EP-SE414T3 Triple-Stage Track Drive Planetary Gearbox

Он EP-SE414T3 is a triple-stage track drive planetary gearbox rated at 80,000 N·m — the highest torque in the Korea Ever-Power SE series covered on this site. With a ratio range of i=76–186 that extends wider than any previous SE model on both ends, and a spring brake at 1,200 N·m that nearly doubles EP-SE413T3's 610 N·m, it serves the 750–1,500+ tonne machine class exclusively.

EP-SE414T3 weighs 680 kg — 260 kg (62%) more than EP-SE413T3. During a hydraulic pressure failure event, this rotating housing mass continues to carry kinetic energy that the spring brake must arrest. A 62% heavier rotating assembly requires proportionally more spring braking force to stop and hold within the same deceleration distance. Korea Ever-Power engineers the brake to halt the housing within a defined rotation angle at maximum design speed — a constraint that scales directly with rotating mass. The larger brake piston, heavier disc stack, and stronger Belleville spring pack in EP-SE414T3 are sized to satisfy this stopping criterion for the 680 kg assembly, not just to hold the machine on a gradient.

EP-SE414T3's minimum ratio is i=76 — the lowest minimum ratio in any T3 SE unit. At i=76, the brake amplification is at its minimum within this unit's operating range. For a 1,000-tonne machine parked on a 15° bench with a 650 mm sprocket radius, the required parking hold per drive is approximately 37,800 N·m. With a 610 N·m brake (SE413T3 level), the effective hold at i=76 would be 610 × 76 = 46,360 N·m — a safety factor of only 1.23×. Korea Ever-Power's engineering standard requires a minimum 2.0× parking safety factor for machines in this weight class, which requires a brake torque of at least 1,000 N·m to achieve 76,000 N·m hold at i=76. The 1,200 N·m brake provides 91,200 N·m at i=76 — a 2.4× factor, satisfying the requirement with margin.

Despite the brake torque nearly doubling from 610 N·m to 1,200 N·m, the hydraulic release pressure remains unchanged at 15–30 bar — the same as every other SE model. This is possible only by increasing the brake piston area proportionally to the increased spring force. A larger piston generates more hydraulic force from the same pressure, compressing stronger springs. In EP-SE414T3, the brake piston diameter and disc pack outer diameter are physically larger than in EP-SE413T3. The multi-disc pack contains more friction discs (larger stack height) and correspondingly larger sintered steel separator plates. This larger brake assembly is one of the contributions to the 260 kg weight increase from EP-SE413T3 — Korea Ever-Power estimates the brake assembly alone accounts for approximately 40–70 kg of the 260 kg total increase.

For machines above 750 tonnes, regulatory and OEM type-approval requirements for emergency brake performance are more stringent than for lighter equipment. In a rope shovel or large mining excavator, a hydraulic failure during travel on a mine bench — where machines may travel at maximum speed near a bench edge — requires the spring brake to stop the machine within a defined distance. The safety case for these machines requires a higher brake torque-to-machine-weight ratio than lighter SE units. Korea Ever-Power verifies brake stopping performance for each specific machine weight and maximum travel speed at the engineering enquiry stage, and EP-SE414T3 is designed to satisfy the most demanding type-approval requirements in this weight class with the 1,200 N·m spring brake specification.

The 1,200 N·m brake assembly — its enlarged piston, extended disc stack (more friction and separator discs), heavier Belleville spring pack, and larger brake housing bore — is physically bigger and heavier than the 610 N·m brake in EP-SE413T3. Larger pistons require thicker housing walls around the bore. The brake alone contributes an estimated 40–70 kg to the total weight increase.

The jump from 60,000 N·m (SE413T3) to 80,000 N·m (SE414T3) is a 33% torque increase. In the final stage, planet gear tooth face width must scale with torque — wider faces mean heavier gears, heavier carriers, and a wider ring gear. The final-stage gear set and housing cross-section growth accounts for the largest single contribution to the 260 kg increase, estimated at 120–150 kg across all three stages.

EP-SE414T3's ratio range extends to i=76 at the low end (vs i=86 for SE413T3). Reaching a lower minimum ratio while also achieving 80,000 N·m requires a different three-stage ratio split than SE413T3's configuration. The stage 1 ratio is set lower to cover the i=76 requirement, and the intermediate stage compensates — this ratio reconfiguration may require larger stage 1 sun and ring gear diameters, adding housing diameter and mass for this stage specifically.

A 1,000-tonne machine imposes approximately 500+ kN of combined radial and axial bearing load at the drum-spindle interface — substantially greater than the 250–300 kN range that EP-SE413T3's bearings handle. The taper roller bearings at this interface must be physically larger in bore, width, and roller length, requiring a larger bearing housing bore and more surrounding metal in the spindle flange. Bearing-driven housing changes add an estimated 20–30 kg.

Mining Rope Shovels — Largest Production Class

Large electric rope shovels — machines with operating weights of 800–1,400 tonnes and dipper capacities exceeding 60–100 cubic metres — require EP-SE414T3 for the propel drive units. The rope shovel's travel cycle is intermittent but demands maximum tractive force when repositioning on soft mine floor, pushing through muck piles, or climbing bench access ramps. At 1,000+ tonnes on a 10° access ramp, the calculated required drive torque exceeds EP-SE413T3's 60,000 N·m capacity. EP-SE414T3 at i=100–140 serves these machines with the 80,000 N·m capacity needed to clear the 1.5–2.0× dynamic factor for rope shovel tramming on uneven mine floor. The 1,200 N·m spring brake at i=120–140 provides 144,000–168,000 N·m per drive — the emergency hold for pressure failure on a ramp during tramming.

Super-Heavy Crawler Cranes — 1,000+ Tonne Lift Class

Crawler cranes with rated lift capacities above 1,000 tonnes — used for offshore jacket installation, refinery reactor vessel lifts, and heavy industrial module erection — have gross vehicle weights that can exceed 800 tonnes in full working configuration. These machines require EP-SE414T3 for the travel undercarriage drives, where machine weight, surface conditions (typically concrete or steel plate on prepared ground), and the mandatory safety case for travel with suspended load converge. The 1,200 N·m spring brake at i=150–186 provides 180,000–223,200 N·m per drive — the mechanical position hold for emergency conditions during a suspended-load positioning move, required by crane type-approval regulations in all major markets.

Large Mining Draglines — Undercarriage Propel Drives

Walking draglines (where the machine is self-propelled via a walking mechanism rather than crawler tracks) represent one end of the scale, while large crawler-mounted draglines at the lighter end of the 750–1,500 tonne class can use EP-SE414T3 for the crawler propel drives. These machines perform infrequent tramming moves between mining panels, but when they do, the full machine weight must be moved over uneven mine floor with low rolling resistance coefficients. The 80,000 N·m capacity per drive provides the sustained tractive effort for these high-weight, intermittent-travel machine propel requirements that EP-SE413T3 cannot meet with adequate safety margin.

Ultra-Heavy Specialised Industrial Transport

Tracked heavy transport platforms for loads above 1,000 tonnes — nuclear reactor pressure vessels, large offshore module sections, bridge girders, and LNG plant process modules — require EP-SE414T3 at high ratios (i=150–186) for the crawler travel drives. Travel speed is measured in metres per minute, but the tractive force requirement scales with total combined weight. The spring brake at i=186 provides 223,200 N·m per drive — the emergency position hold for a hydraulic failure during a critical heavy transport move where uncontrolled movement is not acceptable under any circumstances. Auxiliary winch and tensioner systems on these platforms use worm gear reducers for cable drum self-locking hold, independent of the EP-SE414T3 travel drive spring brake circuit.

Heavy Agricultural Land Preparation — Largest Scale

The largest specialised tracked land-clearing and deep-till platforms at the extreme end of commercial agricultural land development — machines operating on newly converted tropical agricultural land where root systems, organic matter, and waterlogged subsoils impose maximum resistance — may reach the 750+ tonne operating weight class when combined with heavy attached implements. EP-SE414T3 provides the track propel drives for these machines, while the associated multi-output agricultural gearboxes for the land-clearing cutting rotors and deep-till subsoiler assemblies operate on separate PTO power circuits from the EP-SE414T3 travel drives.

Tunnel Boring Machine Backup Gantry and Launch Systems

Large tunnel boring machines in the 10–15 metre diameter class carry backup gantry systems of 800–1,200 tonnes that follow the cutter head on crawler tracks in the tunnel. These gantries carry power, ventilation, segment erection equipment, and spoil removal conveyors. The crawler propel drives for the heaviest gantry systems, particularly in mixed-ground TBMs where gantry travel resistance varies significantly, may require EP-SE414T3 at i=100–140 for the tractive force capacity with the required safety margin. The 1,200 N·m brake provides the emergency hold in the confined tunnel environment where uncontrolled rolling of a 1,000-tonne gantry would be catastrophic.

EP-SE413T3's minimum ratio i=86 corresponds to approximately 40.7 rpm at 3,500 rpm motor input — suitable for the 500–700 tonne class. EP-SE414T3's minimum ratio i=76 corresponds to approximately 46.1 rpm — approximately 13% faster than SE413T3's maximum speed. The larger 750–1,500 tonne machines served by EP-SE414T3 include rope shovels and large draglines that may need faster tramming speed on flat mine haul access despite their greater mass. A rope shovel tramming between positions on a level haul road needs a lower ratio (higher speed) than the same machine climbing a 12° ramp to a new mining panel — EP-SE414T3's i=76 provides the fast tramming option that the machine's operational cycle requires.

At i=186, a 3,500 rpm motor drives the sprocket at approximately 18.8 rpm — the slowest output speed in the entire SE series as presented here, 7% slower than SE413T3's deepest ratio at i=172 (20.3 rpm). At a 650 mm sprocket radius, i=186 produces approximately 0.29 km/h. This ultra-low speed is required for the heaviest tracked transport platforms during critical precision positioning — reactor vessel placement, module final alignment — where the positioning tolerance is measured in millimetres and the machine weight exceeds 1,000 tonnes. At this speed, hydraulic motor speed is low enough for precise flow control without pressure-compensated servo valves in the travel circuit, simplifying the hydraulic system design.

The ratio of maximum to minimum ratio (span) within each unit's range tells the engineer how wide the speed control band is without changing motor displacement. EP-SE413T3: 172 ÷ 86 = 2.0×. EP-SE414T3: 186 ÷ 76 = 2.45×. This 22% wider speed control band in EP-SE414T3 reflects the more varied operational requirements of the 750–1,500 tonne machine class — machines that need both faster repositioning tramming and slower precision positioning than the 500–700 tonne class, covered by a single ratio selection at order. Korea Ever-Power selects the specific ratio from i=76–186 based on the machine's target travel speed and tractive force requirement, returning the recommendation same day.

Torque, Brake, and Ratio Confirmed Same Day

Provide machine gross weight, maximum gradient, target travel speed, motor specification, and incumbent drive model. Korea Ever-Power returns: ratio from i=76–186 for kinematic match; brake adequacy calculation (1,200 N·m × ratio vs your parking and emergency stopping requirement, including safety factor); and dimensional cross-reference — spindle bore, drum OD, sprocket BCD, motor spigot, brake pilot port — same business day, no charge. At 680 kg unit scale, this pre-order engineering confirmation eliminates costly installation errors on a machine where a 30-minute installation error requires a 50-tonne crane return to site.

Pre-Assembled and Brake-Verified at 680 kg

Korea Ever-Power supplies EP-SE414T3 pre-assembled with matched hydraulic motor, overcenter valve, and pressure relief valve. Before shipping: the 1,200 N·m brake is function-tested at the rated pilot pressure — pilot applied (drum rotates freely), pilot released (drum locks within 1 second), oil filled to level. At 680 kg, on-machine brake commissioning would require the crane to hold the unit in position during testing; Korea Ever-Power's pre-shipment brake verification eliminates this requirement entirely. The unit arrives ready for single crane lift into the chassis bore and hydraulic line connection.

Stage-Level Parts and Brake Pack Replacement

Korea Ever-Power stocks all EP-SE414T3 internal components by stage: Stage 1, 2, and 3 sun gear and planet set assemblies; the 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. The 1,200 N·m brake disc pack replacement requires accessing the motor-interface end of the unit — Korea Ever-Power provides the replacement procedure in the service documentation. At 680 kg unit value in a fleet of 750–1,500 tonne machines, component-level planetary gearbox repair is the only economically and practically correct approach. Korea Ever-Power's stage-specific parts availability makes this feasible without a complete unit return.

12/18-Month Warranty — 1,200 N·m Brake Included

12 months from commissioning or 18 months from shipment, covering all three planetary stages, the 1,200 N·m brake assembly (disc pack, Belleville spring pack, piston seal), and the floating face seals. For OEM fleet buyers stocking units before machine assembly, warranty begins at commissioning. Brake assembly warranty is comprehensive — if the 1,200 N·m brake fails to hold its specified torque within the warranty period from any manufacturing defect, Korea Ever-Power replaces the complete brake pack from stock without requiring the 680 kg unit to be returned.

7–14 Days Stock · 30–45 Days Custom

Standard ratio configurations from Korea Ever-Power stock in 7–14 days. Pre-assembled motor packages and custom ratios: 30–45 days. At this unit size and machine class, an unplanned drive failure in a 1,000-tonne rope shovel represents production loss of potentially millions of dollars per day. Korea Ever-Power discusses emergency stock reservation and framework supply terms for fleets at this scale — contact with fleet size and annual volume to discuss reserved production capacity and consignment options.

−25°C to +90°C — Maintained Across 680 kg Housing

EP-SE414T3 maintains the same −25°C to +90°C operating range as all SE units before it. The 680 kg nodular iron thermal mass — at 680 × 500 J/(kg·K) = 340 kJ per degree — provides the highest thermal inertia in the SE series as presented here, giving the longest cold-to-operating-temperature run-up time. At sustained high-duty-cycle travel in ambient above +40°C, Korea Ever-Power provides thermal assessment on request at no charge. Viton and low-temperature seal compounds are available as factory options for operation outside the standard range.

We produce electric rope shovels at 950 tonnes and 1,150 tonnes operating weight. Korea Ever-Power confirmed EP-SE414T3 for both models after calculating that our 12° ramp access gradient at 950 tonnes required a drive torque of approximately 68,000 N·m per side with a 1.7× dynamic factor — beyond EP-SE413T3's 60,000 N·m capacity. At i=105 for our standard operating ratio, the 1,200 N·m brake provides 1,200 × 105 = 126,000 N·m per drive. Our type-approval requires emergency stopping hold of 2.5× the maximum tramming torque; at 126,000 N·m, we achieve a 1.86× factor per drive, and with two drives the combined hold is 252,000 N·m — 3.7× the required tramming torque. This exceeds our type-approval criterion. Korea Ever-Power performed this calculation and sent a written confirmation same day before any order was placed. At 1,800 hours across our first production batch of six units, zero failures.

Our largest crawler crane is rated at 1,600 tonnes lift, with a gross vehicle weight in full working configuration of approximately 910 tonnes. EP-SE414T3 at i=160 is our travel drive specification. The brake at i=160 is 1,200 × 160 = 192,000 N·m per drive. During pick-and-carry at 1,200-tonne load with full counterweight, our safety case requires 240,000 N·m combined hold from both spring brakes — our two drives provide exactly 384,000 N·m combined, a 1.6× factor. This exceeds our regulatory type-approval minimum of 1.5×. The Korea Ever-Power brake verification document — issued before the order — includes this specific calculation for our machine specification. At 3,200 total operating hours across our four production crane units, we have had zero EP-SE414T3 drive failures. The 7–14 day spare-unit availability has allowed us to reduce our on-site spare unit holding from three units to one, since replacement lead times are now predictable and compatible with our scheduled maintenance windows.

We design backup gantry systems for large TBMs in the 12–14 metre bore diameter class. Our largest gantry system weighs 1,050 tonnes fully loaded in tunnel. The crawler propel drives — four drives per gantry — operate at i=130 for our standard design advance rate, with an 11° tunnel grade in the steepest geology. Korea Ever-Power confirmed EP-SE414T3 for this application: the required tractive force at 1,050 tonnes on 11° with a 1.5× service factor is approximately 71,000 N·m per drive — above SE413T3's 60,000 N·m. The 1,200 N·m spring brake at i=130 gives 156,000 N·m per drive emergency hold — essential in a confined tunnel environment where an uncontrolled 1,050-tonne gantry rollback is an absolute safety-critical failure. At 2,400 hours across four tunnel projects (16 drives total), zero mechanical failures. Korea Ever-Power's pre-shipment brake verification document was accepted by all four tunnel project safety authorities as part of the equipment type-approval submission.

ВWhy does the spring brake jump from 610 N·m (SE413T3) to 1,200 N·m — nearly doubling in a single step?

Four independent factors each require a substantially higher spring brake at EP-SE414T3's scale. First, the 680 kg rotating housing requires more braking force to stop within the defined deceleration distance at maximum speed — a 62% heavier assembly than SE413T3. Second, at the minimum ratio i=76, a 610 N·m brake provides only 610×76=46,360 N·m per drive — a safety factor of approximately 1.23× for a 1,000-tonne machine at 15°, well below the 2.0× minimum required for this machine class. The 1,200 N·m brake at i=76 provides 91,200 N·m, a 2.4× factor. Third, despite the higher brake torque, the release pressure remains 15–30 bar by using a physically larger piston and disc pack. Fourth, regulatory type-approval requirements for machines above 750 tonnes impose higher emergency stopping performance criteria. All four factors point to the same conclusion: the step to 1,200 N·m is not a linear increment but a categorical change driven by the weight class transition from 420 kg (SE413T3 machine class) to 680 kg (SE414T3 machine class) and the safety requirements that accompany it.

ВWhat causes the 260 kg weight increase from SE413T3 (420 kg) to SE414T3 (680 kg)?

Four factors account for the 260 kg increase. The larger brake assembly (piston, disc pack, spring pack) contributes an estimated 40–70 kg. The gear sets for 80,000 N·m versus 60,000 N·m require wider tooth faces and larger planet carriers at the final stage — the dominant contributor at an estimated 120–150 kg across all three stages. The ratio range reconfiguration to accommodate i=76 at the low end may require larger stage 1 components compared to SE413T3's i=86 minimum. Finally, the bearings at the drum-spindle interface must be physically larger to handle the 500+ kN combined loads from 750–1,500 tonne machines, adding an estimated 20–30 kg. Unlike the step from SE410T3 to SE413T3 — where three models stabilised at 420 kg through ratio range optimisation — EP-SE414T3's 33% torque increase plus categorical brake upgrade plus extended ratio range simultaneously required housing cross-section growth that couldn't be accommodated within the 420 kg envelope.

ВAt 680 kg, what are the crane and installation requirements for EP-SE414T3?

EP-SE414T3 requires a certified lift rated at ≥1,000 kg capacity — typically a 20–50 tonne telescopic crane or equivalent. Korea Ever-Power's dimensional drawing specifies two chain-attachment points on the drum housing for balanced lifting; the crane angle and chain length are specified to ensure the unit hangs at the correct installation angle for alignment into the spindle bore. Typical installation time is 10–12 hours per side with two qualified technicians and appropriate lifting equipment. Korea Ever-Power supplies the installation documentation with each unit. If installation equipment is insufficient at the machine site, Korea Ever-Power can advise on the minimum crane specification based on the specific chassis dimensions and installation clearance requirements.

ВIs EP-SE414T3 a direct drop-in replacement for Rexroth GFT or Bonfiglioli 700C units at the 80,000 N·m class?

For triple-stage units in the 80,000 N·m torque class, Korea Ever-Power provides an explicit dimensional cross-reference document before order — spindle bore diameter and fit class, drum OD, sprocket bolt circle, hydraulic port thread sizes and positions, motor interface spigot — against your specific legacy model number and ratio code. At this torque class, there are multiple GFT and Bonfiglioli 700C configurations (different ratio codes, different axial lengths for different applications), and the cross-reference confirms which specific EP-SE414T3 configuration matches the specific unit being replaced. Provide the full model number of the incumbent drive, and Korea Ever-Power returns the same-day cross-reference with any dimensional notes flagged explicitly. Rexroth and Bonfiglioli are trademarks of their respective owners, cited for dimensional reference only.