JP2014047857A - Spindle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spindle device and a slinger for the spindle device, capable of preventing deformation of the flinger due to centrifugal force while keeping high-speed rotational performance of a million or more dmn value of a used bearing, and good water-proofing function.SOLUTION: A flinger 40 has a cylindrical boss portion 42 externally fitted to a rotating shaft 11, a flat portion 43 extended from an axial front end of the boss portion 42 to a radial outer side, a taper portion 44 extended in a state of being inclined to an axial rear side toward the radial outer side from a radial outer end portion of the flat portion 43, and an annular portion 45 extended from a radial outer end portion of the taper portion 44 to the axial other end side, and is made of a material having a specific gravity smaller than that of the rotating shaft 11 and a specific strength larger than the rotating shaft 11.

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 liquid is generally supplied to the machining unit for the purpose of lubrication and cooling of machining tools such as cutting tools and grindstones and machining sites. That is, lubrication can improve the machining characteristics, suppress wear on the cutting edge, extend the tool life, and the like. In addition, the thermal expansion of the processing tool and the workpiece is suppressed by cooling, so that the processing accuracy is improved, the thermal welding of the processing portion 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 a bearing to be used of 400,000 or more (more preferably, 500,000 or more), the contact type seal from the contact portion of the contact type seal is used. There is a problem that heat generation is large, the seal member is worn, and it is difficult to maintain waterproof performance for a long period of 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 sealing device in the spindle device for machine tools described in Patent Document 2, a shielding plate that rotates integrally with the tip portion of the spindle is disposed so as to face the tip surface of the housing with a gap. A labyrinth portion is provided between the shielding plate and the front end surface of the housing. With this configuration, the coolant that has bounced off the workpiece or the like is prevented from entering the inside of the housing.

  The spindle device for machine tools described in Patent Document 3 includes a labyrinth seal formed by a spindle cap and an end surface cover, and the labyrinth seal is configured to include a labyrinth chamber. By setting a large value, when the coolant liquid enters the labyrinth chamber through the gap between the spindle cap and the end surface cover, the pressure of the coolant fluid in the labyrinth chamber is reduced to attenuate the flow of the coolant liquid. Further, the coolant liquid is prevented from entering the bearing portion of the main shaft without supplying a large amount of compressed air from the gap between the main shaft and the main shaft housing of the main shaft head toward the tip end side of the main shaft.

  Further, the spindle unit described in Patent Document 4 includes a housing, a rotating shaft that is rotatably mounted on the housing via a bearing, an inner ring pressing member that is screwed to the rotating shaft and presses the inner ring of the bearing, An outer ring pressing member that is fixed to the housing and presses the outer ring of the bearing is disclosed, and a waterproof cover that covers the outer ring pressing member in a non-contact manner is formed on the inner ring pressing member. The waterproof cover prevents cutting water from entering between the outer ring pressing member and the inner ring pressing member, that is, the bearing portion, and eliminates the occurrence of rust and the like.

JP-A-6-226516 JP 2002-263882 A JP 2010-76045 A Japanese Patent Laid-Open No. 11-77529

  By the way, generally a flinger is manufactured with metal materials with comparatively big specific gravity, such as SC material, SCM material, SUS material, 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 in which the dmn value of a bearing used like a rotating shaft of a machine tool is 1 million or more, the flinger is deformed by centrifugal force, and in some cases, the original waterproof function of the flinger may be deteriorated. 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 conventional spindle devices used in an environment where the dmn value of the bearing used is 1 million or more, the size of the flinger is limited in consideration of the magnitude of the centrifugal force. There was room.

  The present invention has been made in view of the above-described problems. The object of the present invention is to provide a flinger by centrifugal force while maintaining a good waterproof function and capable of rotating at a high speed with a dmn value of a bearing used of 1 million or more. It is an object of the present invention to provide a spindle apparatus and a spindle apparatus flinger that can prevent the deformation of the spindle apparatus.

The above object of the present invention can be achieved by the following constitution.
(1) a rotating shaft to which a machining tool is attached at one end in the axial direction;
A housing that rotatably supports the rotating shaft via a bearing;
A flinger that is fixed to the rotating shaft so as to be integrally rotatable, and has a waterproof function to suppress the ingress of liquid into the bearing;
A spindle device comprising:
The flinger includes a cylindrical base portion fitted on the rotation shaft, a flat portion extending radially outward from one axial end portion of the base portion, and a radial direction from a radially outer end portion of the flat portion. A taper portion extending to be inclined toward the other end side in the axial direction toward the outer side, and an annular portion extending from the radially outer end portion of the taper portion to the other end side in the axial direction. , Made of a material having a smaller specific gravity than the rotating shaft and a larger specific strength,
The flat portion and the tapered portion are arranged to face each other with respect to one axial end surface of the housing via a gap.
The spindle device according to claim 1, wherein the annular portion is disposed to face the outer peripheral surface of the housing in a radial direction with a gap.
(2) When the radial distances between the radially outer end of the flat portion and the outer peripheral surface of the annular portion and the rotation center of the rotating shaft are d and D, respectively.
(1/2) D ≦ d ≦ (2/3) D, wherein the spindle device according to (1).
(3) The housing is
A cylindrical member into which the outer ring of the bearing is fitted;
An outer ring pressing member fastened to one axial end surface of the outer cylinder by a screw member extending in the axial direction and positioning the outer ring in the axial direction;
Have
When the radial distance between the radially outer end of the flat portion and the center of the screw member and the rotation center of the rotating shaft is d and B, respectively.
The spindle device according to (1) or (2), wherein B <d.
(4) The spindle apparatus according to any one of (1) to (3), wherein the flinger is made of a fiber-reinforced composite material.

According to the spindle apparatus of the present invention, since the flinger is made of a material having a specific gravity smaller than that of the rotating shaft and a larger specific strength, the action of centrifugal force is reduced. Accordingly, the spindle device can prevent the flinger from being deformed by centrifugal force while maintaining a good waterproof function and capable of rotating at a high speed with a dmn value of a bearing used of 1 million or more.
Further, the flinger extends so as to incline toward the other end side in the axial direction from the one end portion in the axial direction of the base portion toward the radially outer side from the radially outer end portion in the plane portion. And a tapered portion to be provided.
As described above, the flinger has a flat portion that is perpendicular to the rotation axis on the radially inner side, so that the degree of freedom in the arrangement design of the structural member of the housing (the member that constitutes the tip of the spindle) that is disposed to face the flat portion is improved. The cutting characteristics of the spindle device can be improved.
Furthermore, since the flinger has a tapered portion on the radially outer side where the centrifugal force is large, it is possible to suppress stress in the axial direction due to the centrifugal force expansion during rotation.
As described above, it is possible to achieve both the cutting characteristics of the spindle device and the performance of the flinger.

It is sectional drawing of the spindle apparatus which concerns on one Embodiment of this invention. It is a principal part expanded sectional view of the spindle apparatus of FIG. It is sectional drawing of a flinger.

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

  As shown in FIG. 1, the spindle device 10 is a motor built-in spindle device for machine tools, and a rotating shaft 11 has two rows of front bearings that support the tool side (front side in the axial direction, one end side in the axial direction). 50 and 50 and two rows of rear bearings 60 and 60 that support the non-tool side (the rear side in the axial direction and the other side in the axial direction) are rotatably supported by the housing H. The housing H is composed of a front bearing outer ring presser 12 (outer ring presser member), an outer cylinder 13 (cylindrical member), a rear housing 14, and a rear lid 5 in this order from the tool side.

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 processing tool (not shown) to the rotary shaft 11. For example, a grinding wheel quill (not shown) is attached to the tool attachment hole 24 and the female screw 25, thereby enabling grinding.
The configuration of the rotary shaft 11 is not limited as long as a machining tool can be attached to one end side, and a draw bar is slidably inserted into the shaft core of the rotary shaft 11 instead of the tool mounting hole 24 and the female screw 25. You may do it. The draw bar includes a collet portion (not shown) that fixes the tool holder, and biases the collet portion in the counter tool side direction by the force of the 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 on the outer peripheral surface thereof 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.

  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.

  Outer rings 51, 51 of the front bearings 50, 50 are fitted in the outer cylinder 13, and an outer ring spacer 54 is secured by a front bearing outer ring presser 12 fastened with a bolt 15 (screw member) on the front surface in the axial direction of the outer cylinder 13. It is positioned and fixed in the axial direction to the outer cylinder 13 via Inner rings 52, 52 of the front bearings 50, 50 are externally fitted to the rotary shaft 11, and the nut 16 fastened to the rotary shaft 11 is connected to the rotary shaft 11 via an inner ring spacer 55 and a flinger 40 described later. It is positioned and fixed in the axial direction.

  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, and are integrally fixed to the sleeve 18 with bolts 66. The 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.

  Here, in the grinding process using the spindle apparatus 10 as in the present embodiment, generally, a large amount of grinding liquid is supplied to the processing unit, and the processing unit is cooled and the processing powder is removed. In the spindle apparatus 10 of the present embodiment, the flinger 40 is externally fitted to the rotary shaft 11 on the tool side (left side in the figure) from the front bearings 50 and 50 so that the machining fluid does not enter the front bearings 50 and 50. Integral rotation is possible. As described above, the flinger 40 forms a labyrinth seal with the housing H (the front bearing outer ring presser 12 and the outer cylinder 13), and shakes off the grinding fluid from the outside along with the rotation of the rotary shaft 11, so that the front bearing 50, The waterproof function which suppresses the penetration | invasion of the liquid to 50 is given.

  2 and 3, the flinger 40 is made of a material having a specific gravity smaller than that of the rotating shaft 11 and a larger specific strength, more specifically, aramid fiber composite material (AFRP), carbon fiber composite material (CFRP), or the like. Made of resin fiber reinforced composite material. The flinger 40 is a boss portion 42 as a cylindrical base portion that is fitted and fixed to the outer peripheral surface of the rotary shaft 11, and extends radially outward from the front end portion in the axial direction of the boss portion 42. A flat portion 43, a tapered portion 44 extending so as to incline toward the rear side in the axial direction from the radially outer end of the flat portion 43 toward the radially outer end, and the radially outer end of the tapered portion 44 And an annular portion 45 extending in a ring shape toward the rear side in the axial direction.

  Here, on the housing H side surface of the flinger 40, the connection portion R1 between the boss portion 42 and the flat portion 43, the connection portion R2 between the flat portion 43 and the taper portion 44, and the connection between the taper portion 44 and the annular portion 45. The part R3 has a curved cross-sectional shape, and greatly suppresses stress in the thrust direction due to centrifugal force expansion. The curvature radii of these connection portions R1, R2, and R3 are preferably set to 0.3 mm or more, and more preferably 1 mm or more.

  The boss portion 42 is radially opposed to the inner peripheral surface 12c of the front bearing outer ring presser 12 via a slight gap, and in the axial direction by contacting the nut 16 and the inner ring 52 of the front bearing 50. Positioned.

  The flat surface portion 43 and the tapered portion 44 are disposed to face the axial front surface 12a of the front bearing outer ring presser 12 (the front surface in the axial direction of the housing H) with a slight gap. Here, the axial front surface 12a of the front bearing outer ring presser 12 extends so as to incline toward the rear side in the axial direction from the radially outer end of the flat surface 12d toward the radially outer side. The flat surface 12d extends radially outward from the flat portion 43 and faces the flat portion 43 and the tapered portion 44 through a gap, and the tapered surface 12e is connected to the tapered portion 44. It extends in parallel and faces the tapered portion 44 with a gap.

  The annular portion 45 is arranged in a radial direction through a slight gap with respect to the outer peripheral surface 12b of the front bearing outer ring presser and the outer peripheral surface 13a (the outer peripheral surface of the housing H) of the outer cylinder 13 smoothly connected to the outer peripheral surface 12b. Opposed.

  Thus, the flinger 40 is opposed to the front bearing outer ring presser 12 and the outer cylinder 13 constituting the housing H through slight axial gaps and radial gaps, for example, gaps of about 0.1 to 1.0 mm in radius. It is arranged and constitutes a so-called labyrinth seal.

  In particular, an air curtain is formed between the inner peripheral surface of the annular portion 45 and the outer peripheral surfaces 12b and 13a of the front bearing outer ring presser 12 and the outer cylinder 13 due to the difference in peripheral speeds, thereby processing the workpiece. In doing so, a waterproof mechanism is configured to prevent the machining fluid falling on the spindle device 10 from entering the front bearings 50 and 50.

  Further, an annular groove 80 is formed in the outer peripheral surface 13a of the outer cylinder 13 so as to extend radially inward at an axial rearward position that does not face the inner peripheral surface of the annular portion 45 in the radial direction. The axial front end of the annular groove 80 and the axial rear end face of the annular part 45 are located on the same plane orthogonal to the rotation axis 11. Therefore, even when the spindle is stopped, the machining fluid is guided by the annular groove 80 and discharged to the outside, so that it is possible to prevent the machining fluid from entering the labyrinth gap.

  Further, as described above, the flinger 40 of the present invention has a tensile strength higher than that of a metal, and a specific gravity is small, such as an aramid fiber composite material (AFRP) or a carbon fiber composite material (CFRP). It is formed from a composite material. As carbon fiber composite materials, for example, hardened PAN (polyacrylonitrile) as a main raw material made of carbon fiber yarns in parallel or woven fabric (sheet-like) formed of carbon fiber yarns It is manufactured by laminating a number of sheets impregnated with a thermosetting resin such as an epoxy resin containing an agent, winding the sheet around a cored bar, etc., and curing it by heating. 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 a characteristic of the fiber reinforced composite material, the specific gravity is preferably 4.5 (g / cm ³ ) or less, more preferably 2.7 (g / cm ³ ) or less, and the tensile strength (MPa) / density (ρ : G / cm ³ ), the specific strength is preferably 74 (kNm / kg) or more, more preferably 160 (kNm / kg) or more. 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.

  As described above, by using a carbon fiber composite material having a higher specific strength (tensile strength / density) than a general metal, the centrifugal force acting on the flinger 40 can be greatly reduced if the diameter is the same. Can do. 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 is possible to prevent the intrusion into the front bearing 50 by swinging off. Further, since the centrifugal force acting on the annular portion 45 of the flinger 40 is reduced, the opening side (right side in the drawing) of the annular portion 45 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 45 are set long, the length of a labyrinth seal becomes long, and the waterproofing effect improves.

  In addition, the fitting between the flinger 40 and the rotating shaft 11 may be adhesively bonded as a gap fitting with an appropriate gap, or may be an interference fit.

  As described above, the flinger 40 according to the present embodiment is made of a material having a specific gravity smaller than that of the rotary shaft 11 and a larger specific strength, so that the action of centrifugal force is reduced. Thereby, the spindle apparatus 1 can prevent the deformation of the flinger 40 due to centrifugal force while maintaining a good waterproof function and capable of rotating at a high speed with a dmn value of the front bearings 50, 50 of 1 million or more.

  In addition, the flinger 40 of the present embodiment includes a flat portion 43 extending radially outward from the axial front end of the boss portion 42 and an axial direction from the radially outer end of the flat portion 43 toward the radially outer side. And a taper portion 44 extending so as to incline toward the other end side. Here, in order to suppress the stress in the axial direction due to the centrifugal force expansion during the rotation of the flinger 40, it is desirable to increase the taper portion 44 (to make it wide). For example, the flinger 40 has the flat portion 43. It is conceivable that the boss portion 42, the tapered portion 44, and the annular portion 45 are configured. However, as in the present embodiment, the housing H includes the outer cylinder 13 (cylindrical member) in which the outer ring 51 of the front bearing 50 is fitted, and the axial direction of the outer cylinder 13 by the bolt 15 (screw member) extending in the axial direction. When the front bearing outer ring presser 12 (outer ring presser) that is fastened to the front face and positions the outer ring 51 in the axial direction is provided, for example, the space for arranging the bolts 15 is reduced, and the arrangement of the members constituting the spindle tip is arranged. The design will be limited. In such a case, when the bolt 15 is disposed, the axial length of the spindle tip must be increased, and the entire length of the spindle becomes longer. Further, since the location of the front bearing 50 is also shifted to the rear side in the axial direction, the distance between the tool blade edge and the front bearing 50 is increased, the moment load applied to the front bearing 50 is also increased, and the deformation of the main shaft due to cutting is large. There is a risk that problems such as deterioration of the processing accuracy due to a decrease in bearing life and a decrease in rigidity are likely to occur.

However, as described above, the flinger 40 of the present embodiment has the flat surface portion 43 that is orthogonal to the rotation axis on the radially inner side. The cutting characteristics of the spindle device 10 can be improved.
Further, since the flinger 40 has a taper portion 44 on the radially outer side where the centrifugal force is large, the taper portion 44 is deformed in the axial direction during high-speed rotation, so that the surface is extended to the surface extending from the taper portion 44 to the shaft. Stress on the side (radially inward = radial toward the axis of rotation) acts. Since this stress acts as a drag force in the opposite direction to the centrifugal force acting from one end in the axial direction of the boss portion 42 to the flat portion 43 and the tapered portion 44, the centrifugal force can be suppressed. As a result, the internal stress during the rotation of the flinger 40 is reduced, and the radial deformation can be reduced. Therefore, the stress in the axial direction due to the centrifugal force expansion during rotation can be suppressed. As a result, even if the dmn value of the bearings 50 and 60 used for the main shaft (particularly, the dmn value of the front bearing 50 where the flinger 40 is disposed forward) is high speed rotation such as 1 million or more, high waterproof performance is achieved. Can be obtained.
As described above, the cutting characteristics of the spindle device 10 and the performance of the flinger 40 can be ensured at the same time.

  Further, in consideration of both the cutting characteristics of the spindle device 10 and ensuring the performance of the flinger 40, the distance between the radially outer end of the flat portion 43 and the outer peripheral surface of the annular portion 45 and the rotation center of the rotary shaft 11 is It is desirable that (1/2) D ≦ d ≦ (2/3) D be satisfied, where d and D are radial distances, respectively.

  It is more effective to satisfy B <d, where B is the radial distance between the center of the bolt 15 extending in the axial direction and the center of rotation of the rotary shaft 11.

  In addition, this invention is not limited to each embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.

  For example, the flinger 40 is not particularly limited as long as it is made of a material having a specific gravity smaller than that of the rotating shaft 11 and a higher specific strength. For example, a light metal such as aluminum, duralumin, or titanium may be used as the material.

  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.

10 Spindle device 11 Rotating shaft 12 Front bearing outer ring presser (outer ring presser member)
12a Axial front face (one axial end face)
12b Outer peripheral surface 12c Inner peripheral surface 12d Flat surface 12e Tapered surface 13 Outer cylinder (cylindrical member)
13a Outer peripheral surface 15 Bolt (screw member)
16 Nut 40 Flinger 42 Boss (base)
43 Plane portion 44 Taper portion 45 Ring portion 50 Front bearing (bearing)
51 Outer ring 52 Inner ring 53 Ball 54 Outer ring spacer 55 Inner ring spacer H Housing M Motor

Claims (4)

A rotating shaft to which a processing tool is attached on one end side in the axial direction;
A housing that rotatably supports the rotating shaft via a bearing;
A flinger that is fixed to the rotating shaft so as to be integrally rotatable, and has a waterproof function to suppress the ingress of liquid into the bearing;
A spindle device comprising:
The flinger includes a cylindrical base portion fitted on the rotation shaft, a flat portion extending radially outward from one axial end portion of the base portion, and a radial direction from a radially outer end portion of the flat portion. A taper portion extending to be inclined toward the other end side in the axial direction toward the outer side, and an annular portion extending from the radially outer end portion of the taper portion to the other end side in the axial direction. , Made of a material having a smaller specific gravity than the rotating shaft and a larger specific strength,
The flat portion and the tapered portion are arranged to face each other with respect to one axial end surface of the housing via a gap.
The spindle device according to claim 1, wherein the annular portion is disposed to face the outer peripheral surface of the housing in a radial direction with a gap. When the radial distance between the radially outer end portion of the flat portion and the outer peripheral surface of the annular portion and the rotation center of the rotating shaft is d and D, respectively.
2. The spindle apparatus according to claim 1, wherein (1/2) D ≦ d ≦ (2/3) D. The housing is
A cylindrical member into which the outer ring of the bearing is fitted;
An outer ring pressing member fastened to one axial end surface of the outer cylinder by a screw member extending in the axial direction and positioning the outer ring in the axial direction;
Have
When the radial distance between the radially outer end of the flat portion and the center of the screw member and the rotation center of the rotating shaft is d and B, respectively.
The spindle apparatus according to claim 1, wherein B <d. The spindle apparatus according to claim 1, wherein the flinger is made of a fiber-reinforced composite material.

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