Claims:We Claim:
1. A trailing arm lift axle assembly of a vehicle suspension unit, comprising:
an axle tube (101);
wherein the axle tube (101) including a first portion (101a), a middle portion (101b) and a second portion (101c);
characterized in that
a first axle seat (102) mounted on the first portion (101a) and a second axle seat (103) mounted on the second portion (101b) for housing the axle tube (101); and
the first axle seat (102) welded to the first portion (101a) and the second axle seat (103) welded to the second portion (101b) for securing the axle tube (101).
2. The trailing arm lift axle assembly as claimed in claim 1, wherein the first axle seat (102) and the second axle seat (103) including:
an axle side end (201a) and a spindle side end (201b);
an axle side extension (202a) and a spindle side extension (202b) provided for welding with the axle tube (101);
a first groove (204a) provided between the axle side extension (204a) and the spindle side extension (201b) for allowing a first end of a fastening element;
an axle side straight portion (203a) and a spindle side protruding portion (203b) provided for welding with the axle tube (101); and
a second groove (204b) provided between the axle side straight portion (202a) and the spindle side protruding portion (202b) for allowing a second end of the fastening element.
3. The trailing arm lift axle assembly as claimed in claim 2, wherein the fastening element including a U-bolt for securing the axle tube (101) with the first axle seat (102) and the second axle seat (103).
4. The trailing arm lift axle assembly as claimed in claim 1, wherein a projection (205) provided on the axle side extension (202a), the spindle side extension (202b) for contacting the axle tube at a first side;
a projection provided on the axle side straight portion (203a) and the spindle side protruding portion (203b) for contacting the axle tube (101) at a second side; and
a projection (206a) provided on a base surface (206) of the axle tube (101) for contacting the axle tube at a third side thereby securing three point contact of the first axle seat (102) and the second axle seat (103) with the axle tube (101).
5. The trailing arm lift axle assembly as claimed in claim 2, wherein the spindle side protruding portion (202b) extending from a spindle side lower edge (207) towards the spindle side end (201b) for welding and securing with the axle tube (101).
6. The trailing arm lift axle assembly as claimed in claim 2, wherein an upper edge of the axle side extension (202a), the spindle side extension (202b), an axle side straight portion (203a) and the spindle side protruding portion (203b) welded to the axle tube (101) by means of axle seat weld (301).
7. The trailing arm lift axle assembly as claimed in claim 6, wherein the axle seat weld (301) is a two pass weld; and
a size of a fillet of the axle seat weld (301) in a range of 10mm to 14mm.
8. The trailing arm lift axle assembly as claimed in claim 6, wherein the axle seat weld (301) is formed on a neutral axis (303) of the axle tube (101) thereby reducing tensile bending stress on the axle tube.
9. The trailing arm lift axle assembly as claimed in claim 1, wherein the axle tube (101) is deep drawn including a deep drawn depth (501) and the deep drawn depth (501) in a range of 100mm to 270 mm.
10. The trailing arm lift axle assembly as claimed in claim 1, wherein a length of the first axle seat (102) and the second axle seat (103) in a range of 200mm to 230mm.
11. The trailing arm 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.
, Description:A TRAILING ARM LIFT AXLE ASSEMBLY OF A VEHICLE SUSPENSION UNIT
FIELD
[0001] The embodiments herein generally relate to a trailing arm lift axle assembly. More particularly, the disclosure relates to a trailing arm lift 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 trailing arm axle assembly are susceptible to tensile bending stress and consequent failure.
[0004] Therefore, there is a need for an improved trailing arm lift axle assembly in a suspension unit of a vehicle for eliminating the tensile bending stress. Moreover, there is a need for a trailing arm lift 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 trailing arm lift axle assembly of a vehicle suspension unit.
[0007] Another objective of the present disclosure is to provide a trailing arm lift axle assembly in an air suspension of an automobile with higher strength.
[0008] Still another objective of the present disclosure is to provide a trailing arm lift axle assembly of a vehicle suspension unit for reducing tensile bending stress.
[0009] Yet another objective of the present disclosure is to provide a trailing arm lift 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 trailing arm lift axle assembly of a vehicle suspension unit.
[00012] In accordance with an embodiment, the trailing arm lift axle assembly comprises an axle tube wherein the axle tube includes a first portion, a middle portion and a second portion. A first axle seat is mounted on the first portion and a second axle seat is mounted on the second portion for housing the axle tube. The first axle seat is welded to the first portion and the second axle seat is welded to the second portion for securing the axle tube.
[00013] In accordance with an embodiment, the first axle seat and the second axle seat include an axle side end and a spindle side end. An axle side extension and a spindle side extension are provided for welding with the axle tube and a first groove is provided between the axle side extension and the spindle side extension for allowing a first end of a fastening element. An axle side straight portion and a spindle side protruding portion are provided for welding with the axle tube and a second groove is provided between the axle side straight portion and the spindle side protruding portion for allowing a second end of the fastening element. In an embodiment, the fastening element including a U-bolt for securing the axle tube with the first axle seat and the second axle seat.
[00014] In accordance with an embodiment, a projection is provided on the axle side extension, the spindle side extension for contacting the axle tube at a first side, projection is provided on the axle side straight portion and the spindle side protruding portion for contacting the axle tube at a second side and a projection is provided on a base surface of the axle tube for contacting the axle tube at a third side thereby securing three point contact of the first axle seat and the second axle seat with the axle tube. In an embodiment, the spindle side protruding portion extends from a spindle side lower edge towards the spindle side end for welding and securing the axle tube.
[00015] In accordance with an embodiment, an upper edge of the axle side extension, the spindle side extension, an axle side straight portion and the spindle side protruding portion are welded to the axle tube by means of axle seat weld.
[00016] In accordance with an embodiment, the axle seat weld is a two pass weld and a size of a fillet of the axle seat weld in a range of 10mm to 14mm. In an embodiment, the axle seat weld is formed on a neutral axis of the axle tube thereby reducing tensile bending stress on the axle tube.
[00017] In accordance with an embodiment, the axle tube is deep drawn including a deep drawn depth, wherein the deep drawn depth in a range of 100mm to 270 mm.
[00018] In accordance with an embodiment, a length of the first axle seat and the second axle seat in a range of 200mm to 230mm. 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.
[00019] 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
[00020] 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.
[00021] Fig.1 illustrates a schematic of a perspective view of a trailing arm lift axle assembly in a suspension unit, according to an embodiment herein;
[00022] Fig. 2 illustrates a schematic of the first axle seat and the second axle seat of the trailing arm lift axle assembly in suspension unit, according to an embodiment herein;
[00023] Fig. 3 illustrates a schematic of a side view of the axle tube with the first axle seat or the second axle seat, according to an embodiment herein;
[00024] Fig.4 illustrates a schematic of front side sectional view of the trailing arm lift axle assembly in a suspension unit, according to an embodiment herein; and
[00025] Fig. 5 illustrates a schematic of a front side sectional view of the axle tube of the lift axle assembly, according to an embodiment herein.

LIST OF NUMERALS
101 - Axle tube
101a - First portion
101b - Middle portion
101c - Second portion
102 - First axle seat
103 - Second axle seat
201a - Axle side end
201b - Spindle side end
202a - Axle side extension
202b - Spindle side extension
203a - Axle side straight portion
203b - Spindle side protruding portion
204a - First groove
204b - Second groove
205 - Projections
206 - Base surface
206a - Projection
207 - Spindle side lower edge
301 - Axle seat weld
302a - First side
302b - Second side
302c - Third side
303 - Neutral axis
501 - Deep drawn depth

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[00026] 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.
[00027] As mentioned above, there is a need for an improved trailing arm lift axle assembly in a suspension unit of a vehicle for eliminating the tensile bending stress. In particular, there is a need for a trailing arm lift axle assembly of an automobile for improving strength and fatigue life of the suspension unit. The embodiments herein achieve this by providing “A trailing arm 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.
[00028] Fig.1 illustrates a schematic of a perspective view of a trailing arm 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 first axle seat 102 and a second axle seat 103.
[00029] In an embodiment, the axle tube 101 includes a first portion 101a, a middle portion 101b and a second portion 101c. The first axle seat 102 is fixed to the first portion 101a of the axle tube and the second axle seat 103 is fixed to the second portion 101c of the axle tube.
[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 first axle seat and the second axle seat of the trailing arm lift axle assembly in suspension unit.
[00032] In an embodiment, the first axle seat (102) and the second axle seat 103 include an axle side end 201a and a spindle side end 201b. The first axle seat (102) and the second axle seat 103 are provided for housing the axle tube 101.
[00033] In an embodiment, the first axle seat (102) and the second axle seat 103 include a base surface 206. At one side of the first axle seat 102 and the second axle seat 103, an axle side extension 202a and a spindle side extension 202b extend from the base surface 206. At another side of the first axle seat 102 and the second axle seat 103, an axle side straight portion 203a and a spindle side protruding portion 203b extend from the base surface 206.
[00034] The axle side extension 202a, spindle side extension 202b, axle side straight portion 203a and spindle side protruding portion 203b are provided for enclosing the axle tube 101.
[00035] In an embodiment, a first groove 204a formed between the axle side extension 202a and the spindle side extension 202b for allowing a first end of a fastening element. A second groove 204b formed between the axle side straight portion 203a and the spindle side protruding portion 203b for allowing a second end of the fastening element. The fastening element is provided for securing the axle tube with the first axle seat 102 and the second axle seat 103. In an embodiment, the fastening element including but not limited to U-bolt.
[00036] In an embodiment, a projection 205 is provided on the axle side extension 202a, spindle side extension 202b, axle side straight portion 203a and spindle side protruding portion 203b , wherein the projection projecting outwards towards a surface of the axle tube. A projection 206a provided on the base surface 206 and the projection extending upwards towards a surface of the axle tube. The plurality of projection (205) and the projection (206) are provided for securing the axle tube 101.
[00037] In an embodiment, the axle side straight portion 203a extending from a spindle side lower edge 207 towards the spindle side end 201b for improved welding.
[00038] Fig. 3 illustrates a schematic of a side view of the axle tube with the first axle seat or the second axle seat.
[00039] In an embodiment, an upper edge of the axle side extension 202a, spindle side extension 202b, axle side straight portion 203a and spindle side protruding portion 203b are welded to the axle tube by means of an axle seat weld 301.
[00040] In an embodiment, the axle seat weld 301 is formed on a neutral axis 303 of the axle tube 101 for eliminating tensile bending stress on the axle tube 101.
[00041] In an embodiment, the projection (205) provided on the axle side extension (202a), the spindle side extension (202b) contacting the axle tube at a first side (302a), the projection provided on the axle side straight portion (203a) and the spindle side protruding portion (203b) contacting the axle tube (101) at a second side (302b) and the projection (206a) provided on the base surface (206) of the axle tube (101) contacting the axle tube at a third side (302c). The contact of the axle seat 102, 103 at the first side 302a, the second side 302b and the third side 302c provided three point contact of the first axle seat (102) and the second axle seat (103) with the axle tube (101), thereby firmly securing the axle tube 101 and reducing stress induced in the axle seat weld (301).
[00042] Fig.4 illustrates a schematic of front side sectional view of the trailing arm lift axle assembly in a suspension unit. In an embodiment, the axle seat weld 301 is a two pass weld and a size of a fillet of the axle seat weld (301) in a range of 10mm to 14mm. In a preferred embodiment, size of a fillet of the axle seat weld 301 is 12 mm.
[00043] In an embodiment, the axle side straight portion 203a extends from a spindle side lower edge 207 towards the spindle side end 201b for improved welding.
[00044] In an embodiment, a length of the first axle seat (102) and the second axle seat (103) in a range of 200mm to 230mm, preferably in a range of 210mm to 220mm.
[00045] Fig. 5 illustrates a schematic of a front side sectional view of the axle tube of the lift axle assembly. The axle tube 101 is deep drawn including a deep drawn depth (501). In an embodiment, the deep drawn depth (501) in a range of 100mm to 270 mm. The deep drawn depth increases clearance between propeller shaft and the axle tube, thereby increasing height of bump on which the axle tube can ride safely and lift stroke (height up to which the axle tube can be lifted by an air spring during unloaded condition).
[00046] A main advantage of the present disclosure is that the trailing arm lift axle assembly reduces tensile bending stress on the axle tube.
[00047] Another advantage of the present disclosure is that the trailing arm lift axle assembly improves strength and fatigue life of the suspension unit.
[00048] Still another advantage of the present disclosure is that the trailing arm lift axle assembly eliminates welding at a bottom portion of the axle tube.
[00049] Yet another advantage of the present disclosure is that the trailing arm lift axle assembly considerably reduces failure of the axle tube in a suspension unit.
[00050] Still another advantage of the present disclosure is that the lift axle assembly is economical.
[00051] Yet another advantage of the present disclosure is that the trailing arm lift axle assembly increases clearance between propeller shaft and the axle tube thereby increasing the height of bump the axle can ride safely and increases the lift stroke, that is, the height up to which the axle can be lifted by an air spring during unloaded condition.
[00052] 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.