JP2013142414A - Spindle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spindle device rotatable at a high speed where a dmn value is equal to or higher than 1 million and having a favorable waterproof function.SOLUTION: A flinger 40 includes a boss 41 fixed to a rotary shaft 11, a disk 42 extending outward in a diameter direction from the boss 41 and disposed facing an axial direction with a slight gap from the axial-direction front end surface 71 of a front side bearing outer ring press 12 constituting a housing H, and an annular part 43 extending in an axial direction from the disk 42 and disposed facing the diameter direction with a slight gap to the outer circumferential surface 75 of the front side bearing outer ring press 12. The annular part 43 is formed in such a tapered shape that it becomes thinner as it is separated from the disk 42 in the axial direction.

Description

  The present invention relates to a spindle device, and more particularly to a spindle device having a waterproof function and suitable for application to a machine tool.

  A rotating shaft of a spindle device applied to a machine tool or the like rotates at a high speed to perform cutting or grinding of a workpiece. In machining, a large amount of machining fluid is generally supplied to the machining unit for the purpose of lubrication and cooling of the cutting tool and the machining site. That is, lubrication can improve the machining characteristics, suppress wear on the cutting edge, extend the tool life, and the like. Moreover, the thermal expansion of the cutting tool and the workpiece is suppressed by cooling, so that the processing accuracy is improved, the thermal welding of the processing part is prevented, the processing efficiency is improved, and the surface property of the processing surface is improved. Since the distance between the spindle device and the machining unit is close, a large amount of machining liquid is also applied to the front surface of the spindle device. This large amount of machining fluid is likely to enter the bearing that supports the rotating shaft, and if the machining fluid enters the bearing, it may cause poor lubrication or seizure of the bearing. Become. In particular, in bearings that are lubricated with grease or lubricated with grease, the inside of the bearing is at a lower pressure than oil / air lubricated or oil mist lubricated bearings that are supplied with lubricating oil along with air. It is easy to intrude into and requires higher waterproof performance.

  As a general waterproof mechanism, a contact seal such as an oil seal or a V ring is known. However, when this contact type seal is applied to a spindle device used at a high speed rotation with a dmn value of 400,000 or more (more preferably 500,000 or more), heat generated from the contact part of the contact type seal is large. There is a problem that the sealing member is worn and it is difficult to maintain the waterproof performance for a long time. For this reason, in a machine tool, a so-called labyrinth is a non-contact seal in which a flinger is fixed to a front end portion (tool side) of a spindle device so as to be able to rotate integrally with a rotary shaft, and a gap between the flinger and a housing is reduced. The seal is made to be waterproof. The flinger that rotates at a high speed has a labyrinth effect and prevents the machining fluid from entering the bearing by shaking the machining fluid that has fallen on the flinger outward in the radial direction by centrifugal force.

  The waterproofing effect using the flinger's centrifugal force and labyrinth effect increases the centrifugal force by increasing the rotation speed and using a large-diameter flinger, and the gap between the flinger and the housing is as small and long as possible. It is effective. However, when rotating at a high speed or increasing the diameter of the flinger, the centrifugal force and the hoop stress acting on the flinger also increase in proportion thereto.

  As a conventional technique for suppressing the influence of centrifugal force, a collet mounted on a tool is inserted into a taper hole of a tool holding portion, and a nut screwed into the tool holding portion is tightened to fix the tool to the tool holding portion. A tool holder is disclosed in which a carbon fiber layer is wound around the outer peripheral surface of a nut and the expansion of the nut is suppressed by centrifugal force (see, for example, Patent Document 1).

  Further, in the shaft seal device of the rotating machine described in Patent Document 2, the tip of the flinger protruding from the end cover of the rotating machine has a large diameter tapered surface, and the swinging operation is performed by the action of the tapered surface accompanying the rotation of the flinger. It acts to prevent rainwater and oil from entering from the outside.

JP-A-6-226516 Japanese Utility Model Publication No. 2-5655

  In general, the flinger is made of a metal material having a relatively large specific gravity such as an SC material, an SCM material, a SUS material, an AL material, or a CU material. Therefore, if the diameter of the flinger is increased in order to apply a large centrifugal force to the working fluid falling on the flinger, a large centrifugal force acts on the flinger itself, particularly on the outer diameter side. In high-speed rotation with a dmn value of 1 million or more, such as the rotation axis of a machine tool, the flinger may be deformed by centrifugal force, or in extreme cases, the centrifugal force may exceed the tensile strength of the flinger and cause destruction. There is. For this reason, it is necessary to limit the diameter of a flinger and the rotational speed of a rotating shaft to such an extent that the influence of centrifugal force is allowed.

  In the conventional spindle apparatus used in an environment where the dmn value is 1 million or more, the size of the flinger is limited in consideration of the centrifugal force, so there is room for improvement in terms of waterproof performance. .

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a spindle device having a dmn value of 1 million or more and capable of high-speed rotation and a good waterproof function.

The above object of the present invention can be achieved by the following constitution.
(1) a rotating shaft;
A bearing that rotatably supports the rotating shaft with respect to the housing;
A flinger that constitutes at least a part of a waterproofing mechanism that suppresses intrusion of liquid into the bearing and is fixed to the rotating shaft so as to be integrally rotatable,
A spindle device comprising:
The flinger is
A base fixed to the rotating shaft;
A disk portion extending radially outward from the base portion and disposed opposite to the axial end surface of the housing in a axial direction with a slight gap therebetween;
An annular portion that extends in the axial direction from the disk portion and is disposed to face the outer peripheral surface of the housing in a radial direction with a slight gap therebetween;
Have
The spindle device according to claim 1, wherein the annular portion has a tapered shape with a thickness that decreases with increasing distance from the disk portion in the axial direction.
(2) The spindle device according to (1), wherein an inner peripheral surface of the annular portion is a tapered surface having a radial length that increases with distance from the disk portion in the axial direction.
(3) The spindle device according to (1) or (2), wherein the outer peripheral surface of the annular portion is a tapered surface whose radial length decreases as it moves away from the disk portion in the axial direction. .
(4) At least one circumferential groove is recessed in the outer peripheral surface of the housing that faces the annular portion in the radial direction;
The spindle device according to any one of (1) to (3), wherein an end of the circumferential groove overlaps the annular portion in an axial direction.
(5) The base portion is disposed to face the inner peripheral surface of the housing in a radial direction with a slight gap therebetween,
Any one of (1) to (4), wherein the housing has an annular groove recessed in the inner peripheral surface, and a communication hole communicating the annular groove and the outer peripheral surface. Spindle device described in one.
(6) The spindle apparatus according to any one of (1) to (5), wherein at least a part of the flinger is formed of a carbon fiber composite material.

  According to the spindle device described in (1), the annular portion of the flinger disposed so as to face the outer peripheral surface of the housing is formed in a tapered shape whose thickness becomes thinner as it moves away from the disk portion in the axial direction. Therefore, it is difficult for centrifugal force deformation to occur at the tip side of the annular portion, and an increase in the gap at the entrance of the labyrinth can be suppressed, and a good waterproof function can be exhibited.

  According to the spindle device described in (2), even if the liquid enters the labyrinth gap between the inner peripheral surface of the annular portion and the outer peripheral surface of the housing, the centrifugal force generated in the liquid is Therefore, the liquid can be guided by the inner peripheral surface of the annular portion and discharged to the outside of the labyrinth.

  According to the spindle device described in (3), when a liquid adheres to the outer peripheral surface of the annular portion, the centrifugal force generated in the liquid decreases as the distance from the disk portion increases in the axial direction. Accordingly, the liquid can be guided by the outer peripheral surface of the annular portion and can be shaken off in a direction approaching the disk portion, that is, a direction away from the housing.

  According to the spindle device described in (4), the circumferential groove recessed in the outer peripheral surface of the housing overlaps the annular portion with the annular portion in the axial direction. The liquid can be prevented from flowing into the circumferential groove and entering the labyrinth gap between the inner peripheral surface of the annular portion and the outer peripheral surface of the housing. In particular, when the outer peripheral surface of the housing constituting the labyrinth has a tapered shape, the liquid easily enters the labyrinth when the spindle is stopped. However, according to the spindle device having the above configuration, the liquid can be prevented from entering the labyrinth.

  According to the spindle device described in (5), even when the liquid enters the labyrinth between the flinger and the housing, the liquid is accumulated in the annular groove recessed in the inner peripheral surface of the housing, and communicates. Since the liquid is discharged to the outside through the hole, it is possible to further suppress the penetration of the liquid into the bearing.

  According to the spindle device described in (6), since at least a part of the flinger is formed of a carbon fiber composite material, the centrifugal force is reduced by reducing the mass compared to the metal, Since the tensile strength is higher than that, deformation due to centrifugal force is further suppressed. Therefore, the flinger can be used even at a high dmn value, and since the radial length and the axial length can be increased, the liquid can be strongly shaken off and the labyrinth can be ensured for a long time, It becomes possible to obtain good waterproof performance.

It is sectional drawing of the spindle apparatus which concerns on 1st Embodiment of this invention. It is a principal part enlarged view of the spindle apparatus shown in FIG. (A) is an enlarged view of the spindle device shown in FIG. 2, (b) is an enlarged view of the spindle device according to the modified example, and (c) is an enlarged view of the spindle device according to another modified example. FIG. It is a principal part enlarged view of the spindle apparatus which concerns on 2nd Embodiment of this invention. It is a figure which expands and shows the spindle apparatus shown in FIG. 4 further. It is a principal part enlarged view of the spindle apparatus which concerns on 3rd Embodiment of this invention. It is a figure which expands further and shows the spindle apparatus shown in FIG. It is a principal part enlarged view of the spindle apparatus which concerns on 4th Embodiment of this invention. It is sectional drawing of the spindle apparatus which concerns on the modification of 1st Embodiment of this invention. It is sectional drawing of the spindle apparatus which concerns on the modification of 2nd Embodiment of this invention. It is sectional drawing of the spindle apparatus which concerns on the modification of 3rd Embodiment of this invention. It is sectional drawing of the spindle apparatus which concerns on the modification of 4th Embodiment of this invention.

Hereinafter, embodiments of a spindle device according to the present invention will be described in detail with reference to the drawings.
(First embodiment)

  As shown in FIG. 1 to FIG. 3A, the spindle device 10 of the present embodiment is a motor built-in spindle device for a machine tool, and the rotary shaft 11 is on the tool side (front side, front in the axial direction). The housing H is rotatably supported by two rows of front bearings 50, 50 that are supported and two rows of rear bearings 60, 60 that are supported on the counter tool side (rear side, rearward in the axial direction). The housing H is composed of a front bearing outer ring retainer 12, an outer cylinder 13, and a rear housing 14 in this order from the tool side.

  Each front bearing 50 is an angular ball bearing having an outer ring 51, an inner ring 52, a ball 53 as a rolling element arranged with a contact angle, and a cage (not shown). Is an angular ball bearing having an outer ring 61, an inner ring 62, balls 63 as rolling elements, and a cage (not shown). The front bearings 50 and 50 (parallel combination) and the rear bearings 60 and 60 (parallel combination) are arranged to cooperate with each other to form a back combination.

  The outer rings 51, 51 of the front bearings 50, 50 are fitted into the outer cylinder 13, and are fixed to the outer cylinder 13 via the outer ring spacer 54 by the front bearing outer ring presser 12 fastened to the outer cylinder 13 with bolts 15. It is positioned and fixed in the axial direction.

  Further, the inner rings 52, 52 of the front bearings 50, 50 are externally fitted to the rotary shaft 11, and the nuts 16 fastened to the rotary shaft 11 are connected to the rotary shaft 11 via the flinger 40 and the inner ring spacer 55. Positioned and fixed in the direction.

  The flinger 40 is externally fitted to the rotary shaft 11 on the tool side (left side in the figure) with respect to the front bearings 50, 50, and is fixed to the rotary shaft 11 together with the inner rings 52, 52 by a nut 16.

  The outer rings 61 and 61 of the rear bearings 60 and 60 are fitted into a sleeve 18 that is slidably fitted in the rear housing 14 so as to be slidable in the axial direction. The fixed rear bearing outer ring presser 19 is positioned and fixed in the axial direction with respect to the sleeve 18 via the outer ring spacer 64.

  Inner rings 62 and 62 of the rear bearings 60 and 60 are externally fitted to the rotary shaft 11, and are axially directed to the rotary shaft 11 via the inner ring spacer 65 by another nut 21 fastened to the rotary shaft 11. It is fixed to the position. A coil spring 23 is disposed between the rear housing 14 and the rear bearing outer ring retainer 19, and the spring force of the coil spring 23 presses the rear bearing outer ring retainer 19 together with the sleeve 18 backward. Thereby, a preload is applied to the rear bearings 60 and 60.

  On the tool side of the rotary shaft 11, a tool mounting hole 24 and a female screw 25 formed in the axial direction through the center of the shaft are provided. The tool attachment hole 24 and the female screw 25 are used for attaching a tool (not shown) such as a cutting tool to the rotary shaft 11. Instead of the tool mounting hole 24 and the female screw 25, a conventionally known draw bar (not shown) may be slidably inserted into the shaft core of the rotary shaft 11. Each draw bar has a collet portion for fixing a tool holder (not shown), and is biased in the counter tool side direction by the force of a disc spring.

  A rotor 26 disposed so as to be able to rotate integrally with the rotation shaft 11 and a stator 27 disposed around the rotor 26 are disposed substantially at the center in the axial direction between the front bearings 50, 50 and the rear bearings 60, 60 of the rotation shaft 11. With. The stator 27 is fixed to the outer cylinder 13 by fitting the cooling jacket 28 shrink-fitted into the stator 27 into the outer cylinder 13 constituting the housing H. The rotor 26 and the stator 27 constitute a motor M, and by supplying electric power to the stator 27, a rotational force is generated in the rotor 26 to rotate the rotating shaft 11.

  The flinger 40 includes a boss portion 41 as a base portion that is externally fitted and fixed to the rotary shaft 11, a disk portion 42 that extends radially outward from an axial front end portion of the boss portion 41, and the disk portion And an annular portion 43 extending in a ring shape from the radially outer end of 42 toward the rear in the axial direction (front bearing outer ring retainer 12 side). A convex portion 44 that protrudes toward the front bearing outer ring retainer 12 side is formed on the surface facing the front bearing outer ring retainer 12 in the middle in the radial direction of the disk portion 42. The annular portion 43 is formed in a tapered shape such that the thickness decreases as it moves away from the disk portion 42 in the axial direction, that is, toward the rear in the axial direction. More specifically, the inner peripheral surface 45 of the annular portion 43 is formed to be a tapered surface whose radial length increases as the distance from the disc portion 42 in the axial direction increases.

  The front bearing outer ring retainer 12 can accommodate the convex portion 44 on the axial front end surface 71 facing the disc portion 42 of the flinger 40 in the axial direction so as to oppose the convex portion 44 of the flinger 40 through a slight gap. A concave portion 73 is formed. Further, the outer peripheral surface 75 of the front bearing outer ring retainer 12 is formed at the front end in the axial direction, and has a tapered portion 77 whose radial length increases toward the rear in the axial direction, and a radial direction from the rear end in the axial direction of the tapered portion 77. A circumferential groove 79 that is recessed inward by a depth t over the entire circumference, and extends radially outward and axially rearward from the axial rear end of the circumferential groove 79 to the outer periphery of the outer cylinder 13. A large-diameter cylindrical surface 81 that smoothly connects to the surface.

  The boss portion 41 is disposed to face the inner peripheral surface 83 of the front bearing outer ring retainer 12 in a radial direction with a slight gap, and the disk portion 42 is slightly opposed to the axial front end surface 71 of the front bearing outer ring retainer 12. The annular portion 43 is disposed so as to face the taper portion 77 of the outer peripheral surface 75 of the front bearing outer ring retainer 12 in the radial direction with a slight gap therebetween. As described above, the flinger 40 is disposed so as to face the front bearing outer ring presser 12 constituting the housing H via a slight axial gap and a radial gap, for example, a gap of about 0.5 mm, and constitutes a so-called labyrinth seal.

In particular, an air curtain is formed between the inner peripheral surface 45 of the annular portion 43 and the tapered portion 77 due to the difference in peripheral speed, and when the workpiece is machined, the machining fluid that falls on the spindle device 10 is on the front side. The waterproof mechanism for suppressing entering into the bearings 50 and 50 side is comprised. Also, tentatively
Even when the machining liquid enters the labyrinth gap between the inner peripheral surface 45 of the annular part 43 and the taper part 77, the centrifugal force F generated in the machining liquid increases as it goes rearward in the axial direction. The working fluid can be guided by the inner peripheral surface 45 of the annular portion 43 and discharged to the outside of the labyrinth. Further, since the rotation speed of the inner circumferential surface 45 of the annular portion 43 increases as it goes rearward in the axial direction, the pressure in the labyrinth gap between the inner circumferential surface 45 of the annular portion 43 and the tapered portion 77 is Decreases as it goes backward. Therefore, an air flow is generated in the labyrinth gap between the inner peripheral surface 45 of the annular portion 43 and the taper portion 77 toward the rear in the axial direction. It is possible to suppress.

  Here, in the present embodiment, since the taper portion 77 of the outer peripheral surface 75 of the front bearing outer ring retainer 12 forms a labyrinth together with the inner peripheral surface 45 of the annular portion 43, the machining fluid is tapered when the spindle is stopped. 77 is easy to enter the labyrinth. However, since the axial front end 80 of the circumferential groove 79 and the axial rear end face 46 of the annular portion 43 are located on the same plane orthogonal to the rotation shaft 11, even when the spindle is stopped, Since the machining fluid is guided by the circumferential groove 79 and discharged to the outside, the machining fluid can be prevented from entering the labyrinth gap between the inner circumferential surface 45 of the annular portion 43 and the tapered portion 77. .

  Further, the circumferential groove 79 is not limited to the above-described configuration as long as the axial front end portion 80 overlaps the annular portion 43 in the axial direction. For example, as shown in FIG. The front end 80 in the axial direction of the groove 79 may be formed so as to be positioned in front of the rear end face 46 in the axial direction of the annular portion 43, or as shown in FIG. 79 may be formed so as to overlap the annular portion 43 in the axial direction.

  In order to effectively exhibit the waterproof function of the spindle device 10 of the present invention, it is desirable to use the spindle device 10 in a lateral direction (a state in which the axial direction is perpendicular to the gravity direction). In such a configuration, the grinding liquid does not easily enter the labyrinth gap between the outer peripheral surface 75 of the front bearing outer ring retainer 12 and the inner peripheral surface 45 of the annular portion 43, and is accumulated in the circumferential groove 79. The machining fluid can be efficiently discharged to the outside of the spindle device 10 by gravity.

  In addition, the flinger 40 of the present invention is formed of a carbon fiber composite material (CFRP) that has a higher tensile strength and a lower specific gravity than a metal.

  Specifically, as the carbon fiber composite material, for example, a woven fabric (sheet-like shape) made of PAN (polyacrylonitrile) as a main raw material, in which yarns made of carbon fibers are arranged in parallel, or made of yarns made of carbon fibers. ), A plurality of sheets impregnated with a thermosetting resin such as an epoxy resin containing a curing agent are superposed on each other, wound around a core metal, etc., and heated and cured. Moreover, the carbon fiber which used pitch system as the main raw material can also be used. By optimizing the fiber direction and angle, the carbon fiber composite material can optimize physical properties such as tensile strength, tensile elastic modulus, and linear expansion coefficient according to the application.

As the characteristics of the carbon fiber composite material, for example, carbon fiber mainly composed of PAN having a tensile strength of 1800 to 3500 MPa, a tensile elastic modulus of 130 to 280 GPa, and a specific gravity of 1.5 to 2.0 g / cc is used. When used, the tensile strength is equal to or higher than that of conventional high-strength steel and the like, and the specific gravity is about 1/5 (the specific strength is about three times that of a normal metal material). Moreover, since the thermal expansion coefficient can be made −5 to + 12 × 10 ⁻⁶ K ⁻¹ by optimizing the fiber direction and angle, it is about 1 to 1/10 compared with the conventional carbon steel. can do.

  In this way, by using a carbon fiber composite material having a specific gravity smaller than that of metal, if the diameter is the same, the centrifugal force acting on the flinger 40 can be greatly reduced, and the flinger 40 at the time of high-speed rotation can be reduced. The possibility of centrifugal force damage is eliminated. Furthermore, since the tensile strength is equal to or higher than that of metal, deformation due to centrifugal force can be suppressed. Therefore, the restriction on the rotational speed of the rotating shaft 11 and the restriction on the size (radial direction) of the flinger 40 can be greatly relaxed.

  This makes it possible to increase the rotation speed of the flinger 40, which has been difficult to achieve in the past, or to increase the size of the flinger 40. It can be swung away to prevent intrusion into the bearing. Further, since the centrifugal force acting on the annular portion 43 of the flinger 40 is reduced, the opening side (right side in the drawing) of the annular portion 43 having a cantilever structure with relatively low strength is expanded radially outward. Can be suppressed. Thereby, the radial direction length and axial direction length of the annular part 43 are set long, the length of a labyrinth seal becomes long, and the waterproofing effect improves.

  The flinger 40 and the rotating shaft 11 are preferably fitted with a clearance fit of, for example, several μm in consideration of the difference in linear expansion coefficient between the metal and the carbon fiber composite material. Due to the expansion of the shaft 11, a tight fit is achieved. Further, the clearance between the flinger 40 and the front bearing outer ring retainer 12 also takes into account the difference in linear expansion coefficient between them, and interference occurs even if the metal rotary shaft 11 and the front bearing outer ring retainer 12 are thermally expanded. It is set to a gap that is not large (for example, φ0.5 mm or less).

  As described above, according to the spindle device 10 of the present embodiment, the annular portion 43 of the flinger 40 disposed opposite to the outer peripheral surface 75 of the front bearing outer ring presser 12 constituting the housing H is directed rearward in the axial direction. Accordingly, it is formed into a tapered shape whose thickness is reduced. Therefore, centrifugal force deformation hardly occurs on the tip side of the annular portion 43, an increase in the gap on the labyrinth entrance side can be suppressed, and a good waterproof function can be exhibited. If the annular part 43 is formed with the same thickness, the centrifugal force deformation is likely to increase on the tip side, the labyrinth is opened at the mouth, and the machining liquid is liable to enter.

In addition, since the inner peripheral surface 45 of the annular portion 43 is a tapered surface whose radial length increases toward the rear in the axial direction, the inner peripheral surface 45 of the annular portion 43 and the tapered portion 77 Even when the machining fluid enters the labyrinth gap between them, the centrifugal force F generated in the machining fluid increases as it goes rearward in the axial direction, so that the machining fluid is guided by the inner peripheral surface 45 of the annular portion 43. Thus, it can be discharged outside the labyrinth.
Further, since the rotation speed of the inner circumferential surface 45 of the annular portion 43 increases as it goes rearward in the axial direction, the pressure in the labyrinth gap between the inner circumferential surface 45 of the annular portion 43 and the tapered portion 77 is Decreases as it goes backward. Therefore, an air flow is generated in the labyrinth gap between the inner peripheral surface 45 of the annular portion 43 and the taper portion 77 toward the rear in the axial direction. It is possible to suppress.

  In addition, the circumferential groove 79 recessed in the outer peripheral surface 75 of the front bearing outer ring presser 12 constituting the housing H has an end (axial front end 80) on the disc portion 42 side that is pivoted to the annular portion 43. Since it overlaps in the direction, it is possible to prevent the machining liquid from collecting in the circumferential groove 79 and entering the labyrinth gap between the inner circumferential surface 45 of the annular portion 43 and the tapered portion 77 even when the spindle is stopped. Can do.

  In addition, since the flinger 40 is made of a carbon fiber composite material, the centrifugal force is reduced by reducing the mass compared to the metal, and the deformation due to the centrifugal force is increased because the tensile strength is higher than the metal. It is further suppressed. Therefore, the flinger 40 can be used even with a high dmn value, and the radial length and the axial length can be increased, so that the machining fluid can be shaken off and the labyrinth can be ensured long. And good waterproof performance can be obtained.

(Second Embodiment)
Next, a second embodiment of the spindle device of the present invention will be described with reference to FIGS. The spindle device of this embodiment is different from the first embodiment in the configuration of the flinger and the front bearing outer ring retainer. Since other parts are the same as those of the spindle device according to the first embodiment of the present invention, the same parts are denoted by the same or corresponding reference numerals, and description thereof will be simplified or omitted.

  In the front bearing outer ring retainer 12A of the present embodiment, the outer peripheral surface 75 is configured by a small-diameter cylindrical surface 82 formed in the axially forward direction and a large-diameter cylindrical surface 81 formed in the axially rearward direction. It is substantially L-shaped. Further, the annular portion 43 of the flinger 40A has an inner peripheral surface 45 that is substantially cylindrical and is opposed to the small-diameter cylindrical surface 82 in a radial direction with a slight gap, and the outer peripheral surface 47 is directed rearward in the axial direction. Accordingly, the taper surface has a reduced radial length.

  Therefore, according to the spindle apparatus 10 of the present embodiment, when the machining liquid adheres to the outer peripheral surface 47 of the annular portion 43, the centrifugal force G generated in the machining liquid becomes smaller toward the rear in the axial direction. Therefore, the working fluid can be guided by the outer peripheral surface 47 of the annular portion 43 and can be shaken off in the axial direction, that is, in the direction away from the housing H (the direction of the white arrow in FIG. 5).

(Third embodiment)
Next, a third embodiment of the spindle apparatus of the present invention will be described with reference to FIGS. The spindle device of the present embodiment is different from the first embodiment in the configuration of the front bearing outer ring retainer. Since other parts are the same as those of the spindle apparatus of the first embodiment, the same parts are denoted by the same or corresponding reference numerals, and description thereof will be simplified or omitted.

  The front bearing outer ring presser 12B of the present embodiment has an annular groove 85 that is recessed in the inner peripheral surface 83 that faces the boss portion 41 of the flinger 40 in the radial direction, and that is recessed over the entire circumference radially outward. The annular groove 85 and the tapered portion 77 of the outer peripheral surface 75 have a drain hole 87 as a communication hole that communicates in the direction of gravity in the radial direction.

  Therefore, according to the spindle device 10 of the present embodiment, even when the grinding fluid enters between the boss portion 41 of the flinger 40 and the inner peripheral surface 83 of the front bearing outer ring presser 12B, the grinding fluid is It accumulates in the annular groove 85 and is discharged through a drain hole 87 into a labyrinth gap between the inner peripheral surface 45 of the flinger 40 and the outer peripheral surface 75 of the front bearing outer ring retainer 12B. Thereafter, the grinding fluid is efficiently discharged to the outside by the above-described pump effect and centrifugal force, so that it is possible to further suppress the penetration of the grinding fluid into the front bearing 50.

(Fourth embodiment)
Next, a fourth embodiment of the spindle device of the present invention will be described with reference to FIG. The spindle device of the present embodiment is different from the second embodiment in the configuration of the front bearing outer ring retainer. Since other parts are the same as those of the spindle device of the second embodiment, the same parts are denoted by the same or corresponding reference numerals, and the description thereof will be simplified or omitted.

  The front bearing outer ring presser 12C according to the present embodiment includes an annular groove 85 that is recessed in the radially outer direction on the inner circumferential surface 83 facing the boss portion 41 of the flinger 40A over the entire circumference. A drain hole 88 that communicates the annular groove 85 and the large-diameter cylindrical surface 81 of the outer peripheral surface 75 is provided.

  The drain hole 88 includes a first extension hole 89 extending radially outward from the annular groove 85, a second extension hole 90 extending axially rearward from the radially outer end of the first extension hole, And a third extension hole 91 that extends radially outward from the axially rear end of the extension hole 90 and communicates with the large-diameter cylindrical surface 81.

  As described above, according to the spindle device 10 of the present embodiment, even when the grinding liquid enters between the boss portion 41 of the flinger 40A and the inner peripheral surface 83 of the front bearing outer ring retainer 12C, Since the grinding liquid accumulates in the annular groove 85 and is discharged to the outside through the drain hole 88, it is possible to further suppress the penetration of the grinding liquid into the front bearing 50.

In addition, this invention is not limited to each embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
The flinger 40, 40A may be at least partly a carbon fiber composite material. For example, the outer diameter side of the flinger 40, 40A is formed from a carbon fiber composite material, and the inner diameter side is SC material, SCM material, SUS material, You may form from metal materials, such as AL material and CU material.

  Further, as shown in FIGS. 9 to 12, the disc portion 42 of the flinger 40, 40 </ b> A does not necessarily need to be provided with the convex portion 44, and in this case, the axial front end of the front bearing outer ring presser 12, 12 </ b> A, 12 </ b> B, 12 </ b> C. A recess 73 is not formed on the surface 71.

  In each of the above-described embodiments, the ring portion 43 of the flinger 40, 40A is configured to be opposed to the outer peripheral surface 75 of the front bearing outer ring presser 12 constituting the housing H in the radial direction. For example, the annular portion 43 may be configured so as to be opposed to the outer peripheral surface of the outer cylinder 13 constituting the housing H in the radial direction. When configured in this way, instead of the tapered portion 77 and the circumferential groove 79 formed on the outer circumferential surface 75 of the front bearing outer ring retainer 12 in the above-described embodiment, the outer circumferential surface of the outer cylinder 13 is directed rearward in the axial direction. You may provide the taper part and circumferential groove | channel where radial direction length becomes large.

  It goes without saying that the inner peripheral surface 45 and the outer peripheral surface 47 of the annular portion 43 may be tapered by combining the flinger 40 of the first embodiment and the flinger 40A of the second embodiment.

  Further, although the motor built-in type spindle device has been described, the present invention is not limited to this, and the present invention can be similarly applied to a belt drive type spindle device and a motor direct connection drive type spindle device coupled to a rotation shaft of a motor. Further, the present invention is not limited to a spindle device for machine tools, and can be applied to a spindle device of other high-speed rotating equipment that requires a waterproof function.

DESCRIPTION OF SYMBOLS 10 Spindle apparatus 11 Rotating shaft 12, 12A, 12B Front side bearing outer ring holder 13 Outer cylinder 40, 40A Flinger 41 Boss part (base part)
42 Disc part 43 Ring part 45 Inner peripheral surface 47 Outer peripheral surface 50 Front bearing (bearing)
71 Axial front end face (Axial end face)
75 Outer peripheral surface 77 Tapered portion 79 Circumferential groove 80 Axial front end (end)
81 Large-diameter cylindrical surface 82 Small-diameter cylindrical surface 83 Inner peripheral surface 85 Annular groove 87, 88 Drain hole (communication hole)
H housing

Claims (6)

A rotation axis;
A bearing that rotatably supports the rotating shaft with respect to the housing;
A flinger that constitutes at least a part of a waterproofing mechanism that suppresses intrusion of liquid into the bearing and is fixed to the rotating shaft so as to be integrally rotatable,
A spindle device comprising:
The flinger is
A base fixed to the rotating shaft;
A disk portion extending radially outward from the base portion and disposed opposite to the axial end surface of the housing in a axial direction with a slight gap therebetween;
An annular portion that extends in the axial direction from the disk portion and is disposed to face the outer peripheral surface of the housing in a radial direction with a slight gap therebetween;
Have
The spindle device according to claim 1, wherein the annular portion has a tapered shape with a thickness that decreases with increasing distance from the disk portion in the axial direction.   2. The spindle device according to claim 1, wherein an inner circumferential surface of the annular portion is a tapered surface having a radial length that increases with distance from the disk portion in the axial direction.   3. The spindle device according to claim 1, wherein an outer peripheral surface of the annular portion is a tapered surface having a radial length that decreases with distance from the disc portion in the axial direction. At least one circumferential groove is recessed in the outer peripheral surface of the housing that is radially opposed to the annular portion,
4. The spindle device according to claim 1, wherein an end of the circumferential groove on the disk portion side overlaps the annular portion in an axial direction. 5. The base portion is disposed to face the inner peripheral surface of the housing in a radial direction with a slight gap therebetween,
5. The housing according to claim 1, wherein the housing has an annular groove that is recessed in the inner peripheral surface, and a communication hole that communicates the annular groove with the outer peripheral surface. The spindle device as described.   The spindle apparatus according to claim 1, wherein at least a part of the flinger is formed of a carbon fiber composite material.

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