ZR10 Slewing Drive Planetary Gearbox — Right-Angle Bevel-Planetary

The EP-ZR10 marks the transition point in the ZR slewing drive series from medium-duty to genuinely heavy-duty applications. At 11,500 Nm continuous and 24,500 Nm peak output torque, the ZR10 handles the sustained slewing loads that tower cranes in the 12-25 tonne lifting class, hydraulic excavators in the 20-30 tonne operating weight range, and rotary piling rigs generate during their normal working cycles.

With 41 discrete gear ratios across 2-stage, 3-stage, and 4-stage configurations (7.87 to 695), the ZR10 covers everything from moderate-speed excavator upper-structure rotation down to the creep-speed slewing required by ship-loader boom positioning. The bevel-planetary architecture maintains 89-93% efficiency at full rated load — a critical advantage over worm-gear reducers in applications where the drive operates continuously for 4,000-6,000 hours per year.

Tower Cranes (12-25 Tonne Class)

Flat-top and hammerhead tower cranes with jib lengths of 55-70 metres and maximum lifting capacity of 12-25 tonnes. The ZR10 3-stage at ratios 40:1-80:1 provides the torque-to-speed balance these machines require, with 24,500 Nm peak absorbing wind gust shock loads during full-jib rotation. Typical configuration: ZR10**3, ratio 46.30 or 54.58, with B510 fail-safe brake.

Hydraulic Excavators (20-30 Tonne)

Upper-structure slewing on hydraulic excavators in the 20-30 tonne operating weight class demands continuous high torque with frequent start-stop-reverse cycles. The ZR10 2-stage at ratios 7.87-15.16 matches the high-speed, high-duty-cycle slewing profile, driven by axial piston hydraulic motors via BF01/02 input flanges. Typical configuration: ZR10**2, ratio 9.17, BF02 hydraulic input.

Rotary Piling Rigs and Drilling Machines

Piling rig mast rotation and continuous flight auger positioning require smooth, controlled slewing under high static loads from the drill string weight. The ZR10 4-stage at ratios 200:1-350:1 provides the creep-speed precision these operations demand, while the IP67 sealing protects against bentonite slurry, groundwater, and drilling mud that would disable lesser drives within weeks.

Gear Tooth Inspection

Every gear set measured on CNC coordinate measuring machine against DIN 5-6 tolerance. Profile deviation, lead deviation, and pitch error recorded on individual inspection certificate.

Full-Load Torque Test

Each assembled ZR10 unit run at rated output torque for a minimum of 30 minutes on a closed-loop dynamometer test bench. Oil temperature rise, vibration amplitude, and noise level recorded.

IP67 Pressure Leak Test

Housing pressurised to 0.5 bar positive and held for 10 minutes. Any pressure decay exceeding 0.02 bar results in rejection, seal replacement, and retest.

Material Traceability Package

Shipped with: gear steel heat certificates, bearing manufacturer certificates, hardness test reports, dimensional inspection report, and dynamometer test log. Serial number laser-engraved on housing.

What hydraulic motor displacement is typical for the ZR10 in excavator slewing?

For a 25-tonne excavator with the ZR10**2 at ratio 9.17, typical hydraulic motor displacement is 80-107 cc/rev operating at 200-250 bar system pressure. The BF02 input flange accepts most major-brand axial piston motors (Bosch Rexroth A2FM/A6VM, Eaton/Danfoss, Kawasaki) without adapter plates. Motor displacement and operating pressure should be verified against the required output torque and the thermal duty cycle specific to the excavator model.

How does the ZR10 handle the repeated start-stop-reverse cycles in excavator slewing?

Excavator slewing generates frequent bidirectional torque reversals at rates of 6-12 cycles per minute during digging operations. The ZR10 helical planetary gears distribute reversal loads across three simultaneous gear mesh contacts, reducing the impact stress per tooth compared to spur-gear designs. The 24,500 Nm peak rating (approximately 2.1x the 11,500 Nm continuous rating) provides the transient capacity headroom for aggressive start-stop cycling without accelerated gear or bearing wear.

What maintenance does the ZR10 require on a tower crane operating 2,000 hours per year?

At 2,000 hours per year: first oil change at 2,000 hours (end of year 1), then every 4,000 hours (end of year 3, year 5). Check oil level every 500 hours (quarterly). Inspect breather valve every 6 months. Inspect output shaft seal condition at the first annual service. At this duty cycle, seal replacement is not expected within the first 10 years of operation. Full inspection recommended at 20,000 hours (year 10).

Can two ZR10 units be used in a dual-drive slewing arrangement?

Yes. Large tower cranes and port equipment commonly use two slewing drives meshing with the same slewing ring from opposite sides to double the available torque and provide redundancy. Both units must use the same gear ratio to ensure equal load sharing. The output pinion module and tooth count must be identical and the mounting geometry must ensure correct centre distance to the slewing ring. Contact our engineering team for dual-drive configuration dimensional verification.

We run a fleet of 14 excavators in an open-pit mining operation. Switched to ZR10 slewing drives across the fleet over the last two years. Failure rate went from about one drive replacement per month to zero in the last 11 months. The hydraulic motor mounting is a direct swap with our existing machines, which made the transition painless from a workshop perspective.

We specified the ZR10**3 at 46.30 ratio for a new tower crane design. The CAD model data was delivered faster than expected and matched the physical unit within 0.1mm on all critical interfaces. Noise performance surprised us positively. The unit is measurably quieter than the European brand it replaced on our previous model, which helps with urban site noise compliance.

Solid drive, no complaints on performance. We had an issue with the breather valve position on the first batch — it was on the wrong side for our crane frame layout and we had to fabricate a relocation bracket. Brought this up with the factory and they offered to change the breather location on subsequent orders at no extra cost. Second batch was correct. Product itself is excellent.