Slewing gears

ZOLLERN Slewing gearboxes have proved highly successful under extreme operating conditions. They use components common to our complete range (winches, slewing units, industrial gears, free fall winches) giving the advantage of mass production: cost savings from standard parts, reduced lead times, tested and proven designs across the whole range and readily available spares for units in service.

Their principal features and most significant advantages are

  • compact dimensions
  • ease of maintenance
  • long operation life
  • high performance
  • modular design of gear unit
  • functional design

That gives machine designers ready-to-install units for cost-efficient solutions, even where space is at a premium.

 Typical applications are:

  • mobile cranes
  • construction cranes and conveyors
  • material and working elevators
  • loading and cargo handling cranes
  • shipboard and deck cranes
  • rescue and wrecker salvage trucks
  • dockyard and harbour cranes
  • offshore cranes
  • container gantries
  • access platforms
  • azimut & pitch drives for wind turbines

Slewing units

Output torques from 1,400 to 1,550,000 Nm Ratios i = 14 to 1007 (other ratios available on request). When determining the torque, acceleration and deceleration as well as wind effect and slope must be taken into account.

Gear tooth design
Optimized for best possible tooth flank and root load capacity and minimum sliding velocity in accordance with DIN 3990. Externally toothed gears case-hardened and ground, internal gears heat-treated and nitride-hardened.

Lubrication
All gears and anti-friction bearings are splash lubricated. Drive bearings are grease packed for lifetime operation, requiring no further lubrication. Oil level is checked by either dip stick or sight glass.

Efficiency
The efficiency per planetary stage is 98 % and 99 % for the output shaft bearing including sealing.
Example: Slewing gear with 2 planetary stages
η total = 0.98 x 0.98 x 0.99 = 0.95

Bearings
All components carried in antifriction bearings. Needle roller bearings and cylindrical roller bearings in the planetary wheels. Generously dimensioned self aligning roller bearings in the output shaft housing, supporting the pinion.

Installation
Vertical or horizontal as specified

Seals
The drive is sealed by a radial shaft sealing ring with a dust lip and
a) two radial shaft sealing rings
b) the grease packing in the output shaft housing
c) another radial shaft sealing ring
That provides reliable protection against oil loss and penetration of dirt and water.

Drive options
ZOLLERN’s modular system uses hydraulic or electric motors, or free shaft end drives. The drive shaft or sleeve can be designed with DIN 5480 toothing or with a key. A torsionally flexible coupling is also possible.

Brake
Amply dimensioned spring-actuated multi-disc holding brake, hydraulically released, to hold the slewing mass and to brake the slewing mass in case of emergency. Not to be used as a service brake.
Pressure: min. 15 bars, max. 250 bars
Back pressure: max. 0.5 bar allowed
Please consult us if back pressure value exceeds this figure. Connecting line 8 x 1 tubing to DIN 2391 C, as short as possible. Service brake to hold and brake the slewing mass, hydraulically, pneumatically or mechanically operated (optional extra).

Eccentric adjustment
For accurate adjustment of backlash between the output pinion and the driven ring gear, the output shaft assembly can be provided with eccentric adjustment in relation to the flange and output pinion.
Eccentricity
Flange I x = 2.5
Flange II x = 1.5
Flange III x = 1.5

Primer
Specially developed multi-primer with a two-component epoxy resin base. Colour: grey white. A two-component epoxy resin is most suitable for the finish