Selected Properties of Bearings with Helical Groove on the Journal

2011 ◽  
Vol 490 ◽  
pp. 273-281 ◽  
Author(s):  
Jarosław Sep
Keyword(s):  
Flow Rate ◽  
Carrying Capacity ◽  
Rate Increase ◽  
The Other ◽  
Helical Line ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Oil Flow ◽  
Helical Groove ◽  
Flow Rate Increase

The paper presents results of tests concerning slide bearing with helical groove on the journal selected properties. It has been stated that during lubrication with contaminated oil helical groove results in wear decrease. On the other hand while lubricating agent was clean oil helical groove results in load carrying capacity decrease and oil flow rate increase. The proposition of non-dimensional index describing the groove and helical line is also presented in the paper. This index is correlated with bearing characteristics and its wear

Minimised Gear Lubrication by a Minimum Oil/Air Flow Rate

2007 ◽  
Author(s):  
Bernd-Robert Ho¨hn ◽  
Klaus Michaelis ◽  
Hans-Philipp Otto
Keyword(s):  
Flow Rate ◽  
Carrying Capacity ◽  
Failure Modes ◽  
Load Carrying Capacity ◽  
Air Supply ◽  
Load Carrying ◽  
Air Lubrication ◽  
Oil Flow ◽  
Application Potential ◽  
Supply Systems

The objectives of the research project were to investigate the limits concerning possible reduction of lubricant quantity in gears without detrimental influence on the load carrying capacity. The investigations covered the influence of the oil level in dip lubricated systems as well as the oil flow rate in spray lubricated systems namely oil-air supply systems on power loss, heat generation and load carrying capacity. The load carrying capacity in terms of characteristic gear failure modes was determined and was compared to the results using conventional lubricant volumes with dip lubrication. Therefore in back-to-back gear tests the parameters speed, load and oil quantity were varied for examination of the four main gear flank damages: scuffing, wear, pitting and micropitting. The investigations showed the application potential of oil/air lubrication also for heavy duty transmissions nevertheless there exists a natural limitation for lowering the oil quantity in transmissions without detrimental influence on the load carrying capacity.

Numerical investigation of squeeze film lubrication on bioinspired hexagonal patterned surface

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Binbin Su ◽  
Xianghe Zou ◽  
Lirong Huang
Keyword(s):  
Flow Rate ◽  
Carrying Capacity ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Two Dimensional ◽  
Working Mechanism ◽  
Content Type ◽  
Patterned Surface ◽  
Load Carrying ◽  
Film Lubrication

Purpose This paper aims to investigate the squeeze film lubrication properties of hexagonal patterned surface inspired by the epidermis structure of tree frog’s toe pad and numerically explore the working mechanism of hexagonal micropillar during the acquisition process of high adhesive and friction for wet contacts. Design/methodology/approach A two-dimensional elastohydrodynamic numerical model is employed for the squeezing contacts. The pressure distribution, load carrying capacity and liquid flow rate of the squeeze film are obtained through a simultaneous solution of the two-dimensional Reynolds equation and elasticity deformation equations. Findings Higher pressure is found to be longitudinally distributed across individual hexagonal pillar, with pressure peak emerging at the center of hexagonal pillar. Expanding the area density and shrinking the channel depth or initial film thickness will improve the magnitude of squeezing pressure. Relatively lower pressure is generated inside interconnected channels, which reduces the load carrying capacity of the squeeze film. Meanwhile, the introduction of microchannel is revealed to downscale the total mass flow rate of squeezing contacts. Originality/value This paper provides a good proof for the working mechanism of surface microstructures during the acquisition process of high adhesive and friction for wet contacts.

scholarly journals Starred angles supporting secondary trusses

1991 ◽  
Vol 18 (1) ◽  
pp. 118-129
Author(s):  
Murray C. Temple ◽  
Kenneth Hon-Wa Mok
Keyword(s):  
Cross Section ◽  
Carrying Capacity ◽  
Slenderness Ratio ◽  
The Other ◽  
Load Carrying Capacity ◽  
Industrial Buildings ◽  
Compression Members ◽  
Load Carrying ◽  
Structural Connections ◽  
Open Nature

In some large industrial buildings, it is common to span large areas by using primary trusses in one direction and secondary trusses in the other. The secondary trusses frame into the vertical web members in the primary trusses. Starred angles are frequently used as the vertical web members in the primary trusses because of their symmetrical cross section and the ease with which the connections can be made. These starred angles are usually designed as axially loaded members, but the open nature of the cross section and the fact that the secondary truss frames into one of the angles has raised some doubts about this loading assumption. As a result of this concern, an experimental research program was undertaken to investigate the behaviour and strength of starred angle web members supporting secondary trusses. The results obtained indicate that these starred angle compression members are not concentrically loaded, as the stress distribution across the angles is not uniform. It was found that if the slenderness ratio is modified in accordance with the requirements of ASCE Manual 52, the load-carrying capacity of the starred angles supporting secondary trusses can be determined using Clause 13.3.1 of CAN3-S16.1-M84. Key words: angles (starred), buckling, columns (structural), connections, trusses.

scholarly journals Flexural Strength of Fly ash Brick Masonry Wall with four different bond

2021 ◽  
Vol 2070 (1) ◽  
pp. 012190
Author(s):  
S Shenbagavalli ◽  
Ramesh Babu Chokkalingam
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Carrying Capacity ◽  
Masonry Wall ◽  
Crack Pattern ◽  
Brick Masonry ◽  
The Other ◽  
Masonry Walls ◽  
Load Carrying Capacity ◽  
Load Carrying

Abstract The strength of the masonry mainly depends on type of bond, types of bricks, compressive strength of the bricks and mortar used. The types of bonds play a major role in the properties of brick masonry wall. The most common types of bond used in practice are English bond, Flemish bond, Stretcher bond and Header bond. A lot of study has been performed on the load-carrying capacity of masonry walls. In this paper, effort has been taken to study the influence of different bonds on the flexural strength of the flyash brick masonry wall. For this wall of size 1m × 0.76m × 0.22m has been casted, cured for 28 days and tested in a loading frame. From the results, it was found the English bond gave higher flexural strength compared to other bonds such as Flemish, Stretcher and Header bond. The flexural strength of English bond was around 45 to 50% higher than the other bonds. The crack pattern at failure was also noted for all the masonry walls.

Flow Parameters in Hydrostatic Lubrication for Several Bearing Shapes

1960 ◽  
Vol 82 (2) ◽  
pp. 257-264 ◽  
Author(s):  
S. Raynor ◽  
A. Charnes
Keyword(s):  
Conformal Mapping ◽  
Film Thickness ◽  
Flow Rate ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Total Load ◽  
Thrust Bearings ◽  
Flow Parameters ◽  
Load Carrying ◽  
Mapping Techniques

In the case of hydrostatic lubrication the designer of thrust bearings has to make decisions regarding the shape of pads, location of oil holes, and configuration of oil grooves. In this paper several pad shapes and associated oil inlets were investigated using conformal mapping techniques to obtain the total load-carrying capacity, flow rate of oil, oil-film thickness, pressure and velocity distribution. The results of these calculations permit the designer to approximate his chosen configuration by computed models in order to estimate the flow parameters.

Correlation of Relevant Case Properties and the Flank Load Carrying Capacity of Case-Hardened Gears

2015 ◽  
Author(s):  
Johannes Koenig ◽  
Peter Koller ◽  
Thomas Tobie ◽  
Karsten Stahl
Keyword(s):  
Contact Stress ◽  
Carrying Capacity ◽  
Shot Peening ◽  
Positive Influence ◽  
The Other ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Relevant Case ◽  
Tooth Flank ◽  
Current Standards

The flank load carrying capacity of case-hardened gears is significantly influenced by the condition of the case properties. A negatively influenced case, e.g. due to grinding burn, may result in a significantly reduced load carrying capacity of the tooth flank. On the other hand, additional finishing methods such as shot peening and superfinishing allow a positive influence on the case properties, resulting in a further increase of the tooth flank load carrying capacity. The variation of the case properties is not adequately taken into account by the current standards DIN 3990 / ISO 6336. This paper summarizes the results of the FVA research project 521 I. This project investigated the effects of shot peening and superfinishing on the tooth flank load carrying capacity. Based on the experimental results, an extension of the calculation method for the permissible contact stress σHP is proposed.

The Impact of Linear Deformations on Stationary Hydrostatic Thrust Bearings

2002 ◽  
Vol 124 (4) ◽  
pp. 874-877 ◽  
Author(s):  
Noah D. Manring ◽  
Robert E. Johnson ◽  
Harish P. Cherukuri
Keyword(s):  
Pressure Distribution ◽  
Closed Form ◽  
Flow Rate ◽  
Carrying Capacity ◽  
Thrust Bearing ◽  
Load Carrying Capacity ◽  
Thrust Bearings ◽  
Load Carrying ◽  
Number Flow ◽  
The Impact

In this work, the operating sensitivity of the hydrostatic thrust bearing with respect to pressure-induced deformations will be studied in a stationary setting. Using the classical lubrication equations for low Reynold’s number flow, closed-form expressions are generated for describing the pressure distribution, the flow rate, and the load carrying capacity of the bearing. These expressions are developed to consider deformations of the bearing that result in either concave or convex shapes relative to a flat thrust surface. The impact of both shapes is compared, and the sensitivity of the flow rate and the load carrying capacity of the bearing with respect to the magnitude of the deformation is discussed. In summary, it is shown that all deformations increase the flow rate of the bearing and that concave deformations increase the load carrying capacity while convex deformations decrease this same quantity relative to a non-deformed bearing condition.

scholarly journals Concrete Beams Strengthened with Jute Fibers

2019 ◽  
Vol 5 (4) ◽  
pp. 767-776 ◽  
Author(s):  
Yaseen Ali Salih ◽  
Nadia Nazhat Sabeeh ◽  
Mohammed Faeq Yass ◽  
Ahmed Shihab Ahmed ◽  
Ektiffa Saleh Khudhurr
Keyword(s):  
Carrying Capacity ◽  
Concrete Beams ◽  
Natural Fibers ◽  
The Other ◽  
Jute Fiber ◽  
Load Carrying Capacity ◽  
Rc Beams ◽  
The Third ◽  
Load Carrying ◽  
Reference Specimens

Nowadays, the reinforcement of concrete with natural fibers can consider being an effectual scheme to achieve the global demand for sustainable development. Due to sustainability, bio degradability, and environmental friendly, natural fibers are preferred as compared to synthetic fibers. The present study investigated the effect of width and thickness of jute fiber strips on the mechanical properties of reinforced concrete beams (RC beams). The experimental program consisted testing of twenty-four RC beams (150*150*1000 mm) comprised of four groups. The first group consisted of three reference RC beams, the second group consisted of three RC beams strengthened longitudinally with carbon fiber strip (CFRP) of 15 cm width, the third group included nine RC beams strengthened longitudinally with one layer of jute fiber strips (JFRP) having variable width, 5, 10, and 15 cm, and lastly the fourth group which was same as the third group except using double layer of jute fiber strips. Generally, the results showed that toughness, ultimate flexural strength, and load carrying capacity of RC beams strengthened with JFRP were increased with the increase of the strip width and thickness. On the other hand, ductility and stiffness were decreased with the increase of the strip width. Test results showed that load carrying capacity was improved by 5.56 and 11.1% for one layer of jute fiber strips of 5 and 15 cm width respectively as compared with the reference specimens. On the other hand, the load carrying capacity was improved by 3.95 and 8.75 % for two layers of jute fiber strips of 10 and 15 cm width respectively as compared with the one layer strengthened specimens. Concerning the CFRP strengthening, the load carrying capacity was improved by 77.76% as compared with the reference specimens. 

Optimum Design of Porous Gas Bearings With Maximum Load Carrying Capacity and Static Stiffness

2005 ◽  
Author(s):  
V. I. Grabovskii
Keyword(s):  
Flow Rate ◽  
Carrying Capacity ◽  
Load Capacity ◽  
Maximum Load ◽  
Optimum Shape ◽  
Load Carrying Capacity ◽  
Static Stiffness ◽  
Lubricant Flow ◽  
Load Carrying ◽  
Gap Height

The problem of optimum porous infinite sliding bearings design with isothermal compressed lubricant is solved. The sliders and journal bearings with maximum load carrying capacity or maximum a lubricant film static stiffness in conditions of restriction on the lubricant flow rate through a pored insert are examined. The found optimum shapes of bearings depend on problem parameters, determining property of lubricant and insert, conditions of feed and lubricant flow rate through an insert. Besides the bearings shape a size and position of insert are determined. The optimum shape features are the discontinuity of their gap height function and insert arrangement in the vicinity of this function breaking. In the case of journal bearing at fixed gap height only the best sizes of bushing and their positions from a point of view of maximum load capacity are founded. The method of calculus of variations is used.

Mechanical Behaviors of Square Timber Columns Reinforced with AFRP under Axial Compression

2013 ◽  
Vol 790 ◽  
pp. 198-201 ◽  
Author(s):  
Shu Cheng Yuan ◽  
Jiang Feng Dong ◽  
Qing Yuan Wang
Keyword(s):  
Mechanical Properties ◽  
Axial Compression ◽  
Great Improvement ◽  
Carrying Capacity ◽  
Mechanical Performance ◽  
Physical And Mechanical Properties ◽  
The Other ◽  
Load Carrying Capacity ◽  
Mechanical Behaviors ◽  
Load Carrying

In order to apply original timber more effectively, the physical and mechanical properties of timber from camphor wood were tested. In total, seven square short timbers columns were fabricated, and then were reinforced by AFRP sheets with one, two and three layers in different reinforcing arrangements. The results showed that the columns with AFRP gave a great improvement in mechanical performance, and the loading carrying capacity, stiffness and ductility of the columns reinforced were also improved. The results also showed that the specimen with full wrapping of two layers of AFRP gave a higher deflection than the other ones. However, the load carrying capacity of the columns with AFRP arrangement decreased when the layers of AFRP sheets increased to three.

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