What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
However, although the above-mentioned screw belt (2) can achieve the expected effect, it is also found in its actual implementation. Although this structure has multiple grooves on both sides of the main body for the driving and turning of the locking screw tool, However, the groove is only used for driving the screw belt drive, and since the screw will swing on the screw belt, it is impossible to stably align the screw on the screw belt with the point where the screw is to be set. , which leads to great inconvenience in operation and use, and also affects the efficiency of screw and screw installation, so that there is still room for improvement in the overall structural composition.
screw can be equipped with only one spring washer or only one flat washer, or it can also only be equipped with a two-piece combination of flower teeth. The national standard number of the combination screw is represented by GB9074. The commonly used cross recessed small pan head three combination screw national standard is GB9074.8.
Friction type high-strength bolts: suitable for beam and column connections of steel frame structures, solid web beam connections, heavy-duty crane beam connections in industrial plants, braking systems and important structures bearing dynamic loads. Pressure-bearing high-strength bolts: Can be used for shear connections in statically loaded structures that allow a small amount of sliding or in members that are indirectly loaded with dynamic loads. Tensile high-strength bolts: When the bolts are in tension, the fatigue strength is low. Under the action of dynamic load, its bearing capacity is not easy to exceed 0.6P (P is the allowable axial force of the bolt). Therefore, it is only suitable for use under static load. Such as flange butt joints, T-joints, etc. of pressure members.
The flat key transmits torque on the side, has good neutrality, is easy to assemble and disassemble, and cannot realize the axial fixation of the parts on the shaft. Ordinary flat key: Type A, Type B, Type C, Type A is used for shaft grooves machined by end mills. The key is well fixed axially in the groove, but the stress concentration caused by the groove on the shaft is large; Type B is used for disc milling cutters. The machined shaft groove, the stress concentration of the shaft is small; the C type is used for the shaft end; it is suitable for high-speed, high-precision or occasions under variable load and impact, such as fixing gears, sprockets and other rotating parts on the shaft. Guided flat key: The key is fixed on the shaft with a screw, the key and the hub groove are in dynamic fit, and the parts on the shaft can move axially. For the convenience of starting the key, there is a key-starting screw hole. Use the occasions where the axial movement of the parts on the shaft is not large, such as the slip gear in the gearbox. Feather key: The key is fixed on the axle, and the parts on the shaft can move axially with the key; it is used in the occasions where the axial movement of the parts on the shaft is large;
The above content is uploaded by Yueluo or the Internet. If there is any copyright issue, please contact [email protected].
