JP2014047856A - Spindle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spindle device and a flinger for the spindle device capable of preventing deformation of the flinger due to centrifugal force while keeping high-speed rotating performance of a million or more dmn value of a used bearing and a good water-proofing function.SOLUTION: A metallic member 72 is composed of first and second metallic members 70 and 71, the first metallic member 70 is a spacer having a cylindrical portion 70a extended in the axial direction, and the second metallic member 71 is a spacer extended to the radial outer side with respect to the cylindrical portion 70a, and kept into contact with an axial rear face 70d of the cylindrical portion 70a, and an axial front face of an inner ring 62. The flinger 40 has a cylindrical boss portion 40 externally fitted to the cylindrical portion 70a of the first metallic member 70, and an extended portion 45 extended to the radial outer side from the boss portion 42, and composed of a fiber-reinforced composite material. L>L' is satisfied when L is an axial length of the boss portion 42, and L' is an axial length of an outer peripheral face of the cylindrical portion 70a to which the boss portion 42 is externally fitted.

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;
An annular metal member externally fitted to the rotating shaft;
A flinger that is fixed to the periphery of the metal member 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 metal member is composed of first and second metal members,
The first metal member is a spacer having a cylindrical portion extending in the axial direction,
The second metal member is a spacer that extends radially outward from the cylindrical portion and contacts the other axial end surface of the cylindrical portion and one axial end surface of the inner ring of the bearing,
The flinger has a cylindrical base portion fitted on the cylindrical portion of the first metal member, and an extending portion extending radially outward from the base portion, and is made of a fiber-reinforced composite material.
A spindle device, wherein L> L ′, where L is an axial length of the base and L ′ is an axial length of an outer peripheral surface of the cylindrical portion on which the base is fitted.
(2) 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;
An annular metal member externally fitted to the rotating shaft;
A flinger that is fixed to the periphery of the metal member 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 metal member is composed of first and second metal members,
The first metal member is a spacer having a cylindrical portion extending in the axial direction,
The second metal member extends in the axial direction and has another cylindrical portion that contacts the other axial end surface of the cylindrical portion and one axial end surface of the inner ring of the bearing, and the other axial end of the other cylindrical portion. A flanged spacer having another flange extending radially outward from the side,
The flinger includes a cylindrical base portion that is externally fitted to the cylindrical portion of the first metal member and the other cylindrical portion of the second metal member, and an extending portion that extends radially outward from the base portion. And made of a fiber reinforced composite material,
The length in the axial direction of the base is L, and the sum of the axial lengths of the outer peripheral surfaces of the cylindrical portion of the first metal member and the other cylindrical portion of the second metal member to which the base is fitted. A spindle device characterized by L> L ′ when L ′.
(3) a rotating shaft to which a machining tool is attached on one end side in the axial direction;
A housing that rotatably supports the rotating shaft via a bearing;
An annular metal member externally fitted to the rotating shaft;
A flinger that is fixed around the rotary shaft so as to be integrally rotatable, and has a waterproof function to prevent liquid from entering the bearing;
A spindle device comprising:
The metal member is a spacer having a cylindrical portion that extends in the axial direction and abuts against one axial end surface of the inner ring of the bearing,
The flinger has a cylindrical base portion fitted on the cylindrical portion of the metal member, and an extending portion extending radially outward from the base portion, and is made of a fiber-reinforced composite material.
A spindle device, wherein L> L ′, where L is an axial length of the base and L ′ is an axial length of an outer peripheral surface of the cylindrical portion on which the base is fitted.
(4) When the expansion amounts of the axial lengths of the outer peripheral surfaces of the base and the cylindrical portion due to a predetermined temperature rise are ΔL and ΔL ′, respectively, ΔL′−ΔL <L−L ′. The spindle device according to any one of (1) to (3).
(5) The spindle device according to any one of (1) to (3), wherein 0.1 ≦ L−L ′ ≦ 1 (mm).
(6) The spindle device according to (4), wherein ΔL′−ΔL + 0.1 <L−L ′ <ΔL′−ΔL + 1 (mm).

According to the spindle device described in the above (1) to (3), since the flinger is made of a fiber-reinforced composite material having a relatively low specific gravity, 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, when the axial length of the base portion of the flinger is L and the axial length of the portion where the base portion is fitted is L ′, L> L ′ is set. Therefore, when the bearing inner ring is positioned and fixed by tightening the metal members (first and second) that are the spacers in the axial direction with nuts or the like, an axial fastening force can be applied to the flinger through the spacers. Since it is possible, it is possible to ensure fixation.

  According to the spindle device described in the above (4), the base of the flinger and the inner ring or the inner ring or the difference between the amount of expansion ΔL′−ΔL in the axial direction of the portion where the base and the base of the flinger are externally fitted when the temperature is increased. The large white LL ′ with the second metal member was set large (ΔL′−ΔL <LL−L ′). Therefore, even when the temperature rises due to the rotation of the spindle device, the axial fastening force against the flinger can be maintained, and the occurrence of creep can be prevented.

  According to the spindle device described in (5) above, 0.1 ≦ L−L ′ ≦ 1 (mm) is satisfied with respect to the squeezing LL ′ between the base of the flinger and the inner ring or the second metal member. Since it is set, an appropriate axial fastening force is applied to the flinger, and both creep prevention and deformation prevention can be achieved.

  According to the spindle device described in (6) above, each parameter is set so as to satisfy ΔL′−ΔL + 0.1 <L−L ′ <ΔL′−ΔL + 1 (mm). Even when the temperature rises, an appropriate axial fastening force is applied to the flinger, and it is possible to achieve both prevention of creep and prevention of deformation.

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 a figure which shows the dimension of the flinger and metal member of FIG. It is a figure which shows the dimension of the flinger and metal member which concern on the 1st modification of this invention. It is a figure which shows the dimension of the flinger and metal member which concern on the 2nd modification of this invention. It is a figure which shows the dimension of the flinger and metal member which concern on the 3rd modification of this invention. It is a figure which shows the dimension of the flinger and metal member which concern on the 4th modification of this invention. It is a figure which shows the dimension of the flinger and metal member which concern on the 5th modification of this invention. It is sectional drawing of the flinger which concerns on the 6th modification of this invention.

  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 includes a front bearing outer ring presser 12, an outer cylinder 13, a rear housing 14, and a rear lid 5 in 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.

  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. Inner rings 52, 52 of the front bearings 50, 50 are externally fitted to the rotary shaft 11, and are axially connected to the rotary shaft 11 via the inner ring spacer 55 and the metal member 72 by a nut 16 fastened to the rotary shaft 11. Positioned and fixed in the direction.

  The metal member 72 is made of metal such as SC material, SCM material, SUS material, CU material, and the like. It consists of metal members 70 and 71. The fitting between the rotating shaft 11 and the first and second metal members 70 and 71 may be a clearance fitting or an interference fitting.

  As shown in FIG. 2, the first metal member 70 has a cylindrical portion 70 a that extends in the axial direction and a flange portion 70 b that extends radially outward from the axial front side of the cylindrical portion 70 a. The seat. A radial length of the front surface 70c of the flange portion 70b is set so that the nut 16 and the entire surface come into contact with each other.

  Referring also to FIG. 3, the second metal member 71 is a spacer extending radially outward from the cylindrical portion 70 a of the first metal member 70, and the axial front surface 71 a is the first metal member 70. The axial rear surface 70b contacts the axial rear surface 70d of the cylindrical portion 70a, and the axial rear surface 71b contacts the axial front surface of the inner ring 52.

  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 device 10 of the present embodiment, the flinger 40 is a cylinder of the first metal member 70 on the tool side (left side in the drawing) of the front bearings 50 and 50 so that the machining fluid does not enter the front bearings 50 and 50. By being externally fitted to the portion 70a, it is possible to rotate integrally with the rotary shaft 11. 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.

  The flinger 40 is made of a resin fiber reinforced composite material such as an aramid fiber composite material (AFRP) or a carbon fiber composite material (CFRP), and is a base portion that is externally fitted and fixed to the cylindrical portion 70 a of the first metal member 70. A cylindrical boss portion 42, a disk portion 43 extending radially outward from the axial front end portion of the boss portion 42, and a radially outer end portion of the disk portion 43 from the axially rear side. And an extending portion 45 having an annular portion 44 extending in a ring shape. Note that the configuration of the extending portion 45 extending radially outward from the boss portion 42 is not limited to the one having the disk portion 43 and the annular portion 44 as in the present embodiment, and for example, only by the disk portion 43. It may be configured.

  The boss portion 42 is disposed to face the inner peripheral surface 12c of the front bearing outer ring retainer 12 in the radial direction with a slight gap, and is in contact with the axial rear surface 70e of the flange portion 70b of the first metal member 70. It is positioned in the axial direction by contact. The disc portion 43 is disposed to face the axial front surface 12a of the front bearing outer ring retainer 12 (a front surface in the axial direction of the housing H) with a slight gap, and the axial front surface of the disc portion 43 and the front bearing outer ring retainer 12 is disposed. 12a is made into the taper shape which inclines to an axial direction rear side as it goes to a radial direction outer side. The annular portion 44 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. As described above, the flinger 40 is disposed so as to face the front bearing outer ring presser 12 and the outer cylinder 13 constituting the housing H through a slight axial gap and a radial gap, for example, a gap of about 0.5 mm, so-called labyrinth seal. Configure.

  In particular, an air curtain is formed between the inner peripheral surface of the annular portion 44 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 speed, 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.

  Furthermore, an annular groove 80 is formed in the outer peripheral surface 13a of the outer cylinder 13 so as to be directed radially inward at an axial rear position that does not face the inner peripheral surface of the annular portion 44 in the radial direction. The front end portion in the axial direction of the annular groove 80 and the rear end surface in the axial direction of the annular portion 44 are located on the same plane orthogonal to the rotation shaft 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 reinforced 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 can be swung away to prevent intrusion into the bearing. Further, since the centrifugal force acting on the annular portion 44 of the flinger 40 is reduced, the opening side (right side in the drawing) of the annular portion 44 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 44 are set long, the length of a labyrinth seal becomes long, and the waterproofing effect improves.

  Further, the fitting between the flinger 40 and the first metal member 70 may be adhesively bonded as a gap fitting with an appropriate gap, or may be an interference fit.

Here, as shown in FIG. 3, the flinger 40 and the metal member 72 of the present embodiment have an axial length L of the boss portion 42 of the flinger 40, and the cylindrical portion 70 a to which the boss portion 42 is fitted externally. When the axial length of the outer peripheral surface is L ′, L> L ′ is set. Therefore, when the first metal member 70 is tightened in the axial direction with the nut 16 in a state where the boss portion 42 of the flinger 40 is externally fitted to the outer peripheral surface of the cylindrical portion 70 a of the first metal member 70, the boss of the flinger 40 The portion 42 is fixed in the axial direction with respect to the axial front surface 71 a of the second metal member 71. Therefore, the fastening force in the axial direction is applied to the flinger 40 via the first and second metal members 70 and 71, and the fixation can be strengthened.
In addition, the squeezing LL ′ between the boss portion 42 of the flinger 40 and the second metal member 71 is appropriately set according to the manufacturing accuracy (particularly the axial dimensional accuracy) of each component of the spindle device 1. The

  Further, the shishiro LL ′ between the boss portion 42 of the flinger 40 and the second metal member 71 depends on the size and shape of each component of the spindle device 1, but the flinger 40 does not creep and is a fiber-reinforced composite material. In consideration of a compressive force or the like that does not deform, it is generally 0.1 to 1 mm, preferably 0.1 to 0.5 mm.

  Further, while the spindle device 1 is rotating, the temperature of each component may rise due to heat generated by the motor M or the like. The flinger 40 made of a fiber reinforced composite material (for example, PAN-based CFRP) is used as the first metal member. Since the linear expansion coefficient is smaller than 70, the fastening force in the axial direction with respect to the flinger 40 may be lost. More specifically, when the temperature is raised to an arbitrary temperature, the amount of expansion of the axial length of the boss portion 42 of the flinger 40 is ΔL, and the axial direction of the outer peripheral surface of the cylindrical portion 70 a of the first metal member 70 When the expansion amount of the length is ΔL ′, ΔL <ΔL ′, and the squeeze between the boss portion 42 of the flinger 40 and the second metal member 71 is (L−L ′) − (ΔL′−ΔL). Therefore, when (L−L ′) − (ΔL′−ΔL) ≦ 0, the fastening force in the axial direction with respect to the boss portion 42 of the flinger 40 is lost. Therefore, in the present embodiment, by setting so as to satisfy (L−L ′) − (ΔL′−ΔL)> 0, that is, ΔL′−ΔL <L−L ′, the rotation of the spindle device 1 or the like. Even when the temperature is raised by this, the axial fastening force to the flinger 40 can be maintained, and the occurrence of creep can be prevented.

  Further, considering a compressive force or the like that does not cause the flinger 40 to creep and the fiber-reinforced composite material to be deformed, the squeezing between the boss portion 42 of the flinger 40 and the second metal member 71 when the temperature is raised to an arbitrary temperature. (L−L ′) − (ΔL′−ΔL) is approximately 0.1 to 1 mm, preferably 0.1 to 0.5 mm.

  Further, the disk part 43 of the flinger 40 has a tapered shape that is inclined rearward in the axial direction toward the outer side in the radial direction. Therefore, when the disk part 43 is deformed in the axial direction during high-speed rotation, the disk part 43 The stress on the compression side (radially inward = radial toward the rotation axis) acts on the surface extending to the shaft. Since this stress acts as a drag force in the opposite direction to the centrifugal force acting from one axial end portion of the boss portion 42 to the disk portion 43, 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 axial stress due to the centrifugal force expansion during rotation can be suppressed, and the dmn value of the bearings 50 and 60 used for the main shaft (particularly, the dmn value of the front bearing 50 on which the flinger 40 is disposed forward). ) Can achieve high waterproof performance even at high speed rotation such as 1 million or more.

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

  For example, in the above-described embodiment, the metal member 72 is composed of the first and second metal members 70 and 71. However, as shown in FIG. 4, one metal member, more specifically, A flanged spacer having a cylindrical portion 72a sandwiched between the nut 16 and the front surface in the axial direction of the inner ring 52 of the front bearing 50, and a flange portion 72b extending radially outward from the front side in the axial direction of the cylindrical portion 72a. May be. In this case, the axial length L of the boss portion 42 of the flinger 40 is set to be larger than the axial length L ′ of the outer peripheral surface of the cylindrical portion 72a to which the boss portion 42 is fitted (L>). L ′). Even in this case, when the inner ring 52 is positioned and fixed by tightening the metal member 72 in the axial direction with the nut 16, the squeezing between the boss portion 42 of the flinger 40 and the inner ring 52 is LL ′ ( > 0), and the fastening force in the axial direction can be applied to the flinger 40 via the metal member 72, so that the fixing can be ensured.

  As shown in FIGS. 5 and 6, the disk portion 43 of the flinger 40 may be formed so as to extend linearly in the radial direction and have a substantially flat radial cross section. In this case, the axial front surface 12a of the front bearing outer ring presser 12 (the axial front surface of the housing H) is also formed to have a planar shape extending linearly in the radial direction, and the disk portion 43 and the front bearing outer ring presser are formed. The twelve axial front surfaces 12a are arranged to face each other in the axial direction with a slight gap.

  As shown in FIGS. 7 and 8, as long as the first metal member 70 and the metal member 72 have cylindrical portions 70a and 72a that extend at least in the axial direction and on which the flinger 40 is externally fitted, It is not necessary to have 72b.

  As shown in FIG. 9, the second metal member 71 includes another cylindrical portion 71c that extends in the axial direction and comes into contact with the axial rear surface 70d of the first metal member 70 cylindrical portion 70a, and the cylindrical portion 71c. And a flanged spacer having another flange 71d extending radially outward from the rear side in the axial direction. In this case, the boss portion 42 of the flinger 40 is externally fitted to the cylindrical portions 70a and 71c of the first and second metal members 70 and 71, and is sandwiched between the flange portions 70d and 71d from both sides in the axial direction. Here, the axial length L of the boss portion 42 of the flinger 40 is larger than the total L ′ of the axial lengths L0 and L1 of the outer peripheral surfaces of the cylindrical portions 70a and 71c to which the boss portion 42 is fitted. (L> L ′ = L0 + L1). Even in this case, when the inner ring 52 is positioned and fixed by tightening the first and second metal members 70 and 71 in the axial direction with the nut 16, the boss portion 42 of the flinger 40 and the second metal member 70 and 71 are fixed. The squeeze between the metal member 71 and the flange portion 71d becomes LL ′ (> 0), and an axial fastening force can be applied to the flinger 40 via the metal member 72, so that fixing can be ensured. It is.

  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 retainer 12a Axial front surface (one axial end surface)
12b outer peripheral surface 12c inner peripheral surface 13 outer cylinder 13a outer peripheral surface 16 nut 40 flinger 42 boss part (base part)
43 disk part 44 ring part 45 extension part 50 front side bearing (bearing)
51 outer ring 52 inner ring 53 ball 54 outer ring spacer 55 inner ring spacer 70 first metal member 70a cylindrical portion 70b flange 70c axial front surface 70d axial rear surface (other axial end surface)
70e Axial rear surface 71 Second metal member 71a Axial front surface 71b Axial rear surface 71c Cylindrical portion 71d Eaves portion 72 Metal member 72a Cylindrical portion 72b Elevated portion 72e Axial rear surface H Housing M Motor

Claims (6)

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;
An annular metal member externally fitted to the rotating shaft;
A flinger that is fixed to the periphery of the metal member 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 metal member is composed of first and second metal members,
The first metal member is a spacer having a cylindrical portion extending in the axial direction,
The second metal member is a spacer that extends radially outward from the cylindrical portion and contacts the other axial end surface of the cylindrical portion and one axial end surface of the inner ring of the bearing,
The flinger has a cylindrical base portion fitted on the cylindrical portion of the first metal member, and an extending portion extending radially outward from the base portion, and is made of a fiber-reinforced composite material.
A spindle device, wherein L> L ′, where L is an axial length of the base and L ′ is an axial length of an outer peripheral surface of the cylindrical portion on which the base is fitted. 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;
An annular metal member externally fitted to the rotating shaft;
A flinger that is fixed to the periphery of the metal member 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 metal member is composed of first and second metal members,
The first metal member is a spacer having a cylindrical portion extending in the axial direction,
The second metal member extends in the axial direction and has another cylindrical portion that contacts the other axial end surface of the cylindrical portion and one axial end surface of the inner ring of the bearing, and the other axial end of the other cylindrical portion. A flanged spacer having another flange extending radially outward from the side,
The flinger includes a cylindrical base portion that is externally fitted to the cylindrical portion of the first metal member and the other cylindrical portion of the second metal member, and an extending portion that extends radially outward from the base portion. And made of a fiber reinforced composite material,
The length in the axial direction of the base is L, and the sum of the axial lengths of the outer peripheral surfaces of the cylindrical portion of the first metal member and the other cylindrical portion of the second metal member to which the base is fitted. A spindle device characterized by L> L ′ when L ′. 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;
An annular metal member externally fitted to the rotating shaft;
A flinger that is fixed around the rotary shaft so as to be integrally rotatable, and has a waterproof function to prevent liquid from entering the bearing;
A spindle device comprising:
The metal member is a spacer having a cylindrical portion that extends in the axial direction and abuts against one axial end surface of the inner ring of the bearing,
The flinger has a cylindrical base portion fitted on the cylindrical portion of the metal member, and an extending portion extending radially outward from the base portion, and is made of a fiber-reinforced composite material.
A spindle device, wherein L> L ′, where L is an axial length of the base and L ′ is an axial length of an outer peripheral surface of the cylindrical portion on which the base is fitted. When the expansion amounts of the axial lengths of the outer peripheral surfaces of the base portion and the cylindrical portion due to a predetermined temperature increase are ΔL and ΔL ′, respectively, ΔL′−ΔL <L−L ′. Item 4. The spindle device according to any one of Items 1 to 3. The spindle device according to claim 1, wherein 0.1 ≦ L−L ′ ≦ 1 (mm). 5. The spindle device according to claim 4, wherein ΔL′−ΔL + 0.1 <L−L ′ <ΔL′−ΔL + 1 (mm).

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