JPS6111973Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a bearing structure for a small synchronous motor that has excellent lubricating oil retention properties.

The bearing structure of a conventional small synchronous motor is, for example, as shown in Utility Model Application Publication No. 55-82521 "Bearing Member". A bearing member having an oil reservoir formed between a radial groove 3h extending from the hole, a small hole 3f penetrating from one side to the other side facing the radial groove, and a plurality of protrusions 3c formed on the other side is formed in the case. Since the rotor 20 was inserted and fixed into the recessed fitting part 1b, when the rotor 20 magnetically vibrates during rotation, the rigid bodies of the case and the bearing member act as axial supports and generate noise. Furthermore, since the surface tension of the lubricating oil was used to create an oil reservoir between the plurality of protrusions, the oil retention was poor and it was not possible to maintain high performance and long life.

SUMMARY OF THE INVENTION An object of the present invention is to provide a simple bearing structure for a small synchronous motor that eliminates the above-mentioned drawbacks.

The features of this invention are that the recessed part into which the bearing member is inserted and fixed is made of elastic oil-impregnated felt material, and a synthetic resin plate made of foamed resin material with many small holes is placed on this felt material, and these are placed in the oil sump. The end of the rotating shaft of the rotor is brought into sliding contact with a synthetic resin plate made of foamed resin material, and the magnetic vibration of the rotor pushes out oil for lubrication.

The present invention will be explained below with reference to illustrated embodiments. 1st
In FIGS. 1 and 2, a stator 3 having a coil set (not shown) is fixed between an upper case 1 and a lower case 2 by tightening the upper and lower cases with screws or the like. Recessed fitting portions 11 and 21 are formed in the upper and lower cases 1 and 2 so as to face each other, respectively. A pure wool felt material 4, which is an oil-impregnated felt material, is fitted into the recessed fitting portions 11 and 21. Furthermore, the oil-impregnated felt material 4 is free from fuzz and has flexibility to follow the expansion and contraction of the felt material, and has many small holes with a diameter of about 130μ, for example, and has a thin thickness of about 0.3 to 0.5 m/m. An abrasive foamed resin material 5 is placed. Below and above this foamed resin material 5, there is a third
The figure shows a shaft hole 71 and one side surface 7 extending from this shaft hole 71.
The radial groove 72 formed in a and this radial groove 72
A bearing member 7 having an annular groove 74 having a communication hole 73 that communicates with the other side surface 7b is inserted and fixed into the recessed fitting portions 11 and 21 by press fitting or the like. A polyester plate 8 is placed on one side surface 7a of the bearing member 7 and adhered to the lubricating oil to prevent the lubricating oil from leaking out.

The rotor 6 has its center serving as a rotation axis. A metal rotor shaft 61 is implanted, and the rotor shaft is inserted into the shaft hole 71 and its end 6
1a and 61b are brought into contact with the fluff-free foamed resin material 5 with a slight bias.

Gears 13, 14, and 15 of a gear train are supported between the lower case 2 and the stator 3, and the gear 13 is connected to a pinion 63 provided below the rotor 6.
is engaged with.

When the coil set (not shown) is energized, the magnetic pole part of the stator 3 repeats N and S, so the permanent magnet 6
The rotor 6 with 2 rotates. At this time, the rotor 6 swings up and down due to magnetic vibration caused by the relationship between the rotor and the stator, and a force in the axial direction is applied to the rotor 6. As a result, the foamed resin material 5
is pressed, and due to this pressure, lubricating oil oozes out from the oil-impregnated felt material 4 and is circulated in the following order: shaft hole 71 → radial groove 72 → annular groove 74 → communication hole 73 → foamed resin material 5 → felt material 4, thereby creating a lubricating structure. is obtained.
If the foamed resin material 5 has fuzz, the fuzz will enter the shaft hole and hinder rotation, so a material without fuzz is used.

Since the present invention is constructed as described above, the magnetic vibrations are absorbed by the formation of the bearing member, the foamed resin material and the oil-impregnated felt material, and no noise is generated, and the foamed resin material and the oil-impregnated felt material are pressed together by the rotor shaft. lubricating oil is pushed out and supplied to the rotor shaft and shaft hole. Furthermore, since the synthetic resin plate made of foamed resin is in sliding contact with the rotor, no fuzz will appear due to friction, and the lubricating oil oozes out from the small holes, providing good lubricity. A small synchronous motor with a long life is obtained.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and Fig. 1 is an external view of the main parts of a small synchronous motor, Fig. 2 is an exploded cross-sectional side view of the small synchronous motor, and Fig. 3 is a cross-sectional side view of a bearing member. Top view B and bottom view C. DESCRIPTION OF SYMBOLS 1... Upper case, 2... Lower case, 3... Stator, 4... Oil-impregnated felt material, 5... Synthetic resin plate, 6... Rotor, 61... Rotor shaft, 61
a... end of rotor, 7... bearing member, 71...
... shaft hole, 72 ... radial groove, 73 ... communication hole,
74...Annular groove.

Claims (1)

[Scope of utility model registration request] A stator has upper and lower cases that house a rotor, a reduction gear train, etc., a coil set sandwiched between the upper and lower cases, and a stator that is formed in at least one of the upper and lower cases and has a rotation axis for the rotor. A recessed part to be fitted into the recessed part, an oil-impregnated felt material with elasticity housed in this recessed part, a thin synthetic resin plate with many small holes placed on the felt material, and a thin synthetic resin plate placed in the center. A bearing member having a shaft hole for supporting the rotating shaft and inserted and fixed into the recessed fitting portion, an annular groove formed around the shaft hole of this bearing member, and the annular groove and the shaft hole. A plurality of connecting radial grooves and a communication hole formed at the bottom of the annular groove and communicating with the other side are provided, and the end of the rotation shaft is brought into sliding contact with the synthetic resin plate, and the felt is moved by the magnetic vibration of the rotor. A bearing structure for a small synchronous motor that is characterized by pushing out oil contained in the material.