GB2461117A

GB2461117A - A method of reinforcing an axle housing to enable a mounted axle to take larger loads

Info

Publication number: GB2461117A
Application number: GB0811466A
Authority: GB
Inventors: Kevin Andrew Mason
Original assignee: Kam Differentials Ltd
Current assignee: Kam Differentials Ltd
Priority date: 2008-06-23
Filing date: 2008-06-23
Publication date: 2009-12-30
Also published as: GB0811466D0

Abstract

The invention entails a method of strengthening a beam axle having a housing 101 by reinforcing the inside of the axle housing. Ideally, the axle housing has a central bulbous region 102 and two tubular regions 104. To strengthen the axle housing a reinforcing sleeve 108 is located within each tubular region 104, and reinforcing conical / funnel-shaped portions 105, 106, located within the axle bulb and preferably connected together. Spacer elements 109 provide a clearance between the reinforcement parts and the housing. The clearance space is then filled with a setting agent which bonds the housing to the reinforcements forming a stiffened axle housing, thereby enabling an axle mounted within to take larger loads. Ports 114, 115, 116 for injecting the bonding filler may be provided. The reinforcing sleeves may be made so as to be telescopic. The axle housing is envisaged mounted on a vehicle, and may contain its transmission differential gearing. The reinforcements may be retro-fitted.

Description

-Method of Strengthening a Beam Axle and a Beam Axle Strengthened by said Method This invention relates to a method of strengthening a beam axle and a beam axle strengthened by said method.

Beam axles are commonly found in off-road vehicles as well as in heavy-duty trucks and most light and medium duty pickup trucks. They have been used for many years and are generally quite suitable for their originally designed purpose.

Over the years it has become popular to use existing beam axles for vehicles with increased payloads and increasingly powerful engines. For example it is not uncommon for the beam axles of Land Rovers originally intended for use in a vehicle weighing 2.5 tonnes and utilising a 68 brake horsepower engine to be used in vehicles weighing up to 4.2 tonnes and having a 325 horsepower engine.

In order to strengthen the beam axle to accommodate such increased duty it has been usual to weld strengthening bars to the outside of the housing of the beam 1 5 axles along their length where possible. This raises a number of problems. In particular, it is first necessary to cut the strengthening bars to the desired shape. It is then necessary to dismantle the beam axle and hold its housing in a specially made jig whilst the strengthening bar is welded on to the housing to inhibit the housing distorting under the heat of the welding torch. Finally it is necessary to repaint the housing.

The cost of making a jig for each different type of housing is substantial.

Absent a custom made jig it is not unusual for a housing which has a strengthening bar welded to it to be anything from 1mm to 10mm out of axial alignment. This *.* causes excessive wear on differential bearings and other drive components as well as * ** affecting wheel alignment.

In addition, the strengthening bars cannot normally be fixed along the entire * .* length of the housing because of mounting members and other obstructions on the associated vehicle.

* *. The present invention is based on the inventor's observation that there is * * * usually significant free space between the housing of a beam axle and its internal * * * * components. --According to the present invention there is provided a method of strengthening a beam axle having a housing, which method is characterised by the step of reinforcing at least part of the inside of the housing.

Preferably, said housing has a bulbous portion between two tubular portions and said method includes the step of introducing a reinforcing tube into a tubular portion of said housing.

Advantageously, said reinforcing tube comprises two or more sections which when closed, can be inserted into said bulbous portion and which can be telescopically extended to extend along one of said tubular portions.

Preferably, said method includes the step of providing means to inhibit said sections being contracted after deployment to their fully extended position.

Advantageously, said means comprises a groove in said sections and an o-ring in said grooves.

1 5 Preferably, said method includes the step of centralizing said reinforcing tube within a tubular housing.

Advantageously, said step of centralising comprises securing a locating clamp to said housing, said housing having a mounting bracket with an opening to accommodate said reinforcing tube.

Preferably, said method includes the step of inserting one or more spacers between said housing and said reinforcing tube.

Advantageously, at least one of said spacers is castellated to allow the flow of a bonding agent therethrough.

* Preferably, said method includes the step of placing a funnel shaped * ** *..., 25 reinforcing member in said bulbous portion of said housing. ****

Advantageously, said method includes the step of screwing said reinforcing 0.

O.:.. tube into said funnel shaped reinforcing member.

If desired, said reinforcing tube is screwed into said funnel shaped reinforcing * ** member sufficient to pretention said tubular portion of said housing.

Preferably, said method includes the step of placing an inner reinforcing tube within said reinforcing tube.

Advantageously, said reinforcing tube is perforate.

Preferably, said method includes the step of providing a seal at one end of a void defined between said housing and said reinforcing tube.

Advantageously, said method includes the step of introducing a setting agent in said and allowing said setting agent to set.

Preferably, said setting agent is a bonding agent. However, it could also be a resin.

Advantageously, said bonding agent has, when set, a Shore A hardness of from50to90.

Preferably, said bonding agent, before setting, has a viscosity of between 1700 and 2000mPa at a temperature of 25 degrees centigrade.

Advantageously, said bonding agent has a lap shear adhesion of the order of 6.5MPa on a surface that has been sand grit media blasted with 220 grit.

The present invention also provides a beam axle when made by a method according to the present invention. * *S * * * * ** *

I *S*' I *. * I *

IIII

S *.I

I * *S S * * 111'

II I * * S * S.

For a better understanding of the present invention and to show how the same may be carried into effect reference will now be made, by way of example, to the accompanying drawings in which:-Fig. 1 is a simplified section through the housing of a beam axle which has been strengthened by a first method in accordance with the present invention; Fig. 2 is an end view of a funnel shaped reinforcing member shown in Fig. 1; Fig. 3 is a simplified section through the housing of a beam axle which has been strengthened by a second method according to the present invention; Fig. 4 is an end view, partly in section, of a locating clamp which is used in the embodiment shown in Fig. 3; Fig. 5 is an end view, partly in section, of the beam axle shown in Fig. 3; Fig. 6 is an end view, partly in section showing the housing of a beam axle which has been strengthened by a third method according to the present invention; and Fig. 7 is a simplified section through part of a reinforcing tube which can be used in the method of the invention.

Referring to Figure 1 of the drawings there is shown the housing 101 of a beam axle.

The housing 101 has a wall thickness of about 6mm and is made from two sections of pressed flat plate which have been welded together. It comprises a bulbous portion 102 which, in use, accommodates a differential and two tubular portions 103 and 104 which extend outwardly from either side of the bulbous portion 102 and, in use, accommodate respective half shafts.

*1*** The housing 101 shown in Figure 1 has been obtained by removing the * ** transmission components from a standard beam axle and thoroughly cleaning, * degreasing the sandblasting the inside of the housing 101.

: In order to strengthen the housing 101 two funnel shaped reinforcing members 105 and 106 are placed in the bulbous portion 102 of the housing 101 as * ** shown. The funnel shaped reinforcing members 105 and 106 conform to the internal * * * configuration of the bulbous portion 102 of the housing 101 but is spaced from the * * * ** inner si.irfÃ�ce of the housing 101 by about 3mm by a plurality of short spacer -members which are pressed out of the surface of the funnel shaped reinforcing member 105, 106. (An end view of the funnel shaped reinforcing member 105 is shown in Fig. 2). The funnel shaped members 105 and 106 are made of high tensile steel and have a wall thickness of typically 3 to 8mm.

Once the funnel shaped members 105 and 106 have been located a reinforcing tube 108 is introduced into the tubular portion 104 of the housing 101 as shown. The reinforcing tube 108 is made of high tensile steel and has a wall thickness of typically 3 to 8mm. It can conveniently be seamless straight bore tube or extruded or welded tube. The reinforcing tube 108 has an outer diameter which is approximately 2 mm smaller than the internal diameter of the tubular portion 104 of the housing 1. The reinforcing tube 108 is centred in the tubular portion 104 of the housing 101 by spacers 109 which conveniently comprise castellated 0-rings.

A similar reinforcing tube 110 (only the end of which is shown) is introduced into the tubular portion 3 of the housing 1 in a similar manner.

During assembly the reinforced tube 108 is screwed into funnel shaped reinforcing member 105 at threaded connection 111. Similarly, reinforcing tube 110 is screwed into the funnel shaped reinforcing member 106 at threaded connection 112.

Once the funnel shaped reinforcing members 105 and 106 and the reinforcing tubes 108 and 110 are in position a setting composition is introduced into the void between the housing 101 and the funnel shaped reinforcing members 105 and 106 and the reinforced tubing 108 and 110. The setting composition is then allowed to * ** set. * * * * **

Various methods can be used for introducing the setting composition into the 0. ss void. Furthermore, different types of setting composition can be used. These are t,:. discussed below.

Setting compositions: * 0* Various types of setting composition have been tried. At present it appears S * that the most appropriate setting agent will be a bonding agent which secures the funnel shaped reinforcing methbers 105 and 106 and the reinforcing tubes 108 and to the housing 101 but which have a degree of flexibility. If the bonding agent is too hard then cracking may occur and the strength of the lamination will decrease.

Our tests so far suggest that the bonding agent should have a Shore A hardness of between 50 and 90 when set. The bonding agent preferably has a viscosity of between 1700 and 2000m.Pas at 25 degrees centigrade. Lap shear adhesion should be of the order of 6.5MPa on a surface that has been sand grit media blasted with 220 grit. Ideally, the bonding agent will have setting time of around 20 minutes. At the present time we have found a bonding agent manufactured by Robnor Resins Limited of Swindon, England and supplied under the part number EL42OAR to give excellent results. This bonding agent (which the suppliers describe as a two component polyurethane system') has a high adhesion and compressive strength.

Method of Introducing_Setting Composition: The objective is to fill the void between the outer surface of the funnel shaped reinforcing members 105 and 106 and the reinforcing tubes 108 and 110 and the housing 101 completely ie: without any voids.

In the simplest method a bead 113 of silicon mastic (or 0-ring) is placed between the outermost extremity of the reinforcing tube 108 and the housing 101 to form a seal. The housing 101 is then arranged vertically with the seal at the bottom and the bonding agent is poured into the void between the reinforcing tube 108 and the housing 101 at the top of the housing 101.

The bonding agent flows down the void, through the gaps in the castellated spacers and, when set, forms a layer which is bonded to both the hosing 101 and the reinforcing tubes 108 and 110 and the funnel shaped reinforcing members 105 and * ** *... 25 106.

S S.-.

It will be appreciated that this method is only satisfactory when the setting *. compound has a low viscosity.

4. An improved method is to introduce the bonding agent through a nipple 114 * ** provided close to the bead 113. The bonding agent then rises upwardly in the space * S S 5S50.

* * 30 until it reaches the top of the housing 101. * . * *.

If the bonding agent is particularly viscous it may be desirable to have several -nipples, such as nipples 115 and 116 disposed along the length of the housing 101.

If desired the void could be separated into separate compartments by 0-ring seals. In such a case each compartment would be filled separately and would be provided with separate spaced apart nipples for introducing the setting compound into the compartment and for venting air and any vapour formed during the setting of the bonding agent therefrom.

Turning now to Fig. 3, there is shown a housing 201 which has a bulbous portion 202, a tubular portion 203 and a tubular portion 204.

In this embodiment the bulbous portion 202 does not contain funnel shaped reinforcing members similar to funnel shaped reinforcing members 205 and 206 described with reference to Fig. 1.

The tubular portion 204 is reinforce by two reinforcing tubes ie an outer reinforcing tube 208 and an inner reinforcing tube 215. In the embodiment shown the inner reinforcing tube 215 and the outer reinforcing tube 208 are each made of high tensile steel and have a thickness of 3mm. The distance between the outer surface of the inner reinforcing tube 215 and the inner surface of the outer reinforcing tube 208 is 2mm. Similarly, the distance between the outer surface of the outer reinforcing tube 208 and the inner surface of the housing 201 is also 2mm.

The outer extremity of the inner reinforcing tube 215 and outer reinforcing tube 215 are held in juxtaposition by 0-rings. However, the inner extremity of the outer reinforcing member 208 is held in position by a locating clamp which is generally identified by reference numeral 217.

The locating clamp 217 comprises a plate 218 which is bolted to a flange 219 * ..

*...* 25 which defines an opening 220 through which the transmission components of the differential can be inserted. The plate 218 reinforces the flange 219 and has two fingers which extend into the tubular portion 204 to which a mounting bracket 221 is * attached at any point therealong. The mounting bracket supports a plate 222 having * ,* an opening 223 to accommodate the outer reinforcing member 208. The opening 223 * * * 30 is conveniently threaded so that the reinforcing tube 208 can be screwed therein to * * S. pretension the tubular section 204 if desired. For this purpose the free end of the reinforcing member is flared so that it can act against the end of the tubular portion 104 via a seal. The flare can be provided with slots or holes to facilitate rotation thereof. The plate 222 is provided with two nipples to facilitate the injection of bonding agent and the venting of displaced air.

The ends of the void can be sealed and the void filled with a bonding agent as previously described.

Turning now to Fig. 6 there is shown a housing 301 which has been strengthened in a manner similar to that described with reference to Figs, 3 & 4.

However, in this case the inner reinforcing tube 315 is of corrugated cross section.

Other parts in this view which have similar functions to parts shown in the previous figures have been identified by similar reference numerals but in the 300 series.

Referring now to Fig. 7 there are beam axles which are so constructed that, although they can accommodate a half shaft of an appropriate diameter, a reinforcing 1 5 tube such as reinforcing tube 108 cannot be inserted into the outermost extremities of their tubular arms.

In order to meet this problem it is proposed to make a reinforcing tube 308 in two or more sections which are telescopically extendable. In the embodiment shown the reinforcing tube has three sections 324, 325 and 326.

When the sections 324, 325 and 326 are nested within one another and the reinforcing tube 308 has its minimum length it can be introduced through one of the two opposite opening in the bulbous portion of a housing and extended to line the relevant tubular portion. Resilient 0-rings 329 and 330 are compressed into corresponding annular grooves 331 and 332 in the sections 325 and 326 respectively. * **

When the sections 325 and 326 are extended the 0-rings expand to prevent the * .* S sections returning to their original position. The end of the section 326 is provided * ** with a groove 327 and an 0-ring 328 which seals against the inside of the housing to seal the far end of the void prior to injection of the setting agent. The section 324 is * *, provided with holes 333 which overlie the section 325 and the section 326 is provided with holes 334 which overlie the section 326. When the bonding agent is injected part of it flows through the holes 333 and 334 and helps further inhibit the sections 324, 325 and 326 moving with respect to one another.

Whilst the strengthening method of the present invention has thusfar been described in relation to a beam axle which has been removed from a vehicle it should be appreciated that in many vehicles this is not essential and, indeed this offers a major advantage over strengthening which involves welding a bar to the outside of the housing.

In particular, removing and refitting a beam axle can take several hours because of the necessity to remove other components before the beam axle can be removed.

If the beam axle is to be strengthened without being removed from a vehicle then the vehicle is first supported. The road wheels are removed and the brake components disconnected to allow access to the free ends of the housing. The cover is then removed from the bulbous part of the bulbous part of the housing and the transmission components removed. The inside surface of the housing is then thoroughly degreased by passing mops containing degreasing agents through the tubular portions and the bulbous portion. The internal surfaces of the housing are then cleaned using a rotating wire brush at the end of a rod. The inside of the housing is finally wiped clean and dried.

The funnel shaped reinforcing member and reinforcing tube are then fitted and once correctly centred the bonding agent is injected into the void between the housing and the funnel shaped reinforcing member and the reinforcing tube. Because the bonding agent is being introduced with the axle beam in a substantially horizontal position the bonding agent is preferably introduced through nipples located in the side of the housing and displaced air allowed to vent through nipples in the top of the housing. Thus, if the housing 101 were to be strengthened whilst attached to a vehicle the bonding agent would be introduced through nipples 135 and the displaced air allowed to vent through nipples 114, 115 and 116. (The nipples 135 are shown in Fig. 1 although they should strictly be hidden by the reinforcing tube 108).

: * 30 Various modifications to the embodiments described are envisaged. For S... S. * S S * S S.

example, more than two reinforcing tubes could be used where the application demands additional strength and sufficient internal space is available.

It will be appreciated that because it is not necessary to weld a reinforcing bar onto the housing the chances of distortion are minimal. Furthermore additional strength is provided which extends around the whole internal circumference of the tubular portions of the housing.

By flaring the outermost end of the reinforcing tube 108 and using a resilient o-ring 113 the tubular portion 105 of the housing 101 can be pretensioned according to the amount by to which the reinforcing member 108 is screwed into the funnel shaped reinforcing member 105. * .* * * * * ** ***. * * *S*S * .. * * * ***.

S S..

S * S. * S * *S. S. * * S*

Claims

-Claims:- 1. A method of strengthening a beam axle having a housing (101; 201), which method is characterised by the step of reinforcing the inside of at least part of the housing (101;201).
2. A method according to Claim 1, wherein said housing (101;201) has a bulbous portion (102;202) between two tubular portions (103,104;203,204) and said method includes the step of introducing a reinforcing tube (108; 208; 308) into a tubular portion (103,104;203,204) of said housing (101;201).
3. A method according to Claim 2, wherein said reinforcing tube (308) 1 0 comprises two or more sections (324,325,326) which, when closed, can be inserted into said bulbous portion (102;202) and which can be telescopically extended to extend along one of said tubular portions (103,104;203,204).
4. A method according to Claim 1, including the step of providing means (329,331,330,332) to inhibit said sections being contracted after deployment to their fully extended position.
5. A method according to Claim 4, wherein said means comprises a groove (331,332) in said sections (325,326) and an 0-ring (329,220) in said grooves (331,332).
6. A method according to any preceding claim, including the step of centralizing said reinforcing tube (108:208:308) within a tubular housing.
7. A method according to Claim 6, wherein said step of centralising comprises securing a locating clamp (217) to said housing (201), said housing having a mounting bracket (221) with an opening (223) to accommodate said reinforcing tube (108;208;308).
8. A method according to Claim 6 or 7, including the step of inserting one or more spacers between said housing (101;201) and said reinforcing tube (108;208;308).

::::.
9. A method according to Claim 8, wherein at least one of said spacers is castellated to allow the flow of a bonding agent therethrough. * ** * * * *.S. I. * * * * * S.
10. A method according to any preceding Claim including the step of placing a funnel shaped reinforcing member (105,106) in said bulbous portion (102) of said housing (101).
11. A method according to Claim 10 when depended on any of Claims 2 to 9, including the step of screwing said reinforcing tube (108;208;308) into said funnel shaped reinforcing member (105,106).
12. A method according to Claim 11, wherein reinforcing tube (108) is screwed into said funnel shaped reinforcing member (105) sufficient to pretention said tubular portion (104) of said housing (101).
13. A method according to any preceding claim, including the step of placing an inner reinforcing tube (215) within said reinforcing tube (208).
14. A method according to Claim 13 wherein said reinforcing tube (208) is perforate.
15. A method according to Claim 2, or any of claims 3 to 14 when dependent on Claim 2, including the step of providing a seal at one end of a void defined between said housing (101;201) and said reinforcing tube (108;208;308).
16. A method according to any of Claim 15, including the step of introducing a setting agent in said and allowing said setting agent to set.
17. A method according to Claim 16. wherein said setting agent is a bonding agent.
18. A method according to Claim 17, wherein said bonding agent has, when set, a Shore A hardness of from 50 to 90.
19. A method according to Claim 17 or 18, wherein said bonding agent, before setting, has a viscosity of between 1700 and 2000mPa at a temperature of 25 degrees centigrade.
20. A bonding agent as claimed in Claim 17, 18 or 19 wherein said bonding agent has a lap shear adhesion of the order of 6.5MPa on a surface that has been :.:::. sand grit media blasted with 220 grit.
21. A beam axle when made by a method according to any of the preceding claims. * ** * a * S... * aS S S *.