GEOMETRIC TOLERANCES INFLUENCE ON SOCKET SET SCREW CONNECTION DIMENSIONING

Abstract

One of the commonly used bolted connections between two rotating elements is a socket set screw connection. Socket set screw connection is commonly used in couplings, between hub and gear, between hub and pulley etc. During the dimensioning of this bolted connection type dominant are two types of loads shearing and surface pressure. Especially critical cases can occur during the hole center positioning in socket set screw connections. If the hole center is moved from a given position the stresses become higher than predicted and that occurrence can lead to the connection failure. Moving the hole center makes the bolt core shear loaded section smaller and surfaces exposed to pressure smaller in one part and bigger in another part. For the purposes of this investigation, the automatic calculation algorithm has been made, which includes hole position tolerances variation. As dimensioning requirements the output torques and RPMs from standard speed reducers are taken, as well as standard coupling dimensions. Influential factors such as bolt dimension, bolt length, bolt quality, and hole position tolerances are presented. Results are given by diagram for each influential factor. The paper concludes with a discussion and further research direction in this field.