The invention belongs to the field of minitype mechanical pumps and discloses a liquid
dynamic pressure suspension mechanical pump which comprises a
volute, an
impeller, an upper end cover, a brushless
electric machine and a waterproof sleeve, wherein the brushless
electric machine comprises an
electric machine shell, a
silicon steel sheet, a coil, a magnetic steel rotor, a waterproof sleeve, a rotor sleeve and a rotor rotary shaft; and when the liquid
dynamic pressure suspension mechanical pump works, a radial liquid
dynamic pressure bearing can be formed between the outer wall of the rotor sleeve and the inner wall of the waterproof sleeve through liquid and the
radial displacement of the magnetic steel rotor can be limited. As the magnetic steel rotor has
magnetism, magnetic force is generated between the
silicon steel sheet and the magnetic steel rotor, and the magnetic steel rotor moves in the axial direction now. In addition, when liquid enters a gap at the upper part of the magnetic steel rotor, liquid generates upward thrust to the magnetic steel rotor, and
resultant force of thrust in two directions and the magnetic force can limit the
axial displacement of the magnetic steel rotor, so that non-contact suspension of the magnetic steel rotor can be realized.