Bogie Design Features of WAP5 and WAG9 Locomotives PDF

9. BOGIE DESIGN FEATURES The bogies of WAP5 and WAG9 locomotives, designed by M/s ABB Henschel, Germany and manufactured in ABB‟s factory in Australia, incorporate many modern design features. BOGIE OF WAP5 LOCOMOTIVE The WAP5 locomotive is equipped with 2-axle bolster less Bo-Bo bogies with fully...

9. BOGIE DESIGN FEATURES The bogies of WAP5 and WAG9 locomotives, designed by M/s ABB Henschel, Germany and manufactured in ABB‟s factory in Australia, incorporate many modern design features. BOGIE OF WAP5 LOCOMOTIVE The WAP5 locomotive is equipped with 2-axle bolster less Bo-Bo bogies with fully suspended traction motor to reduce unsprung mass. General arrangement of the bogie is shown in Fig.1. The bogie has two stages of suspension. The loco body rests on two pairs of secondary helical springs located on bogie long beams. The bogie frame is supported on primary helical spring, resting on the axle boxes. Transverse flexibility between car body and bogie is provided by the flexi-coil action of the secondary helical springs. Hydraulic dampers are provided in vertical and lateral modes at secondary stage between underframe and bogie frame and in vertical mode in primary stage between axle box and bogie frame to reduce vibrations of the locomotive body. Two dampers provided between loco body and bogie has a special design to give constant damping force in longitudinal mode. One damper is provided on each traction motor to cushion the lateral motion of the motor. Traction links are provided between bogie frame and axle boxes for transfer of traction forces from axle to bogie frame. Traction and breaking forces are transmitted from bogie to underframe through low traction bars. Connection of the traction bars towards the middle of the underframe is aimed to improve the riding behaviour in the cab. The WAP5 loco is equipped with the following pneumatic breaking systems: Automatic train brake, Direct loco brake, parking brake and Anti spin brake. As with the tractive effort, braking effort is transmitted to the bogie frame by the axle journal boxes and guide rods and from the bogie frame to the locomotive by the traction rods. The locomotive is provided with disc brakes for improved braking performance required for high-speed operation. Fully suspended traction motor have been provided to reduce unsprung mass and improve the riding at high speeds. The smaller wheelbase of the 2-axle bogie and flexi-float suspension arrangement help improve curving behaviour and permit the negotiation of curves at higher speeds. BOGIE OF WAG9 LOCOMOTIVE The three axle, three motor Co-Co bogie assembly, is one of the major parts of the WAG9 locomotive. Two bogie assemblies support the entire weight of the locomotive and provide a means for transmission of the tractive effort to the rails. General arrangement of the bogie is shown in Fig.2. The bogies are designed to withstand the stresses and vibrations, resulting from normal rolling stock application. An important function of the bogie is to absorb and isolate shocks caused by vibration in the track bed. The suspension system minimizes the transmission of the shocks to the locomotive underframe. The traction motors are suspended in the bogie frame and on the individual axles. The motors transmit their energy to the driving axles. The motor transmits their energy to the TRACTION ROLLING STOCK : THREE PHASE TECHNOLOGY Page 113 driving axles through a gearbox mounted on the driving axles. The force from the driving axles is transmitted to the contact point between the wheel tread and the rail. Traction force is, in turn transmitted through the axle journal boxes and the guide rods to the bogie frame. The low traction bar, connected between the bogie transom and the car underframe, transmits the tractive forces to the car body. The WAG9 loco is equipped with the following pneumatic braking system: Automatic train brake, direct loco brake, Parking brake and Anti spin brake. As with the tractive effort, braking effort is transmitted to the bogie frame by the axle journal boxes and guide rods and from the bogie frame to the locomotive by the traction rods. Isolation and absorption of shock loads and vibration is performed by the primary and secondary suspension. Movement between the car body and bogie is smoothly controlled by the primary and secondary suspension. Although the springs permit pre-movement in any direction lateral buffers and dampers limit the amount and rate of lateral movement. Rebound limit change and vertical dampers limit the amount and rate of the vertical rebound of the locomotive car body. Yaw (longitudinal) dampers control the car body pitch rate. Guide rods control the fore and aft movement between the axles and the bogie frame while the link rod controls the fore and aft movement between the bogies and the locomotive car body. The primary suspension located between the axles and the bogie frame is provided by twin coil springs on the axle journal box fore and aft of the axle line. Vertical hydraulic dampers are used to dampen the rebound rate of the springs. This “Flexicoil” arrangement permits lateral movement of the axle. Guide rods connected between the axle journal boxes and bogie frame provides longitudinal control on the axle, and the transmission of tractive and braking effort to the bogie frame. Spheribloc rubber bushes in the guide rods allow the axle lateral movement without undue restriction. Secondary suspension is also provided by coil springs and vertical hydraulic dampers located between the bogie frame and the locomotive underframe on each side of the bogie. The weight of the locomotive car body is carried by the secondary suspension springs. The “Flexi Float” arrangement of the secondary suspension allow the locomotive car body to move both laterally and vertically within certain limits relative to the bogies. TRACTION ROLLING STOCK : THREE PHASE TECHNOLOGY Page 114  Fig. 9.1 General Arrangement of Bogie WAP 5 LOCOMOTIVE TRACTION ROLLING STOCK : THREE PHASE TECHNOLOGY Page 115 Fig. 9.2. GENERAL ARRANGEMENT OF BOGIE WAG9 LOCO 1 Sanding box 2 Wheel flange lubrication reservoir 3 Primary suspension damper 4 Secondary suspension yaw damper 5 Wheel flange lubrication reservoir 6 Secondary suspension spring 7 Safety chain 8 Secondary suspension vertical damper 9 Horizontal damper 10 Wheel set guide 11 Bogie frame 12 Sanding box 13 Wheel set 14 Wheel 15 Brake blocks 16 Brake lever 17 Brake cylinder 18 Brake rod 19 Primary suspension spring 20 Wheel flange 21 Sanding pipe 22 Traction link TRACTION ROLLING STOCK : THREE PHASE TECHNOLOGY Page 116