JP6597125B2 - Spindle device - Google Patents

Description

  The present invention relates to a spindle device.

  For example, Patent Document 1 discloses a main shaft device that suppresses chatter vibration of a main shaft during processing by supporting the radial direction of the main shaft with a rolling bearing arranged on the tool side of the main shaft and a hydrostatic bearing with damping properties. Has been.

Japanese Patent No. 555067

  Since the above-mentioned hydrostatic bearing is disposed near the main shaft, heat from the shear heat generation of the fluid of the hydrostatic bearing is transmitted to the main shaft, and a large thermal displacement may occur in the main shaft. Further, there is a problem that the space for collecting the fluid of the hydrostatic bearing is reduced, and the reliability of rotation of the main shaft cannot be ensured.

  It is an object of the present invention to provide a spindle device that can suppress thermal displacement of the spindle and can ensure the reliability of rotation of the spindle.

A spindle device according to the present invention includes a housing, a cylindrical main body portion that holds a rotary tool, and a main shaft that includes a flange portion that projects radially outward from the outer peripheral surface of the main body portion on the rotary tool side, A bearing that rotatably supports the outer peripheral surface of the main body with respect to the housing; and a flange that rotatably supports the housing with respect to the housing, and is disposed outside the radial position of the bearing. A viscoelastic bearing having a damping coefficient larger than the damping coefficient of the bearing, and the flange portion extends radially outward from the outer peripheral surface of the main body portion, and the disk portion a flange portion extending axially from an outer peripheral edge, Ru comprising a.

Thus, since the viscoelastic bearing is provided in the flange portion that projects radially outward from the outer peripheral surface of the main body portion of the main shaft on the rotary tool side, the heat transfer path of the shear heat generation of the fluid of the viscoelastic bearing with respect to the main shaft is provided. become longer. Therefore, the main shaft is hardly affected by the shear heat generation of the fluid, and can suppress the thermal displacement of the main shaft, and can suppress the chatter vibration of the main shaft caused by the deterioration of machining accuracy and the fluctuation of the rotation balance due to the thermal displacement of the main shaft. In addition, since a space for collecting the fluid of the viscoelastic bearing can be secured on the inner peripheral surface of the housing facing the flange portion, the reliability of rotation of the main shaft can be secured, and high-precision machining can be maintained. The flange portion 63 has a large heat capacity and can sufficiently absorb the shear heat generated by the fluid of the hydrostatic bearings 70, 170, and 270.

It is an axial sectional view of the spindle device in the first embodiment of the present invention. It is an enlarged view which shows arrangement | positioning of the hydrostatic bearing of FIG. It is an enlarged view which shows the 1st another example of arrangement | positioning of a hydrostatic bearing. It is an enlarged view which shows the 2nd another example of arrangement | positioning of a hydrostatic bearing. It is an enlarged view which shows arrangement | positioning of the hydrostatic bearing when not providing the cap of FIG. It is an axial sectional view of the spindle device in the second embodiment of the present invention. It is an enlarged view which shows arrangement | positioning of the hydrostatic bearing of FIG. It is sectional drawing which shows the 1st example of the ceramic coating of the flange part of FIG. It is sectional drawing which shows the 2nd example of the ceramic coating of the flange part of FIG. It is sectional drawing which shows the 3rd example of the ceramic coating of the flange part of FIG. It is an enlarged view which shows the cooling part of the 1st example provided in the housing and cap of FIG. It is an enlarged view which shows the cooling part of the 2nd example provided in the housing and cap of FIG.

(First embodiment)
(1. Overall configuration of the spindle device)
Hereinafter, a first embodiment of the spindle device of the present invention will be described with reference to the drawings. The configuration of the spindle device will be described with reference to FIG. As shown in FIG. 1, the main shaft device 1 includes a housing 10, a main shaft 20, a motor 30, a support device 40, and a cap 50 (corresponding to a “shielding member” of the present invention). In the description of the spindle device 1, the left side in FIG. 1 where the rotary tool 21 is held is referred to as the front side, and the right side in FIG. 1 is referred to as the rear side.

  The housing 10 is formed in a hollow cylinder shape through which the main shaft 20 can be inserted. The motor 30 includes a stator 31 that is disposed in a cylinder of the housing 10 and is fixed to the housing 10 and a rotor 32 that is fixed to the main shaft 20. The support device 40 rotatably supports the main shaft 20 with respect to the housing 10. The support device 40 includes a hydrostatic bearing 70 (corresponding to “viscoelastic bearing” of the present invention), rolling bearings 81 to 85 (corresponding to “bearing” of the present invention), and an outer ring support 90.

  The main shaft 20 includes a main body portion 61 and a flange portion 63. The main body 61 is formed in a cylindrical shape, and holds the rotary tool 21 held by the holder 22 on the front side (left side in FIG. 1). And the inner ring | wheel of the rolling bearings 81-85 is engaged with the outer peripheral surface of the main-body part 61. FIG. The flange portion 63 is formed so as to project radially outward from the outer peripheral surface of the main body portion 61 on the rotary tool 21 side. A hydrostatic bearing 70 is disposed on the outer peripheral surface of the flange portion 63.

  In the drawing, the main body 61 is divided into two parts on the front side of the rolling bearing 81 and joined by a not-shown bolt, and the flange part 63 is a front part of the main body 61, that is, two parts shown in FIG. A portion on the inner diameter side of the dotted line L2 (hereinafter referred to as “boss portion 62”) and one member (the flange portion 63 and the boss portion 62 are one member). Since such a shape is determined from the viewpoint of manufacturing and maintenance, the main body 61 (rear side) and the flange 63 are formed of two members as shown in FIG. May be.

  The flange portion 63 includes a disc portion 64 that extends radially outward from an outer peripheral surface that is a predetermined distance away from the front end surface of the boss portion 62 (main body portion 61) in the axial rear direction, and an axial direction from the outer peripheral edge of the disc portion 64. And an eaves portion 65 extending in the direction. The flange portion 65 is a portion on the front side of the alternate long and short dash line L1 shown in FIG. 2, and the disc portion 64 is a portion on the housing 10 side of the two-dot chain line L2 shown in FIG. Since the flange portion 65 is formed so as to extend forward in the axial direction, a path (member) through which heat is transmitted from the flange portion 65 to the rotary tool 21 (holder 22) can be lengthened, and heat generated from the flange portion 65. Is difficult to convey to the rotary tool 21. In addition, the flange portion 65 is a separate member from the disc portion 64 but is integrally coupled.

  The hydrostatic bearing 70 is disposed between the housing 10 and the main shaft 20 in the radial direction and outside the rolling bearings 81 to 84 (including the radial position and outward) beyond the radial position. The hydrostatic bearing 70 supports a portion of the outer peripheral side of the flange portion 65 on the disk portion 64 side with respect to the housing 10. The hydrostatic bearing 70 supplies the main shaft 20 to the housing 10 with a predetermined damping coefficient C and a predetermined spring constant k when a fluid such as oil is supplied to each hydraulic pocket 71 described later at a predetermined flow rate. It functions as a bearing that supports the main shaft 20 in the radial direction.

  The predetermined damping coefficient C set by the hydrostatic bearing 70 is set to be larger than the damping coefficients that the rolling bearings 81 to 84 have. Moreover, the predetermined spring constant k set by the hydrostatic bearing 70 is set to be smaller than the spring constants of the rolling bearings 81 to 84, respectively. The hydrostatic bearing 70 suppresses the vibration of the main shaft 20 (the rotating tool 21) by a damping effect and a spring effect generated by adding a predetermined damping coefficient C and a predetermined spring constant k.

  In the rolling bearings 81 to 84, the outer ring is supported by a cylindrical outer ring support 90, and the inner ring is engaged with the outer peripheral surface of the main body 61 of the main shaft 20. That is, the rolling bearings 81 to 84 rotatably support the main shaft 20 with respect to the housing 10 and the outer ring support 90. For example, ball bearings are applied to the rolling bearings 81 to 84, and the rolling bearings 81 to 84 are arranged on the rotating tool 21 side (front side) from the motor 30. Any ball bearing may be used, and for example, an angular ball bearing that applies a preload in the axial direction of the main shaft 20 may be used.

  On the other hand, the rolling bearing 85 rotatably supports the main shaft 20 with respect to the housing 10. The rolling bearing 85 is, for example, a roller bearing, and is disposed on the opposite side (rear side) of the rotary tool 21 from the motor 30. That is, the rolling bearings 81 to 84 and the bearing 85 are arranged so as to sandwich the motor 30 at the center in the axial direction of the main shaft 20.

  The cap 50 is a cylindrical member, and the inner peripheral surface of the cap 50 is formed on the outer peripheral surface of the boss portion 62 (main body portion 61) and the outer peripheral surface of the disc portion 64 of the flange portion 63 from the outside of the spindle device 1 during processing. It is narrow so as to prevent the coolant from entering, and is formed with a predetermined gap so as not to contact even if the main shaft 20 is bent by a processing load, and is fixed to the housing 10 with a pin 51 or a bolt. The space between the inner peripheral surface of the cap 50 and the outer peripheral surface of the boss portion 62 (main body portion 61) is sealed with an air seal. The space between the inner peripheral surface of the cap 50 and the outer peripheral surface of the boss portion 62 (main body portion 61) may be an oil seal or an O-ring instead of an air seal.

(2. Detailed configuration of hydrostatic bearing)
The configuration of the hydrostatic bearing 70 constituting the support device 40 will be described in detail with reference to FIG. As shown in FIG. 2, the hydrostatic bearing 70 includes a hydraulic pocket 71, a first drain passage 72, a second drain passage 73, a facing surface 74, a facing surface 75, a fluid supply path 76, and a throttle 77. And having.

  The hydraulic pocket 71 has a predetermined gap set on the inner peripheral surface 10a of the housing 10 facing the outer peripheral surface of the flange portion 63 of the main shaft 20 by the oil viscosity, the damping coefficient C for attenuating chatter vibration of the main shaft 20, and the like. And a predetermined number that can cope with the force at the time of processing at three or more locations. The first drain passage 72 and the second drain passage 73 are formed on both axial sides of the hydraulic pocket 71 (in the axial direction of the main shaft 20).

  The fluid supply path 76 connects the hydraulic pocket 71 and a hydraulic pump (not shown) via a flow path 76a. By operating, the hydraulic pump sucks oil from a reservoir (not shown) and supplies the hydraulic pocket 71 with a flow rate of oil indicated by a controller (not shown). The fluid supply path 76 is provided with a throttle 77. Then, oil supplied from the hydraulic pump passes through the throttle 77 and is supplied to the hydraulic pocket 71, and this oil passes through the gap between the outer peripheral surface of the flange portion 63 and the inner peripheral surfaces (land portions) of the walls 78 and 79. It passes through and is discharged to the first drain passage 72 and the second drain passage 73 and collected.

  As shown in FIG. 1, the first drain passage 72 and the second drain passage 73 have connection passages 72a and 73a respectively connected to the drain recovery passage 70a. In the present embodiment, the connection passages 72a and 73a and the drain recovery passage 70a are located directly below the main shaft 20 in the direction of gravity. The drain recovery passage 70a is connected to a reservoir (not shown). On the front side and the rear side of the hydrostatic bearing 70, the space between the outer peripheral surface of the main shaft 20 and the inner peripheral surface 10a of the housing 10 is sealed by an air seal (not shown).

(3. About the arrangement of hydrostatic bearings)
As shown in FIG. 2, the hydrostatic bearing 70 supports a portion of the flange portion 65 side on the outer peripheral side of the flange portion 65 with respect to the housing 10. Thereby, since the static pressure bearing 70 acts on the flange 65 of the main shaft 20, the damping effect of the static pressure bearing 70 can be obtained with certainty.

  The flange portion 63 is formed so as to project outward in the radial direction from the outer peripheral surface of the main body portion 61 of the main shaft 20 on the rotary tool 21 side. As a result, the main shaft 20 is not easily affected by the shear heat generation because the heat transfer path of the shear heat generation of the fluid of the hydrostatic bearing 70 becomes long, and is generated due to the deterioration of the machining accuracy accompanying the thermal displacement of the main shaft 20 and the fluctuation of the rotation balance. The chatter vibration of the main shaft 20 can be suppressed.

  Furthermore, the flange portion 65 of the flange portion 63 is formed so as to extend in the axial direction (front or rear direction) from the outer peripheral edge of the disc portion 64. Thereby, the collar part 65 becomes large in heat capacity, and can fully absorb the shear heat generation of the fluid of the hydrostatic bearing 70. In addition, since the space for collecting the fluid of the hydrostatic bearing 70 can be secured on the inner peripheral surface 10a of the housing 10 facing the flange portion 63, the rotation reliability of the main shaft 20 can be secured and high-precision machining is maintained. it can.

  Further, since the flange portion 63 of the main shaft 20 is substantially covered with the cap 50, the intrusion of coolant from the gap between the flange portion 63 of the main shaft 20 and the cap 50 can be suppressed. That is, the coolant intrusion path is formed between the outer peripheral surface of the boss portion 62 (main body portion 61) of the main shaft 20, the front end surface and outer peripheral surface of the flange portion 63, and the inner peripheral surface and rear end surface of the cap 50. Therefore, the path length can be increased and a seal can be provided, and the labyrinth effect can be exhibited, and the intrusion of coolant is suppressed. Therefore, since the rolling bearing 81 is arrange | positioned more front side and can support the main axis | shaft 20, the tool rigidity of the rotary tool 21 is ensured sufficiently.

(4. Another example of arrangement of hydrostatic bearings)
A first alternative example of the arrangement of the hydrostatic bearing will be described with reference to FIG. 3 shown corresponding to FIG. 3, the same components as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in FIG. 3, the hydrostatic bearing 170 supports the outer peripheral portion of the disc portion 64 of the main shaft 20. Thereby, since the hydrostatic bearing 170 acts directly on the disc part 64 of the main shaft 20, the damping effect of the hydrostatic bearing 70 can be obtained more reliably.

  Even in the arrangement of the hydrostatic bearing 170, by supporting the flange portion 63, as in the arrangement of the hydrostatic bearing 70 illustrated in FIG. Effects such as securing the property can be obtained. In this example, since the hydrostatic bearing 170 supports the outer peripheral portion of the disc portion 64 of the main shaft 20, the main shaft 20 without the flange portion 63 may be used to reduce the cost of components of the main shaft 20. .

  Next, a second alternative example of the arrangement of the hydrostatic bearings will be described with reference to FIG. 4 shown corresponding to FIG. 4, the same components as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in FIG. 4, the hydrostatic bearing 270 supports a portion on the disk portion 64 side on the inner peripheral side of the flange portion 63 of the main shaft 20. Thereby, since the disposition of the hydrostatic bearing 270 can be brought closer to the rotation center direction of the main shaft 20, the influence of the shear heat generation of oil due to the rotation of the main shaft 20 can be reduced. Further, the housing 10 and the like can be reduced in size by reducing the thickness.

(Second embodiment)
(5. Overall configuration of the spindle device)
Hereinafter, a second embodiment of the spindle device of the present invention will be described with reference to the drawings. The configuration of the spindle device will be described with reference to FIGS. 6 and 7 shown corresponding to FIGS. 1 and 2. The same components as those of the spindle device 1 shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in FIGS. 6 and 7, the main shaft device 2 includes a housing 110, a main shaft 120, a motor 30, a support device 140, and a cap 50. In the description of the spindle device 2, the left side of FIGS. 6 and 7 where the rotary tool 21 is held is referred to as a front side, and the right side of FIGS. 6 and 7 is referred to as a rear side.

  The housing 110 is formed in a hollow cylindrical shape through which the main shaft 120 can be inserted in the same manner as the housing 10 of the first embodiment, but the hydrostatic bearing support portion 111 that supports the hydrostatic bearing 70 and the hydrostatic bearing support portion 111. Further, it is divided into a housing main body portion 112 disposed on the rear side. The support device 140 includes a hydrostatic bearing 70, rolling bearings 81 to 85, and an outer ring support 190. Unlike the outer ring support body 90 of the first embodiment, the outer ring support body 190 is formed with a flange portion 191 that protrudes outward at the central portion in the axial direction of the outer periphery. The hydrostatic bearing support 111 is disposed on the front side of the flange 191, and the housing main body 112 is disposed on the rear side of the flange 191.

  The main shaft 120 includes a main body portion 161 and a flange portion 163. The main body 161 is not formed by two members like the main body 61 and the boss 62 of the first embodiment, but is formed by one member. The flange portion 163 is inserted into the outer peripheral surface that is separated from the front end surface of the main body portion 161 in the axial rearward direction by a predetermined distance, and extends radially outward from the outer peripheral edge of the disc portion 164 to both sides in the axial direction. Extending flange 165. That is, the flange portion 163 is formed so that the cross-sectional shape is T-shaped. A hydrostatic bearing 70 is disposed on the outer peripheral surface 165 a of the flange portion 165 of the flange portion 163. Since the flange part 165 is formed so as to extend on both sides in the axial direction, a path (member) through which heat is transmitted from the flange part 165 to the rotary tool 21 (holder 22) can be lengthened, and heat generated from the flange part 165 Is difficult to be transmitted to the rotary tool 21.

  The flange portion 163 is made of a material having a thermal conductivity lower than that of the material constituting the main body portion 161 of the main shaft 120. Generally, since the main body portion 161 of the main shaft 120 is made of an iron-based material, the flange portion 163 is a ceramic material such as zirconia or alumina having a thermal conductivity lower than that of the iron-based material. And CFRP (Carbon fiber Reinforced Plastics).

  The flange portion 163 may be made of an iron-based material whose surface is coated with a ceramic material such as zirconia or alumina. As shown in FIG. 8A, the ceramic material is coated with the ceramic material C at least on the outer peripheral surface 165a of the flange portion 165 where the hydrostatic bearing 70 is disposed. Further, as shown in FIG. 8B, the outer peripheral surface 165a and both side end surfaces 165c, 165d may be coated with a ceramic material C, and as shown in FIG. 8C, the outer peripheral surface 165a, both side end surfaces 165c, 165d and the inner periphery Surface 165b may be coated with ceramic material C.

  Thus, since the flange part 163 is comprised with the material which has low thermal conductivity, it becomes difficult to transmit the heat_generation | fever from the collar part 165 to the rotary tool 21 (holder 22) further. Then, according to the spindle device 2, similar to the spindle device 1 of the first embodiment, effects such as suppression of chatter vibration of the spindle 120 and ensuring of reliability of rotation of the spindle 120 can be obtained. The main shaft 120 needs to ensure strength and durability, and if it is made of a material having a low thermal conductivity, the cost becomes high, and therefore, it is made of an iron-based material.

  Further, at least one of the housing 110 and the cap 50 may be made of a material having a thermal conductivity higher than that of the material constituting the flange portion 163. Examples of the material having high thermal conductivity include copper, brass, aluminum, and aluminum alloy. As a result, the heat generated from the flange portion 165 is easily transmitted to at least one of the housing 110 and the cap 50, so that the generated heat is more difficult to be transmitted to the rotary tool 21 (holder 22). Note that the housing main body 112 and the outer ring support 190 need not be made of the above-described material having high thermal conductivity, but are made of an iron-based material because it is necessary to ensure strength and durability.

  Further, at least one of the outer ring support 190 and the cap 50 may be provided with the cooling unit 100. As the cooling unit 100, as shown in FIG. 9A, a tubular hole 101 through which the coolant passes is provided in at least one of the outer ring support 190 and the cap 50, or the coolant passes as shown in FIG. 9B. A tubular groove 102 is provided on the contact surface with the flange portion 163. Thereby, since the heat generated from the flange portion 165 is cooled by at least one of the outer ring support 190 and the cap 50, the generated heat is more difficult to be transmitted to the rotary tool 21 (holder 22).

(6. Effects)
The spindle device of the present embodiment includes a housing 10, a cylindrical main body 61 that holds the rotary tool 21, and a flange 63 that protrudes radially outward from the outer peripheral surface of the main body 61 on the rotary tool 21 side. The main shaft 20 provided, bearings 81 to 85 that rotatably support the outer peripheral surface of the main body 61 with respect to the housing 10, the flange 63 to be rotatably supported with respect to the housing 10, and the bearings 81 to 85 Hydrostatic bearings 70, 170, 270 (viscoelastic bearings) that are disposed outward (including and beyond the radial position) in the radial direction and have a damping coefficient larger than that of the bearings 81 to 84 And).

  As described above, the hydrostatic bearings 70, 170, and 270 are provided on the flange portion 63 projecting radially outward from the outer peripheral surface of the main body portion 61 of the main shaft 20 on the rotary tool 21 side. The heat transfer path of the shear heat generation of 70 fluid becomes long. Therefore, the main shaft 20 is hardly affected by the shear heat generation of the fluid, can suppress the thermal displacement of the main shaft 20, and the chatter vibration of the main shaft 20 caused by the deterioration of the machining accuracy and the fluctuation of the rotation balance due to the thermal displacement of the main shaft 20. Can be suppressed. Further, since the space for collecting the fluid of the hydrostatic bearings 70, 170, 270 can be secured on the inner peripheral surface 10a of the housing 10 facing the flange portion 63, the reliability of the rotation of the main shaft 20 can be ensured, and the high accuracy. Can be maintained.

  The flange portion 63 includes a disc portion 64 that extends radially outward from the outer peripheral surface of the main body portion 61, and a flange portion 65 that extends in the axial direction from the outer peripheral edge of the disc portion 64. Thereby, the flange part 63 becomes large in heat capacity, and can fully absorb the shear heat generation of the fluid of the hydrostatic bearings 70, 170, and 270.

Further, since the static pressure bearings 70, 170, and 270 support the flange portion 65 with respect to the housing 10, the heat transfer path for shear heat generation of the fluid of the static pressure bearing 70 becomes long, and the spindle 20 is affected by the shear heat generation. It becomes difficult to receive.
Further, since the hydrostatic bearings 70, 170 and 270 support the portion of the flange portion 65 on the side of the disc portion 64 with respect to the housing 10, the hydrostatic bearings 70, 170 and 270 act on the disc portion 64. , 270 can be reliably obtained.

Further, since the hydrostatic bearing 70 supports the outer peripheral portion of the flange 65 with respect to the housing 10, the fluid supply path of the hydrostatic bearings 70, 170, and 270 can be easily formed.
Further, since the hydrostatic bearing 270 supports the inner peripheral portion of the flange portion 65 with respect to the housing 10, the arrangement of the hydrostatic bearing can be moved closer to the rotation center direction of the main shaft 20 (close to the rotation center). The smaller the shear distance of the fluid, the smaller the influence of oil heat generated by the rotation of the main shaft 20. Further, the housing 10 can be thinned, and the size of the main shaft device in the radial direction can be reduced.

Further, since the hydrostatic bearing 170 supports the outer peripheral portion of the disc portion 64 extending in the radial direction from the main body portion 61 with respect to the housing 10, the hydrostatic bearing 170 acts directly on the disc portion 64, so The damping effect of the pressure bearing 170 can be obtained more reliably.
The flange portion 63 includes a disc portion 64 that extends radially outward from the outer peripheral surface of the main body portion 61, and the hydrostatic bearings 70 and 170 are located on the outer peripheral side of the disc portion 64 with respect to the housing 10. To support. As a result, the heat transfer path of the shear heat generation of the fluid of the hydrostatic bearings 70 and 170 becomes long, and the main shaft 20 is hardly affected by the shear heat generation.

Moreover, since the flange part 163 is comprised with the material which has heat conductivity lower than the heat conductivity of the material which comprises the main-body part 161, the heat_generation | fever from the collar part 165 is further transmitted to the rotary tool 21 (holder 22). It becomes difficult.
Moreover, since the cap 50 (shielding member) which shields between the workpiece and the hydrostatic bearing 70,170,270 which the rotary tool 21 processes is provided in the edge part by the side of the rotary tool 21 of the main axis | shaft 20, a main axis | shaft is provided. Intrusion of coolant from the gap between the cap 20 and the cap 50 can be suppressed. Further, it is possible to prevent workpiece chips and the like from entering the hydrostatic bearings 70, 170 and 270.

In addition, since at least one of the cap 50 and the housing 110 is made of a material having a thermal conductivity higher than that of the material constituting the flange portion 163, heat generated from the flange portion 165 is generated by the housing 110 and the cap 110. It becomes easy to be transmitted to at least one of 50, and the said heat_generation | fever becomes further difficult to transmit to the rotary tool 21 (holder 22).
Since at least one of the cap 50 and the outer ring support 190 is provided with the cooling unit 100 that cools the heat generated in the flange portion 163, the heat generated from the flange portion 165 is cooled by at least one of the housing 110 and the cap 50. The heat generation is more difficult to be transmitted to the rotary tool 21 (holder 22).

(7. Others)
In each said embodiment, although the rolling bearings 81-84 were used as a bearing, you may use a fluid bearing. Moreover, although it was set as the structure which provided the cap 50 which shields between the workpiece and the hydrostatic bearing 70 which the rotary tool 21 processes at the edge part by the side of the rotary tool 21 of the main axis | shaft 20, as shown in FIG. The length of the flange portion 63 of the main shaft 20 in the axial direction may be increased without providing the cap 50 and the outer peripheral surface of the flange portion 63 may be covered with the housing 10. In this case, an air seal for preventing coolant from entering is provided on the inner peripheral surface 10 a of the housing 10 facing the outer peripheral surface of the flange portion 63. In addition, although illustration is omitted, a configuration in which the cap 50 is not provided can also be applied to the spindle device 2 of the second embodiment.

  In addition, although it is a well-known matter, when the chatter vibration of the main shafts 20 and 120 (the rotary tool 21) is suppressed by the hydrostatic bearing as described above, it is most efficient depending on the rotary tool 21, the main shafts 20, 120, and the like. There is a range of damping coefficient C and spring constant k that can suppress vibration. Therefore, it is preferable that the hydrostatic bearing is supplied with an oil having a flow rate suitable for obtaining a range of the damping coefficient C and the spring constant k that have a high vibration suppressing effect. However, only a predetermined amount of oil may be supplied to the hydrostatic bearing so that only the range of the damping coefficient C having a high vibration suppressing effect can be obtained. By these, the vibration suppression effect by a hydrostatic bearing becomes a bigger thing.

  10, 110: Housing, 20, 120: Spindle, 21: Rotating tool, 40: Support device, 50: Cap (shielding member), 61, 161: Main body part, 62: Boss part, 63, 163: Flange part, 64 , 164: disc part, 65, 165: collar part, 70, 170, 270: hydrostatic bearing (viscoelastic bearing), 81-85: rolling bearing.

Claims (14)

A housing;
A main body comprising a cylindrical main body for holding the rotary tool, and a flange that projects radially outward from the outer peripheral surface of the main body on the rotary tool side;
A bearing rotatably supporting the outer peripheral surface of the main body with respect to the housing;
A viscoelastic bearing that rotatably supports the flange portion with respect to the housing, and is disposed outside the radial position of the bearing and has a damping coefficient larger than that of the bearing;
Equipped with a,
The flange portion includes a disk portion extending radially outwardly from the outer peripheral surface of the main body portion, and a flange portion extending axially from an outer peripheral edge of the disc portion, Ru includes a spindle device. The spindle device according to claim 1 , wherein the viscoelastic bearing supports the flange portion with respect to the housing. The spindle device according to claim 2 , wherein the viscoelastic bearing supports a portion of the flange portion on the disc portion side with respect to the housing. 4. The spindle device according to claim 2 , wherein the viscoelastic bearing supports a portion on an outer peripheral side of the flange portion with respect to the housing. 4. The spindle device according to claim 2 , wherein the viscoelastic bearing supports a portion on an inner peripheral side of the flange with respect to the housing. 5. The spindle device according to any one of claims 1 to 5 , wherein the flange portion is formed so as to extend from an outer peripheral edge of the disc portion toward the rotary tool. The spindle device according to claim 1 , wherein the viscoelastic bearing supports a portion on an outer peripheral side of the disc portion with respect to the housing. The spindle device according to any one of claims 1 to 7 , wherein the flange portion is made of a material having a thermal conductivity lower than that of a material constituting the main body portion. The end of the rotating tool side of the main shaft, the shielding member for shielding between the viscoelastic bearing and the workpiece in which the rotary tool is machining is provided, according to any one of claims 1- 8 Spindle device. The spindle device according to claim 9 , wherein the shielding member is made of a material having a thermal conductivity higher than that of a material constituting the flange portion.   A housing;
  A main body comprising a cylindrical main body for holding the rotary tool, and a flange that projects radially outward from the outer peripheral surface of the main body on the rotary tool side;
  A bearing rotatably supporting the outer peripheral surface of the main body with respect to the housing;
  A viscoelastic bearing that rotatably supports the flange portion with respect to the housing, and is disposed outside the radial position of the bearing and has a damping coefficient larger than that of the bearing;
  With
  The end of the main shaft on the rotary tool side is made of a material having a thermal conductivity higher than that of the material constituting the flange, and the workpiece to be processed by the rotary tool and the viscoelastic bearing A spindle device provided with a shielding member for shielding between the two. The spindle according to any one of claims 9 to 11 , wherein at least one of the shielding member and the outer ring support that supports the outer ring of the bearing is provided with a cooling unit that cools heat generated in the flange unit. apparatus.   A housing;
  A main body comprising a cylindrical main body for holding the rotary tool, and a flange that projects radially outward from the outer peripheral surface of the main body on the rotary tool side;
  A bearing rotatably supporting the outer peripheral surface of the main body with respect to the housing;
  A viscoelastic bearing that rotatably supports the flange portion with respect to the housing, and is disposed outside the radial position of the bearing and has a damping coefficient larger than that of the bearing;
  With
  The said spindle part is comprised with the material which has a heat conductivity lower than the heat conductivity of the material which comprises the said main-body part. The spindle device according to any one of claims 8 to 13 , wherein the housing is made of a material having a thermal conductivity higher than a thermal conductivity of a material constituting the flange portion.

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