Patent ID: 9346186
Filing Date: 2016-05-24
CPC Classification: B01F,B28C,F16H

Claim Text:
1. A mixer drum driving apparatus for driving a mixer drum carried on a frame of a mixer truck such that the mixer drum is freely rotatable, the mixer drum driving apparatus comprising: a liquid-pressure motor that is configured to drive the mixer drum to rotate; a liquid-pressure pump that is driven by a motive force of an engine of the mixer truck and that is configured to supply working liquid to the liquid-pressure motor; an auxiliary liquid-pressure pump that is provided independently from the liquid-pressure pump and that is driven by an electric motor, the auxiliary liquid-pressure pump is configured to supply working liquid to the liquid-pressure motor; a pressure detector that is configured to detect a liquid pressure of working liquid discharged from the auxiliary liquid-pressure pump; a switching valve that is configured to switch whether or not working liquid discharged from the auxiliary liquid-pressure pump is supplied to the liquid-pressure motor; and a controller that is configured to control the switching valve to open/close the switching valve, the controller being connected to the pressure detector to receive a detection signal from the pressure detector, wherein when the switching valve is in a closed state and the mixer drum is in a state in which the mixer drum is driven to rotate by the liquid-pressure motor driven by the liquid-pressure pump, the controller opens the switching valve if a liquid pressure detected by the pressure detector reaches or exceeds a preset liquid pressure.