The reduction of noise and vibration levels in tracked off-road machines is still a challenge. During operation, high noise and vibration levels are generated by the tracked locomotion sys-tem and at the working station cause worse noise and vibration conditions and significant risk level for operator. On the other hand, the high vibration levels produce detrimental effects on the machine itself, shortening the service time of many components. Research is in progress aimed at finding solutions able to improve the vibroacoustic performance of these tracked lo-comotion systems. The use of rubber tracks has shown to be a good solution for this purpose and studies are in progress to find the best combination of manufacturing methods and rubber technology which lead to the lowest noise and vibration generation as well as to higher traction power and durability. This paper presents the results of experiments aimed at testing two differ-ent types of rubber tracks, mounted on the same tracked loader, as regards vibrations transmitted to the cab structure and noise and vibration levels at the operator position. Acquisitions were performed in travelling conditions both on an asphalt path and an artificial test track. Measure-ments were also repeated in stationary conditions in order to separate the vibration contributions generated by the locomotion system from those due to other significant sources such as the en-gine and the cooling system. Structural vibration were acquired in three different positions on the machine structure with the purpose of characterizing the transmission path from source (tracked system) to receiver. In addition, the total values of the whole-body and hand-arm vibra-tions were determined according to ISO 2631 and ISO 5349 standards and the noise spectrum at the operator measured according to ISO 11201. Results showed how manufacturing technology can greatly affect the noise and vibration generation process.
THE EFFECTS OF DIFFERENT RUBBER TRACKS ON NOISE AND VIBRATION LEVELS AT THE OPERATOR STA-TION OF A TRACKED OFF-ROAD MACHINE
Giuseppe Miccoli;Eleonora Carletti
2017
Abstract
The reduction of noise and vibration levels in tracked off-road machines is still a challenge. During operation, high noise and vibration levels are generated by the tracked locomotion sys-tem and at the working station cause worse noise and vibration conditions and significant risk level for operator. On the other hand, the high vibration levels produce detrimental effects on the machine itself, shortening the service time of many components. Research is in progress aimed at finding solutions able to improve the vibroacoustic performance of these tracked lo-comotion systems. The use of rubber tracks has shown to be a good solution for this purpose and studies are in progress to find the best combination of manufacturing methods and rubber technology which lead to the lowest noise and vibration generation as well as to higher traction power and durability. This paper presents the results of experiments aimed at testing two differ-ent types of rubber tracks, mounted on the same tracked loader, as regards vibrations transmitted to the cab structure and noise and vibration levels at the operator position. Acquisitions were performed in travelling conditions both on an asphalt path and an artificial test track. Measure-ments were also repeated in stationary conditions in order to separate the vibration contributions generated by the locomotion system from those due to other significant sources such as the en-gine and the cooling system. Structural vibration were acquired in three different positions on the machine structure with the purpose of characterizing the transmission path from source (tracked system) to receiver. In addition, the total values of the whole-body and hand-arm vibra-tions were determined according to ISO 2631 and ISO 5349 standards and the noise spectrum at the operator measured according to ISO 11201. Results showed how manufacturing technology can greatly affect the noise and vibration generation process.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
