STRUT BEARING DEVICE, VEHICLE STRUT SUSPENSION, PRODUCING METHOD OF LOWER CASE AND SEAL OF STRUT BEARING DEVICE, AND PRODUCING METHOD OF UPPER CASE AND SEAL OF STRUT BEARING DEVICE

Annular joint surfaces (D, E) of a lower case (3) of a strut bearing device respectively have case-side projections (F, G) that project in an axial direction. Shapes (A) of the case-side projections, seen in an axial direction, continue in a circumferential direction, and vary their position in a radial direction along the circumferential direction. An inner-diameter side seal (8) has a seal-side recess (H) fitted to the case-side projection (F). An outer-diameter side seal (9) has a seal-side recess (I) fitted to the case-side projection (G). With this configuration, joining strength of a seal in a strut bearing device can be increased, and a risk of the breakage of a molding die for molding the seal is lowered.