Composite Gear Research Articles

A new method for testing polymer gear wear rate and performance

This paper provides details of a new test rig design and methodology intended for, and successfully applied to, measuring the gear wear rate and performance of polymer composite gears under both dry and lubricated conditions. One of its unique contributions is that it continuously measures the gear wear rate, a feature essential for understanding polymer gear behaviour. While sharing some concepts with the traditional back-to-back test configuration used for steel gears, the new method introduces a rotary freedom to the block supporting the polymer gears under test. This block rotates if the gear tooth thickness is reduced, which aids control of the test load. The gear surface wear rate is recorded continuously by using a capacitance transducer to measure the pivot block motion. A second unique contribution of the new test method involves splitting the support block so that controlled misaligned gear engagements (not reported in other designs) can be introduced and subsequent changes to wear behaviour studied. The paper first outlines the test rig concepts and design before discussing in more detail the gear wear rate measuring principles, the methods of centre distance adjustment and the achievement of virtually constant gear loading. Finally, a selection test results are presented in summary to further validate the new test method and illustrate potential applications.

Development of an Effective Resource-Saving Design and Methods for Calculating the Parameters of Gears with Compound Wheels

The article presents the design schemes and the principle of operation of the gear transmission with composite wheels and elastic elements. The technique and the results of the analysis to determine the degree of mobility of gears with composite wheels and elastic elements are given. The angular displacement of the composite gears and gear ratios are obtained by the analytical method. Graphic dependencies are constructed and the values of the system parameters are recommended.

Development and investigation on transmission efficiency of functionally graded material-based polybutylene terephthalate spur gears

Application of polymer composite gears is increasing due to their superior properties. They have lower inertia, less weight, and run much quieter than their metal counterparts. In the present work, functionally graded material-based glass fiber reinforced polybutylene terephthalate gears are fabricated with a novel horizontal centrifugal casting technique using an injection molding machine. Conventional technique is used to fabricate homogeneous polybutylene terephthalate gears. Polybutylene terephthalate reinforced with 15 and 30 wt% glass fibers is used to fabricate gears. Unfilled polybutylene terephthalate gear is also manufactured for comparative study. Gradation in functionally graded material gear is verified by scanning electron microscope analysis, and Shore D hardness is measured in three different locations of the fabricated functionally graded material gears. Gradation in functionally graded material gear is also verified by ignition loss test method. Continuous gradation is observed in functionally graded material gear by scanning electron microscope and confirmed by hardness test and ignition loss test. The objective of present work is to investigate and compare the transmission efficiency of homogeneous and functionally graded material gears during operation. A polymer gear test rig is used for the experimental work. Experiments are conducted at various torque and speed combinations for 0.2 million cycles. Life span of fabricated gear is also tested for 10 million cycles. The range of the torque is 0.8–2.6 N m and the range for rotational speed is 500–1400 r/min. The transmission efficiency of the fabricated gears is found to be sensitive to the operating torque.

Tribological Characteristics of Natural Fiber Reinforced Polyester Hybrid Composites

In order to investigate the wear behavior and tooth damage of Madar and Bauhinia Racemosa fibers reinforced polyester, the composite gears were fabricated with varying the fiber weight percentages of 5%, 10%, 15% and 20%. This paper explores the rolling and sliding of the composite gears running against nylon gear with a simplified method of analyzing and understanding the wear and tooth damage. Tests were conducted without external lubrication over a range of loads 4Nm, 8Nm,12Nm and 16Nm using a gear test rig. The test results of composite gears are compared with unreinforced polyester gear (URPE). It was found that the surface temperature was the primary factor affecting the wear rate and an initial relationship between gear surface temperature and load capacity. This composite can be useful for automobile and industrial applications.

Analyzing the Mechanical Behaviour of Carbon Fiber Reinforced Spur Gear with IPN as Matrix Material

The gears are the essential components used in mechanical power transmission in both automobile and industrial machinery. At present, the composite materials are playing a major role in the replacement of conventional materials. The reason for replacing the conventional materials with composite material is that, the composite material posses light weight to stiffness ratio. In this study, the mechanical behavior of composite gears made up of IPN polymer matrix with reinforcement of different carbon fiber proportions. The main objective is to make spur gears using carbon fiber reinforced with interpenetrating polymer network (IPN) resins in various proportions of carbon fiber Chopped strand Mat (CSM) (5%,10%,15%,20%). The study investigates that, the fabricated spur gear of different proportion of IPN and carbon fiber using gear testing rig. Out of this results, the 10% CSM reinforced IPN gears have shown the significant wear reduction as compared with the remaining set of proportions.

Novel Steel and Aramid/Phenol Composite Gear for a Transmission with Optimum Design and FEM Vibration Analysis

Hybrid gears made of steel and fiber-reinforced polymeric composite material are recently attracting electric vehicle designers’ attention due to their possible advantages such as lightweight and lessened transfer of noise and vibration for automotive transmissions. Polymeric composite material may be placed in-between the steel teeth and central hub regions in the radial direction of the gear. The partial usage of polymeric composite material for a gear is expected to reduce the transmissibility of vibration from teeth to hub as well as the weight of the gear-train. Using the finite element method, optimization, vibration and noise analyses have been performed in order to calculate SPL (sound pressure level) for pure steel and hybrid gears, separately. At a specified point of a tooth and a hub, the changes in SPL are computed and are compared to check how effective the polymeric composite region is. The reduction in SPL of the hybrid gear is observed by comparing to that of a pure steel gear. To minimize the weight of the hybrid gear, design optimization is applied by considering fatigue strength of steel and composite material.

The wear resistance improvement of fibre reinforced polymer composite gears

This paper presents experimental investigations into the wear performance of non-reinforced POM (Polyoxymethylene) and 28% GFR POM (glass fibre reinforced POM) gear pairs; polymer running against polymer is a little studied but important system. All the gears were manufactured locally by injection moulding. The injection mould design and manufacturing process are briefly described and progress in the control of injection moulding processes for polymer and fibre reinforced polymer gears is discussed. A specifically designed polymer composite gear test rig was used for this research. Performance differences for the POM and GFR POM gears are observed, notably their loading capacity and failure modes. Both POM and GFR POM gear pairs, showed a clear wear transition torque for a given running speed. Above the transition torque the wear rate accelerated rapidly causing thermal failure, while below the transition torque the gears had a very low specific wear rate. Significant performance enhancements were seen for the GFR POM gears, with an increase of around 50% in load carrying capacity when compared to the non-reinforced POM gears. The wear mechanisms are briefly discussed, noting that most data available for polymer gear design is not representative of these polymer against polymer pairings.

Drop Test Simulations of Composite Leaf Spring Landing Gears

This paper deals with the investigation of the static and dynamic behaviors of composite leaf spring landing gears during the landing phase of an aircraft. An accurate simulation of the overall landing gear mechanism needs to be performed in order to evaluate the forces that result on the fuselage during the impact of the aircraft on the ground. Thus, a model of the leaf spring landing gear was built through the Finite Element Method (FEM), and then its motion was analyzed with a Multibody Simulation (MBS). The results show the force transmitted to the fuselage by straight and curved leaf springs. Different values of thickness and materials were taken into account, in order to evaluate design sensitivities. In conclusion, the relationship between the geometry and material characteristics of the composite landing gear and the force on the fuselage is highlighted in graphs and tables, which can be used for future design and developments of landing gear systems.

The wear behavior and service life of Madar and Bauhinia Racemosa reinforced polyester hybrid composites for gear applications

Abstract In order to investigate the wear behavior and service life of Madar and Bauhinia Racemosa fibers reinforced polyester, the composite gears were fabricated with varying the fiber weight percentages of 5%, 10%, 15% and 20%. This paper examines the rolling and sliding of the composite gears running against nylon gear with a simplified method of analysing and understanding the wear rate and tooth damage. Tests were conducted without external lubrication over a range of loads using a gear test rig. The test results of composite gears are compared with unreinforced polyester gear (URPE). The extremely interesting investigation from the experimental work is the drastically different wear behavior when running composite gears against nylon gears, specifically the low wear rate when compared with URPE. It was found that the surface temperature was the primary factor affecting the wear rate and an initial relationship between gear surface temperature and load capacity.

A Fault Feature Extraction Method for Gearbox with Composite Gear Train Based on EEMD and Translation-Invariant Multiwavelets Neighboring Coefficients

A Fault Feature Extraction Method for Gearbox with Composite Gear Train Based on EEMD and Translation-Invariant Multiwavelets Neighboring Coefficients

Development of mechanism and machine science in Belarus by an example of gears and gear transmissions

In a paper, the important original results on various topics of gears and gear transmissions are generalized and enhanced, which are described at large in the monograph ‘Gears and Transmissions in Belarus: Design, Technology, Estimation of Properties’, Minsk, 2017 (in Russian). Achievements of Byelorussian scientific schools in field of mechanical gear transmissions and polymer composite gears are presented. Technological aspects, models and methods for calculation and design of drives and their components as well as estimation of lifetime, noise and vibration characteristics are described. The complex of key issues for development, manufacturing, diagnostics and testing gears, which largely determines the competitiveness of machines and their transmissions, is considered. The activities of Belarusian scientists in IFToMM are characterised, including their contribution to identification of terminology on gears. The paper is a kind of guide on science-intensive developments of Belarusian specialists in the field under discussion.

Computer-aided design and adoption of standard software on gearing

New automated systems for designing gear drives and adoption of standard computer software on gearing are considered. A review of different software solutions for designing gears, gear drives and gear forming tools is presented. Methodological aspects and numerical results of designing injection-moulded plastic gears and forming mould dies for their manufacturing are shown, including the techniques of tooth profile construction and adjusting gear accuracy parameters. The possibilities of a two-level calculation procedure for strength and wear of composite gears made of dispersion-filled plastics aimed at optimization of reinforcing filler content are noted. The results of application of known standard automated systems, such as IOSO, KIMoS and other for quality improvement of the front loader gearbox and transmissions of “Belarus” tractor are discussed.

Development of the Involute-Cycloid Composite Tooth Profile Gear Pump to Reduce Driving Noise

Development of the Involute-Cycloid Composite Tooth Profile Gear Pump to Reduce Driving Noise

Knowledge discovery in multiobjective optimization problems in engineering via Genetic Programming

Recently, the interest of the researchers has grown in post-optimality analyses, with the search for intrinsic properties of the optimal solutions of a given problem. Innovization has been defined as a process of knowledge discovery, in the form of mathematical relationships between variables, objectives, constraints, and parameters, from the output of an optimization problem. Genetic Programming (GP) is a bio-inspired metaheuristic capable of automatically evolving programs that can be used in this process. In spite of its wide applicability, GP techniques can present some issues when tackling knowledge discovery problems. Here, three modifications are proposed in a GP technique available in the literature for Innovization problems: (i) a method to ensure the consistency of the units of the principles using protected operations that ignore invalid terms, (ii) a strategy to avoid trivial solutions, and (iii) the use of an external archive to store the solutions of interest found during the search. Computational experiments are presented using four engineering case studies (namely, a two-member-truss, a welded beam, the cutting of a metal part, and a composite gear) to verify the capacity of the proposed GP method in finding design principles.

Design and analysis of composite spur gears using finite element method

In this study, the parametric design and contact analysis of composite spur gears are investigated numerically. Composite gear provides an adequate strength to weight ratio, more hardness, durability and low maintenance cost. It is emerging better alternatives for replacing metallic gears. The finite element model of spur gear is developed with the assistance of the Ansys software. In this study each design factor such has stress distributions, strain and deformation are considered to compare composite gear with steel and polymer gears. An APDL gear model has been developed for the design evaluation and comparison study.

Method and Device for Speed Change by the Epicyclic Gear Train with Stepped-Planet Gear Set

Abstract The article describes new method and device for continuously variable speed change management via compound epicyclic gearing with composite planet gears and closed circuit hydrosystem, when the speed control element is either outer ring gear (annulus) or the carrier or sun gear. In each case, the control element connected to closed circuit hydrosystem and can be in motion or immovable depending on the bandwidth of hydrosystem’s regulating throttle. We had held theoretical research and received graphic dependences between velocities of driving, control and driven elements by means of computer programing.

FEA Approach for structural and wear analysis of Araldite LY556 and DNR Composite Gear

Gears are one of the most used elements in the field of mechanical engineering for the transition of power. Gears are designed and manufactured with various materials like nylon, polyacetal, Derlin and Many more. In this research, the spur gear is designed according to the required dimension and is manufactured by composite material made from Araldite LY556 and DNR base material for power transmission. FEM analysis is done on the gear for Dynamic load to find the stress developed in it even the wear analysis to measure wear loss by using LS-Dyna software. Similarly bending strength of a single tooth of gear is being determined for different loads by Ansys software and these results are compared to the analytical results.

A simulation of the fatigue life of light aircraft glass fibre-reinforced composites landing gear

This study uses finite element analysis software to conduct simulations and compares the fatigue behaviour of the aluminium alloy and glass fibre-reinforced composite that is used in light aircraft landing gear. The maximum stress, maximum strain and deformation of landing gear of different shapes (plate and tube shapes) are also determined. The results show that the composite landing gear weighs 45% less than an aluminium equivalent. Of the samples tested, plate-shaped glass fibre-reinforced composite landing gear exhibits the lowest maximum stress under a static load. Regardless of whether the landing gear is plate- or tube-shaped, the maximum strain and deformation for the composite landing gear are more than four times those for the aluminium alloy landing gear. The results for dynamic load show that plate-shaped glass fibre-reinforced composite and tube-shaped aluminium landing gear have similar maximum alternating stress under cyclic loading.

INVESTIGATION OF CONTACT FATIGUE AND OPERATING PERFORMANCE OF NI-WC COMPOSITE ELECTROCOATED GEARS

The objective of the work was to evaluate contact fatigue and operating performance of electrodeposited Ni-WC composite coated gears using experimental technique. The electrodeposited Ni-WC coating was characterized for coating thickness, hardness and crystal structure using Electro-Physik gauge, Rockwell Hardness testing machine and X-Ray Diffraction respectively. The operation condition was estimated using designed test rig and vibration pick with CRO. The results show that coated gears are smoother in operation and offer more resistance to wear and fretting due to increased hardness.

Review of Composite Asymmetric Spur Gear

Gears made from composite materials are widely used in many power and motion transmission applications. Due to lower weight to stiffness ratio, composite gears may be replaced by conventional material gears in power transmission systems.