Due to their cost-effectiveness, pulsator tests are widely adopted as a testing methodology for the investigation of the effects of material and heat and surface treatment on the gear strength with respect to tooth root fatigue fracture. However, sin...
This research presents a comparison between two numerical approaches developed and later compared for studying External Gear Pumps (EGPs). Models have been developed for studying pumps with helical gears. Firstly, a three-dimensional (3D) CFD numeric...
This paper concerns lightweight—up to 800 kg—UGVs (unmanned ground vehicles), where multi-tracked running gears are used to improve the obstacle negotiation performance. A comparison of four different multi-tracked systems and, for refere...
Shift-by-wire technology enables more options concerning the design, placement and functions of gear shifters compared to traditional gear shifters with manual transmission. These variations can impact usability and driver performance. There is a lac...
In this study, static and dynamic analyses of a spur gear pair with linear tip relief and longitudinal crowning were performed. Dynamic experiments were conducted to compare and verify the dynamic analysis results. On the basis of the theory of geari...
This paper proposes a design and implementation of an axial type magnetic gear (MG) based on the composition of the magnetic arrangement. We report a quantitative comparison of two MG topologies with rectangular magnets arranged in series and paralle...
This work aims to analyze the characteristics and importance that design techniques for disassembly assume in the modern design phase of a mechanism. To this end, the study begins by considering a three-dimensional model of a gear motor, taken from t...
Fishery resources overexploitation, together with bycatch and discards, have an impact on marine ecosystems. The adoption of technologically innovative gears is a possible solution to reduce the discard and to enhance the sustainability of fishery, m...
The two-speed automatic transmission can adjust the drive motor speed of electric vehicles and expand their output torque range. This study proposes a rule-based partitioned gear-shifting strategy for pure electric vehicles equipped with a two-speed...
The Atlantic Blue Crab Callinectes sapidus has been recognized as invasive in the Mediterranean Sea, where it now provides a significant contribution to artisanal fisheries. In this study, we compared the efficiency, selectivity, and productivity of...
To address the structural deformation and mechanism jamming frequently observed in critical linkages during retraction and extension of door-coupled landing gear systems, this study proposes a rigid–flexible coupled dynamic modeling approach. A...
The external gear pump, like any other hydraulic component, is vulnerable to failure, which may lead to downtime as well as the failure of other components linked to it, thereby causing production loss. Therefore, establishing a condition monitoring...
The longnose darter Percina nasuta is a rare and cryptic fish that recently disappeared from much of its historic range. We developed and used an environmental DNA (eDNA) assay for longnose darter paired with visual surveys to better determine the sp...
Considering the elasticity of gear solid bodies, the load applied to gear teeth will force theoretically separated gear teeth to get into engaging state in advance. This phenomenon is named as the extended tooth contact (ETC). Effects of the ETC dire...
Stiffness is the main internal excitation of gear system vibration and is the basis for studying the static and dynamic characteristics of the system. Based on the relationship between thermal stress and strain in plane strain theory and combined wit...
Lubricants have a large influence on gearbox power losses. Recent investigations at a gear efficiency test rig have shown the high potential of water-containing gear fluids in drastically reducing load-dependent gear losses and temperatures. In this...
Recently, the 5-axis machining of gears has become increasingly important. This technology enables a flexible production of diverse gear types on a single universal machine with standard tools. In addition to the economic aspects, the focus is on the...
This article focuses on wear tests of spur gears made with the use of additive manufacturing techniques from thermoplastic materials. The following additive manufacturing techniques were employed in this study: Melted and Extruded Modelling (FDM) and...
Internal gear mechanism is widely used in micro-nano satellites due to its compact structure and high precision transmission. However, the vibration coupling caused by the small clearance coupling is more obvious and cannot be ignored under low speed...
In the aerospace industry, thin-web gears are preferred for achieving high power-density transmission. However, thin-webbed structures always lead to out-of-plane resonance during the transmission process, which commonly happens in helical gears, man...
Injection moulding is currently the most widely employed production method for polymer gears. Current standardised gear metrology methods, which are based on metal gear inspection procedures, do not provide the key information regarding the geometric...
This article lists some tips for reducing gear case noise. With this aim, a static analysis was carried out in order to describe how stresses resulting from meshing gears affect the acoustic emissions. Different parameters were taken into account, su...
Aiming at the deficiencies of the traction helical gear transmission system when the EMU is running at high speed, this paper proposes and designs a kind of arc toothed cylindrical gear adapted to the traction of higher speed EMU. A parametric arc to...
The aircraft landing gear system is vital in ensuring the aircraft’s functional completeness and operational safety. The mechanical structures of the landing gear must withstand significant operational forces, including repeated high-intensity...
In this paper, we are looking for the answer to the following question: what geometric deviations do polymer gears made by 3D printing have from the theoretical geometry? From a practical point of view, the question is whether the currently installed...
The time-varying mesh stiffness (TVMS) is the crucial parameter of the dynamic model of the gear system. Accurate calculation of TVMS is essential for effective fault diagnosis of the gear system. A mesh stiffness improved method considering both the...
A combined spiral bevel gear and planetary gear set was designed for bucket elevators to reduce the system’s complexity and improve the system’s efficiency. The dynamic model of a combined spiral bevel gear and a 2K-H planetary gear train...
Gears, as critical power-transmission components in most power equipment, have a particularly urgent need for in situ inspection systems. Traditional gear inspection methods rely on contact inspection instruments, which are not only time-consuming, b...
A new steel–plastic gear set testing methodology has been developed at the Institute of Polymer Technology (LKT). The in situ gear test rig analyses the timing differences between the index pulses of rotary encoders on the input and output shaf...
This paper deals with gear pitting fault diagnosis problem and presents a method by integrating convolutional neural network (CNN) and gated recurrent unit (GRU) networks with vibration and acoustic emission signals to solve the problem. The presente...
Due to the special meshing of convex and concave tooth profiles, an S-shaped tooth profile gear with a few teeth has the advantage of reducing the contact stress and improving the contact ratio. However, the theoretical inseparability of the center d...
Tooth root bending stress and surface contact stress are two major determinants of the load carrying capacity of gear drives. Generally, a high contact ratio has the potential to enhance the gear strength. In this paper, the basic procedures and meth...
Grinding technology exerts an enormous effect on the surface quality of double helical gears, which are subject to stringent requirements in the aviation industry. This study presents a novel gear-gap-space-borrowing grinding method that diverges fro...
This article presents a model of the geometry of teeth profiles based on the path of contact definition. The basic principles of the involute and convex–concave teeth profile generation are described. Due to the more difficult manufacturing of...
The helical gear pair of a box-type vibration exciter of a mine-used linear vibrating screen is subjected to complex excitation and prone to broken tooth failures. At present, investigation regarding the difference and particularity between gear tran...
Traditional design and shaping methods of helical gears may have difficulties in meeting the requirements of multiple performance indicators simultaneously, such as tooth surface accuracy, load-carrying capacity, and transmission efficiency. This stu...
This paper investigates the design methodologies of pure rolling helical gear pumps with various tooth profiles, based on the active design of meshing lines. The transverse active tooth profile of a pure rolling helical gear end face is composed of v...
This paper introduces an experimental approach to study the distribution of power losses in an oil jet-lubricated planetary gear set, with the aim of increasing the efficiency of these gearboxes. A thermal model is developed to estimate power losses...
To solve the design problem of non-circular gears with cusp pitch curves, this paper proposed a new variable-involute and incomplete variable-cycloid composite tooth profile (VIIVC-CTF), deduced the new VIIVC-CTF mathematical model, and constructed t...
In turbomachinery applications, thin-walled gears are cyclic symmetric structures and often subject to dynamic meshing loading which may result in high cycle fatigue (HCF) of the thin-walled gear. To avoid HCF failure, ring dampers are designed for g...
The gear drive generally operates in elastohydrodynamic lubrication (EHL) contacts, and the existence of oil film effectively reduces wear and improves transmission stability. However, little research has been devoted to studying the effect of lubric...
Diagnosis of bearings and gears, traditionally uses the envelope (i.e., demodulation) approach. The spectral kurtosis (SK) is a technique used to identify frequency bands for demodulation. These frequency bands are related to the structural resonance...
The involute profile is used almost exclusively in the manufacturing of spur gears. Nevertheless, in machinery design, the evaluation of environmental factors, such as energy efficiency, has become increasingly important when choosing between feasibl...
Digital twins play a significant role in Industry 4.0, offering the potential to revolutionize machinery maintenance. In this paper, we introduce a new digital twin designed to address the open problem of predicting gear root crack propagation. This...
Calculating the service life of gears under variable loads requires a description of the load-carrying capacity. The current standard for this is the use of the S/N curve. International standards such as ISO 6336 stipulate the use of this approach fo...
This paper presents a method of pitting failure detection in toothed gears based on the reconstruction of the gear case vibrational signal. The effectiveness of the proposed method was tested in an experiment on a power circulation test stand. The au...
This article presents a comparative study of the geometric accuracy of spur gears manufactured by additive manufacturing (3D printing) and by injection molding. Gears were produced from two engineering plastics—POM (polyoxymethylene) for inject...
As an essential part of the transmission system, gearboxes are considered as a major source of vibration. Signal identification of gear vibration is necessary for online monitoring of the mechanical systems. However, in engine-gearbox systems, the ig...
In recent decades, the request for more efficient performances in the aeronautical sector moved researchers to pay particular attention to all the related mechanisms and systems, especially with respect to the saving of power. In this context, the be...
As surface wear is one of the major failure mechanisms in many applications that include polymer gears, lifetime prediction of polymer gears often requires time-consuming and expensive experimental testing. This study introduces a contact mechanics m...
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