Browse Topic: Fluid power systems

Items (3,727)
Agricultural tractors require self-cleaning and cooling technology, especially in hot and dusty environments. This study introduces a novel reversible fan system designed which is incorporating a manually operated lever-type connection mechanism as an alternative to conventional pneumatic systems. Traditional reversible fans often rely on pneumatic actuators for blade rotation control, which can introduce complexity, maintenance challenges, and energy inefficiency. The proposed design replaces pneumatic components with a mechanically optimized lever linkage system, enabling users to manually reverse the fan’s airflow direction with minimal effort. This innovation enhances operational simplicity, reduces dependency on compressed air systems, and low costs as compared to conventional type reversible fan. The lever mechanism, engineered for ergonomic usability, ensures rapid switching between sucker and pusher modes, optimizing the fan’s utility in applications such as dust removal
Debbarma, RespectParwal, MahendraBaghel, Anand
This paper presents an analysis methodology developed to comprehend the impact of pressure spikes in off-highway applications, particularly during PTO (Power Take-Off) clutch engagement. These pressure spikes can adversely affect hydraulic subsystem components such as seals, gaskets, and valve operations. Assessing hydraulic system performance through physical trials can be cumbersome, resulting in longer development times and increased costs. To address this, a methodology was developed in a virtual environment to evaluate hydraulic system performance. The virtual method outlined in this paper is created in a 1D environment using a simulation methodology to replicate the transient behavior of the dynamic system. The hydraulic system primarily includes a relief valve, solenoid valves, a pump, and a clutch. An analytical model was developed for the hydraulic system components with appropriate fidelity to accurately replicate the transient behavior and magnitudes of pressure spikes. This
Memane, NileshKumar, SuneelVeerkar, Vikrant
A futuristic vehicle chassis rendered in precise detail using state-of-the-art CAD software like Blender, Autodesk Alias. The chassis itself is sleek, low-slung, and aerodynamic, constructed from advanced materials such as high-strength alloys or carbon-fibre composites. Its polished, brushed-metal finish not only exudes performance but also emphasizes the refined form and engineered details. Underneath this visually captivating structure, a sophisticated system of self-hydraulic jacks is seamlessly integrated. These jacks are situated adjacent to the four shock absorber mounts. These jacks are designed to lift the chassis specifically at the tyre areas, and the total vehicle, ensuring that underbody maintenance is efficient and that, in critical situations, vital adjustments or emergency lifts can be performed quickly and safely. The design also incorporates an intuitive control system where the necessary buttons are strategically placed to optimize driver convenience. Whether
Gogula, Venkateswarlu
Internal combustion (IC) engines experience several parasitic losses at the vehicle level, including those from cooling fans, hydraulic pumps, air compressors, and alternators. These losses limit the available output power for various applications. By replacing a conventional mechanical or hydraulic fan—typically driven by the engine crankshaft or hydraulic motor—with an electrically operated fan, engine frictional losses (fan drag) can be reduced, resulting in a gain in power. The fuel conserved due to the absence of fan drag contributes to usable power for applications. Mechanical fans operate at a fixed drive ratio that is directly proportional to engine speed, while hydraulic fans rely on a hydraulic motor, drawing power from the engine's alternator. In contrast, electric fans can run at constant speeds, independent of engine RPM, providing higher airflow at maximum torque speeds, which mechanical fans cannot achieve. The cooling performance of the engine remains uncompromised, as
Dewangan, NitinKattula, NitinKamal, Ankit
This specification covers a fluorosilicone (FVMQ) rubber in the form of molded rings.
AMS CE Elastomers Committee
This specification covers an acrylonitrile-butadiene rubber in the form of molded rings, compression seals, O-ring cord, and molded-in-place gaskets for aeronautical and aerospace applications.
AMS CE Elastomers Committee
Automatic unloading vehicles are the most commonly used transportation tools in engineering, with characteristics such as high load capacity, strong adaptability and flexibility. However, the cargo hopper of the automatic unloading vehicle after unloading is prone to many safety hazards due to the driver’s negligence. This paper takes the lead in selecting the type of the dump truck system. On this basis, the mechanical model of the cargo hopper is established. Through the improvement of the hydraulic system and image recognition, combined with speed detection, a set of safety system is designed by using Matlab and Multisim software, and a series of simulations and tests are carried out. The test data are fitted to obtain the final system scheme. It is of great significance for reducing potential safety hazards in practical engineering.
Yu, YitingCong, ShihanLuo, ZheZheng, WenwuLiu, Mingrui
This SAE Aerospace Recommended Practice (ARP) covers procedures or methods to be used for fabricating, handling, testing, and installation of oxygen lines in an aircraft oxygen system.
A-10 Aircraft Oxygen Equipment Committee
This SAE Aerospace Standard (AS) defines the requirements for heavy-duty polytetrafluoroethylene (PTFE) lined, metallic reinforced, hose assemblies suitable for use in 400 °F, 3000 psi aircraft hydraulic systems. Assemblies are suitable where rapid rate pressure pulsing and torsional/ longitudinal flexing may occur, in addition to normal hydraulic system loads.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Pin-on-disk tribometers are used to determine the frictional behaviour and boundary layer dynamics of material pairings. Material pairings are examined under defined conditions in order to reason about the friction behaviour and wear. Pairings for real brake systems with larger pad sizes can be tested on flywheel mass test rigs in order to provide proof of suitability. This is mainly due to a lack of knowledge about the scaling behaviour of friction linings. The Department of Machinery System Design at TU Berlin has combined the classic approach of a pin-on-disk tribometer with a flywheel mass test rig (up to 12.78 kgm2) and thus set up a laboratory brake on which material pairings with different pad shapes and sizes (up to 48 cm2) can be examined. The flywheel mass test rig consists of an adjustable DC-motor that drives a shaft on which variable flywheel masses and brake disks can be installed. The variability allows for different kinetic energies at different friction speeds. The
Heuser, Robert MichaelRosenthal, Tobias RichardWiest, Daniel ChristianMeyer, Henning Jürgen
This ARP provides definitions and background information regarding the physical performance and testing of DDVs. This ARP also provides extensive guidance for the preparation of procurement specifications and functional testing.
A-6B1 Hydraulic Servo Actuation Committee
This SAE Standard specifies uniform methods for the testing of threadless connections for hydraulic fluid power applications. These connections are intended for general application and hydraulic systems on industrial equipment and commercial products. These connections shall be capable of providing leakproof connections in hydraulic systems operating from 95 kPa vacuum to working pressures specified by the manufacturer. Since many factors influence the pressure at which a hydraulic system will or will not perform satisfactorily, it is recommended that sufficient testing be conducted and reviewed by both the user and manufacturer to ensure that required performance levels are met.
Hydraulic Tube Fittings Committee
This SAE Aerospace Standard (AS) defines a series of standardized tube walls to be used for high pressure hydraulic tubing. These tube walls are applicable to all homogenous tube materials (i.e., aluminum, steel, titanium) throughout a rated pressure range of 1000 to 8000 psi and a maximum rated operating temperature range of 160 to 450 °F. All future aerospace applications for which a required tube outside diameter/tube wall combination is not presently available shall be selected from the table contained herein (see Figure 1).
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Rolling bearings with optimized friction and performance characteristics can have a significant influence on reducing the power loss, design envelope and weight of hydraulic motors and pumps, gearboxes and axles in construction machinery. If correctly designed, rolling bearings can make a significant contribution to reducing carbon dioxide emissions. Most construction machinery is still operated conventionally, using diesel engines and hydraulic components. In the widely used adjustable axial piston pumps and motors, the input and output shaft are usually supported by two tapered roller bearings that are adjusted against each other. When designing the bearing support, it is advisable to reduce the preload to precisely the required minimum allowed by the load spectrum. The lower bearing preload leads to permanently lower axial forces between the tapered roller end face and inner ring rib and, therefore, to a corresponding reduction in frictional torque.
Scharting, Stefan
This Aerospace Standard (AS) defines the requirements for polytetrafluoroethylene (PTFE) heavy duty hose assemblies suitable for use in aircraft and missile hydraulic fluid systems service to 8000 psi and -65 to 400 °F. Gaseous service shall be limited to 150 °F.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
This standard establishes the dimensional and visual quality requirements, lot requirements, and packaging and labeling requirements for O-rings molded from AMS7274 rubber. It shall be used for procurement purposes.
A-6C2 Seals Committee
This SAE Aerospace Standard (AS) defines the requirements for loop-type clamps primarily intended for general clamping of tubing for aircraft hydraulic systems.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
A DRL (deep reinforcement learning) algorithm, DDPG (deep deterministic policy gradient), is proposed to address the problems of slow response speed and nonlinear feature of electro-hydrostatic actuator (EHA), a new type of actuation method for active suspension. The model-free RL (reinforcement learning) and the flexibility of optimizing general reward functions are combined with the ability of neural networks to deal with complex temporal problems through the introduction of a new framework called “actor-critic”. A EHA active suspension model is developed and incorporated into a 7-degrees-of-freedom dynamics model of the vehicle, with a reward function consisting of the vehicle dynamics parameters and the EHA pump–valve control signals. The simulation results show that the strategy proposed in this article can be highly adapted to the nonlinear hydraulic system. Compared with iLQR (iterative linear quadratic regulator), DDPG controller exhibits better control performance, achieves
Wang, JiaweiGuo, HuiruDeng, Xiaohe
This SAE Aerospace Standard (AS) establishes the requirements for 24° cone flareless fluid connection fittings and nuts and bite type flareless sleeves for use in aircraft fluid systems at an operating pressure of 5000 psi for the fittings and nuts and 3000 psi for the bite type sleeves.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
This SAE Standard covers normalized electric-resistance welded flash-controlled single-wall, low-carbon steel pressure tubing intended for use as pressure lines and in other applications requiring tubing of a quality suitable for bending, double flaring, beading, forming, and brazing. Material produced to this specification is not intended to be used for single flare applications, due to the potential leak path caused by the Inside Diameter (ID) weld bead or scarfed region. Assumption of risks when using this material for single flare applications shall be defined by agreement between the producer and purchaser. This specification also covers SAE J356 Type-A tubing. The mechanical properties and performance requirements of SAE J356 and SAE J356 Type-A are the same. The SAE J356 or SAE J356 Type-A designation define unique manufacturing differences between coiled and straight material. Nominal reference working pressures for this tubing are listed in ISO 10763 for metric tubing, and SAE
Metallic Tubing Committee
This aerospace test standard establishes the requirements and procedures for evaluating and comparing the impulse fatigue performance of high pressure hydraulic fittings and tubing. This test method may be used to test similar fluid system components, if desired.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
This SAE Aerospace Information Report (AIR) discusses the sources of copper in aviation jet fuels, the impact of copper on thermal stability of jet fuels and the resultant impact on aircraft turbine engine performance, and potential methods for measurement of copper contamination and reduction of the catalytic activity of copper contamination in jet fuels. This document is an information report and does not provide recommendations or stipulate limits for copper concentrations in jet fuels.
AE-5B Aircraft and Engine Fuel and Lubricant Sys Components
This SAE Recommended Practice establishes a uniform fluid specification for reference usage in specific documents, such as fluid power component test procedures, where a fluid designation is required.
CTTC C1, Hydraulic Systems
This SAE Aerospace Standard (AS) defines the requirements for a lightweight polytetrafluoroethylene (PTFE) lined, metallic reinforced, hose assembly suitable for use in high temperature, 400 °F, high pressure, 3000 psi, aircraft hydraulic systems, also for use in pneumatic systems which allow some gaseous diffusion through the PTFE wall.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
This Aerospace Standard (AS) defines the requirements for a heavy duty polytetrafluoroethylene (PTFE) lined, metallic reinforced, hose assembly suitable for use in 400 °F 5000 psi, aircraft and missile hydraulic fluid systems.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
This SAE Aerospace Standard (AS) defines the requirements for a convoluted polytetrafluoroethylene (PTFE) lined, metallic reinforced, hose assembly suitable for use in aerospace fluid systems at temperatures between -65 °F and 400 °F for Class 1 assembly, -65 °F and 275 °F for Class 2 assembly, and at operating pressures per Table 1. The use of these hose assemblies in pneumatic storage systems is not recommended. In addition, installations in which the limits specified herein are exceeded, or in which the application is not covered specifically by this standard, shall be subject to the approval of the procuring activity.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
A reconfigurable experimental seat is useful for seating comfort research and allows researchers to investigate the effects of seat parameters and to propose quantitative guidelines for improving seat comfort. Since 2017, Gustave Eiffel University has such an experimental seat which allows us to carry out parametric studies on the geometric dimensions of a seat and to understand the role of the contact force, particularly that in shear force. Equipped with force and positioning sensors, all contact forces and seat position can be measured. More specifically, it is equipped on the seat with a matrix of 52 cylinders, each adjustable in height and each equipped with a three-axis force sensor. These cylinders make it possible to vary the contact surface of seat pan and measure the distribution of contact forces. More recently, a new system with a matrix of 263 hydraulic cylinders was designed and manufactured to better study the comfort of the backrest in replacement of the three-support
Wang, XuguangBeurier, Georges
This study presents a control co-design method that utilizes a bi-level optimization framework for parallel electric-hydraulic hybrid powertrains, specifically targeting heavy-duty vehicles like class 8 semi-trailer trucks. The primary objective is to minimize battery energy consumption, particularly under high torque demand at low speed, thereby extending both battery lifespan and vehicle driving range. The proposed method formulates a bi-level optimization problem to ensure global optimality in hydraulic energy storage sizing and the development of a high-level energy management strategy. Two nested loops are used: the outer loop applies a Genetic Algorithm (GA) to optimize key design parameters such as accumulator volume and pre-charged pressure, while the inner loop leverages Dynamic Programming (DP) to optimize the energy control strategy in an open-loop format without predefined structural constraints. Both loops use a single objective function, i.e. battery energy consumption
Taaghi, AmirhosseinYoon, Yongsoon
This SAE Aerospace Recommended Practice (ARP) provides recommendations on cavity design, the installation of elastomer type spare seals in these cavities, and information surrounding elastomer material properties after contact with typical shock absorber hydraulic fluid(s) or grease. This ARP is primarily concerned with the use of spare seals on shock absorbers where only a single dynamic seal is fitted and in contact with the slider/shock absorber piston at any one time. These shock absorbers typically have a spare (dynamic) seal gland located on the outer diameter of the lower seal carrier. This spare seal gland is intended to house a spare elastomer contact seal. Split Polytetrafluoroethylene (PTFE) backup rings can also be installed in the spare seal cavity. During operation, if the fitted dynamic shock absorber standard seal begins to fail/leak, then the aircraft can be jacked up, allowing the lower gland nut of the shock absorber to be dropped down. The current used dynamic seal
A-5B Gears, Struts and Couplings Committee
This SAE Aerospace Standard (AS) establishes the minimum performance standards for equipment used as secondary alternating current (AC) electrical power sources in aerospace electric power systems.
AE-7B Power Management, Distribution and Storage
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
With current and future regulations continuing to drive reductions in carbon dioxide equivalent (CO2e) emissions in the on-road industry, the off-road industry is also likely to be regulated for fuel and CO2e savings. This work focuses on converting a heavy-duty off-road material handler from a conventional diesel powertrain to a plug-in series hybrid, achieving a 49% fuel reduction and 29% CO2e reduction via simulation. Control strategies were refined for energy savings, including a regenerative braking strategy to increase regenerative braking and a load-following hydraulic strategy to decrease electrical energy consumption. The load-following hydraulic control shuts off the hydraulic electric machine when it is not needed—an approach not previously seen in a load-sensing, pressure-compensated system. These strategies achieved a 24.1% fuel savings, resulting in total savings of 61% in fuel and 41% in CO2e in the plug-in series compared to the conventional machine. Beyond control
Goodenough, BryantCzarnecki, AlexanderRobinette, DarrellWorm, JeremySubert, DavidKiefer, DylanHeath, MatthewBrunet, BobKisul, RobertLatendresse, PhilWestman, JohnBlack, Andrew
This material type has resistance to hot air, but generally has poor resistance to fuels and lubricants, but usage is not limited to such applications. Each application should be considered separately. This material type has a typical service temperature range of -85 to 500 °F (-65 to 260 °C). The operating temperature range of the material is a general temperature range, but the presence of particular fluids and design parameters may modify this range. Recommendations on the material selection are based on available technical data and are offered as suggestions only. Each user should make his own tests to determine the suitability for his own particular use.
A-6C2 Seals Committee
The Tractor is essential in both agriculture and construction, equipped with a variety of implements for different operational conditions. Its hydraulic system is crucial for controlling these implements during fieldwork and transport. The quadrant assembly is a key part of the tractor’s hydraulic control system, allowing the operator to manage important functions. This includes hydraulic control and draft control, enabling the farmer or operator to use the PC and DC levers to adjust the movement of implements during various tasks. Tractors are commonly used in fields and farms where the soil can be loose and muddy, particularly during wet puddling operations. In these muddy conditions, tractors can accumulate mud in critical components, such as the quadrant assembly. This can lead to functional issues, increased friction, and problems within the hydraulic system, especially affecting the controls for hydraulics and lever shifting for implement handling. As a result, operators may need
K, BheshmaPhadtare, YogeshGomes, MaxsonV, Ashok KumarPerumal, SolairajMagendran, G
Hydropneumatic Struts (HPS) are widely implemented in automobile, aerospace, and construction industries, mainly for the purpose of vibration and shock absorption. The HPS design with integrated gas–oil chamber is relatively more compact and robust, while mixing gas and oil inside the HPS generates gas–oil emulsion and more nonlinearities. This study formulated a nonlinear analytical model of the compact HPS with gas–oil emulsion, considering the real gas law and pressure-dependent LuGre friction model. The polytropic version of the van der Waals (vdW) method for real gas is applied to represent the thermodynamic behavior of nitrogen. The experimental data were collected at a near temperature of 30°C with three charging pressures under excitations in the frequency range of 0.5–6 Hz, considering two flow connection configurations between chambers as one- and two-bleed orifice. The nonlinear behavior of the gas volume fraction of the emulsion was identified based on peak strut velocity
Seifi, AbolfazlYao, YumengYin, YumingMoore, MasihRakheja, Subhash
This SAE Aerospace Recommended Practice (ARP) establishes a method for evaluating the particulate matter extracted from the working fluid of a hydraulic system or component using a membrane. The amount of particulate matter deposited on the membrane due to filtering a given quantity of fluid is visually compared against a standard membrane in order to provide an indication of the cleanliness level of the fluid.
A-6C1 Fluids and Contamination Control Committee
This SAE Aerospace Information Report (AIR) discusses the forms that air may take in aircraft hydraulic systems. Further, the effects of the various air forms on system operation are addressed. Recommended system design to prevent air effects and maintenance procedures to prevent and remove air are provided. Nitrogen leakage from accumulators is also a source of gas in hydraulic systems and may compose a portion of the “air” in the hydraulic system. The term “air” in this report does not differentiate between a gas composed strictly of normal atmospheric air or one that includes a mixture of additional nitrogen as well. The discussions of the report apply equally with any proportions of atmospheric air and nitrogen in the system.
A-6C1 Fluids and Contamination Control Committee
This specification covers requirements for the superfinishing of High Velocity Oxygen/Fuel (HVOF) applied tungsten carbide thermal spray coatings.
AMS B Finishes Processes and Fluids Committee
Autonomous vehicles for mining operations offer increased productivity, reduced total cost of ownership, decreased maintenance costs, improved reliability, and reduced operator exposure to harsh mining environments. A large flow of data exists between the remote operation and the ore haul vehicle, and part of the data becomes information for the maintenance sector which it monitors the operating conditions of various systems. One of the systems deserving attention is the suspension system, responsible for keeping the vehicle running and within a certain vibration condition to keep the asset operational and productive. Thus, this work aims to develop a digital twin-assisted system to evaluate the harmonic response of the vehicle’s body. Two representations were created based on equations of motion that modeled the oscillatory behavior of a mass-damper system. One of the representations indicates a quarter of the ore transport truck’s hydraulic system in a healthy state, called a virtual
Rosa, Leonardo OlimpioBranco, César Tadeu Nasser Medeiros
This paper aims to describe a quarter-car suspension test bench automation process to be utilized in an academic environment. The project is made up of pneumatic system modeling and control system design. An analysis of the bench’s pneumatic system is carried out. This pneumatic system is composed of a pneumatic actuator and a proportional directional control valve, which are responsible for generating the road profile. It is proposed a model to compensate the non-linearities present in the pneumatic system measurement process and the disturbances caused by the under test suspension system, as well as a control strategy for small displacements of the load through linear control approaches, which provide the necessary flexibility to directly influence the parameters affecting the dynamics of the excitation system platform’s displacement, thereby reducing the complexity of the controller design to be adopted. Furthermore, analyses are conducted on the effectiveness of the control in
Siqueira, Matheus AmaralGomes, Pedro CarvalhoTeixeira, Evandro Leonardo SilvaFortaleza, Eugênio Libório FeitosaMorais, Marcus Vinicius Girão
The traditional braking system has been unable to meet the redundant safety requirements of the intelligent vehicle for the braking system. At the same time, under the change of electrification and intelligence, the braking system needs to have the functions of braking boost, braking energy recovery, braking redundancy and so on. Therefore, it is necessary to study the redundant braking boost control of the integrated electro-hydraulic braking system. Based on the brake boost failure problem of the integrated electro-hydraulic brake system, this paper proposes a redundant brake boost control strategy based on the Integrated Brake Control system plus the Redundant Brake Unit configuration, which mainly includes fault diagnosis of Integrated Brake Control brake boost failure, recognition of driver braking intention based on pedal force, pressure control strategy of Integrated Brake Control brake boost and pressure control strategy of Redundant Brake Unit brake boost. The designed control
Dexing, LaoLuping, YanQinghai, SuiLong, CaoShang, GaoZhigang, ChenMingxing, RenZhicheng, Chen
This specification covers the design and installation requirements for Type I and II military aircraft hydraulic systems.
A-6A2 Military Aircraft Committee
Caterpillar has released a cavalcade of new compact track loaders and skid steer loaders. The new CTL models include the 275, 275 XE, 285 and 285 XE. These models join the lineup alongside the 255 and 265, which were introduced last year (www.sae.org/news/2024/02/cat-compact-loaders). The 285 and 285 XE are the largest CTLs Caterpillar has ever produced and reportedly feature greater lift height and lift and tilt breakout forces. “We are excited to launch the next-generation design for our skid steer loader line and expand the performance capabilities to more compact track loader models,” said Trevor Chase, senior product consultant and new product introduction lead for Caterpillar. “Their increased power, lift height, breakout forces, rated operating capacity (ROC) and multiple high-flow auxiliary hydraulic system options give customers a flexible, high-performance machine to get the job done.”
Wolfe, Matt
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