A new generation of Koyo Pillow Blocks

Koyo Bearings, a division of JTEKT Corporation, is introducing its new range of “JHS-3i” high performance Pillow Blocks providing further improvements in the housing stiffness and the sealing- and lubrication performance.

Improved Housing

One of the challenges for the Koyo engineers was to increase the stiffness of the housing itself and to assure a more firm mounting of the housing on the supporting frame. After extensive FEM (Finite Elements Method) analyses and a thorough assessment of the stress concentrations in the old design a more robust design could be developed which increased the strength by up to 30% (depending on the direction of the applied forces – see Figure A1 ), while reducing the weight by around 7% at the same time.

Additionally the Pillow Block bolt seat area was increased and the bottom optimized (the seat with recess was replaced by a flat design), leading to a much more accurate and rigid Pillow Block/frame mounted assembly and thereby increasing robustness and eliminating any possible vibrations (Figure A2).

New Seal Design

The next challenge was to improve the sealing performance to keep foreign particles and substances out of the bearing while keeping the grease in, under the most demanding conditions. After intensive bench testing of different seal designs a new version was developed with a special seal lip configuration using an inwards facing lip to make sure that the grease flows back to the balls and raceway during operation and several “defenses” against intrusion from outside (Figure B1).

The new seal design showed considerable improvement in a dust sprinkle rotation test as can be seen in Figure B2 and was selected as the new standard for the Koyo JHS-3i Pillow Block.

Upgraded Grease

The third improvement for the JHS 3i Pillow Block is the newly applied high quality Lithium Complex grease providing several critical improvements compared to the traditional lithium soap based lubricants. The new grease features a wider allowable temperature- and speed range, resistance against water contamination, vibration and high pressure as well as heavy- and shock loads.