Our range of axles is so wide, so that you could always find an axle most suitable to your needs. Choose the most appropriate suspension method for your trailer, define the needed load capacity and width and we will offer you the closest axle from our standard range. If our recommendation would not fully meet your criteria, we are certainly able to design, produce and test various non-standard versions for you as well.
The suspension characteristics is a key feature of an axle. Therefore, it should not be underrated while designing a trailer. However, the choice of a suitable suspension type very much depends on the trailer’s usage mode. On this page we briefly compare the properties of individual suspension methods.
KNOTT axle types VG & VGB
KNOTT axle types G & GB
KNOTT axle types D & DB
KNOTT axle types KLL & KLLB, SG & SGB
A wheel unit, on which the wheels of a trailer are mounted, is an essential part of each axle. Wherever the loading allows it, uses KNOTT maintenance-free, compact double-row ball bearings, that assure long lifetime and good stability of wheel units even in tough operating conditions of a trailer.
In the case of braked axles, the most significant component of trailer wheel units are drum brakes. Being a key safety element, high demands are laid on brakes. Wheel brakes are liable to homologation for the use in road traffic. KNOTT brakes offer a quality proved by decades with a reliable auto-reverse function (allowing to reverse a trailer despite being equipped with an overrun brake), in combination with innovative technologies like the ANS – automatic brake-shoe clearance adjustment.
For an increased corrosion resistance and hence a longer life, we also offer wheel units with improved bearing seal or an integrated system for rinsing out salt water from the brake drum, used mainly in boat trailers.
As trailers up to 750 kg do not have to be equipped with a service brake system by law, it is possible in this weight category to go for an unbraked axle, which is simpler and hence lighter and cheaper too. The decisive element of an unbraked wheel unit is particularly a quality bearing and a hub with the correct type of wheel connection.
A mechanical drum brake of a simplex design is the most frequently used brake in trailer technology. The braking effect is transferred by brake-shoes to a brake drum and thus, the trailer braking occurs. The brake actuation is purely mechanical. Whether such a wheel brake serves just as a parking brake or for service braking with the help of an overrun brake system, it is a proved, reliable and easy to maintenance conception with relatively simply solvable auto-reverse function (which presents a hardly manageable technical problem with disc brakes for example).
In hydraulic drum brakes, the brake-shoes are controlled by an expanding hydraulic cylinder connected to a hydraulic circuit of the trailer brake system. These brakes are used for higher loading capacities and for atypical trailer designs, where it is impossible to achieve the required braking effect by a mechanical brake system. They are also equipped with an auto-reverse (for trailers up to 3500 kg) and a mechanical actuation of the parking brake.
For trailers heavier than 3500 kg, it is forbidden by legislation to use an overrun brake system. The braking effect from the towing vehicle to trailer brakes is transferred by a compressed air, which actuates air brake cylinders connected directly to mechanical drum brakes, or an air cylinder pulls brake cables, transferring the braking effect to the brakes. In the case of hydraulic wheel brakes, an air-over-hydraulic cylinder is used, where the air pressure converts to a hydraulic pressure in the connected hydraulic circuit, actuating expanding hydraulic cylinders in wheel brakes. We have air cylinders, converters and special brakes in our product range for this use case.
With special requirements come special solutions. Below, you will find examples of some non-standard axle versions, that grew popular within our customers. However, the KNOTT production possibilities are really extensive, therefore do not hesitate to approach us, if your project requires such technical solution, that you could not find on our webpage. You can also find some atypical axles in the steerable chassis section.
We can provide our round profile axles (types G & GB, D & DB) in a lowering design as well. It means, the axle body can rotate in its mounting brackets and a pair of hydraulic cylinders restrains this rotation. Changing the stroke of these cylinders allows us to change the rotation of the axle body and thereby lower the loading platform of a trailer. The hydraulic cylinders can be controlled by the means of mechanical or electric pump. To complement our lowering axles, we also offer the whole hydraulic system sets, including pump, cylinders, hydraulic lines and connecting elements. The maximal load capacity of KNOTT lowering axles is 4500 kg. If required, we can deliver independently lowered half axles too.
These axles found their use mainly in mobile retail fast-food stands and car transporters or delivery trucks, where lowering of the whole chassis speeds up the loading and unloading of goods, compared to a hydraulic platform.
The KNOTT company has also a load balancing system for tandem (twin-axle) trailers in its product range. Axles with a round profile (types G & GB, D & DB) are used. Load balancing of tandem axles found its application in trailers traveling over heavy terrain with deep potholes, where it is needed to assure, that a part of the front axle load transfers to the rear axle. When tandem axles move in tough terrain, it often happens, that the rear axle loses its ground contact due to a pothole and all the loading is carried by the front axle alone, making it suffer significantly. The load balancing system transfers the loading to the rear axle too, which ensures a continuous ground contact of both axles. Another use case for load balancing axles is a situation, when the height of a vehicle’s towing device constantly varies due to a long rear overhang (e.g. on a bus) while driving, and the unloading of the rear trailer axle occurs, leading to the loss of its ground contact and causing instability of the trailer. Load balancing system provides the load transfer from the front axle to the rear one or vice-versa before an axle would lose its ground contact.
Load balancing axles are coupled by connecting rods which may be replaced with hydraulic cylinders, thus adding the lowering function to the load balancing system.
In such a trailer design, where the middle part of a standard axle body would collide with other trailer parts, independently mounted half axles may be used. This allows either achieving a bigger ground clearance in the middle part of the trailer width, or positioning its loading platform very low. This solution also allows a specific trailer design with vertically movable (lowerable) loading platform. The suspension system of half axles may be realised by rubber torsion elements or by coil springs.
