straight axis

Crankshaft: used to realize the conversion of reciprocating motion and rotational motion

Flexible shaft: Mainly used for space transmission where the two transmission axes are not in the same straight line or have relative motion with each other during operation.

Spindle: A shaft that only bears bending moments and not torques

Rotating axis: A shaft subject to both bending moment and torque

Drive shaft: a shaft that is subject only to torque but not bending moment or very small bending moment

Sufficient strength and low sensitivity to stress concentrations

Meet stiffness, wear resistance, corrosion resistance and good processability

For shafts with low requirements or longer shafts, when the diameter of the blank is less than 150mm, rolled round steel can be used

The blanks for important shafts that are subject to large forces and require large production batches can be provided by forging.

For shafts with extremely large diameters and a small number of pieces, weldment blanks can be used

For the production of shafts with large batches, complex shapes, and large sizes, casting blanks can be used

Fatigue fracture caused by insufficient fatigue strength

Plastic deformation due to insufficient static strength

Brittle fracture, wear, deformation and vibration beyond the allowable range

According to the working conditions of the shaft, production batch and economic principles, select the appropriate material, blank form and heat treatment method

According to specific requirements such as the stress on the shaft, the installation position of the parts on the shaft, the matching size and positioning method, the processing method of the shaft, etc., determine the reasonable structural shape and size of the shaft, that is, carry out the structural design of the shaft

Calculate or check the strength of the shaft; for slender shafts with large stresses (such as worm shafts) and shafts with high stiffness requirements, stiffness calculations are also required; for shafts operating at high speeds, due to the risk of resonance, Therefore, vibration stability calculations should be performed

Shaft shoulders and collars

Shaft sleeve (sleeve)

round nut

Conical surface

Shaft end baffle

Retaining ring

Locking retaining ring, set screw

The diameters of adjacent shaft segments on the shaft should not differ too much. Where the diameter changes, try to use fillet transitions with the fillet radius as large as possible. When the increase in fillet radius is limited by the structure, a concave fillet structure can be used or a transition shoulder ring can be installed to position the part axially.

The shaft section on the shaft that matches the hub hole of the component will produce greater stress concentration at the mating edge. The tighter the fit, the harder the part material and the greater the stress concentration. Improvements can be made by opening unloading grooves on the shaft or hub and increasing the diameter of the mating part.

Try to avoid making transverse holes, cuts or grooves on the shaft (such as set screws, tapered pins, retaining rings, round nuts, etc. for positioning needs)

The keyway structure processed by a disk milling cutter has a lower and smoother transition than the keyway groove milled by an end mill; using an involute spline structure instead of a rectangular spline can reduce stress concentration. In addition, avoid designing threaded structures on parts of the shaft that are subject to greater loads.

Fatigue strength safety factor check

Static strength safety factor check