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This paper aims to present a comparison of numerical methods for determining the contact pattern of Gleason-type bevel gears. The mathematical model of tooth contact analysis and the finite element method were taken into consideration. Conclusions have been drawn regarding the usefulness of the considered methods and the compatibility of results. The object of the analysis was a bevel gear characterised by an 18:43 gear ratio and arc tooth line, and manufactured according to the spiral generated modified-roll method.

The mathematical model of tooth contact analysis consists of both the mathematical model of tooth generating and the mathematical model of operating gear set. The first model is used to generate tooth flanks of the pinion and the ring gear in the form of grids of points. Then, such tooth surfaces are used for the tooth contact analysis performed with the other model. It corresponds to the no-load gear meshing condition. The finite element method model was built on the basis of the same tooth flanks obtained with the former model. The commercial finite element method software Abaqus was used to perform two instances of the contact analysis: a very light load, corresponding to the former no-load condition, and the operating load condition. The results obtained using the two models, in the form of the contact pattern for no-load condition, were compared. The effect of heavy load on contact pattern position, shape and size was shown and discussed.

The mathematical models correctly reproduce the shape, position and size of the contact pattern; thus, they can be reliably used to assess the quality of the bevel gear at the early stage of its design.

Determination of the correct geometry of the flank surfaces of the gear and pinion teeth through the observation of contact pattern is a fundamental step in designing of a new aircraft bevel gear.

A possibility of the independent use of the mathematical analysis of the contact pattern has been shown, which, thanks to the compatibility of the results, does not have to be verified experimentally.

The finite element method (FEM) has become the prevalent technique used for analyzing physical phenomena in the field of structural, solid and fluid mechanics. The output of scientific papers is fast growing and professionals are no longer able to be fully up‐to‐date with all the relevant information. The purpose of this paper is to provide a bibliographical review on the application of FEM in mechanical engineering, specifically for the analyses and simulations of gears and gear drives from the theoretical as well as practical points of view.

The following topics on gears and gear drives are handled from the computational points of view: gears in general, spur gears, helical gears, spiral bevel and hypoid gears, worm gears and other gear types and gear drives. The paper is organized into two parts. In the first one each topic is handled in a short text, relevant keywords are presented and current trends in applications of finite element techniques are briefly mentioned. The second part lists references of papers published for the period 1997‐2006.

This bibliography is intended to serve the needs of engineers and researchers as a comprehensive source of published papers on design, analysis and simulation of gears and gear drives.

The bibliography listed is by no means complete but it gives a comprehensive representation of different finite element applications on the subjects. It will save time for readers looking for information dealing with described subjects, not having an access to large databases or willingness to spend time with uncertain information retrieval.

This paper gives a review of the finite element techniques (FE) applied in the analysis and design of machine elements; bolts and screws, belts and chains, springs and dampers, brakes, gears, bearings, gaskets and seals are handled. The range of applications of finite elements on these subjects is extremely wide and cannot be presented in a single paper; therefore the aim of this paper is to give FE researchers/users only an encyclopaedic view of the different possibilities that exist today in the various fields mentioned above. An Appendix included at the end of the paper presents a bibliography on finite element applications in the analysis/design of machine elements for 1977‐1997.

IN 1927 PACKARD introduced for the first time a hypoid rear axle in their private cars in order to keep the universal shaft tunnel in the passenger space as small as possible. Since then hypoid rear axles have been fitted to a very large extent in private cars of conventional construction (engine in front and rear wheel drive).

THE DESIGN and manufacture of the complete flap and slat operating systems and of the tailplane actuator for the A300B Airbus is being undertaken by H. M. Hobson Ltd (now absorbed within the Hydro‐mechanical Products Group of the newly formed Company, Lucas Aerospace Ltd).

The main role of the gears is to ensure smoothness and noiseless service, required power transmission, precision of processing, necessary degree of efficiency and so on. Lubrication is of significant importance to the protection of gears from tribological processes which cause failure of gears. The aim of this study is to investigate the influence of lubricating oils on the reliability of gears. The experimental investigation of the influence of some industrial oils on the tribological behaviour of gears of machine tools has been carried out at a metalworking factory. The paper presents the following: the classification of industrial oils for gears; the flow‐chart of the choice of the industrial oil for gears; the analysis of the symptoms and the causes of failure to gears; the reliability curves of gears in the function of tribological properties of lubricating oils under the operating conditions of investigation here presented. The reliability of gears was found to be affected by both the type of lubricating oil and the viscosity grade.

March 21 and 22, 1973 Building — Labour‐only sub‐contract — “The Lump” — Duties of care by contractor to sub‐contractor — Negligence — Plaintiff sub‐contractor injured by dangerous nip in cement mixer property of contractor — Whether contractor under any contractual duty or other duty to provide safe plant and equipment or to warn of defects — Relevance of sub‐contractor's breach of statutory duty — Construction (General Provisions) Regulations, 1961 (S.I. 1961 No. 1580), regs. 3,42.

This paper recommends an improved design methodology for the slave half of teleoperator systems based on the notion of master‐slave symmetry. Traditional slaves consist of a conventional robot retrofitted with force‐torque sensors. The new methodology eliminates dependence on destabilizing force‐torque‐sensor schemes by augmenting existing master design methods with newly invented cable mechanisms. Design goals such as bandwidth, backdrivability, and force fidelity have been applied successfully to optimize design of the trajectory‐and‐force‐controllable Whole‐Arm Manipulation (WAM) robot. Although not yet used as the slave of a teleoperator system, the results from performance tests of the experimental WAM manipulator are promising. Finally, the authors suggest a new concept ‐ Whole‐Arm Haptics ‐ that is only possible with whole‐arm manipulation, where the user steers the kinematic redundancy directly. Whole‐Arm Haptics allow teleoperators to manipulate objects larger than the slave itself.

In a rotary‐winged aircraft, wherein the control in roll is effected by operating on the rotor either by tilting it bodily or by controlling the pitch angles of the rotor blades to produce a lateral tilting of the path swept by the rotor blades, one or more fixed aerofoil surfaces are situated within the slipstream of the airscrew and so disposed angularly to the slip stream that the effective angle of incidence to the slip stream of the whole or part of such surface on one side of (or above) the longitudinal axis of symmetry of the aircraft differs from that on the other side of (or below) the axis so that an aerodynamic couple is produced tending to neutralise the airscrew reaction torque. As shown, the autorotative rotor 38 may be rocked about transverse or longitudinal pivots by links 51, 47, operated by hand control 44. The motor 32 of the tractor airscrew 33 may drive the rotor 38 when desired through gearing 103x and 85. A rudder bar 55 is connected by cables 67 to steer the tail wheel 64. The rear end of the aircraft body is provided with a horizontal tailplane comprising right‐ and left‐hand valves 57, 57a, Fig. 2, an upper central fixed vertical tail fin 53 and a lower fin 54. The angle of incidence of the part 57 of the tail plane is opposite to that of the other part 57a so that a couple is developed due to the slip stream in the opposite sense to that developed by the reaction torque of the propeller 33. The tail plane pivots about a transverse axis 58 and is provided with upturned tips 56 which effect a stabilising effect in roll, yaw and pitch. The tips 56 are provided with adjustable trailing flaps 71 and the tailplane with flaps 72, while the vertical fin 53 carries an adjustable flap 73. Since the adjustable flaps 71, 73 lie outside and inside the slip stream respectively, correct yawing trim can be obtained at all speeds and throttle openings, and by adjustment of the flaps 72 the rolling couple produced by the tailplane may be made equal and opposite to the airscrew reaction torque. The fins or surfaces for correcting the reaction torque may be arranged cither vertically or horizontally and may be combined with fins or surfaces provided for other purposes, e.g. they may consist of a pair of small horizontal fixed wings incorporated in the wheel undercarriage or in the support for lateral floats, or they may consist of vertical surfaces forming fairings around members of the undercarriage below the body and round a member or members constituting the rotor‐supporting structure above the body, or they may consist of vertical tail fins disposed above and below the body having a differential incidence setting. Specification 393,976 is referred to.

In an aircraft body of truncated but otherwise streamline form, terminating in an opening defining a generally vertical plane extending transversely of the direction of flight, a gunner's support within the aircraft body, a shell closing such opening, and disposed in continuation of the aircraft body, exposing, in such continuation, a shell surface substantially hemispherical in contour, to restore the streamline form, means upon the aircraft body, within such opening, and complemental means on the shell interengaged therewith, co‐operating for guiding the shell to swing about an axis disposed diametrically of the shell's hemispherical contour and substantially parallel to the terminus of the aircraft body, and a gun mount supported for movement conjointly with the shell, and adapted to support a gun projecting from the shell for aiming movement with respect to the shell by a gunner supported upon the support within the aircraft body.