With the philosophy in mind to give full service to our customers, in 2001 we developed our first full plastic gear line to be used in automotive applications. Today plastic molded gears are showing new potentials and new advantages that can be exploited, since they can be easily used for applications that cannot be served by metal gears. Inspection equipment is now capable of measuring these unique parts with great precision.
The Double Flank Gear Rolling test is used to determine and validate process control, simulating gear working conditions and assuring consistency of the molded part in production. Roll testing can give an indication of shrinkage tolerances by detecting/measuring center distance deviation and looking at the total effect of gear errors, but it cannot calculate the amount of error or correction needed. It is usually used to assure that the same gear sizes are molded consistently during the production process. The Double Flank Rolling Test consists of the following parameter evaluations: Fi” - Total composite error (TCE) or Double Flank Rotational Deviation: this represents the difference between the biggest and the smallest center distance during one revolution of the part. Gear quality can be judged from here and when values are out of tolerance, it is possible to easily identify problems and correct them. fi” - Tooth to Tooth error: Represents the quality of the teeth of the gear. It is revealed as a variation in the working center. Fr” - Runout error: Reveals eccentricity errors. Aa” - Average center Distance: Checks the gear size during a rolling test. Master gears are brought into contact with the work gear for testing. Their material and profile quality has to be better than the tested gear, while speed has to be slow enough to guarantee correct movement of the measurement. This depends on the diameter, width and weight of the gear, avoiding the center distance change between the master and tested gear. Also, the measuring force must be correct since it can easily influence test results preventing typical test errors such as profile error, deviation of the outer flank, tooth thickness variations, pitch errors or profile waviness.
By measuring the complete gear, the rolling test allows GVS total quality (100% check) control production for several kinds of gears in plastic as well as metal shafts with toothed co-molded sector for DBW (Drive by-wire), middle gears and pinion gear technologies for automotive. All of these and many others are the controls applied by GVS during production. Through an innovative Machine, we are able to give you a fully automatic 100% inspection. Our great experience in different polymers can help our customer in choosing the best plastic for their specific applications.