JP2504971Y2 - Lubricator for bearings of ultra-high speed rotating shaft - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating device for bearings of ultra-high speed rotating shafts of machine tools and the like.

[0002]

2. Description of the Related Art For example, in a rotary shaft that rotates at an extremely high speed, such as a main shaft of a machine tool or a turbine blower shaft of an exhaust turbine supercharger, it is referred to as jet lubrication or underless lubrication (see Japanese Utility Model Laid-Open No. 4-136323). However, in this case, there is a problem that the shaft power loss caused by stirring a large amount of lubricating oil is very large. Therefore, in the small output motor, it is difficult to rotate at an extremely high speed because of this power loss.

Therefore, oil mist lubrication or oil-air lubrication is used when the rotary shaft rotates at an extremely high speed. For example, as shown in FIG. 4, an oil supply nozzle 103 is provided in the vicinity of a bearing 102 supporting a main shaft 101 of a machine tool. Is arranged, and the inner ring 104 of the bearing 102 is connected to the injection port 103A of the refueling nozzle 103.
Oil mist or oil air is jetted onto the rolling surface 104A by the air pressure feeding force, and the lubricating oil is supplied to the bearing 102.

[0004]

However, in the conventional lubrication device for a bearing of an ultra-high speed rotating shaft, when the bearing 102 is rotated at an ultra-high speed, the rolling element 105 and the cage 106 cause a contact between the side surface of the bearing 102 and the vicinity thereof. The air is agitated to generate a violent air flow, and the jet flow of oil air easily flows to the one with less resistance. Therefore, the injection port 10 of the refueling nozzle 103
From 3A, it becomes difficult for a small amount of lubricating oil injected together with a large amount of compressed air flow to be introduced into the inside of the bearing 102, and the bearing 1
There was a problem that it was difficult for sufficient lubricating oil to reach the contact point 104B of the rolling element 105 on the rolling surface 104A of No. 02. As a result, abnormal heat generation may occur or the bearing 102 may be burned.

For example, a main shaft 1 rotating at 100,000 revolutions / minute
In the case of 01, the rolling element 105 revolves around its own axis, and its revolution speed is about half the rotation of the main shaft 101,
On the other hand, the peripheral speed of the cage 106 is 90 to 100 m / sec.
However, there is a gap between the end surface of the bearing 102 and the injection port 103A, and the injection port 103A is located radially outside the rolling surface 104A. Refueling nozzle 10
No. 3 injection port 103A and rolling element 10 on rolling surface 104A
The distance L to the contact point 104B of 5 becomes long, the jet flow of oil air is obstructed by the violent air flow (film) generated above, and a small amount of lubricating oil is supplied from the refueling nozzle 103 by the subsonic compressed air flow. Even if sprayed, it is difficult for the lubricating oil to reach the contact point 104B on the rolling element 105.

The present invention has been made in order to solve the above-mentioned problems, and an object thereof is to make an injection flow of oil air or the like hardly receive an air flow by a bearing accompanying the super high speed rotation of a main shaft. To provide a lubricating device for a bearing of an ultra-high speed rotating shaft, which can sufficiently supply lubricating oil to a contact point of a rolling element on a rolling surface of the bearing and can suppress a shaft power loss as small as possible. Is.

[0007]

This invention SUMMARY OF THE INVENTION, in bearing lubricating apparatus for ultra high speed shaft for supplying lubricating oil through the air pumping force to the bearing for supporting the rotating shaft, the rotating shaft is drive
It is inserted in the center of the rotor of the dynamic motor and connected with it.
At least one of which is arranged in front of and behind the axial direction of the rotor.
It is rotatably supported by the outer cylinder by a pair of bearings,
A hollow hole having a length extending in the axial direction between the pair of bearings is formed at the center, and is located at the rear end of the rotary shaft.
A non-contact type labyrinth between the rotating shaft and the lubricating hydraulic pipe.
A seal structure is provided, and an annular gap is provided inside the hollow hole of the rotary shaft between the rotary shaft and the inner wall surface of the hollow hole, so that the lubrication hydraulic feed pipe extends substantially over the entire length of the hollow hole. Has been inserted over
In addition, the rotating shaft includes a pair of the hollow holes.
An annular groove is formed near the bearing position.
Lubricating oil supply hole communicating with the penetrating and lubricating oil feed tube toward the outer periphery from the shaped groove is formed with a plurality, further, the inner <br/> ring of each bearing, the lubricant supply hole at one end of the rotary shaft Injection hole with the other end open near the rolling element of each bearing
But characterized that you are formed through the inner race of the respective bearing.

[0008]

In the present invention, oil air or oil mist is pressure-fed into the lubrication hydraulic feed pipe in the hollow hole of the rotating shaft, and the oil air or oil mist passes through the annular gap.
Ri, flows into the annular groove while cooling the rotation axis, is pumped from the lubricating oil supply hole of the rotation shaft through the inner ring of the injection small holes for each bearing to the bearing rolling surface of <br/> inner side of each bearing, After lubrication, oil air or oil mist passes through the inside of each bearing and is discharged to the outside. Oil air flowing through the annular gap to the rear end of the rotary shaft
-Or oil mist is installed at the rear end of the rotary shaft.
Due to the labyrinth seal structure,
Leakage to the part is prevented.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A lubricating device for a bearing of a spindle of a machine tool according to an embodiment of the present invention will be described below with reference to FIGS.

In the drawings, reference numeral 1 is an outer cylinder provided in the spindle head H, and a ring-shaped front lid 2 is fixedly attached to the front end of the outer cylinder 1, and a thicker one is attached to the rear end of the outer cylinder 1. A meat-cylindrical rear lid 3 is fixedly attached.

A front bearing 4 is mounted in the through hole 2A of the front lid 2, a sleeve 5 is mounted inside the rear lid 3, and a rear bearing 7 is mounted in the front portion of the sleeve 5. . A main shaft 8 is supported by the front bearing 4 and the rear bearing 7. A bearing retainer 9 is fixedly provided on the front end surface of the front lid 2.

[0012] the inner peripheral surface 1A of the outer cylinder 1, the motor supporting member 10 is fitted in position between the front cover 2 and rear cover 3, a drive motor for the motor supporting member 10 made of a built-in motor
Data 11 is attached. The drive motor 11 supports the motor
The stator 11A and the rotor 11B fixed to the member 10 are
Have

A ring member 12 is fixedly attached to the rear end portion 3A of the rear lid 3, and the ring member 12 has a shaft portion 13 on its center line and the shaft portion 1 thereof.
3 has an exhaust port 14A on the outer peripheral side, an air passage 14B penetrates through the central axis of the shaft portion 13, and a lubricating hydraulic feed pipe 20 described later is inserted and fixed to the front side portion of the air passage 14B. There is. Rear end of the air passage 14B is contacted to the lubricating oil supply source (not shown) through a pipe or the like.

The main shaft 8 is driven by the low-speed drive motor 11.
Drive through the center of the connector 11B and connected integrally with it.
The rotor 11B of the motor 11 is arranged before and after in the axial direction.
Being rotatably supported by the outer cylinder 1 by a pair of bearings 4 and 7.
I have. The main shaft 8 includes the pair of shafts centered in the axial direction.
A hollow hole 15 having a length extending between the receivers 4 and 7 is formed.
It A female screw portion 16 and a first annular groove 17 are formed on the front end side of the hollow hole 15, and a rear end side of the hollow hole 15 is formed.
The second annular groove 18 is formed . That is, the main shaft 8
Is the position of the pair of bearings 4, 7 in the hollow hole 15.
The annular grooves 17 and 18 are formed near the
It Further, a labyrinth groove 19A and a labyrinth projection 19 are located on the rear end side of the second annular groove 18 and are formed in multiple stages on the outer peripheral surface of the lubricating hydraulic feed pipe 20. The labyrinth groove 19A and the labyrinth protrusion 19 are connected to the main shaft 8 and the lubricating oil pressure.
Form a non-contact type labyrinth seal structure between the pipe 20 and
And prevents the lubricating oil from leaking out between the rear end portion of the main shaft 8 and the lubricating hydraulic feed pipe 20 .

Inside the hollow hole 15 of the main shaft 8 , a lubricating hydraulic pressure is sent.
The tube 20 is inserted over substantially the entire length of the hollow hole 15,
An annular gap 21 is formed along the axial direction between the outer wall surface 20A of the lubricating hydraulic feed pipe 20 and the inner wall surface of the hollow hole 15. The annular gap 21 communicates with the first and second annular grooves 17 and 18. In addition, the main shaft 8 has annular grooves 17, 18
A plurality of lubricating oils that penetrate the main shaft 8 from the outer periphery to the outer periphery
The holes 25 and 28 are formed, and a plurality of lubricating oil supply holes 25 and 2 are formed.
8 communicates with the inside of the lubrication hydraulic feed pipe 20, respectively.

A supply passage 22 is formed inside the lubrication hydraulic feed pipe 20, the front end of the lubrication hydraulic feed pipe 20 is located in the first annular groove 17 of the hollow hole 15, and the front end of the supply passage 22 is It is closed with a lid 22A. A plurality of through holes 23 penetrating the wall body 20B are formed in a cross shape from the supply path 22 at the front end portion of the lubricating hydraulic feed pipe 20, and each through hole 23 is a hollow hole 15
Communicates with the first annular groove 17.

A screw-in type cutting tool 24 is screwed and fixed to the female screw portion 16 of the main shaft 8, and the end of the supply passage 22 is closed by the cutting tool 24 so that lubricating oil is supplied to the main shaft 8. Road 22
It doesn't leak out.

The lubricating oil supply hole 25 on the front side faces the first annular groove 17 of the hollow hole 15 and communicates with the supply passage 22 in the lubricating hydraulic pressure supply pipe 20 through the through hole 23.

[0019] Then, the inner ring 26 of the front bearing 4, a plurality of injection small holes 27 penetrating the inner ring 26 is formed, the double
The number of injection small holes 27 is one end (inner end) is communicated with the front side of the lubricant supply hole 25 of the spindle 8. The position of the injection opening at the other end of the plurality of injection small holes 27 is determined by the inner ring 26 of the front bearing 4.
It is set near the contact point 26C of the rolling element 4A on the rolling surface 26B.

Meanwhile, the inner ring 29 of the rear bearing 7, the inner ring 2
A plurality of injection small holes 30 penetrating 9 are formed, and one end ( inner end ) thereof communicates with the lubricating oil supply hole 28 on the rear side of the main shaft 8. The position of the injection opening at the other end of the plurality of injection small holes 30 is the contact point 2 of the rolling element 7A on the rolling surface 29B of the inner ring 29.
It is set near 9C.

An annular recess 9A communicating with the inside of the front bearing 4 is formed in the through hole of the bearing retainer 9, and the bearing retainer 9 has a first air discharge passage 9B communicating with the annular recess 9A. It is formed along the radial direction. Furthermore, front lid 2
A second air exhaust passage 2B communicating with the first air exhaust passage 9B is formed along the radial direction of the first air exhaust passage 9B.
A third air exhaust passage 1B communicating with B is formed in the outer cylinder 1 along the axial direction, and a fourth air exhaust passage 3B communicating with the third air exhaust passage 1B is provided on the rear lid 3 in the axial direction. The fourth air discharge passage 3B is formed along the line and opens at the rear end surface of the rear lid 3.

The first air exhaust passage 9B, the second air exhaust passage 2B, the third air exhaust passage 1B, and the fourth air exhaust passage 3
The front air discharge passage 31 is formed by B. A rear side air exhaust passage 32 is formed between the outer peripheral surface of the shaft portion 13 of the ring member 12 and the inner peripheral surface of the sleeve 5, and the inlet of the rear side air exhaust passage 32 communicates with the inside of the rear bearing 7. The outlet communicates with the exhaust port 14A of the ring member 12.

The fourth air exhaust passage 3B and the exhaust port 14A
It is connected via a duct or the like to force the exhaust device such as a vacuum pump (not shown) and. Therefore, in the present embodiment, oil air or oil mist is pressure-fed from the lubricating oil supply source to the supply passage 22 of the lubricating hydraulic feed pipe 20 in the hollow hole 15 of the main shaft 8, and part of the oil air or oil mist is From the through hole 23 of the lubricating hydraulic feed pipe 20, it is guided into the first annular groove 17 of the main shaft 8, and the lubricating oil supply hole 25 on the front side from the first annular groove 17 and the plurality of injection small holes 27 of the inner ring 26. And is injected into the inside of the front bearing 4. The oil air or oil mist is pumped to the outer peripheral surface 6A of the inner ring 26, rolling after the moving body 4A has lubricated, is discharged through the inside of the front bearing 4 between the inner ring 26 and the outer ring 26A, further, forcibly exhausted It is guided to the outside by the device through the front air discharge passage 31.

On the other hand, the other part of the oil air or oil mist in the first annular groove 17 of the main shaft 8 is the annular gap 2.
The lubricating oil supply hole 28 on the rear side via the first and second annular grooves 18
Further, it is injected into the inside of the rear bearing 7 through the plurality of injection small holes 30 of the rear bearing 7, and the outer peripheral surface 6 of the inner ring 29 is reached.
After being pumped to B and lubricating the rolling element 7A, the inner ring 29 and the outer
It is discharged through the inside of the rear bearing 7 between the wheels 29A, and is further guided to the outside through the rear side air discharge passage 32 by the forced exhaust device. In the above, the second annular groove 18
The oil air or oil mist flowing to the
Directly from the rear end of the rotating shaft due to the labyrinth seal structure of
Supply to the rear bearing 7 for lubrication.
To be done.

In the above, the first and second annular grooves 17,
18 serves as an oil sump in which the lubricating oil supplied from the lubricating oil 20 is gathered by the centrifugal force generated by the rotation of the main shaft 8 and serves to reliably guide the lubricating oil to the lubricating oil supply holes 25 and 28.

According to the above construction, the inside of the front bearing 4 is
The wheel 26, since the plurality of injection small holes 27 penetrating the inner ring 26 is formed, a plurality of injection small holes of the front bearing 4 27
From the contact point 2 of the rolling element 4A on the rolling surface 26B of the inner ring 26
The distance to 6C is shortened, and the flow of the lubricating oil is accompanied by the super-high speed rotation of the main shaft 8 and the rolling elements 4A of the front bearing 4 and the cage 4B.
The lubricating oil can directly reach the contact point 26C of the rolling surface 26B of the front bearing 4 and receive a sufficient amount of the lubricating oil while receiving almost no air flow in the vicinity.

The rear bearing 7 also includes the front bearing 4
Has the same effect as. That is, the inner ring 29 of the rear bearing 7
, Since a plurality of injection small holes 30 penetrating the inner ring 29 is formed, the inner plurality of injection small holes 30 of the rear bearing 7
The distance to the contact point 29C of the rolling element 7A on the rolling surface 29B of the wheel 29 is shortened, and the flow of the lubricating oil is in the vicinity of the rolling element 7A and the cage 7B of the rear bearing 7 accompanying the super-high speed rotation of the main shaft 8. The lubricating oil can directly reach the contact point 29C of the rolling surface 29B of the rear bearing 7 and receive a sufficient amount of lubricating oil with almost no air flow.

Since the lubricating hydraulic feed pipe 20 is arranged in the hollow hole 15 of the main shaft 8, the volume in the hollow hole 15 is reduced and it is necessary to fill the hollow hole 15 of the main shaft 8 with lubricating oil. In addition, even a small amount of lubricating oil that is pressure-fed from the lubricating hydraulic pressure supply pipe 20 can be reliably supplied to the lubrication location. Therefore, a large amount of lubricating oil is not required unlike the jet lubrication type lubrication device, and the shaft power loss in the bearing portion can be suppressed to be small. Also, it is located on the rear end side of the spindle 8.
Then, a rabbi provided between the main shaft 8 and the lubricating hydraulic feed pipe 20.
Since the rinse seal structure is a non-contact type, the main shaft 8
Even if it rotates at high speed, it does not generate heat like a contact type seal, and sliding contact
There is no power loss due to.

In this embodiment, a plurality of through holes 23 penetrating the wall body 20B from the supply passage 22 inside is formed in the lubricating hydraulic feed pipe 20, and the lubricating oil is supplied from each through hole 23. Lubricating oil is supplied to the holes 25 and 28, but even if the through hole 23 is not formed in the lubricating hydraulic pressure supply pipe 20, the end of the lubricating hydraulic pressure supply pipe 20 is opened, and the lubricating oil supply hole 2 is opened from this opening.
Lubricating oil can also be supplied to 5, 28.

[0030]

According to the present invention as described above, according to the invention], times
Lubricating hydraulic pipe is placed inside the rolling shaft to support the rotating shaft.
An annular gap is formed between at least a pair of bearings,
It is configured so that the lubricating oil flows through the annular gap,
The seal of the annular gap at the rear end of the rotary shaft.
It uses a contact labyrinth seal structure and
Serial to the inner ring of each bearing, the plurality of injection small holes penetrating the inner ring is formed, bearing a plurality of injection small holes for each bearing
The distance to the contact point of the rolling element on the rolling surface of the inner ring becomes shorter, and the flow of the lubricating oil is hardly affected by the air flow in the vicinity of the rolling element of the bearing and the cage accompanying the super high speed rotation of the main shaft. , Rotation
While cooling the shaft and suppressing its heat generation, the lubricating oil does not increase the shaft power loss and directly reaches the contact point of the rolling surface of the inner ring of each bearing, and it is possible to supply a sufficient amount of lubricating oil. There is an effect that can be. In addition, lubrication hydraulic pressure is sent to the rotary shaft.
When arranging pipes, bearings and
Simple structure because it does not use devices such as contact-type seals
Therefore, the super-rotation of the rotating shaft can be smoothly performed.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part showing the vicinity of a front bearing of a lubricating device for a bearing of an ultra-high speed rotating shaft according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part showing the vicinity of a rear bearing of a lubricating device for a bearing of an ultra-high speed rotating shaft according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing an entire lubricating device for a bearing of an ultra-high speed rotating shaft according to an embodiment of the present invention.

FIG. 4 is an enlarged sectional view of a main part of a conventional lubricating device for a bearing of an ultra-high speed rotating shaft.

[Explanation of symbols]

 4 Front bearing 4A Rolling element 7 Rear bearing 7A Rolling element 8 Main shaft 8A Wall 15 Hollow hole 20 Lubricating hydraulic oil supply pipe 25 Front side lubricating oil supply hole 26 Bearing inner ring 27 Injection small hole 28 Rear side lubricating oil supply hole 29 Bearing Inner ring 30 injection small holes

Claims (1)

(57) [Scope of utility model registration request] 1. A lubrication device for a bearing of an ultra-high speed rotating shaft, which supplies lubricating oil to a bearing supporting the rotating shaft via air pressure feeding force, wherein the rotating shaft is inserted through a center of a rotor of a drive motor.
It is connected integrally with the rotor and is placed in front of and behind the rotor in the axial direction.
Rotatably supported on the outer cylinder by at least one pair of bearings
And a pair of bearings that are axially centered
Are hollow hole length is formed over between the inside of the hollow hole of the rotary shaft, between the inner wall of the hollow hole
An annular gap is provided in the lubrication hydraulic pipe so that
And is located at the rear end of the rotary shaft.
A non-contact type labyrinth between the rolling shaft and the lubricating hydraulic pipe.
And seal structure is provided, also, with the axis of rotation of said pair in said hollow bore
An annular groove is formed near the bearing position.
Other with lubricant supply hole communicating with the penetrating and lubricating oil feed tube toward the outer periphery from the shaped groove is formed with a plurality, further, the inner ring of each bearing, one end communicates with the lubricating oil supply hole of the rotary shaft injection pores end is opened in the vicinity of the rolling element of each bearing, formed through the inner race of the respective bearing
Bearing lubricating apparatus for ultra high speed shaft, characterized in that you have been.