Search results

1 – 10 of over 1000
Article
Publication date: 9 March 2015

Lidui Wei, Haijun Wei, Shulin Duan and Yu Zhang

The purpose of this paper is to develop a good calculation model to accurately predict the lubrication characteristic of main bearings of diesel engine and improve the service…

1005

Abstract

Purpose

The purpose of this paper is to develop a good calculation model to accurately predict the lubrication characteristic of main bearings of diesel engine and improve the service life.

Design/methodology/approach

Based on the coupling of the whole flexible engine block and the flexible crankshaft reduced by the Component Mode Synthesis (CMS) method, considering mass-conserving boundary conditions, the average flow model equation and Greenwood/Tripp asperity contact theory, an elastohydrodynamic (EHD)-mixed lubrication model of the main bearings for the diesel engine is developed and researched with the finite volume method and the finite element method.

Findings

Obviously, the mixed lubrication of bearings is normal, while full hydrodynamic lubrication is transient. The results show that under the whole flexible block model, maximum oil film pressure, maximum asperity contact pressure and radial shell deformation decrease, while minimum oil film thickness increases. Oil flow over edge decreases, and so does friction loss. Therefore, coordination deformation ability of whole engine block is favorable to mean load. In the whole block model, friction contact happens on both upper shell and lower shell positions. In addition, average oil film fill ratio at the key position becomes smaller in the whole engine block model, and consequently increases the chances of cavitations erosion more. So, wearing resistance of both upper and lower shells and anti-cavitations erosion ability must be enhanced simultaneously.

Originality/value

Based on the coupling of the whole flexible engine block and the flexible crankshaft reduced by the CMS method, considering mass-conserving boundary conditions, the average flow model equation and Greenwood/Tripp asperity contact theory, an EHD-mixed lubrication model of the main bearings for the diesel engine is built, which can predict the lubrication of journal bearings more accurately.

Details

Industrial Lubrication and Tribology, vol. 67 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 3 February 2012

Jun Sun, Xiaoxia Cai and Liping Liu

The elastic deformation of crankshaft bearing surface will be caused when acted by oil film pressure, which will affect the lubrication performance of crankshaft bearing. The…

3107

Abstract

Purpose

The elastic deformation of crankshaft bearing surface will be caused when acted by oil film pressure, which will affect the lubrication performance of crankshaft bearing. The model of the single bearing housing was usually used in the calculation of the elastic deformation of bearing surface. In actual internal combustion engine, the main bearing housing is combined together with engine block; deformation of the main bearing surface will be affected by deformation of the engine block. The purpose of this paper is to investigate the effect of deformation of the whole engine block on the hydrodynamic lubrication performance of main bearings.

Design/methodology/approach

The loads of main bearings were calculated by the whole crankshaft beam‐element finite element method. The lubrication of crankshaft bearings was analyzed by dynamic method. The elastic deformations of bearing surface under oil film pressure were calculated by compliance matrix method. The compliance matrix was established by finite element analysis.

Findings

It may be not necessary to consider the effect of elastic deformation of bearing surface under film pressure in the lubrication analyses of main bearings for internal combustion engine when the very high calculating accuracy is not required.

Originality/value

The elastohydrodynamic lubrications of crankshaft bearings considering the deformation of engine block were analyzed for the main bearings of an engine. Till now, whether or not the complicated model of the whole cylinder block should be considered to calculate the elastic deformation of main bearing surface in the lubrication analyses of crankshaft main bearings has not been done.

Details

Industrial Lubrication and Tribology, vol. 64 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 June 2000

George K. Chako

Briefly reviews previous literature by the author before presenting an original 12 step system integration protocol designed to ensure the success of companies or countries in…

7283

Abstract

Briefly reviews previous literature by the author before presenting an original 12 step system integration protocol designed to ensure the success of companies or countries in their efforts to develop and market new products. Looks at the issues from different strategic levels such as corporate, international, military and economic. Presents 31 case studies, including the success of Japan in microchips to the failure of Xerox to sell its invention of the Alto personal computer 3 years before Apple: from the success in DNA and Superconductor research to the success of Sunbeam in inventing and marketing food processors: and from the daring invention and production of atomic energy for survival to the successes of sewing machine inventor Howe in co‐operating on patents to compete in markets. Includes 306 questions and answers in order to qualify concepts introduced.

Details

Asia Pacific Journal of Marketing and Logistics, vol. 12 no. 2/3
Type: Research Article
ISSN: 1355-5855

Keywords

Article
Publication date: 1 October 1964

TO say that the Twenty‐fourth S.B.A.C. Show was an unqualified success is perhaps to gild the lily. True there were disappointments— the delay which kept the TSR‐2 on the ground…

165

Abstract

TO say that the Twenty‐fourth S.B.A.C. Show was an unqualified success is perhaps to gild the lily. True there were disappointments— the delay which kept the TSR‐2 on the ground until well after the Show being one—but on the whole the British industry was well pleased with Farnborough week and if future sales could be related to the number of visitors then the order books would be full for many years to come. The total attendance at the Show was well over 400,000—this figure including just under 300,000 members of the public who paid to enter on the last three days of the Show. Those who argued in favour of allowing a two‐year interval between the 1962 Show and this one seem to be fully vindicated, for these attendance figures are an all‐time record. This augurs well for the future for it would appear that potential customers from overseas are still anxious to attend the Farnborough Show, while the public attendance figures indicate that Britain is still air‐minded to a very healthy degree. It is difficult to pick out any one feature or even one aircraft as being really outstanding at Farnborough, but certainly the range of rear‐engined civil jets (HS. 125, BAC One‐Eleven, Trident and VCIQ) served as a re‐minder that British aeronautical engineering prowess is without parallel, while the number of rotorcraft to be seen in the flying display empha‐sized the growing importance of the helicopter in both civil and military operations. As far as the value of Farnborough is concerned, it is certainly a most useful shop window for British aerospace products, and if few new orders are actually received at Farnborough, a very large number are announced— as our ’Orders and Contracts' column on page 332 bears witness. It is not possible to cover every exhibit displayed at the Farnborough Show but the following report describes a wide cross‐section beginning with the exhibits of the major airframe and engine companies.

Details

Aircraft Engineering and Aerospace Technology, vol. 36 no. 10
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 1 April 2003

Georgios I. Zekos

Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some…

88824

Abstract

Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some legal aspects concerning MNEs, cyberspace and e‐commerce as the means of expression of the digital economy. The whole effort of the author is focused on the examination of various aspects of MNEs and their impact upon globalisation and vice versa and how and if we are moving towards a global digital economy.

Details

Managerial Law, vol. 45 no. 1/2
Type: Research Article
ISSN: 0309-0558

Keywords

Article
Publication date: 1 October 1968

NOT perhaps the most vintage of Farnboroughs from the point of view of new aircraft and new technology, but undoubtedly one of the most successful in relation to the business…

Abstract

NOT perhaps the most vintage of Farnboroughs from the point of view of new aircraft and new technology, but undoubtedly one of the most successful in relation to the business done. Some fifteen major orders worth over £32½ million were announced, bringing the total order book for the industry this year to more than £782 million already. This exceeds by a handsome margin the new business won by the industry in any nine‐month period in the past, and it is expected that by the end of the year orders worth well over £800 million will have been received. Highlights of the new British hardware on show were the Hawker Siddeley Nimrod and production Harriers on the military side; the B.A.C. One‐Eleven 500, the Handley Page Jetstream, the Garrett‐engined Short Skyvan, and the Beagle Pups showed the resurgence of the industry's civil interests. The number of foreign aircraft that appeared, sponsored in the main by Rolls‐Royce, bore witness to the strength of Britain's aero engine and aircraft equipment industry, and further evidence of this was found in the exhibition proper with many examples of major items of equipment having been adopted for overseas markets. The overall impression at Farnborough was a new‐found confidence in the future of the industry exemplified by a more aggressive and effective export sales policy that has already proved our ability to deliver the goods. It is not possible to cover all the exhibits shown at Farnborough, but the report following describes many of the interesting items.

Details

Aircraft Engineering and Aerospace Technology, vol. 40 no. 10
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 11 April 2016

Zhenpeng He and Wenqin Gong

This paper aims to give the guidance for the design of the bearing.

Abstract

Purpose

This paper aims to give the guidance for the design of the bearing.

Design/methodology/approach

The finite element method, the multi-body dynamics method, the finite difference method and the tribology are combined to analyze the lubrication.

Findings

The performance parameters of crankshaft-bearing system such as the misalignment, the oil filling ratio and the oil groove are also investigated. Misalignment causes the pressure to incline on one side and the pressure increases obviously. Filling ratio has great relationship with pressure distribution; the factors influencing the filling ratio are also analyzed. Different oil groove models are investigated, as it can provide the theory for oil groove design, and three factors above are always combined to influence the lubrication characteristics.

Originality/value

The optimization of bearing system is conducted by orthogonal test and neural network, unlike the linear optimization theory. Neural network uses the nonlinear theory to optimize crankshaft-bearing system.

Details

Industrial Lubrication and Tribology, vol. 68 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 January 1983

R.G.B. Fyffe

This book is a policy proposal aimed at the democratic left. It is concerned with gradual but radical reform of the socio‐economic system. An integrated policy of industrial and…

11012

Abstract

This book is a policy proposal aimed at the democratic left. It is concerned with gradual but radical reform of the socio‐economic system. An integrated policy of industrial and economic democracy, which centres around the establishment of a new sector of employee‐controlled enterprises, is presented. The proposal would retain the mix‐ed economy, but transform it into a much better “mixture”, with increased employee‐power in all sectors. While there is much of enduring value in our liberal western way of life, gross inequalities of wealth and power persist in our society.

Details

International Journal of Sociology and Social Policy, vol. 3 no. 1/2
Type: Research Article
ISSN: 0144-333X

Keywords

Article
Publication date: 1 September 1970

Accles & Pollock Ltd. of Oldbury, Worcestershire, a TI Steel Tube Division company, will be exhibiting a comprehensive range of precision steel tube and tubular products…

Abstract

Accles & Pollock Ltd. of Oldbury, Worcestershire, a TI Steel Tube Division company, will be exhibiting a comprehensive range of precision steel tube and tubular products, including plain, annularly convoluted and thin wall tube, at Farnborough.

Details

Aircraft Engineering and Aerospace Technology, vol. 42 no. 9
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 16 August 2013

Eduardo Alves Portela Santos, Rosemary Francisco, Maja Pesic and Wil van der Aalst

Increasing flexibility and complexity of modern process‐aware information systems (PAIS) usually leads to less guidance for its users and consequently requires more experienced…

Abstract

Purpose

Increasing flexibility and complexity of modern process‐aware information systems (PAIS) usually leads to less guidance for its users and consequently requires more experienced users. A flexible PAIS allows users to freely choose a specific execution sequence of activities. However, there are no guarantees that the chosen sequence conforms to established business rules. This context proposes a supervisory control service (SCS), which can be used to support end‐users of flexible PAIS during process execution by giving a list of disabled (or enabled) events (activities), i.e. at any point in time a list of possible next steps is given.

Design/methodology/approach

The SCS has been implemented in process mining framework (ProM – www.processmining.org) and the experiment that has been performed shows its feasibility. The computational infrastructure already implemented in ProM allows communication with external applications and allows the SCS to be integrated with PAIS that records events. This paper demonstrated that the SCS in ProM can cooperate with PAIS system in order to support users.

Findings

The SCS proposed in this paper monitors and restricts execution sequences of activities such that business rules are always obeyed. The system offers support based on business rules but does not limit the user by imposing rigid control‐flow structures. Users can adopt this service as a guide to execute activities with a guarantee that business rules are followed and goals are met. The SCS also offers flexibility to users to choose execution sequences.

Originality/value

The paper argues that the proposed approach has many advantages on controlling/supporting flexible processes. Supervisory control theory allows an automatic control synthesis instead of the usual manual and heuristic procedures. Thus, new control actions may be rapidly and automatically designed when modifications, such as redefinition of business rules or activities arrangements, are necessary. The flexible processes can be made to behave optimally with respect to a variety of criteria, where optimal means in minimally restrictive way.

1 – 10 of over 1000