Spherical bearing
Pot Bearing
2019年1月3日
LRB (Lead rubber bearing)
2019年2月26日Spherical bearing
Spherical bearing
Spherical bearing
All structures are flexible and their structural integrity must be maintained under all conditions. A structural bearing is essential to providing free movement between the superstructure and the supporting structure, while ensuring the safe transfer of vertical loads and rotations.
BAOLI spherical bearing is composed by top steel plate, stainless steel plates, PTFE plates, convex middle plate, base steel plate. It has great bearing capacity, can accommodate rotation and movement of superstructure. BAOLI bridge bearings are suitable for any type of structure, especially for large loads and rotation wide bridge and curved bridge.
Design principle
BAOLI spherical bearing ensure the controlled transfer of loads between a structure’s superstructure and its substructure. The design of BAOLI spherical bearing fulfills the requirements of European norm for structural bearings, EN1337-7.
BAOLI spherical bearing are suitable for use in structures with medium.
The bearing is connected to the superstructure and substructure by means of anchor dowels or threaded sleeves(depend on design), or alternatively by means of separate anchor plates with shear studs.
spherical bearing
The bearing is connected to the superstructure and substructure by means of anchor dowels or threaded sleeves(depend on design), or alternatively by means of separate anchor plates with shear studs.
Types
Fixed: Fixed bearings are immovable, can provide horizontal forces in all directions.
1-top steel plate; 2-stainless steel plate; 3-PTFE or (UHMWPE); 4- convex middle plate; 5-sleeve; 6-anchor bolt; 7-rubber sealing ring; 8-base steel plate.
Guided-sliding: Guided bearing can move in one direction, and may provide a horizontal force which perpendicular to that moveable direction.
1-top steel plate; 2- stainless steel plate; 3-PTFE or (UHMWPE); 4- convex middle plate; 5-guide bar; 6-sleeve; 7-anchor bolt; 8-base steel plate.
Free-sliding: Free sliding bearings can move in all directions but cannot provide horizontal forces.
1-top steel plate; 2-stainless steel plate; 3-PTFE or (UHMWPE); 4-convex middle steel; 5-sleeve; 6-anchor bar; 7-base steel plate.
Applicable Standards
- European Standard: EN 1337-7;
- American Standard: AASHTO LRFD Bridge Design Specification and Construction specification;
- British Standard: BS 5400-9.1, BS 5400-9.2;
Technical Performance
| Item | Performance Parameters |
| Vertical Load Capacity | 1.0MN, 1.5MN, 2.0MN, 2.5MN, 3.0MN, 3.5MN, 4.0MN, 4.5MN,
5.0MN, 5.5MN, 6.0MN, 7.0MN, 8.0MN, 9.0MN, 10.0MN, 12.5MN, 15.0MN, 17.5MN, 20.0MN, 22.5MN, 25.0MN, 27.5MN, 30.0MN, 2.5MN, 35.0MN, 37.5MN, 40.0MN, 45.0MN, 50.0MN, 60.0MN, 65.0MN, 70.0MN , other design values. |
| Horizontal Force Capacity | 10% , 15% or 22.5% of the vertical load capacity of the bearing and other design values . |
| Design Rotation Angle θ (rad) | Not less than ±0.02 rad |
| Design Displacement | Transverse direction: ±50mm, other designs.
Longitudinal direction: ±50mm, ±100mm, ±150mm, ±200mm, ±250mm, other designs. |
| Suitable Temperature | Normal Type (CR): -25℃~+60℃;
Cold-resistance Type (NR):-40℃~+60℃ |
| Friction Coefficient μ | Not great than 0.03 |
| Strength Grade of Concrete | Not lower than C40 |
Material
- Steel elements
The Material And Standard Of Steel Elements
| Steel parts | Material | Standard |
| Base steel plate | Cast steel or S355(Gr. 50) steel | EN, AASHTO |
| Convex middle steel | Cast steel or S355(Gr. 50) steel | EN, AASHTO |
| Top steel plate | S355(Gr. 50) steel | EN, AASHTO |
| Bolts | 41Ce4 ( Grade 100) | EN, AASHTO |
| Stainless steel | S304 | EN, AASHTO |
Base steel plate of spherical bearingStainless Steel
The stainless steel conform to ASTM A240/A240M, EN1337-5, or approved equivalent. The roughness of the surface in contact with the PTFE, measured in accordance with CSA B95, does not exceed an arithmetic mean of 0.25 μm.
Convex middle steel with stainless steel plate
- Sliding elements
PTFE sheets
The raw material of PTFE sheets are pure polytetrafluoroethylene free sintered without regenerated or filler materials.
Mechanical and physical properties of PTFE
| Item | requirement |
| Hardness(shore) | 55~70 |
| Mass density(kg/m3) | 2140 ~ 2200 |
| Tensile strength(MPa) | 29~40 |
| Elongation at break(%) | ≥300 |
| Ball hardness(MPa) | 23 ~ 33 |
| Specific weight | 2.14～2.20 |
| Friction coefficient with SS plate (23℃ +/-5) | <0.01 |
| Thickness(mm) | 7~8 |
Modifies ultra-high molecular weight polyethylene (UHMWPE)
Modifies ultra-high molecular weight polyethylene (UHMWPE) have increased wear-resistance and load capacity, it is also suitable for use in sliding bearings for bridge and buildings. With grease dimples and high performance grease, a durable, low-friction sliding surface is ensure. Due to its high durability, the use of UHMWPE greatly reduced maintenance and replacement costs.
UHMWPE used in spherical bearing
UHMWPE used in spherical bearing
Lubricant ( Silicon grease)
Physical and chemical properties of lubricant
| Properties | Requirements |
| Appearance | White, half transparent |
| Worked penetration | 26.5 to 29.5mm |
| Dropping point | ≥180 ℃ |
| Oil separation after 24 h at 100℃ | ≤3 %（mass） |
| Oxidation resistance pressure drop after 100h at 160℃ | ≤0.1 MPa |
| Pour –point of base oil | Below-60 ℃ |
Quality control at BAOLI
Refer to pot bearing
Spherical bearings with vertical load 140 MN, for Dashengguan Yangtze River, Nanjing.
BAOLI special warehouse
Advantage
- CE marked products
- Quality assurance: Quality control from raw material to finished product.
- On time delivery “No waiting around”.
- Cost saving options “Getting you the best price”.
- Small quantity acceptable “Every piece is valuable to us”.
- Professional packing plan to save cost for customers, customers won’t suffer any problem.
Package
Strong traies packages
QUOTATION:
Quotations are supplied on the basis of the types and numbers of the bearing required. We can also design the types of the bearing, if you proveded the follow information:
- Maximum, minimum and permanent vertical loads and corresponding horizontal loads(ULS).
- Displacement And Rotations in longitudinal and transverse directions.
- Other more information (like available space for pot bearing, concrete strength, etc).
