JPH0717246Y2 - Small motor - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is likely to occur at the tip of the shaft where the thrust is applied due to the scattering of the lubricating oil generated by the rotation of the small motor, especially the rotor. The present invention relates to a small motor in which the structure of the lid of the motor case is devised to prevent the lack of lubricating oil.

[Background and problems of the invention]

The conventional small-sized motor is most commonly constructed, for example, as shown in the sectional view of the main part of FIG.

In the figure, 1 is a metallic motor case having an opening at one end, 2 is a lid made of a resin material covering the opening, 3 is a rotor, 4 is a shaft rotating together with the rotor, 5 is a stator, 6 Is a bearing part provided on the lid, 7 is a bearing, and 8 is a brush.

One end of the shaft 4 in such a small motor vertically contacts a flat plate-shaped wall of the bearing portion 6 provided in the lid 2 and receives an axial thrust. Therefore shaft 4
A lubricant is required for the contact portion (thrust receiving portion) between the tip of the bearing and the bearing portion 6, and lubricating oil is used as the lubricant. However, the shaft 4 rotates together with the rotor 3 (hereinafter shaft 4
Is referred to as "rotation", the rotation of the shaft 4 causes the lubricating oil to scatter and the contact portion may run out of oil. Therefore, grease is often used as a lubricant.
However, when grease is used, the drawback of oil scattering can be prevented for the time being, but since grease contains a soap group as its component, it is made of resin integrally with the lid 2 as described above. Since the bearing portion 6 present is abraded and promoted, it also causes a mechanical noise and vibration.

[Purpose and structure of device]

The present invention is intended to solve the above-mentioned drawbacks and problems, and provides a small motor capable of using lubricating oil by integrally forming an oil reservoir having a recess in a bearing portion provided in a lid. I am trying to get it. Therefore, in the small motor of the present invention, the shaft is supported by the bearing provided in the motor case and the lid of the motor case, the shaft is rotatably supported in the motor case, and the inner wall of the lid of the motor case directly supports the shaft. In a small motor having a rotor that receives axial thrust of a shaft, a flat surface thrust receiving portion in contact with a tip end of the shaft on the lid side, which is provided on the inner wall of the lid of the motor case. In addition, an oil sump having an annular recess is integrally formed, and the tip of the shaft is supported by the thrust receiving portion and is surrounded by the oil held in the oil sump. Hereinafter, description will be given with reference to the drawings.

[Example of device]

FIG. 1 (A) is an embodiment of the present invention, and is an enlarged sectional view of a bearing portion for explaining an oil sump by an annular groove, and FIG. 1 (B) is an explanatory view of the oil sump as viewed from an arrow a, Figure 1 (C) shows
The explanatory view of another embodiment in which the annular groove is doubled is shown.

In the figure, 2 is a lid, 4 is a shaft, 6 is a bearing part, 7 is a bearing, 9 is an oil sump, and 10 is oil.

In the case of the embodiment shown in FIG. 1 (A), the bearing portion 6 and the shaft 4
Is in contact with the tip end of the point C (that is, the thrust receiving portion). In order to collect or supply the oil to the point C, the oil sump 9 is provided at a position slightly apart from the point C in this embodiment. The oil sump 9 has an annular shape as shown in FIG. 1 (B), and is formed on the lid 2 as an annular groove in the bearing portion 6 of the lid 2. The central portion of the annular groove is protruded from the annular groove so as to directly receive the axial thrust of the shaft 4. FIG. 1C shows another embodiment in which an annular groove is doubled as the oil sump 9.

In the case of the above-mentioned embodiment, the point C where the tip of the shaft 4 and the bearing 6 contact each other is provided in the flat plate portion of the bearing 6, and a ring is formed on a concentric circle centered on the point where the surface tension of the oil is assisted, that is, the point C. It has an oil sump consisting of a groove.

Each of the oil sumps 9 in the above-mentioned embodiments stores the oil to be scattered without scattering and surrounds the tip portion of the shaft 4 so that the oil is not undesirably starved.

[Effect of device]

As described above, according to the present invention, the bearing 6 which is in contact with the tip of the shaft 4 is provided with the oil sump 9 integrally with the lid 2, so that the oil 10 is prevented from scattering due to the rotation of the shaft 4 and the bearing 6 is prevented. Wear is reduced. As a result, a small motor with less mechanical noise or vibration can be provided.

[Brief description of drawings]

FIG. 1 (A) is an embodiment of the present invention, and is an enlarged sectional view of a bearing portion for explaining an oil sump by an annular groove, and FIG. 1 (B) is an explanatory view of the oil sump as viewed from an arrow a, FIG. 1 (C) is an explanatory view of another embodiment in which the annular groove is doubled, and FIG. 2 is a sectional view of a main part of a conventional small motor. In the figure, 1 is a motor case, 2 is its lid, 3 is a rotor, 4 is a shaft, 6 is a bearing portion provided in the lid, 7 is a bearing, 9 is an oil sump, and 10 is oil.

Claims (1)

[Scope of utility model registration request] 1. A shaft is supported by a bearing provided in a motor case and a lid of the motor case, is rotatably supported in the motor case, and is directly supported by an inner wall of the lid of the motor case in the axial direction of the shaft. In a small-sized motor having a rotor that receives the thrust of, a flat surface-shaped thrust receiving portion in contact with the lid-side tip portion of the shaft, which is provided on the inner wall of the motor case lid, has an annular shape. A small motor characterized in that an oil sump having a recess is integrally formed, and a tip of the shaft is supported by the thrust receiving portion and surrounded by oil held in the oil sump.