The invention discloses an
impeller magneto rheological fluid
brake for a vehicle. The fluid
brake consists of a shell, a braking
impeller, an electromagnetic device, a bearing shaft, a conical
roller bearing, a sealing ring, an end cover and an auxiliary
electromagnetic clutch, wherein the electromagnetic device comprises a
magnet exciting coil and a
magnet insulating
copper sleeve; a half shaft on a driving wheel or a steering joint on a non-driving wheel can be taken as the bearing shaft; blades with rectangular sections are distributed on the peripheries of both sides of a disk of the braking
impeller; the auxiliary
electromagnetic clutch consists of a driving disk, a driven disk and a middle disk which consists of two
branch disks transversely crossing the
brake shell; the two
branch disks are connected through a guide shaft, and form a conjugate friction pair together with the driving and driven disks of the
clutch; and the closing and opening states of the conjugate friction pair are controlled by using the
resultant force of the pre-tightening force of pre-tightening spring groups on both sides of the shell and the electromagnetic force of the
clutch, so that zero-field loss of a
magneto rheological fluid can be effectively avoided by using the brake during normal running of the vehicle, the real-time, active and continuous ABS (Antilock
Brake System) braking process of the vehicle can be realized during braking, and a braking control process with higher performance than that of a hydraulic mechanical
braking system is realized on a low-adhesion
road surface.