Optimisation of grease application to railway tracks

Abstract

Trackside lubricators are designed to deliver grease to passing wheel flanges to reduce wheel and rail wear on curves. Ensuring that they are set up to deliver sufficient grease for the range of vehicles passing a site can be a challenge. For example, vehicle dynamics modelling and site investigations have shown that the wheels of passenger vehicles do not run as close to the rail face as those of freight vehicles, meaning that they are less likely to contact the grease and lubricate subsequent curves. To investigate the effects of different trackside devices, and the influence of parameters governing grease pickup , including lateral wheel displacement and pump durations, a bespoke test rig was built at the University of Sheffield. The rig used a scaled wheel, a short section of rail and a modern trackside lubricator setup. Experiments involving different lateral wheel displacements and pumping durations were carried out, as well as visualisation of grease bulb sizes. This showed how a grease bulb grows. It also indicated that a worn profile is likely to require greater wheel displacement to cause contact with grease bulbs than a new wheel profile. The experimental results showed that increasing pick up of grease can be expected where using an additional component called a GreaseGuide™ fitted to a regular grease dispensing unit (GDU) on the rail. The efficiency of grease pick up was investigated and test results exploring increasing pump durations indicated a relationship between pickup and bulb size. To validate the use of the scaled rig, similar tests were carried out using a full-scale test rig. The full-scale results were compared to the experimental results from the scaled-wheel rig. This showed that whilst there were differences between the two test-rigs in absolute values and anomalous results, overall trends were the same on both test scales. The effect of temperature on bulb size and pumpability of grease was also investigated. This work can be extended further by using the same method to investigate other parameters affecting the lubrication of curves. This can lead to optimised lubricator setup to ensure the track is fully lubricated all of the time.

Multidiscipline design optimization for large-scale complex nonlinear dynamic system based on weak coupling interfaces

“…Finally, the proposal was adopted to replace P8 tread with P12 one, so as to implement the economical re-profiling of wheelset, which has the following four features: i) The anti-RCF design near to flange root is used to avoid the two-point contact on rail shoulder as much as possible; ii) The flange thickness is further reduced by 2 mm, which matches to the UIC 56E1 with bottom inclination of 1/20, and λeN ≈ 0.10; iii) Moreover, UIC60E2 with bottom inclination of 1/40 is partially changed in UK HSR to form hammering impacts but the rail gauge is broadened to1438 mm, to which the P12 tread with flange thickness of 26 mm is matched, λe<0.10; iv) So the economic re-profiling option of wheelset is implemented with the assistance of auxiliary technologies such as proper flange grease spraying [46], and the wheelset re-profiling period is extended twice.…”

Studying the transfer mechanisms of water based top-of-rail products in a wheel/rail interaction

“…Train wheels pass through the puddle picking-up the product and then transferring it back to the rail with each subsequent contact, spreading it further down the track, as shown in Figure 2. 9 Numerous studies have investigated the influence of TOR products on wheel/ rail interface friction using a range of test rigs of different scales, such as a pin-on-disc machine; 10 a twin disc rig, 11,12 full-scale rigs (FSR) 6,13 and scaled-wheel rigs 14 and more recently a high pressure torsion rig 15 However, few studies have investigated product transfer mechanisms that dictate product are pick-up, carry-on along the track and consumption. Some work has been carried out investigating this for grease used for curve lubrication.…”

“…Some work has been carried out investigating this for grease used for curve lubrication. 14,16 While these studies give possible test approaches, the application process and properties for TOR products are very different to greases, so the findings cannot be transferred. One laboratory-based study has been carried out on TOR product pick-up, 17 but in this work, friction was not measured and mechanisms of pick-up/carry-down were not explored in detail.…”

Tribological Performance of Perfluoropolyether (Pfpe)-Based Grease for Potential Application in Automotive Bearings

“…Grease comprises three main components: 1) base oil, 2) thickener and 3) additive packages. Grease lubrication is widely applied in rolling bearings [1], railway tracks [2] and electrical contacts [3]. The broad utilization of grease compared to lubricants in industrial applications is due to its extraordinary characteristics.…”