Matching Of Flat Keys And Keyways

The flat key transmits torque on the side, with good alignment and easy assembly and disassembly, and cannot achieve axial fixation of parts on the shaft.
Ordinary flat key: A-type, B-type, C-type.
The A-type shaft groove used for end milling cutter processing has good axial fixation of the key in the groove, but the groove causes significant stress concentration on the shaft. Type B is used for shaft grooves processed by disc milling cutters, and the stress concentration of the shaft is relatively small; Type C is used for shaft ends. The most widely used, it is also suitable for high-speed, high-precision, or under varying loads and impacts, such as fixing rotating parts such as gears and sprockets on shafts.
Guiding flat key: The key is fixed on the shaft with screws, and the key is in dynamic fit with the hub groove. The parts on the shaft can move axially, and for the convenience of keying, a keying screw hole is opened. In situations where the axial movement of components on the shaft is not significant, such as sliding gears in gearboxes.
Sliding key: The key is fixed on the wheel axle, and the parts on the axle can move axially with the key. Used in situations where the axial movement of components on the shaft is large.
1. In the working diagram, the depth of the shaft groove is marked with t or (d-t), and the depth of the hub groove is marked with d+t1.
2. The deviation of d-t and d+t1 should be selected according to the corresponding deviation, but the deviation of d-t should be taken as a negative value
3. Except for the shaft, keys with smaller profiles are allowed to be used while ensuring the required torque. If necessary, recalculation is necessary to ensure that the contact heights between the keyway and the key are h/2.
4. The deviation of links with looser keys applies to the connection of guided flat keys.
5. The tolerance of the width b of the shaft groove and wheel hub groove on the symmetry of the shaft and wheel hub centerline is based on levels 7-9.
6. When the length to width ratio of the flat key is greater than 8, the parallelism of the two sides of the key in the length direction should comply with the regulations.
7. When needed, the key allows for the opening of the key screw hole