Abstract: A mixer drum driving device includes a mixer drum, a hydraulic motor, a hydraulic pump, an auxiliary hydraulic pump for rotating the mixer drum for mixing by supplying pressure oil to the hydraulic motor independently of the hydraulic pump, and a direct-current brush motor for driving and rotating the auxiliary hydraulic pump. The auxiliary hydraulic pump is driven and rotated by the direct-current brush motor when the engine stops during the rotation of the mixer drum for mixing.

Abstract: A chute swing restricting mechanism for locking a chute supported by a rotary shaft being rotatably arranged on a vehicle body of a concrete mixer truck in a storage position includes an engagement part which is rotatable along with the rotary shaft and has an engagement hole, a swing restricting pin which is movably installed relative to the vehicle body, and an energizing member for energizing the swing restricting pin. The swing restricting pin is configured to be inserted into the engagement hole of the engagement part according to an energizing force of the energizing member when the chute is swung and reaches the storage position.

Abstract: A mixer drum driving device includes a mixer drum, a hydraulic motor, a hydraulic pump, an auxiliary hydraulic pump for rotating the mixer drum for mixing by supplying pressure oil to the hydraulic motor independently of the hydraulic pump, and a direct-current brush motor for driving and rotating the auxiliary hydraulic pump. The auxiliary hydraulic pump is driven and rotated by the direct-current brush motor when the engine stops during the rotation of the mixer drum for mixing.