SFWR GP-A6001 5014297 - Caterpillar

Illustration 1 g06193100
Rear view of a wheel brake assembly
(A) Purge port for the parking brake
(B) Purge port for the service brake
(C) Oil passage for the service brake
(D) Oil passage for the parking brake
(E) Inlet passage for the brake cooling oil
Illustration 2 g06193613
Components of a wheel brake assembly
(1) Spindle housing
(2) Piston for the service brake
(3) Wheel assembly
(4) Plates
(5) Discs
(6) Oil chamber for the service brake
(7) Spring for the service brake
(8) Spring guide
(9) Spring for the parking brake
(10) Piston for the parking brake
(11) Piston housing for the parking brake
(12) Brake anchor
(13) Duo-Cone seal
(14) Spring for the parking brake
(15) Oil chamber for the parking brake
(16) Piston housing for the service brakeWheel assembly (3) is connected to spindle housing (1) by two taper roller bearings. Spindle housing (1) does not turn. Piston housing (11), brake anchor (12), and piston housing (16) are bolted to spindle housing (1). Plates (4) are splined to brake anchor (12). Plates (4) do not turn. Discs (5) are splined to wheel assembly (3). Discs (5) turn with wheel assembly (3).Brake cooling oil flows into the wheel brake through passage (E), cooling plates (4) and discs (5). The brake cooling oil then flows into the final drive and into the axle housing.Purge port (A) is used to remove the air from the hydraulic parking brake system. Purge port (B) is used to remove the air from the hydraulic service brake system.Parking Brake Application
The parking brakes are applied by spring pressure and released by pilot oil pressure.When the parking brakes are engaged, there is no pilot pressure oil at passage (D). Springs (9) and (14) push piston (10), which compresses plates (4) and discs (5) together, preventing the wheel assembly from rotating.When the parking brake is disengaged, pilot pressure oil flows through oil passage (D) into oil chamber (15). Pilot pressure oil forces piston (10) away from plates (4) and discs (5), compressing springs (9) and (14). The reduced friction between plates (4) and discs (5) allows wheel assembly (3) to rotate.Service Brake Application
The service brakes are applied by oil pressure and released by spring pressure.When the service brakes are applied, pressure oil flows through oil passage (C) into oil chamber (6). As the oil pressure increases, piston (2) compresses plates (4) and discs (5) together, slowing the rotation of wheel assembly (3). Continued application of the service brake stops the rotation of wheel assembly (3).When the service brakes are released, pressure oil stops flowing to oil passage (C) and into oil chamber (6). Springs (7) and spring guides (8) pull piston (2) away from plates (4) and discs (5). The reduced friction between plates (4) and discs (5) allows wheel assembly (3) to rotate.