FYH conducts various tests to confirm the dustproof and waterproof performance of rolling bearings with houses. Representative test results are shown below. Dust-spraying rotation test (dust-proof performance) Using a drum-shaped dust-spraying rotary tester, the dust-proof performance of the product is judged by directly throwing dust on the rolling bearing with a seat while running. Rotational speed: 640 min-1 Load: Only belt tension Dust: Aluminum powder (No. 1000 [sieve]) Lubrication: No grease added during operation Abnormal sound, it can be concluded that dust has penetrated. On the other hand, the triple seal assembly (accessory symbol L3) and the assembly with dust cover (accessory symbol C) did not produce abnormality even after 3,000 hours of operation, and exhibited excellent dust-proof performance. Dust-submerged rotation test (dust-proof performance) The dust-proof performance of the product is judged by burying the rolling bearing with a block in dust and rotating it while stirring the dust with an impeller mounted on the shaft. The service conditions of FYH rolling bearings with houses under this test method are the most severe. Rotational speed: 640 min-1 Load: Only belt tension Dust: GC powder (size 500 [sieve]) Lubrication: No grease supplementation during operation Abnormal sound, it can be concluded that dust has penetrated. On the other hand, the triple seal assembly (accessory symbol L3) and the assembly with dust cap (accessory symbol C) did not produce abnormality even after 2,000 hours of operation, and exhibited excellent dust-proof performance. The impeller for the waterproof performance test runs while throwing water on the FYH rolling bearing with a block to judge the waterproof performance of the product. Rotational speed: 380 min-1 Load: Only belt tension Water: Example of tap water waterproof performance test Results After about 1,000 hours of operation for normal products, rust was found on the balls and raceways (outer and inner rings). On the other hand, the triple seal assembly (accessory symbol L3) and the assembly with a dust cover (accessory symbol C) showed rust to the same extent as normal products after about 2,500 hours of operation.