JPH02261031A - Motor - Google Patents

Abstract

PURPOSE:To reduce sliding friction due to rotation by a method wherein either one or both of a thrust receiving washer for retaining a rotary shaft and a fail-off preventing member are formed of oleo-plastic. CONSTITUTION:A thrust receiving washer 12a and a fall-off preventing member 13a are formed of oleo-plastic while spiral grooves 24, 25, which are slanted into the rotating direction of a shaft, are provided on the surfaces of said respective parts. The recess 26 of a rotary shaft 11 is engaged with the engaging part 27 of the fall-off preventing member 13a. According to this method, the sliding friction of the thrust receiving washer and the fall-off preventing member due to the rotation of the shaft may be reduced. On the other hand, oil, entered into the grooves, is retained in the grooves and is pushed toward the central part of said parts in accordance with the rotation of the rotary shaft and the pressure of the oil on the sliding surfaces is increased whereby the sliding friction of said parts may be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to an electric motor using an oil-impregnated sintered bearing.

[Conventional technology]

FIG. 4 is a sectional view showing a conventional electric motor disclosed in, for example, Japanese Utility Model Application Publication No. 62-104548.
) is a frame made of synthetic resin that forms a ventilation passage (2) and has a bearing holding part (4) in the center via a mounting foot (3);
5) is a metal bearing holder provided on this frame by insert molding, (6) is a stator fixed to the outer periphery of this bearing holder, and an insulating cover 8 is attached to the stator core (7).
) is formed by winding the winding (9) through the wire. 00) is an oil-impregnated sintered bearing fitted into the above-mentioned bearing holder ((5), and (11) is rotatably fitted into this oil-impregnated sintered bearing with a thrust receiving washer (12) interposed at the tip. A rotating shaft (14) is attached to a stopper (13) through a bush (15), and a magnet (16) facing the circumferential side of the stator (6)
) and vanes (18) provided on the peripheral side wall of the rotor yoke. (19) is a metal washer fitted into the bearing holder (5), and a lubricating sheet (20) is sandwiched therein. (2
1) is a washer fitted to the rotor (14) attachment side of the rotating shaft (11), and is provided to hold the felt (22) between it and the oil-impregnated sintered bearing QO).

(23) is a famous plate.

The conventional electric motor is constructed as described above, and when the winding (9) is energized, a magnetic field is generated, and the rotor (14) rotates due to the magnetic action with the magnet (16), and the blades (18)
) is used to blow air through the ventilation passage (2), and the oil that flows out from the oil-impregnated sintered bearing (QO) due to rotation is prevented from flowing outside by the washer (21), and is sent through the fer I- (22). It's supposed to circulate.

[Problem to be solved by the invention]

In the conventional electric motor as described above, the end of the rotating shaft (If) is held by two parts, the thrust receiving washer (12) and the retaining member (13), but sliding due to the rotation of the rotating shaft (11) The problem was that the dynamic friction was large and the efficiency was poor.

This invention was made to solve the problem,
The objective is to obtain an electric motor with low sliding friction, easy oil recovery and high oil retention, and a reduction in the number of parts.

[Means to solve the problem]

In the electric motor of the present invention, one or both of the thrust receiving washer and the retaining member are made of oil-impregnated plastic.

Further, one or both of the thrust receiving washer and the retaining member is provided with a groove formed from the center toward the peripheral side.

Moreover, the groove is formed in a spiral shape.

Furthermore, the thrust receiving washer and the retaining member are integrally molded from oil-impregnated plastic.

[Effect]

In this invention, since either or both of the thrust receiving washer and the retaining member are made of oil-impregnated plastic, sliding friction due to rotation of the rotating shaft is reduced.

In addition, because a groove is formed in either or both of the thrust receiving washer and the retaining member from the center toward the peripheral side, oil leaking from the oil-impregnated sintered bearing is collected from the groove, improving oil retention. improves.

Furthermore, since the groove is formed in a spiral shape, the oil that has entered the groove is pushed toward the center, increasing the oil pressure on the sliding surface and reducing friction.

Furthermore, since the thrust receiving washer and the retaining member are integrally molded from oil-impregnated plastic, the number of parts is reduced and sliding friction is reduced.

〔Example〕

FIGS. 1 to 3 are diagrams showing an embodiment of the present invention,
In the figure, (1) to (11), (14), (16) to (
18) and (23) are the same or equivalent parts as the above conventional example, and (+2a) is a thrust receiving washer made of oil-impregnated plastic, and the surface thereof is provided with a spiral groove (24) inclined in the direction of rotation. is being used. (+2b) is a retaining member made of oil-impregnated plastic, and the surface is provided with a spiral i (25) inclined in the direction of rotation, and the inside is engaged with the four parts (26) of the rotating shaft (11). An engaging portion (27) is provided. (28) is an oil cap provided on the fitting end of the rotating shaft (11) of this bearing holder so as to protrude inwardly, and (29) is a bearing holder (5).
) is a lid made of synthetic resin that seals the opening at the insertion end of the counter-rotating shaft (It) by welding using ultrasonic vibration, etc.
An oil reservoir portion (30) is formed in the opposing portion. (3
1) is fitted with the rotating shaft (11) and has an oil moving convex portion (3) formed at one end with a diameter slightly smaller than the diameter of the oil cap (28).
2), which is disposed between the oil cap (28) and the oil-impregnated sintered bearing 00).

In the electric motor configured as described above, the rotor (14
) rotates and the blades (18) blow air through the ventilation passage (2), and among the oil that flows out due to the rotation of the rotating shaft (11), on the side where the rotating shaft (11) is inserted, the oil thrower (31) The surrounding bearing holder (22)
It is returned to the oil throat (31) by the oil cap (28) and does not flow out. On the other hand, on the side where the counter-rotating shaft (+1) is inserted, the opening of the bearing holder (22) is sealed by the lid (29), so oil does not leak outside and the oil flows into the oil reservoir (31). It can be stored, which increases the oil storage capacity and extends the lifespan. Furthermore, the sliding friction of the thrust receiving washer (12a) and the retaining member (13a) due to the rotation of the rotating shaft (11) is reduced because they are made of oil-impregnated plastic, and the groove (24) formed in a spiral shape ( The oil that has entered 25) is retained in the groove (24) <25) and is pushed toward the center as it rotates, increasing the pressure on the sliding surface by 1 and further reducing sliding friction.

In addition, in the above embodiment, the thrust receiving washer (12a)
and a retaining member (13a) are provided respectively,
If a spiral groove similar to the above is provided on the surface and integrally molded with oil-impregnated plastic, the number of parts will be reduced and sliding friction will be reduced.

〔Effect of the invention〕

As explained above, the present invention includes a bearing holder, a stator fixed to the bearing holder and wound with a winding, an oil-impregnated sintered bearing fitted to the bearing holder, and a rotary movement of the oil-impregnated sintered bearing. a rotor having a magnet fixed to the rotary shaft and facing the circumferential side of the stator; By forming one or both of the above-mentioned slip-off prevention members from oil-impregnated plastic, there is an effect that sliding friction can be reduced.

In addition, by providing a groove formed in either or both of the thrust receiving washer and the retaining member from the center toward the peripheral side, it is possible to collect oil and improve oil retention. be.

Furthermore, by forming the groove in a spiral shape, the oil pressure within the groove can be increased as the rotating shaft rotates, which has the effect of further reducing sliding friction.

Furthermore, by integrally molding the thrust receiving washer and the retaining member from oil-impregnated plastic, it is possible to reduce sliding friction and reduce the number of parts.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
)<b) is a plan view and side sectional view showing the thrust receiving washer, FIGS. 3(a) and 3(b) are a plan view and side sectional view showing the retaining member, and FIG. 4 is a conventional electric motor. FIG. In addition, the same reference numerals in each figure indicate the same or equivalent parts.
5) is the bearing holder, (6) is the stator, (9) is the winding, α
O) is an oil-impregnated sintered bearing, (11) is a rotating shaft, (12a) is a thrust receiving washer, (13b) is a retaining member,
(14) is a rotor, (16) is a magnet, (24)
(25) is a groove. spontaneous writing) 5. Detailed description of the invention in the specification to be amended. 6. In the 5th line of page 6 of the statement of contents of the amendment, r (+2b) is
(13a) is corrected as ". 3. Relationship with the case of the person making the amendment Patent applicant address 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name (601) Mitsubishi Electric Corporation Representative Moriya Shiki 4 Agent address Chiyoda, Tokyo 2-2-3 Marunouchi Ward

Claims (4)

[Claims] (1) A bearing holder, a stator fixed to the bearing holder and wound with a winding, an oil-impregnated sintered bearing fitted to the bearing holder, and a stator rotatably fitted to the oil-impregnated sintered bearing. A rotating shaft having a retaining member attached thereto with a thrust receiving washer interposed therebetween, and a rotor having a magnet fixed to the rotating shaft and facing the circumferential side of the stator, the thrust receiving washer and the retaining member An electric motor in which one or both of the above are made of oil-impregnated plastic. (2) The electric motor according to claim 1, wherein one or both of the thrust receiving washer and the retaining member are provided with a groove formed from the center toward the peripheral side. (3) The electric motor according to claim 2, wherein the groove is formed in a spiral shape. (4) a bearing holder, a stator fixed to the bearing holder and wound with a winding, an oil-impregnated sintered bearing fitted to the bearing holder, and a stator rotatably fitted to the oil-impregnated sintered bearing. A rotating shaft having a retaining member attached thereto with a thrust receiving washer interposed therebetween, and a rotor having a magnet fixed to the rotating shaft and facing the circumferential side of the stator, the thrust receiving washer and the retaining member An electric motor integrally molded from oil-impregnated plastic.