152results about How to "Any bend" patented technology

The invention discloses a flexible MEMS resistance-reducing skin and a manufacturing method thereof used for reducing skin friction resistance during the advancing of on-water or underwater vehicles, which employs micro-fine resident bubbles to reduce resistance and belongs to the fields of micro-machinery and fluid dynamics. The upper surface of the skin is a surface layer coated with micro-pit arrays and processed by surface soakage; electrolytic anodes and cathodes of comb-shaped micro-fine planar metal, which are attached on an insulating layer, are arranged at the bottom of the micro-pits; a flexible substrate is positioned below the insulating layer; wire leading terminals for electrodes are arranged on the lower surface of the skin; and both the surface layer and the substrate are made by flexible materials. The overall thickness of the resistance reducing skin is at sub-millimeter level, and the skin is in the status of flexible film. The manufacturing method is an MEMS micro machining technique compatible with the flexible MEMS technology. The flexible MEMS resistance-reducing skin is coated on the outer surfaces of the on-water or underwater vehicles, with power thereof supplied by the on-water or under-water vehicles. Micro-bubbles stably residing in the micro-pits are formed by water electrolysis reaction to coat most parts of the surfaces of the on-water or under-water vehicles, thus realizing the function of reducing skin friction resistance.

The invention belongs to the field of electrode manufacturing technologies and particularly relates to an elastic conductive fiber manufacturing method. The elastic conductive fiber manufacturing method comprises utilizing two motors and a translation stage, fixing two ends of an elastic fiber onto the two motors, and fixing a spinnable carbon nanotube array on the translation stage; pulling out a carbon nanotube thin film from the array and putting the carbon nanotube thin film on the elastic fiber at a preset angle; starting the two motors synchronously to enable the elastic fiber with two ends fixed onto the two motors to rotate along the two motors, continuously winding the continuous carbon nanotube thin film onto the elastic fiber at a preset angle, namely, a helical angle, and enabling the helical angle of the elastic fiber to remain unchanged by setting the movement speed of the translation stage; continuously performing the above process to manufacture and obtain an elastic conductive fiber. The resistance of the elastic conductive fiber can basically remain unchanged under the condition that the stretch rate is 100%. The elastic conductive fiber provides novel materials for manufacturing elastic leaner electronic devices.

The invention discloses an ultra-light flexible crystalline silicon solar cell module and a preparation method thereof. The ultra-light flexible crystalline silicon solar cell module comprises a front film, a solar cell, a support material, packaging adhesives and a rear film, wherein the front film, the packaging adhesive, the solar cell, the packaging adhesive, the support material and the rear film are sequentially arranged and are molded in a vacuum hot-pressing manner. The preparation method comprises the following steps: sequentially laminating the front film, the packaging adhesive, the solar cell, the packaging adhesive, the support material and the rear film from top to bottom; and carrying out a solidification under the vacuum conditions that the temperature is 100-150 DEG C and the pressure is 15Kpa to 30Kpa for 30-60 minutes, so as to obtain the ultra-light flexible crystalline silicon solar cell module. The ultra-light flexible crystalline silicon solar cell module disclosed by the invention has the advantages of high generating efficiency, flexibility, light weight and the like; the preparation method disclosed by the invention is integral molding; and the process is simple.

The invention belongs to the technical field of surface electroplating, and particularly relates to an electroplating brush device. The electroplating brush device comprises a brush application tank,a workpiece fixing device, a brush application device, a drive device, a brush application liquid conveying device and an infrared distance measuring sensor. A controller is used for automatically controlling the workpiece fixing device, the brush application device, the drive device, the brush application liquid conveying device and the infrared distance measuring sensor. A cam is arranged in a center hole of a friction wheel, an extrusion plate is arranged in a sliding groove of the friction wheel in a sliding manner, two air bags are symmetrically arranged on the left side and the right side below the friction wheel, the lower ends of the air bags are connected with second one-way valves, the second one-way valves communicate with water spraying discs, the water spraying discs are fixedly connected to the middle portions of hair bundles, electroplating liquid is evenly sprayed to the upper ends of the hair bundles, and accordingly the uniformity of a workpiece surface clad layer isguaranteed; and when the friction wheel drives the extrusion plate to the upper half part of the cam, the extrusion plate contracts into the friction wheel under the action of elasticity of springs, and accordingly contact between the friction wheel and the workpiece surface cannot be influenced.

The invention discloses a device and a method for detecting dynamic light scattering multi-angle adjustable fiber-optic probe and belongs to the field of the dynamic light scattering nanoparticle detection devices. Two lens angle adjustment mechanisms capable of adjusting the inclination angles of lenses are fixedly arranged on an outer cylinder (1); the inner sides of the two lens angle adjustment mechanisms are fixedly connected with a transmitting lens (9) and a receiving lens (7) by penetrating through the outer cylinder (1), respectively; the two lenses are driven to tilt by a drift angle with a horizontal axis by virtue of the movement of the inner sides of the two lens angle adjustment mechanisms, respectively, and therefore, the inclination angles of the two lenses can be adjusted, respectively. According to the device and the method for detecting dynamic light scattering multi-angle adjustable fiber-optic probe, the lens angle adjustment mechanisms are arranged on one sides of two groups of lenses, respectively, and the mounting angles of the two groups of lenses can be independently adjusted by use of two groups of unassociated lens angle adjustment mechanisms, respectively, and therefore, the angle adjustment range between the two groups of lenses is expanded and the purpose of flexibly adjusting the detection angle of the fiber-optic probe in multiple angles is achieved.

The invention discloses a gas turbine combustion state parameter monitoring system based on a TDLAS technology. The gas turbine combustion state parameter monitoring system comprises a laser emissionmodule, a laser transmission module, a laser data analysis processing module and a combustion state display module which are sequentially connected. During working, required incident laser is generated through the laser emission module; the incident laser and the laser absorbed by the flow field of a combustion chamber are transmitted through a laser transmission module, and a laser signal is converted into an electric signal; effective electric signals are extracted through a laser data analyzing and processing module, flow field temperature, pressure and H2O concentration are inverted, pressure pulsation characteristics are analyzed, combustion efficiency is calculated, and whether flames exist or not is judged; the combustion flow field temperature, the pressure pulsation characteristics, the flame, the combustion efficiency and the like are displayed through a combustion state parameter display module. The combustion state parameters of the gas turbine are measured by adopting a non-contact method, the method has the advantages of no interference to the flow field, wide measurement range, high precision, quick response, simple system composition and the like, and the combustionstate monitoring system of the in-service gas turbine can be simplified.

The invention discloses an ultra-soft and flexible solar cell array and a manufacturing method thereof. The ultra-soft and flexible solar cell array includes flexible solar cell monomers, and a high-transmittance transparent encapsulation layer coated on the surface of the flexible thin-film solar cell monomers is located at the The substrate layer, the reinforcement layer and the heat insulation layer under the flexible thin film solar cell unit are connected through an adhesive layer. The present invention also relates to a manufacturing method of an ultra-light and flexible solar battery array, which is composed of the above-mentioned layers by rolling or coating in order from top to bottom, and then tied and fixed with a hanging rope and a gripper on the surface of the carrier . The ultra-light and flexible solar battery array of the present invention is very thin, small in size, light in weight, easy to manufacture, reliable and durable, saves material and energy in the production process, and can be bent arbitrarily according to the shape of the installation surface, and is suitable for mobile power generation applications.

The invention discloses a polyimide film. The glass transition temperature is 360 to 380 DEG C, the tensile strength is 200 to 220 MPa, and the average linear expansion coefficient within the range of50 to 300 DEG C is 18 to 20 ppm / K; the chemical component of the polyimide film is polyimide, and the structural formula of the polyimide is as shown in the following formula I (the formula I is as shown in the description), wherein n and m represent the polymerization degree of the polymer, m to n is 3-1 to 17-3, and n is an arbitrary positive integer. The polyimide has excellent film-forming characteristic, the polyimide film has superhigh heat resistance and mechanical strength, particularly the polyimide film has the average linear expansion coefficient nearly close to that of a copper foil within a certain high temperature range.

The invention provides a forming method for a flexible liquid crystal cell for a liquid crystal display, which includes the steps: fabricating ITO (indium-tin oxide) patterns, arranging PS (photoresist spacer) supporting columns, coating PI (polyimide) films, forming the cell, cutting, injecting, sealing, performing visual inspection or / and electrical inspection, and the like. The forming method for the flexible liquid crystal cell for the liquid crystal display utilizes the lower PS supporting columns to replace resin powder balls in an original liquid crystal cell, so that the cell thickness is supported. When the cell thickness is small, the PS supporting columns are sufficiently and fixedly adhered with the surface of a substrate and cannot be separated from the substrate to vibrate, so that noise of the liquid crystal screen is avoided.

The present disclosure relates to a self-heated battery based on a carbon nanotube film and a method for fabricating the same. The self-heated battery comprises a battery case, an electrode sheet group disposed in the battery case, and a flexible carbon nanotube film. The flexible carbon nanotube film and the electrode sheet group are separated by a first diaphragm. The electrode sheet group includes a positive electrode sheet, a negative electrode sheet, a second diaphragm, and an electrolyte. The second diaphragm separates the positive electrode sheet from the negative electrode sheet. The electrolyte fills a space among the positive electrode sheet, the negative electrode sheet and the second diaphragm. The positive electrode sheet is provided with a positive electrode tab. The negativeelectrode sheet is provided with a negative electrode tab. The flexible carbon nanotube film is provided with a first tab connected to the positive electrode tab and a second tab connected to the negative electrode tab. The self-heated battery provided by the present disclosure has a fast heating rate and high heating efficiency, and is safe and reliable.

The invention provides a liquid crystal box of a flexible liquid crystal display, which comprises an upper flexible conducting base material, a lower flexible conducting base material, a lower PS (poly styrene) support column, an upper PI (polyimide) film, a lower PI film, liquid crystal and border adhesive. The upper flexible conducting base material comprises an upper polarizer, an upper silicon dioxide layer and an upper ITO (indium tin oxide) film which are arranged in sequence; the lower flexible conducting base material comprises a lower polarizer, a lower silicon dioxide layer and a lower ITO film which are arranged in sequence; the upper flexible conducting base material, the lower flexible conducting base material and the border adhesive are adhered and sealed to form a closed cavity; the liquid crystal is filled in the closed cavity; the lower PS support column and the liquid crystal are arranged between the upper flexible conducting base material and the lower flexible conducting base material; the lower PS support column is connected with the lower flexible conducting base material; the lower PI film is covered on the lower PS support column and the lower flexible conducting base material; and the upper PI film is covered on the upper flexible conducting base material.

The invention discloses a heat conduction fiber-based tank infrared stealth system comprising a heat source, heat conduction fibers, a thermoelectric generation module, a power source, a control module and a cooling module, wherein a plurality of heat conduction fibers are connected with heat sources arranged at different positions in a manner that one end of each heat conduction fiber is connected with one heat source, the other end of each heat conduction fiber is connected with a heat-absorbing face of the thermoelectric generation module, a heat dissipation device is arranged on a cooling end of the thermoelectric generation module, and an electric fan is arranged on a side of the heat dissipation device; a speed regulator is connected with the power source, an industrial control computer and the electric fan; a temperature sensor is connected with the industrial control computer, a relay device is connected with the industrial control computer and the thermoelectric generation module. According to the heat conduction fiber-based tank infrared stealth system, heat of heat sources arranged at different parts of a tank can be conducted to the thermoelectric generation module via the heat conduction fibers, compulsory convection and heat radiation can be realized via the electric fan, and centralized management of heat sources can be realized via the control module; problems that centralized heat management is difficult to realize due to wide distribution of different heat sources, that afterheat cannot be used effectively, and that the temperature of different parts of the tank cannot be detected in real time and other problems can be addressed.

The invention discloses an environment-friendly composite functional flexible fireproof cable. The cable comprises conductor cores, refractory layers, insulating layers, a waterproof layer, a fireproof inner protecting layer and a fireproof outer protecting layer which are sequentially arranged from the inside out, wherein each conductor core is formed by twisting a plurality of soft round copper wires with the same diameter in a layered manner; each refractory layer is processed by a synthetic mineral fireproof composite belt; each insulating layer is made from a 150-DEG C irradiate cross-linked polyolefin halogen-free insulating material; the waterproof layer is made from a heat-proof halogen-free low-smoke high-flame-retardancy material; the fireproof inner protecting layer is processed by a high-temperature resistant high-strength carbon fiber composite belt; and the fireproof outer protecting layer is made from an environment-friendly high-flame-retardancy low-smoke halogen-free polyolefin material. The environment-friendly composite functional flexible fireproof cable is an updated product of a traditional fireproof cable, has the favorable properties of fire resistance, low-temperature resistance, corrosion resistance, large current capacity, high mechanical strength, small size, light weight, long service life, sound grounding performance, good water resistance and the like, and is particularly suitable for occasions which are in strong radiation environments and demand smaller bending radii and high soft strength.

The invention discloses a spiral plate type filter system and method. The filter system comprises a spiral plate filter core, a check valve, a filter shell, a controller, a pure water electromagnetic valve, an unfiltered water electromagnetic valve, a sewage disposal electromagnetic valve, a backwash electromagnetic valve and an air pump; the controller is connected with the pure water electromagnetic valve, the unfiltered water electromagnetic valve, the sewage disposal electromagnetic valve, the backwash electromagnetic valve and the air pump; the unfiltered water electromagnetic valve and the backwash electromagnetic valve are connected with the air pump. According to the spiral plate type filter system and method, the material roles that a metal film filter can be conveniently welded and randomly bent and is high in filter precision are fully played; the filter system is simple in processing technology, capable of easily achieving automatic process production, high in processing efficiency and low in processing cost; the filter is high in strength, suitable for being used in a large-differential-pressure or high-temperature environment, high in unit volume filter efficiency and large in filter amount, and only accounts for one fifth of the size of a common multi-pipe filter for achieving the same filter amount.

The invention relate to the technical field of soft substrate coating grinding devices, in particular to a soft substrate coating grinding device. The soft substrate coating grinding device comprisesa primer layer, material grinding blocks are connected to the upper end of the primer layer at equal distances, a material grinding bulge is connected to an inner cavity of each material grinding block through an adhesion agent in a cemented mode, a TPU soft film substrate is connected to the lower end of the primer layer, and a sponge layer is connected to one end, away from the primer layer, ofthe TPU soft film substrate through a first hot melt glue layer in a cemented mode, and a magic paster is connected to one end, away from the first hot melt glue layer, of the sponge layer through a second hot melt glue layer in a cemented mode. The soft substrate coating grinding device is extremely good in water resisting property, sand dropping and falling-off phenomena do not happen in the life cycle of a product, the TPU coating film of a stereo structure further has an excellent chip removal property and a long service life, the coated product is used for polishing a middle frame of a mobile phone, the obtained product has a long service life and a refined grinding effect, is good in compliance and excellent in abrasion resistance, and a good grinded face can be obtained.

The invention discloses a flexible self-support negative electrode material with a carbon fiber-loaded lithium titanate nanosheet and a preparation method of the flexible self-support negative electrode material. The method comprises the following specific steps of dissolving butyl titanate or titanium isopropylate, lithium hydroxide and hydrogen peroxide into deionized water and then transferring the mixture to a polytetrafluoroethylene container; putting burnt and degummed carbon fiber cloth into the polytetrafluoroethylene container and reacting at 140-160 DEG C in a closed environment for 4-8 hours; taking out the carbon fiber cloth, washing the carbon fiber cloth by using the deionized water, drying the carbon fiber cloth; and carrying out thermal treatment at 500-700 DEG C under inert gas protection or a vacuum condition for 3-5 hours. The invention further provides a battery of using the flexible self-support negative electrode material. According to the flexible self-support negative electrode material, a metal current collector, a conductive additive and a binder used in a conventional preparation process of a negative electrode of a lithium-ion battery do not need to be used, and the operation is simple; the flexible self-support negative electrode material has good conductivity and ionic conductivity, and relatively high battery specific capacity and rate capability; and meanwhile, the flexible self-support negative electrode material can be arbitrarily bended, folded and stretched.

The invention discloses a method for preparing a dielectric layer based on anisotropic wet etching. The method comprises the steps of etching pyramid microstructures which are randomly distributed andhave different sizes on a silicon wafer by using an anisotropic wet etching principle of silicon, and taking the pyramid microstructures as a template to manufacture the dielectric layer with ridge-shaped microstructures which are randomly distributed in a staggered manner. The method is simple in preparation process, low in cost and suitable for batch production. A flexible capacitive sensor prepared by applying the dielectric layer has extremely high sensitivity and relatively high flexibility and can be bent randomly, the sensitivity is 145.5 kPa<-1> under the pressure intensity of 44 Pa,and when the pressure intensity is 30 kPa, the sensitivity is still 32.2 kPa<-1>. The flexibility of the sensor is shown as follows: when the sensor is bent by 180 degrees, the sensor can still work normally.

The invention relates to a flexible two-dimensional material light emitting device. The flexible two-dimensional material light emitting device sequentially comprises a flexible substrate layer (1), a first metal layer, a medium layer (4), a two-dimensional semiconductor material layer (5) and a second metal layer which is arranged on the medium layer (4) and at two ends of the two-dimensional semiconductor material layer (5). Compared with the prior art, the flexible two-dimensional material light emitting device has advantages of good portability, fast photoelectric response speed, high integration density, good processing performance and low cost.

The invention discloses nitrogen-doped carbon flexible paper and a preparing method and application thereof. Melamine foam is subjected to low-temperature thermal oxidation in the air and then to high-temperature thermal treatment in the presence of inert gases under the action of mechanical pressure, so that the nitrogen-doped carbon flexible paper is obtained. Low-temperature thermal treatment is conducted on the melamine foam firstly to introduce a small number of oxygen-containing functional groups into the melamine foam, so that cyclization of the melamine foam is promoted during high-temperature thermal treatment, the nitrogen-doped carbon paper can have high buckling flexibility, the thickness, density and conductivity of the nitrogen-doped carbon flexible paper are regulated within the flexibility range, flexibility is high, and large-scale production can be achieved easily. The prepared flexible paper has connected carbon network structures, has high buckling flexibility, and can be bent freely. The flexible paper has high oxygen reduction catalytic performance. The prepared nitrogen-doped carbon flexible paper can be used as a self-supporting flexible electrode material of a flexible electric device.

The invention provides a universal joint for a submarine optical cable connector box relating to a connecting device for protecting optical cable conductors. The universal joint for a submarine optical cable connector box comprises a joint, a lining and a connecting sleeve, wherein the joint is provided with a ball joint; the lining is sleeved on the ball joint of the joint; and the connecting sleeve is sleeved on the lining. By the transition of the lining, the joint and the connecting sleeve can rotate optionally along a central axis, and the optical cable is not pulled by the generation of excessive bending. The universal joint for a submarine optical cable connector box is reasonably designed and simply structured; and the optical cables in the universal joint can be curved optionally without being bended and pulled. The structure is more suitable for the connection of rigid parts in the optical cable joint and the bending restrictor. The structure of the universal joint for a connector box provided by the invention is simple, the bending performance is good, and a whole length component of the original connector box is divided into three parts which are a bending restrictor part, a connector box steel straight part and a bending restrictor part at another end, so that the construction and maintenance are convenient.

The invention discloses a single-layer transition metal disulfide flexible photodetector preparation method. The method comprises the steps that first, transition metal oxides and sublimated sulfur are used as raw materials to prepare a single-layer thin film through a chemical vapor deposition method; then a vacuum plating method is used to pattern a metal electrode on a PDMS-1 flexible substratewith a copper mesh as a hard mask; and finally, a single-layer transition metal disulfide film is transferred from a growth substrate to the flexible substrate. During the process, a single-layer transition metal disulfide is first transferred to a PMMA film, and then the side, which is adhered with the single-layer transition metal disulfide film, of the PMMA is attached to PDMS-2. After the PMMA film is dissolved, the PDMS-2 is used as a support layer, and a positioning transfer method is used to transfer the single-layer transition metal disulfide film to the flexible substrate PDMS-1. Thephotodetector provided by the invention exhibits good photosensitivity characteristics, and broadens the application field of single-layer transition metal disulfide photodetectors in flexible electronic equipment.

The invention provides coating liquid for heating incombustible tobacco product cigarette paper and a preparation method and application of the coating liquid. The coating liquid is prepared from thestep that tobacco extracting concentrated solution, expanded graphite particles, a dispersing agent and tobacco flavor are evenly mixed and subjected to ultrasonic dispersion for 7-15 minutes. The expanded graphite particles are prepared from the steps that expanded graphite particles with the particle diameters of 5-15[mu]m are placed in an atomizing agent solution, fully stirred under a negativepressure condition and absorb the atomizing agent solution, and drying at a low temperature of 70-100 DEG C is carried out. The tobacco extracting concentrated solution is prepared from the step thata tobacco extracting concentrated solution is subjected to vacuum concentration to the relative concentration of 1.21-1.28g / cm<3>. One surface of cigarette paper substrate paper is coated with the coating liquid evenly and subjected to drying slicing under the condition of 50-65 DEG C to obtain the cigarette paper, the cigarette paper can resist high temperature (about 300 DEG C), and the smoke releasing quantity during smoking can be improved.

The invention relates to the technical field of microelectronics, in particular to a flexible photoelectric detector based on layered transition metal sulfide and a preparation method thereof. The photoelectric detector is formed by sequentially stacking a flexible substrate, a transition metal sulfide film and a metal electrode from bottom to top. The preparation method comprises the following steps: the transition metal sulfide is prepared by a hydrothermal method or a physical vapor deposition method which is low in cost and can be produced on a large scale. A dispersing agent and a thickening agent are added to the transition metal sulfide; the material is dispersed by adopting a ball-milling method to form a transition metal sulfide dispersion liquid; a layer of transition metal sulfide nano-film is formed on a flexible substrate by adopting a spin-coating method; and finally, a metal electrode is prepared by adopting a vacuum coating method by taking a copper net as a hard mask plate. The flexible photoelectric detector is simple in preparation process, high in yield, low in cost and good in flexibility.

The invention discloses a compression-resistant, tensile and anti-interference polyvinyl chloride insulated thin steel wire armored control cable which comprises a cable core. The cable core is formedby twisting an insulated wire core and a control cable in a pair mode. The gap position of the cable core is filled with an elastic plastic body, the cable core is externally wrapped with a first ultrathin steel wire armored layer, the first ultrathin steel wire armored layer is externally provided with an inner sheath, an oxygen isolation layer is arranged outside the inner sheath, the oxygen isolation layer is externally wrapped with a second ultrathin steel wire armored layer, and finally the cable is externally provided with a metal ceramic lining composite tube. The compression-resistant, tensile and anti-interference polyvinyl chloride insulated thin steel wire armored control cable has the advantages of very high tensile strength, good flame retardancy performance, good safety performance, good shielding property, good interference resistance, long service life and the like.

The embodiment of the invention provides a steam compression type circulating system for driving a compressor to achieve waste heat defrosting through a pulsating heat pipe. The system comprises the compressor 101, a condenser 102, a throttle valve 103 and an evaporator 104. The compressor 101 is connected with the condenser 102, the condenser 102 is connected with the throttle valve 103, the throttle valve 103 is connected with the evaporator 104, and the evaporator 104 is connected with the compressor 101. The system further comprises the pulsating heat pipe 105, the evaporation section 105-3 of the pulsating heat pipe is wound around the surface of the compressor 101 and an outlet pipeline of the compressor 101, the condensation section 105-1 of the pulsating heat pipe 105 is wound around the surface of the evaporator 104, and a middle connecting pipeline of the evaporation section and the condensation section of the pulsating heat pipe 105 is a heat insulating section 105-2 of thepulsating heat pipe. The surface of the evaporator is defrosted through waste heat of the compressor, the heat exchange efficiency of the evaporator is improved, thus, the performance of the steam compression type circulating system is improved, the compressor temperature and the condensation temperature can be effectively reduced in the defrosting process, wasted work of the compressor is reduced, lubricating oil is protected, and it is guaranteed that the system can efficiently run in the defrosting process.

The invention belongs to the technical field of metal surface repair, in particular to a metal shell surface repair process. A surface film plating device in the process comprises a brushing tank, a workpiece fixing device, a brushing device, a driving device, a brushing liquid conveying device and an infrared distance measuring sensor; the workpiece fixing device, the brushing device, the drivingdevice, the brushing liquid conveying device and the infrared distance measuring sensor are automatically controlled through a controller; a cam is arranged in a center hole of a friction wheel; an extrusion plate is slidingly mounted in a chute of the friction wheel; two airbags are symmetrically arranged on the left and right sides under the friction wheel; the lower ends of the airbags communicate through a second one-way valve water spraying disc to realize uniform spraying of electroplating liquid to the upper ends of pieces so as to guarantee the surface plating layer uniformity of workpieces; and when the friction wheel drives the extrusion plate to rotate to the upper half part of the cam, the extrusion plate shrinks into the friction wheel under the effect of elastic force of a spring without influencing the contact of the friction wheel and the surfaces of the workpieces.