{"id":991,"date":"2026-06-22T05:21:05","date_gmt":"2026-06-22T05:21:05","guid":{"rendered":"https:\/\/planetary-gearboxes.com\/?post_type=product&p=991"},"modified":"2026-06-22T05:21:06","modified_gmt":"2026-06-22T05:21:06","slug":"zr55-winch-drive-planetary-gearbox-right-angle","status":"publish","type":"product","link":"https:\/\/planetary-gearboxes.com\/es\/producto\/zr55-winch-drive-planetary-gearbox-right-angle\/","title":{"rendered":"ZR55 Winch Drive Planetary Gearbox \u2014 Right-Angle"},"content":{"rendered":"
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<\/p>\n

\n
\n
RIGHT-ANGLE INPUT<\/span>
\nTHIRD ARCHITECTURE<\/span><\/div>\n
\n
\n

ZR55
\nThe motor turns 90 degrees.<\/span><\/h2>\n

The 4xxW mounts coaxially for hydraulic motors. The ZL mounts coaxially for electric motors. The EP-ZR55 winch drive planetary gearbox<\/a> turns the input shaft perpendicular to the drum \u2014 opening the final architecture for every installation where the space behind the drum is occupied by structure, by another machine, or by nothing at all.<\/p>\n<\/div>\n

\n
\n
Continuo<\/span>55,000<\/span><\/div>\n
Peak<\/span>112,000<\/span><\/div>\n
Input RPM<\/span>3,300<\/span><\/div>\n
Stages \/ Pt<\/span>2-5 \/ 24-74<\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n

The ZR55 is the entry point to a seven-model right-angle winch drive family spanning 55,000-175,000 Nm \u2014 running parallel to the ZL series at identical torque levels but with a 90-degree bevel input stage that redirects the motor shaft perpendicular to the drum axis. The bevel stage adds one mandatory gear mesh (the right-angle turn), which is why the ZR series starts at 2 stages (1 bevel + 1 planetary) instead of the ZL single-stage minimum. The 3,300 rpm input speed \u2014 lower than the ZL 4,000-5,000 rpm \u2014 reflects the bevel gear peripheral velocity limit at the ZR housing size. In every other respect \u2014 torque, peak capacity, gear accuracy, sealing, housing material \u2014 the ZR55 matches the ZL55 specification exactly.<\/p>\n<\/section>\n

<\/p>\n

\n

ZR55 Right-Angle 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>\n55,000 Nm<\/td>\n<\/tr>\n
Peak torque<\/td>\n112,000 Nm (2.04x continuous)<\/td>\n<\/tr>\n
Input configuration<\/td>\nRight-angle (90 deg helical bevel + planetary)<\/td>\n<\/tr>\n
Maximum input speed<\/td>\n3,300 rpm<\/td>\n<\/tr>\n
Available stages<\/td>\n2-5 (1 bevel + 1-4 planetary)<\/td>\n<\/tr>\n
Thermal power (Pt)<\/td>\n24 – 74 kW (varies by stage count)<\/td>\n<\/tr>\n
Gear type<\/td>\nHelical bevel + helical planetary, DIN 5-6<\/td>\n<\/tr>\n
Integrated brake<\/td>\nNone (motor brake or external brake)<\/td>\n<\/tr>\n
Sealing \/ Housing<\/td>\nIP67+ FKM \/ 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

<\/p>\n

\n

Right-Angle Input \u2014 Why the Motor Goes Perpendicular and How It Works<\/h2>\n

The ZR bevel stage redirects the motor torque 90 degrees before it enters the planetary gear train. This is not a convenience feature \u2014 it is a geometric necessity for installations where a coaxial motor physically cannot fit.<\/p>\n

\"ZR55<\/p>\n

\n
How the Bevel Stage Works<\/strong><\/p>\n

A matched pair of helical bevel gears \u2014 one on the input shaft (motor side) and one on the intermediate shaft (planetary side) \u2014 mesh at 90 degrees. The bevel pair provides the first ratio reduction (typically 1.5-3.5:1) and the direction change simultaneously. The intermediate shaft then drives the first planetary stage in the same manner as the ZL series. The bevel gears are ground to DIN 5-6 accuracy and operate in the same oil bath as the planetary stages.<\/p>\n<\/div>\n

Why 3,300 RPM Instead of 5,000<\/strong><\/p>\n

Bevel gears at the ZR55 pitch diameter produce tooth peripheral velocities that reach the lubrication film limit at approximately 3,300 rpm. Above this speed, the bevel tooth contact would risk scuffing \u2014 metal-to-metal contact through the oil film. The ZL coaxial series avoids this constraint because it has no bevel stage. The 3,300 rpm ZR limit matches standard 4-pole industrial motors at 50 Hz (3,000 rpm synchronous) and 6-pole motors at 60 Hz (3,600 rpm synchronous) \u2014 both common in industrial and marine applications.<\/p>\n<\/div>\n

What the Right Angle Costs<\/strong><\/p>\n

The bevel stage adds one gear mesh (approximately 1-2% efficiency loss), the bevel gear pair weight, and the right-angle housing volume. The ZR55 at 2-stage (bevel + 1 planetary) is slightly less efficient than the ZL55 at 1-stage (planetary only): approximately 93-94% versus 96-97%. At 5-stage (bevel + 4 planetary), both converge at approximately 90-91% because the additional planetary mesh losses dominate. The right-angle geometry also generates a thrust load on the bevel shaft bearings that the coaxial ZL does not produce \u2014 handled by the heavy-series tapered roller bearings in the ZR housing.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

\n

ZR55 vs ZL55 \u2014 Same Torque, Different Geometry, Different Applications<\/h2>\n
\n\n\n\n\n\n\n\n\n\n\n\n\n
Par\u00e1metro<\/th>\nZL55 (Coaxial)<\/th>\nZR55 (Right-Angle)<\/th>\n<\/tr>\n<\/thead>\n
Continuous \/ Peak<\/td>\n55,000 \/ 112,000<\/td>\n55,000 \/ 112,000<\/td>\n<\/tr>\n
Motor axis<\/td>\nParallel to drum<\/td>\nPerpendicular to drum<\/td>\n<\/tr>\n
Velocidad m\u00e1xima de entrada<\/td>\n4,000 rpm<\/td>\n3,300 rpm<\/td>\n<\/tr>\n
Min stages<\/td>\n1<\/td>\n2 (bevel + 1 planetary)<\/td>\n<\/tr>\n
Max stages<\/td>\n5<\/td>\n5 (bevel + 4 planetary)<\/td>\n<\/tr>\n
Efficiency (2-stage)<\/td>\n~96%<\/td>\n~93-94%<\/td>\n<\/tr>\n
Motor mounting<\/td>\nBehind drum (axial)<\/td>\nBeside\/below drum<\/td>\n<\/tr>\n
Pt \/ Thermal<\/td>\n24-74 kW<\/td>\n24-74 kW<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\n
Choose ZL55 (coaxial) when:<\/strong><\/p>\n

The drum has axial depth for the motor behind the gearbox. The application needs single-stage low ratios (below the ZR minimum). Maximum efficiency matters (96% vs 93%). The motor speed exceeds 3,300 rpm (up to 5,000 rpm for later ZL models).<\/p>\n<\/div>\n

Choose ZR55 (right-angle) when:<\/strong><\/p>\n

No axial space behind the drum \u2014 the motor must mount beside, below, or above. The bulkhead, hull frame, or headframe column is directly behind the drum cavity. The motor alignment is simpler with a perpendicular mount. The motor is a standard 4-pole or 6-pole industrial motor at 3,000-3,300 rpm.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

\n

55,000 Nm Right-Angle \u2014 For Every Winch Where the Motor Cannot Sit Behind the Drum<\/h2>\n

\"ZR55<\/p>\n

\n
\n

Retrofit Crane Hoists in Existing Machinery Rooms<\/h3>\n

Crane hoist conversions where the existing machinery room layout places a bulkhead, hydraulic tank, or structural column directly behind the drum position. A coaxial ZL motor would project into the occupied space. The ZR55 redirects the motor 90 degrees \u2014 mounting it alongside the drum within the existing room footprint. For offshore platform crane conversions where the deck penetrations and structural layout are fixed, the right-angle geometry is often the only way to fit an electric winch drive without structural modification.<\/p>\n<\/div>\n

\n

Marine Deck Winches Against Hull Frames<\/h3>\n

Mooring, towing, and cargo winches mounted against the hull shell plating where the drum axis runs athwartship (across the vessel) and the motor must mount fore-and-aft (along the vessel) to avoid projecting outboard through the hull. The ZR55 right-angle input turns the motor shaft parallel to the ship centreline while the drum operates athwartship \u2014 the standard geometric arrangement for deck winches on tankers, bulk carriers, and offshore support vessels. The slewing drive<\/a> handles the fairlead positioning on the same vessel.<\/p>\n<\/div>\n

\n

Mining Headframe Narrow-Profile Winders<\/h3>\n

Auxiliary winders on mine headframes where the winder house width is constrained by the headframe column spacing. A coaxial motor projecting axially behind the drum would exceed the available depth. The ZR55 mounts the motor perpendicular \u2014 reducing the total assembly depth by 30-40% compared to the coaxial equivalent. For mine electrification<\/a> programmes converting hydraulic auxiliary hoists in existing headframes, the ZR geometry fits where the ZL cannot.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

\n

The ZR Right-Angle Winch Drive Family<\/h2>\n
\n
\"Winch<\/p>\n
\n

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

ZR75 (70,000 Nm) to ZR200 (175,000 Nm) for heavier right-angle winch applications.<\/p>\n<\/div>\n<\/div>\n

\"ZL<\/p>\n
\n

ZL Coaxial Winch Drives \u2192<\/a><\/h3>\n

ZL55 (55,000 Nm) \u2014 same torque, coaxial input, for installations with axial depth.<\/p>\n<\/div>\n<\/div>\n

\"Slewing<\/p>\n
\n

Slewing Drive Planetary Gearbox \u2192<\/a><\/h3>\n

ZR series for crane rotation \u2014 same right-angle architecture, different output function.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

\n

Right-Angle Winch Drive Planetary Gearbox \u2014 ZR Series FAQ<\/h2>\n
\n
\n

Does the bevel stage reduce the reliability compared to the coaxial ZL?<\/h3>\n

The bevel stage adds one gear mesh and one set of thrust bearings \u2014 increasing the theoretical failure modes by one pair compared to the ZL. However, the bevel gears in the ZR series are ground to DIN 5-6 accuracy from the same 20CrMnTi material as the planetary gears, and the heavy-series tapered roller bearings are rated for the full thrust load at 100,000 hours. In practice, the bevel stage is not the life-limiting component \u2014 the output bearings and seals, which are identical between ZR and ZL, determine the overhaul interval. The ZR55 reliability is within 5% of the ZL55 at equivalent duty.<\/p>\n<\/div>\n

\n

Is the ZR55 noisier than the ZL55 due to the bevel stage?<\/h3>\n

Slightly. The helical bevel mesh produces a distinctive mid-frequency whine (800-1,600 Hz) that is not present in the coaxial ZL. The overall noise level is approximately 2-4 dB(A) higher than the ZL55 at equivalent speed and torque \u2014 noticeable in a quiet environment but masked in typical crane or marine machinery room ambient noise. For noise-critical installations (hospitals, residential areas), the ZL coaxial remains the quieter option. For industrial, marine, and mining environments, the ZR noise difference is imperceptible against the ambient background.<\/p>\n<\/div>\n

\n

Can the ZR55 accept the same motor as the ZL55?<\/h3>\n

The motor shaft interface (spline or key coupling) may be identical between ZR and ZL at the same torque level \u2014 verify by serial number. However, the motor mounting flange is different: the ZR55 motor mounts perpendicular to the housing, while the ZL55 motor mounts coaxially. The motor itself (IEC frame, power rating, brake option) can be the same unit \u2014 only the mounting adapter and coupling orientation differ. For fleet commonality, specify the same motor model for both ZR and ZL installations and provide separate mounting adapters.<\/p>\n<\/div>\n

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How much axial space does the ZR55 save compared to the ZL55?<\/h3>\n

The ZR55 gearbox housing behind the drum is approximately 30-40% shorter axially than the ZL55 because the motor does not project behind it. However, the ZR55 adds a lateral dimension \u2014 the bevel housing and motor extend perpendicular to the drum axis by approximately 300-500 mm (depending on motor frame size). The total volume envelope is similar; the shape is different. The ZR55 is compact behind the drum but wide beside it. The ZL55 is narrow beside the drum but deep behind it. Match the geometry to the available space.<\/p>\n<\/div>\n

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Do the ZR and ZL share internal planetary gear components?<\/h3>\n

At the same model number (ZR55 vs ZL55), the planetary stages (stages 2-5 in ZR, stages 1-5 in ZL) share the same gear sets, bearings, carriers, and seals. The bevel stage (unique to ZR) and the input housing (different geometry) are ZR-specific. For fleet operators running both ZR55 and ZL55, the planetary spare parts kits are interchangeable \u2014 only the bevel gear pair and the input bearing set are additional ZR-specific items. Contact Corea Ever-Power<\/a> to confirm parts commonality at your specific serial numbers.<\/p>\n<\/div>\n

\n

What overhaul interval applies to the ZR55?<\/h3>\n

The same 100,000-hour life rating as the ZL55. The bevel stage does not reduce the overhaul interval \u2014 it is designed for the same L10 bearing life and gear fatigue life as the planetary stages. Target first overhaul at 25,000-30,000 hours at 60-80% of continuous rating. Bevel gear inspection at 15,000 hours (included in the standard overhaul scope). Oil changes every 2,000 hours. The bevel gear oil must be the same specification as the planetary oil \u2014 both stages share the same oil bath. Contact Corea Ever-Power<\/a> for the maintenance schedule at your duty profile.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

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Field Reports<\/h2>\n
\n
\n
\n
F<\/div>\n
\n
Finn M. \u2014 Offshore Platform Crane Retrofit Manager<\/div>\n
Verified Purchase \u00b7 Stavanger, Norway \u00b7 March 2026<\/div>\n<\/div>\n
\u2605\u2605\u2605\u2605\u2605<\/div>\n<\/div>\n

40 t offshore platform crane, hydraulic-to-electric conversion. The original machinery room has a structural bulkhead 400 mm behind the drum housing \u2014 impossible to fit a coaxial ZL motor. The ZR55 at ratio 80, 2-stage, with a 300 kW motor mounted perpendicular to the drum, fits within the existing room envelope with 50 mm clearance to the bulkhead. No structural modification required. The conversion eliminated the HPU, oil cooler, and 120 metres of hydraulic hose. The crane has completed 9 months of operation since conversion \u2014 the operators report no perceptible difference in hoisting performance compared to the hydraulic system, but the noise reduction is “dramatic” (their word).<\/p>\n<\/div>\n

\n
\n
H<\/div>\n
\n
Hiroshi T. \u2014 Marine Winch Systems Architect<\/div>\n
Verified Purchase<\/div>\n<\/div>\n
\u2605\u2605\u2605\u2605\u2605<\/div>\n<\/div>\n

Electric mooring winch on an LNG carrier, ZR55 at ratio 120, 3-stage, 150 kW AC motor mounted parallel to the ship centreline while the drum axis runs athwartship. This is the standard geometry for deck winches on large commercial vessels \u2014 the coaxial ZL would have projected the motor outboard through the hull strake. The ZR55 right-angle input is the geometrically correct solution for this installation. The IP67+ sealing has survived 14 months of deck wash and saltwater exposure without any seal degradation. Mooring line snatch loads measured at 2.1x steady-state during berthing in crosswind \u2014 absorbed within the 112,000 Nm peak without any VFD fault.<\/p>\n<\/div>\n

\n
\n
PAG<\/div>\n
\n
Peter G. \u2014 Mine Headframe Modernisation Engineer<\/div>\n
Verified Purchase \u00b7 May 2026<\/div>\n<\/div>\n
\u2605\u2605\u2605\u2605\u2606<\/div>\n<\/div>\n

Auxiliary winder on a 1960s-era mine headframe, ZR55 at ratio 200, 4-stage, 100 kW AC motor. The headframe winder house is 1.2 metres deep between the drum and the back wall \u2014 no room for a coaxial motor. The ZR55 motor mounts vertically below the drum on a bracket welded to the existing headframe column, with the right-angle input turning the torque upward into the drum. Total installation footprint: 600 mm x 800 mm versus the 600 mm x 1,400 mm that the coaxial ZL55 would have required. The 4-star is a vibration observation: the bevel gear mesh produces a 1,200 Hz tonal component that was detectable on the headframe vibration monitor. The amplitude is well within structural limits but the monitoring system initially flagged it as an anomaly until we updated the baseline to include the bevel mesh frequency. For ZR installations on monitored structures, providing the expected bevel mesh frequency range in the commissioning documentation would prevent false alarm investigations.<\/p>\n<\/div>\n<\/div>\n<\/section>\n<\/div>","protected":false},"excerpt":{"rendered":"

The motor turns 90 degrees. The EP-ZR55 opens the third and final winch drive architecture in the Korea Ever-Power catalogue: the right-angle series. Where the 4xxW and ZL series mount the motor coaxially with the drum axis \u2014 the motor shaft points into the drum \u2014 the ZR55 turns the input 90 degrees through a precision helical bevel stage, allowing the motor to sit beside, below, or above the drum rather than behind it. At 55,000 Nm continuous and 112,000 Nm peak \u2014 identical to the coaxial ZL55 \u2014 the ZR55 delivers the same torque through a different geometry for applications where the axial space behind the drum does not exist.<\/div>","protected":false},"featured_media":992,"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-991","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\/es\/wp-json\/wp\/v2\/product\/991","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/planetary-gearboxes.com\/es\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/planetary-gearboxes.com\/es\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/es\/wp-json\/wp\/v2\/comments?post=991"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/es\/wp-json\/wp\/v2\/media\/992"}],"wp:attachment":[{"href":"https:\/\/planetary-gearboxes.com\/es\/wp-json\/wp\/v2\/media?parent=991"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/es\/wp-json\/wp\/v2\/product_brand?post=991"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/es\/wp-json\/wp\/v2\/product_cat?post=991"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/es\/wp-json\/wp\/v2\/product_tag?post=991"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}