JP2005161457A - Main spindle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a main spindle device having the damping function capable of effectively absorbing its vibrational energy even in a little amplitude by vibration. <P>SOLUTION: This main spindle device 10 has a freely rotatable rotary shaft 11, a fixed side bearing 12 having an inner ring 13 fitted around one end of the rotary shaft 11 and having an outer ring 14 fixed to a housing 16, a sleeve 16 arranged on the other end side of the rotary shaft 11, inserted into the housing 16 and movable in the shaft direction of the rotary shaft 11, and an anti-fixed side bearing 17 having an inner ring 18 fitted around the other end of the rotary shaft 11, having an outer ring 19 fixed to the sleeve 16 and preloaded with constant pressure. Silicon oil having a coefficient of kinetic viscosity of 5,000 to 30,000 mm<SP>2</SP>/s of oil at 40°C, is applied to an outer diameter of the sleeve 16. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a spindle device that rotates at high speed, such as a machine tool.

  As an example of a conventional spindle apparatus, a spindle apparatus is known in which a damping characteristic is given to a sleeve to improve vibration characteristics. Such a spindle device has a damping characteristic better than that of its constituent material after a predetermined preload is applied to a bearing that supports the spindle by a preload setting means including a hydraulic cylinder device or the like. It is held by preload holding means such as pressure oil at a constant pressure (see, for example, Patent Document 1).

As another example of a conventional spindle device, there is known a spindle device that suppresses vibration of a sleeve using friction. Such a spindle device includes a housing, a front bearing mounted inside the front side of the housing, a sleeve mounted inside the rear side of the housing so as to be movable within a predetermined range in its axial direction, and a sleeve inside the front side of the sleeve. A rear bearing mounted so as to be movable integrally, a shaft rotatably supported through a front bearing and a rear bearing inside the housing, and a preload for applying a preload in the axial direction to the rear bearing In a preload type spindle having a spring, vibration prevention is provided integrally with the rear bearing of the sleeve and the housing at a position spaced apart in the axial direction, and performs vibration preventing action at equal intervals on the circumference or on the entire circumference. Means are provided (see, for example, Patent Document 2).
JP-A-5-177406 Japanese Patent Laid-Open No. 10-238538

By the way, normally, the main shaft device of constant pressure preload has a structure in which the non-fixed-side bearing slides in the axial direction in order to keep the preload of the bearing constant. At that time, a bearing sleeve is often used so that the bearing is not tilted and caught.
In this case, since the bearing sleeve is slid to make the preload constant, the problem is that vibration tends to occur. Furthermore, even if the same preload is applied, the axial rigidity of the shaft is substantially halved even when the same preload is applied as compared with the fixed position preload spindle device, so that the axial resonance point is lowered and vibration is likely to occur. Therefore, as described in Patent Document 1 and Patent Document 2, a method of reducing the vibration by providing a damping characteristic has been proposed.

  The amount of displacement that the sleeve vibrates in the spindle device that rotates at high speed is actually several μm even at the resonance point of the sleeve, and this vibration of several μm is a problem. In the case of a spindle device for a machine tool, problems such as chattering, degradation of the quality of the machined surface, and increase in noise occur. It has been difficult to effectively reduce the vibration by giving damping characteristics to such a vibration of only a few μm.

  In the above Patent Document 1, when the bearing case vibrates, it is expected that the vibration is damped by the damping characteristic in the cylinder chamber. However, since the oil in the cylinder behaves elastically, the vibration energy is actually reduced. The amount absorbed is small and does not reliably dampen vibration.

  In Patent Document 2, the vibration amplitude is small, and the friction plate elastically supports the sleeve. As a result, it may not be a damping element.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a spindle device having a damping function capable of effectively absorbing vibration energy even with a small vibration amplitude. .

1) A main shaft device according to the present invention includes a rotatable rotating shaft, an inner ring fitted on one end of the rotating shaft, a fixed bearing having an outer ring fixed to a housing, and the other end of the rotating shaft. A sleeve inserted in the housing and movable in the axial direction of the rotating shaft; an inner ring is fitted on the other end of the rotating shaft; an outer ring is fixed to the sleeve and is preloaded at a constant pressure; And a non-fixed side bearing that rotatably supports the rotating shaft, and the outer diameter of the sleeve has a kinematic viscosity at 40 ° C. of 5000 to 30000 mm ² / s. It is characterized in that a certain silicone oil is applied.

According to the spindle device having the above-described configuration, the damping property is obtained by the silicon oil having a high viscosity and a kinematic viscosity at 40 ° C. of 5000 to 30000 mm ² / s applied to the outer diameter of the sleeve.

Therefore, when the sleeve vibrates, shear resistance is generated due to the viscosity of the oil intervening between the outer diameter of the sleeve and the clearance of the housing. However, as a result of calculations and tests, the movement necessary for actually reducing the vibration as the main spindle system is generated. The viscosity was found to be over 5000 mm ² / s. It was also found that the kinematic viscosity should be less than 30000 mm ² / s because the dynamic vibration model changes and another resonance point appears when the viscosity is increased more than necessary. Silicon oil has been found to be suitable for realizing these properties. As a result, it is possible to provide a spindle device having a damping function capable of effectively absorbing vibration energy even with a small vibration amplitude.

  Examples of silicone oil include dimethicone copolyol, which is a modified silicone having surface activity from dimethylpolysiloxane, dimethicone, or silicon rubber. Silicone oil has high viscosity, high density and flat temperature viscosity characteristics (for example, VI value of 120 or more), so there is no sudden increase in viscosity even at low temperatures in winter, and high temperature due to heat generation during use. Since there is little decrease in viscosity, there is little change in the damping characteristics and it can be used under a wide range of temperature conditions.

  2) The main shaft device of the present invention is arranged on a rotatable rotating shaft, an inner ring is fitted on one end of the rotating shaft, a fixed bearing having an outer ring fixed to a housing, and the other end of the rotating shaft. A sleeve inserted in the housing and movable in the axial direction of the rotating shaft, an inner ring is fitted on the other end of the rotating shaft, an outer ring is fixed to the sleeve and is preloaded at a constant pressure, and the fixed bearing And a non-fixed side bearing that rotatably supports the rotating shaft, wherein the sleeve is provided with an elastically supported mass member. .

  According to the spindle device having the above-described configuration, vibration is absorbed by using a dynamic vibration absorber as the mass member. In this way, it is possible to absorb the energy by vibrating the mass added to the sleeve, instead of directly giving the damping between the sleeve and the housing as in the prior art. By appropriately designing this dynamic vibration absorber, it is possible to absorb vibration energy by increasing the vibration amplitude of only the additional mass. Since the amplitude of the additional mass is larger than the vibration amplitude of the sleeve, this vibration energy can be easily absorbed by the damper. As a result, vibration can be reliably absorbed without sacrificing the sliding characteristics of the sleeve at all.

  According to the present invention, it is possible to solve the problem that the vibration cannot be reliably damped as in the prior art, and thereby it is possible to effectively absorb the vibration energy even with a small vibration amplitude. Can be provided.

  Hereinafter, a plurality of preferred embodiments according to the present invention will be described in detail with reference to the drawings. 1 is a cross-sectional view showing a first embodiment of a spindle device according to the present invention, FIG. 2 is an axial vibration model of the spindle device shown in FIG. 1, and FIG. 3 is a diagram showing the magnitude of vibration when the kinematic viscosity of oil is changed. Fig. 4 is a graph showing the frequency response characteristics of the axial vibration of the shaft, Fig. 5 is a graph showing the relationship between the kinematic viscosity and temperature of the oil, and Fig. 6 is a measurement value of the axial vibration of the sleeve when the spindle device is rotated. It is a graph.

  7 is a sectional view showing a second embodiment of the spindle device according to the present invention, FIG. 8 is an axial vibration model of the spindle device shown in FIG. 7, and FIG. 9 is an analysis result of vibration characteristics in the spindle device shown in FIG. It is a table.

As shown in FIG. 1, the main spindle device 10 according to the first embodiment of the present invention includes a rotatable rotating shaft (hereinafter also simply referred to as a shaft) 11 and inner rings 13, 13 at one end of the rotating shaft 11. The outer rings 14 and 14 are fitted to the fixed bearings 12 and 12 fixed to the housing 15 and the other end of the rotary shaft 11. The outer rings 14 and 14 are inserted into the housing 15 and movable in the axial direction of the rotary shaft 11. A sleeve (rear sleeve) 16 and inner rings 18, 18 are fitted on the other end of the rotary shaft 11, and outer rings 19, 19 are fixed to the sleeve 16 and constant pressure preloaded and cooperate with the fixed bearings 12, 12. The spindle device 10 includes anti-fixed bearings 17 and 17 that rotatably support the rotary shaft 11, and the outer diameter of the sleeve 16 has a kinematic viscosity at 40 ° C. of 5000 to 30000 mm ² / s. Some silicone oil is applied.

  The housing 15 includes an inner housing 24, an outer cylinder 21, a rear sleeve housing 22, and a rear cover 23.

  The front cover 20 is disposed at the front end. The outer cylinder 21 is formed in a cylindrical shape, and is externally fitted to an inner housing 24 in which the front fixed side bearings 12 and 12 are fitted. The stator 25 of the built-in motor is fixed to the inner peripheral part. . Lubricating oil nozzles 26, 26 are assembled in the inner housing 24. The stator 25 is supplied with a predetermined current from a motor power line (not shown), thereby generating a rotating magnetic field in the inner periphery.

  The rear sleeve housing 22 is formed in a cylindrical shape, and is externally inserted into the rear sleeve 16 that is externally fitted to the non-fixed side bearings 17 and 17. The rear case 23 is disposed at the rear end.

  The rotary shaft 11 includes a draw bar 27, and the draw bar 27 moves forward and backward against the return spring 28 to clamp or unclamp a tool (not shown). Further, the rotary shaft 11 fixes the rotor 29 of the built-in motor to the inner peripheral portion of the stator 25 in a non-contact manner. The rotor 29 is rotated by the rotating magnetic field generated by the stator 25 and rotates the rotating shaft 11.

  The fixed-side bearings 12 and 12 use ceramic ball angular bearings with an inner diameter of 65 mm in a parallel combination, the inner rings 13 and 13 are fitted on the front end side of the rotary shaft 11, and the outer rings 14 and 14 are fitted on the front sleeve 24. It is fitted.

  The anti-fixed bearings 17 and 17 use ceramic ball angular bearings with an inner diameter of 55 mm in parallel combination as in the fixed bearings 12 and 12, and the inner rings 18 and 18 are fitted on the rear end side of the rotary shaft 11. The outer rings 19 are fitted into the rear sleeve 26.

  The rear sleeve 16 is extrapolated to the outer rings 19 and 19 of the anti-fixed side bearings 17 and 17, and the lubricating oil nozzles 30 and 30 are assembled. The rear sleeve 16 is assembled to a slide surface 32 with the rear sleeve housing 22 via O-rings 31 and 31. The rear sleeve 16 is assembled with a preload piston 34 having a preload spring 33 built in via a holder 35 on the rear side.

  Here, the preload is loaded by pressing the rear sleeve 16 to the right side in FIG. Further, by applying hydraulic pressure from a preload hydraulic inlet 36 provided in the rear cover 23 by an external device (not shown), the preload piston 34 can be pushed rightward in FIG. 1 to apply preload. In this case, the preload can be controlled from the outside.

  A diameter clearance between the inner diameter of the rear sleeve housing 22 and the outer diameter of the rear sleeve 16 is about 35 μm. This size ensures that a clearance is secured and slides even under temperature conditions during rotation of the spindle device 10 (the temperature of the rear sleeve housing 22 does not increase so much even when the rear sleeve 16 becomes hot). Is a possible value.

  In the built-in motor type spindle device 10 that rotates at high speed, the setting value of the diameter clearance is preferably 1/5000 to 1/3000 of the diameter of the rear sleeve 16, and if the clearance is too small, it slides due to thermal expansion. On the other hand, if the clearance is too large, it vibrates not only in the axial direction but also in the radial direction.

  The slide surface 32 is subjected to surface treatment in order to prevent wear and fretting. In this case, hard chrome plating is applied. In order to obtain the same effect, the slide surface 32 can be subjected to electroless nickel plating or the surface hardness can be increased by induction hardening.

The slide surface 32 is coated with silicon oil having a kinematic viscosity at 40 ° C. of 10,000 mm ² / s. The O-rings 31 and 31 have a function of sealing so that silicon oil applied to the slide surface 32 does not escape to the outside.

As shown in FIG. 2, in the axial vibration model, the main shaft device 10 includes two spring elements of fixed side bearings 12 and 12 and anti-fixed side bearings 17 and 17, a rotating shaft 11 and a rear sleeve (sleeve) 16. It can be regarded as a vibration model of a two-degree-of-freedom system having two masses.
The condition in this case is
Rotating shaft mass approx. 15 kg
Rear sleeve mass approx. 6kg
Fixed side bearing axial rigidity 50 N / μm
Anti-fixed side bearing axial rigidity 50N / μm
It is.
The axial stiffness of the bearing was calculated from the balance conditions such as centrifugal force and elastic proximity of the balls (rolling elements) with a preload of 1000 N and a rotational speed of 40000 min ⁻¹ .
When the resonance frequency is calculated using this model,
Resonance frequency = 13000min ^-1 (primary), 35000min ^-1 (secondary)
Thus, there is a resonance point below the maximum rotation speed of 40000 min ⁻¹ . In particular, since the secondary resonance point exists near the maximum rotation speed, the vibration energy becomes large, which is a problem. This can be said in general for a spindle device of constant pressure preload that rotates at a high speed, and it is necessary to devise a method for reducing vibration at a resonance point on the high speed side.
Further, a damping element D is provided between the rear sleeve housing (fixed) 22 and the rear sleeve 16. The damping constant can be approximated as follows by assuming that the rear sleeve 16 floats in the center of the axis of the rear sleeve housing 22 and the oil present in the clearance is a Newtonian fluid.
C = ρνA / dr
C: Damping constant N / (m / s)
dr: Radius clearance m
ρ: Oil specific gravity kg / m ³
ν: Oil viscosity m ² / s
A: Rear sleeve outer diameter area m ²

As shown in FIG. 3, in the axial vibration model of FIG. 2, the degree of vibration at 35000 min ⁻¹ (axial resonance point) when the kinematic viscosity of oil at 40 ° C. was changed was calculated. In the results, the amplitude ratio of the rotating shaft 11 is used to indicate the degree of the magnitude of vibration, and the vibration amplitude of the rotating shaft 11 at infinite attenuation is 1. It can be seen that when the kinematic viscosity of the oil is about 5000 mm ² / s or more, the vibration control effect appears without increasing the amplitude at the resonance point of 35000 min ⁻¹ .

Further, when the damping element is very large, the rear sleeve 16 can be dynamically considered as being fixed, and can be regarded as a vibration model of a one-degree-of-freedom system, and another resonance point appears (for example, 100000 mm ² / s).
Peak around 40Hz). Since the rolling bearing itself cannot be expected to be greatly damped, vibration will be large at this resonance point.

As shown in FIG. 4, the frequency response of the axial vibration of the shaft was calculated using the damping constant of the rear sleeve 16 as a parameter.
As a result of calculation, it was found that the optimum viscosity for suppressing vibration is about 15000 mm ² / s, and that a damping effect having no practical problem can be obtained in the range of 5000 to 30000 mm ² / s.
In order to have generality due to the difference in size, it is a dimensionless number.
Attenuation ratio = C / √ (m · k)
m: Mass of rear sleeve k: When the anti-fixed side bearing spring constant is used, a damping ratio of about 0.6 to 3.5 is a good range. In addition, considering the size effect of the spring constant of the bearing, the area and mass of the rear sleeve, the clearance, etc., it can be seen that the damping ratio is approximately proportional to the kinematic viscosity of the oil for the main shaft with a rotating shaft diameter of φ30 to φ120 mm. A viscosity range of 5000-30000 mm ² / s was found to be effective.

As shown in FIG. 5, when the relationship between the kinematic viscosity and the temperature of the oil was examined, silicone oil was another synthetic oil, VG680 (680 mm ² / s at kinematic viscosity (40 ° C.), viscosity range 612 to 748), etc. The change in kinematic viscosity with respect to the change in temperature is small compared to the ISO grade. The spindle device 10 is assumed to have a working temperature from about −10 ° C. at the start in winter to about 60 ° C., which is a steady temperature of 40000 min ⁻¹ . As is clear from FIG. 4, since the vibration characteristics change when the viscosity changes, it can be seen that silicone oil with little change in viscosity is suitable.

As shown in FIG. 6, in the result of measuring the axial vibration value of the rear sleeve 16 when the spindle device 10 is actually rotated, the vibration value when VG680 is applied is listed as a comparative example.
As a result of measurement, it was found that vibration can be actually suppressed by using silicon oil having a kinematic viscosity at 40 ° C. of 10,000 mm ² / s.

According to the spindle device 10 of the first embodiment, the damping property is achieved by the silicon oil having a high viscosity and a kinematic viscosity at 40 ° C. of 5000 to 30000 mm ² / s applied to the outer diameter of the rear sleeve 16. It has gained. Accordingly, when the rear sleeve 16 vibrates, shear resistance is generated due to the viscosity of the oil interposed in the clearance between the outer diameter of the rear sleeve 16 and the rear sleeve housing 22, but as a result of calculation and test, the actual main shaft system is obtained. It was found that the kinematic viscosity of the oil at 40 ° C required to reduce vibrations was 5000 mm ² / s or more. Also, if the viscosity is higher than necessary, the dynamic vibration model changes and another resonance point appears, so the kinematic viscosity of the oil at 40 ° C must be less than 30000 mm ² / s. It was. Silicon oil has been found to be suitable for realizing these properties. As a result, it is possible to provide a spindle device having a damping function capable of effectively absorbing vibration energy even with a small vibration amplitude.

  Next, a second embodiment of the spindle device according to the present invention will be described with reference to FIG. 7, FIG. 8, and FIG. Note that in the second embodiment, members and the like having the same configurations and functions as those already described are denoted by the same or corresponding reference numerals in the drawing, and the description thereof is simplified or omitted.

  As shown in FIG. 7, in the spindle device 40 of the second embodiment, the rotatable rotating shaft 11 and the inner rings 13 and 13 are fitted on one end of the rotating shaft 11, and the outer rings 14 and 14 are fixed to the housing 15. The fixed bearings 12 and 12, the other end of the rotating shaft 11, the sleeve (rear sleeve) 16 that is inserted in the housing 15 and movable in the axial direction of the rotating shaft 11, and the inner rings 18 and 18 Is externally fitted to the other end of the rotating shaft 11, the outer rings 19, 19 are fixed to the sleeve 16, are preloaded with constant pressure, and work together with the fixed side bearings 12, 12 to support the rotating shaft 11 in a freely rotating manner. The main shaft device 40 includes side bearings 17 and 17, and a sleeve 16 is added with a mass member 41 that is elastically supported.

  The mass member 41 is made of metal and is attached to the rear sleeve 16 as an additional mass via an O-ring 42 and a resin rod 43, and is adjusted so that the axial rigidity of the resin rod 43 becomes a designed spring constant. Has been. The mass member 41 is press-fitted and fixed to the flange portion α of the resin rod 43, and the spring mass system is configured by the l-part elasticity of the resin rod 43. Enclosed oil such as grease is applied around the resin rod 43 of the rod 43 to form a damping element.

The order of the spring constant is 1 N / μm, but in addition to using the resin rod 43, it can be specifically configured by using Hertz contact of a ball (such as a ball bearing). The attenuator is composed of an O-ring and sealed oil. The damping constant can be adjusted experimentally by performing frequency analysis in advance with a dynamic vibration absorber alone.
In the spindle device 40, since there is no resistance O-ring on the outer diameter of the rear sleeve 16, and only grease is applied, slidability is emphasized. Thereby, a preload load can be applied precisely and a highly accurate spindle device can be configured. In such a configuration, vibration has been increased conventionally, but vibration can be suppressed without sacrificing slidability.

  As shown in FIG. 8, in the axial vibration model of the spindle device 40, a dynamic vibration absorber 44 is attached to the rear sleeve 16. Therefore, by appropriately designing the additional mass, the spring, and the damping element, it is possible to vibrate only the additional mass to absorb energy and control the vibration of the rear sleeve 16 and the rotating shaft 11.

  Compared with the main shaft device 10, the main shaft device 40 eliminates the need to insert a damping element directly between the rear sleeve 16 and the rear sleeve housing 22, and can be designed with an emphasis on the slidability of the rear sleeve 16. is there. In the spindle device 10, the O-rings 31 and 31 are used to hold the silicon oil. However, if the O-ring is used, the O-ring has sliding resistance, so that the preload applied to the bearing is equal to the sliding resistance. May fluctuate and hinder precise preload control. On the other hand, in the main shaft device 40, only the sliding property needs to be considered between the rear sleeve 16 and the rear sleeve housing 22, and the damping can be performed by the dynamic vibration absorber 44.

  As shown in FIG. 9, the vibration characteristics when the dynamic vibration absorber 44 having an additional mass of 1 kg, a spring of 0.5 N / μm, and an attenuator C = 1000 N / (m / s) are attached to the spindle device 10. When the analysis result shows the ratio of axial axial displacement when a vibration external force is applied to the rotary shaft 11 (static value is 1), the values of no dynamic vibration absorber and that with dynamic vibration absorber are compared. It can be seen that the vibration absorber 44 can reliably reduce vibration.

  According to the spindle device 40 of the second embodiment, vibration is absorbed by using the dynamic vibration absorber 44 as the mass member 41. In this case, the energy can be absorbed by vibrating the mass added to the sleeve, instead of directly giving the damping between the sleeve and the housing as in the prior art. By appropriately designing the dynamic vibration absorber 44, it is possible to increase the vibration amplitude of only the additional mass and absorb the vibration energy. Since the amplitude of the added mass is large, this vibration energy can be easily absorbed by the damper. As a result, vibration can be reliably absorbed without sacrificing the sliding characteristics of the sleeve at all.

The spindle device according to the present invention is not limited to the above-described embodiment, and appropriate modifications and improvements can be made.
For example, the bearing is not limited to a ceramic ball angular bearing, and various rolling bearings such as a deep groove ball bearing may be applied.

It is sectional drawing which shows 1st Embodiment of the main axis | shaft apparatus which concerns on this invention. 2 is an axial vibration model of the spindle device shown in FIG. 1. It is the graph which investigated the magnitude | size of the vibration at the time of changing the kinematic viscosity of oil in the main shaft apparatus shown in FIG. FIG. 2 is a frequency response characteristic diagram of axial vibration of the spindle in the spindle apparatus shown in FIG. 1. It is a graph which shows the relationship between the kinematic viscosity of oil and temperature in the main shaft apparatus shown in FIG. It is a graph of the axial vibration measured value of a sleeve when rotating the spindle apparatus shown in FIG. It is sectional drawing which shows 2nd Embodiment of the main axis | shaft apparatus which concerns on this invention. 8 is an axial vibration model of the spindle device shown in FIG. 7. It is an analysis result table | surface of the vibration characteristic in the main shaft apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,40 Main shaft apparatus 11 Rotating shaft 12 Fixed side bearing 13 Inner ring 14 Outer ring 16 Rear side sleeve (sleeve)
17 Anti-fixed side bearing 18 Inner ring 19 Outer ring 21 Outer cylinder (housing)
22 Rear sleeve housing (housing)
41 Mass members

Claims (2)

A rotatable axis of rotation,
A fixed-side bearing in which an inner ring is fitted on one end of the rotating shaft and an outer ring is fixed to the housing;
A sleeve disposed on the other end side of the rotating shaft, inserted in the housing and movable in the axial direction of the rotating shaft;
An anti-fixed side bearing in which an inner ring is externally fitted to the other end of the rotating shaft, an outer ring is fixed to the sleeve and constant pressure preloaded, and cooperates with the fixed side bearing to rotatably support the rotating shaft;
A spindle device comprising:
A main spindle device characterized in that silicon oil having a kinematic viscosity at 40 ° C. of 5000 to 30000 mm ² / s is applied to the outer diameter of the sleeve. A rotatable axis of rotation,
A fixed-side bearing in which an inner ring is fitted on one end of the rotating shaft and an outer ring is fixed to the housing;
A sleeve disposed on the other end side of the rotating shaft, inserted in the housing and movable in the axial direction of the rotating shaft;
An anti-fixed side bearing in which an inner ring is externally fitted to the other end of the rotating shaft, an outer ring is fixed to the sleeve and constant pressure preloaded, and cooperates with the fixed side bearing to rotatably support the rotating shaft;
A spindle device comprising:
A main shaft device characterized in that a mass member elastically supported by the sleeve is added.

Images