ZR45 Slewing Drive Planetary Gearbox — Right-Angle Bevel-Planetary, 3-5 Stage

The EP-ZR45 is the flagship of the Korea Ever-Power ZR slewing drive series. Delivering 42,500 Nm continuous output torque and 110,500 Nm peak across 3-stage, 4-stage, and 5-stage planetary reductions, the ZR45 addresses the most demanding slewing mechanisms in industrial engineering: ship-to-shore container cranes, large mining excavators above 80 tonnes, offshore heavy-lift pedestal cranes, and steel mill ladle turret drives. Three precision-matched gear ratios (14.19, 43.43, 109.70) provide targeted solutions for high-speed, medium-speed, and ultra-low-speed slewing. IP67 sealed, DIN 5-6 ground, -40 to +80 deg C rated.

EP-ZR45 — The Flagship Slewing Drive for Heavy-Lift Machinery

Ten/Tá/To EP-ZR45 is the largest frame in the ZR slewing drive series. Where the mid-range ZR06-ZR10 models serve general construction cranes and excavators, the ZR45 targets the machinery that moves the heaviest loads on earth: ship-to-shore gantry cranes handling 40-foot containers at 30+ cycles per hour, mining excavators with bucket payloads exceeding 15 cubic metres, offshore derrick cranes rated for 1,000-tonne lifts, and steel mill ladle turrets rotating 300-tonne molten metal vessels.

At 42,500 Nm continuous and 110,500 Nm peak, the ZR45 produces torque levels that exceed the headline specification (40,500 Nm) published for the series by 5%. This margin exists because the 3-5 stage configurations use the largest available bevel input pair (R16/R10/R06 sub-variants), providing greater tooth contact area than the 2-stage variants of smaller frames.

42,500
Continuous Torque (Nm)
110,500
Peak Torque (Nm)
IP67
Sealed
3-5
Etapy

 

ZR45 Technical Parameters — 3 Precision-Matched Ratio Configurations

Unlike smaller ZR frames that offer dozens of ratio options, the ZR45 concentrates on three optimised reduction points — one per stage count — each engineered for a specific speed class of heavy-lift slewing. All three deliver the same 42,500 Nm continuous / 110,500 Nm peak torque at the output. The engineering trade-off between them is thermal power capacity versus ratio.

Konfigurácia Pomer Cont. Torque (Nm) Max. Torque (Nm) n1 Max (RPM) Pt F / M (kW)
ZR45**3 / R16 14.19 42,500 110,500 2,500 26.5 / 38.0
ZR45**4 / R10 43.43 42,500 110,500 2,500 11.5 / 13.5
ZR45**5 / R06 109.70 42,500 110,500 2,500 9.5 / 12.5
3-Stage / R16 — i=14.19

Highest thermal capacity (26.5-38.0 kW). For high-duty-cycle applications: excavator upper-structure rotation, STS crane slewing with frequent start-stop reversals. Output speed up to 176 rpm at full motor speed.

4-Stage / R10 — i=43.43

Balanced thermal and ratio. For medium-speed crane slewing: port mobile cranes, offshore pedestal cranes, large piling rigs. Output speed up to 57 rpm. The most commonly specified ZR45 variant.

5-Stage / R06 — i=109.70

Maximum reduction for creep-speed positioning: ship-unloader boom slewing, steel mill ladle turret rotation, offshore drilling platform turntable. Output speed up to 23 rpm. Lowest thermal capacity — suitable for intermittent or low-speed continuous duty.

Dual-Drive Configuration — Doubling Capacity or Adding Redundancy

At the 42,500 Nm torque class, many applications — particularly STS container cranes, large mining excavators, and offshore heavy-lift cranes — require either double the torque capacity of a single drive, or redundancy that allows the machine to continue operating safely if one drive fails. The ZR45 is specifically designed for dual-drive mounting, where two units engage the same slewing ring from diametrically opposed positions.

Torque-Doubling Mode

Two ZR45 units at ratio 43.43 deliver a combined 85,000 Nm continuous / 221,000 Nm peak to the slewing ring. Both motors run at equal speed and equal hydraulic flow. The slewing ring pinion module and tooth count must be identical on both units, and the mounting geometry must position the pinions 180 degrees apart on the ring gear for balanced load distribution.

Active Redundancy Mode

Both units share the slewing load equally during normal operation, but the machine can complete its working cycle on a single drive if one unit is taken offline for maintenance. The hydraulic or electrical control system must include a load-sensing circuit that detects unequal motor pressure or current and adjusts flow or frequency to prevent the healthy drive from overloading during single-drive operation.

Mounting Geometry Requirement

Both ZR45 units must use the same gear ratio and the same output pinion specification. The slewing ring manufacturer must verify that the ring gear tooth profile and hardness are rated for the combined mesh force of two pinions. Contact our engineering team for a dual-drive dimensional layout drawing and pinion-to-ring load calculation specific to your slewing ring supplier.

Planetary gearbox internal structure showing gear mesh and bearing arrangement

ZR45 at a Glance

  • Cont. torque42,500 Nm
  • Peak torque110,500 Nm
  • Pomery14.19 / 43.43 / 109.70
  • Max input2,500 rpm
  • Thermal9.5-38.0 kW
  • Etapy3 / 4 / 5
  • SealingIP67 FKM
  • HousingQT600-3

Engineered for the Heaviest Slewing Loads in Industry

ZR45 Slewing Drive Planetary Gearbox 2-4 Stage

Ship-to-Shore Container Cranes

STS cranes handle 25-40 container cycles per hour, each cycle involving an upper-structure slew of 90-180 degrees under wind loads that routinely exceed 10 kN lateral force on the boom. The ZR45**3 at ratio 14.19 provides the high-speed, high-duty-cycle capability these machines demand, with the 26.5-38.0 kW thermal capacity absorbing the heat generated by relentless start-stop-reverse operation without external cooling systems.

Mining Excavators and Rope Shovels (80+ Tonnes)

Hydraulic excavators in the 80-200 tonne operating weight class and electric rope shovels generate sustained slewing torques of 25,000-40,000 Nm during loaded swing. The ZR45**3 at 14.19 ratio, driven by 160-250 cc/rev axial piston motors at 350 bar, matches this requirement. For machines that also need track drive planetary gearboxes in the undercarriage, the ZR45 and EP-SE series share compatible BF-flange hydraulic motor interfaces.

Offshore Heavy-Lift and Steel Mill Applications

Offshore derrick cranes rated for 500-2,000 tonne lifts and steel mill ladle turrets rotating 300-tonne molten metal vessels represent the most severe slewing duty in industrial engineering. The ZR45**5 at ratio 109.70 provides the ultra-low output speed (under 23 rpm) and full 42,500 Nm continuous torque these applications require, while the IP67 sealing and marine-grade coating protect against seawater, molten metal splash, and aggressive chemical environments.

Target Industries

  • STS and RTG container cranes
  • Mining excavators 80-200 t
  • Electric rope shovels
  • Offshore pedestal cranes
  • Offshore drilling turntables
  • Ship-unloader boom rotation
  • Steel mill ladle turrets
  • Large piling rigs

Slewing Drive planetary gearbox application 3

Maintenance Lifecycle — 20-Year Service Projection

Heavy-lift machinery commonly operates for 3,000-5,000 hours per year. The timeline below projects the ZR45 maintenance schedule at 4,000 hours per year, which represents typical port crane or mining excavator utilisation. Adjust intervals proportionally for higher or lower annual operating hours. Contact Korea Ever-Power engineering for a customised maintenance plan based on your specific duty cycle.

500
hrs

First Oil Change (Month 1-2)

Drain the factory-fill oil and refill with ISO VG 220 PAO synthetic gear oil. The first change removes fine metallic wear particles generated during the gear running-in period. Send a 100 ml oil sample for particle count analysis to establish the baseline for future condition monitoring.

4,000
hrs

Scheduled Oil Change + Seal Inspection (Year 1)

Full oil change. Inspect output shaft seal for grease weep. Check breather valve for blockage. Verify mounting bolt torque. Oil sample analysis: compare iron and copper particle levels against the 500-hour baseline. A step-change increase indicates accelerated gear or bearing wear that should be investigated.

8,000
hrs

Extended Inspection (Year 2)

Oil change + oil analysis. Preventive output shaft seal replacement (FKM seals rated for 20,000+ hours, but proactive replacement at half-life eliminates the risk of failure in the field). Inspect the output pinion tooth flanks for pitting or wear using a bore-scope through the inspection port. Check the input bevel gear for heat discolouration.

20K
hrs

Major Overhaul Assessment (Year 5)

Comprehensive inspection: all bearings checked for endplay, all gears inspected for tooth surface condition, housing inspected for micro-cracking at mounting bolt holes. If oil analysis trends have remained stable, the ZR45 is typically cleared for another 20,000-hour service interval with fresh bearings and seals. Many units reach 40,000+ hours (10 years) before requiring gear replacement.

Replacing an Existing Slewing Drive? Dimensional Compatibility Reference

The ZR45 is designed with standardised input and output interfaces that enable dimensional interchange with major European and Japanese slewing drive manufacturers. The table below provides starting-point compatibility guidance. Final interchange confirmation requires a dimensional comparison drawing, which our engineering team provides within 48 hours of receiving the existing drive model number.

Interface ZR45 Standard Compatibility Notes
Input motor mount BF01/02, IS02/IS10, IEC Direct fit for Rexroth A2FM/A6VM, Eaton, Kawasaki axial piston motors
Output shaft options MS, MF, SS, FS, integral pinion Custom output pinion ground to match existing slewing ring module and pressure angle
Housing mounting Flange-mount, foot-mount Adapter plates available for non-standard bolt patterns from legacy installations
Brake integration B12-B615 spring-applied Hydraulic and electric release. Brake torque class matched to application holding requirement

For worm-gear slewing drive replacements: the right-angle output geometry is conceptually identical, but the bevel-planetary ZR45 is typically 20-35% lighter and 30-40% shorter axially than an equivalent-torque worm unit. Foundation bolts and motor connections may require relocation.

System-Level Integration — Related Products

SE401T1 track drive planetary gearbox

Track Drive Planetary Gearboxes →

EP-SE series for crawler undercarriage propulsion on the same heavy excavators that use the ZR45 for upper-structure slewing.

EP-TNF Series Planetary GearboxHigh-Precision Planetary Gearboxes →

BPG/BPGA series for crane hoist fine-positioning, trolley travel servo drives, and container twist-lock rotation mechanisms.

Industrial automation gearbox application

Industrial Bevel Gearboxes →

Right-angle bevel stages for conveyor head drives, ship-unloader luffing mechanisms, and bulk material handling systems that operate alongside ZR45 slewing drives.

Často kladené otázky

Why does the ZR45 only offer 3 ratios when smaller models have 20-40?

At this torque class, the internal gear geometry is optimised for maximum load capacity rather than ratio flexibility. Each of the three ratios represents a thoroughly validated gear mesh configuration with specific tooth contact patterns verified through finite element analysis and physical bench testing. Adding intermediate ratios would require compromised tooth profiles that reduce the safety factor. For applications requiring a ratio between the three standard options, the motor displacement or VFD frequency can be adjusted to fine-tune the output speed without affecting the gearbox torque capacity.

What is the weight of the ZR45, and what lifting provisions are needed for installation?

The ZR45 weight varies by configuration: approximately 280-350 kg depending on stage count and brake option. At this weight, the unit requires mechanical lifting (crane or chain hoist) during installation. Lifting eye-bolts are cast into the housing. A minimum 500 kg capacity rigging arrangement is recommended to provide a 1.5x safety factor. Ensure the mounting surface is prepared and all fasteners are accessible before positioning the drive, as repositioning at this weight involves significant labour.

Can the ZR45 be used with an electric motor instead of a hydraulic motor?

Yes. The IEC input flange option accepts standard IEC electric motors. For STS crane applications, AC induction motors (22-45 kW, 4-pole) controlled by VFDs are the most common electric drive arrangement. For precise positioning, servo motors with closed-loop feedback can also be coupled to the ZR45 through a bell housing adapter. Specify the motor frame size (IEC 180-225) when ordering so we can supply the correct bell housing and coupling assembly.

What lead time should be expected for the ZR45?

Standard lead time for the ZR45 is 6-8 weeks from order confirmation. The 4-stage (i=43.43) variant is the most commonly stocked configuration and may ship in 4-5 weeks depending on inventory. For units requiring classification society witnessed testing (DNV, Lloyd, BV, ABS), allow 10-14 weeks. Expedited manufacturing is available for emergency replacements — contact our team to discuss accelerated scheduling options and the associated surcharge.

Customer Feedback

H
Henrik L. — Chief Engineer, Port Equipment Division
Verified Purchase · Gothenburg, Sweden
★★★★★

We are running dual ZR45**4 drives on two STS cranes at our terminal. After 18 months and roughly 11,000 operating hours, both cranes are performing within original specification. The efficiency improvement over the previous drives reduced our hydraulic oil cooler duty by approximately 22%, which in a port where we run cranes 20 hours a day translates to meaningful energy savings. The documentation package passed our internal audit and DNV class survey without any follow-up queries.

Z
William O. — Maintenance Superintendent
Verified Purchase · Feb 2026
★★★★☆

Replaced the slewing drive on our 120-tonne excavator. The ZR45**3 fits the existing frame with a minor adapter plate modification. Performance is comparable to the OEM unit at about 40% of the price. My only reservation is that at 320 kg, getting this thing in and out of the machine is a two-crane job. I wish there were split-housing or segment-removal options for in-situ maintenance on machines where removing the full upper structure is not practical.

F
Dr. Fabio C. — R&D Manager, Steel Processing
Verified Purchase
★★★★★

Ladle turret application at our steel plant. The ZR45**5 at 109.70 ratio gives us the slow, controlled rotation we need when positioning a 280-tonne ladle under the BOF tap. The previous drive was a worm type that ran extremely hot and needed oil changes every 6 weeks in the summer because of thermal breakdown. The ZR45 runs noticeably cooler and we have extended the oil change to a proper 4,000-hour interval. That alone pays for the drive within the first year.

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