Hydraulic Assembly Research Articles

Modeling of geological and technical measures based on drilling a well with modified valve assembly parameters

In the course of the research, an analysis of the development of geological and technical measures at various fields was carried out. The justified application of these measures has been studied, and recommendations have been made to increase the efficiency of oil recovery based on drilling wells with modified valve assembly parameters. The conducted research allows us to obtain optimal performance indicators of pumping equipment associated with such parameters as pressure, flow, taking into account the lowest cost of repair work. For this purpose, modeling of geological and technical measures based on drilling a well with modified parameters of the hydraulic assembly of the drilling pump has been developed. This design solution allows you to obtain optimal performance of the drilling pump, taking into account the lowest costs for current and major repairs. These studies aimed at finding optimal geological and technical measures (GTM) related to increasing the productivity of drilling pumps and oil recovery in general are very promising and relevant.

Metoda szacowania trwałości lotniczych napędów hydraulicznych

Throughout previous practice, estimating the life of aviation hydraulic drive assemblies has been utilizing a variant, which requires conducting long-lasting studies of the drive assemblies until they move to the unfitness state. Such studies, which enable estimating life a posteriori, are costly and long-lasting. Hence the need to look for new strategies for estimating life. The article presents a method of estimating the durability of a hydraulic drive assembly based on the control of its change in technical condition. Inspection of the technical condition enables timely detection of the condition before the emergency hydraulic assembly. The novelty of the method is to use, to detect the condition before the emergency team, the principle of determining the pre-emptive control parameter tolerance. Pre-emptive tolerances are a set of control parameter values between threshold levels and pre-emergency (allowable) levels. The intensity of depletion of durability (intensity of aging, wear) is random. The paper presents a stochastic description of the control parameter change and the resulting empirical relationships between the control parameter verification time probability density (verification periodicity) and the control parameter value change probability density. The inter-relations between these two functions were described. It also presents empirical relationships enabling the determination of the permissible value for the control parameters and the periodicity of the control parameter checks after exceeding the limit value. An example of estimating the life of a hydraulic piston pump on-board an aircraft operated in the Polish Air Forces was shown. The permissible values and the time for the first control parameter verification after exceeding the limit value were determined for selected control parameters of the hydraulic pump. The proposed method binds life (fitness time) with the physical wear mechanisms concerning the assemblies. It can be applied in work aimed at determining the resource life of technical equipment. Furthermore, it enables utilizing technical equipment according to a technical state strategy with monitoring the parameters.

Electromyographic Assessment of a Shoulder Support Exoskeleton During on-Site Job Tasks

OCCUPATIONAL APPLICATIONSWe performed an ergonomic assessment of a passive upper body exoskeleton at on-site job tasks, using surface electromyography (EMG) to quantify muscular demands at the shoulder. Six workers were assessed during cab assembly, hydraulic assembly, parts painting, parts hanging, and frame welding tasks, both with and without an exoskeleton. Workers were evaluated during consecutive job tasks, at beginning and at end of a shift. EMG amplitudes were measured and compared to recommended threshold limit values (TLVs) to determine fatigue risk values. Wearing the exoskeleton significantly reduced anterior deltoid EMG amplitudes and fatigue risk values during the consecutive job cycles, with no significant effects on the biceps brachii, superior trapezius, or lumbar erector spinae. Reduced EMG amplitudes were found at five of the six job tasks, and in three of the tasks fatigue risk values were reduced from above the TLV without the exoskeleton to below the TLV with the exoskeleton. Workers indicated that they would recommend the exoskeleton to others who perform overhead job tasks, but expressed concern that it might interfere with tasks that involve tight spaces, sitting, and bending over. We suggest evaluating specific job tasks when making decisions about exoskeleton usage.

DESIGN MODELLING AND ANALYSIS OF STANDARDIZED HYDRAULIC POWER PACK

A hydraulic system is a group of hydraulic elements arranged in an order and using these hydraulic elements power is transmitted using a confined liquid i.e., oil. Generally hydraulics will be used where force required is more to do the function. Hydrauliccpowerrunits are driveesystem for hydrauliccmachines. A hydraulic assembly is intended exclusively for integration into machines or systems or to be assembled with other components to form a machines or systems. The product may only be commissioned if it has be integrated into the machine or systems for which it is designed. Hydraulic power units are drive systems for hydraulics machines.

Minimal-invasive Zementaugmentation von osteoporotischen Wirbelkörperfrakturen mit der neuen Radiofrequenz-Kyphoplastie

Minimally invasive cement augmentation of painful osteoporotic vertebral compression fractures in elderly patients. Painful osteoporotic vertebral compression fractures in elderly patients (> 65 years of age) after conservative therapy failure. Painful aggressive primary tumors of the spine or osteolytic metastases to the spine with high risk of vertebral fracture in the palliative care setting. General contraindications for surgical interventions. Local soft-tissue infection. Osteomyelitis, discitis or systemic infection. Coagulopathy refractory to treatment or bleeding diathesis. Asymptomatic vertebral compression fractures. Burst of the posterior vertebral column with high degree of spinal canal stenosis. Primary or metastatic spinal tumors with epidural growth. Prone position on a radiolucent operating table. Fluoroscopic localization of the fractured vertebra using two conventional C-arm devices (anteroposterior and lateral views). Fluoroscopic localization of the fractured vertebra using two conventional C-arm devices (anteroposterior and lateral views). An introducer is inserted through a small skin incision into the pedicle under fluoroscopic guidance. To create a site- and size-specific three-dimensional cavity in the center of the fractured vertebra, the navigational VertecoR™ MidLine Osteotome was inserted through the correctly sited introducer and guided fluoroscopically. As the MidLine Osteotome allows angulation of the tip up to 90° by rotating the handle, a cavity over the midline of the vertebral body can mainly be created through one pedicle. The radiofrequency activated cohesive ultrahigh viscosity PMMA cement (ER(2) bone cement) is injected stepwise on demand by remote control under continuous pressure from the hydraulic assembly into the vertebral body. Bed rest for 6h postoperatively in supine position. Early mobilization without a corset on the day of surgery. Specific back and abdominal exercises that strengthen the back and abdominal muscles. Pain dependent increase of weight bearing. Continue osteoporosis therapy and start specific drug therapy according to the local guidlines if necessary. In all, 44patients (29women, 15men) with a mean age of 73.5years with a total of 62painful osteoporotic vertebral fractures were treated with RF kyphoplasty from May 2009 until July 2010, and followed over a period of 12months. The mean operating time per patient was 36.2min, the operating time per vertebra was 25.7min. All the patients studied experienced an early and persistent significant pain relief even 12months after therapy (8 ± 1.4 vs. 2.7 ± 1.9) according to the visual analogue pain scale. According to the Oswestry Disability Index (ODI) as a disease-specific disability measure all the patients improved significantly (p < 0.001) in the level of disability after operative treatment (56.2 ± 18.8 vs. 34.5 ± 16.6). Cement leakage was detected in 17 out of 62 (27.4 %) augmented vertebrae, whereas all the patients with cement leakage remained asymptomatic. One patient had subsequent vertebral fractures after a period of 6months.

Исследование и создание автоматизированного гидравлического монтажного комплекса ЛЭП ВЛ

Исследование и создание автоматизированного гидравлического монтажного комплекса ЛЭП ВЛ

Design and Development of a Motorized Hydraulic Presser for Farm-Level Virgin Coconut Oil (VCO) Industry Application

A motorized hydraulic pressing device for coconut milk extraction is designed and developed. Design considerations include higher production rate in extracting coconut milk, high quality of milk extracted, maintenance friendliness, and ease and safety of operation. The device is composed of a hydraulic presser frame, perforated cylinder and a hydraulic assembly. It has a variable pressing force which can be controlled by a control valve. The pressing device is expected to help the farm-level VCO producers and cooperatives in enhancing the production efficiency and product quality of virgin coconut oil. Actual testing of the device shows that the amount of milk that can be extracted is considerably increased at a shorter time as compared to the existing devices used by the farm-level VCO farmers. This may result to increase in their productivity, and hence, increasing the profitability of their business. Extraction of coconut milk is optimum at 1500 psi, pressing cycle of 12 and 5 kg weight of coconut meat. Keywords - Mechanical Engineering, motorized hydraulic presser, coconut milk, virgin coconut oil, Surigao City, Philippines

Numerical generation of anisotropic 3D non-Gaussian engineering surfaces with specified 3D surface roughness parameters

Three-dimensional surface roughness of mating parts of engineering assemblies has a significant influence on their functional behaviour. Studies on load bearing capacity in elastohydrodynamic contacts, gap flow analysis in precision hydraulic assemblies using modeled 3D fluid continuum micro gap geometry, etc., have made it possible to quantify the effect of certain 3D surface roughness parameters on frictional behaviour of the assemblies. This set forth the need for artificially generated three-dimensional engineering surfaces having prescribed roughness values for a better understanding and prediction of tribological problems. In this paper, an algorithm is developed for the numerical generation of three-dimensional anisotropic surfaces with prescribed 3D surface roughness parameters. The procedures employ either the Non-linear Conjugate Gradient Method (NCGM) or 2-D Digital Filter method. The results show that both the methods can adequately produce surfaces at small correlation distances, while at higher correlation distances the NCGM yields better results. Comparison between model-simulated output and measurement results of three-dimensional surface roughness of engineering surface show a good match, supporting the validity of the model.

Modelling of fluid continuum considering 3D surface parameters in hydraulic assemblies

Friction in servo hydraulic assemblies reduces the response characteristics of the system. The friction is influenced by various factors including the geometry (form and surface errors) of the sliding surfaces. In this work, functionally significant 3D surface parameters from the Birmingham parameters are investigated for reduced friction. A 3D surface modelling approach is presented using random process modelling as the basis. An exponential decay areal autocorrelation function is used to model the grinding and honing processes which are commonly employed for the manufacture of the hydraulic assemblies. Honed surface is modelled with the crosshatches of appropriate angle. Method of surface modelling is validated using the data obtained through measurements on a practical surface. Different surface maps with varying surface parameters of the ground and honed surfaces are generated. The fluid continuum gap geometries of the hydraulic assemblies are modelled using these surface maps as envelopes. Pressure distribution, velocity and viscous friction force are used as measurands of the frictional characteristics. Using computational fluid dynamics (CFD) approach, these measurands are evaluated for different functionally significant Birmingham parameters. Based on further analysis, negative skewness, lower kurtosis values, higher valley fluid retention index were found to have lower frictional characteristics.

Vertical transport of a field-released genetically engineered microorganism through soil

The vertical movement of a genetically-engineered bacterium released into a sub-surface soil contained within a lysimeter was investigated. The strain used was Pseudomonas fluorescens HK44, a lux-based microbe capable of bioremediating specific polyaromatic hydrocarbons (PAHs). Strain HK44 was inoculated into a 4 m deep by 2.5 m diameter soil lysimeter outfitted with a hydraulic assembly to control groundwater levels. After 230 days, the lysimeter was subjected to a water table manipulation that resulted in significant transport of HK44 cells to depths 60 cm below the original inoculation zone within 20 days. A lysimeter not exposed to water level fluctuations exhibited no significant vertical transport. These results demonstrate the potential distribution of genetically engineered microorganisms in subsurface soil due to groundwater effects.

Investigation of micro-oscillations in end-packing systems of hydraulic assemblies

Investigation of micro-oscillations in end-packing systems of hydraulic assemblies