The optimum size of the diameter with interference fit connections

Abstract

When designing machines and mechanisms for joining parts are often used an interference
fit. In the design of the designer is faced with the necessity of the appointment of the nominal size
of the diameter of the seating surface on which the mating parts with interference will occur.
For this size are presented two contradictory requirements. On the one hand, it should be as
large as possible to increase the interface area and, accordingly, the friction forces. On the other
hand, the size should be as small as possible to increase the contact pressure.
The paper presents the mathematical relationship to determine the optimal size of the
coupling diameter to obtain in conjunction with interference maximum friction torque.
For example, the assembly of pinion shafts excavator EKG-8 determined the optimal size of
the compound and proven its advantage over currently used. At the same time when using the
assembly method with thermal heating by exposure of the female part - gears in the induction
heating setting, in addition to increasing the strength of the joint, reducing the for the assembly of
the heating temperature and the mass of the heated metal. This will reduce the cost of technology
assembly and repair of the excavator parts.