1. When the main body is large equipment, accessories need to be installed, such as sight glass, mechanical seal seat, deceleration frame, etc. At this time, a stud bolt is used, one end is screwed into the main body, and the other end is equipped with a nut after the accessory is installed. Since the accessory is often disassembled, the thread will be worn or damaged, and it is very convenient to use the stud bolt to replace. 2. When the thickness of the connecting body is very large and the bolt length is very long, stud bolts will be used. 3. It is used to connect thick plates and places where it is inconvenient to use hexagonal bolts, such as concrete roof trusses, roof beam suspension monorail beam suspension parts, etc.
In the non-standard mechanical design, when the middle part of the long shaft or rod-shaped structure needs to be threaded, the end is limited and the nut cannot be penetrated, which will cause the problem that the installation cannot be realized. In order to solve this problem, it often has to be cancelled. It is not conducive to the realization of equipment cost reduction and optimal function, and even the problem cannot be solved, and another way out is needed.
The working principle of the nut is to use the friction between the nut and the bolt for self-locking. However, the reliability of this self-locking is reduced under dynamic loads. In some important occasions, we will take some anti-loosening measures to ensure the reliability of the nut locking. Among them, the use of lock nuts is one of the anti-loosening measures. There are also two types of locking nuts. One is to use two identical nuts to screw on the same bolt, and a tightening torque is added between the two nuts to make the bolt connection reliable. The other is a special lock nut, which needs to be used together with a lock washer. As shown in FIG. 1, a plastic gasket 2 is arranged in the center of the nut 1 to play a locking effect, but the process is complicated and the production is inconvenient. One is to drill through threaded holes from the outer surface of the nut to the inner thread surface (usually 2, distributed at 90 on the outer surface), which are used to screw in small-diameter countersunk head screws. The purpose is to apply a thread to the thread. A centripetal force prevents the lock nut from loosening. At present, the lock nut with better quality on the market is inlaid with small copper pieces that are consistent with the thread of the lock nut on the inner surface of the nut, which is used to prevent the radial jacking screw from directly contacting the locked thread and being damaged. By. This kind of lock nut is gradually applied in the shaft end locking of rotating motion parts, such as the anti-looseness of the bearing at the mounting end of the ball screw. The process is equally complex.
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.
Existing wood screws are composed of a threaded portion with a tapered angle and arranged along a tapered stem and a screw head. The head of the screw can be a countersunk head, hemispherical, or other shapes, and the head of the screw has a groove that fits with the tool, a word groove, and a concave cross groove. The taper angle of existing wood screws is either 45 degrees or 60 degrees, and the front end of the taper angle is a pointed point formed by a rotating thread. The existing wood screws have the following three deficiencies in use. Because the taper angle is 45 degrees or 60 degrees, and the thread angle is 71 degrees, the resistance when entering the material is relatively large, so the existing wood screws are manually screwed. It is difficult to screw in, especially when it is used for hardwood materials, and it often happens that the groove of the screw head is screwed out; A large lateral moment will be formed when the screw is screwed, which is prone to the problem of deviation from the position; in addition, because the existing screw is tapered, it will be subjected to both radial force and axial force when entering the material, and its stress state It is more complicated, so it is easy to cause the cracked wood material to burst, and even cause the material to have longitudinal cracks and be unusable.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: large-head knurled hand-tight screws and bolts, non-return washers and nuts, nickel-plated crown screws and nuts, iron internal and external teeth nuts and other products, we can provide you with suitable products. Your fastener solution.