2 edition of Laboratory study of friction in TFE sliding surfaces for bridge bearings found in the catalog.
Laboratory study of friction in TFE sliding surfaces for bridge bearings
T. I. Campbell
1989 by Research and Development Branch, Ontario Ministry of Transportation in [Downsview] .
Written in English
|Statement||T.I. Campbell, W.L. Kong.|
|Contributions||Kong, Wei-ling, 1945-, Ontario. Ministry of Transportation. Research and Development Branch.|
|LC Classifications||TJ1077 .C36 1989|
|The Physical Object|
|Pagination||v, 65 p. :|
|Number of Pages||65|
2) In terms of lubrication, the coefficient of friction is reduced by approximately half the value without lubrication. 3) Considering the low values of the coefficient friction for both materials, there is the possibility of replacing the expensive Teflon with polyamide with the addition of molybdenum disulphide (MoS2). bearings and generate a net pressure increase in the thin lubricant ﬁlm separating the sliding surfaces. This additional pressure increases the separation between the sliding surfaces and corres-pondingly reduces friction and wear. Applications of surface textur-ing include mechanical seals , gas seals [8,9],thrustbearingsFile Size: 1MB. The writers presented in an earlier paper a mathematical model of friction of sliding bearings under conditions of compression and bidirectional motion. The model could account for the dependence of the coefficient of friction on the velocity and direction of sliding. Elastomeric bridge bearings have been occasionally observed to move out of their original position. A simple model for this gradual displacement, also known as “walking,” is developed. The model, through a regularized Coulomb law, incorporates viscous frictional interfaces between the bearing and the girder, abutment, or pier.
A lubricant formulated for rolling friction should be used with Nook Linear Bearings. In applications where operating speeds are low and loads are light, Nook linear bearings can be used without lubrication at a reduced life. However, to protect the highly polished bearing surfaces from corrosion and wear, a lubricant is recommended.
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LABORATORY STUDY OF FRICTION IN TFE SLIDING SURFACES FOR BRIDGE BEARINGS. This report summarizes the state-of-the-art of TFE (tetrafluorethylene) sliding surfaces in bridge bearings, and identifies the parameters which influence the coefficient of friction.
A test program is described which investigates the influence of four of these parameters Cited by: 3. Bearings using tetrafluorethylene (TFE) to provide slide sur faces are widely used in bridge structures. A low-friction TFE surface is used to provide either rotation, by sliding over a curved surface, or translation, by sliding on a plane surface, or a combination of both.
Stainless steel is commonly used for the surface mating with the Size: 4MB. investigate the potential use of TFE as a sliding surface. He concluded that the TFE bearings are suitable for use as highway bridge bearings.
A sub stantial increase in the coefficient of friction for filled TFE was found after cycles of testing. Taylor (~) has found that the coefficient of. Low Friction Sliding Planes of S uch defo rmati ons ar e acceptable for bridge bearings because of T.I.
and Kong, W.L. () Laboratory Study of Friction in TFE Sliding Surfaces for. To fully ascertain the ultimate shear failure state and the friction sliding performance of laminated rubber bearings in bridges, a series of cyclic loading tests were conducted.
The energy dissipation characteristics of the laminated rubber bearings with two end plates, rubber bearings with unilateral friction sliding, and lead rubber bearing (LRB) under low-frequency cyclic loads were Cited by: 1.
Friction bearings made of Mold-flon™ and highly wear-resistant PTFE compounds: the right choice for high pv values and high ther-mal loads, even in case of insuffi-cient lubrication or dry applica-tions.
Our friction bearings feature both excellent tribological proper-ties and chemical resistance to File Size: 1MB. Experimental Evaluation of High-Performance Sliding Surfaces for Bridge Bearings. Two such high-performing sliding surface materials were investigated to study and predict their service life: ultrahigh-molecular-weight polyethylene (UMWP) and glass-filled reinforced PTFE (GFR-PTFE).
This paper describes research and proof-of-concept testing. Campbell, T.I. and Fatemi, M.J., () “Further laboratory studies of friction in TFE slide surface of a bridge bearing.” Report MAT–06, Ministry of Transportation Author: M.
Constantinou. Plain Bearings or Sliding Bearings A “bearing” is a contacting surface through which a load is applied. When there is relative motion between the surfaces, you have a sliding bearing, and you need to deal with friction and wear. This calls for some kind of Size: KB.
In order to examine the friction-control ability of a FM film on the iron oxide-coated steel surface, a series of FM-Fe 2 O 3 composites were tested on the rheometer.
The shear strength versus sliding distance (displacement) relationship of the FM-Fe 2 O 3 films was measured at a constant sliding speed of 1 °/min ( μm/s). The shear stress-displacement curves are plotted in Fig.
by: In this study, the re-centring behaviour of isolation systems composed of sliding bearings with curved surfaces is investigated in shake-table tests carried out on a one-storey steel frame with.
Seite 13 von 25 Due to friction a certain friction power is generated in the bearing: f  Nm PF u W s µ ∧ =•• = ⎡⎤ ⎢⎥⎣⎦ µ: friction factor u: sliding speed P f: friction power For the capacity if a sliding bearing a dimensionless factor is defined: 22 2 0 2 23 FS FS.
In major earthquakes, friction sliding of common laminated elastomeric bearings limits the force transmitted from the superstructure to the substructure.
Experiments were carried out to investigate the ultimate shear performance and the friction sliding response of laminated elastomeric bridge bearings. First, the hysteresis curve of the common laminated elastomeric bearings present narrow Author: Yue Li, Qian Li, Qiqi Wu.
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: Dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact.
Dry friction is subdivided into static friction ("stiction") between non-moving surfaces, and kinetic friction between moving. A plain bearing, or more commonly sliding bearing and slide bearing (in railroading sometimes called a solid bearing, journal bearing, or friction bearing ), is the simplest type of bearing, comprising just a bearing surface and no rolling elements.
Therefore, the journal (i.e., the part of the shaft in contact with the bearing) slides over the bearing surface. This paper describes the effect of velocity and temperature on the friction coefficient of both filled and unfilled rubber vulcanizates sliding on smooth ice.
It has been shown that the mechanism of the friction of rubber on ice is the same as that on other smooth surfaces under similar low sliding speed conditions and that the maximum friction Cited by: 7.
Specific to severe damage to curved bridges in earthquakes caused by the excessive force of the fixed bearings and piers, a new seismic design method on curved bridges considering bearing friction sliding isolation is proposed in this paper.
Seismic model bridge and isolation model bridge with similarity ratio of 1/20 were made and the shaking table comparison test was by: 2. Low friction sliding surfaces for bridge bearings: PTFE weave Low friction sliding surfaces for bridge bearings: PTFE weave.
Published. 1 January ISBN. Author. Taylor, ME. Pages. Reference. LR Share article: Download. Abstract not available. Share article: Want to know more about this project.
unlike all other conventional bearings, the static friction of PTFE is equal to or only marginally higher than the dynamic friction. TECHnICAL DESCRIPTIon oF STAnDARD PTFE SLIDE BEARInGS AvErAgE PrESSurE on PTFE (MPA) MAx. vAluE oF ‘µ’ For luBrIcATEd PTFE MAx.
vAluE oF ‘µ’ For unluBrIcATEd PTFE 5 10 20 2. OVERVIEW. Referring to the Series of elastomeric pad bearings for highway bridges in China [27 Ministry of Transport of Series of elastomeric pad bearings for highway bridges (JT/T ). Beijing: China Communications Press, ], a series of laminated rubber bearing specimens were fabricated with the parameters listed in Table the ultimate shear failure test, the two Cited by: 1.
SPHerICaL BearINGS Goodco Z-Tech spherical bearings consist of an assembly of precision-machined steel components with spherical concave and convex elements in its center. Designed and sized according to the specific requirements of your project, these bearings transfer large vertical loads while accommodating the structure’s relative movement.
Friction is described using five different models that consider the dependence of the coefficient of friction on axial pressure, sliding velocity and temperature. Frictional heating is the most important factor that influences the maximum displacement of the isolation system and floor spectral demands if the static axial pressure is high.
Sliding bearings have good damping properties and a high stiffness. However, stiction and poor sliding friction characteristics limit their use in applications, where high requirements are defined on the smoothness of motion.
By inducing ultrasonic oscillations into the sliding contact it is possible to actively control the by: 5. Other articles where Sliding bearing is discussed: bearing: oil) or gas; these are sliding bearings, and the part of the shaft that turns in the bearing is the journal.
The surfaces in a bearing may be separated also by balls or rollers; these are known as rolling bearings. In. Types of Friction Dry Friction (Coulomb Friction) occurs between unlubricated surfaces of two solids Effects of dry friction acting on exterior surfaces of rigid bodies ME Fluid Friction occurs when adjacent layers in a fluid (liquid or gas) move at a different velocities.
Fluid friction also depends on viscosity of the fluid. Fluid MechanicsFile Size: 1MB. The coefficient of friction when sliding against a polished surface can be as low as which compares with ice sliding on ice.
In addition, its coefficient of friction is the lowest at highest specific pressures which make it particularly suitable for use in structural bearings. Fluorinoid ® PTFE when sliding against Fluorinoid PTFE has a co-efficient of friction value of However when used for skidding heavy structures or as a bridge bearing assembly with a different assembly configuration it may be advantageous to incorporate a lubrication system to assist with reduction of Size: 1MB.
Applications: oil-off, starved, or poor lubrication conditions; reduced sliding friction; adhesive wear protection; moderate rolling contact fatigue improvement and debris damage tolerance ASTI Component types: hydrostatics components, engine components (e.g., roller finger followers), gear shafts, precision pins (e.g., fuel injector plungers).
ptfe teflon sliding bearings, steel pot bearing, mechanical steel bridge bearings sliding bearing ptfe Teflon pipe supports, rubber modular elastomer expansion joint, rubber gaskets is established from in United Arab Emirates Dubai UAE with ISO certification for design and manufacturing offer products commonly known as bridge bearing.
Contact of surfaces in a rubber pad forming process 25 Overview of the tribological system 25 Mechanical properties of the rubber tool and metal sheet 26 Rubber tool 26 Workpiece 33 Surface free energy and work of adhesion 34 Equation of state approach 35 Surface tension components approach 35 Contact angle hysteresis approach Sliding Friction.
Sliding friction exists when one object slides over or across another. Bearings that handle sliding friction are built to allow a rotating shaft or other moving element to slide against the smooth surface of the bearing. Carry Loads. The term load refers to a force or weight that is placed on a bearing.
(2) The rubber bearings with unilateral friction sliding had a similar energy dissipation capacity compared to the LRB. The maximum energy dissipation in a single cycle could reach % of the LRB’s maximum energy dissipation.
With an increase in the sliding distance, the dissipated energy continuously by: 1. Fig. 1: Total sliding distance of steel bridge bearing (Structural Bearings,) There are relevant international standards; AASHTO and ASTM. The durability evaluation of the code should be considering the accumulated moving distance of the friction plate of the bridge bearings increasing friction with the dynamic characteristic.
The main factors that influent the friction coefficient between PTFE and stainless-steel of sliding isolation bearings (SIB) are introduced in this paper. The positive pressure, sliding velocity, air temperature and lubricant all played important roles to the friction coefficient of SIB. By means of experimental investigation, the friction coefficient of SIB is indicated, and according to the Author: Cong Zeng, Zhong Tao, Jun Feng Bai.
This test method is an extension of Test Method G and uses an inclined plane and a paperclip rider to detect the presence or absence of lubricants on the surfaces of flexible webs.
A study to identify free spinning or low rolling friction bearings indicated that the paperclip friction test could be used for rolling friction by simply replacing the paperclip with a rolling element.
Ball bearings. Ball bearings are the most expensive type of bearing. They can handle both radial and axial loads, and they are highly reliable.
There are many types of ball bearings, including angular contact, axial and deep-grove. Next time you’re out skating or just sliding around the house in your socks, consider the physics behind the fun.
The main purpose of this study was to measure the friction torque of thrust ball and roller bearings lubricated with wind turbine gear oils. The measurements among the oils will be compared and conclusions will be taken.
In this work six wind turbine gear oils were considered: 2 Author: Pedro Miguel Pinto Amaro. Sliding friction is not desirable in wheel bearings because A) too much energy is transferred to the wheel.
B) sliding friction will store too much energy. C) the wheel will lock on the axle and not move D) work will be converted into thermal energy, and be dissipated.
PTFE Slide Bearings: Calculating Coefficient of Friction. PTFE is a preferred material in slide bearings for three very specific reasons:Load bearing capacity, Weather ability & Low coefficient of friction. We calculate the PTFE Coefficient of friction by processing gauging the angle of incline.
requirements, less friction in sliding bearings is now needed. The writers have conducted a wide range of tests to examine the characteristics of sliding bearings, whose friction is only under the 15MPa compressive stress.
By the end ofthe writers completed designs of about ten projects using low-friction sliding Size: KB. TFE Sliding Surfaces in Bridge Bearings. Report No.
ME Ministry of Transportation and Communications, Research and Development, Report No. ME, Downsview, Ontario, Canada.PTFE bearing pad, also called Teflon bearing pads, is an important material in bridge dimpled PTFE sheet bonded to the laminated bearing pad for structure friction coefficient reduction and displacement capacity improvement.FRICTION In BA and BAR type bearings fitted with PTFE the coefficient of friction of the sliding surfaces can be assumed to vary between to depending on a number of operating variables.
The most important is bearing pressure, the C of F reduces with increased specific .