Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
Since cable shifting is a new sector for Scania, they want to have methods for analysis
and evaluation of such a system, but also possibilities of making comparisons
between dierent gear shifting devices regardless of the type of system. For that purpose
several measures and plots been have developed in order to work as tools for
evaluation and comparison of gear shift devices. The more important among those
are:meanboxplotslength, Tp-play, system rigidity, and wire buckling degree if a cable
shifting device is to be analyzed.
The report explains how to proceed when doing an analysis with FEM, but also
with rough estimations using simple formulas for calculations of the backlash in the
cable and the eciency. Input to those formulae are the total bending angle, the
friction coecient and the play between the core and the liner. Three dierent gear
shift devices have been investigated with those methods whereas two where with
cable and one was a linkage. Analysis indicates that the amount of increased play
in the system due to wear is about 36 %.
One diculty with transporting push loads in cables is that the core buckles
inside the liner at straight parts. The wire buckling degree has been developed in
order make comparison between dierent cable layings. Therefor is it recommended
to avoid straight parties in order to keep the buckling at a low level.
Regarding the gear shift housing for the cable - a design proposal has been made
that propose that a push force on the lever should give a push force in the cable.
2014. , 48 p.