Division 4.2.3 Test set-up ‘Type A’

A test set-up considered ‘Type A’ consists of a dynamometer on the axle input side and at least one dynamometer on the axle output side(s). Torque measuring devices shall be installed on the axle input- and output- side(s). For type A set-ups with only one dynamometer on the output side, the free rotating end of the axle shall be locked.

To avoid parasitic losses, the torque measuring devices shall be positioned as close as possible to the axle input- and output- side(s) being supported by appropriate bearings.

Additionally mechanical isolation of the torque sensors from parasitic loads of the shafts, for example by installation of additional bearings and a flexible coupling or lightweight cardan shaft between the sensors and one of these bearings can be applied. Figure 1 shows an example for a test test-up of Type A in a two dynamometer lay-out.

For Type A test set-up configurations the manufacturer shall provide an analysis of the parasitic loads. Based on this analysis the approval authority shall decide about the maximum influence of parasitic loads. However the value i_para cannot be lower than 10 %.