A beam axle, rigid axle or solid axle is a dependent suspension design in which a set of wheels is connected laterally by a single beam or shaft. Beam axles were once commonly used at the rear wheels of a vehicle, but historically they have also been used as front axles in four-wheel-drive vehicles. In most automobiles, beam axles have been replaced with front (IFS) and rear independent suspensions (IRS).
Diagonal Panhard rod bolted to a black rectangular profile beam axle on a front-wheel drive 2002 Mazda MPV. This is an example of a "dead axle". A "live axle" doesn't just connect two wheels but drives them.
The Twist-beam rear suspension is a similar suspension design, however its beam axle is able to twist, thereby functioning as an anti-roll bar to control the roll motion of the body, and is considered to be a semi-independent suspension design.
Live axle vs dead axleedit
A live axle in a Jeep. This is the front suspension, using coil springs.
A live axle is a type of beam axle in which the shaft (or, commonly, shafts connected to move as a single unit) also transmits power to the wheels; a beam axle that does not also transmit power is sometimes called a dead axle. While typically used in vehicles with Hotchkiss drive, this suspension system can also be used with other types of power transmission.
Advantagesedit
A beam axle is typically simple in design, rugged, and inexpensive to manufacture.
Only one universal joint or constant-velocity joint (CV) is needed at each steered and driven wheel and none are needed at non-steered wheels; this reduces maintenance requirements and manufacturing costs compared to independent suspensions, which typically require two such joints at each driven wheel.
The CVs are located in metal enclosures attached to the axle housings, there are no rubber CV boots that maybe cut or punctured when off-roading.
A beam axle is space-efficient, an important advantage for off-road applications, as it provides better vehicle articulation and durability in a high load environment.
Camber angle is rigidly fixed by axle geometry; for a live axle, toe is typically fixed as well.
As the vehicle's body rolls during hard cornering, the unchanging camber yields predictable handling—at least on smooth surfaces.
Traction, braking and tire wear characteristics do not change as the suspension is compressed. These are great benefits in a vehicle that carries heavy loads, and together with the beam axle's characteristic strength, this has resulted in front and rear beam axles being nearly universal in buses and heavy-duty trucks. Most light and medium duty pickup trucks, SUVs, and vans also use a beam axle, at least in the rear.
Easier, cheaper to modify, due to less parts, mechanical complexity and typically more empty space (to work with) between suspension components, axles and the vehicle's frame/body.[1]
lift kits to increase body and/or running clearance
larger diameter tyres to increase ground/axle clearance
Disadvantagesedit
A beam axle does not allow each wheel to move independently in response to uneven surfaces, and handling is typically worse than more sophisticated suspension designs.
In turns, the outside wheel is often subjected to adverse camber angles when the inside wheel hits a bump, which can suddenly reduce cornering grip and destabilize the vehicle.
If one wheel on an axle slides off a steep incline or is knocked to one side by a rock (when driving at high speeds), the other wheel will also follow due to the physical connection of the two wheels on an axle. If this happens on the front axle the whole vehicle may suddenly jump towards that side.[2] If there is lack of (enough) steering dampening, the driver maybe suffer dislocated fingers or shoulder due to the sudden steering wheel feedback.[3]
Camber angle cannot change during body roll. Furthermore, the roll center moves in reaction to road irregularities
Toe is typically fixed at zero for a live axle, and dynamic toe control is difficult to implement.
The need for lateral location devices such as a Panhard rod or Watt's linkage adds more unsprung weight and partially offsets the beam axle's advantages in simplicity, space efficiency and cost.
In a vehicle with conventional Hotchkiss drive, the entire axle may twist in its mounts in reaction to torque loads; during hard acceleration, this may reduce traction and induce wheel hop or sudden adverse toe changes.
The bulky differential housing of a Hotchkiss live axle reduces ground clearance, hindering the vehicle's ability to ford deep mud, clear obstacles and negotiate deeply rutted roads.
The differential housing can only be raised by using larger wheels and tires, typically with a penalty in unsprung weight, braking effectiveness and acquisition costs; furthermore, vehicle modifications may be necessary for adequate fender or frame clearance.
Front beam axle suspension is unusually sensitive to any lack of concentricity in the hub and wheel assembly which can cause a side-to-side oscillation ("shimmy") of the steering at certain speeds (typically 60–80 km/h; 40–50 mph), commonly referred to as "death wobble" within the 4x4 community.[4] This is addressed on some vehicles with steering dampers, although removal and careful refitting of the front wheels often cures the problem.
Examplesedit
Modern production vehicles with solid front axleedit
^THE COST OF CHOOSING BIGGER 4x4 TYRES. Retrieved 2024-04-12 – via www.youtube.com.
^2022 Season Video: A Highlight of the Jeepspeed Race Series. Retrieved 2024-04-12 – via www.youtube.com.
^"10 Off Road tips for inside the cab". 4 Wheeling Australia. Retrieved 2024-04-12.
^Lingeman, Jake. "Autoweek explains: What is the 'death wobble'?". Autoweek. Retrieved 2 October 2021.
January 01, 1970
beam, axle, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, october, 2021, . This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Beam axle news newspapers books scholar JSTOR October 2021 Learn how and when to remove this message A beam axle rigid axle or solid axle is a dependent suspension design in which a set of wheels is connected laterally by a single beam or shaft Beam axles were once commonly used at the rear wheels of a vehicle but historically they have also been used as front axles in four wheel drive vehicles In most automobiles beam axles have been replaced with front IFS and rear independent suspensions IRS Diagonal Panhard rod bolted to a black rectangular profile beam axle on a front wheel drive 2002 Mazda MPV This is an example of a dead axle A live axle doesn t just connect two wheels but drives them Contents 1 Implementation 2 Live axle vs dead axle 3 Advantages 4 Disadvantages 5 Examples 5 1 Modern production vehicles with solid front axle 5 2 Unibody modern production vehicles with solid axle 6 See also 7 NotesImplementation edit nbsp Solid axle suspension characteristics Camber change on bumps none on rebound large unsprung weight With a beam axle the camber angle between the wheels is the same no matter where it is in the travel of the suspension A beam axle s fore amp aft location is constrained by either trailing arms semi trailing arms radius rods or leaf springs The lateral location can be constrained by a Panhard rod a Scott Russell linkage or a Watt s linkage or some other arrangement most commonly by the leaf springs Shock absorbers and either leaf springs coil springs or air bags are used to control vertical movement The Twist beam rear suspension is a similar suspension design however its beam axle is able to twist thereby functioning as an anti roll bar to control the roll motion of the body and is considered to be a semi independent suspension design Live axle vs dead axle edit nbsp A live axle in a Jeep This is the front suspension using coil springs See also Axle Dead axle lazy axle A live axle is a type of beam axle in which the shaft or commonly shafts connected to move as a single unit also transmits power to the wheels a beam axle that does not also transmit power is sometimes called a dead axle While typically used in vehicles with Hotchkiss drive this suspension system can also be used with other types of power transmission Advantages editA beam axle is typically simple in design rugged and inexpensive to manufacture Only one universal joint or constant velocity joint CV is needed at each steered and driven wheel and none are needed at non steered wheels this reduces maintenance requirements and manufacturing costs compared to independent suspensions which typically require two such joints at each driven wheel The CVs are located in metal enclosures attached to the axle housings there are no rubber CV boots that maybe cut or punctured when off roading A beam axle is space efficient an important advantage for off road applications as it provides better vehicle articulation and durability in a high load environment Camber angle is rigidly fixed by axle geometry for a live axle toe is typically fixed as well As the vehicle s body rolls during hard cornering the unchanging camber yields predictable handling at least on smooth surfaces Wheel alignment is simplified Traction braking and tire wear characteristics do not change as the suspension is compressed These are great benefits in a vehicle that carries heavy loads and together with the beam axle s characteristic strength this has resulted in front and rear beam axles being nearly universal in buses and heavy duty trucks Most light and medium duty pickup trucks SUVs and vans also use a beam axle at least in the rear Easier cheaper to modify due to less parts mechanical complexity and typically more empty space to work with between suspension components axles and the vehicle s frame body 1 lift kits to increase body and or running clearance larger diameter tyres to increase ground axle clearanceDisadvantages editA beam axle does not allow each wheel to move independently in response to uneven surfaces and handling is typically worse than more sophisticated suspension designs In turns the outside wheel is often subjected to adverse camber angles when the inside wheel hits a bump which can suddenly reduce cornering grip and destabilize the vehicle If one wheel on an axle slides off a steep incline or is knocked to one side by a rock when driving at high speeds the other wheel will also follow due to the physical connection of the two wheels on an axle If this happens on the front axle the whole vehicle may suddenly jump towards that side 2 If there is lack of enough steering dampening the driver maybe suffer dislocated fingers or shoulder due to the sudden steering wheel feedback 3 Camber angle cannot change during body roll Furthermore the roll center moves in reaction to road irregularities Toe is typically fixed at zero for a live axle and dynamic toe control is difficult to implement The mass of the beam is part of the unsprung weight of the vehicle hurting ride quality The need for lateral location devices such as a Panhard rod or Watt s linkage adds more unsprung weight and partially offsets the beam axle s advantages in simplicity space efficiency and cost In a vehicle with conventional Hotchkiss drive the entire axle may twist in its mounts in reaction to torque loads during hard acceleration this may reduce traction and induce wheel hop or sudden adverse toe changes The bulky differential housing of a Hotchkiss live axle reduces ground clearance hindering the vehicle s ability to ford deep mud clear obstacles and negotiate deeply rutted roads The differential housing can only be raised by using larger wheels and tires typically with a penalty in unsprung weight braking effectiveness and acquisition costs furthermore vehicle modifications may be necessary for adequate fender or frame clearance Front beam axle suspension is unusually sensitive to any lack of concentricity in the hub and wheel assembly which can cause a side to side oscillation shimmy of the steering at certain speeds typically 60 80 km h 40 50 mph commonly referred to as death wobble within the 4x4 community 4 This is addressed on some vehicles with steering dampers although removal and careful refitting of the front wheels often cures the problem Examples editModern production vehicles with solid front axle edit Suzuki Jimny Jeep Wrangler Jeep Gladiator Toyota Land Cruiser 70 Series Mercedes Benz G Class 1990 2019 Land Rover Defender 1990 2016 Beijing BJ212 Ford Super Duty Ram Heavy Duty fifth generation Mahindra Bolero Pik Up Unibody modern production vehicles with solid axle edit Jeep Liberty Jeep Grand Cherokee 2004 2010 Jeep Cherokee XJ Jeep Commander 2005 2010 Dodge Nitro Lada NivaSee also editAxle List of auto parts Twist beam rear suspension Wheelset rail transport Notes edit THE COST OF CHOOSING BIGGER 4x4 TYRES Retrieved 2024 04 12 via www youtube com 2022 Season Video A Highlight of the Jeepspeed Race Series Retrieved 2024 04 12 via www youtube com 10 Off Road tips for inside the cab 4 Wheeling Australia Retrieved 2024 04 12 Lingeman Jake Autoweek explains What is the death wobble Autoweek Retrieved 2 October 2021 Retrieved from https en wikipedia org w index php title Beam axle amp oldid 1221290592, wikipedia, wiki, book, books, library,
