Spherical plain bearings are a type of spherical sliding bearing, comprising an inner ring with an outer spherical surface and an outer ring with an inner spherical surface. Relying on a spherical sliding fit, they allow for a certain degree of angular oscillation and self-aligning tilt, making them suitable for low-speed oscillating and reciprocating hinge applications. They can simultaneously withstand combined radial and axial loads and offer outstanding impact resistance.
1. Radial spherical plain bearings (GE series)
Steel-on-steel friction; features lubrication grooves and oil holes, requiring periodic greasing; the suffix ‘-2RS’ denotes double-sided seals for dust protection.
- GE‑E: Single-groove outer ring, without lubrication grooves
- GE‑ES: Single-groove outer ring, with lubrication grooves and oil holes; standard market model
- GEG‑ES: Heavy-duty type, with enlarged ball diameter, specifically for heavy loads
- GEW‑ES: Wide inner ring series
Common models: GE12ES, GE15ES, GE20ES, GE25ES, GE30ES, GE35ES, GE40ES‑2RS.
2. Self-lubricating radial spherical plain bearings (GE‑T series)
Outer ring lined with PTFE fabric; maintenance-free and requires no lubrication, suitable for applications where lubrication is difficult to apply.
3. Rod-end spherical plain bearings (Fish-eye joints)
Available in both internal and external thread versions, integrating the spherical plain bearing into the end of a connecting rod.
- SI: Internal thread rod end; SA: External thread rod end
Common models: SI12, SI16, SA20, etc., frequently used in hydraulic cylinder connecting rods and tie-rod mechanisms.
4. Thrust spherical plain bearings
Primarily designed to withstand axial loads, used in articulated joints subjected to axial forces.
Key Features
- Strong self-aligning capability, capable of compensating for misalignment during assembly and frame deformation
- Face contact design offers high load-bearing capacity and impact resistance; suitable only for low-speed oscillation, not recommended for high-speed rotation
- Steel-on-steel variants require periodic relubrication; self-lubricating variants are maintenance-free but have a slightly lower load-bearing capacity
Applications
Hydraulic cylinders, construction machinery, forging and pressing equipment, automated hinges, agricultural machinery, mining equipment, and vibration-damping articulated mechanisms.
| Title | inner diameter (mm) | outer diameter (mm) | thickness (mm) | Dynamic load (KN) | Static load (KN) | Weight (kg) |
|---|---|---|---|---|---|---|
| SB50A | 50 | 80 | 42 | 254 | 1530 | 0.87 |
| SB45A | 45 | 72 | 36 | 188 | 1130 | 0.6 |
| SB40A | 40 | 62 | 33 | 151 | 906 | 0.375 |
| SB35A | 35 | 55 | 30 | 127 | 765 | 0.3 |
| SB30A | 30 | 50 | 27 | 101 | 609 | 0.225 |
| SB25A | 25 | 42 | 21 | 63.5 | 381 | 0.116 |
| SB22A | 22 | 37 | 19 | 50.2 | 301 | 0.085 |
| SB20A | 20 | 32 | 16 | 38.4 | 231 | 0.053 |
| SB15A | 15 | 26 | 13 | 23.7 | 142 | 0.028 |
| SB13A | 12 | 22 | 11 | 15.9 | 95.3 | 0.019 |
| PB30 | 30 | 66 | 37 | 62.3 | 149 | 0.61 |
| PB28 | 28 | 62 | 35 | 58.4 | 140 | 0.41 |
| PB25 | 25 | 56 | 31 | 46.2 | 111 | 0.39 |
| PB22 | 22 | 50 | 28 | 37.4 | 89.7 | 0.265 |
| PB20 | 20 | 46 | 25 | 30.8 | 74 | 0.21 |
| PB18 | 18 | 42 | 23 | 25.7 | 61.6 | 0.16 |
| PB16 | 16 | 38 | 21 | 21 | 50.4 | 0.111 |
| PB14 | 14 | 34 | 19 | 16.8 | 40.4 | 0.084 |
| PB12 | 12 | 30 | 16 | 13.1 | 31.4 | 0.058 |
| PB10 | 10 | 26 | 14 | 9.81 | 23.5 | 0.039 |