Research of wear resistance and loading ability of rubbers for sheaves with the rubber covering

The polymeric cables with load-carrying capacity to 60 tons are widely applied in the modern lifting and transport equipment at the enterprises of the aerospace industry. The surface of a steel pulley at contact to a polymeric cable has a rubber covering for creation of demanded traction ability. Thus we have next requirements to properties of rubbers for coverings simultaneously: the maximum value of friction coefficient (tractive ability), high wear resistance (wear life), high loading ability (absence of catastrophic wear of rubber) and lifetime of a surface layer of rubber (absence of fatigue cracks for all service life). The contact of rubber and cable made from high modulus polyethylene (HMPE) was considered in the given article. Questions of a choice of structures of rubber for creation of rubber coverings on working surface heavy-loaded pulleys of the lifting and transport equipment of the aerospace industry at contact to a polymeric cable are experimentally solved. Structures of rubber were estimated on base of them frictional properties and loading ability. The design of the stand of back-and-forth motion and technique of researches of a friction coefficient and wear of rubbers is described. The stand design includes crank-and-rod mechanism, loading system of the samples and system of measurement of friction coefficient. At tests at the stand probably change of speed of back-and-forth motion of samples from 0.02 to 0.5 m/s. Pressure upon surfaces of a friction of samples can be regulated in a range from 0.2 to 20 МПа. It depends on weight of cargoes and the sizes of samples. Measurement of friction coefficient was spent by means of strain-gauge unit. Value of a signal from an exit strain-gauge unit was measured by digital remembering oscillograph PCS-500A working complete with the computer. The wear of rubber was defined by the method of artificial bases. Experimental dependences of a friction coefficient and intensity of wear process at pressure upon contacting surfaces of rubber and a cable are receivedSurvey of surfaces of rubber after wear process and supervision over a course of experiments have shown that in this case there is a fatigue wear process of rubber that corresponded to the beginning of separation of rubber macro particles. It is established that at certain pressure the established mode of wear process (linear dependence) passes in the catastrophic Sizes of critical pressure for all investigated rubbers are defined. Use of a finite elements analysis has allowed creating certainly-element model of contact of a cable with a surface of a rubber layer on a pulley. On the basis of the analysis of this model are studied durability of layers of various rubbers from the point of view of formation of fatigue cracks and their durability on wear process.