Brake Lining

Brake linings were invented by Bertha Benz (the wife of Karl Benz, who invented the first patented automobile) during her long-distance car trip, the first in the world, in August 1888, when she told a shoemaker to nail leather onto the brake blocks. The first asbestos brake linings were developed in 1908 by Herbert Frood.[1] Although Frood was the first to implement the use of asbestos brake linings, the heat dissipation properties of the fibres were tested by various scientists, including materials chemist Gwilym Price, who did most of his research and testing at Cambridge, United Kingdom, and various Cambridge-funded institutions.[citation needed]

brake lining

Brake linings are composed of a relatively soft but tough and heat-resistant material with a high coefficient of dynamic friction (and ideally an identical coefficient of static friction) typically mounted to a solid metal backing using high-temperature adhesives or rivets. The complete assembly (including lining and backing) is then often called a brake pad or brake shoe. The dynamic friction coefficient "μ" for most standard brake pads is usually in the range of 0.35 to 0.42. This means that a force of 1000 Newtons on the pad will give a resulting brake force close to 400 Newtons. There are some racing pads that have a very high μ of 0.55 to 0.62 with excellent high-temperature behaviour. These pads have high iron content and will usually outperform any other pad used with iron discs. Though these high μ pads wear themselves and the discs down more quickly, they are nevertheless a good cost effective alternative to more exotic/expensive materials.

Using a typical bicycle brake as an example, the backing would be the metal shell which provides mechanical support, and the lining would be the rubbery portion which contacts the rims when the brakes are applied. In most modern vehicular applications the system is conceptually identical, except the rims would be replaced with solid steel (or sometimes exotic metal) disc. Furthermore, a metal tang is usually incorporated into the pad assembly. The tang contacts the rotors when the linings are worn out, causing an annoying noise designed to alert the motorist that brake servicing is required.

Since the lining is the portion of the braking system which converts the vehicle's kinetic energy into heat, the lining must be capable of surviving high temperatures without excessive wear (leading to frequent replacement) or outgassing (which causes brake fade, a decrease in the stopping power of the brake).

Due to its efficacy, chrysotile asbestos was often a component in brake linings. However, studies such as a 1989 National Institutes of Health item showed an uncommonly high proportion of brake mechanics were afflicted with pleural and peritoneal mesothelioma, both of which are linked to chrysotile and asbestos exposure.[2] Public health authorities generally recommend against inhaling brake dust,[3] chrysotile has been banned in many developed countries, such as Australia in late 2003,[4] and chrysotile has been progressively replaced in most brake linings and pads by other fibers such as the synthetic aramids.

When the lining is worn out, the backing or rivets will contact the rotors or drums during braking, often causing damage requiring re-machining or replacement of the drums or rotors. An annoying squeal caused by the warning tang is designed as a typical audible alert that the pads need to be replaced; some vehicles may also have electrical brake wear indicators. If the squeal or wear indicator is ignored for too long, drum or rotor damage (usually accompanied by an unpleasant grinding sound or sensation) together with degraded braking capacity will be the result.

The brake lining may also become contaminated by oil or leaked brake fluid. Typical symptoms will be brake chatter, where the pads vibrate as the lining grabs and releases the rotor's surface. The solution is to repair and clean the source of the contamination, replace the damaged pads and possibly also have the rotors re-skimmed or replaced if they are damaged.

In the automotive repair industry, consumers can purchase brake pads with a lifetime warranty.[citation needed] These pads use a much harder lining than traditional brake pads and tend to cause excessive wear of the much more expensive rotors or drums. For that reason, consumers should ensure that the new brake pads installed are those specified or supplied by the vehicle's manufacturer.

Brake linings can also be found just about everywhere there are braking systems and clutches, from elevator safety brakes to spindle brakes inside a VCR. The form and materials are frequently different, but the principle is the same.

First of all, are brake pads and brake shoes the same? The short answer is no. While they both carry out a similar function, they operate in different types of braking systems and have different advantages (and disadvantages).

Found in disc brake systems, brake pads are a flat piece of steel with a thick friction material layer on one side. This friction material type varies, depending on vehicle type and size and brake caliper type.

Designed to check both straight on or at a 90 angle to the rotor with offset tips so the gauges can be used without removing the wheel or caliper assembly on many applications. Brake lining gauges identify thickness levels for brake lining inspection. Made from durable, flexible acetal. The gauges are color coded to match SAE or Metric recommendations for brake pad replacement.

Brake lining for brake system, provides BPI are formulated according to the needs of each vehicle, they are made from the best materials to ensure optimal friction braking in conjunction with the front brake system.

A number of brake lining materials representative of original equipment in US, Japanese and European automobiles were characterized in order to determine their composition and microstructure. Their frictional performance was subsequently determined using the Friction Assessment and Screening Test (FAST machine). The goal of this work was to identify each constituent of the friction material, to deduce their individual role in the friction process and to determine the effect of the microstructure on the wear properties.

In our last segment, we reviewed common points of failure in the typical general aviation aircraft brake system. However, even if nothing has actually failed, you will eventually have to replace the brake linings, which wear away over time from normal use. In automobiles, brake linings are permanently attached to metal backing plates, and the entire assembly is disposable. On aircraft, the linings are riveted to reusable parts of the caliper assembly.

These tools are very simple to use: Simply position the backing or pressure plate in the tool and carefully screw down the shaft until the rivet is punched out. Installation of the new linings is just as simple: Remove the punch-out adapter from the tool, place a new rivet in the hole through the new liner, and twist the shaft until the rivet is properly set.

There are many different types of discs on the market today, including chrome discs that resist corrosion. Before selecting a new type of disc for your aircraft, be sure to consult the brake manufacturer to ensure compatibility of the brake disc and the brake lining. While some discs may resist corrosion better than others, they often have different braking properties.

Brake liningRelease date6 July 2014Bolts11x7mm(7 in the engine bay, 1 at each wheel)Damageable?NoPurchasable?NoSourceGarage at homeThe brake lining (: Jarruputkisto) is a car part which can be found inside the garage at home. It is attached to the engine bay with 7x7mm bolts, and each wheel with 1x7mm bolt. Note that you must use an open-ended spanner, a ratchet won't work.

Brake pads and brake linings are made from a blend of no less than 10 to 20 kinds of raw materials. Blending the right materials for the required condition and performance is a highly complicated task requiring specialized know-how, which include leading-edge expertise of Akebono.

Furthermore, friction materials are required to exercise stable effectiveness (minimum fluctuation of effectiveness) under varying conditions, such as vehicle speed, laden weight, or temperature change from brake usage, as well as under different environmental influences including humidity, water, and mud. Strength to withstand thermal disturbances, and mechanical strength are also important design criteria.

Durability is another important property of friction materials as they wear with use. Moreover, when brakes are applied, squeal, noise and vibrations must be minimized. Furthermore, the friction materials should not cause damage to the material they get into contact, such as the disc rotors. Friction materials also require to have low thermal conductivity to prevent temperature buildup of the brakes themselves or brake oil.

Akebono develops and manufactures a wide range of brake pads and brake linings, including those for automobiles, Shinkansen bullet trains, and high-performance cars for motorsports. Various types of materials are used depending on where the brakes are used. When high intensity is required for braking under high temperature and high load conditions, such as Shinkansen bullet trains travelling at speed, metallic friction materials are used. For cars used in Europe where braking from high speeds is relatively common, "low steel" friction materials are used.

Akebono is continuing to develop high performance brakes for the purpose of perfecting the latest brake technologies. The high-performance brakes of Akebono are supplied to various motorsport teams. The expertise acquired from motorsport, which pushes the brakes to their limits, are applied to the development of brake pads and brake linings for passenger cars.

For the development of friction materials, performance as well as quality that assures a long service life must be taken into consideration. This is realized by finding the right combination of raw materials as well as by optimizing the production conditions. There are many steps that must be taken before a product is delivered to our customers. It may take a few months or even a few years to complete this process. Physical and chemical properties of friction materials are evaluated. A test instrument called the dynamometer, on which an actual brake can be fitted, is used to evaluate the friction properties. Actual cars are used to evaluate compatibility between car and brake. We are also developing raw materials which minimize environmental impact. 041b061a72