Browse Topic: Seals and gaskets

Items (3,333)
Power steering pumps are the heart of any hydraulic power steering system. They provide the heavy lifting power required in the form of high-pressure fluid flow that is utilized in powered steering gears or steering racks to assist drivers in vehicle maneuvers, specifically in low-speed situations. Failure of the power steering pump will inevitably increase work needed from the driver to steer a vehicle and decrease the driver comfort at the same time. This article covers investigations into a customer return issue, affecting more than 20% of pumps, for one particular failure mode, pump input shaft seal leakage, and how the failure is not caused by failure at the input shaft nor by failure of the input shaft seal. It was found that internal damage to the pump rotating assembly allows high-pressure oil to overcome the input shaft seal sealing effect. The cause of the failure was determined to be rooted in the manufacturing process, which was re-ordered to reduce the failure rate to an
Bari, Praful RajendraKintner, Jason
This standard establishes the dimensional and visual quality requirements, lot requirements, and packaging and labeling requirements for O-rings machined from AMS3617 polyamide material. It shall be used for procurement purposes.
A-6C2 Seals Committee
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 standard establishes the dimensional and visual quality requirements, lot requirements, and packaging and labeling requirements for O-rings machined from AMS3650 material. It shall be used for procurement purposes.
A-6C2 Seals Committee
This SAE Aerospace Standard (AS) specifies the dimensions, tolerances and size codes (dash numbers) for O-rings with a larger cross-section than those to AS568, for use in glands per MIL-G-5514 where squeeze at low temperature is often insufficient to provide a leak-tight seal.
A-6C2 Seals Committee
This specification and part standard specifies polytetrafluoroethylene (PTFE) resin material and the dimensional requirements for scarf-cut retainers (backup rings) previously specified by MIL-R-8791 and MIL-R-8791/1. The retainers are intended for use in hydraulic and pneumatic system components as anti-extrusion devices in conjunction with seals and O-rings.
A-6C2 Seals Committee
This specification controls surface condition, manufacturing defects and inspection requirements, and defines methods of measurement for elastomeric toroidal sealing rings (O-rings) for static (including gasket) applications.
A-6C2 Seals Committee
This SAE Aerospace Standard (AS) provides a standardized test procedure that can be used to evaluate material capability in a dynamic sealing application. This procedure will be utilized by applicable elastomer material specifications which are used for production of O-rings and other seals. This specification is applicable to the dynamic testing requirements for aerospace elastomer parts utilizing materials conforming to AMS7XXX series specifications, user specifications, or print on a Purchase Order (PO) that calls out this document for aerospace applications. This procedure is intended for testing NBR. Other elastomers may have different requirements which will require a separate procedure.
AMS CE Elastomers 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 document recommends standard gland dimensions for static radial O-ring seal applications specifically for engine and engine control systems and provides recommendations for modifying these glands in special applications.
A-6C2 Seals Committee
The reliability and performance of steering systems in commercial vehicles are paramount, given their direct impact on reducing hazardous driving and improving operational efficiency. The torque overlay system is designed to enhance driver control, feedback, and reduce driver fatigue. However, vulnerabilities such as water ingress under certain environmental conditions have raised significant reliability requirements. This article discusses the systematic investigation into how radial bearing sideloading led to the input shaft seal failing to contact the input shaft. Water was allowed a path to enter the TOS module, affecting the electronic sensor, and faulting out the ADAS functionality. Improvement to the bearing support and sealing design culminated to an enhanced TOS module package able to withstand testing procedures that mimic the environmental and use case situation which caused the ingress.
Bari, Praful RajendraKintner, Jason
This document establishes standard gland design criteria and dimensions for static axial O-ring seal applications without anti-c operating at a maximum pressure of 1500 psi (10345 kPa).
A-6C2 Seals Committee
Different types of gaskets are being used in the engine. Each gasket plays a unique role for the application. In general gaskets are used to prevent leakage and fill the space between the mating surfaces under compression loads. Cylinder head cover gasket is being used in all engines. Engine gasket plays a major role in arresting and protecting the leakage of oil and external dust entry into the system. In this study new cost-effective material were identified, tested, and evaluated as per the applicable standards for the gasket application. The existing material is well known grade as VAMAC—ethylene acrylate monomer (AEM) material and the alternate material introduced is high temperature alkyl acrylate copolymer (HT ACM). In general, with AEM material have its own advantages and also challenges. Even though AEM material have some advantages with respect to temperature and mechanical properties the challenges and struggle come into picture on cost volatility and availability of raw
Deepalakshmi, R.Koorella, KrishnaSivakumar, G.K.
Low density polyurethane foam was first proposed as an alternative to expandable baffles and tapes for sealing vehicle body cavities towards the end of the last century. Despite several inherent advantages for cavity sealing, the high equipment cost of dispensing amongst other reasons, this technology has not spread as widely as expected. With the advent of electric vehicles, there is an increased emphasis on controlling higher frequencies from motors, inverters and other components, and polyurethane foam can be a viable solution by providing more robust sealing. Polyurethane foam sealing is already being employed in the new breed of electric vehicles, but its NVH advantages have not been fully studied or published in literature. Using an existing electric vehicle with conventional expandable baffles & tape sealing measures, a comprehensive evaluation of NVH performance using the closed-cell polyurethane foam solution was conducted. Testing included component level bench test on body
Kavarana, FarokhGuertin, Bill
For years the NVH community has known that openings in the dash sheet metal, such as holes to pass wire harnesses through, creates an acoustical weak point that limits the potential noise reduction of the dash insulation system. These pass-throughs can also be a source of water leaks into the vehicle’s interior. With internal combustion engines and now electric inverter power plants generating significant high frequency sound, the need to seal this area is vital. By molding a lightweight barrier that draws through the fiber/absorber interior decoupler and dash sheet metal which mates to a secondary seal molded into an outer engine dash decoupler, the two opposing molded barriers meet in the engine compartment and compress together forming a seal around the wire harness. This male/female molded seal replaces the conventional snap in grommet and eliminates noise/water leaks. The system Sound Transmission Loss (STL) is equivalent to similarly insulated sheet metal with no holes
Check, JamesMoritz, Charles
When a vehicle is driven at high speed, there exists intricate flow pattern and vortex shedding at the side window area with intense pressure fluctuation. A significant dynamic pressure difference between the vehicle's exterior and interior can render the side window sealing system vulnerable to aspiration. This susceptibility can lead to the generation of leakage noise, adversely affecting acoustic comfort in the vehicle's cabin. This paper delves into the aspiration properties of glassrun seal system under time-varying pressure difference. A nonlinear finite element model of the glassrun seal was established to simulate the quasi-static deformation of the sealing strip during installation process, which aims to obtain the deformed geometric shape and residual stress after this process. Then, the exterior flow field of the glassrun sealing area of a simplified vehicle model was calculated with CFD simulation to obtain the hydrodynamic pressure excitation acting on the outer surface of
Li, HanqiHe, YinzhiZhang, LijunZhang, YongfengYu, WuzhouJiang, ZaixiuBlumrich, ReinhardWiedemann, Jochen
Wind noise is an important indicator for evaluating cabin comfort, and it is essential to accurately predict the wind noise inside the vehicle. In the early stage of automotive design, since the geometry and properties of the sealing strip are often unknown, the contribution of the sealing strip to the wind noise is often directly ignored, which makes the wind noise obtained through simulation in the pre-design stage to be lower than the real value. To investigate the effect of each seal on wind noise, an SUV model was used to simulate the cases of not adding body seals, adding window seals, and further adding door seals, respectively. The contribution of each seal to wind noise was obtained and verified by comparing it with the test results. The influence of the cavity formed at the door seal was also addressed. In the simulations, a CFD solver based on the lattice Boltzmann method (LBM) was used to solve the external flow field, and the noise transmitted into the interior of the
Zhang, YingchaoHe, TengshengWang, YuqiNiu, JiqiangZhang, ZheShen, ChunZhang, Chengchun
This SAE Aerospace Recommended Practice (ARP) is intended to provide guidance on verifying the integrity of inflation pressure sealing systems of aircraft wheel/tire assemblies.
A-5A Wheels, Brakes and Skid Controls Committee
Opening a tailgate can cause rain that has settled on its surfaces to run off onto the customer or into the rear loadspace, causing annoyance. Relatively small adjustments to tailgate seals and encapsulation can effectively mitigate these effects. However, these failure modes tend to be discovered relatively late in the design process as they, to date, need a representative physical system to test – including ensuring that any materials used on the surface flow paths elicit the same liquid flow behaviours (i.e. contact angles and velocity) as would be seen on the production vehicle surfaces. In this work we describe the development and validation of an early-stage simulation approach using a Smoothed Particle Hydrodynamics code (PreonLab). This includes its calibration against fundamental experiments to provide models for the flow of water over automotive surfaces and their subsequent application to a tailgate system simulation which includes fully detailed surrounding vehicle geometry
Gaylard, Adrian PhilipWeatherhead, Duncan
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 specification covers a cast tin bronze in the form of sealing rings (see 8.5).
AMS D Nonferrous Alloys Committee
A lighter, colorable and fully recyclable thermoplastic body seal from Cooper Standard won the annual Innovations in Lightweighting Award given by the Society for Automotive Analysts. At the society's December meeting, Jay Murdock, senior product development engineer for Cooper Standard, accepted the award and said its FlexiCore product was designed with an eye on strong trends in what OEMs want from suppliers: sustainability, carbon neutrality, lightweighting and recyclability.
Clonts, Chris
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
O-rings are essential components in engineering products as they ensure leak-proof sealing and hinders amalgamation of various fluids in the system. O-rings in general have lot of factors that go into deciding the right design for a system. With the help of FEA, O-ring design is varied to ensure optimal results. However, this process is time and resource consuming. Considering this situation, an alternative approach to predict the outcome with the help of DOE study is chosen in this paper. It leverages the Machine Learning models to predict the output parameters effectively with less resources. With the help of performance parameters, this paper proposes a comparison of various native ML models like Linear Regression, Random Forrest, SVM, KNN, Boosting, Artificial Neural Networks and Kriging [7]. The Goal is to systematically compare the prediction performance of various models based on bootstrapping and hypothesis testing techniques to identify the most effective approach. This
Mallu, Venkata ReddyPenumatsa, Venkata Ramana RajuChirravuri, BhaskaraDuddu, VaraprasadMiller, RonaldSahu, Abhishek
The purpose of this SAE Recommended Practice is to establish guidelines for the automatic transmission and hydraulic systems engineer to design rectangular cross section seals for rotating and static grooved shaft applications. Also included are property comparisons of polymeric materials suitable for these applications. Historically, material covered in this document is not intended to include aluminum contact applications.
Automatic Transmission and Transaxle Committee
When a physician injects a patient with medication from a glass vial, they want to know that the drug inside that vial is sterile and stable. That’s where Genesis Packaging Technologies comes in. Genesis Packaging Technologies, formally a division of the West Company, was founded in 1946. Today, Genesis is a one of the leaders in the science and technology of parenteral vial sealing and residual seal force testing.
This study investigated the contact pressure distribution of three combustion seal designs for fuel injectors using both experimental techniques and finite element analysis (FEA). The designs tested included the baseline seal (Design #1), a conical seal (Design #2), and the current production seal (Design #3). In phase 1, a 2D axisymmetric FEA was conducted under worst-case torque conditions (67.8 Nm) to simulate contact pressure, with an axial load of 10 kN and combustion pressure of 21.3 MPa applied to the injector assembly. Phase 2 employed Fuji films to measure the pressure distribution at higher torques (89.5 and 115.2 Nm) in a more realistic scenario, incorporating challenges such as misalignment and eccentric loading. During this phase, Fuji film shearing was a significant challenge, complicating the accurate assessment of pressure profiles. Design #1 failed to maintain the minimum threshold contact pressure of 70 MPa over a 1 mm length, leading to potential leakage. Design #2
Kaliyanda, Aneesh
Most of the heavy commercial vehicles are installed with Pneumatic brake system where the medium is a pressurized pneumatic air generated with the reciprocating air compressor. Heating is an undesirable effect of the compression process during loading cycles as reciprocating air compressors are concerned. Therefore it is necessary to reduce the delivery air temperature of compressor for safer operation of downstream products. The present investigation deals with the measurement of the delivery air temperature of a typical 318 cc water cooled compressor. A through steady state conjugate heat transfer analysis is conducted for the given speed and with the specification cooling water flow rate to predict the delivery air temperature. Pressure drop across the cooling water flow path has been measured and optimum flow rate is arrived to meet the design requirement. The results of characteristic analysis and comparative research show that the cooling system can obviously reduce the cylinder
N, PrabhakarV A, Sahaya IrudayarajRaj, AmalT, Sukumar
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
Aerospace engine components like discs, blisks and rings are engineered to perform in extreme operating environments. They need to withstand intense heat and stress and be as lightweight as possible to meet exacting specifications. These parts are also notoriously difficult to machine, and manufacturers who work with them must meet serious challenges of their own. Holding tight tolerances, maintaining predictable tool life and accounting for internal material stress relief from material removal can be especially difficult when profiling complicated features such as thin-walled flanges, undercut pockets and seal fins.
This specification covers a cast leaded-tin bronze in the form of sealing rings (see 8.5).
AMS D Nonferrous Alloys Committee
This specification covers a fluorocarbon (FKM) rubber in the form of O-rings, O-ring cord, compression seals, and molded-in-place gaskets for aeronautical and aerospace applications.
AMS CE Elastomers Committee
The work investigates the penetration depth of a low environmental impact Cr(III)-based sealing on two anodized Aluminum-Silicon alloys (i.e., EN AC-42200 and EN AC-43200) for brake system applications. EN AC-42200 and EN AC-43200 specimens are: 1) obtained by sectioning of gravity cast components; 2) anodized using different process times to obtain different anodic layer thicknesses; and 3) sealed in a Cr(III)-based proprietary sealing solution at low temperature. The obtained sealed anodic layers are characterized using several techniques including: Glow Discharge Optical Emission Spectroscopy (GDOES), metallographic analyses and Eddy current thickness measurements. Results demonstrate that: a) the Cr(III) concentration within the anodic layers shows an exponentially decreasing trend from the specimen surface toward the anodic layer-substrate interface; b) the typical thickness of the sealing layer is in the order of 1.5μm; and c) the Cr(III) penetration depth is only marginally
Pavesi, AriannaFumagalli, LucaAbello, Mary AngelBonfanti, AndreaMancini, AlessandroVedani, MaurizioBertasi, Federico
Innovators at NASA Johnson Space Center have developed a method using low-viscosity RTV silicone to form durable seals between polymer bladder and metal bulkhead interfaces to be used for inflatable space habitats.
THIS STANDARD ESTABLISHES THE DIMENSIONAL AND VISUAL QUALITY REQUIREMENTS, LOT REQUIREMENTS, AND PACKAGING AND LABELING REQUIREMENTS FOR O-RINGS MOLDED FROM AMS7410 FLUOROCARBON (FKM) RUBBER. IT SHALL BE USED FOR PROCUREMENT PURPOSES.
A-6C2 Seals Committee
Sodium is used as a coolant in the fast reactor’s primary and secondary loops to transfer enthalpy from the reactor and transport it to the expander. However, handling sodium is difficult, and it can be hazardous if it comes into contact with air, which causes an exothermic reaction. During maintenance of sodium loop components, isolation is typically accomplished with valves. The valve leaking is caused by the seal or the gland. Seal leakage is compensated because it occurs within the line, but gland leakage should be zero because the liquid is harmful. To address this requirement, the author attempted to design a special type of valve in which sodium is allowed to rise through an annular path along the stem and heat transfer is augmented in such a way that the required enthalpy is evacuated to freeze sodium inside the annular path, confirming the fail-safe zero gland leakage. A finned tube assembly is fitted around the stem to achieve this concept of expanded surface heat transfer
Kudiyarasan, SwamynathanBiswas , Sitangshu Sekhar
The present study discusses the determination of the Seal drag force in the application where an elastomeric seal is used with a metallic interface in the presence of different fluids. An analytical model was constructed to predict the seal drag force and an experimental test was performed to check the fidelity of the analytical model. A Design of Experiment (DoE) was utilized to perform an experimental test considering different factors affecting the Seal drag force. Statistical tools such as the Test for Equal Variances and One Way Analysis of Variance (ANOVA) were used to draw inferences for the population based on samples tested in the DoE test. It was observed that Glycol fluids lead to lubricant wash-off resulting in increased seal drag force. Additionally, non-lubricated seals tend to show higher seal drag force as compared to lubricated seals.
Yarolkar, MakrandTelore, MilindPatil, Sandip
Inverter is the power electronics component that drives the electrical motor of the electrical driven compressor (EDC) and communicates with the car network. The main function of the inverter is to convert the direct current (DC) voltage of the car battery into alternating current (AC) voltage, which is used to drive the three-phase electric motor. In recent days, inverters are present in all automotive products due to electrification. Inverter contains a printed circuit board (PCB) and electronic components, which are mounted inside a mechanical housing and enclosed by a protective cover. The performance of the electrical drive depends upon the functioning of the inverter. There is a strong demand from the customer to withstand the harsh environmental and testing conditions during its lifetime such as leakage, dust, vibration, thermal tests etc. The failure of the inverter leads to malfunction of the product, hence proper sealing and validation is necessary for inverters to protect
Duraipandi, Arumuga PandianLeon, RenanRibot, HerveRaja, Antony VinothFarooqui, AltafhussainChandrasekaran, Vinoth-Roy
Unlike conventional heat shrink tubes or enclosure systems which only seals wires and splices on the outside, a novel Acrylate based sealing technology developed and introduced by Eurotech is a low viscosity fluid formulated to be applied to the splices either in liquid droplets or by dipping, utilizes fast capillary-wicking action and quick self-cure inside the wires to form a robust, cost effective, flexible, impenetrable seal to prevent moisture damage of wire harnesses and associated electrical components. This technology is an enabler of new wire harness architectures currently limited by the shortcomings of conventional sealing products such as heat shrink tubes which come up short when the splice configurations or geometries become too complex or difficult for sealing from the outside. Sealing mechanism investigation was launched and the results of the analytical experiments are presented to reveal how this unique sealing technology works to effectively withstand pneumatic air
Chung, Dennis
As part of the development of its new powertrain consisting of two electric motors, a combustion engine and a gearbox, Renault SAS followed an original approach to achieve an assembly with an optimized, robust, and reliable link between the main electric motor and the gearbox. The running operation optimization as well as the high reliability is achieved by processing the following topics: filtration of vibrations and operating jolts; solving of tribological problems specific to splined connections, such as fretting corrosion and abrasive tooth wear; avoidance of potential seizure of elements with cyclic relative slippage under load; and eventually, control of wear and tear on the sealing and damping O-rings, which must accept oscillating translational movements at the same time as torque transfer. The aim of this article is to retrace the main steps taken to achieve the desired reliability and performance targets for this type of product. The most remarkable points of this approach
Hay, MaximeDutfoy, LaurentLigier, Jean-louisMerçay, Patrice
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