1.1251.30.12.D.1-RV

I.18 25.30.40 45 D R Roller bearing
  • I.18 25.30.40 45 D R Roller bearing
  • I.18 25.30.40 45 D R Roller bearing
  • I.18 25.30.40 45 D R Roller bearing
  • I.18 25.30.40 45 D R Roller bearing

1.1251.30.12.D.1-RV-I.18 25.30.40 45 D R Roller bearing

The single-row crossed roller slewing bearing with Internal gear is a precision rotational component engineered for applications requiring high accuracy, exceptional rigidity, and reliable performance within a compact envelope. This design utilizes cylindrical rollers arranged in a crossed pattern, offering superior load capacity and rotational precision compared to conventional ball bearing solutions.



Application Areas:

Robotics and automation equipment

Precision rotary tables and indexing systems

Radar and antenna positioning systems

Medical imaging and radiotherapy equipment

High-accuracy solar tracking systems



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

I.18 25.30.40 45 D R Roller bearing
Bearing Type : 1.1251.30.12.D.1-RV
Brand :LYMC
Drawing No. :Drawing 2
Dimensions
Da [mm] :1251
u [mm] :1142
O [mm] :
C [mm] :
Di [mm] :979
Ha [mm] :75
Hb [mm] :75
H [mm] :91
Fixing Holes
La [mm] :1212
na :40
da [mm] :22
Li [mm] :1008
ni :36
di [mm] :22
Gear Teeth
p [mm] :990
M :10
Z :99
Tooth Force
Fz nor [KN] :58
Fz max [KN] :116
Mass [KGS]
[KG] :240

Characteristics

✦ Raceway geometry – The single raceway features a V-shaped profile with a 90° included angle, guiding rollers into precise orthogonal contact with both axial and radial thrust surfaces.

✦ Roller composition – Rollers are manufactured from through-hardened GCr15 bearing steel with a surface hardness of 60–64 HRC and a length-to-diameter ratio of 1.2:1.

✦ Gear tooth specification – Internal gear teeth conform to DIN 3962 grade 6, with a 20° pressure angle and a tip relief modification of 0.02–0.04 mm to optimize meshing under load.

✦ Ring flatness tolerance – Mounting faces are ground to a flatness of 0.02 mm over the entire ring circumference, ensuring even bolt loading and seal compression.

✦ Seal groove dimensions – Seal channels are machined to a depth of 4.5 mm and a width of 3.2 mm, sized for standard profile seals with a lip interference of 0.6 mm.

✦ Bolt hole geometry – Mounting holes are countersunk with a 90° chamfer and positioned on a bolt circle diameter with a positional tolerance of 0.1 mm.


Features

✦ Extends fatigue life in cyclic operation – The line-contact roller design distributes loads over a larger area, significantly increasing the bearing's resistance to repeated stress cycles compared to point-contact designs.

✦ Maintains preload under thermal changes – The matched roller and raceway geometry ensures consistent internal clearance across a wide temperature range, preventing looseness or binding.

✦ Allows flexible pinion positioning – The Internal gear teeth are machined with a generous root radius, enabling the pinion to be positioned at varying center distances without compromising contact pattern.

✦ Reduces lubrication frequency – The optimized roller-end geometry promotes oil film retention, extending the interval between regreasing cycles in continuous operation.

✦ Accommodates mounting errors – The inherent compliance of the crossed roller design compensates for minor parallel misalignment between mounting surfaces, reducing installation precision requirements.

✦ Improves energy efficiency – The low-friction roller profile reduces torque requirements by up to 15% compared to standard designs, lowering overall power consumption.


Further Reading