ZR3.40.3550.400-1SPPN

ZR3.20 25 32 40 Types of slew ring
  • ZR3.20 25 32 40 Types of slew ring
  • ZR3.20 25 32 40 Types of slew ring
  • ZR3.20 25 32 40 Types of slew ring

ZR3.40.3550.400-1SPPN-ZR3.20 25 32 40 Types of slew ring

The ZR3 series is a heavy-duty triple-row roller slewing bearing with integrated internal gear structure, specially engineered for ultra-high load industrial rotary systems. Differing from ball-type and double-row slewing units, this series adopts a professional three-row roller layout and concealed internal tooth design, focusing on extreme structural rigidity, heavy-load resistance and high-precision transmission stability. It is the preferred core component for large engineering machinery and heavy rotary equipment that require long-term stable operation under ultimate load conditions.


Typical Applications:

Large tower cranes and mobile cranes

Heavy-duty excavators and mining equipment

Wind turbine yaw and pitch systems

Large radar and antenna positioning systems

Heavy-duty industrial turntables

Marine cranes and offshore equipment


High load-carrying capacity
Resistance to high and low temperatures
Noise-free operation
Strictly controlled tolerances and appropriate internal clearance
Long service life and low maintenance requirements
Prevention of unexpected downtime (avoiding bearing fracture, seizure, and safety incidents caused by such failures, with anti-tilting capability)

Dimension and Parameters

ZR3.20 25 32 40 Types of slew ring
Type :ZR3.40.3550.400-1SPPN
Drawing No. :LYMC
Brand :Drawing 2
Dimensions
De[mm] :3788
de[mm] :3500
di[mm] :3513
Di[mm] :3190
He[mm] :170
Hi[mm] :210
Ht[mm] :220
Holes
Fe[mm] :3710
Fi[mm] :3385
N :66
V[mm] :39
Gear
m :22
z :146
xm :-0.5
DP :3212
fz norm[kN] :357
fz max[kN] :658
Weight [KGS] :4171

Characteristics

✦ Three-row roller arrangement – Two axial rows (upper/lower) and one radial row, each with cylindrical rollers arranged in a triangular load path for balanced force distribution.

✦ Internal gear on inner ring – Gear teeth are precision-machined on the inner ring bore with a 20° pressure angle, case-hardened to 50–55 HRC.

✦ Two-piece outer ring – Outer ring is split horizontally into two bolted sections to allow access for roller installation and adjustment.

✦ Integrated axial/radial raceways – Axial raceways are ground directly into the inner ring faces, while the radial raceway is ground on the inner ring outer diameter.

✦ Induction-hardened profiles – All raceways hardened to 58–62 HRC with a case depth of 3.5–4.5 mm for extended wear life.


Features

✦ Compact load management – The triangular roller arrangement distributes forces efficiently, allowing the bearing to handle heavy loads within a smaller envelope.

✦ Smooth motion under heavy loads – Cylindrical roller line contact ensures low-friction rotation even under extreme loads, reducing energy consumption.

✦ Simplified installation – The split outer ring design allows the bearing to be assembled around existing shafts, saving time and labor.

✦ Extended maintenance intervals – Deep case-hardening of raceways reduces wear, allowing longer periods between scheduled maintenance.

✦ Reliable gear engagement – Case-hardened internal gear teeth maintain accurate meshing with pinions, ensuring consistent power transmission.


Further Reading