Condition monitoring improves grinding process

Mon­i­tor­ing the con­di­tion of bear­ings is not only a way to detect the need for their replace­ment, but a way to draw con­clu­sions about the state of the entire machine or sys­tem. To illus­trate the ben­e­fits of NSK’s Con­di­tion Mon­i­tor­ing Ser­vice (CMS), two prac­ti­cal exam­ples high­light what can be offered to users of grind­ing machines.
As part of its AIP+ (Added Val­ue Pro­gramme), NSK’s CMS is a method to deter­mine the health of machine com­po­nents such as bear­ings while the machine remains oper­at­ing. A mea­sure­ment sys­tem, spe­cial­ly designed for the pur­pose, records the vibra­tion, tem­per­a­ture and rpm of machine com­po­nents, and analy­ses them using advanced soft­ware. The soft­ware cre­ates the under­ly­ing data used to assess the life expectan­cy of bear­ings, and indi­cates whether there is insuf­fi­cient lubri­ca­tion, for exam­ple, or if there are dents or align­ment errors. This data pro­vides a deep­er insight into the con­di­tion of the total sys­tem or process.
Data from the process can also be used to deter­mine (or at least nar­row down) the caus­es of form errors in the grind­ing process. NSK has used this method at a fac­to­ry of its own in the UK. In this case, form errors were occur­ring on the machine respon­si­ble for grind­ing the bear­ing race­ways. After sev­er­al repair attempts and a fruit­less search for pos­si­ble faults, it was sus­pect­ed that the bear­ings must have a defect. Look­ing to find a defin­i­tive res­o­lu­tion, NSK decid­ed to have a sta­tus analy­sis car­ried out via the CMS.
After read­ing the dri­ve data and con­sid­er­ing impor­tant fac­tors – such bear­ing and motor details – mea­sure­ments were made pri­or to and after replac­ing the bear­ings. The analy­sis showed that nei­ther the spin­dle nor work-head dress­er were the cause of the form errors. This saved the main­te­nance per­son­nel from spend­ing many hours strip­ping down the spin­dle. Instead, the team very quick­ly found the true cause of the issue, after which no fur­ther prob­lems occurred with the race­way form or sur­face finish.