JP2562082Y2 - motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a motor of a type in which a rotating shaft is rotatably supported by a pair of bearings.

[Conventional technology]

In a motor used in a conventional axial fan or the like, two rolling bearings are provided in a radial gap between a cylindrical boss of a motor bracket and a rotating shaft, and the rotating shaft is Has been pivoted to the motor bracket via the rolling bearing.

[Problems to be solved by the invention]

Therefore, conventionally, if the cylindrical boss portion is a synthetic resin,
It was difficult to position the bearing. Further, the cost is high because expensive rolling bearings are used at two places. In some cases, a plain bearing is used instead of a rolling bearing. However, there has been a problem that the life of the bearing is short due to running out of oil.

An object of the present invention is to provide a motor that solves the above problems.

[Means for solving the problem]

In order to solve the above problems, the present invention provides a motor bracket having a cylindrical boss portion, a pair of bearings provided inside the cylindrical boss portion, a rotating shaft rotatably supported by the two bearings, and a cylinder. A motor having a stator fixed to an outer peripheral surface of a boss portion and a rotor having a rotor magnet and fixed to a rotating shaft, wherein the pair of bearings are a rolling bearing and a sliding bearing, Is formed so as to extend more than the axial length of the oil-impregnated sliding contact ring portion in the direction of the rolling bearing and the oil-impregnated sliding contact ring portion, and the inner peripheral surface thereof is not in contact with the rotating shaft. And an annular step formed on the inner peripheral surface of the cylindrical boss portion such that a position corresponding to the oil-containing sliding contact ring portion has a larger diameter than a portion on the rolling bearing side. Section and the above On the outer peripheral side of the oil sliding contact ring, a positioning projection is provided which engages with the annular step from the side opposite to the rolling bearing, and the tip end surface of the oil-impregnated non-contact cylindrical portion is an outer ring of the rolling bearing. Is characterized by being brought into contact with.

In this case, in the oil-impregnated non-contact cylindrical portion, it is desirable that the inner diameter of the cylindrical portion is changed continuously or stepwise.

[Action]

If the oil in the oil-impregnated sliding contact ring portion of the slide bearing disappears or runs short during the rotation of the motor, the oil present in the oil-impregnated non-contact cylindrical section moves axially in its cross section to reach the oil-impregnated sliding contact ring section. Oil is supplied to the gap between the inner peripheral surface in the oil-containing sliding contact ring portion and the outer peripheral surface of the rotating shaft.

By extending the oil-impregnated non-contact cylindrical section larger than the axial length of the oil-impregnated sliding ring section until it comes into contact with the outer ring of the rolling bearing, a large volume of the oil-impregnated non-contact cylindrical section as the oil replenishing section is secured. Can be.

Further, when the sliding bearing is fitted into the cylindrical boss portion, the positioning projection is engaged with the annular step portion of the cylindrical boss portion, so that the positioning of the sliding bearing can be easily performed. When the rolling bearing is fitted in the cylindrical boss portion, the positioning can be easily performed by pushing the rolling bearing until the outer ring comes into contact with the tip end surface of the oil-impregnated non-contact cylindrical portion.

Furthermore, if the inner diameter of the oil-impregnated non-contact cylindrical portion is changed continuously or stepwise by effectively utilizing the gap formed between the rotating shaft and the oil-impregnated non-contact cylindrical portion, the oil-impregnated non-contact By further increasing the volume of the cylindrical portion, the oil content can be increased, that is, the bearing life can be extended.

〔Example〕

Embodiments will be described with reference to the drawings. Figure 1
FIG. 2 shows a (DC) motor portion used for an axial fan or the like. This motor includes a motor bracket 3 having a cylindrical boss portion 4 and a pair of bearings provided inside the cylindrical boss portion 4.
6, a rotating shaft 1 rotatably supported by the cylindrical boss portion 4 via bearings 6, 7, a stator 13 fixed to the outer peripheral surface 12 of the cylindrical boss portion 4, and a rotor magnet 15. And a rotor 16 fixed to one end of the rotating shaft 1. The rotor magnet 15 is a cup-shaped rotor holder for the rotor 16.
It is attached to the inner surface of the outer peripheral wall of 14 and faces the stator 13 closely. (Note that, although this figure is labor-saving, when this motor is used as an electric fan such as an axial fan, the motor bracket 3 also serves as a housing for the electric fan, and the outer surface of the outer peripheral wall of the rotor holder 14 A pair of bearings 6 and 7 are a rolling bearing 6 and a sliding bearing 7. The rolling bearing 6 is disposed on the tip side of the cylindrical boss 4, and the sliding bearing 7 is disposed on the base side. You. The sliding bearing 7 includes an oil-containing sliding contact ring portion 8 that slides on the rotating shaft 1 and a rolling bearing 6.
And an oil-impregnated non-contact cylindrical portion 9 that is formed to extend in the direction of the axis of the ring portion 8 longer than the axial length of the ring portion 8 and that is not in contact with the rotating shaft 1. Further, the tip surface 10 of the oil-impregnated non-contact cylindrical portion 9 comes into contact with the outer ring 11 of the rolling bearing 6.
That is, the sliding bearing 7 is made of an oil-impregnated metal, is press-fitted and fixed to the inner peripheral surface 5 of the cylindrical boss portion 4, the oil-impregnated sliding contact ring section 8 comes into sliding contact with the outer peripheral face 2 of the rotary shaft 1, and has an oil-impregnated non-contact cylindrical shape. The portion 9 keeps a non-contact state with the outer peripheral surface 2. 21 is a stop ring attached to the other end of the rotating shaft 1.

An annular step portion 20 is provided on the inner peripheral surface 5 of the cylindrical boss portion 4 at a position corresponding to the oil-containing sliding contact ring portion 8 so that the base side has a larger diameter than the distal end portion. A positioning protrusion 22 is provided on the outer peripheral side of the sliding ring portion 8. When the slide bearing 7 is fitted into the cylindrical boss portion 4, the positioning protrusion 22 is formed on the annular step portion 20 by the cylindrical boss portion. 4 is fitted from the base side, and the positioning of the sliding bearing 7 is achieved.

During rotation of the motor, the oil contained in the oil-containing sliding contact ring portion 8 oozes out of the minute pores onto the inner peripheral surface 17 of the oil-containing sliding contact ring portion 8 that comes into sliding contact with the outer peripheral surface 2 of the rotating shaft 1, Thereby, lubrication between the outer peripheral surface 2 of the rotating shaft 1 is performed. When the oil initially present in the oil-containing sliding contact ring portion 8 is depleted, as shown in FIG. 2, the oil contained in the non-contact cylindrical portion 9 becomes negative pressure generated in the minute pores. When the oil reaches the oil-impregnated sliding contact ring section 8, it moves in the axial direction, moves in the radial direction when it reaches the oil-impregnated sliding contact ring section 8, and then exudes from the inner circumferential surface 17 of the oil-impregnated sliding contact section 8.

As shown by the imaginary line in FIG. 1, the non-contact cylindrical portion 9 is formed with a stepped portion 18 and the inner diameter of the portion other than the tip is set slightly larger than the outer diameter of the rotary shaft 1. No problem. It is also preferable that a plurality of the step portions 18 are formed so that the non-setting tubular portion 9 has a shape including a plurality of steps.

As another embodiment, as shown in FIG. 3, the inner peripheral surface 19 of the oil-impregnated non-contact cylindrical portion 9 may be formed in a tapered shape. In this case, unlike the embodiment of FIG. , The inner peripheral surface 19
The gap between the shaft and the outer peripheral surface 2 of the rotating shaft changes in the axial direction and is non-uniform.

As for the sliding bearing 7, as shown in FIG. 4, it is also preferable to form only the distal end side of the inner peripheral surface 19 of the oil-impregnated non-contact cylindrical portion 9 into a tapered shape.

The oil-impregnated sliding contact ring section 8 is formed by the oil-impregnated non-contact cylindrical section 9.
If the inner diameter of the oil-containing non-contact cylindrical portion 9 is changed continuously or stepwise as described above, the volume of the non-contact cylindrical portion 9 can be increased. And the oil content can be increased to extend the life of the bearing.

In the embodiment shown in FIGS. 1 to 4 described above, when the rolling bearing 6 is inserted into the inner peripheral surface 5 of the cylindrical boss portion 4 to determine the axial position, the oil bearing non-contact of the sliding bearing 7 is determined. The rolling bearing 6 may be pressed until it comes into contact with the distal end surface 10 of the cylindrical portion 9, and the positioning accuracy of the rolling bearing 6 can be improved.

[Effect of the invention]

The present invention has the following practical effects due to the above-described configuration.

The positioning of the rolling bearing 6 and the sliding bearing 7 in the axial direction can be performed with high accuracy, easily, and quickly.

Since the oil-impregnated non-contact cylindrical portion 9 having a large oil content functions as an oil replenishing section, the oil-impregnated sliding contact ring section 8 can be prevented from running out of oil, and the bearing life is extended.

Since the sliding contact area of the sliding bearing 7 with respect to the rotating shaft 1 is relatively small, that is, the length of the portion that slides on the rotating shaft 1 with high precision is small, and therefore, the manufacture thereof is easy.

If the inner diameter of the oil-impregnated non-contact cylindrical portion 9 is changed continuously or stepwise, the life of the sliding bearing 7 can be further extended.

[Brief description of the drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of an essential part of the slide bearing of FIG. 1, FIG. 3 and FIG.
The drawings are cross-sectional views of main parts showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Rotating shaft, 3 ... Motor bracket, 4 ... Cylindrical boss part, 5 ... Inner peripheral surface, 6 ... Rolling bearing, 7 ... Slide bearing, 8 ... Oil-containing sliding contact ring part, 9 ... Oil-impregnated non-contact tubular part, 10 ... tip end face, 11 ... outer ring, 12 ... outer peripheral face, 13 ...
… Stator, 15… rotor magnet, 16 …… rotor,
20: annular step, 22: positioning projection.

Claims (2)

(57) [Scope of request for utility model registration] A motor bracket having a cylindrical boss portion;
A rotating shaft having a pair of bearings provided inside the cylindrical boss portion, a rotating shaft rotatably supported by the two bearings, a stator fixed to the outer peripheral surface of the cylindrical boss portion, and a rotor magnet; A pair of bearings are a rolling bearing and a sliding bearing, wherein the sliding bearing slides on the rotating shaft, and an oil-containing sliding contact ring portion;
An oil-impregnated non-contact cylindrical portion which is formed so as to extend in the direction of the rolling bearing more than the axial length of the oil-impregnated sliding contact ring section and whose inner peripheral surface is not in contact with the rotating shaft;
An annular step is provided on the inner peripheral surface of the cylindrical boss so that a position corresponding to the oil-impregnated sliding contact ring has a larger diameter than a portion on the rolling bearing side, and an outer peripheral side of the oil-impregnated sliding contact ring is provided. A motor provided with a positioning projection engaging with the annular step from the side opposite to the rolling bearing, and having a tip end surface of the oil-impregnated non-contact cylindrical portion in contact with an outer ring of the rolling bearing. 2. The motor according to claim 1, wherein the inner diameter of the oil-impregnated non-contact cylindrical portion changes continuously or stepwise.