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Reducing the vibrations in Scania’s test cells

Sjöholm, Johan LU (2016) In Diploma work MME820 20161
Machine Elements
Abstract
This thesis aims to present different ways of handling the vibrations for large displacement single cylinder engines (test beds). These test beds are used for development purposes at Scania. The imbalances causing the vibrations are discretized which are then suppressed using counter weights and carefully designed balance shafts. It is found that with some unconventional designs, balance shafts can be used to suppress both oscillating forces and moments. The moment balancing is restricted to a single load condition and engine speed. By dimensioning these shafts with respect to engine assembly’s critical speeds, an engine speed range completely free from resonance behaviour can be achieved. Various balancing measures are presented using... (More)
This thesis aims to present different ways of handling the vibrations for large displacement single cylinder engines (test beds). These test beds are used for development purposes at Scania. The imbalances causing the vibrations are discretized which are then suppressed using counter weights and carefully designed balance shafts. It is found that with some unconventional designs, balance shafts can be used to suppress both oscillating forces and moments. The moment balancing is restricted to a single load condition and engine speed. By dimensioning these shafts with respect to engine assembly’s critical speeds, an engine speed range completely free from resonance behaviour can be achieved. Various balancing measures are presented using numerical simulation from analytically derived equations.

Different types of engine mounts are also studied and evaluated from the test bed perspective. It is shown that the active engine mount systems offers benefits over other engine mount designs. While these systems may be costly and troublesome to implement to road vehicles, several aspects can be identified for the test beds offering cheaper and less complex implementation. (Less)
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author
Sjöholm, Johan LU
supervisor
organization
course
MME820 20161
year
type
H2 - Master's Degree (Two Years)
subject
publication/series
Diploma work
language
English
id
8626495
date added to LUP
2016-02-15 13:52:53
date last changed
2016-02-15 13:52:53
@misc{8626495,
  abstract     = {This thesis aims to present different ways of handling the vibrations for large displacement single cylinder engines (test beds). These test beds are used for development purposes at Scania. The imbalances causing the vibrations are discretized which are then suppressed using counter weights and carefully designed balance shafts. It is found that with some unconventional designs, balance shafts can be used to suppress both oscillating forces and moments. The moment balancing is restricted to a single load condition and engine speed. By dimensioning these shafts with respect to engine assembly’s critical speeds, an engine speed range completely free from resonance behaviour can be achieved. Various balancing measures are presented using numerical simulation from analytically derived equations.

Different types of engine mounts are also studied and evaluated from the test bed perspective. It is shown that the active engine mount systems offers benefits over other engine mount designs. While these systems may be costly and troublesome to implement to road vehicles, several aspects can be identified for the test beds offering cheaper and less complex implementation.},
  author       = {Sjöholm, Johan},
  language     = {eng},
  note         = {Student Paper},
  series       = {Diploma work},
  title        = {Reducing the vibrations in Scania’s test cells},
  year         = {2016},
}