Service Hotline2. Low cycle fatigue Low cycle fatigue means that the fatigue stress is close to or exceeds the yield limit of the material. The material has a certain amount of plastic deformation in each strain cycle. The life is generally in the range of 102 to several times 104, and the fatigue curve is generally used. ε-N curve representation. The finite element calculation results show that after the bolt is screwed into the lock nut, the stress at the root of the threaded piece is large, and part of the surface area is in a yield state, while the strain in the central area of the root of the threaded piece is small, and the strain situation is more complicated. The area with high strain at the root of the thread piece experiences reciprocating loading, which is prone to low cycle fatigue, which reduces the pressure of the thread piece and reduces the screw-out torque.
The locking effect of the spring washer is general, and the important parts are used as little or not as possible, and the self-locking structure is adopted. For spring washers used for high-speed tightening (pneumatic or electric), it is best to use surface phosphating washers to improve their anti-wear performance, otherwise it is easy to burn out or open mouth due to friction and heat, and even damage the surface of the connected parts. For thin plate joints, spring washer construction should not be used. According to statistics, spring washers are used less and less in automobiles.
Bolt: A type of fastener consisting of a head and a screw (a cylinder with an external thread), which needs to be matched with a nut to fasten and connect two parts with through holes. This form of connection is called a bolted connection. If the nut is unscrewed from the bolt, the two parts can be separated, so the bolt connection is a detachable connection. [1] Stud: A type of fastener that has no head and only has external threads on both ends. When connecting, one end of it must be screwed into the part with the internal threaded hole, the other end must pass through the part with the through hole, and then the nut must be screwed on, even if the two parts are tightly connected as a whole. This form of connection is called a stud connection, which is also a detachable connection. It is mainly used for occasions where one of the connected parts is thick, requires a compact structure, or is not suitable for bolt connection due to frequent disassembly. [1] Screw: It is also a type of fastener consisting of a head and a screw. It can be divided into three categories according to the purpose: machine screws, set screws and special-purpose screws. Machine screws are mainly used for a fastened connection between a part with a fixed threaded hole and a part with a through hole, without the need for nut matching (this connection form is called screw connection, which is also a detachable connection; it can also be Cooperate with the nut, it is used for the fast connection between two parts with through holes.) The set screw is mainly used to fix the relative position between the two parts. Special purpose screws, such as eyebolts, are used for hoisting parts. [1] Nuts: with internal threaded holes, generally in the shape of a flat hexagonal column, but also in a flat square column or flat cylindrical shape, with bolts, studs or machine screws, used to fasten and connect two parts, make it a whole. [1] 5. Self-tapping screw: Similar to machine screw, but the thread on the screw is a special thread for self-tapping screw. It is used to fasten and connect two thin metal components to make them a whole. Small holes need to be made in advance on the components. Due to the high hardness of this kind of screw, it can be directly screwed into the hole of the component, so that the Forming a corresponding internal thread [1] 6. Wood screw: It is also similar to a machine screw, but the thread on the screw is a special thread for wood screws, which can be directly screwed into wooden components (or parts) to connect a band through The metal (or non-metallic) part of the hole is fastened to a wooden member. This connection is also a detachable connection. [1] 7. Washers: A type of fastener with an oblate annular shape. It is placed between the supporting surface of the bolt, screw or nut and the surface of the connecting part, which increases the contact surface area of the connected parts, reduces the pressure per unit area and protects the surface of the connected parts from damage; another type of elastic washer, It can also play a role in preventing the nut from loosening. [1] 8. Retaining ring: It is installed in the shaft groove or shaft hole groove of the machine and equipment, and plays the role of preventing the parts on the shaft or the hole from moving left and right. [1] 9. Pins: mainly used for positioning the left and right parts, and some are also used for connecting parts, fixing parts, transmitting power or locking fasteners. [1] 10. Rivet: A type of fastener consisting of a head and a shank, which is used to fasten and connect two parts (or components) with holes to make them a whole. This form of connection is called rivet connection, or riveting for short. It is a non-removable link. Because if the two parts joined together are separated, the rivets on the parts must be broken. [1] 11. Components and connection pairs: Assemblies are a type of fasteners supplied in combination, such as a combination of a certain machine screw (or bolt, self-supplied screw) and a flat washer (or spring washer, lock washer); Connection pair refers to a type of fastener that is supplied by a combination of special bolts, nuts and washers, such as high-strength hexagon head bolt connection pairs for steel structures. [1] 12. Welding nail: a heterogeneous fastener composed of a nail rod and a nail head (or no nail head), which is fixed to a part (or component) by welding, so as to be connected with other parts. .
Here Yueluo eliminates the drawbacks. The purpose of Yueluo is to provide a locking screw by which the gap existing between the locking screw and a transverse hole in a locking screw can be eliminated. Yueluo achieves the proposed object with a locking screw, which has the features of claim 9 . The line connecting the centers of gravity of the respective axially continuous orthogonal cross-sectional areas of the locking screw is regarded as a line. The advantage achieved by Yueluo can basically be seen that, due to the locking screw of Yueluo, the gap between the horizontal hole of the screw and the locking screw can be eliminated. Other advantages are as follows - the insertion accuracy and surgeon time spent remain within the range to date; - the strength of the locking screw is maintained; and - the extraction of an expired broken screw is assured. The further composition of Yueluo and Yueluo is explained in more detail below by means of schematic diagrams of parts of various embodiments.
spring washer is installed under the nut to prevent the nut from loosening. It is stated in the national standard. Hexagonal slotted nuts are specially designed for use with bolts with holes at the end of the screw, so that the cotter pin can be inserted into the hole of the screw from the groove of the nut to prevent the nut from automatically loosening. It is mainly used for vibration loads or alternating loads. . The methods to prevent the nut (or bolt) from automatically loosening in the mechanical design and production are as follows: 1. Add a spring washer; (simple and easy to do) 2. Use a hexagonal slotted nut + a split pin; (increase the processing process) 3 . Pad the stop washer; (increase the processing process compared with the same period of last year) 4. Insert the steel wire into the hexagon head opening of the hexagon bolt. (Increased processing steps compared to the same period of last year) Spring washers are used to prevent loosening. For example, the bolts connecting the motor and the machine base generally need to add spring washers, because the motor vibrates without the spring washers, and the nuts will loosen. Generally, the fasteners on the equipment with vibration There is a spring gasket on it, and there is generally no need to add a gasket on the flange! Whether the spring gasket is added to the flange is related to the medium circulating in the pipeline. If it is easy to generate pulses, it is best to add spring gaskets, as well as high-speed fluid, and the caliber changes frequently. Do not generalize. On some valves, the stuffing box gland All flanges need to be added with spring gaskets. The automatic selection of spring gaskets is included.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: extended screw screws, internal and external teeth, ultra-short thread bolts, fish-eye wear-resistant seals and other products, we can provide you with suitable fastening products piece solution.
