These days, you find plenty of vehicles fitted with ventilated brake discs which allow for superior heat dissipation, and consequently, better braking. The heat that is generated during braking gets stored inside the disc, and then vented into the surroundings through forced convection. The design of the rotor holds significance when it comes to achieving proper cooling.
The arrangement of vanes is one of the factors by which ventilated brake discs can be classified. Following are the main types of cooling vane layouts.
- Straight Vane: This cooling vane forms the most common and popular type in the auto market. Vanes of this type are lighter and carry better cooling capabilities than solid rotors. The rear rotors are often thinner in comparison to the front ones.
- Pillar Vane: Rather than straight vanes, the rotor has random formation comprising dots and lines cast between the friction plates for better heat dissipation.
- Variable Vane: A lot like the pillar vane design, this one holds slightly varying patterns.
These designs are all non-directional, which means both the right and left rotors are made out of the same casting. Meanwhile, vanes with “directional” drilling or slotting are a different thing altogether. Straight vane rotors leave the option open for machining directional slots onto them. These designs can be manufactured at lower costs, mainly because when compared to curved-vane rotors, they only need a single set of tooling.
- Traditional Curved Vane: This vane design is the most commonly used for enhancing the cooling effect in and on a rotor, by pumping in cool air from the wheel's center. Some surface mounted designs also facilitate entry of cool air from the vehicle's inboard side. One disadvantage is that the dust shield often hampers the air inlet, which reduces cooling effectiveness.
- Variable Curved Vane: This includes curved vanes set in a distinctly different arrangement, and sometimes manufactured in a dissimilar shape to the traditionally curved vanes.
- Convergent Vane: This design is considered the most innovative one on the auto scene. The vanes are paired with advanced production technology to boost the achievable cooling efficiency of the brake system. Compared to the traditional curvature, these vanes are highly popular among more experimental auto enthusiasts. It has a wider air inlet, narrower air outlet, and a high number of cooling vanes to match higher heat dissipation requirements, especially in higher-performance brakes.