We Claim:
1. A bogie suspension system (100) assembled into a chassis frame (101) of a
vehicle, having tandem axles (109), spring packs (103), V-reaction rods (106),
straight reaction rods (107) and lateral inter-connecting rods (108), characterized
by comprising:
a trunnion pin cross member (20) formed of an integrated hollow tubular pivot pin-cum frame cross member interconnected between frame side members (102) of the vehicle frame;
a plurality of side support brackets (30) spaced apart each other for mounting the V-reaction rods, the straight reaction rods and the lateral inter¬connecting rod being connected to the vehicle axles;
a plurality of thrust plates (40) encapsulating the ends of the trunnion pin cross member and securely attached to outer side of the frame side members;
a plurality of support plates (50) attached to outer side of the frame side members to arrest and hold the side support brackets with the frame and
a plurality of trunnion housings (60) placed adjacent to the thrust plates and mounted on an upper centre part of the spring packs assembled on the axles or seated on the wear pads of cobra brackets fitted on the axles.
wherein both ends of the trunnion pin cross member are securely assembled to pierce across the frame side members through the side support brackets in such a way that the side support brackets affixed from the inner side of the frame side members are reinforced by both the support plates and the thrust plates attached at the outer side of the frame side members, and then the trunnion housings are pivoting on both ends of the trunnion pin cross member.
2. The bogie suspension system as claimed in claim 1, wherein each side
support bracket (30) is composed of a tubular passage (32) at its upper region to
surround and pass through the trunnion pin cross member (20) within it.

3. The bogie suspension system as claimed in claim 1, wherein each side support bracket (30) is arranged with a cast support (34) for mounting of the free end of the V-reaction rods, where the cast support is extended downwards to support one end of the straight reaction rod while the other ends of both the reaction rods connecting the vehicle axles.
4. The bogie suspension system as claimed in claim 3, wherein the extending downward cast support (34) is formed with a plurality of first, second and third anchoring regions (34a, 34b, 34c) that are respectively placed and positioned for mounting the V-reaction rods, the straight reaction rods and the lateral inter-connecting rod.
5. The bogie suspension system as claimed in claims 3 and 4, wherein the bottom ends of the extended downward cast supports (34) are joined by the lateral inter connecting rod having anchoring provision for bottom radius rod connection.
6. The bogie suspension system as claimed in claim 1, wherein each side support bracket (30) is formed with a bracket plate (36) through which the side support brackets are fastened onto the inner side surface of the frame side members.
7. The bogie suspension system as claimed in claims 3 and 6, wherein the bracket plates (36) are casted with the cast supports (34) for mounting the side support brackets to the inner side of the frame side members.
8. The bogie suspension system as claimed in any of the preceding claims, wherein the bracket plates (36) along with the extending downward cast supports (34) from the inner side of the frame side members (30) are aligned and reinforced by the support plates (50) and the thrust plates (40) being connected and attached on the outer side of the frame side members.

9. The bogie suspension system as claimed in any of the preceding claims, wherein the tubular trunnion pin cross member (20) is formed of a fixed outer diameter with varying thicknesses for different load carrying capacities of the bogie suspension system.
10. The bogie suspension system as claimed in any of the preceding claims, wherein the tubular trunnion pin cross member (20) is formed and press-fitted with a tube-in-tube structure at its ends for higher and varying load carrying capacity of the bogie suspension system.