JP2002005181A - Lubricating device for rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricating device for rolling bearings of a small and light construction, allowing reduction of the running cost and certain lubrication of the rolling bearings and capable of preventaing a temperature rise immediately after oil supplying. SOLUTION: The end of an inner ring spacer 17 whose peripheral surface is made guide slopes 18... is allowed to intrude inside each rolling bearing 1.... Grease 16 extruded from oil supplying spaces 21... via throttle passages 20... is fed to inside the rolling bearings 1... via the guide slopes 18... on the basis of balance between the centrifugal force and surface tension.

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 rolling bearing, which is used for lubricating a rolling bearing for supporting a high-speed rotating shaft such as a main shaft of a machine tool.

[0002]

2. Description of the Related Art A main shaft of a machine tool rotates at a high speed during use. Therefore, such a main shaft must be rotatably supported by a rolling bearing, and a sufficient amount of lubricating oil must be supplied to the inside of the rolling bearing when the main shaft rotates. As a device for feeding lubricating oil to such a rolling bearing that rotatably supports a main shaft inside a housing, Japanese Patent Application Laid-Open No. 10-299784 discloses a lubricating device for a rolling bearing having a structure as shown in FIG. Is described. This lubricating device for a rolling bearing is configured such that lubricating oil can be freely fed into a rolling bearing 1 through a lubricating oil passage 3 provided in an outer race spacer 2. The inner race 4 constituting the rolling bearing 1 has an inner raceway 5 on its outer peripheral surface, and is externally fitted and fixed to the main shaft (not shown) which rotates at a high speed during use. The outer race 6 constituting the rolling bearing 1 has an outer raceway 7 on its inner peripheral surface, and is fitted and supported in the housing (not shown). or,
A plurality of rolling elements 8 are rotatably provided between the inner raceway 5 and the outer raceway 7 while being held by a retainer 9.

Around the main shaft, first and second inner ring spacers 10 and 11 are provided in order from the side of the inner ring 4 so as to be adjacent to the inner ring 4. On the other hand, the outer race spacer 2 is provided inside the housing in a state adjacent to the outer race 6. The lubricating oil passage 3 is provided inside the outer ring spacer 2, and lubricating oil (oil air or oil mist) sent into the lubricating oil passage 3 is supplied to the outer peripheral surface of the inner ring 4 and the outer ring 6. It can be supplied freely into the space 15 in which the plurality of rolling elements 8 are installed between the inner peripheral surface of the rolling element 8 and the inner peripheral surface.
That is, the lubricating oil fed into the lubricating oil passage 3 is blown out from the nozzle holes 13 provided in the outer ring spacer 2, and the inner peripheral surface of the outer ring spacer 2 and the outer peripheral surface of the first inner ring spacer 10. Water is discharged from the end opening of the oil supply gap 14 provided between the rolling bearing 8 and the space 15 provided with the rolling elements 8 inside the rolling bearing 1. The end opening of the oil supply gap 14 is located diametrically inward of the axially intermediate portion of the inner peripheral surface of the outer race 6 constituting the rolling bearing 1. Therefore, the lubricating oil efficiently adheres to the rolling surfaces of the rolling elements 8 irrespective of the air curtains formed at the openings at both ends of the space 15 during high-speed rotation.

[0004]

In the case of the conventional rolling bearing lubricating device constructed and operated as described above, the lubrication of the rolling bearing 1 is good, but it is difficult to increase the rotational speed of the main shaft. There is a problem that said. The reason is as follows. In order to increase the speed of the spindle supported by the rolling bearing 1, the pitch circle diameter (PC
D) needs to be reduced. On the other hand, in the case of the conventional structure shown in FIG. 3, since a part of the outer ring spacer 2 is located on the inner diameter side of the outer ring 6 and the retainer 9, the inner diameter of the outer ring 6 and the retainer 9 is changed. Cannot be reduced, and the PCD cannot be reduced. Therefore, it is difficult to increase the speed of the spindle as described above. In addition, since the outer ring spacer 2 is configured to protrude to the inner diameter side of the retainer 9, the manufacturing process of the outer ring spacer 2 is troublesome, and causes an increase in cost. Other lubricating devices for rolling bearings for rotatably supporting a main shaft of a machine tool and the like are described in, for example, JP-A-6-264934 and JP-A-10-231843. , A similar problem exists.

Japanese Patent Application Laid-Open No. 6-235425 discloses that
As shown in FIG. 4, a part of the hollow inner race spacer 23 is
Of the inner ring spacer 2a from the outer ring spacer 2a.
3 describes a lubricating device for a rolling bearing having a structure in which the lubricating oil fed into the inner ring 3 is discharged from a nozzle hole 13 a provided in the inner ring spacer 23 toward the rolling surface of the rolling element 8. Also in the case of this conventional device, since the inner race spacer 23 having an outer diameter larger than that of the inner raceway 5 is used, it is not only difficult to make the PCD sufficiently small, but also the shapes of the constituent members are complicated and the cost is reduced. Inevitably increases.

[0006] Further, in the case of so-called minute lubrication, the oil air or oil mist in which a small amount of lubricating oil is mixed into the air is continuously supplied to a rotating support portion during operation of a machine tool or the like. Although the fluctuation of the rolling resistance of the rolling bearing is small and the operation of the machine tool or the like can be stably performed, it is inevitable that the equipment becomes large and the operation cost increases. In order to simplify the equipment for refueling and reduce the operating cost, it is conceivable to feed grease or liquid lubricating oil (not oil air or oil mist) into the rolling bearing.

[0007] Such an oil supply structure is disclosed in Japanese Utility Model Laid-Open No. 5-94.
No. 531 describes a structure in which plastic grease is fitted in a grease pocket provided on an inner peripheral surface of an inner ring, and a communication hole is provided between the grease pocket and the outer peripheral surface of the inner ring. . According to such a structure, lubricating oil can be supplied from the plastic grease to the inner raceway provided on the outer peripheral surface of the inner race due to the centrifugal force caused by the rotation of the inner race. However, in the case of such a conventional structure, the amount of the plastic grease that can be held in the grease pocket is limited, so that it is difficult to continuously supply a stable lubricant over a long period of time.

In order to supply grease or liquid lubricating oil to the inside of the rolling bearing for a long period of time, a large-capacity lubricating space is provided outside the rolling bearing, and lubricating oil or lubricating oil in the lubricating space is provided. It is conceivable to feed grease into the rolling bearing. However, when supplying grease or liquid lubricating oil to the inside of a rolling bearing operating at high speed,
If the supply amount and the supply method are not appropriate, the rolling bearing may be damaged. That is, as a result of suddenly supplying a large amount of grease or liquid lubricating oil into the inside of the rolling bearing rotating at high speed, if the stirring resistance rises sharply,
The above-mentioned rolling bearing generates heat suddenly, and there is a possibility that serious damage such as seizure may occur on the rolling bearing. The lubricating device for a rolling bearing of the present invention has been invented in view of such circumstances.

[0009]

A lubricating device for a rolling bearing according to the present invention has an inner raceway on its outer peripheral surface and rotates at a high speed inside a housing, similarly to a conventionally known lubricating device for a rolling bearing. An inner ring that is externally fitted to the shaft, an outer raceway is provided on the inner peripheral surface, and an outer race that is internally fitted to and supported by the housing; an outer race spacer that is adjacent to the outer race and is internally fitted to and supported by the housing; And a plurality of rolling elements provided between the outer ring raceway and the rolling bearing device, in the space where the plurality of rolling elements are installed between the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring. From the lubrication space provided in the outer ring spacer,
A lubricant such as grease or oil is supplied.

[0010] In particular, in the lubricating device for a rolling bearing of the present invention, a guide inclined surface is provided on the outer peripheral surface of the inner race or the inner race spacer which is fitted to and supported on the shaft in a state adjacent to the inner race. . The guide inclined surface is inclined in a direction in which the diameter decreases as the distance from the inner ring raceway increases, and the small-diameter side end portion protrudes axially outward from the end surface of the outer ring and enters the inner diameter side of the outer ring spacer. ing. In addition, there is no portion where the inclination direction or the inclination angle changes suddenly from the small-diameter side end to the large-diameter end adjacent to the inner raceway, and the guide from the inner peripheral surface of the outer race spacer is not provided. The lubricant can be freely supplied to the inclined surface. The amount of lubricant flowing along the guide inclined surface is restricted between a portion of the guide inclined surface where the lubricant is supplied from the oil supply space of the outer ring spacer and the space where the rolling elements are installed. A squeezing section is provided for performing the operation.

[0011]

The operation of the lubricating device for a rolling bearing according to the present invention configured as described above is as follows. At the time of refueling, the lubricant present in the refueling space in the outer race spacer is attached to the inner race or a guide inclined surface provided on the outer peripheral surface of the inner race spacer. The lubricating oil adhering to the guide inclined surface in this way is balanced with the centrifugal force and the surface tension caused by the rotation of the inner race or the inner race spacer fixedly fitted on the shaft, and along the guide inclined surface, It is sent to the large diameter side of the surface and enters the inside of the rolling bearing. After reaching the inner raceway continuous to the large-diameter end of the guide inclined surface, it adheres to the rolling surface of each rolling element, so that the rolling contact portion between each rolling surface and the inner raceway and the outer raceway is formed. Lubricate.

That is, the guide inclined surface extends from the small-diameter end to the large-diameter end adjacent to the inner raceway.
There is no portion such as a step, an oil groove or an edge where the inclination direction or the inclination angle changes suddenly. In other words, there is neither a portion where the inclination direction changes suddenly nor a portion where the inclination angle changes suddenly. Therefore, regardless of the centrifugal force generated with the rotation of the shaft, the lubricating oil adhering to the guide inclined surface does not separate from the guide inclined surface in the middle of the guide inclined surface, It reaches the large diameter end. In this way, the operation of feeding the lubricating oil to the rolling contact portion through the inclined guide surface can be efficiently performed without being hindered by the air curtains formed at both ends of the rolling bearing when the shaft rotates at high speed.

Therefore, even if the rotation speed of the shaft increases, almost all of the lubricant supplied from the oil supply space of the outer race spacer to the inclined surface of the guide reaches the rolling surface of the rolling element. For this reason, even if the amount of the lubricant that is sent out from the oil supply space and adheres to the inclined guide surface is a small amount squeezed by the squeezing portion, the lubrication of the rolling bearing is satisfactorily performed. Further, the supply of the lubricant into the inside of the rolling bearing is performed stably little by little by being squeezed by the above-mentioned throttle portion, so that the rolling bearing does not generate heat suddenly after the supply of the lubricant.
Further, since the volume of the oil supply space provided outside the rolling bearing can be sufficiently ensured, the lubricant can be supplied to the inside of the rolling bearing for a long period of time.

Further, in the case of the lubricating device for a rolling bearing of the present invention, it is not necessary to make the outer ring spacer or the inner ring spacer having an outer diameter larger than the inner ring raceway enter the inner diameter side of the outer ring. For this reason, the PCD of the rolling bearing can be reduced, and the shaft can be rotated at high speed. Moreover, since it is not necessary to make the outer ring spacer enter the inner diameter side of the outer ring, the shape of the outer ring spacer can be simplified, and the lubricating device for a rolling bearing including the outer ring spacer can be reduced in cost.

[0015]

FIG. 1 shows a first embodiment of the present invention. The feature of the present embodiment is that a space 15 in which the rolling elements 8, 8 are installed is provided between the inner peripheral surfaces of the outer rings 6, 6, which constitute the pair of rolling bearings 1, 1, and the outer peripheral surfaces of the inner rings 4, 4. , 1
5, there is a lubricating device for feeding grease 16 as a lubricant. In addition, since the structure of the rolling bearing device is the same as that of the conventional structure shown in FIG. 3, the description of the equivalent parts is omitted or simplified, and the following description focuses on the characteristic parts of the present invention. Will be described.

In the case of the present embodiment, the inner races 4, 4 are made smaller in width in the axial direction (left-right direction in FIG. 1) than the outer races 6, 6, so that the inner races 4, 4 are formed. 4 in the axial direction (the end faces of the inner rings 4 and 4 facing each other) from the axial end faces of the outer rings 6 and 6 (the end faces of the outer rings 6 and 6 facing each other). Are also located at positions closer to the axial center of these outer races 6, 6. An inner ring spacer 1 is provided between the inner rings 4 and 4.
7 is pinched.

The inner ring spacer 17 has an inner peripheral surface formed in a cylindrical shape and an outer peripheral surface formed in a drum shape in which a pair of conical convex inclined surfaces 18 are combined. That is, the outer peripheral surface of the inner ring spacer 17 is inclined in such a direction that the diameter is the smallest at the center in the axial direction and becomes larger toward the end in the axial direction. In the middle of each of the guide inclined surfaces 18, 18, a portion where the inclination direction and the inclination angle change abruptly, such as a step, an oil groove, or an edge, in other words, a line representing the cross-sectional shape is indistinguishable. Does not exist. Each of the guide inclined surfaces 18 is a smooth surface having a surface roughness of 0.8 μmRa or less. The inclination angle θ of the guide inclined surfaces 18 is designed so that the grease adhering to the guide inclined surfaces 18 is efficiently sent to the inner rings 4 based on centrifugal force. Stipulated.

In order to assemble the lubricating device for a rolling bearing according to the present embodiment, the inner race spacer 17 is placed in such a state that both end faces of the inner race spacer 17 are brought into contact with the small-diameter end faces of the inner races 4, 4. And the inner rings 4, 4 are externally fitted and fixed to a main shaft (not shown). The outer diameter of both ends of the inner race spacer 17 is substantially equal to the outer diameter of the small diameter end of each of the inner races 4, which abuts the two ends. The abutting surfaces of the inner race spacer 17 and the inner races 4, 4 regulate the axial dimensions of the inner races 4, 4 so that they are present on the inner diameter side of the rolling elements 8, 8. .

On the other hand, the outer race spacer 2b arranged so as to be sandwiched between the pair of outer races 6, 6 combines a cylindrical outer peripheral surface with a pair of conical concave surfaces 19, 19 inclined in opposite directions to each other. And an inner peripheral surface comprising: The pair of conical concave surfaces 19, 19 forming the inner peripheral surface are located diametrically outward of an intermediate portion of the inner ring spacer 17 in a state where the lubricating device for a rolling bearing is assembled. As it approaches 4, it is inclined in the direction toward the diametrically outward direction.

The diameter of the inner peripheral surface of the outer race spacer 2a as described above is slightly larger than that of the outer peripheral surface of the inner race spacer 17 in a portion corresponding to the axial direction. Therefore, each guide inclined surface 1 constituting the outer peripheral surface of the inner ring spacer 17 is formed.
8, 18 and the conical concave surfaces 19, 19 constituting the inner peripheral surface of the outer ring spacer 2b are closely opposed to each other. And
Throttling channels 20, 20 corresponding to the throttling portion described in the claims are formed between the inner peripheral surfaces at both axial ends of the outer ring spacer 2b and the guide inclined surfaces 18, 18.

Further, the rolling bearings 1 and 1 are provided inside the outer ring spacer 2a through the respective throttle passages 20 and 20.
Oil supply spaces 21 for storing grease 16 to be fed into the inside are provided. Each of these refueling spaces 21, 21
Pressing plates 22, 22 are closely fitted in the inner part of the outer ring spacer 2a (the part closer to the outer diameter of the outer ring spacer 2a in the upper part of FIG. 1), and an air cylinder provided in the outer diameter half of the outer ring spacer 2a. The pressing plates 22 and 22 can be freely pressed by 23 and 23. In a state where the rolling bearing lubrication device is assembled, the main shaft is supported inside the air cylinders 23, 23,
Compressed air can be supplied from a compressed air passage provided in a housing (not shown). In addition, each of the refueling spaces 21, 21
Is opposed to an intermediate portion between the guide inclined surfaces 18, 18. When lubricating a machine tool provided with a main shaft, compressed air is supplied to the air cylinders 23, 23,
The grease 16 is pressed by the pressing plates 22, 22. As a result, this grease 16 is
It passes through 0 and 20 and is extruded little by little out of the outer ring spacer 2a. The operation of pushing out the grease 16 is performed at predetermined time intervals (for example, several hundred hours) when the machine tool is stopped. At the time of non-extrusion, each pressing plate 2
Since the springs 2 and 22 are pulled up by the force of the spring, the grease in the oil supply spaces 21 and 21 does not adhere to the guide inclined surfaces 18 and 18.

As described above, the throttle channels 20, 20
The grease 16 which is pushed out of the outer ring spacer 2b through the outer ring spacer 2b and adheres to the guide inclined surfaces 18, 18 rotates during rotation of the inner ring spacer 17 fitted and fixed to the main shaft during operation of the machine tool. Due to the balance between the centrifugal force and the surface tension, the water is sent along the guide inclined surfaces 18 to the larger diameter side of the guide inclined surfaces 18. That is, the centrifugal force causes a radially outward force to act on the grease 16, but the lubricating oil also has a force that causes the grease 16 to remain attached to the guide inclined surfaces 18, 18 due to surface tension. Join. By balancing these two forces, the grease 16 attached to each of the guide inclined surfaces 18, 18 remains in a state of being attached to each of the guide inclined surfaces 18, 18, and the large diameter of each of the guide inclined surfaces 18, 18. The rolling bearings 1, 1 are fed to the inner side of the plurality of rolling elements 8, 8 (to the inside of the rolling bearing 1).

After reaching the inner ring raceways 5, 5 as they are, they adhere to the rolling surfaces of the rolling elements 8, 8 or from the large-diameter end portions of the inclined guide surfaces 18, 18, respectively. It is blown radially outward by centrifugal force and adheres to the rolling surfaces of the rolling elements 8 and 8. The lubricating oil adhering to the rolling surfaces of the rolling elements 8 and 8 in this manner is directly applied to the rolling surfaces of the rolling elements 8 and 8 and the inner ring raceways 5 and 5 of the inner rings 4 and 4 outer peripheral surfaces. Lubricating the rolling contact portions between the inner peripheral surfaces of the outer rings 6, 6 and the outer ring raceways 7, 7, respectively.

That is, each of the guide inclined surfaces 18, 18 is
Between the small diameter side end and the large diameter end adjacent to each of the inner ring raceways 5, 5, there is no portion such as a step, an oil groove or an edge where the inclination direction and the inclination angle suddenly change. . For this reason, the lubricating oil adhering to each of the guide inclined surfaces 18, 18 is not affected by the centrifugal force generated with the rotation of the main shaft.
The guide slopes 18 reach the large-diameter end of the guide slopes 18 without being separated from the guide slopes 18 in the middle of the guide slopes 18. Then, at the large-diameter side end portion, which reaches the inner ring raceways 5, 5 as it is or the inclination direction and the inclination angle change suddenly, it is swung radially outward by the centrifugal force, and It adheres to the rolling surfaces of the rolling elements 8 and 8. In this way,
The action of feeding grease into the rolling contact portion through each of the guide inclined surfaces 18, 18 is efficiently performed without being hindered by air curtains formed at both ends of the rolling bearings 1, 1 at the time of high-speed rotation of the main shaft. Done. Therefore, even if the rotation speed of the main shaft increases, almost all of the grease 16 pushed out from the throttle passages 20 reaches the rolling surfaces of the rolling elements 8.

For this reason, even if the grease 16 sent out from the oil supply spaces 21 and adhered to the guide inclined surfaces 18 is a small amount of grease which is throttled by the throttle passages 20, Lubrication of each of the rolling bearings 1 and 1 is favorably performed. Further, the supply of the grease 16 to the inside of each of the rolling bearings 1 and 1 is stably performed little by little by being squeezed by the respective throttle passages 20 and 20, so that the stirring resistance after the supply of the grease 16 is reduced. The increase is slight, and the rolling bearings 1 and 1 do not rapidly generate heat. Further, since the volumes of the oil supply spaces 21 and 21 provided outside the rolling bearings 1 and 1 can be sufficiently ensured, the supply of the grease 16 to the inside of each of the rolling bearings 1 and 1 can be performed.
It can be done over a long period of time.

Next, FIG. 2 shows a second embodiment of the present invention.
An example is shown. In the case of this example, instead of omitting the inner ring spacer, an extension 24 is formed on one half (the right half in FIG. 2) of the inner ring 4a constituting the rolling bearing 1a.
The outer peripheral surface of 4 is a guide inclined surface 18a. And
In the outer ring spacer 2c arranged on the outer diameter side of the extension portion 24,
An oil supply space 21a for storing liquid lubricating oil is provided. The lubricating oil in the oil supply space 21a can be discharged little by little onto the guide inclined surface 18a formed on the outer peripheral surface of the extension 18a through the discharge port 25.
For this reason, with the lubrication device for rolling bearings assembled,
With the opening end of the oil supply space 21a facing upward, the discharge port 2
5 are arranged below, and the refueling space 2
The supply of gas into 1a and its stop can be freely performed.
When the supply of gas is made freely (only the oil supply space 21a is allowed to communicate with the outside air), the lubricating oil in the oil supply space 21a is dropped on the guide inclined surface 18a, and the gas supply is stopped (oil supply). When the space 21a and the outside air are shut off), the dripping of the lubricating oil is stopped.

The liquid lubricating oil dropped on the guide inclined surface 18a in this manner is sent into the inside of the rolling bearing 1a with the rotation of the inner ring 4a, and lubricates the rolling bearing 1a. In the case of this example, the rolling bearing 1
The inner peripheral edge of one (the right side in FIG. 2) of the shield ring 26, which is locked to the inner peripheral surface of both ends of the outer ring 6a constituting the outer ring 6a, is close to the guide inclined surface 18a. The diaphragm section described in the section is constituted. For this reason, if the refueling space 21a is temporarily removed from the guide inclined surface 18
Even if a large amount of lubricating oil is supplied to a, the lubricating oil does not enter the inside of the rolling bearing 1a all at once. Therefore, also in the case of this example, the temperature of the rolling bearing 1a does not rise rapidly immediately after refueling. Other operations and the like are the same as in the case of the above-described first example.

[0028]

The lubricating device for a rolling bearing according to the present invention is constructed and operates as described above. Therefore, the lubricating device can be configured with a relatively simple structure and small in size, and can rotate at a high speed regardless of the structure having a low running cost. The lubrication of the bearing portion supporting the shaft to be driven can be reliably performed. Further, since there is no troublesome processing of the component parts, the cost does not increase. Further, it is possible to reduce the PCD of the rolling bearing and rotate the shaft at a higher speed.

[Brief description of the drawings]

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

FIG. 2 is a half sectional view showing the second example.

FIG. 3 is a half sectional view showing a first example of a conventional structure.

FIG. 4 is a partial sectional view showing the second example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1a Rolling bearing 2, 2a, 2b, 2c Outer ring spacer 3 Lubricating oil passage 4, 4a, 4b Inner ring 5 Inner ring track 6, 6a Outer ring 7 Outer ring track 8 Rolling element 9 Cage 10, 10a First inner ring spacer Reference Signs List 11 Second inner ring spacer 13, 13a Nozzle hole 14 Lubrication gap 15 Space 16 Grease 17 Inner ring spacer 18, 18a Guide inclined surface 19 Conical concave surface 20 Restriction flow path 21, 21a Oil supply space 22 Press plate 23 Air cylinder 24 Extension Part 25 Discharge part 26 Shield ring

Claims (1)

[Claims] 1. An inner ring having an inner raceway on an outer peripheral surface and externally fitted and supported on a shaft rotating at high speed inside a housing; an outer race having an outer raceway on an inner peripheral surface and internally fitted and supported in the housing; An outer ring spacer that is fitted and supported in the housing adjacent to the outer ring, and a rolling bearing device including a plurality of rolling elements provided between the inner ring raceway and the outer ring raceway. In a space in which the plurality of rolling elements are installed between the inner peripheral surface of the outer ring and a rolling bearing lubricating device for supplying a lubricant from an oil supply space provided in the outer ring spacer,
A guide inclined surface is provided on an outer peripheral surface of the inner ring or an inner ring spacer that is externally fitted to and supported on the shaft in a state adjacent to the inner ring, and the guide inclined surface has a direction in which the diameter decreases as the distance from the inner ring track increases. The small-diameter end portion projects axially outward from the end surface of the outer ring and enters the inner diameter side of the outer ring spacer, and the large diameter portion adjacent to the inner ring raceway from the small diameter end portion. There is no portion where the inclination direction or the inclination angle changes suddenly up to the side end, and the lubricant can be freely supplied from the inner peripheral surface of the outer ring spacer to the guide inclined surface. Between the portion where the lubricant is supplied from the lubrication space of the outer race spacer and the space in which the rolling elements are installed, for regulating the amount of lubricant flowing along the inclined guide surface. Rolling characterized by the provision of a throttle section Bearing lubricating device.