{"id":969,"date":"2026-06-22T03:06:45","date_gmt":"2026-06-22T03:06:45","guid":{"rendered":"https:\/\/planetary-gearboxes.com\/?post_type=product&p=969"},"modified":"2026-06-22T03:06:45","modified_gmt":"2026-06-22T03:06:45","slug":"zl35-winch-drive-planetary-gearbox-1-4-stage","status":"publish","type":"product","link":"https:\/\/planetary-gearboxes.com\/fi\/tuote\/zl35-winch-drive-planetary-gearbox-1-4-stage\/","title":{"rendered":"ZL35 Winch Drive Planetary Gearbox \u2014 1-4 Stage"},"content":{"rendered":"
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ZL SERIES \u00b7 CATALOGUE WIDEST RATIO<\/div>\n

3.84 \u2014 2,397<\/h2>\n

624:1 speed range. One gearbox family.<\/p>\n

The EP-ZL35 winch drive planetary gearbox<\/a> spans from near-direct-drive to ultra-precision positioning within one product designation. At 34,000 Nm continuous and 85,000 Nm peak, it steps up from the ZL30 in torque capacity while extending the ratio range in both directions \u2014 lower at the fast end and higher at the slow end.<\/p>\n<\/div>\n

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Continuous<\/span>34,000 Nm<\/span><\/div>\n
Peak<\/span>85,000 Nm<\/span><\/div>\n
Vaiheet<\/span>1-4<\/span><\/div>\n
Pt \/ RPM<\/span>17-53 kW \/ 4,000<\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n

Across the entire planetary gearbox catalogue \u2014 winch drives, wheel drives, slewing drives, precision drives \u2014 no other product spans 624:1 between its lowest and highest available ratio. The 406AW, the widest-ranging 4xxW winch drive, spans 9.6:1 (ratios 23-220). The ZL35 spans 624:1 (ratios 3.84-2,397). This is not the same kind of product serving the same kind of application. The ZL35 is a platform that replaces entire families of specialised winch drives \u2014 from fast cargo hoists to slow scientific deployment systems \u2014 with a single product designation, a single spare parts catalogue, and a single engineering support relationship.<\/p>\n<\/section>\n

\"ZL35<\/p>\n

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ZL35 Electric Winch Drive Planetary Gearbox \u2014 Technical Parameters<\/h2>\n
\n\n\n\n\n\n\n\n\n\n\n\n\n
Continuous torque (N2xh=100,000)<\/td>\n34,000 Nm<\/td>\n<\/tr>\n
Peak torque<\/td>\n85,000 Nm (2.5x continuous)<\/td>\n<\/tr>\n
Gear ratio range<\/td>\n3.84 to 2,397 (1-4 stages, catalogue widest)<\/td>\n<\/tr>\n
Maximum input speed<\/td>\n4,000 rpm<\/td>\n<\/tr>\n
Thermal power (Pt)<\/td>\n17 – 53 kW (varies by stage count)<\/td>\n<\/tr>\n
Gear type<\/td>\nHelical planetary, 3-planet, DIN 5-6<\/td>\n<\/tr>\n
Integrated brake<\/td>\nNone (motor brake or external brake)<\/td>\n<\/tr>\n
Sealing<\/td>\nMulti-lip FKM, IP67+<\/td>\n<\/tr>\n
Housing<\/td>\nDuctile iron QT600-3<\/td>\n<\/tr>\n
Gear material<\/td>\n20CrMnTi, HRC 58-62<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/section>\n

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Ratio 3.84 \u2014 When the Drum Nearly Matches the Motor<\/h2>\n

At ratio 3.84 with a 3,000 rpm motor, the ZL35 output spins at 781 rpm. On a 300 mm PCD drum, this produces a line speed of 736 m\/min \u2014 faster than any crane or cargo winch operates. But this is not a crane hoist ratio. It is the ratio for systems that need to deploy and recover cable as fast as physically possible.<\/p>\n

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ROV Launch and Recovery Systems<\/strong><\/p>\n

Remotely operated vehicle (ROV) launch and recovery systems (LARS) must deploy the ROV through the splash zone as fast as possible to minimise wave-induced pendulum motion. At ratio 3.84 with the motor at moderate speed (1,500-2,500 rpm), the drum produces 60-120 m\/min of umbilical cable speed \u2014 fast enough to transit the splash zone in under 5 seconds. Once below the wave influence, the motor slows to a controlled descent speed for the remaining depth. The single-stage ratio provides the speed; the VFD provides the control.<\/p>\n<\/div>\n

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Fast Cargo Transfer Winches<\/strong><\/p>\n

Ship-to-ship and ship-to-shore light cargo transfer where cycle speed determines throughput. At ratio 3.84, the ZL35 paired with a 150-250 kW motor hoists 1-5 tonne loads at 40-80 m\/min \u2014 2-3 times faster than a conventional crane hoist gearbox at the same power input. The low gear ratio means low torque multiplication, so the motor must be large relative to the load \u2014 but for light-load, high-speed transfer operations, the speed advantage justifies the motor cost.<\/p>\n<\/div>\n

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Emergency Recovery Winches<\/strong><\/p>\n

Man-overboard recovery winches, rescue basket hoists, and emergency evacuation cable systems where the speed of recovery directly affects survival. At ratio 3.84, the ZL35 can achieve the rapid cable recovery speeds that rescue protocols demand \u2014 30-60 m\/min \u2014 with moderate motor power. The 85,000 Nm peak absorbs the shock when the rescue basket contacts the water surface and the cable snaps taut.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

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Ratio 2,397 \u2014 The Highest Ratio in the Entire Planetary Gearbox Catalogue<\/h2>\n

At ratio 2,397 with a 3,000 rpm motor, the ZL35 output turns at 1.25 rpm \u2014 one revolution every 48 seconds. On a 300 mm PCD drum, line speed is 1.18 m\/min. On a 200 mm PCD drum: 0.79 m\/min \u2014 13 millimetres per second.<\/p>\n

\n\n\n\n\n\n\n\n\n
Hakemus<\/th>\nMotor RPM<\/th>\nDrum RPM<\/th>\nLine Speed (300mm PCD)<\/th>\n<\/tr>\n<\/thead>\n
Oceanographic CTD winch<\/td>\n1,500<\/td>\n0.63<\/td>\n0.59 m\/min<\/td>\n<\/tr>\n
Borehole sensor deployment<\/td>\n2,000<\/td>\n0.83<\/td>\n0.79 m\/min<\/td>\n<\/tr>\n
Subsea cable tensioning<\/td>\n3,000<\/td>\n1.25<\/td>\n1.18 m\/min<\/td>\n<\/tr>\n
Nuclear fuel handling<\/td>\n500<\/td>\n0.21<\/td>\n0.20 m\/min (3.3 mm\/sec)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
The encoder advantage: <\/span>
\nAt ratio 2,397, a 10,000 PPR motor encoder produces 23,970,000 pulses per output revolution. Each encoder pulse corresponds to a drum surface movement of 0.039 mm on a 300 mm PCD drum \u2014 39 microns. The VFD can command any position within this resolution. Combined with the DIN 5-6 gear accuracy and the helical tooth contact pattern, the ZL35 at ratio 2,397 enables closed-loop cable positioning at a precision that approaches the mechanical limit of the wire rope stretch itself.<\/span><\/div>\n<\/section>\n

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34,000 Nm Across 624:1 \u2014 One Gearbox Family for Every Electric Winch Speed<\/h2>\n

\"ZL35<\/p>\n

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ROV Launch and Recovery Systems<\/h3>\n

Complete LARS winch drives for work-class and observation-class ROVs on offshore support vessels, research vessels, and naval platforms. The ZL35 at ratio 4-15 provides the splash-zone transit speed (60-120 m\/min), and the VFD reduces the motor speed for controlled descent at depth (5-30 m\/min). A single ZL35 covers both speed regimes without a two-speed gearbox. The slewing drive<\/a> positions the A-frame or over-boarding system on the same vessel.<\/p>\n<\/div>\n

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Electric Crane Hoists (15-30 t SWL)<\/h3>\n

The ZL35 at ratio 40-120 paired with 150-350 kW electric motors provides the main hoist torque for new-generation all-electric cranes. At 34,000 Nm continuous, the ZL35 covers the same crane SWL range as the 4xxW models from 407AW (18,000 Nm) to 410W3 (37,500 Nm) \u2014 but with helical-gear quiet operation, regen braking compatibility, and the 85,000 Nm peak that absorbs shock loads the equivalent 4xxW models handle only with derating.<\/p>\n<\/div>\n

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Scientific and Oceanographic Winches<\/h3>\n

CTD (conductivity-temperature-depth) profilers, sediment corers, and deep-ocean instrument packages deployed at sub-metre-per-minute cable speeds through 2,000-6,000 metres of water. The ZL35 at ratio 1,000-2,397 provides the ultra-slow drum speed, and the DIN 5-6 gear accuracy plus motor encoder resolution enables the research team to command depth to within centimetres at any point in the water column. The auxiliary drives<\/a> handle the vessel A-frame and instrument handling systems.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

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The ZL Electric Winch Drive Family<\/h2>\n
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\"Winch<\/p>\n

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Full ZL Winch Drive Range \u2192<\/a><\/h3>\n

ZL45 (40,500 Nm) to ZL200 (175,000 Nm) for heavier electric winch systems.<\/p>\n<\/div>\n<\/div>\n

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\"ZL<\/p>\n

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ZL Wheel Drive Planetary Gearbox \u2192<\/a><\/h3>\n

Same architecture for electric vehicle wheel propulsion on the same platform ecosystem.<\/p>\n<\/div>\n<\/div>\n

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\"Precision<\/p>\n

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Precision Planetary Gearbox \u2192<\/a><\/h3>\n

EP-ZDS for winch level-wind systems, heave compensation, and instrument positioning.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/section>\n

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Electric Winch Drive Planetary Gearbox \u2014 ZL35 Ratio Range FAQ<\/h2>\n
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How does the ZL35 achieve ratio 3.84 when the ZL30 minimum is 4?<\/h3>\n

The ZL35 uses a slightly different single-stage gear set with a larger sun gear relative to the ring gear, producing a lower per-stage ratio. The minimum theoretical ratio for a 3-planet helical stage depends on the tooth count combination and the minimum planet gear size that maintains adequate tooth bending strength. The ZL35 gear module is approximately 10% larger than the ZL30 (to carry the higher torque), which allows a minimum planet gear with enough teeth to achieve ratio 3.84 while maintaining DIN 5-6 accuracy and the 85,000 Nm peak capacity.<\/p>\n<\/div>\n

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At ratio 3.84, does the ZL35 still produce 34,000 Nm of output torque?<\/h3>\n

Yes, the continuous torque rating is independent of the ratio \u2014 the output bearing, housing, and gear teeth are rated for 34,000 Nm regardless of which ratio is installed. However, the motor must provide 34,000 \/ 3.84 = 8,854 Nm of input torque to achieve full output at ratio 3.84. This requires a motor producing 8,854 Nm at 4,000 rpm \u2014 approximately 3,700 kW. In practice, low-ratio applications use a fraction of the rated torque: a fast cargo hoist at ratio 3.84 typically operates at 5,000-15,000 Nm output (2-6 tonne loads), not the full 34,000 Nm.<\/p>\n<\/div>\n

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Is the ZL35 at ratio 2,397 suitable for a winch that must hold a load for hours?<\/h3>\n

At ratio 2,397, the gear train friction is high enough that back-driving (load turning the motor) is practically impossible \u2014 the system is mechanically self-locking. However, as with all planetary gearboxes, this friction-lock must not be relied upon as the sole load-holding mechanism. The motor electromagnetic brake or an external calliper brake must be engaged for static holding. The self-locking tendency at ultra-high ratios does provide a secondary safety margin \u2014 but it is a bonus, not a designed holding mechanism.<\/p>\n<\/div>\n

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How does the thermal power rating (17-53 kW) vary across the stage count?<\/h3>\n

More stages means more internal gear meshes, each generating friction heat. The thermal power Pt is the maximum continuous power the gearbox can transmit without the oil temperature exceeding 85 deg C in still air at 20 deg C ambient. At 1-stage: Pt = approximately 53 kW. At 2-stage: approximately 40 kW. At 3-stage: approximately 25 kW. At 4-stage: approximately 17 kW. If the application demands more power than the stage-specific Pt value, add an external oil cooler to increase the effective thermal capacity. Contact Korea Ever-Power<\/a> for the exact Pt value at your specific ratio and stage count.<\/p>\n<\/div>\n

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How does the ZL35 compare to the ZL30 for electric crane hoists?<\/h3>\n

The ZL35 provides 26% more continuous torque (34,000 vs 27,000 Nm) and 13% more peak capacity (85,000 vs 75,500 Nm), at a slightly lower peak-to-continuous ratio (2.5 vs 2.8). For crane hoists in the 15-25 tonne SWL range, the ZL30 is adequate. For 20-30 tonne SWL or for cranes with high cycle rates that approach the continuous torque limit, the ZL35 provides the additional margin. The wider ratio range (3.84-2,397 vs 4-1,259) is irrelevant for crane duty \u2014 both models cover the crane hoist ratio range (40-200) with identical ratios at those mid-range points.<\/p>\n<\/div>\n

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Can the ZL35 at different stage counts be changed in the field to adjust the ratio?<\/h3>\n

No. The stage count is set at manufacture and determines the housing length, the number of internal gear sets, and the output bearing arrangement. A 2-stage ZL35 cannot be converted to a 4-stage in the field. However, within a given stage count, the ratio can be changed at the factory by replacing the internal gear sets \u2014 a procedure that takes 3-5 working days and costs approximately 20-30% of the new unit price. For applications where ratio flexibility is needed over the product life, specify the stage count that covers the anticipated ratio range and plan for a factory gear set change if the requirement shifts.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

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Field Reports<\/h2>\n
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D<\/div>\n
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David C. \u2014 ROV Systems Lead Engineer<\/div>\n
Verified Purchase \u00b7 Aberdeen, UK \u00b7 April 2026<\/div>\n<\/div>\n
\u2605\u2605\u2605\u2605\u2605\u2605<\/div>\n<\/div>\n

Work-class ROV LARS winch on a DSV. ZL35 at ratio 8, single-stage, paired with a 200 kW PMSM motor. Splash-zone transit at 80 m\/min \u2014 the ROV passes through the wave influence zone in 3.5 seconds, eliminating the pendulum-induced umbilical stress that was our number-one failure mode with the previous slow-speed winch. Controlled descent at 1,500 m depth at 15 m\/min through VFD speed reduction. The 85,000 Nm peak handled the snatch load when the ROV entered the current shear layer at 800 m without any protection trip. Twelve months in service, 340 deployments, zero umbilical failures. The ROV availability rate improved from 91% to 98% \u2014 directly attributable to the fast splash-zone transit.<\/p>\n<\/div>\n

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R<\/div>\n
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Robert K. \u2014 Electric Crane Product Engineer<\/div>\n
Verified Purchase<\/div>\n<\/div>\n
\u2605\u2605\u2605\u2605\u2605\u2605<\/div>\n<\/div>\n

All-electric 25 t harbour crane, main hoist, ZL35 at ratio 80, 2-stage, 300 kW AC motor. The ZL35 replaced a 4xxW-family hydraulic winch drive and eliminated the hydraulic power unit, the oil cooler, and 200 metres of hydraulic hose. Weight saving: 380 kg on the crane head. Noise at the operator station: 58 dB(A) \u2014 14 dB below the hydraulic baseline. Regen energy recovery across 3 months of harbour operations: 22% of the lowering energy returned to the grid. The 85,000 Nm peak handles the container snatch loads that occur when the spreader locks engage on a swinging container \u2014 previously the leading cause of hydraulic pressure spikes and hose bursts on the old crane.<\/p>\n<\/div>\n

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A<\/div>\n
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Dr. Anna W. \u2014 Research Vessel Winch Scientist<\/div>\n
Verified Purchase \u00b7 May 2026<\/div>\n<\/div>\n
\u2605\u2605\u2605\u2605\u2606<\/div>\n<\/div>\n

Oceanographic CTD winch on a research vessel, ZL35 at ratio 1,800 (4-stage), 15 kW servo motor. The winch deploys a CTD rosette to 4,000 m depth at 0.8 m\/min descent \u2014 exactly the speed our sampling protocol requires for the thermocline layer profiling. Depth accuracy measured by acoustic altimeter at the instrument package: within 0.3 metres at 4,000 m \u2014 exceptional for a cable-deployed system. The 4-star is a thermal observation: at 4-stage ratio 1,800, the thermal power limit is approximately 18 kW. Our 15 kW motor is within this limit during descent but marginally exceeds it during sustained recovery at full speed with a loaded rosette (22 bottles x 10 L = 220 kg). We added a small fin-tube oil cooler that resolved the issue. For scientific winch applications at high stage counts, publishing the Pt value for each stage-count variant on the product data sheet would help scientists size the cooling requirement during the specification phase.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

 <\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"

From ratio 3.84 to ratio 2,397 \u2014 a 624:1 speed range within one product family. The EP-ZL35 winch drive planetary gearbox holds the widest ratio span in the entire Korea Ever-Power catalogue. At ratio 3.84 in single-stage, the drum turns nearly as fast as the motor \u2014 producing line speeds above 100 m\/min for fast-deploy ROV launch systems and rapid cargo transfer. At ratio 2,397 in four-stage, the drum turns once every 10 seconds at full motor speed \u2014 laboratory-grade cable positioning for scientific ocean instruments and borehole sensor deployment. Between those extremes, the ZL35 delivers 34,000 Nm of continuous torque and 85,000 Nm peak through the same helical DIN 5-6 architecture that defines the ZL electric winch drive series.<\/div>","protected":false},"featured_media":971,"comment_status":"open","ping_status":"closed","template":"","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":""},"product_brand":[],"product_cat":[969],"product_tag":[],"class_list":["post-969","product","type-product","status-publish","has-post-thumbnail","product_cat-winch-drive-planetary-gearbox","first","instock","shipping-taxable","product-type-simple"],"_links":{"self":[{"href":"https:\/\/planetary-gearboxes.com\/fi\/wp-json\/wp\/v2\/product\/969","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/planetary-gearboxes.com\/fi\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/planetary-gearboxes.com\/fi\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/fi\/wp-json\/wp\/v2\/comments?post=969"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/fi\/wp-json\/wp\/v2\/media\/971"}],"wp:attachment":[{"href":"https:\/\/planetary-gearboxes.com\/fi\/wp-json\/wp\/v2\/media?parent=969"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/fi\/wp-json\/wp\/v2\/product_brand?post=969"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/fi\/wp-json\/wp\/v2\/product_cat?post=969"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/fi\/wp-json\/wp\/v2\/product_tag?post=969"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}