Main shaft device of machine tool and machine tool

Abstract

The invention provides a spindle device of a machine tool and the machine tool. A spindle device of a machine tool includes: a rotating body having a rear end portion and a front end portion for holding a tool; a bearing having an inner ring and an outer ring; a housing that supports the rotating body so as to be rotatable about a first axis by means of a bearing; a supply flow path for supplying a mixed fluid containing oil and air to the bearing; and a recovery flow path that recovers the oil that has passed through the bearing. The rotating body has: a first portion that supports the inner ring and has a first outer peripheral surface; a second portion having a second outer peripheral surface having a smaller diameter than the first outer peripheral surface, the second portion being disposed closer to the first direction side than the first portion; and a stepped surface connecting the first outer peripheral surface and the second outer peripheral surface. The housing has: a third portion that supports the outer ring; and a fourth portion defining an annular housing space for receiving oil from a first gap between the first portion and the third portion. The fourth portion has: an opening portion that guides oil from the annular accommodation space to the recovery flow path; and an annular protrusion protruding in a direction away from the first shaft, the annular protrusion facing both the stepped surface and the annular accommodation space.

Description

Technical Field

[0001] The present invention relates to a spindle device of a machine tool and the machine tool. Background Art

[0002] A lubricating device for a spindle of a machine tool is known.

[0003] As a related technology, Patent Document 1 discloses a lubrication device for a vertical spindle of a machine tool. The lubrication device described in Patent Document 1 includes a vertical spindle rotatably supported within a spindle housing by means of rolling bearings, a nozzle device for spraying lubricating oil onto the rolling bearings, and an oil recovery channel for recovering the lubricating oil supplied to the rolling bearings via an oil drain channel formed within the spindle housing. Furthermore, the lubrication device described in Patent Document 1 includes a labyrinth device disposed below the rolling bearings to form a reservoir for the lubricating oil, an air seal device disposed below the labyrinth device to supply pressurized air to prevent oil leakage caused by the gap between the spindle housing and the vertical spindle, and a mechanical seal device interposed between the labyrinth device and the air seal device to prevent oil leakage caused by cessation of the pressurized air supply.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 63-062638 Summary of the Invention

[0005] An object of the present invention is to provide a spindle device of a machine tool and a machine tool that suppresses oil leakage from a gap between a rotating body and a housing to the outside of the spindle device.

[0006] In some embodiments, a machine tool spindle device includes: a rotating body having a rear end and a front end for holding a tool; a bearing having an inner ring and an outer ring; a housing supporting the rotating body rotatably about a first axis via the bearing; a supply channel for supplying a mixed fluid containing oil and air to the bearing; and a recovery channel for recovering the oil that has passed through the bearing. The rotating body includes: a first portion supporting the inner ring and having a first outer peripheral surface; a second portion having a second outer peripheral surface having a smaller diameter than the first outer peripheral surface and being positioned closer to the first direction than the first portion when the direction from the rear end toward the front end is defined as a first direction; and a stepped surface connecting the first and second outer peripheral surfaces. The housing includes: a third portion supporting the outer ring; and a fourth portion defining an annular receiving space for receiving the oil from a first gap between the first and third portions. The fourth portion includes an opening for guiding the oil from the annular receiving space to the recovery channel; and an annular protrusion facing both the stepped surface and the annular receiving space and projecting away from the first axis.

[0007] In some embodiments, a machine tool comprises: a machining head having a rotating body, a plurality of bearings including a first bearing, a housing rotatably supporting the rotating body via the plurality of bearings, and a first rotary drive device for rotating the rotating body about a first axis; a lubricating device for supplying a mixed fluid comprising oil and air to the first bearing via a supply flow channel; a recovery device for recovering at least a portion of the oil that has passed through the first bearing via a recovery flow channel; a workpiece support device for supporting a workpiece; a moving device for moving the machining head relative to the workpiece support device; and a control device for controlling at least the first rotary drive device and the moving device. The rotating body comprises: a rear end portion; a front end portion for holding a tool; a first portion for supporting an inner ring of the first bearing and having a first outer peripheral surface; a second portion for having a second outer peripheral surface having a smaller diameter than the first outer peripheral surface and being positioned closer to the first direction than the first portion when the direction from the rear end portion toward the front end portion is defined as a first direction; and a stepped surface for connecting the first outer peripheral surface and the second outer peripheral surface. The housing includes a third portion supporting the outer ring of the first bearing, and a fourth portion defining an annular receiving space for receiving the oil from a first gap between the first portion and the third portion. The fourth portion includes an opening for guiding the oil from the annular receiving space to the recovery flow path, and an annular protrusion facing both the step surface and the annular receiving space and protruding in a direction away from the first shaft.

[0008] According to the present invention, it is possible to provide a spindle device of a machine tool and a machine tool in which oil leakage from a gap between a rotating body and a housing to the outside of the spindle device is suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic cross-sectional view schematically showing a spindle device of a machine tool in the first embodiment. Figure 2 is Figure 1 An enlarged view of the portion surrounded by a dashed-dotted quadrilateral A in FIG. Figure 3 This is a schematic cross-sectional view schematically showing a portion of the main spindle device of the machine tool in the first embodiment. Figure 4 This is a schematic cross-sectional view schematically showing a portion of the main spindle device of the machine tool in the first embodiment. Figure 5 This is a schematic cross-sectional view schematically showing a portion of the main spindle device of the machine tool in the first embodiment. Figure 6 This is a schematic cross-sectional view schematically showing a portion of the main spindle device of the machine tool in the first embodiment. Figure 7This is a schematic cross-sectional view schematically showing a portion of a main spindle device of a machine tool in a modified example of the first embodiment. Figure 8 is Figure 6 An enlarged view of the portion indicated by a dashed circle B in FIG. Figure 9 yes Figure 6 The CC arrow cross section in . Figure 10 This is a diagram schematically showing a portion of a main spindle device of a machine tool according to the first embodiment. Figure 11 This is a schematic cross-sectional view schematically showing a portion of the main spindle device of the machine tool in the first embodiment. Figure 12 This is a schematic cross-sectional view schematically showing a portion of a main spindle device of a machine tool in a second modified example of the first embodiment. Figure 13 This is a schematic cross-sectional view schematically showing a portion of the main spindle device of the machine tool in the first embodiment. Figure 14 It is a schematic cross-sectional view schematically showing a spindle device of a machine tool in a second embodiment. Figure 15 is Figure 14 An enlarged view of the portion surrounded by a dashed-dotted quadrilateral D in FIG. Figure 16 This is a schematic cross-sectional view schematically showing a portion of a main spindle device of a machine tool according to a second embodiment. Figure 17 yes Figure 16 EE arrow cross-section diagram. Figure 18 is Figure 16 An enlarged view of the portion indicated by a dashed-dotted circle F in FIG. Figure 19 This is a schematic cross-sectional view schematically showing a portion of a main spindle device of a machine tool according to a second embodiment. Figure 20 This is a schematic cross-sectional view schematically showing a portion of a main spindle device of a machine tool according to a second embodiment. Figure 21 This is a schematic cross-sectional view schematically showing a portion of a main spindle device of a machine tool in a modified example of the second embodiment. Figure 22 It is a schematic cross-sectional view schematically showing a spindle device of a machine tool in a second embodiment. Figure 23 This is a schematic cross-sectional view schematically showing a portion of a main spindle device of a machine tool according to a second embodiment. Figure 24This is a schematic cross-sectional view schematically showing a portion of a main spindle device of a machine tool according to a second embodiment. Figure 25 It is a schematic perspective view schematically showing an example of a machine tool in a third embodiment. Figure 26 It is a schematic perspective view schematically showing another example of the machine tool in the third embodiment. Figure 27 This is a diagram schematically showing a case where a control device can control a plurality of control target devices. Figure 28 It is a schematic cross-sectional view schematically showing a modified example related to the first portion and the second portion of the rotating body. Figure 29 This is a schematic cross-sectional view schematically showing a first modification example related to the first gap. Figure 30 This is a schematic cross-sectional view schematically showing a second modified example related to the first gap. DETAILED DESCRIPTION

[0010] Hereinafter, a spindle device 1 and a machine tool 100 according to an embodiment will be described with reference to the drawings. In the following description of the embodiment, parts and components having the same functions are denoted by the same reference numerals, and repeated description of parts and components denoted by the same reference numerals will be omitted.

[0011] (Definition of direction) In this specification, a direction from the rear end portion 22 of the rotating body 2 toward the front end portion 24 of the rotating body 2 is defined as a “first direction DR1 ,” and a direction opposite to the first direction DR1 is defined as a “second direction DR2 .”

[0012] In this specification, a direction approaching the first axis AX1 serving as the rotation axis of the rotating body 2 is defined as a “radially inward direction DR3” or “inward.” Furthermore, a direction away from the first axis AX1 serving as the rotation axis of the rotating body 2 is defined as a “radially outward direction DR4” or “outward.”

[0013] The direction from the rear end portion 22 of the rotating body 2 toward the front end portion 24 of the rotating body 2 is, for example, downward or horizontal. If the spindle device 1 can change its posture, the direction from the rear end portion 22 of the rotating body 2 toward the front end portion 24 of the rotating body 2 changes according to the change in the posture of the spindle device 1. In this specification, regardless of the actual posture of the spindle device 1, the direction from the rear end portion 22 of the rotating body 2 toward the front end portion 24 of the rotating body is referred to as the "downward direction," and the direction from the front end portion 24 of the rotating body 2 toward the rear end portion 22 of the rotating body is referred to as the "upward direction." Furthermore, in this specification, regardless of the actual posture of the spindle device 1, the surface on the first direction DR1 side is referred to as the "lower surface," and the surface on the second direction DR2 side is referred to as the "upper surface."

[0014] (First embodiment) Reference Figures 1 to 13 A spindle device 1A for a machine tool according to the first embodiment will be described. Figure 1 It is a schematic cross-sectional view schematically showing a spindle device 1A of a machine tool according to the first embodiment. Figure 2 is Figure 1 An enlarged view of the portion surrounded by a dashed-dotted quadrilateral A in FIG. Figure 3 It is a schematic cross-sectional view schematically showing a part of a main spindle device 1A of a machine tool according to the first embodiment. Figure 4 and Figure 5 1A is a schematic cross-sectional view schematically showing a portion of a spindle device 1A for a machine tool according to the first embodiment. Figure 5 Expressed Figure 4 Half of the portion shown. Figure 6 It is a schematic cross-sectional view schematically showing a part of a main spindle device 1A of a machine tool according to the first embodiment. Figure 7 This is a schematic cross-sectional view schematically showing a portion of a spindle device 1A for a machine tool according to a modified example of the first embodiment. Figure 8 is Figure 6 An enlarged view of the portion indicated by a dashed circle B in FIG. Figure 9 yes Figure 6 The CC arrow cross section in . Figure 10 This is a diagram schematically showing a portion of a main spindle device 1A of a machine tool according to the first embodiment. Figure 11 It is a schematic cross-sectional view schematically showing a part of a main spindle device 1A of a machine tool according to the first embodiment. Figure 12 This is a schematic cross-sectional view schematically showing a portion of a spindle device 1A for a machine tool according to a second modified example of the first embodiment. Figure 13 It is a schematic cross-sectional view schematically showing a part of a main spindle device 1A of a machine tool according to the first embodiment.

[0015] like Figure 1 As illustrated, the main spindle device 1A of the machine tool in the first embodiment includes a rotating body 2 , a bearing 3 , a housing 4 , a supply flow path 66 , and a recovery flow path 71 .

[0016] exist Figure 1 In the example described, the rotating body 2 is the rotating shaft 20. The rotating body 2 can rotate around the first axis AX1. The rotating body 2 (more specifically, the rotating shaft 20) has a rear end portion 22 and a front end portion 24 for holding the tool T. In addition, sometimes a tool holder HD for holding the tool T is installed at the front end portion 24. In this case, the tool T is held by the front end portion 24 with the aid of the tool holder HD. Therefore, in this specification, the "front end portion 24 for holding the tool" includes both the front end portion 24 for directly holding the tool T and the front end portion 24 for holding the tool T with the aid of the tool holder HD. In other words, in this specification, the front end portion 24 can be configured to directly hold the tool T, or it can be configured to hold the tool T with the aid of the tool holder HD.

[0017] The housing 4 supports the rotating body 2 via the bearing 3 so as to be rotatable around the first axis AX1. Figure 1 In the described example, the housing 4 is formed by an assembly of a plurality of parts.

[0018] exist Figure 1 In the example described, the spindle device 1A includes a bearing 3 (for example, a first bearing 3a). Figure 2 As illustrated, the bearing 3 (for example, the first bearing 3 a ) includes an inner ring 31 and an outer ring 32 . Furthermore, the bearing 3 (for example, the first bearing 3 a ) includes rolling elements 33 disposed between the inner ring 31 and the outer ring 32 .

[0019] Supply flow channel 66 supplies a mixed fluid consisting of oil and air to bearing 3 (e.g., first bearing 3a). This mixed fluid is sometimes referred to as oil-air. In the oil-air, the air transports the oil. In other words, in the oil-air, the air functions as the transport fluid that transports the oil. More specifically, by supplying oil-air to bearing 3 (e.g., first bearing 3a), the flow of compressed air continuously supplies a small amount of oil to bearing 3 (e.g., first bearing 3a).

[0020] The recovery channel 71 recovers at least a portion of the oil E that has passed through the bearing 3 (e.g., the first bearing 3a). The recovery channel 71 may also recover substantially all of the oil E that has passed through the first bearing 3a. Alternatively, the recovery channel 71 may also recover at least a portion of the air that has passed through the bearing 3.

[0021] like Figure 2 As illustrated, the rotating body 2 (more specifically, the rotating shaft 20 ) includes a first portion 25 , a second portion 26 , and a stepped surface 25 a .

[0022] The first portion 25 supports the inner ring 31a of the bearing 3 (for example, the first bearing 3a). The first portion 25 has a first outer peripheral surface 25u.

[0023] The second portion 26 has a second outer peripheral surface 26u having a smaller diameter than the first outer peripheral surface 25u. In other words, the diameter of the second outer peripheral surface 26u of the second portion 26 is smaller than the diameter of the first outer peripheral surface 25u of the first portion 25. The second portion 26 is arranged further to the first direction DR1 than the first portion 25.

[0024] The step surface 25 a connects the first outer peripheral surface 25 u of the first portion 25 and the second outer peripheral surface 26 u of the second portion 26 .

[0025] like Figure 2 As illustrated, the housing 4 has a third portion 41 and a fourth portion 42 .

[0026] The third portion 41 supports the outer ring 32a of the bearing 3 (for example, the first bearing 3a). A first gap G1 is formed between the first portion 25 of the rotating body 2 and the third portion 41. Figure 2 In the example described, oil E that has passed through the bearing 3 (for example, the first bearing 3a) exists in the first gap G1. The oil E may exist in the first gap G1 in the form of oil gas, oil mist, or liquid oil.

[0027] The fourth portion 42 defines an annular housing space SP that receives the oil E from the first gap G1. The oil E may exist in the annular housing space SP in the form of oil gas, oil mist, or liquid oil.

[0028] exist Figure 2 In the example described, the fourth portion 42 includes the opening 45 that guides the oil E from the annular accommodation space SP to the recovery flow path 71 , and the annular protrusion 441 .

[0029] The annular protrusion 441 faces both the stepped surface 25a and the annular accommodation space SP. Figure 2 In the example described, the surface on the second direction DR2 side (hereinafter referred to as "upper surface 441a") of the multiple surfaces of the annular protrusion 441 faces the stepped surface 25a. Furthermore, the surface on the first direction DR1 side (hereinafter referred to as "lower surface 441d") of the multiple surfaces of the annular protrusion 441 faces the annular receiving space SP.

[0030] The annular protrusion 441 protrudes in a direction away from the first axis AX1. Therefore, it can be said that the annular protrusion 441 is an outward annular protrusion.

[0031] In the machine tool spindle device 1A of the first embodiment, the housing 4 has an annular accommodation space SP. Therefore, the oil E that has passed through the bearing 3 can be temporarily accommodated in the annular accommodation space SP. The oil E in the annular accommodation space SP is recovered by the recovery flow passage 71. This prevents oil from leaking outside the machine tool spindle device 1A through the gap between the rotating body 2 and the housing 4.

[0032] Furthermore, in the first embodiment, the annular protrusion 441 prevents or suppresses the oil E that has entered the annular accommodation space SP from flowing back in the second direction DR2 over the annular protrusion 441. Therefore, in the first embodiment, it is possible to more effectively suppress oil leakage from the gap between the rotating body 2 and the housing 4 to the outside of the spindle device 1A of the machine tool.

[0033] For example, consider a case where it is undesirable for oil to adhere to a workpiece being machined by the tool T. More specifically, consider a case where a workpiece made of a carbon material, to which adhesion of oil would cause problems, is being machined. In such a case, the first embodiment is useful.

[0034] Furthermore, when machining resin materials, etc., using the tool T, dry machining is sometimes employed. In the first embodiment, it is possible to suppress oil leakage outside the spindle device 1A of the machine tool, effectively preventing oil from adhering to the workpiece (e.g., resin material, etc.). Therefore, the first embodiment is also useful when dry machining is employed.

[0035] In the first embodiment, oil leakage around the machine tool spindle assembly 1A can be suppressed, preventing or limiting oil contamination of the working environment. Consequently, the working environment is improved and the environmental burden is reduced. Furthermore, when a coolant is used during workpiece machining (in other words, in non-dry machining), the first embodiment also suppresses oil leakage and prevents oil from mixing with the coolant. Therefore, even in this case, the environmental burden can be reduced.

[0036] (Optional additional structure) Next, refer to Figures 1 to 13 An optional additional configuration that can be adopted in the spindle device 1A of the machine tool according to the first embodiment will be described.

[0037] (Annular storage space SP) exist Figure 3 In order to facilitate understanding of the shape of the annular storage space SP, the annular storage space SP is shaded with dots. Figure 3In the described example, the annular receiving space SP has a shape formed by combining a first rectangular shape SH1 and a second rectangular shape SH2, which is larger than the first rectangular shape, in a longitudinal section passing through the first axis AX1. Alternatively, the annular receiving space SP may have a triangular, trapezoidal, pentagonal, or other shape in a longitudinal section passing through the first axis AX1.

[0038] exist Figure 3 In the example described, the first gap G1 and the annular housing space SP are arranged on a straight line LN parallel to the first axis AX1. In this case, the oil E in the first gap G1 can be smoothly guided to the annular housing space SP.

[0039] (Annular protrusion 44) exist Figures 4 to 6 In the example described, the fourth portion 42 has an annular protrusion 44 that protrudes inward toward the first axis AX1. Figure 5 and Figure 6 In the figure, in order to make it easier to understand the shape of the annular protrusion 44, the annular protrusion 44 is shaded with dots.

[0040] exist Figure 6 In the example described, the annular protrusion 44 includes the annular protrusion 441 protruding outward, a first surface 44a facing the stepped surface 25a, and a second surface 44b facing the outer peripheral surface of the second portion 26 of the rotating body 2 (in other words, the second outer peripheral surface 26u).

[0041] The first surface 44a is a surface on the second direction DR2 side of the annular protrusion 44. The first surface 44a is, for example, an annular surface perpendicular to the first axis AX1. Alternatively, the first surface 44a may be a surface inclined relative to the first axis AX1 or a stepped surface (see Figure 7 ).

[0042] exist Figure 8 In the example described, at least a portion of the first surface 44a is the surface of the outwardly protruding annular protrusion 441. More specifically, at least a portion of the first surface 44a is formed by the surface of the annular protrusion 441 on the second direction DR2 side (in other words, the upper surface 441a of the annular protrusion 441).

[0043] exist Figure 8 In the example described, a second gap G2 is formed between the first surface 44a and the step surface 25a, which is in fluid communication with the first gap G1. Figure 8 In the example described, the second gap G2 is located further in the second direction DR2 than the annular protrusion 441. Figure 8In the example described, a third gap G3 that is in fluid communication with the second gap G2 is formed between the second surface 44 b and the second outer peripheral surface 26 u of the rotating body 2 .

[0044] Consider a path from the first gap G1 to the outside of the main spindle device 1A of the machine tool. This path may cause oil leakage. Figure 8 In the example described, a second gap G2 exists between the first surface 44a and the stepped surface 25a on the path from the first gap G1 to the outside of the machine tool spindle device 1A. Therefore, the presence of the second gap G2 can suppress oil leakage outside the machine tool spindle device 1A via this path.

[0045] exist Figure 8 In the example described, the extending direction of the first gap G1 is different from the extending direction of the second gap G2. Therefore, it is possible to prevent the oil in the first gap G1 from flowing toward the second gap G2. For example, it is possible to prevent the oil moving downward from the first gap G1 from entering the second gap G2. Figure 8 In the described example, the first gap G1 extends in the first direction DR1 , and the second gap G2 extends in the radial direction DR3 (more specifically, a direction perpendicular to and toward the first axis AX1 ).

[0046] like Figure 9 As shown in the example, the difference between the radius RD1 of the outer peripheral edge e1 of the first surface 44a and the radius RD2 of the inner peripheral edge e2 of the first surface 44a is defined as the first width W1. The first width W1 is, for example, 5 mm or more. By making the first width W1 sufficiently large, the oil entering the second gap G2 is prevented or suppressed from reaching the third gap G3 (see Figure 8 In this way, it is possible to further effectively suppress the oil from leaking out of the main spindle device 1A of the machine tool.

[0047] exist Figure 8 In the example described, the annular housing space SP is entirely located closer to the first direction DR1 than the second gap G2. In this case, the possibility of the oil contained in the annular housing space SP flowing back into the second gap G2 can be further effectively reduced.

[0048] exist Figure 8 In the described example, the spindle device 1A of the machine tool has a region SE where the first gap G1 , the second gap G2 , and the annular accommodation space SP intersect, and the second gap G2 communicates with the first gap G1 via the region SE.

[0049] exist Figure 8 In the example described, the third gap G3 is connected to the second gap G2 via the corner CN. In addition, the extending direction of the third gap G3 is different from the extending direction of the second gap G2. Figure 8In the described example, the third gap G3 extends in the first direction DR1 , and the second gap G2 extends in the radial direction DR3 (more specifically, a direction perpendicular to and toward the first axis AX1 ).

[0050] The second surface 44b is a cylindrical surface having the first axis AX1 as its central axis. Figure 8 As illustrated, the length of the second surface 44b along the first axis AX1 is defined as the first length L1. The first length L1 may be greater than the first width W1, less than the first width W1, or equal to the first width W1. The first length L1 may also be greater than or equal to the first width W1 and less than or equal to the first width W1.

[0051] exist Figure 10 In the example described, the annular protrusion 44 has a first annular groove V1 that faces the annular accommodation space SP and is recessed in the radially inward direction DR3. Figure 10 In the figure, for easier understanding of the shape of the first annular groove V1, the portion other than the first annular groove V1 is indicated by a dotted line, and the first annular groove V1 is indicated by a solid line. The first annular groove V1 prevents or suppresses the oil in the annular accommodation space SP from flowing back toward the first gap G1 or the second gap G2.

[0052] exist Figure 10 In the example described, the first annular groove V1 is composed of three surfaces (more specifically, two surfaces 443d and 444d perpendicular to the first axis AX1, and a surface 445d connecting these two surfaces). Figure 10 In the example described above, the first annular groove V1 has a substantially C-shaped longitudinal section passing through the first axis AX1. Alternatively, the first annular groove V1 may be formed of two surfaces. In this case, the first annular groove V1 may also have a substantially V-shaped longitudinal section passing through the first axis AX1.

[0053] exist Figure 10 In the example described, part of the surface of the first annular groove V1 is the surface of the annular protrusion 441. More specifically, part of the surface of the first annular groove V1 is formed by the surface of the annular protrusion 441 on the first direction DR1 side (more specifically, the lower surface 441d of the annular protrusion 441).

[0054] exist Figure 10 In the example described, the annular protrusion 44 has a third surface 44f constituting a portion of the end surface 4f on the first direction DR1 side of the housing 4. The third surface 44f may be a surface perpendicular to the first axis AX1 or a surface slightly inclined relative to the first axis AX1.

[0055] (Annular protrusion 441) exist Figure 11In the described example, the annular protrusion 441 functions as a recovery member that suppresses the oil that has entered the annular housing space SP from returning to the first gap G1 or the second gap G2 .

[0056] like Figure 11 As shown in the example, the distance between the outermost edge e3 of the step surface 25a of the rotating body 2 and the first axis AX1 is defined as a first distance LT1, and the distance between the outermost edge 441e of the annular protrusion 441 and the first axis AX1 is defined as a second distance LT2. Figure 11 In the example described, the second distance LT2 is equal to the first distance LT1. Alternatively, Figure 12 As illustrated, the second distance LT2 may also be smaller than the first distance LT1 .

[0057] When the second distance LT2 is less than or equal to the first distance LT1, the oil E flowing from the first gap G1 toward the first direction DR1 can be prevented or suppressed from colliding with the annular protrusion 441. Therefore, the oil E flowing from the first gap G1 toward the first direction DR1 is less likely to enter the gap between the stepped surface 25a and the annular protrusion 441 (or the second gap G2 between the stepped surface 25a and the first surface 44a).

[0058] exist Figure 13 In the described example, the annular protrusion 441 has an upper surface 441 a , an outer side surface 441 c , and a lower surface 441 d .

[0059] The upper surface 441a is an annular surface facing the stepped surface 25a of the rotating body 2. The upper surface 441a may be perpendicular to the first axis AX1 or may be inclined with respect to a surface perpendicular to the first axis AX1.

[0060] exist Figure 13 In the example described, the outer side surface 441c faces the annular accommodation space SP. In a longitudinal section passing through the first axis AX1, the outer side surface 441c is parallel to the first axis AX1. Alternatively, in a longitudinal section passing through the first axis AX1, the outer side surface 441c may be inclined relative to the first axis AX1.

[0061] exist Figure 13 In the example described, the lower surface 441d is an annular surface facing the annular accommodation space SP. The lower surface 441d may be perpendicular to the first axis AX1 or may be inclined relative to a surface perpendicular to the first axis AX1.

[0062] (Second embodiment) Reference Figures 14 to 24 A spindle device 1B of a machine tool according to a second embodiment will be described. Figure 14 It is a schematic cross-sectional view schematically showing a spindle device 1B of a machine tool according to a second embodiment. Figure 15 is Figure 14 An enlarged view of the portion surrounded by a dashed-dotted quadrilateral D in FIG. Figure 16 It is a schematic cross-sectional view schematically showing a part of a main spindle device 1B of a machine tool according to a second embodiment. Figure 17 yes Figure 16 EE arrow cross-section diagram. Figure 18 is Figure 16 An enlarged view of the portion indicated by a dashed-dotted circle F in FIG. Figure 19 and Figure 20 It is a schematic cross-sectional view schematically showing a part of a main spindle device 1B of a machine tool according to a second embodiment. Figure 21 This is a schematic cross-sectional view schematically showing a portion of a spindle device 1B of a machine tool according to a modified example of the second embodiment. Figure 22 It is a schematic cross-sectional view schematically showing a spindle device 1B of a machine tool according to a second embodiment. Figure 23 and Figure 24 It is a schematic cross-sectional view schematically showing a part of a main spindle device 1B of a machine tool according to a second embodiment.

[0063] The second embodiment will be described primarily with respect to the differences from the first embodiment. Furthermore, in the second embodiment, any repetitive description of matters already described in the first embodiment will be omitted. Therefore, even if not explicitly stated, matters already described in the first embodiment can be applied to the second embodiment. Conversely, all matters described in the second embodiment can be applied to the first embodiment.

[0064] like Figure 14 and Figure 15 As illustrated, the spindle device 1B of the machine tool in the second embodiment includes: (1) a rotating body 2 (more specifically, a rotating shaft 20) having a rear end portion 22 and a front end portion 24 for holding a tool; (2) a bearing 3 (more specifically, a first bearing 3a) having an inner ring 31a and an outer ring 32a; (3) a housing 4, which supports the rotating body 2 so as to be rotatable around the first axis AX1 by means of the bearing 3 (more specifically, by means of a plurality of bearings including the first bearing 3a); (4) a supply flow channel 66, which supplies a mixed fluid containing oil and air to the bearing 3 (more specifically, the first bearing 3a); and (5) a recovery flow channel 71, which recovers the oil that has passed through the bearing 3 (more specifically, the first bearing 3a).

[0065] like Figure 15As illustrated, the rotating body 2 (more specifically, the rotating shaft 20) includes a first portion 25 that supports the inner ring 31a and has a first outer circumferential surface 25u. Furthermore, the rotating body 2 (more specifically, the rotating shaft 20) includes a second portion 26 that has a second outer circumferential surface 26u having a smaller diameter than the first outer circumferential surface 25u and is positioned further in the first direction DR1 than the first portion 25. Furthermore, the rotating body 2 (more specifically, the rotating shaft 20) includes a stepped surface 25a that connects the first outer circumferential surface 25u and the second outer circumferential surface 26u.

[0066] like Figure 15 As shown, the housing 4 includes a third portion 41 that supports the outer ring 32a, and a fourth portion 42 that defines an annular housing space SP that receives the oil E from the first gap G1 between the first portion 25 and the third portion 41. Furthermore, the fourth portion 42 includes an opening 45 that guides the oil E from the annular housing space SP to the recovery flow path 71, and an annular protrusion 441 that faces both the stepped surface 25a and the annular housing space SP and protrudes in a direction away from the first axis AX1.

[0067] Therefore, the main spindle device 1B of the machine tool in the second embodiment achieves the same effects as the main spindle device 1A of the machine tool in the first embodiment.

[0068] (Optional additional structure) Next, refer to Figures 14 to 24 An optional additional configuration that can be adopted in the spindle device 1B of the machine tool in the second embodiment (or the spindle device 1A of the machine tool in the first embodiment described above) will be described.

[0069] (Annular storage space SP) exist Figure 15 In order to facilitate understanding of the shape of the annular receiving space SP, a shadow consisting of dots is applied to the annular receiving space SP. Figure 15 As illustrated, the annular accommodation space SP may have a shape in which the area of ​​a cross section perpendicular to the first axis AX1 increases continuously or stepwise toward the first direction DR1 .

[0070] (Annular protrusion 44) exist Figure 16 and Figure 17 In the example described, the fourth portion 42 has an annular protrusion 44 that protrudes inward toward the first axis AX1. Figure 16 In the figure, in order to make it easier to understand the shape of the annular protrusion 44, the annular protrusion 44 is shaded with dots.

[0071] exist Figure 18In the example described, the annular protrusion 44 includes the annular protrusion 441 protruding outward, a first surface 44 a facing the stepped surface 25 a of the rotating body 2 , and a second surface 44 b facing the second outer peripheral surface 26 u of the rotating body 2 .

[0072] exist Figure 18 In the example described, at least a portion of the first surface 44 a is the surface of the outwardly protruding annular protrusion 441 . More specifically, at least a portion of the first surface 44 a is constituted by the upper surface 441 a of the annular protrusion 441 .

[0073] exist Figure 18 In the example described, a second gap G2 is formed between the first surface 44a and the step surface 25a, which is in fluid communication with the first gap G1. Figure 18 In the example described, the second gap G2 is connected to the first gap G1 via the annular receiving space SP. The second gap G2 is located further in the second direction DR2 than the annular protrusion 441. Figure 18 In the example described, a third gap G3 that is in fluid communication with the second gap G2 is formed between the second surface 44 b and the second outer peripheral surface 26 u of the rotating body 2 .

[0074] exist Figure 18 In the example described, the extending direction of the first gap G1 is different from the extending direction of the second gap G2. Therefore, it is possible to prevent the oil in the first gap G1 from flowing toward the second gap G2. Figure 18 In the described example, the first gap G1 extends in the first direction DR1 , and the second gap G2 extends in the radial direction DR3 (more specifically, a direction perpendicular to and toward the first axis AX1 ).

[0075] exist Figure 18 In the example described, the annular protrusion 44 has a first annular groove V1 facing the annular housing space SP and recessed in the radially inward direction DR3 . The first annular groove V1 prevents or suppresses the oil in the annular housing space SP from flowing back toward the second gap G2 .

[0076] exist Figure 18 In the example described, a portion of the surface of the first annular groove V1 is the surface of the annular protrusion 441. More specifically, a portion of the surface of the first annular groove V1 is constituted by the lower surface 441d of the annular protrusion 441.

[0077] (Configuration of annular storage space SP) exist Figure 18In the example described, the end e4 of the annular receiving space SP on the first direction DR1 side is positioned closer to the first direction DR1 side than the second gap G2, and the end e5 of the annular receiving space SP on the second direction DR2 side is positioned closer to the second direction DR2 side than the second gap G2. In this case, compared to a case where the entire annular receiving space SP is positioned closer to the first direction DR1 side than the second gap G2, the size of the region encompassing the annular receiving space SP and the second gap G2 can be made more compact.

[0078] like Figure 19 As illustrated, the distance between the outermost edge e6 of the first gap G1 and the first axis AX1 is defined as a third distance LT3, and the distance between the outermost edge e7 of the annular accommodation space SP and the first axis AX1 is defined as a fourth distance LT4.

[0079] exist Figure 19 In the example described, the fourth distance LT4 is greater than the third distance LT3. In this case, a portion of the annular housing space SP can be ensured radially outward from the first gap G1 in the direction DR4, thereby increasing the overall volume of the annular housing space SP.

[0080] exist Figure 20 In the example described, the fourth portion 42 of the housing 4 has, in addition to the first annular groove V1 recessed in the radially inward direction DR3 (in other words, in the direction toward the first axis AX1), a second annular groove V2 recessed in the radially outward direction DR4 (in other words, in the direction away from the first axis AX1). Figure 20 In the described example, the second annular groove V2 is arranged to face the annular accommodation space SP and to be opposed to the first annular groove V1 .

[0081] exist Figure 20 In the example described, oil can be contained in both the first annular groove V1 and the second annular groove V2. In this case, the annular containing space SP includes the space defined by the first annular groove V1 and the space defined by the second annular groove V2, and the overall volume of the annular containing space SP can be increased.

[0082] (Configuration of Opening 45) like Figure 8 、 Figure 19 As illustrated, the spindle device 1 of the machine tool includes an opening 45 that guides oil from the annular accommodation space SP to the recovery flow path 71. At least a portion of the opening 45 is positioned closer to the first direction DR1 than the second gap G2. Preferably, at least a portion of the opening 45 is positioned closer to the first direction DR1 than the outermost edge 441e of the annular protrusion 441. Furthermore, preferably, the entire opening 45 is positioned closer to the first direction DR1 than the first surface 44a.

[0083] The distance between the end e4 of the annular storage space SP on the first direction DR1 side and the opening 45 is defined as a fifth distance LT5, and the distance between the end e5 of the annular storage space SP on the second direction DR2 side and the opening 45 is defined as a sixth distance LT6. Figure 19 In the example described, the fifth distance LT5 is smaller than the sixth distance LT6. In this case, the opening 45 is positioned relatively close to the bottom of the annular containment space SP. Consequently, the amount of oil remaining at the bottom of the annular containment space SP without being recovered by the recovery flow passage 71 is reduced. Furthermore, oil is less likely to flow back from the annular containment space SP into the first gap G1.

[0084] exist Figure 20 In the example described, the opening 45 as a whole faces the outer side surface S1 of the annular receiving space SP. Alternatively, Figure 21 As shown in the example, at least a portion of the opening 45 may face the end surface S2 of the annular accommodation space SP in the first direction DR1. Figure 21 In the described example, a portion of the opening 45 faces the outer side surface S1 of the annular housing space SP, and another portion of the opening 45 faces the end surface S2 of the annular housing space SP in the first direction DR1 .

[0085] (Annular protrusion 441) exist Figure 18 In the described example, the annular protrusion 441 functions as a recovery member that suppresses the oil E that has entered the annular housing space SP from entering the second gap G2 .

[0086] exist Figure 19 In the example described, the distance between the outermost edge 441e of the annular protrusion 441 and the first axis AX1 (in other words, the "second distance LT2") is smaller than the distance between the outermost edge e3 of the stepped surface 25a of the rotating body 2 and the first axis AX1 (in other words, the "first distance LT1"). Alternatively, the second distance LT2 may be equal to the first distance LT1.

[0087] When the second distance LT2 is less than or equal to the first distance LT1, it is possible to prevent or suppress the oil E flowing from the first gap G1 toward the first direction DR1 from colliding with the annular protrusion 441. Therefore, the oil E flowing from the first gap G1 toward the first direction DR1 is less likely to enter the gap between the stepped surface 25a and the annular protrusion 441 (or the second gap G2 between the stepped surface 25a and the first surface 44a).

[0088] exist Figure 20 In the described example, the annular protrusion 441 has an upper surface 441 a , an outer side surface 441 c , and a lower surface 441 d .

[0089] The upper surface 441a is an annular surface facing the stepped surface 25a of the rotating body 2. The upper surface 441a may be perpendicular to the first axis AX1 or may be inclined with respect to a surface perpendicular to the first axis AX1.

[0090] exist Figure 20 In the example described, the outer side surface 441c faces the annular accommodation space SP. In a longitudinal section passing through the first axis AX1, the outer side surface 441c is parallel to the first axis AX1. Alternatively, in a longitudinal section passing through the first axis AX1, the outer side surface 441c may be slightly inclined relative to the first axis AX1.

[0091] exist Figure 20 In the example described, the lower surface 441d is an annular surface facing the annular receiving space SP. The lower surface 441d may also include an inclined surface CS that approaches the first axis AX1 as it moves toward the first direction DR1. Figure 20 As shown by the dotted arrow in FIG, the inclined surface CS guides the oil moving upward in the annular housing space SP toward the second gap G2 (more specifically, toward the first axis AX1). Therefore, the oil in the annular housing space SP can be effectively prevented from moving toward the second gap G2.

[0092] exist Figure 20 In the example described, the lower surface 441d includes, in addition to the aforementioned inclined surface CS, a surface HS perpendicular to the first axis AX1. The outer edge of this surface HS is connected to the inner edge of the aforementioned inclined surface CS. Alternatively, either the inclined surface CS or the surface HS may be omitted.

[0093] exist Figure 16 In the example described, the housing 4 includes a first component CP1 (more specifically, an annular first component CP1) including the aforementioned annular protrusion 441, and a second component CP2 (more specifically, an annular second component CP2) that supports the first component CP1. If the first component CP1 including the annular protrusion 441 is a separate component from the second component CP2, the degree of freedom in designing the internal shape of the housing 4 (for example, the degree of freedom in the shape of the annular accommodation space SP) can be increased.

[0094] exist Figure 16 In the described example, the first component CP1 and the second component CP2 each have a portion facing the annular accommodation space SP. Alternatively, the first component CP1 and the second component CP2 may each constitute a portion of the surface defining the first annular groove V1. Furthermore, the first component CP1 may have a substantially L-shaped longitudinal section passing through the first axis AX1. The second component CP2 may also be an end plate disposed at the end of the housing 4 on the side in the first direction DR1.

[0095] exist Figure 16In the example described, the annular protrusion 44 is composed of a plurality of components (CP1, CP2). Alternatively, the annular protrusion 44 may be composed of a single component.

[0096] (Air injection port OP1 and exhaust port 49) exist Figure 18 In the described example, the air injection port OP1 communicating with the third gap G3 is formed between the front end portion 46 of the housing 4 and the rotating body 2 .

[0097] Furthermore, the housing 4 has an air flow path 93 formed therein, through which air supplied from an air source (hereinafter referred to as “second air” to distinguish it from the air in the mixed fluid supplied from the lubrication device) flows.

[0098] Furthermore, the housing 4 is provided with an exhaust port 49 for exhausting the second air. The exhaust port 49 exhausts the second air received from the air flow path 93 into the third gap G3, thereby forming a first air flow from the third gap G3 toward the second gap G2 and a second air flow from the third gap G3 toward the air injection port OP1.

[0099] The second air ejected from the air ejection port OP1 prevents foreign matter such as chips from entering the spindle device 1 of the machine tool through the third gap G3 and the like. More specifically, Figure 14 In the example described, the second air ejected from the air ejection port OP1 forms an air curtain AC around the tool T or the tool holder HD. This air curtain prevents foreign matter such as chips from entering the spindle device 1 of the machine tool through the third gap G3 and the like.

[0100] exist Figure 18 In the example described, the second air flowing from the third gap G3 toward the second gap G2 prevents the oil E from entering the second gap G2 from the first gap G1 or the annular housing space SP. Furthermore, the second air flowing from the third gap G3 toward the second gap G2 pushes the oil that has entered the second gap G2 back toward the annular housing space SP.

[0101] Furthermore, at least a portion of the second air flowing from the third gap G3 toward the second gap G2 reaches the annular housing space SP. The air reaching the annular housing space SP is recovered via the recovery flow path 71.

[0102] (rotating body 2) exist Figure 22 In the example described, the rotating body 2 (more specifically, the rotating shaft 20) includes a rotating shaft body 21, a mounting portion 28 for mounting a tool T, and a rod-shaped member 291 connected to the mounting portion 28. The rod-shaped member 291 is arranged inside the rotating shaft body 21. Figure 22In the example described, if the mounting portion drive device 11 of the machining head 10 presses the rod-shaped member 291 in the first direction DR1, the rod-shaped member 291 and the mounting portion 28 move relative to the rotating shaft body 21 in the first direction DR1. In this state, the tool T mounted on the mounting portion 28 can be replaced with another tool. After the tool is replaced, the biasing member 293 (e.g., a disc spring) disposed on the rotating shaft 20 presses the rod-shaped member 291 in the second direction DR2. This causes the rod-shaped member 291 and the mounting portion 28 to move relative to the rotating shaft body 21 in the second direction DR2.

[0103] exist Figure 23 In order to facilitate understanding of the shape of the first portion 25 of the rotating body 2, a dotted shadow is applied to the first portion 25. Figure 23 In the example described, the first portion 25 and the second portion 26 each constitute a portion of the rotating shaft body 21. In other words, the rotating shaft body 21 includes the first portion 25 and the second portion 26. The first portion 25 and the second portion 26 can be formed from a single component or an assembly of multiple components. Furthermore, the first portion 25 and the second portion 26 can each be formed from a single component or an assembly of multiple components.

[0104] exist Figure 23 In the example described, the first portion 25 has the aforementioned stepped surface 25a and the aforementioned first peripheral surface 25u. Additionally, the first portion 25 may also have a second stepped surface 25b and / or a third peripheral surface 25w. Figure 23 In the example described, the outwardly projecting annular protrusion 250 is defined by the stepped surface 25a, the first outer peripheral surface 25u, and the second stepped surface 25b. In other words, the first portion 25 of the rotating body 2 has the annular protrusion 250, which has the stepped surface 25a, the first outer peripheral surface 25u, and the second stepped surface 25b.

[0105] exist Figure 23 In the example described, the stepped surface 25a is the surface of the first portion 25 facing the first direction DR1. The first outer peripheral surface 25u is the surface that faces at least a portion of the third portion 41 of the housing 4. The second stepped surface 25b is the surface that contacts the end surface of the inner ring 31a of the first bearing 3a facing the first direction DR1. Furthermore, the third outer peripheral surface 25w is the surface that contacts the inner peripheral surface of the inner ring 31a of the first bearing 3a.

[0106] The first portion 25 of the rotating body 2 may also have a first inner peripheral surface 25n in contact with the tool holder HD. Figure 23 In the described example, the first inner peripheral surface 25n is a tapered surface whose diameter increases as it goes toward the first direction DR1.

[0107] exist Figure 23 In the example described, the maximum outer diameter of the second portion 26 of the rotating body 2 is smaller than the outer diameter of the stepped surface 25a. In other words, the entire second portion 26 has a smaller diameter than the outer periphery of the stepped surface 25a.

[0108] exist Figure 23 In the example described, the second portion 26 includes a second outer peripheral surface 26u and an end surface 26f. The end surface 26f is disposed at an end portion of the second portion 26 on the side in the first direction DR1.

[0109] The end surface 26f of the second portion 26 is positioned further in the first direction DR1 than the end surface of the fourth portion 42 of the housing 4 (more specifically, the third surface 44f of the annular protrusion 44).

[0110] The second portion 26 of the rotating body 2 may also have a second inner peripheral surface 26n in contact with the tool holder HD. Figure 23 In the example described, the second inner peripheral surface 26n is a tapered surface whose diameter increases as it goes toward the first direction DR1. Figure 23 In the example described, the inner peripheral surfaces ( 25 n , 26 n ) that come into contact with the tool holder HD are arranged so as to straddle the first portion 25 of the rotating body 2 and the second portion 26 of the rotating body 2 .

[0111] (Shell 4) exist Figure 22 In the described example, the housing 4 includes a front end portion 4 a , a rear end portion 4 b , and an intermediate portion 4 c between the front end portion 4 a and the rear end portion 4 b .

[0112] The front end portion 4a of the housing 4 supports the outer ring of the front bearing. Figure 24 In the example described, the front end portion 4 a of the housing 4 supports the outer ring 32 a of the first bearing 3 a and the outer ring 32 c of the third bearing 3 c .

[0113] The front end portion 4a of the housing 4 includes the third portion 41 and the fourth portion 42. Figure 24 In the example described, the fourth portion 42 includes the entire surface defining the annular accommodation space SP in the housing 4 and the entire annular protrusion 44. The fourth portion 42 is disposed on the first direction DR1 side relative to the third portion 41.

[0114] like Figure 2 or Figure 15 As shown in the example, the fourth portion 42 includes a base portion 43 connected to the third portion 41 and an annular protrusion 44 protruding from the base portion 43 toward the first axis AX1. Figure 8 or Figure 18In the example described, the annular protrusion 44 has a first wall 440a that defines the bottom surface of the annular containing space SP (in other words, the end surface on the first direction DR1 side of the annular containing space SP), a second wall 440b that defines the second surface 44b facing the second outer peripheral surface 26u of the rotating body 2, and an annular protrusion 441 that protrudes from the second wall 440b in a direction away from the first axis AX1.

[0115] exist Figure 18 In the example described, the first wall 440a is an annular wall connected to the base 43 of the fourth portion 42 and extending from the base 43 in the radially inward direction DR3. Furthermore, the second wall 440b is an annular wall connected to the inner edge of the first wall 440a and extending from the inner edge in the second direction DR2. Furthermore, the annular protrusion 441 is connected to the end of the second wall 440b on the side in the second direction DR2 and protrudes from this end in the radially outward direction DR4.

[0116] The housing 4 may also be provided with a flange 47 protruding outwards. Figure 24 In the example described, the flange 47 is disposed on the front end portion 4a of the housing 4. The flange 47 may be provided with the outlet port 71p of the recovery flow path 71.

[0117] The rear end portion 4b of the housing 4 supports the outer ring of the rear bearing. Figure 22 In the example described, the rear end portion 4b of the housing 4 supports the outer ring of the second bearing 3b. The rear end portion 4b may include an end plate 40b disposed at the end of the housing 4 on the side in the second direction DR2.

[0118] exist Figure 22 In the example described, the intermediate portion 4c of the housing 4 has a cylindrical side wall 40c. The intermediate portion 4c of the housing 4 (more specifically, the cylindrical side wall 40c) can also support the stator 51 described later.

[0119] (Bearing 3) exist Figure 22 In the example described above, the plurality of bearings 3 supporting the rotating body 2 for rotation about the first axis AX1 include a first bearing 3a and a second bearing 3b. Alternatively, the plurality of bearings 3 may include a third bearing 3c. The third bearing 3c is disposed between the first bearing 3a and the second bearing 3b along the first axis AX1. The third bearing 3c is, for example, a ball bearing.

[0120] The first bearing 3a constitutes at least a part of the front bearing supporting the front end portion 24 of the rotating body 2. Figure 22In the example described, the first bearing 3a is the bearing that is arranged closest to the first direction DR1 side (in other words, the front end side) among the multiple bearings 3 supporting the rotating body 2. The first bearing 3a is, for example, a ball bearing. The front side bearing supporting the front end portion 24 of the rotating body 2 may also include multiple bearings. Figure 22 In the described example, the front bearing includes the first bearing 3 a and the third bearing 3 c .

[0121] Second bearing 3b forms at least a portion of a rear bearing supporting rear end portion 22 of rotating body 2. Second bearing 3b is, for example, a roller bearing. Second bearing 3b includes an inner ring supported by rotating body 2 and an outer ring supported by housing 4. The rear bearing may also include multiple bearings.

[0122] (First Rotation Driving Device 5) exist Figure 22 In the example described, the spindle device 1 of the machine tool includes a first rotation drive device 5 that rotates the rotating body 2 (more specifically, the rotating shaft 20) around the first axis AX1. The first rotation drive device 5 may also be a first motor. Figure 22 In the example described above, the first rotary drive device 5 (more specifically, the first motor) includes a stator 51 and a rotor 53. In this case, when current is supplied to the stator 51, the rotor 53 rotates around the first axis AX1 due to electromagnetic action. Figure 22 In the example described, the stator 51 is fixed to the housing 4 , and the rotor 53 is fixed to the rotating body 2 (more specifically, the rotating shaft 20 ).

[0123] exist Figure 22 In the example described, the rotor 53 is arranged in the middle portion 23 of the rotating shaft 20. Figure 22 In the described example, the rotor 53 is arranged on the second direction DR2 side relative to the first bearing 3 a , and is arranged on the first direction DR1 side relative to the second bearing 3 b .

[0124] exist Figure 22 In the example described, the first rotational drive device 5 is disposed inside the housing 4. Alternatively, the first rotational drive device 5 may be disposed outside the housing 4. For example, the first rotational drive device 5 disposed outside the housing 4 may rotate the rotating body 2 via any transmission mechanism (e.g., gears, a transmission belt, etc.).

[0125] (Supply flow channel 66) The spindle device 1 of the machine tool includes a supply flow path 66 for supplying a mixed fluid containing oil and air to the bearing 3 (e.g., the first bearing 3a). At least a portion of the supply flow path 66 is disposed in the housing 4. At least a portion of the supply flow path 66 may be formed by a through hole formed in the housing 4.

[0126] The supply flow passage 66 may also supply a mixed fluid containing oil and air to a plurality of bearings including the first bearing 3a. Figure 22 In the example described, the supply flow passage 66 supplies a mixed fluid containing oil and air to the first bearing 3a and the third bearing 3c. Alternatively, the supply flow passage 66 may supply a mixed fluid containing oil and air to the second bearing 3b.

[0127] (Recovery channel 71) The spindle device 1 of the machine tool has a recovery flow channel 71 for recovering the oil E that has passed through the bearing 3 (more specifically, the first bearing 3a). The recovery flow channel 71 can also recover at least a portion of the air supplied from the supply flow channel 66 to the bearing 3 (more specifically, the first bearing 3a). In addition, the recovery flow channel 71 can also recover the air supplied from the air flow channel 93 to the third gap G3 (if necessary, refer to Figure 18 ) of the second air. At least a portion of the recovery flow path 71 is disposed in the housing 4. At least a portion of the recovery flow path 71 may also be formed by a through hole formed in the housing 4.

[0128] (Second recovery flow channel 72) The spindle device 1 of the machine tool may also include a second recovery flow path 72 for recovering the oil-containing fluid containing oil and air from the bearing 3 (more specifically, the first bearing 3a). Figure 22 In the example described, the second recovery flow path 72 is a flow path independent of the recovery flow path 71. Figure 22 In the example described, the second recovery passage 72 directly recovers oil from the bearing 3 (more specifically, the first bearing 3 a ). The oil E that has not been recovered by the second recovery passage 72 but has passed through the bearing 3 (more specifically, the first bearing 3 a ) is recovered by the recovery passage 71 .

[0129] At least a portion of the second recovery flow path 72 is disposed in the housing 4 . At least a portion of the second recovery flow path 72 may be formed as a through hole formed in the housing 4 .

[0130] The second recovery flow channel 72 can also recover the oil-containing fluid containing oil and air from multiple bearings including the first bearing 3a. Figure 22 In the described example, the second recovery flow path 72 recovers the oil-containing fluid from the first bearing 3 a constituting a part of the front bearing and the third bearing 3 c constituting a part of the front bearing.

[0131] (Third recovery channel 73) The spindle device 1 of the machine tool may also include a third recovery flow path 73 for recovering the oil-containing fluid containing oil and air from the second bearing 3b. Figure 22 In the example described, the third recovery flow path 73 is a flow path independent of the recovery flow path 71 and the second recovery flow path 72. Figure 22In the described example, the third recovery flow path 73 recovers oil directly from the second bearing 3 b.

[0132] At least a portion of the third recovery flow path 73 is disposed in the housing 4 . At least a portion of the third recovery flow path 73 may be formed by a through hole formed in the housing 4 .

[0133] The third recovery flow path 73 may also recover the oil-containing fluid from a plurality of bearings including the second bearing 3 b. For example, the third recovery flow path 73 may also recover the oil-containing fluid from a plurality of bearings constituting the rear bearing.

[0134] The air (or oil) not recovered by the recovery flow passage 71, the second recovery flow passage 72 and the third recovery flow passage 73 is discharged from the gap of the spindle device 1 of the machine tool to the outside of the spindle device (see Figure 22 dashed arrow in the figure).

[0135] (Third embodiment) Reference Figures 1 to 27 A machine tool 100 according to a third embodiment will be described. Figure 25 It is a schematic perspective view schematically showing an example of a machine tool 100 according to the third embodiment. Figure 26 It is a schematic perspective view schematically showing another example of the machine tool 100 in the third embodiment. Figure 27 This is a diagram schematically showing a case where the control device 140 can control a plurality of control target devices.

[0136] The third embodiment will be described primarily with respect to the differences from the first and second embodiments. Furthermore, in the third embodiment, repeated descriptions of matters already described in the first or second embodiment will be omitted. Therefore, even if not explicitly stated in the third embodiment, matters already described in the first or second embodiment can of course be applied to the third embodiment.

[0137] like Figure 25 and Figure 27 As illustrated, the machine tool 100 in the third embodiment includes a machining head 10, a lubrication device 6, a recovery device 7, a workpiece support device 110 that supports the workpiece W, a moving device 120 that moves the machining head 10 relative to the workpiece support device 110, and a control device 140 that controls at least the first rotation drive device 5 and the moving device 120.

[0138] like Figure 14As shown in the example, the machining head 10 comprises: (1) a rotating body 2 (more specifically, a rotating shaft 20) having a rear end portion 22 and a front end portion 24 for holding a tool T; (2) a plurality of bearings 3, including a first bearing 3a; (3) a housing 4, which supports the rotating body 2 by means of the plurality of bearings 3 so as to be rotatable around a first axis AX1; and (4) a first rotation drive device 5, which rotates the rotating body 2 around the first axis AX1.

[0139] like Figure 15 As shown, the rotating body 2 (more specifically, the rotating shaft 20) includes a first portion 25, a second portion 26, and a stepped surface 25a. The first portion 25 supports the inner ring 31a of the first bearing 3a and has a first outer peripheral surface 25u. The second portion 26 is positioned further in the first direction DR1 than the first portion 25 and has a second outer peripheral surface 26u with a smaller diameter than the first outer peripheral surface 25u. The stepped surface 25a connects the first outer peripheral surface 25u and the second outer peripheral surface 26u.

[0140] Since the rotating body 2 has been described in the first embodiment or the second embodiment, repeated description of the rotating body 2 will be omitted.

[0141] like Figure 15 As illustrated, the housing 4 includes a third portion 41 supporting the outer ring 32 a of the first bearing 3 a and a fourth portion 42 defining an annular accommodation space SP that receives the oil E from the first gap G1 between the first portion 25 of the rotating body 2 and the third portion 41 .

[0142] The fourth portion 42 includes an opening 45 that guides the oil E from the annular housing space SP to the recovery flow path 71 , and an annular protrusion 441 that faces both the step surface 25 a of the rotating body 2 and the annular housing space SP and protrudes in a direction away from the first axis AX1 .

[0143] Since the housing 4 has been described in the first embodiment or the second embodiment, repeated description of the housing 4 will be omitted.

[0144] exist Figure 22 In the described example, the lubricating device 6 supplies a mixed fluid containing oil and air to the first bearing 3 a via the supply flow path 66 .

[0145] The recovery device 7 recovers at least a portion of the oil E that has passed through the first bearing 3 a via the recovery flow path 71 .

[0146] The third embodiment achieves the same effects as those of the first embodiment (or the second embodiment).

[0147] (Optional additional structure) Next, refer to Figures 1 to 27An optional additional configuration that can be adopted in the machine tool 100 in the third embodiment (or the spindle device 1A of the machine tool in the first embodiment or the spindle device 1B of the machine tool in the second embodiment) will be described.

[0148] (Lubrication device 6) exist Figure 22 In the example described, the lubrication device 6 includes an air source AS1 (eg, an air compressor), an oil tank 62 , a pump 63 , a mixer 64 , a supply flow path 66 , and a supply pipe 68 connecting the mixer 64 and the supply flow path 66 .

[0149] Air source AS1 supplies air to mixer 64. Pump 63 supplies oil from oil tank 62 to mixer 64. Mixer 64 mixes air received from air source AS1 with oil received from oil tank 62 to form a mixed fluid containing oil and air (more specifically, oil-air). Mixer 64 then delivers this mixed fluid to supply flow path 66 via supply pipe 68.

[0150] exist Figure 22 In the example described, the supply pipe 68 is disposed outside the housing 4, and the supply flow channel 66 is disposed inside the housing 4. The supply flow channel 66 supplies a mixed fluid containing oil and air to at least the first bearing 3a. Alternatively, the supply flow channel 66 may also supply a mixed fluid containing oil and air to the second bearing 3b and / or the third bearing 3c.

[0151] (Recovery device 7) exist Figure 22 In the example described, the recovery device 7 includes a recovery channel 71, a first ejector 75a, a first pipe 74a connecting the recovery channel 71 and the first ejector 75a, a first exhaust pipe 76a, an exhaust purifier 77, a recovery container 78, and an air source AS2 (e.g., an air compressor). The air source AS2 of the recovery device 7 can be the same as or different from the air source AS1 of the lubricating device 6.

[0152] The recovery device 7 may also include a second recovery channel 72, a second ejector 75b, a second pipe 74b connecting the second recovery channel 72 and the second ejector 75b, and a second exhaust pipe 76b. Furthermore, the recovery device 7 may also include a third recovery channel 73, a third ejector 75c, a third pipe 74c connecting the third recovery channel 73 and the third ejector 75c, and a third exhaust pipe 76c.

[0153] exist Figure 22 In the example described, the recovery flow path 71 is arranged inside the housing 4, and the first pipe 74a is arranged outside the housing 4. Figure 24In the described example, the recovery flow path 71 and the first pipe 74 a are fluidically connected via the outlet port 71 p provided in the housing 4 (more specifically, the flange 47 ).

[0154] like Figure 24 As shown, the recovery flow path 71 receives oil from the annular housing space SP via the opening 45. More specifically, the recovery flow path 71 receives oil-containing fluid (hereinafter referred to as "first oil-containing fluid") containing at least a portion of the oil that has passed through the first bearing 3a from the annular housing space SP.

[0155] exist Figure 22 In the example described, the first ejector 75a uses air supplied from the air source AS2 (hereinafter referred to as "third air") to generate a negative pressure in the first pipe 74a. Furthermore, the first ejector 75a delivers the third air received from the air source AS2 and the first oil-containing fluid received from the recovery flow path 71 via the first pipe 74a to the exhaust purifier 77 via the first exhaust pipe 76a.

[0156] exist Figure 22 In the example described, the second recovery flow path 72 is arranged inside the shell 4, and the second pipe 74b is arranged outside the shell 4. Figure 22 In the described example, the second recovery flow path 72 and the second pipe 74 b are fluidically connected via a second outlet port 72 p provided on the housing 4 (more specifically, the flange 47 ).

[0157] like Figure 22 As shown, the second recovery flow channel 72 receives the oil-containing fluid (hereinafter referred to as the "second oil-containing fluid") from at least the first bearing 3a. The second recovery flow channel 72 may also receive the second oil-containing fluid from multiple front bearings including the first bearing 3a (e.g., the first bearing 3a and the third bearing 3c).

[0158] exist Figure 22 In the example described, second ejector 75b uses air supplied from air source AS2 (hereinafter referred to as "fourth air") to generate a negative pressure in second conduit 74b. Furthermore, second ejector 75b delivers the fourth air received from air source AS2 and the second oil-containing fluid received from second recovery flow path 72 via second conduit 74b to exhaust purifier 77 via second exhaust conduit 76b.

[0159] exist Figure 22 In the example described, the third recovery flow path 73 is arranged inside the shell 4, and the third pipe 74c is arranged outside the shell 4. Figure 22 In the described example, the third recovery flow path 73 and the third pipe 74 c are fluidically connected via a third outlet port 73 p provided in the housing 4 .

[0160] The third recovery flow path 73 receives the oil-containing fluid (hereinafter referred to as "third oil-containing fluid") from at least the second bearing 3b. The third recovery flow path 73 may also receive the third oil-containing fluid from a plurality of rear bearings including the second bearing 3b.

[0161] exist Figure 22 In the example described, the third ejector 75c uses air supplied from the air source AS2 (hereinafter referred to as "fifth air") to generate a negative pressure in the third duct 74c. Furthermore, the third ejector 75c delivers the fifth air received from the air source AS2 and the third oil-containing fluid received from the third recovery flow path 73 via the third duct 74c to the exhaust purifier 77 via the third exhaust duct 76c.

[0162] The exhaust gas purifier 77 receives oil-containing fluid from multiple injectors (e.g., the first, second, and third injectors 75a, 75b, 75c) including the first injector 75a via multiple exhaust ducts (e.g., the first, second, and third exhaust ducts 76a, 76b, 76c) including the first exhaust duct 76a. Furthermore, the exhaust gas purifier 77 separates the oil-containing fluid received from the multiple exhaust ducts including the first exhaust duct 76a into liquid oil and air. The liquid oil separated from the oil-containing fluid by the exhaust gas purifier 77 is collected in a recovery container 78.

[0163] (Air supply device 9) The machine tool 100 in the third embodiment may also include an air supply device 9 . The air supply device 9 supplies air to an exhaust port 49 formed in the housing 4 .

[0164] exist Figure 22 In the example described, the air supply device 9 includes an air source AS3 (e.g., an air compressor), an air flow passage 93, and an air supply pipe 91 connecting the air source AS3 and the air flow passage 93. The air source AS3 of the air supply device 9 may be the same as or different from the air source AS1 of the lubricating device 6. Furthermore, the air source AS3 of the air supply device 9 may be the same as or different from the air source AS2 of the recovery device 7. The air source AS3 supplies the second air to the air flow passage 93 via the air supply pipe 91.

[0165] exist Figure 22 In the example described, the air supply pipe 91 is arranged outside the housing 4, and the air flow path 93 is arranged inside the housing 4. Figure 22 In the described example, the air supply pipe 91 and the air flow path 93 are fluidically connected via a supply port 93 p provided in the housing 4 (more specifically, the flange 47 ).

[0166] The air flow passage 93 supplies the second air received from the air supply pipe 91 to the exhaust port 49. Figure 18 In the example described, the discharge port 49 discharges the second air received from the air flow path 93 to the third gap G3. The second air discharged to the third gap G3 forms a first air flow from the third gap G3 toward the second gap G2 and a second air flow from the third gap G3 toward the air injection port OP1.

[0167] (Workpiece Support Device 110) exist Figure 25 In the example described, the workpiece support device 110 includes a support member 111 (more specifically, a table 111a) that supports the workpiece W, and a second rotation drive device 112 that rotates the support member 111 (more specifically, the table 111a) about a second axis AX2. The workpiece support device 110 may also include a tilting device 113 that tilts the table 111a about an axis AX3 that is perpendicular to the second axis AX2.

[0168] Alternatively, if Figure 26 As illustrated, the workpiece support device 110 may include a chuck 111 b that holds the workpiece W and a second rotation drive device 112 that rotates the chuck 111 b around the second axis AX2.

[0169] (Mobile device 120) The moving device 120 moves the machining head 10 relative to the workpiece support device 110. The moving device 120 can also be a device that can move the machining head 10 in three dimensions. The moving device 120 can also be a device that can move the machining head 10 along the Z axis parallel to the vertical direction. The moving device 120 can also be a device that can move the machining head 10 along the X axis parallel to the horizontal direction. In addition, the moving device 120 can also be a device that can move the machining head 10 along the Y axis perpendicular to both the X axis and the Z axis. Figure 25 and Figure 26 In the described example, the processing head 10 is supported by the base 130 via the moving device 120 .

[0170] (Control device 140) The control device 140 controls at least the first rotation drive device 5 and the moving device 120 .

[0171] For example, in Figure 27 In the example described, when the control device 140 sends the first movement command J1 to the moving device 120, the moving device 120, upon receiving the first movement command J1, moves the machining head 10 relative to the workpiece support 110. This allows the tool T held by the rotating body 2 to move toward the workpiece W.

[0172] When the control device 140 sends the first rotation command R1 to the first rotation drive device 5 , the first rotation drive device 5 rotates the rotating body 2 about the first axis AX1 , thereby allowing the tool T held by the rotating body 2 to machine the workpiece W.

[0173] Alternatively, the control device 140 may be capable of controlling the lubrication device 6 and / or the recovery device 7 .

[0174] For example, if the control device 140 sends a first control command C1 to the lubrication device 6 (e.g., the air source AS1, the pump 63, the on-off valve, the flow control valve, etc.), the lubrication device 6, upon receiving the first control command C1, supplies a mixed fluid containing oil and air to at least one bearing, including the first bearing 3a. Furthermore, if the control device 140 sends a second control command C2 to the recovery device 7 (e.g., the air source AS2, the on-off valve, the flow control valve, etc.), the recovery device 7, upon receiving the second control command C2, recovers at least a portion of the oil that has passed through the first bearing 3a. Furthermore, the recovery device 7, upon receiving the second control command C2, recovers the oil-containing fluid from the first bearing 3a, the second bearing 3b, and the third bearing 3c.

[0175] Alternatively, the control device 140 may be capable of controlling the air supply device 9. For example, if the control device 140 sends a third control command C3 to the air supply device 9 (e.g., the air source AS3, the on-off valve, the flow control valve, etc.), the air supply device 9, upon receiving the third control command C3, supplies the second air to the exhaust port 49. The exhaust port 49 exhausts the second air received from the air flow passage 93 into the third gap G3. The second air discharged into the third gap G3 forms a first air flow from the third gap G3 toward the second gap G2, and a second air flow from the third gap G3 toward the air injection port OP1.

[0176] The control device 140 may also be capable of controlling the second rotation drive device 112. For example, if the control device 140 sends a second rotation command R2 to the second rotation drive device 112, the second rotation drive device 112 receives the second rotation command R2 and rotates the support member 111 supporting the workpiece W about the second axis AX2.

[0177] like Figure 27 As shown, control device 140 includes a hardware processor 141 (hereinafter referred to as "processor 141"), memory 142, communication circuit 144, and input device 146 (e.g., display 146a with a touch panel). Processor 141, memory 142, communication circuit 144, and input device 146 are interconnected via bus 148.

[0178] The memory 142 stores data 142a required for machining a workpiece and a program 142b for operating the various components of the machine tool 100. The memory 142 is a storage medium readable by the processor 141 of the control device 140. The memory 142 may be, for example, a nonvolatile or volatile semiconductor memory such as RAM, ROM, or flash memory, a magnetic disk, or other memory formats.

[0179] The input device 146 is not limited to the display 146a with a touch panel. For example, the control device 140 may include input devices 146 such as buttons, switches, joysticks, pointing devices, and keyboards, as well as a display that displays data or other information input to the input devices 146. Furthermore, multiple computers may collaborate to function as the control device 140. Furthermore, the memory 142 may be distributed across multiple locations. For example, a portion of the memory 142 may be included in cloud storage.

[0180] The processor 141 of the control device 140 executes a program 142b stored in the memory 142, thereby generating a control command. Furthermore, the communication circuit 144 transmits this control command to the controlled devices (more specifically, the first rotary drive device 5, the moving device 120, the lubricating device 6, the recovery device 7, the air supply device 9, and the second rotary drive device 112). Thus, by executing the program 142b on the processor 141, the control device 140 can control the first rotary drive device 5, the moving device 120, the lubricating device 6, the recovery device 7, the air supply device 9, and the second rotary drive device 112.

[0181] The present invention is not limited to the above-described embodiments or variations. It is apparent that the embodiments or variations may be appropriately modified or altered within the scope of the technical concept of the present invention. Furthermore, the various techniques used in the embodiments or variations may also be applied to other embodiments or variations, as long as no technical contradictions arise. Furthermore, any additional structures in the embodiments or variations may be appropriately omitted.

[0182] For example, in Figure 25 In the example described, the machine tool 100 is a vertical machining center. Alternatively, the machine tool 100 in the embodiment may be a horizontal machining center. Furthermore, the machine tool 100 may be a multi-processor capable of performing machining other than cutting.

[0183] In addition, Figure 2 、 Figure 7 、 Figure 12 、 Figure 15 and Figure 212 shows an example in which the first portion 25 of the rotating body 2 and the second portion 26 of the rotating body 2 are each composed of a portion of the rotating shaft main body 21. Alternatively, Figure 28 As illustrated, at least a portion of the first portion 25 of the rotating body 2 and the second portion 26 of the rotating body 2 may be formed of a member other than the rotating shaft main body 21 .

[0184] exist Figure 28 In the example described, the first portion 25 of the rotating body 2 is composed of a portion of the rotating shaft body 21 and the base end portion BL1 of the inner race retaining body BL. The inner race retaining body BL forms part of the rotating body 2 and has a first outer peripheral surface 25u. Furthermore, the inner race retaining body BL is secured to the rotating shaft body 21 with a securing member such as bolts.

[0185] exist Figure 28 In the example described, the inner ring 31 is supported by the rotating shaft body 21 and the inner ring retaining body BL. In addition, a first gap G1 is formed between the first portion 25 of the rotating body 2 (more specifically, the base end portion BL1 of the inner ring retaining body BL) and the third portion 41 of the housing 4.

[0186] exist Figure 28 In the example described, the second portion 26 of the rotating body 2 is formed by the front end portion BL2 of the inner race retaining body BL. The second portion 26 of the rotating body 2 (more specifically, the front end portion BL2 of the inner race retaining body BL) has a second outer peripheral surface 26u with a smaller diameter than the first outer peripheral surface 25u and is positioned further in the first direction DR1 than the first portion 25 of the rotating body 2 (more specifically, the base end portion BL1 of the inner race retaining body BL).

[0187] exist Figure 28 In the example described, the rotating body 2 (more specifically, the inner ring retaining body BL) has a stepped surface 25a connecting the first outer peripheral surface 25u and the second outer peripheral surface 26u. Furthermore, a second gap G2 is formed between the first surface 44a of the annular protrusion 44 and the stepped surface 25a, which is in fluid communication with the first gap G1. Furthermore, a third gap G3 is formed between the second surface 44b of the annular protrusion 44 and the aforementioned second outer peripheral surface 26u, which is in fluid communication with the second gap G2.

[0188] In addition, Figure 2 、 Figure 7 、 Figure 12 、 Figure 15 and Figure 21 In the example described, the first gap G1 is linear in the longitudinal section including the first axis AX1. Alternatively, Figure 29 As shown in the example, the first gap G1 may also have a labyrinth shape in the longitudinal section including the first axis AX1. Figure 30 As shown in the example, a notch CT may be formed in a portion of the surface defining the first gap G1 . The notch CT may be formed in the first outer peripheral surface 25 u of the rotating body 2 or in the surface of the third portion 41 of the housing 4 . Description of Reference Numerals

[0189] 1, 1A, 1B spindle device of machine tool, 2 rotating body, 3 bearing, 3a first bearing, 3b second bearing, 3c third bearing, 4 housing, 4a front end side portion of housing, 4b rear end side portion of housing, 4c middle portion of housing, 4f end surface of housing, 5 first rotation drive device, 6 lubrication device, 7 recovery device, 9 air supply device, 10 machining head, 11 mounting portion drive device, 20 rotating shaft, 21 rotating shaft main body, 22 rear end portion of rotating body, 23 middle portion of rotating shaft, 24 front end portion of rotating body, 25 first portion, 25a step surface, 25b second step surface, 25n first inner peripheral surface, 25u first outer peripheral surface, 25w third outer peripheral surface, 26 second portion, 26f end surface of second portion, 2 6n second inner circumferential surface, 26u second outer circumferential surface, 28 mounting portion, 31, 31a inner ring, 32, 32a, 32c outer ring, 33 rolling element, 40b end plate, 40c side wall of the housing, 41 third portion, 42 fourth portion, 43 base, 44 annular protrusion, 44a first surface, 44b second surface, 44f third surface, 45 opening, 46 front end, 47 housing flange, 49 discharge port, 51 stator, 53 rotor, 62 oil tank, 63 pump, 64 mixer, 66 supply flow channel, 68 supply pipe, 71 recovery flow channel, 71p outlet port, 72 second recovery flow channel, 72p second outlet port, 73 third recovery flow channel, 73p third outlet port, 74a first pipe, 74b second pipe, 7 4c third pipe, 75a first ejector, 75b second ejector, 75c third ejector, 76a first exhaust pipe, 76b second exhaust pipe, 76c third exhaust pipe, 77 exhaust purifier, 78 recovery container, 91 air supply pipe, 93 air flow channel, 93p supply port, 100 machine tool, 110 workpiece support device, 111 support member, 111a worktable, 111b chuck, 112 second rotary drive device, 113 tilting movement device, 120 movement device, 130 base, 140 control device, 141 hardware processor, 142 memory, 142a data, 142b program, 144 communication circuit, 146 input device, 146a display with touch panel, 148 bus , 250 annular protrusion, 291 rod-shaped member, 293 force-applying member, 440a first wall, 440b second wall, 441 annular protrusion, 441a upper surface, 441c outer side surface, 441d lower surface, 441e outermost edge, 443d, 444d, 445d surfaces constituting the first annular groove, AC air curtain, AS1, AS2, AS3 air source, BL inner ring retaining body, BL1 base end side portion of the inner ring retaining body, BL2 front end side portion of the inner ring retaining body, C1 first control instruction, C2 second control instruction, C3 third control instruction, CN corner, CP1 first component, CP2 second component, CS inclined surface, CT notch, E oil, G1 first gap, G2 second gap, G3 third gap,HD: tool holder, HS: surface perpendicular to the first axis, J1: first movement command, OP1: air jet port, R1: first rotation command, R2: second rotation command, S1: outer side surface, S2: end surface, SP: annular housing space, T: tool, V1: first annular groove, V2: second annular groove, W: workpiece, e1: outer periphery of the first surface, e2: inner periphery of the first surface, e3: outermost edge of the stepped surface, e4: end of the annular housing space on the first direction side, e5: end of the annular housing space on the first direction side, e6: outermost edge of the first gap, e7: outermost edge of the annular housing space.

Claims

1. A spindle device for a machine tool, comprising: a rotating body having a rear end portion and a front end portion for holding a tool; A bearing having an inner ring and an outer ring; a housing, supporting the rotating body so as to be rotatable about a first axis via the bearing; a supply flow passage for supplying a mixed fluid including oil and air to the bearing; and A recovery channel is provided to recover the oil that has passed through the bearing. The rotating body has: A first portion, supporting the inner ring, having a first outer peripheral surface; a second portion having a second outer peripheral surface having a smaller diameter than the first outer peripheral surface and being arranged closer to the first direction side than the first portion when a direction from the rear end portion toward the front end portion is defined as a first direction; and a step surface connecting the first peripheral surface and the second peripheral surface, The housing has: a third portion, supporting the outer ring; and a fourth portion defining an annular receiving space for receiving the oil from a first gap between the first portion and the third portion; The fourth part has: an opening portion for guiding the oil from the annular accommodation space to the recovery flow passage; and The annular protrusion faces both the step surface and the annular accommodation space and protrudes in a direction away from the first axis.

2. The spindle device of a machine tool according to claim 1, wherein: The fourth portion has an annular protrusion protruding toward the first axis, The annular protrusion has: the annular protrusion; a first surface facing the step surface; as well as The second surface faces the second outer peripheral surface.

3. The spindle device of a machine tool according to claim 2, wherein: A second gap is formed between the first surface and the step surface and is in fluid communication with the first gap. A third gap is formed between the second surface and the second outer peripheral surface and is in fluid communication with the second gap.

4. The spindle device of a machine tool according to claim 3, wherein: An air injection port communicating with the third gap is formed between the front end portion of the housing and the rotating body. An air flow passage for the second air supplied from the air source to flow is formed in the housing. The housing has an outlet formed therein for discharging the second air received from the air flow passage toward the third gap, thereby forming a first air flow from the third gap toward the second gap and a second air flow from the third gap toward the air injection port.

5. The spindle device of a machine tool according to claim 3 or 4, wherein: The annular accommodation space is entirely arranged on the first direction side relative to the second gap.

6. The spindle device of a machine tool according to claim 3 or 4, wherein: The second gap is connected to the first gap via the annular receiving space. When the direction opposite to the first direction is defined as a second direction, the end of the annular housing space on the first direction side is arranged closer to the first direction than the second gap, and the end of the annular housing space on the second direction side is arranged closer to the second direction than the second gap.

7. The spindle device of a machine tool according to any one of claims 2 to 6, wherein: The annular protrusion has a first annular groove that is recessed in the direction toward the first axis. The first annular groove faces the annular receiving space.

8. The spindle device of a machine tool according to claim 7, wherein: The fourth portion of the housing has a second annular groove recessed in a direction away from the first axis. The second annular groove faces the annular receiving space.

9. The spindle device of a machine tool according to any one of claims 1 to 8, wherein: The annular protrusion has a lower surface, The lower surface includes an inclined surface that approaches the first axis as it moves toward the first direction.

10. The spindle device of a machine tool according to any one of claims 1 to 9, wherein: The housing has: a first component comprising the annular protrusion; and The second component supports the first component.

11. The spindle device of a machine tool according to any one of claims 1 to 10, wherein: The first gap and the annular accommodation space are arranged on a straight line parallel to the first axis.

12. The spindle device of a machine tool according to any one of claims 1 to 11, wherein: When the distance between the outermost edge of the step surface and the first axis is defined as a first distance, and the distance between the outermost edge of the annular protrusion and the first axis is defined as a second distance, the second distance is less than the first distance.

13. A machine tool comprising: A machining head having a rotating body, a plurality of bearings including a first bearing, a housing rotatably supporting the rotating body via the plurality of bearings, and a first rotation drive device for rotating the rotating body about a first axis; a lubricating device for supplying a mixed fluid comprising oil and air to the first bearing via a supply flow passage; a recovery device for recovering at least a portion of the oil that has passed through the first bearing via a recovery flow channel; a workpiece supporting device, supporting the workpiece; a moving device for moving the machining head relative to the workpiece supporting device; as well as a control device for controlling at least the first rotation drive device and the moving device, The rotating body has: rear end; The front end portion holds the cutting tool; A first portion, supporting an inner ring of the first bearing, having a first outer peripheral surface; a second portion having a second outer peripheral surface having a smaller diameter than the first outer peripheral surface and being arranged closer to the first direction side than the first portion when a direction from the rear end portion toward the front end portion is defined as a first direction; and a step surface connecting the first peripheral surface and the second peripheral surface, The housing has: a third part, supporting the outer ring of the first bearing; and a fourth portion defining an annular receiving space for receiving the oil from a first gap between the first portion and the third portion; The fourth part has: an opening portion for guiding the oil from the annular accommodation space to the recovery flow passage; and The annular protrusion faces both the step surface and the annular accommodation space and protrudes in a direction away from the first axis.

14. The machine tool according to claim 13, wherein: The fourth portion has an annular protrusion protruding toward the first axis, The annular protrusion has: the annular protrusion; a first surface facing the step surface; as well as The second surface faces the second outer peripheral surface.

15. The machine tool according to claim 14, wherein A second gap is formed between the first surface and the step surface and is in fluid communication with the first gap. A third gap is formed between the second surface and the second outer peripheral surface and is in fluid communication with the second gap.

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