69results about How to "High contact fatigue strength" patented technology

The disclosed surface chemical thermal treatment technique for a high-C-Cr bearing comprises: setting parameters, front cleaning, pre-oxidizing, heating, carbonitriding, cooling to diffuse, quenching, and tempering. This invention uses the treatment device in vehicle and motor cycle gear process to form one layer with special tissue and improve contact fatigue strength and surface hardness.

The invention discloses an alloy steel for gears. The weight percentage of the chemical compositions is that: carbon of 0.16 to 0.19 percent; silicon of less than or equal to 0.12 percent; manganese of 0.50 to 0.60 percent; chromium of 1.75 to 1.90 percent; nickel of 1.75 to 1.90 percent; phosphorus of less than or equal to 0.020 percent; sulfur of less than or equal to 0.015; copper of less than or equal to 0.20 percent; aluminum of 0.015 to 0.040 percent; molybdenum of 0.15 to 0.35 percent; tin of less than or equal to 0.020 percent; [oxygen] of less than or equal to 0.002 percent; [nitrogen] of 0.006 to 0.018 percent; [hydrogen] of less than or equal to 0.00015; stibium of less than or equal to 0.008 percent; titanium of less than or equal to 0.01 percent; calcium of less than or equal to 0.0020 percent; and the remainder is iron. The preparation method comprises hydrogen diffusion annealing procedures. The invention is made a carbonization treatment for 16 hours under the same carbonization condition, so the invention has small internal oxidation inclination; the invention has high contact fatigue strength and bending fatigue strength, and is suitable for the gears with the modulus of more than 10.

There is provided an inexpensive rolling element used under high interface pressure such as induction hardened gears, the rolling element being improved in the seizure resistance of its tooth flanks and having a temper hardness of HRC 50 or more at 300° C. To this end, the rolling element is made from a steel material containing at least 0.45 to 1.5 wt % C and one or more alloy elements selected from 0.1 to 0.5 wt % V and 0.3 to 1.5 wt % Cr, and has a rolling contact surface layer having a structure tempered at low temperature in which 2 to 18% by volume cementite disperses in a martensite parent phase formed by induction heating and cooling and containing 0.25 to 0.8 wt % carbon solid-dissolving therein.

The invention discloses an isothermal forging method of a straight bevel gear. A blank and a mold are heated to roughly consistent temperatures respectively, then the blank is placed into the mold and is subjected to forging molding in the mold at the relatively low strain rate, and the straight bevel gear is obtained through aftertreatment, wherein the relatively low strain rate is lower than 0.1 mm/s, and the mold adopts a closed mold forging structure. According to the method, firstly, the blank and the mold are heated to the equal temperature or basically equal temperatures, so that the chilling effect produced when the temperature of the mold is lower than that of the blank is avoided, and the plastic flow of the blank is improved; secondly, the mold adopts the closed mold forging structure, the blank bears three-dimensional compressive stress in the forging process, and thus molding of the blank is facilitated; thirdly, the strain rate is lower than 0.1 mm/s, accordingly, the deformation amount of the blank in unit time is small, deformation is sufficient, and molding of the blank is more facilitated.

The invention relates to a compound reinforcement method for a gear surface. The compound reinforcement method comprises the following steps: firstly, the gear surface is subjected to shot blasting with steel shots with particle size being 0.6-1 mm; then molybdenum disulfide is mixed with particles with particle size being 0.05-0.1 mm, the mixture is used for performing shot blasting continuously on a gear, and the gear with compound reinforced surface is obtained. By means of the coupled effect of two processes including powerful shot blasting and molybdenum disulfide and particle mixed shot blasting, amplitude of tooth surface compressive stress deeper than the stress in single surface treatment process is obtained, and tooth surface hardness is improved substantially. Meanwhile, the lubricity of the gear surface is improved, the friction coefficient of the tooth surface is reduced, the lubricating capacity and the surface smoothness are improved, and gear meshing vibration noise is reduced. The effect of prolonging both the flexible life and contact fatigue life of the gear simultaneously is realized. The method adopts simple process and flexible conditions, can realize batch production and has good application prospect.

Steel for machine structure use for surface hardening containing, by mass %, C: 0.3 to 0.6%, Si: 0.02 to 2.0%, Mn: 1.5% to 3.0%, W: 0.0025 to 0.5%, Al: 0.001 to 0.5%, N: 0.003 to 0.02%, S: 0.0001 to 0.025%, P: 0.0001 to 0.03%, and O: 0.0001 to 0.0050%, having an Mn/S of 70 to 30000, and having a balance of substantially Fe and unavoidable impurities.

The invention discloses a coating material and coating with high contact fatigue strength based on a 304 stainless steel base material. The coating material comprises the following components in percentage by weight: 3-15% of Ni powder, 5-15% of Cr powder, 4-18% of Si powder, 20-40% of Mn powder, 0.1-2% of La2O3 powder, 0-3% of C powder, and the balance of reduced iron powder. The coating material is prepared through the following steps: mixing the powder, adding ball milling mediums and mixed powder into a ball milling pot for ball milling, and then performing vacuum drying and processing at 120 DEG C for 1 h so as to obtain the coating material. The coating is prepared through the following steps: grinding the surface of the 304 stainless steel base material level, paving the coating material on the surface of the 304 stainless steel base material, and performing fusion covering by using complete laser heat treatment equipment so as to obtain the coating with high contact fatigue strength. The coating material and the coating, disclosed by the invention, are higher in contact fatigue strength, simple in preparation technology, and low in building cost, and can be produced in batches.

A method of making a bearing includes providing a bearing intermediate, which is unfinished while having an overall shape of a finished bearing product; and repeatedly impacting a surface of the bearing intermediate at one or more ultrasonic frequencies to modify characteristics of the bearing intermediate. The resulting bearing intermediate or finished bearing product includes nano-size grains at or underneath the surface.

The invention discloses an alloy material for high wear-resistant cold rolls and a preparation method thereof. The alloy material comprises the following chemical elements in percentage by mass: 0.8-0.9% of carbon, 2.1-2.3% of tungsten, 1.2-1.5% of molybdenum, 2.2-2.4% of vanadium, 2.1-2.5% of chromium, 0.05-0.10% of niobium, 0.15-0.20% of lanthanum, 0.05-0.10% of neodymium, 0.4-0.6% of Mn, 0.03-0.05% of Co, not more than 0.030% of P, not more than 0.030% of S and the balance of ferrum. The alloy disclosed by the invention not only has high hardness and wear resistance, but also has good toughness and can resist cracking and stripping caused by bending stress, torsion stress and shearing stress, meanwhile, the alloy has high contact fatigue strength and high breaking tenacity and thermal shock strength, thereby being suitable for making cold rolls. The refining agent disclosed by the invention is applied to casting production, the porosity in a casting is reduced by 1-2 degrees, and oxide inclusions are reduced by about 2 grades.

The invention relates to a steel ball special for a large-sized offshore wind turbine generator bearing and a manufacturing process of the steel ball. The roundness of the steel ball is less than or equal to 0.8 mum, the hardness is 59-64 HRC, the single-grain hardness grain difference is less than or equal to 0.8 HRC, the batch hardness difference is less than or equal to 1.2 HRC, the core hardness is 54-60 HRC, the retained austenite is 8-13 percent, the metallographic structure is 2-3 grade, the surface roughness is less than or equal to 0.8 mum, and the crush load and the compression ratio of the steel ball are 1.2 times greater than international crush load and compression ratio. By selecting raw materials, adopting hot extrusion continuous forming during ball billet forming, adopting a water soluble quenching agent to perform multi-stage quenching during thermal treatment, increasing a secondary stable tempering technology, increasing various technologies such as eddy current nondestructive flaw detection in a process flow, the steel ball has the characteristics of good high contact fatigue strength, high wear resistance, high elastic limit, proper hardness, high impact toughness, good dimensional stability and the like.

The invention provides a thermal treatment method for reducing secondary gear ring nitrogenized deformation. The method comprises the following steps: (a) tempering after a secondary gear ring is roughly processed; (b) tempering; (c) processing by a gear milling machine, and destressing at high temperature; (d) processing by a gear grinding machine, and performing gas nitrogenization, wherein the gas nitrogenization comprises the following steps: uniformly fixing and supporting a plurality of cylindrical clamps in a gear ring groove; flushing a gear ring in a bell type gas nitrogenation oven, heating, and introducing 8-12m<3>/h nitrogen for 3-5 hours; heating to 400-500 DEG C, introducing 4-8m<3>/h ammonia, and insulating for 0.2-0.8 hours; heating to 500-550 DEG C, controlling the flow rate of ammonia to be 10-15m<3>, and penetrating for 60-65 hours, wherein Kn is 6; turning to diffuse, controlling the flow rate of ammonia at 4-6m<3>/h, and diffusing for 30-32 hours, wherein Kn is 2; cooling along with the oven, introducing 8-12m<3>/h nitrogen while cooling; moving the heating mantle when the temperature is reduced to 400-500 DEG C; discharging parts from the oven when the temperature is reduced to lower than 90 DEG C. The thermal treatment method has the characteristics that the deformation is small, a high-hardness high-wearing nitride layer can be obtained on the surface, the contact fatigue strength can be improved, the drawing performance and accurate requirement can be fulfilled, the product quality can be improved, and the like.

The invention discloses a long-service-life high-temperature-resistant textile motor bearing, and belongs to the technical field of high-precision special bearing manufacturing. The long-service-lifehigh-temperature-resistant textile motor bearing is improved in the four aspects of technical design, manufacturing process, bearing lubricating grease selection and bearing manufacturing material, the service life of the improved bearing can be obviously prolonged, and the improved bearing is wear-resistant and high-temperature-resistant. According to the long-service-life high-temperature-resistant textile motor bearing, the working clearance Gr of the bearing is scientifically designed; the mounting clearance and the change clearance of inner and outer rings caused by temperature change areconsidered; and the problems that when the maximum rolling body load of a bearing raceway bearing region is increased during working operation, friction torque and temperature rise are increased dueto clearance change caused by elastic deformation and the bearing adhesion or damage due to fatigue occur too early are mainly solved, so that the service life of the bearing is greatly prolonged.

The invention discloses a helical gear with a Fibonacci helix tooth form. The tooth form of an end face of the helical gear from a root circle to an addendum circle is the Fibonacci helix tooth form, namely a section with a pressure angle a=17-28 degrees is the Fibonacci helix. Compared with an involute tooth form with the identical pitch diameter, the Fibonacci helix tooth form has large radius of curvature, so that contact stress can be reduced effectively, contact fatigue strength of the gear is improved, the service life of the gear is prolonged, and gear load-bearing capacity is improved. Compared with an involute tooth form with the identical radius of curvature, the pitch radius of the Fibonacci helix tooth form is smaller, so that the gear size is small, the weight is small, the rotational inertia is small when the gear rotates at high speed, the noise is low, operation is stable, and the high-speed requirement of the gear can be well met. According to the Fibonacci helix tooth form, the tooth width is limited, overlapping ratio of the Fibonacci helix tooth form can be improved, and continuous meshing conditions of the gear are guaranteed. Meanwhile, meshing contact area is increased, and gear load-bearing capacity is improved.

A rolling element for a continuously variable transmission, including a plurality of rolling members having rolling contact portions that come into rolling contact with each other via lubricating oil. At least one of the rolling contact portions includes an outer surface layer having a surface microhardness of not less than Hv 750, a surface residual compressive stress of not less than 1000 MPa and a residual austenite content of not more than 10% by volume.

The invention discloses a mining dispatch winder. The mining dispatch winder comprises a motor, a winding drum, a transmission device, a clutch, a brake and a machine base; the transmission device is a flow dividing type closed planetary transmission system and is composed of a differential stage and a closed stage, and the differential stage and the closed stage are arranged at the two ends of the winding drum respectively, so that the radiating condition is good, assembling is convenient, limitation to the modulus and the diameter of a gear is smaller, and the tooth root bending fatigue strength and the gear face contact fatigue strength are improved; the flow dividing type closed planetary transmission system is adopted, so that the transmission ratio and the winding drum output torque are improved; the clutch is a radial lever type multi-friction-plate clutch and is installed on a high-speed shaft, and the overload protection function is achieved.

The invention relates to a high-pressure blower, and belongs to the technical field of blower equipment. The high-pressure blower comprises a wind barrel and a motor, wherein the output shaft of the motor extends into the wind barrel, a wind blade is fixedly connected to the extending-in end of the output shaft, a circular bearing cover plate is fixedly connected to the outer side surface of the wind barrel on one side facing to the motor, a through hole is formed in the position of the center of a circle of the bearing cover plate, a bearing seat is arranged on the side surface of the bearing cover plate on one side facing to the motor and is arranged around the through hole, and a bearing is fixedly connected to the inner part of the bearing seat. The bearing cover plate and the bearing respectively consist of the following components by weight percent: 0.12 to 0.15% of C, 0.25 to 0.30% of Si, 0.50 to 0.80% of Mn, 0.50 to 0.80% Cr, 0.05 to 0.10% of Mo, less than or equal to 0.20% of Cu, less than or equal to 0.10% of Ni, less than or equal to 0.025% of S, less than or equal to 0.025% of P, and the balance of Fe. The high-pressure blower has the advantages of rational design and long service life.

A ring for a connection element includes a contact portion intended to cooperate with a contact surface of another ring and a fastening portion intended to be secured to a support. The contact portion is made of a first metallic material and the fastening portion is made of a second metallic material, the hardness of the first material being substantially greater than that of the second material, and the toughness of the second material being substantially greater than that of the first material, the contact portion and the fastening portion being of one piece construction.