Types of Live Rear Axles
There are three types of live rear axles: Semi floating axles, Three quarter floating axles and Full floating axles. Let us see the details of these axles in a brief manner.
What exactly is an Axle?
An axle is a rod or shaft that rotates the wheels while still supporting the vehicle’s weight. Axles are important parts of any automobile and are divided into three categories: front, rear, and stub.
How many axles are there in a vehicle?
Vehicles usually have two axles that turn the wheels. Axles can be more or multiple in larger vehicles that can handle more passengers and the vehicles have more wheels.
It’s easy to figure out how many axles your car or some other vehicle requires. Simply count the pairs of tyres on your car when looking at it from the side. Most automobiles have a total of four tyres, or two sets of tyres, one in the front and one in the back. Two axles are equivalent to two sets of tyres.
Different Axle Types
Axles are divided into three categories:
The rear axle is in charge of supplying power to the drive wheels. It is made up of two halves, known as half shafts, that are joined by a differential. Rear axles are usually live, which means they spin with the wheels of the car.
The front axle, which is located in the front of the car, is in charge of assisting with steering and processing shocks from the road’s rough surface. The beam, the swivel pin, the track rod, and the stub axle are the four main components. Front axles need to be as strong as possible, which is why they’re normally made of carbon or nickel alloy.
Stub axles are fixed to the vehicle’s front wheels and are connected to the front axle by kingpins.
Because dead axles is not linked to the engine, so it is called as dead axles and will not convey the engine’s power. A dead axle, sometimes known as a lazy axle, is a non-powertrain axle that rotates freely. Many vehicles and trailers have dead axles for load-bearing reasons alone. A dead axle that rests immediately in front of a driving axle is known as a pusher axle.
A dead axle that lies in front of the driving axle is known as a tag axle. Dead axles are found on semi-trailers, farm equipment, and some heavy construction equipment. On some cars, the tag axle may be steerable. In some configurations, the wheels on a lazy axle may only make contact with the ground when the weight is considerable.
A live axle is a form of beam axle that delivers power to the wheels via the shaft. The term “live axle” refers to an axle with a differential system that directs engine power to the front wheels.
Aside from transferring weight, the live axle must also provide engine power to the wheels. Although live axles, also known as solid axles, are still used in light trucks and some SUVs, current muscle cars such as the Mustang, Camaro, and Challenger now use independent rear suspension. The wheels are attached to the live axles, which revolve with them.
Live automobile axles, which push a set of wheels, are found in all vehicles that operate on wheels. This kind transmits power and torque to the wheels while also supporting the vehicle’s load weight.
Semi floating axle | Types of Live Rear Axles
The semi floating live rear axles is shown in the diagram. The short rear axle shaft inner end is supported only be the differential side gear. The differential case carries the inner bearing between it and the axle shaft housing that supports it. The inner end of the axle shaft is thus relieved of the task of supporting the weight of the vehicle. The weight of the vehicle is supported by the axle housing. Now the outer end of the axle supports the weight of the vehicle and takes up end thrust. Hence, this construction is called Semi floating rear axle.
The inner end of the axle shaft is splined to the differential side gear. The outer end is flanged and the wheel is bolted directly to it. In some designs, the hub of the wheel is keyed to the outer end of the axle shaft. The axle housing supports the wheel bearing, which is placed inside the outer end of the axle housing. The bearing is held on the axle by a retainer. The bearing is held on the axle by a retainer.
Most axle bearings are pre lubricated. With this arrangement, the brake drum, the wheel, and the bearings retainer plate must be removed in order to withdraw the axle shaft. This arrangement results in the axle shaft helping to support the weight of the vehicle in addition to transmitting rotation to the wheels.
Semi-floating live rear axles are found in cars, SUVs, and mid-size trucks such as ½ tonne trucks and light-duty pickup trucks.
Three quarter floating axle | Types of Live Rear Axles
The three quarter floating live rear axles is shown in picture. In this axle, the wheel hub is supported by the single bearing located in the center of the wheel hub. The wheel hub runs on the axle housing. The axle shaft is keyed rigidly to the wheel hub. This arrangement provides the driving connection and maintains the alignment of the wheel.
The construction at the inner end of the axle shaft is the same as with the semi floating type. This axle is not supported by bearings at either end. The three quarter floating live rear axles has only one bearing at the outer end. It is not as quite as the full floating type.
Full floating axle | Types of Live Rear Axles
The full floating live rear axles is shown in diagram. In this axle, the wheel hub is supported by two bearings. The bearings are running directly upon the axle housing. The axle shaft is fastened to the wheel hub flange by means of a coupling. Through the coupling, the rotary motion of the axle shaft is transmitted to the hub and wheel. With this arrangement, the axle shaft can be removed from the housing without disturbing the wheel by removing the hub cap and the coupling.
In the full floating axle, the axle shaft is not supported at either end by bearings. The position of the axle shaft is maintained by the way that it is supported at both ends. As such, the axle is relieved of all strain caused by the weight of the vehicle or end thrusts. Now, the only function of the axle shaft is to transmit the rotary motion or torque to the wheel. Because of this fact, the axle is called full floating live rear axles.
Full floating axle is the only construction that holds the wheel in position even when the axle shaft breaks. In other types, the wheel comes off and causes the vehicle to drop. The full floating axle is used almost exclusively in trucks.
In all applications, in axle construction either tapered roller or ball bearings are used. Bigger vehicles, such as heavy duty trucks, benefit from fully floating live rear axles. Full floating live rear axles may support certain mid-size trucks with higher towing capacities or who often use four-wheel drive.