ZL45 Winch Drive Planetary Gearbox — 1-4 Stage

ZL45 — 40,500 Nm

Le winch drive planetary gearbox that sits at the exact torque where the crane industry is deciding between hydraulic and electric. The 410W3 at 37,500 Nm represents the hydraulic answer. The 413W3 at 42,500 Nm is the hydraulic heavy-duty option. The ZL45 at 40,500 Nm is the electric alternative to both — same torque class, different propulsion era.

Heavy Electric Crane Hoists (25-40 t SWL)

Next-generation all-electric mobile cranes, offshore platform cranes, and harbour cranes replacing 410W3 and 413W3 hydraulic hoist drives. The ZL45 at ratio 60-140 paired with 200-450 kW electric motors delivers the same lifting performance with 10-14 dB lower noise, 15-25% regen energy recovery, and 200-500 kg lighter installed weight. The slewing drive et wheel drive handle the crane rotation and travel on the same electric platform.

Electric Marine Deck Cranes

All-electric ship-mounted cranes on offshore support vessels, naval platforms, and research vessels where the vessel is transitioning to hybrid-electric or full-electric propulsion. The ZL45 hoist drive integrates with the vessel power management system — the VFD communicates with the vessel energy management controller to schedule heavy lifts during periods of generator surplus and regen braking during periods of grid demand. The IP67+ sealing handles the marine deck environment without the environmental risk of hydraulic oil spills.

Electric Mining Auxiliary Hoists

Auxiliary hoists at mine shafts handling equipment, materials, and personnel at depths of 200-600 metres. The ZL45 at ratio 100-300 paired with a 100-250 kW AC motor provides the auxiliary winding capacity that supports the main production winder. Mine electrification programmes are converting auxiliary hoists from hydraulic to electric first (lower risk, lower cost) before tackling the main winder — the ZL45 is the entry point for this mine electrification sequence.

Can the ZL45 physically replace a 410W3 or 413W3 in an existing crane without drum modification?

Generally no. The ZL45 housing diameter, bolt pattern, and output shaft dimensions are different from the 4xxW series. A hydraulic-to-electric conversion at the winch drive level requires a new drum housing designed around the ZL45 mounting interface. However, the drum barrel, cable, and reeving arrangement can usually be retained — only the gearbox-to-drum interface changes. For a mid-life crane conversion, the drum modification typically costs 10-15% of the total conversion budget. For a new-build crane, there is no penalty — the drum is designed for the ZL45 from the start.

Does the ZL45 without an internal brake meet EN 14492 lifting safety requirements?

EN 14492 requires at least two independent braking means for power-driven lifting. The ZL45 complies when paired with: (1) a motor-integrated electromagnetic brake on the motor shaft, AND (2) an external drum calliper brake OR the VFD electronic braking function (if accepted by the notified body as an independent braking means). Most European notified bodies accept motor brake + calliper brake. Some accept motor brake + VFD electronic braking if the VFD has a SIL-2 rated safe-torque-off function. Verify with the crane certification body before committing to the braking architecture.

How does the ZL45 total-cost-of-ownership compare to the 410W3 hydraulic equivalent?

The ZL45 plus electric motor plus VFD typically costs 15-30% more in upfront capital than the 410W3 plus hydraulic motor plus HPU. However, the electric system eliminates hydraulic oil changes (2-4 per year), hydraulic hose replacements (every 5-7 years), pump seal replacements, and HPU filter changes. Regen braking reduces the energy consumption by 15-25%. The estimated TCO break-even for cranes operating 2,000+ hours per year is 18-30 months. For cranes operating 4,000+ hours per year (offshore platforms, production harbours), the break-even can be as short as 12 months.

What motor frame size is typical for the ZL45 at ratio 80 on a 25 t crane hoist?

At ratio 80 with a 500 mm PCD drum, 8-part reeving, SWL 25 t: line pull = 25,000 x 9.81 / 8 = 30,656 N. Drum torque = 30,656 x 0.25 = 7,664 Nm. At 15 m/min hoist speed: drum rpm = 15 / (3.14 x 0.5) = 9.55 rpm. Motor rpm = 9.55 x 80 = 764 rpm. Motor power = 7,664 x 764 x 2 x 3.14 / 60 = 613 kW peak during acceleration, approximately 350 kW sustained at full load. A 400 kW AC motor (IEC frame 355 or 400) is typical. With VFD: the motor operates at variable speed from 0-764 rpm for this hoist speed, or up to 2,500-4,000 rpm at light load for fast empty-hook return.

Why does the ZL45 maximum ratio (1,745) drop below the ZL35 maximum (2,397)?

The ZL45 uses a slightly larger gear module than the ZL35 to carry the higher torque. Larger gears produce a lower maximum per-stage ratio because the minimum planet gear size (set by tooth count and bending strength) becomes a larger fraction of the ring gear diameter. Over four stages, this difference compounds: each stage achieves approximately 5-8% less ratio than the ZL35, resulting in a 4-stage maximum of 1,745 versus 2,397. For applications needing ratios above 1,745 at this torque level, contact Korea Ever-Power for a 5-stage custom configuration or consider the ZL35 at a derated continuous torque.

Can the winch drive handle the duty cycle of an offshore platform crane running 24/7?

Yes, within the thermal power limit of the selected stage count. An offshore platform crane typically operates at 30-50% duty cycle over a 24-hour period (150-300 lifts at 3-8 minutes per cycle). At 2-stage ratio 80 with a 350 kW motor: average power throughput = 350 x 0.4 (40% duty) = 140 kW average thermal load. The 2-stage Pt without cooler is approximately 42 kW — exceeded. With external cooler (+50%): 63 kW — still exceeded. Solution: add an external cooler sized for the average thermal load (140 kW) plus 20% margin, or derate the duty cycle. For 24/7 offshore crane duty, always specify an external oil cooler regardless of the thermal calculation — the consequence of thermal shutdown during an offshore lift is unacceptable.

Mid-life conversion of a 30 t offshore platform crane from hydraulic (410W3) to electric (ZL45 at ratio 90, 400 kW PMSM). The conversion eliminated the HPU, cooler, reservoir, and 165 metres of hydraulic hose from the crane machinery house. Weight saving: 420 kg on the crane head — which recovered 1.8 tonnes of SWL capacity at maximum boom extension. Energy consumption reduced by 31% (regen + elimination of hydraulic standby losses). Noise at the operator station dropped from 72 dB(A) to 57 dB(A) — the operators describe the crane as "silent" compared to the hydraulic baseline. Conversion payback period: 22 months at current electricity rates. The next two platform cranes in the fleet are already specified for ZL45 conversion.

New-build 35 t all-electric harbour crane, ZL45 at ratio 100, 2-stage, 350 kW AC motor. We evaluated the 413W3 hydraulic option during the concept phase and the ZL45 electric option during the detail design. The ZL45 won on three criteria: 14 dB quieter (the crane operates 200 metres from a residential area), 380 kg lighter at the crane head (structural cost saving on the boom), and 23% lower annual energy cost with regen. The 95,000 Nm peak handled the container snatch loads during our 6-month commissioning without any VFD fault or thermal trip. The harbour authority is now specifying all-electric as the standard for new crane procurements.

Auxiliary hoist at a 450-metre copper mine, ZL45 at ratio 200, 3-stage, 150 kW AC motor. This is the first electric winch drive installed as part of our mine-wide electrification programme — replacing a hydraulic auxiliary hoist that required a dedicated HPU, oil cooler, and 4 annual oil changes. The ZL45 eliminated all hydraulic maintenance on this hoist. The mine ventilation load dropped by 2.3 kW (no hydraulic heat rejection into the underground air circuit). The 4-star is a thermal observation consistent with the ZL series: at 3-stage ratio 200, the Pt is approximately 28 kW. Our 150 kW motor at the actual operating duty (35% continuous) produces approximately 52 kW average thermal load — exceeding the unaided Pt. We added an external cooler. For mine electrification programmes converting multiple hoists, bundling the cooler specification with the gearbox specification in a single procurement package would simplify the conversion process.