Types of coordination
(1) Clearance fit
The cooperation with clearance (including minimum clearance equal to zero) is called team cooperation. At this time, the tolerance zone of the hole is one of the tolerance zones of the shaft
As the actual dimensions of the hole and shaft are allowed to change within their respective tolerance bands, the clearance of the hole and shaft fit is also variable. When the hole is the maximum limit size and the shaft is the minimum limit size, the assembled hole and shaft are in the most loose state, which is called the maximum gap
When the hole is the minimum limit size and the shaft is the maximum limit size, the assembled hole and shaft are in the most tight matching state, which is called the minimum clearance xmin
(2) Interference fit
A fit with interference (including minimum interference equal to zero) is called interference fit. At this point, the tolerance zone of the hole is below the tolerance zone of the shaft
In the interference fit, the difference between the maximum limit size of the hole minus the minimum limit size of the shaft is the minimum interference Ymin, which is the most loose state of the hole and shaft fit; the difference between the minimum limit size of the hole and the maximum limit size of the shaft is the maximum interference ymax
It is the most tight state of hole and shaft fit.
(3) Transition fit
A fit that may have clearance or interference is called a transition fit. At this point, the tolerance zone of the hole intersects the tolerance zone of the shaft
The difference between the maximum limit size of the hole and the minimum limit dimension of the shaft is the maximum clearance xmax, which is the most loose state of the hole and shaft fit; the difference value of the minimum limit size of the hole minus the maximum limit dimension of the shaft is the maximum interference ymax, which is the hole and shaft matching
The tightest state of closure.
The difference of three types of coordination
(1) Clearance fit
a. The actual size of the hole is always greater than or equal to the actual size of the shaft
b. The tolerance band of the hole is above the tolerance zone of the shaft
c. It is allowed that the relative motion can be produced after the hole shaft fits
(2) Interference fit
a. The actual size of the hole is always less than or equal to the actual size of the shaft
b. The tolerance zone of the hole is below the tolerance zone of the shaft
c. It is allowed to fix the position of the parts or transfer the load after the hole and shaft fit
(3) Transition fit
a. The actual size of the hole may be larger or smaller than the actual size of the shaft
b. Tolerance and cross hole with tolerance
c. When the hole and shaft fit, there may be clearance or interference