JPH0419970Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a bearing mechanism with a lubricating oil recovery mechanism for an electric motor, and particularly relates to a bearing mechanism with a lubricating oil recovery mechanism for an electric motor that is used with an inclined rotor shaft. It is something.

[Prior Art] FIG. 5 is a partial cross-sectional view showing the overall configuration of a conventional electric motor, and FIG. 6 is a cross-sectional view of essential parts showing a conventional bearing mechanism with a lubricating oil recovery mechanism.

In both figures, 1 and 2 are the main body casings of the electric motor that are formed by being divided into two parts in the axial direction, and both have a deep dish shape with a flange at the open end, and 3 has the lower part inside the open end of the main casing 1. The upper part is a stator press-fitted into the inner surface of the open end of the main body casing 2,
The main body casing 2 and the main body casing 2 are positioned with respect to each other by the stator 3 and are integrally connected at their flange portions. 4 is a rotor shaft, 5 is a rotor core fixed to this rotor shaft 4, 6 is an oil-impregnated bearing made of oil-impregnated metal, etc. that supports this rotor shaft 4, and the electric motor is placed so that the rotor shaft 4 is vertical. There is.

Figure 6 shows an enlarged view of the bearing mechanism located at the top of this motor (main body casing 2 side).
Reference numeral 7 denotes a two-stage cylindrical metal pad having a large diameter portion and a small diameter portion, and a flange portion 7a provided on the outer periphery of the opening side of the large diameter portion is attached to the center of the upper bottom portion of the main body casing 2 via a rubber packing 8. installed. Reference numeral 9 denotes an annular oil supply felt, which circumscribes the oil-impregnated bearing 6 and whose outer periphery is supported by the inner surface of the large diameter portion of the metal pad 7. Reference numeral 10 denotes a washer-like holding plate, which is a stepped part of the metal pad 7 so as to rotatably hold the oil-impregnated bearing 6 between the conical surface machined around the central hole and the center of the main body casing 2. It's being held down.
Reference numeral 11 designates an annular oil recovery felt fitted into the inner surface of the small diameter portion of the metal pad 7, and is in contact with the oil supply felt 9 through a small hole provided in the holding plate 10. Reference numerals 12 and 13 denote an oil drain collar and a spacer 1 rotatably supported on the rotor shaft 4 at a position corresponding to the oil recovery felt 11.
4 is a snap spring that is fitted into a groove machined on the outer periphery of the rotor shaft 4 and fixed in the axial direction, and prevents the oil draining collar 12 and the spacer 13 from moving downward in the axial direction (toward the center of the motor). .

The conventional bearing mechanism is configured as described above, and when the stator 3 is energized, it is excited and the rotor shaft 4 and rotor core 5 are supported by the oil-impregnated bearing 6 and rotate. When the rotor shaft 4 starts rotating, the lubricating oil oozes out onto the bearing surface of the oil-impregnated bearing 6, as shown in the partial cross-sectional view of FIG. Provides a lubricating effect.
A portion of this lubricating oil gradually moves downward along the surface of the rotor shaft 4 as the rotor shaft 4 rotates, and reaches the upper end surface of the spacer 13 . Then, when the amount of lubricating oil that collects here increases and the centrifugal force becomes balanced with the surface tension (cohesive force), the lubricating oil is gradually pushed out in the radial direction from the upper end surface of the spacer 13 and further transfers to the oil cutting collar 12. Finally, the centrifugal force blows the oil outward from the oil drain collar 12 and absorbs it into the oil recovery felt 11. When the amount of lubricating oil absorbed by the oil recovery felt 11 is larger than that of the oil supply felt 9, it is sucked out and recovered by the oil supply felt 9 through the contact portion, and is gradually transferred to the oil-impregnated bearing 6 again. Move in the direction of and repeat the above process. In this way, the lubricating oil is used repeatedly with minimal loss, providing for long-term use of the motor without lubrication.

[Problems to be solved by the invention] In the conventional bearing mechanism as described above, since the distance between the oil recovery felt 11 and the oil drain collar 12 is large, the lubricating oil droplets 15 that collect at the tip of the oil drain collar 12 are The centrifugal force overcomes the surface tension of the lubricating oil droplets 15, and the rotational speed must be higher than that at which they can be dispersed to be effective. That is, as shown in the partial cross-sectional view illustrating recovery of lubricating oil during low-speed rotation in FIG. The oil may gradually bleed downward along the surface of the oil drain collar 12 or the rotor shaft 4, fall downward due to its weight, or run down the surface of the oil drain collar 12 or the rotor shaft 4 while the operation is stopped. There was a problem in that it could not be recovered.

The technology disclosed in Utility Model Application Publication No. 58-131149 also
With this type of problem, oil recovery works when the axis is horizontal, but does not work when the axis is vertical.

Further, the technique disclosed in Japanese Utility Model Application Publication No. 57-127556 works when the shaft is horizontal, but when the shaft is vertical, oil recovery does not work unless the shaft is rotated at a considerably high speed.

This idea was made to solve this problem, and even when the rotor shaft is used at low speed for a long time, and even if the rotor shaft is not installed horizontally, the lubricating oil can be absorbed into the oil recovery felt. The purpose is to obtain a bearing mechanism that can be reliably recovered.

[Means for solving the problem] In the bearing mechanism according to this invention, under the usage conditions that cause the above problem, the size of the lubricating oil droplets formed on the outer periphery of the oil collar due to centrifugal force is small in the radial direction. It was found that an equilibrium state was reached between 0.3 mm and 2.0 mm, and it did not increase significantly even if the operation continued beyond that point.From this, the distance between the oil recovery felt and the oil drain collar was adjusted to the minimum operating speed. 1.5 in consideration
mm or more.

[Function] In this invention, even if the rotation of the rotor shaft is low and the size of the lubricating oil droplets reaches equilibrium and does not scatter, the distance between the oil recovery felt and the oil drain collar is such that the lubricating oil droplets in the equilibrium state are Since the lubricating oil droplets are set to be smaller than the size, the lubricating oil droplets are surely collected in the oil collecting felt and used repeatedly.

[Example] Figures 1 and 2 show an embodiment of this invention. Figure 1 is a cross-sectional view of a main part showing a bearing mechanism with a lubricating oil recovery mechanism of this invention, and Figure 2 is a cross-sectional view of a main part of the bearing mechanism with a lubricating oil recovery mechanism of this invention. FIG. 2 is a plan view of an oil recovery felt.

In the drawings, numerals 1 to 10 and 12 to 14, excluding the oil recovery felt 11, indicate the same components as the conventional bearing mechanism with a lubricating oil recovery mechanism. In this invention, the oil recovery felt 11 has a basic annular shape as shown in FIG. is set to be 1.5 mm or less.

In the bearing mechanism configured as above,
Even if the rotor shaft 4 rotates at a low speed and lubricating oil droplets do not scatter, the oil recovery felt 11 and the oil drain collar 12
Since the distance between the oil collecting felt 11 and the oil collecting felt 11 is set to 1.5 mm or less, the lubricating oil droplets bulging in the radial direction due to centrifugal force can be absorbed and reliably collected at the tip of the convex portion 11a of the oil collecting felt 11. In particular, the rotor shaft 4 at this time is not limited to being installed horizontally, but can also be used when being installed vertically or obliquely.

In the above embodiment, the convex portion 11a is provided at one location on the inner surface of the oil recovery felt 11, but the same operation can be expected even if the convex portion 11a is provided at two or more locations. In this case, since the lubricating oil droplets are collected at a plurality of locations, the oil-impregnated state of the oil collecting felt 11 becomes more uniform, and therefore the collected lubricating oil is more evenly dispersed in the oil supply felt 9.

FIG. 3 shows another embodiment of the present invention,
In this case, instead of providing the convex portion 11a on the oil recovery felt 11, the oil recovery felt 11 is the same as the conventional bearing mechanism described above, and the outer diameter of the oil drain collar 12 is made larger, so that the oil recovery felt 11 and the oil The distance from the cutting collar 12 is set to 1.5 mm or less. As shown in FIG. 3, lubricating oil droplets that swell due to centrifugal force on the outer periphery of the oil drain collar 12 are absorbed by the oil recovery felt 11.

FIG. 4 shows still another embodiment of the present invention, in which the oil recovery felt 11 has exactly the same shape as the conventional bearing mechanism described above, except for the sixth embodiment.
Adjust the outer diameter of the spacer 13 in the figure to the oil drain collar 1 in the figure.
The outer diameter of oil recovery felt 1 should be larger than that of oil recovery felt 1.
1 and the spacer 13 is set to 1.5 mm or less. According to this figure 4, 1
6 is an oil drain collar that functions as an oil drain,
Reference numeral 17 denotes a spacer, and the centrifugal force is greatest at the outer periphery of the oil draining collar 16, where the lubricating oil droplets bulging in the radial direction are absorbed by the oil recovery felt 11 and are surely recovered.

[Effects of the invention] As explained above, the bearing mechanism of the electric motor of this invention consists of the convex portion of the approximately annular oil recovery felt, the rotor shaft surface oil cutter collar corresponding to the oil recovery felt, and the oil recovery felt. Minimum spacing 1.5mm
By setting the following, lubricating oil can be reliably recovered even when the rotor is used at low speed or when the rotor shaft is not installed horizontally.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view showing a bearing mechanism with a lubricating oil recovery mechanism of a motor bearing mechanism in an embodiment of this invention, Fig. 2 is a plan view of an oil recovery felt used in the embodiment of Fig. 1; Fig. 3 is a partial sectional view showing a bearing mechanism with a lubricating oil recovery mechanism of a motor bearing mechanism according to another embodiment of this invention, and Fig. 4 shows a motor bearing mechanism according to still another embodiment of this invention. Figure 5 is a partial cross-sectional side view of an electric motor with a conventional bearing mechanism, Figure 6 is a partial cross-sectional view showing an enlarged view of the bearing mechanism in Figure 5, and Figure 7 is a high-speed motor with a conventional bearing mechanism. FIG. 8 is a partial sectional view illustrating recovery of lubricating oil during rotation, and FIG. 8 is a partial sectional view illustrating recovery of lubricating oil during low speed rotation, which also has the same problem. In the figure, 1, 2...main casing, 4...
... Rotor shaft, 9 ... Oil supply felt, 11 ... Oil recovery felt, 12, 16 ... Oil drain collar. In addition, in the figures, the same reference numerals and symbols indicate the same or equivalent parts.

Claims (1)

[Claims for Utility Model Registration] An oil-impregnated bearing held in a main body casing of an electric motor, a substantially annular oil-feeding felt circumscribing the periphery of the oil-impregnated bearing, and a rotor shaft adjacent to the oil-filling felt in the axial direction of the oil-impregnated bearing. a substantially annular oil recovery felt that is arranged to surround the oil recovery felt and has a convex portion formed therein; and an oil cutting collar provided on the rotor shaft surface corresponding to the oil recovery felt, the oil recovery felt and the oil A bearing mechanism for an electric motor characterized in that the minimum distance between the cutting collar and the collar is set to 1.5 mm or less.