Wear prediction system of joint gear of industrial robots based on facility life cycle simulation

To improve the productivity of manufacturing systems, it is necessary to make best use of the capacities of manufacturing facilities. However, the facilities suffer from operational and environmental stress during operation, and their functions degrade due to deterioration of their components. Hence, if the aging process of facilities can be estimated, this will be useful for various purposes such as reliability design of the facility, operational planning, and maintenance planning. For this purpose, we have studied a life cycle simulation in which the aging process of facility under specified operating conditions is evaluated. In this paper, we have applied the life cycle simulation to industrial robots equipped with wave gears for their joints, and proposed a method for evaluating wear of tooth surface of the gear taking account of the Elasto-Hydrodynamic Lubrication of grease. As a result of the simulation, we find that deterioration process of the gears is divided into two patterns depending on the magnitude of operational load. The results of the experiments gave good agreement with the value obtained by the system.