Browse Topic: Brake drums

Items (174)

Driveline Parking Brake Test Procedure for Medium Duty Vehicles

J2690_202110 (Current)

10/28/2021

This SAE Recommended Practice establishes uniform test procedures for friction based parking brake components used in conjunction with hydraulic service braked vehicles with a gross vehicle weight rating greater than 4500 kg (10 000 lb). The components covered in this document are the primary actuation and the foundation park brake. Various peripheral devices such as application dashboard switches or indicators are not included. These test procedures include the following: a Brake Related Tests 1 Brake Functional Performance 2 Brake Dynamic Torque Performance 3 Brake Corrosion Resistance 4 Brake Endurance with Torque 5 Brake Endurance without Torque 6 Vibration Resistance 7 Brake Ultimate Static Load 8 Brake Lining Wear Adjuster Function b Actuation Related Tests 1 Mechanical Actuator Functional Performance 2 Mechanical Actuator Endurance 3 Mechanical Actuator Quick Release 4 Mechanical Actuator Ultimate Load 5 Spring Apply Actuator Functional Performance 6 Spring Apply Actuator Operating Temperature Range 7 Spring Apply Actuator Endurance 8 Spring Apply Actuator Corrosion Resistance 9 Spring Apply Actuator On-Off Switch 10 Spring Apply Actuator Vibration

Truck and Bus Hydraulic Brake Committee

Disc Wheel and Hub or Drum Interface Dimensions - Truck and Bus

J694_202104 (Current)

4/30/2021

This SAE Recommended Practice contains dimensions and their tolerances concerning disc wheel to hub or drum interface areas for truck and bus applications. Disc wheels designed only for single wheel applications (not dual wheels) for light trucks and special or less common applications are not covered in this document.

Truck and Bus Wheel Committee

Dimensional Compatibility for Commercial Vehicles Fitment of Complete Wheels in Drum Brake Applications - Truck and Bus

J1865_202011 (Current)

11/4/2020

This SAE Recommended Practice defines a clearance line for establishing dimensional compatibility between drum brakes and wheels with 19.5 inch, 22.5 inch, and 24.5 inch diameter rims. Wheels designed for use with drum brakes may not be suitable for disc brake applications. The lines provided establish the maximum envelope for brakes, including all clearances, and minimum envelope for complete wheels to allow for interchangeability. This document addresses the dimensional characteristics only, and makes no reference to the performance, operational dynamic deflections, or heat dissipation of the system. Valve clearances have not been included in the fitment lines. Bent valves may be required to clear brake drums. Disc brake applications may require additional running clearances beyond those provided by the minimum contour lines. Mounting systems as noted are referenced in SAE J694.

Truck and Bus Wheel Committee

Air Brake Performance and Wear Test Code Commercial Vehicle Inertia Dynamometer

J2115_202008 (Current)

8/20/2020

This SAE Standard provides test procedures for air and air-over-hydraulic disc or drum brakes used for on-highway commercial vehicles over 4536 kg (10000 pounds) GVWR. This recommended practice includes the pass/fail criteria of Federal Motor Vehicle Safety Standard No. TP-121D-01.

Truck and Bus Foundation Brake Committee

Dimension Compatibility for Commercial Vehicle Wheels to Air Disc Brake Calipers - Truck and Bus

J2803_202006 (Current)

6/5/2020

This SAE Recommended Practice defines the boundary line for establishing dimensional compatibility between air disc brake calipers and 22.5 x 8.25 inch disc wheels, including bent valve stems on steel wheels and manufacturer recommended valve stems on aluminum wheels. The line establishes the minimum wheel with valve stem envelope to allow interchangeability. The line does not accommodate customer-specific wheels (such as OEM-specific stylized wheels) or customer-specific brakes. This document addresses dimensional characteristics only and makes no reference to the performance, operational dynamic deflections or heat dissipation of the system. It is up to the system integrator to ensure sufficient clearance exists between the caliper, wheel and valve stem to provide safe operating conditions. Mounting systems as noted are referenced in SAE J694.

Truck and Bus Wheel Committee

Outboard Mounted Brake Drum/Disc Wheel Hub Interface Dimensions - Truck and Bus

J1671_201910 (Historical)10/17/2019

Truck and Bus Wheel Committee

Fatigue Life Prediction of Heavy Duty Automobile’s Brake Drum through Coupled Thermo-Mechanical Analysis

2019-28-003110/11/2019

The aim of this paper is to demonstrate the methodology to simulate the induced stresses/strains due to thermo-mechanical loading of automobile brake drum.. The brake drum undergoes mechanical load due to applied brake pressure and thermal load due to friction generated between brake pad and brake drum while brake is applied. This coupled thermo-mechanical loading affects the life of the brake drum as the stiffness of the brake drum is reduced. The conventional method of simulating this problem is done using Lagrangian discretization in which the load is applied and inertia effect due to angular velocity is applied to a drum at static condition. In contrast, in this paper Eulerian discretization is adopted for finite element analysis, in which drum brake model is discretized as spatially dependent that facilitates actual rotation of brake drum with simultaneous application of brake load resulting more precise simulation. A sequentially coupled transient thermo-mechanical analysis is carried out using ABAQUS 6.12 simulation tool to predict the induced stresses/strains and fatigue life of the brake drum.

Annamalai, Krishnamoorthy, Naiju, Chooriyaparambil Damodaran

Setting Preload in Heavy-Duty Wheel Bearings

J2535_201910 (Current)10/7/2019

Truck and Bus Wheel Committee

Divergence of Thickness Loss vs. Weight Loss, Friction and Wear Behavior of Heavy Truck Brake Blocks: Development of a New Test Procedure for the Chase Tester

2019-01-21079/15/2019

Heavy truck brake blocks are found to swell (or expand) permanently during testing or usage, especially so at high temperatures, thus leading to longer durability as measured by thickness loss, similar to light vehicle disc pads. This swelling phenomenon occurs continuously in the layer adjacent to the friction surface during testing or usage; not a one time event. The thickness loss estimated from the weight loss is always greater than measured thickness loss. Brake block wear does not increase linearly with increasing normal load, and the load-sensitivity of block wear is very much dependent on the products. A new test procedure has been developed for generating friction-vs.-temperature and wear-vs.-temperature data at a constant temperature employing intermittent braking on the Chase Brake Lining Quality Tester (SAE J661) and friction material wear can be compared on equivalent-work basis.

Rathee, Aman, Sharma, Devendra Kumar, Singh, Shivraj, Rhee, Seong Kwan

Inboard Mounted Disc Brake Rotor/Disc Wheel Hub Interface Dimensions - Commercial Vehicles

J2696_201909 (Historical)9/3/2019

Truck and Bus Wheel Committee

Brake Block Effectiveness Rating

J1802_201906 (Current)6/6/2019

Truck and Bus Foundation Brake Committee

Physical and Virtual Simulation of Lightweight Brake Drum Design for Heavy Duty Commercial Vehicles Using Alternate Material Technologies

2018-01-189710/5/2018

Brake drum in commercial vehicles is very important aggregate contributing towards major weight in brake system module. The main function of brake drum is to dissipate kinetic energy of vehicle into thermal energy, as a results in braking operation major load comes on brake drum. Hence this is very critical component for vehicle safety and stability [1]. Objective of this paper is to increase the pay load, which is utmost important parameter for commercial vehicle end customers. To achieve the light weighing target, alternate materials such as Spheroidal graphite iron (SGI) has been evaluated for development of brake drum. Many critical parameters in terms of reliability, safety and durability, thickness of hub, wheel loading, heat generation on drum, manufacturing and assembly process are taken into consideration. The sensitivity of these parameters is studied for optimum design, could be chosen complying each other’s values. Digital thermal performance evaluated in house, fine-tuned and verified by correlating with test data available for existing cast iron design and then applied for new design with alternate materials. In two different designs around 10 Kgs weight saving per brake drum has been achieved as compared to conventional grey cast iron brake drum. Considering the most demanding 10x2 haulage platform in current commercial market approximately 100 Kgs payload increment for fleet owners was achieved, which will result in end customer profitability.

Kandreegula, Suresh Kumar, Deshmukh, Himanshu, Prasad, Shivdayal, Paroche, Sonu, Anil Shah, Ashesh

Truck Brake Failure: Differences between Failure Modes for Drum and Disc Brakes

2018-01-05284/3/2018

On-highway heavy trucks are fitted with air disc brakes with increasing frequency. Disc brakes and traditional air drum brakes have different adjustment and heat dissipation characteristics. These differences lead to different failure modes when overheated. This paper describes how adjustment and other in-use factors affect the general braking capability of on-highway trucks fitted with disc and drum brakes. Simulations of a loaded tractor-trailer on a long, down-hill grade are used to predict brake temperature increase over time, and how that temperature increase can result in a runaway condition. The tractor and trailer are modeled with both traditional drum brakes and new disc brakes to illustrate operational differences between the two brake types.

Day, Terry D.

Combined Hill Descent Braking Strategy for Heavy Truck in the Featured-Slope

2017-01-25359/17/2017

The continuous braking for the brake drum will cause the brake thermal decay when the heavy truck is driving down the long slope in the mountain areas. It reduces the heavy truck’s braking performance and the braking safety. The engine braking and the hydraulic retarder braking both consume the kinetic energy of the heavy truck and can assist the truck driving in the mountain areas. This research proposes a combined hill descent braking strategy for heavy truck based on the recorded information of the slopes to ensure the braking safety of the heavy truck. The vehicle dynamic model and the brake drum temperature rising model are established to analyze the drum’s temperature variation during the downhill progress of the heavy truck. Then based on the slope information, the combined braking temperature variation is analyzed considering the characteristics of the engine braking, the drum braking and the hydraulic retarder braking. The research result shows that the brake drum’s temperature decreases by 69.9°C and reaches 193.1°C after the heavy truck goes down the chosen slope with the combined braking strategy. The brake thermal decay of the brake drum could be avoided and the brake safety could be ensured after using the combined hill descent braking strategy.

Xu, Yongbing, Mei, Binyu, Xiao, Longjie, XIA, Wanyang, Tan, Gangfeng

The Effect of Commercial Vehicle Head-Up Display Reminding System on Driving Safety in Mountainous Area

2017-01-25009/17/2017

Head-up Display (HUD) system can avoid drivers’ distraction on dashboard and effectively reduce collisions caused by emergency events, which is gradually being realized by researchers around the world. However, the current HUD only displays information like speed, fuel consumption, other information like acceleration and braking can’t be displayed yet. This research will use the indicator symbol‘s color and position change to remind drivers to brake or accelerate. Drivers can do driving operation timely and accurately. The system has the advantages of safety, intuition and real-time. The vehicle safe speed is calculated according to the road parameters, like adhesion coefficient and slope, and vehicle parameters, such as vehicle mass and centroid. Then, the appropriate braking operations are obtained by combining the vehicle driving state. The braking information is corresponded to the color and position change of the indicator symbol to prompt the drivers by the HUD interface. At the same time, under different driving conditions, experiments will be carried out to find out the difference of driver’s braking operations when there is braking information presentation or there is not. The effects of different braking operations on driving safety performance will be evaluated. Compared with the condition of no braking information presentation, braking information presentation can make the start braking time ahead of schedule. In addition, the emergency braking situation will be reduced appropriately. The results show that the braking information presentation based on the HUD system has significant effects on improving driving safety.

Huang, Bo, Xia, Wanyang, Tan, Gangfeng, Xiao, Longjie, Wang, Zongsong

Conversion of Drum Brake System to Disc Brake with CAE and CFD: Resulted in Optimized Brake Rotor Design and Improved Performance

2017-26-02611/10/2017

Paper explains conversion of existing drum brake system to disc brake system with complete digital validation at structural as well as thermal level to make sure First Time Right Design before physical part development. To provide leverage to quick design, modification and selection of brake system according to vehicle configuration, a virtual computational fluid dynamics (CFD) simulation process is developed and validated with test results. Temperature variation over brake drum and disc in internal standard braking cycle is measured virtually and correlated with test results. Also Fade testing criteria’s were considered during CFD analysis. This up gradation is must considering technology enhancement trend and safety in automotive segment. In current competitive market scenario and as per customer requirements, front disc brake module is becoming necessary not only for passenger segment but also for commercial segment vehicle. Brake system design is challenging task as it deals with safety norms and also required to meet stringent performance. Brake Rotor is very important component in brake system which is expected to withstand high braking torque and dissipate heat during braking event. Hence proper design and selection of braking system is very important before implementing on vehicle. Also rigorous testing process to measure the temperature rise of disc, calliper and hub of brake system is very important along with physical testing at vehicle level. Brake rotor is major part of disc brake system and First step of development is design calculation, followed up with CAD model preparation and later on CAE. All vehicle level structural loads considered during digital/CAE validation and post structural analysis, CFD analysis is completed. Detailed brake thermal loading cycle in terms of braking heat flux, meshing methodology and simulation processes revealed in paper. A transient simulation of three different types of disc profile performed. In transient thermal simulation of brake system, maximum temperature rise over disc and pads at different location are monitored and evaluated. These were compared with similar case of drum brake system. Based on conduction heat loss and convection heat loss calculation, the brake cooling effect is evaluated. Finally after confirmation from CFD analysis Brake rotor/ Brake system design frozen. All digital simulation results co-related with physical rig level and vehicle level testing, and results were acceptable. Finally weight optimized disc brake system meeting all performance criteria implemented in 8 × 2 commercial vehicle at all wheel ends. It resulted in customer delight with 20% payload increment and performance improvement from drum brake system to Disc brake system.

Anil Shah, Ashesh, Patidar, Ashok

Test Component Specifications

J1802/1_201607 (Current)7/27/2016

Truck and Bus Foundation Brake Committee

Dimensional Compatibility for Commercial Vehicles Fitment of Complete Wheels in Drum Brake Applications - Truck and Bus

J1865_201607 (Historical)7/1/2016

Truck and Bus Wheel Committee

Disc Wheel and Hub or Drum Interface Dimensions - Truck and Bus

J694_201505 (Historical)5/12/2015

Truck and Bus Wheel Committee

Outboard Mounted Brake Drum/Disc Wheel Hub Interface Dimensions - Truck and Bus

J1671_201502 (Historical)2/20/2015

Truck and Bus Wheel Committee

Parametric Study of Hub Cum Brake Drum for Optimum Design Performance

2015-26-00791/14/2015

Brake drum is an important component in automotive, which is a link between axle and wheel. It performance is of utmost importance as it is related to the safety of the car as well to the passengers. Many design parameters are taken into consideration while designing the brake drum. The sensitivity of these parameters is studied for optimum design of brake drum. The critical parameters in terms of reliability, safety & durability could be the cross section, thickness of hub, interference & surface roughness between bearing and hub, wheel loading, heat generation on drum, manufacturing and assembly process. The brake drum design is derived by considering these parameters. Hence the sensitivity of these parameters is studied both virtually & physically, in detail. The optimum value of each parameter could be chosen complying each other's values. In this study it could be found that the proof stress for hub material can be crossed due to reasons of a) excess interference between wheel bearing and hub and uneven contact stress due to influence of form errors (cylindricity) & b) vehicle load transfer during cornering maneuvering condition. To have cost effective & optimum design performance of cast iron (CI) brake drum; it is compulsory and evident to study variation of all parameter under all operating & abuse conditions for the uncertain behavior of gray cast iron and manufacturing process variations.

Sahu, Ram Ranjan, Sinha, Jayant

Brake Block Effectiveness Rating

J1802_201410 (Historical)10/27/2014

Truck and Bus Foundation Brake Committee

Design and Development of Bimetal Brake Drum to Improve Heat Dissipation and Weight Reduction

2014-01-22849/30/2014

Automotive component light weighing is one of the major goals for original equipment manufacturers (OEM's) globally. Significant advances are being made in developing light-weight high performance components. In order to achieve weight savings in vehicles, the OEM's and component suppliers are increasingly using ultra-high-strength steel, aluminum, magnesium, plastics and composites. One way is to develop a light weight high performance component through multi material concept. In this present study, a bimetal brake drum of inner ring cast iron and outer shell of aluminum has been made in two different design configurations. In two different designs, 40 and 26% weight saving has been achieved as compared to conventional gray cast iron brake drum. The component level performance has been evaluated by dynamometer test. The heat dissipation and wear behavior has been analyzed. In both designs, the wear performance of the bimetal brake drum was similar to the gray cast iron material. The heat dissipation behavior of the bimetal brake drum in both designs was found to be better than conventional gray cast iron brake drum.

Raj, Sunil, Ravi Shankar, S

Latest Developments in the High Performance Machining of Cast Iron Brake Discs with PCBN and Ceramic Cutting Materials and Tailored Tooling

2014-01-25039/28/2014

The brake discs and brake drums used on motor vehicles are, in 90% of applications, made from grey cast iron. Although other designs such as composite systems comprising of a grey iron braking band and a light weight mounting bell made from aluminum, Al-MMC or entire ceramic brake discs have been developed, cast iron will continue to play a major role as a work piece material for brakes. Cast iron offers advantages in material characteristics such as good thermal conductivity, high compressive strength and damping capacity. In addition it shows a superior casting behavior and also an unbeatable competitive price per part, when compared to other brake materials or designs. Ongoing research in material and casting science are leading to new types of alloyed CI materials, fulfilling the increasing demands in terms of performance but also increasing the demands for a reliable and economical production. As a product of high volume production the economics and productive manufacturing of the brake discs is a fundamental issue to ensure the competitiveness of the manufacturers. The output and final cost per part are highly influenced by the manufacturing technology, the cutting materials and tooling systems applied. Further development of Ceramics and PCBN (Polycristalline Cubic Boron Nitride) cutting materials, customized tooling and work path planning are the basics for best machining results and minimum manufacturing costs.

Schneider, Johannes

Comparison of Various Concepts of Twin Leading Brake Performance by Method of Virtual Simulation

2014-01-25009/28/2014

Prevailing cut-throat competition in Indian Two wheeler market requires design engineers to enhance performance of traditional braking systems with reduction in cost and weight. The increasing need of road safety however requires the braking system to minimize stopping distance and increasing Mean Fully Developed Deceleration (MFDD). The purpose of this study is to augment the braking performance of two wheeler by comparing various combinations of twin leading drum brake layouts by method of Virtual Simulation. The conventional drum brake system utilizes one cam, one pivot, one leading shoe member and one trailing shoe member. In the event of braking, leading shoe causes the generation of drag force. The other shoe is “trailing”, moving against the direction of rotation, is thrown away from the friction surface of the drum and is far less effective. The present study highlights the incorporation and enhancement of braking characteristics of bigger brake drum system into smaller brake drum system through the adoption of double leading shoe concept with the added advantage of reduction in cost. The study necessitates the designing of a multi body dynamic model so as to extract the best braking performance with respect to typical braking system against different double leading shoe geometry and actuation mechanisms.

Ghosh, Shiwalik, Anthonysamy, Baskar, Kaushik, Ravi

SAE Off-Highway Engineering 2013-10-17

13OFHD101710/17/2013

Heavy-duty composite brake crack prediction Engineers used both analytical and dynamometer data to determine the damage tolerance of a selectively reinforced aluminum MMC brake drum, which provided some answers but left a lot of questions.

Parking Brake Lock Clip Design Process and Failure Analysis in the Rear Brake Drum

2013-01-20499/30/2013

The aim is to analyse the various causes of failure of lock clip in Parking Brake Cable which comes out of its place rendering the emergency or the parking brake ineffective and to come up with feasible solutions so that the parking cable doesn't comes out of the rear brake drum.

Singh, Jaideep, Chaudhary, Anshika, Kumar, Sanjeev, Batra, Lakshya

Service Brake Structural Integrity Test Procedure - Passenger Car

J229_201306 (Current)6/12/2013

Road Test Procedures Standards Committee

Analysis of Drum Brake System with Computational Methods

2013-36-00225/15/2013

1 Commercial vehicles have been more and more equipped with more powerful engines allowing considerable increase in size and load capacity. With this increase in capacity, it becomes important to evaluate the efficiency of the brake system to ensure vehicle safety during transportation of people and materials. Braking efficiency of a vehicle is significantly affected by the heat generated by friction between stationary components and rotors. This heat raises the temperature of the components in brake assembly reducing the friction coefficient at the interface between brake lining and drum. Once the friction coefficient is reduced, the braking torque decreases. As consequence, it may cause undesirable scenarios such as braking performance loss due to overheating, tire burst, hub grease melting, brake lining failure, thermal cracking, geometric distortions and brake locking. All these scenarios directly impact the vehicle safety, generating demand for accurate predictions of components temperatures and thermal efficiency in the early stage of development. The purpose of this work is to use computational methods to simulate the cooling effect on the drums in order to provide necessary improvements in the final design of the brake. The present study describes the thermal behavior of a drum brake assembly of a MAN commercial truck by using of Computational Fluid Dynamics technique (CFD). The validation of this method will bring several benefits to the brake development, like reduction of the design time and reduction of the prototype and application tests costs. This paper describes CFD analysis of the unsteady heat dissipated through the truck rear wheels components (including hubs, brake drums, brake linings, rims and tires) after one typical cycle of brake application. After computational simulation, CFD results were validated using a dataset obtained from experimental tests.

Travaglia, Carlos Abilio Passos, Araujo, Joao, Bochi, Marcelo, Yoneda, Adrian, Costa, Alvaro, Souza, Alysson, Cunha, Rodivaldo, Beninca, Evandro

Avoiding False Positive Asbestos Analysis in Polymer Matrix Composite Brake Linings

2013-01-04934/8/2013

Asbestos has been banned in many countries as industrial material, however the utilization of those fibers in brake linings results in friction properties that are so convenient, that linings containing them are still commercially available. To replace asbestos a large number of mineral phases is utilized in the formulation of polymer based friction material, and it is sometimes difficult to establish if they are present or not in finished brake pads and linings. Several clay minerals have been mistaken for asbestos because they present X-ray diffraction peaks that overlap with the diagnostic asbestos peak. A method to distinguish between the presence of regulated fiber minerals and allowed clay minerals in brake linings is presented using X-ray diffraction in association with a thermal treatment.

Hinrichs, Ruth, Vasconcellos, Marcos A.Z.

Setting Preload in Heavy-Duty Wheel Bearings

J2535_201302 (Historical)2/11/2013

Truck and Bus Wheel Committee

Light-Weight Aluminum Composite Brake Drum Damage Tolerance

2012-01-19229/24/2012

The use of Aluminum Metal Matrix Composites (MMC's) is becoming a viable solution to help meet the new regulations of the medium to heavy-duty truck markets. The objective of this paper is to present both analytical and dynamometer data that demonstrate the damage tolerance of a selectively reinforced Aluminum MMC brake drum. In particular, dissimilar coefficients of thermal expansion (CTEs) between the MMC and Aluminum portion of the drum results in favorable compressive stresses in the Aluminum. This state of stress facilitates the slowing of crack growth for flaws whose depth reaches the boundary between MMC and Aluminum. This paper will present an analytical study utilizing finite-element models to predict stress levels in a drum subject to thermal and mechanical loading. Examination of the stress-fields for braking events at room temperature and elevated temperature provides evidence of the aforementioned compressive stresses in the Aluminum portion of the drum. Additionally, fracture mechanics methods are utilized to calculate crack propagation for a particular event. The analytical approach for crack growth prediction utilizes the finite element models of the brake drum in combination with a detailed submodel, into which cracks were introduced at various depths. ANSYS was used to calculate stress intensity factor at each crack depth for the duty cycle under consideration, followed by a calculation of crack depth verses loading cycles. Dynamometer testing was also completed which demonstrates this damage tolerance. Dynamometer data will be presented that shows MMC's maintain performance under certain test cycles even with a crack in the aluminum MMC brake drum. In short, these simulation tools, models, and data demonstrate that aluminum MMC components can be a viable way to offer new technology solutions for the medium to heavy duty truck markets.

Kero, Matt, Hewer, Thomas, Zills, Jeremy

Inboard Mounted Disc Brake Rotor/Disc Wheel Hub Interface Dimensions - Commercial Vehicles

J2696_201205 (Historical)5/29/2012

Truck and Bus Wheel Committee

Hot Powder Preform Forging Technique for Making Brake Pad

2011-28-007610/6/2011

The present study deals with development of iron based MMC employed for brake pads by ‘Hot Powder Preform Forging’ technique. The conventional technique i.e. Compacting and sintering for manufacturing metalloceramic brake pads was successfully and economically replaced by using above process. Higher density levels can be achieved by hot powder pre-form forging technique hitherto not possible by sintering route. The mechanical properties of these materials were characterized using ASTM standards. Compacting and sintering technology suffers from certain major limitations such as inadequate joining of friction element with backing plate, poor density levels achieved in friction element owing to limited application of pressure during compacting, poor thermal conductivity due to high levels of porosity in the product, poor strength due to segregation of the impurities along prior particle boundaries (PPB's), anisotropy in the strength of the product owing to preferred direction due of pressing, and, wide variations in final characteristics due to large number of variables involved. Besides above, cost of raw material and consumables along with heavy capital equipments makes this technique costly and only large scale production is possible where these costs are distributed in the large volume of production. In contrast to these limitations, the present technique can offer brake pads of much simpler chemistry but with improved performance on account of simultaneous application of pressure and temperature and with better control of variables.

Ghazi, A. A. S., Chandra, K., Misra, P. S.

Test Component Specifications

J1802/1_201105 (Historical)5/16/2011

Truck and Bus Foundation Brake Committee

SAE Off-Highway Engineering 2011-02-04

11OFHD02042/4/2011

A quiet revolution Optimizing design, while minimizing NVH, in off-highway equipment and systems. Inferential sensing Engineers propose an onboard electronics hardware and software architecture that can deliver condition-based maintenance solutions in a low-cost platform. Lightweight but heavy duty A look at the design, analysis, testing, and application engineering performed to develop a selectively reinforced brake drum made of aluminum metal matrix composite. Shifting gears smoothly Ric Kleine, a 30-year veteran of Cummins Inc. and former SAE Commercial Vehicle VP, seeks continuity over change as he moves into SAE's driver's seat.

Theoretical Modeling and FEM Analysis of the Thermo-mechanical Dynamics of Ventilated Disc Brakes

2010-01-00754/12/2010

Prediction and analysis of the thermo-mechanical coupling behavior in friction braking system is very important for the design and application of vehicle brakes, such as brake judder, brake squeal, brake wear, brake cracks, brake fade. This paper aims to establish a macro-structural model of the thermo-mechanical dynamics of the ventilated disc brake with asymmetrical outer and inner disc thickness, taking into account the friction-velocity curve of the disc pad couple acquired by testing. On the basis of finite elements analysis of the model, the predictions of the thermo-mechanical responses of the brake disc are presented, including disc transient temperature field and normal stress in radial, circular and axial directions, disc lateral deformation and disc thickness variation. Numerical predictions of the disc surface temperature and later distortion are compared with experimental measurements obtained by thermocouples and non-contact displacement sensors. Simulation results show complex interactions among frictional, thermal and mechanical dynamics, affected by the asymmetrical outer and inner disc thickness, which can be concluded from the detailed observation over the calculated curves. Such a model seems to be a suitable base for the study of the thermo-mechanical behavior and for the design of disc brakes.

Zhang, Lijun, Meng, Dejian, Yu, Zhuoping

Effects of Chemical Components and Manufacturing Process of Cast Iron Brake Disc on its Resonant Frequency Variation

2009-01-303010/11/2009

Many engineers have been working to reduce brake noise in many ways for a long time. So far, a progress has been made in preventing and predicting brake noise. Nevertheless, there are some discrepancies of brake noise generation propensity between testing for the prototype and the production. As known in general, the reason for this unpredicted brake noise occurrence in production is partly due to the variation of the resonant frequency, material and the other unpredictable or unmanageable variations of the components in a brake system. In this paper, effects of chemical components and casting process of gray iron brake disc on its resonant frequency variation have been studied. Especially this paper is focused on the variation in material aspects and manufacturing parameters during disc casting in usual production condition. And their effects are investigated by the variation of out-of-plane modal resonant frequency.

Lee, Jae Young, Park, Hyun Dal, Kim, Seong Jin, Han, Jae Min, Kim, Yoon Cheol, Lim, Jong Dae, Kim, Jeong Kyu

Experimental Research on Heavy-Duty Tractor Heat Performance of Brake

2009-01-303910/11/2009

From the viewpoint of energy conservation and transformation, this paper researches on the braking heat generation and brake temperature change characteristics during heavy-duty tractors brake, and a temperature-predicting model of brake drum is established. According to this model, firstly the entire vehicle kinetic energy is distributed thrice between front and rear axle, tire and road surface friction and sliding friction between hoof and drum, between linings and brake drum, and then the input heat of each drum brakes is figured out through the transformed kinetic energy. Secondly, each brake drum absorbs the heat and results in temperature rise, and dynamics temperature of brake drum is calculated considered cooling due to radiation, conduction, and convection. Thirdly, according to a heavy-duty tractor cooling tests curves under different velocities, heat descending time and convection coefficient are enacted as two evaluation parameters of drum heat diffusivity; therefore the index formula of convective coefficients is induced. Finally, the repeated brake tests in accordance with national compulsory standards are carried out to verify the brake drum thermal model, and the result indicates that values of calculation have good consistency with the experimental results, then the model can be used to predict the brake hot performance in the design phase of heavy-duty tractor, so as to shorten the vehicle development cycle and reduce test cost.

Wang, Xuanfeng, Liang, Yingchun, Huang, Chaosheng, Ying, Guozeng

A Low-Cost Material Design of Gray Iron for Heavy-Duty Brake Drums

2009-01-02164/20/2009

For heavy-duty brake drums and rotors, grade G3500 is commonly used per SAE J431. Numerous studies have shown that grade G3500 alloyed with molybdenum (Mo) and nickel (Ni) is necessary in many heavy-duty applications. Because of the recent rapid rise in raw material costs of Mo and Ni, and the manufacturers’ inability to pass the costs onto the customers, there is a real need to develop new chemistries that will provide a relief to the cost pressure while maintaining the performance of the parts. In this paper, a low cost chemistry is proposed based on a material design concept that is centered on the microstructure design, which in turn is based upon the performance requirements of the parts. The chemical composition and casting processes are subsequently constructed to achieve a set of pre-described microstructure characteristics. Dynometer tests of simulated road conditions and limited road tests have shown that the brake drums made with new low-cost chemistry exhibited equal or better performances than the parts made with the existing higher cost chemistry.

Huang, Yanjun

Brake Block Effectiveness Rating

J1802_200812 (Historical)12/17/2008

Truck and Bus Foundation Brake Committee

Effect of Thermo-Mechanical Behavior on Drum Brake Labyrinth Design

2008-32-00669/9/2008

In low speed bikes drum brakes are used on large scale. In drum brake system, brake shoes are relatively more enclosed by neighboring parts compared to disc brakes. Hence, drum brake cooling is not efficient like disc brake. This results in higher steady state temperature, which may lead to brake noise, brake fading, glazing etc. in drum brakes. Further, the high temperature plays a key role for design of labyrinths too. Hence, designing of the drum brakes for extreme heating is critical. This paper elucidates the thermo-mechanical behavior in two-wheeler drum brakes under extreme braking and their consequence manifesting itself in permanent distortions resulting in the brake failure. Experiments as well numerical simulations are carried out to investigate the thermo-mechanical behavior of drum brakes. Experiments are conducted at extreme braking for maximum thermal loading on the drum brake. The rise in temperature of the drum is measured with sensor. The generated heat energy causes brake drum to expand both in lateral and radial directions. Under extreme braking condition rubbing of brake drum with brake panel is observed in the case of low clearance between drum and panel. Hence it is important to design the drum braking system taking extreme thermal loading into consideration. At design stage it is essential to predict the proper clearances and dimensions of the drum brake for better thermal performance and safety. Numerical simulations are conducted to predict the thermal behavior of drum brakes under severe braking condition. Finite element analysis has been performed with commercially available software. Thermal expansion comparisons are made between spoke wheels and alloy wheels. The simulation method is useful for design validation of the drum brake system upfront of the product development.

Singh, Om Prakash, Mohan, S., Mangaraju, Venkata, Babu, R.

Creating an Automated Brake Inspection System with Machine Vision

TBMG-135916/1/2008

A Tier 1 automotive supplier of brake drum assemblies with customers here and abroad has tried a number of different vision systems for brake drum assembly inspection, but have had very limited success. The main problem with the previous systems was their dependence on using pattern matching, which proved inadequate in handling the wide variations and complexities in the assemblies.

“Sticky” Lining – the Phenomena, Mechanism and Prevention

2008-01-08194/14/2008

An unique bonding mechanism was studied after several instances, where the linings stuck to the brake drums on transit buses, were reported. Evidences suggested that the linings were “glued” to the brake drums surface after wear debris (dust) was turned into “adhesive paste” through complicated thermal and chemical changes. Factors such as the friction materials, environment and service conditions, which could activate and deactivate the lining bonding, were observed and discussed. The prevention measures are proposed.

Huang, YJ (Yanjun), Wen, Xinyu, Zhu, Yulong

Dimensional Compatibility for Commercial Vehicles Fitment of Complete Wheels in Drum Brake Applications—Truck and Bus

J1865_200707 (Historical)

7/31/2007

This SAE Recommended Practice defines a clearance line for establishing dimensional compatibility between drum brakes and wheels with 19.5 in, 22.5 in, and 24.5 in diameter rims. Wheels designed for use with drum brakes may not be suitable for disc brake applications. The clearance line establishes the maximum envelope for brakes and minimum envelope for complete wheels to allow for interchangeability. This document addresses the dimensional characteristics only, and makes no reference to the performance, operational dynamic deflections, or heat dissipation of the system. Valve clearances have not been included in the fitment lines. Bent valves may be required to clear brake drums. Disc brake applications may require additional running clearances beyond those provided by the minimum contour lines. Mounting systems as noted are referenced in SAE J694.

Truck and Bus Wheel Committee

Disc Wheel/Hub or Drum Interface Dimensions—Truck and Bus

J694_200706 (Historical)

6/21/2007

This SAE Recommended Practice contains dimensions and their tolerances concerning disc wheel to hub or drum interface areas for commercial vehicles and multipurpose passenger vehicles. Stamped disc wheels for single applications and special or less common applications are not covered in this document.

Truck and Bus Wheel Committee