Spindle device, end face cover and machine tool

Abstract

The invention provides a spindle device, an end face cover and a machine tool. The spindle device includes: a spindle having one end to which a cutter is mounted; a spindle housing rotatably supporting the spindle; a spindle cover having an annular shape centered on the rotation center of the spindle, the spindle cover being fixed to an end of the spindle housing in the one end direction; the end face cover is in an annular shape with the rotation center as the center and fixed to one end of the main shaft. A first labyrinth part is formed between the main shaft cover and the end face cover, annularly extends with the rotation center as the center, and is opened towards one end part. The spindle cover has a first cover groove including a first cover inclined surface that extends toward one end toward the inside in the radial direction of the spindle cover. The end face cover is provided with a first cover labyrinth surface arranged on the outer periphery of the radial outer side of the end face cover; and a cover inclined surface extending from an end portion of the first cover labyrinth surface in the direction of the one end portion toward the radial inner side of the end face cover in the direction of the one end portion and closer to the direction of the one end portion than the first cover inclined surface. The first labyrinth portion is composed of a first cover groove, a first cover labyrinth surface, and a cover inclined surface.

Description

Technical Field

[0001] The invention relates to a spindle device, an end face cover and a machine tool. Background Art

[0002] The machine tool can spray coolant when processing a workpiece, changing a tool, etc. The machine tool spindle device described in Patent Document 1 includes a spindle and a spindle housing. The spindle is mounted with a tool for cutting a workpiece. The spindle housing supports the spindle in a rotatable manner. The machine tool spindle device has an annular spindle cover fixed to the lower end of the spindle housing, and an annular end face cover fixed to the lower end of the spindle. The machine tool spindle device forms a labyrinth chamber between the vicinity of the lower end of the spindle cover and the vicinity of the outer peripheral surface of the end face cover. The labyrinth chamber is used to suppress the intrusion of splashes of coolant between the spindle and the spindle housing.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2010-76045 Summary of the invention

[0004] In the above-mentioned machine tool spindle device, when the coolant droplets that have entered the labyrinth chamber are discharged from the labyrinth chamber, the flow of the coolant from the labyrinth chamber to the discharge direction may become weaker depending on the shape of the labyrinth chamber. At this time, the coolant droplets may easily enter between the spindle and the spindle housing through the labyrinth chamber. For example, if the coolant droplets reach the bearings provided between the spindle and the spindle housing, the bearings may be damaged.

[0005] An object of the present invention is to provide a spindle device, an end cover and a machine tool capable of suppressing the splash of coolant from intruding between a spindle and a spindle housing.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a spindle device, comprising: a spindle, one end of which is used to install a tool; a spindle housing, which supports the spindle in a rotatable manner; a spindle cover, which has a ring shape with the rotation center of the spindle as the center, and is fixed to the end of the spindle housing in the direction of one end, and the one end direction is the direction from the other end of the spindle to the one end of the spindle; and an end face cover, which has a ring shape with the rotation center as the center, and is fixed to the one end of the spindle, and the spindle device forms a first labyrinth portion between the spindle cover and the end face cover, and the first labyrinth portion is a ring with the rotation center as the center. The spindle cover is a space extending in a shape and opening toward the one end, the spindle cover having a first cover groove, the first cover groove including a first cover inclined surface, the first cover inclined surface extending toward the one end as it moves radially inwardly toward the spindle cover, the end face cover having: a first cover labyrinth surface, arranged on the outer peripheral portion of the radially outer side of the end face cover; and a cover inclined surface, extending from an end portion of the first cover labyrinth surface in the direction of the one end as it moves radially inwardly toward the one end portion of the end face cover, and located at a position closer to the one end portion than the first cover inclined surface, the first labyrinth portion being composed of the first cover groove, the first cover labyrinth surface and the cover inclined surface.

[0007] According to the spindle device of the present invention, when the droplets of coolant invade the first labyrinth portion, the droplets of coolant collide with the inclined surface of the first cover and easily flow along the inclined surface of the first cover toward one end. After that, the droplets of coolant easily flow along the inclined surface of the cover. As the droplets of coolant flow along the inclined surface of the cover, the flow of the droplets of coolant from the first labyrinth portion toward one end is likely to become stronger. Therefore, the spindle device can suppress the intrusion pressure of the droplets of coolant into the first labyrinth portion. Therefore, the spindle device can suppress the intrusion of the droplets of coolant between the spindle and the spindle housing.

[0008] The spindle device of the present invention has a second labyrinth formed between the spindle cover and the end face cover, the second labyrinth is a space extending in an annular shape with the rotation center as the center at a position closer to the radial inner side of the spindle than the first labyrinth and connected to the first labyrinth, the spindle cover has a second cover groove, the second cover groove has a second cover inclined surface at a position closer to the radial inner side of the spindle cover than the first cover inclined surface, the second cover inclined surface extends toward the one end as it moves toward the radial inner side of the spindle cover, the end face cover has a second cover labyrinth surface adjacent to the radial inner side of the end face cover relative to the first cover labyrinth surface, the second labyrinth is composed of the second cover groove and the second cover labyrinth surface, the size of the acute angle formed by the first cover inclined surface relative to the rotation center is smaller than the size of the acute angle formed by the second cover inclined surface relative to the rotation center. The spindle device can further enhance the flow of the droplets of the coolant from the first labyrinth to the one end. Therefore, the spindle device can further suppress the droplets of the coolant from invading between the spindle and the spindle housing.

[0009] In the spindle device of the present invention, the first cover groove includes a cover connecting surface extending from the end of the first cover inclined surface opposite to the one end direction toward the one end direction. Since the cover connecting surface extends toward the one end direction, in the spindle device, the droplets of coolant invading the first labyrinth portion can easily reach the end of the first cover inclined surface opposite to the one end direction. Therefore, the spindle device can ensure the distance of the droplets of coolant invading the first labyrinth portion before being discharged from the first labyrinth portion. Therefore, the flow of the droplets of coolant from the first labyrinth portion toward the one end direction can be further enhanced. Therefore, the spindle device can further suppress the droplets of coolant from invading between the spindle and the spindle housing.

[0010] In the spindle device of the present invention, the first cover groove includes a third cover inclined surface, the third cover inclined surface extends from the end of the cover connecting surface in the direction of the one end toward the radially outer side of the spindle cover toward the one end, the end face cover has a cover end face, the cover end face extends from the end of the cover inclined surface located at the radial inner side of the end face cover toward the radial inner side of the end face cover, and the cover end face is located at a position closer to the one end direction than the end of the third cover inclined surface located at the radial outer side of the end face cover. The spindle device can ensure the distance of the droplets of coolant invading the first labyrinth part before being discharged from the first labyrinth part. Therefore, the flow of the droplets of coolant from the first labyrinth part toward the one end direction can be further enhanced. Therefore, the spindle device can further suppress the droplets of coolant from invading between the spindle and the spindle housing.

[0011] In order to solve the above-mentioned problems, the present invention also provides an end face cover for a spindle device, the spindle device comprising: a spindle, one end of which is used to install a tool; a spindle housing, which supports the spindle in a rotatable manner; and a spindle cover, which has a ring shape centered on the rotation center of the spindle and is fixed to the end of the spindle housing in the direction of one end, the one end direction being the direction from the other end of the spindle to the one end of the spindle, the spindle cover having a first cover groove, the first cover groove including a first cover inclined surface, the first cover inclined surface extending toward the one end direction as it moves radially inwardly of the spindle cover, and the end face cover is fixed to the one end of the spindle. In the state: it has an annular shape with the rotation center as the center, and has a first cover labyrinth surface and a cover inclined surface, the first cover labyrinth surface is arranged on the outer peripheral portion of the radial outer side of the end face cover, the cover inclined surface extends from the end of the first cover labyrinth surface in the direction of the one end portion as it moves toward the radial inner side of the end face cover in the direction of the one end portion, and is located at a position closer to the direction of the one end portion than the first cover inclined surface, a first labyrinth portion is formed between the spindle cover and the end face cover, the first labyrinth portion is a space extending in an annular shape with the rotation center as the center and opening in the direction of the one end portion, and the first labyrinth portion is composed of the first cover groove, the first cover labyrinth surface and the cover inclined surface. By using the end face cover for the spindle device, the same effect as the above-mentioned spindle device of the present invention can be achieved.

[0012] In order to solve the above problems, the present invention also provides a machine tool, comprising: a spindle device; and a driving part for driving the spindle device, the spindle device comprising: a spindle, one end of which is used to install a tool; a spindle housing, which supports the spindle in a rotatable manner; a spindle cover, which has a ring shape centered on the rotation center of the spindle and is fixed to an end of the spindle housing in the direction of one end, the one end direction being the direction from the other end of the spindle to the one end of the spindle; and an end face cover, which has a ring shape centered on the rotation center and is fixed to the one end of the spindle, a first labyrinth portion is formed between the spindle cover and the end face cover, and the first labyrinth portion is The spindle cover is a space that extends in an annular shape with the rotation center as the center and opens toward the one end. The spindle cover has a first cover groove, the first cover groove includes a first cover inclined surface, and the first cover inclined surface extends toward the one end as it moves toward the radial inner side of the spindle cover. The end face cover has: a first cover labyrinth surface, which is arranged on the outer peripheral portion of the radial outer side of the end face cover; and a cover inclined surface, which extends toward the one end as it moves toward the radial inner side of the end face cover from the end of the first cover labyrinth surface in the direction of the one end and is located closer to the one end than the first cover inclined surface. The first labyrinth portion is composed of the first cover groove, the first cover labyrinth surface, and the cover inclined surface. The machine tool can achieve the same effect as the spindle device of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a perspective view of the machine tool 1 as viewed from the upper left front.

[0014] Figure 2 This is an exploded perspective view of the spindle device 3 as viewed from the lower right front.

[0015] Figure 3 This is a cross-sectional view of the spindle device 3 as viewed from the right along a plane passing through the rotation center C and perpendicular to the left-right direction.

[0016] Figure 4 yes Figure 3 An enlarged view of area A1 is shown.

[0017] Figure 5 yes Figure 4 An enlarged view of area A2 is shown. DETAILED DESCRIPTION

[0018] A machine tool 1 according to an embodiment of the present invention is described with reference to the accompanying drawings. The following description uses left and right, front and back, and up and down directions indicated by arrows in the drawings. The left and right directions, front and back directions, and up and down directions of the machine tool 1 are referred to as the X-axis direction, Y-axis direction, and Z-axis direction of the machine tool 1, respectively.

[0019] Reference Figure 1 , the schematic structure of the machine tool 1 is described. The machine tool 1 is mounted on a spindle 30 (refer to Figure 3 ) rotates the tool 4 on the workpiece W, and relatively moves the tool 4 and the workpiece W in the X, Y, and Z axis directions, thereby processing the workpiece W. The machine tool 1 is a vertical machine tool in which a spindle 30 extends in the up-down direction.

[0020] The machine tool 1 includes a base 2, a worktable 10, an X-axis feed mechanism 9, a Y-axis feed mechanism 8, a column 5, a spindle device 3, and a tool changing device 17. The base 2 is arranged at the lower part of the machine tool 1 and is roughly rectangular. The worktable 10 is arranged at the front part of the upper surface of the base 2 and extends in a planar shape in the front, back, left and right directions. The worktable 10 is used to hold the workpiece W. The X-axis feed mechanism 9 is arranged below the worktable 10, and supports the worktable 10 so that it can move in the X-axis direction. The Y-axis feed mechanism 8 is arranged below the X-axis feed mechanism 9, and supports the worktable 10 via the X-axis feed mechanism 9 so that it can move in the Y-axis direction.

[0021] The column 5 extends upward from the rear portion of the upper surface of the base 2 and is in the shape of a rectangular parallelepiped. The spindle device 3 is arranged in front of the column 5 and is supported by the column 5 via the plate 19 so as to be able to rise and fall in the Z-axis direction. The spindle device 3 is mounted with a tool 4. The tool 4 is formed by mounting a tool body 4A on a tool holding portion 4B. The tool body 4A is a drill bit or the like. The tool holding portion 4B has a shape corresponding to the mounting hole 31 described later, and in this embodiment has a tapered shape with a hole diameter decreasing as it goes upward (see Figure 3 The tool changing device 17 is arranged in front of the main spindle device 3 and is fixed to the column 5 via a plate 18. The tool changing device 17 changes the tool 4 mounted on the main spindle device 3 with another tool (not shown).

[0022] The machine tool 1 drives the X-axis motor and the Y-axis motor (not shown) to move the worktable 10 in the X-axis direction and the Y-axis direction by using the X-axis feed mechanism 9 and the Y-axis feed mechanism 8. The machine tool 1 drives the spindle motor 40 to rotate the tool 4, and drives the Z-axis motor (not shown) to move the spindle device 3 in the Z-axis direction along the column 5. The machine tool 1 moves the workpiece W on the worktable 10 and the tool 4 relative to each other, and the tool 4 cuts the workpiece W on the worktable 10.

[0023] Reference Figures 1 to 4 , the detailed structure of the spindle device 3 is described. Figures 1 to 3 As shown, the spindle device 3 includes a spindle housing 20, a spindle 30, a spindle motor 40, a spindle cover 50, and an end cover 80. Figure 1 As shown, the spindle housing 20 extends in the up-down direction and is fixed on the plate 19. Figures 2 to 4As shown, the spindle housing 20 is cylindrical and is formed with a support hole 21. The support hole 21 extends upward from a lower end portion 20A of the spindle housing 20.

[0024] The main shaft 30 is disposed in the support hole 21 and extends in the up-down direction. Figure 2 , Figure 4 As shown, the lower end portion 30A of the spindle 30 protrudes downward further than the lower end portion 20A of the spindle housing 20. The spindle 30 includes a step portion 33. The step portion 33 is located near the lower end portion 30A of the spindle 30 and protrudes radially outward from the outer peripheral surface 32 of the spindle 30. The outer diameter of the step portion 33 is smaller than the inner diameter of the spindle housing 20.

[0025] The spindle 30 is cylindrical and has a mounting hole 31 formed therein. The mounting hole 31 extends upward from the lower end 30A of the spindle 30 and is tapered in a manner such that the diameter of the hole decreases as it moves upward. The tool holding portion 4B (see Figure 3 ). In this state, a holding mechanism (not shown) for holding the tool 4 is driven to attach the tool 4 to the lower end portion 30A of the spindle 30.

[0026] like Figure 3 , Figure 4 As shown, the spindle 30 is rotatably supported on the spindle housing 20 by one or more bearings 22. The rotation center C of the spindle 30 passes through the radial center of the spindle 30 in a plan view and extends in the vertical direction. The number of bearings 22 is not particularly limited, and in this embodiment, there are four. The plurality of bearings 22 are respectively arranged in the support holes 21 and arranged in the vertical direction with the spacing member 23 therebetween.

[0027] The spindle motor 40 is fixed to the upper portion of the spindle housing 20. The output shaft 41 of the spindle motor 40 extends downward from the spindle motor 40 and is fixed to the upper end portion 30B of the spindle 30. Therefore, when the spindle motor 40 is driven, the spindle 30 rotates around the rotation center C.

[0028] like Figure 2 , Figure 4 As shown, the spindle cover 50 includes a first cover 60 and a second cover 70. The first cover 60 and the second cover 70 are respectively annular. The inner diameter of the first cover 60 and the inner diameter of the second cover 70 are respectively slightly larger than the outer diameter of the lower end portion 30A of the spindle 30. The lower end portion 30A of the spindle 30 is respectively inserted into the first cover 60 and the second cover 70. The first cover 60 is fixed to the lower end portion 20A of the spindle housing 20 from below by a plurality of bolts 14. The second cover 70 is fixed to the lower end portion of the first cover 60 from below by a plurality of bolts 15. Therefore, even if the spindle 30 rotates, the first cover 60 and the second cover 70 do not rotate.

[0029] The spindle cover 50 is annular as a whole and is fixed to the lower end portion 20A of the spindle housing 20. When the spindle cover 50 is fixed to the lower end portion 20A of the spindle housing 20, the center of the spindle cover 50 coincides with the rotation center C of the spindle 30 in a plan view.

[0030] The end face cover 80 is annular. The inner diameter of the end face cover 80 is slightly larger than the outer diameter of the lower end portion 30A of the spindle 30. Therefore, the lower end portion 30A of the spindle 30 is inserted into the end face cover 80. The outer diameter of the end face cover 80 is slightly smaller than the inner diameter of the second cover 70. The end face cover 80 is arranged radially inside the second cover 70. The end face cover 80 is fixed to the lower end portion 30A of the spindle 30 from below by a plurality of bolts 16. Therefore, when the spindle 30 rotates, the end face cover 80 rotates together with the spindle 30. In the state where the end face cover 80 is fixed to the lower end portion 30A of the spindle 30, the rotation center of the end face cover 80 coincides with the rotation center C of the spindle 30.

[0031] Reference Figure 4 , Figure 5 , the detailed structure of the spindle cover 50 and the end cover 80 is described. The spindle 30, the spindle cover 50 (the first cover 60, the second cover 70), and the end cover 80 are respectively located on concentric circles centered on the rotation center C. Therefore, the radial directions of the spindle 30, the spindle cover 50 (the first cover 60, the second cover 70), and the end cover 80 are consistent. Hereinafter, each radial direction is referred to as a "radial direction". The radial outer side is the direction away from the rotation center C when viewed from above, and the radial inner side is the direction close to the rotation center C when viewed from above.

[0032] The direction that goes upward as it goes radially outward is called "direction Y1". The direction opposite to direction Y1, that is, the direction that goes downward as it goes radially inward is called "direction Y2". The direction that goes downward as it goes radially outward is called "direction Y3". The direction opposite to direction Y3, that is, the direction that goes upward as it goes radially inward is called "direction Y4".

[0033] Hereinafter, the shape of a structure such as a surface or space, unless otherwise specified, indicates the cross-sectional shape of a plane passing through the rotation center C and along the rotation center C. For example, "the support portion 61 is rectangular" indicates that the cross-sectional shape of the support portion 61, which is cut along the plane passing through the rotation center C and along the rotation center C, is rectangular. The structure such as a surface or space represented by the cross section extends in a ring shape with the rotation center C as the center. For example, the cross section of the support portion 61 is rectangular and extends in a ring shape with the rotation center C as the center.

[0034] A direction perpendicular to a certain direction is referred to as "another direction". In a surface structure, an end of a direction that moves toward another direction as it moves toward a certain direction is an end of the certain direction and is also an end of the other direction. For example, the end of the cover inclined surface 71C in the direction Y1 is the radially outer end of the cover inclined surface 71C and is also the upper end of the cover inclined surface 71C.

[0035] like Figure 4 As shown, the first cover 60 includes a support portion 61 and a labyrinth forming portion 62. The support portion 61 is located at the upper portion of the first cover 60 and is rectangular. The support portion 61 is fixed to the lower end portion 20A of the spindle housing 20, and supports the bearing 22 from below via the step portion 33. The support portion 61 includes an inner circumferential surface 61A and a bottom surface 61B. The inner circumferential surface 61A is located at the radial inner end portion of the support portion 61, and extends in the up and down direction. An air passage 98 is formed between the inner circumferential surface 61A and the outer circumferential surface 32 of the spindle 30. The air passage 98 is a space where compressed air flows, and is connected to a compressor (not shown) via a pipe (not shown). The compressor supplies compressed air to the air passage 98.

[0036] The bottom surface 61B is located at the lower end of the support portion 61 and extends in the radial direction. The bottom surface 61B forms a coolant passage 99 between the bottom surface 61B and the upper surface 71A of the labyrinth forming portion 71 described later. The coolant passage 99 is a space where the coolant flows, and is connected to a coolant supply source (not shown) via a pipe (not shown). The coolant supply source stores the coolant and supplies the stored coolant to the coolant passage 99.

[0037] like Figure 5 As shown, the labyrinth forming portion 62 is located at the lower portion of the radial inner side of the first cover 60, and is connected to the lower portion of the radial inner side of the support portion 61. The labyrinth forming portion 62 includes a cover connecting surface 62A, a cover inclined surface 62B, a cover connecting surface 62C, a cover inclined surface 62D, a cover connecting surface 62E, a cover connecting surface 62F, and a cover inclined surface 62G. The cover connecting surface 62A extends downward from the radial inner end of the bottom surface 61B of the support portion 61. The cover inclined surface 62B extends in the direction Y2 from the lower end of the cover connecting surface 62A. The cover inclined surface 62B, together with the cover connecting surface 71B and the cover inclined surface 71C described later, constitute a first cover groove 91A. The first cover groove 91A is in a V-shape that opens downward.

[0038] The size of the acute angle θ1 formed by the cover inclined surface 62B with respect to the rotation center C is smaller than the size of the acute angle θ2 formed by the cover inclined surface 62D described later with respect to the rotation center C. The size of the acute angle θ2 is not particularly limited, and is 45° in the present embodiment. The size of the acute angle θ1 is not particularly limited, and is, for example, preferably smaller than 45°, and is 30° in the present embodiment.

[0039] The cover connection surface 62C extends upward from the end of the cover inclined surface 62B in the direction Y2. The cover inclined surface 62D extends from the upper end of the cover connection surface 62C in the direction Y2 and is located radially inside the cover inclined surface 62B. The cover connection surface 62C and the cover inclined surface 62D constitute the second cover groove 92A. The second cover groove 92A is in a V shape that opens downward. The second cover groove 92A is located radially inside the first cover groove 91A and is adjacent to the first cover groove 91A.

[0040] The cover connecting surface 62E extends upward from the end of the cover inclined surface 62D in the direction Y2. The cover connecting surface 62F extends radially inward from the upper end of the cover connecting surface 62E. The cover inclined surface 62G extends in the direction Y2 from the radial inner end of the cover connecting surface 62F and is located radially inside the cover inclined surface 62D. The end of the cover inclined surface 62G in the direction Y2 is connected to the lower end of the inner circumferential surface 61A of the support portion 61. The cover connecting surface 62E, the cover connecting surface 62F and the cover inclined surface 62G constitute a third cover groove 93A. The third cover groove 93A is in the shape of a U that opens downward. The third cover groove 93A is located radially inside the second cover groove 92A and is adjacent to the second cover groove 92A.

[0041] The second cover 70 includes a labyrinth forming portion 71 and a nozzle forming portion 72. The labyrinth forming portion 71 is located at the upper portion of the second cover 70 and includes an upper surface 71A, a cover connecting surface 71B, and a cover inclined surface 71C. The upper surface 71A is located on the same plane as the bottom 61B of the support portion 61 and extends in the radial direction. A coolant passage 99 is formed between the upper surface 71A and the bottom 61B.

[0042] The cover connection surface 71B is substantially located on the same plane as the cover connection surface 62A, and extends downward from the radial inner end of the upper surface 71A. The lower end of the cover connection surface 71B is located below the end of the cover inclined surface 62B in the direction Y1, and is located above the end of the cover inclined surface 62B in the direction Y2. In the first cover groove 91A, a portion of the cover connection surface 71B that is lower than the end of the cover inclined surface 62B in the direction Y1 extends downward from the end of the cover inclined surface 62B in the direction Y1. The cover inclined surface 71C extends in the direction Y3 from the lower end of the cover connection surface 71B.

[0043] The nozzle forming portion 72 is connected to the lower end of the labyrinth forming portion 71 and includes a nozzle surface 72A. The nozzle surface 72A further extends in the direction Y3 from the end of the cover inclined surface 71C in the direction Y3. The size of the acute angle θ3 formed by the nozzle surface 72A with respect to the rotation center C is not particularly limited, but in the present embodiment, it is larger than the size of the acute angle θ4 formed by the cover inclined surface 71C with respect to the rotation center C.

[0044] The nozzle surface 72A is formed with a plurality of nozzles 721. The plurality of nozzles 721 are respectively opened and connected to the coolant passage 99. The plurality of nozzles 721 respectively spray the coolant supplied from the coolant supply source radially inward via the coolant passage 99 (see arrow F1). When the sprayed coolant contacts the tool 4, the tool 4 is cleaned.

[0045] The end face cover 80 includes a labyrinth forming portion 81, a cover inclined surface 82, and a cover end face 83. The labyrinth forming portion 81 is arranged at the outer peripheral portion of the radially outer side of the end face cover 80, and is opposite to the labyrinth forming portions 62 and 71. The outer peripheral portion of the radially outer side of the end face cover 80 is a portion of the end face cover 80 that constitutes the outer peripheral surface of the end face cover 80, and in this embodiment, refers to a portion of the end face cover 80 that is arranged radially outward of the hole through which the bolt 16 penetrates. The labyrinth forming portion 81 includes a cover inclined surface 81A, a cover connection surface 81B, a cover connection surface 81C, a cover inclined surface 81D, a cover connection surface 81E, a cover inclined surface 81F, and a cover connection surface 81G.

[0046] The cover inclined surface 81A is located below the cover inclined surface 62G and extends in the Y1 direction from the radial inner end of the labyrinth forming portion 81. The cover connecting surface 81B extends radially outward from the end of the cover inclined surface 81A in the direction Y1. The cover inclined surface 81A and the cover connecting surface 81B constitute a third cover labyrinth surface 93B. The third cover labyrinth surface 93B is located radially inward of the second cover labyrinth surface 92B described later and is adjacent to the second cover labyrinth surface 92B.

[0047] The cover connection surface 81C extends downward from the radially outer end of the cover connection surface 81B. The cover inclined surface 81D extends in the direction Y3 from the lower end of the cover connection surface 81C. The cover connection surface 81C and the cover inclined surface 81D constitute a second cover labyrinth surface 92B. The second cover labyrinth surface 92B is located radially inside the first cover labyrinth surface 91B described later and is adjacent to the first cover labyrinth surface 91B.

[0048] The cover connection surface 81E extends downward from the end of the cover inclined surface 81D in the direction Y3. The cover inclined surface 81F extends in the direction Y3 from the lower end of the cover connection surface 81E. The size of the acute angle θ5 formed by the cover inclined surface 81F with respect to the rotation center C is not particularly limited. In the present embodiment, it is smaller than the size of the acute angle θ6 formed by the cover inclined surface 81D with respect to the rotation center C. The cover connection surface 81G extends downward from the end of the cover inclined surface 81F in the direction Y3. The cover connection surface 81E, the cover inclined surface 81F, and the cover connection surface 81G constitute the first cover labyrinth surface 91B.

[0049] The cover inclined surface 82 extends from the lower end of the cover connection surface 81G in the direction Y2 and is located below the cover inclined surface 62B. The cover inclined surface 82 extends from the radially outer end of the cover end surface 83 described later in the Y1 direction. The size of the acute angle θ7 formed by the cover inclined surface 82 with respect to the rotation center C is not particularly limited, but in this embodiment, it is 45°, which is larger than the size of the acute angle θ1 formed by the cover inclined surface 62B with respect to the rotation center C.

[0050] The cover end surface 83 extends radially inward from the end of the cover inclined surface 82 in the direction Y2. The cover end surface 83 faces downward and is located at the lower end of the end surface cover 80. Figure 5 In the figure, the position of the end of the cover inclined surface 82 in the direction Y1 in the vertical direction is shown by position P2, and the position of the end of the cover inclined surface 82 in the direction Y2 is shown by position P3. Position P3 is consistent with the position of the cover end surface 83 in the vertical direction. Figure 5 In FIG. 1 , the position of the end of the cover inclined surface 71C of the labyrinth forming portion 71 in the direction Y3 is indicated by the position P1. The position P2 is located above the position P1. The position P3 is located below the position P1.

[0051] According to the above structure, the spindle device 3 forms a first labyrinth portion 91, a second labyrinth portion 92, and a third labyrinth portion 93 between the spindle cover 50 and the end cover 80. The first labyrinth portion 91 is a space surrounded by the first cover groove 91A, the first cover labyrinth surface 91B, and the cover inclined surface 82. The first labyrinth portion 91 is open downward. The second labyrinth portion 92 is a space surrounded by the second cover groove 92A and the second cover labyrinth surface 92B, and is located radially inward of the first labyrinth portion 91. The second labyrinth portion 92 is connected to the first labyrinth portion 91 through the gap between the cover connection surface 62C and the cover connection surface 81E in the radial direction.

[0052] The third labyrinth portion 93 is a space surrounded by the third cover groove 93A and the third cover labyrinth surface 93B, and is located radially inward of the second labyrinth portion 92. The third labyrinth portion 93 is connected to the second labyrinth portion 92 via a gap between the cover connection surface 62E and the cover connection surface 81C in the radial direction. The third labyrinth portion 93 is connected to the air passage 98 via a gap between the outer peripheral surface 32 of the main shaft 30 and the inner peripheral surface 61A of the support portion 61 in the radial direction.

[0053] When the coolant sprayed from the multiple nozzles 721 contacts the tool 4, the coolant splashes. At this time, the coolant droplets pass through the first labyrinth section 91, the second labyrinth section 92, and the third labyrinth section 93 in sequence, invade between the spindle 30 and the spindle housing 20, and may reach multiple bearings 22. The compressed air supplied by the compressor through the air passage 98 flows through the third labyrinth section 93, the second labyrinth section 92, and the first labyrinth section 91 in sequence, and is sprayed downward from the first labyrinth section 91 (refer to arrow F2). Therefore, the compressed air supplied by the compressor acts as an air seal for suppressing the coolant droplets from invading between the spindle 30 and the spindle housing 20.

[0054] The spindle device 3 described above can mainly achieve the following effects by using the end cover 80. The machine tool 1 can also achieve the same effects. The following effects are examples of the effects achieved by the above-mentioned embodiment.

[0055] Assuming that there is no cover inclined surface 82 extending radially inward from the lower end of the cover connection surface 81G, the droplets of coolant intruding into the first labyrinth portion 91 are likely to have a disordered flow in the first labyrinth portion 91. According to the above embodiment, the first labyrinth portion 91 is composed of the first cover groove 91A, the first cover labyrinth surface 91B and the cover inclined surface 82. Therefore, when the droplets of coolant intrude into the first labyrinth portion 91, the droplets of coolant collide with the cover inclined surface 62B in the first cover groove 91A, and are likely to flow downward along the cover inclined surface 62B (refer to arrow F3). After that, the droplets of coolant are likely to flow along the cover inclined surface 82. Thus, the disordered flow of the droplets of coolant in the first labyrinth portion 91 can be suppressed. Therefore, the flow of the droplets of coolant from the first labyrinth portion 91 to the bottom is likely to become strong. Therefore, the spindle device 3 can suppress the intrusion pressure of the droplets of coolant intruding into the first labyrinth portion 91 by using the end face cover 80. Therefore, the spindle device 3 can suppress the splash of the coolant from entering between the spindle 30 and the spindle housing 20. Therefore, the spindle device 3 can suppress the supply amount of compressed air from the compressor that functions as an air seal, and can suppress the environmental load.

[0056] According to the above embodiment, the acute angle θ1 formed by the cover inclined surface 62B with respect to the rotation center C is smaller than the acute angle θ2 formed by the cover inclined surface 62D with respect to the rotation center C. Therefore, the spindle device 3 can further enhance the flow of the coolant from the first labyrinth portion 91 downward. Therefore, the spindle device 3 can further suppress the splashing of the coolant from intruding between the spindle 30 and the spindle housing 20.

[0057] According to the above-mentioned embodiment, the first cover groove 91A includes a cover connection surface 71B. Since the cover connection surface 71B extends downward, in the spindle device 3, the droplets of the coolant invading the first labyrinth portion 91 can easily reach the upper end of the cover inclined surface 62B. Therefore, the spindle device 3 can ensure the distance of the droplets of the coolant invading the first labyrinth portion 91 before being discharged from the first labyrinth portion 91. Therefore, the flow of the droplets of the coolant from the first labyrinth portion 91 to the bottom can be further enhanced. Therefore, the spindle device 3 can further suppress the droplets of the coolant from invading between the spindle 30 and the spindle housing 20.

[0058] According to the above-mentioned embodiment, the cover end surface 83 (position P3) is located below the end (position P1) of the cover inclined surface 71C in the direction Y3. That is, the cover end surface 83 is arranged at a position farther from the spindle 30 in the up-down direction (the axial direction of the spindle 30). Therefore, the spindle device 3 can ensure the distance of the droplets of the coolant invading the first labyrinth part 91 before being discharged from the first labyrinth part 91. Therefore, the flow of the droplets of the coolant from the first labyrinth part 91 to the bottom can be further enhanced. Therefore, the spindle device 3 can further suppress the droplets of the coolant from invading between the spindle 30 and the spindle housing 20.

[0059] In the above-mentioned embodiment, the bottom of the machine tool 1 is equivalent to the "one end direction" of the present invention. The cover inclined surface 62B is equivalent to the "first cover inclined surface" of the present invention. The cover inclined surface 82 is equivalent to the "cover inclined surface" of the present invention. The cover inclined surface 62D is equivalent to the "second cover inclined surface" of the present invention. The acute angle θ1 is equivalent to the "acute angle formed by the first cover inclined surface relative to the rotation center" of the present invention. The acute angle θ2 is equivalent to the "acute angle formed by the second cover inclined surface relative to the rotation center" of the present invention. The cover connecting surface 71B is equivalent to the "cover connecting surface" of the present invention. The cover inclined surface 71C is equivalent to the "third cover inclined surface" of the present invention.

[0060] The present invention can make changes to the above-mentioned embodiments. For example, the spindle device 3 can be configured to be rotated 90 degrees with the spindle 30 extending in the horizontal direction (e.g., the front-to-back direction). That is, the machine tool 1 can be a horizontal machine tool with the spindle 30 extending in the horizontal direction (e.g., the front-to-back direction). The driving axis of the machine tool 1 is not limited to the three axes of XYZ, but can also be a single axis, two axes, or more than four axes.

[0061] In the above embodiment, the acute angle θ1 may be the same as the acute angle θ2. The acute angle θ3 may be the same as the acute angle θ4. The acute angle θ5 may be the same as the acute angle θ6. The acute angle θ7 may be the same as the acute angle θ1.

[0062] In the above-described embodiment, the spindle device 3 may omit one or both of the second labyrinth portion 92 and the third labyrinth portion 93 , or may further form another labyrinth portion radially inward of the third labyrinth portion 93 .

[0063] The shapes of the first labyrinth portion 91, the second labyrinth portion 92, and the third labyrinth portion 93 are not limited to the above-described embodiments. For example, in the first labyrinth portion 91, the lower end portion of the cover connecting surface 71B may be located at the same position as the end portion of the cover inclined surface 62B in the direction Y1 in the up-down direction, or may be located above the end portion of the cover inclined surface 62B in the direction Y1. Furthermore, in the first labyrinth portion 91, the first cover groove 91A may be a U-shape that opens downward. That is, the first cover groove 91A may include a connecting surface that extends radially between the end portion of the cover inclined surface 62B in the direction Y1 and the upper end portion of the cover connecting surface 71B.

[0064] In the above embodiment, the first cover 60 and the second cover 70 are formed separately. In contrast, the first cover 60 and the second cover 70 may be formed integrally. The second cover 70 may be fixed to the spindle housing 20. The fixing method of the first cover 60 and the second cover 70, the fixing method of the first cover 60 and the spindle housing 20, and the fixing method of the end cover 80 and the spindle 30 are not limited to fixing with bolts. For example, threads may be formed on the cover connection surface 62A and the cover connection surface 71B, respectively.

[0065] In the above embodiment, the coolant is ejected from the nozzle 721. In contrast, the coolant may be ejected from an ejection device that is not integral with the spindle device 3. The cover end surface 83 may be located at the same position as the end of the cover inclined surface 71C in the direction Y3 in the vertical direction, or may be located above the end of the cover inclined surface 71C in the direction Y3.

Claims

1. A spindle device, comprising: A spindle, one end of which is used to mount a tool; A spindle housing, rotatably supporting the spindle; A spindle cover having an annular shape centered on the rotation center of the spindle and fixed to an end portion of the spindle housing in a direction of one end portion, the direction of the one end portion being a direction from the other end portion of the spindle toward the one end portion of the spindle; as well as an end cover having a ring shape centered on the rotation center and fixed to the one end of the main shaft, The spindle device forms a first labyrinth between the spindle cover and the end cover. The first labyrinth is a space extending in an annular shape with the rotation center as the center and opening toward the one end. The spindle cover has a first cover groove, the first cover groove includes a first cover inclined surface, and the first cover inclined surface extends toward the one end portion as it moves radially inward of the spindle cover. The end cover has: A first cover labyrinth surface is arranged at the outer peripheral portion of the radial outer side of the end cover; as well as a cover inclined surface extending from an end portion of the first cover labyrinth surface in the direction of the one end portion toward the radially inner side of the end face cover toward the one end portion and located closer to the one end portion than the first cover inclined surface, The first labyrinth portion is composed of the first cover groove, the first cover labyrinth surface, and the cover inclined surface.

2. The spindle device according to claim 1, characterized in that: A second labyrinth is formed between the spindle cover and the end cover. The second labyrinth is a space extending in an annular shape with the rotation center as the center at a position radially inward of the spindle than the first labyrinth and connected to the first labyrinth. The spindle cover has a second cover groove, the second cover groove has a second cover inclined surface at a position radially inward of the spindle cover than the first cover inclined surface, and the second cover inclined surface extends toward the one end portion as it moves radially inward of the spindle cover. The end face cover has a second cover labyrinth surface adjacent to the first cover labyrinth surface on the radial inner side of the end face cover, The second labyrinth portion is composed of the second cover groove and the second cover labyrinth surface. The acute angle formed by the first cover inclined surface with respect to the rotation center is smaller than the acute angle formed by the second cover inclined surface with respect to the rotation center.

3. The spindle device according to claim 1 or 2, characterized in that: The first cover groove includes a cover connection surface extending from an end portion of the first cover inclined surface opposite to the one end portion in a direction toward the one end portion.

4. The spindle device according to claim 3, characterized in that: The first cover groove includes a third cover inclined surface, and the third cover inclined surface extends from an end of the cover connecting surface in the direction of the one end toward the radially outer side of the spindle cover toward the one end. The end face cover has a cover end face, and the cover end face extends from an end of the cover inclined surface located at the radial inner side of the end face cover toward the radial inner side of the end face cover, The cover end surface is located closer to the one end direction than an end of the third cover inclined surface located radially outward of the end surface cover.

5. An end cover for a spindle device, the spindle device comprising: A spindle, one end of which is used to mount a tool; A spindle housing, rotatably supporting the spindle; as well as The spindle cover has an annular shape centered on the rotation center of the spindle and is fixed to an end portion of the spindle housing in the direction of one end portion, wherein the direction of the one end portion is a direction from the other end portion of the spindle to the one end portion of the spindle, and the spindle cover has a first cover groove, wherein the first cover groove includes a first cover inclined surface, and the first cover inclined surface extends toward the one end portion direction as it moves radially inwardly of the spindle cover. When the end cover is fixed to the one end of the main shaft: has a ring shape centered on the rotation center, A first cover labyrinth surface and a cover inclined surface, wherein the first cover labyrinth surface is arranged at the outer peripheral portion of the radial outer side of the end face cover, and the cover inclined surface extends from the end of the first cover labyrinth surface in the direction of the one end portion toward the radial inner side of the end face cover toward the one end portion, and is located at a position closer to the one end portion than the first cover inclined surface. A first labyrinth is formed between the spindle cover and the end cover. The first labyrinth is a space extending in an annular shape with the rotation center as the center and opening toward the one end. The first labyrinth portion is composed of the first cover groove, the first cover labyrinth surface, and the cover inclined surface.

6. A machine tool comprising: Spindle device; as well as A driving unit, used to drive the spindle device, The spindle device comprises: A spindle, one end of which is used to mount a tool; A spindle housing, rotatably supporting the spindle; a spindle cover having an annular shape centered on the rotation center of the spindle and fixed to an end portion of the spindle housing in a direction of one end portion, the direction of the one end portion being a direction from the other end portion of the spindle toward the one end portion of the spindle; and an end cover having a ring shape centered on the rotation center and fixed to the one end of the main shaft, A first labyrinth is formed between the spindle cover and the end cover. The first labyrinth is a space extending in an annular shape with the rotation center as the center and opening toward the one end. The spindle cover has a first cover groove, the first cover groove includes a first cover inclined surface, and the first cover inclined surface extends toward the one end portion as it moves radially inward of the spindle cover. The end cover has: A first cover labyrinth surface is provided at an outer peripheral portion of the radially outer side of the end face cover; and a cover inclined surface extending from an end portion of the first cover labyrinth surface in the direction of the one end portion toward the radially inner side of the end face cover toward the one end portion and located closer to the one end portion than the first cover inclined surface, The first labyrinth portion is composed of the first cover groove, the first cover labyrinth surface, and the cover inclined surface.

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