Technique for evaluating the efficiency of a V-belt variator in a light vehicle

V-belt variators with automatic pressure mechanisms have prevailed in light vehicles, such as scooters, snowmobiles, quads, all-terrain vehicles, etc. In this regard, it is necessary to develop a methodology for assessing the efficiency of the variator to determine the necessary parameters and performance of the V-belt variator of light vehicles. These vehicles have a small mass (up to 750 kg) and cost and, as a rule, are equipped with engines of low power (up to 75 kW). The constructive simplicity and high manufacturability of the manufacture of a few parts of the V-belt variator, and therefore the lowest cost of them, with a sufficiently high reliability level today provided the variator with the maximum value of the indicator in the form of the “reliability / cost” ratio. This is one of the factors that allowed the V-belt variators to gain leadership in the transmissions of these vehicles. To assess the efficiency of the V-belt variator of a vehicle, a method for estimating the instantaneous positions of the variator operation is necessary, which will help determine the instantaneous values of the necessary parameters and give an opinion on the performance of the variator in this state and the subsequent transient, its speed and efficiency. The technique is based on the determination of the axial forces created by the pressure mechanisms and the radial forces arising from them, the tension forces of the belt branches, taking into account the circumferential force from the transmitted torque. The peculiarity of this technique is to determine the exact position (angles of inclination and direction) of these forces both in the plane of the belt contour and perpendicular to it. The developed technique allows to estimate the work of the designed V-belt variator in all possible engine modes. In addition, the methodology shows the reasons for the inefficient operation of the variator, and also provides recommendations for their elimination. Further development of this technique will allow the design of new constructions of variators with the necessary properties.

variator, pulley, V-belt, belt circuit, powerplant, traction factor, efficiency, interaxle distance, belt tension, torque