Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M1/00—Testing static or dynamic balance of machines or structures
  • G01M1/30—Compensating imbalance
  • G01M1/32—Compensating imbalance by adding material to the body to be tested, e.g. by correcting-weights
  • G01M1/326—Compensating imbalance by adding material to the body to be tested, e.g. by correcting-weights the body being a vehicle wheel
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C19/00—Tyre parts or constructions not otherwise provided for
  • B60C19/003—Balancing means attached to the tyre
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C5/00—Inflatable pneumatic tyres or inner tubes
  • B60C5/004—Inflatable pneumatic tyres or inner tubes filled at least partially with liquid
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M171/00—Lubricating compositions characterised by purely physical criteria, e.g. containing as base-material, thickener or additive, ingredients which are characterised exclusively by their numerically specified physical properties, i.e. containing ingredients which are physically well-defined but for which the chemical nature is either unspecified or only very vaguely indicated
  • C10M171/06—Particles of special shape or size
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
  • F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
  • F16F15/32—Correcting- or balancing-weights or equivalent means for balancing rotating bodies, e.g. vehicle wheels
  • F16F15/36—Correcting- or balancing-weights or equivalent means for balancing rotating bodies, e.g. vehicle wheels operating automatically, i.e. where, for a given amount of imbalance, there is movement of masses until balance is achieved
  • F16F15/363—Correcting- or balancing-weights or equivalent means for balancing rotating bodies, e.g. vehicle wheels operating automatically, i.e. where, for a given amount of imbalance, there is movement of masses until balance is achieved using rolling bodies, e.g. balls free to move in a circumferential direction
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
  • F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
  • F16F15/32—Correcting- or balancing-weights or equivalent means for balancing rotating bodies, e.g. vehicle wheels
  • F16F15/36—Correcting- or balancing-weights or equivalent means for balancing rotating bodies, e.g. vehicle wheels operating automatically, i.e. where, for a given amount of imbalance, there is movement of masses until balance is achieved
  • F16F15/366—Correcting- or balancing-weights or equivalent means for balancing rotating bodies, e.g. vehicle wheels operating automatically, i.e. where, for a given amount of imbalance, there is movement of masses until balance is achieved using fluid or powder means, i.e. non-discrete material

Definitions

• the present invention relates to tyre balancing compositions for use in eliminating/reducing vibrations in motor vehicle wheel assemblies related to tyre and rim imperfections, as well as to the use of such compositions.
• Vibrations in rolling wheel assemblies (tyre + rim) are caused by several, different types of tyre imperfections, the most important being:
• European Patent No. 0557365 describes a different approach to reduction of vibrations induced by wheel assembly imperfections, comprising introduction of a visco-plastic gel into the tyre cavity.
• the principle behind the action of such gels is that they are able to flow under the stresses induced by vibrations and therefore spontaneously distribute themselves in a rolling tyre in such a way that the vibrations are reduced irrespective of what type of imperfections they are induced by.
• the efficiency of these balancing gels as compared to lead weight balancing can be demonstrated experimentally by measuring vertical accelerations on the spring leg of a front axle with its wheels running under load against a rotating drum.
• a drawback with gel compositions in general is that a fairly large amount of gel must employed per tyre since a gel is not able to form localized "lumps" in the manner of a lead weight but must instead form a film layer with a continuously and gradually changing depth in order to provide the required balancing.
• the object of the present invention is to eliminate or substantially reduce the above mentioned remaining level of vertical accelerations as well as provide a significant reduction of the amount of composition needed per tyre. It has now been found that by incorporating or imbedding into the gel layer a certain amount of solid masses or bodies of a certain size, said size being at least sufficiently large to enable the bodies to move through the gel layer under the influence of acceleration forces induced by imbalances, but not so large so as to themselves begin to induce vibrations, greatly enhances and expands the ability of the composition to reduce vibration and to balance wheel assemblies.
• the invention therefore concerns a tyre balancing composition which comprises on the one hand a visco-plastic gel and on the other hand solid bodies having an average smallest dimension in the range of 0.5-5 mm.
• solid as applied to the bodies is intended to mean particles having a continuous and fairly smooth surface, but not necessarily having no voids or cavities.
• a solid body within the meaning of the present invention may be hollow or have internal porosities, although a truly solid body, i.e. one having a continuous material phase all through and no cavities or porosities, is preferred.
• the invention also relates to a tyre balancing composition kit, a balancing composition according to the invention contained in a wheel assembly, as well as a method for balancing motor vehicle wheel assemblies.
• the gels in which the solid bodies are present or imbedded to form the compositions of the invention will in the following be known as DFC (Dynamic Force Compensation) gels.
• the solid bodies imbedded in the gels to act as moving masses may be any type of solid bodies of the specified dimensions which are able to be dispersed discretely in a visco- plastic gel.
• the bodies have an average ratio ⁇ between their smallest and their largest dimension of ⁇ ⁇ 2 since particles with larger such aspect ratios tend only to move with ease in the longitudinal direction, ⁇ preferably being ⁇ 1.5, in particular around 1.
• the smallest dimension of the bodies is, as stated above, in the range 0.5-5 mm.
• the average smallest dimension of the bodies is in the range of 1-4 mm, in particular around 3 mm.
• Suitable visco-plastic gels that will enable imbedded masses move in order to compensate vibrational forces to a smaller or larger degree can be defined in rheological (as measured with a Stress Tech Rheometer from Rheologica AB, Lund, Sweden) by the following characteristics:
• the Storage Modulus is around 9000 Pa at 22°C.
• the Critical Yield Stress is preferably around 30 Pa at 22°C.
• the composition of the invention should preferably also exhibit suitable adhesive properties ("stickiness") with respect to the tyre and the bodies.
• adhesion between tyre inner lining and the visco-plastic gels as well as the adhesion between imbedded masses and the visco-plastic gels may be evaluated in the following two step practical test:
• Step 1
• a two mm thick, 100x100 mm square of the visco-plastic gel to be tested is applied to the middle of a sheet (200x200 mm) of chloro-butyl rubber glued onto a stiff support (metal plate) as well as to the middle of a similar sheet of butyl rubber.
• the two sheets are raised into a vertical position and left standing for 24 hours at 22°C and 65% R.H. If the displacement of the upper rim of the gel-square is less than 3 mm on both test surfaces, the adhesion of the gel component to tyre inner linings is deemed satisfactory.
• a two mm thick, 100x100 mm square of a visco-plastic gel that conforms to the requirements of Step 1 of this test is applied to the middle of a sheet (200x200 mm) of chloro-butyl rubber glued onto a stiff support (metal plate), and 10 HD polyethylene disk- shaped pellets (specific weight 0.9, disk average diameter: 4.5 mm, disk average height 3 mm) are inserted randomly into the gel.
• the sheet is raised into a vertical position and left standing for 24 hours at 22°C and 65% R.H. If the average displacement of the pellets is less than 2 mm, the adhesion of the gel component to solid masses is deemed satisfactory.
• Visco-plastic gels that conform to both step both Step 1 and Step 2 of this test are considered suitable with respect to adhesive properties.
• visco plastic gels suitable for use in this invention should preferably also satisfy certain other physical and chemical criteria that will ensure optimum function under the operating conditions and environment of this particular application, such as:
• the visco-plastic gels in which the solid bodies are imbedded to form the balancing compositions of the invention, may be of any chemical composition which provides the visco-plastic properties required, preferably as defined above as well as with the other physical and chemical properties enumerated above.
• Such visco-plastic gels will typically be composed from on the one hand one or more organic base oils having a suitably low viscosity index and on the other hand a gel former.
• Non-limiting examples of base oils are mineral oil, polyol esters of fatty acids derived from synthetic or naturally occurring polyols and fatty acids, synthetic hydrocarbon oils such as polypropylene oils, poly-alpha-olefins, polybutenes, polyglycols such as liquid polyethylene glycol or liquid polypropylene glycol, or ethylene oxide/propylene oxide copoiymers, as well as mixtures thereof.
• Non-limiting examples of gel formers are colloidal silicas, polyacrylic acids, bentonite clay and metal soaps.
• the solid bodies may suitably be shaped as prolate or oblate ellipsoids, cylinders, rectangular paralleipipeds, or spheres, or mixtures of such bodies. They may be prepared through any method known in the art such as emulsion polymerisation of polymers or cutting rectangular or circular cross-section extrudates into suitable lengths. In order that the solid bodies do not interact unduly with the inside of the tyre when under the influence of centrifugal forces, it is preferred that the apparent specific gravity of the solid bodies is in the range of 500-3000 kg/m 3 , more preferably 600-2000 kg/m 3 , in particular 700-1000 kg/m 3 , especially 800-900 kg/m 3 .
• apparent specific gravity refers to the ratio between the weight of each individual solid body and the volume enclosed by the outer, continuous surface, Thus, it will be clear that if the bodies are hollow or otherwise include voids or are porous, the apparent specific gravity may lower than the nominal specific gravity of the material from which the bodies are made.
• the solid bodies should preferably be made from a material which does not interact unsuitably with the visco-plastic gel.
• suitable materials for the solid bodies are various polymers such as polyolefins, e.g. polyethylene (either high or low density) or polypropylene; polystyrene; polyvinyl chloride; polyamides, e.g nylons; rubbers such as butyl rubber or latex; or glass.
• the content of solid bodies in the composition of the invention may vary within fairly wide limits since the purpose of the bodies is to able to move in the gel layer in order to establish zones with a high concentration of solid bodies to act as balancing elements.
• the weight ratio between the solid bodies and the gel is preferably from 10:1 to 1 :10, more preferably from 5:1 to 1 :5, in particular from 2:1 to 3:1 , such as from 1 :1 to 1 :2.
• the invention further concerns a tyre balancing composition kit comprising i) a first container containing a visco-plastic gel, and ii) a second container containing solid bodies having their average smallest dimension in the range of 0.5-5 mm.
• the visco-plastic gel and the solid bodies, respectively, preferably are defined as and/or exhibit the properties and attributes listed above.
• the weight ratio between the amount of visco-plastic gel in the first container and the amount of solid bodies in the second container is from 10:1 to 1 :10, preferably from 5:1 to 1 :5, in particular from 2:1 to 3: 1 , such as from 1 :1 to 1 :2.
• the amounts of the visco-plastic gel and the solid bodies in the first and second containers, respectively, of the balancing kit according to the invention are adapted to be applied to one single automobile tyre, whether a passenger automobile tyre, a truck tyre or the like.
• Such amounts will typically be from 50 to 400 g per tyre for passenger vehicle tyres, and 300-1000 g per tyre for truck tyres.
• the present invention likewise further relates to a tyre balancing composition according to the invention as defined above contained within the air cavity of a motor vehicle tyre.
• the invention also relates to a method for balancing a motor vehicle wheel assembly, said method comprising the steps of
• the amount of visco-plastic gel applied to the inside of the tyre should preferably be in the range of 0.01-1 grams per cm 2 , more preferably 0.02-0.5 grams, in particular 0.02-0.1 grams per cm 2 , of the inner lining surface of the tyre adjacent the part of the tyre that actually contacts the road (the tyre tread).
• the amount of solid masses in the tyre balancing kit of the invention applied to the inside of the tyre should preferably be between 10 and 200 g for car tyres and between 50 and 500 g for truck tyres, more preferably between 10 and 100 g for car tyres and between 50 and 300 g for truck tyres, in particular 20-80 g and 80-150 g, respectively.
• a DFC-gel (250 g) consisting of 1 weight part of HD polyethylene disks (specific weight 0.9, disk average diameter: 4.5 mm, disk average height 3 mm), and 2 weight parts of a visco-plastic gel according to European patent no. 0557365 and consisting of an ethylene oxide (EO)/propylene oxide(PO) copolymer (UCON 50-HB-5100 from Union Carbide, theoretical molecular weight equal to 4000) and fumed silica (Aerosil 202 from Degussa), was introduced into the cavity of a Michelin 175/65/R14 tyre. The tyre was mounted on a car and driven until all vibrations disappeared. The wheel assembly was dismounted from the car, and measurement in a spin-balancing machine showed only insignificant residual weight imbalance. Inspection of the inner tyre wall showed an uneven distribution of the polyethylene pellets as would be expected if balancing is to take place.
• EO ethylene oxide
• PO propylene oxide
• a visco-plastic gel according to European patent no. 0557365 and consisting of an ethylene oxide/propylene oxide copolymer (L1 from Lyondell Chemical Worldwide, Inc., EO to PO ratio equal to 1 :1 and theoretical molecular weight (Mw) equal to 6500) (74.0%), castor oil No. 1 (18.5%) and fumed silica (Aerosil A300 from Degussa) (7.5%) was introduced into the cavity of a Michelin 175/65/R14 tyre and spread around the inner perimeter.
• HD polyethylene disks specific weight 0.9, disk average diameter: 4.5 mm, disk average height 3 mm were then sprinkled evenly on top of the gel layer.
• the tyre was mounted on a car and driven until all vibrations disappeared.
• the wheel assembly was dismounted from the car, and measurement in a spin-balancing machine showed only insignificant residual weight imbalance. Inspection of the inner tyre wall showed a distribution of the polyethylene pellets as would be expected if balancing is to take place.
• LD polyethylene spheres (specific weight 0.85, sphere average diameter: 4 mm) were then sprinkled evenly on top the gel layer.
• the tyre was mounted on a sports utility vehicle and driven until all vibrations disappeared.
• the wheel assembly was dismounted from the vehicle, and measurement in a spin-balancing machine showed only insignificant residual weight imbalance. Inspection of the inner tyre wall showed a distribution of the polyethylene spheres as would be expected if balancing is to take place.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Aviation & Aerospace Engineering (AREA)
• Acoustics & Sound (AREA)
• General Physics & Mathematics (AREA)
• Organic Chemistry (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Tires In General (AREA)
• Lubricants (AREA)

Priority Applications (13)

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Citations (5)

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• 1999
  • 1999-06-24 EP EP99112199A patent/EP1063106A1/en not_active Withdrawn
• 2000
  • 2000-06-21 JP JP2001506117A patent/JP4996799B2/ja not_active Expired - Fee Related
  • 2000-06-21 DE DE60015335T patent/DE60015335T2/de not_active Expired - Lifetime
  • 2000-06-21 PL PL352457A patent/PL205201B1/pl unknown
  • 2000-06-21 CA CA002376998A patent/CA2376998C/en not_active Expired - Lifetime
  • 2000-06-21 HK HK02104790.2A patent/HK1043092B/en not_active IP Right Cessation
  • 2000-06-21 AU AU53908/00A patent/AU757703B2/en not_active Expired
  • 2000-06-21 MX MXPA01013243A patent/MXPA01013243A/es active IP Right Grant
  • 2000-06-21 AT AT00938582T patent/ATE280680T1/de not_active IP Right Cessation
  • 2000-06-21 CN CNB008093628A patent/CN1198738C/zh not_active Expired - Fee Related
  • 2000-06-21 WO PCT/DK2000/000331 patent/WO2001000430A1/en not_active Ceased
  • 2000-06-21 HU HU0201802A patent/HU223270B1/hu active IP Right Revival
  • 2000-06-21 TR TR2001/03750T patent/TR200103750T2/xx unknown
  • 2000-06-21 EP EP20000938582 patent/EP1196299B1/en not_active Expired - Lifetime
  • 2000-06-22 MY MYPI20002834A patent/MY127888A/en unknown
  • 2000-06-23 AR ARP000103139A patent/AR024451A1/es unknown
  • 2000-06-23 TW TW089112424A patent/TW459106B/zh not_active IP Right Cessation
• 2001
  • 2001-12-20 ZA ZA200110480A patent/ZA200110480B/xx unknown
  • 2001-12-21 NO NO20016305A patent/NO320037B1/no not_active IP Right Cessation
• 2005
  • 2005-03-14 US US11/080,952 patent/US20050159534A1/en not_active Abandoned
• 2010
  • 2010-04-08 US US12/756,679 patent/US9671305B2/en not_active Expired - Fee Related

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