Showing papers on "Disc brake published in 2012"

Prediction of the cooling factors of a vehicle brake disc and its influence on the results of a thermal numerical simulation

Abstract: In the process of developing the brake disc, it is necessary that we predict the suitability of the design. In this manner, we can affirm that even the first prototype will satisfy all of the customer homologation requests. Usually those comprise different sequential braking tests in which the maximal achieved temperature is the criterion that governs brake disc suitability. The knowledge of how to predict the behavior of a brake disc in the early pretesting phase has a significant impact on development costs and time. The common method that is used for predicting the temperatures in the brake disc during braking is numerical simulation analysis. With the help of Computational Fluid Dynamics, the flow through a vehicle ventilated brake disc of known geometry was determined, and the wall heat transfer coefficients for all vehicle speeds and brake disc temperatures were calculated. The results were then imported into a thermal numerical simulation of a sequential-braking vehicle test. The results showed that the consideration of cooling factors has a significant impact on temperature courses. To obtain accurate results from the numerical simulation and to simulate the vehicle test precisely, the proper wall heat transfer coefficients must be considered. The proposed method produces more accurate numerical results and enables the development engineer to develop suitable brake disc geometry in the early pretesting phase.

Disk brake hub assembly

Abstract: A brake hub assembly including a brake hub and a brake disk having a first brake surface, a second brake surface spaced axially from the first brake surface, and a plurality of ribs extending between the first and second brake surfaces. Where the brake hub is thermally isolated from the brake hub by various combinations of spacers, torque pins, torque lugs, and the like.

Intelligent control of braking process

Abstract: Intelligent modeling, prediction and control of the braking process are not an easy task if using classical modeling techniques, regarding its complexity. In this paper, the new approach has been proposed for easy and effective monitoring, modeling, prediction, and control of the braking process i.e. the brake performance during a braking cycle. The context based control of the disc brake actuation pressure was used for improving the dynamic control of braking process versus influence of the previous and current values of the disc brake actuation pressure, the vehicle speed, and the brake interface temperature. For these purposes, two different dynamic neural models have been developed and integrated into the microcontroller. Microcontrollers are resource intensive and cost effective platforms that offer possibilities to associate with commonly used artificial intelligence techniques. The neural models, based on recurrent dynamic neural networks, are implemented in 8-bit CMOS microcontroller for control of the disc brake actuation pressure during a braking cycle. The first neural model was used for modeling and prediction of the braking process output (braking torque). Based on such acquired knowledge about the real brake operation, the inverse neural model has been developed which was able to predict the brake actuation pressure needed for achieving previously selected (desired) braking torque value in accordance with the previous and current influence of the pressure, speed, and the brake interface temperature. Both neural models have had inherent abilities for on-line learning and prediction during each braking cycle and an intelligent adaptation to the change of influences of pressure, speed, and temperature on the braking process.

Selection of Best Formulation for Semi-Metallic Brake Friction Materials Development

Abstract: Brake friction materials play an important role in braking system They convert the kinetic energy of a moving car to thermal energy by friction during braking process The ideal brake friction material should have constant coefficient of friction under various operating conditions such as applied loads, temperature, speeds, mode of braking and in dry or wet conditions so as to maintain the braking characteristics of a vehicle Besides, it should also posses various desirable properties such as resistance to heat, water and oil, has low wear rate and high thermal stability, exhibits low noise, and does not damage the brake disc However, it is practically impossible to have all these desired properties Therefore, some requirements have to be compromised in order to achieve some other requirements In general, each formulation of friction material has its own unique frictional behaviours and wear-resistance characteristics

Bicycle disc brake rotor

Abstract: A bicycle disc brake rotor basically has an outer portion, an inner portion and an intermediate portion. The outer portion is made of a first material. The inner portion is made of the first material. The intermediate portion is disposed between the outer portion and the inner portion. The intermediate portion is made of the first material. The intermediate portion is partially laminated by a layer made of a second material. The second material is different from the first material. The layer has a contour tracing a contour of the intermediate portion.

Thermal behavior of full and ventilated disc brakes of vehicles

Abstract: Braking is a process which converts a vehicle’s kinetic energy into mechanical energy which must be dissipated in the form of heat. During the braking phase, the frictional heat generated at the interface of the disc and pads can lead to high temperatures. This phenomenon is even more important than the tangential stress. The relative sliding speeds during contact are also important. The prediction of surface temperature for a brake rotor is regarded as an important step in studying brake system performance. The frictional heat generated on the rotor surface can influence excessive temperature rise which, in turn, leads to undesirable effects such as thermal elastic instability (TEI), premature wear, brake fluid vaporization (BFV) and thermally excited vibrations (TEV). The objective of this study is to analyze the thermal behavior of the full and ventilated brake discs of the vehicles using computing code ANSYS. The modeling of the temperature distribution in the disc brake is used to identify all the factors and the entering parameters concerned at the time of the braking operation, such as the type of braking, the geometric design of the disc and the material used. The results obtained by the simulation are satisfactory compared to those of the specialized literature.

Coupled structual / thermal analysis of disc brake

Abstract: The motive of undertaking this project of “Coupled Structural / Thermal Analysis of Disc Brake” is to study and evaluate the performance under severe braking conditions and there by assist in disc rotor design and analysis. This study is of disc brake used for cars. ANSYS package is a dedicated finite element package used for determining the temperature distribution, variation of stresses and deformation across the disc brake profile. In this present work, an attempt has been made to investigate the effect of stiffness, strength and variations in disc brake rotor design on the predicted stress and temperature distributions. By identifying the true design features, the extended service life and long term stability is assured. A transient thermal analysis has been carried out to investigate the temperature variation across the disc using axisymmetric elements. Further structural analysis is also carried out by coupling thermal analysis.

Calliper body for disc brake

Abstract: Calliper body (4) for disk brake having two elongated elements (5 and 6) on opposite sides of the disk and suitable for supporting and pressing pads (13 and 14) against the disk (2), each of said 'elongated bodies (5 and 6) comprising an exit portion (97) of thrust means suitable for facing one of said pads (13, 14), each of said exit portions (97) having a boundary (96) delimited on the opposite side to the rotation axis (9) by an upper boundary (98) which borders a radially outer portion (21, 22) of the elongated body, said calliper body (4) having at least one connection bridge (3) with an inner bridge side (30, 31) facing towards the calliper body, said radially outer portion being divisible, along its direct tangential extension parallel to the circumferential direction, into three substantially equal sections (23, 24, 25 or 26, 27, 28), of which two lateral sections (23 and 25 or 26 and 28) and one interposed central section (24, 27), wherein said calliper body (4) comprises at least one reinforcement element (41, 42, 43, 44) suitable for firmly connecting one said inner bridge side (30, 31) to one said central section (24, 27) of the adjacent radially outer portion (21, 22), said at least one reinforcement element at least partially surmounting said upper boundary (98) and said pads (13 and 14); and wherein the crossing of the projection in a direction parallel to the axial direction (9) of the central section (24, 27) of the radially outer portion (21, 22), with the projection in a circumferential direction of the central section (33, 36) of the bridge side (30, 31), defines a radial through aperture (20) which places the space between the elongated bodies (5,6) in communication with the outside of the calliper body (4) so as to permit the outflow of hot air from inside the calliper body (4) outwards.

Power generating apparatus of renewable energy type and method of attaching and detaching blade

Abstract: It is intended to provide a power generating apparatus of renewable energy type in which a braking mechanism is attached to a rotor arranged upstream of a hydraulic transmission while saving space, and a method of attaching and detaching a blade for the apparatus. The power generating apparatus of renewable energy type is provided with: a rotor having a hub and a main shaft, the hub having at least one blade mounted thereon, the main shaft being coupled to the hub; a generator which generates power by torque inputted from the rotor; and a hydraulic transmission which transmits the torque from the rotor to the generator. A brake disc is fixed to the rotor by tightening together with the hub and the main shaft. A brake caliper is provided to force a brake pad against the brake disc to apply a braking force to the rotor.

Brake cylinder device and disk brake device

Abstract: Provided is a compact brake cylinder device capable of increasing the brake force output from a brake output unit that moves along with a rod, without requiring the device to be made larger. A piston (24) sections off a pressure chamber (43) within a main cylinder (20a), surrounds the axial periphery of a rod (22), and moves in a direct line parallel with the direction of motion of the rod (22). With the supply of a pressure fluid to the pressure chamber (43) the piston (24) moves outward relative to the main cylinder (20a) in opposition to the biasing force of a rod-biasing spring (23). An oscillating member (46) of a force-multiplying mechanism (25) is biased by the piston (24) moving in the outward direction, oscillates, and biases the rod (22), causing the rod (22) to move in the forward direction. In this way, the force-multiplying mechanism (25) multiplies the drive force from the piston (24) so as to act on the rod (22). The brake output unit (21) moves in the forward direction along with the rod (22) and outputs brake force.

Stress and Temperature Distribution Study in a Functionally Graded Brake Disk

Abstract: In this paper, finite element elastic contact analysis of a functionally graded (FG) hollow brake disk in contact with pad, subjected to rotation, contact pressure and frictional heat is presented. The material properties vary through the thickness according to a power-law characterised by a grading index, n. The material property is purely steel at the core part and gradually moves and approaches to the ceramic properties at the surfaces of the FGM disk. In this task, thermal analyses are performed on two ventilated disk brake one of them is constructed of functionally graded composite material and the other is a homogeny disk brake which is constructed of steel alloy. In this study three-dimensional finite element model and ABAQUS software is used. Through comparison of temperature and displacement fields the benefits of using functionally graded material is investigated. It is shown that temperature variation in FGM disk is much lower than steel disks, it may be concluded that FGMs disk restrain the growth of thermal perturbation and delay the contact separation ..

Research of the Transient Temperature Field and Friction Properties on Disc Brakes

Abstract: According to the real dimension of the braking disc, the finite element modeling for three-dimensional transient cyclic symmetry during the long downhill braking is established. The distribution of the transient temperature field of the brake disc during the braking are analyzed. The variation of the friction factor combined with the temperature characteristics of the friction factor during the braking are analyzed. The analysis result show: During the braking, the temperature of the brake rises increasingly and reaches the top temperature of 316.04°C at the end of braking process, the high temperature section concentrates in the far area of the friction surface; The changes of the friction factor is relatively stable during the long downhill braking. There is no obvious thermal recession. (Abstract)

Simulation braking bench for automobile disc brake

Abstract: The utility model discloses a simulation braking bench of an automobile disc brake and belongs to the technical field of automobile testing. A frequency converter is connected with a frequency conversion motor, the frequency converter is connected with a torque and rotation speed sensor through an elastic pin coupler, two spindles are fixed on a middle rack through four bearing bases, the spindles are connected with the torque and rotation speed sensor through the elastic pin coupler, and the two spindles are connected together through the elastic pin coupler, fly wheels are arranged on the spindles, and a slipping toothed electromagnetic clutch is arranged between each fly wheel and the corresponding spindle. A braking system is an automobile control system real object, fixed on a right rack through a support and connected with the spindles through couplings. An air cross-ventilation device is arranged beside a braking disc, an eddy current vibration measuring sensor is installed on a braking caliper, a thermal imager and an acoustic meter are placed nearby the braking caliper, and a positive pressure sensor is embedded in a braking sheet. The simulation braking bench can simulate working of the braking system authentically, so that the whole simulation progress approaches the rear condition, and the detection data are reliable.

Floating type train brake pad capable of replacing friction block

Abstract: The invention discloses a brake pad which is applied to a disc type brake system of a high-speed train. A friction block constituted by the brake pad can be flexibly replaced. The brake pad comprises a brake pad back plate which is made of a metal material, an elastic supporting sheet, the friction block and a circular spring clamp, wherein the elastic supporting sheet is provided with a spherical supporting surface and a central guide hole; the lower part of the friction block is provided with a spherical supporting surface and a positioning and connecting shaft which is provided with a clamping groove; the connecting shaft can penetrate through the central guide hole and a back plate positioning hole of the elastic supporting sheet and is locked on the back plate by the circular spring clamp to realize floating connection; the friction block is provided with a polygonal block with a blind hole in the center; and every three friction blocks form an interlocking group, so that the rotation of the friction block during working of the brake pad is prevented. The brake pad can achieve the maximum contact friction area of the brake pad and a brake disc in a train braking process, so that the braking process is stable and the brake pad has the functions of damping, vibration reduction, noise reduction, heat dissipation and the like. The friction block is easy to replace, so that the train operation cost is lowered.

In-wheel motor system

Abstract: An in-wheel motor system capable of maximizing the efficiency in using a wheel space by improving a mounting structure thereof, the in-wheel motor system installed at a wheel of a vehicle to transmit a rotational force including an axle installed at the wheel of the wheel and rotating together with the wheel, an in-wheel motor mounted inside the wheel and provided with a rotor and a stator that are used to generate a rotational force to drive the wheel, the rotor, and the stator disposed to face each other while having an accommodation space thereinbetween, a cycloid decelerator installed at a center of the in-wheel motor, and provided with an output shaft to transmit a rotational force at a reduced speed from the in-wheel motor to the axle and an input shaft that passes through the in-wheel motor and rotates together with the rotor, a disc installed at one end portion of the input shaft that protrudes by passing through the in-wheel motor, and a disc brake configured to provide a braking force by pressing the disc, wherein the in-wheel motor and the cycloid decelerator are disposed in a space formed inside the wheel.

Brake lining for railroad car

Abstract: A brake lining for a railroad car brake includes friction members which are pressed onto the sliding surface of a brake disc, and a back plate which is attached to a brake caliper in order to support the friction members. The friction members are dividedly arranged in a radial direction and in a circumferential direction of the brake disc. A disc spring is disposed between each respective friction member and the back plate. An outer peripheral surface of the friction members facing the back plate is formed in a convex curved shape in an area outside the elastic member. When a light pressing force is applied, a pressing force is transmitted from the back plate to the friction members via the disc springs. When a heavy pressing force is applied, the back plate and a rounded surface portion make contact, thereby directly transmitting a pressing force to the friction members.

Guide Pin For Disc Brake Assembly And Disc Brake Assembly Including Such A Guide Pin

Abstract: A disc brake assembly comprises: an anchor bracket having at least one bore formed therein, the bore defining a first axis; a brake caliper slidably secured to the anchor bracket; a pair of brake pads carried by the disc brake assembly; and at least one guide pin adapted to be disposed in the bore of the anchor bracket, the at least one guide pin defining a second axis; wherein when the at least one guide pin is disposed in the at least one bore of the anchor bracket, the second axis of the at least one guide pin is configured to be offset relative to the first axis of the at least one bore such that there is provided at least one defined point of contact between only a portion of a shank portion of the at least one guide pin and a portion of an inner surface of the at least one bore.

Disc for disc brakes

Abstract: A disc for a disc brake comprises a supporting bell (2), a braking strip (3) coaxial with the bell, and a plurality of cylindrical pins for connecting the braking strip (3) to the supporting bell (2). The pins project from radial sockets (7) formed in the supporting bell (2) to engage in corresponding blind holes (8) formed in the braking strip (3). Advantageously, the pins are fixed immovably to the braking strip (3) and are housed in the radial sockets (7) of the supporting bell (2) in such a way that they can slide radially, so as to allow the braking strip (3) to expand radially, thus remaining coplanar with itself.

In-Vehicle Brake System Temperature Model

Abstract: The brakes system is critical with respect to vehicle safety. One situation during which the brake system is put to the test is an Alpine descent. Such a descent causes very high brake system temperatures and may even induce brake fluid vaporization. In following report an In-Vehicle Brake System Temperature Model is developed and tested. This model makes use of the information that is available on the vehicle CAN-bus in order to estimate the temperature of the brake system and detect the risk of brake fluid vaporization. Implementing such a model in production vehicles would improve vehicle safety and in the long run allow downsizing of the brake system without giving in on any safety margins. Firstly, possible approaches for estimating the amount of kinetic energy that is converted into heat by the brake system are investigated. A Feed-Forward model is developed that uses the pressure in the primary hydraulic circuit as input. The problem with such a Feed-Forward Model is that the friction coefficient is variable. A Feed-Back model that uses the vehicle deceleration as input gives better results. The challenge in this approach lies in the fact that not all required inputs for the Feed-Back Model are known. Secondly, the Temperature Estimation Model is developed. This is composed of models of different parts of the brake system which are combined and matched to the measurements. The brake disc is modeled as a lumped mass. The brake pad is modeled as a Finite Difference Thermal Model. The fluid and surrounding caliper are modeled as one lumped mass which receives its heat through conduction from the brake pad and spreads the heat into the surroundings by means of convection. Finally, for the Human Machine Interface, several active and passive intervention concepts are proposed. One important challenge to take into account is the uncertainty in the brake fluid boiling temperature, which decreases over the course of time due to brake hygroscopic effects.

Brake assembly including independently activatable brake actuators

Abstract: A braking system may include a plurality of independently activatable groups of brake actuators, which may allow the braking force applied to a brake disc stack to be modified, e.g., in response a type of braking event. In some examples, a braking system comprises a brake assembly that includes a brake stack and a plurality of brake actuators. Each brake actuator may be configured to compress the brake stack when the brake actuator is activated. The braking system may further comprise a processor configured to detect a first type of braking event and, in response, activate a first number of brake actuators to compress the brake stack. The processor may further be configured to detect a second type of braking event and, in response, activate a second number of brake actuators to compress the brake stack, the first number being less than the second number.

Surface anti-oxidation processing method for aircraft carbon brake disc

Abstract: The invention discloses a surface anti-oxidation processing method for an aircraft carbon brake disc, which comprises the following steps: firstly, coating a layer of phosphate coating solution on the surface of a material needing to be processed, and forming a bottom phosphate coating through high temperature heat treatment; secondly, coating a layer of slurry coating which uses refractory ceramic powders as the main raw material and uses the phosphate coating solution as solution on the surface of the bottom phosphate coating; and finally forming a composite coating through the high temperature heat treatment. The composite coating of the invention has anticatalytic effect, and can improve the high temperature anti-oxidation capacity of C/C composite materials, such as the aircraft carbon brake disc and the like, under the condition of sea or salt spray pollution; and the ceramic component in the composite coating is melted and flows at high temperature so as to effectively heal thecrackles in the coating, delay the time that oxygen is contacted with C/C materials, and improve the oxidation resistance of the composite coating.

Production method of ceramic automobile braking friction plate

Abstract: The invention relates to a vehicle braking friction material and an improvement technique for a production method thereof, in particular to a ceramic automobile braking friction plate. The ceramic automobile braking friction plate comprises the following components in percentage by weight: 3 to 6 percent of organic silicon modified phenolic resin, 2 to 10 percent of super cotton ceramic fibers, 1to 6 percent of organic fibers, 2 to 10 percent of sage green silicate short fibers, 2 to 6 percent of one or two of metallic copper and metallic aluminum, 2 to 15 percent of porous coke, 4 to 12 percent of graphite, 2 to 10 percent of noise reduction agent, 2 to 8 percent of rubber granules, 2 to 8 percent of metal sulfide and the balance of performance regulator. The production method comprisesthe steps of rear panel preparation, raw material treatment, weighing and proportioning, mixing, blank pre-formation, hot pressing and sizing, thermal treatment and curing, burr removal and spraying,chamfer flat-grinding, surface coking, marking, packing and warehousing. The ceramic automobile braking friction plate solves the problems that the conventional asbestos type and semi-metal type friction plates cannot meet the requirements of high-end markets and the production process is relatively laggard, and the ceramic automobile braking friction plat is mainly applied in an automobile disk brake.

Effects of Pad Surface Topography on Disc Brake Squeal

Abstract: Brake squeal has always been a major NVH problem to many car makers due to significant number of warranty claims. Brake squeal is a high frequency noise (above 1 kHz) emanating from car disc brakes that get excited due to one or more mechanisms such as mode coupling, stick-slip, hammering and sprag-slip. This paper attempts to investigate the effects of brake pad surface topography on squeal generation. Two pairs of a non-asbestos organic (NAO) brake pad will be tested on a brake dynamometer test rig. Surface topography of the brake pad will be analyzed through microscopic techniques using energy dispersive X-ray analysis (EDX), and optical microscope.

Method for determining wear state of wear of brake lining on wheel brake of motor vehicle brake assembly, involves detecting operating force exercised by operation process on break, and compensating temperature dependence of brake

Abstract: The method involve detecting a parameter e.g. operation stroke, in which a translatory movable operating part (22) of an electromechanical brake actuator (2) is put back during an operation process on a wheel brake (10). Another parameter e.g. operating force, is exercised by the operation process on the wheel brake. A wear state of a brake lining is determined based on the parameters. Two measured values for the parameters are recorded during the operating process on the wheel brake. Temperature dependence of rigidity of the wheel brake is compensated by using a temperature model. Independent claims are also included for the following: (1) a computer program product comprising a set of instructions to perform a method for determining wear state of a brake lining of a wheel brake of a motor car brake assembly (2) a device for determining wear state of a brake lining of a wheel brake of a motor car brake assembly (3) a motor car brake assembly.