JP2002361540A - Spindle device of machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spindle device of a machine tool capable of rapidly discharging a lubricating oil used in lubricating a bearing. SOLUTION: In the spindle device of the machine tool, angular ball bearings 3-6 for rotatably supporting a spindle 2 with respect to a fixed housing 1 are lubricated by feeding oil air to the bearings 3-6 from one side through an oil feed passage 25, and discharging the oil air used in lubricating the bearings 3-6 from the other side of the bearings 3-6 through an oil discharge passage 29. Collars 12, 14 and 15 are fixed around the spindle 2 on the oil air discharge side of the angular ball bearings 3-6. Outwardly directed flanges 30, 31 and 32 are integrally formed on the collars 12, 14 and 15. Circumferential edge parts of the outwardly directed flanges 30, 31 and 32 face the oil discharge passage 29.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle device for a machine tool, wherein lubrication of a bearing for rotatably supporting a spindle with respect to a fixed housing is performed by feeding oil air to the bearing from one side through an oil supply passage. The present invention relates to a spindle device for a machine tool, which is configured to discharge oil air used for lubrication of a bearing from the other side surface of a bearing through an oil discharge passage.

[0002] In this specification, "oil air" includes both oil mist and oil air.

[0003]

2. Description of the Related Art For example, in a spindle device of a machine tool having a vertical spindle, conventionally, a spindle is rotatably supported inside a fixed housing via a plurality of rolling bearings.
From the fixed housing to the collar for fixing the outer ring of the bearing, an oil supply passage is formed, one end of which is open toward one side of each bearing. Similarly, the fixed housing has one end opening on the other side of each bearing on the inner peripheral surface of the fixed housing. A drainage passage that is open at the bottom is formed.

[0004] Lubrication of the bearing for rotatably supporting the main shaft with respect to the fixed housing is performed as follows. That is, lubrication of the bearing is performed by sending oil air from one side to the bearing through the oil supply passage and discharging oil air used for lubrication of the bearing from the other side of the bearing through the oil discharge passage. .

FIGS. 5 to 7 show an example of the conventional spindle device as described above. In FIG. 6, for convenience, the oil supply passage and the oil discharge passage are illustrated as being different from the actual positions and located at the same position in the circumferential direction.

In the following description, the vertical and horizontal directions in FIGS. 1 and 5 are referred to as vertical and horizontal directions, respectively.

Referring to FIGS. 5 and 6, a fixed housing is shown.
A vertical hollow main shaft (2) is arranged inside (1), and two angular ball bearings (3) arranged in parallel at the lower part of the main shaft (2) at two places spaced apart in the vertical direction. (4) (5) (6)
It is rotatably supported by. The upper two angular ball bearings (3) and (4) are arranged in a parallel combination such that the rear faces of the outer rings (3a) and (4a) face downward, and the lower two angular ball bearings (5) and (6) are The outer races (5a) and (6a) are arranged in parallel so that the front faces downward. These angular ball bearings (3) to (6) receive a radial load and a thrust load in two directions.

The outer ring (3) of all the angular contact ball bearings (3) to (6)
a) to (6a) are sandwiched between a step (1a) formed on the inner peripheral surface of the fixed housing (1) and a lid (7) fixed to a lower end of the fixed housing (1). And outer rings (3a) to (6
The collars (8), (9) and (10) are interposed between a). The inner peripheral surface of the fixed housing (1) has a step (1a)
Is provided with a small-diameter portion (1b) for forming. Also,
On the lid (7), a cylindrical portion (7a) fitted into the fixed housing (1) is integrally formed, and a cutout (7b) is formed from the upper end of the cylindrical portion (7a). I have. The inner ring (3b) (4b) (5b) (6b) of all angular contact ball bearings (3) to (6) is
Step (2a) formed on the outer peripheral surface of, and a nut (11) screwed to the lower end of the main shaft (2) is sandwiched, between the adjacent inner ring (3b) ~ (6b) and Uppermost inner ring (3a) and step
Collars (12), (13), (14), and (15) are interposed between (2a) and (2a), respectively.

As shown in FIG. 7, a collar (8) disposed between outer rings (3a) and (4a) of the upper two angular ball bearings (3) and (4).
A thick-walled inward flange (16) is formed integrally with the upper part of the inner peripheral surface of the inner wall. The outer diameter of the outer peripheral surface of the lower half (8a) of the collar (8) is smaller than the outer diameter of the outer peripheral surface of the upper half (8b).
An annular gap (17) is provided over the entire circumference between the inner peripheral surface of the collar (8) and the outer peripheral surface of the lower half (8a) of the collar (8) (see FIG. 6). Further, a notch (18) is formed in the lower half (8a) of the collar (8) from the lower end thereof. In the illustrated example, the number of the notches (18) is one, but this can be changed as appropriate. The collar (8) extends from the outer peripheral surface of the upper half portion (8b) to the radially inner end side of the inward flange (16) and has a distal end bent upward to open on the upper surface of the inward flange (16). A substantially L-shaped through hole (19) is formed.

The collar (10) arranged between the outer rings (5a) and (6a) of the lower two angular ball bearings (5) and (6) is vertically symmetric with the collar (8) shown in FIG. , The same parts are denoted by the same reference numerals. . Outer ring (4a) of the second angular contact ball bearing (4) from the top
A thick inward flange (20) is provided at each of the upper and lower ends of the inner peripheral surface of the collar (9) disposed between the outer ring (5a) of the second lower angular ball bearing (5). It is formed integrally. The collar (9) has a substantially L-shape that extends from the upper end of the outer peripheral surface to the radially inner end of the upper inward flange (20) and is bent upward to open to the upper surface of the inward flange (20). The through hole (21) is formed, and extends from the lower end of the outer peripheral surface to the lower inward flange (20) radially inner end side and bends downward to open to the lower surface of the inward flange (20). A substantially L-shaped through hole (22) is formed.

An outward flange (23) is integrated with a collar (15) disposed between the step (2a) of the main shaft (2) and the inner ring (3b) of the uppermost angular ball bearing (3). Is formed.

The height of the left side portion of the fixed housing (1) is slightly lower than the upper two angular ball bearings (3) and (4), and the lower two angular ball bearings (5) and (6). Also, linear through holes (24A) (24B) (24C) (24D) extending radially inward from the outer peripheral surface thereof are formed at slightly higher height positions. These through holes (24A) to (24D) communicate with the through holes (19), (21), and (22) of the collars (8) to (10), respectively. Then, each through hole (24A) to (24A) of the fixed housing (1)
D) and the through holes (19), (21), (22) of the collars (8) to (10) form an oil supply passage (25).

At the lower end of the right side portion of the fixed housing (1), its outer periphery is located at a height slightly lower than the lowest angular ball bearing (6) and corresponding to the notch (7b) of the lid (7). A short straight lateral through hole (26) extending radially inward from the surface is formed. In the right side of the fixed housing (1), a straight vertical hole (27) extending upward from the inner peripheral surface of the horizontal through hole (26) and leading to the small diameter portion (1b) of the fixed housing (1). ) Is formed. In addition, the height of the rightmost portion of the fixed housing (1) is slightly higher than the uppermost angular ball bearing (3), and the collar (8) and the collar (8) between the upper two angular ball bearings (3) (4). At the height position corresponding to the notch (18) of the collar (10) between the two lower angular ball bearings (5) and (6), respectively, radially inward from the inner circumferential surface of the vertical hole (27) And short straight through holes (28A), (28B), and (28C) extending in the vertical direction. The holes (26), (27), (28A), (28B), and (28C) form an oil discharge passage (29).

In the spindle device having such a configuration, the spindle
During the rotation of (2), lubricating oil air is supplied to each oil supply passage (25).
Into the through holes (19), (21), (2)
It discharges from the radial inner end opening of 2) toward the angular ball bearings (3) to (6). At this time, the through holes of the collars (8) to (10)
(19) In order to ensure that the oil air discharged from (21) and (22) reaches the angular contact ball bearings (3) to (6), supply oil air pre-pressurized to an arbitrary pressure higher than the atmospheric pressure in each lubrication. Send it to the road (25). Thus, each angular contact ball bearing
The lubrication of (3) to (6) is performed.

Here, since the oil discharge passage (29) communicates with the atmosphere, the pressure inside the oil discharge passage (29) is substantially equal to the atmospheric pressure and lower than the pressure on the supply side. Therefore, the oil air supplied from one side of the angular contact ball bearings (3) to (6) escapes to the other side, and directly passes through the lateral through hole (2).
8A) into the oil drain passageway (29) from the radial inner end opening, and through the notch (7b) into the oil drain passageway (29) from the radial inner end opening of the lateral through hole (26). Through the notch (18) and the gap (17), enters the oil drain passageway (29) from the radially inner end opening of the lateral through hole (28B) (28C), and passes through the oil drain passageway (29). Released into the atmosphere.

[0016]

However, in the conventional spindle device, the inner and outer rings of the angular ball bearings (3) to (6)
(3b)-(6b), (3a)-(6a) and lubricating oil adhering to the surface of the ball, the outer ring side collars (8)-(10), and the uppermost inner ring side collar (15) Gradually gather to form a large lump. Such lubricating oil moves while being pushed by the flow of air. However, if the flow of air is weak or there is a place where there is a step and the air stays, the lubricating oil stays there.

When lubricating oil stagnates in the angular contact ball bearings (3) to (6), the amount of lubricating oil in the bearings (3) to (6) becomes excessive.
The lubricating oil present in the angular contact ball bearings (3) to (6) promotes the generation of heat due to its stirring resistance.If excessive lubricating oil is present in the bearings (3) to (6), the calorific value will be reduced. It becomes large and the bearing temperature rises excessively. If the bearing temperature rises, the lubricating oil deteriorates and the bearing preload increases.
(3) to (6) may be damaged.

In particular, the upper two angular ball bearings (3)
In (4), since oil air is supplied from below, it temporarily exits the bearings (3) (4) and adheres to the surface of the upper collar (15) (8) and stagnates Since the lubricating oil flows back to the bearings (3) and (4) by its own weight, the above problem becomes more remarkable.

An object of the present invention is to solve the above-mentioned problems and to provide a spindle device of a machine tool capable of quickly discharging lubricating oil used for lubricating a bearing.

[0020]

According to a first aspect of the present invention, there is provided a spindle device for a machine tool, wherein a bearing for rotatably supporting a spindle with respect to a fixed housing is lubricated on one side through an oil supply passage. Oil air into the bearing from
A spindle device for a machine tool, which is configured to discharge oil air used for lubrication of a bearing from the other side of the bearing through an oil drainage passage, wherein a collar is provided around a spindle on an oil air discharge side of the bearing. Is fixed to the collar, and an outward flange is fixedly provided on the collar, and a peripheral portion of the outward flange faces the oil discharge passage.

According to the first aspect of the present invention, when the main shaft rotates,
When oil air is fed into the bearing from one side through the oil supply path, the lubricating oil that has been sent adheres to the outward flange of the collar after passing through the bearing, and the collar fixed to the main shaft rotates with the main shaft. As a result, the flange moves toward the peripheral edge of the outward flange due to centrifugal force, and at the same time, is skipped from the peripheral edge, and is quickly and reliably fed into the oil drainage passage. In particular, in a spindle device having a vertical spindle,
Even when supplying oil air from below the bearing, the lubricating oil that once comes out of the bearing adheres to the outward flange, moves to the peripheral edge of the outward flange by centrifugal force, and is blown off from the peripheral edge , Is reliably fed into the oil drain. Therefore, the excessive lubricating oil does not stay inside the bearing, and the heat generation due to the stirring resistance of the lubricating oil is suppressed, so that an excessive rise in the temperature of the bearing is prevented. As a result, deterioration of the lubricating oil and an increase in the bearing preload are suppressed, and damage to the bearing is prevented.

According to a second aspect of the present invention, there is provided a spindle device for a machine tool according to the first aspect, wherein a surface of the outward flange facing the bearing for discharging the oil air is directed radially outward in a direction away from the bearing. It is inclined. In this case, the movement of the lubricating oil attached to the inclined surface of the outward flange toward the peripheral portion due to the centrifugal force and the scattering from the peripheral portion are efficiently performed.

According to a third aspect of the present invention, there is provided a spindle device for a machine tool according to the first or second aspect, wherein a surface of the outward flange facing the bearing for discharging oil air extends from the inner peripheral edge to the outer peripheral edge. In addition, a plurality of grooves, each of which has an opening at the distal end surface of the outward flange, are formed at intervals in the circumferential direction. In this case, the lubricating oil adhering to the outward flange of the collar after passing through the bearing,
Due to the centrifugal force, it is guided by the groove and moves toward the peripheral edge of the outward flange, and at the same time, is skipped from the peripheral edge. Scattering is performed more efficiently.

According to a fourth aspect of the present invention, in the spindle device for a machine tool according to the third aspect of the present invention, the groove formed in the outward flange is curved rearward in the rotational direction of the main shaft from radially inward to outward. Is what it is. The shape of such a groove is, for example, a shape like a blade of a centrifugal pump. In this case, the most efficient movement of the lubricating oil attached to the outward flange toward the peripheral edge due to the centrifugal force and scattering from the peripheral edge is obtained.

In any one of the first to fourth aspects of the present invention, the surface of the outward flange facing away from the bearing from which oil air is discharged is inclined toward the bearing toward the outside in the radial direction. There is. In this case, even when the lubricating oil that has passed through the bearing reaches the surface of the outward flange on the side opposite to the bearing, it is moved to the peripheral edge of the outward flange by centrifugal force and is blown off the peripheral edge, so To the oil drain.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2,
The same components and portions as those shown in FIGS. 5 to 7 are denoted by the same reference numerals. In addition, FIG. 2, similarly to FIG. 6, shows that the oil supply passage and the oil discharge passage are located at the same position in the circumferential direction, unlike the actual position, for convenience.

As shown in FIGS. 1 and 2, in the case of this embodiment, the inner rings of the upper two angular ball bearings (3) and (4)
(3b) Collar (12) arranged between (4b) and fixed to main shaft (2)
Lower and lower two angular contact ball bearings (5) (6)
The collars (14) arranged between the inner rings (5b) and (6b) and fixed to the main shaft (2) have collars on the outer rings (3a) to (6a) side at the upper end, respectively.
(8) (10) Outward flange (30) (31) so as not to interfere
Are integrally formed. These outward flanges (30)
The outer peripheral surface of (31) has a notch (18) and a horizontal through hole (28B)
(28C), notch (18) and gap
It faces the oil drain (29) via (17). The collar (15) arranged between the inner ring (3b) and the step (2a) of the uppermost angular ball bearing (3) and fixed to the main shaft (2) has an outward flange (23). Instead, an outward flange (32) whose outer peripheral surface is at the same height as the lateral through hole (28A) is integrally formed, and the tip thereof faces the oil drain passage (29). The upper surface of each outward flange (30), (31), (32) is inclined downward toward the outside in the radial direction, and the lower surface is also inclined upward toward the outside in the radial direction. The upper inclined surface is indicated by (30a) (31a) (32a),
The lower inclined surfaces are indicated by (30b), (31b), and (32b).

A nut (11) screwed to the main shaft (2) is integrally formed with a thick-walled outward flange (33), and the upper surface thereof is inclined downward radially outward. I have. This inclined surface is indicated by (33a).

Further, the inward flange (16) of the collar (8)
Is inclined downward toward the outside in the radial direction.
This inclined surface is indicated by (16a).

In such a spindle device, when lubricating the angular ball bearings (3) to (6) during rotation of the spindle (2), the oil air of the lubricating oil is supplied to each of the oil supply passages (25) as in the related art. Into the pressurized state, through holes (19) of each collar (8) to (10)
(21) Angular contact ball bearings (3) to (22)
Discharge toward (6). The discharged oil air escapes to the other side surface. That is, for the upper two angular ball bearings (3) and (4), the oil air of the lubricating oil is supplied from below and discharged upward, and for the lower two angular ball bearings (5) and (6), Oil air of the lubricating oil is supplied from above and discharged downward.

The lubricating oil discharged from the upper two angular ball bearings (3) and (4) is supplied to the outward flanges of the collars (15) and (12).
(32) The collars (15) and (12) attached to the lower inclined surfaces (32b) and (30b) of the (30) and fixed to the main shaft (2) rotate with the main shaft (2). Outward flange (32) (3
It moves to the periphery of 0) and scatters from the periphery.
The scattered lubricating oil directly enters the oil drain passageway (29) through the radially inner end opening of the horizontal through hole (28A), or the notch (18)
Into the annular gap (17) and through this gap (17)
Through the radially inner end opening of the horizontal through hole (28B)
Enter (29). Then, the oil is discharged into the atmosphere through an oil drain passage (29). Upper inclined surface (32a) of outward flange (32) (30)
The lubricating oil adhering to (30a) is also drained in the same manner as above (29)
And is discharged into the atmosphere through a drainage passage (29). In addition, the lubricating oil attached to the outer peripheral surface of the portion of the collar (12) above the outward flange (30), and the collar (8)
The lubricating oil adhering to the outer peripheral surface of the inward flange (16) and the inclined surface (16a) of the collar (12) drips onto the upper inclined surface (30a) of the outward flange (30) of the collar (12), and operates in the same manner as above. Oil drain
(29), and is discharged to the atmosphere through an oil drain (29).

The lubricating oil discharged from the lower two angular ball bearings (5) and (6) is supplied to the outward flange (31) of the collar (14).
Upper inclined surface (31a) and outward flange of nut (11)
The collar (14) and the nut (11) attached to the inclined surface (33a) of (33) and fixed to the main shaft (2) rotate with the main shaft (2), so that the outward flange (31) is generated by centrifugal force. It moves to the periphery of (33) and scatters from the periphery. The scattered lubricating oil enters the annular gap (17) through the notch (18) and passes through the gap (17) from the radially inner end opening of the lateral through hole (28C) to the oil drain passage (29). Or through the notch (7b) into the oil drain passageway (29) from the radially inner end opening of the lateral through hole (26). Then, the oil is discharged into the atmosphere through an oil drain passage (29). Lubricating oil adhering to the lower inclined surface (31b) of the outward flange (31) of the collar (14) also enters the oil drain passage (29) in the same manner as described above, and passes through the oil drain passage (29) to the atmosphere. Is discharged inside.

Therefore, the excessive lubricating oil does not stay in the angular ball bearings (3) to (6), and the heat generation due to the lubricating oil stirring resistance is suppressed, so that the excessive temperature rise of the bearing is prevented. As a result, damage to the angular contact ball bearings (3) to (6) due to deterioration of the lubricating oil and increase in the bearing preload is prevented.

FIGS. 3 and 4 show another embodiment of the spindle device according to the present invention. 3 and 4, the same components and portions as those shown in FIGS. 1 and 2 are denoted by the same reference numerals.

As shown in FIGS. 3 and 4, in the case of this embodiment, the inner rings of the upper two angular ball bearings (3) and (4)
(3b) Outward flange (30) of collar (12) arranged between (4b)
And the collar disposed between the step (2a) of the main shaft (2) and the uppermost angular ball bearing (3).
The lower inclined surface (32a) of the outward flange (32) of (15)
In addition, a plurality of grooves (40) each extending from the inner peripheral edge to the outer peripheral edge and having a tip opened on the outer peripheral surface of the outward flange (30),
A plurality are formed at intervals in the radial direction. These grooves
The (40) is curved backward in the rotation direction of the main shaft (2) outward when viewed from below, and has a shape like, for example, a blade of a centrifugal pump. Further, the groove (40) gradually becomes deeper from the inside in the radial direction to the outside. Although not shown, the inner rings of the lower two angular contact ball bearings (5) and (6)
(5b) Outward flange (31) of collar (14) arranged between (6b)
The groove (40) is also formed on the upper inclined surface (31a) and the upper inclined surface (33a) of the outward flange (33) of the nut (11).
Are formed.

The groove (40) is formed so that the main shaft (2) faces outward.
It is not limited to the one curved backward in the rotation direction, and may be linearly inclined outward in the rotation direction behind the main shaft (2).

In this embodiment, an angular contact ball bearing
The lubrication of (3) to (6) is performed in the same manner as in the embodiment shown in FIGS. Upper two angular ball bearings (3)
Ejected from (4) the outward flanges (3
2) The lubricating oil adhering to the lower inclined surfaces (32b) (30b) of (30) is guided to the groove (40) by centrifugal force due to the rotation of the main shaft (2), and is directed to the outward flange (32) (30). ) Moves to the peripheral edge side and scatters from the peripheral edge part, so that the lubricating oil moves to the peripheral edge side due to the centrifugal force of the lubricating oil and scatters from the peripheral edge more efficiently. Outward flanges (31) of collar (14) and nuts discharged from lower two angular ball bearings (5) (6)
The lubricating oil adhering to the upper inclined surfaces (31a) and (33a) of the outward flange (33) of (11) is also guided by the grooves by centrifugal force due to the rotation of the main shaft (2) and is directed to the outward flange (31) ( It moves to the periphery of 33) and scatters from the periphery.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a spindle device according to the present invention.

FIG. 2 is an enlarged view of a main part of FIG. 1 and shows the oil supply passage and the oil discharge passage as different from actual positions for convenience and at the same position in the circumferential direction.

FIG. 3 is a view corresponding to FIG. 2, showing another embodiment of the spindle device according to the present invention;

FIG. 4 is a perspective view showing an inner ring side collar used in another embodiment of the spindle device according to the present invention.

FIG. 5 is a longitudinal sectional view showing a conventional spindle device.

FIG. 6 is an enlarged view of a main part of FIG. 5 and, for convenience, the oil supply path and the oil discharge path are different from the actual positions and are shown as being at the same position in the circumferential direction.

FIG. 7 is a partially cutaway perspective view showing an outer ring side collar used in a conventional spindle device.

[Explanation of symbols]

 (1): Fixed housing (2): Main shaft (3) (4) (5) (6): Angular contact ball bearing (12) (14) (15): Collar (25): Oil supply path (29): Oil drain Road (30) (31) (32): Outward flange (40): Groove

Claims (4)

[Claims] The lubrication of a bearing that rotatably supports a main shaft with respect to a fixed housing is performed by feeding oil air from one side to the bearing through an oil supply passage, and the oil air used for lubrication of the bearing is supplied to the other of the bearing. A spindle device of a machine tool adapted to be discharged by discharging from a side surface through an oil drainage passage, wherein a collar is fixed around a spindle on an oil air discharge side of a bearing, and an outward flange is fixedly provided on the collar. A spindle device of a machine tool, in which a peripheral portion of an outward flange faces an oil drain. 2. The spindle device for a machine tool according to claim 1, wherein a surface of the outward flange facing the bearing for discharging the oil air is inclined radially outward in a direction away from the bearing. 3. A plurality of grooves extending from the inner peripheral edge to the outer peripheral edge of the outward flange facing the bearing for discharging the oil air and having a front end opening on the front end surface of the outward flange, are formed in the outward flange. 3. The main spindle device for a machine tool according to claim 1, wherein said main shaft device is formed at an interval. 4. The main spindle device for a machine tool according to claim 3, wherein the groove formed in the outward flange is curved rearward in the rotational direction of the main spindle from the radially inner side to the outer side.