ZR30 Slewing Drive Planetary Gearbox — Right-Angle Bevel-Planetary, 2-5 Stage

Ang EP-ZR30 sits directly below the flagship ZR45 in the ZR slewing drive series and delivers what the ZR45 cannot: a wide selection of 58 gear ratios across five stage configurations. Where the ZR45 concentrates on three optimised ratio points for the heaviest loads, the ZR30 provides the ratio density needed when precise speed matching is as important as raw torque capacity.

At 32,000 Nm continuous and 55,000 Nm peak — 19% above the published headline of 27,000 Nm — the ZR30 handles the sustained slewing loads of large excavators, shipyard gantry cranes, and heavy mining conveyor head drives. Three torque tiers (32,000 / 31,000 / 25,000 Nm) de-rate gradually across the ratio table, with 67% of all ratios (39 of 58) delivering the full 32,000 Nm without reduction.

Profile grinding after carburising and quenching

Large Excavators (35-50 Tonne Class)

Hydraulic excavators in the 35-50 tonne operating weight range generate sustained upper-structure slewing torques of 20,000-32,000 Nm during production digging. The ZR30**2 at ratio 14.19 driven by a 200-250 cc/rev axial piston motor at 350 bar provides the high-speed rotation and 55,000 Nm peak capacity these machines demand for aggressive loading cycles. The EP-SE track drive series provides the matching undercarriage propulsion.

Shipyard Gantry Cranes and Goliath Cranes

Shipyard goliath cranes and hull-block transporters with lifting capacities of 200-600 tonnes require slewing torques of 25,000-30,000 Nm for controlled boom or gantry rotation. The ZR30 3-stage at ratios 51:1-70:1 provides the torque density these cranes need in a frame size that fits within the tight mechanical envelopes of shipyard crane pedestals. The 58-ratio selection ensures the optimal speed match without external speed reduction stages.

Mining Conveyor Head Drives and Stackers

Overland conveyor stacker and reclaimer slewing mechanisms in open-pit mining operations rotate under constant radial loading from the boom self-weight plus material flow forces. The ZR30 5-stage at ratios 800:1-1,800:1 provides ultra-low-speed boom rotation at the full 31,000 Nm continuous, while the IP67 sealing resists the iron ore dust, coal fines, and seasonal rainfall common at surface mining sites.

When should I choose the ZR30 over the ZR45 flagship?

If your application requires more than 32,000 Nm continuous or more than 55,000 Nm peak, the ZR45 is necessary. If the torque requirement falls within the ZR30 envelope, the ZR30 offers 58 ratios (versus 3 for the ZR45), a lighter frame, shorter lead time, and lower cost. The ZR30 is also the better choice when precise ratio matching matters — the 58-option table almost always has a closer match to the calculated optimum than the ZR45 fixed three-point set.

What is the weight of the ZR30?

Approximately 220-300 kg depending on stage count and brake option. The 5-stage with B615 brake is the heaviest variant. At this weight, mechanical lifting is required for installation — see the ZR19 page for detailed handling and lifting guidance that applies equally to the ZR30 frame.

Can the ZR30 gears be inspected without removing the unit from the machine?

The output pinion teeth can be inspected visually through the pinion-ring mesh access area without removing the unit. The internal planetary gears can be inspected using a bore-scope through the inspection port on the housing. For detailed internal inspection (bearing condition, gear contact pattern analysis), the unit must be removed and partially disassembled at the factory or a qualified service facility.

Is 20CrMnTi gear steel equivalent to the SAE 8620 used by European manufacturers?

20CrMnTi and SAE 8620 (EN 20MnCr5) are both carburising steels with similar case hardness after heat treatment (HRC 58-62). The primary metallurgical difference is the titanium content in 20CrMnTi, which provides grain refinement during carburising and slightly higher impact toughness at the case-core transition zone. In terms of gear performance at rated load, the two materials produce equivalent contact fatigue life and bending fatigue strength when processed to the same DIN quality class.

Stacker-reclaimer slewing drive replacement at an iron ore operation. The previous unit was an old European brand that was no longer manufactured. Ever-Power matched the mounting dimensions from the old drawing and delivered a ZR30**5 at 867.63 ratio that bolted in without modification. Running 14 hours a day in red dust conditions. Oil analysis at the 3,000-hour mark showed lower particle counts than the old unit had at the same interval. Very satisfied with the metallurgy and build quality.

Goliath crane slewing, ZR30**3 at 64.30 ratio. The unit has been in service for 11 months on our 400-tonne hull-block transporter. Performance is stable and the thermal behaviour matches the factory prediction — sump temperature stabilises at 72 deg C under continuous duty, well within limits. The gear grinding quality is evident from the low noise level. Our quality inspector noted the material certificates are thorough and met our internal traceability requirements without additional requests.

Excavator slewing drive swap on a 42-tonne machine. The ZR30**2 performs well and the hydraulic BF02 interface is a clean fit. The unit weighs about 260 kg and getting it positioned in the upper structure of this particular machine required some creative rigging because the access hatch is tight. My suggestion to Ever-Power: provide a recommended rigging diagram for common excavator models in the installation manual. That would save a lot of time for mechanics who are installing this for the first time.