{"id":993,"date":"2026-06-22T06:13:55","date_gmt":"2026-06-22T06:13:55","guid":{"rendered":"https:\/\/planetary-gearboxes.com\/?post_type=product&p=993"},"modified":"2026-06-22T06:13:56","modified_gmt":"2026-06-22T06:13:56","slug":"zr75-winch-drive-planetary-gearbox-right-angle","status":"publish","type":"product","link":"https:\/\/planetary-gearboxes.com\/sr\/\u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\/zr75-winch-drive-planetary-gearbox-right-angle\/","title":{"rendered":"ZR75 Winch Drive Planetary Gearbox \u2014 Right-Angle"},"content":{"rendered":"
\n

<\/p>\n

\n
\n
\n
RIGHT-ANGLE<\/span>
\n40-60 t SWEET SPOT<\/span><\/div>\n

ZR75 \u2014 70,000 Nm<\/h2>\n

The right-angle twin of the most-specified ZL model. Same 70,000 Nm continuous, same 175,000 Nm peak, different motor axis \u2014 for every 40-60 t winch drive<\/a> installation where the coaxial geometry hits a wall.<\/p>\n<\/div>\n

\n
\n
\n
70,000<\/div>\n
Nm Cont.<\/div>\n<\/div>\n
\n
175,000<\/div>\n
Nm Peak<\/div>\n<\/div>\n
\n
3,100<\/div>\n
RPM<\/div>\n<\/div>\n
\n
2-5<\/div>\n
Stages<\/div>\n<\/div>\n<\/div>\n
Pt 24-86 kW<\/span>
\nDIN 5-6<\/span>
\nIP67+<\/span>
\nPeak 2.5x<\/span><\/div>\n<\/div>\n<\/div>\n

The ZR75 is the second model in the ZR right-angle winch drive series and the one that serves the largest crane market segment: 40-60 tonne SWL. At 70,000 Nm continuous and 175,000 Nm peak \u2014 identical to the ZL75 coaxial \u2014 the ZR75 covers the same crane SWL range but with the motor mounted perpendicular to the drum axis. The input speed drops from the ZR55 3,300 rpm to 3,100 rpm because the larger bevel gears in the ZR75 produce higher tooth peripheral velocities at the same shaft speed \u2014 requiring the speed ceiling to decrease as the torque (and bevel gear diameter) increases.<\/p>\n<\/section>\n

<\/p>\n

\n

ZR75 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>\n70,000 Nm<\/td>\n<\/tr>\n
Peak torque<\/td>\n175,000 Nm (2.5x continuous)<\/td>\n<\/tr>\n
Input configuration<\/td>\nRight-angle (90 deg helical bevel + planetary)<\/td>\n<\/tr>\n
Maximum input speed<\/td>\n3,100 rpm<\/td>\n<\/tr>\n
Available stages<\/td>\n2-5 (1 bevel + 1-4 planetary)<\/td>\n<\/tr>\n
Thermal power (Pt)<\/td>\n24 – 86 kW<\/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
\u041c\u0430\u0442\u0435\u0440\u0438\u0458\u0430\u043b \u0437\u0443\u043f\u0447\u0430\u043d\u0438\u043a\u0430<\/td>\n20CrMnTi, HRC 58-62<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/section>\n

<\/p>\n

\n

3,100 RPM \u2014 Why the Right-Angle Input Speed Decreases as the ZR Series Gets Larger<\/h2>\n

The ZR55 accepts 3,300 rpm. The ZR75 accepts 3,100 rpm. This 200 rpm reduction is not arbitrary \u2014 it follows a physical constraint that defines the entire ZR series.<\/p>\n

\n\n\n\n\n\n\n\n\n\n
ZR Model<\/th>\nTorque (Nm)<\/th>\nMax RPM<\/th>\nMin Stages<\/th>\nTrend<\/th>\n<\/tr>\n<\/thead>\n
ZR55<\/td>\n55,000<\/td>\n3,300<\/td>\n2<\/td>\n\u2588\u2588\u2588\u2588\u2588\u2588<\/td>\n<\/tr>\n
ZR75<\/td>\n70,000<\/td>\n3,100<\/td>\n2<\/td>\n\u2588\u2588\u2588\u2588\u2588<\/td>\n<\/tr>\n
ZR85-ZR95<\/td>\n88-115k<\/td>\n3,100<\/td>\n2<\/td>\n\u2588\u2588\u2588\u2588\u2588<\/td>\n<\/tr>\n
ZR120-ZR150<\/td>\n133-160k<\/td>\n3,000<\/td>\n3<\/td>\n\u2588\u2588\u2588\u2588<\/td>\n<\/tr>\n
ZR200<\/td>\n175,000<\/td>\n3,000<\/td>\n4<\/td>\n\u2588\u2588\u2588\u2588<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
The dual constraint: <\/span>
\nAs torque increases, the bevel gears grow in diameter to carry the higher load. Larger diameter at the same RPM means higher tooth peripheral velocity \u2014 eventually reaching the lubrication film limit. The ZR series manages this by reducing the RPM ceiling (3,300\u21923,100\u21923,000) AND by increasing the minimum stage count (2\u21923\u21924) at the largest models. The ZR75 at 3,100 rpm matches standard 4-pole industrial motors at both 50 Hz (3,000 rpm) and 60 Hz (3,600 rpm, derated to 3,100) \u2014 the most common motor speeds in the global industrial market.<\/span><\/div>\n<\/section>\n

<\/p>\n

\n

The Right-Angle Retrofit \u2014 ZR75 for 40-60 t Crane Conversions in Constrained Spaces<\/h2>\n

The 40-60 tonne SWL crane class is where the highest volume of hydraulic-to-electric conversions is happening today. And the majority of those cranes were designed with the hydraulic motor mounted coaxially inside the drum \u2014 which means the existing machinery room layout has been optimised for a coaxial geometry that may not suit an electric motor.<\/p>\n

\"ZR75<\/p>\n

\n
The Retrofit Geometry Problem<\/strong><\/p>\n

A hydraulic motor at 160 cc\/rev is approximately 200 mm in diameter and 300 mm long \u2014 it sits inside the drum cavity behind the gearbox. An electric motor at 400 kW is approximately 500 mm in diameter and 700 mm long \u2014 it projects far beyond the drum cavity into the machinery room. If the machinery room has 400-600 mm of free space behind the drum (common on offshore platform cranes and harbour cranes built in the 1990s-2010s), the electric motor does not fit coaxially. The ZR75 redirects the motor perpendicular \u2014 fitting a 700 mm long motor into the 1,200-2,000 mm of lateral space that most machinery rooms provide beside the drum.<\/p>\n<\/div>\n

What the ZR75 Saves in a Conversion<\/strong><\/p>\n

By avoiding structural modification to the machinery room: typically USD 50,000-200,000 in steel work, welding, NDT, and re-certification \u2014 depending on whether the structure is a vessel (class survey required), an offshore platform (structural modification permit required), or a harbour crane (less costly but still significant). The ZR75 pays for itself in structural modification avoidance before the first lift is made.<\/p>\n<\/div>\n

The Conversion Decision Tree<\/strong><\/p>\n

Step 1: Measure the axial depth behind the drum. Step 2: If the electric motor fits coaxially, specify ZL75. Step 3: If it does not, specify ZR75. Both deliver 70,000 Nm \/ 175,000 Nm. Both use the same DIN 5-6 helical planetary stages. The only difference is the input geometry and the 500 rpm lower input speed (3,100 vs 4,000 for ZL75). Contact \u041a\u043e\u0440\u0435\u0458\u0430 \u0415\u0432\u0435\u0440-\u041f\u0430\u0443\u0435\u0440<\/a> with your machinery room dimensions for a geometry recommendation.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

\n

70,000 Nm Right-Angle \u2014 The Conversion Enabler for the Largest Crane Retrofit Market<\/h2>\n

\"ZR75<\/p>\n

\n
\n

Offshore Platform Crane Conversions (40-60 t)<\/h3>\n

Mid-life hydraulic-to-electric conversions on offshore platform cranes where the existing deck layout, structural penetrations, and machinery room geometry are fixed. The ZR75 is the model that makes these conversions physically possible without structural redesign \u2014 delivering the same 70,000 Nm torque and 175,000 Nm peak as the coaxial ZL75 through a geometry that fits the existing space. The slewing drive<\/a> conversion follows on the same platform.<\/p>\n<\/div>\n

\n

Large Marine Deck Winches<\/h3>\n

Anchor handling, towing, and mooring winches on vessels where the drum axis runs athwartship and the motor must mount fore-and-aft. The ZR75 at 70,000 Nm provides the main deck winch torque for vessels in the 5,000-15,000 DWT range \u2014 cargo ships, offshore support vessels, and multi-purpose vessels. The 3,100 rpm input matches the 4-pole AC motors that vessel electrical systems standardise on. The IP67+ sealing survives the deck-mounted marine environment.<\/p>\n<\/div>\n

\n

Heavy Industrial Hoists in Existing Buildings<\/h3>\n

Overhead crane hoist replacements in steelworks, power stations, and heavy manufacturing plants where the crane bridge beam limits the axial depth above the drum. The ZR75 mounts the motor horizontally alongside the drum, keeping the total height within the existing crane bridge clearance. For industrial modernisation<\/a> programmes where the building structure cannot be modified, the ZR right-angle geometry is often the only way to upgrade the hoist drive to electric without raising the roof.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

\n

The ZR Right-Angle and ZL Coaxial Families<\/h2>\n
\n
\"Winch<\/p>\n
\n

Full ZR Right-Angle Range \u2192<\/a><\/h3>\n

ZR85 (88,000 Nm) to ZR200 (175,000 Nm) for heavier right-angle winch applications.<\/p>\n<\/div>\n<\/div>\n

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

ZL75 Coaxial Equivalent \u2192<\/a><\/h3>\n

Same 70,000\/175,000 Nm, coaxial input at 4,000 rpm \u2014 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 on the same retrofit and new-build platforms.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

\n

Right-Angle Winch Drive Planetary Gearbox \u2014 ZR75 Retrofit FAQ<\/h2>\n
\n
\n

Does the 200 rpm speed reduction (3,100 vs 3,300 on ZR55) affect motor selection?<\/h3>\n

For 4-pole motors at 50 Hz (3,000 rpm synchronous): no impact \u2014 the motor already runs below 3,100 rpm. For 4-pole motors at 60 Hz (3,600 rpm synchronous): the motor must be derated or frequency-limited to 3,100 rpm by the VFD \u2014 a standard parameterisation that takes one configuration step. For 2-pole motors at 50 Hz (3,000 rpm synchronous): the motor runs at or below the ZR75 limit. The 3,100 rpm ceiling is compatible with all standard industrial motor speeds without hardware changes.<\/p>\n<\/div>\n

\n

Can the ZR75 and ZL75 share planetary spare parts?<\/h3>\n

Yes. The planetary stages (stages 2-5 in ZR75, stages 1-5 in ZL75 at overlapping ratios) share the same gear sets, bearings, carriers, and seals. Only the bevel gear pair, bevel shaft bearings, and input housing section are ZR-specific. For fleet operators running both ZR75 and ZL75 on different cranes, the planetary spare parts are fully interchangeable \u2014 significantly reducing the combined inventory requirement.<\/p>\n<\/div>\n

\n

How much structural modification does the ZR75 typically avoid in a platform crane retrofit?<\/h3>\n

On a typical offshore platform crane conversion from hydraulic to electric: the ZR75 avoids extending the machinery room aft (which requires cutting and re-welding the deck structure, re-certifying the structural modification, and potentially moving or rerouting piping and cabling behind the new bulkhead position). Estimated cost avoidance: USD 80,000-250,000 depending on the platform type and the classification society survey scope. On harbour and shipyard cranes: USD 30,000-80,000 in structural steel and civil works.<\/p>\n<\/div>\n

\n

Does the ZR75 right-angle affect the regen braking capability?<\/h3>\n

No. Regenerative torque flows from the drum through the planetary stages and through the bevel stage to the motor in exactly the same way as hoisting torque flows from the motor to the drum. The bevel stage is bidirectional \u2014 it transmits torque equally in both directions with the same efficiency loss (1-2%). The ZR75 regen recovery rate is approximately 1-2% lower than the ZL75 due to the additional bevel mesh loss \u2014 a negligible difference in practice (for example, 22% recovery on ZL75 versus 21% on ZR75 at identical duty).<\/p>\n<\/div>\n

\n

Can the ZR75 motor be mounted in any orientation \u2014 horizontal, vertical, inverted?<\/h3>\n

Yes. The right-angle input accepts the motor in any orientation perpendicular to the drum axis \u2014 horizontal (motor beside the drum), vertical (motor above or below), or any intermediate angle. The oil bath lubrication system works in all orientations provided the housing is filled to the correct level for the installed angle. For vertical motor mounting (common on narrow headframes), verify that the motor bearing lubrication system is rated for vertical operation. Contact \u041a\u043e\u0440\u0435\u0458\u0430 \u0415\u0432\u0435\u0440-\u041f\u0430\u0443\u0435\u0440<\/a> for the oil fill level at your specific mounting angle.<\/p>\n<\/div>\n

\n

What overhaul interval applies to the ZR75?<\/h3>\n

The same 100,000-hour life rating as the ZL75. Target first overhaul at 25,000-30,000 hours. The bevel gear inspection is included in the standard overhaul scope \u2014 no separate bevel-specific maintenance is required. Oil changes every 2,000 hours (the bevel and planetary stages share the same oil bath). Seal replacement at 10,000-15,000 hours. For retrofit cranes operating at 2,000-4,000 hours per year, the first overhaul falls at approximately 6-15 years of service. Contact \u041a\u043e\u0440\u0435\u0458\u0430 \u0415\u0432\u0435\u0440-\u041f\u0430\u0443\u0435\u0440<\/a> for maintenance scheduling at your specific duty profile.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

\n

Field Reports<\/h2>\n
\n
\n
\n
R<\/div>\n
\n
Rune E. \u2014 Offshore Crane Electrification Programme Lead<\/div>\n
Verified Purchase \u00b7 Stavanger, Norway \u00b7 March 2026<\/div>\n<\/div>\n
\u2605\u2605\u2605\u2605\u2605<\/div>\n<\/div>\n

50 t offshore platform crane, hydraulic-to-electric conversion. The machinery room survey showed 520 mm of free space behind the drum \u2014 enough for the hydraulic motor but not for a 400 kW electric motor (680 mm deep). The ZL75 was our first specification; the ZR75 was the rescue. Motor mounted horizontally to starboard of the drum, right-angle input turning the torque into the drum. Zero structural modification. The conversion cost came in 22% under budget because we avoided the deck extension that the ZL75 would have required. After 11 months of operation: same hoisting performance as the ZL75 installations on our newer platforms, 21% regen recovery (versus 23% on the ZL75 \u2014 the 2% difference is the bevel mesh loss, exactly as predicted). We are now surveying 6 additional platform cranes for ZR75 conversion.<\/p>\n<\/div>\n

\n
\n
Y<\/div>\n
\n
Yuki N. \u2014 Shipbuilding Crane Modernisation Engineer<\/div>\n
Verified Purchase<\/div>\n<\/div>\n
\u2605\u2605\u2605\u2605\u2605<\/div>\n<\/div>\n

60 t shipyard gantry crane, ZR75 at ratio 140, 3-stage, 350 kW AC motor mounted vertically below the drum on the gantry trolley. The crane bridge beam is 800 mm deep \u2014 no room for a coaxial motor above the drum. The ZR75 vertical motor mounting keeps the total hoist assembly height to 650 mm, fitting within the bridge clearance with 150 mm to spare. The crane positioned a 55-tonne engine block to within 4 mm of the foundation bolts on the first approach \u2014 the DIN 5-6 accuracy and the 175,000 Nm peak absorbed the block engagement shock without any perceptible hesitation in the hoist speed. The shipyard has ordered 3 additional ZR75 units for the remaining gantry cranes.<\/p>\n<\/div>\n

\n
\n
G<\/div>\n
\n
Graham W. \u2014 Harbour Crane Fleet Modernisation Manager<\/div>\n
Verified Purchase \u00b7 April 2026<\/div>\n<\/div>\n
\u2605\u2605\u2605\u2605\u2606<\/div>\n<\/div>\n

40 t harbour portal crane, ZR75 at ratio 80, 2-stage, 400 kW AC motor. The crane operates 200 metres from a residential area \u2014 noise was the primary specification driver. The ZR75 helical gear noise at 64 dB(A) at the operator station is a substantial improvement over the previous hydraulic system at 76 dB(A). The right-angle mounting was necessary because the portal crane machinery house has a steel access stairway 450 mm behind the drum position. The 4-star is a maintenance access observation: the bevel housing on the ZR75 projects laterally from the drum housing, and the oil drain plug for the bevel section is positioned facing the stairway \u2014 requiring the crane maintenance team to reach across the stairway handrail to access the drain. Rotating the bevel housing 90 degrees during installation would have positioned the drain plug on the accessible side. For future ZR installations, a commissioning note recommending that the maintenance team verify oil drain accessibility before final bolting would prevent this recurring issue.<\/p>\n<\/div>\n<\/div>\n<\/section>\n<\/div>","protected":false},"excerpt":{"rendered":"

The right-angle sweet spot. The EP-ZR75 is the right-angle counterpart of the ZL75 \u2014 the most-specified ZL model in the electric winch drive catalogue \u2014 delivering the same 70,000 Nm continuous and 175,000 Nm peak through a 90-degree bevel input for installations where a coaxial motor cannot fit. At 40-60 tonne SWL, this is the crane capacity class where more cranes are being converted from hydraulic to electric than any other segment. And the majority of those conversions encounter the same geometric constraint: the existing machinery room has no axial depth behind the drum for a coaxial motor. The ZR75 at 3,100 rpm input is the model that makes those conversions possible.<\/div>","protected":false},"featured_media":994,"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-993","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\/sr\/wp-json\/wp\/v2\/product\/993","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/planetary-gearboxes.com\/sr\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/planetary-gearboxes.com\/sr\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/sr\/wp-json\/wp\/v2\/comments?post=993"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/sr\/wp-json\/wp\/v2\/media\/994"}],"wp:attachment":[{"href":"https:\/\/planetary-gearboxes.com\/sr\/wp-json\/wp\/v2\/media?parent=993"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/sr\/wp-json\/wp\/v2\/product_brand?post=993"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/sr\/wp-json\/wp\/v2\/product_cat?post=993"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/planetary-gearboxes.com\/sr\/wp-json\/wp\/v2\/product_tag?post=993"}],"curies":[{"name":"\u0412\u041f","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}