PROTECTION EFFICIENCY OF PROCESS EQUIPMENT DRIVES ADAPTIVE FRICTION CLUTCHES

2020 ◽  
Author(s):  
M.D. Gavrilenko ◽  
Keyword(s):  
Load Capacity ◽  
Control Device ◽  
Operating Conditions ◽  
Process Equipment ◽  
Kinematic Scheme ◽  
Friction Materials ◽  
Protection Efficiency ◽  
High Coefficient ◽  
Machine Type ◽  
Friction Clutch

The authors show that the adaptive friction clutch, which is optimal for a particular drive depends on the type of technological machines, formulated in the process of calculation and design of drive requirements for the level of protection of its elements and components against overload, the degree of responsibility of the machine operating conditions of the clutch, the transmission and the whole machine, type, and Kinematic scheme of the drive, and the techno-economic requirements and drive the car. The accuracy of the selected type of clutch, set in its calculations and design, depends on the predicted dispersion of the friction coefficient during operation, the location of the clutch in the drive (if there are other conditions than minimizing the total weight, dimensions and cost of the drive) and the requirements for the overall dimensions, weight and cost of the drive. The use of new friction materials with a high coefficient of friction in adaptive friction clutches with combined, positive-negative and positive feedback, as well as in clutches with a bifunctional control device is optimal, which will significantly increase the rated load capacity of the clutches.

Calculation and design of adaptive friction second-generation couplings (first version)

2020 ◽  
Author(s):  
M.P. Shishkarev ◽  
Keyword(s):  
Second Generation ◽  
Load Capacity ◽  
Control Device ◽  
Load Characteristic ◽  
Friction Clutch ◽  
Nominal Load ◽  
Clutch Control

The method of calculating an adaptive friction clutch with a separate power closure (the first option) is given.The features of calculating the values of the clutch control device parameters to ensure the highest accuracy of operation at a given nominal load capacity are shown. Explanations are given when calculating the values of the control device parameters depending on the shape of the load characteristic of the coupling.

Development of an unmanned tractor chassis for precision farming

2020 ◽  
pp. 47-53
Author(s):  
YU.V. Galyishev ◽  
R.Yu. Dobretsov ◽  
G.P. Porshnev ◽  
E.G. Saharova ◽  
D.V. Uvakina ◽  
...  
Keyword(s):  
Precision Farming ◽  
Autonomous Control ◽  
Kinematic Scheme ◽  
Local Complex ◽  
Friction Clutch

The development of the chassis of an unmanned tractor for a local complex of precision fanning is considered. The design is based on the kinematic scheme of the shaft gearbox, which implements a large number of modes and the principle of two-line transmission. A feature of this scheme is the presence of parallel load shafts. Keywords: wheeled tractor, autonomous control, two-line transmission, slipping, disc friction clutch. [email protected]

Paper 16: Friction in Wet Clutches

1967 ◽  
Vol 182 (14) ◽  
pp. 132-138 ◽  
Author(s):  
E. M. Evans ◽  
J. Whittle
Keyword(s):  
Coefficient Of Friction ◽  
Power Transmission ◽  
Sliding Speed ◽  
Friction Materials ◽  
Friction Characteristics ◽  
Sliding Surfaces ◽  
Base Oils ◽  
Wet Friction ◽  
Friction Clutch ◽  
The Coefficient Of Friction

This paper is intended to demonstrate that designers of wet clutches for power transmission can obtain the optimum friction characteristics for specific applications by considering the interaction between friction materials and lubricants. A friction clutch plate rig is described and the friction results obtained are presented. It is shown that a wide variation of coefficients of friction and frictional characteristics in wet friction clutches can be obtained by changing the oils and friction materials. In particular the coefficient of friction is dependent upon (1) the oil, (2) the materials of the sliding surfaces, (3) sliding speed, and (4) temperature. It is also shown that the coefficient of friction is affected by ( a) refining treatment given to the oil, ( b) different base oils, and ( c) additives.

An Accurate Solution of the Gas Lubricated, Flat Sector Thrust Bearing

1977 ◽  
Vol 99 (1) ◽  
pp. 82-88 ◽  
Author(s):  
I. Etsion ◽  
D. P. Fleming
Keyword(s):  
Film Thickness ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Thickness Distribution ◽  
Maximum Load ◽  
Accurate Solution ◽  
Operating Conditions ◽  
Thrust Bearings ◽  
Practical Design ◽  
Minimum Film Thickness

A flat sector shaped pad geometry for gas lubricated thrust bearings is analyzed considering both pitch and roll angles of the pad and the true film thickness distribution. Maximum load capacity is achieved when the pad is tilted so as to create a uniform minimum film thickness along the pad trailing edge. Performance characteristics for various geometries and operating conditions of gas thrust bearings are presented in the form of design curves. A comparison is made with the rectangular slider approximation. It is found that this approximation is unsafe for practical design, since it always overestimates load capacity.

Sacrificial Protection Efficiency Calculations Based on the Results of Stochastically Simulating the Parameters

2021 ◽  
Vol 410 ◽  
pp. 566-571
Author(s):  
Svetlana S. Vinogradova ◽  
Ramilya F. Tazieva ◽  
Anna N. Akhmetova
Keyword(s):  
Operating Conditions ◽  
Oil Refining ◽  
Environmental Aspects ◽  
Protection Level ◽  
Protection Efficiency ◽  
Internal Surfaces ◽  
Protection Systems ◽  
Active Protection ◽  
Refining Processes ◽  
Sacrificial Protection

Unique corrosion conditions in oil refining processes lead to the necessity of using passive and active protection systems, aimed at preventing from damages and ensuring the correct operating conditions of machines. To prevent from the development of corrosion processes on the internal surfaces of horizontal settlers, sacrificial protection is used. Before installing such a protection, they usually calculate the number of protectors to be installed in parallel. Some inputs are stochastic by their nature, which should be considered in assessing the risk of non-achieving the required protection level. The probabilistic model proposed to calculate the parameters of sacrificial tank protection that allows performing an exploratory design based on considering various environmental aspects to decide on the efficiency of sacrificial protection and to assess the achievement of the required protection level.

scholarly journals On the Two-Scale Modelling of Elastohydrodynamic Lubrication in Tilted-Pad Bearings

Lubricants ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 78 ◽  
Author(s):  
Gregory de Boer ◽  
Andreas Almqvist
Keyword(s):  
Surface Topography ◽  
Load Capacity ◽  
Three Dimensional ◽  
Elastohydrodynamic Lubrication ◽  
Multiscale Methods ◽  
Operating Conditions ◽  
Real Surface ◽  
Micro Scale ◽  
Macro Scale ◽  
Heterogeneous Multiscale

A two-scale method for modelling the Elastohydrodynamic Lubrication (EHL) of tilted-pad bearings is derived and a range of solutions are presented. The method is developed from previous publications and is based on the Heterogeneous Multiscale Methods (HMM). It facilitates, by means of homogenization, incorporating the effects of surface topography in the analysis of tilted-pad bearings. New to this article is the investigation of three-dimensional bearings, including the effects of both ideal and real surface topographies, micro-cavitation, and the metamodeling procedure used in coupling the problem scales. Solutions for smooth bearing surfaces, and under pure hydrodynamic operating conditions, obtained with the present two-scale EHL model, demonstrate equivalence to those obtained from well-established homogenization methods. Solutions obtained for elastohydrodynamic operating conditions, show a dependency of the solution to the pad thickness and load capacity of the bearing. More precisely, the response for the real surface topography was found to be stiffer in comparison to the ideal. Micro-scale results demonstrate periodicity of the flow and surface topography and this is consistent with the requirements of the HMM. The means of selecting micro-scale simulations based on intermediate macro-scale solutions, in the metamodeling approach, was developed for larger dimensionality and subsequent calibration. An analysis of the present metamodeling approach indicates improved performance in comparison to previous studies.

scholarly journals Thin Gas Film Isothermal Condensation in Aerodynamic Bearings

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Eliott Guenat ◽  
Jürg Schiffmann
Keyword(s):  
High Speed ◽  
Waste Heat ◽  
Load Capacity ◽  
Saturation Pressure ◽  
Operating Conditions ◽  
Fluid Film ◽  
Small Scale ◽  
Vapor Compression ◽  
Density Profiles ◽  
Film Pressure

Abstract High-speed small-scale turbomachinery for waste heat recovery and vapor compression cycles is typically supported on gas-lubricated bearings operating close to the saturation conditions of the lubricant. Under particular conditions, the gas film might locally reach the saturation pressure with potentially hazardous effects on the performance of the gas bearing. The present work introduces a model based on the Reynolds equation and the development of cavitation modeling in liquid-lubricated bearings for condensing gas bearings. The effect of condensation on load capacity and pressure and density profiles is investigated for two one-dimensional bearing geometries (parabolic and Rayleigh step) and varying operating conditions. The results suggest that the load capacity is generally negatively affected if condensation occurs. An experimental setup consisting of a Rayleigh-step gas journal bearing with pressure taps to measure the local fluid film pressure is presented and operated in R245fa in near-saturated conditions. The comparison between the evolution of the fluid film pressure under perfect gas and near saturation conditions clearly suggests the occurrence of condensation in the fluid film. These results are corroborated by the very good agreement with the model prediction.

Simulation studies on static thermal behaviour of true elliptical and orthogonally displaced non-circular journal bearing

2016 ◽  
Vol 68 (3) ◽  
pp. 349-360 ◽  
Author(s):  
Amit Singla ◽  
Amit Chauhan
Keyword(s):  
Journal Bearing ◽  
Load Capacity ◽  
Current Trend ◽  
Operating Conditions ◽  
Performance Characteristics ◽  
Film Pressure ◽  
Content Type ◽  
Oil Film ◽  
Ellipticity Ratio ◽  
Oil Film Pressure

Purpose The current trend of modern industry is to use machineries which rotate at high speed along with the capability of carrying heavy rotor loads. This paper aims at static thermal analysis of two different profiles of non-circular journal bearings – a true elliptical bearing and orthogonal bearing. Design/methodology/approach The Reynolds equation has been solved through finite difference method to compute the oil film pressure. Parabolic temperature profile approximation technique has been used to solve the energy equation and thus used for computation of various bearing performance characteristics such as thermo-hydrodynamic oil film pressure, temperature, load capacity, Sommerfeld number and power loss characteristics across the bearing. The effect of ellipticity ratio on the bearing performance characteristics has also been obtained for both the elliptical and vertical offset bearing using three different commercially available grades of oil (Hydrol 32, 68 and 100). Findings It has been observed that the thermo-hydrodynamic pressure and temperature rise of the oil film is less in orthogonal bearing as compared to the true elliptical bearing for same operating conditions. The effect of ellipticity ratio of non-circularity on bearing performance parameters have been observed to be less in case of elliptical bearing as compared to orthogonal bearing. It has been concluded that though the rise in oil film temperature is high for true elliptical bearing, but still it should be preferred over orthogonal profile under study, as it has comparably good load-carrying capacity. Originality/value The performance parametric analysis will help the designers to select such kind of non-circular journal bearing for various applications.

Study on the Treatment of Nitrogen Oxides by Compound Bio-Filter

2012 ◽  
Vol 610-613 ◽  
pp. 1824-1828
Author(s):  
Zhi Fei Liu ◽  
De Hong Pang
Keyword(s):  
Removal Efficiency ◽  
Gas Flow ◽  
Load Capacity ◽  
Packing Material ◽  
Operating Conditions ◽  
Inlet Concentration ◽  
Trickling Filter ◽  
Spray Volume ◽  
Packing Layer ◽  
Empty Bed Residence Time

Activated carbon and wood chips were applied respectively as packing material of bio-trickling filter and bio-filter which composed the compound bio-filter and the effect of different operating parameters on NOx removal efficiency were studied. The results show that the best operating conditions of the compound bio-filter are: NO inlet concentration 604.5 mg/m3, spray volume 1.2 L/h, gas flow 0.6 m3/h(empty bed residence time 103.7 s).In such cases,NOx removal efficiency is over 96% and NOx removal load of the packing material is 29.66 g/(m3•h) . The remove of NOx is mainly completed by the packing layer of 0~50 cm height both in the bio-trickling filter and in the bio-filter, that is to say ,when the total packing layer height of the compound bio-filter is 100 cm, the purification effect is ideal and economical; The system can return to normal in about 7 hr when the dynamic load changes largely and suddenly, showing that it has strong anti shock load capacity.

Review of the Study on Load Capacity of Oil-Film Bearings

2014 ◽  
Vol 900 ◽  
pp. 405-409
Author(s):  
Xiang Jun Yu ◽  
Zuo Xin Li ◽  
Ke Nan Shen ◽  
Shuang You ◽  
An Jun Wu
Keyword(s):  
Dynamic Simulation ◽  
Experimental Test ◽  
Load Capacity ◽  
Operating Conditions ◽  
Mechanical Transmission ◽  
Paper Briefly ◽  
Scaled Model ◽  
Oil Film ◽  
Depth Study ◽  
The Stability

The oil-film bearings are widely used in mechanical transmission due to the good performance. In normal operating conditions, the journal and bearing shell are separated by the oil film, which contributes to the reduction of wear. And the stability and reliability of oil film has a great effect on load capacity. The paper briefly introduces research methods of the load capacity of oil-film bearings and points out some aspects of large oil-film bearings for in-depth study. Then combining dynamic simulation with experimental test on the scaled model of whole machine, a dynamic research idea is presented for large oil-film bearings.

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