Modelling of Bearing Ball Lapping Machines for Vibration Monitoring and Quality Control


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Sebastiano Rizzo1*, Irene Pessolano2, Daniela Maffiodo2, Raffaella Sesana2

1* TN Italy spa, 378, Corso Torino – 10064 Pinerolo, Torino, Italy

2 Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy


A ball lapping machine is typically a manufacturing device in which bearing balls are finished between two lapping plates, namely a “stationary” plate and a “rotary” plate. During this process, some undesired phenomena may occur; a monitoring process is needed, to avoid defects like diameter variation, geometrical variances, etc.

Nowadays this process monitoring relies on operator experience and on periodical control of product samples collected during lapping.

Aim of the research is to correlate the vibrational behavior of the lapping machine with the output quality of the manufactured bearing balls and to obtain an automatic or semiautomatic product release based on process data analysis.

A flexible dynamic multibody model (FMBD) of the lapping machine (Figure 1) is implemented for the lapping machine. Moreover, some experimental tests are performed on a lapping machine by placing several accelerometers on the machine with the aim of investigating the vibrational behavior of the machine and correlate some parameters to the onset of Quality product variation.

The vibrational behavior is simulated in working conditions to compare the theoretical simulations with the experimental results (Figure 2).

The success of this study allows to imagine the possibility of extending these activities to other process control and to extend the possibility on this application.

Figure 1: muldy body model of the lapping machine (left) vs actual machine (right)


Figure 2: research flow chart

Please feel free to join Sebastiano Rizzo presentation between 15 – 18 March at the Bearing Expo & B2B Meetings event. Apart from that, you can always contact Sebastiano Rizzo for your individualized advice and questions.

About Sebastiano Rizzo
Company: Tsubaki Nakashima Co. Ltd.
Position: Director
Department: Global Quality & Central Laboratory
Higher education: Material master post diploma

Sebastiano Rizzo received in 1995 a master post diploma issued by Italian Ministry of University and Technological Research related to metallurgical processes.

Currently in charge of Global Quality and Central Laboratory of Tsubaki Nakashima company. His activities are related to process/product development increasing the final applications knowledge and possible performance benefits.

From 2010 to 2012 oversaw development on piston/pins/liners manufacturing company, with responsibility on the metallurgical processes and technical development.

In 2000-2010, he was in Formula 1 racing car company in the material engineering helping to increase the reliability and successes. Between 1995-2010 he had experience in a steelmaking company succeeding to improve the process capability and reliability.

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