Jones & Shipman 1307 EIU ID grinding spindle from a universal cylindrical grinder
Jones & Shipman 1307 EIU, 20,000 RPM, grease lubrication, pulley driven
The bearings in this ID grinding cartridge spindle were very noisy when rotated in assembly incoming, confirming our customer’s indication. Upon disassembly we noted that the grease in both the front and rear pairs of bearings was contaminated with coolant and swarf. This severe degradation of the bearing lubrication would account for our customer’s other stated observation of high heat during operation. We also noted that the quill pilot ID taper had excessive runout of 6-8µm when measured on the bare shaft.
We completed an in-house kiss grind of the quill pilot ID taper, and rebuilt the spindle with all new bearings. We finished this rebuild with our final test run, break-in, trim balance and final QC. The outgoing runout of the quill pilot ID taper was <2µm. The spindle temperature never exceeded 85°F, measured at both the front and rear of the cartridge during final test run.