Clevis pins are elements commonly used in machine construction. They are connectors in designs with joint structure. They connect elements moving relatively to each other in machine mechanics systems. The rule in machine systems is to meet the conditions for securing the pin against axial movement. Preventing the clevis pin from extending can be implemented by:
- proper shaping of the pin;
- ensuring tight fit in the structural part of the joint;
- securing pins thanks to cotter pins, securing plates, nut.
Clevis pin joints must always be able to rotate through one of the joint members. In systems with complex kinematics, clevis pins form the basis for the operation of machines. Looseness resulting from bolted connections are transferred to the efficiency and functionality of the entire system. Structurally, in mechanical systems, these details are fitted in a variety of ways. For example:
- for crane type cantilever systems – tight and sliding fits;
- for systems of technological machines with a hydraulic drive – sliding fits;
- for track drive systems – loose fit.
According to PN-EN ISO 286-2: 2010 (formerly: PN-EN 20286-2) tolerance classes IT5 to IT11 apply to machine parts of the “bolt connections” type. Therefore, when producing clevis pins, it is important to meet the dimensional tolerance requirements. The method of fitting pins in machine systems is always dependent on the tolerance of bearing seats or sleeves cooperating with the pins.
Design models of clevis pins.
In terms of construction, machine components called clevis pins can be divided into:
- Single-stage clevis pins (where the joint elements have the same seat diameters) and Multi-stage pins;
- Headless clevis pins (plain, i.e. for which protection with cotter pins, circlips) must be ensured, Headed / flange clevis pins.
From the strength side, the pins are subjected to bending and shearing. Therefore, the material from which the clevis pins are made is important when it comes to the durability of these machine parts. The type of machining – turning and / or grinding – is also important.
The materials from which we manufacture pins.
Most often these machine elements are made of carburizing steel – for example 16HG (16MnCr5). Sometimes from steel for heat treatment, for example 40HM (42CrMo4) or 36HNM (36NiCrMo4).
Examples of pins manufactured in our company.
Our company carries out short-series and serial production of pins according to the customer’s specifications and documentation, as well as production of standard bolts according to the standards specified in the PN-EN 22340: 2000 (without head) and PN-EN 22341: 2000 (with head) standards. The latter is the production for non-standard versions of special materials.