6832 results about "Friction coefficient" patented technology

There can be provided a sealing stopper for a syringe, having very high sealing property and sliding property, and a prefilled syringe using this sealing stopper and capable of preserving a medicament for a long time and operating in easy and precise manner during injecting. This syringe is also excellent in sanitary and operating property during a step of formulation or preservation of a medicament. In this sealing stopper for a syringe, a surface of the rubber body is laminated with a tetrafluoroethylene resin film or ultra-high molecular weight polyethylene film having an average roughness Ra on the central line of the surface in a range of at most 0.05 mu m and a kinematic friction coefficient of at most 0.2.

The invention relates to improved means for preventing buckling and therefore eversion of thin-walled, flexible, floppy gastrointestinal liners implanted in the digestive tract of an animal. The implantable devices include an anchor adapted for attachment within a natural body lumen and a thin-walled, floppy sleeve open at both ends and defining a lumen therebetween. A substantial length of the sleeve has material characteristics that result in the sleeve being prone to buckling and therefore eversion in the presence of retrograde pressures. Exemplary anti-buckling mechanisms provide an increased stiffness and/or an increased friction coefficient between the anchor and the proximal end of the sleeve to resist buckling and therefore eversion. In some embodiments, the anti-buckling mechanism is as a wire coupled along the substantial length of the sleeve.

Improved methods of controlling the stability of a vehicle are provided via the cooperative operation of vehicle stability control systems such as an Active Yaw Control system, Antilock Braking System, and Traction Control System. These methods use recognition of road surface information including the road friction coefficient (mu), wheel slippage, and yaw deviations. The methods then modify the settings of the active damping system and/or the distribution of drive torque, as necessary, to increase/reduce damping in the suspension and shift torque application at the wheels, thus preventing a significant shift of load in the vehicle and/or improving vehicle drivability and comfort. The adjustments of the active damping system or torque distribution temporarily override any characteristics that were pre-selected by the driver.

Methods and systems are described for improved drilling operations through the use of real-time drilling data to predict bit wear, lithology, pore pressure, a rotating friction coefficient, permeability, and cost in real-time and to adjust drilling parameters in real-time based on the predictions. The real-time lithology prediction is made by processing the real-time drilling data through a multilayer neural network. The real-time bit wear prediction is made by using the real-time drilling data to predict a bit efficiency factor and to detect changes in the bit efficiency factor over time. These predictions may be used to adjust drilling parameters in the drilling operation in real-time, subject to override by the operator. The methods and systems may also include determining various downhole hydraulics parameters and a rotary friction factor. Historical data may be used in combination with real-time data to provide expert system assistance and to identify safety concerns.

The frequency of an information signal indicative of the vibration of a wheel detected by an acceleration sensor 11 mounted to a wheel 1 or the frequency of an information signal indicative of a change in the pressure of a gas in a tire detected by a pressure sensor 31 installed in the tire is analyzed by frequency analyzing means 14 (34), the band value of the obtained vibration spectrum or pressure change spectrum is detected, and a vibration level or pressure change level at the detected frequency band is compared with a vibration level table 15T showing the relationship between road friction coefficient μ and vibration level stored in vibration level storage means 15, or a pressure change level table 35T showing the relationship between road friction coefficient μ and pressure change level stored in pressure change level storage means 35 to estimate a road friction coefficient μ. Therefore, it is possible to estimate the value of road friction coefficient μ accurately and improve the safety of a car.

The invention relates to a self-greasing paint which can prevent screw thread from sticking and wearing and a preparation method thereof. The self-greasing paint which can prevent screw thread from sticking and wearing is a two-component self-greasing paint that consists of a component A and a component B. Component A consists of raw materials with weight proportion of 40-90 percent of film-forming material, 5-60 percent of solid greasing material, 0-10 percent of additive, 0-50 percent of solvent, 0-10 percent of color paint and 0-10 percent of filling while component B consists of raw materials with weight proportion of 50-100 percent of curing agent and 0-50 percent of solvent. The weight ratio of component A and component B is 1 to 0.1-5. The friction coefficient of the coat formed by the paint is low and the paint has self greasing function, anti-sticking and wearing resistant performances; the invention reduces and even avoids the use of grease and solves pollution problem caused by grease. The self-greasing paint is applicable to various mechanical parts such as bolt, screw, etc., in particular to screw threads of oil pipe, cashing and drill rod, etc. that are special for oil industry.

The invention provides a multifunctional vacuum friction and wear testing machine, which not only can simulate special environmental atmospheres such as vacuum, radiation and corrosion, but also can conduct tribology tests in a relatively wide speed and load range by using various contact manners (ball-disc and pin-disc). The multifunctional vacuum friction and wear testing machine mainly comprises a vacuum system, a friction and wear system, a power transmission system, a control system, and the like, wherein the friction and wear system comprises a lever structure (22) used for fixing a test sample fixture (20) and capable of freely rotating in a horizontal direction and a vertical direction; the lever structure (22) comprises a cantilever beam (18) and a vertical arm (23) which are arranged in a perpendicular manner; the cantilever beam (18) is connected with the vertical arm (23) through a two degree of freedom bearing structure (17); positions of the cantilever beam (18) and the vertical arm (23) can be adjusted in the horizontal direction and the vertical direction through the control of a manipulator (15) and a hand wheel structure (13), so that the test sample fixture (20) can accurately move within two degrees of freedom; and a temperature sensor (2) and a pressure sensor (3) are mounted on the test sample fixture (20), so as to detect/monitor friction coefficients and temperature variations during the tribology tests.

A touchscreen including a touch sensitive layer wherein the user perceived surface roughness or friction coefficient is variable and dynamically controlled. The level of user perceived surface roughness or friction coefficient is related to the information that is displayed at the position at which an object touches the touch sensitive layer. The surface roughness is not locally changed but rather for a complete portion of the touchscreen or for the whole touchscreen simultaneously. Because the modulation of user experience surface roughness or friction coefficient is faster than the user interaction, the user will experience that the surface roughness of certain areas of the display is different from other areas, depending on the information that is being shown, although in fact the surface roughness or friction coefficient is uniform over the whole portion or the whole display at any given point of time.

A method for reducing a friction coefficient adjacent a lubricated surface, and a lubricant composition for reducing a friction coefficient between lubricated surfaces. The method includes providing an amount of metal-containing dispersed in a fully formulated lubricant composition containing a base oil of lubricating viscosity, wherein the nanoparticles have an average particles size ranging from about 1 to about 10 nanometers. The lubricant composition containing the metal-containing nanoparticles is applied to a surface to be lubricated.

The invention discloses a device and a method for testing linear reciprocating sliding friction and abrasion; the device consists of a transducer, a workbench, a sample table, a dragging frame, a force sensor, a changeover switch, a counter, a locking device, a guideway, a baffle, a cable wire, a reducer, a peak value stabilizer, a control part and an auxiliary component; the equipment can automatically complete the abrasion test of an arranged period and can manually complete the test to friction coefficient. The testing method comprises the following steps of: leading the friction block and the sample to reciprocate to slide horizontally with constant pressure, obtaining an abrasion weight loss rate after abrading, keeping a certain positive pressure and leading the sliding block to move from stillness to uniform movement, thus obtaining the maximum static friction coefficient and the sliding friction coefficient. The device and the method can realize uniformly linear and reciprocating relative sliding abrasion in long unidirectional journey, test the maximum static friction coefficient between two bodies and the maximum static friction coefficient, the speed, the load and the adjustable journey with other materials, and can be widely applied to the detection of various samples of different materials and different structural forms.

A belt speed reducing apparatus for an electric power steering apparatus includes a drive pulley having a first helical gear, a driven pulley having a second helical gear and a drive belt having a third helical gear in which a relationship of tan β<μ is established between a twist angle β of the respective helical gears and a friction coefficient μ between the first or the second helical gear and the third helical gear. Further, an electric power steering apparatus for adjusting a backlash between gears of a speed reducing apparatus brought in mesh with each other or adjusting a tension of a belt of a speed reducing apparatus.

An image forming method including forming an electrostatic latent image on an image bearing member; developing the electrostatic latent image with a developer including a toner to prepare a toner image on the image bearing member; transferring the toner image onto a receiving material; and cleaning the surface of the image bearing member with a cleaning blade; wherein a surface of the image bearing member has a friction coefficient of from 0.10 to 0.40, and wherein the toner has an average circularity of from 0.97 to 1.00 and includes toner particles and a particulate material having an average particle diameter of from 0.03 to 1 μm, wherein the particulate material is externally added to the toner particles by a wet method.

The invention discloses an environmental ceramic base friction material free of copper or metal and a preparation method of the material. The environmental ceramic base friction material is characterized by comprising the following components by weight percent: 6-12% of phenolic resin, 2-10% of ceramic fiber, 2-8% of inorganic fiber, 2-10% of rubber, 4-12% of graphite, 10-25% of potassium titanate lamella, 3-15% of mineral fiber, 4-20% of metal sulfur compound, 6-20% of grinding aid and 5-20% of filler. The prepared friction material has excellent friction and wear properties, high heat-conducting property, excellent high-temperature decline property, stable friction coefficient, and excellent noise performance.

The invention belongs to the technical field of friction material, and in particular relates to a graphene-nano polytetrafluoroethylene composite filler with a function of reducing friction, as well as a preparation method and the application of the composite filler. The composite filler comprises the following main components in parts by weight: 1 part of modified graphene and 1-20 parts of modified nano polytetrafluoroethylene; the preparation method of the composite filler comprises the following steps: separately reacting graphene and nano polytetrafluoroethylene with amination reagent and carboxylation reagent to obtain the modified graphene and the modified nano polytetrafluoroethylene; carrying condensation reaction so that the modified graphene and the modified nano polytetrafluoroethylene are connected with each other by a covalent bond to obtain the graphene-nano polytetrafluoroethylene composite filler. The function of friction reduction of the graphene and the function of lubrication of the nano polytetrafluoroethylene are utilized at the same time; after the composite filler is added to a polymer material, the friction coefficient and the wear rate of the material can be reduced, and the mechanical property of the material can be improved.

A method for sterilizing a medical device comprising a hydrophilic coating using radiation said method comprising the steps of bringing the medical device-having such coating in contact with an aqueous liquid for wetting the hydrophilic coating, said liquid comprising a solution of a hydrophilic polymer and sterilizing the device by applying a sufficient amount of radiation provides coated devices showing a significantly increased and prolonged water retention and lower friction coefficient when wet.

The invention relates to a modification scheme decision-making system and method for a bituminous pavement, and belongs to the field of pavement maintenance technologies. According to the system, based on a B/S structure, a pavement structure strength index (PSSI), a pavement riding quality index (RQI), a pavement crack index (PCI) and a pavement rut depth index (RDI) serve as control indexes, a rut depth (RD), a friction coefficient (SFC), a crack rate (CR) and a functional damage rate (FDR) serve as single-value triggering indexes, a negative index model, a modification S model and a structure behavior model are adopted for the system, a user can designate model parameters according to needs to achieve different prediction effects, maintenance history and performance index prediction are combined to be analyzed, and detection data of the pavement over the years are uniformly stored in a lane-division mode. The minimum length unit for evaluating the performance of the pavement is 200 m, in this way, the resolution ratio of original state evaluation of the pavement is increased, a basis is provided for refining a maintenance design, and the function of displaying path, region and road segment basic information is achieved.

When spherical calcium carbonate is produced by blowing a carbon dioxide gas or a carbon dioxide-containing gas into an aqueous suspension containing calcium hydroxide to react them, after start of the reaction, an aqueous solution or suspension of a water-soluble phosphoric acid compound or a water-soluble salt thereof is added to the reaction mixture when carbonation ratio reaches 2 to 10%, and the reaction is further allowed to continue at a low gas blowing rate of 1.0 NL/minute or lower (step (a)). Subsequently, an aqueous suspension containing calcium hydroxide and an aqueous solution or suspension of a water-soluble phosphoric acid compound or a water-soluble salt thereof are added to the reaction mixture, and a carbon dioxide gas or a carbon dioxide-containing gas is introduced to allow to react and thereby produce spherical calcium carbonate having a mean particle diameter of 10 μm or larger. This production method is performed under high velocity revolution from the start of the reaction to the end of the step (a) This method provides calcite type spherical calcium carbonate showing high brightness and small friction coefficient, and having a shape comparatively close to a true sphere and a mean particle diameter of 10 μm or larger.

The invention belongs to the technical field of materials, and specifically relates to a nano-carbon-reinforced wear-resistant composite material. The nano-carbon-reinforced wear-resistant composite material comprises the following components in percentage by mass: 55-99% of metal powder, 0.1-35% of ceramic powder, and 0.01-15% of nano-carbon, wherein the metal powder is used as a composite material matrix; the ceramic powder is used as a wear-resistant filling material; and the nano-carbon comprises single-wall carbon nano-tubes, multi-wall carbon nano-tubes and other materials, and is mainly used for improving the heat-conducting performance, strength, toughness, wear resistance and other performances of the composite material. The wear-resistant composite material disclosed by the invention can keep a stable friction coefficient and a low wear rate under the conditions of a heavy load, a high speed, and long-time braking.

A method and a system for estimating a friction coefficient between a driven wheel and a surface. The method uses a Fourier series to calculate the friction coefficient. More specifically, a desired wheel slip ratio is calculated using received sensor readings related to a system state and a desired wheel speed determined from various system conditions or user inputs. A Fourier series is used to estimate the friction coefficient. The method is generally cycled many times each second to allow for varying road conditions by adjusting the Fourier series coefficients after each cycle. The system generally includes a wheel speed sensor and an accelerometer providing signals to a processor or various modules to perform the above method.