Browse Topic: Hydraulic drives

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The Fault-Augmented Approach for the Systematic Simulation of Fault Behavior in Multi-Domain Systems in Aerospace2018-01-191710/30/2018
A library for modelling faults in multi-domain physical systems is introduced. The library is based on the simulation of fault effects on the system’s behavior. The motivation of how and why to model faults systematically as well as a description of the Modelica®-based library structure with a wizard supporting the semi-automatic augmentation process of faults are outlined. The fault types are classified into continuous and discrete with dedicated type definitions. The application of the Fault library is exemplified in the field of aerospace electrohydraulic actuator. The actuator is equipped with hydromechanical, electrical and digital systems for mitigating failures, which should be tested at an early stage of design. To perform the tests, a multi-domain, dynamic system model is created, wherein failures are systematically simulated using a special approach for fault augmentation. In addition, several complementary tests are obtained by a variants simulation and the simulation
Kolesnikov, Artem, Andreev, Maxim, Abel, Andreas
Technical Paper
The Study on Co-Simulation Based Tracked Vehicle Path Tracking Control2015-01-111404/14/2015
The tracked vehicle with a fully hydraulic driving system, which has a strong traveling performance of passing and mobility ability in the complex terrain, is a typical system of mechanical-electrical-hydraulic integration. At the same time, for the good low-speed stability of the hydraulic system, this vehicle is widely applied in most engineering projects. However, for the complexity and unpredictability of the motion state in the complex environment and the power matching of the driving system, the driving path of the tracked vehicle with hydraulic driving is difficult to control. Moreover, for the complicated interaction between mechanics, the establishment of the mathematical model is much more complex, and the traditional mechanics-control and hydraulic-control co-simulation can not accurately simulate this physical phenomenon. The kinematic and dynamics characteristics of the tracked vehicle are studied firstly, and the dynamics model is built. Meanwhile, the hydraulic system is
Wang, Can, Yang, Bo, Tan, Gangfeng, Wang, YiRui, Zhou, Li
Technical Paper
EPA Patent License/Hybrid Vehicle TechnologyRS-BNA-00401/19/2011
Notice announces the intention of the EPA to grant a co-exclusive, royalty-bearing, revocable patent license pursuant to 37 CFR 404 to Oakland Technologies LLC, of Farmington Hills, Mich. The patents covered by the license pertain to hybrid vehicle technology, particularly hydraulic hybrid drive systems, methods, and components. EPA will grant the license unless objections are received by Feb. 3, 2011. Comments are due Feb. 3, 2011. Contact: David Read; EPA, National Vehicle Fuel Emissions Laboratory; (734-214-4367)
Regulation
SAE Off-Highway Engineering 2001-10-01OFHOCT0110/01/2001
More with less through electronic components Off-highway engineers have had to walk a precarious path in recent years by developing engine technologies that offer customers better vehicle performance and regulators lower emissions. The promises and problems of electrohydraulics Engineers acknowledge that electrohydraulics are the way of the future for the off-highway industry, and that the field itself could use a good public-relations campaign to attract more engineering students. Deere goes all out for agriculture To some, it may seem odd that John Deere picked this particular economy to launch over 50 new products, the most in its 164-year history. To others it reeks of confidence. Switching control in hydraulic drives Researchers from Johannes Kepler University believe agricultural machinery can be improved by further advances in motion generation.
Magazine Issue
Improved Reliability Brake Pneumatic Drive2000-01-263909/11/2000
The main requirements to which the brake system of a vehicle should respond are provision of the standard operation speed and protection features of the control pneumatic drive in case of a malfunction of any of its elements. The article describes a design of modified pneumatic brake drive having improved protection properties in case of damage of a diaphragm of any brake chambers, and methodology of parameter optimization of such drive allowing to create a layout of drive assemblies with the necessary operation speed for MAZ truck-based road trains.
Uspenskiy, Alexander, Pavlovich, Alexander
Technical Paper
Switching Type Control of Hydraulic Drives - a Promising Perspective for Advanced Actuation in Agricultural Machinery2000-01-255909/11/2000
Further advances in agricultural machinery require - amongst others - means for fast and precise positioning. Hydraulic drives fit very well to the environmental conditions of this machinery and can provide the required performance. State of the art methods of fluid power control by servo or proportional valve technology are not adequate for cost and maintenance reasons. Switching techniques are an alternative. Various concepts of switching exist. Some of these also show good efficiency. To put these techniques to practice requires very fast switching valves which currently are not available. One promising concept to realize such valves is outlined.
Scheidl, R., Garstenauer, M., Manhartsgruber, B.
Technical Paper
Symbols for Hydrodynamic DrivesJ640_200003 (Historical)03/10/2000
The following system of symbols is recommended for use in technical papers and engineering reports dealing with hydrodynamic drives.
Automatic Transmission and Transaxle Committee
Recommended Practice
New Machine Concept for Hydroforming Tubes and Extrusions, Part 11999-01-067803/01/1999
By inner pressure hydroforming a great variety of parts can be produced. This is especially true when forming tubes in a single action press with high closing forces. In cooperation with industrial companies at the Institute for Metal Forming Technology of the University of Stuttgart, Germany, a new concept for presses specially designed for hydroforming tubes and extrusions was developed. The press has a capacity of a 3500 tons closing force and a press table size of 2500 mm × 900 mm. A great reduction in costs can be achieved by integrating spacers between the frame of the press and the ram. This paper introduces this new press and discusses different press concepts for hydroforming tubes and extrusions.
Siegert, K., Schwager, A., Rieger, R., Häussermann, M.
Technical Paper
Robust Control of Hydraulic Servos96179508/01/1996
Developing controllers for hydraulic servos is difficult due to the inherent uncertainty and nonlinear characteristics of the system. Systems are classed as uncertain when they are subject to unknown parameter variations or disturbances, or when there is incomplete knowledge of the system model, all of which are common in hydraulic servo systems. However, unlike conventional control techniques, the use of modern control methods means that system uncertainty can be considered at the controller design stage, and consequently robust controllers can be developed. In this paper the robust control of hydraulic servo systems is considered, and sources of uncertainty typical in hydraulic drives are discussed. The effect of ignoring these uncertainties is demonstrated by simulation experiments of a hydraulic servo, comparing conventional control techniques to the modern approach of H∞ optimal control. The implementation of modern controllers is also discussed.
Hampson, S. P., Chawdhry, P. K., Burrows, C. R.
Technical Paper
Laboratory Evaluation of Simple Tillage Tools at High Speed95212809/01/1995
The performance of simple tool shapes in terms of draft with speed of operation was evaluated in the soil bin facility of the Department of Agricultural and Bioresource Engineering, University of Saskatchewan. A hydraulic driven monorail system was developed, which was capable of speeds up to 10 m/s. The results showed that the disturbed soil remained close to the cutting path, and the elliptical shape exhibited the lowest draft increment with speed.
Rosa, Uriel A., Kushwaha, R. Lal
Technical Paper
How the Variation of Chemical Composition of Diesel Fuel Affects the Operation of a Kind of Engine from the National Market91171109/01/1991
The constant needs for planning on energy subject in any country, are mainly based on making the best use of available raw materials, keeping up the fuel quality in the market and promoting the production of high added value products.- With regard to diesel fuels, refining worldwide trends together with the arrival of various raw materials, have been pressing negatively on the quality of these fuels used in fast diesel engines, fact to be studied in order to obtain the optimum equation “Quality/Operation”.- The present work has specifically studied four alternative fuel formulations in comparison with the respective reference diesel oils currently used in Argentina and whose general features permit an international standard resemblance. Engine operating characteristics have been defined as a function of the variation in the fuel chemical composition.-
Nadal, Lia Ester, Varales, Ricardo, Monros, Antonip, Levrino, Juan Carlos
Technical Paper
Low-Speed, High-Torque Radial Piston Hydraulic Motors; The New Generation85153809/01/1985
The Low-Speed, High-Torque (LSHT) radial piston hydraulic motor was first introduced in 1896. While it was relatively efficient, very little improvement of the basic design was seen for almost 60 years. As a consequence, the acceptance of the units as a viable alternative to the conventional drive system of a high speed power source coupled to a multi-stage speed reducer was very limited. It was not until the mid 1950's that the second generation designs produced commercially available models that had improved both reliability and performance to the point of gaining true market acceptance. No longer seen as an alternative, the LSHT motor drive was recognized as an improvement over the conventional system in a rapidly expanding number of applications. In subsequent years the numbers of manufacturers grew, each with their own approach to applying the radial piston concept. However, hydraulic pump technology outpaced LSHT motor technology and machine designers found themselves with highly
Smith, J. W.
Technical Paper
Application of Hydrostatic Transmissions to Increase User Value84110109/01/1984
When using hydrostatic transmissions, both the transmission initial cost and the impact of transmission performance on operating costs are important determinants of user value. In the development process, machine designers must make decisions in the areas of component sizing, transmission configuration, and control selection. These decisions depend on machine design goals for function, vehicle configuration, productivity, fuel economy and expected life. Some relationships of these design variables are discussed to enable more cost effective transmission application.
Pollman, Fred W.
Technical Paper
Microcomputer Control of Steering on a Small Tractor (Mower)82105202/01/1982
An automatically guided mower has been developed which uses microprocessor controlled hydraulics to control steering and to perform error analysis. Once initiated, the mower will follow the contrast line between high and low grass and continue until the plot of grass is mowed. The type of sensor, along with the control and error algorithms have broad applications in mobile hydraulics.
Nine, Philip L., Griffin, Hugh A.
Technical Paper
Hydraulic Systems on Commercial Vehicles79077202/01/1979
Hydraulic systems have been utilized on mobile equipment for a substantial number of years. However, the variety of their usage on commercial vehicles has been limited compared with that of agricultural or construction equipment. This paper illustrates applications of hydraulic systems and descriptions of proper system design on the commercial vehicle.
Peterson, Phil
Technical Paper
Practical Considerations in Hydraulic Drive Systems77077102/01/1977
The first section of this paper is a discussion of twenty four practical considerations of designing hydrostatic and hydraulic drives. It is intended to cover some of the more common mistakes made in circuit design. It includes suggestions on how to avoid the problems and in some cases specific examples of components that are available that could be considered. The second section is a “checklist” of questions that are designed to help the designer recognize the potential problem and probe for the solutions. Many times, simply recognizing the problem automatically brings forth a solution. That's the idea behing this paper.
Nielson, Rolland
Technical Paper
Processing and Engineering of the Polyurethane Technology for the Automotive Industry74102602/01/1974
In dependency from the formulation of the initial components Polyol and Isocyanate, flexible, semi-rigid, rigid or structural Polyurethane foams are suitable for the most varied production of blocks or mouldings. It is the target of our review to present to you the latest standards of such processing techniques as are applicable to the manufacture of Polyurethane mouldings from the point of view of the automotive industry. In doing so, I shall make special mention of particularly developed, custom-made machines and installations.
Pahl, Fritz W.
Technical Paper
Stability Analysis of an Articulated Vehicle Steering System71052702/01/1971
A steering system for an articulated vehicle was analyzed to gain an improved understanding of the closed loop stability characteristics. The analysis was applied to an electrohydraulic system and is applicable to more general types of systems. Since the parameters of electrohydraulic valves are well known, a simulation model including the hydraulic system and the vehicle dynamics, was easily derived. Using the simulation, the oil mass resonance was determined to be the most critical parameter and was controlled by adding compensation in the steering system closed loop. The paper describes the steering system, simulation model, and stability criteria.
Scholl, Rolland D., Klein, Richard E.
Technical Paper
Hydraulic Power Units for Supersonic Aircraft67052902/01/1967
The requirements of hydraulic power units for the Supersonic Transport are compared with those for present commercial aircraft and with the requirements that have been met in supersonic military applications Trends in component power, speed, flow and other parameters, and their effects on component design are discussed.
Lambeck, R. P.
Technical Paper
Mining - A Problem in Earthmoving67027302/01/1967
The mining industry of the United States moves about 7 billion tons of earth and rock per year. Much conventional earthmoving equipment is used in mining, particularly surface mining, but the special problems of the industry suggest that machines designed for mining would be better than machines designed for the construction industry in many applications. Underground mining now uses little automotive equipment. Systems of mining are reviewed to suggest to designers possible applications for new types of automotive equipment.
Spokes, Ernest M.
Technical Paper
Controls for Gas Turbines Driving Centrifugal Compressors67014201/09/1967
Aircraft gas turbines are used to drive free trubine-centrifugal compressor combinations in stationary installations. This combination is used for gas compression and power generation in the natural gas transmission, processing, and utility industry. This article discusses the use of aircraft gas turbines to drive gas compressors. The control design criteria and concepts for the start-up sequence based on the location and load are explained. Safety controls for unattended remote installations are discussed.
Lenz, Hans D.
Technical Paper
Truck Mounted Utility Winches and Drive Installations64008901/01/1964
Utility winches are reliable and durable pieces of equipment. Their installation on the truck chassis frame is not difficult to accomplish. However, as pure mechanical drives become more complex, the problem of proper location and configuration is intensified. In this connection, hydraulic motor drives offer improved flexibility and reduced installation problems at the sacrifice of some power loss. Although considerable progress has been made in the technical development and application of constant load utility winches and hydraulic drive installations, important advances are still to be realized, especially with regard to achieving higher efficiency and more compact design units.
Balogh, Roy
Technical Paper
A Look at Winches for Utility Vehicles64009101/01/1964
A brief history of truck winches is presented in this paper. Various types of conventional worm and gear winches available today are reviewed with comments on the performance of each type. Mention is made of several recently introduced electric and hydraulic drive winches. Constant load winches are discussed. An indication of future winches is presented along with their probable improved features. The importance of filling users’ requirements in present and future winch arrangements is stressed.
Morrow, J. E.
Technical Paper
CONSTANT SPEED DRIVE STARTER UNITS60008401/01/1960
WOOD, PALMER R.
Technical Paper
HYDRAULIC CONTROLS FOR TRUCKS AND BUSES58033801/01/1958
THOMAS, T. H.
Technical Paper
YOUR CAN CAN BEAT THE HEAT53004601/01/1953
BAKER, M. W., McCoy, D. C.
Technical Paper
2-Stage Torque Converter and Double Clutch52022001/01/1952
THE development of the two-stage torque converter with automatic double clutch is presented here. The author covers particularly the substitution of casting for fabrication for several of the units in the transmission.
Schaefer, R.M.
Technical Paper
The Polyphase Torque Converter49019801/01/1949
KELLEY, OLIVER K.
Technical Paper
THE V HYDRAULIC TRANSMISSION49022501/01/1949
AN automatic transmission designed for use on buses is described here. Important advantages of this transmission are said to include: 1. Nearly 100% accessibility of the major working parts while it is installed on the bus. 2. Excellent performance. 3. A single fluid system, which requires no torque-converter seals. 4. Reduced weight - about 300 lb. 5. Easy subassembly replacement. 6. Low operating cost.
SCHJOLIN, HANS O.
Technical Paper
NEW HYDRAULIC APPLICATIONS For TOMORROW'S AUTOMOTIVE DESIGNS47007001/01/1947
Hayden, Merrill A.
Technical Paper
Hydraulic Transmission Performance46012501/01/1946
DEIMEL, A. H.
Technical Paper
IMPORTANT OR TROUBLESOME OPERATING PROBLEMS and BENEFICIAL NEW PRACTICES40000901/01/1940
Technical Paper
THE YELLOW COACH HYDRAULIC TRANSMISSION40000801/01/1940
Green, G.A., Wiggers, John
Technical Paper
PROBLEMS IN AIRCRAFT ACCESSORY DRIVES39010701/01/1939
Lansing, R. P.
Technical Paper
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