The invention relates to an electric pump for an automobile drive-by-wire
braking system and belongs to automobile industries. The electric pump for the automobile drive-by-wire
braking system is applied into the automobile drive-by-wire
braking system. A guide sleeve is matched with a cylinder body inner hole in an interference mode, one axial end of the guide sleeve makes contact with a limiting step of the cylinder body inner hole, and the surface of a guide sleeve inner hole is a cylindrical surface; the two sides of the cylindrical surface are symmetrically provided with axial guide rail straight grooves, an axial rack straight groove is formed in the bottom of the cylindrical surface, and the
diameter of a sealing cylindrical surface is larger than that of a guiding part; a secondary packing cup is sleeved with the sealing cylindrical surface of a
piston, strip-shaped protruded guide rails are symmetrically arranged on the two axial sides of a cylindrical surface of the guiding part, and racks are arranged at the bottom of the cylindrical surface of the guiding part in the axial direction; and the sealing cylindrical surface of the
piston is matched with a cylinder body primary hole in an interval mode, the guiding part is matched with the cylindrical surface of the guide sleeve inner hole in the interval mode, and the guide rail straight grooves are matched with the guide rails in the interval mode. The electric pump for the automobile drive-by-wire braking
system has the advantages that the structure is novel, the number of teeth, engaged with the racks, of transposition
gear drive wheels is automatically switched under a low-temperature state so that the pressure-building
stroke of the
piston can be reduced, return
stroke time of the piston is increased, timely supplement of braking fluid at a low temperature is facilitated, and the reliable work of the electric pump under the low-temperature state is ensured.