A micro DC motor

Abstract

The invention discloses a micro direct current motor which comprises a motor housing, a stator assembly and a rotor assembly. The stator assembly and the rotor assembly are arranged in the motor housing. The rotor assembly comprises an impeller and an impeller rotation shaft. The exterior surface of the rotation shaft is provided with two annular first rolling ball grooves at interval. The exterior part of the rotation shaft is sleeved by an installation sleeve that surrounds the two annular first rolling ball grooves. The inner wall of the installation sleeve is provided with two corresponding second rolling ball grooves at interval. A plurality of rolling balls is placed between the first rolling ball grooves and the second rolling ball grooves. The micro direct current motor of the invention does not utilize bearings as the rotation connection components, exempt from the jolting and shaking of the rotation shaft due to the gaps formed during the assembling of the outer rings and the inner rings of bearings and rolling balls. At the same time, the springs between two bearings can be saved. Therefore, the assembled structure is a simplified one. And even at a high speed, the rotation shaft runs stably without producing sounds.

Description

technical field [0001] The invention relates to a motor, in particular to a miniature DC motor. Background technique [0002] The rotor assembly of a DC motor may include an impeller that rotates relative to a shroud secured within the turbine. DC motors are mainly used in vacuum cleaners, hand dryers, etc. as the driving source for vacuuming, and the speed of the motor part of the turbine can be as high as 50,000 to 100,000 rpm. At this high speed, the precision of the rotor assembly is very high. The bearings of the rotor assembly will inevitably vibrate during the rotation process. The rotor assembly vibrates due to unbalanced force, which will cause the impeller to vibrate relative to the cover and generate noise. [0003] Patent Application No. 201280041747.0 discloses a rotor assembly comprising a shaft, a bearing assembly, an impeller and a cover, the impeller and bearing assembly are mounted to the shaft, and the cover is mounted to the bearing assembly to cover the...

AI Technical Summary

Problems solved by technology

Although this prior art has greatly improved the performance of the rotor at high speed, the assembly structure is complex, and the spring force is used to eliminate the impact of the jump, so it has a certain scope of application. When the load exceeds the spring force, it will still affect the stability of the shaft.

Images