of Paraná, the Side Gearbox is often the first point of failure in imported machines. Standard light-duty chain drives stretch and snap under the load of deep tillage (25cm+).
エバーパワーの SG-Series (Side Gearbox) offers two distinct drive technologies: Full-Gear Side Drive for maximum durability in heavy soils, and Reinforced Chain Drive for cost-effective performance in lighter applications. Both systems are housed in structural castings designed to act as a rigid side-frame for the tiller, maintaining perfect rotor alignment even under extreme flex.
Technology Comparison: Gear Drive vs. Chain Drive
Option A: Full-Gear Side Drive
The Heavyweight Champion. This system uses a train of three or four large spur gears (Engrenagens Retas) to transmit power. It is the standard for heavy-duty tillers (>80HP) used in sugar cane and land reclamation.
- ✅ Zero Stretch: Gears do not stretch like chains. Timing remains perfect forever.
- ✅ High Torque: Capable of transmitting 200% more torque than a chain system.
- ✅ No Maintenance: No tensioning required. Just check the oil level.
- ❌ Weight: Significantly heavier, adding to the implement’s total mass.
- ❌ Cost: Higher manufacturing cost due to precision gear grinding.
Option B: Reinforced Chain Drive
The Efficient Standard. Utilizing heavy-duty ASA 100 or ASA 120 roller chains running in an oil bath. Ideal for medium-duty tillers (40-80HP) in vegetable and grain farming.
- ✅ Shock Absorption: The chain slack provides a natural cushion against rock impacts.
- ✅ Lightweight: Reduces the side weight, preventing the tiller from listing.
- ✅ Efficiency: Slightly higher mechanical efficiency (less friction) than gear trains.
- ❌ Maintenance: Requires periodic tensioning to prevent “chain slap” and case wear.
- ❌ Stretch: Over time, the chain elongates, requiring eventual replacement.
Technical Specifications: SG-Series (Side Gearbox)
| パラメータ | 仕様 | パラメータ | 仕様 |
|---|---|---|---|
| 入力電力 | 30 HP – 160 HP (22-120 kW) | 比率 | Variable via Sprockets/Gears |
| 入力シャフト | Splined / Keyed (From Cross Shaft) | ローター速度 | 180 – 320 RPM |
| ギアタイプ | Module 6 / Module 8 Spur | Chain Type | ASA 100H / 120H / 140H |
| ハウジング材質 | Ductile Iron QT450 / Steel Fab | Housing Thickness | 12mm – 18mm Wall |
| 出力軸 | Flanged Hub (6-Bolt / 8-Bolt) | Stub Axle Dia | 50mm / 60mm / 70mm |
| ギア素材 | 20CrMnTiH (Carburized) | テンショナー | Automatic Spring / Manual Bolt |
| シーリング | メカニカルフェイスシール（デュオコーン） | 潤滑 | Oil Bath (SAE 140 / Grease) |
| オイル容量 | 2.5 Liters – 5.0 Liters | 取り付け | Lateral Bolt Pattern |
| Skid Shoe Mount | Integrated Bosses | Cover Plate | Stamped Steel / Cast Iron |
| 重さ | 40 kg – 110 kg | ベアリングタイプ | Tapered Roller / Cylindrical |
| ペイント | エポキシハイビルド | 保証 | 18ヶ月 |
| 互換性 | マスキオ／クーン／バルダン | 応用 | Wet Rice / Dry Land |
Engineering the “Soil Interface”
1. The “Duo-Cone” Seal Revolution
The lower bearing of the side gearbox operates below the soil line. Standard rubber lip seals are destroyed in hours by the abrasive silica paste formed by sandy soil and sap. EVER-POWER utilizes フローティングメカニカルフェイスシール（デュオコーン）. Two lapped metal rings rotate against each other, creating a perfect seal that is impervious to mud, wire, and plastic twine. This technology, borrowed from track excavators, extends seal life by 500% in rice paddies.
2. Module 8 Gear Strength
For gear-drive models, tooth strength is paramount. When a rotor blade hits a buried stump, the shock load tries to shear the gear teeth. We use Module 6 to Module 8 Spur Gears with a wide face width (40-50mm). The gears are forged from 20CrMnTiH steel and carburized to 60 HRC. The “Idler Gear” runs on needle roller bearings to minimize friction and heat generation.
3. Structural Casing Design
The side gearbox acts as a structural member of the tiller frame. It must resist bending and twisting forces. Our housings are cast from ダクタイル鋳鉄（QT450） with internal ribbing. Unlike welded steel boxes which can warp and cause chain misalignment, the cast iron box maintains perfect bearing geometry even when the tiller is dragged diagonally through the field.
4. Chain Tension Management
For chain-drive models, slack is the enemy. A loose chain whips against the casing, wearing a hole through the oil bath. We include a heavy-duty Spring-Loaded Tensioner Shoe made from wear-resistant polymer (UHMWPE). This shoe applies constant pressure to the slack side of the chain, compensating for stretch and dampening vibration, ensuring smooth power delivery.
ローカライズされたアプリケーション: ブラジルの農業ビジネス
Rice Paddy Tillage (Rio Grande do Sul)
In flooded rice fields (“Lama”), tillers work submerged. Water ingress turns oil into mayonnaise, destroying bearings. Our SG-Series “Paddy Special” gearboxes feature a Pressurized Breather System and double-sealed inspection covers. The Duo-Cone seals are mandatory here to prevent water entry.
Sugar Cane Renovation (São Paulo)
Breaking up sugar cane ratoons involves cutting through massive root balls. This creates severe shock loads. We recommend the Full-Gear Side Drive for this application. The rigid gear train provides the positive torque needed to slice through the roots without the “elasticity” of a chain drive, which can lead to surging.
📒 フィールドエンジニアのログ：「叩く」チェーン
“January 2026, Petrolina, PE. A fruit farmer complained of a loud banging noise from his 2-meter rotavator. We opened the side chain case. The ASA 100 chain had stretched by 3% and had worn a deep groove into the cast iron housing.”
“The manual tensioner bolt had vibrated loose.
Solution: We replaced the chain and the damaged case cover. Crucially, we retrofitted the unit with our Automatic Spring Tensioner Kit. This self-adjusting device takes up the slack as the chain wears, keeping it tight against the sprockets. We also switched to a high-tack ‘Chain & Bar’ oil that clings to the links better than standard gear oil. The unit is now silent and maintenance-free.”
よくある質問（OEM/B2B）
1. Which is better: Gear Drive or Chain Drive?
It depends on your soil. For rocky or light soil, Chain Drive is better (cheaper, shock absorbing). For heavy clay, deep tillage, or huge acreage (sugar cane), Gear Drive is superior (stronger, maintenance-free). Gear drive is generally 30% more expensive.
2. Can I retrofit a Duo-Cone seal to my old gearbox?
Generally, no. Duo-Cone seals require a specific machined seat in the housing and the output hub. However, we sell complete “Lower Hub Assembly” kits that include the housing cap, bearings, and Duo-Cone seal, which can be bolted onto compatible EVER-POWER gearboxes.
3. What oil should I use for the side gearbox?
For Gear Drives, use SAE 140 or ISO VG 460 gear oil. For Chain Drives, use semi-fluid grease (NLGI 00) or a tacky chain oil. Do not use standard hydraulic oil, as it is too thin to cushion the impact loads.
4. Are parts compatible with Maschio or Kuhn tillers?
Our SG-Series is designed as a functional replacement for many common European designs (Maschio B/C series, etc.). While internal gears may not interchange directly, the complete side box assembly often fits the same mounting pattern.
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