Patent ID: 8128290

Claim:
A rolling bearing unit including a sensor, the rolling bearing unit comprising: a first raceway member, on an outer circumferential surface of which a raceway surface is provided; a second raceway member, on an inner circumferential surface of which a raceway surface is provided; a plurality of rolling elements arranged between the raceway surface of the first raceway member and the raceway surface of the second raceway member; a base plate, a shape of which is formed into an annular and flat shape, including a through-hole that the first raceway member penetrates; a plane-shaped first coil arranged so that the first coil surrounds an overall circumference of the first raceway member; and a plurality of plane-shaped second coils arranged around the first coil along a circumferential direction of the first coil, wherein the base plate includes a first portion which is formed into an annular and flat shape and includes the through-hole that the first raceway member penetrates and a second portion which is formed into a flat shape and crosses the first portion, wherein the first coil is arranged in the first portion, and wherein the second coils are arranged in the second portion.