A, 1, 1) main purpose overview
On the supporting shaft rotary parts (
Such as gear)
;
2)
Transfer movement and power.
Second, the classification, according to the bearing points 1)
Shaft: work under bending moment and torque of shaft.
Such as: shaft of reducer.
The cylindrical gear reducer, will suffer from two shaft bearing and lateral force generated by the bending moment of the gear, at the same time, between the gear and the coupling shaft section will also withstand the torque, so for the shaft.
2)
Spindle: work under bending moment and not only bear the shaft torque.
According to the work whether the axis rotation can be divided into: rotating spindle: work only under bending moment and the rotation axis.
Fixed spindle: work under bending moment and do not turn the shaft only.
【
Problem 】
What kind of bicycle front wheel shaft belong to?
Cycling to work front wheel hub and ball relative to the fork and the axle rotate together, and fixed axle itself, and only under transverse force produced by bending moment, bicycle front axle is fixed spindle.
3)
Shaft: work only under the torque under bending moment of the axle.
Such as: automotive the axis of rotation of the shaft is used to transfer the movement of the engine to the car rear axle, transmission torque, only and not under bending moment, so for the shaft.
2, according to the axis shape points 1)
Direct axis: the shaft section of axis for the same straight line.
Direct axis according to the different shape can be divided into: optical axis: simple shape, less stress concentration, easy processing, but the shaft parts is not easy to assemble and positioning.
Often used in the spindle and the shaft.
Ladder shaft: characteristics, in contrast to the optical axis, often used for rotating shaft.
Optical axis and the axial note: direct axis is solid commonly, if need other parts installed in the shaft or reduce the quality of the shaft, the shaft can be made into hollow.
2)
Crankshaft: each shaft axis not in a straight line, special parts, mainly used in internal combustion engine.
3)
Wire soft shaft: axis can be arbitrary bending, flexible rotation.
Three, the material of shaft 1, carbon steel: 30, 35, 45, 50 (
Are fire or conditioning)
The most widely used, 45.
Low price, is not sensitive to stress concentration, good workability.
2, medium and low carbon alloy steel: high strength, long service life, sensitive to stress concentration, used for overloading, small size of the shaft.
Q: when insufficient rigidity of shaft, how to improve the stiffness of shaft?
Structure.
Four, structure design of shaft 1, objective: to determine the size of the shaft, shape: d, 1 -
—
Flexibility is very large.
2, 1)
On the shaft and the shaft parts to determine the working position;
2)
Reasonable force -
—
To improve the strength and stiffness of shaft axis structure;
3)
Axis has a good processing, assembly craft, reduce stress concentration;
3, 1) the ladder shaft structure design
For shaft parts assembly scheme 2)
The parts on the shaft is fixed (
1)
Axial fixed a, with the aid of the shaft itself shape positioning: shoulder, conical shaft head;
B, by means of retaining ring, round nut, sleeve positioning, etc.
(
2)
Weeks to set key, spline, forming connection, elastic ring joint, interference, pin, etc. -
—
Connection shaft hub.
4, axial structural manufacturability design shaft segment: 1, which is to be grinding wheel, the groove.
2, need to cut thread shaft section: thread relief groove.
3, should be shaft end chamfering: cX45 ° -
—
Easy to assemble.
4, the assembly period shoulds not be too long.
5, fixed in different parts of the keyway should decorate on the same bus, to reduce the number of clamping.
