Claims:We Claim:
1. A lift axle assembly of a vehicle suspension unit, comprising:
an axle tube (101);
wherein the axle tube (101) including a left portion (101a), a middle portion (101c) and a right portion (101b);
characterized in that
a bottom cup (201) welded to the axle tube (101) at the left portion (101a) and the right portion (101b), wherein the bottom cup (201) housing the axle tube (101).
2. The lift axle assembly as claimed in claim 1, wherein a first edge (402a) and a second edge (402b) of the bottom cup (201) welded to the axle tube (101) through a bottom cup weld (401) on the axle tube (101).
3. The lift axle assembly as claimed in claim 2, wherein the bottom cup weld (401) formed on the axle tube (101) at the neutral axis of the axle tube (101), thereby eliminating tensile bending stress on the axle tube (101).
4. The lift axle assembly as claimed in claim 1, wherein a bottom plate (203) welded to an outer surface (201b) of the bottom cup (201) for supporting the bottom cup (201).
5. The lift axle assembly as claimed in claim 1, wherein the bottom cup (201) including a bend (204) forming a bent portion (204a) and a straight portion (204b) for housing a curve in the axle tube (101).
6. The lift axle assembly as claimed in claim 4 and 5, wherein the bottom plate (203) including a cut region (303) for accommodating the bend (204) of the bottom cup (201).
7. The lift axle assembly as claimed in claim 5, wherein a length of the bottom cup (201) in a range of 200mm to 210mm and an arc length of the bend (204) in a range of 1mm to 50 mm.
8. The lift axle assembly as claimed in claim 1, wherein a diameter of the axle tube (101) in a range of 120mm to 160mm and a thickness of the axle tube (101) in a range of 20mm to 25mm.
9. The lift axle assembly as claimed in claim 4, wherein a width (302) of the bottom plate (203) in a range of 140 mm to 150 mm.
10. The lift axle assembly as claimed in claim 2, wherein the bottom cup weld (401) is a fillet weld formed using a 3 pass weld; and
a size of the fillet in a range of 8mm to 12mm.
, Description:A LIFT AXLE ASSEMBLY OF A VEHICLE SUSPENSION UNIT
FIELD
[0001] The embodiments herein generally relate to an axle assembly. More particularly, the disclosure relates to an axle assembly in an air suspension system of an automobile.
BACKGROUND AND PRIOR ART
[0002] A suspension system is provided in automobiles for improving ride handling and imparting comfort. The suspension system helps in maintaining contact between tires of a vehicle and the road surface and evenly balancing weight of the vehicle. Improper and uneven road conditions generate forces on the vehicle, and the effect of these forces are dampened and absorbed by components of the suspension system.
[0003] Generally, heavy commercial vehicles such as Buses, trucks, trailers use an air suspension system as it provides better support in variable road conditions. An axle assembly is an important component of the air suspension unit that is used for supporting the vehicle. The axle assembly endures loads due to many forces such as braking, driving, cornering and other factors. The design of an axle assembly is crucial for reducing stresses, imparting strength and thereby increasing the life of the suspension system. However, the existing designs of axle assembly are susceptible to tensile bending stress and consequent failure.
[0004] Therefore, there is a need for an improved axle assembly in a suspension unit of a vehicle for eliminating the tensile bending stress. Moreover, there is a need for an axle assembly of an automobile for improving strength and fatigue life of the suspension unit.
OBJECTS
[0005] Some of the objects of the present disclosure are described herein below:
[0006] The main objective of the present disclosure is to provide an improved axle assembly of a vehicle suspension unit.
[0007] Another objective of the present disclosure is to provide an axle assembly in an air suspension of an automobile with higher strength.
[0008] Still another objective of the present disclosure is to provide an axle assembly of a vehicle suspension unit for reducing tensile bending stress.
[0009] Yet another objective of the present disclosure is to provide an axle assembly of a vehicle suspension unit with increased strength and fatigue life.
[00010] The other objectives and advantages of the present disclosure will be apparent from the following description when read in conjunction with the accompanying drawings, which are incorporated for illustration of preferred embodiments of the present disclosure and are not intended to limit the scope thereof.
SUMMARY
[00011] In view of the foregoing, an embodiment herein provides a lift axle assembly of a vehicle suspension unit.
[00012] In accordance with an embodiment, the lift axle assembly comprises an axle tube, wherein the axle tube includes a left portion, a middle portion and a right portion. A bottom cup is welded to the axle tube at the left portion and the right portion, wherein the bottom cup houses the axle tube.
[00013] In accordance with an embodiment, a first edge and a second edge of the bottom cup is welded to the axle tube through a bottom cup weld at a neutral axis of the axis tube, thereby eliminating tensile bending stress on the axle tube. In an embodiment, the bottom cup weld is a fillet weld formed using a 3 pass weld and a size of the fillet in a range of 8mm to 12mm.
[00014] In accordance with an embodiment, a bottom plate is welded to an outer surface of the bottom cup between the first side rib and the second side rib for supporting the bottom cup and load mounted on the axle tube.
[00015] In accordance with an embodiment, the bottom cup includes a bend forming a bent portion and a straight portion for housing a curve in the axle tube. In an embodiment, the bottom plate includes a cut region for accommodating the bend of the bottom cup.
[00016] In accordance with an embodiment, a length of the bottom cup in a range of 200mm to 210mm and an arc length of the bend in a range of 1mm to 50 mm. In an embodiment, a diameter of the axle tube in a range of 120mm to 160mm and a thickness of the axle tube in a range of 20mm to 25mm. In an embodiment a width of the bottom plate is in a range of 140 mm to 150 mm.
[00017] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF DRAWINGS
[00018] The detailed description is set forth with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items.
[00019] Fig.1 illustrates a schematic of a perspective view of a lift axle assembly in a suspension unit, according to an embodiment herein;
[00020] Fig. 2 illustrates a schematic of the left mounting bracket assembly and the right mounting bracket assembly of the lift axle assembly in a suspension unit, according to an embodiment herein;
[00021] Fig. 3a illustrates a schematic of a right side view of the left mounting bracket assembly and the right mounting bracket assembly of the lift axle assembly in suspension unit, according to an embodiment herein;
[00022] Fig.3b illustrates a schematic of a bottom side section view of the left mounting bracket assembly and the right mounting bracket assembly of the lift axle assembly in a suspension unit, according to an embodiment herein;
[00023] Fig. 4 illustrates a schematic of a left side section view of the axle tube with the bottom cup, according to an embodiment herein; and
[00024] Fig. 5 illustrates a schematic of a front side sectional view of the lift axle assembly, according to an embodiment herein
LIST OF NUMERALS
101 - Axle tube
101a - Left portion
101b - Right portion
101c - Middle portion
102 - Left mounting bracket assembly
103 - Right mounting bracket assembly
104 - Air spring left mounting plate
105 - Air spring right mounting plate
201 - Bottom cup
201a - Inner surface
201b - Outer surface
201c - First end
201d - Second end
202a - First side rib
202b - Second side rib
203 - Bottom plate
204 - Bend region
204a - Bent portion
204b - Straight portion
301 - Side ribs weld
302 - Width of bottom plate
303 - Cut portion
304 - Bottom plate weld
401 - Weld
402a - First edge of the bottom cup
402b - Second edge of the bottom cup

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[00025] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[00026] As mentioned above, there is a need for an improved axle assembly in a suspension unit of a vehicle for eliminating the tensile bending stress. In particular, there is a need for an axle assembly of an automobile for improving strength and fatigue life of the suspension unit. The embodiments herein achieve this by providing “A lift axle assembly of a vehicle suspension unit”. Referring now to the drawings, and more particularly to Fig.1 through Fig.5, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.
[00027] Fig.1 illustrates a schematic of a perspective view of a lift axle assembly in a suspension unit. In an embodiment, the lift axle assembly 100 is provided in an air suspension unit and includes an axle tube 101, a left mounting bracket assembly 102 and a right mounting bracket assembly 103.
[00028] In an embodiment, the axle tube includes a left portion 101a, a right portion 101b and a middle portion 101c. The left mounting bracket assembly 102 is provided at the left portion 101a of the axle tube and the right mounting bracket assembly 103 is provided at the right portion 101b of the axle tube.
[00029] An air spring left mounting plate 104 is attached to the left mounting bracket assembly 102 and an air spring right mounting plate 105 is attached to the right mounting bracket assembly 103.
[00030] In an embodiment, a diameter of the axle tube is in a range of 120mm to 160mm, preferably 141.3 mm and a thickness of the axle tube in a range of 20mm to 25mm, preferably 23 mm.
[00031] Fig. 2 illustrates a schematic of the left mounting bracket assembly and the right mounting bracket assembly of the lift axle assembly in suspension unit.
[00032] In an embodiment, a bottom cup 201, and a bottom plate 203 are provided, wherein the left mounting bracket assembly 102 and the right mounting bracket assembly 103 are welded to the bottom cup 201.
[00033] The left mounting bracket assembly 102 and the right mounting bracket assembly 103 include a first side rib 202a, a second side rib 202b
[00034] In an embodiment, the bottom cup 201 is provided for housing the axle tube 101. The bottom cup 201 including an inner surface 201a and an outer surface 201b, a first end 201c and a second end 201d. A shape of the inner surface 201a is based on a shape of the axle tube for housing the axle tube 101. The axle tube 101 is mounted on the inner surface 201a of the bottom cup 201 and the axle tube 101 is welded to the inner surface 201a of the bottom cup 201.
[00035] In an embodiment, the first side rib 202a is attached to the bottom cup 201 towards the first end 201c side and the second side rib 202b is attached to the bottom cup 201 towards the second end 201d side. In an embodiment, the first side rib 202a and the second side rib 202b are welded to the outer surface 201b of the bottom cup 201.
[00036] In an embodiment, the bottom plate 203 is fixed to the outer surface 201a of the bottom cup 201 between the first side rib 202a and the second side rib 202b. The bottom plate 203 is provided for supporting load mounted on the axle tube 101. The bottom plate 203 is fixed to the outer surface 201b of the bottom cup 201 through welding.
[00037] In an embodiment, the bottom cup 201 includes a bend region 204 forming a bent portion 204a and a straight portion 204b. The bent portion 204a is inclined at an angle relative to the straight portion 204b for housing the axle tube 101 with the first portion 101a having a curve and the second portion 101b having a curve.
[00038] Fig. 3a illustrates a schematic of a right side view of the left mounting bracket assembly and the right mounting bracket assembly of the lift axle assembly in suspension unit. The first side rib 202a is welded to the bottom cup 201 by a side rib weld 301. In an embodiment, a length of the side rib weld 301 is in a range of 180 mm to 210 mm, preferably 190 mm to 200 mm.
[00039] Fig.3b illustrates a schematic of a bottom side section view of the left mounting bracket assembly and the right mounting bracket assembly of the lift axle assembly in a suspension unit. In an embodiment, the bottom cup 201 is fabricated with the bottom plate 203 by means of bottom plate weld 304. The bottom plate 301 includes a cut portion 303 for accommodating the bend region 204 of the bottom cup 201.
[00040] In an embodiment, a width 302 of the bottom plate is in a range of 120 mm to 170 mm, preferable 140mm to 150mm.
[00041] Fig. 4 illustrates a schematic of a left side section view of the axle tube with the bottom cup. The bottom cup 201 is fabricated with the axle tube by means of a bottom cup weld 401. The bottom cup welded 401 is welded between a first edge 402a of the bottom cup 201 and the axle tube 101 and a second edge 402a of the bottom cup 201 and the axle tube 101.
[00042] In an embodiment, the bottom cup weld 401 is not welded to the axle tube 101 at a region enclosed by an angle a for eliminating tensile bending stress on the axle tube 101. The angle a is angle of bottom arc radius of the axle tube. The bottom cup weld 401 is welded to the axle tube 101 at neutral axis of the axle tube, thereby eliminating bending stress in the bottom cup weld.
[00043] In an embodiment, the bottom cup weld 401 is a fillet weld in a range of 8mm to 12mm, preferably 10 mm. The bottom cup weld is created as 3 pass weld.
[00044] Fig. 5 illustrates a schematic of a front side sectional view of the lift axle assembly. A length of the bottom cup 201 is in a range of 180mm to 230 mm, preferably 200mm to 210 mm. An arc length of the bend 204 is in a range of 1mm to 50mm.
[00045] A main advantage of the present disclosure is that the lift axle assembly reduces tensile bending stress on the axle tube.
[00046] Another advantage of the present disclosure is that the lift axle assembly improves strength and fatigue life of the suspension unit.
[00047] Still another advantage of the present disclosure is that the lift axle assembly eliminates welding at a bottom portion of the axle tube.
[00048] Yet another advantage of the present disclosure is that the lift axle assembly considerably reduces failure of the axle tube in a suspension unit.
[00049] Still another advantage of the present disclosure is that the lift axle assembly is economical.
[00050] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. 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 embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.