ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Brake Components and functions

Updated on October 26, 2010
Source

Brake Components and Functions

A disc brake system usually consists of break disc rotor, two brake pads and a caliper (SAE International, 2007). The combination of these components allows the rotating wheel to experience severe braking in a short stopping distance. The braking surface is the area on which the braking action of the friction material takes place (Limpert, 1999).

Figure illustrated the disc brake system components on a passenger vehicle. The centre part of the brake disc has a circular aperture, which is locates on the wheel hub (SAE International, 2007). It is surrounded by a number of holes for the wheel bolts. The brake disc rotates along with the wheel. The normal load, produced when the brake is actuated result in the generation of an in-plane friction force at the disc-pad interface. This in turn produces a brake torque about the centre of rotation of the wheel as shown in Figure. The reaction to the brake torque is seen in the brake force, between the tire and ground, which slow the vehicle.


The ventilated brake disc is a one-piece casting with the groves and for passenger vehicle with cooling fins between the two braking surfaces. This enables air to circulate between the braking surfaces, making them less sensitive to heat build-up and more resistant to fade. Dirt and water do not generally affect the braking action since contaminants are thrown off by the centrifugal action of the brake disc or scraped off by the pads. In addition, the equal clamping action of the two brake pads tends to ensure uniform, straight-line stops (SAE International, 2007).

The two main functions of the brake rotor are the transmission of mechanical force and the dissipation of heat, produced when functioning at both medium and high temperature (Limpert, 1999). This means that the materials used for brake discs must be able to support high temperatures (Grieve et al., 1998). The rotor material must be cost effective, allowing for potential reductions in weight as well as for the stability of the components (Ioannidis et al., 2005).

A solid disc brake consists of a rubbing surface and a top hat section (Bae and Wicket, 2000). The section that connects these two parts is known as the neck (Yumoto and Okamura, 2006). The rubbing surface section is the area where a tangential friction force is generated when the disc interacts with a stationary pad to stop the moving vehicle. The disc rubbing surface area is sometimes known as the cheek (Grieve et al., 1998)(Koetniyom, 2000). A top hat section is connected to the disc rubbing surface and mounted to the vehicle wheel hub.

A disc brake which has separate inboard and outboard rubbing surfaces with cooling vanes or fins in between is known as a ventilated rotor. These vanes allow the air to flow through the structure and cool the rubbing surfaces during and after all braking events. There are two types of ventilated disc: front-vented and back-vented. Figure shows the front-vented type of disc brake, where the top hat section is connected by the neck to the outboard rubbing surface. On the other hand, a neck that connects the inboard rubbing surface with the top hat section as shown in Figure creates what is known as a back-vented disc (SAE International, 2007).


The friction between the pad and disc plays a decisive role in defining the amount of the brake pad is designed to rub against the disc surface leading to diminution of pedal force required to obtain a given rate of deceleration (Papinniemi et al., 2002). This factor is also important in designing brakes for the balanced operation of a vehicle as brake imbalance can lead to a yaw torque about the vertical that could compromise the vehicle stability. The additional task for the brake disc is to induce air movement, as air moving over the rubbing surface of the disc reduces the heats build up (Valvano and Lee, 2000).

The brake pad is designed to rub against the disc surface leading to diminution of vehicle speed, thereby converting mechanical work into thermal energy. The structure of the pads can be very complex (Nicholson, 1995). They can consist of different materials or numerous parallel layers as shown in Figure. There are many different types of friction material on the market which can be classified into the following categories: semi-metallic (SM), non-asbestos organic (NAO) and sintered metal (Anderson, 1992). A friction material is mounted to a rigid metal back plate using adhesive. A substrate material is sometimes located in between the friction material and back plate. The main function of the substrate material is to act as a thermal insulator that will prevent an excessive flow of heat towards the piston and brake fluid as well as damping vibration. The backplate distributes the force exerted by the piston over the pad contact surface (Lee et al., 2003a). An anti noise layer or shim located behind the backing plate minimizes the transmission of vibrations produced during braking action.


The caliper, which contains one or more pistons, holds the two brake pads on either side of the rotor. The movement of the pistons is controlled by a hydraulic system (SAE International, 2007). When hydraulic pressure is applied by pressing the brake pedal, the piston is pushed forward to press the inner pad against the rotor while the housing is pushed in the opposite direction to press the outer pad against the rotor, hence generating a hydraulic clamp around the rotor. For the fixed (non-floating) caliper type of disc brake system, each piston presses the brake pad against its respective side of the brake rubbing surface, as shown in Figure . Meanwhile the floating caliper housing, which is designed to slide on its support, reacts by shifting and pushing the pads against both sides of the disc as shown in Figure (SAE International, 2007).



Comments

    0 of 8192 characters used
    Post Comment

    • profile image

      pomysean 

      5 years ago

      A picture is worth one thousand words. It means a pictures exposes one thousand feelings and this article have one picture which shows different aspects of brake pad's working. Mr. Martin express negative impact which is not up to mark. You can see different types of Certric Brake Pads.

      http://autoplicity.com/manufacturer/1394-centric-b...

    • profile image

      martin 

      5 years ago

      this website is sooo stupid. you don't get any information out of this dumb website. this makes me want to go die in a hole, that's how bad it is

    • profile image

      aizat 

      5 years ago

      yeah!!!

    • profile imageAUTHOR

      zedatszoopa 

      7 years ago

      yup2...sure..i prefer carbon-carbon composite material..

    • POWERS1205 profile image

      POWERS1205 

      7 years ago

      Very well written! If I may ask, what is your braking material preference? I'm partial to the ceramics.

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://hubpages.com/privacy-policy#gdpr

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)