VRINGS FRANCEJOINT | Alldatasheet
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Technical content
QUALITY & EXPERTISE FOR YOUR SEALING NEEDS V'RINGS 1. Description V'Rings are seal parts that are very often combined with other types of seals such as radial shaft seals. They are also used as the primary seal in other cases. As they offer optimal axial sealing, V'Rings are used to protect the metal parts against dirt, grease, oil and dust. They are frequently used in mechanical transmissions, rolling-mills, machine tools, etc. As a technical component made completely of rubber, V'Rings have three parts:
- the body: the thickest part of the seal, which is clamped in place on the rotating axle and permits rotation.
- the hinge: the part connecting the sealing lip to the body of the seal, which provides a certain amount of flexibility, thus preventing significant position stresses.
- the sealing lip: the part that compensates for radial runout (angle deviations in the rotating axle) as well as significant tolerance gaps other than those recommended by its flexibility. It therefore ensures sealing on the opposing metal surface. Stretched on the shaft, the V'Ring must be positioned at a precise distance in relation to the opposing metal friction surface (or back) to guarantee optimal sealing under axial pre-stressing of the sealing lip. The V'Ring turns with the rotating shaft and depending on the circumferential speed, the centrifugal force acting on the sealing lip repels it on the outside, which reduces compression. Beyond a certain speed, the sealing lip must not come into constant contact with the opposing metal wall, as sealing is not guaranteed. ROTARY SEALS | V'RINGS
www.francejoint.com 2. Materials
2.1 RUBBERS
The table below provides an overview of the different rubber families. ABBREVIATION ISO 1629 ASTM 1418 FRANCE JOINT CODE CHEMICAL NAME ACM B Polyacrylate AEM V Ethylene acrylate rubber EPDM C Ethylene Propylene Diene Monomer rubber FKM G Fluorinated rubber HNBR HK Hydrogenated Nitrile Butadiene rubber NBR K Nitrile Butadiene rubber } ACM (Polyacrylate) Polymers containing ethyl acrylate (or butyl acrylate) have a small amount of monomer, which is necessary for cross- linking; ACM is a material with better heat resistance than NBR. It is often used for automatic gearboxes. Chemical resistance Mineral oils (motor oils, gear box oils, ATF oils) Atmospheric and ozone agents Compatibility issue Glycol-based brake fluids (Dot 3 & 4) Aromatic and chlorinated hydrocarbons Water and steam Acids, alkalis and amines Temperature range -25°C / +150°C (short-term peak at +160°C) } AEM (ethylene acrylate rubber) As a methyl acrylate and ethylene copolymer, AEM is considered to be better resistant to heat than ACM. Its characteristics make it an intermediary between the ACM and FKM. Resistance to chemicals Cooling fluids Aggressive mineral oils Atmospheric agents Water Compatibility issue Aromatic solvents Strong acids Brake fluids Gearbox oils ATF oils Temperature range -40°C/+150°C ROTARY SEALS | V'RINGS
www.francejoint.com } EPDM (Ethylene Propylene Diene Monomer rubber) As an Ethylene Propylene Diene Monomer copolymer, EPDM is commonly used for hot water taps, cooling systems, brake systems, dishwashers and washing machines. Resistance to chemicals Hot water and steam up to +150°C Glycol-based brake fluids (Dot 3 & 4) and silicone-based brake fluids (Dot 5) Organic and inorganic acids Cleaning agents, sodium and potassium alkalis Hydraulic fluids (HFD-R) Silicone oils and greases Polar solvents (alcohols, ketones and esters) Atmospheric and ozone agents Compatibility issue Mineral oils and greases Hydrocarbons Low impermeability to gas Temperature range -45°C / +150°C (short-term peak at +175°C) } FKM (fluorinated rubber) Depending on their structure and fluorine content, fluoroelastomers can vary in terms of chemical resistance and resistance to cold. This FKM-based rubber is very often used for high-temperature hydraulics and pneumatics, for industrial valves, injection/fuel systems, motor seals and high-vacuum systems. Resistance to chemicals Mineral oils and greases, ASTM n°1, IRM 902 and IRM 903 oils. Fire-resistant liquids (HFD) Silicone oils and greases Mineral and vegetable oils and greases Aliphatic hydrocarbons (propane, butane, petroleum) Aromatic hydrocarbons (benzene, toluene) Chlorinated hydrocarbons (trichlorethylene) Fuel (including high alcohol content) Atmospheric and ozone agents Compatibility issue Glycol-based brake fluids Ammonia gas Organic acids with a low molecular weight (formic and acetic acids) Temperature range -20°C / +200°C (short-term peak at +230°C) } HNBR (Hydrogenated Nitrile Butadiene Rubber) This HNBR-based elastomer is obtained through selective hydrogenation of the NBR's butadiene groups. It is commonly used for power-assisted steering and for air conditioning. Chemical resistance Aliphatic hydrocarbons Mineral and vegetable oils and greases Fire-resistant fluids (HFA, HFB and HFC) Diluted acids, saline solutions and bases for operation at an average temperature Water and steam up to +150°C Atmospheric and ozone agents Compatibility issue Chlorinated hydrocarbons Polar solvents (ketones, esters and ethers) Strong acids Temperature range -30°C / +150°C (short-term peak at +160°C) ROTARY SEALS | V'RINGS
www.francejoint.com } NBR (Nitrile Butadiene Rubber) Nitrile rubber (NBR) is the general term for acrylonitrile-butadiene copolymer. The ACN content can vary between 18% and 50%. While the acrylonitrile content is important, the resistance to oil and fuel is more so. Conversely, the elasticity and compression set are not as good. The NBR has good mechanical properties and good wear resistance. However, its resistance to atmospheric agents and the ozone is relatively low. Chemical resistance Aliphatic hydrocarbons (propane, butane, petroleum, diesel fuel) Mineral oils and greases Fire-resistant fluids (HFA, HFB and HFC) Diluted acids, low-temperature alkaline and saline solutions Water (up to +100°C max) Compatibility issue Fuels with high aromatic content Aromatic hydrocarbons (benzene) Chlorinated hydrocarbons (trichlorethylene) Polar solvents (ketone, acetone, acetic acid, ethylene-ester) Strong acids Glycol-based brake fluids Atmospheric and ozone agents Temperature range -30°C / +100°C (short-term peak at +120°C)
2.2 CHEMICAL COMPATIBILITY
A "Chemical compatibility guide" catalogue can be downloaded from our website: www.francejoint.com You can also use our online "Chemical compatibility" tool free of charge. These two tools enable you to measure the behaviour of our materials that come into contact with the majority of existing fluids. The data displayed is the result of rigorous testing at the ambient temperature and takes previous publications into consideration. Test results are not fully representative because of the specific features of your application. The tests performed actually do not consider additives and impurities that may exist under actual conditions of use, nor the potential elevation of temperatures. Other parameters can also alter the behaviour of our materials, such as the hardness, compression set, abrasion, etc. We therefore recommend performing your own tests to verify the compatibility of our materials depending on your specific application. Our technical team can provide you with any additional information.
2.3 TEMPERATURE RESISTANCE
The temperature strongly influences the physical properties of materials. The graph below sets out the temperature limits for each material. However, we can provide custom-made hybrids depending on your needs (e.g. NBR or FKM capable of withstanding temperatures of -40°C) NBR HNBR ACM AEM EPDM FKM /f_luids with our materials Temperature (°C) -100 -50 0 50 100 150 200 250 300 350 Operating temperature Under particular conditions with special materials Only applicable data with compatible ROTARY SEALS | V'RINGS
www.francejoint.com 3. Technical data
3.1 LOSS OF POWER
The sealing lip of a V'Ring exerts such a low pressure on the contact surface area that the loss of power resulting from it is also low. The variations in power loss depend on the circumferential speed as well as the diameter of the axis in rotation, as shown in the graph below. At speeds greater than 11 m/sec, the sealing lip has a tendency to detach itself, as the centrifugal force is greater. 0 2 4 6 8 10 12 14 16 18 Peripheral speed (m/s) d = 25,00 mm d = 50,00 mm d = 75,00 mm d = 120,00 mm d = 150,00 mm d = 190,00 mm Frictional loss (W)
3.2 SHAFT DESIGN
Considering that the V'Ring is stretched and tightened on the shaft, it is driven into rotation with the shaft. The tolerance and surface roughness requirements (Ra ≤ 3.2 µm) are relatively moderate. We recommend carefully selecting the size using the dimensional chart for applications in which power loss and V'Ring lifespan are important criteria. If the diameter of the shaft Ød1 overlaps two potential V'Ring choices, we recommend selecting the larger V'Ring. The tightness on the shaft will in fact reduce, like the contact pressure of the lip on the back.
3.3 DESIGN OF THE BACK
a. Surface roughness The quality of the back side considerably influences the lifespan of the V'Ring in contact. The surface roughness on the back side is determined according to the fluid to be slaked and the circumferential speed of the shaft. Roughness Ra Circumferential speed v Media 0.40 µm - 0.80 µm > 10.0 m/sec Oil, water 0.80 µm - 1.60 µm 5.0 m/sec - 10.0 m/sec Oil splashes, grease, water splashes 1.60 µm - 2.00 µm 1.0 m/sec - 5.0 m/sec Grease, dirt, water splashes 2.00 µm - 2.50 µm < 1.0 m/s Grease, dirt The surface roughness on the back side must not exceed Ra 0.05 µm. b. Flatness The flatness of the back is essential, even more so when rotation speeds are high. The maximum acceptable deviation is 0.40 mm for 100.00 mm.
3.4 AXIAL SUPPORT
Ød2 C ØD2 b Installing the V'Ring is recommended when the axial support is at full stop. This is also recommended for applications where tightening between the V'Ring and the shaft is relatively weak and where the circumferential speed will exceed 6.0 - 8.0 m/sec. The table below sets out the calculation method for the diameter of the support Ød2. V'Ring profiles Diameter Ød2 BECA 120VA Ød1 + 0.50 x C BECA 120VE Ød1 + 9.00 mm BECA 120VL Ød1 + 3.00 mm BECA 120VS Ød1 + 0.50 x C ROTARY SEALS | V'RINGS
QUALITY & EXPERTISE FOR YOUR SEALING NEEDS DESCRIPTION The BECA 120VA profile is a standard rubber facial effect V'Ring composed of a flat rear face. ADVANTAGES Excellent chemical compatibility and wide temperature range, depending on the type of material chosen Low friction Good elasticity APPLICATIONS Electric motors Power transmissions Bearing protections MATERIALS FKM 60 and 70 Shore A NBR 60 and 70 Shore A V'RINGS BECA 120VA ØD2 Ød1 Ød ØD3 bB A C | DIMENSIONS Part number Shaft diameter Ød1 Inside diameter Ød Width before fitting B Height of the body C Width of the body A Width after fitting b ØD2 Max ØD3 Min ROTARY SEALS | V'RINGS | BECA 120VA
www.francejoint.com Part number Shaft diameter Ød1 Inside diameter Ød Width before fitting B Height of the body C Width of the body A Width after fitting b ØD2 Max ØD3 Min ROTARY SEALS | V'RINGS | BECA 120VA
QUALITY & EXPERTISE FOR YOUR SEALING NEEDS DESCRIPTION The BECA 120VE profile is a facial effect V'Ring with a large radial section and is used for large dimensions. ADVANTAGES Excellent chemical compatibility and wide temperature range, depending on the type of material chosen Low friction Good elasticity Used as a secondary seal for heavy-duty applications Greater axial movement is possible APPLICATIONS Mobile hydraulics Axles MATERIALS FKM 60 and 70 Shore A NBR 60 and 70 Shore A V'RINGS BECA 120VE ØD2 Ød1 Ød ØD3 bB A C | DIMENSIONS Part number Shaft diameter Ød1 Inside diameter Ød Width before fitting B Height of the body C Width of the body A Width after fitting b ØD2 Max ØD3 Min ROTARY SEALS | V'RINGS | BECA 120VE
www.francejoint.com Part number Shaft diameter Ød1 Inside diameter Ød Width before fitting B Height of the body C Width of the body A Width after fitting b ØD2 Max ØD3 Min ROTARY SEALS | V'RINGS | BECA 120VE
QUALITY & EXPERTISE FOR YOUR SEALING NEEDS DESCRIPTION The BECA 120VL profile is a rubber facial effect V'Ring. ADVANTAGES Excellent chemical compatibility and wide temperature range, depending on the type of material chosen Low friction Good elasticity Suitable for confined spaces, substituting labyrinth seals APPLICATIONS General industry MATERIALS FKM 60 and 70 Shore A NBR 60 and 70 Shore A V'RINGS BECA 120VL ØD2 Ød1 Ød ØD3 bB A C | DIMENSIONS Part number Shaft diameter Ød1 Inside diameter Ød Width before fitting B Height of the body C Width of the body A Width after fitting b ØD2 Max ØD3 Min ROTARY SEALS | V'RINGS | BECA 120VL
www.francejoint.com Part number Shaft diameter Ød1 Inside diameter Ød Width before fitting B Height of the body C Width of the body A Width after fitting b ØD2 Max ØD3 Min ROTARY SEALS | V'RINGS | BECA 120VL
QUALITY & EXPERTISE FOR YOUR SEALING NEEDS DESCRIPTION The BECA 120VS profile is a rubber facial effect V'Ring composed of a conical rear face with a large body with a low radial section. ADVANTAGES Excellent chemical compatibility and wide temperature range, depending on the type of material chosen Low friction Good elasticity Firm grip on the shaft APPLICATIONS Agriculture Automotive MATERIALS FKM 60 and 70 Shore A NBR 60 and 70 Shore A V'RINGS BECA 120VS ØD2 Ød1 Ød ØD3 bB A C | DIMENSIONS Part number Shaft diameter Ød1 Inside diameter Ød Width before fitting B Height of the body C Width of the body A Width after fitting b ØD2 Max ØD3 Min ROTARY SEALS | V'RINGS | BECA 120VS
Ød1 Inside diameter Ød Width before fitting B Height of the body C Width of the body A Width after fitting b ØD2 Max ØD3 Min ROTARY SEALS | V'RINGS | BECA 120VS FRANCE JOINT SAS Zone Artisanale Le Mortier - B.P . 50009 - Cugand - 85613 Montaigu Cedex - France Ph. +33 (0)2 51 42 13 76 - Fax +33 (0)2 51 43 61 14 - Email: contact@francejoint.fr - Website: www.francejoint.com