noise and vibration priority low

... a gear ratio of 19:31 and the standard 18,000 (x 4) line encoders and 12 bit digital recording, the resolution would be to about 0.1 second of arc and more than adequate for ... second order characteristic and will give good vibration information above the natural frequency of the loop while ignoring speed variations or vibrations well below the natural frequency ... frequencies are down at 5 Hz as may occur with worms and wheels the acceleration for 1 um is only 0.0001 g and is down below the noise level so this method is not suitable. Double

Ngày tải lên: 05/08/2014, 09:20

... analysis and add bands in groups If the original record was for 10 s the bandwith would be 0.1 Hz and adding 10 bands would widen the bandwidth to 1 Hz The addition is an addition of power in the bands ... frequency tuned resonant filter which scanned slowly up through the range This method is slow, expensive and not very discriminating and requires long vibration traces for analysis It also has the ... presentation works well for random phenomena and for most natural processes such as wave motion at sea where all frequencies exist Halve the bandwidth (by altering the frequency scale) and we detect half

Ngày tải lên: 05/08/2014, 09:20

... improved and that is the oddity that the statistical scatter on the final noise levels is increased. A poor and rather noisy design might give a Improvements 183 measured noise level ... factor to below 4. Improvements 181 Untuned (Lanchester) dampers which use only mass and viscous damping will work over a range of frequencies but require greater mass and give much ... (or installation) and is very expensive to achieve. On the assumption that development has investigated permissible loaded T.E. and found that it must be kept below, say, 4 um at

Ngày tải lên: 05/08/2014, 09:20

... and disadvantages The advantages of splitting the power are mentioned above in terms of reduction of weight and size and frontal area (for aeroplanes and water turbines) and ... average 2nd and 3rd planet phases and so be at 180° and the next at 24 0° as the 3rd planet dominates, while the final sixth will average between 24 0° and 360° (or 0°) and so be at ... sun and carrier speeds and multiply by the number of teeth on the sun to get the tooth meshing frequency or the corresponding difference between carrier and annulus speeds and

Ngày tải lên: 05/08/2014, 09:20

... meshes to rattle and give noise and there are fewer high speed shafts so lubrication and churning losses are lower. Lower tooth frequencies generally give lower noise. 226 Chapter ... powerful method for reducing the volume of information and eliminating random noise and non-synchronous vibration In general,... change of vibration means in terms of damage It is worthwhile ... Tyne, September 1994. 14 Low Contact Ratio Gears 14.1 Advantages Conventional industrial gears tend to use the standard 20° pressure angle and standard proportions and thus encounter undercutting

Ngày tải lên: 05/08/2014, 09:20

... different parts of its surface The standard techniques of frequency analysis and monitoring the amplitudes of the ball rotation and passing frequencies work well and will usually give clear warning ... highest) amplitude position and then use that point as the standard reference point A possible alternative is to both excite and measure at a bearing housing so that the local vibration response is ... Fig 16.3 and then add the results and the estimates of the tooth effects as discussed in section 16.6 16.2 Hydraulic vibrators As electromagnetic vibrators are large and very heavy yet low on force,

Ngày tải lên: 05/08/2014, 09:20

... for the high speed gears and bearings is totally unsuitable for the low speed gears and bearings It is advisable to bias the choice toward the low speed bearings and increase the viscosity ... is little random effect. Any variation would suggest randomness. Coherence analysis routines carry out this check and compare how much of the measured output power (at a Vibration ... 4406 and the figures are Group Particles... gears and rolling bearings, the two figures which are usually quoted (and are of most interest) are for the number of particles above 5 um and

Ngày tải lên: 05/08/2014, 09:20

... time when noise and strength are directly connected is when the teeth are allowed to come out of contact and then produce high forces in the following impact. High noise and high ... noisier) and so noise is associated with failure. Usually there is little connection between noise and strength and if a system keeps the gear teeth in contact it is rare for vibration ... strength dominant on the two lower gears, requiring bedding checks, and noise dominant on the three higher gears, requiring T.E. checks. 19.2 Design for low noise helicals From a "philosophical"

Ngày tải lên: 05/08/2014, 09:20

... Niemann, G and Baethge, J., 'Transmission error, tooth stiffness, and noise of parallel axis gears.' VDI-Z, Vol 2, 1970, No and No Palmer, D and Munro, R.G., 'Measurements of transmission error, vibration ... however, noise is the critical factor, "design load" may refer to the condition where noise has to be a minimum and may be only 10% of the permitted maximum load If the requirement is for minimum noise ... short, or intermediate relief In 1970, Neimann in Germany [4] and Munro in the U.K introduced and developed the ideas of "long" and "short" relief designs for the two extreme load cases where...

Ngày tải lên: 13/12/2013, 03:15

... Understanding Gear Noise, J Derek Smith Chains for Power Transmission and Material Handling: Design and Applications Handbook, American Chain Association Corrosion and Corrosion Protection Handbook, ... Revised and Expanded, Earl Logan, Jr 86 Vibrations of Shells and Plates: Second Edition, Revised and Expanded, Werner Soedel 87 Steam Plant Calculations Manual: Second Edition, Revised and Expanded, ... Couplings and Joints: Design, Selection, and Application, Second Edition, Revised and Expanded, Jon R Mancuso 122 Thermodynamics: Processes and Applications, Earl Logan, Jr 123 Gear Noise and Vibration, ...

Ngày tải lên: 13/12/2013, 03:15

... paths (paths and 3) of noise and vibration caused by airborne excitation of walls and columns in the mechanical equipment room These paths make it impossible to achieve the low noise levels that ... Values for Sound Attenuators General Types and Applications of Vibration Isolators Vibration Isolation Mounting for Centrifugal and Axial-Flow Fans Vibration Isolation Mounting for Reciprocating ... against the noise of all the noisiest possible equipment; such overdesign would require thicker and heavier walls and floors than required by most of the equipment The noise estimates and the noise...

Ngày tải lên: 28/03/2014, 18:20