JP3016111B2 - Ultra high speed cylindrical roller bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultra-high-speed cylindrical roller bearing used for a support portion of a high-speed rotating shaft, such as a gas generator high-speed shaft used in an aircraft or a power generation facility, or a machine tool main shaft. .

[0002]

2. Description of the Related Art FIGS. 3 to 5 show an ultra-high-speed cylindrical roller bearing for supporting an ultra-high-speed rotating shaft conventionally used. FIG. 4 shows the raceway surface of the outer race 01 in a bilobe shape with the bearing incorporated, and FIG. 5 shows the trilobe shape in the raceway surface. As shown in these figures, by making the raceway surface of either the outer ring 01 or the inner ring 04 a non-circular shape, the relative position is regulated by the retainer 03, and the raceway surface of the outer ring 01 and the inner ring The rolling elements 02 interposed between the raceway surfaces of the inner ring 04 rotate while controlling skidding on these raceway surfaces, and revolve around the raceway surface of the inner ring 04.

[0003] A scoop 09 is fixed to one side of a flange portion 06 protruding from a rotating shaft 05 for fixing the inner ring 04 with the inner ring 04 interposed therebetween. The scoop 09 receives refueling 08 ejected from a refueling nozzle 07 disposed on the outer peripheral surface of the rotating shaft 05. An oil passage 011 is formed in the inner diameter surface of the scoop 09 so as to communicate with the opening of the scoop 09 in parallel with the axis of the rotating shaft 05. One end between the inner surface of the inner ring 04 and the outer surface of the flange portion 06 has an oil passage 011.
And a lubricating oil passage groove 010 whose cross-sectional area is enlarged inward from the connecting portion is formed. Further, the front end side nozzle 012 and the rear end side nozzle 013 which are respectively opened at the front end side and the rear end side of the rolling element 02 which rolls on the raceway surface of the inner ring 04 penetrate through the inner ring 04 in the radial direction. It is provided. The front-end side nozzle 012 and the rear-end side nozzle 013 are provided with a phase difference of 90 ° to each other, open to the raceway surface of the inner ring 04, and provided two in the circumferential direction.

Accordingly, the oil supply 08 received by the scoop 09 passes through the oil passage 011, passes through the lubricating oil passage groove 010, the front end side nozzle 012, and the rear end side nozzle 013, and passes through the inner race 04.
Are discharged to the front end side and the rear end side of the rolling element 02 having a phase difference of 90 ° of the raceway surface, and an oil film is formed between the contact surface of the rolling element 02 and the raceway surfaces of the inner ring 04 and the outer ring 01. Perform lubrication.

When the rotating shaft 05 is supported by such an ultra-high-speed cylindrical roller bearing, the inner ring 04
The rolling element 02 that rolls on the raceway surface of FIG. 4 exaggerates the non-circularity. As shown in FIGS. 4 and 5, the raceway surface of the inner ring 04 and the raceway surface of the outer ring 01 approach each other. A certain rolling element 02 is in a preload state, and in the portion where the preload is applied, the contact surface pressure between the inner and outer raceway surfaces and the rolling element increases. For this reason, the rolling element 02 is controlled in skidding, and rolls between the raceways of the inner ring 04 and the outer ring 01, and at the same time as the rotation speed of the rotating shaft 05, the inner ring 0
4 revolves around the orbital plane.

However, when the rotation speed of the rotating shaft 05 increases, the effect of the centrifugal force on the rolling elements 02 is also added, and the rolling elements 0
The contact surface pressure of the preload portion 2 becomes too high, and a problem occurs in durability. That is, FIG. 2 is a diagram showing the non-roundness of the outer raceway surface of the bilobe-shaped bearing shown in FIG. 4 and the calculated life of the bearing. As shown in this diagram, when the d · N value is constant, , The calculated life of the bearing decreases as the outer raceway surface non-roundness increases. Here, d is the diameter of the rotating shaft 05 (m /
m) and N are the number of rotations of the rotating shaft 05 per minute (rpm)
It is. In addition, when the rolling element 02 locally passes through a preload portion in which the contact surface pressure is increased, vibration is generated in this portion. However, there is a disadvantage that this vibration increases as the rotation speed increases.

[0007]

SUMMARY OF THE INVENTION Therefore, the present invention solves the above-mentioned disadvantages of the conventional bearing, and even if the speed is increased,
It is an object of the present invention to provide an ultra-high-speed cylindrical roller bearing that can dramatically increase the service life and reduce the vibration of the rolling elements.

[0008]

Therefore, the ultrahigh-speed cylindrical roller bearing of the present invention has the following means. (1) The raceway surface of the inner race and the raceway surface of the outer race on which the rolling elements are interposed are formed in a substantially perfect circular shape. (2) A nozzle for supplying lubricating oil to the front end portion and the rear end portion of the rolling element penetrates from the inner surface of the inner ring to the raceway surface of the inner ring or the end surface of the rolling element at substantially the same phase angle position of the inner ring. Provided.

[0009]

According to the ultrahigh-speed cylindrical roller bearing of the present invention, (1) no local preload is applied to the rolling element, that is, since the contact surface pressure does not locally increase, the shaft to be supported is superhigh-speed. Even if it rotates, the rolling elements or the raceway surfaces of the inner and outer races are not damaged, and the bearing life can be extended. Further, the vibration caused by the rolling element passing through the local preload portion is eliminated, and the vibration of the bearing can be reduced. (2) Also, by making the raceways of the inner ring and the outer ring substantially circular, skidding that has conventionally occurred between the rolling element and the raceway is reduced to the raceway surface of the inner race or the end face of the rolling element. The rolling element is driven in the revolving direction by the lubricating oil supplied from the nozzle and having the so-called speed component in the revolving direction around the raceway surface of the inner ring, so that it is not generated. Furthermore, since the same amount of lubricating oil is simultaneously supplied from the respective nozzles provided at substantially the same phase angle at the front end and the rear end of the rolling element, the revolving speed of the front end and the rear end of the rolling element is reduced. It is possible to make them coincide with each other, thereby preventing the occurrence of skew of the rolling elements. Also, by adjusting the supply amount of the lubricating oil, the revolving speed of the rolling element can be set to an appropriate speed that does not cause skid damage.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of an ultrahigh-speed cylindrical roller bearing according to the present invention. FIG. 1 is a drawing showing one embodiment of the ultrahigh-speed cylindrical roller bearing of the present invention, and FIG.
1 is a side sectional view, and FIG. 1B is a sectional view taken along the line AA of FIG. 1A.

As shown in the figure, a flange 5 provided on a rotating shaft 5 is provided.
An inner ring 4 is installed on one outer peripheral surface by fitting its inner diameter surface. Outside the inner race 4, a raceway surface 22 formed by making the outer diameter surface of the inner race 4 a substantially perfect circle is provided at an interval, and a raceway surface 21 formed by a substantially perfect circle is provided on the inner diameter surface. An outer ring 1 is provided. Between the raceway surface 22 of the inner race 4 and the raceway surface 21 of the outer race 1, a radial clearance is provided between the raceway surface 22 and the raceway surface 21, and the cylindrical rolling element 2 is interposed.
Twelve rolling elements 2 are arranged at a constant pitch in the circumferential direction.
The interval between the adjacent rolling elements 2 is regulated by the cage 3,
The raceways 22, 21 of the inner and outer races 4, 1 rotate on their own axis, and revolve between the raceways 22, 21.

On the inner diameter surface 12 of the inner ring 4, lubricating oil passage grooves 8 for passing lubricating oil are formed at 90 ° intervals between the inner ring 4 and the outer peripheral surface of the flange portion 51 of the rotating shaft 5. Lubricating oil passage groove 8
Are formed so that the cross-sectional area increases from both sides toward the center of the inner ring 4 in the axial direction, so that the cross-sectional area becomes maximum at the center. The inner ring 4 has a raceway surface 2 of the inner ring 4.
At both ends of the rolling element 2 interposed therebetween, a nozzle 9 having one end opened and the other end opened to a lubricating oil passage groove 8 provided on the inner diameter surface is bored in the radial direction. The nozzles 9 opening at both ends of the rolling element 2 are provided at substantially the same phase angle, that is, at substantially the same angular position in the circumferential direction.

On both sides of the inner ring 4 fitted on the flange 51 of the rotating shaft 5, scoops 10 are fixedly provided on the outer peripheral surface of the flange 51. A groove is provided on the inner diameter surface of the scoop 10 in contact with the outer peripheral surface of the flange portion 51.
An oil passage 7 communicating with the lubricating oil passage groove 8 is formed between the oil passage 7 and the outer diameter surface 1. Further, an oil supply pipe 6 provided with an injection port is provided toward both side openings of the scoop 10.

In this embodiment, the outer ring 1 fixed to the support (not shown), the inner ring 4 fitted to the outer peripheral surface of the flange 51 of the rotating shaft 5, and the raceway surface 21 of the outer ring 1 The rotating shaft 5 is supported by a cylindrical roller bearing composed of a rolling element 2 that revolves while rolling between the raceway surfaces 22 of the inner ring 5, and the rotating shaft 5 rotates at an ultra high speed with a dN value of 2.2 million or more of the bearing. The lubricating oil, which is provided on both sides of the inner ring 4 and is directed to the opening on both sides of the scoop 10, is injected from the spout of the oil supply pipe 6 through the oil passage 7, and the same amount of lubricating oil is simultaneously lubricated from both sides. It flows into the oil passage groove 8. The lubricating oil flowing into the lubricating oil passage groove 8 is accelerated by the centrifugal force acting on the rotating inner ring 4 together with the rotating shaft 5, and passes through the nozzle 9 to the raceway surface 22 of the inner ring 4.
It is injected more.

The lubricating oil injected from the raceway surface 22 of the inner race 4 has a radial velocity component and flows between the outer peripheral surface of the rolling element 2 and the raceways 21 and 22 of the inner race 4 and the outer race 1. The contact surface is lubricated, and the circumferential speed component is
To cause the rolling element 2 to generate a revolving speed. Thereby, a radial gap is provided between the outer peripheral surface of the rolling element 2 and the substantially circular raceway surfaces 21 and 22 of the outer ring 1 and the inner ring 4, and a pre-pressed portion, that is, The rolling element 2 revolves at a fixed ratio to the rotation speed of the rotating shaft 5 without providing a portion where the surface pressure increases. The revolution speed of the rolling element 2 can be controlled by adjusting the amount of lubricating oil supplied from the nozzle 9. Thereby, the revolving speed of the rolling element 2 can be set to an appropriate value that does not cause skid damage.

Further, the raceway surfaces 22 of the inner race 4 and the outer race 1,
By making a substantially circular circle 21 and providing a radial gap between the contact surface of the rolling element 2 and the portion where the contact surface pressure of the rolling element 2 is increased, the fact that the bearing becomes larger particularly as the rotational speed increases, , And the life of the bearing can be prolonged.

That is, FIG. 2 is a diagram showing the calculated life of a bearing having an inner ring having a substantially circular raceway surface and an outer ring having a raceway surface having variously changed non-roundness. It has been shown that as the non-circularity decreases, the life of the bearing increases. In particular, it is shown that if the degree of non-roundness is about 80 μm or less, the same level of durability as that of a perfect circle can be expected.

Further, since the phase angle of the opening of the nozzle 9 to the raceway surface 22 is set to be substantially the same between the two nozzles 9 opening at both ends of the rolling element 2, At the same time, the same amount of lubricating oil is jetted out, the force in the revolving direction received from the lubricating oil at both ends of the rolling element 2 becomes the same, the revolving speed of both ends of the rolling element 2 becomes the same, and the rolling element 2 is skewed. The occurrence of the skew phenomenon which occurs due to this can be prevented.

In the above-described embodiment, two nozzles 9 are provided at both ends of the rolling element 2. However, the third nozzle opening at the center inner raceway surface 22 of the rolling element 2 is shown. May be provided. As a result, the driving force for driving the rolling elements 2 in the revolving direction can be increased, and the driving force of the nozzles 9 acting on the rolling elements 2 can be well balanced, so that the occurrence of skew can be further prevented. .

[0020]

As described above, according to the ultrahigh-speed cylindrical roller bearing of the present invention, the following effects can be obtained by the structure shown in the claims. (1) Since no local preload is applied, the local contact surface pressure between the inner and outer races and the rolling elements does not increase. As a result, even if the rotating shaft for supporting rotates at a very high speed, the rolling elements,
Or, it will not damage the raceway surface of the inner and outer rings,
The life of the bearing can be extended. In addition, the vibration generated by the local preload is eliminated, and the vibration can be reduced. (2) Also, by making the raceway surfaces of the inner ring and the outer ring substantially circular, skidding, which has conventionally occurred, is supplied from the inner raceway surfaces at both ends of the rolling element or the nozzles at the end surface of the rolling element. The rolling element is driven in the revolving direction by the lubricating oil in which the so-called speed component in the revolving direction around the raceway surface of the inner ring is not generated. (3) Furthermore, the lubricating oil is simultaneously provided from the respective nozzles provided at substantially the same phase at the front end and the rear end of the rolling element.
Since the same amount is supplied, the revolving speed of the front end portion and the revolving speed of the rear end portion of the rolling element can be made coincident, and the occurrence of skew of the rolling element can be prevented. Also, by adjusting the supply amount of the lubricating oil, the revolving speed of the rolling element can be set to an appropriate speed that does not cause skid damage.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of an ultrahigh-speed cylindrical roller bearing according to the present invention, wherein FIG. 1 (A) is a side sectional view and FIG. 1 (B) is FIG.
(A) arrow AA sectional view,

FIG. 2 is a diagram showing the non-circularity of the outer raceway surface and the calculated bearing life,

FIG. 3 is a side sectional view showing a conventional cylindrical roller bearing;

4 is a cross-sectional view taken along the line BB in FIG. 3, showing an example of a non-true circle of the conventional cylindrical roller bearing in an exaggerated manner;

5 is an exaggerated cross-sectional view of another example of the conventional cylindrical roller bearing taken along line BB in FIG. 3;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 outer ring 2 rolling element 3 retainer 4 outer ring 5 rotating shaft 6 oil supply pipe 7 oil passage 8 lubricating oil passage groove 9 nozzle 10 scoop 21 outer ring raceway surface 22 inner raceway surface 51 flange of rotating shaft

────────────────────────────────────────────────── ─── Continuing on the front page (72) Koji Ishikawa 3066 Oyumida, Ogata, Kuwana-shi, Mie Pref. Inside NTN Co., Ltd. −37625 (JP, U) Japanese Utility Model Hei 5-30559 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16C 33/66 F16C 19/26

Claims (1)

(57) [Claims] 1. An inner ring fixed to an outer periphery of a high-speed rotating shaft, an outer ring fixed to a support of the shaft, and a relative position maintained by being interposed between a raceway surface of the inner ring and a raceway surface of the outer ring. In the super-high-speed cylindrical roller bearing that is formed of a cylindrical rolling element that is rolled by being regulated by a container, the raceway surface of the inner ring, and the raceway surface of the outer ring are formed in a substantially perfect circle, A nozzle for supplying lubricating oil to each of the front end portion and the rear end portion of the rolling element is provided so as to penetrate from the inner surface of the inner race having substantially the same phase to the raceway surface or the end surface portion of the rolling element. Ultra high speed cylindrical roller bearing characterized by: