There Are Two SCARA Robots at the Heart of the System
The strong urge to use the most advanced technologies, suggesting cutting-edge process solutions, has always been the key to the development of the Fag-Melò’s activities: This concern specializes in the design and construction of assembly and testing systems which are largely meant for the gear motors world and in general for the mechanical components industry. In the case in point, we are talking about an automatic plant, designed fro the automatic lubrication of the sealing rings, an issue which is common not only to gear motor manufacturers but to any application where there is a rotating shaft.
by Fabrizio Garnero e Giorgia Stella
Fag-Melò srl is a concern which specializes in the design and construction of assembly and testing systems, handling systems and special automation systems meant above all for the gear motor and mechanical components industries and for aluminium foundries. These markets establish a continuity with the company’s early days; in 1987 the company was founded to produce hydraulic blocks and plants and hydraulic units. The two founder partners, Franco Aldrovandi and Antonio Gilioli, who later left the company for different reasons, had accrued a long professional experience in these domains, one as a distributor of hydraulic components and the other employed by Magneti Marelli as manager of the Technical Plants.
“To this day, Fag-Melò cooperates with different companies which manufacture gear units” Marcello Aldrovandi explains; today, having taken over from his father Franco, he successfully manages the company based in San Cesario Sul Panaro. “Between Modena and Bologna there are several production concerns of this type; we could easily describe it as a real Italian district present on this territory. It was therefore normal and natural to start cooperating with many of the companies in the area. Geographical proximity, knowledge of suppliers and clients in common and the transfer of professionals from one company to another contributed over time to establish Fag-Melò as a competent partner, appreciated for its capability of suggesting cutting-edge process solutions in this particular domain”.
Evidence of this capability is provided by an automatic plant developed for the automatic lubrication of the sealing rings, an issue familiar not just to companies manufacturing gear motors but also to all applications including a rotating shaft.
It separates rings, lubricates them and deposits them neatly
Rings normally used in the construction of gear motors are made out of rubber. To increase their working life a layer of lubricating grease must be placed on the internal ring to lubricate the area which is in contact with the rotating shaft. This operation, in most cases, is carried out manually by an operator who with a brush applies a thin layer of grease. It is evident that in this way it is difficult to apply a constant amount of grease, but above all there is the risk that an insufficient amount of grease may jeopardize the life span of the product where the ring must be mounted. In the specific case of the plant developed by Fag-Melò, the operator loads the loose rings in one of the loading hoppers without worrying about their positioning since the machine will take care of directing and separating them. The operator of course also places the empty poxes where the rings will be palletized.
The machine can manage up to three types of boxes with different sizes. In this way the capacity of each box may be customized, depending on the requests of the various assembly centres.
By means of a bar code reader the operator identifies the code on the box; the machine automatically loads the work program and, quite autonomously, separates the rings, lubricates them and neatly places them in the boxes.
Manufacturing without interruptions
The machine designed by Fag-Melò allows to lubricate various types of rings in sizes which vary from 20 by 32 by 7 to 60 by 90 by 10 mm; this requested the presence of two loading hoppers, so as to eliminate down time between one production lot and another.
Various production lots must indeed follow one another uninterrupted and since even rings with different sizes may be loaded in the two hoppers, the machine is set up automatically without any need for the operator to take action. The client, besides, requested a production autonomy of 1 hour at top speed, to allow the operator to distribute the boxes containing the rings to the various assembly centres present in the plant without having the machine stop. For this reason the system has been equipped with two conveyor belts which upload and download the boxes automatically so as to guarantee what has been requested.
The SCARA robot handles the rings with rather high dynamics
Speaking about runtime, it should be mentioned that the productivity envisaged by the specifications is 20 items per minute, which implies rather high handling dynamics. This suggested the introduction of two SCARA robots by Denso, which were considered the most appropriate for this type of application, since the rings must be manipulated with their axis constantly vertical. The gripping system which was developed allowed, by means of an appropriate programming of the robot, to lubricate the ring without having to deposit it on a dedicated work station. This would have increased the cycle time with a consequent reduction in productivity.
“Even in this case we worked with KLAIN robotics for the integration of the SCARA robots, which we has already used in the past for another application to dose sealant on gear unit cases” Mr Aldovrandi again stated, adding: “Denso robots’ reliability is proven and KLAIN’s technical service is always fast, which is very important for us given the very compressed development times which, increasingly often, characterize our job. Why should we change?”