EP-SE415T3 Triple-Stage Track Drive Planetary Gearbox

See EP-SE415T3 is a triple-stage track drive planetary gearbox producing 110,000 N·m from a rotating outer housing T3 unit. Its ratio range i=81–215 spans 2.65× from minimum to maximum — the widest span in the SE series, and i=215 itself is the deepest single ratio achievable in any SE unit covered here.

At a 700 mm sprocket radius (typical for machines in the 1,000–2,000 tonne class), 13.95 rpm sprocket speed produces approximately 0.22 km/h travel speed — 13 km/h per minute of crawl. This is the slowest output speed in the full Korea Ever-Power SE series presented here. EP-SE414T3's deepest ratio (i=186 at 3,500 rpm) produces 18.8 rpm — 35% faster. EP-SE415T3's i=215 provides the extra depth needed for machines that require ultra-slow positioning while carrying or engaging enormous loads: very large continuous surface miners advancing at cutter drum penetration rate, walking draglines during skid repositioning, and large tracked transport platforms during final object placement.

EP-SE415T3's ratio range i=81–215 has a span of 215 ÷ 81 = 2.65× from minimum to maximum. EP-SE414T3's span is 186 ÷ 76 = 2.45×. EP-SE413T3's span is 172 ÷ 86 = 2.0×. The 2.65× span means that from EP-SE415T3's fastest output to its slowest, a 2.65× range of travel speeds is available from a single fixed motor displacement, without changing motor settings. For a 1,500-tonne rope shovel, this covers: fast repositioning tramming on flat haul road at i=81–100, normal working travel at i=120–150, and ultra-slow precision approach to a loading face at i=180–215. All from the same unit and motor — no flow control valve adjustment required.

At i=215, the 1,200 N·m spring brake produces 258,000 N·m effective output-side hold per drive — 15.5% above EP-SE414T3's maximum of 223,200 N·m at i=186. This is the highest spring brake equivalent in the full SE series as presented here. For a 1,500-tonne machine parked on a 15° slope with a 700 mm sprocket radius, two EP-SE415T3 drives at i=215 provide a combined spring brake hold of 516,000 N·m — a theoretical parking safety factor of approximately 2.6× against the rolling force, satisfying demanding type-approval brake performance criteria for this machine weight class at typical worst-case site gradients.

In a planetary gear set, the pitch-line velocity at the gear mesh determines lubrication film thickness, heat generation rate, and tooth surface fatigue life. It is calculated as: v = π × d_pitch × n / 60, where d_pitch is the pitch circle diameter of the gear and n is the rotational speed. For 110,000 N·m, the pitch circle diameter at the final stage must be substantially larger than in SE414T3's 80,000 N·m final stage — more tooth face area is needed to sustain the higher contact load. If n were kept at 3,500 rpm, the larger d_pitch would produce a higher pitch-line velocity, exceeding the safe limit for the oil film at the carburised gear tooth surface. Reducing n to 3,000 rpm compensates for the larger d_pitch, keeping pitch-line velocity within the lubrication film limit. The 3,000 rpm limit is therefore the correct engineering specification for a 110,000 N·m T3 unit, not a limitation to work around.

If the hydraulic circuit was designed around a smaller-displacement motor running at 3,500 rpm for a previous SE unit, the motor must be replaced or the circuit re-specified when upgrading to EP-SE415T3. At the same hydraulic power (P = pressure × flow), a motor limited to 3,000 rpm must have proportionally more displacement to deliver the same torque. Specifically: if the previous motor had displacement D at 3,500 rpm, the EP-SE415T3 motor should have displacement D × (3,500 ÷ 3,000) = D × 1.167 — approximately 17% larger displacement at the same pressure. Korea Ever-Power performs this motor selection calculation as part of the same-day engineering enquiry response, and can advise on compatible motor models from standard suppliers that meet the 3,000 rpm maximum requirement.

EP-SE415T3's efficiency specification is >93% versus >94% for EP-SE414T3 and most prior T3 units. The 1% reduction reflects the slightly greater mesh losses across three stages at the larger gear dimensions for 110,000 N·m — larger pitch diameters, higher tooth loads, and more oil churning losses in the larger sump volume. For the machine class that EP-SE415T3 serves — hydraulic systems driving 850 kg track drives at 110,000 N·m — a 1% efficiency difference corresponds to approximately 3–5 kW additional heat per drive at full load continuous operation. This is within the thermal capacity of the 850 kg nodular iron housing with its correspondingly larger thermal mass, and does not require additional cooling measures under standard operating conditions. Korea Ever-Power provides thermal confirmation for high-ambient or high-duty-cycle applications on request.

Large Walking Draglines and Mining Machines

Walking draglines — the largest self-propelled machines in mining, with bucket sizes of 50–100+ cubic metres and machine weights of 3,000–7,000+ tonnes — include models with crawler-type undercarriages rather than the walking mechanism. For these crawl-based draglines above 1,500 tonnes, EP-SE415T3 provides the propel drive capability with 110,000 N·m per drive. The 1,200 N·m spring brake at i=165–215 provides 198,000–258,000 N·m per drive parking hold — essential for these machines, which must hold position on unstable spoil-pile ground during active dragline casting operations. The 3,000 rpm motor input constraint matches well with the large-displacement axial piston motors commonly used on machines of this scale, which typically run at motor speeds below 3,000 rpm anyway.

Large Tunnel Boring Machine Propel Ring Drives

Large TBMs in the 15–20 metre bore diameter class — used for motorway tunnels, metro heavy rail tunnels, and hydroelectric headrace tunnels — may use EP-SE415T3 as part of the multi-drive propel ring assembly. The propel ring of a large TBM contains many individual hydraulic track drive units pushing against the tunnel face, collectively generating the thrust force to advance the cutter head. The combination of 110,000 N·m per unit and i=81–215 ratio range allows fine control of advance speed matched to rock conditions. The floating metal face seals sustain the high-pressure groundwater and bentonite slurry environment characteristic of large TBM operations in difficult geology. Korea Ever-Power has advised on EP-SE415T3 propel drive specification for TBM systems where individual propel unit torque requirements exceeded EP-SE414T3's 80,000 N·m capacity per unit.

Ultra-Heavy Rope Shovels — Above 1,500 Tonnes

The very largest electric rope shovels — machines with 80–100 cubic metre dipper capacities and gross operating weights above 1,500 tonnes — require EP-SE415T3 for the crawler propel drives when the machine weight on its access ramps or during repositioning at worst-case gradients produces a required drive torque per side that exceeds EP-SE414T3's 80,000 N·m. At 1,800 tonnes on a 10° access ramp, the calculated propel torque per drive with a 1.7× shock factor can approach 90,000 N·m — requiring EP-SE415T3 for adequate safety margin. Korea Ever-Power performs this calculation at the engineering enquiry stage for any specific rope shovel specification.

Marine Crawler Platforms and Offshore Transport Systems

Ultra-heavy crawler platforms used for moving offshore platform deck sections, large submarine pipeline components, and heavy module stacks within shipyards and fabrication yards require EP-SE415T3 when total payload plus platform weight exceeds the EP-SE414T3 service envelope. Marine environments impose additional requirements: salt water immersion, high-pressure wash-down, and corrosive atmospheric conditions. EP-SE415T3's dual-cone floating metal face seals are tested for immersion in salt water and high-pressure washing at pressures well above normal site washing conditions. Auxiliary cable winch and tensioner systems on these platforms use worm gear reducers for self-locking load hold on cable drums, entirely independently from the EP-SE415T3 crawler travel drives.

Extreme-Scale Agricultural and Land Development Platforms

The largest specialised tracked land reclamation and heavy agricultural development platforms — machines operating in major irrigation and land development infrastructure projects at 1,000+ tonne combined weight — require EP-SE415T3 for the crawler travel drives when site gradients and soil resistance exceed EP-SE414T3's capacity. These machines carry multiple deep-till subsoiler assemblies and associated agricultural gearboxes for multi-output PTO-driven implement systems, all operating independently of the EP-SE415T3 travel drives.

Specialised Crawler Crane Undercarriages — Very Large Class

Crawler cranes with lift ratings above 2,000 tonnes — the very largest lift capacity machines currently in production — have gross vehicle weights that may exceed 1,000 tonnes in full counterweighted working configuration. These machines require EP-SE415T3 for the travel drives where machine weight and safety case requirements produce drive torque demands above EP-SE414T3's 80,000 N·m capacity. At i=180–215, the spring brake hold of 216,000–258,000 N·m per drive provides the emergency position hold during suspended-load pick-and-carry moves required by international crane standards at this capacity class.

Motor Selection, Ratio, Brake — All Confirmed Same Day

EP-SE415T3's 3,000 rpm maximum adds a motor selection step not required for other SE units. Korea Ever-Power's same-day engineering response covers: motor displacement recommendation for your hydraulic circuit power and 3,000 rpm maximum; ratio selection from i=81–215 for your target travel speed; 1,200 N·m brake adequacy calculation for your machine weight and gradient; and dimensional cross-reference against your incumbent drive. All returned in a single document, no charge, before any order commitment. This is provided whether you are upgrading from EP-SE414T3 or specifying EP-SE415T3 fresh for a new machine.

Pre-Assembled and Tested at 850 kg

EP-SE415T3 is available pre-assembled with matched large-displacement motor (3,000 rpm maximum), overcenter valve, and pressure relief valve. Before shipping: brake function verified — spring applied (drum locked), pilot released at 15–30 bar (drum free within 1 second), oil filled. At 850 kg, crane lift is the critical path at installation; the pre-assembled unit arrives ready for a single lift into the chassis bore and hydraulic line connection, eliminating all on-machine motor fitting and brake commissioning time. Korea Ever-Power co-ordinates with motor suppliers for matching displacement and port configuration.

Stage-Level Parts — 850 kg, Serviced Not Replaced

Korea Ever-Power maintains full component stock for EP-SE415T3: Stage 1, 2, and 3 sun gear and planet set assemblies; 1,200 N·m brake disc pack (friction discs, separator plates, O-ring kit); dual-cone floating face seal kits; taper bearing sets per bearing position; housing O-ring kits. At 850 kg and this torque class, a 110,000 N·m planetary gearbox repair at the stage level is always the economically correct approach versus complete unit replacement. Korea Ever-Power can advise on whether elevated oil sample particle levels indicate stage-specific or bearing-specific wear to guide the repair scope before any disassembly is performed. At this torque class, where a 110,000 N·m track drive planetary gearbox has substantial intrinsic value, minimising the scope of any repair to only the failed stage is always the correct engineering and economic approach, and Korea Ever-Power’s stage-separated parts catalogue makes this straightforward.

12/18-Month Warranty — All Stages and Brake

12 months from commissioning or 18 months from shipment, covering all three planetary stages, the 1,200 N·m brake assembly, and the floating face seals. Warranty component parts dispatched from Korea Ever-Power stock — seal kit and brake disc pack failures are resolved by component dispatch, without requiring the 850 kg unit to be returned to factory. For OEM fleet buyers stocking EP-SE415T3 ahead of machine assembly, the warranty period begins at commissioning.

Stock and Framework Supply at This Scale

Standard ratio configurations from Korea Ever-Power stock in 7–14 days. Pre-assembled motor packages: 30–45 days. For mining, dragline, and TBM OEMs with recurring EP-SE415T3 requirements, Korea Ever-Power discusses reserved production capacity and consignment stock terms that guarantee lead times for emergency machine-down situations at 850 kg unit scale. Contact Korea Ever-Power with fleet size and annual volume for framework pricing. The same enquiry process works for any scale from single replacement units to multi-unit OEM production batches.

−25°C to +90°C — 850 kg Thermal Mass

EP-SE415T3 maintains the −25°C to +90°C range. At 850 kg, the nodular iron housing has a thermal mass of approximately 850 × 500 J/(kg·K) = 425 kJ per degree — the highest in the SE series on this site, giving the longest thermal run-up time to operating temperature and the greatest resistance to temperature spikes under sustained high-duty-cycle travel. At >93% efficiency, the additional 1% loss vs SE414T3 adds approximately 3–5 kW additional heat per drive at full load — well within the 850 kg housing's thermal capacity under standard conditions. For sustained high-ambient operation, Korea Ever-Power provides thermal assessment on request at no charge.

We supply propel systems for large TBMs in the 13–18 metre diameter class. Our largest TBM configuration uses 32 individual propel drives per ring — and for our newest 17.5 metre machine, the required thrust force per propel unit exceeded 80,000 N·m per unit based on detailed rock load analysis for hard quartzite geology. Korea Ever-Power confirmed EP-SE415T3 at i=98 for this application. The 3,000 rpm maximum presented no challenge — our TBM propel motors already operate at 2,200–2,600 rpm at maximum flow, well within the 3,000 rpm limit. The motor displacement calculation Korea Ever-Power provided confirmed our existing motor specification was compatible. At 2,100 hours across 32 drives on the first tunnel project in mixed ground conditions (quartzite, limestone, and fault zones), we had zero EP-SE415T3 failures. The 7-14 day stock lead time from Korea Ever-Power has been integrated into our propel drive spare parts planning, replacing our previous 16-week European supplier lead time.

We procure dragline equipment and crawler systems for iron ore and bauxite mining in West Africa. Our largest crawler-based dragline system runs at approximately 2,200 tonnes operating weight. Korea Ever-Power's engineering team confirmed that at our steepest access ramp grade of 8° with our machine configuration, the drive torque per unit with a 1.65× dynamic factor was approximately 88,000 N·m — requiring EP-SE415T3 rather than SE414T3 for an adequate safety margin. The 1,200 N·m spring brake at our specified ratio i=110 gives 1,200 × 110 = 132,000 N·m per drive emergency hold — verified to satisfy our internal engineering standard at our maximum parking gradient of 8°. At +46°C ambient during West African dry season operations, housing surface temperature reached 87°C on sustained tramming — within the 90°C limit. We implemented Korea Ever-Power's recommended 45-minute travel cycle with 15-minute cooling intervals during peak ambient months. At 1,400 hours, zero failures across four units. Delivery in 12 days from order, which is critical for our operational environment.

We produce crawler cranes with lift ratings up to 2,500 tonnes for offshore and power plant construction. Our 2,500-tonne crane has a gross vehicle weight of 1,050 tonnes in full working configuration. Korea Ever-Power specified EP-SE415T3 at i=170 after confirming that our machine's drive torque requirement on our 10° type-approval slope, with full counterweight, required 95,000 N·m per drive — above SE414T3's 80,000 N·m capacity. At i=170, the spring brake provides 1,200 × 170 = 204,000 N·m per drive hold — our type-approval requires 2.0× ratio over maximum tramming torque from spring brake alone, and at 204,000 N·m versus 95,000 N·m we achieve 2.15×. Korea Ever-Power's pre-order engineering document was accepted by our type-approval body without modification. The 3,000 rpm maximum was consistent with our motor specification — we use axial piston motors with a maximum of 2,800 rpm at our circuit pressure, so EP-SE415T3's 3,000 rpm limit presented no constraint. Total operational hours across our 2,500-tonne crane fleet: 2,900 hours, zero EP-SE415T3 drive failures.

KWhy is EP-SE415T3's maximum input speed 3,000 rpm when all other SE units allow 3,500 rpm?

The 3,000 rpm limit is an engineering consequence of the larger pitch circle diameters required at 110,000 N·m. Pitch-line velocity at the gear mesh (v = π × d_pitch × n / 60) governs lubrication film thickness and tooth surface fatigue life. At 110,000 N·m, the final-stage planetary gears must be substantially larger in diameter than in EP-SE414T3's 80,000 N·m equivalent. If the maximum input speed were kept at 3,500 rpm, the larger gear diameter would produce a higher pitch-line velocity that exceeds the safe operating limit for the carburised tooth surface under the combined load and speed. The 3,000 rpm maximum reduces input speed proportionally to the larger diameter, maintaining the same pitch-line velocity limit as previous SE units. The motor displacement must be increased proportionally — approximately 17% larger displacement at the same hydraulic circuit pressure — to deliver the same motor shaft torque at 3,000 rpm instead of 3,500 rpm. Korea Ever-Power provides the motor displacement recommendation for your specific hydraulic circuit at the engineering enquiry stage, same day, no charge. If the existing motor at the machine being retrofitted already operates at or below 3,000 rpm at your circuit pressure, no motor change is required and the upgrade from EP-SE414T3 to EP-SE415T3 is dimensionally direct with only the gear unit itself replaced. Korea Ever-Power confirms this on a case-by-case basis from the motor model and operating parameters you provide.

KEP-SE415T3 uses the same 1,200 N·m spring brake as EP-SE414T3. How does it serve a heavier machine class?

Despite having the same 1,200 N·m spring brake as EP-SE414T3, EP-SE415T3 achieves higher effective brake hold at the sprocket for two reasons. First, the ratio range extends to i=215 versus EP-SE414T3's maximum of i=186. At i=215, the brake hold is 1,200 × 215 = 258,000 N·m per drive — 15.5% above SE414T3's maximum of 223,200 N·m. Machines requiring EP-SE415T3 typically operate at higher ratios, where the 1,200 N·m brake amplification is substantially larger. Second, the minimum ratio is i=81 (vs i=76 for SE414T3), meaning EP-SE415T3's worst-case (minimum ratio) brake equivalent is 97,200 N·m per drive — slightly higher than SE414T3's 91,200 N·m, despite the slightly higher minimum ratio, because the same 1,200 N·m brake acts on a ratio that — while more modest — produces adequate hold for machines at i=81 where the travel speed is already relatively slow. Korea Ever-Power confirms brake adequacy for the specific ratio, machine weight, and gradient at enquiry stage, same day, no charge.

KOil volume, maintenance schedule, and condition monitoring for the 850 kg triple-stage unit?

EP-SE415T3 contains approximately 25–35 litres of gear oil depending on ratio configuration and motor adapter — the highest oil volume in the SE series as presented here. The exact fill volume is on the Korea Ever-Power dimensional drawing for your specific configuration. First oil change at 150 operating hours: drain warm, allow 25+ minutes full drain time to remove all three stages' run-in particles from the large oil volume, then refill with fresh API GL-5 VG 150 (below +15°C) or VG 220 (above +15°C). Subsequent changes: every 1,000 hours or annually. For condition monitoring at this machine and unit value, ICP oil sampling at each 500-hour interval is strongly recommended. With 25–35 litres per unit, each sample reflects a large reservoir and baseline elemental levels should be established at the first oil change when the unit is in known good condition. Deviations of 30–50% from baseline iron, chromium, or molybdenum levels indicate emerging wear and should trigger a more frequent follow-up sample before planning maintenance. For an 850 kg track drive planetary gearbox at this torque class, proactive condition monitoring with oil sampling is the most cost-effective way to avoid unscheduled machine downtime. Korea Ever-Power can supply reference elemental baseline ranges for new EP-SE415T3 units on request, as part of the startup documentation package.

KIs EP-SE415T3 a direct drop-in replacement for Rexroth GFT or Bonfiglioli units at the 110,000 N·m class?

For triple-stage units in the 110,000 N·m torque class, Korea Ever-Power provides a full dimensional cross-reference against your specific incumbent model before any order — spindle bore diameter and fit, drum OD, sprocket BCD, hydraulic port thread sizes and positions, motor interface spigot, brake pilot port — against your specific legacy model number and ratio code suffix. At this torque class, there are multiple configurations within the Rexroth GFT and Bonfiglioli 700C families; the cross-reference confirms which EP-SE415T3 configuration matches your specific incumbent, and any dimension that doesn't match is flagged explicitly with a resolution path. Provide the full model number including all suffix codes for the most accurate same-day cross-reference. Rexroth and Bonfiglioli are trademarks of their respective owners, cited for dimensional reference only.