Guide shoes for elevators with composite liners

This case study was compiled based on the results of controlled operation of the guide shoes complete with composite liners produced by Oxafen Tech. The liners were made of wear-resistant material Oxafen (TU-2256-010-58516576-2009) and handed over for installation to the facility of controlled monitoring (Elevator No. L3 - Contract MOS OTIS - E2NA-5666) located at: 1, Teatralnaya Ploschad, Moscow, Russian Federation (the "Bolshoi Theatre").

The purpose of the installation was to determine the possibility of increasing the service lifetime by using the anti-friction material Oxafen in the friction units experiencing an increased load during the operation of the elevator.

The basis for carrying out the controlled operation was increased wear and tear of the shoe liners supplied by the manufacturer (Liftmaterial München). The period of increased wear and tear observed since the elevator was commissioned totaled 90 days. The average wear and tear time of the "original" shoe liners is 7 days. The shoe liner was installed in 2011 and has not been changed ever since.

In December 2011, after the executed installation of a set of shoes (eight pieces) complete with liners made of composite material Oxafen produced by Oxafen Tech, the elevator No. L3 was put under controlled operation by the specialists of the Bolshoi Theatre elevator department jointly with the representatives of MOS OTIS.

In the course of the controlled operation, routine inspections of the operability status of the installed liners and mating elements were carried out.

The first phase of the controlled operation was carried out in the mode of increased wear and tear loads: The elevator car was skewed, on the surface of the guides there were sections with roughness.

The second phase of the controlled operation was carried out after elimination of increased wear and tear loads (in normal mode).

During the period from the beginning of December 2011 to the end of May 2012 (6 months) of the controlled operation of elevator No. L3 in different modes:

• a decrease in the intensity of wear and tear of shoe liners by 4 times (and more) was determined in comparison with the "original" ones;
• the possibility of operation in the mode of insufficient lubrication of friction surfaces of composite shoes and mating elements was established;
• compliance of the mechanical and tribotechnical characteristics of the polymeric composite material Oxafen specified by the manufacturer (Oxafen Tech) with increased loads affecting the elements of the friction units of the elevator was confirmed .