Learning mechanical design axis point, quick get!

Axis is in the middle of the bearing or gear wheel in the middle or in the middle of the cylindrical objects, but there are also less local is square. With rotary shaft is one of the bearing rotating parts and to transmit motion, torque or bending moment of mechanical parts. General for round rods, metal paragraphs can have different diameter, for rotary movement of the parts in the machine is installed on the shaft. 1, the classification of shaft, shaft type many, according to the different axis shape can be divided into direct axis, crank shaft, and flexible shaft. The crankshaft is often used in reciprocating machinery ( Such as internal combustion engine, compressed air, etc. ) , flexible shaft rotary motion can be sensitive to the demand of position, often used in medical equipment, we only discuss direct axis in the article. Direct axis carriage according to their different can be divided into three types of shaft, spindle and the shaft. Shaft: accept bending moment and torque both at work, is the most common mechanical axis, such as various of the reducer shaft, etc. ; Bring about turn axis axis: used to only accept bending bearing rotating parts and not transmitted torque, some of the spindle rotation, such as the axis of the railway vehicle, some of the spindle is not turning, such as the shaft supporting pulley and so on; Bring heart shaft: mainly used to transmit torque and not accept bending moment, such as to the long axis of the moving crane, automobile drive shaft, etc. Shaft materials mainly adopts carbon steel or alloy steel, ductile iron or alloy cast iron may be adopted. Shaft to ordinary depends on the strength and stiffness, high speed also depends on the vibration stability; Bring the shaft, shaft axis 2 commonly used material is carbon steel and alloy steel. Than carbon steel alloy steel and low price, small sensitive rationality of stress concentration, good mechanical properties are compared, so the application is relatively common. The blank common use rolling round steel or steel shaft forgings. Forging internal organization compare with average, good strength, so the important shaft forging billet should be adopted. 3, the construction design of shaft axis structure design is reasonable sure axis and all construction appearance, size, designs for the shaft of the important steps. It consists of shaft parts of device type, size and location, parts of fixed way, the nature of the load, direction, size and spread condition, bearing type and size, shaft blank, manufacturing and assembly process, equipment and transportation, the shaft of the relevant factors of deformation, etc. Designers can design based on shaft detailed requests to stop, when it is necessary to do a few plans to stop match, in order to select the best design plan, the following is a common shaft structure design criterion, save material, reduce weight, as far as possible USES such as strength size or large cross section shape coefficient of the cross section shape; Accurate positioning, stable, easy to shaft parts assembly, disassembly and adjustment; Used in a variety of structural measures to reduce the intensity of stress concentration and progress; To facilitate processing manufacturing and ensure accuracy; 4, axial location of axis parts and fixed axis parts of axial positioning and fixing methods commonly used have a shoulder, collar, locking collar, sleeve, round nut and lock washer with elastic ring, shaft end ring and conical surface, etc. 5, shaft repair. 1 shaft bending deformation correction shaft deformation is too large, can be cold pressing correction or part of the flame heating correction. Correction of bearing parts should be correct, especially we should pay attention to not to make the ladder shaft stress concentration due to correction around the corner. Bring about shaft bending deformation correction ( Left) And repair (journal of wear Right) 5. 2 journal wear repair usually use first alleviation of grinding shaft geometry shape error, and then the metal spraying or brush plating, serious when can welding or set set of repair, set set when the set with the shaft for surplus to cooperate. 5. 3 spline, slotting, thread repair available gas welding or surfacing welding method to repair worn tooth profile, then the wear of the spline as root, milling spline. Keyway damage after, can properly increase the keyway or the old welding grooves, and with the new key. The screw thread damage on the shaft, should stop welding, heavy threading. Bring spline slotting repair