Gearbox Housings Research Articles

Additive manufacturing as a resource-saving alternative in the manufacturing process of marine gearbox housing

ABSTRACT Marine gearbox housings are large components of several metres in length and tonnes of weight. The conventional manufacturing process is a time-consuming and elaborate process with the necessity to oversize the components from a load point of view. This results in a redundant amount of energy and resources for manufacturing. In contrast, wire arc additive manufacturing (WAAM) offers the possibility to realize a load- and weight-optimized design and provides an energy- and resource-efficient alternative in the manufacturing of marine gearbox housings. It has been shown that this additive manufacturing process provides the potential of 41% energy reduction and 36% material reduction compared to the iron cast manufacturing process. This is due to the modification of the load flow and the use of the hybrid manufacturing production as well as the possibility to include bionic structures in the gearbox design.

Lightweight gearbox housing with enhanced vibro-acoustic behavior through the use of locally resonant metamaterials

Mass reduction of automotive components enhances vehicles’ performance and extends their driving range. However, lightweight construction typically leads to noise and vibration issues. Hence, the development of lightweight components must go in tandem with advancements in the field of noise and vibration. This work focuses on the lightweighting of the gearbox housings (GBHs) and on the introduction of vibroacoustic metamaterials to improve their Noise, Vibration, and Harshness (NVH) characteristics. Topology optimization methods were used to reduce the mass of a GBH. Its noise emission was evaluated numerically, before and after the mass reduction. Locally resonant metamaterial (LRM) solutions were applied in the GBH and then tested in numerical simulations. This analysis showed the LRM solutions reduce the emission of noise in the predicted band gaps (BGs), while also providing significant attenuation across the entire frequency spectrum under consideration. The experimental results confirmed the effectiveness of the LRM attenuation concept and the trends observed in the numerical results. Vibration was also attenuated in parts of the GBH where the LRM was not applied. Attenuation of in-plane housing vibration was also observed. The proposed LRM solutions are lightweight, passive and low-cost solutions that can implemented in housings to enhance their NVH characteristics.

EVALUATION OF THE RELIABILITY OF «GANZ» PORTAL CRANE MECHANISMS

Portal cranes are widely used in various ports for transhipment operations. However, today in the river and sea ports of Ukraine, more than 88% of cranes have fulfilled the standard service life and continue to be operated. Since portal cranes are the main link in the technological process, therefore, the productivity of Port lines depends on their reliable and trouble-free operation. The analysis of statistical data shows that the processing and long-term operation of portal cranes in the mode of intense cyclic loading leads to the formation of fatigue defects and the subsequent failure of their components and accidents [1-9]. Therefore, ensuring safe and reliable operation is one of the main tasks in the design, modernization and operation of cranes. The analysis of works] showed that the reliability of portal crane mechanisms that have been soldered for more than 35 years in sea and river ports has not been sufficiently studied. For research, 24 identical Ganz cranes with a lifting capacity of 16 tons were selected, which operate in clamshell mode in sea and river ports. The analysis uses information contained in the respective maintenance and repair logs of the respective cranes from 2008 to 2021. Data analysis shows that the greatest number of failures is observed in the mechanisms of movement, lifting, changing the boom departure and metal structures of cranes. It should be noted that up to 75% of all time is spent on restoring the operation of reducers. The reasons for the failure of movement mechanisms are: wear of gears and shafts of gearboxes, destruction and wear of bearings in gearboxes, cracks in gearbox housings. The failures of the mechanisms for changing the reach of the boom are caused by wear of the teeth of the racks and gears, bearings and gear housings of the mechanism.

МЕТОД РАСЧЕТА УСТАНОВОК ИНФРАКРАСНОЙ ОБРАБОТКИ ПОЛИМЕРНЫХ ПОКРЫТИЙ ПРИ ВОССТАНОВЛЕНИИ КОРПУСНЫХ ДЕТАЛЕЙ АВТОТРАКТОРНОЙ ТЕХНИКИ

Application of polymer coatings for restoration of worn-out bearing holes in housing parts of automotive equipment provides multiple increase of their service life, reduction of repair costs, improvement of reliability. The highest efficiency is achieved by applying elastomeric coatings. To cure the material and achieve high mechanical properties, the coating, after application, is subjected to thermal treatment by convective or thermoradiation methods. Coatings after treatment by a thermoradiation method, in comparison with convective, have significantly lower porosity and higher quality. A model of infrared heating of type I body parts (gearbox housing, car and tractor transfer case housing) has been developed, which takes into account the heat capacity of the material and the design parameters of the part, the ambient temperature and the steady temperature of the part during heating, the design parameters of the infrared radiation installation. The model allows you to calculate the rate of temperature increase and the time of heating the part to the required temperature by infrared heating. The article describes in detail the algorithm and provides a computer program for calculating the structural and technological parameters of the infrared processing plant for elastomeric coatings applied during the restoration of bearing holes in the body parts of the equipment. Heating of the gearbox housings of GAZ-24 and GAZ-53A cars showed a high coincidence of the design and experimental values of infrared heating parameters. The difference between the actual heating temperature of the body part and the design temperature is from 1.5 to 2.4%, the heating time is from 6.1 to 8.2%, which is a confirmation of the correctness of the developed method for calculating the structural and technological parameters of infrared installations. An experimental assessment of the quality of elastomeric coatings after heat treatment by various methods was carried out. Compared to the convective method, after infrared treatment, the quality of elastomer coatings increased F-40S: the area of the destroyed coating decreased by 1.33 times, the concentration of pores in the coating - by 1.24 times.

Advanced method of including housing stiffness into calculation of gear systems

One of the central goals during the design of helical gear systems is the achievement of a well-distributed contact load in the gear mesh. An equal load distribution is a key factor for a high load carrying capacity, the economic use of materials and a long lifetime. Mesh misalignment can be caused by tooth deflections, manufacturing deviations or elastic deformation of the shaft-bearing system and the gearbox housing. Those deformations have to be taken into account during the design process of adequate tooth-flank geometry. Elastic deformations of gearbox housings can be significant, especially in the case of automotive applications with aluminium cases. This paper presents an advanced method of including housing stiffness into the calculation of gear systems. A validation of the approach is carried out by comparing the calculated deformations with measurements of a static test rig of a hypoid gearbox.Many calculation programs offer the opportunity to analyse the deformation behaviour of the shaft-bearing-housing system. Most of the components in these programs are described by analytic approaches. However, components that are geometrically more complex, like the housing or planet carriers cannot be represented as easily as that by analytic expressions. There are several alternatives to take into account the elasticity of those objects. One way is to model the stiffness of the bores using imported stiffness matrices. These matrices contain the elasticity of the bores itself as well as crossover influences between the bearings. The reduced stiffness matrices may be the result of a static reduction of the geometry using the finite element method (FEM). As state of the art, the reduction is mostly carried out at the centre points of the bearing bores. The proposed advanced method uses the static reduction of geometries on several points at the bores, distributed over the circumference. This approach offers a more detailed modelling of the elastic behaviour of complex geometries within the analytic deformation calculation of gear systems. To validate the advanced approach, the calculation results of the elastic deflections of the shaft-bearing-housing system is compared with measurements of a static test rig. In the course of these comparisons, the influence of different modelling methods of gearbox housings on the accuracy of the calculation results is discussed.

Investigations of High-Strength Mg-Al-Ca-Mn Alloys with a Broad Range of Ca+Al Contents.

The low mass and high specific stiffness of Mg alloys make them particularly interesting as means of transportation. Due to further desirable properties, such as good machinability and excellent castability, Mg alloys have gained acceptance as castings in high-volume applications, such as gearbox housings and automotive steering wheels. However, in forming processes, such as extrusion and forging, Mg alloys find little to no industrial use at the moment. The reasons for this are their poor formability, which is reflected in limited processing speeds and low ductility, and their modest mechanical performance, compared to competing materials, such as Al alloys and high-strength steels. Much research is being conducted worldwide on high-strength Mg alloys, most of which rely on high levels of rare earths, making these materials both ecologically and economically questionable. Here, it is shown that high yield strengths (>300 MPa) can be achieved in the Mg–Al–Ca system while maintaining good ductility, using only low-cost elements. The investigations have shown that these properties can be adjusted over broad alloy compositions, which greatly simplifies both the processing and recyclability.

Изыскание новых конструкционных материалов и технологии изготовления прочных корпусов редукторов и центробежных насосов

Изыскание новых конструкционных материалов и технологии изготовления прочных корпусов редукторов и центробежных насосов

Reducing mass while improving the operational behavior: form optimization of planetary gearbox housings

The optimization of load sharing between planets is one of the most important goals in planetary gearbox design. Unevenly distributed load will cause locally higher flank pressures and therefore, less durability of gears and bearings. Furthermore, unevenly distributed or fluctuating loads can cause excitations in the gear mesh and structural vibrations. The load sharing in planetary gear stages depends on the individual stiffness conditions in each mesh position. The stiffness is not only influenced by the gear geometry but also by the surrounding structural elements like shafts, housings and torque arms. In wind industry these components are often designed very stiff in order to reduce their effect on the operational behavior.Within this paper, a method is presented, which allows combining the structural optimization process with a tooth contact analysis for planetary gearboxes. By means of this combined approach, it is possible to optimize the housing structure of the ring gear in terms of mass reduction while keeping the operational behavior in focus. With a weighted design objective function, it is possible to decide whether the main objective should be load distribution, excitation behavior, low mass or a balanced design.

Design of sensor integrating gears: methodical development, integration and verification of an in-Situ MEMS sensor system

State of the art vibration-based condition monitoring at gearbox housings faces uncertainties in the interpretation of measurement data due to signal transformations and noise. The state of research shows that direct measurements at the source of vibrations with integrated sensors provide higher quality data. Capacitive MEMS sensors seem predestined for integration, but there is limited research covering compactly integrated MEMS sensor systems for condition monitoring by vibration measurement. In this contribution an integrated MEMS sensor system is designed methodically based on VDI 2206. A sensor system is selected based on requirements extracted of previous contributions and verified on a rotational shaker test rig. Afterwards it is integrated on a gear wheel in a gear test bench. Several verification measurements using different principles and locations are performed to verify the measurands. Results show that the gear mesh vibrations including the sidebands can be measured with the integrated sensors which provide superior signal-noise-ratios compared to other locations. This proofs that the sensor integrating gear system is principally able to perform high quality condition monitoring.

The Effect of Selected Operational Factors on the Vibroactivity of Upper Gearbox Housings Made of Composite Materials.

This paper presents the results of laboratory tests in which evaluation was performed regarding the effect of selected operating factors on the vibroactivity of upper gearbox housings made of three different fiber reinforced polymer composite materials with diverse layouts (cross and random) and types of reinforcing fibers: glass fiber and carbon fiber. The results of tests for composite housings were compared with those for a steel housing. The tests showed that composite housings had a weight lower by more than 60% compared to the steel housing. A multisensor measuring system consisting of vibration acceleration transducers, a directional microphone and a data acquisition card with software was used for the study. Tests of the vibroactivity of upper gear housings were carried out at different loads and rotational speeds of toothed gears. The study showed that composite housings are less sensitive to changes in the rotational speed that steel housings. The tests showed that at a higher rotational speed of the gear transmission, housings made of composite materials had a comparable or lower level of vibration. Tests and analyses of the vibroactivity of housings performed at different loads of the gear allow the conclusion that composite housings, despite a considerably lower weight than steel housings, are less sensitive to changes in the load of the gearing.

An Overview of Quasicrystal Reinforced Magnesium Metal Matrix Composites

The strength of metals and their alloys are enhanced by adding secondary reinforcement particles like Conventional crystalline and non-crystalline particles such as SiC, glass and Al2O3. These particles provide weak interfacial bonding due to the crystallographic structure mismatch or undesirable interface reaction products. Quasicrystals provide strong interfaces with the matrix due to their low interfacial energy. Their low strength and stiffness make them useful in non-critical stress applications such as instrument panels, seat frames and gear box housings. Reinforcing quasicrystals to Mg alloys greatly enhances their strength or stiffness. The literature on quasicrystal (in-situ and ex-situ) reinforced Mg alloy composites are critically reviewed to show the importance of quasicrystal reinforcement in Mg alloys and the effect of different manufacturing process technologies such as casting process, powder metallurgy, hot extrusion on mechanical properties.

New improvement opportunities through applying topology optimization combined with 3D printing to the construction of gearbox housings

The construction of gearbox housings is severely restricted by all the currently used machining processes. 3D metal printing opens up new possibilities in this area. However, a clear additional benefit compared to the standard cast housing must be given, in order to make additive manufacturing viable. The objective of the present project was to research both the potential and restrictions of additive manufacturing technologies regarding the design of gearbox housings. As a result of this investigation, a topology optimized lightweight gearbox housing with integrated oil channels and scraper was obtained. The topology optimization process of the new gearbox was carried out in two work steps. The first consisted of the determination and design of the primary load-bearing structure of the housing. Therefore, an iterative design process was needed in order to develop the final support structure, because the topology optimization only provides a design draft of the framework structure. Concerning the iteration, an FEM analysis was performed to check and improve the draft after each loop. During the evaluation, safety and weight were compared with the previous version. During the second step of the topology optimization, the structure of all the oil channels was developed, creating a morphological box. Finally, the new gearbox housing was generated by combining the topology optimization with the concepts from the morphological box. Selective Laser Melting (SLM) was chosen for manufacturing because it allows the printing of components of the desired dimension with the required accuracy. The developed gearbox prototype was printed using the aluminum alloy AlSi10Mg (A360). Due to the flexibility of the SLM technology, it was possible to fulfill all specific design criteria while also showing the typical topology-optimized structure too. Afterwards, the housing was machined to achieve precise dimensions and tolerances. Finally, the gearbox was assembled, and both its mechanical integrity and the functionality of the integrated oil systems were fully checked with short-term tests.

Impact of Application of Selected Composite Materials on the Weight and Vibroactivity of the Upper Gearbox Housing.

In this paper, exploratory studies on the application of fibre-reinforced polymer composites in the construction of gearbox housing elements that are used for transport means, as an alternative to traditionally used materials, were undertaken. Composite materials with three types of reinforcement were used: a glass-chopped strand mat, glass fabric, and carbon fabric. The manufactured elements were subjected to weight assessment and vibroactivity tests, including the recording of vibration and noise. The obtained results were compared to the values recorded for housings made of steel. It has been found that composite housings, while maintaining geometric similarity, are characterised by at least 60% lower weight compared to steel housings. It has been shown that in the frequency range below 1 kHz, composite housings are characterised by the presence of resonant frequencies with higher amplitudes than steel housings. At higher frequency ranges—above 1 kHz—composite housings had a lower vibroactivity level than steel housing. They allowed a significant reduction in the level of vibration and noise in this frequency range. The results obtained indicate that composite gearbox housings can be a good alternative to steel-based solutions.

Effect of inner stiffeners on vibration and noise levels of gearbox housing without changing the mass

Especially, with the advancement of technology, mechanical parts need to be designed to be lighter and more durable. In the industry, gears are the most common power transmission equipment, and for this equipment, increasing durability and rigidity has an essential importance. During power transmission, undesired vibration and noise arise in gear systems. In addition to gear design, gearbox housing design is also essential to reduce the radiation of undesired structure-borne noise and vibration. In order to reduce noise and vibration levels, some modifications are frequently used on gearbox housings. In this study, three different gearbox housing designs (basic, cross and cellular) are formed and analysed by using ANSYS® software. The design alternatives for housings have been formed inside of the structure as different quantities of longitudinal and transverse stiffeners. In addition, all the external dimensions and the mass of these three housing designs are equal in order to observe just vibration and noise reduction. Fast Fourier Transform (FFT), statistical properties of vibration signals and sound levels of the gearbox have used for comparisons to determine which gearbox have better vibration and sound levels.

Influence of natural aging on the mechanical properties of high pressure die casting (HPDC) EN AC 46000-AlSi9Cu3(Fe) Al alloy

Abstract The standard aluminum alloy AlSi9Cu3(Fe) is the most common Al alloy used to produce castings by means of high-pressure casting technology and has wide application in the automotive industry, especially for motor mounts, gearbox housings, filter housings, generator housings, turbocharger housings, etc. The advantages of AlSi9Cu3(Fe) alloy are relatively good mechanical properties, strength and hardness, although it shows slightly lower elasticity and corrosion resistance. The artificial aging process or stabilization annealing can be used to improve the dimensional stability of castings, with the aim of achieving better mechanical properties as soon as possible. In this paper, the influence of natural aging time on the mechanical properties of AlSi9Cu3(Fe) alloy as well as on microstructure development was investigated. Specimens were prepared by high pressure die casting technology under optimized parameters. Chemical content was determined by optical emission spectroscopy. Thermodynamic calculation was performed by Thermo-Calc 5 software and transformation temperatures during dynamic measurement were followed by differential scanning calorimetry. Tensile properties after 3 and 30 days of aging, as well as 7 months, were determined by a tensile test at an MTS 810 instrument. Metallographic analysis was carried out by optical microscope and field-emission scanning electron microscope. Results showed a significant increase in tensile strength, yield strength and elongation with aging time and formation of (αAl + βSi), Alx(Fe,Mn)ySiz, Al2Cu-Si, Al5FeSi and Al-Mg2Si-Cu phases.

Fatigue failure analysis of high speed train gearbox housings

Abstract The present work addresses the formation of fatigue cracks in gearbox housings of high speed trains. Systematic studies of fracture analysis, finite element analysis, and field tests under actual stress and acceleration conditions are employed. Time domain, frequency domain, and time-frequency domain analyses indicate that the first two natural vibration modes are excited by out-of-round wheels and rail-track irregularities, and the superposition of these vibration modes results in the occurrence of the beat phenomenon, where the amplitude of the vibration modulates periodically, which increases the likelihood of exceeding fatigue limits, and produces greater structural damage. Analyses reveal that the fatigue strength of the failure region is reduced by the casting process, which eventually leads to the formation of fatigue cracks. Our findings suggest that the gearbox housing casting process should be improved to reduce casting porosity, and the housing structure must be redesigned to avoid the resonance frequencies associated with wheel-rail excitation at operational speeds.

Increasing Performances in High Pressure Casting Process of Aluminium Alloys

The purpose of this paper is to present the influence of the casting parameters in the process of producing aluminium alloy components of gearbox housing type in automotive industry. The project has as objectives the minimization of the most common casting defects met in casting of gearbox housings through adjusting the parameters of the process. In order to minimize these defects, it was studied the casting speeds in phases I and II, multiplication pressure of phase III and the mould temperature that is influenced by both the cooling channels inside the mould and the spraying process of the mould (lubrication/cooling) that helps regulate the optimum temperature. The experimental results showed that the casting defects such as pores, cast in stages, shrinkage cavities, gas holes and tightness are significantly reduced by periodically controlling and correcting the specific casting parameters.

Challenges and Solutions in the Development of Magnesium Sheet for Sustainable Vehicle Concepts

Magnesium as the lightest structural metal offers significant potential weight saving compared with steel and aluminium. Cast magnesium components are widely used, e.g. as engine blocks or gear box housings. To open more opportunities for weight saving, it is necessary to widen the application fields to wrought products, such as large thin walled components for which sheets as semi-finished products are needed. The production and processing of magnesium sheets material is currently hampered by the limited formability of magnesium and high costs. The use of the twin-roll casting (TRC) as a cost-effective manufacturing process and the development of new calcium-containing alloys are leading to a decisive reduction of those obstacles.

Combination of microscopic model and VoF-multiphase approach for numerical simulation of nodular cast iron solidification

The ongoing increase in the size and capacity of state-of-the-art wind power plants is highlighting the need to reduce the weight of critical components, such as hubs, main shaft bearing housings, gear box housings and support bases. These components are manufactured as nodular iron castings (spheroid graphite iron, or SGI). A weight reduction of up to 20% is achievable by optimizing the geometry to minimize volume, thus enabling significant downsizing of wind power plants. One method for enhancing quality control in the production of thick-walled SGI castings, and thus reducing tolerances and, consequently, enabling castings of smaller volume is via a casting simulation of mould filling and solidification based on a combination of microscopic model and VoF-multiphase approach. Coupled fluid flow with heat transport and phase transformation kinetics during solidification is described by partial differential equations and solved using the finite volume method. The flow of multiple phases is described using a volume of fluid approach. Mass conservation equations are solved separately for both liquid and solid phases. At the micro-level, the diffusion-controlled growth model for grey iron eutectic grains by Wetterfall et al. is combined with a growth model for white iron eutectic grains. The micro-solidification model is coupled with macro-transport equations via source terms in the energy and continuity equations. As a first step the methodology was applied to a simple geometry to investigate the impact of mould-filling on the grey-to-white transition prediction in nodular cast iron.

Numerical Simulation and Production Trial of Aluminum Alloy Gear Box Housing

Die casting processing analysis was conducted and the gating system and the cooling system were designed for aluminum alloy gearbox housings. Numerical simulation software PROCAST was used to calculate the filling and solidification sequence and the temperature field of die castings. The reasonable designs of the gating system and the cooling system were obtained. The feasible die casting mould was designed and manufactured. Production trial showed that, casting molding effect is good, and there were not defects such as misrun, cold lap. After machining, there were not defects exceeding the allowed limited values including porosity, shrinkage, and slag inclusion in the products. The trial showed that the product mold design and die casting technology achieved the desired effect, which can realize batch production.