Browse Topic: Hydraulic equipment
The following list consists of hose data provided as of December 2023 and is for convenience in determining acceptability of nonmetallic flexible hose assemblies intended for usage under 46 CFR 56.60-25. Where the maximum allowable working pressure (MAWP) or type of fitting is not specified, use the manufacturer's recommended MAWP or type of fitting. This list has been compiled by SAE staff from information provided by the manufacturers whose product listings appear in this document. Manufacturers wishing to list their products in this document shall: a Successfully test their hose to the requirements of SAE J1942, Table 1. b Submit a letter of certification to the SAE J1942 test requirements for each specific type of hose tested (see sample table, Table 1) along with the test results. All sizes should be included in the same letter which must also include all of the information necessary to make a SAE J1942-1 listing. c SAE will review the letter and may, at their discretion, request to see further test results. A copy of the submittal letter marked “Accepted for Listing” will be returned to the applicant upon approval. d The cutoff date for inclusion of a hose listing in the annual SAE Handbook is September 30 of the preceding year. However, listed hoses may be used on vessels as soon as the “Accepted for Listing” letter is issued by SAE.
As the automotive industry undergoes significant changes in the dynamic behavior of vehicles and increasing demand for rapid product design, accurate prediction of product performance in the early stages has become more crucial than ever in the competitive environment. Shim-stack-type hydraulic dampers are widely used in automotive parts for both internal combustion engine (ICE) vehicles and electric vehicles (EV). EVs are even more sensitive to damper performance as ICE, which is a major NVH source has been removed. However, the industry still faces challenges in obtaining accurate models of dampers due to their highly nonlinear hydro-mechanical behavior. Bleed slits in a shim-stack-type hydraulic damper play a key role in determining the blow-off characteristics of dampers, and therefore, accurate prediction of the blow-off characteristics is crucial in evaluating the damping performance of a vehicle. Bleed flow analyses are conducted at two levels: component level and assembly system level. For the component level analysis, computational fluid dynamics (CFD) is utilized to analyze bleed flow characteristics corresponding to various bleed slits, which are validated by conducting experimental flow bench tests. For the assembly system level analysis, a dynamic 1-dimensional (1-D) system model is developed for a target passive hydraulic damper to evaluate the effect of bleed slits on the assembly level. The damper characteristic of the proposed method and a conventional method with a constant discharge coefficient are compared. An experimentally measured damper characteristic from a dynamo is used to validate the system model.
Reducing weight from components and systems is a major trend in passenger vehicles to boost fuel efficiency and driving range - it's not a strategy typically associated with construction machinery and stationary applications. Liebherr Components contends that such off-highway applications also can benefit from utilizing lighter-weight components and has spent years developing the expertise and production capabilities to add them to its hydraulics portfolio. Liebherr recently revealed “hybrid” hydraulic cylinders - components made of steel but wrapped in carbon-fiber-reinforced plastic (CFRP) - that can be up to 50% lighter than traditional all-steel cylinders. Depending on the application and customer preference, the weight savings can increase operating speeds, allow larger attachments and booms, and raise payloads - or, as in road-going vehicles, reduce CO2 emissions and fuel consumption during operation, the company said.
This SAE Aerospace Recommended Practice (ARP) covers the design and installation requirements for hydraulic systems (up to 8000 psig [56 MPa]) for ground support equipment (GSE). This ARP is derived from AS5440, which provides hydraulic system requirements for aircraft. The recommendations herein are primarily intended for GSE that exchange hydraulic fluid with the aircraft, such as hydraulic service carts, rather than GSE with non-interfacing hydraulic systems. The GSE may be mobile, portable, or stationary.
This SAE Aerospace Standard (AS) provides general design and test requirements for a flat cut-off pressure compensated, variable delivery hydraulic pump for use in a civil aircraft hydraulic system with a rated system pressure up to 5000 psi (34500 kPa). NOTE: Hydraulic pumps may incorporate features such as a clutch in the input drive, which will not be covered by this standard.
This SAE Aerospace Information Report (AIR) provides basic information on the use of slipper seal sealing devices when used as piston (OD) and rod (ID) seals in aerospace fluid power components such as actuators, valves, and swivel joints, including: The definition of a slipper seal and the description of the basic types in use. Guidelines for selecting the type of slipper seal for a given design requirement are provided in terms of friction, leakage, service life, installation characteristics, and interchangeability.
Traditionally, agricultural sprayer machines were custom-built on a four-wheel chassis. These custom-built units were heavy, expensive, and not easily adapted to other farm applications. Sprayers are typically used to apply herbicides, insecticides, and fertilizer. Naturally, it would be more practical if a machine could be used for other functions such as tilling, loading, and baling.
Mobile hydraulic machines are the unrecognized stars of the world. Digging the channels, loading the piles, excavating at various altitude and varying ambient are extremely tough work a machine does only with the help of hydraulics. Reservoirs to store the hydraulic oil plays key role in accomplishing these jobs. Most of the reservoir compromises with their shape and aesthetic due to compactness of the machine. The hydraulic reservoir performs various duties, the primary and obvious job of the reservoir is to hold the hydraulic fluid and used to circulate into the actuators of the system via pumps and valves whereas reservoirs are also responsible for providing enough surface area for the cooling of the hydraulic fluid. Over the year, physical testing is the only way for evaluating the effectiveness of the hydraulic reservoir, however with advancement in numerical techniques, like Multiphase 3D CFD approaches, this issue can be easily addressed by virtual analysis much ahead of the physical testing. The advantage of virtual validation saves huge cost and provide accuracy for future design. In this paper, a numerical simulation approach will be discussed to solve one of the construction complex reservoirs. The residence time and internal design modifications will be discussed to conclude the CFD approach along with the physical test verification.
This work presents a new design of ventilation pillars in ventilated brake discs. The use of National Advisory Committee for Aeronautics (NACA) aerodynamic profiles is proposed. Of the references consulted, there is no standard or procedure that indicates how the pillars should be installed in the ventilated discs. Therefore, it is proposed using the Kaplan’s error triangles theory of turbo hydraulic machinery to have a geometrically orderly way of placing the NACA 66-209 profiles from the suction diameter to the discharge diameter. To validate this new design, a 1:1 scale acrylic disc model was constructed, and tests were conducted in water using the particle tracking velocimetry technique to characterize the water model. The water experiment was performed at test speeds of 35, 41, 48, and 54 rpm. From the experiment in water, it is possible to visualize the flow field from the suction diameter to the model discharge diameter and scale the results to the prototype in air. Being 54 rpm in water equivalent to N = 1020 rpm in air, the radial velocity is 15.4% higher than a straight vanes disc. In addition, comparing the mass flow at the point of maximum speed, it is observed that the results obtained in this work are 40.21%, 65.49%, and 98.11% higher than those obtained by other works. Finally, the error of the accumulated experimental bias is extremely low, where the maximum error did not reach 1.17%. For this reason, it can be ensured that both the measurements made as well as the results obtained are highly reliable.
This standard covers mobile hydraulic excavator controls and the specific arrangement and direction of motion for the primary controls. This standard applies to mobile hydraulic excavators as described in ISO 7135—Earthmoving machinery—Hydraulic excavators—Terminology and commercial specifications, and ISO 6165—Earthmoving machinery—Basic types—Vocabulary.
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