Plastic tuners for power steering pump noise reduction.

Abstract

Tuning cables of various designs are commonly included in automotive power steering systems to reduce the undesirable effects of pressure pulsations generated in the power steering pump. A recent development which has the potential to reduce noise is the plastic tuner (PT). The main benefit of this device when compared with the existing spiral wound steel tuner (SWST) is the vastly reduced cost associated with the methods of manufacturing. Despite the apparent attractiveness of such a device, the PT has not been widely implemented by automotive fluid system suppliers. The main reason is relatively little is known about the performance of these devices and indeed their comparative performance with respect to a SWST. This research seeks to address this issue by developing a better understanding of the PT using experimental and analytical techniques to examine the acoustic noise reduction mechanisms of a variety of PT designs. This thesis examines the relevant literature associated with the subject and covers several noise reduction techniques that can be applied to this research. The literature review section highlights a general gap in the knowledge base, where little specific detail exists that has not been derived experimentally from SWSTs. As such the general aim of this research is to further the knowledge into PTs, investigate the significant parameters of PT designs, and generate a suitable system model. The methodology proposed to achieve these aims is explained in detail and experimental and theoretical approaches are outlined. Finally, conclusions derived from the experimental investigations are discussed and a comparison is drawn between experimental and predicted results. For all PT parameters evaluated, good agreement is illustrated between predicted and experimental results.