Posted to News on 16th Jul 2020, 00:00
CBTB electromagnetic brake offers advantages to electric vehicle manufacturers
From cars to off-highway and autonomous industrial vehicles, electrification is the future. To achieve electrification, OEM manufacturers are required to design new vehicle platforms to accommodate dual drivetrains. This process of development is driving popularity for optimised power transmission components which help to reduce weight and extend range.
Responding to this requirement, Warner Electric has introduced the CBTB, which is a high dissipating electromagnetic brake. An innovative solution, the CBTB overcomes the limitations of wet braking systems in electrified vehicles.
In an electric vehicle, a dual drivetrain system incorporates both combustion and electric powertrains. For off-highway vehicles, this dual drivetrain must be accommodated within the vehicle platform. This must be achieved without adverse effects on the size of the vehicle: its operation or ground clearance for example. The issue is that dual drivetrain systems are inherently heavier, which makes accommodating them within a vehicle design efficiently a challenge. If not overcome, the vehicle will become too large and heavy to capitalise on efficiency potential gains – reducing overall range and usefulness.
Choosing optimised components within a vehicle design can help. For key powertrain assemblies such as brakes however, there are few alternatives. Bringing an inherently heavy dual drivetrain vehicle to a stop converts large amounts of energy to heat, which must be dissipated by the brake to ensure continued stopping power. A high dissipating brake is a must.
Traditionally, vehicle OEMs would turn to a wet multi-disc brake with hydraulic actuation to provide the required dissipation and performance. Wet multi-disc braking systems are not ideal for dual drivetrain electric vehicles. First of all, two different brakes are required to service each drivetrain, which adds weight. Supporting hydraulic lines also present a risk in terms of oil leaks from the system. In terms of reducing weight in these vehicles, a more streamlined solution is preferable.
An expert in electromagnetic brakes, Warner Electric, a leading brand of Altra Industrial Motion Corp., has tackled the limitations of wet multi-disc braking systems head on with the CBTB. This compact double-disc electromagnetic brake is dry, eliminating hydraulics altogether. Designed to provide high heat dissipation and braking torque – the CBTB provides the winning combination of high performance and a narrow footprint.
The CBTB’s differentiating factors that deliver its high dissipation properties include a special mechanical arrangement within the brake and the addition of Warner Electric’s W134 brake friction material. Developed in-house to eliminate fluctuations in friction material quality and provide consistent braking performance across a range of operating temperatures, W134 integrates perfectly with the CBTB to provide high energy dissipation and reduced overall wear.
A double-disc design ensures that the CBTB is naturally compact. The arrangement allows the brake to sit between two independent drive shafts within a reduced footprint. This removes the need for packaging multiple units of brakes, as well as the hydraulics required to actuate a wet multi-disc braking system. The result is reduced overall weight. As an added benefit, any risk of oil leakage is also eliminated.
To accommodate for sudden stops, the CBTB is available with a dual stage configuration to enable smoother braking during these events. This removes the harsh braking penalties associated with standard electromagnetic brake designs, which are a consequence of their on/off operation.
Additional options include a hand release lever and the Warner Electric Sensor (WES). The WES is an intelligent and compact sensor that provides data on brake position and overall wear, allowing vehicle operators to quickly digest key brake parameters and plan effective maintenance accordingly.
OEM vehicle manufacturers are currently in an arms race towards electrification; therefore having a solution which does not require hydraulic actuation is key to innovate ahead of competition. Brakes are an integral part of any vehicle powertrain, by specifying the CBTB manufacturers can ensure reliable high dissipation braking performance, matched by the design efficiency that is defining the race to full electrification.
Warner Electric offers its customers a global presence. Localised centres in key markets allow end users to draw on extensive experience and on-site support for electromagnetic brakes such as the CBTB. This allows brake designs, installations and maintenance to be optimised to application, providing even greater efficiency and performance benefits.
