| 摘要 |
PROBLEM TO BE SOLVED: To provide a bearing unit with built-in rotary encoder capable of improving product yields and productivity. SOLUTION: A sensor retaining hole 51 is drilled on a lower part of a central portion of an outer ring 3 in an axial direction, and a magnetic sensor 5 being one side of a constituent element of a rotary encoder 53 is internally inserted and firmly fixed in the sensor hole 51. Further, a cylindrical portion 57 which is located inside rather than a small rib 25 is arranged on a first inner ring 15, and a tone wheel 59 being other side of a constituent element of the rotary encoder 53 is externally fitted and firmly fixed on the cylindrical portion 57. The tone wheel 59 is a radial magnetic type in which magnetic rubber is vulcanized onto core metals, and the outer diameter D2 of the wheel is set to be smaller than the outer diameter D1 of a small rib 25. |
