EP-HC-9.311-JCG Rotary Tiller Gearbox with Drive Shaft – 50HP Complete Assembly
★ One Order Number, One Complete Assembly — The 50HP Rotary Tiller Gearbox That Comes With Its Own Matched Drive Shaft
这 EP-9.311-JCG eliminates the most common installation frustration with rotary tiller gearboxes: sourcing a separately compatible PTO drive shaft. The gearbox unit (1:3 ratio, 50HP, 540RPM, Module 4.35) and its drive shaft are supplied as a pre-matched assembly in 14 standard length options — L=375mm through L=1,500mm, at 14 incremental steps. Whether your tractor’s PTO output sits 400mm or 1,400mm from the cultivator input, there is a JCG size that fits without cutting, welding, or compromising the shaft’s rated torque capacity. Every assembly is 100% load-tested as a unit before dispatch by Korea Ever-Power Agricultural Machinery Co., Ltd. — serving South Korea, Japan, and the wider Asia-Pacific region.
EP-9.311-JCG — Complete Rotary Tiller Gearbox & Drive Shaft Assembly
EP-9.311-JCG · 50HP · 1:3 Ratio · 21kg · L=375–1,500mm
The standard EP-9.311 is Korea Ever-Power's 50HP, 1:3-ratio rotary tiller gearbox — a proven unit used across South Korea, Japan, and Southeast Asia on mid-size utility tractors in the 40–55HP class. The EP-9.311-JCG is that same gearbox supplied as a complete assembly with a matched PTO drive shaft, integrated at the factory and tested as a single unit before dispatch.
The "JCG" designation indicates the drive shaft is included and factory-configured to the gearbox's input specification: 1 3/8″ Z6 spline engagement, rated for the full 50HP torque capacity of the gearbox, with cross-joint angles matched to the assembly dimensions. This is not a gearbox with a shaft bolted alongside it in the same box — the shaft-to-gearbox engagement is assembled, aligned, and tested as one mechanism. The load test that every EP-9.311-JCG unit undergoes before dispatch runs the complete assembly, not the gearbox in isolation.
Why does this matter? In practice, the most common cause of early PTO shaft failure on rotary tillers is not shaft quality — it is mismatched shaft length causing the cross-joint to operate at an angle outside its design range. A shaft that is 50mm too short creates a joint angle of 3–5° above the design maximum, which increases joint wear rate by 40–80% at 540RPM. The EP-9.311-JCG series resolves this by providing 14 standard length increments, each engineered to maintain correct joint angles when fitted to the corresponding tractor-cultivator spacing range. The correct size is selected at the time of order — not cut down from a longer unit in the field.
Replacement Reference: The EP-9.311-JCG is engineered to match the specification of comparable Bondioli & Pavesi, Comer Industries, and Brevini Power Transmission complete tiller drive assemblies in the 50HP / 1:3 ratio class with integrated PTO shaft. Korea Ever-Power is not affiliated with or an authorised distributor of these brands. Model references are provided solely to assist customers in identifying compatible specifications.
变速箱技术规格
The gearbox unit within the EP-9.311-JCG assembly is identical in specification to the standalone EP-9.311. Module 4.35 represents a deliberate mid-point between the M3.45 used in the lighter EP-9.310 (30HP) and the M6.0 used in the EP-75 at 75HP — appropriate for the sustained 50HP loads of mid-size cultivator operation without the weight penalty of a heavier gear section. The 36/12 tooth count achieves the 1:3 reduction cleanly, with no common factors between the two gears beyond 1, which distributes wear evenly across all tooth pairs rather than concentrating it on repeated contact pairs.
| 范围 | 价值 | Technical Notes |
|---|---|---|
| 模型 | EP-9.311-JCG | Rotary Cultivator Series — gearbox + drive shaft complete assembly |
| 速度比 | 1 : 3 | Speed reducer — rotor turns at 1/3 of PTO input speed |
| Teeth Count | 36 / 12 | Crown gear / Drive pinion — no common factors, even tooth load distribution |
| 齿轮模块 | 4.35 | Optimised for 50HP sustained load — heavier than EP-9.310 (M3.45), lighter than EP-75 (M6.0+) |
| 额定功率 | 50 HP | ≈ 37.3 kW continuous duty |
| 额定输入速度 | 540 转/分 | Standard agricultural tractor PTO speed |
| Rotor Output RPM | ≈ 180 RPM | At rated 540 RPM PTO input — standard deep-tillage rotor speed |
| 输入轴 | 1 3/8″ Z6 spline | ISO 500 standard — drive shaft end matched to this at factory |
| 输出轴 | Optic axis (plain round) | Standard cultivator rotor tube interface |
| 房屋材料 | Nodular cast iron (GGG50) | High toughness, excellent shock absorption, low noise |
| Gearbox Net Weight | 21 kg | Gearbox only; drive shaft weight varies by length (see shaft table) |
The Drive Shaft Series — 14 Lengths, One Correct Fit
The defining characteristic of the EP-9.311-JCG is its 14-size drive shaft series. Every size is specified and tested to maintain correct cross-joint operating angles when installed in the corresponding tractor-to-cultivator distance range. Selecting the correct size at the point of order eliminates the field-fitting compromise of cutting a stock shaft down — which alters the shaft's dynamic balance and invalidates the joint angle design — or stretching an undersized shaft to the limit of its telescoping travel, which removes the safety margin against full compression under draft loads.
| 尺寸 | L — Overall Length (mm) | L1 — Stub Length (mm) | Typical Tractor–Cultivator Spacing |
|---|---|---|---|
| -1 | 375 | 220 | Very short reach — compact tractor, close-coupled tiller |
| -2 | 500 | 345 | Short reach — Korean compact tractors, 3-point hitch close mount |
| -3 | 615 | 490 | Standard compact tractor — common Korean / Japanese 25–35HP class |
| -4 | 670 | 515 | Standard mid-size tractor — Daedong CX / LS XR / TYM T series |
| -5 | 700 | 545 | Standard mid-size — Kubota M / Yanmar YT series, Japan domestic |
| -6 | 780 | 625 | Mid-size with extended hitch — common Vietnamese / Thai utility tractors |
| -7 | 810 | 655 | Most common size for Korean 40–55HP utility tractors ← popular |
| -8 | 950 | 795 | Extended mid-size — tractors with longer hitch-to-PTO distance |
| -9 | 1,060 | 905 | Large utility tractors — John Deere 5E / New Holland T4 Asia spec |
| -10 | 1,140 | 985 | Large frame tractors with mid-mount PTO extension |
| -11 | 1,200 | 1,045 | Long-reach installation — trailed cultivator attachment |
| -12 | 1,250 | 1,095 | Extra-long reach — large trailed cultivator, drawbar attachment |
| -13 | 1,350 | 1,195 | Specialist long-reach — OEM configurations, custom implements |
| -14 | 1,500 | 1,345 | Maximum reach — trailed or semi-mounted large cultivator frames |
How to measure for size selection: With the tractor PTO shaft in the retracted (shortest) position and the cultivator in its working position, measure the distance from the PTO output face to the cultivator gearbox input face. Select the JCG size whose L dimension is 50–100mm longer than your measured distance — this provides the correct telescoping overlap for joint angle and compression safety margin. If your measurement falls between two sizes, always select the longer one. Contact Korea Ever-Power with your tractor make/model and cultivator working width if you are unsure which size applies.
Assembly dimensional reference — L (overall) and L1 (stub) per engineering drawing
The engineering drawing on the original datasheet defines two key dimensions for each size: L (overall assembly length, from tractor PTO face to cultivator input face when both cross-joints are at nominal angle) and L1 (the stub shaft length, which determines the telescoping range available for hitch lift and lower). The difference between L and L1 — approximately 155mm across all sizes — represents the fixed gearbox-side engagement length. This consistent offset means the table above can be used directly: select the size whose L is 50–100mm above your measured spacing, and L1 will automatically provide adequate telescoping travel for standard 3-point hitch operation.
The shaft tube outer diameter is Φ99mm (from the engineering cross-section), with an inner sliding tube at Φ40–Φ40.03mm tolerance — a precision sliding fit that eliminates the lateral slop that causes noise and uneven wear in loose-tolerance shafts. The tube-to-tube engagement uses a splined internal profile rather than a plain round bore, maintaining torque transfer alignment through the full telescoping range.
EP-9.311-JCG vs EP-9.311 — Which Version Do You Need?
Both products use the same gearbox mechanism. The choice comes down to your supply situation and installation requirements.
Recommendation: Choose the EP-9.311-JCG for any new-build installation, for complete cultivator replacement (where both the old gearbox and shaft are being replaced), or for OEM production where assembly consistency matters. Choose the standalone EP-9.311 only when you are replacing the gearbox on an existing machine where the PTO drive shaft is still serviceable and confirmed compatible.
The Engineering Behind Correct Shaft Length Selection
Drive shaft length is not simply a matter of reaching from point A to point B. Three mechanical factors make precision length selection critical for both safety and service life in a 旋耕机变速箱 drive system:
Cross-Joint Operating Angle
A Cardan cross-joint has a maximum design operating angle — typically 15–20° for agricultural shafts at 540RPM. Beyond this angle, the velocity variation through the joint cycle creates vibration that loads the bearings unevenly at twice the rotational frequency. A shaft that is too short forces the joint to a steeper angle during hitch lift, potentially exceeding this limit. Each JCG size is engineered so that at maximum hitch lift the joint angle stays within 12°.
Telescoping Overlap Safety Margin
When the tractor pitches forward on uneven ground, the effective distance between PTO and cultivator input increases. A shaft with insufficient telescoping overlap can reach its fully extended limit during these moments, transmitting a sudden tensile load through the cross-joint bearings and gearbox input bearing rather than absorbing it through the sliding tube. The JCG series L/L1 design ensures a minimum 100mm of remaining overlap at maximum hitch lift with the correct size installed.
Dynamic Balance & Critical Speed
Every rotating shaft has a critical speed — the RPM at which its natural frequency matches the rotational frequency, causing resonant vibration. At 540RPM, a shaft longer than approximately 1,600mm approaches the critical speed of a standard 60mm OD agricultural shaft tube. The EP-9.311-JCG maximum length of 1,500mm (size -14) is set below this threshold. Each size is balanced as assembled — do not modify shaft length after delivery, as this disrupts the factory balance.
These three factors explain why the EP-9.311-JCG's 14-size series exists rather than a single adjustable unit: each size is a specific engineering solution to a specific installation range, not an interchangeable commodity. This also explains why Korea Ever-Power test-runs each complete assembly before dispatch — joint angle, overlap travel, and shaft balance all interact with the gearbox bearing loads in ways that only a running test can fully verify.
Construction Quality — Gearbox & Shaft
Gearbox: GGG50 Nodular Iron Housing
The housing absorbs tine-impact loads transmitted back through the rotor shaft into the output bearing. GGG50 ductile iron's elongation at break (18%) provides the micro-deformation capacity to dissipate these energy spikes without crack propagation — a property that grey iron, with less than 1% elongation, cannot match at these sustained operating duty cycles.
Gearbox: Carburised & Quench-Hardened Bevel Gears
Both bevel gears are carburised to 0.8–1.2mm case depth and quench-hardened to HRC 58–62. At 1:3 ratio and 50HP, the crown gear carries significant sustained bending loads at 180RPM. The hardened tooth face prevents the micro-pitting that develops on softer surfaces under repetitive Hertzian contact stress — the characteristic failure mode of under-specified tiller gearboxes at the 300–500 hour mark.
Drive Shaft: Precision-Tolerance Sliding Tube
The inner and outer tube pair is machined to Φ40–Φ40.03mm sliding tolerance — 0.03mm total clearance across a 40mm bore. This tight fit eliminates the 0.1–0.3mm slop found in lower-cost shafts that causes the shaft to run eccentrically, creating the characteristic clatter during the unloaded start-up phase and accelerating spline wear on both the shaft and the gearbox input socket.
Drive Shaft: Cross-Joint & Yoke Assembly
The cross-joint bearings use needle roller elements — the correct bearing type for agricultural PTO shafts where the combination of high torque and oscillating joint angle creates complex load vectors that ball bearings handle poorly over extended hours. Yokes are forged steel, not pressed steel plate, giving the joint the structural rigidity to prevent deflection under the full 50HP torque load at steep angles.
Safety Guard
Each EP-9.311-JCG assembly includes a full-length plastic safety guard over the rotating shaft — required by agricultural machinery safety standards in South Korea (KMSS), Japan (JAS), and most ASEAN member states. The guard is fitted and tested as part of the assembly before dispatch. Do not operate the machine with the guard removed or damaged.
100% Complete-Assembly Load Test
Unlike the standalone EP-9.311 where only the gearbox is bench-tested, the EP-9.311-JCG test runs the complete assembly — gearbox plus shaft — at full rated load. This confirms that the shaft-to-gearbox spline engagement is within tolerance, the joint angles at the selected size are within design limits, and the assembly produces no vibration anomalies that would indicate a shaft or bearing issue. This is the value of a pre-assembled kit that cannot be replicated by checking gearbox and shaft separately.
Where the EP-9.311-JCG Is Used
Why Korea Ever-Power for Your Complete Tiller Drive System
Complete assembly manufacturing — gearbox and shaft tested as one unit
Korea Ever-Power Agricultural Machinery Co., Ltd. manufactures and assembles both the gearbox and drive shaft components of the EP-9.311-JCG in-house — this is not a gearbox paired with a third-party shaft. In-house production of both elements means the assembly tolerances and test procedures are designed around the interaction between the two components, not around each component in isolation. Our 19-year production history, 3,800 m² facility, and 90-person technical team provide the manufacturing depth required for this level of assembly integration.
For buyers in South Korea and Japan, Korea Ever-Power's Asia-Pacific supply position means a lead time of 3–7 business days on stocked sizes — compared to 4–8 weeks for equivalent European-sourced assemblies. Complete export documentation (commercial invoice, packing list, Certificate of Origin, test report) is prepared for each shipment, supporting smooth customs clearance under RCEP and bilateral trade agreements applicable to Korean and Japanese agricultural machinery imports.
Related Products & Complete Drive Components
What Customers Say About the EP-9.311-JCG
Frequently Asked Questions — EP-9.311-JCG
其他信息
| 编辑 | CXM |
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