spindle

Machine tool spindle is a typical by torsion - bending combined action of shaft parts, it is to stress (medium load), under impact load is not large also, if using sliding bearings, journal place for wear. So most of the 45 steel manufacturing, and tempering treatment, journal place by surface quenching to strengthen. Load is bigger, use and cr and low alloy steel to make. Lathe spindle selection results are as follows: material: 45 steel. Heat treatment: overall conditioning, journal and taper hole surface hardening. Performance requirements: overall hardness NB220 ~ HB240; Journal and cone hole in the HRC52 hardness. Process route: forging, normalizing, tempering and roughing and finishing - surface quenching and low temperature tempering, grinding. The shaft working stress is very low, the impact load is not big, 45 steel treatment yield limit of 400 mpa above, can fully meet the requirements. Now there are part of the machine tool spindle can be used ductile cast iron manufacturing.

Tractor half shaft

       Car half shaft is a typical by torque shaft parts, but working stress is larger, and the considerable impact load, its structure as shown in figure 5 shows. The largest diameter up to fifty mm left and right sides, with 45 steel manufacturing, even water quench also can make the surface hardening depth 10% radius. In order to improve the hardenability, and in oil quenching to prevent deformation and cracking, medium and small car half shaft general use and cr manufacturing, heavy vehicle and crmnmo etc h high steel manufacturing. Example: optimus 45 half shaft material: and cr. Heat treatment: overall quenched and tempered. Performance requirements: stem HRC37 ~ HRC44; Disk department cylindrical HRC24 ~ HRC34. Process route: cutting, forging, normalizing, tempering, mechanical processing, plate of drilling and grinding spline.

       Machine gear

       Machine gear working condition is good, work stress is not big, medium speed, stable without strong impact, so the tooth surface strength, core strength and toughness requirements are not too high, generally with the 45 steel manufacturing, using high frequency quenching surface strengthening, tooth surface hardness can reach HRC52 or so, the bending fatigue or surface fatigue is enough. Gear quenched and tempered, core can ensure that there is about HB220 hardness and greater than 4 kg? M/cm2 impact toughness, can meet the job requirements. For part of the requirements of high gear, usable alloy quenched and tempered steel (such as and cr, etc.) manufacturing. Then the core strength and toughness have improved, bending fatigue and surface fatigue resistance are also increasing. Example: ordinary lathe headstock gear. Material: 45 steel. Heat treatment: normalizing or quenched and tempered, tooth of high frequency quenching and low temperature tempering. Performance requirements: gear core hardness is HB220 ~ HB250; Tooth surface hardness HRC52. Process route: cutting, forging, normalizing or annealing, rough machining, quenched and tempered or normalized - finishing - high frequency quenching and low temperature tempering (pull spline hole) - fine grinding.

        Tractor gear

        Tractor gear working conditions than machine gear bad, especially the main drive system of gear, they stress is bigger, overload and the impact is frequent, so the material requirements of higher. Due to the bending and contact stress are large, with high frequency quenching strengthening surface can't guarantee requirements, so the important gear with carburizing, quenching for strengthening treatment. So this kind of gear generally alloy carburizing steel and cr or twenty crmnti and other manufacturing, especially the latter in our tractor gear production in the most widely used. In order to further improve the gear durability, besides carburizing, quenching outside, still can use peening processing surface strengthening treatment technology. Shot-blast, tooth surface hardness can improve HRC1 ~ 3 units, durability can improve 7 ~ 11 times. Example: tractor rear axle cone driving gear. Material: twenty crmnti steel. Heat treatment: carburizing, quenching and low temperature tempering, carburizing layer deep 1.2 mm to 1.6 mm. Performance requirements: tooth surface hardness HRC58 ~ HRC62, core hardness HRC33 ~ HRC48. Process route: cutting, forging, normalizing, cutting, carburizing, quenching and low temperature tempering, grinding. Above all kinds of parts of material selection, only as a mechanical parts when select material for simulation reference. Many of which is the result of long-term accumulation of experience. Experience is very important, but if only by experience is not to get the best effect. In the concrete material, to refer to the related mechanical design manual, engineering material manual, combined with the actual situation to carry on the primary election, important parts in the primaries, need to undertake strength calculation check, determine the parts size, still need to review the selected material h in compliance with requirements, and determine the technical conditions of heat treatment. At present more good method is, according to the components of the working conditions and failure mode, the parts can choose materials for quantitative analysis, and then refer to the related experience to make the final decision to select material.