JPH0979271A - Rotary shaft supporting device having lubricating function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a rotary shaft supporting device to supply lubricating oil to a bearing in the upper part, even in the case that lubricating oil can not be supplied through the inside of a rotary shaft. SOLUTION: An upper end part of a rotary shaft 2a is loosely inserted to a circular recessed hole 13. A helical groove or helical protrusive streak is formed in an external peripheral surface of the upper end part of the rotary shaft 2a and an internal peripheral surface of the circular recessed hole 13. When the rotary shaft 2a is rotated, this helical groove or helical protrusive streak functions as an axial flow pump, and lubricating oil sucked from a lubricating oil reservoir 5 is supplied to bearings 4b, 4b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION A rotary shaft support device having a lubricating function according to the present invention is incorporated in, for example, various mechanical devices having a rotary shaft provided in a vertical direction, and a bearing for supporting the rotary shaft is lubricated. Supply oil.

[0002]

2. Description of the Related Art There are various types of mechanical devices having a vertical or vertical tilting shaft. To support the rotary shaft of such a mechanical device, a rolling bearing including a ball bearing or a tapered roller bearing, or a bearing such as a sliding bearing is used. When such a bearing is used in a severe condition (a large load or a high rotation speed), it is necessary to continuously supply the lubricating oil to the bearing while the rotary shaft is rotating. In such a case, as a lubricating device that can be manufactured inexpensively without the need for a lubricating oil pump or the like, a structure for supplying lubricating oil to the bearing by utilizing the rotational movement of the rotating shaft has been conventionally known. .

FIG. 3 shows a rotary shaft supporting device having a lubricating function, which incorporates such a conventionally known lubricating device. Inside the bottomed cylindrical housing 1, there is a rotary shaft 2
Are provided in the vertical direction. Support plates 3, 3 are provided at upper and lower two positions inside the housing 1, and each support plate 3,
The rotary shaft 2 is rotatably supported by deep groove type ball bearings 4 and 4 fitted and fixed to the inner peripheral edge portion of the rotary shaft 3. The rotating shaft 2 has a hollow cylindrical shape, the upper end (not shown) is closed, and the lower end is open. A lubricating oil sump 5 is provided at the bottom of the housing 1, and the lower end of the rotary shaft 2 is inserted into the lubricating oil sump 5. Further, discharge holes 6, 6 for communicating the inside and outside of the rotary shaft 2 are formed in an intermediate portion of the rotary shaft 2 and directly above the ball bearings 4, 4. Further, the outer peripheral surface of the intermediate portion of the rotary shaft 2 has
A rotor 7 is fixed to a portion between the pair of ball bearings 4 and 4, and a stator 8 is fixed to a portion of the inner peripheral surface of the housing 1 facing the outer peripheral surface of the rotor 7. The rotor 7 and the stator 8 form an electric motor 9 for driving the rotary shaft 2 to rotate.

When the electric motor 9 is energized, the rotary shaft 2
When is rotated at a high speed, the fluid in the rotary shaft 2 is discharged to the outside of the rotary shaft 2 through the discharge holes 6 by the centrifugal force. As a result, the pressure inside the rotary shaft 2 decreases (becomes a negative pressure), and the lubricating oil present in the lubricating oil sump 5 is sucked into the rotary shaft 2. The lubricating oil thus sucked into the rotary shaft 2 is discharged from the discharge holes 6 based on the centrifugal force and poured into the ball bearings 4 and 4, respectively. Lubricate 4, 4.

[0005]

In the conventional structure shown in FIG. 3, when the shape of the rotating shaft provided in the up-down direction changes midway, the bearing existing above the changed part cannot be lubricated. There is. For example, when there is a portion having a remarkably small cross-sectional area in the middle of the rotating shaft, the portion cannot be made hollow in order to secure rigidity, and the lubricating oil cannot be sent above this portion. Also, if there is a crank part in the middle of the rotating shaft for converting rotational motion into reciprocating motion, it is difficult to machine this crank part hollow, so lubricating oil should also be provided above the crank part. not send. Furthermore,
When the rotating shaft has a structure in which a plurality of divided elements are connected by a coupling member, depending on the structure of the coupling member, the lubricating oil cannot be sent above the coupling member. The rotary shaft supporting device having the lubricating function of the present invention is invented so that the lubricating oil can be supplied to the bearing existing above even in such a case.

[0006]

A rotary shaft supporting device having a lubricating function of the present invention includes a housing, a rotary shaft provided inside the housing, and the rotary shaft rotatably supported inside the housing. And a bearing for The rotary shaft is arranged in the vertical direction such as the vertical direction or the tilt direction. A circular concave hole having an inner diameter slightly larger than the outer diameter of the upper end of the rotary shaft is provided in the upper part of the housing in a state of opening downward, and the rotary shaft is provided inside the circular concave hole. The upper end of is inserted loosely. Then, a spiral structure portion such as a spiral groove or a spiral ridge is formed on at least one peripheral surface of the inner peripheral surface of the circular recess and the outer peripheral surface of the upper end portion of the rotary shaft. Further, a lubricating oil sump is provided in the housing below the bearing, and the lubricating oil sump and the inside of the circular recess are communicated by an oil supply passage. Then, the spiral direction of the spiral structure portion is regulated to push the fluid existing in the circular concave hole below the opening of the circular concave hole as the rotary shaft rotates.

[0007]

In the rotary shaft supporting device having the lubricating function of the present invention configured as described above, the spiral structure portion pushes out the fluid in the circular recess downward as the rotary shaft rotates, and Decrease the pressure of (make negative pressure). As a result, the lubricating oil existing in the lubricating oil sump of the housing is sucked into the circular recess through the oil supply passage. The lubricating oil thus sucked into the circular concave hole is pushed out of the circular concave hole by the spiral structure portion, poured into the bearing supporting the rotary shaft, and lubricates the bearing.

[0008]

1 and 2 show an embodiment of the present invention. A rotating shaft 2a is arranged inside the bottomed cylindrical housing 1 in the vertical direction. The rotating shaft 2a is formed by connecting a hollow cylindrical lower half element 10 and a circular rod-shaped upper half element 11 concentrically with each other by a coupling 12 and capable of transmitting rotational movement. Support plates 3a, 3a are provided at upper and lower two positions inside the lower half of the housing 1, and each support plate 3a
Deep groove type ball bearing 4 fitted and fixed to the inner peripheral edge portions of a and 3a
The lower half element 10 is rotatably supported by a and 4a. Further, support plates 3b and 3b are provided at two upper and lower positions inside the upper half of the housing 1, and the support plates 3b and 3b are provided.
Deep groove type ball bearings 4b, 4b fitted and fixed to the inner peripheral edge of b
Thus, the upper half element 11 is rotatably supported.

The hollow circular tubular lower half element 10 is closed at its upper end and opened at its lower end. The lower end of the lower half element 10 is inserted into the lubricating oil sump 5 provided at the bottom of the housing 1. Further, discharge holes 6a, 6a for communicating the inside and outside of the lower half element 10 are formed in the intermediate portion and the upper end portion of the lower half element 10 just above the ball bearings 4a, 4a. . Further, the lower half element 10
The rotor 7 is fixed to the intermediate outer peripheral surface between the pair of ball bearings 4a, 4a, and the stator 8 is fixed to the inner peripheral surface of the housing 1 facing the outer peripheral surface of the rotor 7. are doing. The rotor 7 and the stator 8 constitute an electric motor 9 for rotationally driving the rotary shaft 2a including the lower half element 10. Incidentally, a part of the rotary shaft 2a rotatably driven by the electric motor 9 is provided with a power take-out means (not shown) such as a pulley, a gear, and a crank to take out a necessary driving force.

On the other hand, a circular recess 13 is formed in the center of the lower surface of the block 17 fixed to the inside of the upper part of the housing 1. The inner diameter R ₁₃ of the circular recessed hole 13 are slightly larger (R _13> D ₁₁₎ than the outer diameter D ₁₁ of the upper end portion of the upper half element 11. An annular recess 14 having a diameter sufficiently larger than that of the circular recess 13 is formed on the lower surface of the block 17 around the lower end opening of the circular recess 13 over the entire circumference. The upper end of the upper half element 11 is loosely inserted inside the circular recess 13. A spiral groove 15 is formed on the outer peripheral surface of the upper end of the upper half element 11. The spiral direction of the spiral groove 15 depends on the electric motor 9 described above.
The fluid existing in the circular recess 13 is regulated in a direction to push the fluid below the opening of the circular recess 13 in accordance with the rotation of the rotary shaft 2a caused by the energization of the rotary shaft 2a. Therefore, the circular recess 13 and the upper end of the upper half element 11 constitute a kind of axial flow pump.

Further, on the inner peripheral surface of the upper end portion of the circular recessed hole 13, an oil supply passage 16 constituted by a pipe, a hose or the like is provided.
Through the top of. The lower end of the oil supply passage 16 communicates with the lubricating oil sump 5.

The rotary shaft supporting device having the lubricating function of the present invention having the above-described structure is provided with the ball bearings 4a and 4b as the rotary shaft 2a rotates due to the electric power supplied to the electric motor 9.
Supply lubricating oil to. The action of supplying lubricating oil to the ball bearings 4a, 4a supporting the lower half element 10 of the rotating shaft 2a is as follows.
Since it is the same as the conventional structure shown in FIG. 3 described above, redundant description will be omitted. The operation of the portion for supplying the lubricating oil to the ball bearings 4b, 4b supporting the upper half element 11, which is a feature of the present invention, will be described below.

When the upper half element 11 constituting the rotary shaft 2a rotates at a high speed, the spiral groove 15 formed on the outer peripheral surface of the upper end portion of the upper half element 11 pushes the fluid in the circular concave hole 13 downward. Immediately after the energization of the electric motor 9 is started, there is almost no lubricating oil in the circular concave hole 13, so the fluid is the air existing in the circular concave hole 13 and the oil supply passage 16. In this way, when the air existing in the circular recessed hole 13 and the oil supply passage 16 is pushed out from the lower end opening of the circular recessed hole 13, the pressure in the circular recessed hole 13 and the oil supply passage 16 decreases (becomes negative pressure). The lubricating oil existing in the lubricating oil sump 5 is sucked into the circular recess 13 through the oil supply passage 16. The lubricating oil thus sucked into the circular recess 13 is pushed out of the circular recess 13 by the spiral groove 15. The lubricating oil thus pushed out from the circular recess 13 first adheres to the inner peripheral surface of the annular recess 14 by centrifugal force, and then flows down along the inner peripheral surface. And
A pair of upper and lower ball bearings 4b, 4 for supporting the upper half element 11
The ball bearing 4b on the upper side of b
Lubricate. Next, the lubricating oil drops toward the ball bearing 4b on the lower side to lubricate the ball bearing 4b as well. The lubricating oil that lubricates both ball bearings 4b and 4b in this manner is collected in the lubricating oil sump 5 and used again for lubricating the ball bearings 4a and 4b.

In the illustrated embodiment, the spiral groove is formed on the outer peripheral surface of the upper end portion of the upper half element 11, but the spiral groove is used instead of the outer peripheral surface of the upper half element 11 or. It may be formed on the inner peripheral surface of the circular recess 13 together with the outer peripheral surface of the upper end portion. Further, a spiral ridge may be formed on each of the peripheral surfaces instead of the spiral groove. Further, the number of ball bearings to which the lubricating oil is supplied by the axial flow pump configured to include the spiral groove (or the spiral ridge) does not have to be plural, and only one may be used. If this ball bearing is only one, even if the rotating shaft is arranged with a slight inclination, by shortening the distance between the circular concave hole and the ball bearing,
Lubricating oil can be sufficiently supplied to this ball bearing. Further, the upper portion (upper half element 11 in the illustrated embodiment) of the rotary shaft that constitutes the axial pump by the circular concave hole does not necessarily have to be a circular rod-shaped solid body. As in the conventional structure, a hollow circular tube may be used, and the conventional lubricating oil supply structure and the lubricating oil supply structure of the present invention may be provided together. Also, in the illustrated embodiment,
Although the structure in which the lower half element 10 and the upper half element 11 are connected by the coupling 12 is shown as the rotating shaft 2a, it is a matter of course that the present invention is not limited to the structure provided with such a coupling 12. Further, the bearing to which the lubricating oil is to be supplied is not limited to the ball bearing, and includes not only other rolling bearings such as a tapered roller bearing and various thrust bearings but also a slide bearing. Further, even if the lubricating oil sump is located below the bearing to which the lubricating oil should be supplied by the structure of the present invention,
It does not necessarily have to be provided at the bottom of the housing 1. For example, when it is considered that the entire length (height) of the rotating shaft cannot be sufficiently sucked up to the upper end of the rotating shaft from the bottom of the housing 1, a lubricating oil sump is provided in the middle of the housing 1. It can also be provided. Of course, in this case,
The lubricating oil after bearing lubrication is returned to the lubricating oil sump provided in the intermediate portion.

[0015]

Since the rotary shaft supporting device having the lubricating function of the present invention is constructed and operates as described above, the upper part of the rotary shaft is supported regardless of the shape of the rotary shaft arranged in the vertical direction. Lubricating oil can be reliably sent to the bearing.
Therefore, it is possible to contribute to the improvement of the reliability and durability of various devices having the rotating shafts arranged in the vertical direction.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged view of the upper part of FIG.

FIG. 3 is a partial vertical cross-sectional view showing a conventional structure.

[Explanation of symbols]

 1 Housing 2, 2a Rotating shaft 3, 3a, 3b Support plate 4, 4a, 4b Ball bearing 5 Lubricating oil reservoir 6, 6a Discharge hole 7 Rotor 8 Stator 9 Electric motor 10 Lower half element 11 Upper half element 12 Coupling 13 Circular Recessed hole 14 Annular recessed portion 15 Spiral groove 16 Oil supply passage 17 Block

Claims (1)

[Claims] 1. A housing, a rotating shaft vertically arranged inside the housing, a bearing for rotatably supporting the rotating shaft inside the housing, and a bearing provided on an upper portion of the housing. A circular concave hole that opens downward and has an inner diameter slightly larger than the outer diameter of the upper end of the rotary shaft, the inner peripheral surface of the circular concave hole, and the upper end of the rotary shaft that is inserted into the circular concave hole. The spiral structure portion formed on at least one of the outer peripheral surfaces of the portion, the lubricating oil reservoir provided in the housing below the bearing, and the lubricating oil reservoir and the inner side of the circular recess hole communicating with each other. Lubrication that regulates the spiral direction of the spiral structure portion in a direction in which the fluid existing in the circular recess is pushed out below the opening of the circular recess with the rotation of the rotating shaft. Rotating shaft support device with function .