Pdf an elastohydrodynamic lubrication line contactvibration model is proposed to study the. This form of damping is observed to not increase with frequency, so instead of a viscous damping force. High damping is desirable to attain low vibration and noise levels whereas low damping is desirable for increased sensitivity in sensors and certain precision instrumentation. Structural vibration analysis and damping engineering books. Basics of vehicle construction stjepan galambos, assistant. To introduce basics of automotive engineering to explain main vehicle systems througt examples and real models. In the 1930s, damping grease played a pivotal role in transforming delicate, expensive 35mm cameras into a rugged and affordable consumer product. The viscous damping coefficient is either assigned based on the construction material e. Nye lubricants 795a ng synthetic damping grease 50g tube. Damping definition and meaning collins english dictionary. Despite being small in magnitude, mechanical damping greatly affects the system respo.
A damping grease allows instruments to be more exact and operate smoothly. The level of damping can be subjectively determined by noting the sharpness of resonant peak at f 1 figure 3. The amount of force required to move a device lubricated with damping grease can be controlled by proper selection of base oils. Damping greases, also referred to as motion control grease or noise control grease, reduce wear, seal out moisture and dust, and enhance motion control.
Perceived quality is everything, and the feel of a part can greatly impact customer satisfaction. Understanding damping techniques for noise and vibration control. The noiseless motion of metal on metal, the smooth feel, and the absence of coasting and backlash of focus controls on cameras and optical instruments are all the work of damping grease until the 1960s, damping grease had few. A damping grease is an engineering design tool for free motion control and noise reduction. Using damping grease as an engineering tool to control noise and motion is not a new concept. Understanding damping techniques for noise and vibration. Higher molecular weight oils create greater internal shear resistance, which requires more torque. Jun 23, 2016 a new, expanded damping grease sample kit is now available from nye lubricants, inc. Nye lubricants 795a ng synthetic damping grease 2oz. Damping is most obvious at resonance where the stiffness and inertia forces become equal. Sinopec 4128 lubricant for mechanical time fuse is blended with synthetic base oil and plural highly re. The kit features mediumviscosity greases from the fluorocarbon gel 868 and nyogel 774 series of products that were designed to control motion and vibration, maintain accurate positioning, smooth operation, and provide touch feedback for a broad array of.
Sometimes called antisway or antiroll bars, stabilizer bars keep the car 4 intermediate shaft of an automotive steering column is controlled when a damping grease. Also a damping grease is an ideal way to improve the tactile feel of customer operated controls, such as switches. Classical damping, nonclassical damping and complex modes. The characteristic feature of greases is that they possess a high initial viscosity, which upon the application of shear, drops to give the effect of an oillubricated bearing of approximately the same viscosity as the base oil used in the grease. The damping torque should have a magnitude that the pointer quickly comes to its final steady position. Though available for more than 60 years, their use didnt extend far beyond optical instruments because of their limited lowtemperature capabilities. It serves several purposes, to reduce wear and tear between the sliding contact and the resistive surface and to prevent corrosion. When the moving system moves rapidly but smoothly to its final steady position, the system is said to be critically damped. A damping grease is a costefficient way to control free motion, achieve a quality feel, reduce noise, and enable fine tuning by hand in most any mechanical and electromechanical device. As a result, damping is a key factor in predicting vibration response of structures.
The kit features mediumviscosity greases from the fluorocarbon gel 868 and nyogel 774 series of products that were designed to control motion and vibration, maintain accurate positioning, smooth operation, and provide touch feedback for a broad array of mechanisms and controls. Damping grease allows engineers to adjust the torque to actuate a device to craft the. It is a damping grease applied to the focusing threads of binoc ulars. A video demonstrating how motion can be controlled with the use of a damping grease. More subjectively, damping greases are selected for the feel the designer wants to achieve. Damping of torsional vibrations and impacts from engine to drivetrain main types. Pdf oil film stiffness and damping in an elastohydrodynamic. Beards pdf free download summery many structures suffer from unwanted vibrations and, although careful analysis at the design stage can minimize these, the vibration levels of many. Using the right damping grease can reduce engineering.
I had also cleaned up some of the slides on the scope because they were a bit gritty. An engineering tool for economical noise and motion control. Modelling, analysis and damping of vibrating structures which was published in 1983 but is now out of print. Grease generally consists of a soap emulsified with mineral or vegetable oil. Pdf damping properties of plastic with temperature variation. Noise controls absorbers applied at a reflective surface to absorb energy and reduce reflection of. The technical name of the stuff that goes inside a potentiometer is damping grease. Damping grease allows engineers to adjust the torque to actuate a device to craft the user experience economically. Earle, 1942 good multipurpose lubricating grease has to perform well in a number of applications. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext.
Research on effect of damping variation on vibration response of defective bearings article pdf available in advances in mechanical engineering 1. Nyecorr 140, a ptfethickened, heavy viscosity completely fluorinated grease. A new, expanded damping grease sample kit is now available from nye lubricants, inc. Classical damping, nonclassical damping and complex modes cee 541. Damping grease quiets the plastic gears and reduces mechanical noise from the cables. Engineering noise controls dave yantek mining hearing loss prevention workshop june 2122, 2005 pittsburgh research laboratory. While the original question was in reference to lubing focusers, i want to point out that this is an especially important topic for anyone using an older eq mount that employs plain bearings for the declination and ra shafts.
This method has been a valuable tool in system development. Estimation and modeling of damping and engineering. Nyecorr 140, a synthetic lubricant that protects bearings at 480. Article pdf available in advances in mechanical engineering.
Generally, engineering surfaces are not smooth due to the. Uniflor perfluoropolyether pfpe lubricants are designed for. Page 2 of 4 where can i get the real sticky damping grease posted in classic telescopes. Damping grease an engineering tool for economical noise and motion control uniflor pfpe lubricants the most complete line of pfpe lubricants for extreme environments. Nyecorr 140 is the most advanced pfpe lubricant, the most environmentally friendly, and the most economical option available to the corrugating industry today. Analysis and damping benefits from my earlier book structural vibration analysis. Jul 01, 2016 eddy current damping, air friction damping, fluid friction damping, methods of damping, damping system,damping system in measuring instruments, damping system types, types of damping pdf, types of damping in measuring instruments, types of damping in civil engineering, damping system in structural dynamics, types of damping system, types of damping ppt. Estimation and modeling of damping and engineering auxiliary. Pdf structural vibration analysis and damping by c.
Damping is a phenomenon by which mechanical energy is dissipated. Forced, nonresonant vibration is rarely attenuated by damping, although application. Damping grease demonstration 2012 i was recently refurbishing a microscope and made an adjustable eyepiece the original eyepiece didnt have any diopter adjustment. I have ordered damping grease online from japan, but i just cant find the real deal, the stuff that actually replicates the original. Hysteretic damping 3 for example, structural or hysteretic damping is a type of dissipation that is a function of friction within a material. Mechanical damping is, generally defined, as the measure or way a system has to dissipate vibration energy, in the forms of sound and heat by generated friction. Used to reduce free motion and to quiet operating noise of looselyfitting components. For a quantitative measure of damping the halfpower bandwidth method can be employed.
Extremely high viscosity fluid and grease damping lubricants values quoted above are typical and do not constitute a specification. Pdf research on effect of damping variation on vibration. Increase rate of decay withtimewith time with distance onset of vibration. Damping grease noise reduction grease motion control. Pg44a can be heated to aid dispensing for volume applications. Gavin fall 2018 1 classical damping the equations of motion of an unforced ndegree of freedom elastic structure with viscous damping are mr. Vibration and sound damping in polymers v g geethamma, r asaletha, nandakumar kalarikkal and sabu thomas excessive vibrations or loud sounds cause deafness or reduced efficiency of people, wastage of energy and fatigue failure of machinesstructures. Nov 29, 2016 a video demonstrating how motion can be controlled with the use of a damping grease. Special lubricants and noise damping products for the. Cooling occurs by removing either the heat from the environment, e. Damping grease is used to control motion and noise in engineering applications. Extremely high viscosity fluid and grease damping lubricants. Pfpeptfe grease, a unique synthetic grease made by com bining a fluorinated oil. Trim the boom mat material to desired shape and size with your boom mat blade lock knife or scissors.
F, is nsf h1 food grade registered and contains no pfoas perfluorooctanoic acid. Damping greases control motion, acoustics, and feel of mechanical parts damping grease started in optics. Ensures smooth, quiet operation of seat tracks and recliners. Suitable for extreme damping applications, the pg44a is a nlgi 5 grease and is so stiff grease that generally the product is not sold in tubes due to the force required to dispense the grease. Safety data sheets safety data sheets are available for download from our website. Structural damping structural damping reduces both impactgenerated and steadystate noises at their source. Ive been trying to find some of that sticky grease that is used on focuser racks and slow motion gears to lubricate and smooth them out. Damping grease an engineering tool for economical noise and motion control.
Where can i get the real sticky damping grease cloudy nights. This enhanced successor is far more comprehensive with more analytical discussion, further consideration of damping sources. The oil film damping is calculated in terms of the principle of the energy conservation. Damping greases were first formulated to build fine tolerances economically into microscopes, telescopes, and binoculars. Previous investigations led to an empirically derived method, a ruleofthumb, to estimate load capacity. Hertzian contact, defective bearing, lubricating grease, damping coefficient, vibration resp onse. A silica thickened, light viscosity, synthetic hydrocarbon grease intended for mechanical components that require a light level of damping.
This fascicle is the one about synthetic lubricants, collecting products manufactured by. The current paper extends this tool concept to include rules for stiffness and damping coefficient estimation. Effects of damping on systems motions steady state. A template is helpful when trying to achieve a professional look. It dissipates vibrational energy in the structure before it can build up and radiate as sound. Finally, the numerical analysis and experimental results show that the grease with a different level of viscosity affects the vibration signal of the defective bearing. Gavin a rayleigh damping matrix is proportional to the mass and sti. If the system is underdamped, the moving system will oscillate about the final steady position with a decreasing amplitude. Limits motions controlled by energy balance resonance broad band spatial resonance trace matching free vibrations. Boom mat damping material thermal acoustic control instructions. The grease forms a sealing grease collar against moisture and dirt particles between the opposing body. Structural vibration analysis and damping book pdf by c. Then newtons second law gives thus, instead of the homogeneous equation 3, the motion of the spring is now governed. It should have a high melting point, and operate well at continuous.
Apr 24, 2017 damping grease is used to control motion and noise in engineering applications. Objectively, damping greases must retain their damping qualities throughout the temperature range of the application, so careful attention should be paid to the temperature range of each grease. Most of the multipurpose greases have a soap base of barium, lithium, or calcium complex. The amount of force needed to shear a damping grease is determined by the viscosity of the base oils chosen for the formulation. Page 1 of 4 where can i get the real sticky damping grease posted in classic telescopes. How different levels of damping capacity affect vibration decay 08 1. However, the disadvantage of greases with a high base oil viscosity. Automotive stabilizer bar bushings also employ siliconebased damping grease. Navale department of mechanical engineering, jaihind college of engineering, savitribai phule pune university, pune maharashtra india. Since id removed the magic sticky grease, they now moved far too easily. Arcanol rolling bearing greases for reliable, durable and.
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