Brushless DC motor structure

Abstract

The present invention relates to a brushless DC motor structure providing at least a dust-filtering element between a holder of a rotor and a bearing. The dust-filtering element is made of a porous and absorbent material and nearly or slightly contacts with the holder and a spindle. As such, when particles and dust in air enter the motor structure to be completely filtered, blocked, and absorbed by the porous dust-filtering element, no particles and dust will get into the spindle seat to be mixed with lubricant in formation of oil sludge, thereby ruling out the blocking and locking issue of the spindle arising from the oil sludge and prolonging the operation life span of the motor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view showing a conventional brushless motor structure;

FIG. 2 is a cross-sectional view illustrative of Republic of China patent no. 588809; and

FIG. 3 is a cross-sectional view of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention relates to a brushless DC motor structure, which utilizes a porous dust-filtering element having absorbent function to prevent the ingress of particles and dust into the inner part of a motor spindle seat and prevent the spindle from being blocked and locked by the spindle, so as to prolong the operation life span of the motor.

Please refer to FIG. 3, the brushless DC motor structure contains a base 31, a stator 32 and a rotor 33, wherein a spindle seat 1 is centrally disposed in the base 31, a stator 32 is disposed on a periphery of the spindle seat 1, at least a bearing 11 is contained in the spindle seat 1, and a locating ring 41 is disposed above the bearing.

A holder 34 is centrally formed in the stator 33. A spindle 12 is buried in the holder 34. The spindle 12 can pass through the bore of the bearing 12, and a fastener 14 is fixed in an angular groove 13 of the spindle 12, such that the rotor can be loosely integrated with the base 31.

The present invention is characterized by having a plurality of dust-filtering elements 4 disposed between the holder 34 of the rotor 33 and the bearing 11 inside the spindle seat 1. The dust-filtering element can be made of a porous and absorbent material such as sheep felt, sponge, non-woven cloth and the like and nearly or slightly contacts with the holder 34 of the rotor and the inner surface of the spindle seat 1.

When motor rotates, lubricant inside the spindle seat 1 is driven by rotation of the spindle 12 to self-generate a circulation effect providing a pump suction force inside the spindle seat 1 to suck particles and dust in air in the spindle seat 1. Being filtered, blocked and absorbed by the porous dust-filtering element 4, particles and dust won't get into the spindle seat 1, nor will they be mixed with lubricant to form oil sludge. Certainly, there will be no blocking and locking issue of the spindle arising from oil sludge either.

Even though the material such as sheep felt, sponge, non-woven cloth and the like slightly contacts with the holder 34 of the rotor 33 while motor is rotating, rotation speed of the spindle 12 won't be affected or slowed down, and after the material such as sheep felt, sponge, non-woven cloth and the like slightly contacts with and rubs against the holder 34 of the rotor 33, electrostatic charge will be generated to attract, filter and absorb particles and dust so as to attain an optimal dustproof effect and prolong the life cycle of motor.

By means of the mentioned design, instead of passive dust isolation only, the present invention also provides the functions for blocking, filtering and absorbing particles and dust, which can effectively and surely prevent the ingress of particles and dust in air into the spindle seat. The issue that the spindle is blocked and locked by oil sludge is avoided, and the motor operation life cycle is prolonged. Therefore, the present invention not only has a novelty and a progressiveness, but also has an industry utility.

While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.

Claims

1. A brushless DC motor structure, comprising: a base centrally provided a spindle seat;a bearing accommodated in said spindle seat;a stator disposed on a periphery of said spindle seat;a rotor centrally provided a holder;a spindle fixed in said holder and passing through a bore of said bearing for said rotor to be loosely bundled with said base;at least a dust-filtering element disposed between said holder of said rotor and said bearing and inside said spindle seat, made of-a porous and absorbent material, and nearly or slightly contacting with said holder of said rotor and an inner surface of said spindle seat.

2. The brushless DC motor structure of claim 1, wherein said dust-filtering element is made of sheep felt.

3. The brushless DC motor structure of claim 1, wherein said dust-filtering element is made of sponge.

4. The brushless DC motor structure of claim 1, wherein said dust-filtering element is made of non-woven cloth.

5. The brushless DC motor structure of claim 1, wherein a locating ring is disposed between a top place of said bearing and said dust-filtering element.

6. The brushless DC motor structure of claim 1, wherein an end portion of said spindle passing through said bore of said bearing has an angular groove fastened by a fastener.