HERCULES STRUCTURAL BEARINGS

  

Our Range of Structural Bearings, includes, but not limited to:

•POT / POT cum PTFE Bearings.
•Rocker, Rocker cum Roller bearings.
•Metallic Guided Bearings.
•Spherical/ Disc Bearings.
•Anti Uplift Bearing.

The Bearings are manufactured in accordance with MORT&H/IRC/AASHTO/    BS specifications.

 

POT / POT-CUM-PTFE TYPE STRUCTURAL BEARINGS

CONCEPT :-

The concept behind the confined Elastomeric POT Bearing is very simple.

A shallow steel cylinder, called as POT is inserted with a thin, neat fitting disc of Elastomerwhich has a recess to accept the flat Brass Sealing Rings. A steel Piston is then inserted into the POT and bears against the Elastomeric disc. The resulting assembly is frequently perceived as being similar to that of an hydraulic fluid sealed within the POT and the PISTON arrangement but is free to rotate about any horizontal axis with minimum resistance which is a highly desirable feature of bridge bearing. By keeping rotational resistance to a minimum, a uniform distribution of load to the structure is ensured.

INITIAL DESIGN CONSIDERATION

 

Experience has shown that POT TYPE bearings are rarely supplied as standard items. The extensive possible coexisting combination of vertical loads and horizontal forces, translations -longitudinal and / or transversely, together with varying requirements of rotational capacity, are such that all POT-CUM PTFE bearings are custom designed and are manufactured  project specific.

PRIMARY DESIGN CONSIDERATIONS

The Primary Design consideration are the vertical & horizontal loads, translation & rotational requirements.

As far as applied loads are concerned, co-existing minimum & maximum vertical / horizontal loads are a critical consideration & may in fact, dictate the final design of the bearing.

Basic designs required to determine the physical dimensions of the bearings can be generated promptly from in house customized computer programs.

SECONDARY DESIGN CONSIDERATIONS

These take into account such factors as method of attachment to the proposed structure, as well  as translation requirements, preset / offset requirements to cater for irreversible translation, together with project specific corrosion protection requirements.

At the same time, detailed analysis for the internal configuration of  bearing is undertaken.

The inputs required for the design of POT Bearings is summarized in the attached format.


PARAMETER FORM FOR POT / POT-cum-PTFE BEARINGS

  

FEATURES of POT / POT-CUM-PTFE BEARINGS

•Compact.
•Multi Directional Rotation.
•Unlimited Translation / Movement Capacity.
•Complex Load & Movement Combination.
•No Elastic Counterstroke.`
 
 

Basic Configurations :-

POT / POT-cum-PTFE Bearings comes in three basic configurations:

FIXED TYPE   -             Designated as “ HFX ”

FREE FLOAT TYPE   -   Designated as “ HFF ”

SLIDE GUIDE TYPE   -   Designated as “ HSG ”


Fixed Type \"HFX\"

  

A type of POT BEARING which alongwith  vertical loads, bears and transmits horizontal forces in any direction and allows rotation about any axis in horizontal plane without permitting any movement.

Performance Characteristics :-

-Bears Vertical Loads.
-Provide Lateral restraint in any

  Horizontal axis.

-Equal rotation about any axis in

  Horizontal Plane.

- Must be locked to the structure.


FREE FLOAT TYPE \'HFF\'

  

A type of POT Bearing which bears & transmits vertical load & allows movement in any direction in the horizontal plane and accommodates rotation about any axis in horizontal plane.

Performance Characteristics :-

- Bears Vertical Loads.

-Equal rotation about any horizontal

  axis.

-Free sliding translation both in

  longitudinal & transverse directions.

-Friction alone can be used to locate

  this type of bearing in the structure.

  However Positive locating devices

  shall be used to connect the bearing

  with the structure.`


Slide Guide Type \'HSG\'

  

A type of POT Bearing which along with vertical loads bears & transmits horizontal force in one direction only & allows movement perpendicular to that direction. This Bearing configuration allows rotation in any axis in the horizontal plane.

Performance Characteristics :-

-Bears Vertical Loads.
-Restrained in one direction, free to

  slide normal to restrained direction.

-Equal rotation about any horizontal

  axis.

- Must be restrained in the structure.

Other than the standard types of POT / POT – cum - PTFE Bearings illustrated above, HSSPL also having expertise in Design & Manufacturing other type of Steel Bearings & also the POT Bearings with additional attachments to suit the project specific requirements. These are mainly –

 

-Anti- Up-Lift Bearing.
-Pin Bearing.
-Guided Pin Bearing.

ANTI-UP-LIFT BEARING

  

Anti-Up-Lift Bearings are capable of resisting negative vertical forces that are not accommodated by ‘normal’ bearings. Their application is very common on simply rested bridge span in which the abutment are very oblique to the direction of traffic lane. The effect of the live loads is particularly onerous to the unloading of the bearings which are more distant from the bridge deck center of gravity. Their most common application is that on continuous overpasses of the expressway type, characterized by a much longer central span than the two shortest lateral spans.


PIN BEARING

  

These bearing consists of a metal pin provided within a metal cylinder to bear & transmit horizontal forces along any direction in the horizontal plane and accommodating the rotation about any axis in Horizontal Plane. Pin bearings cannot bear or transmit any vertical load.


GUIDED PIN BEARING

  

These  bearings consists of a sliding assembly with restraint along a desired direction to bear and transmit horizontal force and are capable of allowing movements in the direction perpendicular to the direction of horizontal force. Guided Pin Bearings are capable of allowing rotation only about an axis perpendicular to the plane of sliding. Guided Pin Bearing cannot bears or transmit any Vertical Load.


SPHERICAL BEARINGS

  

Spherical PTFE Bearing consist of a backing plate with a convex spherical surface & a covering plate on top having a concave spherical surface. Between these two surfaces a dimpled PTFE sheet is fixed having dimples filled with long lasting silicone grease which provides friction free sliding to the mating material of the concave sliding surface.


ROCKER CUM ROLLER BEARINGS

These type of bearings consists of rollers sandwiched between a saddle plate and a bottom plate. Rocker cum roller bearings offer longitudinal movement through rollers which roll along guide bars attached to saddle plate and bottom plate. Rotational movement is through a rocker pin which gives a see-saw rocking motion to the top plate. The rollers are connected by a spacer plate for unidirectional movement.


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