The technology behind the Shock Pulse Method The Shock Generator The technology behind the Shock Pulse Method The Shock Pulse transducer 5-7 f1 f2 fm 32 kHz The SPM® Transducer o o o o o 5-7 times more sensitive to shocks then vibration transducers Well defined amplitude response at its resonance frequency Mechanically tuned, filter out low frequency vibrations (band pass filter) Well defined and fast dampening of the resonance Signal, “ringing” Electrical tuning 32 kHz Data Acquisition Transducer RPM Data Acquisition SPM Digital Enveloping Signal after bandpass filter After rectifying After enveloping Transients from Shocks Time dBsv Time Signal to Noise Ratio HD-Normalization HDi Development of SPM®HD Industry challenges • • • Expensive breakdowns Short pre-warning time Long delivery times on replacements Technical challenges • • • Low rpm Changes in the process Disturbances Twin Wire Press 13 S roll on lower section Time signal HD before bearing replacement in December 2009 15 RPM Fig Case 1: Time signal HD after replacement in December, 2009 Twin Wire Press 13 nip 3, DS on lower section Twin Wire Press 13 nip 3, DS on lower section SPM HD Time signal from April 2009 10 RPM rev Fig Case 2: Time signal HD late April, 2009 Twin Wire Press 13 nip 3, DS on lower section Time signal HD before bearing replacement in January 2010 rev Cracked inner race, spalling along entire inner race months’ forewarning Note the typical, cracked inner race pattern Twin Wire Press 13 nip 3, DS on lower section Time signal HD after bearing replacement in January 2010 Twin Wire Press 13 nip 3, DS on lower section HDm values from mid-October 2009 Decreased values after bearing replacement in January 2010 Bearing change October 2009 January 2010 Twin Wire Press 12 Nip 2, FS on lower section Twin Wire Press 12 Nip 2, FS on lower section Time signal HD before bearing replacement in February 2010 10 RPM Cracked inner race, spalling on both inner and outer races months’ forewarning Note the typical, cracked inner race pattern Twin Wire Press 12 Nip 2, FS on lower section HDm values after bearing replacement in February 2010 15 RPM Revolution Fig 14 Case 3: Time signal HD late April, 2009 Twin Wire Press 12 Nip 2, FS on lower section HDm values from mid-October 2009 Decreased values after bearing replacement in February 2010 Bearing change October 2009 February2010 Twin Wire Press 11 Nip 2, DS, Lower section Twin Wire Press 11 Nip 2, DS, Lower section Time signal HD from January 2010 before replacement 15 RPM Severely damaged outer race Inner race no signs of damage About months’ forewarning Fig 21 Case 4: Time signal HD late January, 2010 Twin Wire Press 11 Nip 2, DS, Lower section HD Time signal November 2009 – after replacement 14 RPM Fig 20 Case 4: Time signal HD November, 2009 Twin Wire Press 11 Nip 2, DS, Lower section HDm values from mid-October 2009 Decreased values after bearing replacement in February 2010 Bearing replaced October 2009 November 2009 Fig 23 Case 4: HDm values from mid October, 2009 onwards showing decreased values after bearing replacement February 2010 © Copyright SPM Instrument AB 2010 71914 B ... Acquisition SPM Digital Enveloping Signal after bandpass filter After rectifying After enveloping Transients from Shocks Time dBsv Time Signal to Noise Ratio HD- Normalization HDi Development of SPM HD. .. accurate readings from a complex signal Random Impacts are filtered out HDsv 30 20 10 Time Number of impacts Disturbance 10 20 30 HDsv Direct evaluation Disturbance Rejector Data Acquisition RPM •... The technology behind the Shock Pulse Method The Shock Pulse transducer 5-7 f1 f2 fm 32 kHz The SPM Transducer o o o o o 5-7 times more sensitive to shocks then vibration transducers Well defined