Effect and consequence analysis of expanding PIN-technology in various types of heavy machinery

Abstract

Expanding pin systems can be applied in any joint, moveable, or fixed, in any type of machine, crane, or equipment, in almost any type of industry, globally. There are a variety of different versions of expanding pins depending on the type and severity of challenges the joints are exposed to during operation, or assembly and disassembly. There are expanding pins with one sleeve only, typically for non-moveable joints connecting structure to structure. Other pins have two sleeves for wedge locking the pin assembly to the machine supports, or even four sleeves so the pin can be locked to a bearing as well. The main advantages with these types of pin solutions are reduced wear, reduced risk of pin breakage, loosening, and crack damages on the pin and machine supports, reduced loss of operational or production time, reduced loss of work hours in mounting and dissembling of machines, cranes, and other equipment. In addition, improved functionality of bearings, improved huge flange shear capacities, and the possibility to use the expanding pin system in combination with 3D printed repair inserts to reduce downtime due to repairs of damaged pin supports. This coincides with societal, and authority requirements regarding reduction of losses due to inefficient or incorrect machines, material, procedures, and mindset. The expanding PIN-technology (also referred to as Bondura Technology) is a relatively new invention whose mechanics, failure characteristics and associated effects and consequences when used in various heavy machinery are not well documented. Thus, this thesis is intended to fill the knowledge gap through literature studies, surveys, experimental tests, calculations, and numerical analysis approaches. The experimental tests focused on, (a) studying the effects of expanding pin applied in spherical bearings, (b) investigating how to reduce the downtime when repair of support bores is required using the expanding pin as a tool in combination with 3D printed repair inserts, (c) improving huge flange shear capacity, (d) understanding how self-loosening of preloaded bolts can be avoided, and (e) identifying the interactions and stress behaviour between pin and support. In this thesis, results from nine published studies about the effects and consequences regarding use of expanding pins in heavy machinery are presented. The studies are mainly based on, (i) a questionnaire-based survey among 58 stakeholders related to expanding pins, based in 10 countries and 3 continents, (ii) traditional expanding pin systems, and (iii) some newly developed pin solutions, in addition to (iv) two literature studies. The study results indicate that stakeholders such as OEMs, Engineering companies (or departments), End-users, and those working with service, repair, and maintenance, highly valuate expanding pin solutions, compared to standard cylindrical pins. The studied pin solution is regarded as safer, faster to install and retrieve, less risk of wear damage, and it is also seen as an important economical factor. In addition, the expanding pin solution can improve bearing function and flange shear capacities, and the anti-loosening bolt can prevent bolt-nut loosening due to vibrations.