Bolster-less slider bogie suspension

Abstract

A bolster-less slider bogie suspension (200) in accordance with the disclosed invention comprises of a set of leaf springs (5), a trunnion (10), torque rod (15), axle top mounting brackets (20), stabilizer bar and shackle (25), slip guide mounts (30), linking brackets (35), rebound straps (40), U-Bolts (45) and a stabilizer bar and shackle linkage (50). The disclosed invention improves driver comfort, thereby improving their productivity, does not use bolsters and therefore has a longer issue free usage life and does not use leaf springs that have been provided with Z-bend, thereby reducing the probability of damage to the lower leaf's of the set of leaf springs (5) provided in a leaf spring suspension system.

Description

TITLE OF THE INVENTION“BOLSTER-LESS SLIDER BOGIE SUSPENSION”Field of Invention

[0001] The invention relates to leaf spring suspension used in heavy commercial vehicles. It more particularly relates to mounting arrangement provided for linking the leaf spring to the axle top mounting bracket.Background of the Invention

[0002] The conventional leaf spring suspension for heavy vehicles are facing frequent wear issues in bolsters provided for linking the ends of the leaf springs with the axle top mounting bracket. These rubber bolsters which are currently in use have a limited average life of 2000 hrs. In addition to that, bolster jamming is another phenomenon that leads to failures of rubber bolsters and A-frame bushes in existing leaf spring suspension.

[0003] As the replacement for this component has to allow for sideward articulation of the ends of the leaf spring and also be durable enough to last the entire usage life of the vehicle, the options available for replacing this part have to meet a very stringent reliability and durability requirement. In currently existing options for making a Bolster-less Bogie, bolster feature is removed and wear pads are introduced in its place. In such leaf spring suspensions, the ends of the bogie spring slides over the hardened wear pad which are mounted on the rear axle top mounting brackets. But this option faces another unique problem in that it has a Z-bend along the ends of the leaf spring sliding on the slides. These Z-bends in springs introduce operational stresses that negatively affect the leaf springs life, and leads to leaf spring breakage before the end of rated life of the heavy commercial vehicle in extreme conditions. Therefore, it is the objective of the disclosed invention toprovide a leaf spring suspension for heavy commercial vehicles that does not uses bolsters.

[0004] It is another objective of the present invention to provide a leaf spring suspension that does not include leaf spring with Z-bend in the leaf spring sliding over the component linking said leaf spring suspension to the axle top mounting bracket.

[0005] It is still another objective of the present invention to provide bolster less leaf spring suspension for heavy commercial vehicles that is durable and reliable and that can last the entire rated life of the heavy commercial vehicle.Summary of the Invention

[0006] The bolster-less slider bogie suspension in accordance with the disclosed invention, achieving the stated objectives comprises of, a set of leaf springs, a trunnion, torque rods, axle top mounting brackets, stabilizer bar and shackle, slip guide mounts, linking brackets, rebound straps, U-Bolts, and a stabilizer bar and shackle linkage. The lowest of said set of leaf springs is supported on top the trunnion, the U-Bolts mounted along the centre of the set of leaf springs, connect and hold said set of leaf spring on the top of said trunnion. The linking brackets are located on the set of leaf springs at a position between the U-Bolts and the ends of largest leaf springs forming a part of set of leaf springs. The ends of the largest leaf springs of the set of leaf springs are supported along its lower surface and contained on its sides by said slip guide mounts. The slip guide mounts are positioned above and connected to the top of the axle top mounting brackets. The lower end of the axle top mounting bracket receives one end of the torque rods, the other end of the torque rods are received at a receiving location provided on the lower end of the trunnion. The stabilizer bar and shackle linkage comprises of an attachment plate, stabilizer bar and shackle and supporting brackets. The stabilizer bar and shackle linkage is connected to rearmost slip guide mounts and axle top mounting bracket through said attachment plate positioned between said slip guide mounts and axletop mounting bracket. A stabilizer bar shackle is rotatably linked to one end of said attachment plate. The stabilizer bar shackle, at its other end, is also rotatably linked to one end of the stabilizer bar. The stabilizer bar is supported in an opening given in supported the supporting brackets attached to the chassis of the heavy commercial vehicle. This construction is mirrored on the right side of the vehicle as well, with the stabilizer bar being linked to its counterpart stabilizer bar shackle on the other bolster-less slider bogie suspension provided on the right side of the vehicle.Brief Description of Drawings

[0007] The present invention is illustrated in the accompanying drawings that contain references numerals for indicating its various parts. The description of the present invention would therefore be better understood with reference to accompanying diagrams, wherein

[0008] Figure 1 disclose the assembly of the preferred embodiment of the present invention in its fully assembled condition.

[0009] Figure 2 disclose the side view of the slip guide mount as per the preferred embodiment of the present invention as disclosed in Figure 1.

[0010] Figure 3 discloses an isometric view of the slip guide mount as shown in Figure 2.

[0011] Figure 4 discloses a cut section view of a leaf spring suspension as provided with the slip guide mount in accordance with the preferred embodiment of the disclosed invention.

[0012] Figure 5 a leaf spring suspension as provided with the slip guide mount in accordance with the preferred embodiment of the disclosed invention.

[0013] Figure 6 discloses an RLDA graph showing the performance of leaf spring suspension with the slip guide mount in the heavy vehicle’s laden condition.

[0014] Figure 7 discloses an RLDA graph showing the performance of leaf spring suspension with the slip guide mount in the heavy vehicle’s unladen condition.Detailed Description of the Invention

[0015] Referring to the set of figures 1, a bolster-less slider bogie suspension (200) in accordance with the disclosed invention comprises of a set of leaf springs (5), a trunnion (10), torque rod (15), axle top mounting brackets (20), stabilizer bar and shackle (25), slip guide mounts (30), linking brackets (35), rebound straps (40), U- Bolts (45) and a stabilizer bar and shackle linkage (50).

[0016] The lowest of said set of leaf springs (5) is supported on top the trunnion (10). The U-Bolts (45) mounted along the centre of the set of leaf springs (5), connect and hold said set of leaf spring (5) on the top of said trunnion (10). The linking brackets (35) are located on the set of leaf springs (5) at a position between the U-Bolts (45) and the ends of largest leaf springs forming a part of set of leaf springs (5).

[0017] The ends of the largest leaf springs of the set of leaf springs (5) are supported along its lower surface and contained on its sides by said slip guide mounts (30). The slip guide mounts (30) are positioned above and connected to the top of the axle top mounting brackets (20). The lower end of the axle top mounting bracket (20) receives one end of the torque rod (15). The other end of the torque rod (15) are received at a receiving location provided on the lower end of the trunnion (10).

[0018] The stabilizer bar and shackle linkage (50) (refer fig. 5) is comprised of an attachment plate (23), stabilizer bar and shackle (25) and supporting brackets (27). The stabilizer bar and shackle linkage (50) is connected to rearmost slip guide mounts (30) and axle top mounting bracket (20) through said attachment plate (23) positioned between said slip guide mounts (30) and axle top mounting bracket (20).A stabilizer bar shackle (25 S) is rotatably linked to one end of said attachment plate (23). The stabilizer bar shackle (25S), at its other end, is also rotatably linked to one end of the stabilizer bar (25L). The stabilizer bar (25L) is supported in an opening given in supported the supporting brackets (27) attached to the chassis of the heavy commercial vehicle. The construction is mirrored on the right side of the vehicle as well, with the stabilizer bar (25L) being linked to its counterpart stabilizer bar shackle (25 S) on the other bolster-less slider bogie suspension provided on the right side of the vehicle.

[0019] The slip guide mounts (30) (refer fig. 3), has two top ribs (30TR) and a sliding plane (30SP) located between said two top ribs (30TR). A side rib (30SR) provided on the side of the slip guide mounts (30) is aligned with the centre of the sliding plane (30SP). Two side attachment points (30APS) are located on the either side of the side rib (30SR) on the side surface of the slip guide mount (30). The base of the slip guide mounts (30) is formed by a flat plate like portion (30LS). A projecting portion of the flat plate like portion (30LS) receives the side rib (30SR) on its centre. Attachment points (30APL) are provided on both sides of the side rib (30SR) on the flat plate like portion (30LS). The ends of the lowest of the set of leaf springs (5) received in the sliding plane (30SP) are free to slide on it, while the two top ribs 30(TR) prevent any unwanted sideward movements.

[0020] Along with the lateral stability being provided with the help of side ribs (30SR) over the slip guide mounts (30), bolster-less slider bogie suspension (200) is also prone to vertical movement that can lead to detachment of Bogie from the axle. In order to check the concerned vertical motion of the set of leaf spring (5), rebound strap (40) is introduced in the proposed bolster less slider bogie suspension (200).

[0021] The two ends of the rebound strap (40) are attached to the side attachment points (30APS) with conventional fasteners. The conventional fasteners, so utilised, include any fastener items such as nuts, bolts, rivets etc that are manufactured inaccordance with established national or international industry standards. The side attachment points (30APS) are provided on only one side of the slip guide mounts (30). The attachment points (30APL) are provided on both projecting sides of the flat plate like portion (30LS). The side rib (30SR) is provided on both sides of the slip guide mount (30).

[0022] Referring to Fig. 5, it can be seen that the no. of joints is reduced in the bolster-less slider bogie suspension (200) and Z-bend is not required in the bogie spring (lowest of the leaf springs of the set of leaf springs (5)).

[0023] Figs. 6 and 7 shows the RLDA analysis report of 8035T with bolster-less slider bogie suspension (200) in laden and unladen condition respectively. In unladen working condition, comfort level in existing and proposed bogie suspension is observed as same while in case of laden working condition, better ride comfort is observed for bolster-less bogie suspension. The lines for slider boogie OL mines is lower than lines representing performance of in typical conditions for a conventional leaf springs suspension system provided with bolsters. The line for slider boogie UL mine remains lower than lines representing acceptable exposure limit for far longer than that of the conventional leaf spring suspension system provided with bolster. This gives clear indication of improvement in performance bought out by the use of bolster-less bogie suspension (200). In other words, in unladen working condition (refer to fig. 6), the RMS line for bolster-less bogie suspension (200) is seemingly lower than then existing bogie suspension. RMS line in RLDA diagrams represents the amplitude of vibrations at different frequency which effect the ride comfort. The lower the RMS values, the better the comfort. In overload condition (refer to fig. 7), RMS values are closer, which concludes approximately the same ride comfort for both the existing and proposed bogie suspensions.

[0024] Unlike Bogie Suspension with bolster, bolster less slider bogie suspension (200) provided with slip guide mounts (30) provide additional advantage of variation in stiffness. Due to sliding behaviour, with increase in loading conditions,span for bogie suspension changes that further leads to increase in stiffness. This becomes possible as the lowest leafs of the set of leaf springs (5) that are received within the slip guide mounts (30) can be provided with different curvature than the other leaf springs.

[0025] When the vehicle passes over the road surface irregularity, the wheels supported on the axles received within the axle top mounting brackets (20) push the ends of the set of leaf springs (5) received on the slip guide mounts (30) upwards. This causes deflection of first the lowest of the leafs that are received in the slip guide mounts (30), and then other leafs of the set of leaf springs (5) if the load is higher or the road surface irregularity is very big. This gives the suspension its variable stiffnesss characteristic. The slip guide mounts (30) enable provision of this by virtue of their shape. The stabilizer bar and shackle linkage (50) prevents extreme variation in response between the bolster-less slider bogie suspension provided on either side of the vehicle by linking there movements through the stabilizer bar and shackle (25). When the vehicle has passed over the road surface irregularity and returned to a level plain. The set of leaf springs (5) are decompressed in the reverse order of which in they were compressed in the first instance.

[0026] The bolster-less slider bogie suspension (200) having the disclosed construction achieves all the stated objectives.

[0027] Technical advantages offered by the invention i.e., the bolster-less slider bogie suspension (200) are-It improves driver comfort, thereby improving there productivity.It does not use bolsters and therefore has a longer issue free usage life.It does not use leaf springs that have been provided with Z-bend, thereby reducing the probability of damage to the lower leaf’s of the set of leaf springs provided in a leaf spring suspension system.It improves the durability and reliability of the leaf spring suspension system.It allows provision of variable stiffness feature in leaf spring suspension system, as lowest of the set of leaf springs received within the slip guide mount can be provided with different curvature than the rest of the leaf springs.

[0028] It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the present invention has been herein described in terms of its preferred embodiment, those skilled in the art will recognize that the preferred embodiment herein disclosed, can be practiced with modifications within the scope of the invention herein described.

Claims

CLAIMS:We Claim,1. A bolster-less slider bogie suspension (200) in accordance with the disclosed invention comprises of,• a set of leaf springs (5),• a trunnion (10),• torque rod (15),• axle top mounting brackets (20),• stabilizer bar and shackle (25), slip guide mounts (30),• linking brackets (35),• rebound straps (40),• U-Bolts (45), and• a stabilizer bar and shackle linkage (50); wherein,- the lowest of said set of leaf springs (5) is supported on top the trunnion (10), the U-Bolts (45) mounted along the centre of the set of leaf springs (5), connect and hold said set of leaf spring (5) on the top of said trunnion (10);- the linking brackets (35) are located on the set of leaf springs (5) at a position between the U-Bolts (45) and the ends of largest leaf springs forming a part of set of leaf springs (5);- the ends of the largest leaf springs of the set of leaf springs (5) are supported along its lower surface and contained on its sides by said slip guide mounts- the slip guide mounts (30) are positioned above and connected to the top of the axle top mounting brackets (20);- the lower end of the axle top mounting bracket (20) receives one end of the torque rod (15), the other end of the torque rod (15) are received at a receiving location provided on the lower end of the trunnion (10);- the stabilizer bar and shackle linkage (50) comprises of an attachment plate (23), stabilizer bar and shackle (25) and supporting brackets (27), the stabilizer bar and shackle linkage (50) is connected to rearmost slip guide mounts (30) and axle top mounting bracket (20) through said attachment plate (23) positioned between said slip guide mounts (30) and axle top mounting bracket (20); and- the two ends of the rebound strap (40) are attached to side attachment points (30APS) of slip guide mounts (30) with conventional fasteners.

2. The bolster-less slider bogie suspension (200) as claimed in claim 2, wherein, a stabilizer bar shackle (25 S) is rotatably linked to one end of said attachment plate (23), the stabilizer bar shackle (25 S), at its other end, is also rotatably linked to one end of the stabilizer bar (25L);- the stabilizer bar (25L) is supported in an opening given in supported the supporting brackets (27) attached to the chassis of the heavy commercial vehicle; and this construction is mirrored on the right side of the vehicle as well, with the stabilizer bar (25L) being linked to its counterpart stabilizer bar shackle(25 S) on the other bolster-less slider bogie suspension provided on the right side of the vehicle.

3. The bolster-less slider bogie suspension (200) as claimed in claim 2, wherein,- the slip guide mounts (30), has two top ribs (30TR) and a sliding plane (30SP) located between said two top ribs (30TR), a side rib (30SR) provided on the side of the slip guide mounts (30) is aligned with the centre of the sliding plane (30SP), two side attachment points (30APS) are located on the either side of the side rib (30SR) on the side surface of the slip guide mount (30), the base of the slip guide mounts (30) is formed by a flat plate like portion (30LS); and a proj ecting portion of the flat plate like portion (30LS) receives the side rib (30SR) on its centre, attachment points (30APL) are provided on both sides of the side rib (30SR) on the flat plate like portion (30LS), the ends of the lowest of the set of leaf springs (5) received in the sliding plane (30SP) are free to slide on it, while the two top ribs 30(TR) prevent any unwanted sideward movements.

4. The bolster-less slider bogie suspension (200) as claimed in claim 3, wherein, the side attachment points (30APS) are provided on only one side of the slip guide mounts (30), the attachment points (30APL) are provided on both projecting sides of the flat plate like portion (30LS), the side rib (30SR) is provided on both sides of the slip guide mount (30).Dated: 23 November 2024

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