66results about How to "High bending fatigue strength" patented technology

The invention belongs to the alloy steel field, particularly relating to steel for a fine grain carburization gear and a preparation method thereof. The steel comprises the following chemical compositions in weight percentage: 0.15 to 0.25 percent of C, less than or equal to 0.35 percent of Si, 0.60 to 0.90 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.010 percent of S, 0.80 to 1.20 percent of Cr, 0.15 to 0.35 percent of Mo, 0.02 to 0.08 percent of Nb, 0.0005 to 0.0035 percent of B, 0.02 to 0.06 percent of Al, 0.01 to 0.04 percent of Ti, less than or equal to 0.015 percent of [N], less than or equal to 0.0015 percent of [O], the balance being Fe and inevitable impurities. Meanwhile, Ti is more than or equal to 2[N] and B is more than or equal to ([N] minus Ti / 3.4) / 1.4 plus 0.001; and the rolling production process with the finish-to-gage temperature below 900 DEG C is adopted. Compared with the prior carburization gear steel 20CrMoH, the grain size of the steel after carburizing and quenching exceeds ten grade, the bending fatigue resistance(sigama-1) is improved by more than 15 percent and the contact fatigue life(L10) is improved by more than 30 percent.

Disclosed is a mixed powder for powder metallurgy which is obtained by diffusing and adhering 0.05-1.0 mass% of Mo over the surface of an iron base powder which contains, as a prealloy, not more than 0.5 mass% of Mn and 0.2-1.5 mass% of Mo, thereby forming an alloy steel powder, and then blending 0.2-5 mass% of an Ni powder and / or 0.2-3 mass% of a Cu powder into the thus-formed alloy steel powder. A dense sintered body having excellent tensile strength and bending fatigue strength can be produced from such a mixed powder.

The invention relates to the field of laser processing, and in particular relates to a method for reinforcement of metal surfaces by large area laser shock. The invention adopts laser shock reinforcement for interval shocks on the surface of a workpiece according to a certain trajectory, and large area lap connection shock on the workpiece can be achieved by multilayer stacking. The method can effectively reduce the residual tensile stress generated in the shock region boundary during the laser shock reinforcement, meanwhile avoids the absorption layer destruction and workpiece warpage, and can obtain a uniformly distributed shock reinforcement effect.

The invention discloses a powder metallurgy manufacturing method for a valve flap of a check valve. The powder metallurgy manufacturing method comprises the following steps of: a, selecting the following powder raw materials in percentage by weight to form the valve flap through powder metallurgy one-time pressing: balance of iron-base powder, 0.7 percent of carbon, 0.9 percent of molybdenum, 1.1 percent of aluminum, 0.9 percent of magnesium, 0.3 percent of tree ash and 0.8 percent of zinc stearate; and b, placing the valve flap product obtained by sintering and forming into engine oil of No. 20-30 to soak for 2-3 hours, and performing water atomization steam treatment at the temperature of 550-650 DEG C for 3-5 hours. The valve flap is a powder metallurgy material which is mainly made of alloy steel powder and has the characteristics of capabilities of improving the strength, the corrosion resistance and the wear resistance of metal components and reducing the manufacturing cost.

The invention discloses an asymmetric involute worm and bevel gear pair. The asymmetric involute worm and bevel gear pair comprises a worm and a bevel gear, the two sides of gear teeth of the worm are provided with a worm mesh side tooth profile and a worm non-mesh side tooth profile respectively, and the two sides of gear teeth of the bevel gear are provided with a bevel gear mesh side tooth profile and a bevel gear non-mesh side tooth profile respectively, wherein the axial modulus of the worm is m1, the end face modulus of the bevel gear is m2, the pressure angle of the worm mesh side tooth profile is alpha1, the pressure angle of the worm non-mesh side tooth profile is alpha2, the pressure angle of the bevel gear mesh side tooth profile is alpha3, the pressure angle of the bevel gear non-mesh side tooth profile is alpha4, and the following conditions are met: a, alpha1>alpha2, and alpha3>alpha4; b, when m1=m2, alpha1=alpha3, and alpha2=alpha4; when m1 is not equal to m2, m1cosalpha1=m2cosalpha3, and m1cosaplha2= m2cosalpha4. According to the asymmetric involute worm and bevel gear pair, tooth root fracture of the bevel gear can be effectively avoided, and the shock resistance and the bearing capacity of the asymmetric involute worm and bevel gear pair in transmission are improved.

The invention concerns a sintered metal part which has a densified surface and sintered density of at least 7.35 g / cm3 and a core structure distinguished by a pore structure obtained by single pressing to at least 7.35 g / cm3 and single sintering of a mixture of a coarse iron or iron-based powder and optional additives.

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.

The invention discloses a thermal treatment method of a spline shaft head of a transmission shaft. The method is characterized by sequentially comprising a normalizing process and a medium-frequency induction quenching process, wherein the normalizing process sequentially comprises two steps of: (I) heating the spline shaft head by a push disc-type heating furnace, wherein the heating temperature is 850+ / -10 DEG C, and the heating time is 120 minutes; and (II) performing air cooling for 2-3 hours; the medium-frequency induction quenching process comprises two steps of: (I) quenching, wherein the surface quenching area of the spline shaft head comprises a spline part and a full-oil seal table part, and the depth of the hardening layer is 4-6mm; and (II) low-temperature tempering. Compared with the same kind of hardening and tempering and medium-frequency induction quenching technology (needing tempering at a high temperature of 680+ / -10 DEG C for 150 minutes), the method disclosed by the invention greatly saves resources on the premise of guaranteeing the static torsional strength and fatigue life of the spline shaft head, reduces the production cost, has positive social significance of low carbon and environmental protection, and remarkably improves the product competitiveness.

The invention discloses a compressor 38CrMoAl steel treatment technology, and relates to a 38CrMoAl steel treatment hardening and tempering and surface hardening heat treatment technology. The problems of shallowness, low hardness, poor wear and acid-salt corrosion resistance and low hardening and tempering treatment mechanical performances of a hardened layer generated through traditional surface heat treatment of 38CrMoAl steel are solved in the invention. The heat treatment technology comprises the steps of 38CrMoAl steel forging and stamping molding, hardening and tempering, and surface hardening treatment. The technology disclosed in the invention can completely avoid the disadvantages of shallowness, low hardness after finish grinding, and low hardening and tempering treatment mechanical performances of traditional nitridized hardened layers, improves the surface hardness to above HRc70, improves the wear resistance by 50%, and improves the acid-salt corrosion resistance by above 40%. The mechanical performances improve by 40-50%, the bending fatigue life prolongs by above 100 times, the bending fatigue strength improves by 100%, and the fatigue strength stress concentration susceptibility is substantially inhibited.

An electroslag casting technology for manufacturing antiwear bimetal teeth of bucket, which is composed of tooth handle and tooth tip, features that a symmetrical water cooled multi-layer crystallizer is attached to the working surface of tooth handle, high-Cr cast iron is used as consumble electrode of electroslag casting to form multiple tooth tips at the same time, the low-carbon alloy steel or Mn steel is melted to form a bucket tooth cluster, and it is then cut with a conductive cutting apparatus to obtain individual teeth. Its advantages are high antiwear and anti-impact performance, high bending strength, high productivity and high utilization rate of raw material.

A radial roller bearing for storing shafts in wind turbine transmissions, which has an external bearing ring with an inner runway, an internal bearing ring arranged coaxial thereto provided with an external runway, and a plurality of roller bodies that displace on the runways between the bearing rings held at regular intervals by a bearing cage. To prevent slip, the roller bodies are replaced by hollow rollers that have a greater diameter and a smaller elasticity module than the roller bodies ensuring, when the radial roller bearing is in the load-free state, permanent contact with the bearing rings, a permanent drive of the bearing cage and that the roller bodies have kinematic rotation. The hollow rollers have a higher bending strength, and their internal cover surface has a maximum surface roughness of Rz≦25 μm preventing localized peaks of tension, without any disaggregation in the axial direction.

The invention belongs to the field of design and manufacturing of automobile wheels, in particular to the technique of forming of steel wheels rim with variable cross section, adopting the technique of blanking, circle rolling, flash butt welding, welding slag clearing, multi-channel roll forming, flow turning, finishing operation and punching valve hole to lead product to be formed. By adopting the technique of first rolling then spinning and making full use of plastic deformation characteristic of materials, so that anti-bending fatigue strength, radial fatigue strength and shock resistance of the rim can be improved; the technique of the invention has the advantages of simple technique, convenient operation and easy control, at the same time reducing weight of the rim by 10 to 18 percent, which saves raw materials.

The invention relates to an arc cycloid harmonic tooth profile, a generation method and device thereof and a storage medium. The method comprises the steps that a flexible gear coordinate system is established; according to the shape tooth profile parameters of a flexible gear tooth top arc, a flexible gear common tangent, a flexible gear tooth bottom horizontal cycloid and a flexible gear tooth root transition arc, corresponding flexible gear tooth profile coordinates are determined correspondingly; a corresponding flexible gear tooth profile is determined according to the flexible gear toothprofile coordinates and preset harmonic transmission parameters, and rigid gear tooth profile points are determined according to the flexible gear tooth profile; and parameter fitting is performed onthe rigid gear tooth profile points, and a corresponding rigid gear tooth profile curve equation is determined. The flexible gear tooth top adopts arc curves, so that the tooth profile bearing capacity is ensured; the flexible gear tooth bottom adopts a flat cycloid curve, so that the gear tooth meshing conjugate interval and the tooth root bending fatigue strength are increased; sharp point contact and tooth profile interference of the flexible gear in the engaging-in and engaging-out processes are reduced by adopting a tooth root transition arc; and the actual meshing condition is considered, a conjugate rigid gear curve is solved by utilizing a harmonic drive envelope conjugate theory, and complete conjugation is ensured.

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.

The invention relates to a spiral bevel gear machining method, in particular to a spiral bevel gear machining method based on a universal four-axis numerical control machine tool and a ball-end milling cutter. By steps of tooth surface discrete point calculation, gear solid modeling, ball-end milling cutter diameter determination, cutter path creation, tooth surface machining parameter calculationand tooth surface machining process, various spiral bevel gears can be machined on a universal four-axis numerical control miller without purchasing of expensive special machine tools or milling cutter discs. Compared with gear blend surfaces machined by milling cutter discs, the blend surface machined by the ball-end milling cutter has larger radius of curvature, and bending fatigue strength ofthe gears can be improved. Compared with the one-side cantilever arrangement mode when the gears are machined by the milling cutter discs, the two-end support mode of a chuck and a tailstock tip has better rigidity, deformation caused by cutting force can be reduced, and accordingly, machining accuracy of tooth surfaces is improved.

The present invention provides: a soft-nitrided component which, even when having been produced through water cooling after soft nitriding, has a flex fatigue strength of 600 MPa or higher and excellent straightenability; and a non-heat-treated steel for soft nitriding, which is suitable for use as a raw material for the soft-nitrided component. The non-heat-treated steel for soft nitriding has a chemical composition that contains 0.25-0.35%, excluding 0.35%, C, 0.15-0.35% Si, 0.85-1.20% Mn, up to 0.10% S, 0.010-0.030%, excluding 0.010%, Al, 0.003-0.020% Ti, and 0.010-0.020% N, with the remainder comprising Fe and impurities, in which P =0.08% and Cr=0.10%, and that satisfies 0.02C+0.22Mn+0.87Cr+0.85Al+0.72=0.96 and 2.40C-0.54Mn-9.26Cr-0.01Al+1.59=0.90.

The invention discloses a gear tooth surface shot peening finishing method in the technical field of gear tooth surface processing. The method concretely comprises the following steps of S1, heating agear tooth surface; S2, utilizing shots sprayed through a peening machine for strengthening the gear tooth surface, and enabling the tooth surface to form a residual compressive stress layer; S3, carrying out induction quenching processing on the residual compressive stress layer formed on the tooth surface, then carrying out secondary shot peening processing, and forming a high surface residualstress; and S4, after finishing shot peening, electroplating a surface of the residual compressive stress layer of the gear tooth surface, and then roasting and dehydrogenizing, so that the accuracy of a tooth shape is improved. According to the gear tooth surface shot peening finishing method provided by the invention, the gear bending fatigue resistance can be improved, the tooth surface fatigueresistance is improved, continuously machining tool marks can be eliminated at the same time, a lubricating condition of the tooth surface is improved, and meanwhile, after electroplating processing,grinding processing has no need to be carried out after shot peening, so that the accuracy of the tooth shape is improved, and a shot peening strengthening effect cannot be weakened at the same time.

Disclosed is a mixed powder for powder metallurgy which is obtained by diffusing and adhering 0.05-1.0 mass% of Mo over the surface of an iron base powder which contains, as a prealloy, not more than 0.5 mass% of Mn and 0.2-1.5 mass% of Mo, thereby forming an alloy steel powder, and then blending 0.2-5 mass% of an Ni powder and / or 0.2-3 mass% of a Cu powder into the thus-formed alloy steel powder. A dense sintered body having excellent tensile strength and bending fatigue strength can be produced from such a mixed powder.

A radial roller bearing for shafts in wind turbine transmissions, which includes an external bearing ring with an inner runway, an internal bearing ring arranged coaxial thereto which has an outer raceway and roller bodies on runways between bearing rings spaced circumferentially by a bearing cage and distributed uniformly on a circumference replaced by hollow rollers. To prevent slip, the hollow rollers have a greater diameter and lower modulus of elasticity ensuring, in a load-free state, continuous contact by the radial roller bearing with the bearing rings and continuous drive for the bearing cage and roller bodies at kinematic rotation speed. The hollow rollers have increased bending fatigue strength, and their inner envelope surfaces are formed by mechanical processing for further inherent compression stresses of at least −200 MPa, superimposed on the hollow rollers maximum load stress along with the inherent compression stresses resulting from their heat treatment.

The invention discloses a non-symmetric involute worm and gear pair which comprises a worm rod and a worm wheel, wherein a worm rod engagement side tooth profile and a worm rod non-engagement side tooth profile are arranged on the two sides of a wheel tooth of the worm rod respectively; a worm wheel engagement side tooth profile and a worm wheel non-engagement side tooth profile are arranged on the two sides of a wheel tooth of the worm wheel respectively; the axial modulus of the worm rod is m1; the transverse modulus of the worm wheel is m2; the pressure angle of the worm rod engagement side tooth profile is alpha 1; the pressure angle of the worm rod non-engagement side tooth profile is alpha 2; the pressure angle of the worm wheel engagement side tooth profile is alpha 3; the pressure angle of the worm wheel non-engagement side tooth profile is alpha 4; to guarantee the worm rod and the worm wheel to be correctly engaged under the circumstance that the included angle sigma between the shafts of the worm rod and the worm wheel is 90 degrees, the addendum coefficients and the tip clearance coefficients of the worm rod engagement side tooth profile and the worm rod non-engagement side tooth profile meet the following conditions: a, alpha 1 is more than alpha 2 and alpha 3 is more than alpha 4; and b, when m1 is equal to m2, alpha 1 is equal to alpha 3 and alpha 2 is equal to alpha 4; and when m1 is not equal to m2, m1*cos alpha 1 is equal to m2*cos alpha 3 and m1*cos alpha 2 is equal to m2*cos alpha 4.

A joint structure of a branch connector for a common rail capable of securing axial force applied to a seal surface and a branch connector and increasing bending fatigue strength of the branch connector is provided. In the joint structure of the branch connector for the common rail which includes a screw sleeve concentric with a bearing surface of a main pipe rail and connects a branch connector to the main pipe rail via a sleeve washer which has been externally fixed to the branch connector in advance to be combined therewith as one piece, a clearance is provided between an inner surface of the sleeve washer at an external opening thereof and an outer surface of the branch connector.

A steel for carburizing or carbonitriding use consisting of, by mass %, C: 0.1 to 0.3%, Si: 0.01 to 0.15%, Mn: 0.6 to 1.5%, S: 0.012 to 0.05%, Cr: 0.5 to 2.0%, Al: 0.030 to 0.050%, Ti: 0.0006 to 0.0025%, N: 0.010 to 0.025%, and 0: 0.0006 to 0.0012%, and, optionally, at least one selected from Mo≦0.5%, Ni≦1.5% and Cu≦0.4%, and the balance of Fe and impurities. P and Nb are P≦0.025% and Nb≦0.003% respectively. Formulas of [−5.0≦log(Ti×N)≦−4.4] and [−12.5≦log(Al2×O3≦−11.7] are satisfied. Austenite grain coarsening is prevented even when the steel is heated in the process of carburizing or carbonitriding, and even under various hot forging temperatures. The steel has excellent bending fatigue strength after carburizing or carbonitriding.

The invention relates to a strong preloaded crankshaft machining technology. The strong preloaded crankshaft machining technology is characterized by firstly carrying out rough machining on a crankshaft, finely turning shaft necks and round corners of a main shaft and a connecting rod by adopting a turning lathe after the crankshaft is subjected to the rough machining, carrying out strong rolling on the shaft necks and the round corners of the main shaft and the connecting rod by a rolling machine tool after fine turning is completed, and enabling the rolling resultant force which is loaded on a rolling cutter to be 32000-40000N, the rolling turns to be 6-8 and the radial run-out of a main shaft neck of the crankshaft to be controlled within 0.15-0.3mm after rolling; carrying out fine grinding after the strong rolling is completed. After the shaft necks and the round corners of the main shaft and the connecting rod are finely turned by the turning lathe, the machining allowance of the main shaft neck is reserved by 1.0-1.4mm, the machining allowance of the shaft neck of the connecting rod is reserved by 0.6-1.0 mm, the round corners can be machined according to the lower limit of a finished round corner of the crankshaft, and the center distance is deviated to the direction of the connecting rod by 0.05-0.1 mm. According to the strong preloaded crankshaft machining technology disclosed by the invention, the technological process is reasonable, the machining is simple and convenient, and the quality problems of bearing score of an engine caused by rolling embossment of the crankshaft and over-proof form and location tolerance can be fundamentally prevented from happening; the strong preloaded crankshaft machining technology is particularly suitable for machining medium-power and high-power spheroidal graphite cast iron crankshafts.

The present application concerns a canister (10) for containing an active agent, such as a desiccant agent, an oxygen scavenger, or a scented agent and for allowing the active agent to interact with the environment of the canister (10), such as absorbing moisture or oxygen, when the canister is closed. The canister comprises a canister body (12) having a peripheral body wall (11) defining an upper opening (13) for inserting the active agent into the canister body (12), and a non-removable snap-on cap (14) cooperating with the canister body (12) so as to close the upper opening (13), the cap (14) comprising a peripheral skirt (C5). The peripheral body wall (11) comprises a step (B2) formed between a first portion (B5) of the peripheral body wall (11) located adjacent to the upper opening (13) and a second portion (B6) of the peripheral body wall (11) located beneath the first portion (B5). The first portion (B5) is at least partially thinner than the second portion (B6) so as to form the step (B2), wherein an inner shape of the peripheral skirt (C5) and an outer shape of the first portion (B5) of the peripheral body wall (11) are adapted to form a snap-on fit between the cap (14) and the canister body (12) wherein the cap (14) at least partially laterally surrounds the first portion (B5). According to the invention, a vertical extension of the peripheral skirt (C5) is smaller than a vertical extension of the first portion (B5) of the peripheral body wall (11) so as to form a gap (J8') between the step (B2) and the peripheral skirt (C5) when the cap (14) is snapped onto the canister body (12).

The invention discloses a connecting rod part processing method. A material is 40 Cr. The processing method is characterized by including following steps: (1), charging the material into a furnace, and heating; (2), blanking a rolled material to obtain needed specification, directly performing surface quenching after rough machining without tempering to form a semi-finished product; (3), carburizing and quenching to obtain a non-tempered connecting rod, wherein quenching temperature is 850-950 DEG C, quenching time is 60-90 min, and a quenching agent is water or oil; (4), punching and edge-cutting, wherein roughness Ra is less than 1.6 um; (5), polishing and refining, wherein roughness Ra is less than 0.4 um; (6), sequentially performing rust preventing, inspecting, packaging and warehousing. By using the connecting rod part processing method, process parameters of each stage are controlled strictly, and processes are reduced remarkably; the connecting rod part processing method is simple in process, convenient to operate and low in energy consumption.

A bearing pressure-resistant member, including a matrix and a carbide dispersed in the matrix, the carbide having an average particle size of not more than 0.3 μm. A carbon (C) content in an outer surface of the bearing pressure-resistant member is in a range of 0.6 to 1.5 mass percent. A process for making the bearing pressure-resistant member including subjecting a workpiece containing C to either of gas carburizing and gas carbonitriding to enhance the C content in the outer surface of the workpiece to 0.6 to 1.5 mass percent, holding the workpiece at a first temperature not more than an Ac1 transformation point under reduced pressure, heating the workpiece to a second temperature not less than the Ac1 transformation point under reduced pressure, followed by holding the workpiece at the second temperature, and subjecting the workpiece to quenching.

The invention relates to a preparation method of a low-voltage electrode foil with good bending fatigue strength. The preparation method comprises the following steps: performing oil removal operation on a first aluminum foil, a second aluminum foil and a third aluminum foil; the first aluminum foil is sequentially subjected to pre-electrolysis, electrolytic corrosion, cleaning and drying operation; coating the first aluminum foil with the aluminum-based slurry so as to form primary slurry coating layers on the front and back surfaces of the first aluminum foil; the second aluminum foil and the third aluminum foil are attached to the primary pasting layers in a one-to-one correspondence mode to form composite aluminum foil; performing cold rolling treatment on the composite aluminum foil; and sequentially heating and cooling the composite aluminum foil to obtain the product. In the actual manufacturing and forming process, the electrode foil used as the middle core layer is still fully corroded, so that the phenomenon that the capacitance of the low-voltage electrode foil is greatly reduced due to the change of a preparation process route is avoided. Besides, actual experimental data show that the low-voltage electrode foil prepared by the method has better bending fatigue strength on the premise of keeping the overall thickness unchanged.