17-11-2012, 01:49 PM
TROUBLESHOOTING IN RAILWAY WHEEL
[attachment=39964]
INTRODUCTION
In rail vehicles, axle box provide the connection between the wheel set and bogie frame. It also transmits vertical and horizontal loads between vehicle body and wheel set. Modern railway vehicles are equipped with roller bearing axle boxes only, as they offer so many advantages as compared to plain bearings. Primary advantages of using roller bearings in axle box is significant reduction in friction. This is particularly great at starting and low speed operation of the rail vehicle. With low tractive effort required at startup, locomotive can pull heavier train loads and operate at higher speeds. Roller bearing axle boxes have now become safer operating unit and required little maintenance.
Rollers are guided by ribs/flanges of outer and inner rings. Additional advantages of cylindrical roller bearing axle box is extremely simple assembly. These bearings are easy to inspect and dismantle. Bearings are also easy to inspect and maintain cost effectively. Axle box with cylindrical roller bearings have been proven for their excellent performance, high degree of safety and reliability in Indian railways.
Cylindrical roller bearings are mostly used in duplex arrangement. Two bearings and loose lip form a complete set for an axle box. Bearing inner rings are shrink fitted on the journal with inner distance piece in between. Outer rings are face clamped by tightening between axle box shoulder and end cover, with outer distance between them. Bearing are designed and manufactured to provide the required radial and axle clearances. The unit is grease lubricated. Sealing is generally labyrinth type, provided by thrower. This is a standard and proven arrangement, used world wide in various railway systems due to it’s simplicity as well as reliability. Further the arrangement is easy to assemble, disassemble and inspect.
• Axle box housing
Housing is made from steel casting and precision machined. Bore of housing provides seating for bearing outer ring. Thrower end side of housing has grooves to from labyrinth type sealing with thrower, after assembly on the axle. Housing is fitted with liners, equalizer seat, grease nipple, bush, fasteners etc, depending upon type and application. Liners are subjected to heavy wear therefore made from hard manganese steel for wear resistance. Because of the considerable hardness of manganese steel, liners can not be milled or planed or bent easily.
• End Cover
End covers are made from steel casting or forging and then machined. Depending upon type of locomotive, end covers are supplied with various execution to facilitate fitment of accessories such as hasler speedometer, axle alternator, VDO speedometer, earthing connection etc.
• Thrower
Thrower is made from steel forging and precision machined. Thrower provides location to bearing inner ring and from a labyrinth sealing after axel box assembly. These are packed and supplied separately.
• Inner Distance Piece and Outer Distance Piece
Both distance pieces are generally made from cast iron. Width of both distance pieces is precision ground.
• Clamping Plates
Clamping plates are also made from steel forging, and machined accurately. Depending upon the assembly requirement, clamping plates come with different variation e.g. (i) plain (ii) hasler speedometer (iii) axel alternator etc. These are packed and supplied separately.
• Inner Thrust Collar and Outer Thrust Collar
Inner and outer thrust collars hold the conical thrust pad or rubber spring in high speed locomotive axel boxes. These are made from steel forging and precision machined. The tapered surface of these parts provide seats for the rubber spring.
• Conical Thrust Pad (Rubber Spring)
Conical thrust pad is basically a rubber spring, which provides axial resilience in the axel box assembly. The item conforms to IRS-R63 specification.
[attachment=39964]
INTRODUCTION
In rail vehicles, axle box provide the connection between the wheel set and bogie frame. It also transmits vertical and horizontal loads between vehicle body and wheel set. Modern railway vehicles are equipped with roller bearing axle boxes only, as they offer so many advantages as compared to plain bearings. Primary advantages of using roller bearings in axle box is significant reduction in friction. This is particularly great at starting and low speed operation of the rail vehicle. With low tractive effort required at startup, locomotive can pull heavier train loads and operate at higher speeds. Roller bearing axle boxes have now become safer operating unit and required little maintenance.
Rollers are guided by ribs/flanges of outer and inner rings. Additional advantages of cylindrical roller bearing axle box is extremely simple assembly. These bearings are easy to inspect and dismantle. Bearings are also easy to inspect and maintain cost effectively. Axle box with cylindrical roller bearings have been proven for their excellent performance, high degree of safety and reliability in Indian railways.
Cylindrical roller bearings are mostly used in duplex arrangement. Two bearings and loose lip form a complete set for an axle box. Bearing inner rings are shrink fitted on the journal with inner distance piece in between. Outer rings are face clamped by tightening between axle box shoulder and end cover, with outer distance between them. Bearing are designed and manufactured to provide the required radial and axle clearances. The unit is grease lubricated. Sealing is generally labyrinth type, provided by thrower. This is a standard and proven arrangement, used world wide in various railway systems due to it’s simplicity as well as reliability. Further the arrangement is easy to assemble, disassemble and inspect.
• Axle box housing
Housing is made from steel casting and precision machined. Bore of housing provides seating for bearing outer ring. Thrower end side of housing has grooves to from labyrinth type sealing with thrower, after assembly on the axle. Housing is fitted with liners, equalizer seat, grease nipple, bush, fasteners etc, depending upon type and application. Liners are subjected to heavy wear therefore made from hard manganese steel for wear resistance. Because of the considerable hardness of manganese steel, liners can not be milled or planed or bent easily.
• End Cover
End covers are made from steel casting or forging and then machined. Depending upon type of locomotive, end covers are supplied with various execution to facilitate fitment of accessories such as hasler speedometer, axle alternator, VDO speedometer, earthing connection etc.
• Thrower
Thrower is made from steel forging and precision machined. Thrower provides location to bearing inner ring and from a labyrinth sealing after axel box assembly. These are packed and supplied separately.
• Inner Distance Piece and Outer Distance Piece
Both distance pieces are generally made from cast iron. Width of both distance pieces is precision ground.
• Clamping Plates
Clamping plates are also made from steel forging, and machined accurately. Depending upon the assembly requirement, clamping plates come with different variation e.g. (i) plain (ii) hasler speedometer (iii) axel alternator etc. These are packed and supplied separately.
• Inner Thrust Collar and Outer Thrust Collar
Inner and outer thrust collars hold the conical thrust pad or rubber spring in high speed locomotive axel boxes. These are made from steel forging and precision machined. The tapered surface of these parts provide seats for the rubber spring.
• Conical Thrust Pad (Rubber Spring)
Conical thrust pad is basically a rubber spring, which provides axial resilience in the axel box assembly. The item conforms to IRS-R63 specification.