Browse Topic: Fluid power systems

Items (3,944)
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
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 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
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
This SAE Information Report is primarily to familiarize the designer of hydraulic powered machinery with the necessity for oil filtration in the hydraulic power circuit, the degree of system cleanliness required, types of filtration and filters available, and their location and maintenance in the hydraulic circuit
CTTC C1, Hydraulic Systems
To describe laboratory methods for determining and reporting the contaminant level of the wetted portion of hydraulic fluid power components, parts, subsystems and systems, and of fill fluids. For each type of item, it provides a method of obtaining the liquid sample and the contamination level thereof. It also includes procedures for establishing a sampling plan and guidelines for establishing levels of acceptance, but does not set those levels
CTTC C1, Hydraulic Systems
ABSTRACT At the request of the US Army’s Tank Automotive Command (TACOM) a device was built to measure the suspension parameters of any military wheeled vehicle. This is part of an ongoing effort to model and predict vehicle dynamic behavior. The new machine is called the Suspension Parameter Identification and Evaluation Rig (SPIdER) and has a capacity intended to cover all of the military’s wheeled vehicles. The machine operates by holding the vehicle body nominally fixed while hydraulic cylinders move an “axle frame” in bounce or roll under each axle being tested. Up to two axles may be tested at once. Forces at the tires and motions of the wheel centers in three dimensions and two angles are measured. Other motions of the suspension and the minimal motions of the vehicle body are measured. For steer axles the steering ratio, Ackerman steer characteristics, and kingpin orientation are measured
Andreatta, DaleHeydinger, GarySidhu, AnmolBixel, RonaldKurec, AleksanderSingh, AmandeepBaseski, IgorSkorupa, Thomas
ABSTRACT Motorized ground forces spend considerable resources in equipping for situational awareness capabilities. Given requirements spanning command, control, surveillance, and reconnaissance of a battlefield, there has been no single mast technology that can support each of these with elevated sensors and weapons. A tough, extremely low weight modular mast system has been designed to be quickly attached or removed from a ground vehicle to provide different operational capabilities depending on the payload. The design allows for easy modification to fit functional needs on different vehicles and platforms. At the heart of the technology is a proprietary super-fiber pressurized tube which elevates the payload on a column of moderate gas pressure eliminating cumbersome hydraulic/mechanical systems. An internal, simple alignment system and gyroscope-maintained verticality allow a stable, elevated platform without introducing instability to the vehicle. The system is capable of
Townsend, Phillip L.Bhatnagar, VivekMartinez, RudyWarnakulasuriya, Frank
ABSTRACT In this paper we present an intelligent power controller for a vehicle power system that employs multiple power sources. In particular we focus on a vehicle power system architecture that is used in vehicles such as Mine Resistant Ambush Protected (MRAP) vehicle. These vehicles are designed to survive IED (Improvised Explosive Devices) attacks and ambushes. The power system has the following major components: a “clean” bus, a “dirty” bus, an engine, a hydraulic system and a switch between the clean and the dirty bus. We developed algorithms for intelligent energy management for this type of vehicle power system including DP (Dynamic Programming) optimization, DP online control and a machine learning technique that combines neural networks with DP to train an intelligent power controller. We present experiments conducted through modeling and simulation using a generic commercial software tool and a lab hardware setup
Chen, ZhihangMurphey, Yi L.Chen, ZhengMasrur, AbulMi, Chris
ABSTRACT Variable displacement pumps have been used in automotive transmissions for decades. L3T had high confidence that a Variable Displacement Oil (VDO) pump would increase overall transmission efficiency. An off-the-shelf (OTS) or OTS modified pump in this pressure and flow range was not found. Therefore, a VDO pump is being developed with the known risk of replacing a highly reliable pump with a new better performing pump of unknown reliability. In this document the development of this VDO pump is discussed. Initial testing of the VDO pump demonstrated an average 25HP savings in pumping losses throughout the transmission operating ranges. At this point, durability testing has not been performed
Bol, Stephen
ABSTRACT This paper discusses the semi-active suspension system developed by A.M. General to provide mobility and maneuverability for tactical, wheeled vehicles
Tackett, WendellLovell, JeffreyBrown, Chris
ABSTRACT This paper develops a linear closed form equation as required for automatic plowing depth control of a mine clearing combat vehicle. The vehicle will be tasked with using its Mine Clearing Blade (MCB) to remove surface laid and buried land mines on undulating terrain so that other vehicles can follow its path without the threat of mines. Blade control must be automatic to ensure that the target depth of the cleared path is achieved and all mines on the path are removed. A closed form solution for real-time computing relating the MCB motion and hydraulic actuator movement is developed and implemented. The equations are provided in symbolic form so that the dimensions of the mechanism can be directly substituted and/or modified without re-derivation. Results were verified with field measured data and implemented in the controller of a real vehicle to successfully achieve objective goal of Automatic Mine Clearing
Tsai, Fuh-FengStrittmatter, Kevin
This test code describes tests for determining characteristics of hydraulic positive displacement motors as used on off-road self-propelled work machines as referenced in SAE J1116
CTTC C1, Hydraulic Systems
Air suspension systems are increasingly in demand in high-end cars due to their ability to vary ride height based on vehicle loads, road conditions, and speeds. This trend has driven manufacturers to enhance the performance of these systems. Predicting and optimizing the performance of the air spring system for various vehicle loads and conditions has become essential. The performance of an air suspension system is typically measured by its ability to suspend the vehicle within a specified target time. Therefore, it is necessary to model the air spring system—including the air spring, compressor, pneumatic lines, and valves—and integrate it with the vehicle. This modeling helps in predicting performance and optimizing the system. Additionally, a validated system model enables other important calculations, such as sizing the valves, pneumatic hoses, and compressors. In this study, a complete air spring system model has been developed alongside a 15-degrees-of-freedom car chassis to
Ahmed, Saad AnwarHupfeld, JanRajput, Brijesh
This SAE Aerospace Recommended Practice (ARP) provides an overview of the various types of polytetrafluoroethylene (PTFE) backup rings for hydraulic and pneumatic fluid power applications, including their advantages and disadvantages
A-6C2 Seals Committee
ARP6366 defines a comprehensive and widely-accepted set of specification guidelines to be considered by those seeking to use or design fiber optic sensors for aerospace applications. Some of the most common applications for fiber optic sensing within aerospace include inertial guidance and navigation (gyros) and structural monitoring (temperature, strain, and vibration sensing). Common sensor infrastructure elements include: transmitting and receiving opto-electronics (e.g., sources and receivers); multiplexing and demultiplexing optics; optical cabling; and signal processing (both hardware and firmware/software
AS-3 Fiber Optics and Applied Photonics Committee
This document provides an orientation to fusion splicing technology for optical fibers and fiber optic cable. It is intended for managers, designers, installers, and repair and maintenance personnel who need to understand the process of fusion splicing. This technology is widely used in telecommunications and industrial applications, and is finding acceptance in aerospace applications
AS-3 Fiber Optics and Applied Photonics Committee
This SAE Aerospace Recommended Practice (ARP) describes a method of conducting an endurance test using contaminated air when the applicable specification requires non-recirculation of the contaminants. The objective of the test is to determine the resistance of the engine mounted components to wear or damage caused by the contaminated air. The method described herein calls for non-recirculation of the contaminants and is intended to provide a uniform distribution of the contaminant at the inlet to the Unit Under Test (UUT). The UUT may require the use of a hydraulic fluid for actuation of components within the test unit. Contamination of the test hydraulic fluid is not part of this recommended practice. If contaminated hydraulic fluid is required by the applicable test specification, refer to MAP749
AC-9 Aircraft Environmental Systems Committee
This Aerospace Information Report (AIR) is limited in scope to the general consideration of environmental control system noise and its effect on occupant comfort. Additional information on the control of environmental control system noise may be found in 2.3 and in the documents referenced throughout the text. This document does not contain sufficient direction and detail to accomplish effective and complete acoustic designs
AC-9 Aircraft Environmental Systems Committee
A well-designed cooling system is crucial in construction machines for efficient heat dissipation from vital components, including the Radiator(RAD), Oil Cooler (OC) and Intercooler (IC). The radiator ensures optimal engine performance and longevity by maintaining a stable operating temperature. Oil Coolers preserve hydraulic system efficiency. Inter Coolers optimize engine performance through denser intake air. The robust cooling system enhances system reliability, reduces downtime, avoid overdesigned system, and increases operator safety in demanding construction environments. The size and location of heat exchangers are critical in cooling system design. Using 1D simulation tool KULI for cooling system design offers the benefits of comprehensive system simulation, optimization of thermal management, reduced development time and costs, enhanced system reliability, improved integration with other systems, and real-world testing and validation. The tool enables time and cost-effective
Dewangan, NitinKattula, NitinGoklani, Mohit
To provide a method by which to assess the cleanliness of new hydraulic fluids. The method is applicable to new mineral and synthetic hydraulic fluids - regardless of packaging. This SAE Standard is not intended as a procedure for operating equipment
CTTC C1, Hydraulic Systems
This SAE Standard covers specifications and performance requirements for 37-degree and 45-degree single and double flares for tube ends intended for use with SAE J512, SAE J513, SAE J514, and ISO 8434-2 connectors. The flares described in this document are intended for use with SAE metallic tube materials. Considerations such as the effects of wall thickness selection for specific working pressures, identifying the appropriate length of thread engagements for specific applications with mating connectors, and other associated criteria shall be the responsibility of the user. For applicable nominal reference working pressures for hydraulic tubing, refer to SAE J1065 and ISO 10763. In an effort to standardize within a global marketplace and ensure that companies can remain competitive in an international market, it is the intent of this document to promote the use of metric tube and connector sizes, which will: Lead to one global system. Guide users to a preferred system. Reduce
Hydraulic Tube Fittings Committee
This SAE Aerospace Information Report (AIR) describes the aspects of hydraulic system design and installation to minimize the effects of lightning. Techniques for effective electrical bonding, hydraulic system lightning protection, and lightning protection verification techniques are discussed
A-6A1 Commercial Aircraft Committee
This specification establishes the design, performance, and test requirements for hydraulic quantity measuring fuses intended to be used for hydraulic circuit protection
A-6C5 Components Committee
Electrification isn't just a matter of switching out the diesel engine for an electric motor. It requires a thorough review of connected systems - particularly the hydraulic system. Using the same components in electric machines as those used in conventional machines often requires more battery power or a larger electric motor. For this reason, OEMs have discovered the need to rethink efficiency and productivity when electrifying machines. MPG Makine Prodüksiyon Grubu learned this firsthand when designing a truck-mounted electric crane for one of its Netherlands-based customers. The Konya, Turkey-based OEM produces truck-mounted hydraulic cranes with folding and telescopic booms as well as aerial work platforms and tree trans-planter machines
Avci, Gökhan
Hydraulic systems in aircraft largely comprise of metallic components with high strength to weight ratios. Some examples of such material include Aluminum and Titanium alloys which are typically chosen for low and high-pressure applications respectively. For aircraft fluid conveyance products, hydraulic conduits are fabricated by axisymmetric turning to support flow conditions. The hydraulic conduits can have grooved interfaced design within for placement of elastomeric sealing components. This article presents a systematic study carried out on common loads experienced by fluid carrying conduits and the failure modes induced. Firstly, a static structural analysis was carried out on each of the geometries of the test articles to identify the locations having areas of high stress concentration. Test articles of various wall thicknesses and internal diameters were pressure impulse tested at different conditions of side loads to identify cycle numbers till failure and failure locations. On
Paidimarri, VishalJacob, KrupaHarish, UppuHovis, David
This specification covers an acrylonitrile-butadiene (NBR) elastomer that can be used to manufacture product in the form of sheet, strip, tubing, extrusions, and molded shapes. For molded rings, compression seals, O-ring cord, and molded-in-place gaskets for aeronautical and aerospace applications, use the AMS-P-83461 specification or the MIL-PRF-25732 specification
AMS CE Elastomers Committee
This SAE Aerospace Information Report (AIR) lists military and industry specifications, standards, recommended practices, and information reports applicable to aerospace hydraulic and pneumatic systems and components
A-6 Aerospace Actuation, Control and Fluid Power Systems
DHT hybrid transmission assembly control system discussed in this paper includes hydraulic control, hybrid mode switching control, shift control, dual motor control, clutch and motor thermal management. The hybrid mode is divided into four modes: the EV mode, the serial mode, the parallel mode and the launch mode. Hydraulic control includes torque-pressure conversion, clutch pressure kiss point adaption, clutch oil filling time adaption. Shift control includes shift type decision, shift sequence control, shift inertia process based on motor intervention. Thermal management includes clutch flow and motor flow distribution. Motor control include the current control, mode control and boost strategy of permanent magnet synchronous motor in dual hybrid system, which has good stability and robustness. Motor mode includes initialization mode, normal mode, fault mode, active discharge mode, power off mode. The boost strategy of the hybrid system is based on boost mode management, boost target
Jing, JunchaoZhang, JunzhiLiu, YiqiangWang, ZhentaoXue, Tianjian
Positive displacement pumps are key components in automotive and hydraulic fluid systems, often serving as the primary power source and a major source of noise in both on-highway and off-highway vehicles. Specifically, gerotor pumps are widely utilized in vehicle coolant, lubricating, and other fluid systems for both conventional and electric powertrains. This study introduces a novel method for predicting noise in gerotor pumps by combining a Computational Acoustics (CA) approach with a 3D Computational Fluid Dynamics (CFD) approach, both implemented in the Simerics–MP+ code. The CFD simulation includes the detailed transient motion of the rotors (including related mesh motion) and models the intricate cavitation/air release phenomena at varying pump speeds. The acoustic simulation employs a Ffowcs–Williams Hawkings (FW–H) integral formulation to predict sound generation and propagation based on the detailed flow field predictions from the CFD model. Simulations of two different
Taghizadeh, SalarNg, Kok ChianHoren, JezrahDhar, Sujan
The automatic transmission of a specialized vehicle encountered challenges in achieving stable oil filling time due to the considerable variability of related parameters and the non-linear trends in the variation of individual product parameters over time. To investigate the underlying causes of this phenomenon and enhance the oil filling efficiency, a detailed model of the clutch oil filling process during gear shifting was established in this paper, which included dynamic models of the key components such as the hydraulic system, clutch, proportional valve, and oil passages. Physical experiments were performed on the test bench to compare with the simulation results. The results showed that the correlation between the simulation model and the test bench was well, which verified the effectiveness of the simulation model. Based on analyzing the clutch filling process, the effects of parameters such as orifice diameter, piston cavity clearance, clutch gap, and oil injection pressure on
Guo, JunFeng, GuangjunWu, JinglaiZhang, Yunqing
A semi-active suspension system provides superior safety, ride, and handling performance for a vehicle by continuously varying the damping based on vehicle motions, where semi-active hydraulic damper (SAHD) is the most critical component. Today, SAHD’s are standard in most of the premium segments of vehicles and optional extras in mid-size and compact vehicle segments. Electric vehicles require larger sized SAHD’s to meet heavier vehicle loads and meet ride and handling requirements. The aim of this paper is to highlight the design and development methodology of a base valve for larger bore-size for semi-active hydraulic damper. The workflow follows to present a process for base valve design to meet structural strength and, the key steps of design calculations of the hydraulic performance. The design of the base valve and suction disks architecture was engineered with the aid of Computer Aided simulations. The structural performance was analyzed using the Finite Element Analysis (FEA
Chintala, ParameshPatwa, AakashSankaran, Shivanand
This paper details testing for torque converter clutch (TCC) characterization during steady state and dynamic operation under controlled slip conditions on a dynamometer setup. The subject torque converter under test is a twin plate clutch with a dual stage turbine damper without a centrifugal pendulum absorber. An overview is provided of the dynamometer setup, hydraulic system and control techniques for regulating the apply pressure to the torque converter and clutch. To quantify the performance of the clutch in terms of control stability, pressure to torque relationship and the dynamic behavior during apply and release, a matrix of oil temperatures, output speeds, input torques, and clutch apply pressures were imposed upon the torque converter. The torque capacity of the clutch is estimated with the dimensions of the friction surfaces and pressure plate and an enhanced lookup data of K-factor obtained through testing of the hydrodynamics at input torques from 10 to 200 Nm over a
Robinette, DarrellBlough, JasonJurmu, LukeReynolds, CraigScheich, Andrew
This document defines the requirements for weld fittings and machine weldments using an orbiting welding head suitable for use on cold worked 3AL-2.5V titanium, 21Cr-6Ni-9Mn CRES, and 718 nickel alloy tubing. Fitting standards covered by this specification include non-separable welded elbow, tee, and reducer fittings, and reconnectable 24-degree cone fittings, such as sleeves and unions
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
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