Rocker Cum Roller Bearing

Product Description

Our company offer excellent quality Rocker Cum Roller Bearing. This roller bearing is used in civil engineering and infrastructure projects such as bridges, buildings, and dams. It is designed to allow for movement and rotation between two structural elements while providing support and stability. This roller bearing is generally composed of two main parts: a flat plate, or rocker, that rests on the support structure, and a curved plate, or roller, that is attached to the supported structure. Moreover, this roller bearing has the ability to support heavy loads while allowing for movement and rotation between two structural elements.

A Rocker Cum Roller Bearing is a type of mechanical bridge bearing designed to support vertical loads while allowing controlled rotational and translational movements of the bridge superstructure. It combines the functions of both a rocker bearing (rotation about a horizontal axis) and a roller bearing (translation along a horizontal plane), making it ideal for bridges with significant longitudinal movement and rotational requirements.

This bearing type is commonly used in steel and reinforced concrete bridges where the structural design demands both rotation due to bending and expansion or contraction due to temperature variations, shrinkage, or creep.

Main Functions

• To transmit vertical loads from the bridge superstructure to the substructure safely.

• To permit longitudinal movements caused by temperature changes, creep, or shrinkage.

• To allow rotational movement due to live loads, dead loads, and structural deflection.

• To minimize restraint forces and prevent undesirable stresses in the bridge deck or substructure.

Construction Details

A typical Rocker Cum Roller Bearing assembly consists of the following key components:

1. Top Plate (Sole Plate):
   Attached to the superstructure to transfer loads to the bearing.

2. Rocker Plate / Rocker Pin:
   Allows rotational movement about a horizontal axis.

3. Roller Assembly:
   Consists of one or more steel rollers that permit longitudinal movement.

4. Bottom Plate (Masonry Plate / Base Plate):
   Anchored to the pier or abutment to distribute load uniformly.

5. Guide and Restraint System:
   Ensures correct movement direction and alignment.

6. Dust Seal and Side Stops:
   Prevent ingress of debris and control lateral displacement.

Materials

• Structural Steel: IS 2062 Grade E250 or E350 / ASTM A36 / A572.

• Rollers and Pins: High-strength forged steel, hardened and ground for wear resistance.

• Bearings Surfaces: Machined and polished to reduce friction.

• Corrosion Protection: Hot-dip galvanizing, zinc metallizing, or epoxy painting as per design.

Performance Characteristics

• Vertical Load Capacity: As per design (typically from 100 kN to several thousand kN).

• Rotation Capacity: Up to 0.02 radians (as per IRC:83 / BS 5400 / AASHTO standards).

• Movement Range: Depends on bridge span and temperature variation, generally 40 mm to 150 mm.

• Friction Coefficient:  0.03 for roller surfaces.

• Durability: Designed for long service life with minimal maintenance.