JP2538801Y2 - Bearing lubrication device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating device for a bearing used at a high speed, for example, a bearing for rotating a main shaft of a machine tool.

[0002]

2. Description of the Related Art In bearings used under high-speed rotation, such as bearings used in main spindles of machine tools and jet engines of aircraft, a considerable temperature difference occurs between an inner ring and an outer ring. Due to an increase in preload due to the difference, there is a tendency that the bearing temperature increases and the bearing life is shortened. Conventionally,
In order to suppress the temperature rise of the inner ring, for example, an underless lubrication device as shown in FIG. 8 is used. The underless lubrication device simultaneously cools the inner ring 11 and lubricates the bearings by supplying lubricating oil to a through hole 11a running axially below the raceway surface of the inner ring 11. A scoop 11b is integrally formed on one end surface of the inner ring 11, and one end of the through hole 11a communicates with an inner space of the scoop 11b. Then, the lubricating oil is injected from the injection hole 12a provided in the bearing fixing member 12 toward the space inside the scoop 11b, and flows into the through hole 11a. The lubricating oil flowing into the through hole 11a travels along the through hole 11a, and a part of the lubricating oil is supplied into the bearing from a radial hole 11c that radially connects the through hole 11a and the inside of the bearing.

[0003]

In the lubricating apparatus having the above structure, the thrust of the lubricating oil in the through hole 11a is obtained from the centrifugal force accompanying the rotation of the inner ring. That is, the component fsin θ of the centrifugal force f in the direction of the through hole is used as the thrust of the lubricating oil by inclining the through hole 11a radially outward with respect to the axis by the angle θ. The thrust f sin θ is proportional to the magnitude of the angle θ if the centrifugal force f is constant.
Due to the relationship with the wall thickness of 11, the angle θ cannot be so large. Therefore, this type of conventional lubrication device
It is difficult to ensure sufficient circulation of the lubricating oil in the through-hole, and as a result, there is a problem that a sufficient lubricating / cooling effect cannot be expected.

[0004] As shown in Fig. 9, the injection hole 12a is oriented in the axial direction, and the lubricating oil is supplied to the through hole 11a in a state where the peripheral speed is zero. Then, the lubricating oil is accelerated to the inner ring rotation speed V in the through hole 11a. The energy for accelerating the lubricating oil to the speed V is directly used as the torque loss of the bearing.

[0005] Therefore, an object of the present invention is to increase the flowability of lubricating oil in a through hole and to reduce the torque loss of a bearing.

[0006]

In the present invention, the direction of the injection hole is inclined with respect to the axis in the rotation direction of the inner ring. Also,
The through hole was inclined with respect to the axis in the anti-rotation direction of the inner ring with respect to the opening on the injection hole side, and the direction of the injection hole was inclined with respect to the axis in the rotation direction of the inner ring.

In addition, the direction of the injection hole is inclined in the direction of rotation of the inner race with respect to the axis.

Further, the through hole is inclined with respect to the axis in the anti-rotation direction of the inner ring with respect to the opening on the injection hole side, and the direction of the injection hole is inclined with respect to the axis in the rotation direction of the inner ring. .

[0009]

The thrust can be applied to the lubricating oil flowing into the through hole by inclining the through hole of the inner ring in a predetermined direction. Referring to FIG. 5, the lubricating oil supplied from the injection hole 8a to the through hole 2a is accelerated to the rotation speed V of the inner ring. The velocity vector V of the lubricating oil is such that the through hole 2a has an axis 1a with respect to the opening 2d on the side of the injection hole 8a.
Is inclined in the anti-rotation direction of the inner ring 2 by an angle θ1, so that the velocity vector V1 in the direction along the through hole 2a =
Vsin θ1 and the velocity vector V in the direction perpendicular to the through hole 2a
2 = Vcos θ1. Therefore, the lubricating oil is given the velocity V1, and proceeds sequentially in the through hole 2a from the opening 2d to the other outlet. In other words, the rotation of the inner ring 2 in the direction indicated by the arrow in FIG.
Along the line at a predetermined speed. That is, by providing the inclination angle θ1, the flowability of the lubricating oil can be increased as compared with the conventional one.

On the other hand, the lubricating oil supplied from the injection hole 8a to the through hole 2a is accelerated to the rotation speed V of the inner ring 2, and the energy required for this acceleration is the torque loss of the bearing. Therefore, as shown in the figure, the direction of the injection hole 8a is inclined by an angle θ2 in the rotation direction of the inner ring 2 with respect to the axis 1a, and the lubricating oil injected from the injection hole 8a is preliminarily supplied with the initial velocity S1 = Scos θ2 (S is the initial speed in the injection direction), it is possible to reduce the amount of energy required to accelerate to the inner wheel speed V. That is, since the lubricating oil from the injection hole 8a is accelerated by (V-S1), the amount of energy required for acceleration for the speed S1 is omitted. Thereby, the torque loss of the bearing can be reduced.

[0011]

Embodiments of the present invention will be described below.

FIG. 1 shows an embodiment in which the present invention is applied to an angular ball bearing. The angular ball bearing includes an inner ring 2 fixed to a shaft 1 and an outer ring 4 fixed to a housing 3.
And a plurality of balls 5 rotatably interposed between the inner and outer rings 2 and 4
And a retainer 6 for keeping the balls 5 at equal circumferential intervals. A scoop 2 b is formed by extending one end of the inner ring 2, and a through hole 2 a communicating with the inner space 7 of the scoop 2 b is provided below the raceway surface of the inner ring 2. And the radial direction hole 2c which connects the through-hole 2a and the inside of a bearing is formed. The outer ring spacer 8 in contact with the outer ring 4 is formed with an injection hole 8a facing the opening 2d of the through hole 2a.
Sprays the lubricating oil supplied from the nozzle 8b toward the opening 2d.

As shown in FIG. 2, in this lubricating apparatus, in the above-described configuration, the through-hole 2a is formed with respect to the axis 1a with respect to the axis 1a by an angle .theta. It is characterized by being inclined. As described above, by inclining the through hole 2a in a predetermined direction,
The flowability of the lubricating oil in the through hole 2a can be improved. In this embodiment, the through hole 2a is parallel to the axis 1a in the radial direction.

FIG. 3 is characterized in that, in the configuration shown in FIGS. 1 and 2, the direction of the injection hole 8a is inclined by an angle θ2 in the rotation direction of the inner ring 2 with respect to the axis 1a. As described above, since the lubricating oil injected from the injection hole 8a has an initial velocity in the circumferential direction, the torque loss of the bearing is reduced.

FIG. 4 shows an embodiment in which the radial hole 2c is inclined by an angle θ3, and this configuration is added to one of the configurations shown in the above two embodiments. By doing so, the lubricating oil easily flows into the bearing, and the lubricating effect can be further enhanced.

FIG. 6 shows an embodiment in which the scoop 7 is not formed on the inner race 2. In the bearing of this embodiment, the inner ring 2 and the outer ring 4 have the same width, and are particularly suitable for use under ultra-high speed rotation. That is, in consideration of the possibility that the centrifugal expansion of the scoop portion causes a change in the curvature of the inner ring groove or a partial contact between the inner ring 2 and the shaft 1 under the ultrahigh-speed rotation, the scoop portion may be replaced. In addition, by forming a circumferential groove 2e having a role similar to that of the scoop on the end face of the inner ring 2, the above-mentioned problem is solved, and optimal use at ultra-high speed is ensured. The through hole 2a is inclined at an angle θ1 in a predetermined direction, and the opening 2d communicates with the circumferential groove 2e. The other parts are substantially the same as those shown in FIGS. The configuration shown in this embodiment has, in addition to the above-mentioned advantages, additional advantages such as a reduction in heat treatment deformation due to simplification of the inner ring shape and a reduction in manufacturing cost.

FIG. 7 shows an embodiment in which the circumferential groove 2e is inclined by an angle θ5 in the radial direction with respect to the axis in the configuration shown in FIG.

In addition, a configuration in which the direction of the injection hole 8a is inclined in the direction shown in FIG. 3 and a configuration in which the radial hole 2c is inclined in the direction shown in FIG. 4 are added to the configuration shown in FIGS. You may do so.

Although not shown, a configuration in which the direction of the injection holes 8a is inclined in the direction shown in FIG. 3 may be added to the configuration of the conventional lubrication device shown in FIG. in this case,
Although the flowability of the lubricating oil is the same as the conventional one, it is effective in reducing the torque loss of the bearing.

In the above embodiment, an example in which the present invention is applied to an angular ball bearing is illustrated. However, the present invention is generally applied to rolling bearings such as tapered roller bearings and deep groove ball bearings regardless of the type of bearing. can do.

If the inner ring 2 has two components, a through hole 2a is formed, and lubricating oil is supplied to the through hole 2a from the injection hole 8a facing the opening 2d of the through hole 2a. It can be widely applied regardless of the configuration and structure of other parts.

[0022]

According to the present invention, by inclining the through-hole of the inner race in a predetermined direction, the pumping action can be performed on the through-hole itself.
The flowability of the lubricating oil in the through holes can be improved.
Thereby, lubrication and cooling of the bearing can be effectively performed.

Further, by inclining the direction of the injection hole in a predetermined direction, a predetermined circumferential speed can be given to the lubricating oil injected from the injection hole, so that the torque loss of the bearing can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a plan view showing a main part of an inner ring in FIG.

FIG. 3 is a plan view showing a main part of an inner race according to another embodiment of the present invention.

FIG. 4 is a sectional view showing another embodiment of the present invention.

FIG. 5 is a plan view for explaining the operation of the present invention.

FIG. 6 is a cross-sectional view, a front view, and a plan view of a main portion of an inner ring showing another embodiment of the present invention.

FIG. 7 is a sectional view showing another embodiment of the present invention.

FIG. 8 is a sectional view showing a conventional lubrication device.

FIG. 9 is a plan view showing a main part of an inner ring in FIG. 8;

[Explanation of symbols]

 1 shaft 1a axis 2 inner ring 2a through hole 2d opening 8a injection hole

Claims (2)

(57) [Scope of request for utility model registration] 1. A bearing lubrication device for providing a through hole in an inner race, and lubricating and cooling the bearing by flowing lubricating oil from an injection hole facing the opening of the through hole into the through hole. A lubricating device for a bearing, wherein the direction of the injection hole is inclined with respect to the axis in the rotation direction of the inner ring. 2. A bearing lubrication device for providing a through hole in an inner race, and lubricating and cooling the bearing by flowing lubricating oil from an injection hole facing the opening of the through hole into the through hole. The through hole is inclined with respect to the axis in the anti-rotation direction of the inner ring with respect to the opening on the injection hole side, and the direction of the injection hole is inclined with respect to the axis in the rotation direction of the inner ring. The bearing lubrication device.