Disc brake device and method for assembling same

A disc brake device comprising:

• a caliper having a plurality of cylinders on an inner side in an axial direction with respect to a rotor;
• a plurality of pistons fitted into the plurality of cylinders, respectively;
• a plurality of rotation-linear motion conversion mechanisms that are disposed in the plurality of cylinders, that are configured to push out each of the plurality of pistons toward the rotor by converting a rotational motion into a linear motion, and that include rotation members and linear motion members;
• a motor gear unit that is supported and fixed to the caliper and includes an electric motor, a plurality of output members disposed coaxially with the rotation members and configured to transmit rotation of the electric motor to the rotation members, the number of which is the same as the number of the rotation members, and a housing accommodating the electric motor and the plurality of output members;
• a plurality of annular seals that are disposed coaxially with the rotation members and configured to perform sealing between the caliper and the housing, the number of which is the same as the number of the rotation members;
• a position restriction portion configured to restrict a position of the motor gear unit with respect to the caliper;
• and
• a fixing portion configured to fix the caliper and the housing, wherein
• the annular seals are sandwiched in the axial direction between the caliper and the housing,
• the position restriction portion includes:
• at least one caliper-side restriction portion provided on the caliper, which is disposed non-coaxially with the rotation member and is configured to serve as a reference of a position of the rotation member;
• and at least one housing-side restriction portion provided on the housing, which is disposed non-coaxially with the output member and is configured to serve as a reference of a position of the output member, and is configured to restrict a position of the housing with respect to the caliper by bringing the caliper-side restriction portion and the housing-side restriction portion into contact with each other, and
• the caliper-side restriction portion has a convex shape protruding in the axial direction.