Stopping vehicles of all sizes
Brembo is addressing the specific braking requirements of light-, medium- and heavy-duty vehicles with a new range of calipers, discs, parking brakes and ventilation systems
The work demanded of a braking system and the heat that it must dissipate during braking are directly proportional to the mass of the vehicle and the speed it is travelling at when braking starts. The brakes, therefore, have to work the hardest when the vehicle is fully loaded and at maximum operating speed. Such conditions that are relatively common for a commercial vehicle.
Light commercial vehicles (up to 6 tons), used for mid-long range transport, require braking systems that offer superior performance and can withstand the stress caused by a combination of intense use, heavy loading and high braking speeds typical of these vehicles. Medium commercial vehicles, weighing generally between 6 and 16 tons, combine the manoeuvrability necessary for city centres with the performance required for long haul journeys and particularly demanding missions. Heavy commercial vehicles (over 16 tons), used predominantly for nationwide and international transport on highways with very high mileages and average speeds, require braking systems designed with particular regard for the durability of their components.
Italian manufacturer of automotive brake systems Brembo tackles each of these challenges differently with dedicated product development strategies for calipers, discs, parking brakes and ventilation systems.
Brembo produces braking systems comprising brake discs with diameters up to 300mm featuring its pillar venting technology (PVT) and cast iron hydraulic calipers for light-duty vehicles. The company produces front disc brake systems consisting of oversized hydraulic calipers and pads, and ventilated discs with diameters up to 330mm for medium-duty vehicles and ventilated discs with diameters up to 432mm for heavy-duty vehicles.
The calipers in a commercial vehicle must ensure superlative reliability, integrity and safety for years and in all conditions. To achieve this, all the components of the caliper must be engineered to exacting standards and suitably protected from the elements.
The design of the seals plays a major part in preventing infiltration and corrosion. Aspects such as reliability, durability and maintenance also play key roles in the design process. For vehicles up to a gross vehicle weight of 6 tons, Brembo designs and manufactures single- and dual-piston front and rear floating hydraulic calipers made from cast iron. For vehicles between 6 and 10 tons, Brembo produces oversized floating hydraulic calipers to satisfy the greater demands for braking power of such vehicles.
Brembo’s new range of electric combined sliding (ECS) calipers simultaneously carries out the function of the service brake and integrated electromechanical parking brake. Built to withstand the stresses and loads typical of light-, medium- and heavy-duty vehicles, the ECS calipers are integrated
into the vehicle’s electronic stability control (ESC) system. The integration provides additional features compared to a traditional hand brake, such as assistance for uphill starts, vehicle slip prevention, manual/ automatic parking brake release, parking safety with hot brake discs and emergency braking.
Brembo customises service brakes according to customer requirements: a commercial vehicle manufacturer can opt for different combinations of piston diameter, surface and pad volume.
There are no peaks in the daily usage of a braking system for commercial vehicles. Instead, the system is subjected to repetitive thermo-mechanical stress, which the brake disc must withstand effectively. Brembo produces a range of cast iron discs sized appropriately to increase resistance to the thermo-mechanical stresses that occur on heavy vehicles.
For critical applications such as industrial vehicles, Brembo uses its patented pillar venting technology, which according to the company, improves material distribution, increase heat exchange surface area and produce greater air turbulence in the ventilation gap. All of these factors significantly contribute to reducing cooling times and minimizing thermal cracks. The discs produced for these vehicles range from 280mm diameter components weighing approximately 9kg for light commercial vehicles, to units up to 432 mm in diameter and weighing over 36kg for heavy industrial vehicles.
Even though they don’t reach the 1200oc of a Formula 1 car, the braking systems on heavy-weight vehicles can also overheat and potentially cause thermal cracks to appear on the surface of the disc. Brembo is introducing pillar venting technology that can dramatically improve the cooling performance of the system. This ventilation system is characterised by a pillar structure designed specifically for each individual system. The pillars are arranged in three bands on the braking platform. According to Brembo, they increase resistance to thermal cracking by up to 30% to increase the lifespan of the disc.
Every band of the disc has a different pillar structure, designed to achieve the optimum benefit from the dynamic flow of air. The improved air flow also contributes to a drop in operational temperature of up to 30%, providing a longer life for the brake pads. Another important advantage is a reduction in the weight of the disc, which can be up to 10%. This decreases both fuel consumption and emissions of pollutants and, most importantly, the reduction in unsprung weight increases performance, driving comfort and handling.
This ventilation system is the result of two years of dedicated research by Brembo at its Kilometro Rosso site, where it has been tailored to the specific needs of individual braking systems. For a quarter of a century Brembo has concentrated its research on the shape of the ventilation chamber. One of the first results was the development of the PVT ventilation system in the mid-1980s by replacing traditional lugs with a series of pillars to improve both the safety of the system and the life of the disc. In 2004, Brembo designed and patented the T Pillar, primarily for use on Iveco heavy-duty vehicles. As the name suggests, the outer pillars are characterised by their T-shape and have proved to be particularly effective on heavyweight commercial and industrial vehicles. In 2010, Brembo introduced the star pillar ventilation system, which employs star-shaped pillars to disperse the heat better, reduce the risk of thermal shock of the disc and increase pad life.
Brembo supplies mechanical and electrical parking brake systems. The first one may either be integrated with a caliper or drum, or isolated in drum in hat (DIH) installations. For parking of commercial vehicles weighing up to 8 tons, Brembo has developed the electric drum in hat (EDIH), a two-servo brake with a specific electromechanical actuator to ensure safe parking when the brake discs are hot. It can also be used as an emergency brake. The electro-mechanical actuator has been designed to compensate the loss in EDIH lever load typical of duo-servo drum brakes. Another important feature is the total absence of drag in all conditions. This is possible through the monitoring of the EDIH lever position during release. Further advantages of the Brembo EDIH are the possibility to release the parking brake manually in case of failure, and the capability to park the vehicle on a certain slope in case of failure of one of the two actuators.
Electric combined sliding caliper.
Brembo electro-hydraulic actuator.
Different stages of ventilation systems.
Electric drum in hat, two-servo brake.