From the
mechanical characteristics viewpoint, electric motor bolts are not put under any particular stress, because the
rotor makes its revolutions without putting them into any mechanical stress.
Unlike some critical bolts of the internal combustion engine, such as the
cylinder head bolts, the
electric motor bolts are not subject to extreme thermal expansion.
As was mentioned, they are characterized by their length and rectilinearity.
Electric motor bolts have a diameter-to-length ratio particularly extreme. The tolerance inside the hole in which they have to be fastened is very narrow, so they must be fully straight to avoid interferences with the internal hole diameter.
Despite this need, during heat treatment, the electric motor bolts tend to deform due to their length, and for this reason, the achievement of perfect rectilinearity is the most critical part of the production phase.
To give an idea of the geometry of the electric motor bolts: their length reaches over 30 times the diameter, a very extreme ratio that by far surpasses that envisaged in internal combustion engine bolts.
To make a comparison, the cylinder head bolts of the internal combustion engine, which in turn have a critical rectilinearity ratio, usually have a length 20 times the diameter or even less.
For this reason, it is essential to carry out a series of dedicated machining and transformations to straighten the electric motor bolts during the various production cycle stages, guaranteeing the demanded rectilinearity.
Thanks to its production process optimization, today Brugola OEB can supply the market with excellent quality electric motor bolts, supported by decades of innovation and custom machining in the field of the most critical fastening elements demanded by the automotive market.
Our bolts do not allow errors or imperfections.
This is why 100% of our products are inspected at the end of the production cycle to guarantee Zero Defects, a characteristic that has always set us apart from the competition, both for productions for internal combustion engines and for electric motor bolts.