Brake apparatus for vehicle

A brake apparatus for a vehicle comprising:

• a caliper module having a cylinder part that faces a pad plate module;
• a piston module installed on the cylinder part so as to be movable forward or rearward and configured to deform the cylinder part by using a reaction force generated when the pad plate module is pressed;
• a transmission module installed on the cylinder part and configured to move the piston module forward or rearward;
• and
• an actuator connected to the transmission module,
• wherein an installation angle of the transmission module with respect to the piston module is changed when the cylinder part is deformed, such that a movement of the transmission module relative to the cylinder part is prevented,
• wherein the actuator comprises,
• a housing;
• a drive part configured to generate power;
• a power transmission part disposed in the housing and configured to transmit the power to the piston module while rotating in conjunction with an operation of the drive part;
• and
• an anti-collision part disposed between the housing and the power transmission part and configured to prevent a collision between the housing and the power transmission part,
• wherein the power transmission part comprises:
• a first power transmission part configured to rotate by receiving the power from the drive part;
• a second power transmission part configured to engage with the first power transmission part and rotate in conjunction with a rotation of the first power transmission part;
• and
• a third power transmission part configured to engage with the second power transmission part and rotate in the same direction as the first power transmission part in conjunction with a rotation of the second power transmission part,
• wherein the second power transmission part comprises:
• a second rotary shaft, which is the rotary shaft of the anti-collision part penetrates through the through hole of the anti-collision part and is fixed to the housing;
• a first gear configured to rotate about the second rotary shaft and engage with the first power transmission part;
• a second gear configured to extend from the first gear, have a smaller diameter than the first gear, and engage with the third power transmission part;
• and
• a first friction reducer disposed between the first gear and the second rotary shaft and configured to support the first gear so that the first gear is rotatable,
• wherein the first friction reducer comprises:
• an insertion portion in sliding contact with an inner peripheral surface of the first gear and configured such that the second rotary shaft is inserted into the insertion portion;
• a support portion extending in a radial direction of the insertion portion and configured to adjoin the housing and support the insertion portion;
• and
• a cut-out portion configured to penetrate the insertion portion and induce deformation of the insertion portion when the second rotary shaft is inserted into the insertion portion.