Bearing cap having sensor unit, and rolling bearing unit

A bearing cap having a sensor unit comprising:

• a bearing cap mounted to an axially inboard end portion of an outer ring with plugging an axially inboard end opening of the outer ring configured to rotatably support a hub having an encoder supported to an axially inboard end portion of the hub towards an inner diameter-side of the outer ring via a plurality of rolling elements;
• and
• a sensor unit including a sensor and a sensor holder supported and fixed to the bearing cap with holding the sensor, wherein
• the bearing cap includes:
• a fitting cylinder part fitted and fixed to the axially inboard end portion of the outer ring;
• and
• a bottom plate part extending radially inwards from an axial portion of the fitting cylinder part,
• at least the bottom plate part is made by injection molding of synthetic resin,
• the bottom plate part is provided with a holder support part at a position axially facing a part of the encoder, which is an upper position of two positions adjacent to each other in an upper and lower direction at a using state, and is also provided with a nut holding part at a lower position of the two positions,
• the holder support part and the nut holding part are spaced from each other with protruding axially inwards from an axially inboard surface of the bottom plate part,
• the holder support part includes a notched cylinder shape having a discontinuous part at one place in a circumferential direction and the discontinuous part is arranged at a lower part at the using state,
• the nut holding part is configured to hold a nut at an inner diameter-side thereof,
• an upper surface, which faces a lower surface of the holder support part at the using state, of an outer peripheral surface of the nut holding part is configured as a convex curved surface of which a part facing the discontinuous part is positioned at the uppermost part,
• the sensor holder includes:
• a holder main body part holding the sensor at an axially outboard end portion and inserted into the holder support part;
• and
• an mounting flange part, which is provided at a portion of the holder main body part protruding axially inwards from an inside of the holder support part and is configured to bring an axially outboard surface of the mounting flange part into contact with at least an axially inboard end face of the nut holding part out of an axially inboard end face of the holder support part and the axially inboard end face of the nut holding part, and
• the sensor holder is supported and fixed to the bearing cap by screwing a male screw part of a bolt axially inserted into the mounting flange part to the nut.