Patent ID: 8893860

Claim:
A brake device for a work vehicle adapted to be disposed within an axle housing of the work vehicle, the brake device comprising: a brake unit including a brake disc plate, and a piston having a slide portion slidably supported by the axle housing and a pressure portion on which a pressure surface is formed for pressing the brake disc plate; and a slack adjuster mechanism that maintains a clearance between the piston and the brake disc plate at a predetermined clearance by mechanically adjusting a non-actuated position of the piston, the slack adjuster mechanism being formed by a member arranged on a piston rear surface side disposed on an opposite side from the brake disc plate and arranged further on an inner peripheral side than a slide portion of the piston, the member disposed further on the piston rear surface side than a pressure portion side end surface of the piston, wherein the slide portion of the piston is formed in a tubular shape and axially protruding from a lateral surface opposite to the pressure surface of the pressure portion, the slack adjuster mechanism includes a tubular carrier having a plurality of cases, the carrier being disposed on the inner peripheral side of the slide portion of the piston, a rod disposed within each of the cases and axially movable, the rod having a tip portion protruding from the case and being coupled to an inner peripheral part of the piston, the rod having a tip surface positioned further on the piston rear surface side than the pressure portion side end surface of the piston, and an adjustment portion disposed within each of the cases, the adjustment portion being configured to adjust a protruded amount of the rod from the case in a non-actuated state of the piston in accordance with an abrasion amount of the brake disc plate, and each of the cases includes sequentially from a brake unit side along an axial direction a first opening through which the rod penetrates, a second opening having a diameter greater than a diameter of the first opening, and a third opening in which the adjustment portion is disposed, the third opening having a diameter greater than the diameter of the second opening.